1 //===--- SemaInit.cpp - Semantic Analysis for Initializers ----------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements semantic analysis for initializers.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "clang/Sema/Initialization.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/DeclObjC.h"
17 #include "clang/AST/ExprCXX.h"
18 #include "clang/AST/ExprObjC.h"
19 #include "clang/AST/TypeLoc.h"
20 #include "clang/Basic/TargetInfo.h"
21 #include "clang/Sema/Designator.h"
22 #include "clang/Sema/Lookup.h"
23 #include "clang/Sema/SemaInternal.h"
24 #include "llvm/ADT/APInt.h"
25 #include "llvm/ADT/SmallString.h"
26 #include "llvm/Support/ErrorHandling.h"
27 #include "llvm/Support/raw_ostream.h"
28 #include <map>
29
30 using namespace clang;
31
32 //===----------------------------------------------------------------------===//
33 // Sema Initialization Checking
34 //===----------------------------------------------------------------------===//
35
36 /// \brief Check whether T is compatible with a wide character type (wchar_t,
37 /// char16_t or char32_t).
IsWideCharCompatible(QualType T,ASTContext & Context)38 static bool IsWideCharCompatible(QualType T, ASTContext &Context) {
39 if (Context.typesAreCompatible(Context.getWideCharType(), T))
40 return true;
41 if (Context.getLangOpts().CPlusPlus || Context.getLangOpts().C11) {
42 return Context.typesAreCompatible(Context.Char16Ty, T) ||
43 Context.typesAreCompatible(Context.Char32Ty, T);
44 }
45 return false;
46 }
47
48 enum StringInitFailureKind {
49 SIF_None,
50 SIF_NarrowStringIntoWideChar,
51 SIF_WideStringIntoChar,
52 SIF_IncompatWideStringIntoWideChar,
53 SIF_Other
54 };
55
56 /// \brief Check whether the array of type AT can be initialized by the Init
57 /// expression by means of string initialization. Returns SIF_None if so,
58 /// otherwise returns a StringInitFailureKind that describes why the
59 /// initialization would not work.
IsStringInit(Expr * Init,const ArrayType * AT,ASTContext & Context)60 static StringInitFailureKind IsStringInit(Expr *Init, const ArrayType *AT,
61 ASTContext &Context) {
62 if (!isa<ConstantArrayType>(AT) && !isa<IncompleteArrayType>(AT))
63 return SIF_Other;
64
65 // See if this is a string literal or @encode.
66 Init = Init->IgnoreParens();
67
68 // Handle @encode, which is a narrow string.
69 if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType())
70 return SIF_None;
71
72 // Otherwise we can only handle string literals.
73 StringLiteral *SL = dyn_cast<StringLiteral>(Init);
74 if (!SL)
75 return SIF_Other;
76
77 const QualType ElemTy =
78 Context.getCanonicalType(AT->getElementType()).getUnqualifiedType();
79
80 switch (SL->getKind()) {
81 case StringLiteral::Ascii:
82 case StringLiteral::UTF8:
83 // char array can be initialized with a narrow string.
84 // Only allow char x[] = "foo"; not char x[] = L"foo";
85 if (ElemTy->isCharType())
86 return SIF_None;
87 if (IsWideCharCompatible(ElemTy, Context))
88 return SIF_NarrowStringIntoWideChar;
89 return SIF_Other;
90 // C99 6.7.8p15 (with correction from DR343), or C11 6.7.9p15:
91 // "An array with element type compatible with a qualified or unqualified
92 // version of wchar_t, char16_t, or char32_t may be initialized by a wide
93 // string literal with the corresponding encoding prefix (L, u, or U,
94 // respectively), optionally enclosed in braces.
