//===--- SemaExpr.cpp - Semantic Analysis for Expressions -----------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements semantic analysis for expressions. // //===----------------------------------------------------------------------===// #include "clang/Sema/SemaInternal.h" #include "TreeTransform.h" #include "clang/AST/ASTConsumer.h" #include "clang/AST/ASTContext.h" #include "clang/AST/ASTLambda.h" #include "clang/AST/ASTMutationListener.h" #include "clang/AST/CXXInheritance.h" #include "clang/AST/DeclObjC.h" #include "clang/AST/DeclTemplate.h" #include "clang/AST/EvaluatedExprVisitor.h" #include "clang/AST/Expr.h" #include "clang/AST/ExprCXX.h" #include "clang/AST/ExprObjC.h" #include "clang/AST/ExprOpenMP.h" #include "clang/AST/RecursiveASTVisitor.h" #include "clang/AST/TypeLoc.h" #include "clang/Basic/PartialDiagnostic.h" #include "clang/Basic/SourceManager.h" #include "clang/Basic/TargetInfo.h" #include "clang/Lex/LiteralSupport.h" #include "clang/Lex/Preprocessor.h" #include "clang/Sema/AnalysisBasedWarnings.h" #include "clang/Sema/DeclSpec.h" #include "clang/Sema/DelayedDiagnostic.h" #include "clang/Sema/Designator.h" #include "clang/Sema/Initialization.h" #include "clang/Sema/Lookup.h" #include "clang/Sema/ParsedTemplate.h" #include "clang/Sema/Scope.h" #include "clang/Sema/ScopeInfo.h" #include "clang/Sema/SemaFixItUtils.h" #include "clang/Sema/Template.h" #include "llvm/Support/ConvertUTF.h" using namespace clang; using namespace sema; /// \brief Determine whether the use of this declaration is valid, without /// emitting diagnostics. bool Sema::CanUseDecl(NamedDecl *D) { // See if this is an auto-typed variable whose initializer we are parsing. if (ParsingInitForAutoVars.count(D)) return false; // See if this is a deleted function. if (FunctionDecl *FD = dyn_cast(D)) { if (FD->isDeleted()) return false; // If the function has a deduced return type, and we can't deduce it, // then we can't use it either. if (getLangOpts().CPlusPlus14 && FD->getReturnType()->isUndeducedType() && DeduceReturnType(FD, SourceLocation(), /*Diagnose*/ false)) return false; } // See if this function is unavailable. if (D->getAvailability() == AR_Unavailable && cast(CurContext)->getAvailability() != AR_Unavailable) return false; return true; } static void DiagnoseUnusedOfDecl(Sema &S, NamedDecl *D, SourceLocation Loc) { // Warn if this is used but marked unused. if (D->hasAttr()) { const Decl *DC = cast_or_null(S.getCurObjCLexicalContext()); if (DC && !DC->hasAttr()) S.Diag(Loc, diag::warn_used_but_marked_unused) << D->getDeclName(); } } static bool HasRedeclarationWithoutAvailabilityInCategory(const Decl *D) { const auto *OMD = dyn_cast(D); if (!OMD) return false; const ObjCInterfaceDecl *OID = OMD->getClassInterface(); if (!OID) return false; for (const ObjCCategoryDecl *Cat : OID->visible_categories()) if (ObjCMethodDecl *CatMeth = Cat->getMethod(OMD->getSelector(), OMD->isInstanceMethod())) if (!CatMeth->hasAttr()) return true; return false; } static AvailabilityResult DiagnoseAvailabilityOfDecl(Sema &S, NamedDecl *D, SourceLocation Loc, const ObjCInterfaceDecl *UnknownObjCClass, bool ObjCPropertyAccess) { // See if this declaration is unavailable or deprecated. std::string Message; AvailabilityResult Result = D->getAvailability(&Message); // For typedefs, if the typedef declaration appears available look // to the underlying type to see if it is more restrictive. while (const TypedefNameDecl *TD = dyn_cast(D)) { if (Result == AR_Available) { if (const TagType *TT = TD->getUnderlyingType()->getAs()) { D = TT->getDecl(); Result = D->getAvailability(&Message); continue; } } break; } // Forward class declarations get their attributes from their definition. if (ObjCInterfaceDecl *IDecl = dyn_cast(D)) { if (IDecl->getDefinition()) { D = IDecl->getDefinition(); Result = D->getAvailability(&Message); } } if (const EnumConstantDecl *ECD = dyn_cast(D)) if (Result == AR_Available) { const DeclContext *DC = ECD->getDeclContext(); if (const EnumDecl *TheEnumDecl = dyn_cast(DC)) Result = TheEnumDecl->getAvailability(&Message); } const ObjCPropertyDecl *ObjCPDecl = nullptr; if (Result == AR_Deprecated || Result == AR_Unavailable || AR_NotYetIntroduced) { if (const ObjCMethodDecl *MD = dyn_cast(D)) { if (const ObjCPropertyDecl *PD = MD->findPropertyDecl()) { AvailabilityResult PDeclResult = PD->getAvailability(nullptr); if (PDeclResult == Result) ObjCPDecl = PD; } } } switch (Result) { case AR_Available: break; case AR_Deprecated: if (S.getCurContextAvailability() != AR_Deprecated) S.EmitAvailabilityWarning(Sema::AD_Deprecation, D, Message, Loc, UnknownObjCClass, ObjCPDecl, ObjCPropertyAccess); break; case AR_NotYetIntroduced: { // Don't do this for enums, they can't be redeclared. if (isa(D) || isa(D)) break; bool Warn = !D->getAttr()->isInherited(); // Objective-C method declarations in categories are not modelled as // redeclarations, so manually look for a redeclaration in a category // if necessary. if (Warn && HasRedeclarationWithoutAvailabilityInCategory(D)) Warn = false; // In general, D will point to the most recent redeclaration. However, // for `@class A;` decls, this isn't true -- manually go through the // redecl chain in that case. if (Warn && isa(D)) for (Decl *Redecl = D->getMostRecentDecl(); Redecl && Warn; Redecl = Redecl->getPreviousDecl()) if (!Redecl->hasAttr() || Redecl->getAttr()->isInherited()) Warn = false; if (Warn) S.EmitAvailabilityWarning(Sema::AD_Partial, D, Message, Loc, UnknownObjCClass, ObjCPDecl, ObjCPropertyAccess); break; } case AR_Unavailable: if (S.getCurContextAvailability() != AR_Unavailable) S.EmitAvailabilityWarning(Sema::AD_Unavailable, D, Message, Loc, UnknownObjCClass, ObjCPDecl, ObjCPropertyAccess); break; } return Result; } /// \brief Emit a note explaining that this function is deleted. void Sema::NoteDeletedFunction(FunctionDecl *Decl) { assert(Decl->isDeleted()); CXXMethodDecl *Method = dyn_cast(Decl); if (Method && Method->isDeleted() && Method->isDefaulted()) { // If the method was explicitly defaulted, point at that declaration. if (!Method->isImplicit()) Diag(Decl->getLocation(), diag::note_implicitly_deleted); // Try to diagnose why this special member function was implicitly // deleted. This might fail, if that reason no longer applies. CXXSpecialMember CSM = getSpecialMember(Method); if (CSM != CXXInvalid) ShouldDeleteSpecialMember(Method, CSM, /*Diagnose=*/true); return; } if (CXXConstructorDecl *CD = dyn_cast(Decl)) { if (CXXConstructorDecl *BaseCD = const_cast(CD->getInheritedConstructor())) { Diag(Decl->getLocation(), diag::note_inherited_deleted_here); if (BaseCD->isDeleted()) { NoteDeletedFunction(BaseCD); } else { // FIXME: An explanation of why exactly it can't be inherited // would be nice. Diag(BaseCD->getLocation(), diag::note_cannot_inherit); } return; } } Diag(Decl->getLocation(), diag::note_availability_specified_here) << Decl << true; } /// \brief Determine whether a FunctionDecl was ever declared with an /// explicit storage class. static bool hasAnyExplicitStorageClass(const FunctionDecl *D) { for (auto I : D->redecls()) { if (I->getStorageClass() != SC_None) return true; } return false; } /// \brief Check whether we're in an extern inline function and referring to a /// variable or function with internal linkage (C11 6.7.4p3). /// /// This is only a warning because we used to silently accept this code, but /// in many cases it will not behave correctly. This is not enabled in C++ mode /// because the restriction language is a bit weaker (C++11 [basic.def.odr]p6) /// and so while there may still be user mistakes, most of the time we can't /// prove that there are errors. static void diagnoseUseOfInternalDeclInInlineFunction(Sema &S, const NamedDecl *D, SourceLocation Loc) { // This is disabled under C++; there are too many ways for this to fire in // contexts where the warning is a false positive, or where it is technically // correct but benign. if (S.getLangOpts().CPlusPlus) return; // Check if this is an inlined function or method. FunctionDecl *Current = S.getCurFunctionDecl(); if (!Current) return; if (!Current->isInlined()) return; if (!Current->isExternallyVisible()) return; // Check if the decl has internal linkage. if (D->getFormalLinkage() != InternalLinkage) return; // Downgrade from ExtWarn to Extension if // (1) the supposedly external inline function is in the main file, // and probably won't be included anywhere else. // (2) the thing we're referencing is a pure function. // (3) the thing we're referencing is another inline function. // This last can give us false negatives, but it's better than warning on // wrappers for simple C library functions. const FunctionDecl *UsedFn = dyn_cast(D); bool DowngradeWarning = S.getSourceManager().isInMainFile(Loc); if (!DowngradeWarning && UsedFn) DowngradeWarning = UsedFn->isInlined() || UsedFn->hasAttr(); S.Diag(Loc, DowngradeWarning ? diag::ext_internal_in_extern_inline_quiet : diag::ext_internal_in_extern_inline) << /*IsVar=*/!UsedFn << D; S.MaybeSuggestAddingStaticToDecl(Current); S.Diag(D->getCanonicalDecl()->getLocation(), diag::note_entity_declared_at) << D; } void Sema::MaybeSuggestAddingStaticToDecl(const FunctionDecl *Cur) { const FunctionDecl *First = Cur->getFirstDecl(); // Suggest "static" on the function, if possible. if (!hasAnyExplicitStorageClass(First)) { SourceLocation DeclBegin = First->getSourceRange().getBegin(); Diag(DeclBegin, diag::note_convert_inline_to_static) << Cur << FixItHint::CreateInsertion(DeclBegin, "static "); } } /// \brief Determine whether the use of this declaration is valid, and /// emit any corresponding diagnostics. /// /// This routine diagnoses various problems with referencing /// declarations that can occur when using a declaration. For example, /// it might warn if a deprecated or unavailable declaration is being /// used, or produce an error (and return true) if a C++0x deleted /// function is being used. /// /// \returns true if there was an error (this declaration cannot be /// referenced), false otherwise. /// bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc, const ObjCInterfaceDecl *UnknownObjCClass, bool ObjCPropertyAccess) { if (getLangOpts().CPlusPlus && isa(D)) { // If there were any diagnostics suppressed by template argument deduction, // emit them now. auto Pos = SuppressedDiagnostics.find(D->getCanonicalDecl()); if (Pos != SuppressedDiagnostics.end()) { for (const PartialDiagnosticAt &Suppressed : Pos->second) Diag(Suppressed.first, Suppressed.second); // Clear out the list of suppressed diagnostics, so that we don't emit // them again for this specialization. However, we don't obsolete this // entry from the table, because we want to avoid ever emitting these // diagnostics again. Pos->second.clear(); } // C++ [basic.start.main]p3: // The function 'main' shall not be used within a program. if (cast(D)->isMain()) Diag(Loc, diag::ext_main_used); } // See if this is an auto-typed variable whose initializer we are parsing. if (ParsingInitForAutoVars.count(D)) { const AutoType *AT = cast(D)->getType()->getContainedAutoType(); Diag(Loc, diag::err_auto_variable_cannot_appear_in_own_initializer) << D->getDeclName() << (unsigned)AT->getKeyword(); return true; } // See if this is a deleted function. if (FunctionDecl *FD = dyn_cast(D)) { if (FD->isDeleted()) { Diag(Loc, diag::err_deleted_function_use); NoteDeletedFunction(FD); return true; } // If the function has a deduced return type, and we can't deduce it, // then we can't use it either. if (getLangOpts().CPlusPlus14 && FD->getReturnType()->isUndeducedType() && DeduceReturnType(FD, Loc)) return true; } DiagnoseAvailabilityOfDecl(*this, D, Loc, UnknownObjCClass, ObjCPropertyAccess); DiagnoseUnusedOfDecl(*this, D, Loc); diagnoseUseOfInternalDeclInInlineFunction(*this, D, Loc); return false; } /// \brief Retrieve the message suffix that should be added to a /// diagnostic complaining about the given function being deleted or /// unavailable. std::string Sema::getDeletedOrUnavailableSuffix(const FunctionDecl *FD) { std::string Message; if (FD->getAvailability(&Message)) return ": " + Message; return std::string(); } /// DiagnoseSentinelCalls - This routine checks whether a call or /// message-send is to a declaration with the sentinel attribute, and /// if so, it checks that the requirements of the sentinel are /// satisfied. void Sema::DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc, ArrayRef Args) { const SentinelAttr *attr = D->getAttr(); if (!attr) return; // The number of formal parameters of the declaration. unsigned numFormalParams; // The kind of declaration. This is also an index into a %select in // the diagnostic. enum CalleeType { CT_Function, CT_Method, CT_Block } calleeType; if (ObjCMethodDecl *MD = dyn_cast(D)) { numFormalParams = MD->param_size(); calleeType = CT_Method; } else if (FunctionDecl *FD = dyn_cast(D)) { numFormalParams = FD->param_size(); calleeType = CT_Function; } else if (isa(D)) { QualType type = cast(D)->getType(); const FunctionType *fn = nullptr; if (const PointerType *ptr = type->getAs()) { fn = ptr->getPointeeType()->getAs(); if (!fn) return; calleeType = CT_Function; } else if (const BlockPointerType *ptr = type->getAs()) { fn = ptr->getPointeeType()->castAs(); calleeType = CT_Block; } else { return; } if (const FunctionProtoType *proto = dyn_cast(fn)) { numFormalParams = proto->getNumParams(); } else { numFormalParams = 0; } } else { return; } // "nullPos" is the number of formal parameters at the end which // effectively count as part of the variadic arguments. This is // useful if you would prefer to not have *any* formal parameters, // but the language forces you to have at least one. unsigned nullPos = attr->getNullPos(); assert((nullPos == 0 || nullPos == 1) && "invalid null position on sentinel"); numFormalParams = (nullPos > numFormalParams ? 0 : numFormalParams - nullPos); // The number of arguments which should follow the sentinel. unsigned numArgsAfterSentinel = attr->getSentinel(); // If there aren't enough arguments for all the formal parameters, // the sentinel, and the args after the sentinel, complain. if (Args.size() < numFormalParams + numArgsAfterSentinel + 1) { Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); Diag(D->getLocation(), diag::note_sentinel_here) << int(calleeType); return; } // Otherwise, find the sentinel expression. Expr *sentinelExpr = Args[Args.size() - numArgsAfterSentinel - 1]; if (!sentinelExpr) return; if (sentinelExpr->isValueDependent()) return; if (Context.isSentinelNullExpr(sentinelExpr)) return; // Pick a reasonable string to insert. Optimistically use 'nil', 'nullptr', // or 'NULL' if those are actually defined in the context. Only use // 'nil' for ObjC methods, where it's much more likely that the // variadic arguments form a list of object pointers. SourceLocation MissingNilLoc = getLocForEndOfToken(sentinelExpr->getLocEnd()); std::string NullValue; if (calleeType == CT_Method && PP.isMacroDefined("nil")) NullValue = "nil"; else if (getLangOpts().CPlusPlus11) NullValue = "nullptr"; else if (PP.isMacroDefined("NULL")) NullValue = "NULL"; else NullValue = "(void*) 0"; if (MissingNilLoc.isInvalid()) Diag(Loc, diag::warn_missing_sentinel) << int(calleeType); else Diag(MissingNilLoc, diag::warn_missing_sentinel) << int(calleeType) << FixItHint::CreateInsertion(MissingNilLoc, ", " + NullValue); Diag(D->getLocation(), diag::note_sentinel_here) << int(calleeType); } SourceRange Sema::getExprRange(Expr *E) const { return E ? E->getSourceRange() : SourceRange(); } //===----------------------------------------------------------------------===// // Standard Promotions and Conversions //===----------------------------------------------------------------------===// /// DefaultFunctionArrayConversion (C99 6.3.2.1p3, C99 6.3.2.1p4). ExprResult Sema::DefaultFunctionArrayConversion(Expr *E, bool Diagnose) { // Handle any placeholder expressions which made it here. if (E->getType()->isPlaceholderType()) { ExprResult result = CheckPlaceholderExpr(E); if (result.isInvalid()) return ExprError(); E = result.get(); } QualType Ty = E->getType(); assert(!Ty.isNull() && "DefaultFunctionArrayConversion - missing type"); if (Ty->isFunctionType()) { // If we are here, we are not calling a function but taking // its address (which is not allowed in OpenCL v1.0 s6.8.a.3). if (getLangOpts().OpenCL) { if (Diagnose) Diag(E->getExprLoc(), diag::err_opencl_taking_function_address); return ExprError(); } if (auto *DRE = dyn_cast(E->IgnoreParenCasts())) if (auto *FD = dyn_cast(DRE->getDecl())) if (!checkAddressOfFunctionIsAvailable(FD, Diagnose, E->getExprLoc())) return ExprError(); E = ImpCastExprToType(E, Context.getPointerType(Ty), CK_FunctionToPointerDecay).get(); } else if (Ty->isArrayType()) { // In C90 mode, arrays only promote to pointers if the array expression is // an lvalue. The relevant legalese is C90 6.2.2.1p3: "an lvalue that has // type 'array of type' is converted to an expression that has type 'pointer // to type'...". In C99 this was changed to: C99 6.3.2.1p3: "an expression // that has type 'array of type' ...". The relevant change is "an lvalue" // (C90) to "an expression" (C99). // // C++ 4.2p1: // An lvalue or rvalue of type "array of N T" or "array of unknown bound of // T" can be converted to an rvalue of type "pointer to T". // if (getLangOpts().C99 || getLangOpts().CPlusPlus || E->isLValue()) E = ImpCastExprToType(E, Context.getArrayDecayedType(Ty), CK_ArrayToPointerDecay).get(); } return E; } static void CheckForNullPointerDereference(Sema &S, Expr *E) { // Check to see if we are dereferencing a null pointer. If so, // and if not volatile-qualified, this is undefined behavior that the // optimizer will delete, so warn about it. People sometimes try to use this // to get a deterministic trap and are surprised by clang's behavior. This // only handles the pattern "*null", which is a very syntactic check. if (UnaryOperator *UO = dyn_cast(E->IgnoreParenCasts())) if (UO->getOpcode() == UO_Deref && UO->getSubExpr()->IgnoreParenCasts()-> isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull) && !UO->getType().isVolatileQualified()) { S.DiagRuntimeBehavior(UO->getOperatorLoc(), UO, S.PDiag(diag::warn_indirection_through_null) << UO->getSubExpr()->getSourceRange()); S.DiagRuntimeBehavior(UO->getOperatorLoc(), UO, S.PDiag(diag::note_indirection_through_null)); } } static void DiagnoseDirectIsaAccess(Sema &S, const ObjCIvarRefExpr *OIRE, SourceLocation AssignLoc, const Expr* RHS) { const ObjCIvarDecl *IV = OIRE->getDecl(); if (!IV) return; DeclarationName MemberName = IV->getDeclName(); IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); if (!Member || !Member->isStr("isa")) return; const Expr *Base = OIRE->getBase(); QualType BaseType = Base->getType(); if (OIRE->isArrow()) BaseType = BaseType->getPointeeType(); if (const ObjCObjectType *OTy = BaseType->getAs()) if (ObjCInterfaceDecl *IDecl = OTy->getInterface()) { ObjCInterfaceDecl *ClassDeclared = nullptr; ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); if (!ClassDeclared->getSuperClass() && (*ClassDeclared->ivar_begin()) == IV) { if (RHS) { NamedDecl *ObjectSetClass = S.LookupSingleName(S.TUScope, &S.Context.Idents.get("object_setClass"), SourceLocation(), S.LookupOrdinaryName); if (ObjectSetClass) { SourceLocation RHSLocEnd = S.getLocForEndOfToken(RHS->getLocEnd()); S.Diag(OIRE->getExprLoc(), diag::warn_objc_isa_assign) << FixItHint::CreateInsertion(OIRE->getLocStart(), "object_setClass(") << FixItHint::CreateReplacement(SourceRange(OIRE->getOpLoc(), AssignLoc), ",") << FixItHint::CreateInsertion(RHSLocEnd, ")"); } else S.Diag(OIRE->getLocation(), diag::warn_objc_isa_assign); } else { NamedDecl *ObjectGetClass = S.LookupSingleName(S.TUScope, &S.Context.Idents.get("object_getClass"), SourceLocation(), S.LookupOrdinaryName); if (ObjectGetClass) S.Diag(OIRE->getExprLoc(), diag::warn_objc_isa_use) << FixItHint::CreateInsertion(OIRE->getLocStart(), "object_getClass(") << FixItHint::CreateReplacement( SourceRange(OIRE->getOpLoc(), OIRE->getLocEnd()), ")"); else S.Diag(OIRE->getLocation(), diag::warn_objc_isa_use); } S.Diag(IV->getLocation(), diag::note_ivar_decl); } } } ExprResult Sema::DefaultLvalueConversion(Expr *E) { // Handle any placeholder expressions which made it here. if (E->getType()->isPlaceholderType()) { ExprResult result = CheckPlaceholderExpr(E); if (result.isInvalid()) return ExprError(); E = result.get(); } // C++ [conv.lval]p1: // A glvalue of a non-function, non-array type T can be // converted to a prvalue. if (!E->isGLValue()) return E; QualType T = E->getType(); assert(!T.isNull() && "r-value conversion on typeless expression?"); // We don't want to throw lvalue-to-rvalue casts on top of // expressions of certain types in C++. if (getLangOpts().CPlusPlus && (E->getType() == Context.OverloadTy || T->isDependentType() || T->isRecordType())) return E; // The C standard is actually really unclear on this point, and // DR106 tells us what the result should be but not why. It's // generally best to say that void types just doesn't undergo // lvalue-to-rvalue at all. Note that expressions of unqualified // 'void' type are never l-values, but qualified void can be. if (T->isVoidType()) return E; // OpenCL usually rejects direct accesses to values of 'half' type. if (getLangOpts().OpenCL && !getOpenCLOptions().cl_khr_fp16 && T->isHalfType()) { Diag(E->getExprLoc(), diag::err_opencl_half_load_store) << 0 << T; return ExprError(); } CheckForNullPointerDereference(*this, E); if (const ObjCIsaExpr *OISA = dyn_cast(E->IgnoreParenCasts())) { NamedDecl *ObjectGetClass = LookupSingleName(TUScope, &Context.Idents.get("object_getClass"), SourceLocation(), LookupOrdinaryName); if (ObjectGetClass) Diag(E->getExprLoc(), diag::warn_objc_isa_use) << FixItHint::CreateInsertion(OISA->getLocStart(), "object_getClass(") << FixItHint::CreateReplacement( SourceRange(OISA->getOpLoc(), OISA->getIsaMemberLoc()), ")"); else Diag(E->getExprLoc(), diag::warn_objc_isa_use); } else if (const ObjCIvarRefExpr *OIRE = dyn_cast(E->IgnoreParenCasts())) DiagnoseDirectIsaAccess(*this, OIRE, SourceLocation(), /* Expr*/nullptr); // C++ [conv.lval]p1: // [...] If T is a non-class type, the type of the prvalue is the // cv-unqualified version of T. Otherwise, the type of the // rvalue is T. // // C99 6.3.2.1p2: // If the lvalue has qualified type, the value has the unqualified // version of the type of the lvalue; otherwise, the value has the // type of the lvalue. if (T.hasQualifiers()) T = T.getUnqualifiedType(); // Under the MS ABI, lock down the inheritance model now. if (T->isMemberPointerType() && Context.getTargetInfo().getCXXABI().isMicrosoft()) (void)isCompleteType(E->getExprLoc(), T); UpdateMarkingForLValueToRValue(E); // Loading a __weak object implicitly retains the value, so we need a cleanup to // balance that. if (getLangOpts().ObjCAutoRefCount && E->getType().getObjCLifetime() == Qualifiers::OCL_Weak) ExprNeedsCleanups = true; ExprResult Res = ImplicitCastExpr::Create(Context, T, CK_LValueToRValue, E, nullptr, VK_RValue); // C11 6.3.2.1p2: // ... if the lvalue has atomic type, the value has the non-atomic version // of the type of the lvalue ... if (const AtomicType *Atomic = T->getAs()) { T = Atomic->getValueType().getUnqualifiedType(); Res = ImplicitCastExpr::Create(Context, T, CK_AtomicToNonAtomic, Res.get(), nullptr, VK_RValue); } return Res; } ExprResult Sema::DefaultFunctionArrayLvalueConversion(Expr *E, bool Diagnose) { ExprResult Res = DefaultFunctionArrayConversion(E, Diagnose); if (Res.isInvalid()) return ExprError(); Res = DefaultLvalueConversion(Res.get()); if (Res.isInvalid()) return ExprError(); return Res; } /// CallExprUnaryConversions - a special case of an unary conversion /// performed on a function designator of a call expression. ExprResult Sema::CallExprUnaryConversions(Expr *E) { QualType Ty = E->getType(); ExprResult Res = E; // Only do implicit cast for a function type, but not for a pointer // to function type. if (Ty->isFunctionType()) { Res = ImpCastExprToType(E, Context.getPointerType(Ty), CK_FunctionToPointerDecay).get(); if (Res.isInvalid()) return ExprError(); } Res = DefaultLvalueConversion(Res.get()); if (Res.isInvalid()) return ExprError(); return Res.get(); } /// UsualUnaryConversions - Performs various conversions that are common to most /// operators (C99 6.3). The conversions of array and function types are /// sometimes suppressed. For example, the array->pointer conversion doesn't /// apply if the array is an argument to the sizeof or address (&) operators. /// In these instances, this routine should *not* be called. ExprResult Sema::UsualUnaryConversions(Expr *E) { // First, convert to an r-value. ExprResult Res = DefaultFunctionArrayLvalueConversion(E); if (Res.isInvalid()) return ExprError(); E = Res.get(); QualType Ty = E->getType(); assert(!Ty.isNull() && "UsualUnaryConversions - missing type"); // Half FP have to be promoted to float unless it is natively supported if (Ty->isHalfType() && !getLangOpts().NativeHalfType) return ImpCastExprToType(Res.get(), Context.FloatTy, CK_FloatingCast); // Try to perform integral promotions if the object has a theoretically // promotable type. if (Ty->isIntegralOrUnscopedEnumerationType()) { // C99 6.3.1.1p2: // // The following may be used in an expression wherever an int or // unsigned int may be used: // - an object or expression with an integer type whose integer // conversion rank is less than or equal to the rank of int // and unsigned int. // - A bit-field of type _Bool, int, signed int, or unsigned int. // // If an int can represent all values of the original type, the // value is converted to an int; otherwise, it is converted to an // unsigned int. These are called the integer promotions. All // other types are unchanged by the integer promotions. QualType PTy = Context.isPromotableBitField(E); if (!PTy.isNull()) { E = ImpCastExprToType(E, PTy, CK_IntegralCast).get(); return E; } if (Ty->isPromotableIntegerType()) { QualType PT = Context.getPromotedIntegerType(Ty); E = ImpCastExprToType(E, PT, CK_IntegralCast).get(); return E; } } return E; } /// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that /// do not have a prototype. Arguments that have type float or __fp16 /// are promoted to double. All other argument types are converted by /// UsualUnaryConversions(). ExprResult Sema::DefaultArgumentPromotion(Expr *E) { QualType Ty = E->getType(); assert(!Ty.isNull() && "DefaultArgumentPromotion - missing type"); ExprResult Res = UsualUnaryConversions(E); if (Res.isInvalid()) return ExprError(); E = Res.get(); // If this is a 'float' or '__fp16' (CVR qualified or typedef) promote to // double. const BuiltinType *BTy = Ty->getAs(); if (BTy && (BTy->getKind() == BuiltinType::Half || BTy->getKind() == BuiltinType::Float)) E = ImpCastExprToType(E, Context.DoubleTy, CK_FloatingCast).get(); // C++ performs lvalue-to-rvalue conversion as a default argument // promotion, even on class types, but note: // C++11 [conv.lval]p2: // When an lvalue-to-rvalue conversion occurs in an unevaluated // operand or a subexpression thereof the value contained in the // referenced object is not accessed. Otherwise, if the glvalue // has a class type, the conversion copy-initializes a temporary // of type T from the glvalue and the result of the conversion // is a prvalue for the temporary. // FIXME: add some way to gate this entire thing for correctness in // potentially potentially evaluated contexts. if (getLangOpts().CPlusPlus && E->isGLValue() && !isUnevaluatedContext()) { ExprResult Temp = PerformCopyInitialization( InitializedEntity::InitializeTemporary(E->getType()), E->getExprLoc(), E); if (Temp.isInvalid()) return ExprError(); E = Temp.get(); } return E; } /// Determine the degree of POD-ness for an expression. /// Incomplete types are considered POD, since this check can be performed /// when we're in an unevaluated context. Sema::VarArgKind Sema::isValidVarArgType(const QualType &Ty) { if (Ty->isIncompleteType()) { // C++11 [expr.call]p7: // After these conversions, if the argument does not have arithmetic, // enumeration, pointer, pointer to member, or class type, the program // is ill-formed. // // Since we've already performed array-to-pointer and function-to-pointer // decay, the only such type in C++ is cv void. This also handles // initializer lists as variadic arguments. if (Ty->isVoidType()) return VAK_Invalid; if (Ty->isObjCObjectType()) return VAK_Invalid; return VAK_Valid; } if (Ty.isCXX98PODType(Context)) return VAK_Valid; // C++11 [expr.call]p7: // Passing a potentially-evaluated argument of class type (Clause 9) // having a non-trivial copy constructor, a non-trivial move constructor, // or a non-trivial destructor, with no corresponding parameter, // is conditionally-supported with implementation-defined semantics. if (getLangOpts().CPlusPlus11 && !Ty->isDependentType()) if (CXXRecordDecl *Record = Ty->getAsCXXRecordDecl()) if (!Record->hasNonTrivialCopyConstructor() && !Record->hasNonTrivialMoveConstructor() && !Record->hasNonTrivialDestructor()) return VAK_ValidInCXX11; if (getLangOpts().ObjCAutoRefCount && Ty->isObjCLifetimeType()) return VAK_Valid; if (Ty->isObjCObjectType()) return VAK_Invalid; if (getLangOpts().MSVCCompat) return VAK_MSVCUndefined; // FIXME: In C++11, these cases are conditionally-supported, meaning we're // permitted to reject them. We should consider doing so. return VAK_Undefined; } void Sema::checkVariadicArgument(const Expr *E, VariadicCallType CT) { // Don't allow one to pass an Objective-C interface to a vararg. const QualType &Ty = E->getType(); VarArgKind VAK = isValidVarArgType(Ty); // Complain about passing non-POD types through varargs. switch (VAK) { case VAK_ValidInCXX11: DiagRuntimeBehavior( E->getLocStart(), nullptr, PDiag(diag::warn_cxx98_compat_pass_non_pod_arg_to_vararg) << Ty << CT); // Fall through. case VAK_Valid: if (Ty->isRecordType()) { // This is unlikely to be what the user intended. If the class has a // 'c_str' member function, the user probably meant to call that. DiagRuntimeBehavior(E->getLocStart(), nullptr, PDiag(diag::warn_pass_class_arg_to_vararg) << Ty << CT << hasCStrMethod(E) << ".c_str()"); } break; case VAK_Undefined: case VAK_MSVCUndefined: DiagRuntimeBehavior( E->getLocStart(), nullptr, PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg) << getLangOpts().CPlusPlus11 << Ty << CT); break; case VAK_Invalid: if (Ty->isObjCObjectType()) DiagRuntimeBehavior( E->getLocStart(), nullptr, PDiag(diag::err_cannot_pass_objc_interface_to_vararg) << Ty << CT); else Diag(E->getLocStart(), diag::err_cannot_pass_to_vararg) << isa(E) << Ty << CT; break; } } /// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but /// will create a trap if the resulting type is not a POD type. ExprResult Sema::DefaultVariadicArgumentPromotion(Expr *E, VariadicCallType CT, FunctionDecl *FDecl) { if (const BuiltinType *PlaceholderTy = E->getType()->getAsPlaceholderType()) { // Strip the unbridged-cast placeholder expression off, if applicable. if (PlaceholderTy->getKind() == BuiltinType::ARCUnbridgedCast && (CT == VariadicMethod || (FDecl && FDecl->hasAttr()))) { E = stripARCUnbridgedCast(E); // Otherwise, do normal placeholder checking. } else { ExprResult ExprRes = CheckPlaceholderExpr(E); if (ExprRes.isInvalid()) return ExprError(); E = ExprRes.get(); } } ExprResult ExprRes = DefaultArgumentPromotion(E); if (ExprRes.isInvalid()) return ExprError(); E = ExprRes.get(); // Diagnostics regarding non-POD argument types are // emitted along with format string checking in Sema::CheckFunctionCall(). if (isValidVarArgType(E->getType()) == VAK_Undefined) { // Turn this into a trap. CXXScopeSpec SS; SourceLocation TemplateKWLoc; UnqualifiedId Name; Name.setIdentifier(PP.getIdentifierInfo("__builtin_trap"), E->getLocStart()); ExprResult TrapFn = ActOnIdExpression(TUScope, SS, TemplateKWLoc, Name, true, false); if (TrapFn.isInvalid()) return ExprError(); ExprResult Call = ActOnCallExpr(TUScope, TrapFn.get(), E->getLocStart(), None, E->getLocEnd()); if (Call.isInvalid()) return ExprError(); ExprResult Comma = ActOnBinOp(TUScope, E->getLocStart(), tok::comma, Call.get(), E); if (Comma.isInvalid()) return ExprError(); return Comma.get(); } if (!getLangOpts().CPlusPlus && RequireCompleteType(E->getExprLoc(), E->getType(), diag::err_call_incomplete_argument)) return ExprError(); return E; } /// \brief Converts an integer to complex float type. Helper function of /// UsualArithmeticConversions() /// /// \return false if the integer expression is an integer type and is /// successfully converted to the complex type. static bool handleIntegerToComplexFloatConversion(Sema &S, ExprResult &IntExpr, ExprResult &ComplexExpr, QualType IntTy, QualType ComplexTy, bool SkipCast) { if (IntTy->isComplexType() || IntTy->isRealFloatingType()) return true; if (SkipCast) return false; if (IntTy->isIntegerType()) { QualType fpTy = cast(ComplexTy)->getElementType(); IntExpr = S.ImpCastExprToType(IntExpr.get(), fpTy, CK_IntegralToFloating); IntExpr = S.ImpCastExprToType(IntExpr.get(), ComplexTy, CK_FloatingRealToComplex); } else { assert(IntTy->isComplexIntegerType()); IntExpr = S.ImpCastExprToType(IntExpr.get(), ComplexTy, CK_IntegralComplexToFloatingComplex); } return false; } /// \brief Handle arithmetic conversion with complex types. Helper function of /// UsualArithmeticConversions() static QualType handleComplexFloatConversion(Sema &S, ExprResult &LHS, ExprResult &RHS, QualType LHSType, QualType RHSType, bool IsCompAssign) { // if we have an integer operand, the result is the complex type. if (!handleIntegerToComplexFloatConversion(S, RHS, LHS, RHSType, LHSType, /*skipCast*/false)) return LHSType; if (!handleIntegerToComplexFloatConversion(S, LHS, RHS, LHSType, RHSType, /*skipCast*/IsCompAssign)) return RHSType; // This handles complex/complex, complex/float, or float/complex. // When both operands are complex, the shorter operand is converted to the // type of the longer, and that is the type of the result. This corresponds // to what is done when combining two real floating-point operands. // The fun begins when size promotion occur across type domains. // From H&S 6.3.4: When one operand is complex and the other is a real // floating-point type, the less precise type is converted, within it's // real or complex domain, to the precision of the other type. For example, // when combining a "long double" with a "double _Complex", the // "double _Complex" is promoted to "long double _Complex". // Compute the rank of the two types, regardless of whether they are complex. int Order = S.Context.getFloatingTypeOrder(LHSType, RHSType); auto *LHSComplexType = dyn_cast(LHSType); auto *RHSComplexType = dyn_cast(RHSType); QualType LHSElementType = LHSComplexType ? LHSComplexType->getElementType() : LHSType; QualType RHSElementType = RHSComplexType ? RHSComplexType->getElementType() : RHSType; QualType ResultType = S.Context.getComplexType(LHSElementType); if (Order < 0) { // Promote the precision of the LHS if not an assignment. ResultType = S.Context.getComplexType(RHSElementType); if (!IsCompAssign) { if (LHSComplexType) LHS = S.ImpCastExprToType(LHS.get(), ResultType, CK_FloatingComplexCast); else LHS = S.ImpCastExprToType(LHS.get(), RHSElementType, CK_FloatingCast); } } else if (Order > 0) { // Promote the precision of the RHS. if (RHSComplexType) RHS = S.ImpCastExprToType(RHS.get(), ResultType, CK_FloatingComplexCast); else RHS = S.ImpCastExprToType(RHS.get(), LHSElementType, CK_FloatingCast); } return ResultType; } /// \brief Hande arithmetic conversion from integer to float. Helper function /// of UsualArithmeticConversions() static QualType handleIntToFloatConversion(Sema &S, ExprResult &FloatExpr, ExprResult &IntExpr, QualType FloatTy, QualType IntTy, bool ConvertFloat, bool ConvertInt) { if (IntTy->isIntegerType()) { if (ConvertInt) // Convert intExpr to the lhs floating point type. IntExpr = S.ImpCastExprToType(IntExpr.get(), FloatTy, CK_IntegralToFloating); return FloatTy; } // Convert both sides to the appropriate complex float. assert(IntTy->isComplexIntegerType()); QualType result = S.Context.getComplexType(FloatTy); // _Complex int -> _Complex float if (ConvertInt) IntExpr = S.ImpCastExprToType(IntExpr.get(), result, CK_IntegralComplexToFloatingComplex); // float -> _Complex float if (ConvertFloat) FloatExpr = S.ImpCastExprToType(FloatExpr.get(), result, CK_FloatingRealToComplex); return result; } /// \brief Handle arithmethic conversion with floating point types. Helper /// function of UsualArithmeticConversions() static QualType handleFloatConversion(Sema &S, ExprResult &LHS, ExprResult &RHS, QualType LHSType, QualType RHSType, bool IsCompAssign) { bool LHSFloat = LHSType->isRealFloatingType(); bool RHSFloat = RHSType->isRealFloatingType(); // If we have two real floating types, convert the smaller operand // to the bigger result. if (LHSFloat && RHSFloat) { int order = S.Context.getFloatingTypeOrder(LHSType, RHSType); if (order > 0) { RHS = S.ImpCastExprToType(RHS.get(), LHSType, CK_FloatingCast); return LHSType; } assert(order < 0 && "illegal float comparison"); if (!IsCompAssign) LHS = S.ImpCastExprToType(LHS.get(), RHSType, CK_FloatingCast); return RHSType; } if (LHSFloat) { // Half FP has to be promoted to float unless it is natively supported if (LHSType->isHalfType() && !S.getLangOpts().NativeHalfType) LHSType = S.Context.FloatTy; return handleIntToFloatConversion(S, LHS, RHS, LHSType, RHSType, /*convertFloat=*/!IsCompAssign, /*convertInt=*/ true); } assert(RHSFloat); return handleIntToFloatConversion(S, RHS, LHS, RHSType, LHSType, /*convertInt=*/ true, /*convertFloat=*/!IsCompAssign); } typedef ExprResult PerformCastFn(Sema &S, Expr *operand, QualType toType); namespace { /// These helper callbacks are placed in an anonymous namespace to /// permit their use as function template parameters. ExprResult doIntegralCast(Sema &S, Expr *op, QualType toType) { return S.ImpCastExprToType(op, toType, CK_IntegralCast); } ExprResult doComplexIntegralCast(Sema &S, Expr *op, QualType toType) { return S.ImpCastExprToType(op, S.Context.getComplexType(toType), CK_IntegralComplexCast); } } /// \brief Handle integer arithmetic conversions. Helper function of /// UsualArithmeticConversions() template static QualType handleIntegerConversion(Sema &S, ExprResult &LHS, ExprResult &RHS, QualType LHSType, QualType RHSType, bool IsCompAssign) { // The rules for this case are in C99 6.3.1.8 int order = S.Context.getIntegerTypeOrder(LHSType, RHSType); bool LHSSigned = LHSType->hasSignedIntegerRepresentation(); bool RHSSigned = RHSType->hasSignedIntegerRepresentation(); if (LHSSigned == RHSSigned) { // Same signedness; use the higher-ranked type if (order >= 0) { RHS = (*doRHSCast)(S, RHS.get(), LHSType); return LHSType; } else if (!IsCompAssign) LHS = (*doLHSCast)(S, LHS.get(), RHSType); return RHSType; } else if (order != (LHSSigned ? 1 : -1)) { // The unsigned type has greater than or equal rank to the // signed type, so use the unsigned type if (RHSSigned) { RHS = (*doRHSCast)(S, RHS.get(), LHSType); return LHSType; } else if (!IsCompAssign) LHS = (*doLHSCast)(S, LHS.get(), RHSType); return RHSType; } else if (S.Context.getIntWidth(LHSType) != S.Context.getIntWidth(RHSType)) { // The two types are different widths; if we are here, that // means the signed type is larger than the unsigned type, so // use the signed type. if (LHSSigned) { RHS = (*doRHSCast)(S, RHS.get(), LHSType); return LHSType; } else if (!IsCompAssign) LHS = (*doLHSCast)(S, LHS.get(), RHSType); return RHSType; } else { // The signed type is higher-ranked than the unsigned type, // but isn't actually any bigger (like unsigned int and long // on most 32-bit systems). Use the unsigned type corresponding // to the signed type. QualType result = S.Context.getCorrespondingUnsignedType(LHSSigned ? LHSType : RHSType); RHS = (*doRHSCast)(S, RHS.get(), result); if (!IsCompAssign) LHS = (*doLHSCast)(S, LHS.get(), result); return result; } } /// \brief Handle conversions with GCC complex int extension. Helper function /// of UsualArithmeticConversions() static QualType handleComplexIntConversion(Sema &S, ExprResult &LHS, ExprResult &RHS, QualType LHSType, QualType RHSType, bool IsCompAssign) { const ComplexType *LHSComplexInt = LHSType->getAsComplexIntegerType(); const ComplexType *RHSComplexInt = RHSType->getAsComplexIntegerType(); if (LHSComplexInt && RHSComplexInt) { QualType LHSEltType = LHSComplexInt->getElementType(); QualType RHSEltType = RHSComplexInt->getElementType(); QualType ScalarType = handleIntegerConversion (S, LHS, RHS, LHSEltType, RHSEltType, IsCompAssign); return S.Context.getComplexType(ScalarType); } if (LHSComplexInt) { QualType LHSEltType = LHSComplexInt->getElementType(); QualType ScalarType = handleIntegerConversion (S, LHS, RHS, LHSEltType, RHSType, IsCompAssign); QualType ComplexType = S.Context.getComplexType(ScalarType); RHS = S.ImpCastExprToType(RHS.get(), ComplexType, CK_IntegralRealToComplex); return ComplexType; } assert(RHSComplexInt); QualType RHSEltType = RHSComplexInt->getElementType(); QualType ScalarType = handleIntegerConversion (S, LHS, RHS, LHSType, RHSEltType, IsCompAssign); QualType ComplexType = S.Context.getComplexType(ScalarType); if (!IsCompAssign) LHS = S.ImpCastExprToType(LHS.get(), ComplexType, CK_IntegralRealToComplex); return ComplexType; } /// UsualArithmeticConversions - Performs various conversions that are common to /// binary operators (C99 6.3.1.8). If both operands aren't arithmetic, this /// routine returns the first non-arithmetic type found. The client is /// responsible for emitting appropriate error diagnostics. QualType Sema::UsualArithmeticConversions(ExprResult &LHS, ExprResult &RHS, bool IsCompAssign) { if (!IsCompAssign) { LHS = UsualUnaryConversions(LHS.get()); if (LHS.isInvalid()) return QualType(); } RHS = UsualUnaryConversions(RHS.get()); if (RHS.isInvalid()) return QualType(); // For conversion purposes, we ignore any qualifiers. // For example, "const float" and "float" are equivalent. QualType LHSType = Context.getCanonicalType(LHS.get()->getType()).getUnqualifiedType(); QualType RHSType = Context.getCanonicalType(RHS.get()->getType()).getUnqualifiedType(); // For conversion purposes, we ignore any atomic qualifier on the LHS. if (const AtomicType *AtomicLHS = LHSType->getAs()) LHSType = AtomicLHS->getValueType(); // If both types are identical, no conversion is needed. if (LHSType == RHSType) return LHSType; // If either side is a non-arithmetic type (e.g. a pointer), we are done. // The caller can deal with this (e.g. pointer + int). if (!LHSType->isArithmeticType() || !RHSType->isArithmeticType()) return QualType(); // Apply unary and bitfield promotions to the LHS's type. QualType LHSUnpromotedType = LHSType; if (LHSType->isPromotableIntegerType()) LHSType = Context.getPromotedIntegerType(LHSType); QualType LHSBitfieldPromoteTy = Context.isPromotableBitField(LHS.get()); if (!LHSBitfieldPromoteTy.isNull()) LHSType = LHSBitfieldPromoteTy; if (LHSType != LHSUnpromotedType && !IsCompAssign) LHS = ImpCastExprToType(LHS.get(), LHSType, CK_IntegralCast); // If both types are identical, no conversion is needed. if (LHSType == RHSType) return LHSType; // At this point, we have two different arithmetic types. // Handle complex types first (C99 6.3.1.8p1). if (LHSType->isComplexType() || RHSType->isComplexType()) return handleComplexFloatConversion(*this, LHS, RHS, LHSType, RHSType, IsCompAssign); // Now handle "real" floating types (i.e. float, double, long double). if (LHSType->isRealFloatingType() || RHSType->isRealFloatingType()) return handleFloatConversion(*this, LHS, RHS, LHSType, RHSType, IsCompAssign); // Handle GCC complex int extension. if (LHSType->isComplexIntegerType() || RHSType->isComplexIntegerType()) return handleComplexIntConversion(*this, LHS, RHS, LHSType, RHSType, IsCompAssign); // Finally, we have two differing integer types. return handleIntegerConversion (*this, LHS, RHS, LHSType, RHSType, IsCompAssign); } //===----------------------------------------------------------------------===// // Semantic Analysis for various Expression Types //===----------------------------------------------------------------------===// ExprResult Sema::ActOnGenericSelectionExpr(SourceLocation KeyLoc, SourceLocation DefaultLoc, SourceLocation RParenLoc, Expr *ControllingExpr, ArrayRef ArgTypes, ArrayRef ArgExprs) { unsigned NumAssocs = ArgTypes.size(); assert(NumAssocs == ArgExprs.size()); TypeSourceInfo **Types = new TypeSourceInfo*[NumAssocs]; for (unsigned i = 0; i < NumAssocs; ++i) { if (ArgTypes[i]) (void) GetTypeFromParser(ArgTypes[i], &Types[i]); else Types[i] = nullptr; } ExprResult ER = CreateGenericSelectionExpr(KeyLoc, DefaultLoc, RParenLoc, ControllingExpr, llvm::makeArrayRef(Types, NumAssocs), ArgExprs); delete [] Types; return ER; } ExprResult Sema::CreateGenericSelectionExpr(SourceLocation KeyLoc, SourceLocation DefaultLoc, SourceLocation RParenLoc, Expr *ControllingExpr, ArrayRef Types, ArrayRef Exprs) { unsigned NumAssocs = Types.size(); assert(NumAssocs == Exprs.size()); // Decay and strip qualifiers for the controlling expression type, and handle // placeholder type replacement. See committee discussion from WG14 DR423. ExprResult R = DefaultFunctionArrayLvalueConversion(ControllingExpr); if (R.isInvalid()) return ExprError(); ControllingExpr = R.get(); // The controlling expression is an unevaluated operand, so side effects are // likely unintended. if (ActiveTemplateInstantiations.empty() && ControllingExpr->HasSideEffects(Context, false)) Diag(ControllingExpr->getExprLoc(), diag::warn_side_effects_unevaluated_context); bool TypeErrorFound = false, IsResultDependent = ControllingExpr->isTypeDependent(), ContainsUnexpandedParameterPack = ControllingExpr->containsUnexpandedParameterPack(); for (unsigned i = 0; i < NumAssocs; ++i) { if (Exprs[i]->containsUnexpandedParameterPack()) ContainsUnexpandedParameterPack = true; if (Types[i]) { if (Types[i]->getType()->containsUnexpandedParameterPack()) ContainsUnexpandedParameterPack = true; if (Types[i]->getType()->isDependentType()) { IsResultDependent = true; } else { // C11 6.5.1.1p2 "The type name in a generic association shall specify a // complete object type other than a variably modified type." unsigned D = 0; if (Types[i]->getType()->isIncompleteType()) D = diag::err_assoc_type_incomplete; else if (!Types[i]->getType()->isObjectType()) D = diag::err_assoc_type_nonobject; else if (Types[i]->getType()->isVariablyModifiedType()) D = diag::err_assoc_type_variably_modified; if (D != 0) { Diag(Types[i]->getTypeLoc().getBeginLoc(), D) << Types[i]->getTypeLoc().getSourceRange() << Types[i]->getType(); TypeErrorFound = true; } // C11 6.5.1.1p2 "No two generic associations in the same generic // selection shall specify compatible types." for (unsigned j = i+1; j < NumAssocs; ++j) if (Types[j] && !Types[j]->getType()->isDependentType() && Context.typesAreCompatible(Types[i]->getType(), Types[j]->getType())) { Diag(Types[j]->getTypeLoc().getBeginLoc(), diag::err_assoc_compatible_types) << Types[j]->getTypeLoc().getSourceRange() << Types[j]->getType() << Types[i]->getType(); Diag(Types[i]->getTypeLoc().getBeginLoc(), diag::note_compat_assoc) << Types[i]->getTypeLoc().getSourceRange() << Types[i]->getType(); TypeErrorFound = true; } } } } if (TypeErrorFound) return ExprError(); // If we determined that the generic selection is result-dependent, don't // try to compute the result expression. if (IsResultDependent) return new (Context) GenericSelectionExpr( Context, KeyLoc, ControllingExpr, Types, Exprs, DefaultLoc, RParenLoc, ContainsUnexpandedParameterPack); SmallVector CompatIndices; unsigned DefaultIndex = -1U; for (unsigned i = 0; i < NumAssocs; ++i) { if (!Types[i]) DefaultIndex = i; else if (Context.typesAreCompatible(ControllingExpr->getType(), Types[i]->getType())) CompatIndices.push_back(i); } // C11 6.5.1.1p2 "The controlling expression of a generic selection shall have // type compatible with at most one of the types named in its generic // association list." if (CompatIndices.size() > 1) { // We strip parens here because the controlling expression is typically // parenthesized in macro definitions. ControllingExpr = ControllingExpr->IgnoreParens(); Diag(ControllingExpr->getLocStart(), diag::err_generic_sel_multi_match) << ControllingExpr->getSourceRange() << ControllingExpr->getType() << (unsigned) CompatIndices.size(); for (unsigned I : CompatIndices) { Diag(Types[I]->getTypeLoc().getBeginLoc(), diag::note_compat_assoc) << Types[I]->getTypeLoc().getSourceRange() << Types[I]->getType(); } return ExprError(); } // C11 6.5.1.1p2 "If a generic selection has no default generic association, // its controlling expression shall have type compatible with exactly one of // the types named in its generic association list." if (DefaultIndex == -1U && CompatIndices.size() == 0) { // We strip parens here because the controlling expression is typically // parenthesized in macro definitions. ControllingExpr = ControllingExpr->IgnoreParens(); Diag(ControllingExpr->getLocStart(), diag::err_generic_sel_no_match) << ControllingExpr->getSourceRange() << ControllingExpr->getType(); return ExprError(); } // C11 6.5.1.1p3 "If a generic selection has a generic association with a // type name that is compatible with the type of the controlling expression, // then the result expression of the generic selection is the expression // in that generic association. Otherwise, the result expression of the // generic selection is the expression in the default generic association." unsigned ResultIndex = CompatIndices.size() ? CompatIndices[0] : DefaultIndex; return new (Context) GenericSelectionExpr( Context, KeyLoc, ControllingExpr, Types, Exprs, DefaultLoc, RParenLoc, ContainsUnexpandedParameterPack, ResultIndex); } /// getUDSuffixLoc - Create a SourceLocation for a ud-suffix, given the /// location of the token and the offset of the ud-suffix within it. static SourceLocation getUDSuffixLoc(Sema &S, SourceLocation TokLoc, unsigned Offset) { return Lexer::AdvanceToTokenCharacter(TokLoc, Offset, S.getSourceManager(), S.getLangOpts()); } /// BuildCookedLiteralOperatorCall - A user-defined literal was found. Look up /// the corresponding cooked (non-raw) literal operator, and build a call to it. static ExprResult BuildCookedLiteralOperatorCall(Sema &S, Scope *Scope, IdentifierInfo *UDSuffix, SourceLocation UDSuffixLoc, ArrayRef Args, SourceLocation LitEndLoc) { assert(Args.size() <= 2 && "too many arguments for literal operator"); QualType ArgTy[2]; for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { ArgTy[ArgIdx] = Args[ArgIdx]->getType(); if (ArgTy[ArgIdx]->isArrayType()) ArgTy[ArgIdx] = S.Context.getArrayDecayedType(ArgTy[ArgIdx]); } DeclarationName OpName = S.Context.DeclarationNames.getCXXLiteralOperatorName(UDSuffix); DeclarationNameInfo OpNameInfo(OpName, UDSuffixLoc); OpNameInfo.setCXXLiteralOperatorNameLoc(UDSuffixLoc); LookupResult R(S, OpName, UDSuffixLoc, Sema::LookupOrdinaryName); if (S.LookupLiteralOperator(Scope, R, llvm::makeArrayRef(ArgTy, Args.size()), /*AllowRaw*/false, /*AllowTemplate*/false, /*AllowStringTemplate*/false) == Sema::LOLR_Error) return ExprError(); return S.BuildLiteralOperatorCall(R, OpNameInfo, Args, LitEndLoc); } /// ActOnStringLiteral - The specified tokens were lexed as pasted string /// fragments (e.g. "foo" "bar" L"baz"). The result string has to handle string /// concatenation ([C99 5.1.1.2, translation phase #6]), so it may come from /// multiple tokens. However, the common case is that StringToks points to one /// string. /// ExprResult Sema::ActOnStringLiteral(ArrayRef StringToks, Scope *UDLScope) { assert(!StringToks.empty() && "Must have at least one string!"); StringLiteralParser Literal(StringToks, PP); if (Literal.hadError) return ExprError(); SmallVector StringTokLocs; for (const Token &Tok : StringToks) StringTokLocs.push_back(Tok.getLocation()); QualType CharTy = Context.CharTy; StringLiteral::StringKind Kind = StringLiteral::Ascii; if (Literal.isWide()) { CharTy = Context.getWideCharType(); Kind = StringLiteral::Wide; } else if (Literal.isUTF8()) { Kind = StringLiteral::UTF8; } else if (Literal.isUTF16()) { CharTy = Context.Char16Ty; Kind = StringLiteral::UTF16; } else if (Literal.isUTF32()) { CharTy = Context.Char32Ty; Kind = StringLiteral::UTF32; } else if (Literal.isPascal()) { CharTy = Context.UnsignedCharTy; } QualType CharTyConst = CharTy; // A C++ string literal has a const-qualified element type (C++ 2.13.4p1). if (getLangOpts().CPlusPlus || getLangOpts().ConstStrings) CharTyConst.addConst(); // Get an array type for the string, according to C99 6.4.5. This includes // the nul terminator character as well as the string length for pascal // strings. QualType StrTy = Context.getConstantArrayType(CharTyConst, llvm::APInt(32, Literal.GetNumStringChars()+1), ArrayType::Normal, 0); // OpenCL v1.1 s6.5.3: a string literal is in the constant address space. if (getLangOpts().OpenCL) { StrTy = Context.getAddrSpaceQualType(StrTy, LangAS::opencl_constant); } // Pass &StringTokLocs[0], StringTokLocs.size() to factory! StringLiteral *Lit = StringLiteral::Create(Context, Literal.GetString(), Kind, Literal.Pascal, StrTy, &StringTokLocs[0], StringTokLocs.size()); if (Literal.getUDSuffix().empty()) return Lit; // We're building a user-defined literal. IdentifierInfo *UDSuffix = &Context.Idents.get(Literal.getUDSuffix()); SourceLocation UDSuffixLoc = getUDSuffixLoc(*this, StringTokLocs[Literal.getUDSuffixToken()], Literal.getUDSuffixOffset()); // Make sure we're allowed user-defined literals here. if (!UDLScope) return ExprError(Diag(UDSuffixLoc, diag::err_invalid_string_udl)); // C++11 [lex.ext]p5: The literal L is treated as a call of the form // operator "" X (str, len) QualType SizeType = Context.getSizeType(); DeclarationName OpName = Context.DeclarationNames.getCXXLiteralOperatorName(UDSuffix); DeclarationNameInfo OpNameInfo(OpName, UDSuffixLoc); OpNameInfo.setCXXLiteralOperatorNameLoc(UDSuffixLoc); QualType ArgTy[] = { Context.getArrayDecayedType(StrTy), SizeType }; LookupResult R(*this, OpName, UDSuffixLoc, LookupOrdinaryName); switch (LookupLiteralOperator(UDLScope, R, ArgTy, /*AllowRaw*/false, /*AllowTemplate*/false, /*AllowStringTemplate*/true)) { case LOLR_Cooked: { llvm::APInt Len(Context.getIntWidth(SizeType), Literal.GetNumStringChars()); IntegerLiteral *LenArg = IntegerLiteral::Create(Context, Len, SizeType, StringTokLocs[0]); Expr *Args[] = { Lit, LenArg }; return BuildLiteralOperatorCall(R, OpNameInfo, Args, StringTokLocs.back()); } case LOLR_StringTemplate: { TemplateArgumentListInfo ExplicitArgs; unsigned CharBits = Context.getIntWidth(CharTy); bool CharIsUnsigned = CharTy->isUnsignedIntegerType(); llvm::APSInt Value(CharBits, CharIsUnsigned); TemplateArgument TypeArg(CharTy); TemplateArgumentLocInfo TypeArgInfo(Context.getTrivialTypeSourceInfo(CharTy)); ExplicitArgs.addArgument(TemplateArgumentLoc(TypeArg, TypeArgInfo)); for (unsigned I = 0, N = Lit->getLength(); I != N; ++I) { Value = Lit->getCodeUnit(I); TemplateArgument Arg(Context, Value, CharTy); TemplateArgumentLocInfo ArgInfo; ExplicitArgs.addArgument(TemplateArgumentLoc(Arg, ArgInfo)); } return BuildLiteralOperatorCall(R, OpNameInfo, None, StringTokLocs.back(), &ExplicitArgs); } case LOLR_Raw: case LOLR_Template: llvm_unreachable("unexpected literal operator lookup result"); case LOLR_Error: return ExprError(); } llvm_unreachable("unexpected literal operator lookup result"); } ExprResult Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK, SourceLocation Loc, const CXXScopeSpec *SS) { DeclarationNameInfo NameInfo(D->getDeclName(), Loc); return BuildDeclRefExpr(D, Ty, VK, NameInfo, SS); } /// BuildDeclRefExpr - Build an expression that references a /// declaration that does not require a closure capture. ExprResult Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK, const DeclarationNameInfo &NameInfo, const CXXScopeSpec *SS, NamedDecl *FoundD, const TemplateArgumentListInfo *TemplateArgs) { if (getLangOpts().CUDA) if (const FunctionDecl *Caller = dyn_cast(CurContext)) if (const FunctionDecl *Callee = dyn_cast(D)) { if (CheckCUDATarget(Caller, Callee)) { Diag(NameInfo.getLoc(), diag::err_ref_bad_target) << IdentifyCUDATarget(Callee) << D->getIdentifier() << IdentifyCUDATarget(Caller); Diag(D->getLocation(), diag::note_previous_decl) << D->getIdentifier(); return ExprError(); } } bool RefersToCapturedVariable = isa(D) && NeedToCaptureVariable(cast(D), NameInfo.getLoc()); DeclRefExpr *E; if (isa(D)) { VarTemplateSpecializationDecl *VarSpec = cast(D); E = DeclRefExpr::Create(Context, SS ? SS->getWithLocInContext(Context) : NestedNameSpecifierLoc(), VarSpec->getTemplateKeywordLoc(), D, RefersToCapturedVariable, NameInfo.getLoc(), Ty, VK, FoundD, TemplateArgs); } else { assert(!TemplateArgs && "No template arguments for non-variable" " template specialization references"); E = DeclRefExpr::Create(Context, SS ? SS->getWithLocInContext(Context) : NestedNameSpecifierLoc(), SourceLocation(), D, RefersToCapturedVariable, NameInfo, Ty, VK, FoundD); } MarkDeclRefReferenced(E); if (getLangOpts().ObjCWeak && isa(D) && Ty.getObjCLifetime() == Qualifiers::OCL_Weak && !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, E->getLocStart())) recordUseOfEvaluatedWeak(E); // Just in case we're building an illegal pointer-to-member. FieldDecl *FD = dyn_cast(D); if (FD && FD->isBitField()) E->setObjectKind(OK_BitField); return E; } /// Decomposes the given name into a DeclarationNameInfo, its location, and /// possibly a list of template arguments. /// /// If this produces template arguments, it is permitted to call /// DecomposeTemplateName. /// /// This actually loses a lot of source location information for /// non-standard name kinds; we should consider preserving that in /// some way. void Sema::DecomposeUnqualifiedId(const UnqualifiedId &Id, TemplateArgumentListInfo &Buffer, DeclarationNameInfo &NameInfo, const TemplateArgumentListInfo *&TemplateArgs) { if (Id.getKind() == UnqualifiedId::IK_TemplateId) { Buffer.setLAngleLoc(Id.TemplateId->LAngleLoc); Buffer.setRAngleLoc(Id.TemplateId->RAngleLoc); ASTTemplateArgsPtr TemplateArgsPtr(Id.TemplateId->getTemplateArgs(), Id.TemplateId->NumArgs); translateTemplateArguments(TemplateArgsPtr, Buffer); TemplateName TName = Id.TemplateId->Template.get(); SourceLocation TNameLoc = Id.TemplateId->TemplateNameLoc; NameInfo = Context.getNameForTemplate(TName, TNameLoc); TemplateArgs = &Buffer; } else { NameInfo = GetNameFromUnqualifiedId(Id); TemplateArgs = nullptr; } } static void emitEmptyLookupTypoDiagnostic( const TypoCorrection &TC, Sema &SemaRef, const CXXScopeSpec &SS, DeclarationName Typo, SourceLocation TypoLoc, ArrayRef Args, unsigned DiagnosticID, unsigned DiagnosticSuggestID) { DeclContext *Ctx = SS.isEmpty() ? nullptr : SemaRef.computeDeclContext(SS, false); if (!TC) { // Emit a special diagnostic for failed member lookups. // FIXME: computing the declaration context might fail here (?) if (Ctx) SemaRef.Diag(TypoLoc, diag::err_no_member) << Typo << Ctx << SS.getRange(); else SemaRef.Diag(TypoLoc, DiagnosticID) << Typo; return; } std::string CorrectedStr = TC.getAsString(SemaRef.getLangOpts()); bool DroppedSpecifier = TC.WillReplaceSpecifier() && Typo.getAsString() == CorrectedStr; unsigned NoteID = (TC.getCorrectionDecl() && isa(TC.getCorrectionDecl())) ? diag::note_implicit_param_decl : diag::note_previous_decl; if (!Ctx) SemaRef.diagnoseTypo(TC, SemaRef.PDiag(DiagnosticSuggestID) << Typo, SemaRef.PDiag(NoteID)); else SemaRef.diagnoseTypo(TC, SemaRef.PDiag(diag::err_no_member_suggest) << Typo << Ctx << DroppedSpecifier << SS.getRange(), SemaRef.PDiag(NoteID)); } /// Diagnose an empty lookup. /// /// \return false if new lookup candidates were found bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R, std::unique_ptr CCC, TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef Args, TypoExpr **Out) { DeclarationName Name = R.getLookupName(); unsigned diagnostic = diag::err_undeclared_var_use; unsigned diagnostic_suggest = diag::err_undeclared_var_use_suggest; if (Name.getNameKind() == DeclarationName::CXXOperatorName || Name.getNameKind() == DeclarationName::CXXLiteralOperatorName || Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { diagnostic = diag::err_undeclared_use; diagnostic_suggest = diag::err_undeclared_use_suggest; } // If the original lookup was an unqualified lookup, fake an // unqualified lookup. This is useful when (for example) the // original lookup would not have found something because it was a // dependent name. DeclContext *DC = SS.isEmpty() ? CurContext : nullptr; while (DC) { if (isa(DC)) { LookupQualifiedName(R, DC); if (!R.empty()) { // Don't give errors about ambiguities in this lookup. R.suppressDiagnostics(); // During a default argument instantiation the CurContext points // to a CXXMethodDecl; but we can't apply a this-> fixit inside a // function parameter list, hence add an explicit check. bool isDefaultArgument = !ActiveTemplateInstantiations.empty() && ActiveTemplateInstantiations.back().Kind == ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation; CXXMethodDecl *CurMethod = dyn_cast(CurContext); bool isInstance = CurMethod && CurMethod->isInstance() && DC == CurMethod->getParent() && !isDefaultArgument; // Give a code modification hint to insert 'this->'. // TODO: fixit for inserting 'Base::' in the other cases. // Actually quite difficult! if (getLangOpts().MSVCCompat) diagnostic = diag::ext_found_via_dependent_bases_lookup; if (isInstance) { Diag(R.getNameLoc(), diagnostic) << Name << FixItHint::CreateInsertion(R.getNameLoc(), "this->"); CheckCXXThisCapture(R.getNameLoc()); } else { Diag(R.getNameLoc(), diagnostic) << Name; } // Do we really want to note all of these? for (NamedDecl *D : R) Diag(D->getLocation(), diag::note_dependent_var_use); // Return true if we are inside a default argument instantiation // and the found name refers to an instance member function, otherwise // the function calling DiagnoseEmptyLookup will try to create an // implicit member call and this is wrong for default argument. if (isDefaultArgument && ((*R.begin())->isCXXInstanceMember())) { Diag(R.getNameLoc(), diag::err_member_call_without_object); return true; } // Tell the callee to try to recover. return false; } R.clear(); } // In Microsoft mode, if we are performing lookup from within a friend // function definition declared at class scope then we must set // DC to the lexical parent to be able to search into the parent // class. if (getLangOpts().MSVCCompat && isa(DC) && cast(DC)->getFriendObjectKind() && DC->getLexicalParent()->isRecord()) DC = DC->getLexicalParent(); else DC = DC->getParent(); } // We didn't find anything, so try to correct for a typo. TypoCorrection Corrected; if (S && Out) { SourceLocation TypoLoc = R.getNameLoc(); assert(!ExplicitTemplateArgs && "Diagnosing an empty lookup with explicit template args!"); *Out = CorrectTypoDelayed( R.getLookupNameInfo(), R.getLookupKind(), S, &SS, std::move(CCC), [=](const TypoCorrection &TC) { emitEmptyLookupTypoDiagnostic(TC, *this, SS, Name, TypoLoc, Args, diagnostic, diagnostic_suggest); }, nullptr, CTK_ErrorRecovery); if (*Out) return true; } else if (S && (Corrected = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS, std::move(CCC), CTK_ErrorRecovery))) { std::string CorrectedStr(Corrected.getAsString(getLangOpts())); bool DroppedSpecifier = Corrected.WillReplaceSpecifier() && Name.getAsString() == CorrectedStr; R.setLookupName(Corrected.getCorrection()); bool AcceptableWithRecovery = false; bool AcceptableWithoutRecovery = false; NamedDecl *ND = Corrected.getCorrectionDecl(); if (ND) { if (Corrected.isOverloaded()) { OverloadCandidateSet OCS(R.getNameLoc(), OverloadCandidateSet::CSK_Normal); OverloadCandidateSet::iterator Best; for (NamedDecl *CD : Corrected) { if (FunctionTemplateDecl *FTD = dyn_cast(CD)) AddTemplateOverloadCandidate( FTD, DeclAccessPair::make(FTD, AS_none), ExplicitTemplateArgs, Args, OCS); else if (FunctionDecl *FD = dyn_cast(CD)) if (!ExplicitTemplateArgs || ExplicitTemplateArgs->size() == 0) AddOverloadCandidate(FD, DeclAccessPair::make(FD, AS_none), Args, OCS); } switch (OCS.BestViableFunction(*this, R.getNameLoc(), Best)) { case OR_Success: ND = Best->Function; Corrected.setCorrectionDecl(ND); break; default: // FIXME: Arbitrarily pick the first declaration for the note. Corrected.setCorrectionDecl(ND); break; } } R.addDecl(ND); if (getLangOpts().CPlusPlus && ND->isCXXClassMember()) { CXXRecordDecl *Record = nullptr; if (Corrected.getCorrectionSpecifier()) { const Type *Ty = Corrected.getCorrectionSpecifier()->getAsType(); Record = Ty->getAsCXXRecordDecl(); } if (!Record) Record = cast( ND->getDeclContext()->getRedeclContext()); R.setNamingClass(Record); } AcceptableWithRecovery = isa(ND) || isa(ND); // FIXME: If we ended up with a typo for a type name or // Objective-C class name, we're in trouble because the parser // is in the wrong place to recover. Suggest the typo // correction, but don't make it a fix-it since we're not going // to recover well anyway. AcceptableWithoutRecovery = isa(ND) || isa(ND); } else { // FIXME: We found a keyword. Suggest it, but don't provide a fix-it // because we aren't able to recover. AcceptableWithoutRecovery = true; } if (AcceptableWithRecovery || AcceptableWithoutRecovery) { unsigned NoteID = (Corrected.getCorrectionDecl() && isa(Corrected.getCorrectionDecl())) ? diag::note_implicit_param_decl : diag::note_previous_decl; if (SS.isEmpty()) diagnoseTypo(Corrected, PDiag(diagnostic_suggest) << Name, PDiag(NoteID), AcceptableWithRecovery); else diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest) << Name << computeDeclContext(SS, false) << DroppedSpecifier << SS.getRange(), PDiag(NoteID), AcceptableWithRecovery); // Tell the callee whether to try to recover. return !AcceptableWithRecovery; } } R.clear(); // Emit a special diagnostic for failed member lookups. // FIXME: computing the declaration context might fail here (?) if (!SS.isEmpty()) { Diag(R.getNameLoc(), diag::err_no_member) << Name << computeDeclContext(SS, false) << SS.getRange(); return true; } // Give up, we can't recover. Diag(R.getNameLoc(), diagnostic) << Name; return true; } /// In Microsoft mode, if we are inside a template class whose parent class has /// dependent base classes, and we can't resolve an unqualified identifier, then /// assume the identifier is a member of a dependent base class. We can only /// recover successfully in static methods, instance methods, and other contexts /// where 'this' is available. This doesn't precisely match MSVC's /// instantiation model, but it's close enough. static Expr * recoverFromMSUnqualifiedLookup(Sema &S, ASTContext &Context, DeclarationNameInfo &NameInfo, SourceLocation TemplateKWLoc, const TemplateArgumentListInfo *TemplateArgs) { // Only try to recover from lookup into dependent bases in static methods or // contexts where 'this' is available. QualType ThisType = S.getCurrentThisType(); const CXXRecordDecl *RD = nullptr; if (!ThisType.isNull()) RD = ThisType->getPointeeType()->getAsCXXRecordDecl(); else if (auto *MD = dyn_cast(S.CurContext)) RD = MD->getParent(); if (!RD || !RD->hasAnyDependentBases()) return nullptr; // Diagnose this as unqualified lookup into a dependent base class. If 'this' // is available, suggest inserting 'this->' as a fixit. SourceLocation Loc = NameInfo.getLoc(); auto DB = S.Diag(Loc, diag::ext_undeclared_unqual_id_with_dependent_base); DB << NameInfo.getName() << RD; if (!ThisType.isNull()) { DB << FixItHint::CreateInsertion(Loc, "this->"); return CXXDependentScopeMemberExpr::Create( Context, /*This=*/nullptr, ThisType, /*IsArrow=*/true, /*Op=*/SourceLocation(), NestedNameSpecifierLoc(), TemplateKWLoc, /*FirstQualifierInScope=*/nullptr, NameInfo, TemplateArgs); } // Synthesize a fake NNS that points to the derived class. This will // perform name lookup during template instantiation. CXXScopeSpec SS; auto *NNS = NestedNameSpecifier::Create(Context, nullptr, true, RD->getTypeForDecl()); SS.MakeTrivial(Context, NNS, SourceRange(Loc, Loc)); return DependentScopeDeclRefExpr::Create( Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo, TemplateArgs); } ExprResult Sema::ActOnIdExpression(Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc, UnqualifiedId &Id, bool HasTrailingLParen, bool IsAddressOfOperand, std::unique_ptr CCC, bool IsInlineAsmIdentifier, Token *KeywordReplacement) { assert(!(IsAddressOfOperand && HasTrailingLParen) && "cannot be direct & operand and have a trailing lparen"); if (SS.isInvalid()) return ExprError(); TemplateArgumentListInfo TemplateArgsBuffer; // Decompose the UnqualifiedId into the following data. DeclarationNameInfo NameInfo; const TemplateArgumentListInfo *TemplateArgs; DecomposeUnqualifiedId(Id, TemplateArgsBuffer, NameInfo, TemplateArgs); DeclarationName Name = NameInfo.getName(); IdentifierInfo *II = Name.getAsIdentifierInfo(); SourceLocation NameLoc = NameInfo.getLoc(); // C++ [temp.dep.expr]p3: // An id-expression is type-dependent if it contains: // -- an identifier that was declared with a dependent type, // (note: handled after lookup) // -- a template-id that is dependent, // (note: handled in BuildTemplateIdExpr) // -- a conversion-function-id that specifies a dependent type, // -- a nested-name-specifier that contains a class-name that // names a dependent type. // Determine whether this is a member of an unknown specialization; // we need to handle these differently. bool DependentID = false; if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName && Name.getCXXNameType()->isDependentType()) { DependentID = true; } else if (SS.isSet()) { if (DeclContext *DC = computeDeclContext(SS, false)) { if (RequireCompleteDeclContext(SS, DC)) return ExprError(); } else { DependentID = true; } } if (DependentID) return ActOnDependentIdExpression(SS, TemplateKWLoc, NameInfo, IsAddressOfOperand, TemplateArgs); // Perform the required lookup. LookupResult R(*this, NameInfo, (Id.getKind() == UnqualifiedId::IK_ImplicitSelfParam) ? LookupObjCImplicitSelfParam : LookupOrdinaryName); if (TemplateArgs) { // Lookup the template name again to correctly establish the context in // which it was found. This is really unfortunate as we already did the // lookup to determine that it was a template name in the first place. If // this becomes a performance hit, we can work harder to preserve those // results until we get here but it's likely not worth it. bool MemberOfUnknownSpecialization; LookupTemplateName(R, S, SS, QualType(), /*EnteringContext=*/false, MemberOfUnknownSpecialization); if (MemberOfUnknownSpecialization || (R.getResultKind() == LookupResult::NotFoundInCurrentInstantiation)) return ActOnDependentIdExpression(SS, TemplateKWLoc, NameInfo, IsAddressOfOperand, TemplateArgs); } else { bool IvarLookupFollowUp = II && !SS.isSet() && getCurMethodDecl(); LookupParsedName(R, S, &SS, !IvarLookupFollowUp); // If the result might be in a dependent base class, this is a dependent // id-expression. if (R.getResultKind() == LookupResult::NotFoundInCurrentInstantiation) return ActOnDependentIdExpression(SS, TemplateKWLoc, NameInfo, IsAddressOfOperand, TemplateArgs); // If this reference is in an Objective-C method, then we need to do // some special Objective-C lookup, too. if (IvarLookupFollowUp) { ExprResult E(LookupInObjCMethod(R, S, II, true)); if (E.isInvalid()) return ExprError(); if (Expr *Ex = E.getAs()) return Ex; } } if (R.isAmbiguous()) return ExprError(); // This could be an implicitly declared function reference (legal in C90, // extension in C99, forbidden in C++). if (R.empty() && HasTrailingLParen && II && !getLangOpts().CPlusPlus) { NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S); if (D) R.addDecl(D); } // Determine whether this name might be a candidate for // argument-dependent lookup. bool ADL = UseArgumentDependentLookup(SS, R, HasTrailingLParen); if (R.empty() && !ADL) { if (SS.isEmpty() && getLangOpts().MSVCCompat) { if (Expr *E = recoverFromMSUnqualifiedLookup(*this, Context, NameInfo, TemplateKWLoc, TemplateArgs)) return E; } // Don't diagnose an empty lookup for inline assembly. if (IsInlineAsmIdentifier) return ExprError(); // If this name wasn't predeclared and if this is not a function // call, diagnose the problem. TypoExpr *TE = nullptr; auto DefaultValidator = llvm::make_unique( II, SS.isValid() ? SS.getScopeRep() : nullptr); DefaultValidator->IsAddressOfOperand = IsAddressOfOperand; assert((!CCC || CCC->IsAddressOfOperand == IsAddressOfOperand) && "Typo correction callback misconfigured"); if (CCC) { // Make sure the callback knows what the typo being diagnosed is. CCC->setTypoName(II); if (SS.isValid()) CCC->setTypoNNS(SS.getScopeRep()); } if (DiagnoseEmptyLookup(S, SS, R, CCC ? std::move(CCC) : std::move(DefaultValidator), nullptr, None, &TE)) { if (TE && KeywordReplacement) { auto &State = getTypoExprState(TE); auto BestTC = State.Consumer->getNextCorrection(); if (BestTC.isKeyword()) { auto *II = BestTC.getCorrectionAsIdentifierInfo(); if (State.DiagHandler) State.DiagHandler(BestTC); KeywordReplacement->startToken(); KeywordReplacement->setKind(II->getTokenID()); KeywordReplacement->setIdentifierInfo(II); KeywordReplacement->setLocation(BestTC.getCorrectionRange().getBegin()); // Clean up the state associated with the TypoExpr, since it has // now been diagnosed (without a call to CorrectDelayedTyposInExpr). clearDelayedTypo(TE); // Signal that a correction to a keyword was performed by returning a // valid-but-null ExprResult. return (Expr*)nullptr; } State.Consumer->resetCorrectionStream(); } return TE ? TE : ExprError(); } assert(!R.empty() && "DiagnoseEmptyLookup returned false but added no results"); // If we found an Objective-C instance variable, let // LookupInObjCMethod build the appropriate expression to // reference the ivar. if (ObjCIvarDecl *Ivar = R.getAsSingle()) { R.clear(); ExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier())); // In a hopelessly buggy code, Objective-C instance variable // lookup fails and no expression will be built to reference it. if (!E.isInvalid() && !E.get()) return ExprError(); return E; } } // This is guaranteed from this point on. assert(!R.empty() || ADL); // Check whether this might be a C++ implicit instance member access. // C++ [class.mfct.non-static]p3: // When an id-expression that is not part of a class member access // syntax and not used to form a pointer to member is used in the // body of a non-static member function of class X, if name lookup // resolves the name in the id-expression to a non-static non-type // member of some class C, the id-expression is transformed into a // class member access expression using (*this) as the // postfix-expression to the left of the . operator. // // But we don't actually need to do this for '&' operands if R // resolved to a function or overloaded function set, because the // expression is ill-formed if it actually works out to be a // non-static member function: // // C++ [expr.ref]p4: // Otherwise, if E1.E2 refers to a non-static member function. . . // [t]he expression can be used only as the left-hand operand of a // member function call. // // There are other safeguards against such uses, but it's important // to get this right here so that we don't end up making a // spuriously dependent expression if we're inside a dependent // instance method. if (!R.empty() && (*R.begin())->isCXXClassMember()) { bool MightBeImplicitMember; if (!IsAddressOfOperand) MightBeImplicitMember = true; else if (!SS.isEmpty()) MightBeImplicitMember = false; else if (R.isOverloadedResult()) MightBeImplicitMember = false; else if (R.isUnresolvableResult()) MightBeImplicitMember = true; else MightBeImplicitMember = isa(R.getFoundDecl()) || isa(R.getFoundDecl()) || isa(R.getFoundDecl()); if (MightBeImplicitMember) return BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, R, TemplateArgs, S); } if (TemplateArgs || TemplateKWLoc.isValid()) { // In C++1y, if this is a variable template id, then check it // in BuildTemplateIdExpr(). // The single lookup result must be a variable template declaration. if (Id.getKind() == UnqualifiedId::IK_TemplateId && Id.TemplateId && Id.TemplateId->Kind == TNK_Var_template) { assert(R.getAsSingle() && "There should only be one declaration found."); } return BuildTemplateIdExpr(SS, TemplateKWLoc, R, ADL, TemplateArgs); } return BuildDeclarationNameExpr(SS, R, ADL); } /// BuildQualifiedDeclarationNameExpr - Build a C++ qualified /// declaration name, generally during template instantiation. /// There's a large number of things which don't need to be done along /// this path. ExprResult Sema::BuildQualifiedDeclarationNameExpr( CXXScopeSpec &SS, const DeclarationNameInfo &NameInfo, bool IsAddressOfOperand, const Scope *S, TypeSourceInfo **RecoveryTSI) { DeclContext *DC = computeDeclContext(SS, false); if (!DC) return BuildDependentDeclRefExpr(SS, /*TemplateKWLoc=*/SourceLocation(), NameInfo, /*TemplateArgs=*/nullptr); if (RequireCompleteDeclContext(SS, DC)) return ExprError(); LookupResult R(*this, NameInfo, LookupOrdinaryName); LookupQualifiedName(R, DC); if (R.isAmbiguous()) return ExprError(); if (R.getResultKind() == LookupResult::NotFoundInCurrentInstantiation) return BuildDependentDeclRefExpr(SS, /*TemplateKWLoc=*/SourceLocation(), NameInfo, /*TemplateArgs=*/nullptr); if (R.empty()) { Diag(NameInfo.getLoc(), diag::err_no_member) << NameInfo.getName() << DC << SS.getRange(); return ExprError(); } if (const TypeDecl *TD = R.getAsSingle()) { // Diagnose a missing typename if this resolved unambiguously to a type in // a dependent context. If we can recover with a type, downgrade this to // a warning in Microsoft compatibility mode. unsigned DiagID = diag::err_typename_missing; if (RecoveryTSI && getLangOpts().MSVCCompat) DiagID = diag::ext_typename_missing; SourceLocation Loc = SS.getBeginLoc(); auto D = Diag(Loc, DiagID); D << SS.getScopeRep() << NameInfo.getName().getAsString() << SourceRange(Loc, NameInfo.getEndLoc()); // Don't recover if the caller isn't expecting us to or if we're in a SFINAE // context. if (!RecoveryTSI) return ExprError(); // Only issue the fixit if we're prepared to recover. D << FixItHint::CreateInsertion(Loc, "typename "); // Recover by pretending this was an elaborated type. QualType Ty = Context.getTypeDeclType(TD); TypeLocBuilder TLB; TLB.pushTypeSpec(Ty).setNameLoc(NameInfo.getLoc()); QualType ET = getElaboratedType(ETK_None, SS, Ty); ElaboratedTypeLoc QTL = TLB.push(ET); QTL.setElaboratedKeywordLoc(SourceLocation()); QTL.setQualifierLoc(SS.getWithLocInContext(Context)); *RecoveryTSI = TLB.getTypeSourceInfo(Context, ET); return ExprEmpty(); } // Defend against this resolving to an implicit member access. We usually // won't get here if this might be a legitimate a class member (we end up in // BuildMemberReferenceExpr instead), but this can be valid if we're forming // a pointer-to-member or in an unevaluated context in C++11. if (!R.empty() && (*R.begin())->isCXXClassMember() && !IsAddressOfOperand) return BuildPossibleImplicitMemberExpr(SS, /*TemplateKWLoc=*/SourceLocation(), R, /*TemplateArgs=*/nullptr, S); return BuildDeclarationNameExpr(SS, R, /* ADL */ false); } /// LookupInObjCMethod - The parser has read a name in, and Sema has /// detected that we're currently inside an ObjC method. Perform some /// additional lookup. /// /// Ideally, most of this would be done by lookup, but there's /// actually quite a lot of extra work involved. /// /// Returns a null sentinel to indicate trivial success. ExprResult Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S, IdentifierInfo *II, bool AllowBuiltinCreation) { SourceLocation Loc = Lookup.getNameLoc(); ObjCMethodDecl *CurMethod = getCurMethodDecl(); // Check for error condition which is already reported. if (!CurMethod) return ExprError(); // There are two cases to handle here. 1) scoped lookup could have failed, // in which case we should look for an ivar. 2) scoped lookup could have // found a decl, but that decl is outside the current instance method (i.e. // a global variable). In these two cases, we do a lookup for an ivar with // this name, if the lookup sucedes, we replace it our current decl. // If we're in a class method, we don't normally want to look for // ivars. But if we don't find anything else, and there's an // ivar, that's an error. bool IsClassMethod = CurMethod->isClassMethod(); bool LookForIvars; if (Lookup.empty()) LookForIvars = true; else if (IsClassMethod) LookForIvars = false; else LookForIvars = (Lookup.isSingleResult() && Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); ObjCInterfaceDecl *IFace = nullptr; if (LookForIvars) { IFace = CurMethod->getClassInterface(); ObjCInterfaceDecl *ClassDeclared; ObjCIvarDecl *IV = nullptr; if (IFace && (IV = IFace->lookupInstanceVariable(II, ClassDeclared))) { // Diagnose using an ivar in a class method. if (IsClassMethod) return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) << IV->getDeclName()); // If we're referencing an invalid decl, just return this as a silent // error node. The error diagnostic was already emitted on the decl. if (IV->isInvalidDecl()) return ExprError(); // Check if referencing a field with __attribute__((deprecated)). if (DiagnoseUseOfDecl(IV, Loc)) return ExprError(); // Diagnose the use of an ivar outside of the declaring class. if (IV->getAccessControl() == ObjCIvarDecl::Private && !declaresSameEntity(ClassDeclared, IFace) && !getLangOpts().DebuggerSupport) Diag(Loc, diag::error_private_ivar_access) << IV->getDeclName(); // FIXME: This should use a new expr for a direct reference, don't // turn this into Self->ivar, just return a BareIVarExpr or something. IdentifierInfo &II = Context.Idents.get("self"); UnqualifiedId SelfName; SelfName.setIdentifier(&II, SourceLocation()); SelfName.setKind(UnqualifiedId::IK_ImplicitSelfParam); CXXScopeSpec SelfScopeSpec; SourceLocation TemplateKWLoc; ExprResult SelfExpr = ActOnIdExpression(S, SelfScopeSpec, TemplateKWLoc, SelfName, false, false); if (SelfExpr.isInvalid()) return ExprError(); SelfExpr = DefaultLvalueConversion(SelfExpr.get()); if (SelfExpr.isInvalid()) return ExprError(); MarkAnyDeclReferenced(Loc, IV, true); ObjCMethodFamily MF = CurMethod->getMethodFamily(); if (MF != OMF_init && MF != OMF_dealloc && MF != OMF_finalize && !IvarBacksCurrentMethodAccessor(IFace, CurMethod, IV)) Diag(Loc, diag::warn_direct_ivar_access) << IV->getDeclName(); ObjCIvarRefExpr *Result = new (Context) ObjCIvarRefExpr(IV, IV->getUsageType(SelfExpr.get()->getType()), Loc, IV->getLocation(), SelfExpr.get(), true, true); if (getLangOpts().ObjCAutoRefCount) { if (IV->getType().getObjCLifetime() == Qualifiers::OCL_Weak) { if (!Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, Loc)) recordUseOfEvaluatedWeak(Result); } if (CurContext->isClosure()) Diag(Loc, diag::warn_implicitly_retains_self) << FixItHint::CreateInsertion(Loc, "self->"); } return Result; } } else if (CurMethod->isInstanceMethod()) { // We should warn if a local variable hides an ivar. if (ObjCInterfaceDecl *IFace = CurMethod->getClassInterface()) { ObjCInterfaceDecl *ClassDeclared; if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { if (IV->getAccessControl() != ObjCIvarDecl::Private || declaresSameEntity(IFace, ClassDeclared)) Diag(Loc, diag::warn_ivar_use_hidden) << IV->getDeclName(); } } } else if (Lookup.isSingleResult() && Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()) { // If accessing a stand-alone ivar in a class method, this is an error. if (const ObjCIvarDecl *IV = dyn_cast(Lookup.getFoundDecl())) return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) << IV->getDeclName()); } if (Lookup.empty() && II && AllowBuiltinCreation) { // FIXME. Consolidate this with similar code in LookupName. if (unsigned BuiltinID = II->getBuiltinID()) { if (!(getLangOpts().CPlusPlus && Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))) { NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, S, Lookup.isForRedeclaration(), Lookup.getNameLoc()); if (D) Lookup.addDecl(D); } } } // Sentinel value saying that we didn't do anything special. return ExprResult((Expr *)nullptr); } /// \brief Cast a base object to a member's actual type. /// /// Logically this happens in three phases: /// /// * First we cast from the base type to the naming class. /// The naming class is the class into which we were looking /// when we found the member; it's the qualifier type if a /// qualifier was provided, and otherwise it's the base type. /// /// * Next we cast from the naming class to the declaring class. /// If the member we found was brought into a class's scope by /// a using declaration, this is that class; otherwise it's /// the class declaring the member. /// /// * Finally we cast from the declaring class to the "true" /// declaring class of the member. This conversion does not /// obey access control. ExprResult Sema::PerformObjectMemberConversion(Expr *From, NestedNameSpecifier *Qualifier, NamedDecl *FoundDecl, NamedDecl *Member) { CXXRecordDecl *RD = dyn_cast(Member->getDeclContext()); if (!RD) return From; QualType DestRecordType; QualType DestType; QualType FromRecordType; QualType FromType = From->getType(); bool PointerConversions = false; if (isa(Member)) { DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD)); if (FromType->getAs()) { DestType = Context.getPointerType(DestRecordType); FromRecordType = FromType->getPointeeType(); PointerConversions = true; } else { DestType = DestRecordType; FromRecordType = FromType; } } else if (CXXMethodDecl *Method = dyn_cast(Member)) { if (Method->isStatic()) return From; DestType = Method->getThisType(Context); DestRecordType = DestType->getPointeeType(); if (FromType->getAs()) { FromRecordType = FromType->getPointeeType(); PointerConversions = true; } else { FromRecordType = FromType; DestType = DestRecordType; } } else { // No conversion necessary. return From; } if (DestType->isDependentType() || FromType->isDependentType()) return From; // If the unqualified types are the same, no conversion is necessary. if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) return From; SourceRange FromRange = From->getSourceRange(); SourceLocation FromLoc = FromRange.getBegin(); ExprValueKind VK = From->getValueKind(); // C++ [class.member.lookup]p8: // [...] Ambiguities can often be resolved by qualifying a name with its // class name. // // If the member was a qualified name and the qualified referred to a // specific base subobject type, we'll cast to that intermediate type // first and then to the object in which the member is declared. That allows // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as: // // class Base { public: int x; }; // class Derived1 : public Base { }; // class Derived2 : public Base { }; // class VeryDerived : public Derived1, public Derived2 { void f(); }; // // void VeryDerived::f() { // x = 17; // error: ambiguous base subobjects // Derived1::x = 17; // okay, pick the Base subobject of Derived1 // } if (Qualifier && Qualifier->getAsType()) { QualType QType = QualType(Qualifier->getAsType(), 0); assert(QType->isRecordType() && "lookup done with non-record type"); QualType QRecordType = QualType(QType->getAs(), 0); // In C++98, the qualifier type doesn't actually have to be a base // type of the object type, in which case we just ignore it. // Otherwise build the appropriate casts. if (IsDerivedFrom(FromLoc, FromRecordType, QRecordType)) { CXXCastPath BasePath; if (CheckDerivedToBaseConversion(FromRecordType, QRecordType, FromLoc, FromRange, &BasePath)) return ExprError(); if (PointerConversions) QType = Context.getPointerType(QType); From = ImpCastExprToType(From, QType, CK_UncheckedDerivedToBase, VK, &BasePath).get(); FromType = QType; FromRecordType = QRecordType; // If the qualifier type was the same as the destination type, // we're done. if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) return From; } } bool IgnoreAccess = false; // If we actually found the member through a using declaration, cast // down to the using declaration's type. // // Pointer equality is fine here because only one declaration of a // class ever has member declarations. if (FoundDecl->getDeclContext() != Member->getDeclContext()) { assert(isa(FoundDecl)); QualType URecordType = Context.getTypeDeclType( cast(FoundDecl->getDeclContext())); // We only need to do this if the naming-class to declaring-class // conversion is non-trivial. if (!Context.hasSameUnqualifiedType(FromRecordType, URecordType)) { assert(IsDerivedFrom(FromLoc, FromRecordType, URecordType)); CXXCastPath BasePath; if (CheckDerivedToBaseConversion(FromRecordType, URecordType, FromLoc, FromRange, &BasePath)) return ExprError(); QualType UType = URecordType; if (PointerConversions) UType = Context.getPointerType(UType); From = ImpCastExprToType(From, UType, CK_UncheckedDerivedToBase, VK, &BasePath).get(); FromType = UType; FromRecordType = URecordType; } // We don't do access control for the conversion from the // declaring class to the true declaring class. IgnoreAccess = true; } CXXCastPath BasePath; if (CheckDerivedToBaseConversion(FromRecordType, DestRecordType, FromLoc, FromRange, &BasePath, IgnoreAccess)) return ExprError(); return ImpCastExprToType(From, DestType, CK_UncheckedDerivedToBase, VK, &BasePath); } bool Sema::UseArgumentDependentLookup(const CXXScopeSpec &SS, const LookupResult &R, bool HasTrailingLParen) { // Only when used directly as the postfix-expression of a call. if (!HasTrailingLParen) return false; // Never if a scope specifier was provided. if (SS.isSet()) return false; // Only in C++ or ObjC++. if (!getLangOpts().CPlusPlus) return false; // Turn off ADL when we find certain kinds of declarations during // normal lookup: for (NamedDecl *D : R) { // C++0x [basic.lookup.argdep]p3: // -- a declaration of a class member // Since using decls preserve this property, we check this on the // original decl. if (D->isCXXClassMember()) return false; // C++0x [basic.lookup.argdep]p3: // -- a block-scope function declaration that is not a // using-declaration // NOTE: we also trigger this for function templates (in fact, we // don't check the decl type at all, since all other decl types // turn off ADL anyway). if (isa(D)) D = cast(D)->getTargetDecl(); else if (D->getLexicalDeclContext()->isFunctionOrMethod()) return false; // C++0x [basic.lookup.argdep]p3: // -- a declaration that is neither a function or a function // template // And also for builtin functions. if (isa(D)) { FunctionDecl *FDecl = cast(D); // But also builtin functions. if (FDecl->getBuiltinID() && FDecl->isImplicit()) return false; } else if (!isa(D)) return false; } return true; } /// Diagnoses obvious problems with the use of the given declaration /// as an expression. This is only actually called for lookups that /// were not overloaded, and it doesn't promise that the declaration /// will in fact be used. static bool CheckDeclInExpr(Sema &S, SourceLocation Loc, NamedDecl *D) { if (isa(D)) { S.Diag(Loc, diag::err_unexpected_typedef) << D->getDeclName(); return true; } if (isa(D)) { S.Diag(Loc, diag::err_unexpected_interface) << D->getDeclName(); return true; } if (isa(D)) { S.Diag(Loc, diag::err_unexpected_namespace) << D->getDeclName(); return true; } return false; } ExprResult Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, LookupResult &R, bool NeedsADL, bool AcceptInvalidDecl) { // If this is a single, fully-resolved result and we don't need ADL, // just build an ordinary singleton decl ref. if (!NeedsADL && R.isSingleResult() && !R.getAsSingle()) return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), R.getFoundDecl(), R.getRepresentativeDecl(), nullptr, AcceptInvalidDecl); // We only need to check the declaration if there's exactly one // result, because in the overloaded case the results can only be // functions and function templates. if (R.isSingleResult() && CheckDeclInExpr(*this, R.getNameLoc(), R.getFoundDecl())) return ExprError(); // Otherwise, just build an unresolved lookup expression. Suppress // any lookup-related diagnostics; we'll hash these out later, when // we've picked a target. R.suppressDiagnostics(); UnresolvedLookupExpr *ULE = UnresolvedLookupExpr::Create(Context, R.getNamingClass(), SS.getWithLocInContext(Context), R.getLookupNameInfo(), NeedsADL, R.isOverloadedResult(), R.begin(), R.end()); return ULE; } /// \brief Complete semantic analysis for a reference to the given declaration. ExprResult Sema::BuildDeclarationNameExpr( const CXXScopeSpec &SS, const DeclarationNameInfo &NameInfo, NamedDecl *D, NamedDecl *FoundD, const TemplateArgumentListInfo *TemplateArgs, bool AcceptInvalidDecl) { assert(D && "Cannot refer to a NULL declaration"); assert(!isa(D) && "Cannot refer unambiguously to a function template"); SourceLocation Loc = NameInfo.getLoc(); if (CheckDeclInExpr(*this, Loc, D)) return ExprError(); if (TemplateDecl *Template = dyn_cast(D)) { // Specifically diagnose references to class templates that are missing // a template argument list. Diag(Loc, diag::err_template_decl_ref) << (isa(D) ? 1 : 0) << Template << SS.getRange(); Diag(Template->getLocation(), diag::note_template_decl_here); return ExprError(); } // Make sure that we're referring to a value. ValueDecl *VD = dyn_cast(D); if (!VD) { Diag(Loc, diag::err_ref_non_value) << D << SS.getRange(); Diag(D->getLocation(), diag::note_declared_at); return ExprError(); } // Check whether this declaration can be used. Note that we suppress // this check when we're going to perform argument-dependent lookup // on this function name, because this might not be the function // that overload resolution actually selects. if (DiagnoseUseOfDecl(VD, Loc)) return ExprError(); // Only create DeclRefExpr's for valid Decl's. if (VD->isInvalidDecl() && !AcceptInvalidDecl) return ExprError(); // Handle members of anonymous structs and unions. If we got here, // and the reference is to a class member indirect field, then this // must be the subject of a pointer-to-member expression. if (IndirectFieldDecl *indirectField = dyn_cast(VD)) if (!indirectField->isCXXClassMember()) return BuildAnonymousStructUnionMemberReference(SS, NameInfo.getLoc(), indirectField); { QualType type = VD->getType(); ExprValueKind valueKind = VK_RValue; switch (D->getKind()) { // Ignore all the non-ValueDecl kinds. #define ABSTRACT_DECL(kind) #define VALUE(type, base) #define DECL(type, base) \ case Decl::type: #include "clang/AST/DeclNodes.inc" llvm_unreachable("invalid value decl kind"); // These shouldn't make it here. case Decl::ObjCAtDefsField: case Decl::ObjCIvar: llvm_unreachable("forming non-member reference to ivar?"); // Enum constants are always r-values and never references. // Unresolved using declarations are dependent. case Decl::EnumConstant: case Decl::UnresolvedUsingValue: valueKind = VK_RValue; break; // Fields and indirect fields that got here must be for // pointer-to-member expressions; we just call them l-values for // internal consistency, because this subexpression doesn't really // exist in the high-level semantics. case Decl::Field: case Decl::IndirectField: assert(getLangOpts().CPlusPlus && "building reference to field in C?"); // These can't have reference type in well-formed programs, but // for internal consistency we do this anyway. type = type.getNonReferenceType(); valueKind = VK_LValue; break; // Non-type template parameters are either l-values or r-values // depending on the type. case Decl::NonTypeTemplateParm: { if (const ReferenceType *reftype = type->getAs()) { type = reftype->getPointeeType(); valueKind = VK_LValue; // even if the parameter is an r-value reference break; } // For non-references, we need to strip qualifiers just in case // the template parameter was declared as 'const int' or whatever. valueKind = VK_RValue; type = type.getUnqualifiedType(); break; } case Decl::Var: case Decl::VarTemplateSpecialization: case Decl::VarTemplatePartialSpecialization: // In C, "extern void blah;" is valid and is an r-value. if (!getLangOpts().CPlusPlus && !type.hasQualifiers() && type->isVoidType()) { valueKind = VK_RValue; break; } // fallthrough case Decl::ImplicitParam: case Decl::ParmVar: { // These are always l-values. valueKind = VK_LValue; type = type.getNonReferenceType(); // FIXME: Does the addition of const really only apply in // potentially-evaluated contexts? Since the variable isn't actually // captured in an unevaluated context, it seems that the answer is no. if (!isUnevaluatedContext()) { QualType CapturedType = getCapturedDeclRefType(cast(VD), Loc); if (!CapturedType.isNull()) type = CapturedType; } break; } case Decl::Function: { if (unsigned BID = cast(VD)->getBuiltinID()) { if (!Context.BuiltinInfo.isPredefinedLibFunction(BID)) { type = Context.BuiltinFnTy; valueKind = VK_RValue; break; } } const FunctionType *fty = type->castAs(); // If we're referring to a function with an __unknown_anytype // result type, make the entire expression __unknown_anytype. if (fty->getReturnType() == Context.UnknownAnyTy) { type = Context.UnknownAnyTy; valueKind = VK_RValue; break; } // Functions are l-values in C++. if (getLangOpts().CPlusPlus) { valueKind = VK_LValue; break; } // C99 DR 316 says that, if a function type comes from a // function definition (without a prototype), that type is only // used for checking compatibility. Therefore, when referencing // the function, we pretend that we don't have the full function // type. if (!cast(VD)->hasPrototype() && isa(fty)) type = Context.getFunctionNoProtoType(fty->getReturnType(), fty->getExtInfo()); // Functions are r-values in C. valueKind = VK_RValue; break; } case Decl::MSProperty: valueKind = VK_LValue; break; case Decl::CXXMethod: // If we're referring to a method with an __unknown_anytype // result type, make the entire expression __unknown_anytype. // This should only be possible with a type written directly. if (const FunctionProtoType *proto = dyn_cast(VD->getType())) if (proto->getReturnType() == Context.UnknownAnyTy) { type = Context.UnknownAnyTy; valueKind = VK_RValue; break; } // C++ methods are l-values if static, r-values if non-static. if (cast(VD)->isStatic()) { valueKind = VK_LValue; break; } // fallthrough case Decl::CXXConversion: case Decl::CXXDestructor: case Decl::CXXConstructor: valueKind = VK_RValue; break; } return BuildDeclRefExpr(VD, type, valueKind, NameInfo, &SS, FoundD, TemplateArgs); } } static void ConvertUTF8ToWideString(unsigned CharByteWidth, StringRef Source, SmallString<32> &Target) { Target.resize(CharByteWidth * (Source.size() + 1)); char *ResultPtr = &Target[0]; const UTF8 *ErrorPtr; bool success = ConvertUTF8toWide(CharByteWidth, Source, ResultPtr, ErrorPtr); (void)success; assert(success); Target.resize(ResultPtr - &Target[0]); } ExprResult Sema::BuildPredefinedExpr(SourceLocation Loc, PredefinedExpr::IdentType IT) { // Pick the current block, lambda, captured statement or function. Decl *currentDecl = nullptr; if (const BlockScopeInfo *BSI = getCurBlock()) currentDecl = BSI->TheDecl; else if (const LambdaScopeInfo *LSI = getCurLambda()) currentDecl = LSI->CallOperator; else if (const CapturedRegionScopeInfo *CSI = getCurCapturedRegion()) currentDecl = CSI->TheCapturedDecl; else currentDecl = getCurFunctionOrMethodDecl(); if (!currentDecl) { Diag(Loc, diag::ext_predef_outside_function); currentDecl = Context.getTranslationUnitDecl(); } QualType ResTy; StringLiteral *SL = nullptr; if (cast(currentDecl)->isDependentContext()) ResTy = Context.DependentTy; else { // Pre-defined identifiers are of type char[x], where x is the length of // the string. auto Str = PredefinedExpr::ComputeName(IT, currentDecl); unsigned Length = Str.length(); llvm::APInt LengthI(32, Length + 1); if (IT == PredefinedExpr::LFunction) { ResTy = Context.WideCharTy.withConst(); SmallString<32> RawChars; ConvertUTF8ToWideString(Context.getTypeSizeInChars(ResTy).getQuantity(), Str, RawChars); ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, /*IndexTypeQuals*/ 0); SL = StringLiteral::Create(Context, RawChars, StringLiteral::Wide, /*Pascal*/ false, ResTy, Loc); } else { ResTy = Context.CharTy.withConst(); ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, /*IndexTypeQuals*/ 0); SL = StringLiteral::Create(Context, Str, StringLiteral::Ascii, /*Pascal*/ false, ResTy, Loc); } } return new (Context) PredefinedExpr(Loc, ResTy, IT, SL); } ExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, tok::TokenKind Kind) { PredefinedExpr::IdentType IT; switch (Kind) { default: llvm_unreachable("Unknown simple primary expr!"); case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2] case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break; case tok::kw___FUNCDNAME__: IT = PredefinedExpr::FuncDName; break; // [MS] case tok::kw___FUNCSIG__: IT = PredefinedExpr::FuncSig; break; // [MS] case tok::kw_L__FUNCTION__: IT = PredefinedExpr::LFunction; break; case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break; } return BuildPredefinedExpr(Loc, IT); } ExprResult Sema::ActOnCharacterConstant(const Token &Tok, Scope *UDLScope) { SmallString<16> CharBuffer; bool Invalid = false; StringRef ThisTok = PP.getSpelling(Tok, CharBuffer, &Invalid); if (Invalid) return ExprError(); CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), Tok.getLocation(), PP, Tok.getKind()); if (Literal.hadError()) return ExprError(); QualType Ty; if (Literal.isWide()) Ty = Context.WideCharTy; // L'x' -> wchar_t in C and C++. else if (Literal.isUTF16()) Ty = Context.Char16Ty; // u'x' -> char16_t in C11 and C++11. else if (Literal.isUTF32()) Ty = Context.Char32Ty; // U'x' -> char32_t in C11 and C++11. else if (!getLangOpts().CPlusPlus || Literal.isMultiChar()) Ty = Context.IntTy; // 'x' -> int in C, 'wxyz' -> int in C++. else Ty = Context.CharTy; // 'x' -> char in C++ CharacterLiteral::CharacterKind Kind = CharacterLiteral::Ascii; if (Literal.isWide()) Kind = CharacterLiteral::Wide; else if (Literal.isUTF16()) Kind = CharacterLiteral::UTF16; else if (Literal.isUTF32()) Kind = CharacterLiteral::UTF32; Expr *Lit = new (Context) CharacterLiteral(Literal.getValue(), Kind, Ty, Tok.getLocation()); if (Literal.getUDSuffix().empty()) return Lit; // We're building a user-defined literal. IdentifierInfo *UDSuffix = &Context.Idents.get(Literal.getUDSuffix()); SourceLocation UDSuffixLoc = getUDSuffixLoc(*this, Tok.getLocation(), Literal.getUDSuffixOffset()); // Make sure we're allowed user-defined literals here. if (!UDLScope) return ExprError(Diag(UDSuffixLoc, diag::err_invalid_character_udl)); // C++11 [lex.ext]p6: The literal L is treated as a call of the form // operator "" X (ch) return BuildCookedLiteralOperatorCall(*this, UDLScope, UDSuffix, UDSuffixLoc, Lit, Tok.getLocation()); } ExprResult Sema::ActOnIntegerConstant(SourceLocation Loc, uint64_t Val) { unsigned IntSize = Context.getTargetInfo().getIntWidth(); return IntegerLiteral::Create(Context, llvm::APInt(IntSize, Val), Context.IntTy, Loc); } static Expr *BuildFloatingLiteral(Sema &S, NumericLiteralParser &Literal, QualType Ty, SourceLocation Loc) { const llvm::fltSemantics &Format = S.Context.getFloatTypeSemantics(Ty); using llvm::APFloat; APFloat Val(Format); APFloat::opStatus result = Literal.GetFloatValue(Val); // Overflow is always an error, but underflow is only an error if // we underflowed to zero (APFloat reports denormals as underflow). if ((result & APFloat::opOverflow) || ((result & APFloat::opUnderflow) && Val.isZero())) { unsigned diagnostic; SmallString<20> buffer; if (result & APFloat::opOverflow) { diagnostic = diag::warn_float_overflow; APFloat::getLargest(Format).toString(buffer); } else { diagnostic = diag::warn_float_underflow; APFloat::getSmallest(Format).toString(buffer); } S.Diag(Loc, diagnostic) << Ty << StringRef(buffer.data(), buffer.size()); } bool isExact = (result == APFloat::opOK); return FloatingLiteral::Create(S.Context, Val, isExact, Ty, Loc); } bool Sema::CheckLoopHintExpr(Expr *E, SourceLocation Loc) { assert(E && "Invalid expression"); if (E->isValueDependent()) return false; QualType QT = E->getType(); if (!QT->isIntegerType() || QT->isBooleanType() || QT->isCharType()) { Diag(E->getExprLoc(), diag::err_pragma_loop_invalid_argument_type) << QT; return true; } llvm::APSInt ValueAPS; ExprResult R = VerifyIntegerConstantExpression(E, &ValueAPS); if (R.isInvalid()) return true; bool ValueIsPositive = ValueAPS.isStrictlyPositive(); if (!ValueIsPositive || ValueAPS.getActiveBits() > 31) { Diag(E->getExprLoc(), diag::err_pragma_loop_invalid_argument_value) << ValueAPS.toString(10) << ValueIsPositive; return true; } return false; } ExprResult Sema::ActOnNumericConstant(const Token &Tok, Scope *UDLScope) { // Fast path for a single digit (which is quite common). A single digit // cannot have a trigraph, escaped newline, radix prefix, or suffix. if (Tok.getLength() == 1) { const char Val = PP.getSpellingOfSingleCharacterNumericConstant(Tok); return ActOnIntegerConstant(Tok.getLocation(), Val-'0'); } SmallString<128> SpellingBuffer; // NumericLiteralParser wants to overread by one character. Add padding to // the buffer in case the token is copied to the buffer. If getSpelling() // returns a StringRef to the memory buffer, it should have a null char at // the EOF, so it is also safe. SpellingBuffer.resize(Tok.getLength() + 1); // Get the spelling of the token, which eliminates trigraphs, etc. bool Invalid = false; StringRef TokSpelling = PP.getSpelling(Tok, SpellingBuffer, &Invalid); if (Invalid) return ExprError(); NumericLiteralParser Literal(TokSpelling, Tok.getLocation(), PP); if (Literal.hadError) return ExprError(); if (Literal.hasUDSuffix()) { // We're building a user-defined literal. IdentifierInfo *UDSuffix = &Context.Idents.get(Literal.getUDSuffix()); SourceLocation UDSuffixLoc = getUDSuffixLoc(*this, Tok.getLocation(), Literal.getUDSuffixOffset()); // Make sure we're allowed user-defined literals here. if (!UDLScope) return ExprError(Diag(UDSuffixLoc, diag::err_invalid_numeric_udl)); QualType CookedTy; if (Literal.isFloatingLiteral()) { // C++11 [lex.ext]p4: If S contains a literal operator with parameter type // long double, the literal is treated as a call of the form // operator "" X (f L) CookedTy = Context.LongDoubleTy; } else { // C++11 [lex.ext]p3: If S contains a literal operator with parameter type // unsigned long long, the literal is treated as a call of the form // operator "" X (n ULL) CookedTy = Context.UnsignedLongLongTy; } DeclarationName OpName = Context.DeclarationNames.getCXXLiteralOperatorName(UDSuffix); DeclarationNameInfo OpNameInfo(OpName, UDSuffixLoc); OpNameInfo.setCXXLiteralOperatorNameLoc(UDSuffixLoc); SourceLocation TokLoc = Tok.getLocation(); // Perform literal operator lookup to determine if we're building a raw // literal or a cooked one. LookupResult R(*this, OpName, UDSuffixLoc, LookupOrdinaryName); switch (LookupLiteralOperator(UDLScope, R, CookedTy, /*AllowRaw*/true, /*AllowTemplate*/true, /*AllowStringTemplate*/false)) { case LOLR_Error: return ExprError(); case LOLR_Cooked: { Expr *Lit; if (Literal.isFloatingLiteral()) { Lit = BuildFloatingLiteral(*this, Literal, CookedTy, Tok.getLocation()); } else { llvm::APInt ResultVal(Context.getTargetInfo().getLongLongWidth(), 0); if (Literal.GetIntegerValue(ResultVal)) Diag(Tok.getLocation(), diag::err_integer_literal_too_large) << /* Unsigned */ 1; Lit = IntegerLiteral::Create(Context, ResultVal, CookedTy, Tok.getLocation()); } return BuildLiteralOperatorCall(R, OpNameInfo, Lit, TokLoc); } case LOLR_Raw: { // C++11 [lit.ext]p3, p4: If S contains a raw literal operator, the // literal is treated as a call of the form // operator "" X ("n") unsigned Length = Literal.getUDSuffixOffset(); QualType StrTy = Context.getConstantArrayType( Context.CharTy.withConst(), llvm::APInt(32, Length + 1), ArrayType::Normal, 0); Expr *Lit = StringLiteral::Create( Context, StringRef(TokSpelling.data(), Length), StringLiteral::Ascii, /*Pascal*/false, StrTy, &TokLoc, 1); return BuildLiteralOperatorCall(R, OpNameInfo, Lit, TokLoc); } case LOLR_Template: { // C++11 [lit.ext]p3, p4: Otherwise (S contains a literal operator // template), L is treated as a call fo the form // operator "" X <'c1', 'c2', ... 'ck'>() // where n is the source character sequence c1 c2 ... ck. TemplateArgumentListInfo ExplicitArgs; unsigned CharBits = Context.getIntWidth(Context.CharTy); bool CharIsUnsigned = Context.CharTy->isUnsignedIntegerType(); llvm::APSInt Value(CharBits, CharIsUnsigned); for (unsigned I = 0, N = Literal.getUDSuffixOffset(); I != N; ++I) { Value = TokSpelling[I]; TemplateArgument Arg(Context, Value, Context.CharTy); TemplateArgumentLocInfo ArgInfo; ExplicitArgs.addArgument(TemplateArgumentLoc(Arg, ArgInfo)); } return BuildLiteralOperatorCall(R, OpNameInfo, None, TokLoc, &ExplicitArgs); } case LOLR_StringTemplate: llvm_unreachable("unexpected literal operator lookup result"); } } Expr *Res; if (Literal.isFloatingLiteral()) { QualType Ty; if (Literal.isFloat) Ty = Context.FloatTy; else if (!Literal.isLong) Ty = Context.DoubleTy; else Ty = Context.LongDoubleTy; Res = BuildFloatingLiteral(*this, Literal, Ty, Tok.getLocation()); if (Ty == Context.DoubleTy) { if (getLangOpts().SinglePrecisionConstants) { Res = ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast).get(); } else if (getLangOpts().OpenCL && !((getLangOpts().OpenCLVersion >= 120) || getOpenCLOptions().cl_khr_fp64)) { Diag(Tok.getLocation(), diag::warn_double_const_requires_fp64); Res = ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast).get(); } } } else if (!Literal.isIntegerLiteral()) { return ExprError(); } else { QualType Ty; // 'long long' is a C99 or C++11 feature. if (!getLangOpts().C99 && Literal.isLongLong) { if (getLangOpts().CPlusPlus) Diag(Tok.getLocation(), getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_longlong : diag::ext_cxx11_longlong); else Diag(Tok.getLocation(), diag::ext_c99_longlong); } // Get the value in the widest-possible width. unsigned MaxWidth = Context.getTargetInfo().getIntMaxTWidth(); llvm::APInt ResultVal(MaxWidth, 0); if (Literal.GetIntegerValue(ResultVal)) { // If this value didn't fit into uintmax_t, error and force to ull. Diag(Tok.getLocation(), diag::err_integer_literal_too_large) << /* Unsigned */ 1; Ty = Context.UnsignedLongLongTy; assert(Context.getTypeSize(Ty) == ResultVal.getBitWidth() && "long long is not intmax_t?"); } else { // If this value fits into a ULL, try to figure out what else it fits into // according to the rules of C99 6.4.4.1p5. // Octal, Hexadecimal, and integers with a U suffix are allowed to // be an unsigned int. bool AllowUnsigned = Literal.isUnsigned || Literal.getRadix() != 10; // Check from smallest to largest, picking the smallest type we can. unsigned Width = 0; // Microsoft specific integer suffixes are explicitly sized. if (Literal.MicrosoftInteger) { if (Literal.MicrosoftInteger == 8 && !Literal.isUnsigned) { Width = 8; Ty = Context.CharTy; } else { Width = Literal.MicrosoftInteger; Ty = Context.getIntTypeForBitwidth(Width, /*Signed=*/!Literal.isUnsigned); } } if (Ty.isNull() && !Literal.isLong && !Literal.isLongLong) { // Are int/unsigned possibilities? unsigned IntSize = Context.getTargetInfo().getIntWidth(); // Does it fit in a unsigned int? if (ResultVal.isIntN(IntSize)) { // Does it fit in a signed int? if (!Literal.isUnsigned && ResultVal[IntSize-1] == 0) Ty = Context.IntTy; else if (AllowUnsigned) Ty = Context.UnsignedIntTy; Width = IntSize; } } // Are long/unsigned long possibilities? if (Ty.isNull() && !Literal.isLongLong) { unsigned LongSize = Context.getTargetInfo().getLongWidth(); // Does it fit in a unsigned long? if (ResultVal.isIntN(LongSize)) { // Does it fit in a signed long? if (!Literal.isUnsigned && ResultVal[LongSize-1] == 0) Ty = Context.LongTy; else if (AllowUnsigned) Ty = Context.UnsignedLongTy; // Check according to the rules of C90 6.1.3.2p5. C++03 [lex.icon]p2 // is compatible. else if (!getLangOpts().C99 && !getLangOpts().CPlusPlus11) { const unsigned LongLongSize = Context.getTargetInfo().getLongLongWidth(); Diag(Tok.getLocation(), getLangOpts().CPlusPlus ? Literal.isLong ? diag::warn_old_implicitly_unsigned_long_cxx : /*C++98 UB*/ diag:: ext_old_implicitly_unsigned_long_cxx : diag::warn_old_implicitly_unsigned_long) << (LongLongSize > LongSize ? /*will have type 'long long'*/ 0 : /*will be ill-formed*/ 1); Ty = Context.UnsignedLongTy; } Width = LongSize; } } // Check long long if needed. if (Ty.isNull()) { unsigned LongLongSize = Context.getTargetInfo().getLongLongWidth(); // Does it fit in a unsigned long long? if (ResultVal.isIntN(LongLongSize)) { // Does it fit in a signed long long? // To be compatible with MSVC, hex integer literals ending with the // LL or i64 suffix are always signed in Microsoft mode. if (!Literal.isUnsigned && (ResultVal[LongLongSize-1] == 0 || (getLangOpts().MicrosoftExt && Literal.isLongLong))) Ty = Context.LongLongTy; else if (AllowUnsigned) Ty = Context.UnsignedLongLongTy; Width = LongLongSize; } } // If we still couldn't decide a type, we probably have something that // does not fit in a signed long long, but has no U suffix. if (Ty.isNull()) { Diag(Tok.getLocation(), diag::ext_integer_literal_too_large_for_signed); Ty = Context.UnsignedLongLongTy; Width = Context.getTargetInfo().getLongLongWidth(); } if (ResultVal.getBitWidth() != Width) ResultVal = ResultVal.trunc(Width); } Res = IntegerLiteral::Create(Context, ResultVal, Ty, Tok.getLocation()); } // If this is an imaginary literal, create the ImaginaryLiteral wrapper. if (Literal.isImaginary) Res = new (Context) ImaginaryLiteral(Res, Context.getComplexType(Res->getType())); return Res; } ExprResult Sema::ActOnParenExpr(SourceLocation L, SourceLocation R, Expr *E) { assert(E && "ActOnParenExpr() missing expr"); return new (Context) ParenExpr(L, R, E); } static bool CheckVecStepTraitOperandType(Sema &S, QualType T, SourceLocation Loc, SourceRange ArgRange) { // [OpenCL 1.1 6.11.12] "The vec_step built-in function takes a built-in // scalar or vector data type argument..." // Every built-in scalar type (OpenCL 1.1 6.1.1) is either an arithmetic // type (C99 6.2.5p18) or void. if (!(T->isArithmeticType() || T->isVoidType() || T->isVectorType())) { S.Diag(Loc, diag::err_vecstep_non_scalar_vector_type) << T << ArgRange; return true; } assert((T->isVoidType() || !T->isIncompleteType()) && "Scalar types should always be complete"); return false; } static bool CheckExtensionTraitOperandType(Sema &S, QualType T, SourceLocation Loc, SourceRange ArgRange, UnaryExprOrTypeTrait TraitKind) { // Invalid types must be hard errors for SFINAE in C++. if (S.LangOpts.CPlusPlus) return true; // C99 6.5.3.4p1: if (T->isFunctionType() && (TraitKind == UETT_SizeOf || TraitKind == UETT_AlignOf)) { // sizeof(function)/alignof(function) is allowed as an extension. S.Diag(Loc, diag::ext_sizeof_alignof_function_type) << TraitKind << ArgRange; return false; } // Allow sizeof(void)/alignof(void) as an extension, unless in OpenCL where // this is an error (OpenCL v1.1 s6.3.k) if (T->isVoidType()) { unsigned DiagID = S.LangOpts.OpenCL ? diag::err_opencl_sizeof_alignof_type : diag::ext_sizeof_alignof_void_type; S.Diag(Loc, DiagID) << TraitKind << ArgRange; return false; } return true; } static bool CheckObjCTraitOperandConstraints(Sema &S, QualType T, SourceLocation Loc, SourceRange ArgRange, UnaryExprOrTypeTrait TraitKind) { // Reject sizeof(interface) and sizeof(interface) if the // runtime doesn't allow it. if (!S.LangOpts.ObjCRuntime.allowsSizeofAlignof() && T->isObjCObjectType()) { S.Diag(Loc, diag::err_sizeof_nonfragile_interface) << T << (TraitKind == UETT_SizeOf) << ArgRange; return true; } return false; } /// \brief Check whether E is a pointer from a decayed array type (the decayed /// pointer type is equal to T) and emit a warning if it is. static void warnOnSizeofOnArrayDecay(Sema &S, SourceLocation Loc, QualType T, Expr *E) { // Don't warn if the operation changed the type. if (T != E->getType()) return; // Now look for array decays. ImplicitCastExpr *ICE = dyn_cast(E); if (!ICE || ICE->getCastKind() != CK_ArrayToPointerDecay) return; S.Diag(Loc, diag::warn_sizeof_array_decay) << ICE->getSourceRange() << ICE->getType() << ICE->getSubExpr()->getType(); } /// \brief Check the constraints on expression operands to unary type expression /// and type traits. /// /// Completes any types necessary and validates the constraints on the operand /// expression. The logic mostly mirrors the type-based overload, but may modify /// the expression as it completes the type for that expression through template /// instantiation, etc. bool Sema::CheckUnaryExprOrTypeTraitOperand(Expr *E, UnaryExprOrTypeTrait ExprKind) { QualType ExprTy = E->getType(); assert(!ExprTy->isReferenceType()); if (ExprKind == UETT_VecStep) return CheckVecStepTraitOperandType(*this, ExprTy, E->getExprLoc(), E->getSourceRange()); // Whitelist some types as extensions if (!CheckExtensionTraitOperandType(*this, ExprTy, E->getExprLoc(), E->getSourceRange(), ExprKind)) return false; // 'alignof' applied to an expression only requires the base element type of // the expression to be complete. 