95 case StringLiteral::UTF16:
96 if (Context.typesAreCompatible(Context.Char16Ty, ElemTy))
97 return SIF_None;
98 if (ElemTy->isCharType())
99 return SIF_WideStringIntoChar;
100 if (IsWideCharCompatible(ElemTy, Context))
101 return SIF_IncompatWideStringIntoWideChar;
102 return SIF_Other;
103 case StringLiteral::UTF32:
104 if (Context.typesAreCompatible(Context.Char32Ty, ElemTy))
105 return SIF_None;
106 if (ElemTy->isCharType())
107 return SIF_WideStringIntoChar;
108 if (IsWideCharCompatible(ElemTy, Context))
109 return SIF_IncompatWideStringIntoWideChar;
110 return SIF_Other;
111 case StringLiteral::Wide:
112 if (Context.typesAreCompatible(Context.getWideCharType(), ElemTy))
113 return SIF_None;
114 if (ElemTy->isCharType())
115 return SIF_WideStringIntoChar;
116 if (IsWideCharCompatible(ElemTy, Context))
117 return SIF_IncompatWideStringIntoWideChar;
118 return SIF_Other;
119 }
120
121 llvm_unreachable("missed a StringLiteral kind?");
122 }
123
IsStringInit(Expr * init,QualType declType,ASTContext & Context)124 static StringInitFailureKind IsStringInit(Expr *init, QualType declType,
125 ASTContext &Context) {
126 const ArrayType *arrayType = Context.getAsArrayType(declType);
127 if (!arrayType)
128 return SIF_Other;
129 return IsStringInit(init, arrayType, Context);
130 }
131
132 /// Update the type of a string literal, including any surrounding parentheses,
133 /// to match the type of the object which it is initializing.
updateStringLiteralType(Expr * E,QualType Ty)134 static void updateStringLiteralType(Expr *E, QualType Ty) {
135 while (true) {
136 E->setType(Ty);
137 if (isa<StringLiteral>(E) || isa<ObjCEncodeExpr>(E))
138 break;
139 else if (ParenExpr *PE = dyn_cast<ParenExpr>(E))
140 E = PE->getSubExpr();
141 else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E))
142 E = UO->getSubExpr();
143 else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E))
144 E = GSE->getResultExpr();
145 else
146 llvm_unreachable("unexpected expr in string literal init");
147 }
148 }
149
CheckStringInit(Expr * Str,QualType & DeclT,const ArrayType * AT,Sema & S)150 static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT,
151 Sema &S) {
152 // Get the length of the string as parsed.
153 auto *ConstantArrayTy =
154 cast<ConstantArrayType>(Str->getType()->getAsArrayTypeUnsafe());
155 uint64_t StrLength = ConstantArrayTy->getSize().getZExtValue();
156
157 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) {
158 // C99 6.7.8p14. We have an array of character type with unknown size
159 // being initialized to a string literal.
160 llvm::APInt ConstVal(32, StrLength);
161 // Return a new array type (C99 6.7.8p22).
162 DeclT = S.Context.getConstantArrayType(IAT->getElementType(),
163 ConstVal,
164 ArrayType::Normal, 0);
165 updateStringLiteralType(Str, DeclT);
166 return;
167 }
168
169 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT);
170
171 // We have an array of character type with known size. However,
172 // the size may be smaller or larger than the string we are initializing.
173 // FIXME: Avoid truncation for 64-bit length strings.
174 if (S.getLangOpts().CPlusPlus) {
175 if (StringLiteral *SL = dyn_cast<StringLiteral>(Str->IgnoreParens())) {
176 // For Pascal strings it's OK to strip off the terminating null character,
177 // so the example below is valid:
178 //
179 // unsigned char a[2] = "\pa";
180 if (SL->isPascal())
181 StrLength--;
182 }
183
184 // [dcl.init.string]p2
185 if (StrLength > CAT->getSize().getZExtValue())
186 S.Diag(Str->getLocStart(),
187 diag::err_initializer_string_for_char_array_too_long)
188 << Str->getSourceRange();
189 } else {
190 // C99 6.7.8p14.