'sizeof' requires the expression's type to // be complete (and will attempt to complete it if it's an array of unknown // bound). if (ExprKind == UETT_AlignOf) { if (RequireCompleteType(E->getExprLoc(), Context.getBaseElementType(E->getType()), diag::err_sizeof_alignof_incomplete_type, ExprKind, E->getSourceRange())) return true; } else { if (RequireCompleteExprType(E, diag::err_sizeof_alignof_incomplete_type, ExprKind, E->getSourceRange())) return true; } // Completing the expression's type may have changed it. ExprTy = E->getType(); assert(!ExprTy->isReferenceType()); if (ExprTy->isFunctionType()) { Diag(E->getExprLoc(), diag::err_sizeof_alignof_function_type) << ExprKind << E->getSourceRange(); return true; } // The operand for sizeof and alignof is in an unevaluated expression context, // so side effects could result in unintended consequences. if ((ExprKind == UETT_SizeOf || ExprKind == UETT_AlignOf) && ActiveTemplateInstantiations.empty() && E->HasSideEffects(Context, false)) Diag(E->getExprLoc(), diag::warn_side_effects_unevaluated_context); if (CheckObjCTraitOperandConstraints(*this, ExprTy, E->getExprLoc(), E->getSourceRange(), ExprKind)) return true; if (ExprKind == UETT_SizeOf) { if (DeclRefExpr *DeclRef = dyn_cast(E->IgnoreParens())) { if (ParmVarDecl *PVD = dyn_cast(DeclRef->getFoundDecl())) { QualType OType = PVD->getOriginalType(); QualType Type = PVD->getType(); if (Type->isPointerType() && OType->isArrayType()) { Diag(E->getExprLoc(), diag::warn_sizeof_array_param) << Type << OType; Diag(PVD->getLocation(), diag::note_declared_at); } } } // Warn on "sizeof(array op x)" and "sizeof(x op array)", where the array // decays into a pointer and returns an unintended result. This is most // likely a typo for "sizeof(array) op x". if (BinaryOperator *BO = dyn_cast(E->IgnoreParens())) { warnOnSizeofOnArrayDecay(*this, BO->getOperatorLoc(), BO->getType(), BO->getLHS()); warnOnSizeofOnArrayDecay(*this, BO->getOperatorLoc(), BO->getType(), BO->getRHS()); } } return false; } /// \brief Check the constraints on operands to unary expression and type /// traits. /// /// This will complete any types necessary, and validate the various constraints /// on those operands. /// /// The UsualUnaryConversions() function is *not* called by this routine. /// C99 6.3.2.1p[2-4] all state: /// Except when it is the operand of the sizeof operator ... /// /// C++ [expr.sizeof]p4 /// The lvalue-to-rvalue, array-to-pointer, and function-to-pointer /// standard conversions are not applied to the operand of sizeof. /// /// This policy is followed for all of the unary trait expressions. bool Sema::CheckUnaryExprOrTypeTraitOperand(QualType ExprType, SourceLocation OpLoc, SourceRange ExprRange, UnaryExprOrTypeTrait ExprKind) { if (ExprType->isDependentType()) return false; // C++ [expr.sizeof]p2: // When applied to a reference or a reference type, the result // is the size of the referenced type. // C++11 [expr.alignof]p3: // When alignof is applied to a reference type, the result // shall be the alignment of the referenced type. if (const ReferenceType *Ref = ExprType->getAs()) ExprType = Ref->getPointeeType(); // C11 6.5.3.4/3, C++11 [expr.alignof]p3: // When alignof or _Alignof is applied to an array type, the result // is the alignment of the element type. if (ExprKind == UETT_AlignOf || ExprKind == UETT_OpenMPRequiredSimdAlign) ExprType = Context.getBaseElementType(ExprType); if (ExprKind == UETT_VecStep) return CheckVecStepTraitOperandType(*this, ExprType, OpLoc, ExprRange); // Whitelist some types as extensions if (!CheckExtensionTraitOperandType(*this, ExprType, OpLoc, ExprRange, ExprKind)) return false; if (RequireCompleteType(OpLoc, ExprType, diag::err_sizeof_alignof_incomplete_type, ExprKind, ExprRange)) return true; if (ExprType->isFunctionType()) { Diag(OpLoc, diag::err_sizeof_alignof_function_type) << ExprKind << ExprRange; return true; } if (CheckObjCTraitOperandConstraints(*this, ExprType, OpLoc, ExprRange, ExprKind)) return true; return false; } static bool CheckAlignOfExpr(Sema &S, Expr *E) { E = E->IgnoreParens(); // Cannot know anything else if the expression is dependent. if (E->isTypeDependent()) return false; if (E->getObjectKind() == OK_BitField) { S.Diag(E->getExprLoc(), diag::err_sizeof_alignof_typeof_bitfield) << 1 << E->getSourceRange(); return true; } ValueDecl *D = nullptr; if (DeclRefExpr *DRE = dyn_cast(E)) { D = DRE->getDecl(); } else if (MemberExpr *ME = dyn_cast(E)) { D = ME->getMemberDecl(); } // If it's a field, require the containing struct to have a // complete definition so that we can compute the layout. // // This can happen in C++11 onwards, either by naming the member // in a way that is not transformed into a member access expression // (in an unevaluated operand, for instance), or by naming the member // in a trailing-return-type. // // For the record, since __alignof__ on expressions is a GCC // extension, GCC seems to permit this but always gives the // nonsensical answer 0. // // We don't really need the layout here --- we could instead just // directly check for all the appropriate alignment-lowing // attributes --- but that would require duplicating a lot of // logic that just isn't worth duplicating for such a marginal // use-case. if (FieldDecl *FD = dyn_cast_or_null(D)) { // Fast path this check, since we at least know the record has a // definition if we can find a member of it. if (!FD->getParent()->isCompleteDefinition()) { S.Diag(E->getExprLoc(), diag::err_alignof_member_of_incomplete_type) << E->getSourceRange(); return true; } // Otherwise, if it's a field, and the field doesn't have // reference type, then it must have a complete type (or be a // flexible array member, which we explicitly want to // white-list anyway), which makes the following checks trivial. if (!FD->getType()->isReferenceType()) return false; } return S.CheckUnaryExprOrTypeTraitOperand(E, UETT_AlignOf); } bool Sema::CheckVecStepExpr(Expr *E) { E = E->IgnoreParens(); // Cannot know anything else if the expression is dependent. if (E->isTypeDependent()) return false; return CheckUnaryExprOrTypeTraitOperand(E, UETT_VecStep); } /// \brief Build a sizeof or alignof expression given a type operand. ExprResult Sema::CreateUnaryExprOrTypeTraitExpr(TypeSourceInfo *TInfo, SourceLocation OpLoc, UnaryExprOrTypeTrait ExprKind, SourceRange R) { if (!TInfo) return ExprError(); QualType T = TInfo->getType(); if (!T->isDependentType() && CheckUnaryExprOrTypeTraitOperand(T, OpLoc, R, ExprKind)) return ExprError(); // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. return new (Context) UnaryExprOrTypeTraitExpr( ExprKind, TInfo, Context.getSizeType(), OpLoc, R.getEnd()); } /// \brief Build a sizeof or alignof expression given an expression /// operand. ExprResult Sema::CreateUnaryExprOrTypeTraitExpr(Expr *E, SourceLocation OpLoc, UnaryExprOrTypeTrait ExprKind) { ExprResult PE = CheckPlaceholderExpr(E); if (PE.isInvalid()) return ExprError(); E = PE.get(); // Verify that the operand is valid. bool isInvalid = false; if (E->isTypeDependent()) { // Delay type-checking for type-dependent expressions. } else if (ExprKind == UETT_AlignOf) { isInvalid = CheckAlignOfExpr(*this, E); } else if (ExprKind == UETT_VecStep) { isInvalid = CheckVecStepExpr(E); } else if (ExprKind == UETT_OpenMPRequiredSimdAlign) { Diag(E->getExprLoc(), diag::err_openmp_default_simd_align_expr); isInvalid = true; } else if (E->refersToBitField()) { // C99 6.5.3.4p1. Diag(E->getExprLoc(), diag::err_sizeof_alignof_typeof_bitfield) << 0; isInvalid = true; } else { isInvalid = CheckUnaryExprOrTypeTraitOperand(E, UETT_SizeOf); } if (isInvalid) return ExprError(); if (ExprKind == UETT_SizeOf && E->getType()->isVariableArrayType()) { PE = TransformToPotentiallyEvaluated(E); if (PE.isInvalid()) return ExprError(); E = PE.get(); } // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. return new (Context) UnaryExprOrTypeTraitExpr( ExprKind, E, Context.getSizeType(), OpLoc, E->getSourceRange().getEnd()); } /// ActOnUnaryExprOrTypeTraitExpr - Handle @c sizeof(type) and @c sizeof @c /// expr and the same for @c alignof and @c __alignof /// Note that the ArgRange is invalid if isType is false. ExprResult Sema::ActOnUnaryExprOrTypeTraitExpr(SourceLocation OpLoc, UnaryExprOrTypeTrait ExprKind, bool IsType, void *TyOrEx, SourceRange ArgRange) { // If error parsing type, ignore. if (!TyOrEx) return ExprError(); if (IsType) { TypeSourceInfo *TInfo; (void) GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrEx), &TInfo); return CreateUnaryExprOrTypeTraitExpr(TInfo, OpLoc, ExprKind, ArgRange); } Expr *ArgEx = (Expr *)TyOrEx; ExprResult Result = CreateUnaryExprOrTypeTraitExpr(ArgEx, OpLoc, ExprKind); return Result; } static QualType CheckRealImagOperand(Sema &S, ExprResult &V, SourceLocation Loc, bool IsReal) { if (V.get()->isTypeDependent()) return S.Context.DependentTy; // _Real and _Imag are only l-values for normal l-values. if (V.get()->getObjectKind() != OK_Ordinary) { V = S.DefaultLvalueConversion(V.get()); if (V.isInvalid()) return QualType(); } // These operators return the element type of a complex type. if (const ComplexType *CT = V.get()->getType()->getAs()) return CT->getElementType(); // Otherwise they pass through real integer and floating point types here. if (V.get()->getType()->isArithmeticType()) return V.get()->getType(); // Test for placeholders. ExprResult PR = S.CheckPlaceholderExpr(V.get()); if (PR.isInvalid()) return QualType(); if (PR.get() != V.get()) { V = PR; return CheckRealImagOperand(S, V, Loc, IsReal); } // Reject anything else. S.Diag(Loc, diag::err_realimag_invalid_type) << V.get()->getType() << (IsReal ? "__real" : "__imag"); return QualType(); } ExprResult Sema::ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc, tok::TokenKind Kind, Expr *Input) { UnaryOperatorKind Opc; switch (Kind) { default: llvm_unreachable("Unknown unary op!"); case tok::plusplus: Opc = UO_PostInc; break; case tok::minusminus: Opc = UO_PostDec; break; } // Since this might is a postfix expression, get rid of ParenListExprs. ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Input); if (Result.isInvalid()) return ExprError(); Input = Result.get(); return BuildUnaryOp(S, OpLoc, Opc, Input); } /// \brief Diagnose if arithmetic on the given ObjC pointer is illegal. /// /// \return true on error static bool checkArithmeticOnObjCPointer(Sema &S, SourceLocation opLoc, Expr *op) { assert(op->getType()->isObjCObjectPointerType()); if (S.LangOpts.ObjCRuntime.allowsPointerArithmetic() && !S.LangOpts.ObjCSubscriptingLegacyRuntime) return false; S.Diag(opLoc, diag::err_arithmetic_nonfragile_interface) << op->getType()->castAs()->getPointeeType() << op->getSourceRange(); return true; } static bool isMSPropertySubscriptExpr(Sema &S, Expr *Base) { auto *BaseNoParens = Base->IgnoreParens(); if (auto *MSProp = dyn_cast(BaseNoParens)) return MSProp->getPropertyDecl()->getType()->isArrayType(); return isa(BaseNoParens); } ExprResult Sema::ActOnArraySubscriptExpr(Scope *S, Expr *base, SourceLocation lbLoc, Expr *idx, SourceLocation rbLoc) { if (base && !base->getType().isNull() && base->getType()->isSpecificPlaceholderType(BuiltinType::OMPArraySection)) return ActOnOMPArraySectionExpr(base, lbLoc, idx, SourceLocation(), /*Length=*/nullptr, rbLoc); // Since this might be a postfix expression, get rid of ParenListExprs. if (isa(base)) { ExprResult result = MaybeConvertParenListExprToParenExpr(S, base); if (result.isInvalid()) return ExprError(); base = result.get(); } // Handle any non-overload placeholder types in the base and index // expressions. We can't handle overloads here because the other // operand might be an overloadable type, in which case the overload // resolution for the operator overload should get the first crack // at the overload. bool IsMSPropertySubscript = false; if (base->getType()->isNonOverloadPlaceholderType()) { IsMSPropertySubscript = isMSPropertySubscriptExpr(*this, base); if (!IsMSPropertySubscript) { ExprResult result = CheckPlaceholderExpr(base); if (result.isInvalid()) return ExprError(); base = result.get(); } } if (idx->getType()->isNonOverloadPlaceholderType()) { ExprResult result = CheckPlaceholderExpr(idx); if (result.isInvalid()) return ExprError(); idx = result.get(); } // Build an unanalyzed expression if either operand is type-dependent. if (getLangOpts().CPlusPlus && (base->isTypeDependent() || idx->isTypeDependent())) { return new (Context) ArraySubscriptExpr(base, idx, Context.DependentTy, VK_LValue, OK_Ordinary, rbLoc); } // MSDN, property (C++) // https://msdn.microsoft.com/en-us/library/yhfk0thd(v=vs.120).aspx // This attribute can also be used in the declaration of an empty array in a // class or structure definition. For example: // __declspec(property(get=GetX, put=PutX)) int x[]; // The above statement indicates that x[] can be used with one or more array // indices. In this case, i=p->x[a][b] will be turned into i=p->GetX(a, b), // and p->x[a][b] = i will be turned into p->PutX(a, b, i); if (IsMSPropertySubscript) { // Build MS property subscript expression if base is MS property reference // or MS property subscript. return new (Context) MSPropertySubscriptExpr( base, idx, Context.PseudoObjectTy, VK_LValue, OK_Ordinary, rbLoc); } // Use C++ overloaded-operator rules if either operand has record // type. The spec says to do this if either type is *overloadable*, // but enum types can't declare subscript operators or conversion // operators, so there's nothing interesting for overload resolution // to do if there aren't any record types involved. // // ObjC pointers have their own subscripting logic that is not tied // to overload resolution and so should not take this path. if (getLangOpts().CPlusPlus && (base->getType()->isRecordType() || (!base->getType()->isObjCObjectPointerType() && idx->getType()->isRecordType()))) { return CreateOverloadedArraySubscriptExpr(lbLoc, rbLoc, base, idx); } return CreateBuiltinArraySubscriptExpr(base, lbLoc, idx, rbLoc); } ExprResult Sema::ActOnOMPArraySectionExpr(Expr *Base, SourceLocation LBLoc, Expr *LowerBound, SourceLocation ColonLoc, Expr *Length, SourceLocation RBLoc) { if (Base->getType()->isPlaceholderType() && !Base->getType()->isSpecificPlaceholderType( BuiltinType::OMPArraySection)) { ExprResult Result = CheckPlaceholderExpr(Base); if (Result.isInvalid()) return ExprError(); Base = Result.get(); } if (LowerBound && LowerBound->getType()->isNonOverloadPlaceholderType()) { ExprResult Result = CheckPlaceholderExpr(LowerBound); if (Result.isInvalid()) return ExprError(); LowerBound = Result.get(); } if (Length && Length->getType()->isNonOverloadPlaceholderType()) { ExprResult Result = CheckPlaceholderExpr(Length); if (Result.isInvalid()) return ExprError(); Length = Result.get(); } // Build an unanalyzed expression if either operand is type-dependent. if (Base->isTypeDependent() || (LowerBound && (LowerBound->isTypeDependent() || LowerBound->isValueDependent())) || (Length && (Length->isTypeDependent() || Length->isValueDependent()))) { return new (Context) OMPArraySectionExpr(Base, LowerBound, Length, Context.DependentTy, VK_LValue, OK_Ordinary, ColonLoc, RBLoc); } // Perform default conversions. QualType OriginalTy = OMPArraySectionExpr::getBaseOriginalType(Base); QualType ResultTy; if (OriginalTy->isAnyPointerType()) { ResultTy = OriginalTy->getPointeeType(); } else if (OriginalTy->isArrayType()) { ResultTy = OriginalTy->getAsArrayTypeUnsafe()->getElementType(); } else { return ExprError( Diag(Base->getExprLoc(), diag::err_omp_typecheck_section_value) << Base->getSourceRange()); } // C99 6.5.2.1p1 if (LowerBound) { auto Res = PerformOpenMPImplicitIntegerConversion(LowerBound->getExprLoc(), LowerBound); if (Res.isInvalid()) return ExprError(Diag(LowerBound->getExprLoc(), diag::err_omp_typecheck_section_not_integer) << 0 << LowerBound->getSourceRange()); LowerBound = Res.get(); if (LowerBound->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || LowerBound->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) Diag(LowerBound->getExprLoc(), diag::warn_omp_section_is_char) << 0 << LowerBound->getSourceRange(); } if (Length) { auto Res = PerformOpenMPImplicitIntegerConversion(Length->getExprLoc(), Length); if (Res.isInvalid()) return ExprError(Diag(Length->getExprLoc(), diag::err_omp_typecheck_section_not_integer) << 1 << Length->getSourceRange()); Length = Res.get(); if (Length->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || Length->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) Diag(Length->getExprLoc(), diag::warn_omp_section_is_char) << 1 << Length->getSourceRange(); } // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, // C++ [expr.sub]p1: The type "T" shall be a completely-defined object // type. Note that functions are not objects, and that (in C99 parlance) // incomplete types are not object types. if (ResultTy->isFunctionType()) { Diag(Base->getExprLoc(), diag::err_omp_section_function_type) << ResultTy << Base->getSourceRange(); return ExprError(); } if (RequireCompleteType(Base->getExprLoc(), ResultTy, diag::err_omp_section_incomplete_type, Base)) return ExprError(); if (LowerBound) { llvm::APSInt LowerBoundValue; if (LowerBound->EvaluateAsInt(LowerBoundValue, Context)) { // OpenMP 4.0, [2.4 Array Sections] // The lower-bound and length must evaluate to non-negative integers. if (LowerBoundValue.isNegative()) { Diag(LowerBound->getExprLoc(), diag::err_omp_section_negative) << 0 << LowerBoundValue.toString(/*Radix=*/10, /*Signed=*/true) << LowerBound->getSourceRange(); return ExprError(); } } } if (Length) { llvm::APSInt LengthValue; if (Length->EvaluateAsInt(LengthValue, Context)) { // OpenMP 4.0, [2.4 Array Sections] // The lower-bound and length must evaluate to non-negative integers. if (LengthValue.isNegative()) { Diag(Length->getExprLoc(), diag::err_omp_section_negative) << 1 << LengthValue.toString(/*Radix=*/10, /*Signed=*/true) << Length->getSourceRange(); return ExprError(); } } } else if (ColonLoc.isValid() && (OriginalTy.isNull() || (!OriginalTy->isConstantArrayType() && !OriginalTy->isVariableArrayType()))) { // OpenMP 4.0, [2.4 Array Sections] // When the size of the array dimension is not known, the length must be // specified explicitly. Diag(ColonLoc, diag::err_omp_section_length_undefined) << (!OriginalTy.isNull() && OriginalTy->isArrayType()); return ExprError(); } return new (Context) OMPArraySectionExpr(Base, LowerBound, Length, Context.OMPArraySectionTy, VK_LValue, OK_Ordinary, ColonLoc, RBLoc); } ExprResult Sema::CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc, Expr *Idx, SourceLocation RLoc) { Expr *LHSExp = Base; Expr *RHSExp = Idx; // Perform default conversions. if (!LHSExp->getType()->getAs()) { ExprResult Result = DefaultFunctionArrayLvalueConversion(LHSExp); if (Result.isInvalid()) return ExprError(); LHSExp = Result.get(); } ExprResult Result = DefaultFunctionArrayLvalueConversion(RHSExp); if (Result.isInvalid()) return ExprError(); RHSExp = Result.get(); QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType(); ExprValueKind VK = VK_LValue; ExprObjectKind OK = OK_Ordinary; // C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent // to the expression *((e1)+(e2)). This means the array "Base" may actually be // in the subscript position. As a result, we need to derive the array base // and index from the expression types. Expr *BaseExpr, *IndexExpr; QualType ResultType; if (LHSTy->isDependentType() || RHSTy->isDependentType()) { BaseExpr = LHSExp; IndexExpr = RHSExp; ResultType = Context.DependentTy; } else if (const PointerType *PTy = LHSTy->getAs()) { BaseExpr = LHSExp; IndexExpr = RHSExp; ResultType = PTy->getPointeeType(); } else if (const ObjCObjectPointerType *PTy = LHSTy->getAs()) { BaseExpr = LHSExp; IndexExpr = RHSExp; // Use custom logic if this should be the pseudo-object subscript // expression. if (!LangOpts.isSubscriptPointerArithmetic()) return BuildObjCSubscriptExpression(RLoc, BaseExpr, IndexExpr, nullptr, nullptr); ResultType = PTy->getPointeeType(); } else if (const PointerType *PTy = RHSTy->getAs()) { // Handle the uncommon case of "123[Ptr]". BaseExpr = RHSExp; IndexExpr = LHSExp; ResultType = PTy->getPointeeType(); } else if (const ObjCObjectPointerType *PTy = RHSTy->getAs()) { // Handle the uncommon case of "123[Ptr]". BaseExpr = RHSExp; IndexExpr = LHSExp; ResultType = PTy->getPointeeType(); if (!LangOpts.isSubscriptPointerArithmetic()) { Diag(LLoc, diag::err_subscript_nonfragile_interface) << ResultType << BaseExpr->getSourceRange(); return ExprError(); } } else if (const VectorType *VTy = LHSTy->getAs()) { BaseExpr = LHSExp; // vectors: V[123] IndexExpr = RHSExp; VK = LHSExp->getValueKind(); if (VK != VK_RValue) OK = OK_VectorComponent; // FIXME: need to deal with const... ResultType = VTy->getElementType(); } else if (LHSTy->isArrayType()) { // If we see an array that wasn't promoted by // DefaultFunctionArrayLvalueConversion, it must be an array that // wasn't promoted because of the C90 rule that doesn't // allow promoting non-lvalue arrays. Warn, then // force the promotion here. Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << LHSExp->getSourceRange(); LHSExp = ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy), CK_ArrayToPointerDecay).get(); LHSTy = LHSExp->getType(); BaseExpr = LHSExp; IndexExpr = RHSExp; ResultType = LHSTy->getAs()->getPointeeType(); } else if (RHSTy->isArrayType()) { // Same as previous, except for 123[f().a] case Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << RHSExp->getSourceRange(); RHSExp = ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy), CK_ArrayToPointerDecay).get(); RHSTy = RHSExp->getType(); BaseExpr = RHSExp; IndexExpr = LHSExp; ResultType = RHSTy->getAs()->getPointeeType(); } else { return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value) << LHSExp->getSourceRange() << RHSExp->getSourceRange()); } // C99 6.5.2.1p1 if (!IndexExpr->getType()->isIntegerType() && !IndexExpr->isTypeDependent()) return ExprError(Diag(LLoc, diag::err_typecheck_subscript_not_integer) << IndexExpr->getSourceRange()); if ((IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) && !IndexExpr->isTypeDependent()) Diag(LLoc, diag::warn_subscript_is_char) << IndexExpr->getSourceRange(); // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, // C++ [expr.sub]p1: The type "T" shall be a completely-defined object // type. Note that Functions are not objects, and that (in C99 parlance) // incomplete types are not object types. if (ResultType->isFunctionType()) { Diag(BaseExpr->getLocStart(), diag::err_subscript_function_type) << ResultType << BaseExpr->getSourceRange(); return ExprError(); } if (ResultType->isVoidType() && !getLangOpts().CPlusPlus) { // GNU extension: subscripting on pointer to void Diag(LLoc, diag::ext_gnu_subscript_void_type) << BaseExpr->getSourceRange(); // C forbids expressions of unqualified void type from being l-values. // See IsCForbiddenLValueType. if (!ResultType.hasQualifiers()) VK = VK_RValue; } else if (!ResultType->isDependentType() && RequireCompleteType(LLoc, ResultType, diag::err_subscript_incomplete_type, BaseExpr)) return ExprError(); assert(VK == VK_RValue || LangOpts.CPlusPlus || !ResultType.isCForbiddenLValueType()); return new (Context) ArraySubscriptExpr(LHSExp, RHSExp, ResultType, VK, OK, RLoc); } ExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc, FunctionDecl *FD, ParmVarDecl *Param) { if (Param->hasUnparsedDefaultArg()) { Diag(CallLoc, diag::err_use_of_default_argument_to_function_declared_later) << FD << cast(FD->getDeclContext())->getDeclName(); Diag(UnparsedDefaultArgLocs[Param], diag::note_default_argument_declared_here); return ExprError(); } if (Param->hasUninstantiatedDefaultArg()) { Expr *UninstExpr = Param->getUninstantiatedDefaultArg(); EnterExpressionEvaluationContext EvalContext(*this, PotentiallyEvaluated, Param); // Instantiate the expression. MultiLevelTemplateArgumentList MutiLevelArgList = getTemplateInstantiationArgs(FD, nullptr, /*RelativeToPrimary=*/true); InstantiatingTemplate Inst(*this, CallLoc, Param, MutiLevelArgList.getInnermost()); if (Inst.isInvalid()) return ExprError(); ExprResult Result; { // C++ [dcl.fct.default]p5: // The names in the [default argument] expression are bound, and // the semantic constraints are checked, at the point where the // default argument expression appears. ContextRAII SavedContext(*this, FD); LocalInstantiationScope Local(*this); Result = SubstExpr(UninstExpr, MutiLevelArgList); } if (Result.isInvalid()) return ExprError(); // Check the expression as an initializer for the parameter. InitializedEntity Entity = InitializedEntity::InitializeParameter(Context, Param); InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(), /*FIXME:EqualLoc*/UninstExpr->getLocStart()); Expr *ResultE = Result.getAs(); InitializationSequence InitSeq(*this, Entity, Kind, ResultE); Result = InitSeq.Perform(*this, Entity, Kind, ResultE); if (Result.isInvalid()) return ExprError(); Expr *Arg = Result.getAs(); CheckCompletedExpr(Arg, Param->getOuterLocStart()); // Build the default argument expression. return CXXDefaultArgExpr::Create(Context, CallLoc, Param, Arg); } // If the default expression creates temporaries, we need to // push them to the current stack of expression temporaries so they'll // be properly destroyed. // FIXME: We should really be rebuilding the default argument with new // bound temporaries; see the comment in PR5810. // We don't need to do that with block decls, though, because // blocks in default argument expression can never capture anything. if (isa(Param->getInit())) { // Set the "needs cleanups" bit regardless of whether there are // any explicit objects. ExprNeedsCleanups = true; // Append all the objects to the cleanup list. Right now, this // should always be a no-op, because blocks in default argument // expressions should never be able to capture anything. assert(!cast(Param->getInit())->getNumObjects() && "default argument expression has capturing blocks?"); } // We already type-checked the argument, so we know it works. // Just mark all of the declarations in this potentially-evaluated expression // as being "referenced". MarkDeclarationsReferencedInExpr(Param->getDefaultArg(), /*SkipLocalVariables=*/true); return CXXDefaultArgExpr::Create(Context, CallLoc, Param); } Sema::VariadicCallType Sema::getVariadicCallType(FunctionDecl *FDecl, const FunctionProtoType *Proto, Expr *Fn) { if (Proto && Proto->isVariadic()) { if (dyn_cast_or_null(FDecl)) return VariadicConstructor; else if (Fn && Fn->getType()->isBlockPointerType()) return VariadicBlock; else if (FDecl) { if (CXXMethodDecl *Method = dyn_cast_or_null(FDecl)) if (Method->isInstance()) return VariadicMethod; } else if (Fn && Fn->getType() == Context.BoundMemberTy) return VariadicMethod; return VariadicFunction; } return VariadicDoesNotApply; } namespace { class FunctionCallCCC : public FunctionCallFilterCCC { public: FunctionCallCCC(Sema &SemaRef, const IdentifierInfo *FuncName, unsigned NumArgs, MemberExpr *ME) : FunctionCallFilterCCC(SemaRef, NumArgs, false, ME), FunctionName(FuncName) {} bool ValidateCandidate(const TypoCorrection &candidate) override { if (!candidate.getCorrectionSpecifier() || candidate.getCorrectionAsIdentifierInfo() != FunctionName) { return false; } return FunctionCallFilterCCC::ValidateCandidate(candidate); } private: const IdentifierInfo *const FunctionName; }; } static TypoCorrection TryTypoCorrectionForCall(Sema &S, Expr *Fn, FunctionDecl *FDecl, ArrayRef Args) { MemberExpr *ME = dyn_cast(Fn); DeclarationName FuncName = FDecl->getDeclName(); SourceLocation NameLoc = ME ? ME->getMemberLoc() : Fn->getLocStart(); if (TypoCorrection Corrected = S.CorrectTypo( DeclarationNameInfo(FuncName, NameLoc), Sema::LookupOrdinaryName, S.getScopeForContext(S.CurContext), nullptr, llvm::make_unique(S, FuncName.getAsIdentifierInfo(), Args.size(), ME), Sema::CTK_ErrorRecovery)) { if (NamedDecl *ND = Corrected.getCorrectionDecl()) { if (Corrected.isOverloaded()) { OverloadCandidateSet OCS(NameLoc, OverloadCandidateSet::CSK_Normal); OverloadCandidateSet::iterator Best; for (NamedDecl *CD : Corrected) { if (FunctionDecl *FD = dyn_cast(CD)) S.AddOverloadCandidate(FD, DeclAccessPair::make(FD, AS_none), Args, OCS); } switch (OCS.BestViableFunction(S, NameLoc, Best)) { case OR_Success: ND = Best->Function; Corrected.setCorrectionDecl(ND); break; default: break; } } if (isa(ND) || isa(ND)) { return Corrected; } } } return TypoCorrection(); } /// ConvertArgumentsForCall - Converts the arguments specified in /// Args/NumArgs to the parameter types of the function FDecl with /// function prototype Proto. Call is the call expression itself, and /// Fn is the function expression. For a C++ member function, this /// routine does not attempt to convert the object argument. Returns /// true if the call is ill-formed. bool Sema::ConvertArgumentsForCall(CallExpr *Call, Expr *Fn, FunctionDecl *FDecl, const FunctionProtoType *Proto, ArrayRef Args, SourceLocation RParenLoc, bool IsExecConfig) { // Bail out early if calling a builtin with custom typechecking. if (FDecl) if (unsigned ID = FDecl->getBuiltinID()) if (Context.BuiltinInfo.hasCustomTypechecking(ID)) return false; // C99 6.5.2.2p7 - the arguments are implicitly converted, as if by // assignment, to the types of the corresponding parameter, ... unsigned NumParams = Proto->getNumParams(); bool Invalid = false; unsigned MinArgs = FDecl ? FDecl->getMinRequiredArguments() : NumParams; unsigned FnKind = Fn->getType()->isBlockPointerType() ? 1 /* block */ : (IsExecConfig ? 3 /* kernel function (exec config) */ : 0 /* function */); // If too few arguments are available (and we don't have default // arguments for the remaining parameters), don't make the call. if (Args.size() < NumParams) { if (Args.size() < MinArgs) { TypoCorrection TC; if (FDecl && (TC = TryTypoCorrectionForCall(*this, Fn, FDecl, Args))) { unsigned diag_id = MinArgs == NumParams && !Proto->isVariadic() ? diag::err_typecheck_call_too_few_args_suggest : diag::err_typecheck_call_too_few_args_at_least_suggest; diagnoseTypo(TC, PDiag(diag_id) << FnKind << MinArgs << static_cast(Args.size()) << TC.getCorrectionRange()); } else if (MinArgs == 1 && FDecl && FDecl->getParamDecl(0)->getDeclName()) Diag(RParenLoc, MinArgs == NumParams && !Proto->isVariadic() ? diag::err_typecheck_call_too_few_args_one : diag::err_typecheck_call_too_few_args_at_least_one) << FnKind << FDecl->getParamDecl(0) << Fn->getSourceRange(); else Diag(RParenLoc, MinArgs == NumParams && !Proto->isVariadic() ? diag::err_typecheck_call_too_few_args : diag::err_typecheck_call_too_few_args_at_least) << FnKind << MinArgs << static_cast(Args.size()) << Fn->getSourceRange(); // Emit the location of the prototype. if (!TC && FDecl && !FDecl->getBuiltinID() && !IsExecConfig) Diag(FDecl->getLocStart(), diag::note_callee_decl) << FDecl; return true; } Call->setNumArgs(Context, NumParams); } // If too many are passed and not variadic, error on the extras and drop // them. if (Args.size() > NumParams) { if (!Proto->isVariadic()) { TypoCorrection TC; if (FDecl && (TC = TryTypoCorrectionForCall(*this, Fn, FDecl, Args))) { unsigned diag_id = MinArgs == NumParams && !Proto->isVariadic() ? diag::err_typecheck_call_too_many_args_suggest : diag::err_typecheck_call_too_many_args_at_most_suggest; diagnoseTypo(TC, PDiag(diag_id) << FnKind << NumParams << static_cast(Args.size()) << TC.getCorrectionRange()); } else if (NumParams == 1 && FDecl && FDecl->getParamDecl(0)->getDeclName()) Diag(Args[NumParams]->getLocStart(), MinArgs == NumParams ? diag::err_typecheck_call_too_many_args_one : diag::err_typecheck_call_too_many_args_at_most_one) << FnKind << FDecl->getParamDecl(0) << static_cast(Args.size()) << Fn->getSourceRange() << SourceRange(Args[NumParams]->getLocStart(), Args.back()->getLocEnd()); else Diag(Args[NumParams]->getLocStart(), MinArgs == NumParams ? diag::err_typecheck_call_too_many_args : diag::err_typecheck_call_too_many_args_at_most) << FnKind << NumParams << static_cast(Args.size()) << Fn->getSourceRange() << SourceRange(Args[NumParams]->getLocStart(), Args.back()->getLocEnd()); // Emit the location of the prototype. if (!TC && FDecl && !FDecl->getBuiltinID() && !IsExecConfig) Diag(FDecl->getLocStart(), diag::note_callee_decl) << FDecl; // This deletes the extra arguments. Call->setNumArgs(Context, NumParams); return true; } } SmallVector AllArgs; VariadicCallType CallType = getVariadicCallType(FDecl, Proto, Fn); Invalid = GatherArgumentsForCall(Call->getLocStart(), FDecl, Proto, 0, Args, AllArgs, CallType); if (Invalid) return true; unsigned TotalNumArgs = AllArgs.size(); for (unsigned i = 0; i < TotalNumArgs; ++i) Call->setArg(i, AllArgs[i]); return false; } bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, FunctionDecl *FDecl, const FunctionProtoType *Proto, unsigned FirstParam, ArrayRef Args, SmallVectorImpl &AllArgs, VariadicCallType CallType, bool AllowExplicit, bool IsListInitialization) { unsigned NumParams = Proto->getNumParams(); bool Invalid = false; size_t ArgIx = 0; // Continue to check argument types (even if we have too few/many args). for (unsigned i = FirstParam; i < NumParams; i++) { QualType ProtoArgType = Proto->getParamType(i); Expr *Arg; ParmVarDecl *Param = FDecl ? FDecl->getParamDecl(i) : nullptr; if (ArgIx < Args.size()) { Arg = Args[ArgIx++]; if (RequireCompleteType(Arg->getLocStart(), ProtoArgType, diag::err_call_incomplete_argument, Arg)) return true; // Strip the unbridged-cast placeholder expression off, if applicable. bool CFAudited = false; if (Arg->getType() == Context.ARCUnbridgedCastTy && FDecl && FDecl->hasAttr() && (!Param || !Param->hasAttr())) Arg = stripARCUnbridgedCast(Arg); else if (getLangOpts().ObjCAutoRefCount && FDecl && FDecl->hasAttr() && (!Param || !Param->hasAttr())) CFAudited = true; InitializedEntity Entity = Param ? InitializedEntity::InitializeParameter(Context, Param, ProtoArgType) : InitializedEntity::InitializeParameter( Context, ProtoArgType, Proto->isParamConsumed(i)); // Remember that parameter belongs to a CF audited API. if (CFAudited) Entity.setParameterCFAudited(); ExprResult ArgE = PerformCopyInitialization( Entity, SourceLocation(), Arg, IsListInitialization, AllowExplicit); if (ArgE.isInvalid()) return true; Arg = ArgE.getAs(); } else { assert(Param && "can't use default arguments without a known callee"); ExprResult ArgExpr = BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); if (ArgExpr.isInvalid()) return true; Arg = ArgExpr.getAs(); } // Check for array bounds violations for each argument to the call. This // check only triggers warnings when the argument isn't a more complex Expr // with its own checking, such as a BinaryOperator. CheckArrayAccess(Arg); // Check for violations of C99 static array rules (C99 6.7.5.3p7). CheckStaticArrayArgument(CallLoc, Param, Arg); AllArgs.push_back(Arg); } // If this is a variadic call, handle args passed through "...". if (CallType != VariadicDoesNotApply) { // Assume that extern "C" functions with variadic arguments that // return __unknown_anytype aren't *really* variadic. if (Proto->getReturnType() == Context.UnknownAnyTy && FDecl && FDecl->isExternC()) { for (Expr *A : Args.slice(ArgIx)) { QualType paramType; // ignored ExprResult arg = checkUnknownAnyArg(CallLoc, A, paramType); Invalid |= arg.isInvalid(); AllArgs.push_back(arg.get()); } // Otherwise do argument promotion, (C99 6.5.2.2p7). } else { for (Expr *A : Args.slice(ArgIx)) { ExprResult Arg = DefaultVariadicArgumentPromotion(A, CallType, FDecl); Invalid |= Arg.isInvalid(); AllArgs.push_back(Arg.get()); } } // Check for array bounds violations. for (Expr *A : Args.slice(ArgIx)) CheckArrayAccess(A); } return Invalid; } static void DiagnoseCalleeStaticArrayParam(Sema &S, ParmVarDecl *PVD) { TypeLoc TL = PVD->getTypeSourceInfo()->getTypeLoc(); if (DecayedTypeLoc DTL = TL.getAs()) TL = DTL.getOriginalLoc(); if (ArrayTypeLoc ATL = TL.getAs()) S.Diag(PVD->getLocation(), diag::note_callee_static_array) << ATL.getLocalSourceRange(); } /// CheckStaticArrayArgument - If the given argument corresponds to a static /// array parameter, check that it is non-null, and that if it is formed by /// array-to-pointer decay, the underlying array is sufficiently large. /// /// C99 6.7.5.3p7: If the keyword static also appears within the [ and ] of the /// array type derivation, then for each call to the function, the value of the /// corresponding actual argument shall provide access to the first element of /// an array with at least as many elements as specified by the size expression. void Sema::CheckStaticArrayArgument(SourceLocation CallLoc, ParmVarDecl *Param, const Expr *ArgExpr) { // Static array parameters are not supported in C++. if (!Param || getLangOpts().CPlusPlus) return; QualType OrigTy = Param->getOriginalType(); const ArrayType *AT = Context.getAsArrayType(OrigTy); if (!AT || AT->getSizeModifier() != ArrayType::Static) return; if (ArgExpr->isNullPointerConstant(Context, Expr::NPC_NeverValueDependent)) { Diag(CallLoc, diag::warn_null_arg) << ArgExpr->getSourceRange(); DiagnoseCalleeStaticArrayParam(*this, Param); return; } const ConstantArrayType *CAT = dyn_cast(AT); if (!CAT) return; const ConstantArrayType *ArgCAT = Context.getAsConstantArrayType(ArgExpr->IgnoreParenImpCasts()->getType()); if (!ArgCAT) return; if (ArgCAT->getSize().ult(CAT->getSize())) { Diag(CallLoc, diag::warn_static_array_too_small) << ArgExpr->getSourceRange() << (unsigned) ArgCAT->getSize().getZExtValue() << (unsigned) CAT->getSize().getZExtValue(); DiagnoseCalleeStaticArrayParam(*this, Param); } } /// Given a function expression of unknown-any type, try to rebuild it /// to have a function type. static ExprResult rebuildUnknownAnyFunction(Sema &S, Expr *fn); /// Is the given type a placeholder that we need to lower out /// immediately during argument processing? static bool isPlaceholderToRemoveAsArg(QualType type) { // Placeholders are never sugared. const BuiltinType *placeholder = dyn_cast(type); if (!placeholder) return false; switch (placeholder->getKind()) { // Ignore all the non-placeholder types. #define PLACEHOLDER_TYPE(ID, SINGLETON_ID) #define BUILTIN_TYPE(ID, SINGLETON_ID) case BuiltinType::ID: #include "clang/AST/BuiltinTypes.def" return false; // We cannot lower out overload sets; they might validly be resolved // by the call machinery. case BuiltinType::Overload: return false; // Unbridged casts in ARC can be handled in some call positions and // should be left in place. case BuiltinType::ARCUnbridgedCast: return false; // Pseudo-objects should be converted as soon as possible. case BuiltinType::PseudoObject: return true; // The debugger mode could theoretically but currently does not try // to resolve unknown-typed arguments based on known parameter types. case BuiltinType::UnknownAny: return true; // These are always invalid as call arguments and should be reported. case BuiltinType::BoundMember: case BuiltinType::BuiltinFn: case BuiltinType::OMPArraySection: return true; } llvm_unreachable("bad builtin type kind"); } /// Check an argument list for placeholders that we won't try to /// handle later. static bool checkArgsForPlaceholders(Sema &S, MultiExprArg args) { // Apply this processing to all the arguments at once instead of // dying at the first failure. bool hasInvalid = false; for (size_t i = 0, e = args.size(); i != e; i++) { if (isPlaceholderToRemoveAsArg(args[i]->getType())) { ExprResult result = S.CheckPlaceholderExpr(args[i]); if (result.isInvalid()) hasInvalid = true; else args[i] = result.get(); } else if (hasInvalid) { (void)S.CorrectDelayedTyposInExpr(args[i]); } } return hasInvalid; } /// If a builtin function has a pointer argument with no explicit address /// space, than it should be able to accept a pointer to any address /// space as input. In order to do this, we need to replace the /// standard builtin declaration with one that uses the same address space /// as the call. /// /// \returns nullptr If this builtin is not a candidate for a rewrite i.e. /// it does not contain any pointer arguments without /// an address space qualifer. Otherwise the rewritten /// FunctionDecl is returned. /// TODO: Handle pointer return types. static FunctionDecl *rewriteBuiltinFunctionDecl(Sema *Sema, ASTContext &Context, const FunctionDecl *FDecl, MultiExprArg ArgExprs) { QualType DeclType = FDecl->getType(); const FunctionProtoType *FT = dyn_cast(DeclType); if (!Context.BuiltinInfo.hasPtrArgsOrResult(FDecl->getBuiltinID()) || !FT || FT->isVariadic() || ArgExprs.size() != FT->getNumParams()) return nullptr; bool NeedsNewDecl = false; unsigned i = 0; SmallVector OverloadParams; for (QualType ParamType : FT->param_types()) { // Convert array arguments to pointer to simplify type lookup. Expr *Arg = Sema->DefaultFunctionArrayLvalueConversion(ArgExprs[i++]).get(); QualType ArgType = Arg->getType(); if (!ParamType->isPointerType() || ParamType.getQualifiers().hasAddressSpace() || !ArgType->isPointerType() || !ArgType->getPointeeType().getQualifiers().hasAddressSpace()) { OverloadParams.push_back(ParamType); continue; } NeedsNewDecl = true; unsigned AS = ArgType->getPointeeType().getQualifiers().getAddressSpace(); QualType PointeeType = ParamType->getPointeeType(); PointeeType = Context.getAddrSpaceQualType(PointeeType, AS); OverloadParams.push_back(Context.getPointerType(PointeeType)); } if (!NeedsNewDecl) return nullptr; FunctionProtoType::ExtProtoInfo EPI; QualType OverloadTy = Context.getFunctionType(FT->getReturnType(), OverloadParams, EPI); DeclContext *Parent = Context.getTranslationUnitDecl(); FunctionDecl *OverloadDecl = FunctionDecl::Create(Context, Parent, FDecl->getLocation(), FDecl->getLocation(), FDecl->getIdentifier(), OverloadTy, /*TInfo=*/nullptr, SC_Extern, false, /*hasPrototype=*/true); SmallVector Params; FT = cast(OverloadTy); for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) { QualType ParamType = FT->getParamType(i); ParmVarDecl *Parm = ParmVarDecl::Create(Context, OverloadDecl, SourceLocation(), SourceLocation(), nullptr, ParamType, /*TInfo=*/nullptr, SC_None, nullptr); Parm->setScopeInfo(0, i); Params.push_back(Parm); } OverloadDecl->setParams(Params); return OverloadDecl; } /// ActOnCallExpr - Handle a call to Fn with the specified array of arguments. /// This provides the location of the left/right parens and a list of comma /// locations. ExprResult Sema::ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc, MultiExprArg ArgExprs, SourceLocation RParenLoc, Expr *ExecConfig, bool IsExecConfig) { // Since this might be a postfix expression, get rid of ParenListExprs. ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Fn); if (Result.isInvalid()) return ExprError(); Fn = Result.get(); if (checkArgsForPlaceholders(*this, ArgExprs)) return ExprError(); if (getLangOpts().CPlusPlus) { // If this is a pseudo-destructor expression, build the call immediately. if (isa(Fn)) { if (!ArgExprs.empty()) { // Pseudo-destructor calls should not have any arguments. Diag(Fn->getLocStart(), diag::err_pseudo_dtor_call_with_args) << FixItHint::CreateRemoval( SourceRange(ArgExprs.front()->getLocStart(), ArgExprs.back()->getLocEnd())); } return new (Context) CallExpr(Context, Fn, None, Context.VoidTy, VK_RValue, RParenLoc); } if (Fn->getType() == Context.PseudoObjectTy) { ExprResult result = CheckPlaceholderExpr(Fn); if (result.isInvalid()) return ExprError(); Fn = result.get(); } // Determine whether this is a dependent call inside a C++ template, // in which case we won't do any semantic analysis now. // FIXME: Will need to cache the results of name lookup (including ADL) in // Fn. bool Dependent = false; if (Fn->isTypeDependent()) Dependent = true; else if (Expr::hasAnyTypeDependentArguments(ArgExprs)) Dependent = true; if (Dependent) { if (ExecConfig) { return new (Context) CUDAKernelCallExpr( Context, Fn, cast(ExecConfig), ArgExprs, Context.DependentTy, VK_RValue, RParenLoc); } else { return new (Context) CallExpr( Context, Fn, ArgExprs, Context.DependentTy, VK_RValue, RParenLoc); } } // Determine whether this is a call to an object (C++ [over.call.object]). if (Fn->getType()->isRecordType()) return BuildCallToObjectOfClassType(S, Fn, LParenLoc, ArgExprs, RParenLoc); if (Fn->getType() == Context.UnknownAnyTy) { ExprResult result = rebuildUnknownAnyFunction(*this, Fn); if (result.isInvalid()) return ExprError(); Fn = result.get(); } if (Fn->getType() == Context.BoundMemberTy) { return BuildCallToMemberFunction(S, Fn, LParenLoc, ArgExprs, RParenLoc); } } // Check for overloaded calls. This can happen even in C due to extensions. if (Fn->getType() == Context.OverloadTy) { OverloadExpr::FindResult find = OverloadExpr::find(Fn); // We aren't supposed to apply this logic for if there's an '&' involved. if (!find.HasFormOfMemberPointer) { OverloadExpr *ovl = find.Expression; if (isa(ovl)) { UnresolvedLookupExpr *ULE = cast(ovl); return BuildOverloadedCallExpr(S, Fn, ULE, LParenLoc, ArgExprs, RParenLoc, ExecConfig); } else { return BuildCallToMemberFunction(S, Fn, LParenLoc, ArgExprs, RParenLoc); } } } // If we're directly calling a function, get the appropriate declaration. if (Fn->getType() == Context.UnknownAnyTy) { ExprResult result = rebuildUnknownAnyFunction(*this, Fn); if (result.isInvalid()) return ExprError(); Fn = result.get(); } Expr *NakedFn = Fn->IgnoreParens(); NamedDecl *NDecl = nullptr; if (UnaryOperator *UnOp = dyn_cast(NakedFn)) if (UnOp->getOpcode() == UO_AddrOf) NakedFn = UnOp->getSubExpr()->IgnoreParens(); if (isa(NakedFn)) { NDecl = cast(NakedFn)->getDecl(); FunctionDecl *FDecl = dyn_cast(NDecl); if (FDecl && FDecl->getBuiltinID()) { // Rewrite the function decl for this builtin by replacing paramaters // with no explicit address space with the address space of the arguments // in ArgExprs. if ((FDecl = rewriteBuiltinFunctionDecl(this, Context, FDecl, ArgExprs))) { NDecl = FDecl; Fn = DeclRefExpr::Create(Context, FDecl->getQualifierLoc(), SourceLocation(), FDecl, false, SourceLocation(), FDecl->getType(), Fn->getValueKind(), FDecl); } } } else if (isa(NakedFn)) NDecl = cast(NakedFn)->getMemberDecl(); if (FunctionDecl *FD = dyn_cast_or_null(NDecl)) { if (FD->hasAttr()) { if (const EnableIfAttr *Attr = CheckEnableIf(FD, ArgExprs, true)) { Diag(Fn->getLocStart(), isa(FD) ? diag::err_ovl_no_viable_member_function_in_call : diag::err_ovl_no_viable_function_in_call) << FD << FD->getSourceRange(); Diag(FD->getLocation(), diag::note_ovl_candidate_disabled_by_enable_if_attr) << Attr->getCond()->getSourceRange() << Attr->getMessage(); } } } return BuildResolvedCallExpr(Fn, NDecl, LParenLoc, ArgExprs, RParenLoc, ExecConfig, IsExecConfig); } /// ActOnAsTypeExpr - create a new asType (bitcast) from the arguments. /// /// __builtin_astype( value, dst type ) /// ExprResult Sema::ActOnAsTypeExpr(Expr *E, ParsedType ParsedDestTy, SourceLocation BuiltinLoc, SourceLocation RParenLoc) { ExprValueKind VK = VK_RValue; ExprObjectKind OK = OK_Ordinary; QualType DstTy = GetTypeFromParser(ParsedDestTy); QualType SrcTy = E->getType(); if (Context.getTypeSize(DstTy) != Context.getTypeSize(SrcTy)) return ExprError(Diag(BuiltinLoc, diag::err_invalid_astype_of_different_size) << DstTy << SrcTy << E->getSourceRange()); return new (Context) AsTypeExpr(E, DstTy, VK, OK, BuiltinLoc, RParenLoc); } /// ActOnConvertVectorExpr - create a new convert-vector expression from the /// provided arguments. /// /// __builtin_convertvector( value, dst type ) /// ExprResult Sema::ActOnConvertVectorExpr(Expr *E, ParsedType ParsedDestTy, SourceLocation BuiltinLoc, SourceLocation RParenLoc) { TypeSourceInfo *TInfo; GetTypeFromParser(ParsedDestTy, &TInfo); return SemaConvertVectorExpr(E, TInfo, BuiltinLoc, RParenLoc); } /// BuildResolvedCallExpr - Build a call to a resolved expression, /// i.e. an expression not of \p OverloadTy. The expression should /// unary-convert to an expression of function-pointer or /// block-pointer type. /// /// \param NDecl the declaration being called, if available ExprResult Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, SourceLocation LParenLoc, ArrayRef Args, SourceLocation RParenLoc, Expr *Config, bool IsExecConfig) { FunctionDecl *FDecl = dyn_cast_or_null(NDecl); unsigned BuiltinID = (FDecl ? FDecl->getBuiltinID() : 0); // Promote the function operand. // We special-case function promotion here because we only allow promoting // builtin functions to function pointers in the callee of a call. ExprResult Result; if (BuiltinID && Fn->getType()->isSpecificBuiltinType(BuiltinType::BuiltinFn)) { Result = ImpCastExprToType(Fn, Context.getPointerType(FDecl->getType()), CK_BuiltinFnToFnPtr).get(); } else { Result = CallExprUnaryConversions(Fn); } if (Result.isInvalid()) return ExprError(); Fn = Result.get(); // Make the call expr early, before semantic checks. This guarantees cleanup // of arguments and function on error. CallExpr *TheCall; if (Config) TheCall = new (Context) CUDAKernelCallExpr(Context, Fn, cast(Config), Args, Context.BoolTy, VK_RValue, RParenLoc); else TheCall = new (Context) CallExpr(Context, Fn, Args, Context.BoolTy, VK_RValue, RParenLoc); if (!getLangOpts().CPlusPlus) { // C cannot always handle TypoExpr nodes in builtin calls and direct // function calls as their argument checking don't necessarily handle // dependent types properly, so make sure any TypoExprs have been // dealt with. ExprResult Result = CorrectDelayedTyposInExpr(TheCall); if (!Result.isUsable()) return ExprError(); TheCall = dyn_cast(Result.get()); if (!TheCall) return Result; Args = llvm::makeArrayRef(TheCall->getArgs(), TheCall->getNumArgs()); } // Bail out early if calling a builtin with custom typechecking. if (BuiltinID && Context.BuiltinInfo.hasCustomTypechecking(BuiltinID)) return CheckBuiltinFunctionCall(FDecl, BuiltinID, TheCall); retry: const FunctionType *FuncT; if (const PointerType *PT = Fn->getType()->getAs()) { // C99 6.5.2.2p1 - "The expression that denotes the called function shall // have type pointer to function". FuncT = PT->getPointeeType()->getAs(); if (!FuncT) return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) << Fn->getType() << Fn->getSourceRange()); } else if (const BlockPointerType *BPT = Fn->getType()->getAs()) { FuncT = BPT->getPointeeType()->castAs(); } else { // Handle calls to expressions of unknown-any type. if (Fn->getType() == Context.UnknownAnyTy) { ExprResult rewrite = rebuildUnknownAnyFunction(*this, Fn); if (rewrite.isInvalid()) return ExprError(); Fn = rewrite.get(); TheCall->setCallee(Fn); goto retry; } return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) << Fn->getType() << Fn->getSourceRange()); } if (getLangOpts().CUDA) { if (Config) { // CUDA: Kernel calls must be to global functions if (FDecl && !FDecl->hasAttr()) return ExprError(Diag(LParenLoc,diag::err_kern_call_not_global_function) << FDecl->getName() << Fn->getSourceRange()); // CUDA: Kernel function must have 'void' return type if (!FuncT->getReturnType()->isVoidType()) return ExprError(Diag(LParenLoc, diag::err_kern_type_not_void_return) << Fn->getType() << Fn->getSourceRange()); } else { // CUDA: Calls to global functions must be configured if (FDecl && FDecl->hasAttr()) return ExprError(Diag(LParenLoc, diag::err_global_call_not_config) << FDecl->getName() << Fn->getSourceRange()); } } // Check for a valid return type if (CheckCallReturnType(FuncT->getReturnType(), Fn->getLocStart(), TheCall, FDecl)) return ExprError(); // We know the result type of the call, set it. TheCall->setType(FuncT->getCallResultType(Context)); TheCall->setValueKind(Expr::getValueKindForType(FuncT->getReturnType())); const FunctionProtoType *Proto = dyn_cast(FuncT); if (Proto) { if (ConvertArgumentsForCall(TheCall, Fn, FDecl, Proto, Args, RParenLoc, IsExecConfig)) return ExprError(); } else { assert(isa(FuncT) && "Unknown FunctionType!"); if (FDecl) { // Check if we have too few/too many template arguments, based // on our knowledge of the function definition. const FunctionDecl *Def = nullptr; if (FDecl->hasBody(Def) && Args.size() != Def->param_size()) { Proto = Def->getType()->getAs(); if (!Proto || !(Proto->isVariadic() && Args.size() >= Def->param_size())) Diag(RParenLoc, diag::warn_call_wrong_number_of_arguments) << (Args.size() > Def->param_size()) << FDecl << Fn->getSourceRange(); } // If the function we're calling isn't a function prototype, but we have // a function prototype from a prior declaratiom, use that prototype. if (!FDecl->hasPrototype()) Proto = FDecl->getType()->getAs(); } // Promote the arguments (C99 6.5.2.2p6). for (unsigned i = 0, e = Args.size(); i != e; i++) { Expr *Arg = Args[i]; if (Proto && i < Proto->getNumParams()) { InitializedEntity Entity = InitializedEntity::InitializeParameter( Context, Proto->getParamType(i), Proto->isParamConsumed(i)); ExprResult ArgE = PerformCopyInitialization(Entity, SourceLocation(), Arg); if (ArgE.isInvalid()) return true; Arg = ArgE.getAs(); } else { ExprResult ArgE = DefaultArgumentPromotion(Arg); if (ArgE.isInvalid()) return true; Arg = ArgE.getAs(); } if (RequireCompleteType(Arg->getLocStart(), Arg->getType(), diag::err_call_incomplete_argument, Arg)) return ExprError(); TheCall->setArg(i, Arg); } } if (CXXMethodDecl *Method = dyn_cast_or_null(FDecl)) if (!Method->isStatic()) return ExprError(Diag(LParenLoc, diag::err_member_call_without_object) << Fn->getSourceRange()); // Check for sentinels if (NDecl) DiagnoseSentinelCalls(NDecl, LParenLoc, Args); // Do special checking on direct calls to functions. if (FDecl) { if (CheckFunctionCall(FDecl, TheCall, Proto)) return ExprError(); if (BuiltinID) return CheckBuiltinFunctionCall(FDecl, BuiltinID, TheCall); } else if (NDecl) { if (CheckPointerCall(NDecl, TheCall, Proto)) return ExprError(); } else { if (CheckOtherCall(TheCall, Proto)) return ExprError(); } return MaybeBindToTemporary(TheCall); } ExprResult Sema::ActOnCompoundLiteral(SourceLocation LParenLoc, ParsedType Ty, SourceLocation RParenLoc, Expr *InitExpr) { assert(Ty && "ActOnCompoundLiteral(): missing type"); assert(InitExpr && "ActOnCompoundLiteral(): missing expression"); TypeSourceInfo *TInfo; QualType literalType = GetTypeFromParser(Ty, &TInfo); if (!TInfo) TInfo = Context.getTrivialTypeSourceInfo(literalType); return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, InitExpr); } ExprResult Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo, SourceLocation RParenLoc, Expr *LiteralExpr) { QualType literalType = TInfo->getType(); if (literalType->isArrayType()) { if (RequireCompleteType(LParenLoc, Context.getBaseElementType(literalType), diag::err_illegal_decl_array_incomplete_type, SourceRange(LParenLoc, LiteralExpr->getSourceRange().getEnd()))) return ExprError(); if (literalType->isVariableArrayType()) return ExprError(Diag(LParenLoc, diag::err_variable_object_no_init) << SourceRange(LParenLoc, LiteralExpr->getSourceRange().getEnd())); } else if (!literalType->isDependentType() && RequireCompleteType(LParenLoc, literalType, diag::err_typecheck_decl_incomplete_type, SourceRange(LParenLoc, LiteralExpr->getSourceRange().getEnd()))) return ExprError(); InitializedEntity Entity = InitializedEntity::InitializeCompoundLiteralInit(TInfo); InitializationKind Kind = InitializationKind::CreateCStyleCast(LParenLoc, SourceRange(LParenLoc, RParenLoc), /*InitList=*/true); InitializationSequence InitSeq(*this, Entity, Kind, LiteralExpr); ExprResult Result = InitSeq.Perform(*this, Entity, Kind, LiteralExpr, &literalType); if (Result.isInvalid()) return ExprError(); LiteralExpr = Result.get(); bool isFileScope = getCurFunctionOrMethodDecl() == nullptr; if (isFileScope && !LiteralExpr->isTypeDependent() && !LiteralExpr->isValueDependent() && !literalType->isDependentType()) { // 6.5.2.5p3 if (CheckForConstantInitializer(LiteralExpr, literalType)) return ExprError(); } // In C, compound literals are l-values for some reason. ExprValueKind VK = getLangOpts().CPlusPlus ? VK_RValue : VK_LValue; return MaybeBindToTemporary( new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType, VK, LiteralExpr, isFileScope)); } ExprResult Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg InitArgList, SourceLocation RBraceLoc) { // Immediately handle non-overload placeholders. Overloads can be // resolved contextually, but everything else here can't. for (unsigned I = 0, E = InitArgList.size(); I != E; ++I) { if (InitArgList[I]->getType()->isNonOverloadPlaceholderType()) { ExprResult result = CheckPlaceholderExpr(InitArgList[I]); // Ignore failures; dropping the entire initializer list because // of one failure would be terrible for indexing/etc. if (result.isInvalid()) continue; InitArgList[I] = result.get(); } } // Semantic analysis for initializers is done by ActOnDeclarator() and // CheckInitializer() - it requires knowledge of the object being intialized. InitListExpr *E = new (Context) InitListExpr(Context, LBraceLoc, InitArgList, RBraceLoc); E->setType(Context.VoidTy); // FIXME: just a place holder for now. return E; } /// Do an explicit extend of the given block pointer if we're in ARC. void Sema::maybeExtendBlockObject(ExprResult &E) { assert(E.get()->getType()->isBlockPointerType()); assert(E.get()->isRValue()); // Only do this in an r-value context. if (!getLangOpts().ObjCAutoRefCount) return; E = ImplicitCastExpr::Create(Context, E.get()->getType(), CK_ARCExtendBlockObject, E.get(), /*base path*/ nullptr, VK_RValue); ExprNeedsCleanups = true; } /// Prepare a conversion of the given expression to an ObjC object /// pointer type. CastKind Sema::PrepareCastToObjCObjectPointer(ExprResult &E) { QualType type = E.get()->getType(); if (type->isObjCObjectPointerType()) { return CK_BitCast; } else if (type->isBlockPointerType()) { maybeExtendBlockObject(E); return CK_BlockPointerToObjCPointerCast; } else { assert(type->isPointerType()); return CK_CPointerToObjCPointerCast; } } /// Prepares for a scalar cast, performing all the necessary stages /// except the final cast and returning the kind required. CastKind Sema::PrepareScalarCast(ExprResult &Src, QualType DestTy) { // Both Src and Dest are scalar types, i.e. arithmetic or pointer. // Also, callers should have filtered out the invalid cases with // pointers. Everything else should be possible. QualType SrcTy = Src.get()->getType(); if (Context.hasSameUnqualifiedType(SrcTy, DestTy)) return CK_NoOp; switch (Type::ScalarTypeKind SrcKind = SrcTy->getScalarTypeKind()) { case Type::STK_MemberPointer: llvm_unreachable("member pointer type in C"); case Type::STK_CPointer: case Type::STK_BlockPointer: case Type::STK_ObjCObjectPointer: switch (DestTy->getScalarTypeKind()) { case Type::STK_CPointer: { unsigned SrcAS = SrcTy->getPointeeType().getAddressSpace(); unsigned DestAS = DestTy->getPointeeType().getAddressSpace(); if (SrcAS != DestAS) return CK_AddressSpaceConversion; return CK_BitCast; } case Type::STK_BlockPointer: return (SrcKind == Type::STK_BlockPointer ? CK_BitCast : CK_AnyPointerToBlockPointerCast); case Type::STK_ObjCObjectPointer: if (SrcKind == Type::STK_ObjCObjectPointer) return CK_BitCast; if (SrcKind == Type::STK_CPointer) return CK_CPointerToObjCPointerCast; maybeExtendBlockObject(Src); return CK_BlockPointerToObjCPointerCast; case Type::STK_Bool: return CK_PointerToBoolean; case Type::STK_Integral: return CK_PointerToIntegral; case Type::STK_Floating: case Type::STK_FloatingComplex: case Type::STK_IntegralComplex: case Type::STK_MemberPointer: llvm_unreachable("illegal cast from pointer"); } llvm_unreachable("Should have returned before this"); case Type::STK_Bool: // casting from bool is like casting from an integer case Type::STK_Integral: switch (DestTy->getScalarTypeKind()) { case Type::STK_CPointer: case Type::STK_ObjCObjectPointer: case Type::STK_BlockPointer: if (Src.get()->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) return CK_NullToPointer; return CK_IntegralToPointer; case Type::STK_Bool: return CK_IntegralToBoolean; case Type::STK_Integral: return CK_IntegralCast; case Type::STK_Floating: return CK_IntegralToFloating; case Type::STK_IntegralComplex: Src = ImpCastExprToType(Src.get(), DestTy->castAs()->getElementType(), CK_IntegralCast); return CK_IntegralRealToComplex; case Type::STK_FloatingComplex: Src = ImpCastExprToType(Src.get(), DestTy->castAs()->getElementType(), CK_IntegralToFloating); return CK_FloatingRealToComplex; case Type::STK_MemberPointer: llvm_unreachable("member pointer type in C"); } llvm_unreachable("Should have returned before this"); case Type::STK_Floating: switch (DestTy->getScalarTypeKind()) { case Type::STK_Floating: return CK_FloatingCast; case Type::STK_Bool: return CK_FloatingToBoolean; case Type::STK_Integral: return CK_FloatingToIntegral; case Type::STK_FloatingComplex: Src = ImpCastExprToType(Src.get(), DestTy->castAs()->getElementType(), CK_FloatingCast); return CK_FloatingRealToComplex; case Type::STK_IntegralComplex: Src = ImpCastExprToType(Src.get(), DestTy->castAs()->getElementType(), CK_FloatingToIntegral); return CK_IntegralRealToComplex; case Type::STK_CPointer: case Type::STK_ObjCObjectPointer: case Type::STK_BlockPointer: llvm_unreachable("valid float->pointer cast?"); case Type::STK_MemberPointer: llvm_unreachable("member pointer type in C"); } llvm_unreachable("Should have returned before this"); case Type::STK_FloatingComplex: switch (DestTy->getScalarTypeKind()) { case Type::STK_FloatingComplex: return CK_FloatingComplexCast; case Type::STK_IntegralComplex: return CK_FloatingComplexToIntegralComplex; case Type::STK_Floating: { QualType ET = SrcTy->castAs()->getElementType(); if (Context.hasSameType(ET, DestTy)) return CK_FloatingComplexToReal; Src = ImpCastExprToType(Src.get(), ET, CK_FloatingComplexToReal); return CK_FloatingCast; } case Type::STK_Bool: return CK_FloatingComplexToBoolean; case Type::STK_Integral: Src = ImpCastExprToType(Src.get(), SrcTy->castAs()->getElementType(), CK_FloatingComplexToReal); return CK_FloatingToIntegral; case Type::STK_CPointer: case Type::STK_ObjCObjectPointer: case Type::STK_BlockPointer: llvm_unreachable("valid complex float->pointer cast?"); case Type::STK_MemberPointer: llvm_unreachable("member pointer type in C"); } llvm_unreachable("Should have returned before this"); case Type::STK_IntegralComplex: switch (DestTy->getScalarTypeKind()) { case Type::STK_FloatingComplex: return CK_IntegralComplexToFloatingComplex; case Type::STK_IntegralComplex: return CK_IntegralComplexCast; case Type::STK_Integral: { QualType ET = SrcTy->castAs()->getElementType(); if (Context.hasSameType(ET, DestTy)) return CK_IntegralComplexToReal; Src = ImpCastExprToType(Src.get(), ET, CK_IntegralComplexToReal); return CK_IntegralCast; } case Type::STK_Bool: return CK_IntegralComplexToBoolean; case Type::STK_Floating: Src = ImpCastExprToType(Src.get(), SrcTy->castAs()->getElementType(), CK_IntegralComplexToReal); return CK_IntegralToFloating; case Type::STK_CPointer: case Type::STK_ObjCObjectPointer: case Type::STK_BlockPointer: llvm_unreachable("valid complex int->pointer cast?"); case Type::STK_MemberPointer: llvm_unreachable("member pointer type in C"); } llvm_unreachable("Should have returned before this"); } llvm_unreachable("Unhandled scalar cast"); } static bool breakDownVectorType(QualType type, uint64_t &len, QualType &eltType) { // Vectors are simple. if (const VectorType *vecType = type->getAs()) { len = vecType->getNumElements(); eltType = vecType->getElementType(); assert(eltType->isScalarType()); return true; } // We allow lax conversion to and from non-vector types, but only if // they're real types (i.e. non-complex, non-pointer scalar types). if (!type->isRealType()) return false; len = 1; eltType = type; return true; } /// Are the two types lax-compatible vector types? That is, given /// that one of them is a vector, do they have equal storage sizes, /// where the storage size is the number of elements times the element /// size? /// /// This will also return false if either of the types is neither a /// vector nor a real type. bool Sema::areLaxCompatibleVectorTypes(QualType srcTy, QualType destTy) { assert(destTy->isVectorType() || srcTy->isVectorType()); // Disallow lax conversions between scalars and ExtVectors (these // conversions are allowed for other vector types because common headers // depend on them). Most scalar OP ExtVector cases are handled by the // splat path anyway, which does what we want (convert, not bitcast). // What this rules out for ExtVectors is crazy things like char4*float. if (srcTy->isScalarType() && destTy->isExtVectorType()) return false; if (destTy->isScalarType() && srcTy->isExtVectorType()) return false; uint64_t srcLen, destLen; QualType srcEltTy, destEltTy; if (!breakDownVectorType(srcTy, srcLen, srcEltTy)) return false; if (!breakDownVectorType(destTy, destLen, destEltTy)) return false; // ASTContext::getTypeSize will return the size rounded up to a // power of 2, so instead of using that, we need to use the raw // element size multiplied by the element count. uint64_t srcEltSize = Context.getTypeSize(srcEltTy); uint64_t destEltSize = Context.getTypeSize(destEltTy); return (srcLen * srcEltSize == destLen * destEltSize); } /// Is this a legal conversion between two types, one of which is /// known to be a vector type? bool Sema::isLaxVectorConversion(QualType srcTy, QualType destTy) { assert(destTy->isVectorType() || srcTy->isVectorType()); if (!Context.getLangOpts().LaxVectorConversions) return false; return areLaxCompatibleVectorTypes(srcTy, destTy); } bool Sema::CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, CastKind &Kind) { assert(VectorTy->isVectorType() && "Not a vector type!"); if (Ty->isVectorType() || Ty->isIntegralType(Context)) { if (!areLaxCompatibleVectorTypes(Ty, VectorTy)) return Diag(R.getBegin(), Ty->isVectorType() ? diag::err_invalid_conversion_between_vectors : diag::err_invalid_conversion_between_vector_and_integer) << VectorTy << Ty << R; } else return Diag(R.getBegin(), diag::err_invalid_conversion_between_vector_and_scalar) << VectorTy << Ty << R; Kind = CK_BitCast; return false; } ExprResult Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *CastExpr, CastKind &Kind) { assert(DestTy->isExtVectorType() && "Not an extended vector type!"); QualType SrcTy = CastExpr->getType(); // If SrcTy is a VectorType, the total size must match to explicitly cast to // an ExtVectorType. // In OpenCL, casts between vectors of different types are not allowed. // (See OpenCL 6.2). if (SrcTy->isVectorType()) { if (!areLaxCompatibleVectorTypes(SrcTy, DestTy) || (getLangOpts().OpenCL && (DestTy.getCanonicalType() != SrcTy.getCanonicalType()))) { Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors) << DestTy << SrcTy << R; return ExprError(); } Kind = CK_BitCast; return CastExpr; } // All non-pointer scalars can be cast to ExtVector type. The appropriate // conversion will take place first from scalar to elt type, and then // splat from elt type to vector. if (SrcTy->isPointerType()) return Diag(R.getBegin(), diag::err_invalid_conversion_between_vector_and_scalar) << DestTy << SrcTy << R; QualType DestElemTy = DestTy->getAs()->getElementType(); ExprResult CastExprRes = CastExpr; CastKind CK = PrepareScalarCast(CastExprRes, DestElemTy); if (CastExprRes.isInvalid()) return ExprError(); CastExpr = ImpCastExprToType(CastExprRes.get(), DestElemTy, CK).get(); Kind = CK_VectorSplat; return CastExpr; } ExprResult Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc, Declarator &D, ParsedType &Ty, SourceLocation RParenLoc, Expr *CastExpr) { assert(!D.isInvalidType() && (CastExpr != nullptr) && "ActOnCastExpr(): missing type or expr"); TypeSourceInfo *castTInfo = GetTypeForDeclaratorCast(D, CastExpr->getType()); if (D.isInvalidType()) return ExprError(); if (getLangOpts().CPlusPlus) { // Check that there are no default arguments (C++ only). CheckExtraCXXDefaultArguments(D); } else { // Make sure any TypoExprs have been dealt with. ExprResult Res = CorrectDelayedTyposInExpr(CastExpr); if (!Res.isUsable()) return ExprError(); CastExpr = Res.get(); } checkUnusedDeclAttributes(D); QualType castType = castTInfo->getType(); Ty = CreateParsedType(castType, castTInfo); bool isVectorLiteral = false; // Check for an altivec or OpenCL literal, // i.e. all the elements are integer constants. ParenExpr *PE = dyn_cast(CastExpr); ParenListExpr *PLE = dyn_cast(CastExpr); if ((getLangOpts().AltiVec || getLangOpts().ZVector || getLangOpts().OpenCL) && castType->isVectorType() && (PE || PLE)) { if (PLE && PLE->getNumExprs() == 0) { Diag(PLE->getExprLoc(), diag::err_altivec_empty_initializer); return ExprError(); } if (PE || PLE->getNumExprs() == 1) { Expr *E = (PE ? PE->getSubExpr() : PLE->getExpr(0)); if (!E->getType()->isVectorType()) isVectorLiteral = true; } else isVectorLiteral = true; } // If this is a vector initializer, '(' type ')' '(' init, ..., init ')' // then handle it as such. if (isVectorLiteral) return BuildVectorLiteral(LParenLoc, RParenLoc, CastExpr, castTInfo); // If the Expr being casted is a ParenListExpr, handle it specially. // This is not an AltiVec-style cast, so turn the ParenListExpr into a // sequence of BinOp comma operators. if (isa(CastExpr)) { ExprResult Result = MaybeConvertParenListExprToParenExpr(S, CastExpr); if (Result.isInvalid()) return ExprError(); CastExpr = Result.get(); } if (getLangOpts().CPlusPlus && !castType->isVoidType() && !getSourceManager().isInSystemMacro(LParenLoc)) Diag(LParenLoc, diag::warn_old_style_cast) << CastExpr->getSourceRange(); CheckTollFreeBridgeCast(castType, CastExpr); CheckObjCBridgeRelatedCast(castType, CastExpr); return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, CastExpr); } ExprResult Sema::BuildVectorLiteral(SourceLocation LParenLoc, SourceLocation RParenLoc, Expr *E, TypeSourceInfo *TInfo) { assert((isa(E) || isa(E)) && "Expected paren or paren list expression"); Expr **exprs; unsigned numExprs; Expr *subExpr; SourceLocation LiteralLParenLoc, LiteralRParenLoc; if (ParenListExpr *PE = dyn_cast(E)) { LiteralLParenLoc = PE->getLParenLoc(); LiteralRParenLoc = PE->getRParenLoc(); exprs = PE->getExprs(); numExprs = PE->getNumExprs(); } else { // isa by assertion at function entrance LiteralLParenLoc = cast(E)->getLParen(); LiteralRParenLoc = cast(E)->getRParen(); subExpr = cast(E)->getSubExpr(); exprs = &subExpr; numExprs = 1; } QualType Ty = TInfo->getType(); assert(Ty->isVectorType() && "Expected vector type"); SmallVector initExprs; const VectorType *VTy = Ty->getAs(); unsigned numElems = Ty->getAs()->getNumElements(); // '(...)' form of vector initialization in AltiVec: the number of // initializers must be one or must match the size of the vector. // If a single value is specified in the initializer then it will be // replicated to all the components of the vector if (VTy->getVectorKind() == VectorType::AltiVecVector) { // The number of initializers must be one or must match the size of the // vector. If a single value is specified in the initializer then it will // be replicated to all the components of the vector if (numExprs == 1) { QualType ElemTy = Ty->getAs()->getElementType(); ExprResult Literal = DefaultLvalueConversion(exprs[0]); if (Literal.isInvalid()) return ExprError(); Literal = ImpCastExprToType(Literal.get(), ElemTy, PrepareScalarCast(Literal, ElemTy)); return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, Literal.get()); } else if (numExprs < numElems) { Diag(E->getExprLoc(), diag::err_incorrect_number_of_vector_initializers); return ExprError(); } else initExprs.append(exprs, exprs + numExprs); } else { // For OpenCL, when the number of initializers is a single value, // it will be replicated to all components of the vector. if (getLangOpts().OpenCL && VTy->getVectorKind() == VectorType::GenericVector && numExprs == 1) { QualType ElemTy = Ty->getAs()->getElementType(); ExprResult Literal = DefaultLvalueConversion(exprs[0]); if (Literal.isInvalid()) return ExprError(); Literal = ImpCastExprToType(Literal.get(), ElemTy, PrepareScalarCast(Literal, ElemTy)); return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, Literal.get()); } initExprs.append(exprs, exprs + numExprs); } // FIXME: This means that pretty-printing the final AST will produce curly // braces instead of the original commas. InitListExpr *initE = new (Context) InitListExpr(Context, LiteralLParenLoc, initExprs, LiteralRParenLoc); initE->setType(Ty); return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, initE); } /// This is not an AltiVec-style cast or or C++ direct-initialization, so turn /// the ParenListExpr into a sequence of comma binary operators. ExprResult Sema::MaybeConvertParenListExprToParenExpr(Scope *S, Expr *OrigExpr) { ParenListExpr *E = dyn_cast(OrigExpr); if (!E) return OrigExpr; ExprResult Result(E->getExpr(0)); for (unsigned i = 1, e = E->getNumExprs(); i != e && !Result.isInvalid(); ++i) Result = ActOnBinOp(S, E->getExprLoc(), tok::comma, Result.get(), E->getExpr(i)); if (Result.isInvalid()) return ExprError(); return ActOnParenExpr(E->getLParenLoc(), E->getRParenLoc(), Result.get()); } ExprResult Sema::ActOnParenListExpr(SourceLocation L, SourceLocation R, MultiExprArg Val) { Expr *expr = new (Context) ParenListExpr(Context, L, Val, R); return expr; } /// \brief Emit a specialized diagnostic when one expression is a null pointer /// constant and the other is not a pointer. Returns true if a diagnostic is /// emitted. bool Sema::DiagnoseConditionalForNull(Expr *LHSExpr, Expr *RHSExpr, SourceLocation QuestionLoc) { Expr *NullExpr = LHSExpr; Expr *NonPointerExpr = RHSExpr; Expr::NullPointerConstantKind NullKind = NullExpr->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull); if (NullKind == Expr::NPCK_NotNull) { NullExpr = RHSExpr; NonPointerExpr = LHSExpr; NullKind = NullExpr->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull); } if (NullKind == Expr::NPCK_NotNull) return false; if (NullKind == Expr::NPCK_ZeroExpression) return false; if (NullKind == Expr::NPCK_ZeroLiteral) { // In this case, check to make sure that we got here from a "NULL" // string in the source code. NullExpr = NullExpr->IgnoreParenImpCasts(); SourceLocation loc = NullExpr->getExprLoc(); if (!findMacroSpelling(loc, "NULL")) return false; } int DiagType = (NullKind == Expr::NPCK_CXX11_nullptr); Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands_null) << NonPointerExpr->getType() << DiagType << NonPointerExpr->getSourceRange(); return true; } /// \brief Return false if the condition expression is valid, true otherwise. static bool checkCondition(Sema &S, Expr *Cond, SourceLocation QuestionLoc) { QualType CondTy = Cond->getType(); // OpenCL v1.1 s6.3.i says the condition cannot be a floating point type. if (S.getLangOpts().OpenCL && CondTy->isFloatingType()) { S.Diag(QuestionLoc, diag::err_typecheck_cond_expect_nonfloat) << CondTy << Cond->getSourceRange(); return true; } // C99 6.5.15p2 if (CondTy->isScalarType()) return false; S.Diag(QuestionLoc, diag::err_typecheck_cond_expect_scalar) << CondTy << Cond->getSourceRange(); return true; } /// \brief Handle when one or both operands are void type. static QualType checkConditionalVoidType(Sema &S, ExprResult &LHS, ExprResult &RHS) { Expr *LHSExpr = LHS.get(); Expr *RHSExpr = RHS.get(); if (!LHSExpr->getType()->isVoidType()) S.Diag(RHSExpr->getLocStart(), diag::ext_typecheck_cond_one_void) << RHSExpr->getSourceRange(); if (!RHSExpr->getType()->isVoidType()) S.Diag(LHSExpr->getLocStart(), diag::ext_typecheck_cond_one_void) << LHSExpr->getSourceRange(); LHS = S.ImpCastExprToType(LHS.get(), S.Context.VoidTy, CK_ToVoid); RHS = S.ImpCastExprToType(RHS.get(), S.Context.VoidTy, CK_ToVoid); return S.Context.VoidTy; } /// \brief Return false if the NullExpr can be promoted to PointerTy, /// true otherwise. static bool checkConditionalNullPointer(Sema &S, ExprResult &NullExpr, QualType PointerTy) { if ((!PointerTy->isAnyPointerType() && !PointerTy->isBlockPointerType()) || !NullExpr.get()->isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNull)) return true; NullExpr = S.ImpCastExprToType(NullExpr.get(), PointerTy, CK_NullToPointer); return false; } /// \brief Checks compatibility between two pointers and return the resulting /// type. static QualType checkConditionalPointerCompatibility(Sema &S, ExprResult &LHS, ExprResult &RHS, SourceLocation Loc) { QualType LHSTy = LHS.get()->getType(); QualType RHSTy = RHS.get()->getType(); if (S.Context.hasSameType(LHSTy, RHSTy)) { // Two identical pointers types are always compatible. return LHSTy; } QualType lhptee, rhptee; // Get the pointee types. bool IsBlockPointer = false; if (const BlockPointerType *LHSBTy = LHSTy->getAs()) { lhptee = LHSBTy->getPointeeType(); rhptee = RHSTy->castAs()->getPointeeType(); IsBlockPointer = true; } else { lhptee = LHSTy->castAs()->getPointeeType(); rhptee = RHSTy->castAs()->getPointeeType(); } // C99 6.5.15p6: If both operands are pointers to compatible types or to // differently qualified versions of compatible types, the result type is // a pointer to an appropriately qualified version of the composite // type. // Only CVR-qualifiers exist in the standard, and the differently-qualified // clause doesn't make sense for our extensions. E.g. address space 2 should // be incompatible with address space 3: they may live on different devices or // anything. Qualifiers lhQual = lhptee.getQualifiers(); Qualifiers rhQual = rhptee.getQualifiers(); unsigned MergedCVRQual = lhQual.getCVRQualifiers() | rhQual.getCVRQualifiers(); lhQual.removeCVRQualifiers(); rhQual.removeCVRQualifiers(); lhptee = S.Context.getQualifiedType(lhptee.getUnqualifiedType(), lhQual); rhptee = S.Context.getQualifiedType(rhptee.getUnqualifiedType(), rhQual); QualType CompositeTy = S.Context.mergeTypes(lhptee, rhptee); if (CompositeTy.isNull()) { S.Diag(Loc, diag::ext_typecheck_cond_incompatible_pointers) << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); // In this situation, we assume void* type. No especially good // reason, but this is what gcc does, and we do have to pick // to get a consistent AST. QualType incompatTy = S.Context.getPointerType(S.Context.VoidTy); LHS = S.ImpCastExprToType(LHS.get(), incompatTy, CK_BitCast); RHS = S.ImpCastExprToType(RHS.get(), incompatTy, CK_BitCast); return incompatTy; } // The pointer types are compatible. QualType ResultTy = CompositeTy.withCVRQualifiers(MergedCVRQual); if (IsBlockPointer) ResultTy = S.Context.getBlockPointerType(ResultTy); else ResultTy = S.Context.getPointerType(ResultTy); LHS = S.ImpCastExprToType(LHS.get(), ResultTy, CK_BitCast); RHS = S.ImpCastExprToType(RHS.get(), ResultTy, CK_BitCast); return ResultTy; } /// \brief Return the resulting type when the operands are both block pointers. static QualType checkConditionalBlockPointerCompatibility(Sema &S, ExprResult &LHS, ExprResult &RHS, SourceLocation Loc) { QualType LHSTy = LHS.get()->getType(); QualType RHSTy = RHS.get()->getType(); if (!LHSTy->isBlockPointerType() || !RHSTy->isBlockPointerType()) { if (LHSTy->isVoidPointerType() || RHSTy->isVoidPointerType()) { QualType destType = S.Context.getPointerType(S.Context.VoidTy); LHS = S.ImpCastExprToType(LHS.get(), destType, CK_BitCast); RHS = S.ImpCastExprToType(RHS.get(), destType, CK_BitCast); return destType; } S.Diag(Loc, diag::err_typecheck_cond_incompatible_operands) << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } // We have 2 block pointer types. return checkConditionalPointerCompatibility(S, LHS, RHS, Loc); } /// \brief Return the resulting type when the operands are both pointers. static QualType checkConditionalObjectPointersCompatibility(Sema &S, ExprResult &LHS, ExprResult &RHS, SourceLocation Loc) { // get the pointer types QualType LHSTy = LHS.get()->getType(); QualType RHSTy = RHS.get()->getType(); // get the "pointed to" types QualType lhptee = LHSTy->getAs()->getPointeeType(); QualType rhptee = RHSTy->getAs()->getPointeeType(); // ignore qualifiers on void (C99 6.5.15p3, clause 6) if (lhptee->isVoidType() && rhptee->isIncompleteOrObjectType()) { // Figure out necessary qualifiers (C99 6.5.15p6) QualType destPointee = S.Context.getQualifiedType(lhptee, rhptee.getQualifiers()); QualType destType = S.Context.getPointerType(destPointee); // Add qualifiers if necessary. LHS = S.ImpCastExprToType(LHS.get(), destType, CK_NoOp); // Promote to void*. RHS = S.ImpCastExprToType(RHS.get(), destType, CK_BitCast); return destType; } if (rhptee->isVoidType() && lhptee->isIncompleteOrObjectType()) { QualType destPointee = S.Context.getQualifiedType(rhptee, lhptee.getQualifiers()); QualType destType = S.Context.getPointerType(destPointee); // Add qualifiers if necessary. RHS = S.ImpCastExprToType(RHS.get(), destType, CK_NoOp); // Promote to void*. LHS = S.ImpCastExprToType(LHS.get(), destType, CK_BitCast); return destType; } return checkConditionalPointerCompatibility(S, LHS, RHS, Loc); } /// \brief Return false if the first expression is not an integer and the second /// expression is not a pointer, true otherwise. static bool checkPointerIntegerMismatch(Sema &S, ExprResult &Int, Expr* PointerExpr, SourceLocation Loc, bool IsIntFirstExpr) { if (!PointerExpr->getType()->isPointerType() || !Int.get()->getType()->isIntegerType()) return false; Expr *Expr1 = IsIntFirstExpr ? Int.get() : PointerExpr; Expr *Expr2 = IsIntFirstExpr ? PointerExpr : Int.get(); S.Diag(Loc, diag::ext_typecheck_cond_pointer_integer_mismatch) << Expr1->getType() << Expr2->getType() << Expr1->getSourceRange() << Expr2->getSourceRange(); Int = S.ImpCastExprToType(Int.get(), PointerExpr->getType(), CK_IntegralToPointer); return true; } /// \brief Simple conversion between integer and floating point types. /// /// Used when handling the OpenCL conditional operator where the /// condition is a vector while the other operands are scalar. /// /// OpenCL v1.1 s6.3.i and s6.11.6 together require that the scalar /// types are either integer or floating type. Between the two /// operands, the type with the higher rank is defined as the "result /// type". The other operand needs to be promoted to the same type. No /// other type promotion is allowed. We cannot use /// UsualArithmeticConversions() for this purpose, since it always /// promotes promotable types. static QualType OpenCLArithmeticConversions(Sema &S, ExprResult &LHS, ExprResult &RHS, SourceLocation QuestionLoc) { LHS = S.DefaultFunctionArrayLvalueConversion(LHS.get()); if (LHS.isInvalid()) return QualType(); RHS = S.DefaultFunctionArrayLvalueConversion(RHS.get()); if (RHS.isInvalid()) return QualType(); // For conversion purposes, we ignore any qualifiers. // For example, "const float" and "float" are equivalent. QualType LHSType = S.Context.getCanonicalType(LHS.get()->getType()).getUnqualifiedType(); QualType RHSType = S.Context.getCanonicalType(RHS.get()->getType()).getUnqualifiedType(); if (!LHSType->isIntegerType() && !LHSType->isRealFloatingType()) { S.Diag(QuestionLoc, diag::err_typecheck_cond_expect_int_float) << LHSType << LHS.get()->getSourceRange(); return QualType(); } if (!RHSType->isIntegerType() && !RHSType->isRealFloatingType()) { S.Diag(QuestionLoc, diag::err_typecheck_cond_expect_int_float) << RHSType << RHS.get()->getSourceRange(); return QualType(); } // If both types are identical, no conversion is needed. if (LHSType == RHSType) return LHSType; // Now handle "real" floating types (i.e. float, double, long double). if (LHSType->isRealFloatingType() || RHSType->isRealFloatingType()) return handleFloatConversion(S, LHS, RHS, LHSType, RHSType, /*IsCompAssign = */ false); // Finally, we have two differing integer types. return handleIntegerConversion (S, LHS, RHS, LHSType, RHSType, /*IsCompAssign = */ false); } /// \brief Convert scalar operands to a vector that matches the /// condition in length. /// /// Used when handling the OpenCL conditional operator where the /// condition is a vector while the other operands are scalar. /// /// We first compute the "result type" for the scalar operands /// according to OpenCL v1.1 s6.3.i. Both operands are then converted /// into a vector of that type where the length matches the condition /// vector type. s6.11.6 requires that the element types of the result /// and the condition must have the same number of bits. static QualType OpenCLConvertScalarsToVectors(Sema &S, ExprResult &LHS, ExprResult &RHS, QualType CondTy, SourceLocation QuestionLoc) { QualType ResTy = OpenCLArithmeticConversions(S, LHS, RHS, QuestionLoc); if (ResTy.isNull()) return QualType(); const VectorType *CV = CondTy->getAs(); assert(CV); // Determine the vector result type unsigned NumElements = CV->getNumElements(); QualType VectorTy = S.Context.getExtVectorType(ResTy, NumElements); // Ensure that all types have the same number of bits if (S.Context.getTypeSize(CV->getElementType()) != S.Context.getTypeSize(ResTy)) { // Since VectorTy is created internally, it does not pretty print // with an OpenCL name. Instead, we just print a description. std::string EleTyName = ResTy.getUnqualifiedType().getAsString(); SmallString<64> Str; llvm::raw_svector_ostream OS(Str); OS << "(vector of " << NumElements << " '" << EleTyName << "' values)"; S.Diag(QuestionLoc, diag::err_conditional_vector_element_size) << CondTy << OS.str(); return QualType(); } // Convert operands to the vector result type LHS = S.ImpCastExprToType(LHS.get(), VectorTy, CK_VectorSplat); RHS = S.ImpCastExprToType(RHS.get(), VectorTy, CK_VectorSplat); return VectorTy; } /// \brief Return false if this is a valid OpenCL condition vector static bool checkOpenCLConditionVector(Sema &S, Expr *Cond, SourceLocation QuestionLoc) { // OpenCL v1.1 s6.11.6 says the elements of the vector must be of // integral type. const VectorType *CondTy = Cond->getType()->getAs(); assert(CondTy); QualType EleTy = CondTy->getElementType(); if (EleTy->isIntegerType()) return false; S.Diag(QuestionLoc, diag::err_typecheck_cond_expect_nonfloat) << Cond->getType() << Cond->getSourceRange(); return true; } /// \brief Return false if the vector condition type and the vector /// result type are compatible. /// /// OpenCL v1.1 s6.11.6 requires that both vector types have the same /// number of elements, and their element types have the same number /// of bits. static bool checkVectorResult(Sema &S, QualType CondTy, QualType VecResTy, SourceLocation QuestionLoc) { const VectorType *CV = CondTy->getAs(); const VectorType *RV = VecResTy->getAs(); assert(CV && RV); if (CV->getNumElements() != RV->getNumElements()) { S.Diag(QuestionLoc, diag::err_conditional_vector_size) << CondTy << VecResTy; return true; } QualType CVE = CV->getElementType(); QualType RVE = RV->getElementType(); if (S.Context.getTypeSize(CVE) != S.Context.getTypeSize(RVE)) { S.Diag(QuestionLoc, diag::err_conditional_vector_element_size) << CondTy << VecResTy; return true; } return false; } /// \brief Return the resulting type for the conditional operator in /// OpenCL (aka "ternary selection operator", OpenCL v1.1 /// s6.3.i) when the condition is a vector type. static QualType OpenCLCheckVectorConditional(Sema &S, ExprResult &Cond, ExprResult &LHS, ExprResult &RHS, SourceLocation QuestionLoc) { Cond = S.DefaultFunctionArrayLvalueConversion(Cond.get()); if (Cond.isInvalid()) return QualType(); QualType CondTy = Cond.get()->getType(); if (checkOpenCLConditionVector(S, Cond.get(), QuestionLoc)) return QualType(); // If either operand is a vector then find the vector type of the // result as specified in OpenCL v1.1 s6.3.i. if (LHS.get()->getType()->isVectorType() || RHS.get()->getType()->isVectorType()) { QualType VecResTy = S.CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false, /*AllowBothBool*/true, /*AllowBoolConversions*/false); if (VecResTy.isNull()) return QualType(); // The result type must match the condition type as specified in // OpenCL v1.1 s6.11.6. if (checkVectorResult(S, CondTy, VecResTy, QuestionLoc)) return QualType(); return VecResTy; } // Both operands are scalar. return OpenCLConvertScalarsToVectors(S, LHS, RHS, CondTy, QuestionLoc); } /// Note that LHS is not null here, even if this is the gnu "x ?: y" extension. /// In that case, LHS = cond. /// C99 6.5.15 QualType Sema::CheckConditionalOperands(ExprResult &Cond, ExprResult &LHS, ExprResult &RHS, ExprValueKind &VK, ExprObjectKind &OK, SourceLocation QuestionLoc) { ExprResult LHSResult = CheckPlaceholderExpr(LHS.get()); if (!LHSResult.isUsable()) return QualType(); LHS = LHSResult; ExprResult RHSResult = CheckPlaceholderExpr(RHS.get()); if (!RHSResult.isUsable()) return QualType(); RHS = RHSResult; // C++ is sufficiently different to merit its own checker. if (getLangOpts().CPlusPlus) return CXXCheckConditionalOperands(Cond, LHS, RHS, VK, OK, QuestionLoc); VK = VK_RValue; OK = OK_Ordinary; // The OpenCL operator with a vector condition is sufficiently // different to merit its own checker. if (getLangOpts().OpenCL && Cond.get()->getType()->isVectorType()) return OpenCLCheckVectorConditional(*this, Cond, LHS, RHS, QuestionLoc); // First, check the condition. Cond = UsualUnaryConversions(Cond.get()); if (Cond.isInvalid()) return QualType(); if (checkCondition(*this, Cond.get(), QuestionLoc)) return QualType(); // Now check the two expressions. if (LHS.get()->getType()->isVectorType() || RHS.get()->getType()->isVectorType()) return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false, /*AllowBothBool*/true, /*AllowBoolConversions*/false); QualType ResTy = UsualArithmeticConversions(LHS, RHS); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); QualType LHSTy = LHS.get()->getType(); QualType RHSTy = RHS.get()->getType(); // If both operands have arithmetic type, do the usual arithmetic conversions // to find a common type: C99 6.5.15p3,5. if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) { LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy)); RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy)); return ResTy; } // If both operands are the same structure or union type, the result is that // type. if (const RecordType *LHSRT = LHSTy->getAs()) { // C99 6.5.15p3 if (const RecordType *RHSRT = RHSTy->getAs()) if (LHSRT->getDecl() == RHSRT->getDecl()) // "If both the operands have structure or union type, the result has // that type." This implies that CV qualifiers are dropped. return LHSTy.getUnqualifiedType(); // FIXME: Type of conditional expression must be complete in C mode. } // C99 6.5.15p5: "If both operands have void type, the result has void type." // The following || allows only one side to be void (a GCC-ism). if (LHSTy->isVoidType() || RHSTy->isVoidType()) { return checkConditionalVoidType(*this, LHS, RHS); } // C99 6.5.15p6 - "if one operand is a null pointer constant, the result has // the type of the other operand." if (!checkConditionalNullPointer(*this, RHS, LHSTy)) return LHSTy; if (!checkConditionalNullPointer(*this, LHS, RHSTy)) return RHSTy; // All objective-c pointer type analysis is done here. QualType compositeType = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); if (!compositeType.isNull()) return compositeType; // Handle block pointer types. if (LHSTy->isBlockPointerType() || RHSTy->isBlockPointerType()) return checkConditionalBlockPointerCompatibility(*this, LHS, RHS, QuestionLoc); // Check constraints for C object pointers types (C99 6.5.15p3,6). if (LHSTy->isPointerType() && RHSTy->isPointerType()) return checkConditionalObjectPointersCompatibility(*this, LHS, RHS, QuestionLoc); // GCC compatibility: soften pointer/integer mismatch. Note that // null pointers have been filtered out by this point. if (checkPointerIntegerMismatch(*this, LHS, RHS.get(), QuestionLoc, /*isIntFirstExpr=*/true)) return RHSTy; if (checkPointerIntegerMismatch(*this, RHS, LHS.get(), QuestionLoc, /*isIntFirstExpr=*/false)) return LHSTy; // Emit a better diagnostic if one of the expressions is a null pointer // constant and the other is not a pointer type. In this case, the user most // likely forgot to take the address of the other expression. if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) return QualType(); // Otherwise, the operands are not compatible. Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } /// FindCompositeObjCPointerType - Helper method to find composite type of /// two objective-c pointer types of the two input expressions. QualType Sema::FindCompositeObjCPointerType(ExprResult &LHS, ExprResult &RHS, SourceLocation QuestionLoc) { QualType LHSTy = LHS.get()->getType(); QualType RHSTy = RHS.get()->getType(); // Handle things like Class and struct objc_class*. Here we case the result // to the pseudo-builtin, because that will be implicitly cast back to the // redefinition type if an attempt is made to access its fields. if (LHSTy->isObjCClassType() && (Context.hasSameType(RHSTy, Context.getObjCClassRedefinitionType()))) { RHS = ImpCastExprToType(RHS.get(), LHSTy, CK_CPointerToObjCPointerCast); return LHSTy; } if (RHSTy->isObjCClassType() && (Context.hasSameType(LHSTy, Context.getObjCClassRedefinitionType()))) { LHS = ImpCastExprToType(LHS.get(), RHSTy, CK_CPointerToObjCPointerCast); return RHSTy; } // And the same for struct objc_object* / id if (LHSTy->isObjCIdType() && (Context.hasSameType(RHSTy, Context.getObjCIdRedefinitionType()))) { RHS = ImpCastExprToType(RHS.get(), LHSTy, CK_CPointerToObjCPointerCast); return LHSTy; } if (RHSTy->isObjCIdType() && (Context.hasSameType(LHSTy, Context.getObjCIdRedefinitionType()))) { LHS = ImpCastExprToType(LHS.get(), RHSTy, CK_CPointerToObjCPointerCast); return RHSTy; } // And the same for struct objc_selector* / SEL if (Context.isObjCSelType(LHSTy) && (Context.hasSameType(RHSTy, Context.getObjCSelRedefinitionType()))) { RHS = ImpCastExprToType(RHS.get(), LHSTy, CK_BitCast); return LHSTy; } if (Context.isObjCSelType(RHSTy) && (Context.hasSameType(LHSTy, Context.getObjCSelRedefinitionType()))) { LHS = ImpCastExprToType(LHS.get(), RHSTy, CK_BitCast); return RHSTy; } // Check constraints for Objective-C object pointers types. if (LHSTy->isObjCObjectPointerType() && RHSTy->isObjCObjectPointerType()) { if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { // Two identical object pointer types are always compatible. return LHSTy; } const ObjCObjectPointerType *LHSOPT = LHSTy->castAs(); const ObjCObjectPointerType *RHSOPT = RHSTy->castAs(); QualType compositeType = LHSTy; // If both operands are interfaces and either operand can be // assigned to the other, use that type as the composite // type. This allows // xxx ? (A*) a : (B*) b // where B is a subclass of A. // // Additionally, as for assignment, if either type is 'id' // allow silent coercion. Finally, if the types are // incompatible then make sure to use 'id' as the composite // type so the result is acceptable for sending messages to. // FIXME: Consider unifying with 'areComparableObjCPointerTypes'. // It could return the composite type. if (!(compositeType = Context.areCommonBaseCompatible(LHSOPT, RHSOPT)).isNull()) { // Nothing more to do. } else if (Context.canAssignObjCInterfaces(LHSOPT, RHSOPT)) { compositeType = RHSOPT->isObjCBuiltinType() ? RHSTy : LHSTy; } else if (Context.canAssignObjCInterfaces(RHSOPT, LHSOPT)) { compositeType = LHSOPT->isObjCBuiltinType() ? LHSTy : RHSTy; } else if ((LHSTy->isObjCQualifiedIdType() || RHSTy->isObjCQualifiedIdType()) && Context.ObjCQualifiedIdTypesAreCompatible(LHSTy, RHSTy, true)) { // Need to handle "id" explicitly. // GCC allows qualified id and any Objective-C type to devolve to // id. Currently localizing to here until clear this should be // part of ObjCQualifiedIdTypesAreCompatible. compositeType = Context.getObjCIdType(); } else if (LHSTy->isObjCIdType() || RHSTy->isObjCIdType()) { compositeType = Context.getObjCIdType(); } else { Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands) << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); QualType incompatTy = Context.getObjCIdType(); LHS = ImpCastExprToType(LHS.get(), incompatTy, CK_BitCast); RHS = ImpCastExprToType(RHS.get(), incompatTy, CK_BitCast); return incompatTy; } // The object pointer types are compatible. LHS = ImpCastExprToType(LHS.get(), compositeType, CK_BitCast); RHS = ImpCastExprToType(RHS.get(), compositeType, CK_BitCast); return compositeType; } // Check Objective-C object pointer types and 'void *' if (LHSTy->isVoidPointerType() && RHSTy->isObjCObjectPointerType()) { if (getLangOpts().ObjCAutoRefCount) { // ARC forbids the implicit conversion of object pointers to 'void *', // so these types are not compatible. Diag(QuestionLoc, diag::err_cond_voidptr_arc) << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); LHS = RHS = true; return QualType(); } QualType lhptee = LHSTy->getAs()->getPointeeType(); QualType rhptee = RHSTy->getAs()->getPointeeType(); QualType destPointee = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); QualType destType = Context.getPointerType(destPointee); // Add qualifiers if necessary. LHS = ImpCastExprToType(LHS.get(), destType, CK_NoOp); // Promote to void*. RHS = ImpCastExprToType(RHS.get(), destType, CK_BitCast); return destType; } if (LHSTy->isObjCObjectPointerType() && RHSTy->isVoidPointerType()) { if (getLangOpts().ObjCAutoRefCount) { // ARC forbids the implicit conversion of object pointers to 'void *', // so these types are not compatible. Diag(QuestionLoc, diag::err_cond_voidptr_arc) << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); LHS = RHS = true; return QualType(); } QualType lhptee = LHSTy->getAs()->getPointeeType(); QualType rhptee = RHSTy->getAs()->getPointeeType(); QualType destPointee = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); QualType destType = Context.getPointerType(destPointee); // Add qualifiers if necessary. RHS = ImpCastExprToType(RHS.get(), destType, CK_NoOp); // Promote to void*. LHS = ImpCastExprToType(LHS.get(), destType, CK_BitCast); return destType; } return QualType(); } /// SuggestParentheses - Emit a note with a fixit hint that wraps /// ParenRange in parentheses. static void SuggestParentheses(Sema &Self, SourceLocation Loc, const PartialDiagnostic &Note, SourceRange ParenRange) { SourceLocation EndLoc = Self.getLocForEndOfToken(ParenRange.getEnd()); if (ParenRange.getBegin().isFileID() && ParenRange.getEnd().isFileID() && EndLoc.isValid()) { Self.Diag(Loc, Note) << FixItHint::CreateInsertion(ParenRange.getBegin(), "(") << FixItHint::CreateInsertion(EndLoc, ")"); } else { // We can't display the parentheses, so just show the bare note. Self.Diag(Loc, Note) << ParenRange; } } static bool IsArithmeticOp(BinaryOperatorKind Opc) { return BinaryOperator::isAdditiveOp(Opc) || BinaryOperator::isMultiplicativeOp(Opc) || BinaryOperator::isShiftOp(Opc); } /// IsArithmeticBinaryExpr - Returns true if E is an arithmetic binary /// expression, either using a built-in or overloaded operator, /// and sets *OpCode to the opcode and *RHSExprs to the right-hand side /// expression. static bool IsArithmeticBinaryExpr(Expr *E, BinaryOperatorKind *Opcode, Expr **RHSExprs) { // Don't strip parenthesis: we should not warn if E is in parenthesis. E = E->IgnoreImpCasts(); E = E->IgnoreConversionOperator(); E = E->IgnoreImpCasts(); // Built-in binary operator. if (BinaryOperator *OP = dyn_cast(E)) { if (IsArithmeticOp(OP->getOpcode())) { *Opcode = OP->getOpcode(); *RHSExprs = OP->getRHS(); return true; } } // Overloaded operator. if (CXXOperatorCallExpr *Call = dyn_cast(E)) { if (Call->getNumArgs() != 2) return false; // Make sure this is really a binary operator that is safe to pass into // BinaryOperator::getOverloadedOpcode(), e.g. it's not a subscript op. OverloadedOperatorKind OO = Call->getOperator(); if (OO < OO_Plus || OO > OO_Arrow || OO == OO_PlusPlus || OO == OO_MinusMinus) return false; BinaryOperatorKind OpKind = BinaryOperator::getOverloadedOpcode(OO); if (IsArithmeticOp(OpKind)) { *Opcode = OpKind; *RHSExprs = Call->getArg(1); return true; } } return false; } /// ExprLooksBoolean - Returns true if E looks boolean, i.e. it has boolean type /// or is a logical expression such as (x==y) which has int type, but is /// commonly interpreted as boolean. static bool ExprLooksBoolean(Expr *E) { E = E->IgnoreParenImpCasts(); if (E->getType()->isBooleanType()) return true; if (BinaryOperator *OP = dyn_cast(E)) return OP->isComparisonOp() || OP->isLogicalOp(); if (UnaryOperator *OP = dyn_cast(E)) return OP->getOpcode() == UO_LNot; if (E->getType()->isPointerType()) return true; return false; } /// DiagnoseConditionalPrecedence - Emit a warning when a conditional operator /// and binary operator are mixed in a way that suggests the programmer assumed /// the conditional operator has higher precedence, for example: /// "int x = a + someBinaryCondition ? 1 : 2". static void DiagnoseConditionalPrecedence(Sema &Self, SourceLocation OpLoc, Expr *Condition, Expr *LHSExpr, Expr *RHSExpr) { BinaryOperatorKind CondOpcode; Expr *CondRHS; if (!IsArithmeticBinaryExpr(Condition, &CondOpcode, &CondRHS)) return; if (!ExprLooksBoolean(CondRHS)) return; // The condition is an arithmetic binary expression, with a right- // hand side that looks boolean, so warn. Self.Diag(OpLoc, diag::warn_precedence_conditional) << Condition->getSourceRange() << BinaryOperator::getOpcodeStr(CondOpcode); SuggestParentheses(Self, OpLoc, Self.PDiag(diag::note_precedence_silence) << BinaryOperator::getOpcodeStr(CondOpcode), SourceRange(Condition->getLocStart(), Condition->getLocEnd())); SuggestParentheses(Self, OpLoc, Self.PDiag(diag::note_precedence_conditional_first), SourceRange(CondRHS->getLocStart(), RHSExpr->getLocEnd())); } /// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null /// in the case of a the GNU conditional expr extension. ExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc, SourceLocation ColonLoc, Expr *CondExpr, Expr *LHSExpr, Expr *RHSExpr) { if (!getLangOpts().CPlusPlus) { // C cannot handle TypoExpr nodes in the condition because it // doesn't handle dependent types properly, so make sure any TypoExprs have // been dealt with before checking the operands. ExprResult CondResult = CorrectDelayedTyposInExpr(CondExpr); if (!CondResult.isUsable()) return ExprError(); CondExpr = CondResult.get(); } // If this is the gnu "x ?: y" extension, analyze the types as though the LHS // was the condition. OpaqueValueExpr *opaqueValue = nullptr; Expr *commonExpr = nullptr; if (!LHSExpr) { commonExpr = CondExpr; // Lower out placeholder types first. This is important so that we don't // try to capture a placeholder. This happens in few cases in C++; such // as Objective-C++'s dictionary subscripting syntax. if (commonExpr->hasPlaceholderType()) { ExprResult result = CheckPlaceholderExpr(commonExpr); if (!result.isUsable()) return ExprError(); commonExpr = result.get(); } // We usually want to apply unary conversions *before* saving, except // in the special case of a C++ l-value conditional. if (!(getLangOpts().CPlusPlus && !commonExpr->isTypeDependent() && commonExpr->getValueKind() == RHSExpr->getValueKind() && commonExpr->isGLValue() && commonExpr->isOrdinaryOrBitFieldObject() && RHSExpr->isOrdinaryOrBitFieldObject() && Context.hasSameType(commonExpr->getType(), RHSExpr->getType()))) { ExprResult commonRes = UsualUnaryConversions(commonExpr); if (commonRes.isInvalid()) return ExprError(); commonExpr = commonRes.get(); } opaqueValue = new (Context) OpaqueValueExpr(commonExpr->getExprLoc(), commonExpr->getType(), commonExpr->getValueKind(), commonExpr->getObjectKind(), commonExpr); LHSExpr = CondExpr = opaqueValue; } ExprValueKind VK = VK_RValue; ExprObjectKind OK = OK_Ordinary; ExprResult Cond = CondExpr, LHS = LHSExpr, RHS = RHSExpr; QualType result = CheckConditionalOperands(Cond, LHS, RHS, VK, OK, QuestionLoc); if (result.isNull() || Cond.isInvalid() || LHS.isInvalid() || RHS.isInvalid()) return ExprError(); DiagnoseConditionalPrecedence(*this, QuestionLoc, Cond.get(), LHS.get(), RHS.get()); CheckBoolLikeConversion(Cond.get(), QuestionLoc); if (!commonExpr) return new (Context) ConditionalOperator(Cond.get(), QuestionLoc, LHS.get(), ColonLoc, RHS.get(), result, VK, OK); return new (Context) BinaryConditionalOperator( commonExpr, opaqueValue, Cond.get(), LHS.get(), RHS.get(), QuestionLoc, ColonLoc, result, VK, OK); } // checkPointerTypesForAssignment - This is a very tricky routine (despite // being closely modeled after the C99 spec:-). The odd characteristic of this // routine is it effectively iqnores the qualifiers on the top level pointee. // This circumvents the usual type rules specified in 6.2.7p1 & 6.7.5.[1-3]. // FIXME: add a couple examples in this comment. static Sema::AssignConvertType checkPointerTypesForAssignment(Sema &S, QualType LHSType, QualType RHSType) { assert(LHSType.isCanonical() && "LHS not canonicalized!"); assert(RHSType.isCanonical() && "RHS not canonicalized!"); // get the "pointed to" type (ignoring qualifiers at the top level) const Type *lhptee, *rhptee; Qualifiers lhq, rhq; std::tie(lhptee, lhq) = cast(LHSType)->getPointeeType().split().asPair(); std::tie(rhptee, rhq) = cast(RHSType)->getPointeeType().split().asPair(); Sema::AssignConvertType ConvTy = Sema::Compatible; // C99 6.5.16.1p1: This following citation is common to constraints // 3 & 4 (below). ...and the type *pointed to* by the left has all the // qualifiers of the type *pointed to* by the right; // As a special case, 'non-__weak A *' -> 'non-__weak const *' is okay. if (lhq.getObjCLifetime() != rhq.getObjCLifetime() && lhq.compatiblyIncludesObjCLifetime(rhq)) { // Ignore lifetime for further calculation. lhq.removeObjCLifetime(); rhq.removeObjCLifetime(); } if (!lhq.compatiblyIncludes(rhq)) { // Treat address-space mismatches as fatal. TODO: address subspaces if (!lhq.isAddressSpaceSupersetOf(rhq)) ConvTy = Sema::IncompatiblePointerDiscardsQualifiers; // It's okay to add or remove GC or lifetime qualifiers when converting to // and from void*. else if (lhq.withoutObjCGCAttr().withoutObjCLifetime() .compatiblyIncludes( rhq.withoutObjCGCAttr().withoutObjCLifetime()) && (lhptee->isVoidType() || rhptee->isVoidType())) ; // keep old // Treat lifetime mismatches as fatal. else if (lhq.getObjCLifetime() != rhq.getObjCLifetime()) ConvTy = Sema::IncompatiblePointerDiscardsQualifiers; // For GCC compatibility, other qualifier mismatches are treated // as still compatible in C. else ConvTy = Sema::CompatiblePointerDiscardsQualifiers; } // C99 6.5.16.1p1 (constraint 4): If one operand is a pointer to an object or // incomplete type and the other is a pointer to a qualified or unqualified // version of void... if (lhptee->isVoidType()) { if (rhptee->isIncompleteOrObjectType()) return ConvTy; // As an extension, we allow cast to/from void* to function pointer. assert(rhptee->isFunctionType()); return Sema::FunctionVoidPointer; } if (rhptee->isVoidType()) { if (lhptee->isIncompleteOrObjectType()) return ConvTy; // As an extension, we allow cast to/from void* to function pointer. assert(lhptee->isFunctionType()); return Sema::FunctionVoidPointer; } // C99 6.5.16.1p1 (constraint 3): both operands are pointers to qualified or // unqualified versions of compatible types, ... QualType ltrans = QualType(lhptee, 0), rtrans = QualType(rhptee, 0); if (!S.Context.typesAreCompatible(ltrans, rtrans)) { // Check if the pointee types are compatible ignoring the sign. // We explicitly check for char so that we catch "char" vs // "unsigned char" on systems where "char" is unsigned. if (lhptee->isCharType()) ltrans = S.Context.UnsignedCharTy; else if (lhptee->hasSignedIntegerRepresentation()) ltrans = S.Context.getCorrespondingUnsignedType(ltrans); if (rhptee->isCharType()) rtrans = S.Context.UnsignedCharTy; else if (rhptee->hasSignedIntegerRepresentation()) rtrans = S.Context.getCorrespondingUnsignedType(rtrans); if (ltrans == rtrans) { // Types are compatible ignoring the sign. Qualifier incompatibility // takes priority over sign incompatibility because the sign // warning can be disabled. if (ConvTy != Sema::Compatible) return ConvTy; return Sema::IncompatiblePointerSign; } // If we are a multi-level pointer, it's possible that our issue is simply // one of qualification - e.g. char ** -> const char ** is not allowed. If // the eventual target type is the same and the pointers have the same // level of indirection, this must be the issue. if (isa(lhptee) && isa(rhptee)) { do { lhptee = cast(lhptee)->getPointeeType().getTypePtr(); rhptee = cast(rhptee)->getPointeeType().getTypePtr(); } while (isa(lhptee) && isa(rhptee)); if (lhptee == rhptee) return Sema::IncompatibleNestedPointerQualifiers; } // General pointer incompatibility takes priority over qualifiers. return Sema::IncompatiblePointer; } if (!S.getLangOpts().CPlusPlus && S.IsNoReturnConversion(ltrans, rtrans, ltrans)) return Sema::IncompatiblePointer; return ConvTy; } /// checkBlockPointerTypesForAssignment - This routine determines whether two /// block pointer types are compatible or whether a block and normal pointer /// are compatible. It is more restrict than comparing two function pointer // types. static Sema::AssignConvertType checkBlockPointerTypesForAssignment(Sema &S, QualType LHSType, QualType RHSType) { assert(LHSType.isCanonical() && "LHS not canonicalized!"); assert(RHSType.isCanonical() && "RHS not canonicalized!"); QualType lhptee, rhptee; // get the "pointed to" type (ignoring qualifiers at the top level) lhptee = cast(LHSType)->getPointeeType(); rhptee = cast(RHSType)->getPointeeType(); // In C++, the types have to match exactly. if (S.getLangOpts().CPlusPlus) return Sema::IncompatibleBlockPointer; Sema::AssignConvertType ConvTy = Sema::Compatible; // For blocks we enforce that qualifiers are identical. if (lhptee.getLocalQualifiers() != rhptee.getLocalQualifiers()) ConvTy = Sema::CompatiblePointerDiscardsQualifiers; if (!S.Context.typesAreBlockPointerCompatible(LHSType, RHSType)) return Sema::IncompatibleBlockPointer; return ConvTy; } /// checkObjCPointerTypesForAssignment - Compares two objective-c pointer types /// for assignment compatibility. static Sema::AssignConvertType checkObjCPointerTypesForAssignment(Sema &S, QualType LHSType, QualType RHSType) { assert(LHSType.isCanonical() && "LHS was not canonicalized!"); assert(RHSType.isCanonical() && "RHS was not canonicalized!"); if (LHSType->isObjCBuiltinType()) { // Class is not compatible with ObjC object pointers. if (LHSType->isObjCClassType() && !RHSType->isObjCBuiltinType() && !RHSType->isObjCQualifiedClassType()) return Sema::IncompatiblePointer; return Sema::Compatible; } if (RHSType->isObjCBuiltinType()) { if (RHSType->isObjCClassType() && !LHSType->isObjCBuiltinType() && !LHSType->isObjCQualifiedClassType()) return Sema::IncompatiblePointer; return Sema::Compatible; } QualType lhptee = LHSType->getAs()->getPointeeType(); QualType rhptee = RHSType->getAs()->getPointeeType(); if (!lhptee.isAtLeastAsQualifiedAs(rhptee) && // make an exception for id

!LHSType->isObjCQualifiedIdType()) return Sema::CompatiblePointerDiscardsQualifiers; if (S.Context.typesAreCompatible(LHSType, RHSType)) return Sema::Compatible; if (LHSType->isObjCQualifiedIdType() || RHSType->isObjCQualifiedIdType()) return Sema::IncompatibleObjCQualifiedId; return Sema::IncompatiblePointer; } Sema::AssignConvertType Sema::CheckAssignmentConstraints(SourceLocation Loc, QualType LHSType, QualType RHSType) { // Fake up an opaque expression. We don't actually care about what // cast operations are required, so if CheckAssignmentConstraints // adds casts to this they'll be wasted, but fortunately that doesn't // usually happen on valid code. OpaqueValueExpr RHSExpr(Loc, RHSType, VK_RValue); ExprResult RHSPtr = &RHSExpr; CastKind K = CK_Invalid; return CheckAssignmentConstraints(LHSType, RHSPtr, K, /*ConvertRHS=*/false); } /// CheckAssignmentConstraints (C99 6.5.16) - This routine currently /// has code to accommodate several GCC extensions when type checking /// pointers. Here are some objectionable examples that GCC considers warnings: /// /// int a, *pint; /// short *pshort; /// struct foo *pfoo; /// /// pint = pshort; // warning: assignment from incompatible pointer type /// a = pint; // warning: assignment makes integer from pointer without a cast /// pint = a; // warning: assignment makes pointer from integer without a cast /// pint = pfoo; // warning: assignment from incompatible pointer type /// /// As a result, the code for dealing with pointers is more complex than the /// C99 spec dictates. /// /// Sets 'Kind' for any result kind except Incompatible. Sema::AssignConvertType Sema::CheckAssignmentConstraints(QualType LHSType, ExprResult &RHS, CastKind &Kind, bool ConvertRHS) { QualType RHSType = RHS.get()->getType(); QualType OrigLHSType = LHSType; // Get canonical types. We're not formatting these types, just comparing // them. LHSType = Context.getCanonicalType(LHSType).getUnqualifiedType(); RHSType = Context.getCanonicalType(RHSType).getUnqualifiedType(); // Common case: no conversion required. if (LHSType == RHSType) { Kind = CK_NoOp; return Compatible; } // If we have an atomic type, try a non-atomic assignment, then just add an // atomic qualification step. if (const AtomicType *AtomicTy = dyn_cast(LHSType)) { Sema::AssignConvertType result = CheckAssignmentConstraints(AtomicTy->getValueType(), RHS, Kind); if (result != Compatible) return result; if (Kind != CK_NoOp && ConvertRHS) RHS = ImpCastExprToType(RHS.get(), AtomicTy->getValueType(), Kind); Kind = CK_NonAtomicToAtomic; return Compatible; } // If the left-hand side is a reference type, then we are in a // (rare!) case where we've allowed the use of references in C, // e.g., as a parameter type in a built-in function. In this case, // just make sure that the type referenced is compatible with the // right-hand side type. The caller is responsible for adjusting // LHSType so that the resulting expression does not have reference // type. if (const ReferenceType *LHSTypeRef = LHSType->getAs()) { if (Context.typesAreCompatible(LHSTypeRef->getPointeeType(), RHSType)) { Kind = CK_LValueBitCast; return Compatible; } return Incompatible; } // Allow scalar to ExtVector assignments, and assignments of an ExtVector type // to the same ExtVector type. if (LHSType->isExtVectorType()) { if (RHSType->isExtVectorType()) return Incompatible; if (RHSType->isArithmeticType()) { // CK_VectorSplat does T -> vector T, so first cast to the // element type. QualType elType = cast(LHSType)->getElementType(); if (elType != RHSType && ConvertRHS) { Kind = PrepareScalarCast(RHS, elType); RHS = ImpCastExprToType(RHS.get(), elType, Kind); } Kind = CK_VectorSplat; return Compatible; } } // Conversions to or from vector type. if (LHSType->isVectorType() || RHSType->isVectorType()) { if (LHSType->isVectorType() && RHSType->isVectorType()) { // Allow assignments of an AltiVec vector type to an equivalent GCC // vector type and vice versa if (Context.areCompatibleVectorTypes(LHSType, RHSType)) { Kind = CK_BitCast; return Compatible; } // If we are allowing lax vector conversions, and LHS and RHS are both // vectors, the total size only needs to be the same. This is a bitcast; // no bits are changed but the result type is different. if (isLaxVectorConversion(RHSType, LHSType)) { Kind = CK_BitCast; return IncompatibleVectors; } } return Incompatible; } // Arithmetic conversions. if (LHSType->isArithmeticType() && RHSType->isArithmeticType() && !