191 if (StrLength-1 > CAT->getSize().getZExtValue())
192 S.Diag(Str->getLocStart(),
193 diag::ext_initializer_string_for_char_array_too_long)
194 << Str->getSourceRange();
195 }
196
197 // Set the type to the actual size that we are initializing. If we have
198 // something like:
199 // char x[1] = "foo";
200 // then this will set the string literal's type to char[1].
201 updateStringLiteralType(Str, DeclT);
202 }
203
204 //===----------------------------------------------------------------------===//
205 // Semantic checking for initializer lists.
206 //===----------------------------------------------------------------------===//
207
208 namespace {
209
210 /// @brief Semantic checking for initializer lists.
211 ///
212 /// The InitListChecker class contains a set of routines that each
213 /// handle the initialization of a certain kind of entity, e.g.,
214 /// arrays, vectors, struct/union types, scalars, etc. The
215 /// InitListChecker itself performs a recursive walk of the subobject
216 /// structure of the type to be initialized, while stepping through
217 /// the initializer list one element at a time. The IList and Index
218 /// parameters to each of the Check* routines contain the active
219 /// (syntactic) initializer list and the index into that initializer
220 /// list that represents the current initializer. Each routine is
221 /// responsible for moving that Index forward as it consumes elements.
222 ///
223 /// Each Check* routine also has a StructuredList/StructuredIndex
224 /// arguments, which contains the current "structured" (semantic)
225 /// initializer list and the index into that initializer list where we
226 /// are copying initializers as we map them over to the semantic
227 /// list. Once we have completed our recursive walk of the subobject
228 /// structure, we will have constructed a full semantic initializer
229 /// list.
230 ///
231 /// C99 designators cause changes in the initializer list traversal,
232 /// because they make the initialization "jump" into a specific
233 /// subobject and then continue the initialization from that
234 /// point. CheckDesignatedInitializer() recursively steps into the
235 /// designated subobject and manages backing out the recursion to
236 /// initialize the subobjects after the one designated.
237 class InitListChecker {
238 Sema &SemaRef;
239 bool hadError;
240 bool VerifyOnly; // no diagnostics, no structure building
241 bool TreatUnavailableAsInvalid; // Used only in VerifyOnly mode.
242 llvm::DenseMap<InitListExpr *, InitListExpr *> SyntacticToSemantic;
243 InitListExpr *FullyStructuredList;
244
245 void CheckImplicitInitList(const InitializedEntity &Entity,
246 InitListExpr *ParentIList, QualType T,
247 unsigned &Index, InitListExpr *StructuredList,
248 unsigned &StructuredIndex);
249 void CheckExplicitInitList(const InitializedEntity &Entity,
250 InitListExpr *IList, QualType &T,
251 InitListExpr *StructuredList,
252 bool TopLevelObject = false);
253 void CheckListElementTypes(const InitializedEntity &Entity,
254 InitListExpr *IList, QualType &DeclType,
255 bool SubobjectIsDesignatorContext,
256 unsigned &Index,
257 InitListExpr *StructuredList,
258 unsigned &StructuredIndex,
259 bool TopLevelObject = false);
260 void CheckSubElementType(const InitializedEntity &Entity,
261 InitListExpr *IList, QualType ElemType,
262 unsigned &Index,
263 InitListExpr *StructuredList,
264 unsigned &StructuredIndex);
265 void CheckComplexType(const InitializedEntity &Entity,
266 InitListExpr *IList, QualType DeclType,
267 unsigned &Index,
268 InitListExpr *StructuredList,
269 unsigned &StructuredIndex);
270 void CheckScalarType(const InitializedEntity &Entity,
271 InitListExpr *IList, QualType DeclType,
272 unsigned &Index,
273 InitListExpr *StructuredList,
274 unsigned &StructuredIndex);
275 void CheckReferenceType(const InitializedEntity &Entity,
276 InitListExpr *IList, QualType DeclType,
277 unsigned &Index,
278 InitListExpr *StructuredList,
279 unsigned &StructuredIndex);
280 void CheckVectorType(const InitializedEntity &Entity,
281 InitListExpr *IList, QualType DeclType, unsigned &Index,
282 InitListExpr *StructuredList,
283 unsigned &StructuredIndex);
284 void CheckStructUnionTypes(const InitializedEntity &Entity,
285 InitListExpr *IList, QualType DeclType,
286 CXXRecordDecl::base_class_range Bases,
287 RecordDecl::field_iterator Field,
288 bool SubobjectIsDesignatorContext, unsigned &Index,
289 InitListExpr *StructuredList,
290 unsigned &StructuredIndex,
291 bool TopLevelObject = false);
292 void CheckArrayType(const InitializedEntity &Entity,
293 InitListExpr *IList, QualType &DeclType,
294 llvm::APSInt elementIndex,
295 bool SubobjectIsDesignatorContext, unsigned &Index,
296 InitListExpr *StructuredList,
297 unsigned &StructuredIndex);
298 bool CheckDesignatedInitializer(const InitializedEntity &Entity,
299 InitListExpr *IList, DesignatedInitExpr *DIE,
300 unsigned DesigIdx,
301 QualType &CurrentObjectType,
302 RecordDecl::field_iterator *NextField,
303 llvm::APSInt *NextElementIndex,
304 unsigned &Index,
305 InitListExpr *StructuredList,
306 unsigned &StructuredIndex,
307 bool FinishSubobjectInit,
308 bool TopLevelObject);
309 InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
310 QualType CurrentObjectType,
311 InitListExpr *StructuredList,
312 unsigned StructuredIndex,
313 SourceRange InitRange,
314 bool IsFullyOverwritten = false);
315 void UpdateStructuredListElement(InitListExpr *StructuredList,
316 unsigned &StructuredIndex,
317 Expr *expr);
318 int numArrayElements(QualType DeclType);
319 int numStructUnionElements(QualType DeclType);
320
321 static ExprResult PerformEmptyInit(Sema &SemaRef,
322 SourceLocation Loc,
323 const InitializedEntity &Entity,
324 bool VerifyOnly,
325 bool TreatUnavailableAsInvalid);
326
327 // Explanation on the "FillWithNoInit" mode:
328 //
329 // Assume we have the following definitions (Case#1):
330 // struct P { char x[6][6]; } xp = { .x[1] = "bar" };
331 // struct PP { struct P lp; } l = { .lp = xp, .lp.x[1][2] = 'f' };
332 //
333 // l.lp.x[1][0..1] should not be filled with implicit initializers because the
334 // "base" initializer "xp" will provide values for them; l.lp.x[1] will be "baf".
335 //
336 // But if we have (Case#2):
337 // struct PP l = { .lp = xp, .lp.x[1] = { [2] = 'f' } };
338 //
339 // l.lp.x[1][0..1] are implicitly initialized and do not use values from the
340 // "base" initializer; l.lp.x[1] will be "\0\0f\0\0\0".
341 //
342 // To distinguish Case#1 from Case#2, and also to avoid leaving many "holes"
343 // in the InitListExpr, the "holes" in Case#1 are filled not with empty
344 // initializers but with special "NoInitExpr" place holders, which tells the
345 // CodeGen not to generate any initializers for these parts.
346 void FillInEmptyInitForBase(unsigned Init, const CXXBaseSpecifier &Base,
347 const InitializedEntity &ParentEntity,
348 InitListExpr *ILE, bool &RequiresSecondPass,
349 bool FillWithNoInit);
350 void FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
351 const InitializedEntity &ParentEntity,
352 InitListExpr *ILE, bool &RequiresSecondPass,
353 bool FillWithNoInit = false);
354 void FillInEmptyInitializations(const InitializedEntity &Entity,
355 InitListExpr *ILE, bool &RequiresSecondPass,
356 bool FillWithNoInit = false);
357 bool CheckFlexibleArrayInit(const InitializedEntity &Entity,
358 Expr *InitExpr, FieldDecl *Field,
359 bool TopLevelObject);
360 void CheckEmptyInitializable(const InitializedEntity &Entity,
361 SourceLocation Loc);
362
363 public:
364 InitListChecker(Sema &S, const InitializedEntity &Entity,
365 InitListExpr *IL, QualType &T, bool VerifyOnly,
366 bool TreatUnavailableAsInvalid);
HadError()367 bool HadError() { return hadError; }
368
369 // @brief Retrieves the fully-structured initializer list used for
370 // semantic analysis and code generation.