(getLangOpts().CPlusPlus && LHSType->isEnumeralType())) { if (ConvertRHS) Kind = PrepareScalarCast(RHS, LHSType); return Compatible; } // Conversions to normal pointers. if (const PointerType *LHSPointer = dyn_cast(LHSType)) { // U* -> T* if (isa(RHSType)) { unsigned AddrSpaceL = LHSPointer->getPointeeType().getAddressSpace(); unsigned AddrSpaceR = RHSType->getPointeeType().getAddressSpace(); Kind = AddrSpaceL != AddrSpaceR ? CK_AddressSpaceConversion : CK_BitCast; return checkPointerTypesForAssignment(*this, LHSType, RHSType); } // int -> T* if (RHSType->isIntegerType()) { Kind = CK_IntegralToPointer; // FIXME: null? return IntToPointer; } // C pointers are not compatible with ObjC object pointers, // with two exceptions: if (isa(RHSType)) { // - conversions to void* if (LHSPointer->getPointeeType()->isVoidType()) { Kind = CK_BitCast; return Compatible; } // - conversions from 'Class' to the redefinition type if (RHSType->isObjCClassType() && Context.hasSameType(LHSType, Context.getObjCClassRedefinitionType())) { Kind = CK_BitCast; return Compatible; } Kind = CK_BitCast; return IncompatiblePointer; } // U^ -> void* if (RHSType->getAs()) { if (LHSPointer->getPointeeType()->isVoidType()) { Kind = CK_BitCast; return Compatible; } } return Incompatible; } // Conversions to block pointers. if (isa(LHSType)) { // U^ -> T^ if (RHSType->isBlockPointerType()) { Kind = CK_BitCast; return checkBlockPointerTypesForAssignment(*this, LHSType, RHSType); } // int or null -> T^ if (RHSType->isIntegerType()) { Kind = CK_IntegralToPointer; // FIXME: null return IntToBlockPointer; } // id -> T^ if (getLangOpts().ObjC1 && RHSType->isObjCIdType()) { Kind = CK_AnyPointerToBlockPointerCast; return Compatible; } // void* -> T^ if (const PointerType *RHSPT = RHSType->getAs()) if (RHSPT->getPointeeType()->isVoidType()) { Kind = CK_AnyPointerToBlockPointerCast; return Compatible; } return Incompatible; } // Conversions to Objective-C pointers. if (isa(LHSType)) { // A* -> B* if (RHSType->isObjCObjectPointerType()) { Kind = CK_BitCast; Sema::AssignConvertType result = checkObjCPointerTypesForAssignment(*this, LHSType, RHSType); if (getLangOpts().ObjCAutoRefCount && result == Compatible && !CheckObjCARCUnavailableWeakConversion(OrigLHSType, RHSType)) result = IncompatibleObjCWeakRef; return result; } // int or null -> A* if (RHSType->isIntegerType()) { Kind = CK_IntegralToPointer; // FIXME: null return IntToPointer; } // In general, C pointers are not compatible with ObjC object pointers, // with two exceptions: if (isa(RHSType)) { Kind = CK_CPointerToObjCPointerCast; // - conversions from 'void*' if (RHSType->isVoidPointerType()) { return Compatible; } // - conversions to 'Class' from its redefinition type if (LHSType->isObjCClassType() && Context.hasSameType(RHSType, Context.getObjCClassRedefinitionType())) { return Compatible; } return IncompatiblePointer; } // Only under strict condition T^ is compatible with an Objective-C pointer. if (RHSType->isBlockPointerType() && LHSType->isBlockCompatibleObjCPointerType(Context)) { if (ConvertRHS) maybeExtendBlockObject(RHS); Kind = CK_BlockPointerToObjCPointerCast; return Compatible; } return Incompatible; } // Conversions from pointers that are not covered by the above. if (isa(RHSType)) { // T* -> _Bool if (LHSType == Context.BoolTy) { Kind = CK_PointerToBoolean; return Compatible; } // T* -> int if (LHSType->isIntegerType()) { Kind = CK_PointerToIntegral; return PointerToInt; } return Incompatible; } // Conversions from Objective-C pointers that are not covered by the above. if (isa(RHSType)) { // T* -> _Bool if (LHSType == Context.BoolTy) { Kind = CK_PointerToBoolean; return Compatible; } // T* -> int if (LHSType->isIntegerType()) { Kind = CK_PointerToIntegral; return PointerToInt; } return Incompatible; } // struct A -> struct B if (isa(LHSType) && isa(RHSType)) { if (Context.typesAreCompatible(LHSType, RHSType)) { Kind = CK_NoOp; return Compatible; } } return Incompatible; } /// \brief Constructs a transparent union from an expression that is /// used to initialize the transparent union. static void ConstructTransparentUnion(Sema &S, ASTContext &C, ExprResult &EResult, QualType UnionType, FieldDecl *Field) { // Build an initializer list that designates the appropriate member // of the transparent union. Expr *E = EResult.get(); InitListExpr *Initializer = new (C) InitListExpr(C, SourceLocation(), E, SourceLocation()); Initializer->setType(UnionType); Initializer->setInitializedFieldInUnion(Field); // Build a compound literal constructing a value of the transparent // union type from this initializer list. TypeSourceInfo *unionTInfo = C.getTrivialTypeSourceInfo(UnionType); EResult = new (C) CompoundLiteralExpr(SourceLocation(), unionTInfo, UnionType, VK_RValue, Initializer, false); } Sema::AssignConvertType Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, ExprResult &RHS) { QualType RHSType = RHS.get()->getType(); // If the ArgType is a Union type, we want to handle a potential // transparent_union GCC extension. const RecordType *UT = ArgType->getAsUnionType(); if (!UT || !UT->getDecl()->hasAttr()) return Incompatible; // The field to initialize within the transparent union. RecordDecl *UD = UT->getDecl(); FieldDecl *InitField = nullptr; // It's compatible if the expression matches any of the fields. for (auto *it : UD->fields()) { if (it->getType()->isPointerType()) { // If the transparent union contains a pointer type, we allow: // 1) void pointer // 2) null pointer constant if (RHSType->isPointerType()) if (RHSType->castAs()->getPointeeType()->isVoidType()) { RHS = ImpCastExprToType(RHS.get(), it->getType(), CK_BitCast); InitField = it; break; } if (RHS.get()->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { RHS = ImpCastExprToType(RHS.get(), it->getType(), CK_NullToPointer); InitField = it; break; } } CastKind Kind = CK_Invalid; if (CheckAssignmentConstraints(it->getType(), RHS, Kind) == Compatible) { RHS = ImpCastExprToType(RHS.get(), it->getType(), Kind); InitField = it; break; } } if (!InitField) return Incompatible; ConstructTransparentUnion(*this, Context, RHS, ArgType, InitField); return Compatible; } Sema::AssignConvertType Sema::CheckSingleAssignmentConstraints(QualType LHSType, ExprResult &CallerRHS, bool Diagnose, bool DiagnoseCFAudited, bool ConvertRHS) { // If ConvertRHS is false, we want to leave the caller's RHS untouched. Sadly, // we can't avoid *all* modifications at the moment, so we need some somewhere // to put the updated value. ExprResult LocalRHS = CallerRHS; ExprResult &RHS = ConvertRHS ? CallerRHS : LocalRHS; if (getLangOpts().CPlusPlus) { if (!LHSType->isRecordType() && !LHSType->isAtomicType()) { // C++ 5.17p3: If the left operand is not of class type, the // expression is implicitly converted (C++ 4) to the // cv-unqualified type of the left operand. ExprResult Res; if (Diagnose) { Res = PerformImplicitConversion(RHS.get(), LHSType.getUnqualifiedType(), AA_Assigning); } else { ImplicitConversionSequence ICS = TryImplicitConversion(RHS.get(), LHSType.getUnqualifiedType(), /*SuppressUserConversions=*/false, /*AllowExplicit=*/false, /*InOverloadResolution=*/false, /*CStyle=*/false, /*AllowObjCWritebackConversion=*/false); if (ICS.isFailure()) return Incompatible; Res = PerformImplicitConversion(RHS.get(), LHSType.getUnqualifiedType(), ICS, AA_Assigning); } if (Res.isInvalid()) return Incompatible; Sema::AssignConvertType result = Compatible; if (getLangOpts().ObjCAutoRefCount && !CheckObjCARCUnavailableWeakConversion(LHSType, RHS.get()->getType())) result = IncompatibleObjCWeakRef; RHS = Res; return result; } // FIXME: Currently, we fall through and treat C++ classes like C // structures. // FIXME: We also fall through for atomics; not sure what should // happen there, though. } else if (RHS.get()->getType() == Context.OverloadTy) { // As a set of extensions to C, we support overloading on functions. These // functions need to be resolved here. DeclAccessPair DAP; if (FunctionDecl *FD = ResolveAddressOfOverloadedFunction( RHS.get(), LHSType, /*Complain=*/false, DAP)) RHS = FixOverloadedFunctionReference(RHS.get(), DAP, FD); else return Incompatible; } // C99 6.5.16.1p1: the left operand is a pointer and the right is // a null pointer constant. if ((LHSType->isPointerType() || LHSType->isObjCObjectPointerType() || LHSType->isBlockPointerType()) && RHS.get()->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { CastKind Kind; CXXCastPath Path; CheckPointerConversion(RHS.get(), LHSType, Kind, Path, false); if (ConvertRHS) RHS = ImpCastExprToType(RHS.get(), LHSType, Kind, VK_RValue, &Path); return Compatible; } // This check seems unnatural, however it is necessary to ensure the proper // conversion of functions/arrays. If the conversion were done for all // DeclExpr's (created by ActOnIdExpression), it would mess up the unary // expressions that suppress this implicit conversion (&, sizeof). // // Suppress this for references: C++ 8.5.3p5. if (!LHSType->isReferenceType()) { // FIXME: We potentially allocate here even if ConvertRHS is false. RHS = DefaultFunctionArrayLvalueConversion(RHS.get(), Diagnose); if (RHS.isInvalid()) return Incompatible; } Expr *PRE = RHS.get()->IgnoreParenCasts(); if (ObjCProtocolExpr *OPE = dyn_cast(PRE)) { ObjCProtocolDecl *PDecl = OPE->getProtocol(); if (PDecl && !PDecl->hasDefinition()) { Diag(PRE->getExprLoc(), diag::warn_atprotocol_protocol) << PDecl->getName(); Diag(PDecl->getLocation(), diag::note_entity_declared_at) << PDecl; } } CastKind Kind = CK_Invalid; Sema::AssignConvertType result = CheckAssignmentConstraints(LHSType, RHS, Kind, ConvertRHS); // C99 6.5.16.1p2: The value of the right operand is converted to the // type of the assignment expression. // CheckAssignmentConstraints allows the left-hand side to be a reference, // so that we can use references in built-in functions even in C. // The getNonReferenceType() call makes sure that the resulting expression // does not have reference type. if (result != Incompatible && RHS.get()->getType() != LHSType) { QualType Ty = LHSType.getNonLValueExprType(Context); Expr *E = RHS.get(); if (getLangOpts().ObjCAutoRefCount) CheckObjCARCConversion(SourceRange(), Ty, E, CCK_ImplicitConversion, DiagnoseCFAudited); if (getLangOpts().ObjC1 && (CheckObjCBridgeRelatedConversions(E->getLocStart(), LHSType, E->getType(), E) || ConversionToObjCStringLiteralCheck(LHSType, E))) { RHS = E; return Compatible; } if (ConvertRHS) RHS = ImpCastExprToType(E, Ty, Kind); } return result; } QualType Sema::InvalidOperands(SourceLocation Loc, ExprResult &LHS, ExprResult &RHS) { Diag(Loc, diag::err_typecheck_invalid_operands) << LHS.get()->getType() << RHS.get()->getType() << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } /// Try to convert a value of non-vector type to a vector type by converting /// the type to the element type of the vector and then performing a splat. /// If the language is OpenCL, we only use conversions that promote scalar /// rank; for C, Obj-C, and C++ we allow any real scalar conversion except /// for float->int. /// /// \param scalar - if non-null, actually perform the conversions /// \return true if the operation fails (but without diagnosing the failure) static bool tryVectorConvertAndSplat(Sema &S, ExprResult *scalar, QualType scalarTy, QualType vectorEltTy, QualType vectorTy) { // The conversion to apply to the scalar before splatting it, // if necessary. CastKind scalarCast = CK_Invalid; if (vectorEltTy->isIntegralType(S.Context)) { if (!scalarTy->isIntegralType(S.Context)) return true; if (S.getLangOpts().OpenCL && S.Context.getIntegerTypeOrder(vectorEltTy, scalarTy) < 0) return true; scalarCast = CK_IntegralCast; } else if (vectorEltTy->isRealFloatingType()) { if (scalarTy->isRealFloatingType()) { if (S.getLangOpts().OpenCL && S.Context.getFloatingTypeOrder(vectorEltTy, scalarTy) < 0) return true; scalarCast = CK_FloatingCast; } else if (scalarTy->isIntegralType(S.Context)) scalarCast = CK_IntegralToFloating; else return true; } else { return true; } // Adjust scalar if desired. if (scalar) { if (scalarCast != CK_Invalid) *scalar = S.ImpCastExprToType(scalar->get(), vectorEltTy, scalarCast); *scalar = S.ImpCastExprToType(scalar->get(), vectorTy, CK_VectorSplat); } return false; } QualType Sema::CheckVectorOperands(ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsCompAssign, bool AllowBothBool, bool AllowBoolConversions) { if (!IsCompAssign) { LHS = DefaultFunctionArrayLvalueConversion(LHS.get()); if (LHS.isInvalid()) return QualType(); } RHS = DefaultFunctionArrayLvalueConversion(RHS.get()); if (RHS.isInvalid()) return QualType(); // For conversion purposes, we ignore any qualifiers. // For example, "const float" and "float" are equivalent. QualType LHSType = LHS.get()->getType().getUnqualifiedType(); QualType RHSType = RHS.get()->getType().getUnqualifiedType(); const VectorType *LHSVecType = LHSType->getAs(); const VectorType *RHSVecType = RHSType->getAs(); assert(LHSVecType || RHSVecType); // AltiVec-style "vector bool op vector bool" combinations are allowed // for some operators but not others. if (!AllowBothBool && LHSVecType && LHSVecType->getVectorKind() == VectorType::AltiVecBool && RHSVecType && RHSVecType->getVectorKind() == VectorType::AltiVecBool) return InvalidOperands(Loc, LHS, RHS); // If the vector types are identical, return. if (Context.hasSameType(LHSType, RHSType)) return LHSType; // If we have compatible AltiVec and GCC vector types, use the AltiVec type. if (LHSVecType && RHSVecType && Context.areCompatibleVectorTypes(LHSType, RHSType)) { if (isa(LHSVecType)) { RHS = ImpCastExprToType(RHS.get(), LHSType, CK_BitCast); return LHSType; } if (!IsCompAssign) LHS = ImpCastExprToType(LHS.get(), RHSType, CK_BitCast); return RHSType; } // AllowBoolConversions says that bool and non-bool AltiVec vectors // can be mixed, with the result being the non-bool type. The non-bool // operand must have integer element type. if (AllowBoolConversions && LHSVecType && RHSVecType && LHSVecType->getNumElements() == RHSVecType->getNumElements() && (Context.getTypeSize(LHSVecType->getElementType()) == Context.getTypeSize(RHSVecType->getElementType()))) { if (LHSVecType->getVectorKind() == VectorType::AltiVecVector && LHSVecType->getElementType()->isIntegerType() && RHSVecType->getVectorKind() == VectorType::AltiVecBool) { RHS = ImpCastExprToType(RHS.get(), LHSType, CK_BitCast); return LHSType; } if (!IsCompAssign && LHSVecType->getVectorKind() == VectorType::AltiVecBool && RHSVecType->getVectorKind() == VectorType::AltiVecVector && RHSVecType->getElementType()->isIntegerType()) { LHS = ImpCastExprToType(LHS.get(), RHSType, CK_BitCast); return RHSType; } } // If there's an ext-vector type and a scalar, try to convert the scalar to // the vector element type and splat. if (!RHSVecType && isa(LHSVecType)) { if (!tryVectorConvertAndSplat(*this, &RHS, RHSType, LHSVecType->getElementType(), LHSType)) return LHSType; } if (!LHSVecType && isa(RHSVecType)) { if (!tryVectorConvertAndSplat(*this, (IsCompAssign ? nullptr : &LHS), LHSType, RHSVecType->getElementType(), RHSType)) return RHSType; } // If we're allowing lax vector conversions, only the total (data) size // needs to be the same. // FIXME: Should we really be allowing this? // FIXME: We really just pick the LHS type arbitrarily? if (isLaxVectorConversion(RHSType, LHSType)) { QualType resultType = LHSType; RHS = ImpCastExprToType(RHS.get(), resultType, CK_BitCast); return resultType; } // Okay, the expression is invalid. // If there's a non-vector, non-real operand, diagnose that. if ((!RHSVecType && !RHSType->isRealType()) || (!LHSVecType && !LHSType->isRealType())) { Diag(Loc, diag::err_typecheck_vector_not_convertable_non_scalar) << LHSType << RHSType << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } // OpenCL V1.1 6.2.6.p1: // If the operands are of more than one vector type, then an error shall // occur. Implicit conversions between vector types are not permitted, per // section 6.2.1. if (getLangOpts().OpenCL && RHSVecType && isa(RHSVecType) && LHSVecType && isa(LHSVecType)) { Diag(Loc, diag::err_opencl_implicit_vector_conversion) << LHSType << RHSType; return QualType(); } // Otherwise, use the generic diagnostic. Diag(Loc, diag::err_typecheck_vector_not_convertable) << LHSType << RHSType << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } // checkArithmeticNull - Detect when a NULL constant is used improperly in an // expression. These are mainly cases where the null pointer is used as an // integer instead of a pointer. static void checkArithmeticNull(Sema &S, ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsCompare) { // The canonical way to check for a GNU null is with isNullPointerConstant, // but we use a bit of a hack here for speed; this is a relatively // hot path, and isNullPointerConstant is slow. bool LHSNull = isa(LHS.get()->IgnoreParenImpCasts()); bool RHSNull = isa(RHS.get()->IgnoreParenImpCasts()); QualType NonNullType = LHSNull ? RHS.get()->getType() : LHS.get()->getType(); // Avoid analyzing cases where the result will either be invalid (and // diagnosed as such) or entirely valid and not something to warn about. if ((!LHSNull && !RHSNull) || NonNullType->isBlockPointerType() || NonNullType->isMemberPointerType() || NonNullType->isFunctionType()) return; // Comparison operations would not make sense with a null pointer no matter // what the other expression is. if (!IsCompare) { S.Diag(Loc, diag::warn_null_in_arithmetic_operation) << (LHSNull ? LHS.get()->getSourceRange() : SourceRange()) << (RHSNull ? RHS.get()->getSourceRange() : SourceRange()); return; } // The rest of the operations only make sense with a null pointer // if the other expression is a pointer. if (LHSNull == RHSNull || NonNullType->isAnyPointerType() || NonNullType->canDecayToPointerType()) return; S.Diag(Loc, diag::warn_null_in_comparison_operation) << LHSNull /* LHS is NULL */ << NonNullType << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); } static void DiagnoseBadDivideOrRemainderValues(Sema& S, ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsDiv) { // Check for division/remainder by zero. llvm::APSInt RHSValue; if (!RHS.get()->isValueDependent() && RHS.get()->EvaluateAsInt(RHSValue, S.Context) && RHSValue == 0) S.DiagRuntimeBehavior(Loc, RHS.get(), S.PDiag(diag::warn_remainder_division_by_zero) << IsDiv << RHS.get()->getSourceRange()); } QualType Sema::CheckMultiplyDivideOperands(ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsCompAssign, bool IsDiv) { checkArithmeticNull(*this, LHS, RHS, Loc, /*isCompare=*/false); if (LHS.get()->getType()->isVectorType() || RHS.get()->getType()->isVectorType()) return CheckVectorOperands(LHS, RHS, Loc, IsCompAssign, /*AllowBothBool*/getLangOpts().AltiVec, /*AllowBoolConversions*/false); QualType compType = UsualArithmeticConversions(LHS, RHS, IsCompAssign); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); if (compType.isNull() || !compType->isArithmeticType()) return InvalidOperands(Loc, LHS, RHS); if (IsDiv) DiagnoseBadDivideOrRemainderValues(*this, LHS, RHS, Loc, IsDiv); return compType; } QualType Sema::CheckRemainderOperands( ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsCompAssign) { checkArithmeticNull(*this, LHS, RHS, Loc, /*isCompare=*/false); if (LHS.get()->getType()->isVectorType() || RHS.get()->getType()->isVectorType()) { if (LHS.get()->getType()->hasIntegerRepresentation() && RHS.get()->getType()->hasIntegerRepresentation()) return CheckVectorOperands(LHS, RHS, Loc, IsCompAssign, /*AllowBothBool*/getLangOpts().AltiVec, /*AllowBoolConversions*/false); return InvalidOperands(Loc, LHS, RHS); } QualType compType = UsualArithmeticConversions(LHS, RHS, IsCompAssign); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); if (compType.isNull() || !compType->isIntegerType()) return InvalidOperands(Loc, LHS, RHS); DiagnoseBadDivideOrRemainderValues(*this, LHS, RHS, Loc, false /* IsDiv */); return compType; } /// \brief Diagnose invalid arithmetic on two void pointers. static void diagnoseArithmeticOnTwoVoidPointers(Sema &S, SourceLocation Loc, Expr *LHSExpr, Expr *RHSExpr) { S.Diag(Loc, S.getLangOpts().CPlusPlus ? diag::err_typecheck_pointer_arith_void_type : diag::ext_gnu_void_ptr) << 1 /* two pointers */ << LHSExpr->getSourceRange() << RHSExpr->getSourceRange(); } /// \brief Diagnose invalid arithmetic on a void pointer. static void diagnoseArithmeticOnVoidPointer(Sema &S, SourceLocation Loc, Expr *Pointer) { S.Diag(Loc, S.getLangOpts().CPlusPlus ? diag::err_typecheck_pointer_arith_void_type : diag::ext_gnu_void_ptr) << 0 /* one pointer */ << Pointer->getSourceRange(); } /// \brief Diagnose invalid arithmetic on two function pointers. static void diagnoseArithmeticOnTwoFunctionPointers(Sema &S, SourceLocation Loc, Expr *LHS, Expr *RHS) { assert(LHS->getType()->isAnyPointerType()); assert(RHS->getType()->isAnyPointerType()); S.Diag(Loc, S.getLangOpts().CPlusPlus ? diag::err_typecheck_pointer_arith_function_type : diag::ext_gnu_ptr_func_arith) << 1 /* two pointers */ << LHS->getType()->getPointeeType() // We only show the second type if it differs from the first. << (unsigned)!S.Context.hasSameUnqualifiedType(LHS->getType(), RHS->getType()) << RHS->getType()->getPointeeType() << LHS->getSourceRange() << RHS->getSourceRange(); } /// \brief Diagnose invalid arithmetic on a function pointer. static void diagnoseArithmeticOnFunctionPointer(Sema &S, SourceLocation Loc, Expr *Pointer) { assert(Pointer->getType()->isAnyPointerType()); S.Diag(Loc, S.getLangOpts().CPlusPlus ? diag::err_typecheck_pointer_arith_function_type : diag::ext_gnu_ptr_func_arith) << 0 /* one pointer */ << Pointer->getType()->getPointeeType() << 0 /* one pointer, so only one type */ << Pointer->getSourceRange(); } /// \brief Emit error if Operand is incomplete pointer type /// /// \returns True if pointer has incomplete type static bool checkArithmeticIncompletePointerType(Sema &S, SourceLocation Loc, Expr *Operand) { QualType ResType = Operand->getType(); if (const AtomicType *ResAtomicType = ResType->getAs()) ResType = ResAtomicType->getValueType(); assert(ResType->isAnyPointerType() && !ResType->isDependentType()); QualType PointeeTy = ResType->getPointeeType(); return S.RequireCompleteType(Loc, PointeeTy, diag::err_typecheck_arithmetic_incomplete_type, PointeeTy, Operand->getSourceRange()); } /// \brief Check the validity of an arithmetic pointer operand. /// /// If the operand has pointer type, this code will check for pointer types /// which are invalid in arithmetic operations. These will be diagnosed /// appropriately, including whether or not the use is supported as an /// extension. /// /// \returns True when the operand is valid to use (even if as an extension). static bool checkArithmeticOpPointerOperand(Sema &S, SourceLocation Loc, Expr *Operand) { QualType ResType = Operand->getType(); if (const AtomicType *ResAtomicType = ResType->getAs()) ResType = ResAtomicType->getValueType(); if (!ResType->isAnyPointerType()) return true; QualType PointeeTy = ResType->getPointeeType(); if (PointeeTy->isVoidType()) { diagnoseArithmeticOnVoidPointer(S, Loc, Operand); return !S.getLangOpts().CPlusPlus; } if (PointeeTy->isFunctionType()) { diagnoseArithmeticOnFunctionPointer(S, Loc, Operand); return !S.getLangOpts().CPlusPlus; } if (checkArithmeticIncompletePointerType(S, Loc, Operand)) return false; return true; } /// \brief Check the validity of a binary arithmetic operation w.r.t. pointer /// operands. /// /// This routine will diagnose any invalid arithmetic on pointer operands much /// like \see checkArithmeticOpPointerOperand. However, it has special logic /// for emitting a single diagnostic even for operations where both LHS and RHS /// are (potentially problematic) pointers. /// /// \returns True when the operand is valid to use (even if as an extension). static bool checkArithmeticBinOpPointerOperands(Sema &S, SourceLocation Loc, Expr *LHSExpr, Expr *RHSExpr) { bool isLHSPointer = LHSExpr->getType()->isAnyPointerType(); bool isRHSPointer = RHSExpr->getType()->isAnyPointerType(); if (!isLHSPointer && !isRHSPointer) return true; QualType LHSPointeeTy, RHSPointeeTy; if (isLHSPointer) LHSPointeeTy = LHSExpr->getType()->getPointeeType(); if (isRHSPointer) RHSPointeeTy = RHSExpr->getType()->getPointeeType(); // if both are pointers check if operation is valid wrt address spaces if (S.getLangOpts().OpenCL && isLHSPointer && isRHSPointer) { const PointerType *lhsPtr = LHSExpr->getType()->getAs(); const PointerType *rhsPtr = RHSExpr->getType()->getAs(); if (!lhsPtr->isAddressSpaceOverlapping(*rhsPtr)) { S.Diag(Loc, diag::err_typecheck_op_on_nonoverlapping_address_space_pointers) << LHSExpr->getType() << RHSExpr->getType() << 1 /*arithmetic op*/ << LHSExpr->getSourceRange() << RHSExpr->getSourceRange(); return false; } } // Check for arithmetic on pointers to incomplete types. bool isLHSVoidPtr = isLHSPointer && LHSPointeeTy->isVoidType(); bool isRHSVoidPtr = isRHSPointer && RHSPointeeTy->isVoidType(); if (isLHSVoidPtr || isRHSVoidPtr) { if (!isRHSVoidPtr) diagnoseArithmeticOnVoidPointer(S, Loc, LHSExpr); else if (!isLHSVoidPtr) diagnoseArithmeticOnVoidPointer(S, Loc, RHSExpr); else diagnoseArithmeticOnTwoVoidPointers(S, Loc, LHSExpr, RHSExpr); return !S.getLangOpts().CPlusPlus; } bool isLHSFuncPtr = isLHSPointer && LHSPointeeTy->isFunctionType(); bool isRHSFuncPtr = isRHSPointer && RHSPointeeTy->isFunctionType(); if (isLHSFuncPtr || isRHSFuncPtr) { if (!isRHSFuncPtr) diagnoseArithmeticOnFunctionPointer(S, Loc, LHSExpr); else if (!isLHSFuncPtr) diagnoseArithmeticOnFunctionPointer(S, Loc, RHSExpr); else diagnoseArithmeticOnTwoFunctionPointers(S, Loc, LHSExpr, RHSExpr); return !S.getLangOpts().CPlusPlus; } if (isLHSPointer && checkArithmeticIncompletePointerType(S, Loc, LHSExpr)) return false; if (isRHSPointer && checkArithmeticIncompletePointerType(S, Loc, RHSExpr)) return false; return true; } /// diagnoseStringPlusInt - Emit a warning when adding an integer to a string /// literal. static void diagnoseStringPlusInt(Sema &Self, SourceLocation OpLoc, Expr *LHSExpr, Expr *RHSExpr) { StringLiteral* StrExpr = dyn_cast(LHSExpr->IgnoreImpCasts()); Expr* IndexExpr = RHSExpr; if (!StrExpr) { StrExpr = dyn_cast(RHSExpr->IgnoreImpCasts()); IndexExpr = LHSExpr; } bool IsStringPlusInt = StrExpr && IndexExpr->getType()->isIntegralOrUnscopedEnumerationType(); if (!IsStringPlusInt || IndexExpr->isValueDependent()) return; llvm::APSInt index; if (IndexExpr->EvaluateAsInt(index, Self.getASTContext())) { unsigned StrLenWithNull = StrExpr->getLength() + 1; if (index.isNonNegative() && index <= llvm::APSInt(llvm::APInt(index.getBitWidth(), StrLenWithNull), index.isUnsigned())) return; } SourceRange DiagRange(LHSExpr->getLocStart(), RHSExpr->getLocEnd()); Self.Diag(OpLoc, diag::warn_string_plus_int) << DiagRange << IndexExpr->IgnoreImpCasts()->getType(); // Only print a fixit for "str" + int, not for int + "str". if (IndexExpr == RHSExpr) { SourceLocation EndLoc = Self.getLocForEndOfToken(RHSExpr->getLocEnd()); Self.Diag(OpLoc, diag::note_string_plus_scalar_silence) << FixItHint::CreateInsertion(LHSExpr->getLocStart(), "&") << FixItHint::CreateReplacement(SourceRange(OpLoc), "[") << FixItHint::CreateInsertion(EndLoc, "]"); } else Self.Diag(OpLoc, diag::note_string_plus_scalar_silence); } /// \brief Emit a warning when adding a char literal to a string. static void diagnoseStringPlusChar(Sema &Self, SourceLocation OpLoc, Expr *LHSExpr, Expr *RHSExpr) { const Expr *StringRefExpr = LHSExpr; const CharacterLiteral *CharExpr = dyn_cast(RHSExpr->IgnoreImpCasts()); if (!CharExpr) { CharExpr = dyn_cast(LHSExpr->IgnoreImpCasts()); StringRefExpr = RHSExpr; } if (!CharExpr || !StringRefExpr) return; const QualType StringType = StringRefExpr->getType(); // Return if not a PointerType. if (!StringType->isAnyPointerType()) return; // Return if not a CharacterType. if (!StringType->getPointeeType()->isAnyCharacterType()) return; ASTContext &Ctx = Self.getASTContext(); SourceRange DiagRange(LHSExpr->getLocStart(), RHSExpr->getLocEnd()); const QualType CharType = CharExpr->getType(); if (!CharType->isAnyCharacterType() && CharType->isIntegerType() && llvm::isUIntN(Ctx.getCharWidth(), CharExpr->getValue())) { Self.Diag(OpLoc, diag::warn_string_plus_char) << DiagRange << Ctx.CharTy; } else { Self.Diag(OpLoc, diag::warn_string_plus_char) << DiagRange << CharExpr->getType(); } // Only print a fixit for str + char, not for char + str. if (isa(RHSExpr->IgnoreImpCasts())) { SourceLocation EndLoc = Self.getLocForEndOfToken(RHSExpr->getLocEnd()); Self.Diag(OpLoc, diag::note_string_plus_scalar_silence) << FixItHint::CreateInsertion(LHSExpr->getLocStart(), "&") << FixItHint::CreateReplacement(SourceRange(OpLoc), "[") << FixItHint::CreateInsertion(EndLoc, "]"); } else { Self.Diag(OpLoc, diag::note_string_plus_scalar_silence); } } /// \brief Emit error when two pointers are incompatible. static void diagnosePointerIncompatibility(Sema &S, SourceLocation Loc, Expr *LHSExpr, Expr *RHSExpr) { assert(LHSExpr->getType()->isAnyPointerType()); assert(RHSExpr->getType()->isAnyPointerType()); S.Diag(Loc, diag::err_typecheck_sub_ptr_compatible) << LHSExpr->getType() << RHSExpr->getType() << LHSExpr->getSourceRange() << RHSExpr->getSourceRange(); } // C99 6.5.6 QualType Sema::CheckAdditionOperands(ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, BinaryOperatorKind Opc, QualType* CompLHSTy) { checkArithmeticNull(*this, LHS, RHS, Loc, /*isCompare=*/false); if (LHS.get()->getType()->isVectorType() || RHS.get()->getType()->isVectorType()) { QualType compType = CheckVectorOperands( LHS, RHS, Loc, CompLHSTy, /*AllowBothBool*/getLangOpts().AltiVec, /*AllowBoolConversions*/getLangOpts().ZVector); if (CompLHSTy) *CompLHSTy = compType; return compType; } QualType compType = UsualArithmeticConversions(LHS, RHS, CompLHSTy); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); // Diagnose "string literal" '+' int and string '+' "char literal". if (Opc == BO_Add) { diagnoseStringPlusInt(*this, Loc, LHS.get(), RHS.get()); diagnoseStringPlusChar(*this, Loc, LHS.get(), RHS.get()); } // handle the common case first (both operands are arithmetic). if (!compType.isNull() && compType->isArithmeticType()) { if (CompLHSTy) *CompLHSTy = compType; return compType; } // Type-checking. Ultimately the pointer's going to be in PExp; // note that we bias towards the LHS being the pointer. Expr *PExp = LHS.get(), *IExp = RHS.get(); bool isObjCPointer; if (PExp->getType()->isPointerType()) { isObjCPointer = false; } else if (PExp->getType()->isObjCObjectPointerType()) { isObjCPointer = true; } else { std::swap(PExp, IExp); if (PExp->getType()->isPointerType()) { isObjCPointer = false; } else if (PExp->getType()->isObjCObjectPointerType()) { isObjCPointer = true; } else { return InvalidOperands(Loc, LHS, RHS); } } assert(PExp->getType()->isAnyPointerType()); if (!IExp->getType()->isIntegerType()) return InvalidOperands(Loc, LHS, RHS); if (!checkArithmeticOpPointerOperand(*this, Loc, PExp)) return QualType(); if (isObjCPointer && checkArithmeticOnObjCPointer(*this, Loc, PExp)) return QualType(); // Check array bounds for pointer arithemtic CheckArrayAccess(PExp, IExp); if (CompLHSTy) { QualType LHSTy = Context.isPromotableBitField(LHS.get()); if (LHSTy.isNull()) { LHSTy = LHS.get()->getType(); if (LHSTy->isPromotableIntegerType()) LHSTy = Context.getPromotedIntegerType(LHSTy); } *CompLHSTy = LHSTy; } return PExp->getType(); } // C99 6.5.6 QualType Sema::CheckSubtractionOperands(ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, QualType* CompLHSTy) { checkArithmeticNull(*this, LHS, RHS, Loc, /*isCompare=*/false); if (LHS.get()->getType()->isVectorType() || RHS.get()->getType()->isVectorType()) { QualType compType = CheckVectorOperands( LHS, RHS, Loc, CompLHSTy, /*AllowBothBool*/getLangOpts().AltiVec, /*AllowBoolConversions*/getLangOpts().ZVector); if (CompLHSTy) *CompLHSTy = compType; return compType; } QualType compType = UsualArithmeticConversions(LHS, RHS, CompLHSTy); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); // Enforce type constraints: C99 6.5.6p3. // Handle the common case first (both operands are arithmetic). if (!compType.isNull() && compType->isArithmeticType()) { if (CompLHSTy) *CompLHSTy = compType; return compType; } // Either ptr - int or ptr - ptr. if (LHS.get()->getType()->isAnyPointerType()) { QualType lpointee = LHS.get()->getType()->getPointeeType(); // Diagnose bad cases where we step over interface counts. if (LHS.get()->getType()->isObjCObjectPointerType() && checkArithmeticOnObjCPointer(*this, Loc, LHS.get())) return QualType(); // The result type of a pointer-int computation is the pointer type. if (RHS.get()->getType()->isIntegerType()) { if (!checkArithmeticOpPointerOperand(*this, Loc, LHS.get())) return QualType(); // Check array bounds for pointer arithemtic CheckArrayAccess(LHS.get(), RHS.get(), /*ArraySubscriptExpr*/nullptr, /*AllowOnePastEnd*/true, /*IndexNegated*/true); if (CompLHSTy) *CompLHSTy = LHS.get()->getType(); return LHS.get()->getType(); } // Handle pointer-pointer subtractions. if (const PointerType *RHSPTy = RHS.get()->getType()->getAs()) { QualType rpointee = RHSPTy->getPointeeType(); if (getLangOpts().CPlusPlus) { // Pointee types must be the same: C++ [expr.add] if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) { diagnosePointerIncompatibility(*this, Loc, LHS.get(), RHS.get()); } } else { // Pointee types must be compatible C99 6.5.6p3 if (!Context.typesAreCompatible( Context.getCanonicalType(lpointee).getUnqualifiedType(), Context.getCanonicalType(rpointee).getUnqualifiedType())) { diagnosePointerIncompatibility(*this, Loc, LHS.get(), RHS.get()); return QualType(); } } if (!checkArithmeticBinOpPointerOperands(*this, Loc, LHS.get(), RHS.get())) return QualType(); // The pointee type may have zero size. As an extension, a structure or // union may have zero size or an array may have zero length. In this // case subtraction does not make sense. if (!rpointee->isVoidType() && !rpointee->isFunctionType()) { CharUnits ElementSize = Context.getTypeSizeInChars(rpointee); if (ElementSize.isZero()) { Diag(Loc,diag::warn_sub_ptr_zero_size_types) << rpointee.getUnqualifiedType() << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); } } if (CompLHSTy) *CompLHSTy = LHS.get()->getType(); return Context.getPointerDiffType(); } } return InvalidOperands(Loc, LHS, RHS); } static bool isScopedEnumerationType(QualType T) { if (const EnumType *ET = T->getAs()) return ET->getDecl()->isScoped(); return false; } static void DiagnoseBadShiftValues(Sema& S, ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, BinaryOperatorKind Opc, QualType LHSType) { // OpenCL 6.3j: shift values are effectively % word size of LHS (more defined), // so skip remaining warnings as we don't want to modify values within Sema. if (S.getLangOpts().OpenCL) return; llvm::APSInt Right; // Check right/shifter operand if (RHS.get()->isValueDependent() || !RHS.get()->EvaluateAsInt(Right, S.Context)) return; if (Right.isNegative()) { S.DiagRuntimeBehavior(Loc, RHS.get(), S.PDiag(diag::warn_shift_negative) << RHS.get()->getSourceRange()); return; } llvm::APInt LeftBits(Right.getBitWidth(), S.Context.getTypeSize(LHS.get()->getType())); if (Right.uge(LeftBits)) { S.DiagRuntimeBehavior(Loc, RHS.get(), S.PDiag(diag::warn_shift_gt_typewidth) << RHS.get()->getSourceRange()); return; } if (Opc != BO_Shl) return; // When left shifting an ICE which is signed, we can check for overflow which // according to C++ has undefined behavior ([expr.shift] 5.8/2). Unsigned // integers have defined behavior modulo one more than the maximum value // representable in the result type, so never warn for those. llvm::APSInt Left; if (LHS.get()->isValueDependent() || LHSType->hasUnsignedIntegerRepresentation() || !LHS.get()->EvaluateAsInt(Left, S.Context)) return; // If LHS does not have a signed type and non-negative value // then, the behavior is undefined. Warn about it. if (Left.isNegative()) { S.DiagRuntimeBehavior(Loc, LHS.get(), S.PDiag(diag::warn_shift_lhs_negative) << LHS.get()->getSourceRange()); return; } llvm::APInt ResultBits = static_cast(Right) + Left.getMinSignedBits(); if (LeftBits.uge(ResultBits)) return; llvm::APSInt Result = Left.extend(ResultBits.getLimitedValue()); Result = Result.shl(Right); // Print the bit representation of the signed integer as an unsigned // hexadecimal number. SmallString<40> HexResult; Result.toString(HexResult, 16, /*Signed =*/false, /*Literal =*/true); // If we are only missing a sign bit, this is less likely to result in actual // bugs -- if the result is cast back to an unsigned type, it will have the // expected value. Thus we place this behind a different warning that can be // turned off separately if needed. if (LeftBits == ResultBits - 1) { S.Diag(Loc, diag::warn_shift_result_sets_sign_bit) << HexResult << LHSType << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return; } S.Diag(Loc, diag::warn_shift_result_gt_typewidth) << HexResult.str() << Result.getMinSignedBits() << LHSType << Left.getBitWidth() << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); } /// \brief Return the resulting type when an OpenCL vector is shifted /// by a scalar or vector shift amount. static QualType checkOpenCLVectorShift(Sema &S, ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsCompAssign) { // OpenCL v1.1 s6.3.j says RHS can be a vector only if LHS is a vector. if (!LHS.get()->getType()->isVectorType()) { S.Diag(Loc, diag::err_shift_rhs_only_vector) << RHS.get()->getType() << LHS.get()->getType() << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } if (!IsCompAssign) { LHS = S.UsualUnaryConversions(LHS.get()); if (LHS.isInvalid()) return QualType(); } RHS = S.UsualUnaryConversions(RHS.get()); if (RHS.isInvalid()) return QualType(); QualType LHSType = LHS.get()->getType(); const VectorType *LHSVecTy = LHSType->getAs(); QualType LHSEleType = LHSVecTy->getElementType(); // Note that RHS might not be a vector. QualType RHSType = RHS.get()->getType(); const VectorType *RHSVecTy = RHSType->getAs(); QualType RHSEleType = RHSVecTy ? RHSVecTy->getElementType() : RHSType; // OpenCL v1.1 s6.3.j says that the operands need to be integers. if (!LHSEleType->isIntegerType()) { S.Diag(Loc, diag::err_typecheck_expect_int) << LHS.get()->getType() << LHS.get()->getSourceRange(); return QualType(); } if (!RHSEleType->isIntegerType()) { S.Diag(Loc, diag::err_typecheck_expect_int) << RHS.get()->getType() << RHS.get()->getSourceRange(); return QualType(); } if (RHSVecTy) { // OpenCL v1.1 s6.3.j says that for vector types, the operators // are applied component-wise. So if RHS is a vector, then ensure // that the number of elements is the same as LHS... if (RHSVecTy->getNumElements() != LHSVecTy->getNumElements()) { S.Diag(Loc, diag::err_typecheck_vector_lengths_not_equal) << LHS.get()->getType() << RHS.get()->getType() << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); return QualType(); } } else { // ...else expand RHS to match the number of elements in LHS. QualType VecTy = S.Context.getExtVectorType(RHSEleType, LHSVecTy->getNumElements()); RHS = S.ImpCastExprToType(RHS.get(), VecTy, CK_VectorSplat); } return LHSType; } // C99 6.5.7 QualType Sema::CheckShiftOperands(ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, BinaryOperatorKind Opc, bool IsCompAssign) { checkArithmeticNull(*this, LHS, RHS, Loc, /*isCompare=*/false); // Vector shifts promote their scalar inputs to vector type. if (LHS.get()->getType()->isVectorType() || RHS.get()->getType()->isVectorType()) { if (LangOpts.OpenCL) return checkOpenCLVectorShift(*this, LHS, RHS, Loc, IsCompAssign); if (LangOpts.ZVector) { // The shift operators for the z vector extensions work basically // like OpenCL shifts, except that neither the LHS nor the RHS is // allowed to be a "vector bool". if (auto LHSVecType = LHS.get()->getType()->getAs()) if (LHSVecType->getVectorKind() == VectorType::AltiVecBool) return InvalidOperands(Loc, LHS, RHS); if (auto RHSVecType = RHS.get()->getType()->getAs()) if (RHSVecType->getVectorKind() == VectorType::AltiVecBool) return InvalidOperands(Loc, LHS, RHS); return checkOpenCLVectorShift(*this, LHS, RHS, Loc, IsCompAssign); } return CheckVectorOperands(LHS, RHS, Loc, IsCompAssign, /*AllowBothBool*/true, /*AllowBoolConversions*/false); } // Shifts don't perform usual arithmetic conversions, they just do integer // promotions on each operand. C99 6.5.7p3 // For the LHS, do usual unary conversions, but then reset them away // if this is a compound assignment. ExprResult OldLHS = LHS; LHS = UsualUnaryConversions(LHS.get()); if (LHS.isInvalid()) return QualType(); QualType LHSType = LHS.get()->getType(); if (IsCompAssign) LHS = OldLHS; // The RHS is simpler. RHS = UsualUnaryConversions(RHS.get()); if (RHS.isInvalid()) return QualType(); QualType RHSType = RHS.get()->getType(); // C99 6.5.7p2: Each of the operands shall have integer type. if (!LHSType->hasIntegerRepresentation() || !RHSType->hasIntegerRepresentation()) return InvalidOperands(Loc, LHS, RHS); // C++0x: Don't allow scoped enums. FIXME: Use something better than // hasIntegerRepresentation() above instead of this. if (isScopedEnumerationType(LHSType) || isScopedEnumerationType(RHSType)) { return InvalidOperands(Loc, LHS, RHS); } // Sanity-check shift operands DiagnoseBadShiftValues(*this, LHS, RHS, Loc, Opc, LHSType); // "The type of the result is that of the promoted left operand." return LHSType; } static bool IsWithinTemplateSpecialization(Decl *D) { if (DeclContext *DC = D->getDeclContext()) { if (isa(DC)) return true; if (FunctionDecl *FD = dyn_cast(DC)) return FD->isFunctionTemplateSpecialization(); } return false; } /// If two different enums are compared, raise a warning. static void checkEnumComparison(Sema &S, SourceLocation Loc, Expr *LHS, Expr *RHS) { QualType LHSStrippedType = LHS->IgnoreParenImpCasts()->getType(); QualType RHSStrippedType = RHS->IgnoreParenImpCasts()->getType(); const EnumType *LHSEnumType = LHSStrippedType->getAs(); if (!LHSEnumType) return; const EnumType *RHSEnumType = RHSStrippedType->getAs(); if (!RHSEnumType) return; // Ignore anonymous enums. if (!LHSEnumType->getDecl()->getIdentifier()) return; if (!RHSEnumType->getDecl()->getIdentifier()) return; if (S.Context.hasSameUnqualifiedType(LHSStrippedType, RHSStrippedType)) return; S.Diag(Loc, diag::warn_comparison_of_mixed_enum_types) << LHSStrippedType << RHSStrippedType << LHS->getSourceRange() << RHS->getSourceRange(); } /// \brief Diagnose bad pointer comparisons. static void diagnoseDistinctPointerComparison(Sema &S, SourceLocation Loc, ExprResult &LHS, ExprResult &RHS, bool IsError) { S.Diag(Loc, IsError ? diag::err_typecheck_comparison_of_distinct_pointers : diag::ext_typecheck_comparison_of_distinct_pointers) << LHS.get()->getType() << RHS.get()->getType() << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); } /// \brief Returns false if the pointers are converted to a composite type, /// true otherwise. static bool convertPointersToCompositeType(Sema &S, SourceLocation Loc, ExprResult &LHS, ExprResult &RHS) { // C++ [expr.rel]p2: // [...] Pointer conversions (4.10) and qualification // conversions (4.4) are performed on pointer operands (or on // a pointer operand and a null pointer constant) to bring // them to their composite pointer type. [...] // // C++ [expr.eq]p1 uses the same notion for (in)equality // comparisons of pointers. // C++ [expr.eq]p2: // In addition, pointers to members can be compared, or a pointer to // member and a null pointer constant. Pointer to member conversions // (4.11) and qualification conversions (4.4) are performed to bring // them to a common type. If one operand is a null pointer constant, // the common type is the type of the other operand. Otherwise, the // common type is a pointer to member type similar (4.4) to the type // of one of the operands, with a cv-qualification signature (4.4) // that is the union of the cv-qualification signatures of the operand // types. QualType LHSType = LHS.get()->getType(); QualType RHSType = RHS.get()->getType(); assert((LHSType->isPointerType() && RHSType->isPointerType()) || (LHSType->isMemberPointerType() && RHSType->isMemberPointerType())); bool NonStandardCompositeType = false; bool *BoolPtr = S.isSFINAEContext() ? nullptr : &NonStandardCompositeType; QualType T = S.FindCompositePointerType(Loc, LHS, RHS, BoolPtr); if (T.isNull()) { diagnoseDistinctPointerComparison(S, Loc, LHS, RHS, /*isError*/true); return true; } if (NonStandardCompositeType) S.Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) << LHSType << RHSType << T << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); LHS = S.ImpCastExprToType(LHS.get(), T, CK_BitCast); RHS = S.ImpCastExprToType(RHS.get(), T, CK_BitCast); return false; } static void diagnoseFunctionPointerToVoidComparison(Sema &S, SourceLocation Loc, ExprResult &LHS, ExprResult &RHS, bool IsError) { S.Diag(Loc, IsError ? diag::err_typecheck_comparison_of_fptr_to_void : diag::ext_typecheck_comparison_of_fptr_to_void) << LHS.get()->getType() << RHS.get()->getType() << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); } static bool isObjCObjectLiteral(ExprResult &E) { switch (E.get()->IgnoreParenImpCasts()->getStmtClass()) { case Stmt::ObjCArrayLiteralClass: case Stmt::ObjCDictionaryLiteralClass: case Stmt::ObjCStringLiteralClass: case Stmt::ObjCBoxedExprClass: return true; default: // Note that ObjCBoolLiteral is NOT an object literal! return false; } } static bool hasIsEqualMethod(Sema &S, const Expr *LHS, const Expr *RHS) { const ObjCObjectPointerType *Type = LHS->getType()->getAs(); // If this is not actually an Objective-C object, bail out. if (!Type) return false; // Get the LHS object's interface type. QualType InterfaceType = Type->getPointeeType(); // If the RHS isn't an Objective-C object, bail out. if (!RHS->getType()->isObjCObjectPointerType()) return false; // Try to find the -isEqual: method. Selector IsEqualSel = S.NSAPIObj->getIsEqualSelector(); ObjCMethodDecl *Method = S.LookupMethodInObjectType(IsEqualSel, InterfaceType, /*instance=*/true); if (!Method) { if (Type->isObjCIdType()) { // For 'id', just check the global pool. Method = S.LookupInstanceMethodInGlobalPool(IsEqualSel, SourceRange(), /*receiverId=*/true); } else { // Check protocols. Method = S.LookupMethodInQualifiedType(IsEqualSel, Type, /*instance=*/true); } } if (!Method) return false; QualType T = Method->parameters()[0]->getType(); if (!T->isObjCObjectPointerType()) return false; QualType R = Method->getReturnType(); if (!R->isScalarType()) return false; return true; } Sema::ObjCLiteralKind Sema::CheckLiteralKind(Expr *FromE) { FromE = FromE->IgnoreParenImpCasts(); switch (FromE->getStmtClass()) { default: break; case Stmt::ObjCStringLiteralClass: // "string literal" return LK_String; case Stmt::ObjCArrayLiteralClass: // "array literal" return LK_Array; case Stmt::ObjCDictionaryLiteralClass: // "dictionary literal" return LK_Dictionary; case Stmt::BlockExprClass: return LK_Block; case Stmt::ObjCBoxedExprClass: { Expr *Inner = cast(FromE)->getSubExpr()->IgnoreParens(); switch (Inner->getStmtClass()) { case Stmt::IntegerLiteralClass: case Stmt::FloatingLiteralClass: case Stmt::CharacterLiteralClass: case Stmt::ObjCBoolLiteralExprClass: case Stmt::CXXBoolLiteralExprClass: // "numeric literal" return LK_Numeric; case Stmt::ImplicitCastExprClass: { CastKind CK = cast(Inner)->getCastKind(); // Boolean literals can be represented by implicit casts. if (CK == CK_IntegralToBoolean || CK == CK_IntegralCast) return LK_Numeric; break; } default: break; } return LK_Boxed; } } return LK_None; } static void diagnoseObjCLiteralComparison(Sema &S, SourceLocation Loc, ExprResult &LHS, ExprResult &RHS, BinaryOperator::Opcode Opc){ Expr *Literal; Expr *Other; if (isObjCObjectLiteral(LHS)) { Literal = LHS.get(); Other = RHS.get(); } else { Literal = RHS.get(); Other = LHS.get(); } // Don't warn on comparisons against nil. Other = Other->IgnoreParenCasts(); if (Other->isNullPointerConstant(S.getASTContext(), Expr::NPC_ValueDependentIsNotNull)) return; // This should be kept in sync with warn_objc_literal_comparison. // LK_String should always be after the other literals, since it has its own // warning flag. Sema::ObjCLiteralKind LiteralKind = S.CheckLiteralKind(Literal); assert(LiteralKind != Sema::LK_Block); if (LiteralKind == Sema::LK_None) { llvm_unreachable("Unknown Objective-C object literal kind"); } if (LiteralKind == Sema::LK_String) S.Diag(Loc, diag::warn_objc_string_literal_comparison) << Literal->getSourceRange(); else S.Diag(Loc, diag::warn_objc_literal_comparison) << LiteralKind << Literal->getSourceRange(); if (BinaryOperator::isEqualityOp(Opc) && hasIsEqualMethod(S, LHS.get(), RHS.get())) { SourceLocation Start = LHS.get()->getLocStart(); SourceLocation End = S.getLocForEndOfToken(RHS.get()->getLocEnd()); CharSourceRange OpRange = CharSourceRange::getCharRange(Loc, S.getLocForEndOfToken(Loc)); S.Diag(Loc, diag::note_objc_literal_comparison_isequal) << FixItHint::CreateInsertion(Start, Opc == BO_EQ ? "[" : "![") << FixItHint::CreateReplacement(OpRange, " isEqual:") << FixItHint::CreateInsertion(End, "]"); } } static void diagnoseLogicalNotOnLHSofComparison(Sema &S, ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, BinaryOperatorKind Opc) { // Check that left hand side is !something. UnaryOperator *UO = dyn_cast(LHS.get()->IgnoreImpCasts()); if (!UO || UO->getOpcode() != UO_LNot) return; // Only check if the right hand side is non-bool arithmetic type. if (RHS.get()->isKnownToHaveBooleanValue()) return; // Make sure that the something in !something is not bool. Expr *SubExpr = UO->getSubExpr()->IgnoreImpCasts(); if (SubExpr->isKnownToHaveBooleanValue()) return; // Emit warning. S.Diag(UO->getOperatorLoc(), diag::warn_logical_not_on_lhs_of_comparison) << Loc; // First note suggest !(x < y) SourceLocation FirstOpen = SubExpr->getLocStart(); SourceLocation FirstClose = RHS.get()->getLocEnd(); FirstClose = S.getLocForEndOfToken(FirstClose); if (FirstClose.isInvalid()) FirstOpen = SourceLocation(); S.Diag(UO->getOperatorLoc(), diag::note_logical_not_fix) << FixItHint::CreateInsertion(FirstOpen, "(") << FixItHint::CreateInsertion(FirstClose, ")"); // Second note suggests (!x) < y SourceLocation SecondOpen = LHS.get()->getLocStart(); SourceLocation SecondClose = LHS.get()->getLocEnd(); SecondClose = S.getLocForEndOfToken(SecondClose); if (SecondClose.isInvalid()) SecondOpen = SourceLocation(); S.Diag(UO->getOperatorLoc(), diag::note_logical_not_silence_with_parens) << FixItHint::CreateInsertion(SecondOpen, "(") << FixItHint::CreateInsertion(SecondClose, ")"); } // Get the decl for a simple expression: a reference to a variable, // an implicit C++ field reference, or an implicit ObjC ivar reference. static ValueDecl *getCompareDecl(Expr *E) { if (DeclRefExpr* DR = dyn_cast(E)) return DR->getDecl(); if (ObjCIvarRefExpr* Ivar = dyn_cast(E)) { if (Ivar->isFreeIvar()) return Ivar->getDecl(); } if (MemberExpr* Mem = dyn_cast(E)) { if (Mem->isImplicitAccess()) return Mem->getMemberDecl(); } return nullptr; } // C99 6.5.8, C++ [expr.rel] QualType Sema::CheckCompareOperands(ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, BinaryOperatorKind Opc, bool IsRelational) { checkArithmeticNull(*this, LHS, RHS, Loc, /*isCompare=*/true); // Handle vector comparisons separately. if (LHS.get()->getType()->isVectorType() || RHS.get()->getType()->isVectorType()) return CheckVectorCompareOperands(LHS, RHS, Loc, IsRelational); QualType LHSType = LHS.get()->getType(); QualType RHSType = RHS.get()->getType(); Expr *LHSStripped = LHS.get()->IgnoreParenImpCasts(); Expr *RHSStripped = RHS.get()->IgnoreParenImpCasts(); checkEnumComparison(*this, Loc, LHS.get(), RHS.get()); diagnoseLogicalNotOnLHSofComparison(*this, LHS, RHS, Loc, Opc); if (!LHSType->hasFloatingRepresentation() && !(LHSType->isBlockPointerType() && IsRelational) && !LHS.get()->getLocStart().isMacroID() && !RHS.get()->getLocStart().isMacroID() && ActiveTemplateInstantiations.empty()) { // For non-floating point types, check for self-comparisons of the form // x == x, x != x, x < x, etc. These always evaluate to a constant, and // often indicate logic errors in the program. // // NOTE: Don't warn about comparison expressions resulting from macro // expansion. Also don't warn about comparisons which are only self // comparisons within a template specialization. The warnings should catch // obvious cases in the definition of the template anyways. The idea is to // warn when the typed comparison operator will always evaluate to the same // result. ValueDecl *DL = getCompareDecl(LHSStripped); ValueDecl *DR = getCompareDecl(RHSStripped); if (DL && DR && DL == DR && !IsWithinTemplateSpecialization(DL)) { DiagRuntimeBehavior(Loc, nullptr, PDiag(diag::warn_comparison_always) << 0 // self- << (Opc == BO_EQ || Opc == BO_LE || Opc == BO_GE)); } else if (DL && DR && LHSType->isArrayType() && RHSType->isArrayType() && !DL->getType()->isReferenceType() && !DR->getType()->isReferenceType()) { // what is it always going to eval to? char always_evals_to; switch(Opc) { case BO_EQ: // e.g. array1 == array2 always_evals_to = 0; // false break; case BO_NE: // e.g. array1 != array2 always_evals_to = 1; // true break; default: // best we can say is 'a constant' always_evals_to = 2; // e.g. array1 <= array2 break; } DiagRuntimeBehavior(Loc, nullptr, PDiag(diag::warn_comparison_always) << 1 // array << always_evals_to); } if (isa(LHSStripped)) LHSStripped = LHSStripped->IgnoreParenCasts(); if (isa(RHSStripped)) RHSStripped = RHSStripped->IgnoreParenCasts(); // Warn about comparisons against a string constant (unless the other // operand is null), the user probably wants strcmp. Expr *literalString = nullptr; Expr *literalStringStripped = nullptr; if ((isa(LHSStripped) || isa(LHSStripped)) && !RHSStripped->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { literalString = LHS.get(); literalStringStripped = LHSStripped; } else if ((isa(RHSStripped) || isa(RHSStripped)) && !LHSStripped->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { literalString = RHS.get(); literalStringStripped = RHSStripped; } if (literalString) { DiagRuntimeBehavior(Loc, nullptr, PDiag(diag::warn_stringcompare) << isa(literalStringStripped) << literalString->getSourceRange()); } } // C99 6.5.8p3 / C99 6.5.9p4 UsualArithmeticConversions(LHS, RHS); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); LHSType = LHS.get()->getType(); RHSType = RHS.get()->getType(); // The result of comparisons is 'bool' in C++, 'int' in C. QualType ResultTy = Context.getLogicalOperationType(); if (IsRelational) { if (LHSType->isRealType() && RHSType->isRealType()) return ResultTy; } else { // Check for comparisons of floating point operands using != and ==. if (LHSType->hasFloatingRepresentation()) CheckFloatComparison(Loc, LHS.get(), RHS.get()); if (LHSType->isArithmeticType() && RHSType->isArithmeticType()) return ResultTy; } const Expr::NullPointerConstantKind LHSNullKind = LHS.get()->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull); const Expr::NullPointerConstantKind RHSNullKind = RHS.get()->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull); bool LHSIsNull = LHSNullKind != Expr::NPCK_NotNull; bool RHSIsNull = RHSNullKind != Expr::NPCK_NotNull; if (!IsRelational && LHSIsNull != RHSIsNull) { bool IsEquality = Opc == BO_EQ; if (RHSIsNull) DiagnoseAlwaysNonNullPointer(LHS.get(), RHSNullKind, IsEquality, RHS.get()->getSourceRange()); else DiagnoseAlwaysNonNullPointer(RHS.get(), LHSNullKind, IsEquality, LHS.get()->getSourceRange()); } // All of the following pointer-related warnings are GCC extensions, except // when handling null pointer constants. if (LHSType->isPointerType() && RHSType->isPointerType()) { // C99 6.5.8p2 QualType LCanPointeeTy = LHSType->castAs()->getPointeeType().getCanonicalType(); QualType RCanPointeeTy = RHSType->castAs()->getPointeeType().getCanonicalType(); if (getLangOpts().CPlusPlus) { if (LCanPointeeTy == RCanPointeeTy) return ResultTy; if (!IsRelational && (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { // Valid unless comparison between non-null pointer and function pointer // This is a gcc extension compatibility comparison. // In a SFINAE context, we treat this as a hard error to maintain // conformance with the C++ standard. if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) && !LHSIsNull && !RHSIsNull) { diagnoseFunctionPointerToVoidComparison( *this, Loc, LHS, RHS, /*isError*/ (bool)isSFINAEContext()); if (isSFINAEContext()) return QualType(); RHS = ImpCastExprToType(RHS.get(), LHSType, CK_BitCast); return ResultTy; } } if (convertPointersToCompositeType(*this, Loc, LHS, RHS)) return QualType(); else return ResultTy; } // C99 6.5.9p2 and C99 6.5.8p2 if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(), RCanPointeeTy.getUnqualifiedType())) { // Valid unless a relational comparison of function pointers if (IsRelational && LCanPointeeTy->isFunctionType()) { Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers) << LHSType << RHSType << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); } } else if (!IsRelational && (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { // Valid unless comparison between non-null pointer and function pointer if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) && !LHSIsNull && !RHSIsNull) diagnoseFunctionPointerToVoidComparison(*this, Loc, LHS, RHS, /*isError*/false); } else { // Invalid diagnoseDistinctPointerComparison(*this, Loc, LHS, RHS, /*isError*/false); } if (LCanPointeeTy != RCanPointeeTy) { // Treat NULL constant as a special case in OpenCL. if (getLangOpts().OpenCL && !LHSIsNull && !RHSIsNull) { const PointerType *LHSPtr = LHSType->getAs(); if (!LHSPtr->isAddressSpaceOverlapping(*RHSType->getAs())) { Diag(Loc, diag::err_typecheck_op_on_nonoverlapping_address_space_pointers) << LHSType << RHSType << 0 /* comparison */ << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); } } unsigned AddrSpaceL = LCanPointeeTy.getAddressSpace(); unsigned AddrSpaceR = RCanPointeeTy.getAddressSpace(); CastKind Kind = AddrSpaceL != AddrSpaceR ? CK_AddressSpaceConversion : CK_BitCast; if (LHSIsNull && !RHSIsNull) LHS = ImpCastExprToType(LHS.get(), RHSType, Kind); else RHS = ImpCastExprToType(RHS.get(), LHSType, Kind); } return ResultTy; } if (getLangOpts().CPlusPlus) { // Comparison of nullptr_t with itself. if (LHSType->isNullPtrType() && RHSType->isNullPtrType()) return ResultTy; // Comparison of pointers with null pointer constants and equality // comparisons of member pointers to null pointer constants. if (RHSIsNull && ((LHSType->isAnyPointerType() || LHSType->isNullPtrType()) || (!IsRelational && (LHSType->isMemberPointerType() || LHSType->isBlockPointerType())))) { RHS = ImpCastExprToType(RHS.get(), LHSType, LHSType->isMemberPointerType() ? CK_NullToMemberPointer : CK_NullToPointer); return ResultTy; } if (LHSIsNull && ((RHSType->isAnyPointerType() || RHSType->isNullPtrType()) || (!IsRelational && (RHSType->isMemberPointerType() || RHSType->isBlockPointerType())))) { LHS = ImpCastExprToType(LHS.get(), RHSType, RHSType->isMemberPointerType() ? CK_NullToMemberPointer : CK_NullToPointer); return ResultTy; } // Comparison of member pointers. if (!IsRelational && LHSType->isMemberPointerType() && RHSType->isMemberPointerType()) { if (convertPointersToCompositeType(*this, Loc, LHS, RHS)) return QualType(); else return ResultTy; } // Handle scoped enumeration types specifically, since they don't promote // to integers. if (LHS.get()->getType()->isEnumeralType() && Context.hasSameUnqualifiedType(LHS.get()->getType(), RHS.get()->getType())) return ResultTy; } // Handle block pointer types. if (!IsRelational && LHSType->isBlockPointerType() && RHSType->isBlockPointerType()) { QualType lpointee = LHSType->castAs()->getPointeeType(); QualType rpointee = RHSType->castAs()->getPointeeType(); if (!LHSIsNull && !RHSIsNull && !Context.typesAreCompatible(lpointee, rpointee)) { Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) << LHSType << RHSType << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); } RHS = ImpCastExprToType(RHS.get(), LHSType, CK_BitCast); return ResultTy; } // Allow block pointers to be compared with null pointer constants. if (!IsRelational && ((LHSType->isBlockPointerType() && RHSType->isPointerType()) || (LHSType->isPointerType() && RHSType->isBlockPointerType()))) { if (!LHSIsNull && !RHSIsNull) { if (!((RHSType->isPointerType() && RHSType->castAs() ->getPointeeType()->isVoidType()) || (LHSType->isPointerType() && LHSType->castAs() ->getPointeeType()->isVoidType()))) Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) << LHSType << RHSType << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); } if (LHSIsNull && !RHSIsNull) LHS = ImpCastExprToType(LHS.get(), RHSType, RHSType->isPointerType() ? CK_BitCast : CK_AnyPointerToBlockPointerCast); else RHS = ImpCastExprToType(RHS.get(), LHSType, LHSType->isPointerType() ? CK_BitCast : CK_AnyPointerToBlockPointerCast); return ResultTy; } if (LHSType->isObjCObjectPointerType() || RHSType->isObjCObjectPointerType()) { const PointerType *LPT = LHSType->getAs(); const PointerType *RPT = RHSType->getAs(); if (LPT || RPT) { bool LPtrToVoid = LPT ? LPT->getPointeeType()->isVoidType() : false; bool RPtrToVoid = RPT ? RPT->getPointeeType()->isVoidType() : false; if (!LPtrToVoid && !RPtrToVoid && !Context.typesAreCompatible(LHSType, RHSType)) { diagnoseDistinctPointerComparison(*this, Loc, LHS, RHS, /*isError*/false); } if (LHSIsNull && !RHSIsNull) { Expr *E = LHS.get(); if (getLangOpts().ObjCAutoRefCount) CheckObjCARCConversion(SourceRange(), RHSType, E, CCK_ImplicitConversion); LHS = ImpCastExprToType(E, RHSType, RPT ? CK_BitCast :CK_CPointerToObjCPointerCast); } else { Expr *E = RHS.get(); if (getLangOpts().ObjCAutoRefCount) CheckObjCARCConversion(SourceRange(), LHSType, E, CCK_ImplicitConversion, false, Opc); RHS = ImpCastExprToType(E, LHSType, LPT ? CK_BitCast :CK_CPointerToObjCPointerCast); } return ResultTy; } if (LHSType->isObjCObjectPointerType() && RHSType->isObjCObjectPointerType()) { if (!Context.areComparableObjCPointerTypes(LHSType, RHSType)) diagnoseDistinctPointerComparison(*this, Loc, LHS, RHS, /*isError*/false); if (isObjCObjectLiteral(LHS) || isObjCObjectLiteral(RHS)) diagnoseObjCLiteralComparison(*this, Loc, LHS, RHS, Opc); if (LHSIsNull && !RHSIsNull) LHS = ImpCastExprToType(LHS.get(), RHSType, CK_BitCast); else RHS = ImpCastExprToType(RHS.get(), LHSType, CK_BitCast); return ResultTy; } } if ((LHSType->isAnyPointerType() && RHSType->isIntegerType()) || (LHSType->isIntegerType() && RHSType->isAnyPointerType())) { unsigned DiagID = 0; bool isError = false; if (LangOpts.DebuggerSupport) { // Under a debugger, allow the comparison of pointers to integers, // since users tend to want to compare addresses. } else if ((LHSIsNull && LHSType->isIntegerType()) || (RHSIsNull && RHSType->isIntegerType())) { if (IsRelational && !getLangOpts().CPlusPlus) DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; } else if (IsRelational && !getLangOpts().CPlusPlus) DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; else if (getLangOpts().CPlusPlus) { DiagID = diag::err_typecheck_comparison_of_pointer_integer; isError = true; } else DiagID = diag::ext_typecheck_comparison_of_pointer_integer; if (DiagID) { Diag(Loc, DiagID) << LHSType << RHSType << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); if (isError) return QualType(); } if (LHSType->isIntegerType()) LHS = ImpCastExprToType(LHS.get(), RHSType, LHSIsNull ? CK_NullToPointer : CK_IntegralToPointer); else RHS = ImpCastExprToType(RHS.get(), LHSType, RHSIsNull ? CK_NullToPointer : CK_IntegralToPointer); return ResultTy; } // Handle block pointers. if (!IsRelational && RHSIsNull && LHSType->isBlockPointerType() && RHSType->isIntegerType()) { RHS = ImpCastExprToType(RHS.get(), LHSType, CK_NullToPointer); return ResultTy; } if (!IsRelational && LHSIsNull && LHSType->isIntegerType() && RHSType->isBlockPointerType()) { LHS = ImpCastExprToType(LHS.get(), RHSType, CK_NullToPointer); return ResultTy; } return InvalidOperands(Loc, LHS, RHS); } // Return a signed type that is of identical size and number of elements. // For floating point vectors, return an integer type of identical size // and number of elements. QualType Sema::GetSignedVectorType(QualType V) { const VectorType *VTy = V->getAs(); unsigned TypeSize = Context.getTypeSize(VTy->getElementType()); if (TypeSize == Context.getTypeSize(Context.CharTy)) return Context.getExtVectorType(Context.CharTy, VTy->getNumElements()); else if (TypeSize == Context.getTypeSize(Context.ShortTy)) return Context.getExtVectorType(Context.ShortTy, VTy->getNumElements()); else if (TypeSize == Context.getTypeSize(Context.IntTy)) return Context.getExtVectorType(Context.IntTy, VTy->getNumElements()); else if (TypeSize == Context.getTypeSize(Context.LongTy)) return Context.getExtVectorType(Context.LongTy, VTy->getNumElements()); assert(TypeSize == Context.getTypeSize(Context.LongLongTy) && "Unhandled vector element size in vector compare"); return Context.getExtVectorType(Context.LongLongTy, VTy->getNumElements()); } /// CheckVectorCompareOperands - vector comparisons are a clang extension that /// operates on extended vector types. Instead of producing an IntTy result, /// like a scalar comparison, a vector comparison produces a vector of integer /// types. QualType Sema::CheckVectorCompareOperands(ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsRelational) { // Check to make sure we're operating on vectors of the same type and width, // Allowing one side to be a scalar of element type. QualType vType = CheckVectorOperands(LHS, RHS, Loc, /*isCompAssign*/false, /*AllowBothBool*/true, /*AllowBoolConversions*/getLangOpts().ZVector); if (vType.isNull()) return vType; QualType LHSType = LHS.get()->getType(); // If AltiVec, the comparison results in a numeric type, i.e. // bool for C++, int for C if (getLangOpts().AltiVec && vType->getAs()->getVectorKind() == VectorType::AltiVecVector) return Context.getLogicalOperationType(); // For non-floating point types, check for self-comparisons of the form // x == x, x != x, x < x, etc. These always evaluate to a constant, and // often indicate logic errors in the program. if (!LHSType->hasFloatingRepresentation() && ActiveTemplateInstantiations.empty()) { if (DeclRefExpr* DRL = dyn_cast(LHS.get()->IgnoreParenImpCasts())) if (DeclRefExpr* DRR = dyn_cast(RHS.get()->IgnoreParenImpCasts())) if (DRL->getDecl() == DRR->getDecl()) DiagRuntimeBehavior(Loc, nullptr, PDiag(diag::warn_comparison_always) << 0 // self- << 2 // "a constant" ); } // Check for comparisons of floating point operands using != and ==. if (!IsRelational && LHSType->hasFloatingRepresentation()) { assert (RHS.get()->getType()->hasFloatingRepresentation()); CheckFloatComparison(Loc, LHS.get(), RHS.get()); } // Return a signed type for the vector. return GetSignedVectorType(LHSType); } QualType Sema::CheckVectorLogicalOperands(ExprResult &LHS, ExprResult &RHS, SourceLocation Loc) { // Ensure that either both operands are of the same vector type, or // one operand is of a vector type and the other is of its element type. QualType vType = CheckVectorOperands(LHS, RHS, Loc, false, /*AllowBothBool*/true, /*AllowBoolConversions*/false); if (vType.isNull()) return InvalidOperands(Loc, LHS, RHS); if (getLangOpts().OpenCL && getLangOpts().OpenCLVersion < 120 && vType->hasFloatingRepresentation()) return InvalidOperands(Loc, LHS, RHS); return GetSignedVectorType(LHS.get()->getType()); } inline QualType Sema::CheckBitwiseOperands( ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsCompAssign) { checkArithmeticNull(*this, LHS, RHS, Loc, /*isCompare=*/false); if (LHS.get()->getType()->isVectorType() || RHS.get()->getType()->isVectorType()) { if (LHS.get()->getType()->hasIntegerRepresentation() && RHS.get()->getType()->hasIntegerRepresentation()) return CheckVectorOperands(LHS, RHS, Loc, IsCompAssign, /*AllowBothBool*/true, /*AllowBoolConversions*/getLangOpts().ZVector); return InvalidOperands(Loc, LHS, RHS); } ExprResult LHSResult = LHS, RHSResult = RHS; QualType compType = UsualArithmeticConversions(LHSResult, RHSResult, IsCompAssign); if (LHSResult.isInvalid() || RHSResult.isInvalid()) return QualType(); LHS = LHSResult.get(); RHS = RHSResult.get(); if (!compType.isNull() && compType->isIntegralOrUnscopedEnumerationType()) return compType; return InvalidOperands(Loc, LHS, RHS); } // C99 6.5.[13,14] inline QualType Sema::CheckLogicalOperands(ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, BinaryOperatorKind Opc) { // Check vector operands differently. if (LHS.get()->getType()->isVectorType() || RHS.get()->getType()->isVectorType()) return CheckVectorLogicalOperands(LHS, RHS, Loc); // Diagnose cases where the user write a logical and/or but probably meant a // bitwise one. We do this when the LHS is a non-bool integer and the RHS // is a constant. if (LHS.get()->getType()->isIntegerType() && !LHS.get()->getType()->isBooleanType() && RHS.get()->getType()->isIntegerType() && !RHS.get()->isValueDependent() && // Don't warn in macros or template instantiations. !Loc.isMacroID() && ActiveTemplateInstantiations.empty()) { // If the RHS can be constant folded, and if it constant folds to something // that isn't 0 or 1 (which indicate a potential logical operation that // happened to fold to true/false) then warn. // Parens on the RHS are ignored. llvm::APSInt Result; if (RHS.get()->EvaluateAsInt(Result, Context)) if ((getLangOpts().Bool && !RHS.get()->getType()->isBooleanType() && !RHS.get()->getExprLoc().isMacroID()) || (Result != 0 && Result != 1)) { Diag(Loc, diag::warn_logical_instead_of_bitwise) << RHS.get()->getSourceRange() << (Opc == BO_LAnd ? "&&" : "||"); // Suggest replacing the logical operator with the bitwise version Diag(Loc, diag::note_logical_instead_of_bitwise_change_operator) << (Opc == BO_LAnd ? "&" : "|") << FixItHint::CreateReplacement(SourceRange( Loc, getLocForEndOfToken(Loc)), Opc == BO_LAnd ? "&" : "|"); if (Opc == BO_LAnd) // Suggest replacing "Foo() && kNonZero" with "Foo()" Diag(Loc, diag::note_logical_instead_of_bitwise_remove_constant) << FixItHint::CreateRemoval( SourceRange(getLocForEndOfToken(LHS.get()->getLocEnd()), RHS.get()->getLocEnd())); } } if (!Context.getLangOpts().CPlusPlus) { // OpenCL v1.1 s6.3.g: The logical operators and (&&), or (||) do // not operate on the built-in scalar and vector float types. if (Context.getLangOpts().OpenCL && Context.getLangOpts().OpenCLVersion < 120) { if (LHS.get()->getType()->isFloatingType() || RHS.get()->getType()->isFloatingType()) return InvalidOperands(Loc, LHS, RHS); } LHS = UsualUnaryConversions(LHS.get()); if (LHS.isInvalid()) return QualType(); RHS = UsualUnaryConversions(RHS.get()); if (RHS.isInvalid()) return QualType(); if (!LHS.get()->getType()->isScalarType() || !RHS.get()->getType()->isScalarType()) return InvalidOperands(Loc, LHS, RHS); return Context.IntTy; } // The following is safe because we only use this method for // non-overloadable operands. // C++ [expr.log.and]p1 // C++ [expr.log.or]p1 // The operands are both contextually converted to type bool. ExprResult LHSRes = PerformContextuallyConvertToBool(LHS.get()); if (LHSRes.isInvalid()) return InvalidOperands(Loc, LHS, RHS); LHS = LHSRes; ExprResult RHSRes = PerformContextuallyConvertToBool(RHS.get()); if (RHSRes.isInvalid()) return InvalidOperands(Loc, LHS, RHS); RHS = RHSRes; // C++ [expr.log.and]p2 // C++ [expr.log.or]p2 // The result is a bool. return Context.BoolTy; } static bool IsReadonlyMessage(Expr *E, Sema &S) { const MemberExpr *ME = dyn_cast(E); if (!ME) return false; if (!isa(ME->getMemberDecl())) return false; ObjCMessageExpr *Base = dyn_cast(ME->getBase()->IgnoreParenImpCasts()); if (!Base) return false; return Base->getMethodDecl() != nullptr; } /// Is the given expression (which must be 'const') a reference to a /// variable which was originally non-const, but which has become /// 'const' due to being captured within a block? enum NonConstCaptureKind { NCCK_None, NCCK_Block, NCCK_Lambda }; static NonConstCaptureKind isReferenceToNonConstCapture(Sema &S, Expr *E) { assert(E->isLValue() && E->getType().isConstQualified()); E = E->IgnoreParens(); // Must be a reference to a declaration from an enclosing scope. DeclRefExpr *DRE = dyn_cast(E); if (!DRE) return NCCK_None; if (!DRE->refersToEnclosingVariableOrCapture()) return NCCK_None; // The declaration must be a variable which is not declared 'const'. VarDecl *var = dyn_cast(DRE->getDecl()); if (!var) return NCCK_None; if (var->getType().isConstQualified()) return NCCK_None; assert(var->hasLocalStorage() && "capture added 'const' to non-local?"); // Decide whether the first capture was for a block or a lambda. DeclContext *DC = S.CurContext, *Prev = nullptr; while (DC != var->getDeclContext()) { Prev = DC; DC = DC->getParent(); } // Unless we have an init-capture, we've gone one step too far. if (!var->isInitCapture()) DC = Prev; return (isa(DC) ? NCCK_Block : NCCK_Lambda); } static bool IsTypeModifiable(QualType Ty, bool IsDereference) { Ty = Ty.getNonReferenceType(); if (IsDereference && Ty->isPointerType()) Ty = Ty->getPointeeType(); return !Ty.isConstQualified(); } /// Emit the "read-only variable not assignable" error and print notes to give /// more information about why the variable is not assignable, such as pointing /// to the declaration of a const variable, showing that a method is const, or /// that the function is returning a const reference. static void DiagnoseConstAssignment(Sema &S, const Expr *E, SourceLocation Loc) { // Update err_typecheck_assign_const and note_typecheck_assign_const // when this enum is changed. enum { ConstFunction, ConstVariable, ConstMember, ConstMethod, ConstUnknown, // Keep as last element }; SourceRange ExprRange = E->getSourceRange(); // Only emit one error on the first const found. All other consts will emit // a note to the error. bool DiagnosticEmitted = false; // Track if the current expression is the result of a derefence, and if the // next checked expression is the result of a derefence. bool IsDereference = false; bool NextIsDereference = false; // Loop to process MemberExpr chains. while (true) { IsDereference = NextIsDereference; NextIsDereference = false; E = E->IgnoreParenImpCasts(); if (const MemberExpr *ME = dyn_cast(E)) { NextIsDereference = ME->isArrow(); const ValueDecl *VD = ME->getMemberDecl(); if (const FieldDecl *Field = dyn_cast(VD)) { // Mutable fields can be modified even if the class is const. if (Field->isMutable()) { assert(DiagnosticEmitted && "Expected diagnostic not emitted."); break; } if (!IsTypeModifiable(Field->getType(), IsDereference)) { if (!DiagnosticEmitted) { S.Diag(Loc, diag::err_typecheck_assign_const) << ExprRange << ConstMember << false /*static*/ << Field << Field->getType(); DiagnosticEmitted = true; } S.Diag(VD->getLocation(), diag::note_typecheck_assign_const) << ConstMember << false /*static*/ << Field << Field->getType() << Field->getSourceRange(); } E = ME->getBase(); continue; } else if (const VarDecl *VDecl = dyn_cast(VD)) { if (VDecl->getType().isConstQualified()) { if (!DiagnosticEmitted) { S.Diag(Loc, diag::err_typecheck_assign_const) << ExprRange << ConstMember << true /*static*/ << VDecl << VDecl->getType(); DiagnosticEmitted = true; } S.Diag(VD->getLocation(), diag::note_typecheck_assign_const) << ConstMember << true /*static*/ << VDecl << VDecl->getType() << VDecl->getSourceRange(); } // Static fields do not inherit constness from parents. break; } break; } // End MemberExpr break; } if (const CallExpr *CE = dyn_cast(E)) { // Function calls const FunctionDecl *FD = CE->getDirectCallee(); if (FD && !IsTypeModifiable(FD->getReturnType(), IsDereference)) { if (!DiagnosticEmitted) { S.Diag(Loc, diag::err_typecheck_assign_const) << ExprRange << ConstFunction << FD; DiagnosticEmitted = true; } S.Diag(FD->getReturnTypeSourceRange().getBegin(), diag::note_typecheck_assign_const) << ConstFunction << FD << FD->getReturnType() << FD->getReturnTypeSourceRange(); } } else if (const DeclRefExpr *DRE = dyn_cast(E)) { // Point to variable declaration. if (const ValueDecl *VD = DRE->getDecl()) { if (!IsTypeModifiable(VD->getType(), IsDereference)) { if (!DiagnosticEmitted) { S.Diag(Loc, diag::err_typecheck_assign_const) << ExprRange << ConstVariable << VD << VD->getType(); DiagnosticEmitted = true; } S.Diag(VD->getLocation(), diag::note_typecheck_assign_const) << ConstVariable << VD << VD->getType() << VD->getSourceRange(); } } } else if (isa(E)) { if (const DeclContext *DC = S.getFunctionLevelDeclContext()) { if (const CXXMethodDecl *MD = dyn_cast(DC)) { if (MD->isConst()) { if (!DiagnosticEmitted) { S.Diag(Loc, diag::err_typecheck_assign_const) << ExprRange << ConstMethod << MD; DiagnosticEmitted = true; } S.Diag(MD->getLocation(), diag::note_typecheck_assign_const) << ConstMethod << MD << MD->getSourceRange(); } } } } if (DiagnosticEmitted) return; // Can't determine a more specific message, so display the generic error. S.Diag(Loc, diag::err_typecheck_assign_const) << ExprRange << ConstUnknown; } /// CheckForModifiableLvalue - Verify that E is a modifiable lvalue. If not, /// emit an error and return true. If so, return false. static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { assert(!E->hasPlaceholderType(BuiltinType::PseudoObject)); SourceLocation OrigLoc = Loc; Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context, &Loc); if (IsLV == Expr::MLV_ClassTemporary && IsReadonlyMessage(E, S)) IsLV = Expr::MLV_InvalidMessageExpression; if (IsLV == Expr::MLV_Valid) return false; unsigned DiagID = 0; bool NeedType = false; switch (IsLV) { // C99 6.5.16p2 case Expr::MLV_ConstQualified: // Use a specialized diagnostic when we're assigning to an object // from an enclosing function or block. if (NonConstCaptureKind NCCK = isReferenceToNonConstCapture(S, E)) { if (NCCK == NCCK_Block) DiagID = diag::err_block_decl_ref_not_modifiable_lvalue; else DiagID = diag::err_lambda_decl_ref_not_modifiable_lvalue; break; } // In ARC, use some specialized diagnostics for occasions where we // infer 'const'. These are always pseudo-strong variables. if (S.getLangOpts().ObjCAutoRefCount) { DeclRefExpr *declRef = dyn_cast(E->IgnoreParenCasts()); if (declRef && isa(declRef->getDecl())) { VarDecl *var = cast(declRef->getDecl()); // Use the normal diagnostic if it's pseudo-__strong but the // user actually wrote 'const'. if (var->isARCPseudoStrong() && (!var->getTypeSourceInfo() || !var->getTypeSourceInfo()->getType().isConstQualified())) { // There are two pseudo-strong cases: // - self ObjCMethodDecl *method = S.getCurMethodDecl(); if (method && var == method->getSelfDecl()) DiagID = method->isClassMethod() ? diag::err_typecheck_arc_assign_self_class_method : diag::err_typecheck_arc_assign_self; // - fast enumeration variables else DiagID = diag::err_typecheck_arr_assign_enumeration; SourceRange Assign; if (Loc != OrigLoc) Assign = SourceRange(OrigLoc, OrigLoc); S.Diag(Loc, DiagID) << E->getSourceRange() << Assign; // We need to preserve the AST regardless, so migration tool // can do its job. return false; } } } // If none of the special cases above are triggered, then this is a // simple const assignment. if (DiagID == 0) { DiagnoseConstAssignment(S, E, Loc); return true; } break; case Expr::MLV_ConstAddrSpace: DiagnoseConstAssignment(S, E, Loc); return true; case Expr::MLV_ArrayType: case Expr::MLV_ArrayTemporary: DiagID = diag::err_typecheck_array_not_modifiable_lvalue; NeedType = true; break; case Expr::MLV_NotObjectType: DiagID = diag::err_typecheck_non_object_not_modifiable_lvalue; NeedType = true; break; case Expr::MLV_LValueCast: DiagID = diag::err_typecheck_lvalue_casts_not_supported; break; case Expr::MLV_Valid: llvm_unreachable("did not take early return for MLV_Valid"); case Expr::MLV_InvalidExpression: case Expr::MLV_MemberFunction: case Expr::MLV_ClassTemporary: DiagID = diag::err_typecheck_expression_not_modifiable_lvalue; break; case Expr::MLV_IncompleteType: case Expr::MLV_IncompleteVoidType: return S.RequireCompleteType(Loc, E->getType(), diag::err_typecheck_incomplete_type_not_modifiable_lvalue, E); case Expr::MLV_DuplicateVectorComponents: DiagID = diag::err_typecheck_duplicate_vector_components_not_mlvalue; break; case Expr::MLV_NoSetterProperty: llvm_unreachable("readonly properties should be processed differently"); case Expr::MLV_InvalidMessageExpression: DiagID = diag::error_readonly_message_assignment; break; case Expr::MLV_SubObjCPropertySetting: DiagID = diag::error_no_subobject_property_setting; break; } SourceRange Assign; if (Loc != OrigLoc) Assign = SourceRange(OrigLoc, OrigLoc); if (NeedType) S.Diag(Loc, DiagID) << E->getType() << E->getSourceRange() << Assign; else S.Diag(Loc, DiagID) << E->getSourceRange() << Assign; return true; } static void CheckIdentityFieldAssignment(Expr *LHSExpr, Expr *RHSExpr, SourceLocation Loc, Sema &Sema) { // C / C++ fields MemberExpr *ML = dyn_cast(LHSExpr); MemberExpr *MR = dyn_cast(RHSExpr); if (ML && MR && ML->getMemberDecl() == MR->getMemberDecl()) { if (isa(ML->getBase()) && isa(MR->getBase())) Sema.Diag(Loc, diag::warn_identity_field_assign) << 0; } // Objective-C instance variables ObjCIvarRefExpr *OL = dyn_cast(LHSExpr); ObjCIvarRefExpr *OR = dyn_cast(RHSExpr); if (OL && OR && OL->getDecl() == OR->getDecl()) { DeclRefExpr *RL = dyn_cast(OL->getBase()->IgnoreImpCasts()); DeclRefExpr *RR = dyn_cast(OR->getBase()->IgnoreImpCasts()); if (RL && RR && RL->getDecl() == RR->getDecl()) Sema.Diag(Loc, diag::warn_identity_field_assign) << 1; } } // C99 6.5.16.1 QualType Sema::CheckAssignmentOperands(Expr *LHSExpr, ExprResult &RHS, SourceLocation Loc, QualType CompoundType) { assert(!LHSExpr->hasPlaceholderType(BuiltinType::PseudoObject)); // Verify that LHS is a modifiable lvalue, and emit error if not. if (CheckForModifiableLvalue(LHSExpr, Loc, *this)) return QualType(); QualType LHSType = LHSExpr->getType(); QualType RHSType = CompoundType.isNull() ? RHS.get()->getType() : CompoundType; AssignConvertType ConvTy; if (CompoundType.isNull()) { Expr *RHSCheck = RHS.get(); CheckIdentityFieldAssignment(LHSExpr, RHSCheck, Loc, *this); QualType LHSTy(LHSType); ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS); if (RHS.isInvalid()) return QualType(); // Special case of NSObject attributes on c-style pointer types. if (ConvTy == IncompatiblePointer && ((Context.isObjCNSObjectType(LHSType) && RHSType->isObjCObjectPointerType()) || (Context.isObjCNSObjectType(RHSType) && LHSType->isObjCObjectPointerType()))) ConvTy = Compatible; if (ConvTy == Compatible && LHSType->isObjCObjectType()) Diag(Loc, diag::err_objc_object_assignment) << LHSType; // If the RHS is a unary plus or minus, check to see if they = and + are // right next to each other. If so, the user may have typo'd "x =+ 4" // instead of "x += 4". if (ImplicitCastExpr *ICE = dyn_cast(RHSCheck)) RHSCheck = ICE->getSubExpr(); if (UnaryOperator *UO = dyn_cast(RHSCheck)) { if ((UO->getOpcode() == UO_Plus || UO->getOpcode() == UO_Minus) && Loc.isFileID() && UO->getOperatorLoc().isFileID() && // Only if the two operators are exactly adjacent. Loc.getLocWithOffset(1) == UO->getOperatorLoc() && // And there is a space or other character before the subexpr of the // unary +/-. We don't want to warn on "x=-1". Loc.getLocWithOffset(2) != UO->getSubExpr()->getLocStart() && UO->getSubExpr()->getLocStart().isFileID()) { Diag(Loc, diag::warn_not_compound_assign) << (UO->getOpcode() == UO_Plus ? "+" : "-") << SourceRange(UO->getOperatorLoc(), UO->getOperatorLoc()); } } if (ConvTy == Compatible) { if (LHSType.getObjCLifetime() == Qualifiers::OCL_Strong) { // Warn about retain cycles where a block captures the LHS, but // not if the LHS is a simple variable into which the block is // being stored...unless that variable can be captured by reference! const Expr *InnerLHS = LHSExpr->IgnoreParenCasts(); const DeclRefExpr *DRE = dyn_cast(InnerLHS); if (!DRE || DRE->getDecl()->hasAttr()) checkRetainCycles(LHSExpr, RHS.get()); // It is safe to assign a weak reference into a strong variable. // Although this code can still have problems: // id x = self.weakProp; // id y = self.weakProp; // we do not warn to warn spuriously when 'x' and 'y' are on separate // paths through the function. This should be revisited if // -Wrepeated-use-of-weak is made flow-sensitive. if (!Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, RHS.get()->getLocStart())) getCurFunction()->markSafeWeakUse(RHS.get()); } else if (getLangOpts().ObjCAutoRefCount) { checkUnsafeExprAssigns(Loc, LHSExpr, RHS.get()); } } } else { // Compound assignment "x += y" ConvTy = CheckAssignmentConstraints(Loc, LHSType, RHSType); } if (DiagnoseAssignmentResult(ConvTy, Loc, LHSType, RHSType, RHS.get(), AA_Assigning)) return QualType(); CheckForNullPointerDereference(*this, LHSExpr); // C99 6.5.16p3: The type of an assignment expression is the type of the // left operand unless the left operand has qualified type, in which case // it is the unqualified version of the type of the left operand. // C99 6.5.16.1p2: In simple assignment, the value of the right operand // is converted to the type of the assignment expression (above). // C++ 5.17p1: the type of the assignment expression is that of its left // operand. return (getLangOpts().CPlusPlus ? LHSType : LHSType.getUnqualifiedType()); } // C99 6.5.17 static QualType CheckCommaOperands(Sema &S, ExprResult &LHS, ExprResult &RHS, SourceLocation Loc) { LHS = S.CheckPlaceholderExpr(LHS.get()); RHS = S.CheckPlaceholderExpr(RHS.get()); if (LHS.isInvalid() || RHS.isInvalid()) return QualType(); // C's comma performs lvalue conversion (C99 6.3.2.1) on both its // operands, but not unary promotions. // C++'s comma does not do any conversions at all (C++ [expr.comma]p1). // So we treat the LHS as a ignored value, and in C++ we allow the // containing site to determine what should be done with the RHS. LHS = S.IgnoredValueConversions(LHS.get()); if (LHS.isInvalid()) return QualType(); S.DiagnoseUnusedExprResult(LHS.get()); if (!S.getLangOpts().CPlusPlus) { RHS = S.DefaultFunctionArrayLvalueConversion(RHS.get()); if (RHS.isInvalid()) return QualType(); if (!RHS.get()->getType()->isVoidType()) S.RequireCompleteType(Loc, RHS.get()->getType(), diag::err_incomplete_type); } return RHS.get()->getType(); } /// CheckIncrementDecrementOperand - unlike most "Check" methods, this routine /// doesn't need to call UsualUnaryConversions or UsualArithmeticConversions. static QualType CheckIncrementDecrementOperand(Sema &S, Expr *Op, ExprValueKind &VK, ExprObjectKind &OK, SourceLocation OpLoc, bool IsInc, bool IsPrefix) { if (Op->isTypeDependent()) return S.Context.DependentTy; QualType ResType = Op->getType(); // Atomic types can be used for increment / decrement where the non-atomic // versions can, so ignore the _Atomic() specifier for the purpose of // checking. if (const AtomicType *ResAtomicType = ResType->getAs()) ResType = ResAtomicType->getValueType(); assert(!ResType.isNull() && "no type for increment/decrement expression"); if (S.getLangOpts().CPlusPlus && ResType->isBooleanType()) { // Decrement of bool is not allowed. if (!IsInc) { S.Diag(OpLoc, diag::err_decrement_bool) << Op->getSourceRange(); return QualType(); } // Increment of bool sets it to true, but is deprecated. S.Diag(OpLoc, S.getLangOpts().CPlusPlus1z ? diag::ext_increment_bool : diag::warn_increment_bool) << Op->getSourceRange(); } else if (S.getLangOpts().CPlusPlus && ResType->isEnumeralType()) { // Error on enum increments and decrements in C++ mode S.Diag(OpLoc, diag::err_increment_decrement_enum) << IsInc << ResType; return QualType(); } else if (ResType->isRealType()) { // OK! } else if (ResType->isPointerType()) { // C99 6.5.2.4p2, 6.5.6p2 if (!checkArithmeticOpPointerOperand(S, OpLoc, Op)) return QualType(); } else if (ResType->isObjCObjectPointerType()) { // On modern runtimes, ObjC pointer arithmetic is forbidden. // Otherwise, we just need a complete type. if (checkArithmeticIncompletePointerType(S, OpLoc, Op) || checkArithmeticOnObjCPointer(S, OpLoc, Op)) return QualType(); } else if (ResType->isAnyComplexType()) { // C99 does not support ++/-- on complex types, we allow as an extension. S.Diag(OpLoc, diag::ext_integer_increment_complex) << ResType << Op->getSourceRange(); } else if (ResType->isPlaceholderType()) { ExprResult PR = S.CheckPlaceholderExpr(Op); if (PR.isInvalid()) return QualType(); return CheckIncrementDecrementOperand(S, PR.get(), VK, OK, OpLoc, IsInc, IsPrefix); } else if (S.getLangOpts().AltiVec && ResType->isVectorType()) { // OK! ( C/C++ Language Extensions for CBEA(Version 2.6) 10.3 ) } else if (S.getLangOpts().ZVector && ResType->isVectorType() && (ResType->getAs()->getVectorKind() != VectorType::AltiVecBool)) { // The z vector extensions allow ++ and -- for non-bool vectors. } else if(S.getLangOpts().OpenCL && ResType->isVectorType() && ResType->getAs()->getElementType()->isIntegerType()) { // OpenCL V1.2 6.3 says dec/inc ops operate on integer vector types. } else { S.Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement) << ResType << int(IsInc) << Op->getSourceRange(); return QualType(); } // At this point, we know we have a real, complex or pointer type. // Now make sure the operand is a modifiable lvalue. if (CheckForModifiableLvalue(Op, OpLoc, S)) return QualType(); // In C++, a prefix increment is the same type as the operand. Otherwise // (in C or with postfix), the increment is the unqualified type of the // operand. if (IsPrefix && S.getLangOpts().CPlusPlus) { VK = VK_LValue; OK = Op->getObjectKind(); return ResType; } else { VK = VK_RValue; return ResType.getUnqualifiedType(); } } /// getPrimaryDecl - Helper function for CheckAddressOfOperand(). /// This routine allows us to typecheck complex/recursive expressions /// where the declaration is needed for type checking. We only need to /// handle cases when the expression references a function designator /// or is an lvalue. Here are some examples: /// - &(x) => x /// - &*****f => f for f a function designator. /// - &s.xx => s /// - &s.zz[1].yy -> s, if zz is an array /// - *(x + 1) -> x, if x is an array /// - &"123"[2] -> 0 /// - & __real__ x -> x static ValueDecl *getPrimaryDecl(Expr *E) { switch (E->getStmtClass()) { case Stmt::DeclRefExprClass: return cast(E)->getDecl(); case Stmt::MemberExprClass: // If this is an arrow operator, the address is an offset from // the base's value, so the object the base refers to is // irrelevant. if (cast(E)->isArrow()) return nullptr; // Otherwise, the expression refers to a part of the base return getPrimaryDecl(cast(E)->getBase()); case Stmt::ArraySubscriptExprClass: { // FIXME: This code shouldn't be necessary! We should catch the implicit // promotion of register arrays earlier. Expr* Base = cast(E)->getBase(); if (ImplicitCastExpr* ICE = dyn_cast(Base)) { if (ICE->getSubExpr()->getType()->isArrayType()) return getPrimaryDecl(ICE->getSubExpr()); } return nullptr; } case Stmt::UnaryOperatorClass: { UnaryOperator *UO = cast(E); switch(UO->getOpcode()) { case UO_Real: case UO_Imag: case UO_Extension: return getPrimaryDecl(UO->getSubExpr()); default: return nullptr; } } case Stmt::ParenExprClass: return getPrimaryDecl(cast(E)->getSubExpr()); case Stmt::ImplicitCastExprClass: // If the result of an implicit cast is an l-value, we care about // the sub-expression; otherwise, the result here doesn't matter. return getPrimaryDecl(cast(E)->getSubExpr()); default: return nullptr; } } namespace { enum { AO_Bit_Field = 0, AO_Vector_Element = 1, AO_Property_Expansion = 2, AO_Register_Variable = 3, AO_No_Error = 4 }; } /// \brief Diagnose invalid operand for address of operations. /// /// \param Type The type of operand which cannot have its address taken. static void diagnoseAddressOfInvalidType(Sema &S, SourceLocation Loc, Expr *E, unsigned Type) { S.Diag(Loc, diag::err_typecheck_address_of) << Type << E->getSourceRange(); } /// CheckAddressOfOperand - The operand of & must be either a function /// designator or an lvalue designating an object. If it is an lvalue, the /// object cannot be declared with storage class register or be a bit field. /// Note: The usual conversions are *not* applied to the operand of the & /// operator (C99 6.3.2.1p[2-4]), and its result is never an lvalue. /// In C++, the operand might be an overloaded function name, in which case /// we allow the '&' but retain the overloaded-function type. QualType Sema::CheckAddressOfOperand(ExprResult &OrigOp, SourceLocation OpLoc) { if (const BuiltinType *PTy = OrigOp.get()->getType()->getAsPlaceholderType()){ if (PTy->getKind() == BuiltinType::Overload) { Expr *E = OrigOp.get()->IgnoreParens(); if (!isa(E)) { assert(cast(E)->getOpcode() == UO_AddrOf); Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof_addrof_function) << OrigOp.get()->getSourceRange(); return QualType(); } OverloadExpr *Ovl = cast(E); if (isa(Ovl)) if (!ResolveSingleFunctionTemplateSpecialization(Ovl)) { Diag(OpLoc, diag::err_invalid_form_pointer_member_function) << OrigOp.get()->getSourceRange(); return QualType(); } return Context.OverloadTy; } if (PTy->getKind() == BuiltinType::UnknownAny) return Context.UnknownAnyTy; if (PTy->getKind() == BuiltinType::BoundMember) { Diag(OpLoc, diag::err_invalid_form_pointer_member_function) << OrigOp.get()->getSourceRange(); return QualType(); } OrigOp = CheckPlaceholderExpr(OrigOp.get()); if (OrigOp.isInvalid()) return QualType(); } if (OrigOp.get()->isTypeDependent()) return Context.DependentTy; assert(!OrigOp.get()->getType()->isPlaceholderType()); // Make sure to ignore parentheses in subsequent checks Expr *op = OrigOp.get()->IgnoreParens(); // OpenCL v1.0 s6.8.a.3: Pointers to functions are not allowed. if (LangOpts.OpenCL && op->getType()->isFunctionType()) { Diag(op->getExprLoc(), diag::err_opencl_taking_function_address); return QualType(); } if (getLangOpts().C99) { // Implement C99-only parts of addressof rules. if (UnaryOperator* uOp = dyn_cast(op)) { if (uOp->getOpcode() == UO_Deref) // Per C99 6.5.3.2, the address of a deref always returns a valid result // (assuming the deref expression is valid). return uOp->getSubExpr()->getType(); } // Technically, there should be a check for array subscript // expressions here, but the result of one is always an lvalue anyway. } ValueDecl *dcl = getPrimaryDecl(op); if (auto *FD = dyn_cast_or_null(dcl)) if (!checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true, op->getLocStart())) return QualType(); Expr::LValueClassification lval = op->ClassifyLValue(Context); unsigned AddressOfError = AO_No_Error; if (lval == Expr::LV_ClassTemporary || lval == Expr::LV_ArrayTemporary) { bool sfinae = (bool)isSFINAEContext(); Diag(OpLoc, isSFINAEContext() ? diag::err_typecheck_addrof_temporary : diag::ext_typecheck_addrof_temporary) << op->getType() << op->getSourceRange(); if (sfinae) return QualType(); // Materialize the temporary as an lvalue so that we can take its address. OrigOp = op = new (Context) MaterializeTemporaryExpr(op->getType(), OrigOp.get(), true); } else if (isa(op)) { return Context.getPointerType(op->getType()); } else if (lval == Expr::LV_MemberFunction) { // If it's an instance method, make a member pointer. // The expression must have exactly the form &A::foo. // If the underlying expression isn't a decl ref, give up. if (!isa(op)) { Diag(OpLoc, diag::err_invalid_form_pointer_member_function) << OrigOp.get()->getSourceRange(); return QualType(); } DeclRefExpr *DRE = cast(op); CXXMethodDecl *MD = cast(DRE->getDecl()); // The id-expression was parenthesized. if (OrigOp.get() != DRE) { Diag(OpLoc, diag::err_parens_pointer_member_function) << OrigOp.get()->getSourceRange(); // The method was named without a qualifier. } else if (!DRE->getQualifier()) { if (MD->getParent()->getName().empty()) Diag(OpLoc, diag::err_unqualified_pointer_member_function) << op->getSourceRange(); else { SmallString<32> Str; StringRef Qual = (MD->getParent()->getName() + "::").toStringRef(Str); Diag(OpLoc, diag::err_unqualified_pointer_member_function) << op->getSourceRange() << FixItHint::CreateInsertion(op->getSourceRange().getBegin(), Qual); } } // Taking the address of a dtor is illegal per C++ [class.dtor]p2. if (isa(MD)) Diag(OpLoc, diag::err_typecheck_addrof_dtor) << op->getSourceRange(); QualType MPTy = Context.getMemberPointerType( op->getType(), Context.getTypeDeclType(MD->getParent()).getTypePtr()); // Under the MS ABI, lock down the inheritance model now. if (Context.getTargetInfo().getCXXABI().isMicrosoft()) (void)isCompleteType(OpLoc, MPTy); return MPTy; } else if (lval != Expr::LV_Valid && lval != Expr::LV_IncompleteVoidType) { // C99 6.5.3.2p1 // The operand must be either an l-value or a function designator if (!op->getType()->isFunctionType()) { // Use a special diagnostic for loads from property references. if (isa(op)) { AddressOfError = AO_Property_Expansion; } else { Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof) << op->getType() << op->getSourceRange(); return QualType(); } } } else if (op->getObjectKind() == OK_BitField) { // C99 6.5.3.2p1 // The operand cannot be a bit-field AddressOfError = AO_Bit_Field; } else if (op->getObjectKind() == OK_VectorComponent) { // The operand cannot be an element of a vector AddressOfError = AO_Vector_Element; } else if (dcl) { // C99 6.5.3.2p1 // We have an lvalue with a decl. Make sure the decl is not declared // with the register storage-class specifier. if (const VarDecl *vd = dyn_cast(dcl)) { // in C++ it is not error to take address of a register // variable (c++03 7.1.1P3) if (vd->getStorageClass() == SC_Register && !getLangOpts().CPlusPlus) { AddressOfError = AO_Register_Variable; } } else if (isa(dcl)) { AddressOfError = AO_Property_Expansion; } else if (isa(dcl)) { return Context.OverloadTy; } else if (isa(dcl) || isa(dcl)) { // Okay: we can take the address of a field. // Could be a pointer to member, though, if there is an explicit // scope qualifier for the class. if (isa(op) && cast(op)->getQualifier()) { DeclContext *Ctx = dcl->getDeclContext(); if (Ctx && Ctx->isRecord()) { if (dcl->getType()->isReferenceType()) { Diag(OpLoc, diag::err_cannot_form_pointer_to_member_of_reference_type) << dcl->getDeclName() << dcl->getType(); return QualType(); } while (cast(Ctx)->isAnonymousStructOrUnion()) Ctx = Ctx->getParent(); QualType MPTy = Context.getMemberPointerType( op->getType(), Context.getTypeDeclType(cast(Ctx)).getTypePtr()); // Under the MS ABI, lock down the inheritance model now. if (Context.getTargetInfo().getCXXABI().isMicrosoft()) (void)isCompleteType(OpLoc, MPTy); return MPTy; } } } else if (!isa(dcl) && !isa(dcl)) llvm_unreachable("Unknown/unexpected decl type"); } if (AddressOfError != AO_No_Error) { diagnoseAddressOfInvalidType(*this, OpLoc, op, AddressOfError); return QualType(); } if (lval == Expr::LV_IncompleteVoidType) { // Taking the address of a void variable is technically illegal, but we // allow it in cases which are otherwise valid. // Example: "extern void x; void* y = &x;". Diag(OpLoc, diag::ext_typecheck_addrof_void) << op->getSourceRange(); } // If the operand has type "type", the result has type "pointer to type". if (op->getType()->isObjCObjectType()) return Context.getObjCObjectPointerType(op->getType()); return Context.getPointerType(op->getType()); } static void RecordModifiableNonNullParam(Sema &S, const Expr *Exp) { const DeclRefExpr *DRE = dyn_cast(Exp); if (!DRE) return; const Decl *D = DRE->getDecl(); if (!D) return; const ParmVarDecl *Param = dyn_cast(D); if (!Param) return; if (const FunctionDecl* FD = dyn_cast(Param->getDeclContext())) if (!FD->hasAttr() && !Param->hasAttr()) return; if (FunctionScopeInfo *FD = S.getCurFunction()) if (!FD->ModifiedNonNullParams.count(Param)) FD->ModifiedNonNullParams.insert(Param); } /// CheckIndirectionOperand - Type check unary indirection (prefix '*'). static QualType CheckIndirectionOperand(Sema &S, Expr *Op, ExprValueKind &VK, SourceLocation OpLoc) { if (Op->isTypeDependent()) return S.Context.DependentTy; ExprResult ConvResult = S.UsualUnaryConversions(Op); if (ConvResult.isInvalid()) return QualType(); Op = ConvResult.get(); QualType OpTy = Op->getType(); QualType Result; if (isa(Op)) { QualType OpOrigType = Op->IgnoreParenCasts()->getType(); S.CheckCompatibleReinterpretCast(OpOrigType, OpTy, /*IsDereference*/true, Op->getSourceRange()); } if (const PointerType *PT = OpTy->getAs()) Result = PT->getPointeeType(); else if (const ObjCObjectPointerType *OPT = OpTy->getAs()) Result = OPT->getPointeeType(); else { ExprResult PR = S.CheckPlaceholderExpr(Op); if (PR.isInvalid()) return QualType(); if (PR.get() != Op) return CheckIndirectionOperand(S, PR.get(), VK, OpLoc); } if (Result.isNull()) { S.Diag(OpLoc, diag::err_typecheck_indirection_requires_pointer) << OpTy << Op->getSourceRange(); return QualType(); } // Note that per both C89 and C99, indirection is always legal, even if Result // is an incomplete type or void. It would be possible to warn about // dereferencing a void pointer, but it's completely well-defined, and such a // warning is unlikely to catch any mistakes. In C++, indirection is not valid // for pointers to 'void' but is fine for any other pointer type: // // C++ [expr.unary.op]p1: // [...] the expression to which [the unary * operator] is applied shall // be a pointer to an object type, or a pointer to a function type if (S.getLangOpts().CPlusPlus && Result->isVoidType()) S.Diag(OpLoc, diag::ext_typecheck_indirection_through_void_pointer) << OpTy << Op->getSourceRange(); // Dereferences are usually l-values... VK = VK_LValue; // ...except that certain expressions are never l-values in C. if (!S.getLangOpts().CPlusPlus && Result.isCForbiddenLValueType()) VK = VK_RValue; return Result; } BinaryOperatorKind Sema::ConvertTokenKindToBinaryOpcode(tok::TokenKind Kind) { BinaryOperatorKind Opc; switch (Kind) { default: llvm_unreachable("Unknown binop!"); case tok::periodstar: Opc = BO_PtrMemD; break; case tok::arrowstar: Opc = BO_PtrMemI; break; case tok::star: Opc = BO_Mul; break; case tok::slash: Opc = BO_Div; break; case tok::percent: Opc = BO_Rem; break; case tok::plus: Opc = BO_Add; break; case tok::minus: Opc = BO_Sub; break; case tok::lessless: Opc = BO_Shl; break; case tok::greatergreater: Opc = BO_Shr; break; case tok::lessequal: Opc = BO_LE; break; case tok::less: Opc = BO_LT; break; case tok::greaterequal: Opc = BO_GE; break; case tok::greater: Opc = BO_GT; break; case tok::exclaimequal: Opc = BO_NE; break; case tok::equalequal: Opc = BO_EQ; break; case tok::amp: Opc = BO_And; break; case tok::caret: Opc = BO_Xor; break; case tok::pipe: Opc = BO_Or; break; case tok::ampamp: Opc = BO_LAnd; break; case tok::pipepipe: Opc = BO_LOr; break; case tok::equal: Opc = BO_Assign; break; case tok::starequal: Opc = BO_MulAssign; break; case tok::slashequal: Opc = BO_DivAssign; break; case tok::percentequal: Opc = BO_RemAssign; break; case tok::plusequal: Opc = BO_AddAssign; break; case tok::minusequal: Opc = BO_SubAssign; break; case tok::lesslessequal: Opc = BO_ShlAssign; break; case tok::greatergreaterequal: Opc = BO_ShrAssign; break; case tok::ampequal: Opc = BO_AndAssign; break; case tok::caretequal: Opc = BO_XorAssign; break; case tok::pipeequal: Opc = BO_OrAssign; break; case tok::comma: Opc = BO_Comma; break; } return Opc; } static inline UnaryOperatorKind ConvertTokenKindToUnaryOpcode( tok::TokenKind Kind) { UnaryOperatorKind Opc; switch (Kind) { default: llvm_unreachable("Unknown unary op!"); case tok::plusplus: Opc = UO_PreInc; break; case tok::minusminus: Opc = UO_PreDec; break; case tok::amp: Opc = UO_AddrOf; break; case tok::star: Opc = UO_Deref; break; case tok::plus: Opc = UO_Plus; break; case tok::minus: Opc = UO_Minus; break; case tok::tilde: Opc = UO_Not; break; case tok::exclaim: Opc = UO_LNot; break; case tok::kw___real: Opc = UO_Real; break; case tok::kw___imag: Opc = UO_Imag; break; case tok::kw___extension__: Opc = UO_Extension; break; } return Opc; } /// DiagnoseSelfAssignment - Emits a warning if a value is assigned to itself. /// This warning is only emitted for builtin assignment operations. It is also /// suppressed in the event of macro expansions. static void DiagnoseSelfAssignment(Sema &S, Expr *LHSExpr, Expr *RHSExpr, SourceLocation OpLoc) { if (!S.ActiveTemplateInstantiations.empty()) return; if (OpLoc.isInvalid() || OpLoc.isMacroID()) return; LHSExpr = LHSExpr->IgnoreParenImpCasts(); RHSExpr = RHSExpr->IgnoreParenImpCasts(); const DeclRefExpr *LHSDeclRef = dyn_cast(LHSExpr); const DeclRefExpr *RHSDeclRef = dyn_cast(RHSExpr); if (!LHSDeclRef || !RHSDeclRef || LHSDeclRef->getLocation().isMacroID() || RHSDeclRef->getLocation().isMacroID()) return; const ValueDecl *LHSDecl = cast(LHSDeclRef->getDecl()->getCanonicalDecl()); const ValueDecl *RHSDecl = cast(RHSDeclRef->getDecl()->getCanonicalDecl()); if (LHSDecl != RHSDecl) return; if (LHSDecl->getType().isVolatileQualified()) return; if (const ReferenceType *RefTy = LHSDecl->getType()->getAs()) if (RefTy->getPointeeType().isVolatileQualified()) return; S.Diag(OpLoc, diag::warn_self_assignment) << LHSDeclRef->getType() << LHSExpr->getSourceRange() << RHSExpr->getSourceRange(); } /// Check if a bitwise-& is performed on an Objective-C pointer. This /// is usually indicative of introspection within the Objective-C pointer. static void checkObjCPointerIntrospection(Sema &S, ExprResult &L, ExprResult &R, SourceLocation OpLoc) { if (!S.getLangOpts().ObjC1) return; const Expr *ObjCPointerExpr = nullptr, *OtherExpr = nullptr; const Expr *LHS = L.get(); const Expr *RHS = R.get(); if (LHS->IgnoreParenCasts()->getType()->isObjCObjectPointerType()) { ObjCPointerExpr = LHS; OtherExpr = RHS; } else if (RHS->IgnoreParenCasts()->getType()->isObjCObjectPointerType()) { ObjCPointerExpr = RHS; OtherExpr = LHS; } // This warning is deliberately made very specific to reduce false // positives with logic that uses '&' for hashing. This logic mainly // looks for code trying to introspect into tagged pointers, which // code should generally never do. if (ObjCPointerExpr && isa(OtherExpr->IgnoreParenCasts())) { unsigned Diag = diag::warn_objc_pointer_masking; // Determine if we are introspecting the result of performSelectorXXX. const Expr *Ex = ObjCPointerExpr->IgnoreParenCasts(); // Special case messages to -performSelector and friends, which // can return non-pointer values boxed in a pointer value. // Some clients may wish to silence warnings in this subcase. if (const ObjCMessageExpr *ME = dyn_cast(Ex)) { Selector S = ME->getSelector(); StringRef SelArg0 = S.getNameForSlot(0); if (SelArg0.startswith("performSelector")) Diag = diag::warn_objc_pointer_masking_performSelector; } S.Diag(OpLoc, Diag) << ObjCPointerExpr->getSourceRange(); } } static NamedDecl *getDeclFromExpr(Expr *E) { if (!E) return nullptr; if (auto *DRE = dyn_cast(E)) return DRE->getDecl(); if (auto *ME = dyn_cast(E)) return ME->getMemberDecl(); if (auto *IRE = dyn_cast(E)) return IRE->getDecl(); return nullptr; } /// CreateBuiltinBinOp - Creates a new built-in binary operation with /// operator @p Opc at location @c TokLoc. This routine only supports /// built-in operations; ActOnBinOp handles overloaded operators. ExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, BinaryOperatorKind Opc, Expr *LHSExpr, Expr *RHSExpr) { if (getLangOpts().CPlusPlus11 && isa(RHSExpr)) { // The syntax only allows initializer lists on the RHS of assignment, // so we don't need to worry about accepting invalid code for // non-assignment operators. // C++11 5.17p9: // The meaning of x = {v} [...] is that of x = T(v) [...]. The meaning // of x = {} is x = T(). InitializationKind Kind = InitializationKind::CreateDirectList(RHSExpr->getLocStart()); InitializedEntity Entity = InitializedEntity::InitializeTemporary(LHSExpr->getType()); InitializationSequence InitSeq(*this, Entity, Kind, RHSExpr); ExprResult Init = InitSeq.Perform(*this, Entity, Kind, RHSExpr); if (Init.isInvalid()) return Init; RHSExpr = Init.get(); } ExprResult LHS = LHSExpr, RHS = RHSExpr; QualType ResultTy; // Result type of the binary operator. // The following two variables are used for compound assignment operators QualType CompLHSTy; // Type of LHS after promotions for computation QualType CompResultTy; // Type of computation result ExprValueKind VK = VK_RValue; ExprObjectKind OK = OK_Ordinary; if (!getLangOpts().CPlusPlus) { // C cannot handle TypoExpr nodes on either side of a binop because it // doesn't handle dependent types properly, so make sure any TypoExprs have // been dealt with before checking the operands. LHS = CorrectDelayedTyposInExpr(LHSExpr); RHS = CorrectDelayedTyposInExpr(RHSExpr, [Opc, LHS](Expr *E) { if (Opc != BO_Assign) return ExprResult(E); // Avoid correcting the RHS to the same Expr as the LHS. Decl *D = getDeclFromExpr(E); return (D && D == getDeclFromExpr(LHS.get())) ? ExprError() : E; }); if (!LHS.isUsable() || !RHS.isUsable()) return ExprError(); } if (getLangOpts().OpenCL) { // OpenCLC v2.0 s6.13.11.1 allows atomic variables to be initialized by // the ATOMIC_VAR_INIT macro. if (LHSExpr->getType()->isAtomicType() || RHSExpr->getType()->isAtomicType()) { SourceRange SR(LHSExpr->getLocStart(), RHSExpr->getLocEnd()); if (BO_Assign == Opc) Diag(OpLoc, diag::err_atomic_init_constant) << SR; else ResultTy = InvalidOperands(OpLoc, LHS, RHS); return ExprError(); } } switch (Opc) { case BO_Assign: ResultTy = CheckAssignmentOperands(LHS.get(), RHS, OpLoc, QualType()); if (getLangOpts().CPlusPlus && LHS.get()->getObjectKind() != OK_ObjCProperty) { VK = LHS.get()->getValueKind(); OK = LHS.get()->getObjectKind(); } if (!ResultTy.isNull()) { DiagnoseSelfAssignment(*this, LHS.get(), RHS.get(), OpLoc); DiagnoseSelfMove(LHS.get(), RHS.get(), OpLoc); } RecordModifiableNonNullParam(*this, LHS.get()); break; case BO_PtrMemD: case BO_PtrMemI: ResultTy = CheckPointerToMemberOperands(LHS, RHS, VK, OpLoc, Opc == BO_PtrMemI); break; case BO_Mul: case BO_Div: ResultTy = CheckMultiplyDivideOperands(LHS, RHS, OpLoc, false, Opc == BO_Div); break; case BO_Rem: ResultTy = CheckRemainderOperands(LHS, RHS, OpLoc); break; case BO_Add: ResultTy = CheckAdditionOperands(LHS, RHS, OpLoc, Opc); break; case BO_Sub: ResultTy = CheckSubtractionOperands(LHS, RHS, OpLoc); break; case BO_Shl: case BO_Shr: ResultTy = CheckShiftOperands(LHS, RHS, OpLoc, Opc); break; case BO_LE: case BO_LT: case BO_GE: case BO_GT: ResultTy = CheckCompareOperands(LHS, RHS, OpLoc, Opc, true); break; case BO_EQ: case BO_NE: ResultTy = CheckCompareOperands(LHS, RHS, OpLoc, Opc, false); break; case BO_And: checkObjCPointerIntrospection(*this, LHS, RHS, OpLoc); case BO_Xor: case BO_Or: ResultTy = CheckBitwiseOperands(LHS, RHS, OpLoc); break; case BO_LAnd: case BO_LOr: ResultTy = CheckLogicalOperands(LHS, RHS, OpLoc, Opc); break; case BO_MulAssign: case BO_DivAssign: CompResultTy = CheckMultiplyDivideOperands(LHS, RHS, OpLoc, true, Opc == BO_DivAssign); CompLHSTy = CompResultTy; if (!CompResultTy.isNull() && !LHS.isInvalid() && !RHS.isInvalid()) ResultTy = CheckAssignmentOperands(LHS.get(), RHS, OpLoc, CompResultTy); break; case BO_RemAssign: CompResultTy = CheckRemainderOperands(LHS, RHS, OpLoc, true); CompLHSTy = CompResultTy; if (!CompResultTy.isNull() && !LHS.isInvalid() && !RHS.isInvalid()) ResultTy = CheckAssignmentOperands(LHS.get(), RHS, OpLoc, CompResultTy); break; case BO_AddAssign: CompResultTy = CheckAdditionOperands(LHS, RHS, OpLoc, Opc, &CompLHSTy); if (!CompResultTy.isNull() && !LHS.isInvalid() && !RHS.isInvalid()) ResultTy = CheckAssignmentOperands(LHS.get(), RHS, OpLoc, CompResultTy); break; case BO_SubAssign: CompResultTy = CheckSubtractionOperands(LHS, RHS, OpLoc, &CompLHSTy); if (!CompResultTy.isNull() && !LHS.isInvalid() && !RHS.isInvalid()) ResultTy = CheckAssignmentOperands(LHS.get(), RHS, OpLoc, CompResultTy); break; case BO_ShlAssign: case BO_ShrAssign: CompResultTy = CheckShiftOperands(LHS, RHS, OpLoc, Opc, true); CompLHSTy = CompResultTy; if (!CompResultTy.isNull() && !LHS.isInvalid() && !RHS.isInvalid()) ResultTy = CheckAssignmentOperands(LHS.get(), RHS, OpLoc, CompResultTy); break; case BO_AndAssign: case BO_OrAssign: // fallthrough DiagnoseSelfAssignment(*this, LHS.get(), RHS.get(), OpLoc); case BO_XorAssign: CompResultTy = CheckBitwiseOperands(LHS, RHS, OpLoc, true); CompLHSTy = CompResultTy; if (!CompResultTy.isNull() && !LHS.isInvalid() && !RHS.isInvalid()) ResultTy = CheckAssignmentOperands(LHS.get(), RHS, OpLoc, CompResultTy); break; case BO_Comma: ResultTy = CheckCommaOperands(*this, LHS, RHS, OpLoc); if (getLangOpts().CPlusPlus && !RHS.isInvalid()) { VK = RHS.get()->getValueKind(); OK = RHS.get()->getObjectKind(); } break; } if (ResultTy.isNull() || LHS.isInvalid() || RHS.isInvalid()) return ExprError(); // Check for array bounds violations for both sides of the BinaryOperator CheckArrayAccess(LHS.get()); CheckArrayAccess(RHS.get()); if (const ObjCIsaExpr *OISA = dyn_cast(LHS.get()->IgnoreParenCasts())) { NamedDecl *ObjectSetClass = LookupSingleName(TUScope, &Context.Idents.get("object_setClass"), SourceLocation(), LookupOrdinaryName); if (ObjectSetClass && isa(LHS.get())) { SourceLocation RHSLocEnd = getLocForEndOfToken(RHS.get()->getLocEnd()); Diag(LHS.get()->getExprLoc(), diag::warn_objc_isa_assign) << FixItHint::CreateInsertion(LHS.get()->getLocStart(), "object_setClass(") << FixItHint::CreateReplacement(SourceRange(OISA->getOpLoc(), OpLoc), ",") << FixItHint::CreateInsertion(RHSLocEnd, ")"); } else Diag(LHS.get()->getExprLoc(), diag::warn_objc_isa_assign); } else if (const ObjCIvarRefExpr *OIRE = dyn_cast(LHS.get()->IgnoreParenCasts())) DiagnoseDirectIsaAccess(*this, OIRE, OpLoc, RHS.get()); if (CompResultTy.isNull()) return new (Context) BinaryOperator(LHS.get(), RHS.get(), Opc, ResultTy, VK, OK, OpLoc, FPFeatures.fp_contract); if (getLangOpts().CPlusPlus && LHS.get()->getObjectKind() != OK_ObjCProperty) { VK = VK_LValue; OK = LHS.get()->getObjectKind(); } return new (Context) CompoundAssignOperator( LHS.get(), RHS.get(), Opc, ResultTy, VK, OK, CompLHSTy, CompResultTy, OpLoc, FPFeatures.fp_contract); } /// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison /// operators are mixed in a way that suggests that the programmer forgot that /// comparison operators have higher precedence. The most typical example of /// such code is "flags & 0x0020 != 0", which is equivalent to "flags & 1". static void DiagnoseBitwisePrecedence(Sema &Self, BinaryOperatorKind Opc, SourceLocation OpLoc, Expr *LHSExpr, Expr *RHSExpr) { BinaryOperator *LHSBO = dyn_cast(LHSExpr); BinaryOperator *RHSBO = dyn_cast(RHSExpr); // Check that one of the sides is a comparison operator and the other isn't. bool isLeftComp = LHSBO && LHSBO->isComparisonOp(); bool isRightComp = RHSBO && RHSBO->isComparisonOp(); if (isLeftComp == isRightComp) return; // Bitwise operations are sometimes used as eager logical ops. // Don't diagnose this. bool isLeftBitwise = LHSBO && LHSBO->isBitwiseOp(); bool isRightBitwise = RHSBO && RHSBO->isBitwiseOp(); if (isLeftBitwise || isRightBitwise) return; SourceRange DiagRange = isLeftComp ? SourceRange(LHSExpr->getLocStart(), OpLoc) : SourceRange(OpLoc, RHSExpr->getLocEnd()); StringRef OpStr = isLeftComp ? LHSBO->getOpcodeStr() : RHSBO->getOpcodeStr(); SourceRange ParensRange = isLeftComp ? SourceRange(LHSBO->getRHS()->getLocStart(), RHSExpr->getLocEnd()) : SourceRange(LHSExpr->getLocStart(), RHSBO->getLHS()->getLocEnd()); Self.Diag(OpLoc, diag::warn_precedence_bitwise_rel) << DiagRange << BinaryOperator::getOpcodeStr(Opc) << OpStr; SuggestParentheses(Self, OpLoc, Self.PDiag(diag::note_precedence_silence) << OpStr, (isLeftComp ? LHSExpr : RHSExpr)->getSourceRange()); SuggestParentheses(Self, OpLoc, Self.PDiag(diag::note_precedence_bitwise_first) << BinaryOperator::getOpcodeStr(Opc), ParensRange); } /// \brief It accepts a '&&' expr that is inside a '||' one. /// Emit a diagnostic together with a fixit hint that wraps the '&&' expression /// in parentheses. static void EmitDiagnosticForLogicalAndInLogicalOr(Sema &Self, SourceLocation OpLoc, BinaryOperator *Bop) { assert(Bop->getOpcode() == BO_LAnd); Self.Diag(Bop->getOperatorLoc(), diag::warn_logical_and_in_logical_or) << Bop->getSourceRange() << OpLoc; SuggestParentheses(Self, Bop->getOperatorLoc(), Self.PDiag(diag::note_precedence_silence) << Bop->getOpcodeStr(), Bop->getSourceRange()); } /// \brief Returns true if the given expression can be evaluated as a constant /// 'true'. static bool EvaluatesAsTrue(Sema &S, Expr *E) { bool Res; return !E->isValueDependent() && E->EvaluateAsBooleanCondition(Res, S.getASTContext()) && Res; } /// \brief Returns true if the given expression can be evaluated as a constant /// 'false'. static bool EvaluatesAsFalse(Sema &S, Expr *E) { bool Res; return !E->isValueDependent() && E->EvaluateAsBooleanCondition(Res, S.getASTContext()) && !Res; } /// \brief Look for '&&' in the left hand of a '||' expr. static void DiagnoseLogicalAndInLogicalOrLHS(Sema &S, SourceLocation OpLoc, Expr *LHSExpr, Expr *RHSExpr) { if (BinaryOperator *Bop = dyn_cast(LHSExpr)) { if (Bop->getOpcode() == BO_LAnd) { // If it's "a && b || 0" don't warn since the precedence doesn't matter. if (EvaluatesAsFalse(S, RHSExpr)) return; // If it's "1 && a || b" don't warn since the precedence doesn't matter. if (!EvaluatesAsTrue(S, Bop->getLHS())) return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, Bop); } else if (Bop->getOpcode() == BO_LOr) { if (BinaryOperator *RBop = dyn_cast(Bop->getRHS())) { // If it's "a || b && 1 || c" we didn't warn earlier for // "a || b && 1", but warn now. if (RBop->getOpcode() == BO_LAnd && EvaluatesAsTrue(S, RBop->getRHS())) return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, RBop); } } } } /// \brief Look for '&&' in the right hand of a '||' expr. static void DiagnoseLogicalAndInLogicalOrRHS(Sema &S, SourceLocation OpLoc, Expr *LHSExpr, Expr *RHSExpr) { if (BinaryOperator *Bop = dyn_cast(RHSExpr)) { if (Bop->getOpcode() == BO_LAnd) { // If it's "0 || a && b" don't warn since the precedence doesn't matter. if (EvaluatesAsFalse(S, LHSExpr)) return; // If it's "a || b && 1" don't warn since the precedence doesn't matter. if (!EvaluatesAsTrue(S, Bop->getRHS())) return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, Bop); } } } /// \brief Look for bitwise op in the left or right hand of a bitwise op with /// lower precedence and emit a diagnostic together with a fixit hint that wraps /// the '&' expression in parentheses. static void DiagnoseBitwiseOpInBitwiseOp(Sema &S, BinaryOperatorKind Opc, SourceLocation OpLoc, Expr *SubExpr) { if (BinaryOperator *Bop = dyn_cast(SubExpr)) { if (Bop->isBitwiseOp() && Bop->getOpcode() < Opc) { S.Diag(Bop->getOperatorLoc(), diag::warn_bitwise_op_in_bitwise_op) << Bop->getOpcodeStr() << BinaryOperator::getOpcodeStr(Opc) << Bop->getSourceRange() << OpLoc; SuggestParentheses(S, Bop->getOperatorLoc(), S.PDiag(diag::note_precedence_silence) << Bop->getOpcodeStr(), Bop->getSourceRange()); } } } static void DiagnoseAdditionInShift(Sema &S, SourceLocation OpLoc, Expr *SubExpr, StringRef Shift) { if (BinaryOperator *Bop = dyn_cast(SubExpr)) { if (Bop->getOpcode() == BO_Add || Bop->getOpcode() == BO_Sub) { StringRef Op = Bop->getOpcodeStr(); S.Diag(Bop->getOperatorLoc(), diag::warn_addition_in_bitshift) << Bop->getSourceRange() << OpLoc << Shift << Op; SuggestParentheses(S, Bop->getOperatorLoc(), S.PDiag(diag::note_precedence_silence) << Op, Bop->getSourceRange()); } } } static void DiagnoseShiftCompare(Sema &S, SourceLocation OpLoc, Expr *LHSExpr, Expr *RHSExpr) { CXXOperatorCallExpr *OCE = dyn_cast(LHSExpr); if (!OCE) return; FunctionDecl *FD = OCE->getDirectCallee(); if (!FD || !FD->isOverloadedOperator()) return; OverloadedOperatorKind Kind = FD->getOverloadedOperator(); if (Kind != OO_LessLess && Kind != OO_GreaterGreater) return; S.Diag(OpLoc, diag::warn_overloaded_shift_in_comparison) << LHSExpr->getSourceRange() << RHSExpr->getSourceRange() << (Kind == OO_LessLess); SuggestParentheses(S, OCE->getOperatorLoc(), S.PDiag(diag::note_precedence_silence) << (Kind == OO_LessLess ? "<<" : ">>"), OCE->getSourceRange()); SuggestParentheses(S, OpLoc, S.PDiag(diag::note_evaluate_comparison_first), SourceRange(OCE->getArg(1)->getLocStart(), RHSExpr->getLocEnd())); } /// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky /// precedence. static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperatorKind Opc, SourceLocation OpLoc, Expr *LHSExpr, Expr *RHSExpr){ // Diagnose "arg1 'bitwise' arg2 'eq' arg3". if (BinaryOperator::isBitwiseOp(Opc)) DiagnoseBitwisePrecedence(Self, Opc, OpLoc, LHSExpr, RHSExpr); // Diagnose "arg1 & arg2 | arg3" if ((Opc == BO_Or || Opc == BO_Xor) && !OpLoc.isMacroID()/* Don't warn in macros. */) { DiagnoseBitwiseOpInBitwiseOp(Self, Opc, OpLoc, LHSExpr); DiagnoseBitwiseOpInBitwiseOp(Self, Opc, OpLoc, RHSExpr); } // Warn about arg1 || arg2 && arg3, as GCC 4.3+ does. // We don't warn for 'assert(a || b && "bad")' since this is safe. if (Opc == BO_LOr && !OpLoc.isMacroID()/* Don't warn in macros. */) { DiagnoseLogicalAndInLogicalOrLHS(Self, OpLoc, LHSExpr, RHSExpr); DiagnoseLogicalAndInLogicalOrRHS(Self, OpLoc, LHSExpr, RHSExpr); } if ((Opc == BO_Shl && LHSExpr->getType()->isIntegralType(Self.getASTContext())) || Opc == BO_Shr) { StringRef Shift = BinaryOperator::getOpcodeStr(Opc); DiagnoseAdditionInShift(Self, OpLoc, LHSExpr, Shift); DiagnoseAdditionInShift(Self, OpLoc, RHSExpr, Shift); } // Warn on overloaded shift operators and comparisons, such as: // cout << 5 == 4; if (BinaryOperator::isComparisonOp(Opc)) DiagnoseShiftCompare(Self, OpLoc, LHSExpr, RHSExpr); } // Binary Operators. 'Tok' is the token for the operator. ExprResult Sema::ActOnBinOp(Scope *S, SourceLocation TokLoc, tok::TokenKind Kind, Expr *LHSExpr, Expr *RHSExpr) { BinaryOperatorKind Opc = ConvertTokenKindToBinaryOpcode(Kind); assert(LHSExpr && "ActOnBinOp(): missing left expression"); assert(RHSExpr && "ActOnBinOp(): missing right expression"); // Emit warnings for tricky precedence issues, e.g. "bitfield & 0x4 == 0" DiagnoseBinOpPrecedence(*this, Opc, TokLoc, LHSExpr, RHSExpr); return BuildBinOp(S, TokLoc, Opc, LHSExpr, RHSExpr); } /// Build an overloaded binary operator expression in the given scope. static ExprResult BuildOverloadedBinOp(Sema &S, Scope *Sc, SourceLocation OpLoc, BinaryOperatorKind Opc, Expr *LHS, Expr *RHS) { // Find all of the overloaded operators visible from this // point. We perform both an operator-name lookup from the local // scope and an argument-dependent lookup based on the types of // the arguments. UnresolvedSet<16> Functions; OverloadedOperatorKind OverOp = BinaryOperator::getOverloadedOperator(Opc); if (Sc && OverOp != OO_None && OverOp != OO_Equal) S.LookupOverloadedOperatorName(OverOp, Sc, LHS->getType(), RHS->getType(), Functions); // Build the (potentially-overloaded, potentially-dependent) // binary operation. return S.CreateOverloadedBinOp(OpLoc, Opc, Functions, LHS, RHS); } ExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc, BinaryOperatorKind Opc, Expr *LHSExpr, Expr *RHSExpr) { // We want to end up calling one of checkPseudoObjectAssignment // (if the LHS is a pseudo-object), BuildOverloadedBinOp (if // both expressions are overloadable or either is type-dependent), // or CreateBuiltinBinOp (in any other case). We also want to get // any placeholder types out of the way. // Handle pseudo-objects in the LHS. if (const BuiltinType *pty = LHSExpr->getType()->getAsPlaceholderType()) { // Assignments with a pseudo-object l-value need special analysis. if (pty->getKind() == BuiltinType::PseudoObject && BinaryOperator::isAssignmentOp(Opc)) return checkPseudoObjectAssignment(S, OpLoc, Opc, LHSExpr, RHSExpr); // Don't resolve overloads if the other type is overloadable. if (pty->getKind() == BuiltinType::Overload) { // We can't actually test that if we still have a placeholder, // though. Fortunately, none of the exceptions we see in that // code below are valid when the LHS is an overload set. Note // that an overload set can be dependently-typed, but it never // instantiates to having an overloadable type. ExprResult resolvedRHS = CheckPlaceholderExpr(RHSExpr); if (resolvedRHS.isInvalid()) return ExprError(); RHSExpr = resolvedRHS.get(); if (RHSExpr->isTypeDependent() || RHSExpr->getType()->isOverloadableType()) return BuildOverloadedBinOp(*this, S, OpLoc, Opc, LHSExpr, RHSExpr); } ExprResult LHS = CheckPlaceholderExpr(LHSExpr); if (LHS.isInvalid()) return ExprError(); LHSExpr = LHS.get(); } // Handle pseudo-objects in the RHS. if (const BuiltinType *pty = RHSExpr->getType()->getAsPlaceholderType()) { // An overload in the RHS can potentially be resolved by the type // being assigned to. if (Opc == BO_Assign && pty->getKind() == BuiltinType::Overload) { if (LHSExpr->isTypeDependent() || RHSExpr->isTypeDependent()) return BuildOverloadedBinOp(*this, S, OpLoc, Opc, LHSExpr, RHSExpr); if (LHSExpr->getType()->isOverloadableType()) return BuildOverloadedBinOp(*this, S, OpLoc, Opc, LHSExpr, RHSExpr); return CreateBuiltinBinOp(OpLoc, Opc, LHSExpr, RHSExpr); } // Don't resolve overloads if the other type is overloadable. if (pty->getKind() == BuiltinType::Overload && LHSExpr->getType()->isOverloadableType()) return BuildOverloadedBinOp(*this, S, OpLoc, Opc, LHSExpr, RHSExpr); ExprResult resolvedRHS = CheckPlaceholderExpr(RHSExpr); if (!resolvedRHS.isUsable()) return ExprError(); RHSExpr = resolvedRHS.get(); } if (getLangOpts().CPlusPlus) { // If either expression is type-dependent, always build an // overloaded op. if (LHSExpr->isTypeDependent() || RHSExpr->isTypeDependent()) return BuildOverloadedBinOp(*this, S, OpLoc, Opc, LHSExpr, RHSExpr); // Otherwise, build an overloaded op if either expression has an // overloadable type. if (LHSExpr->getType()->isOverloadableType() || RHSExpr->getType()->isOverloadableType()) return BuildOverloadedBinOp(*this, S, OpLoc, Opc, LHSExpr, RHSExpr); } // Build a built-in binary operation. return CreateBuiltinBinOp(OpLoc, Opc, LHSExpr, RHSExpr); } ExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc, Expr *InputExpr) { ExprResult Input = InputExpr; ExprValueKind VK = VK_RValue; ExprObjectKind OK = OK_Ordinary; QualType resultType; if (getLangOpts().OpenCL) { // The only legal unary operation for atomics is '&'. if (Opc != UO_AddrOf && InputExpr->getType()->isAtomicType()) { return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) << InputExpr->getType() << Input.get()->getSourceRange()); } } switch (Opc) { case UO_PreInc: case UO_PreDec: case UO_PostInc: case UO_PostDec: resultType = CheckIncrementDecrementOperand(*this, Input.get(), VK, OK, OpLoc, Opc == UO_PreInc || Opc == UO_PostInc, Opc == UO_PreInc || Opc == UO_PreDec); break; case UO_AddrOf: resultType = CheckAddressOfOperand(Input, OpLoc); RecordModifiableNonNullParam(*this, InputExpr); break; case UO_Deref: { Input = DefaultFunctionArrayLvalueConversion(Input.get()); if (Input.isInvalid()) return ExprError(); resultType = CheckIndirectionOperand(*this, Input.get(), VK, OpLoc); break; } case UO_Plus: case UO_Minus: Input = UsualUnaryConversions(Input.get()); if (Input.isInvalid()) return ExprError(); resultType = Input.get()->getType(); if (resultType->isDependentType()) break; if (resultType->isArithmeticType()) // C99 6.5.3.3p1 break; else if (resultType->isVectorType() && // The z vector extensions don't allow + or - with bool vectors. (!Context.getLangOpts().ZVector || resultType->getAs()->getVectorKind() != VectorType::AltiVecBool)) break; else if (getLangOpts().CPlusPlus && // C++ [expr.unary.op]p6 Opc == UO_Plus && resultType->isPointerType()) break; return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) << resultType << Input.get()->getSourceRange()); case UO_Not: // bitwise complement Input = UsualUnaryConversions(Input.get()); if (Input.isInvalid()) return ExprError(); resultType = Input.get()->getType(); if (resultType->isDependentType()) break; // C99 6.5.3.3p1. We allow complex int and float as a GCC extension. if (resultType->isComplexType() || resultType->isComplexIntegerType()) // C99 does not support '~' for complex conjugation. Diag(OpLoc, diag::ext_integer_complement_complex) << resultType << Input.get()->getSourceRange(); else if (resultType->hasIntegerRepresentation()) break; else if (resultType->isExtVectorType()) { if (Context.getLangOpts().OpenCL) { // OpenCL v1.1 s6.3.f: The bitwise operator not (~) does not operate // on vector float types. QualType T = resultType->getAs()->getElementType(); if (!T->isIntegerType()) return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) << resultType << Input.get()->getSourceRange()); } break; } else { return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) << resultType << Input.get()->getSourceRange()); } break; case UO_LNot: // logical negation // Unlike +/-/~, integer promotions aren't done here (C99 6.5.3.3p5). Input = DefaultFunctionArrayLvalueConversion(Input.get()); if (Input.isInvalid()) return ExprError(); resultType = Input.get()->getType(); // Though we still have to promote half FP to float... if (resultType->isHalfType() && !Context.getLangOpts().NativeHalfType) { Input = ImpCastExprToType(Input.get(), Context.FloatTy, CK_FloatingCast).get(); resultType = Context.FloatTy; } if (resultType->isDependentType()) break; if (resultType->isScalarType() && !isScopedEnumerationType(resultType)) { // C99 6.5.3.3p1: ok, fallthrough; if (Context.getLangOpts().CPlusPlus) { // C++03 [expr.unary.op]p8, C++0x [expr.unary.op]p9: // operand contextually converted to bool. Input = ImpCastExprToType(Input.get(), Context.BoolTy, ScalarTypeToBooleanCastKind(resultType)); } else if (Context.getLangOpts().OpenCL && Context.getLangOpts().OpenCLVersion < 120) { // OpenCL v1.1 6.3.h: The logical operator not (!) does not // operate on scalar float types. if (!resultType->isIntegerType()) return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) << resultType << Input.get()->getSourceRange()); } } else if (resultType->isExtVectorType()) { if (Context.getLangOpts().OpenCL && Context.getLangOpts().OpenCLVersion < 120) { // OpenCL v1.1 6.3.h: The logical operator not (!) does not // operate on vector float types. QualType T = resultType->getAs()->getElementType(); if (!T->isIntegerType()) return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) << resultType << Input.get()->getSourceRange()); } // Vector logical not returns the signed variant of the operand type. resultType = GetSignedVectorType(resultType); break; } else { return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) << resultType << Input.get()->getSourceRange()); } // LNot always has type int. C99 6.5.3.3p5. // In C++, it's bool. C++ 5.3.1p8 resultType = Context.getLogicalOperationType(); break; case UO_Real: case UO_Imag: resultType = CheckRealImagOperand(*this, Input, OpLoc, Opc == UO_Real); // _Real maps ordinary l-values into ordinary l-values. _Imag maps ordinary // complex l-values to ordinary l-values and all other values to r-values. if (Input.isInvalid()) return ExprError(); if (Opc == UO_Real || Input.get()->getType()->isAnyComplexType()) { if (Input.get()->getValueKind() != VK_RValue && Input.get()->getObjectKind() == OK_Ordinary) VK = Input.get()->getValueKind(); } else if (!getLangOpts().CPlusPlus) { // In C, a volatile scalar is read by __imag. In C++, it is not. Input = DefaultLvalueConversion(Input.get()); } break; case UO_Extension: case UO_Coawait: resultType = Input.get()->getType(); VK = Input.get()->getValueKind(); OK = Input.get()->getObjectKind(); break; } if (resultType.isNull() || Input.isInvalid()) return ExprError(); // Check for array bounds violations in the operand of the UnaryOperator, // except for the '*' and '&' operators that have to be handled specially // by CheckArrayAccess (as there are special cases like &array[arraysize] // that are explicitly defined as valid by the standard). if (Opc != UO_AddrOf && Opc != UO_Deref) CheckArrayAccess(Input.get()); return new (Context) UnaryOperator(Input.get(), Opc, resultType, VK, OK, OpLoc); } /// \brief Determine whether the given expression is a qualified member /// access expression, of a form that could be turned into a pointer to member /// with the address-of operator. static bool isQualifiedMemberAccess(Expr *E) { if (DeclRefExpr *DRE = dyn_cast(E)) { if (!DRE->getQualifier()) return false; ValueDecl *VD = DRE->getDecl(); if (!VD->isCXXClassMember()) return false; if (isa(VD) || isa(VD)) return true; if (CXXMethodDecl *Method = dyn_cast(VD)) return Method->isInstance(); return false; } if (UnresolvedLookupExpr *ULE = dyn_cast(E)) { if (!ULE->getQualifier()) return false; for (NamedDecl *D : ULE->decls()) { if (CXXMethodDecl *Method = dyn_cast(D)) { if (Method->isInstance()) return true; } else { // Overload set does not contain methods. break; } } return false; } return false; } ExprResult Sema::BuildUnaryOp(Scope *S, SourceLocation OpLoc, UnaryOperatorKind Opc, Expr *Input) { // First things first: handle placeholders so that the // overloaded-operator check considers the right type. if (const BuiltinType *pty = Input->getType()->getAsPlaceholderType()) { // Increment and decrement of pseudo-object references. if (pty->getKind() == BuiltinType::PseudoObject && UnaryOperator::isIncrementDecrementOp(Opc)) return checkPseudoObjectIncDec(S, OpLoc, Opc, Input); // extension is always a builtin operator. if (Opc == UO_Extension) return CreateBuiltinUnaryOp(OpLoc, Opc, Input); // & gets special logic for several kinds of placeholder. // The builtin code knows what to do. if (Opc == UO_AddrOf && (pty->getKind() == BuiltinType::Overload || pty->getKind() == BuiltinType::UnknownAny || pty->getKind() == BuiltinType::BoundMember)) return CreateBuiltinUnaryOp(OpLoc, Opc, Input); // Anything else needs to be handled now. ExprResult Result = CheckPlaceholderExpr(Input); if (Result.isInvalid()) return ExprError(); Input = Result.get(); } if (getLangOpts().CPlusPlus && Input->getType()->isOverloadableType() && UnaryOperator::getOverloadedOperator(Opc) != OO_None && !(Opc == UO_AddrOf && isQualifiedMemberAccess(Input))) { // Find all of the overloaded operators visible from this // point. We perform both an operator-name lookup from the local // scope and an argument-dependent lookup based on the types of // the arguments. UnresolvedSet<16> Functions; OverloadedOperatorKind OverOp = UnaryOperator::getOverloadedOperator(Opc); if (S && OverOp != OO_None) LookupOverloadedOperatorName(OverOp, S, Input->getType(), QualType(), Functions); return CreateOverloadedUnaryOp(OpLoc, Opc, Functions, Input); } return CreateBuiltinUnaryOp(OpLoc, Opc, Input); } // Unary Operators. 'Tok' is the token for the operator. ExprResult Sema::ActOnUnaryOp(Scope *S, SourceLocation OpLoc, tok::TokenKind Op, Expr *Input) { return BuildUnaryOp(S, OpLoc, ConvertTokenKindToUnaryOpcode(Op), Input); } /// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo". ExprResult Sema::ActOnAddrLabel(SourceLocation OpLoc, SourceLocation LabLoc, LabelDecl *TheDecl) { TheDecl->markUsed(Context); // Create the AST node. The address of a label always has type 'void*'. return new (Context) AddrLabelExpr(OpLoc, LabLoc, TheDecl, Context.getPointerType(Context.VoidTy)); } /// Given the last statement in a statement-expression, check whether /// the result is a producing expression (like a call to an /// ns_returns_retained function) and, if so, rebuild it to hoist the /// release out of the full-expression. Otherwise, return null. /// Cannot fail. static Expr *maybeRebuildARCConsumingStmt(Stmt *Statement) { // Should always be wrapped with one of these. ExprWithCleanups *cleanups = dyn_cast(Statement); if (!cleanups) return nullptr; ImplicitCastExpr *cast = dyn_cast(cleanups->getSubExpr()); if (!cast || cast->getCastKind() != CK_ARCConsumeObject) return nullptr; // Splice out the cast. This shouldn't modify any interesting // features of the statement. Expr *producer = cast->getSubExpr(); assert(producer->getType() == cast->getType()); assert(producer->getValueKind() == cast->getValueKind()); cleanups->setSubExpr(producer); return cleanups; } void Sema::ActOnStartStmtExpr() { PushExpressionEvaluationContext(ExprEvalContexts.back().Context); } void Sema::ActOnStmtExprError() { // Note that function is also called by TreeTransform when leaving a // StmtExpr scope without rebuilding anything. DiscardCleanupsInEvaluationContext(); PopExpressionEvaluationContext(); } ExprResult Sema::ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt, SourceLocation RPLoc) { // "({..})" assert(SubStmt && isa(SubStmt) && "Invalid action invocation!"); CompoundStmt *Compound = cast(SubStmt); if (hasAnyUnrecoverableErrorsInThisFunction()) DiscardCleanupsInEvaluationContext(); assert(!ExprNeedsCleanups && "cleanups within StmtExpr not correctly bound!"); PopExpressionEvaluationContext(); // FIXME: there are a variety of strange constraints to enforce here, for // example, it is not possible to goto into a stmt expression apparently. // More semantic analysis is needed. // If there are sub-stmts in the compound stmt, take the type of the last one // as the type of the stmtexpr. QualType Ty = Context.VoidTy; bool StmtExprMayBindToTemp = false; if (!Compound->body_empty()) { Stmt *LastStmt = Compound->body_back(); LabelStmt *LastLabelStmt = nullptr; // If LastStmt is a label, skip down through into the body. while (LabelStmt *Label = dyn_cast(LastStmt)) { LastLabelStmt = Label; LastStmt = Label->getSubStmt(); } if (Expr *LastE = dyn_cast(LastStmt)) { // Do function/array conversion on the last expression, but not // lvalue-to-rvalue. However, initialize an unqualified type. ExprResult LastExpr = DefaultFunctionArrayConversion(LastE); if (LastExpr.isInvalid()) return ExprError(); Ty = LastExpr.get()->getType().getUnqualifiedType(); if (!Ty->isDependentType() && !LastExpr.get()->isTypeDependent()) { // In ARC, if the final expression ends in a consume, splice // the consume out and bind it later. In the alternate case // (when dealing with a retainable type), the result // initialization will create a produce. In both cases the // result will be +1, and we'll need to balance that out with // a bind. if (Expr *rebuiltLastStmt = maybeRebuildARCConsumingStmt(LastExpr.get())) { LastExpr = rebuiltLastStmt; } else { LastExpr = PerformCopyInitialization( InitializedEntity::InitializeResult(LPLoc, Ty, false), SourceLocation(), LastExpr); } if (LastExpr.isInvalid()) return ExprError(); if (LastExpr.get() != nullptr) { if (!LastLabelStmt) Compound->setLastStmt(LastExpr.get()); else LastLabelStmt->setSubStmt(LastExpr.get()); StmtExprMayBindToTemp = true; } } } } // FIXME: Check that expression type is complete/non-abstract; statement // expressions are not lvalues. Expr *ResStmtExpr = new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc); if (StmtExprMayBindToTemp) return MaybeBindToTemporary(ResStmtExpr); return ResStmtExpr; } ExprResult Sema::BuildBuiltinOffsetOf(SourceLocation BuiltinLoc, TypeSourceInfo *TInfo, ArrayRef Components, SourceLocation RParenLoc) { QualType ArgTy = TInfo->getType(); bool Dependent = ArgTy->isDependentType(); SourceRange TypeRange = TInfo->getTypeLoc().getLocalSourceRange(); // We must have at least one component that refers to the type, and the first // one is known to be a field designator. Verify that the ArgTy represents // a struct/union/class. if (!Dependent && !ArgTy->isRecordType()) return ExprError(Diag(BuiltinLoc, diag::err_offsetof_record_type) << ArgTy << TypeRange); // Type must be complete per C99 7.17p3 because a declaring a variable // with an incomplete type would be ill-formed. if (!Dependent && RequireCompleteType(BuiltinLoc, ArgTy, diag::err_offsetof_incomplete_type, TypeRange)) return ExprError(); // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a // GCC extension, diagnose them. // FIXME: This diagnostic isn't actually visible because the location is in // a system header! if (Components.size() != 1) Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) << SourceRange(Components[1].LocStart, Components.back().LocEnd); bool DidWarnAboutNonPOD = false; QualType CurrentType = ArgTy; typedef OffsetOfExpr::OffsetOfNode OffsetOfNode; SmallVector Comps; SmallVector Exprs; for (const OffsetOfComponent &OC : Components) { if (OC.isBrackets) { // Offset of an array sub-field. TODO: Should we allow vector elements? if (!CurrentType->isDependentType()) { const ArrayType *AT = Context.getAsArrayType(CurrentType); if(!AT) return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) << CurrentType); CurrentType = AT->getElementType(); } else CurrentType = Context.DependentTy; ExprResult IdxRval = DefaultLvalueConversion(static_cast(OC.U.E)); if (IdxRval.isInvalid()) return ExprError(); Expr *Idx = IdxRval.get(); // The expression must be an integral expression. // FIXME: An integral constant expression? if (!Idx->isTypeDependent() && !Idx->isValueDependent() && !Idx->getType()->isIntegerType()) return ExprError(Diag(Idx->getLocStart(), diag::err_typecheck_subscript_not_integer) << Idx->getSourceRange()); // Record this array index. Comps.push_back(OffsetOfNode(OC.LocStart, Exprs.size(), OC.LocEnd)); Exprs.push_back(Idx); continue; } // Offset of a field. if (CurrentType->isDependentType()) { // We have the offset of a field, but we can't look into the dependent // type. Just record the identifier of the field. Comps.push_back(OffsetOfNode(OC.LocStart, OC.U.IdentInfo, OC.LocEnd)); CurrentType = Context.DependentTy; continue; } // We need to have a complete type to look into. if (RequireCompleteType(OC.LocStart, CurrentType, diag::err_offsetof_incomplete_type)) return ExprError(); // Look for the designated field. const RecordType *RC = CurrentType->getAs(); if (!RC) return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) << CurrentType); RecordDecl *RD = RC->getDecl(); // C++ [lib.support.types]p5: // The macro offsetof accepts a restricted set of type arguments in this // International Standard. type shall be a POD structure or a POD union // (clause 9). // C++11 [support.types]p4: // If type is not a standard-layout class (Clause 9), the results are // undefined. if (CXXRecordDecl *CRD = dyn_cast(RD)) { bool IsSafe = LangOpts.CPlusPlus11? CRD->isStandardLayout() : CRD->isPOD(); unsigned DiagID = LangOpts.CPlusPlus11? diag::ext_offsetof_non_standardlayout_type : diag::ext_offsetof_non_pod_type; if (!IsSafe && !DidWarnAboutNonPOD && DiagRuntimeBehavior(BuiltinLoc, nullptr, PDiag(DiagID) << SourceRange(Components[0].LocStart, OC.LocEnd) << CurrentType)) DidWarnAboutNonPOD = true; } // Look for the field. LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); LookupQualifiedName(R, RD); FieldDecl *MemberDecl = R.getAsSingle(); IndirectFieldDecl *IndirectMemberDecl = nullptr; if (!MemberDecl) { if ((IndirectMemberDecl = R.getAsSingle())) MemberDecl = IndirectMemberDecl->getAnonField(); } if (!MemberDecl) return ExprError(Diag(BuiltinLoc, diag::err_no_member) << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, OC.LocEnd)); // C99 7.17p3: // (If the specified member is a bit-field, the behavior is undefined.) // // We diagnose this as an error. if (MemberDecl->isBitField()) { Diag(OC.LocEnd, diag::err_offsetof_bitfield) << MemberDecl->getDeclName() << SourceRange(BuiltinLoc, RParenLoc); Diag(MemberDecl->getLocation(), diag::note_bitfield_decl); return ExprError(); } RecordDecl *Parent = MemberDecl->getParent(); if (IndirectMemberDecl) Parent = cast(IndirectMemberDecl->getDeclContext()); // If the member was found in a base class, introduce OffsetOfNodes for // the base class indirections. CXXBasePaths Paths; if (IsDerivedFrom(OC.LocStart, CurrentType, Context.getTypeDeclType(Parent), Paths)) { if (Paths.getDetectedVirtual()) { Diag(OC.LocEnd, diag::err_offsetof_field_of_virtual_base) << MemberDecl->getDeclName() << SourceRange(BuiltinLoc, RParenLoc); return ExprError(); } CXXBasePath &Path = Paths.front(); for (const CXXBasePathElement &B : Path) Comps.push_back(OffsetOfNode(B.Base)); } if (IndirectMemberDecl) { for (auto *FI : IndirectMemberDecl->chain()) { assert(isa(FI)); Comps.push_back(OffsetOfNode(OC.LocStart, cast(FI), OC.LocEnd)); } } else Comps.push_back(OffsetOfNode(OC.LocStart, MemberDecl, OC.LocEnd)); CurrentType = MemberDecl->getType().getNonReferenceType(); } return OffsetOfExpr::Create(Context, Context.getSizeType(), BuiltinLoc, TInfo, Comps, Exprs, RParenLoc); } ExprResult Sema::ActOnBuiltinOffsetOf(Scope *S, SourceLocation BuiltinLoc, SourceLocation TypeLoc, ParsedType ParsedArgTy, ArrayRef Components, SourceLocation RParenLoc) { TypeSourceInfo *ArgTInfo; QualType ArgTy = GetTypeFromParser(ParsedArgTy, &ArgTInfo); if (ArgTy.isNull()) return ExprError(); if (!ArgTInfo) ArgTInfo = Context.getTrivialTypeSourceInfo(ArgTy, TypeLoc); return BuildBuiltinOffsetOf(BuiltinLoc, ArgTInfo, Components, RParenLoc); } ExprResult Sema::ActOnChooseExpr(SourceLocation BuiltinLoc, Expr *CondExpr, Expr *LHSExpr, Expr *RHSExpr, SourceLocation RPLoc) { assert((CondExpr && LHSExpr && RHSExpr) && "Missing type argument(s)"); ExprValueKind VK = VK_RValue; ExprObjectKind OK = OK_Ordinary; QualType resType; bool ValueDependent = false; bool CondIsTrue = false; if (CondExpr->isTypeDependent() || CondExpr->isValueDependent()) { resType = Context.DependentTy; ValueDependent = true; } else { // The conditional expression is required to be a constant expression. llvm::APSInt condEval(32); ExprResult CondICE = VerifyIntegerConstantExpression(CondExpr, &condEval, diag::err_typecheck_choose_expr_requires_constant, false); if (CondICE.isInvalid()) return ExprError(); CondExpr = CondICE.get(); CondIsTrue = condEval.getZExtValue(); // If the condition is > zero, then the AST type is the same as the LSHExpr. Expr *ActiveExpr = CondIsTrue ? LHSExpr : RHSExpr; resType = ActiveExpr->getType(); ValueDependent = ActiveExpr->isValueDependent(); VK = ActiveExpr->getValueKind(); OK = ActiveExpr->getObjectKind(); } return new (Context) ChooseExpr(BuiltinLoc, CondExpr, LHSExpr, RHSExpr, resType, VK, OK, RPLoc, CondIsTrue, resType->isDependentType(), ValueDependent); } //===----------------------------------------------------------------------===// // Clang Extensions. //===----------------------------------------------------------------------===// /// ActOnBlockStart - This callback is invoked when a block literal is started. void Sema::ActOnBlockStart(SourceLocation CaretLoc, Scope *CurScope) { BlockDecl *Block = BlockDecl::Create(Context, CurContext, CaretLoc); if (LangOpts.CPlusPlus) { Decl *ManglingContextDecl; if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(Block->getDeclContext(), ManglingContextDecl)) { unsigned ManglingNumber = MCtx->getManglingNumber(Block); Block->setBlockMangling(ManglingNumber, ManglingContextDecl); } } PushBlockScope(CurScope, Block); CurContext->addDecl(Block); if (CurScope) PushDeclContext(CurScope, Block); else CurContext = Block; getCurBlock()->HasImplicitReturnType = true; // Enter a new evaluation context to insulate the block from any // cleanups from the enclosing full-expression. PushExpressionEvaluationContext(PotentiallyEvaluated); } void Sema::ActOnBlockArguments(SourceLocation CaretLoc, Declarator &ParamInfo, Scope *CurScope) { assert(ParamInfo.getIdentifier() == nullptr && "block-id should have no identifier!"); assert(ParamInfo.getContext() == Declarator::BlockLiteralContext); BlockScopeInfo *CurBlock = getCurBlock(); TypeSourceInfo *Sig = GetTypeForDeclarator(ParamInfo, CurScope); QualType T = Sig->getType(); // FIXME: We should allow unexpanded parameter packs here, but that would, // in turn, make the block expression contain unexpanded parameter packs. if (DiagnoseUnexpandedParameterPack(CaretLoc, Sig, UPPC_Block)) { // Drop the parameters. FunctionProtoType::ExtProtoInfo EPI; EPI.HasTrailingReturn = false; EPI.TypeQuals |= DeclSpec::TQ_const; T = Context.getFunctionType(Context.DependentTy, None, EPI); Sig = Context.getTrivialTypeSourceInfo(T); } // GetTypeForDeclarator always produces a function type for a block // literal signature. Furthermore, it is always a FunctionProtoType // unless the function was written with a typedef. assert(T->isFunctionType() && "GetTypeForDeclarator made a non-function block signature"); // Look for an explicit signature in that function type. FunctionProtoTypeLoc ExplicitSignature; TypeLoc tmp = Sig->getTypeLoc().IgnoreParens(); if ((ExplicitSignature = tmp.getAs())) { // Check whether that explicit signature was synthesized by // GetTypeForDeclarator. If so, don't save that as part of the // written signature. if (ExplicitSignature.getLocalRangeBegin() == ExplicitSignature.getLocalRangeEnd()) { // This would be much cheaper if we stored TypeLocs instead of // TypeSourceInfos. TypeLoc Result = ExplicitSignature.getReturnLoc(); unsigned Size = Result.getFullDataSize(); Sig = Context.CreateTypeSourceInfo(Result.getType(), Size); Sig->getTypeLoc().initializeFullCopy(Result, Size); ExplicitSignature = FunctionProtoTypeLoc(); } } CurBlock->TheDecl->setSignatureAsWritten(Sig); CurBlock->FunctionType = T; const FunctionType *Fn = T->getAs(); QualType RetTy = Fn->getReturnType(); bool isVariadic = (isa(Fn) && cast(Fn)->isVariadic()); CurBlock->TheDecl->setIsVariadic(isVariadic); // Context.DependentTy is used as a placeholder for a missing block // return type. TODO: what should we do with declarators like: // ^ * { ... } // If the answer is "apply template argument deduction".... if (RetTy != Context.DependentTy) { CurBlock->ReturnType = RetTy; CurBlock->TheDecl->setBlockMissingReturnType(false); CurBlock->HasImplicitReturnType = false; } // Push block parameters from the declarator if we had them. SmallVector Params; if (ExplicitSignature) { for (unsigned I = 0, E = ExplicitSignature.getNumParams(); I != E; ++I) { ParmVarDecl *Param = ExplicitSignature.getParam(I); if (Param->getIdentifier() == nullptr && !Param->isImplicit() && !Param->isInvalidDecl() && !getLangOpts().CPlusPlus) Diag(Param->getLocation(), diag::err_parameter_name_omitted); Params.push_back(Param); } // Fake up parameter variables if we have a typedef, like // ^ fntype { ... } } else if (const FunctionProtoType *Fn = T->getAs()) { for (const auto &I : Fn->param_types()) { ParmVarDecl *Param = BuildParmVarDeclForTypedef( CurBlock->TheDecl, ParamInfo.getLocStart(), I); Params.push_back(Param); } } // Set the parameters on the block decl. if (!Params.empty()) { CurBlock->TheDecl->setParams(Params); CheckParmsForFunctionDef(CurBlock->TheDecl->param_begin(), CurBlock->TheDecl->param_end(), /*CheckParameterNames=*/false); } // Finally we can process decl attributes. ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); // Put the parameter variables in scope. for (auto AI : CurBlock->TheDecl->params()) { AI->setOwningFunction(CurBlock->TheDecl); // If this has an identifier, add it to the scope stack. if (AI->getIdentifier()) { CheckShadow(CurBlock->TheScope, AI); PushOnScopeChains(AI, CurBlock->TheScope); } } } /// ActOnBlockError - If there is an error parsing a block, this callback /// is invoked to pop the information about the block from the action impl. void Sema::ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope) { // Leave the expression-evaluation context. DiscardCleanupsInEvaluationContext(); PopExpressionEvaluationContext(); // Pop off CurBlock, handle nested blocks. PopDeclContext(); PopFunctionScopeInfo(); } /// ActOnBlockStmtExpr - This is called when the body of a block statement /// literal was successfully completed. ^(int x){...} ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc, Stmt *Body, Scope *CurScope) { // If blocks are disabled, emit an error. if (!LangOpts.Blocks) Diag(CaretLoc, diag::err_blocks_disable); // Leave the expression-evaluation context. if (hasAnyUnrecoverableErrorsInThisFunction()) DiscardCleanupsInEvaluationContext(); assert(!ExprNeedsCleanups && "cleanups within block not correctly bound!"); PopExpressionEvaluationContext(); BlockScopeInfo *BSI = cast(FunctionScopes.back()); if (BSI->HasImplicitReturnType) deduceClosureReturnType(*BSI); PopDeclContext(); QualType RetTy = Context.VoidTy; if (!BSI->ReturnType.isNull()) RetTy = BSI->ReturnType; bool NoReturn = BSI->TheDecl->hasAttr(); QualType BlockTy; // Set the captured variables on the block. // FIXME: Share capture structure between BlockDecl and CapturingScopeInfo! SmallVector Captures; for (CapturingScopeInfo::Capture &Cap : BSI->Captures) { if (Cap.isThisCapture()) continue; BlockDecl::Capture NewCap(Cap.getVariable(), Cap.isBlockCapture(), Cap.isNested(), Cap.getInitExpr()); Captures.push_back(NewCap); } BSI->TheDecl->setCaptures(Context, Captures, BSI->CXXThisCaptureIndex != 0); // If the user wrote a function type in some form, try to use that. if (!BSI->FunctionType.isNull()) { const FunctionType *FTy = BSI->FunctionType->getAs(); FunctionType::ExtInfo Ext = FTy->getExtInfo(); if (NoReturn && !Ext.getNoReturn()) Ext = Ext.withNoReturn(true); // Turn protoless block types into nullary block types. if (isa(FTy)) { FunctionProtoType::ExtProtoInfo EPI; EPI.ExtInfo = Ext; BlockTy = Context.getFunctionType(RetTy, None, EPI); // Otherwise, if we don't need to change anything about the function type, // preserve its sugar structure. } else if (FTy->getReturnType() == RetTy && (!NoReturn || FTy->getNoReturnAttr())) { BlockTy = BSI->FunctionType; // Otherwise, make the minimal modifications to the function type. } else { const FunctionProtoType *FPT = cast(FTy); FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); EPI.TypeQuals = 0; // FIXME: silently? EPI.ExtInfo = Ext; BlockTy = Context.getFunctionType(RetTy, FPT->getParamTypes(), EPI); } // If we don't have a function type, just build one from nothing. } else { FunctionProtoType::ExtProtoInfo EPI; EPI.ExtInfo = FunctionType::ExtInfo().withNoReturn(NoReturn); BlockTy = Context.getFunctionType(RetTy, None, EPI); } DiagnoseUnusedParameters(BSI->TheDecl->param_begin(), BSI->TheDecl->param_end()); BlockTy = Context.getBlockPointerType(BlockTy); // If needed, diagnose invalid gotos and switches in the block. if (getCurFunction()->NeedsScopeChecking() && !PP.isCodeCompletionEnabled()) DiagnoseInvalidJumps(cast(Body)); BSI->TheDecl->setBody(cast(Body)); // Try to apply the named return value optimization. We have to check again // if we can do this, though, because blocks keep return statements around // to deduce an implicit return type. if (getLangOpts().CPlusPlus && RetTy->isRecordType() && !BSI->TheDecl->isDependentContext()) computeNRVO(Body, BSI); BlockExpr *Result = new (Context) BlockExpr(BSI->TheDecl, BlockTy); AnalysisBasedWarnings::Policy WP = AnalysisWarnings.getDefaultPolicy(); PopFunctionScopeInfo(&WP, Result->getBlockDecl(), Result); // If the block isn't obviously global, i.e. it captures anything at // all, then we need to do a few things in the surrounding context: if (Result->getBlockDecl()->hasCaptures()) { // First, this expression has a new cleanup object. ExprCleanupObjects.push_back(Result->getBlockDecl()); ExprNeedsCleanups = true; // It also gets a branch-protected scope if any of the captured // variables needs destruction. for (const auto &CI : Result->getBlockDecl()->captures()) { const VarDecl *var = CI.getVariable(); if (var->getType().isDestructedType() != QualType::DK_none) { getCurFunction()->setHasBranchProtectedScope(); break; } } } return Result; } ExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc, Expr *E, ParsedType Ty, SourceLocation RPLoc) { TypeSourceInfo *TInfo; GetTypeFromParser(Ty, &TInfo); return BuildVAArgExpr(BuiltinLoc, E, TInfo, RPLoc); } ExprResult Sema::BuildVAArgExpr(SourceLocation BuiltinLoc, Expr *E, TypeSourceInfo *TInfo, SourceLocation RPLoc) { Expr *OrigExpr = E; bool IsMS = false; // It might be a __builtin_ms_va_list. (But don't ever mark a va_arg() // as Microsoft ABI on an actual Microsoft platform, where // __builtin_ms_va_list and __builtin_va_list are the same.) if (!E->isTypeDependent() && Context.getTargetInfo().hasBuiltinMSVaList() && Context.getTargetInfo().getBuiltinVaListKind() != TargetInfo::CharPtrBuiltinVaList) { QualType MSVaListType = Context.getBuiltinMSVaListType(); if (Context.hasSameType(MSVaListType, E->getType())) { if (CheckForModifiableLvalue(E, BuiltinLoc, *this)) return ExprError(); IsMS = true; } } // Get the va_list type QualType VaListType = Context.getBuiltinVaListType(); if (!IsMS) { if (VaListType->isArrayType()) { // Deal with implicit array decay; for example, on x86-64, // va_list is an array, but it's supposed to decay to // a pointer for va_arg. VaListType = Context.getArrayDecayedType(VaListType); // Make sure the input expression also decays appropriately. ExprResult Result = UsualUnaryConversions(E); if (Result.isInvalid()) return ExprError(); E = Result.get(); } else if (VaListType->isRecordType() && getLangOpts().CPlusPlus) { // If va_list is a record type and we are compiling in C++ mode, // check the argument using reference binding. InitializedEntity Entity = InitializedEntity::InitializeParameter( Context, Context.getLValueReferenceType(VaListType), false); ExprResult Init = PerformCopyInitialization(Entity, SourceLocation(), E); if (Init.isInvalid()) return ExprError(); E = Init.getAs(); } else { // Otherwise, the va_list argument must be an l-value because // it is modified by va_arg. if (!E->isTypeDependent() && CheckForModifiableLvalue(E, BuiltinLoc, *this)) return ExprError(); } } if (!IsMS && !E->isTypeDependent() && !Context.hasSameType(VaListType, E->getType())) return ExprError(Diag(E->getLocStart(), diag::err_first_argument_to_va_arg_not_of_type_va_list) << OrigExpr->getType() << E->getSourceRange()); if (!TInfo->getType()->isDependentType()) { if (RequireCompleteType(TInfo->getTypeLoc().getBeginLoc(), TInfo->getType(), diag::err_second_parameter_to_va_arg_incomplete, TInfo->getTypeLoc())) return ExprError(); if (RequireNonAbstractType(TInfo->getTypeLoc().getBeginLoc(), TInfo->getType(), diag::err_second_parameter_to_va_arg_abstract, TInfo->getTypeLoc())) return ExprError(); if (!TInfo->getType().isPODType(Context)) { Diag(TInfo->getTypeLoc().getBeginLoc(), TInfo->getType()->isObjCLifetimeType() ? diag::warn_second_parameter_to_va_arg_ownership_qualified : diag::warn_second_parameter_to_va_arg_not_pod) << TInfo->getType() << TInfo->getTypeLoc().getSourceRange(); } // Check for va_arg where arguments of the given type will be promoted // (i.e. this va_arg is guaranteed to have undefined behavior). QualType PromoteType; if (TInfo->getType()->isPromotableIntegerType()) { PromoteType = Context.getPromotedIntegerType(TInfo->getType()); if (Context.typesAreCompatible(PromoteType, TInfo->getType())) PromoteType = QualType(); } if (TInfo->getType()->isSpecificBuiltinType(BuiltinType::Float)) PromoteType = Context.DoubleTy; if (!PromoteType.isNull()) DiagRuntimeBehavior(TInfo->getTypeLoc().getBeginLoc(), E, PDiag(diag::warn_second_parameter_to_va_arg_never_compatible) << TInfo->getType() << PromoteType << TInfo->getTypeLoc().getSourceRange()); } QualType T = TInfo->getType().getNonLValueExprType(Context); return new (Context) VAArgExpr(BuiltinLoc, E, TInfo, RPLoc, T, IsMS); } ExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) { // The type of __null will be int or long, depending on the size of // pointers on the target. QualType Ty; unsigned pw = Context.getTargetInfo().getPointerWidth(0); if (pw == Context.getTargetInfo().getIntWidth()) Ty = Context.IntTy; else if (pw == Context.getTargetInfo().getLongWidth()) Ty = Context.LongTy; else if (pw == Context.getTargetInfo().getLongLongWidth()) Ty = Context.LongLongTy; else { llvm_unreachable("I don't know size of pointer!"); } return new (Context) GNUNullExpr(Ty, TokenLoc); } bool Sema::ConversionToObjCStringLiteralCheck(QualType DstType, Expr *&Exp) { if (!getLangOpts().ObjC1) return false; const ObjCObjectPointerType *PT = DstType->getAs(); if (!PT) return false; if (!PT->isObjCIdType()) { // Check if the destination is the 'NSString' interface. const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); if (!ID || !ID->getIdentifier()->isStr("NSString")) return false; } // Ignore any parens, implicit casts (should only be // array-to-pointer decays), and not-so-opaque values. The last is // important for making this trigger for property assignments. Expr *SrcExpr = Exp->IgnoreParenImpCasts(); if (OpaqueValueExpr *OV = dyn_cast(SrcExpr)) if (OV->getSourceExpr()) SrcExpr = OV->getSourceExpr()->IgnoreParenImpCasts(); StringLiteral *SL = dyn_cast(SrcExpr); if (!SL || !SL->isAscii()) return false; Diag(SL->getLocStart(), diag::err_missing_atsign_prefix) << FixItHint::CreateInsertion(SL->getLocStart(), "@"); Exp = BuildObjCStringLiteral(SL->getLocStart(), SL).get(); return true; } static bool maybeDiagnoseAssignmentToFunction(Sema &S, QualType DstType, const Expr *SrcExpr) { if (!DstType->isFunctionPointerType() || !SrcExpr->getType()->isFunctionType()) return false; auto *DRE = dyn_cast(SrcExpr->IgnoreParenImpCasts()); if (!DRE) return false; auto *FD = dyn_cast(DRE->getDecl()); if (!FD) return false; return !S.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true, SrcExpr->getLocStart()); } bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, SourceLocation Loc, QualType DstType, QualType SrcType, Expr *SrcExpr, AssignmentAction Action, bool *Complained) { if (Complained) *Complained = false; // Decode the result (notice that AST's are still created for extensions). bool CheckInferredResultType = false; bool isInvalid = false; unsigned DiagKind = 0; FixItHint Hint; ConversionFixItGenerator ConvHints; bool MayHaveConvFixit = false; bool MayHaveFunctionDiff = false; const ObjCInterfaceDecl *IFace = nullptr; const ObjCProtocolDecl *PDecl = nullptr; switch (ConvTy) { case Compatible: DiagnoseAssignmentEnum(DstType, SrcType, SrcExpr); return false; case PointerToInt: DiagKind = diag::ext_typecheck_convert_pointer_int; ConvHints.tryToFixConversion(SrcExpr, SrcType, DstType, *this); MayHaveConvFixit = true; break; case IntToPointer: DiagKind = diag::ext_typecheck_convert_int_pointer; ConvHints.tryToFixConversion(SrcExpr, SrcType, DstType, *this); MayHaveConvFixit = true; break; case IncompatiblePointer: DiagKind = (Action == AA_Passing_CFAudited ? diag::err_arc_typecheck_convert_incompatible_pointer : diag::ext_typecheck_convert_incompatible_pointer); CheckInferredResultType = DstType->isObjCObjectPointerType() && SrcType->isObjCObjectPointerType(); if (Hint.isNull() && !CheckInferredResultType) { ConvHints.tryToFixConversion(SrcExpr, SrcType, DstType, *this); } else if (CheckInferredResultType) { SrcType = SrcType.getUnqualifiedType(); DstType = DstType.getUnqualifiedType(); } MayHaveConvFixit = true; break; case IncompatiblePointerSign: DiagKind = diag::ext_typecheck_convert_incompatible_pointer_sign; break; case FunctionVoidPointer: DiagKind = diag::ext_typecheck_convert_pointer_void_func; break; case IncompatiblePointerDiscardsQualifiers: { // Perform array-to-pointer decay if necessary. if (SrcType->isArrayType()) SrcType = Context.getArrayDecayedType(SrcType); Qualifiers lhq = SrcType->getPointeeType().getQualifiers(); Qualifiers rhq = DstType->getPointeeType().getQualifiers(); if (lhq.getAddressSpace() != rhq.getAddressSpace()) { DiagKind = diag::err_typecheck_incompatible_address_space; break; } else if (lhq.getObjCLifetime() != rhq.getObjCLifetime()) { DiagKind = diag::err_typecheck_incompatible_ownership; break; } llvm_unreachable("unknown error case for discarding qualifiers!"); // fallthrough } case CompatiblePointerDiscardsQualifiers: // If the qualifiers lost were because we were applying the // (deprecated) C++ conversion from a string literal to a char* // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME: // Ideally, this check would be performed in // checkPointerTypesForAssignment. However, that would require a // bit of refactoring (so that the second argument is an // expression, rather than a type), which should be done as part // of a larger effort to fix checkPointerTypesForAssignment for // C++ semantics. if (getLangOpts().CPlusPlus && IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType)) return false; DiagKind = diag::ext_typecheck_convert_discards_qualifiers; break; case IncompatibleNestedPointerQualifiers: DiagKind = diag::ext_nested_pointer_qualifier_mismatch; break; case IntToBlockPointer: DiagKind = diag::err_int_to_block_pointer; break; case IncompatibleBlockPointer: DiagKind = diag::err_typecheck_convert_incompatible_block_pointer; break; case IncompatibleObjCQualifiedId: { if (SrcType->isObjCQualifiedIdType()) { const ObjCObjectPointerType *srcOPT = SrcType->getAs(); for (auto *srcProto : srcOPT->quals()) { PDecl = srcProto; break; } if (const ObjCInterfaceType *IFaceT = DstType->getAs()->getInterfaceType()) IFace = IFaceT->getDecl(); } else if (DstType->isObjCQualifiedIdType()) { const ObjCObjectPointerType *dstOPT = DstType->getAs(); for (auto *dstProto : dstOPT->quals()) { PDecl = dstProto; break; } if (const ObjCInterfaceType *IFaceT = SrcType->getAs()->getInterfaceType()) IFace = IFaceT->getDecl(); } DiagKind = diag::warn_incompatible_qualified_id; break; } case IncompatibleVectors: DiagKind = diag::warn_incompatible_vectors; break; case IncompatibleObjCWeakRef: DiagKind = diag::err_arc_weak_unavailable_assign; break; case Incompatible: if (maybeDiagnoseAssignmentToFunction(*this, DstType, SrcExpr)) { if (Complained) *Complained = true; return true; } DiagKind = diag::err_typecheck_convert_incompatible; ConvHints.tryToFixConversion(SrcExpr, SrcType, DstType, *this); MayHaveConvFixit = true; isInvalid = true; MayHaveFunctionDiff = true; break; } QualType FirstType, SecondType; switch (Action) { case AA_Assigning: case AA_Initializing: // The destination type comes first. FirstType = DstType; SecondType = SrcType; break; case AA_Returning: case AA_Passing: case AA_Passing_CFAudited: case AA_Converting: case AA_Sending: case AA_Casting: // The source type comes first. FirstType = SrcType; SecondType = DstType; break; } PartialDiagnostic FDiag = PDiag(DiagKind); if (Action == AA_Passing_CFAudited) FDiag << FirstType << SecondType << AA_Passing << SrcExpr->getSourceRange(); else FDiag << FirstType << SecondType << Action << SrcExpr->getSourceRange(); // If we can fix the conversion, suggest the FixIts. assert(ConvHints.isNull() || Hint.isNull()); if (!ConvHints.isNull()) { for (FixItHint &H : ConvHints.Hints) FDiag << H; } else { FDiag << Hint; } if (MayHaveConvFixit) { FDiag << (unsigned) (ConvHints.Kind); } if (MayHaveFunctionDiff) HandleFunctionTypeMismatch(FDiag, SecondType, FirstType); Diag(Loc, FDiag); if (DiagKind == diag::warn_incompatible_qualified_id && PDecl && IFace && !IFace->hasDefinition()) Diag(IFace->getLocation(), diag::not_incomplete_class_and_qualified_id) << IFace->getName() << PDecl->getName(); if (SecondType == Context.OverloadTy) NoteAllOverloadCandidates(OverloadExpr::find(SrcExpr).Expression, FirstType, /*TakingAddress=*/true); if (CheckInferredResultType) EmitRelatedResultTypeNote(SrcExpr); if (Action == AA_Returning && ConvTy == IncompatiblePointer) EmitRelatedResultTypeNoteForReturn(DstType); if (Complained) *Complained = true; return isInvalid; } ExprResult Sema::VerifyIntegerConstantExpression(Expr *E, llvm::APSInt *Result) { class SimpleICEDiagnoser : public VerifyICEDiagnoser { public: void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) override { S.Diag(Loc, diag::err_expr_not_ice) << S.LangOpts.CPlusPlus << SR; } } Diagnoser; return VerifyIntegerConstantExpression(E, Result, Diagnoser); } ExprResult Sema::VerifyIntegerConstantExpression(Expr *E, llvm::APSInt *Result, unsigned DiagID, bool AllowFold) { class IDDiagnoser : public VerifyICEDiagnoser { unsigned DiagID; public: IDDiagnoser(unsigned DiagID) : VerifyICEDiagnoser(DiagID == 0), DiagID(DiagID) { } void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) override { S.Diag(Loc, DiagID) << SR; } } Diagnoser(DiagID); return VerifyIntegerConstantExpression(E, Result, Diagnoser, AllowFold); } void Sema::VerifyICEDiagnoser::diagnoseFold(Sema &S, SourceLocation Loc, SourceRange SR) { S.Diag(Loc, diag::ext_expr_not_ice) << SR << S.LangOpts.CPlusPlus; } ExprResult Sema::VerifyIntegerConstantExpression(Expr *E, llvm::APSInt *Result, VerifyICEDiagnoser &Diagnoser, bool AllowFold) { SourceLocation DiagLoc = E->getLocStart(); if (getLangOpts().CPlusPlus11) { // C++11 [expr.const]p5: // If an expression of literal class type is used in a context where an // integral constant expression is required, then that class type shall // have a single non-explicit conversion function to an integral or // unscoped enumeration type ExprResult Converted; class CXX11ConvertDiagnoser : public ICEConvertDiagnoser { public: CXX11ConvertDiagnoser(bool Silent) : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, Silent, true) {} SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, QualType T) override { return S.Diag(Loc, diag::err_ice_not_integral) << T; } SemaDiagnosticBuilder diagnoseIncomplete( Sema &S, SourceLocation Loc, QualType T) override { return S.Diag(Loc, diag::err_ice_incomplete_type) << T; } SemaDiagnosticBuilder diagnoseExplicitConv( Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { return S.Diag(Loc, diag::err_ice_explicit_conversion) << T << ConvTy; } SemaDiagnosticBuilder noteExplicitConv( Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { return S.Diag(Conv->getLocation(), diag::note_ice_conversion_here) << ConvTy->isEnumeralType() << ConvTy; } SemaDiagnosticBuilder diagnoseAmbiguous( Sema &S, SourceLocation Loc, QualType T) override { return S.Diag(Loc, diag::err_ice_ambiguous_conversion) << T; } SemaDiagnosticBuilder noteAmbiguous( Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { return S.Diag(Conv->getLocation(), diag::note_ice_conversion_here) << ConvTy->isEnumeralType() << ConvTy; } SemaDiagnosticBuilder diagnoseConversion( Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { llvm_unreachable("conversion functions are permitted"); } } ConvertDiagnoser(Diagnoser.Suppress); Converted = PerformContextualImplicitConversion(DiagLoc, E, ConvertDiagnoser); if (Converted.isInvalid()) return Converted; E = Converted.get(); if (!E->getType()->isIntegralOrUnscopedEnumerationType()) return ExprError(); } else if (!E->getType()->isIntegralOrUnscopedEnumerationType()) { // An ICE must be of integral or unscoped enumeration type. if (!Diagnoser.Suppress) Diagnoser.diagnoseNotICE(*this, DiagLoc, E->getSourceRange()); return ExprError(); } // Circumvent ICE checking in C++11 to avoid evaluating the expression twice // in the non-ICE case. if (!getLangOpts().CPlusPlus11 && E->isIntegerConstantExpr(Context)) { if (Result) *Result = E->EvaluateKnownConstInt(Context); return E; } Expr::EvalResult EvalResult; SmallVector Notes; EvalResult.Diag = &Notes; // Try to evaluate the expression, and produce diagnostics explaining why it's // not a constant expression as a side-effect. bool Folded = E->EvaluateAsRValue(EvalResult, Context) && EvalResult.Val.isInt() && !EvalResult.HasSideEffects; // In C++11, we can rely on diagnostics being produced for any expression // which is not a constant expression. If no diagnostics were produced, then // this is a constant expression. if (Folded && getLangOpts().CPlusPlus11 && Notes.empty()) { if (Result) *Result = EvalResult.Val.getInt(); return E; } // If our only note is the usual "invalid subexpression" note, just point // the caret at its location rather than producing an essentially // redundant note. if (Notes.size() == 1 && Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr) { DiagLoc = Notes[0].first; Notes.clear(); } if (!Folded || !AllowFold) { if (!Diagnoser.Suppress) { Diagnoser.diagnoseNotICE(*this, DiagLoc, E->getSourceRange()); for (const PartialDiagnosticAt &Note : Notes) Diag(Note.first, Note.second); } return ExprError(); } Diagnoser.diagnoseFold(*this, DiagLoc, E->getSourceRange()); for (const PartialDiagnosticAt &Note : Notes) Diag(Note.first, Note.second); if (Result) *Result = EvalResult.Val.getInt(); return E; } namespace { // Handle the case where we conclude a expression which we speculatively // considered to be unevaluated is actually evaluated. class TransformToPE : public TreeTransform { typedef TreeTransform BaseTransform; public: TransformToPE(Sema &SemaRef) : BaseTransform(SemaRef) { } // Make sure we redo semantic analysis bool AlwaysRebuild() { return true; } // Make sure we handle LabelStmts correctly. // FIXME: This does the right thing, but maybe we need a more general // fix to TreeTransform? StmtResult TransformLabelStmt(LabelStmt *S) { S->getDecl()->setStmt(nullptr); return BaseTransform::TransformLabelStmt(S); } // We need to special-case DeclRefExprs referring to FieldDecls which // are not part of a member pointer formation; normal TreeTransforming // doesn't catch this case because of the way we represent them in the AST. // FIXME: This is a bit ugly; is it really the best way to handle this // case? // // Error on DeclRefExprs referring to FieldDecls. ExprResult TransformDeclRefExpr(DeclRefExpr *E) { if (isa(E->getDecl()) && !SemaRef.isUnevaluatedContext()) return SemaRef.Diag(E->getLocation(), diag::err_invalid_non_static_member_use) << E->getDecl() << E->getSourceRange(); return BaseTransform::TransformDeclRefExpr(E); } // Exception: filter out member pointer formation ExprResult TransformUnaryOperator(UnaryOperator *E) { if (E->getOpcode() == UO_AddrOf && E->getType()->isMemberPointerType()) return E; return BaseTransform::TransformUnaryOperator(E); } ExprResult TransformLambdaExpr(LambdaExpr *E) { // Lambdas never need to be transformed. return E; } }; } ExprResult Sema::TransformToPotentiallyEvaluated(Expr *E) { assert(isUnevaluatedContext() && "Should only transform unevaluated expressions"); ExprEvalContexts.back().Context = ExprEvalContexts[ExprEvalContexts.size()-2].Context; if (isUnevaluatedContext()) return E; return TransformToPE(*this).TransformExpr(E); } void Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext, Decl *LambdaContextDecl, bool IsDecltype) { ExprEvalContexts.emplace_back(NewContext, ExprCleanupObjects.size(), ExprNeedsCleanups, LambdaContextDecl, IsDecltype); ExprNeedsCleanups = false; if (!MaybeODRUseExprs.empty()) std::swap(MaybeODRUseExprs, ExprEvalContexts.back().SavedMaybeODRUseExprs); } void Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext, ReuseLambdaContextDecl_t, bool IsDecltype) { Decl *ClosureContextDecl = ExprEvalContexts.back().ManglingContextDecl; PushExpressionEvaluationContext(NewContext, ClosureContextDecl, IsDecltype); } void Sema::PopExpressionEvaluationContext() { ExpressionEvaluationContextRecord& Rec = ExprEvalContexts.back(); unsigned NumTypos = Rec.NumTypos; if (!Rec.Lambdas.empty()) { if (Rec.isUnevaluated() || Rec.Context == ConstantEvaluated) { unsigned D; if (Rec.isUnevaluated()) { // C++11 [expr.prim.lambda]p2: // A lambda-expression shall not appear in an unevaluated operand // (Clause 5). D = diag::err_lambda_unevaluated_operand; } else { // C++1y [expr.const]p2: // A conditional-expression e is a core constant expression unless the // evaluation of e, following the rules of the abstract machine, would // evaluate [...] a lambda-expression. D = diag::err_lambda_in_constant_expression; } for (const auto *L : Rec.Lambdas) Diag(L->getLocStart(), D); } else { // Mark the capture expressions odr-used. This was deferred // during lambda expression creation. for (auto *Lambda : Rec.Lambdas) { for (auto *C : Lambda->capture_inits()) MarkDeclarationsReferencedInExpr(C); } } } // When are coming out of an unevaluated context, clear out any // temporaries that we may have created as part of the evaluation of // the expression in that context: they aren't relevant because they // will never be constructed. if (Rec.isUnevaluated() || Rec.Context == ConstantEvaluated) { ExprCleanupObjects.erase(ExprCleanupObjects.begin() + Rec.NumCleanupObjects, ExprCleanupObjects.end()); ExprNeedsCleanups = Rec.ParentNeedsCleanups; CleanupVarDeclMarking(); std::swap(MaybeODRUseExprs, Rec.SavedMaybeODRUseExprs); // Otherwise, merge the contexts together. } else { ExprNeedsCleanups |= Rec.ParentNeedsCleanups; MaybeODRUseExprs.insert(Rec.SavedMaybeODRUseExprs.begin(), Rec.SavedMaybeODRUseExprs.end()); } // Pop the current expression evaluation context off the stack. ExprEvalContexts.pop_back(); if (!ExprEvalContexts.empty()) ExprEvalContexts.back().NumTypos += NumTypos; else assert(NumTypos == 0 && "There are outstanding typos after popping the " "last ExpressionEvaluationContextRecord"); } void Sema::DiscardCleanupsInEvaluationContext() { ExprCleanupObjects.erase( ExprCleanupObjects.begin() + ExprEvalContexts.back().NumCleanupObjects, ExprCleanupObjects.end()); ExprNeedsCleanups = false; MaybeODRUseExprs.clear(); } ExprResult Sema::HandleExprEvaluationContextForTypeof(Expr *E) { if (!E->getType()->isVariablyModifiedType()) return E; return TransformToPotentiallyEvaluated(E); } static bool IsPotentiallyEvaluatedContext(Sema &SemaRef) { // Do not mark anything as "used" within a dependent context; wait for // an instantiation. if (SemaRef.CurContext->isDependentContext()) return false; switch (SemaRef.ExprEvalContexts.back().Context) { case Sema::Unevaluated: case Sema::UnevaluatedAbstract: // We are in an expression that is not potentially evaluated; do nothing. // (Depending on how you read the standard, we actually do need to do // something here for null pointer constants, but the standard's // definition of a null pointer constant is completely crazy.) return false; case Sema::ConstantEvaluated: case Sema::PotentiallyEvaluated: // We are in a potentially evaluated expression (or a constant-expression // in C++03); we need to do implicit template instantiation, implicitly // define class members, and mark most declarations as used. return true; case Sema::PotentiallyEvaluatedIfUsed: // Referenced declarations will only be used if the construct in the // containing expression is used. return false; } llvm_unreachable("Invalid context"); } /// \brief Mark a function referenced, and check whether it is odr-used /// (C++ [basic.def.odr]p2, C99 6.9p3) void Sema::MarkFunctionReferenced(SourceLocation Loc, FunctionDecl *Func, bool OdrUse) { assert(Func && "No function?"); Func->setReferenced(); // C++11 [basic.def.odr]p3: // A function whose name appears as a potentially-evaluated expression is // odr-used if it is the unique lookup result or the selected member of a // set of overloaded functions [...]. // // We (incorrectly) mark overload resolution as an unevaluated context, so we // can just check that here. Skip the rest of this function if we've already // marked the function as used. if (Func->isUsed(/*CheckUsedAttr=*/false) || !IsPotentiallyEvaluatedContext(*this)) { // C++11 [temp.inst]p3: // Unless a function template specialization has been explicitly // instantiated or explicitly specialized, the function template // specialization is implicitly instantiated when the specialization is // referenced in a context that requires a function definition to exist. // // We consider constexpr function templates to be referenced in a context // that requires a definition to exist whenever they are referenced. // // FIXME: This instantiates constexpr functions too frequently. If this is // really an unevaluated context (and we're not just in the definition of a // function template or overload resolution or other cases which we // incorrectly consider to be unevaluated contexts), and we're not in a // subexpression which we actually need to evaluate (for instance, a // template argument, array bound or an expression in a braced-init-list), // we are not permitted to instantiate this constexpr function definition. // // FIXME: This also implicitly defines special members too frequently. They // are only supposed to be implicitly defined if they are odr-used, but they // are not odr-used from constant expressions in unevaluated contexts. // However, they cannot be referenced if they are deleted, and they are // deleted whenever the implicit definition of the special member would // fail. if (!Func->isConstexpr() || Func->getBody()) return; CXXMethodDecl *MD = dyn_cast(Func); if (!Func->isImplicitlyInstantiable() && (!MD || MD->isUserProvided())) return; } // Note that this declaration has been used. if (CXXConstructorDecl *Constructor = dyn_cast(Func)) { Constructor = cast(Constructor->getFirstDecl()); if (Constructor->isDefaulted() && !Constructor->isDeleted()) { if (Constructor->isDefaultConstructor()) { if (Constructor->isTrivial() && !Constructor->hasAttr()) return; DefineImplicitDefaultConstructor(Loc, Constructor); } else if (Constructor->isCopyConstructor()) { DefineImplicitCopyConstructor(Loc, Constructor); } else if (Constructor->isMoveConstructor()) { DefineImplicitMoveConstructor(Loc, Constructor); } } else if (Constructor->getInheritedConstructor()) { DefineInheritingConstructor(Loc, Constructor); } } else if (CXXDestructorDecl *Destructor = dyn_cast(Func)) { Destructor = cast(Destructor->getFirstDecl()); if (Destructor->isDefaulted() && !Destructor->isDeleted()) { if (Destructor->isTrivial() && !Destructor->hasAttr()) return; DefineImplicitDestructor(Loc, Destructor); } if (Destructor->isVirtual() && getLangOpts().AppleKext) MarkVTableUsed(Loc, Destructor->getParent()); } else if (CXXMethodDecl *MethodDecl = dyn_cast(Func)) { if (MethodDecl->isOverloadedOperator() && MethodDecl->getOverloadedOperator() == OO_Equal) { MethodDecl = cast(MethodDecl->getFirstDecl()); if (MethodDecl->isDefaulted() && !MethodDecl->isDeleted()) { if (MethodDecl->isCopyAssignmentOperator()) DefineImplicitCopyAssignment(Loc, MethodDecl); else DefineImplicitMoveAssignment(Loc, MethodDecl); } } else if (isa(MethodDecl) && MethodDecl->getParent()->isLambda()) { CXXConversionDecl *Conversion = cast(MethodDecl->getFirstDecl()); if (Conversion->isLambdaToBlockPointerConversion()) DefineImplicitLambdaToBlockPointerConversion(Loc, Conversion); else DefineImplicitLambdaToFunctionPointerConversion(Loc, Conversion); } else if (MethodDecl->isVirtual() && getLangOpts().AppleKext) MarkVTableUsed(Loc, MethodDecl->getParent()); } // Recursive functions should be marked when used from another function. // FIXME: Is this really right? if (CurContext == Func) return; // Resolve the exception specification for any function which is // used: CodeGen will need it. const FunctionProtoType *FPT = Func->getType()->getAs(); if (FPT && isUnresolvedExceptionSpec(FPT->getExceptionSpecType())) ResolveExceptionSpec(Loc, FPT); if (!OdrUse) return; // Implicit instantiation of function templates and member functions of // class templates. if (Func->isImplicitlyInstantiable()) { bool AlreadyInstantiated = false; SourceLocation PointOfInstantiation = Loc; if (FunctionTemplateSpecializationInfo *SpecInfo = Func->getTemplateSpecializationInfo()) { if (SpecInfo->getPointOfInstantiation().isInvalid()) SpecInfo->setPointOfInstantiation(Loc); else if (SpecInfo->getTemplateSpecializationKind() == TSK_ImplicitInstantiation) { AlreadyInstantiated = true; PointOfInstantiation = SpecInfo->getPointOfInstantiation(); } } else if (MemberSpecializationInfo *MSInfo = Func->getMemberSpecializationInfo()) { if (MSInfo->getPointOfInstantiation().isInvalid()) MSInfo->setPointOfInstantiation(Loc); else if (MSInfo->getTemplateSpecializationKind() == TSK_ImplicitInstantiation) { AlreadyInstantiated = true; PointOfInstantiation = MSInfo->getPointOfInstantiation(); } } if (!AlreadyInstantiated || Func->isConstexpr()) { if (isa(Func->getDeclContext()) && cast(Func->getDeclContext())->isLocalClass() && ActiveTemplateInstantiations.size()) PendingLocalImplicitInstantiations.push_back( std::make_pair(Func, PointOfInstantiation)); else if (Func->isConstexpr()) // Do not defer instantiations of constexpr functions, to avoid the // expression evaluator needing to call back into Sema if it sees a // call to such a function. InstantiateFunctionDefinition(PointOfInstantiation, Func); else { PendingInstantiations.push_back(std::make_pair(Func, PointOfInstantiation)); // Notify the consumer that a function was implicitly instantiated. Consumer.HandleCXXImplicitFunctionInstantiation(Func); } } } else { // Walk redefinitions, as some of them may be instantiable. for (auto i : Func->redecls()) { if (!i->isUsed(false) && i->isImplicitlyInstantiable()) MarkFunctionReferenced(Loc, i); } } // Keep track of used but undefined functions. if (!Func->isDefined()) { if (mightHaveNonExternalLinkage(Func)) UndefinedButUsed.insert(std::make_pair(Func->getCanonicalDecl(), Loc)); else if (Func->getMostRecentDecl()->isInlined() && !LangOpts.GNUInline && !Func->getMostRecentDecl()->hasAttr()) UndefinedButUsed.insert(std::make_pair(Func->getCanonicalDecl(), Loc)); } // Normally the most current decl is marked used while processing the use and // any subsequent decls are marked used by decl merging. This fails with // template instantiation since marking can happen at the end of the file // and, because of the two phase lookup, this function is called with at // decl in the middle of a decl chain. We loop to maintain the invariant // that once a decl is used, all decls after it are also used. for (FunctionDecl *F = Func->getMostRecentDecl();; F = F->getPreviousDecl()) { F->markUsed(Context); if (F == Func) break; } } static void diagnoseUncapturableValueReference(Sema &S, SourceLocation loc, VarDecl *var, DeclContext *DC) { DeclContext *VarDC = var->getDeclContext(); // If the parameter still belongs to the translation unit, then // we're actually just using one parameter in the declaration of // the next. if (isa(var) && isa(VarDC)) return; // For C code, don't diagnose about capture if we're not actually in code // right now; it's impossible to write a non-constant expression outside of // function context, so we'll get other (more useful) diagnostics later. // // For C++, things get a bit more nasty... it would be nice to suppress this // diagnostic for certain cases like using a local variable in an array bound // for a member of a local class, but the correct predicate is not obvious. if (!S.getLangOpts().CPlusPlus && !S.CurContext->isFunctionOrMethod()) return; if (isa(VarDC) && cast(VarDC->getParent())->isLambda()) { S.Diag(loc, diag::err_reference_to_local_var_in_enclosing_lambda) << var->getIdentifier(); } else if (FunctionDecl *fn = dyn_cast(VarDC)) { S.Diag(loc, diag::err_reference_to_local_var_in_enclosing_function) << var->getIdentifier() << fn->getDeclName(); } else if (isa(VarDC)) { S.Diag(loc, diag::err_reference_to_local_var_in_enclosing_block) << var->getIdentifier(); } else { // FIXME: Is there any other context where a local variable can be // declared? S.Diag(loc, diag::err_reference_to_local_var_in_enclosing_context) << var->getIdentifier(); } S.Diag(var->getLocation(), diag::note_entity_declared_at) << var->getIdentifier(); // FIXME: Add additional diagnostic info about class etc. which prevents // capture. } static bool isVariableAlreadyCapturedInScopeInfo(CapturingScopeInfo *CSI, VarDecl *Var, bool &SubCapturesAreNested, QualType &CaptureType, QualType &DeclRefType) { // Check whether we've already captured it. if (CSI->CaptureMap.count(Var)) { // If we found a capture, any subcaptures are nested. SubCapturesAreNested = true; // Retrieve the capture type for this variable. CaptureType = CSI->getCapture(Var).getCaptureType(); // Compute the type of an expression that refers to this variable. DeclRefType = CaptureType.getNonReferenceType(); // Similarly to mutable captures in lambda, all the OpenMP captures by copy // are mutable in the sense that user can change their value - they are // private instances of the captured declarations. const CapturingScopeInfo::Capture &Cap = CSI->getCapture(Var); if (Cap.isCopyCapture() && !(isa(CSI) && cast(CSI)->Mutable) && !(isa(CSI) && cast(CSI)->CapRegionKind == CR_OpenMP)) DeclRefType.addConst(); return true; } return false; } // Only block literals, captured statements, and lambda expressions can // capture; other scopes don't work. static DeclContext *getParentOfCapturingContextOrNull(DeclContext *DC, VarDecl *Var, SourceLocation Loc, const bool Diagnose, Sema &S) { if (isa(DC) || isa(DC) || isLambdaCallOperator(DC)) return getLambdaAwareParentOfDeclContext(DC); else if (Var->hasLocalStorage()) { if (Diagnose) diagnoseUncapturableValueReference(S, Loc, Var, DC); } return nullptr; } // Certain capturing entities (lambdas, blocks etc.) are not allowed to capture // certain types of variables (unnamed, variably modified types etc.) // so check for eligibility. static bool isVariableCapturable(CapturingScopeInfo *CSI, VarDecl *Var, SourceLocation Loc, const bool Diagnose, Sema &S) { bool IsBlock = isa(CSI); bool IsLambda = isa(CSI); // Lambdas are not allowed to capture unnamed variables // (e.g. anonymous unions). // FIXME: The C++11 rule don't actually state this explicitly, but I'm // assuming that's the intent. if (IsLambda && !Var->getDeclName()) { if (Diagnose) { S.Diag(Loc, diag::err_lambda_capture_anonymous_var); S.Diag(Var->getLocation(), diag::note_declared_at); } return false; } // Prohibit variably-modified types in blocks; they're difficult to deal with. if (Var->getType()->isVariablyModifiedType() && IsBlock) { if (Diagnose) { S.Diag(Loc, diag::err_ref_vm_type); S.Diag(Var->getLocation(), diag::note_previous_decl) << Var->getDeclName(); } return false; } // Prohibit structs with flexible array members too. // We cannot capture what is in the tail end of the struct. if (const RecordType *VTTy = Var->getType()->getAs()) { if (VTTy->getDecl()->hasFlexibleArrayMember()) { if (Diagnose) { if (IsBlock) S.Diag(Loc, diag::err_ref_flexarray_type); else S.Diag(Loc, diag::err_lambda_capture_flexarray_type) << Var->getDeclName(); S.Diag(Var->getLocation(), diag::note_previous_decl) << Var->getDeclName(); } return false; } } const bool HasBlocksAttr = Var->hasAttr(); // Lambdas and captured statements are not allowed to capture __block // variables; they don't support the expected semantics. if (HasBlocksAttr && (IsLambda || isa(CSI))) { if (Diagnose) { S.Diag(Loc, diag::err_capture_block_variable) << Var->getDeclName() << !IsLambda; S.Diag(Var->getLocation(), diag::note_previous_decl) << Var->getDeclName(); } return false; } return true; } // Returns true if the capture by block was successful. static bool captureInBlock(BlockScopeInfo *BSI, VarDecl *Var, SourceLocation Loc, const bool BuildAndDiagnose, QualType &CaptureType, QualType &DeclRefType, const bool Nested, Sema &S) { Expr *CopyExpr = nullptr; bool ByRef = false; // Blocks are not allowed to capture arrays. if (CaptureType->isArrayType()) { if (BuildAndDiagnose) { S.Diag(Loc, diag::err_ref_array_type); S.Diag(Var->getLocation(), diag::note_previous_decl) << Var->getDeclName(); } return false; } // Forbid the block-capture of autoreleasing variables. if (CaptureType.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) { if (BuildAndDiagnose) { S.Diag(Loc, diag::err_arc_autoreleasing_capture) << /*block*/ 0; S.Diag(Var->getLocation(), diag::note_previous_decl) << Var->getDeclName(); } return false; } const bool HasBlocksAttr = Var->hasAttr(); if (HasBlocksAttr || CaptureType->isReferenceType()) { // Block capture by reference does not change the capture or // declaration reference types. ByRef = true; } else { // Block capture by copy introduces 'const'. CaptureType = CaptureType.getNonReferenceType().withConst(); DeclRefType = CaptureType; if (S.getLangOpts().CPlusPlus && BuildAndDiagnose) { if (const RecordType *Record = DeclRefType->getAs()) { // The capture logic needs the destructor, so make sure we mark it. // Usually this is unnecessary because most local variables have // their destructors marked at declaration time, but parameters are // an exception because it's technically only the call site that // actually requires the destructor. if (isa(Var)) S.FinalizeVarWithDestructor(Var, Record); // Enter a new evaluation context to insulate the copy // full-expression. EnterExpressionEvaluationContext scope(S, S.PotentiallyEvaluated); // According to the blocks spec, the capture of a variable from // the stack requires a const copy constructor. This is not true // of the copy/move done to move a __block variable to the heap. Expr *DeclRef = new (S.Context) DeclRefExpr(Var, Nested, DeclRefType.withConst(), VK_LValue, Loc); ExprResult Result = S.PerformCopyInitialization( InitializedEntity::InitializeBlock(Var->getLocation(), CaptureType, false), Loc, DeclRef); // Build a full-expression copy expression if initialization // succeeded and used a non-trivial constructor. Recover from // errors by pretending that the copy isn't necessary. if (!Result.isInvalid() && !cast(Result.get())->getConstructor() ->isTrivial()) { Result = S.MaybeCreateExprWithCleanups(Result); CopyExpr = Result.get(); } } } } // Actually capture the variable. if (BuildAndDiagnose) BSI->addCapture(Var, HasBlocksAttr, ByRef, Nested, Loc, SourceLocation(), CaptureType, CopyExpr); return true; } /// \brief Capture the given variable in the captured region. static bool captureInCapturedRegion(CapturedRegionScopeInfo *RSI, VarDecl *Var, SourceLocation Loc, const bool BuildAndDiagnose, QualType &CaptureType, QualType &DeclRefType, const bool RefersToCapturedVariable, Sema &S) { // By default, capture variables by reference. bool ByRef = true; // Using an LValue reference type is consistent with Lambdas (see below). if (S.getLangOpts().OpenMP) { ByRef = S.IsOpenMPCapturedByRef(Var, RSI); if (S.IsOpenMPCapturedVar(Var)) DeclRefType = DeclRefType.getUnqualifiedType(); } if (ByRef) CaptureType = S.Context.getLValueReferenceType(DeclRefType); else CaptureType = DeclRefType; Expr *CopyExpr = nullptr; if (BuildAndDiagnose) { // The current implementation assumes that all variables are captured // by references. Since there is no capture by copy, no expression // evaluation will be needed. RecordDecl *RD = RSI->TheRecordDecl; FieldDecl *Field = FieldDecl::Create(S.Context, RD, Loc, Loc, nullptr, CaptureType, S.Context.getTrivialTypeSourceInfo(CaptureType, Loc), nullptr, false, ICIS_NoInit); Field->setImplicit(true); Field->setAccess(AS_private); RD->addDecl(Field); CopyExpr = new (S.Context) DeclRefExpr(Var, RefersToCapturedVariable, DeclRefType, VK_LValue, Loc); Var->setReferenced(true); Var->markUsed(S.Context); } // Actually capture the variable. if (BuildAndDiagnose) RSI->addCapture(Var, /*isBlock*/false, ByRef, RefersToCapturedVariable, Loc, SourceLocation(), CaptureType, CopyExpr); return true; } /// \brief Create a field within the lambda class for the variable /// being captured. static void addAsFieldToClosureType(Sema &S, LambdaScopeInfo *LSI, VarDecl *Var, QualType FieldType, QualType DeclRefType, SourceLocation Loc, bool RefersToCapturedVariable) { CXXRecordDecl *Lambda = LSI->Lambda; // Build the non-static data member. FieldDecl *Field = FieldDecl::Create(S.Context, Lambda, Loc, Loc, nullptr, FieldType, S.Context.getTrivialTypeSourceInfo(FieldType, Loc), nullptr, false, ICIS_NoInit); Field->setImplicit(true); Field->setAccess(AS_private); Lambda->addDecl(Field); } /// \brief Capture the given variable in the lambda. static bool captureInLambda(LambdaScopeInfo *LSI, VarDecl *Var, SourceLocation Loc, const bool BuildAndDiagnose, QualType &CaptureType, QualType &DeclRefType, const bool RefersToCapturedVariable, const Sema::TryCaptureKind Kind, SourceLocation EllipsisLoc, const bool IsTopScope, Sema &S) { // Determine whether we are capturing by reference or by value. bool ByRef = false; if (IsTopScope && Kind != Sema::TryCapture_Implicit) { ByRef = (Kind == Sema::TryCapture_ExplicitByRef); } else { ByRef = (LSI->ImpCaptureStyle == LambdaScopeInfo::ImpCap_LambdaByref); } // Compute the type of the field that will capture this variable. if (ByRef) { // C++11 [expr.prim.lambda]p15: // An entity is captured by reference if it is implicitly or // explicitly captured but not captured by copy. It is // unspecified whether additional unnamed non-static data // members are declared in the closure type for entities // captured by reference. // // FIXME: It is not clear whether we want to build an lvalue reference // to the DeclRefType or to CaptureType.getNonReferenceType(). GCC appears // to do the former, while EDG does the latter. Core issue 1249 will // clarify, but for now we follow GCC because it's a more permissive and // easily defensible position. CaptureType = S.Context.getLValueReferenceType(DeclRefType); } else { // C++11 [expr.prim.lambda]p14: // For each entity captured by copy, an unnamed non-static // data member is declared in the closure type. The // declaration order of these members is unspecified. The type // of such a data member is the type of the corresponding // captured entity if the entity is not a reference to an // object, or the referenced type otherwise. [Note: If the // captured entity is a reference to a function, the // corresponding data member is also a reference to a // function. - end note ] if (const ReferenceType *RefType = CaptureType->getAs()){ if (!RefType->getPointeeType()->isFunctionType()) CaptureType = RefType->getPointeeType(); } // Forbid the lambda copy-capture of autoreleasing variables. if (CaptureType.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) { if (BuildAndDiagnose) { S.Diag(Loc, diag::err_arc_autoreleasing_capture) << /*lambda*/ 1; S.Diag(Var->getLocation(), diag::note_previous_decl) << Var->getDeclName(); } return false; } // Make sure that by-copy captures are of a complete and non-abstract type. if (BuildAndDiagnose) { if (!CaptureType->isDependentType() && S.RequireCompleteType(Loc, CaptureType, diag::err_capture_of_incomplete_type, Var->getDeclName())) return false; if (S.RequireNonAbstractType(Loc, CaptureType, diag::err_capture_of_abstract_type)) return false; } } // Capture this variable in the lambda. if (BuildAndDiagnose) addAsFieldToClosureType(S, LSI, Var, CaptureType, DeclRefType, Loc, RefersToCapturedVariable); // Compute the type of a reference to this captured variable. if (ByRef) DeclRefType = CaptureType.getNonReferenceType(); else { // C++ [expr.prim.lambda]p5: // The closure type for a lambda-expression has a public inline // function call operator [...]. This function call operator is // declared const (9.3.1) if and only if the lambda-expression’s // parameter-declaration-clause is not followed by mutable. DeclRefType = CaptureType.getNonReferenceType(); if (!LSI->Mutable && !CaptureType->isReferenceType()) DeclRefType.addConst(); } // Add the capture. if (BuildAndDiagnose) LSI->addCapture(Var, /*IsBlock=*/false, ByRef, RefersToCapturedVariable, Loc, EllipsisLoc, CaptureType, /*CopyExpr=*/nullptr); return true; } bool Sema::tryCaptureVariable( VarDecl *Var, SourceLocation ExprLoc, TryCaptureKind Kind, SourceLocation EllipsisLoc, bool BuildAndDiagnose, QualType &CaptureType, QualType &DeclRefType, const unsigned *const FunctionScopeIndexToStopAt) { // An init-capture is notionally from the context surrounding its // declaration, but its parent DC is the lambda class. DeclContext *VarDC = Var->getDeclContext(); if (Var->isInitCapture()) VarDC = VarDC->getParent(); DeclContext *DC = CurContext; const unsigned MaxFunctionScopesIndex = FunctionScopeIndexToStopAt ? *FunctionScopeIndexToStopAt : FunctionScopes.size() - 1; // We need to sync up the Declaration Context with the // FunctionScopeIndexToStopAt if (FunctionScopeIndexToStopAt) { unsigned FSIndex = FunctionScopes.size() - 1; while (FSIndex != MaxFunctionScopesIndex) { DC = getLambdaAwareParentOfDeclContext(DC); --FSIndex; } } // If the variable is declared in the current context, there is no need to // capture it. if (VarDC == DC) return true; // Capture global variables if it is required to use private copy of this // variable. bool IsGlobal = !Var->hasLocalStorage(); if (IsGlobal && !(LangOpts.OpenMP && IsOpenMPCapturedVar(Var))) return true; // Walk up the stack to determine whether we can capture the variable, // performing the "simple" checks that don't depend on type. We stop when // we've either hit the declared scope of the variable or find an existing // capture of that variable. We start from the innermost capturing-entity // (the DC) and ensure that all intervening capturing-entities // (blocks/lambdas etc.) between the innermost capturer and the variable`s // declcontext can either capture the variable or have already captured // the variable. CaptureType = Var->getType(); DeclRefType = CaptureType.getNonReferenceType(); bool Nested = false; bool Explicit = (Kind != TryCapture_Implicit); unsigned FunctionScopesIndex = MaxFunctionScopesIndex; unsigned OpenMPLevel = 0; do { // Only block literals, captured statements, and lambda expressions can // capture; other scopes don't work. DeclContext *ParentDC = getParentOfCapturingContextOrNull(DC, Var, ExprLoc, BuildAndDiagnose, *this); // We need to check for the parent *first* because, if we *have* // private-captured a global variable, we need to recursively capture it in // intermediate blocks, lambdas, etc. if (!ParentDC) { if (IsGlobal) { FunctionScopesIndex = MaxFunctionScopesIndex - 1; break; } return true; } FunctionScopeInfo *FSI = FunctionScopes[FunctionScopesIndex]; CapturingScopeInfo *CSI = cast(FSI); // Check whether we've already captured it. if (isVariableAlreadyCapturedInScopeInfo(CSI, Var, Nested, CaptureType, DeclRefType)) break; // If we are instantiating a generic lambda call operator body, // we do not want to capture new variables. What was captured // during either a lambdas transformation or initial parsing // should be used. if (isGenericLambdaCallOperatorSpecialization(DC)) { if (BuildAndDiagnose) { LambdaScopeInfo *LSI = cast(CSI); if (LSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_None) { Diag(ExprLoc, diag::err_lambda_impcap) << Var->getDeclName(); Diag(Var->getLocation(), diag::note_previous_decl) << Var->getDeclName(); Diag(LSI->Lambda->getLocStart(), diag::note_lambda_decl); } else diagnoseUncapturableValueReference(*this, ExprLoc, Var, DC); } return true; } // Certain capturing entities (lambdas, blocks etc.) are not allowed to capture // certain types of variables (unnamed, variably modified types etc.) // so check for eligibility. if (!isVariableCapturable(CSI, Var, ExprLoc, BuildAndDiagnose, *this)) return true; // Try to capture variable-length arrays types. if (Var->getType()->isVariablyModifiedType()) { // We're going to walk down into the type and look for VLA // expressions. QualType QTy = Var->getType(); if (ParmVarDecl *PVD = dyn_cast_or_null(Var)) QTy = PVD->getOriginalType(); do { const Type *Ty = QTy.getTypePtr(); switch (Ty->getTypeClass()) { #define TYPE(Class, Base) #define ABSTRACT_TYPE(Class, Base) #define NON_CANONICAL_TYPE(Class, Base) #define DEPENDENT_TYPE(Class, Base) case Type::Class: #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) #include "clang/AST/TypeNodes.def" QTy = QualType(); break; // These types are never variably-modified. case Type::Builtin: case Type::Complex: case Type::Vector: case Type::ExtVector: case Type::Record: case Type::Enum: case Type::Elaborated: case Type::TemplateSpecialization: case Type::ObjCObject: case Type::ObjCInterface: case Type::ObjCObjectPointer: llvm_unreachable("type class is never variably-modified!"); case Type::Adjusted: QTy = cast(Ty)->getOriginalType(); break; case Type::Decayed: QTy = cast(Ty)->getPointeeType(); break; case Type::Pointer: QTy = cast(Ty)->getPointeeType(); break; case Type::BlockPointer: QTy = cast(Ty)->getPointeeType(); break; case Type::LValueReference: case Type::RValueReference: QTy = cast(Ty)->getPointeeType(); break; case Type::MemberPointer: QTy = cast(Ty)->getPointeeType(); break; case Type::ConstantArray: case Type::IncompleteArray: // Losing element qualification here is fine. QTy = cast(Ty)->getElementType(); break; case Type::VariableArray: { // Losing element qualification here is fine. const VariableArrayType *VAT = cast(Ty); // Unknown size indication requires no size computation. // Otherwise, evaluate and record it. if (auto Size = VAT->getSizeExpr()) { if (!CSI->isVLATypeCaptured(VAT)) { RecordDecl *CapRecord = nullptr; if (auto LSI = dyn_cast(CSI)) { CapRecord = LSI->Lambda; } else if (auto CRSI = dyn_cast(CSI)) { CapRecord = CRSI->TheRecordDecl; } if (CapRecord) { auto ExprLoc = Size->getExprLoc(); auto SizeType = Context.getSizeType(); // Build the non-static data member. auto Field = FieldDecl::Create( Context, CapRecord, ExprLoc, ExprLoc, /*Id*/ nullptr, SizeType, /*TInfo*/ nullptr, /*BW*/ nullptr, /*Mutable*/ false, /*InitStyle*/ ICIS_NoInit); Field->setImplicit(true); Field->setAccess(AS_private); Field->setCapturedVLAType(VAT); CapRecord->addDecl(Field); CSI->addVLATypeCapture(ExprLoc, SizeType); } } } QTy = VAT->getElementType(); break; } case Type::FunctionProto: case Type::FunctionNoProto: QTy = cast(Ty)->getReturnType(); break; case Type::Paren: case Type::TypeOf: case Type::UnaryTransform: case Type::Attributed: case Type::SubstTemplateTypeParm: case Type::PackExpansion: // Keep walking after single level desugaring. QTy = QTy.getSingleStepDesugaredType(getASTContext()); break; case Type::Typedef: QTy = cast(Ty)->desugar(); break; case Type::Decltype: QTy = cast(Ty)->desugar(); break; case Type::Auto: QTy = cast(Ty)->getDeducedType(); break; case Type::TypeOfExpr: QTy = cast(Ty)->getUnderlyingExpr()->getType(); break; case Type::Atomic: QTy = cast(Ty)->getValueType(); break; } } while (!QTy.isNull() && QTy->isVariablyModifiedType()); } if (getLangOpts().OpenMP) { if (auto *RSI = dyn_cast(CSI)) { // OpenMP private variables should not be captured in outer scope, so // just break here. Similarly, global variables that are captured in a // target region should not be captured outside the scope of the region. if (RSI->CapRegionKind == CR_OpenMP) { auto isTargetCap = isOpenMPTargetCapturedVar(Var, OpenMPLevel); // When we detect target captures we are looking from inside the // target region, therefore we need to propagate the capture from the // enclosing region. Therefore, the capture is not initially nested. if (isTargetCap) FunctionScopesIndex--; if (isTargetCap || isOpenMPPrivateVar(Var, OpenMPLevel)) { Nested = !isTargetCap; DeclRefType = DeclRefType.getUnqualifiedType(); CaptureType = Context.getLValueReferenceType(DeclRefType); break; } ++OpenMPLevel; } } } if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_None && !Explicit) { // No capture-default, and this is not an explicit capture // so cannot capture this variable. if (BuildAndDiagnose) { Diag(ExprLoc, diag::err_lambda_impcap) << Var->getDeclName(); Diag(Var->getLocation(), diag::note_previous_decl) << Var->getDeclName(); Diag(cast(CSI)->Lambda->getLocStart(), diag::note_lambda_decl); // FIXME: If we error out because an outer lambda can not implicitly // capture a variable that an inner lambda explicitly captures, we // should have the inner lambda do the explicit capture - because // it makes for cleaner diagnostics later. This would purely be done // so that the diagnostic does not misleadingly claim that a variable // can not be captured by a lambda implicitly even though it is captured // explicitly. Suggestion: // - create const bool VariableCaptureWasInitiallyExplicit = Explicit // at the function head // - cache the StartingDeclContext - this must be a lambda // - captureInLambda in the innermost lambda the variable. } return true; } FunctionScopesIndex--; DC = ParentDC; Explicit = false; } while (!VarDC->Equals(DC)); // Walk back down the scope stack, (e.g. from outer lambda to inner lambda) // computing the type of the capture at each step, checking type-specific // requirements, and adding captures if requested. // If the variable had already been captured previously, we start capturing // at the lambda nested within that one. for (unsigned I = ++FunctionScopesIndex, N = MaxFunctionScopesIndex + 1; I != N; ++I) { CapturingScopeInfo *CSI = cast(FunctionScopes[I]); if (BlockScopeInfo *BSI = dyn_cast(CSI)) { if (!captureInBlock(BSI, Var, ExprLoc, BuildAndDiagnose, CaptureType, DeclRefType, Nested, *this)) return true; Nested = true; } else if (CapturedRegionScopeInfo *RSI = dyn_cast(CSI)) { if (!captureInCapturedRegion(RSI, Var, ExprLoc, BuildAndDiagnose, CaptureType, DeclRefType, Nested, *this)) return true; Nested = true; } else { LambdaScopeInfo *LSI = cast(CSI); if (!captureInLambda(LSI, Var, ExprLoc, BuildAndDiagnose, CaptureType, DeclRefType, Nested, Kind, EllipsisLoc, /*IsTopScope*/I == N - 1, *this)) return true; Nested = true; } } return false; } bool Sema::tryCaptureVariable(VarDecl *Var, SourceLocation Loc, TryCaptureKind Kind, SourceLocation EllipsisLoc) { QualType CaptureType; QualType DeclRefType; return tryCaptureVariable(Var, Loc, Kind, EllipsisLoc, /*BuildAndDiagnose=*/true, CaptureType, DeclRefType, nullptr); } bool Sema::NeedToCaptureVariable(VarDecl *Var, SourceLocation Loc) { QualType CaptureType; QualType DeclRefType; return !tryCaptureVariable(Var, Loc, TryCapture_Implicit, SourceLocation(), /*BuildAndDiagnose=*/false, CaptureType, DeclRefType, nullptr); } QualType Sema::getCapturedDeclRefType(VarDecl *Var, SourceLocation Loc) { QualType CaptureType; QualType DeclRefType; // Determine whether we can capture this variable. if (tryCaptureVariable(Var, Loc, TryCapture_Implicit, SourceLocation(), /*BuildAndDiagnose=*/false, CaptureType, DeclRefType, nullptr)) return QualType(); return DeclRefType; } // If either the type of the variable or the initializer is dependent, // return false. Otherwise, determine whether the variable is a constant // expression. Use this if you need to know if a variable that might or // might not be dependent is truly a constant expression. static inline bool IsVariableNonDependentAndAConstantExpression(VarDecl *Var, ASTContext &Context) { if (Var->getType()->isDependentType()) return false; const VarDecl *DefVD = nullptr; Var->getAnyInitializer(DefVD); if (!DefVD) return false; EvaluatedStmt *Eval = DefVD->ensureEvaluatedStmt(); Expr *Init = cast(Eval->Value); if (Init->isValueDependent()) return false; return IsVariableAConstantExpression(Var, Context); } void Sema::UpdateMarkingForLValueToRValue(Expr *E) { // Per C++11 [basic.def.odr], a variable is odr-used "unless it is // an object that satisfies the requirements for appearing in a // constant expression (5.19) and the lvalue-to-rvalue conversion (4.1) // is immediately applied." This function handles the lvalue-to-rvalue // conversion part. MaybeODRUseExprs.erase(E->IgnoreParens()); // If we are in a lambda, check if this DeclRefExpr or MemberExpr refers // to a variable that is a constant expression, and if so, identify it as // a reference to a variable that does not involve an odr-use of that // variable. if (LambdaScopeInfo *LSI = getCurLambda()) { Expr *SansParensExpr = E->IgnoreParens(); VarDecl *Var = nullptr; if (DeclRefExpr *DRE = dyn_cast(SansParensExpr)) Var = dyn_cast(DRE->getFoundDecl()); else if (MemberExpr *ME = dyn_cast(SansParensExpr)) Var = dyn_cast(ME->getMemberDecl()); if (Var && IsVariableNonDependentAndAConstantExpression(Var, Context)) LSI->markVariableExprAsNonODRUsed(SansParensExpr); } } ExprResult Sema::ActOnConstantExpression(ExprResult Res) { Res = CorrectDelayedTyposInExpr(Res); if (!Res.isUsable()) return Res; // If a constant-expression is a reference to a variable where we delay // deciding whether it is an odr-use, just assume we will apply the // lvalue-to-rvalue conversion. In the one case where this doesn't happen // (a non-type template argument), we have special handling anyway. UpdateMarkingForLValueToRValue(Res.get()); return Res; } void Sema::CleanupVarDeclMarking() { for (Expr *E : MaybeODRUseExprs) { VarDecl *Var; SourceLocation Loc; if (DeclRefExpr *DRE = dyn_cast(E)) { Var = cast(DRE->getDecl()); Loc = DRE->getLocation(); } else if (MemberExpr *ME = dyn_cast(E)) { Var = cast(ME->getMemberDecl()); Loc = ME->getMemberLoc(); } else { llvm_unreachable("Unexpected expression"); } MarkVarDeclODRUsed(Var, Loc, *this, /*MaxFunctionScopeIndex Pointer*/ nullptr); } MaybeODRUseExprs.clear(); } static void DoMarkVarDeclReferenced(Sema &SemaRef, SourceLocation Loc, VarDecl *Var, Expr *E) { assert((!E || isa(E) || isa(E)) && "Invalid Expr argument to DoMarkVarDeclReferenced"); Var->setReferenced(); TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind(); bool MarkODRUsed = true; // If the context is not potentially evaluated, this is not an odr-use and // does not trigger instantiation. if (!IsPotentiallyEvaluatedContext(SemaRef)) { if (SemaRef.isUnevaluatedContext()) return; // If we don't yet know whether this context is going to end up being an // evaluated context, and we're referencing a variable from an enclosing // scope, add a potential capture. // // FIXME: Is this necessary? These contexts are only used for default // arguments, where local variables can't be used. const bool RefersToEnclosingScope = (SemaRef.CurContext != Var->getDeclContext() && Var->getDeclContext()->isFunctionOrMethod() && Var->hasLocalStorage()); if (RefersToEnclosingScope) { if (LambdaScopeInfo *const LSI = SemaRef.getCurLambda()) { // If a variable could potentially be odr-used, defer marking it so // until we finish analyzing the full expression for any // lvalue-to-rvalue // or discarded value conversions that would obviate odr-use. // Add it to the list of potential captures that will be analyzed // later (ActOnFinishFullExpr) for eventual capture and odr-use marking // unless the variable is a reference that was initialized by a constant // expression (this will never need to be captured or odr-used). assert(E && "Capture variable should be used in an expression."); if (!Var->getType()->isReferenceType() || !IsVariableNonDependentAndAConstantExpression(Var, SemaRef.Context)) LSI->addPotentialCapture(E->IgnoreParens()); } } if (!isTemplateInstantiation(TSK)) return; // Instantiate, but do not mark as odr-used, variable templates. MarkODRUsed = false; } VarTemplateSpecializationDecl *VarSpec = dyn_cast(Var); assert(!isa(Var) && "Can't instantiate a partial template specialization."); // Perform implicit instantiation of static data members, static data member // templates of class templates, and variable template specializations. Delay // instantiations of variable templates, except for those that could be used // in a constant expression. if (isTemplateInstantiation(TSK)) { bool TryInstantiating = TSK == TSK_ImplicitInstantiation; if (TryInstantiating && !isa(Var)) { if (Var->getPointOfInstantiation().isInvalid()) { // This is a modification of an existing AST node. Notify listeners. if (ASTMutationListener *L = SemaRef.getASTMutationListener()) L->StaticDataMemberInstantiated(Var); } else if (!Var->isUsableInConstantExpressions(SemaRef.Context)) // Don't bother trying to instantiate it again, unless we might need // its initializer before we get to the end of the TU. TryInstantiating = false; } if (Var->getPointOfInstantiation().isInvalid()) Var->setTemplateSpecializationKind(TSK, Loc); if (TryInstantiating) { SourceLocation PointOfInstantiation = Var->getPointOfInstantiation(); bool InstantiationDependent = false; bool IsNonDependent = VarSpec ? !TemplateSpecializationType::anyDependentTemplateArguments( VarSpec->getTemplateArgsInfo(), InstantiationDependent) : true; // Do not instantiate specializations that are still type-dependent. if (IsNonDependent) { if (Var->isUsableInConstantExpressions(SemaRef.Context)) { // Do not defer instantiations of variables which could be used in a // constant expression. SemaRef.InstantiateVariableDefinition(PointOfInstantiation, Var); } else { SemaRef.PendingInstantiations .push_back(std::make_pair(Var, PointOfInstantiation)); } } } } if(!MarkODRUsed) return; // Per C++11 [basic.def.odr], a variable is odr-used "unless it satisfies // the requirements for appearing in a constant expression (5.19) and, if // it is an object, the lvalue-to-rvalue conversion (4.1) // is immediately applied." We check the first part here, and // Sema::UpdateMarkingForLValueToRValue deals with the second part. // Note that we use the C++11 definition everywhere because nothing in // C++03 depends on whether we get the C++03 version correct. The second // part does not apply to references, since they are not objects. if (E && IsVariableAConstantExpression(Var, SemaRef.Context)) { // A reference initialized by a constant expression can never be // odr-used, so simply ignore it. if (!Var->getType()->isReferenceType()) SemaRef.MaybeODRUseExprs.insert(E); } else MarkVarDeclODRUsed(Var, Loc, SemaRef, /*MaxFunctionScopeIndex ptr*/ nullptr); } /// \brief Mark a variable referenced, and check whether it is odr-used /// (C++ [basic.def.odr]p2, C99 6.9p3). Note that this should not be /// used directly for normal expressions referring to VarDecl. void Sema::MarkVariableReferenced(SourceLocation Loc, VarDecl *Var) { DoMarkVarDeclReferenced(*this, Loc, Var, nullptr); } static void MarkExprReferenced(Sema &SemaRef, SourceLocation Loc, Decl *D, Expr *E, bool OdrUse) { if (VarDecl *Var = dyn_cast(D)) { DoMarkVarDeclReferenced(SemaRef, Loc, Var, E); return; } SemaRef.MarkAnyDeclReferenced(Loc, D, OdrUse); // If this is a call to a method via a cast, also mark the method in the // derived class used in case codegen can devirtualize the call. const MemberExpr *ME = dyn_cast(E); if (!ME) return; CXXMethodDecl *MD = dyn_cast(ME->getMemberDecl()); if (!MD) return; // Only attempt to devirtualize if this is truly a virtual call. bool IsVirtualCall = MD->isVirtual() && ME->performsVirtualDispatch(SemaRef.getLangOpts()); if (!IsVirtualCall) return; const Expr *Base = ME->getBase(); const CXXRecordDecl *MostDerivedClassDecl = Base->getBestDynamicClassType(); if (!MostDerivedClassDecl) return; CXXMethodDecl *DM = MD->getCorrespondingMethodInClass(MostDerivedClassDecl); if (!DM || DM->isPure()) return; SemaRef.MarkAnyDeclReferenced(Loc, DM, OdrUse); } /// \brief Perform reference-marking and odr-use handling for a DeclRefExpr. void Sema::MarkDeclRefReferenced(DeclRefExpr *E) { // TODO: update this with DR# once a defect report is filed. // C++11 defect. The address of a pure member should not be an ODR use, even // if it's a qualified reference. bool OdrUse = true; if (CXXMethodDecl *Method = dyn_cast(E->getDecl())) if (Method->isVirtual()) OdrUse = false; MarkExprReferenced(*this, E->getLocation(), E->getDecl(), E, OdrUse); } /// \brief Perform reference-marking and odr-use handling for a MemberExpr. void Sema::MarkMemberReferenced(MemberExpr *E) { // C++11 [basic.def.odr]p2: // A non-overloaded function whose name appears as a potentially-evaluated // expression or a member of a set of candidate functions, if selected by // overload resolution when referred to from a potentially-evaluated // expression, is odr-used, unless it is a pure virtual function and its // name is not explicitly qualified. bool OdrUse = true; if (E->performsVirtualDispatch(getLangOpts())) { if (CXXMethodDecl *Method = dyn_cast(E->getMemberDecl())) if (Method->isPure()) OdrUse = false; } SourceLocation Loc = E->getMemberLoc().isValid() ? E->getMemberLoc() : E->getLocStart(); MarkExprReferenced(*this, Loc, E->getMemberDecl(), E, OdrUse); } /// \brief Perform marking for a reference to an arbitrary declaration. It /// marks the declaration referenced, and performs odr-use checking for /// functions and variables. This method should not be used when building a /// normal expression which refers to a variable. void Sema::MarkAnyDeclReferenced(SourceLocation Loc, Decl *D, bool OdrUse) { if (OdrUse) { if (auto *VD = dyn_cast(D)) { MarkVariableReferenced(Loc, VD); return; } } if (auto *FD = dyn_cast(D)) { MarkFunctionReferenced(Loc, FD, OdrUse); return; } D->setReferenced(); } namespace { // Mark all of the declarations referenced // FIXME: Not fully implemented yet! We need to have a better understanding // of when we're entering class MarkReferencedDecls : public RecursiveASTVisitor { Sema &S; SourceLocation Loc; public: typedef RecursiveASTVisitor Inherited; MarkReferencedDecls(Sema &S, SourceLocation Loc) : S(S), Loc(Loc) { } bool TraverseTemplateArgument(const TemplateArgument &Arg); bool TraverseRecordType(RecordType *T); }; } bool MarkReferencedDecls::TraverseTemplateArgument( const TemplateArgument &Arg) { if (Arg.getKind() == TemplateArgument::Declaration) { if (Decl *D = Arg.getAsDecl()) S.MarkAnyDeclReferenced(Loc, D, true); } return Inherited::TraverseTemplateArgument(Arg); } bool MarkReferencedDecls::TraverseRecordType(RecordType *T) { if (ClassTemplateSpecializationDecl *Spec = dyn_cast(T->getDecl())) { const TemplateArgumentList &Args = Spec->getTemplateArgs(); return TraverseTemplateArguments(Args.data(), Args.size()); } return true; } void Sema::MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T) { MarkReferencedDecls Marker(*this, Loc); Marker.TraverseType(Context.getCanonicalType(T)); } namespace { /// \brief Helper class that marks all of the declarations referenced by /// potentially-evaluated subexpressions as "referenced". class EvaluatedExprMarker : public EvaluatedExprVisitor { Sema &S; bool SkipLocalVariables; public: typedef EvaluatedExprVisitor Inherited; EvaluatedExprMarker(Sema &S, bool SkipLocalVariables) : Inherited(S.Context), S(S), SkipLocalVariables(SkipLocalVariables) { } void VisitDeclRefExpr(DeclRefExpr *E) { // If we were asked not to visit local variables, don't. if (SkipLocalVariables) { if (VarDecl *VD = dyn_cast(E->getDecl())) if (VD->hasLocalStorage()) return; } S.MarkDeclRefReferenced(E); } void VisitMemberExpr(MemberExpr *E) { S.MarkMemberReferenced(E); Inherited::VisitMemberExpr(E); } void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) { S.MarkFunctionReferenced(E->getLocStart(), const_cast(E->getTemporary()->getDestructor())); Visit(E->getSubExpr()); } void VisitCXXNewExpr(CXXNewExpr *E) { if (E->getOperatorNew()) S.MarkFunctionReferenced(E->getLocStart(), E->getOperatorNew()); if (E->getOperatorDelete()) S.MarkFunctionReferenced(E->getLocStart(), E->getOperatorDelete()); Inherited::VisitCXXNewExpr(E); } void VisitCXXDeleteExpr(CXXDeleteExpr *E) { if (E->getOperatorDelete()) S.MarkFunctionReferenced(E->getLocStart(), E->getOperatorDelete()); QualType Destroyed = S.Context.getBaseElementType(E->getDestroyedType()); if (const RecordType *DestroyedRec = Destroyed->getAs()) { CXXRecordDecl *Record = cast(DestroyedRec->getDecl()); S.MarkFunctionReferenced(E->getLocStart(), S.LookupDestructor(Record)); } Inherited::VisitCXXDeleteExpr(E); } void VisitCXXConstructExpr(CXXConstructExpr *E) { S.MarkFunctionReferenced(E->getLocStart(), E->getConstructor()); Inherited::VisitCXXConstructExpr(E); } void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) { Visit(E->getExpr()); } void VisitImplicitCastExpr(ImplicitCastExpr *E) { Inherited::VisitImplicitCastExpr(E); if (E->getCastKind() == CK_LValueToRValue) S.UpdateMarkingForLValueToRValue(E->getSubExpr()); } }; } /// \brief Mark any declarations that appear within this expression or any /// potentially-evaluated subexpressions as "referenced". /// /// \param SkipLocalVariables If true, don't mark local variables as /// 'referenced'. void Sema::MarkDeclarationsReferencedInExpr(Expr *E, bool SkipLocalVariables) { EvaluatedExprMarker(*this, SkipLocalVariables).Visit(E); } /// \brief Emit a diagnostic that describes an effect on the run-time behavior /// of the program being compiled. /// /// This routine emits the given diagnostic when the code currently being /// type-checked is "potentially evaluated", meaning that there is a /// possibility that the code will actually be executable. Code in sizeof() /// expressions, code used only during overload resolution, etc., are not /// potentially evaluated. This routine will suppress such diagnostics or, /// in the absolutely nutty case of potentially potentially evaluated /// expressions (C++ typeid), queue the diagnostic to potentially emit it /// later. /// /// This routine should be used for all diagnostics that describe the run-time /// behavior of a program, such as passing a non-POD value through an ellipsis. /// Failure to do so will likely result in spurious diagnostics or failures /// during overload resolution or within sizeof/alignof/typeof/typeid. bool Sema::DiagRuntimeBehavior(SourceLocation Loc, const Stmt *Statement, const PartialDiagnostic &PD) { switch (ExprEvalContexts.back().Context) { case Unevaluated: case UnevaluatedAbstract: // The argument will never be evaluated, so don't complain. break; case ConstantEvaluated: // Relevant diagnostics should be produced by constant evaluation. break; case PotentiallyEvaluated: case PotentiallyEvaluatedIfUsed: if (Statement && getCurFunctionOrMethodDecl()) { FunctionScopes.back()->PossiblyUnreachableDiags. push_back(sema::PossiblyUnreachableDiag(PD, Loc, Statement)); } else Diag(Loc, PD); return true; } return false; } bool Sema::CheckCallReturnType(QualType ReturnType, SourceLocation Loc, CallExpr *CE, FunctionDecl *FD) { if (ReturnType->isVoidType() || !ReturnType->isIncompleteType()) return false; // If we're inside a decltype's expression, don't check for a valid return // type or construct temporaries until we know whether this is the last call. if (ExprEvalContexts.back().IsDecltype) { ExprEvalContexts.back().DelayedDecltypeCalls.push_back(CE); return false; } class CallReturnIncompleteDiagnoser : public TypeDiagnoser { FunctionDecl *FD; CallExpr *CE; public: CallReturnIncompleteDiagnoser(FunctionDecl *FD, CallExpr *CE) : FD(FD), CE(CE) { } void diagnose(Sema &S, SourceLocation Loc, QualType T) override { if (!FD) { S.Diag(Loc, diag::err_call_incomplete_return) << T << CE->getSourceRange(); return; } S.Diag(Loc, diag::err_call_function_incomplete_return) << CE->getSourceRange() << FD->getDeclName() << T; S.Diag(FD->getLocation(), diag::note_entity_declared_at) << FD->getDeclName(); } } Diagnoser(FD, CE); if (RequireCompleteType(Loc, ReturnType, Diagnoser)) return true; return false; } // Diagnose the s/=/==/ and s/\|=/!=/ typos. Note that adding parentheses // will prevent this condition from triggering, which is what we want. void Sema::DiagnoseAssignmentAsCondition(Expr *E) { SourceLocation Loc; unsigned diagnostic = diag::warn_condition_is_assignment; bool IsOrAssign = false; if (BinaryOperator *Op = dyn_cast(E)) { if (Op->getOpcode() != BO_Assign && Op->getOpcode() != BO_OrAssign) return; IsOrAssign = Op->getOpcode() == BO_OrAssign; // Greylist some idioms by putting them into a warning subcategory. if (ObjCMessageExpr *ME = dyn_cast(Op->getRHS()->IgnoreParenCasts())) { Selector Sel = ME->getSelector(); // self = [ init...] if (isSelfExpr(Op->getLHS()) && ME->getMethodFamily() == OMF_init) diagnostic = diag::warn_condition_is_idiomatic_assignment; // = [ nextObject] else if (Sel.isUnarySelector() && Sel.getNameForSlot(0) == "nextObject") diagnostic = diag::warn_condition_is_idiomatic_assignment; } Loc = Op->getOperatorLoc(); } else if (CXXOperatorCallExpr *Op = dyn_cast(E)) { if (Op->getOperator() != OO_Equal && Op->getOperator() != OO_PipeEqual) return; IsOrAssign = Op->getOperator() == OO_PipeEqual; Loc = Op->getOperatorLoc(); } else if (PseudoObjectExpr *POE = dyn_cast(E)) return DiagnoseAssignmentAsCondition(POE->getSyntacticForm()); else { // Not an assignment. return; } Diag(Loc, diagnostic) << E->getSourceRange(); SourceLocation Open = E->getLocStart(); SourceLocation Close = getLocForEndOfToken(E->getSourceRange().getEnd()); Diag(Loc, diag::note_condition_assign_silence) << FixItHint::CreateInsertion(Open, "(") << FixItHint::CreateInsertion(Close, ")"); if (IsOrAssign) Diag(Loc, diag::note_condition_or_assign_to_comparison) << FixItHint::CreateReplacement(Loc, "!="); else Diag(Loc, diag::note_condition_assign_to_comparison) << FixItHint::CreateReplacement(Loc, "=="); } /// \brief Redundant parentheses over an equality comparison can indicate /// that the user intended an assignment used as condition. void Sema::DiagnoseEqualityWithExtraParens(ParenExpr *ParenE) { // Don't warn if the parens came from a macro. SourceLocation parenLoc = ParenE->getLocStart(); if (parenLoc.isInvalid() || parenLoc.isMacroID()) return; // Don't warn for dependent expressions. if (ParenE->isTypeDependent()) return; Expr *E = ParenE->IgnoreParens(); if (BinaryOperator *opE = dyn_cast(E)) if (opE->getOpcode() == BO_EQ && opE->getLHS()->IgnoreParenImpCasts()->isModifiableLvalue(Context) == Expr::MLV_Valid) { SourceLocation Loc = opE->getOperatorLoc(); Diag(Loc, diag::warn_equality_with_extra_parens) << E->getSourceRange(); SourceRange ParenERange = ParenE->getSourceRange(); Diag(Loc, diag::note_equality_comparison_silence) << FixItHint::CreateRemoval(ParenERange.getBegin()) << FixItHint::CreateRemoval(ParenERange.getEnd()); Diag(Loc, diag::note_equality_comparison_to_assign) << FixItHint::CreateReplacement(Loc, "="); } } ExprResult Sema::CheckBooleanCondition(Expr *E, SourceLocation Loc) { DiagnoseAssignmentAsCondition(E); if (ParenExpr *parenE = dyn_cast(E)) DiagnoseEqualityWithExtraParens(parenE); ExprResult result = CheckPlaceholderExpr(E); if (result.isInvalid()) return ExprError(); E = result.get(); if (!E->isTypeDependent()) { if (getLangOpts().CPlusPlus) return CheckCXXBooleanCondition(E); // C++ 6.4p4 ExprResult ERes = DefaultFunctionArrayLvalueConversion(E); if (ERes.isInvalid()) return ExprError(); E = ERes.get(); QualType T = E->getType(); if (!T->isScalarType()) { // C99 6.8.4.1p1 Diag(Loc, diag::err_typecheck_statement_requires_scalar) << T << E->getSourceRange(); return ExprError(); } CheckBoolLikeConversion(E, Loc); } return E; } ExprResult Sema::ActOnBooleanCondition(Scope *S, SourceLocation Loc, Expr *SubExpr) { if (!SubExpr) return ExprError(); return CheckBooleanCondition(SubExpr, Loc); } namespace { /// A visitor for rebuilding a call to an __unknown_any expression /// to have an appropriate type. struct RebuildUnknownAnyFunction : StmtVisitor { Sema &S; RebuildUnknownAnyFunction(Sema &S) : S(S) {} ExprResult VisitStmt(Stmt *S) { llvm_unreachable("unexpected statement!"); } ExprResult VisitExpr(Expr *E) { S.Diag(E->getExprLoc(), diag::err_unsupported_unknown_any_call) << E->getSourceRange(); return ExprError(); } /// Rebuild an expression which simply semantically wraps another /// expression which it shares the type and value kind of. template ExprResult rebuildSugarExpr(T *E) { ExprResult SubResult = Visit(E->getSubExpr()); if (SubResult.isInvalid()) return ExprError(); Expr *SubExpr = SubResult.get(); E->setSubExpr(SubExpr); E->setType(SubExpr->getType()); E->setValueKind(SubExpr->getValueKind()); assert(E->getObjectKind() == OK_Ordinary); return E; } ExprResult VisitParenExpr(ParenExpr *E) { return rebuildSugarExpr(E); } ExprResult VisitUnaryExtension(UnaryOperator *E) { return rebuildSugarExpr(E); } ExprResult VisitUnaryAddrOf(UnaryOperator *E) { ExprResult SubResult = Visit(E->getSubExpr()); if (SubResult.isInvalid()) return ExprError(); Expr *SubExpr = SubResult.get(); E->setSubExpr(SubExpr); E->setType(S.Context.getPointerType(SubExpr->getType())); assert(E->getValueKind() == VK_RValue); assert(E->getObjectKind() == OK_Ordinary); return E; } ExprResult resolveDecl(Expr *E, ValueDecl *VD) { if (!isa(VD)) return VisitExpr(E); E->setType(VD->getType()); assert(E->getValueKind() == VK_RValue); if (S.getLangOpts().CPlusPlus && !(isa(VD) && cast(VD)->isInstance())) E->setValueKind(VK_LValue); return E; } ExprResult VisitMemberExpr(MemberExpr *E) { return resolveDecl(E, E->getMemberDecl()); } ExprResult VisitDeclRefExpr(DeclRefExpr *E) { return resolveDecl(E, E->getDecl()); } }; } /// Given a function expression of unknown-any type, try to rebuild it /// to have a function type. static ExprResult rebuildUnknownAnyFunction(Sema &S, Expr *FunctionExpr) { ExprResult Result = RebuildUnknownAnyFunction(S).Visit(FunctionExpr); if (Result.isInvalid()) return ExprError(); return S.DefaultFunctionArrayConversion(Result.get()); } namespace { /// A visitor for rebuilding an expression of type __unknown_anytype /// into one which resolves the type directly on the referring /// expression. Strict preservation of the original source /// structure is not a goal. struct RebuildUnknownAnyExpr : StmtVisitor { Sema &S; /// The current destination type. QualType DestType; RebuildUnknownAnyExpr(Sema &S, QualType CastType) : S(S), DestType(CastType) {} ExprResult VisitStmt(Stmt *S) { llvm_unreachable("unexpected statement!"); } ExprResult VisitExpr(Expr *E) { S.Diag(E->getExprLoc(), diag::err_unsupported_unknown_any_expr) << E->getSourceRange(); return ExprError(); } ExprResult VisitCallExpr(CallExpr *E); ExprResult VisitObjCMessageExpr(ObjCMessageExpr *E); /// Rebuild an expression which simply semantically wraps another /// expression which it shares the type and value kind of. template ExprResult rebuildSugarExpr(T *E) { ExprResult SubResult = Visit(E->getSubExpr()); if (SubResult.isInvalid()) return ExprError(); Expr *SubExpr = SubResult.get(); E->setSubExpr(SubExpr); E->setType(SubExpr->getType()); E->setValueKind(SubExpr->getValueKind()); assert(E->getObjectKind() == OK_Ordinary); return E; } ExprResult VisitParenExpr(ParenExpr *E) { return rebuildSugarExpr(E); } ExprResult VisitUnaryExtension(UnaryOperator *E) { return rebuildSugarExpr(E); } ExprResult VisitUnaryAddrOf(UnaryOperator *E) { const PointerType *Ptr = DestType->getAs(); if (!Ptr) { S.Diag(E->getOperatorLoc(), diag::err_unknown_any_addrof) << E->getSourceRange(); return ExprError(); } assert(E->getValueKind() == VK_RValue); assert(E->getObjectKind() == OK_Ordinary); E->setType(DestType); // Build the sub-expression as if it were an object of the pointee type. DestType = Ptr->getPointeeType(); ExprResult SubResult = Visit(E->getSubExpr()); if (SubResult.isInvalid()) return ExprError(); E->setSubExpr(SubResult.get()); return E; } ExprResult VisitImplicitCastExpr(ImplicitCastExpr *E); ExprResult resolveDecl(Expr *E, ValueDecl *VD); ExprResult VisitMemberExpr(MemberExpr *E) { return resolveDecl(E, E->getMemberDecl()); } ExprResult VisitDeclRefExpr(DeclRefExpr *E) { return resolveDecl(E, E->getDecl()); } }; } /// Rebuilds a call expression which yielded __unknown_anytype. ExprResult RebuildUnknownAnyExpr::VisitCallExpr(CallExpr *E) { Expr *CalleeExpr = E->getCallee(); enum FnKind { FK_MemberFunction, FK_FunctionPointer, FK_BlockPointer }; FnKind Kind; QualType CalleeType = CalleeExpr->getType(); if (CalleeType == S.Context.BoundMemberTy) { assert(isa(E) || isa(E)); Kind = FK_MemberFunction; CalleeType = Expr::findBoundMemberType(CalleeExpr); } else if (const PointerType *Ptr = CalleeType->getAs()) { CalleeType = Ptr->getPointeeType(); Kind = FK_FunctionPointer; } else { CalleeType = CalleeType->castAs()->getPointeeType(); Kind = FK_BlockPointer; } const FunctionType *FnType = CalleeType->castAs(); // Verify that this is a legal result type of a function. if (DestType->isArrayType() || DestType->isFunctionType()) { unsigned diagID = diag::err_func_returning_array_function; if (Kind == FK_BlockPointer) diagID = diag::err_block_returning_array_function; S.Diag(E->getExprLoc(), diagID) << DestType->isFunctionType() << DestType; return ExprError(); } // Otherwise, go ahead and set DestType as the call's result. E->setType(DestType.getNonLValueExprType(S.Context)); E->setValueKind(Expr::getValueKindForType(DestType)); assert(E->getObjectKind() == OK_Ordinary); // Rebuild the function type, replacing the result type with DestType. const FunctionProtoType *Proto = dyn_cast(FnType); if (Proto) { // __unknown_anytype(...) is a special case used by the debugger when // it has no idea what a function's signature is. // // We want to build this call essentially under the K&R // unprototyped rules, but making a FunctionNoProtoType in C++ // would foul up all sorts of assumptions. However, we cannot // simply pass all arguments as variadic arguments, nor can we // portably just call the function under a non-variadic type; see // the comment on IR-gen's TargetInfo::isNoProtoCallVariadic. // However, it turns out that in practice it is generally safe to // call a function declared as "A foo(B,C,D);" under the prototype // "A foo(B,C,D,...);". The only known exception is with the // Windows ABI, where any variadic function is implicitly cdecl // regardless of its normal CC. Therefore we change the parameter // types to match the types of the arguments. // // This is a hack, but it is far superior to moving the // corresponding target-specific code from IR-gen to Sema/AST. ArrayRef ParamTypes = Proto->getParamTypes(); SmallVector ArgTypes; if (ParamTypes.empty() && Proto->isVariadic()) { // the special case ArgTypes.reserve(E->getNumArgs()); for (unsigned i = 0, e = E->getNumArgs(); i != e; ++i) { Expr *Arg = E->getArg(i); QualType ArgType = Arg->getType(); if (E->isLValue()) { ArgType = S.Context.getLValueReferenceType(ArgType); } else if (E->isXValue()) { ArgType = S.Context.getRValueReferenceType(ArgType); } ArgTypes.push_back(ArgType); } ParamTypes = ArgTypes; } DestType = S.Context.getFunctionType(DestType, ParamTypes, Proto->getExtProtoInfo()); } else { DestType = S.Context.getFunctionNoProtoType(DestType, FnType->getExtInfo()); } // Rebuild the appropriate pointer-to-function type. switch (Kind) { case FK_MemberFunction: // Nothing to do. break; case FK_FunctionPointer: DestType = S.Context.getPointerType(DestType); break; case FK_BlockPointer: DestType = S.Context.getBlockPointerType(DestType); break; } // Finally, we can recurse. ExprResult CalleeResult = Visit(CalleeExpr); if (!CalleeResult.isUsable()) return ExprError(); E->setCallee(CalleeResult.get()); // Bind a temporary if necessary. return S.MaybeBindToTemporary(E); } ExprResult RebuildUnknownAnyExpr::VisitObjCMessageExpr(ObjCMessageExpr *E) { // Verify that this is a legal result type of a call. if (DestType->isArrayType() || DestType->isFunctionType()) { S.Diag(E->getExprLoc(), diag::err_func_returning_array_function) << DestType->isFunctionType() << DestType; return ExprError(); } // Rewrite the method result type if available. if (ObjCMethodDecl *Method = E->getMethodDecl()) { assert(Method->getReturnType() == S.Context.UnknownAnyTy); Method->setReturnType(DestType); } // Change the type of the message. E->setType(DestType.getNonReferenceType()); E->setValueKind(Expr::getValueKindForType(DestType)); return S.MaybeBindToTemporary(E); } ExprResult RebuildUnknownAnyExpr::VisitImplicitCastExpr(ImplicitCastExpr *E) { // The only case we should ever see here is a function-to-pointer decay. if (E->getCastKind() == CK_FunctionToPointerDecay) { assert(E->getValueKind() == VK_RValue); assert(E->getObjectKind() == OK_Ordinary); E->setType(DestType); // Rebuild the sub-expression as the pointee (function) type. DestType = DestType->castAs()->getPointeeType(); ExprResult Result = Visit(E->getSubExpr()); if (!Result.isUsable()) return ExprError(); E->setSubExpr(Result.get()); return E; } else if (E->getCastKind() == CK_LValueToRValue) { assert(E->getValueKind() == VK_RValue); assert(E->getObjectKind() == OK_Ordinary); assert(isa(E->getType())); E->setType(DestType); // The sub-expression has to be a lvalue reference, so rebuild it as such. DestType = S.Context.getLValueReferenceType(DestType); ExprResult Result = Visit(E->getSubExpr()); if (!Result.isUsable()) return ExprError(); E->setSubExpr(Result.get()); return E; } else { llvm_unreachable("Unhandled cast type!"); } } ExprResult RebuildUnknownAnyExpr::resolveDecl(Expr *E, ValueDecl *VD) { ExprValueKind ValueKind = VK_LValue; QualType Type = DestType; // We know how to make this work for certain kinds of decls: // - functions if (FunctionDecl *FD = dyn_cast(VD)) { if (const PointerType *Ptr = Type->getAs()) { DestType = Ptr->getPointeeType(); ExprResult Result = resolveDecl(E, VD); if (Result.isInvalid()) return ExprError(); return S.ImpCastExprToType(Result.get(), Type, CK_FunctionToPointerDecay, VK_RValue); } if (!Type->isFunctionType()) { S.Diag(E->getExprLoc(), diag::err_unknown_any_function) << VD << E->getSourceRange(); return ExprError(); } if (const FunctionProtoType *FT = Type->getAs()) { // We must match the FunctionDecl's type to the hack introduced in // RebuildUnknownAnyExpr::VisitCallExpr to vararg functions of unknown // type. See the lengthy commentary in that routine. QualType FDT = FD->getType(); const FunctionType *FnType = FDT->castAs(); const FunctionProtoType *Proto = dyn_cast_or_null(FnType); DeclRefExpr *DRE = dyn_cast(E); if (DRE && Proto && Proto->getParamTypes().empty() && Proto->isVariadic()) { SourceLocation Loc = FD->getLocation(); FunctionDecl *NewFD = FunctionDecl::Create(FD->getASTContext(), FD->getDeclContext(), Loc, Loc, FD->getNameInfo().getName(), DestType, FD->getTypeSourceInfo(), SC_None, false/*isInlineSpecified*/, FD->hasPrototype(), false/*isConstexprSpecified*/); if (FD->getQualifier()) NewFD->setQualifierInfo(FD->getQualifierLoc()); SmallVector Params; for (const auto &AI : FT->param_types()) { ParmVarDecl *Param = S.BuildParmVarDeclForTypedef(FD, Loc, AI); Param->setScopeInfo(0, Params.size()); Params.push_back(Param); } NewFD->setParams(Params); DRE->setDecl(NewFD); VD = DRE->getDecl(); } } if (CXXMethodDecl *MD = dyn_cast(FD)) if (MD->isInstance()) { ValueKind = VK_RValue; Type = S.Context.BoundMemberTy; } // Function references aren't l-values in C. if (!S.getLangOpts().CPlusPlus) ValueKind = VK_RValue; // - variables } else if (isa(VD)) { if (const ReferenceType *RefTy = Type->getAs()) { Type = RefTy->getPointeeType(); } else if (Type->isFunctionType()) { S.Diag(E->getExprLoc(), diag::err_unknown_any_var_function_type) << VD << E->getSourceRange(); return ExprError(); } // - nothing else } else { S.Diag(E->getExprLoc(), diag::err_unsupported_unknown_any_decl) << VD << E->getSourceRange(); return ExprError(); } // Modifying the declaration like this is friendly to IR-gen but // also really dangerous. VD->setType(DestType); E->setType(Type); E->setValueKind(ValueKind); return E; } /// Check a cast of an unknown-any type. We intentionally only /// trigger this for C-style casts. ExprResult Sema::checkUnknownAnyCast(SourceRange TypeRange, QualType CastType, Expr *CastExpr, CastKind &CastKind, ExprValueKind &VK, CXXCastPath &Path) { // Rewrite the casted expression from scratch. ExprResult result = RebuildUnknownAnyExpr(*this, CastType).Visit(CastExpr); if (!result.isUsable()) return ExprError(); CastExpr = result.get(); VK = CastExpr->getValueKind(); CastKind = CK_NoOp; return CastExpr; } ExprResult Sema::forceUnknownAnyToType(Expr *E, QualType ToType) { return RebuildUnknownAnyExpr(*this, ToType).Visit(E); } ExprResult Sema::checkUnknownAnyArg(SourceLocation callLoc, Expr *arg, QualType ¶mType) { // If the syntactic form of the argument is not an explicit cast of // any sort, just do default argument promotion. ExplicitCastExpr *castArg = dyn_cast(arg->IgnoreParens()); if (!castArg) { ExprResult result = DefaultArgumentPromotion(arg); if (result.isInvalid()) return ExprError(); paramType = result.get()->getType(); return result; } // Otherwise, use the type that was written in the explicit cast. assert(!arg->hasPlaceholderType()); paramType = castArg->getTypeAsWritten(); // Copy-initialize a parameter of that type. InitializedEntity entity = InitializedEntity::InitializeParameter(Context, paramType, /*consumed*/ false); return PerformCopyInitialization(entity, callLoc, arg); } static ExprResult diagnoseUnknownAnyExpr(Sema &S, Expr *E) { Expr *orig = E; unsigned diagID = diag::err_uncasted_use_of_unknown_any; while (true) { E = E->IgnoreParenImpCasts(); if (CallExpr *call = dyn_cast(E)) { E = call->getCallee(); diagID = diag::err_uncasted_call_of_unknown_any; } else { break; } } SourceLocation loc; NamedDecl *d; if (DeclRefExpr *ref = dyn_cast(E)) { loc = ref->getLocation(); d = ref->getDecl(); } else if (MemberExpr *mem = dyn_cast(E)) { loc = mem->getMemberLoc(); d = mem->getMemberDecl(); } else if (ObjCMessageExpr *msg = dyn_cast(E)) { diagID = diag::err_uncasted_call_of_unknown_any; loc = msg->getSelectorStartLoc(); d = msg->getMethodDecl(); if (!d) { S.Diag(loc, diag::err_uncasted_send_to_unknown_any_method) << static_cast(msg->isClassMessage()) << msg->getSelector() << orig->getSourceRange(); return ExprError(); } } else { S.Diag(E->getExprLoc(), diag::err_unsupported_unknown_any_expr) << E->getSourceRange(); return ExprError(); } S.Diag(loc, diagID) << d << orig->getSourceRange(); // Never recoverable. return ExprError(); } /// Check for operands with placeholder types and complain if found. /// Returns true if there was an error and no recovery was possible. ExprResult Sema::CheckPlaceholderExpr(Expr *E) { if (!getLangOpts().CPlusPlus) { // C cannot handle TypoExpr nodes on either side of a binop because it // doesn't handle dependent types properly, so make sure any TypoExprs have // been dealt with before checking the operands. ExprResult Result = CorrectDelayedTyposInExpr(E); if (!Result.isUsable()) return ExprError(); E = Result.get(); } const BuiltinType *placeholderType = E->getType()->getAsPlaceholderType(); if (!placeholderType) return E; switch (placeholderType->getKind()) { // Overloaded expressions. case BuiltinType::Overload: { // Try to resolve a single function template specialization. // This is obligatory. ExprResult result = E; if (ResolveAndFixSingleFunctionTemplateSpecialization(result, false)) { return result; // If that failed, try to recover with a call. } else { tryToRecoverWithCall(result, PDiag(diag::err_ovl_unresolvable), /*complain*/ true); return result; } } // Bound member functions. case BuiltinType::BoundMember: { ExprResult result = E; const Expr *BME = E->IgnoreParens(); PartialDiagnostic PD = PDiag(diag::err_bound_member_function); // Try to give a nicer diagnostic if it is a bound member that we recognize. if (isa(BME)) { PD = PDiag(diag::err_dtor_expr_without_call) << /*pseudo-destructor*/ 1; } else if (const auto *ME = dyn_cast(BME)) { if (ME->getMemberNameInfo().getName().getNameKind() == DeclarationName::CXXDestructorName) PD = PDiag(diag::err_dtor_expr_without_call) << /*destructor*/ 0; } tryToRecoverWithCall(result, PD, /*complain*/ true); return result; } // ARC unbridged casts. case BuiltinType::ARCUnbridgedCast: { Expr *realCast = stripARCUnbridgedCast(E); diagnoseARCUnbridgedCast(realCast); return realCast; } // Expressions of unknown type. case BuiltinType::UnknownAny: return diagnoseUnknownAnyExpr(*this, E); // Pseudo-objects. case BuiltinType::PseudoObject: return checkPseudoObjectRValue(E); case BuiltinType::BuiltinFn: { // Accept __noop without parens by implicitly converting it to a call expr. auto *DRE = dyn_cast(E->IgnoreParenImpCasts()); if (DRE) { auto *FD = cast(DRE->getDecl()); if (FD->getBuiltinID() == Builtin::BI__noop) { E = ImpCastExprToType(E, Context.getPointerType(FD->getType()), CK_BuiltinFnToFnPtr).get(); return new (Context) CallExpr(Context, E, None, Context.IntTy, VK_RValue, SourceLocation()); } } Diag(E->getLocStart(), diag::err_builtin_fn_use); return ExprError(); } // Expressions of unknown type. case BuiltinType::OMPArraySection: Diag(E->getLocStart(), diag::err_omp_array_section_use); return ExprError(); // Everything else should be impossible. #define BUILTIN_TYPE(Id, SingletonId) \ case BuiltinType::Id: #define PLACEHOLDER_TYPE(Id, SingletonId) #include "clang/AST/BuiltinTypes.def" break; } llvm_unreachable("invalid placeholder type!"); } bool Sema::CheckCaseExpression(Expr *E) { if (E->isTypeDependent()) return true; if (E->isValueDependent() || E->isIntegerConstantExpr(Context)) return E->getType()->isIntegralOrEnumerationType(); return false; } /// ActOnObjCBoolLiteral - Parse {__objc_yes,__objc_no} literals. ExprResult Sema::ActOnObjCBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) { assert((Kind == tok::kw___objc_yes || Kind == tok::kw___objc_no) && "Unknown Objective-C Boolean value!"); QualType BoolT = Context.ObjCBuiltinBoolTy; if (!Context.getBOOLDecl()) { LookupResult Result(*this, &Context.Idents.get("BOOL"), OpLoc, Sema::LookupOrdinaryName); if (LookupName(Result, getCurScope()) && Result.isSingleResult()) { NamedDecl *ND = Result.getFoundDecl(); if (TypedefDecl *TD = dyn_cast(ND)) Context.setBOOLDecl(TD); } } if (Context.getBOOLDecl()) BoolT = Context.getBOOLType(); return new (Context) ObjCBoolLiteralExpr(Kind == tok::kw___objc_yes, BoolT, OpLoc); }