getFullyStructuredList() const371 InitListExpr *getFullyStructuredList() const { return FullyStructuredList; }
372 };
373
374 } // end anonymous namespace
375
PerformEmptyInit(Sema & SemaRef,SourceLocation Loc,const InitializedEntity & Entity,bool VerifyOnly,bool TreatUnavailableAsInvalid)376 ExprResult InitListChecker::PerformEmptyInit(Sema &SemaRef,
377 SourceLocation Loc,
378 const InitializedEntity &Entity,
379 bool VerifyOnly,
380 bool TreatUnavailableAsInvalid) {
381 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc,
382 true);
383 MultiExprArg SubInit;
384 Expr *InitExpr;
385 InitListExpr DummyInitList(SemaRef.Context, Loc, None, Loc);
386
387 // C++ [dcl.init.aggr]p7:
388 // If there are fewer initializer-clauses in the list than there are
389 // members in the aggregate, then each member not explicitly initialized
390 // ...
391 bool EmptyInitList = SemaRef.getLangOpts().CPlusPlus11 &&
392 Entity.getType()->getBaseElementTypeUnsafe()->isRecordType();
393 if (EmptyInitList) {
394 // C++1y / DR1070:
395 // shall be initialized [...] from an empty initializer list.
396 //
397 // We apply the resolution of this DR to C++11 but not C++98, since C++98
398 // does not have useful semantics for initialization from an init list.
399 // We treat this as copy-initialization, because aggregate initialization
400 // always performs copy-initialization on its elements.
401 //
402 // Only do this if we're initializing a class type, to avoid filling in
403 // the initializer list where possible.
404 InitExpr = VerifyOnly ? &DummyInitList : new (SemaRef.Context)
405 InitListExpr(SemaRef.Context, Loc, None, Loc);
406 InitExpr->setType(SemaRef.Context.VoidTy);
407 SubInit = InitExpr;
408 Kind = InitializationKind::CreateCopy(Loc, Loc);
409 } else {
410 // C++03:
411 // shall be value-initialized.
412 }
413
414 InitializationSequence InitSeq(SemaRef, Entity, Kind, SubInit);
415 // libstdc++4.6 marks the vector default constructor as explicit in
416 // _GLIBCXX_DEBUG mode, so recover using the C++03 logic in that case.
417 // stlport does so too. Look for std::__debug for libstdc++, and for
418 // std:: for stlport. This is effectively a compiler-side implementation of
419 // LWG2193.
420 if (!InitSeq && EmptyInitList && InitSeq.getFailureKind() ==
421 InitializationSequence::FK_ExplicitConstructor) {
422 OverloadCandidateSet::iterator Best;
423 OverloadingResult O =
424 InitSeq.getFailedCandidateSet()
425 .BestViableFunction(SemaRef, Kind.getLocation(), Best);
426 (void)O;
427 assert(O == OR_Success && "Inconsistent overload resolution");
428 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
429 CXXRecordDecl *R = CtorDecl->getParent();
430
431 if (CtorDecl->getMinRequiredArguments() == 0 &&
432 CtorDecl->isExplicit() && R->getDeclName() &&
433 SemaRef.SourceMgr.isInSystemHeader(CtorDecl->getLocation())) {
434 bool IsInStd = false;
435 for (NamespaceDecl *ND = dyn_cast<NamespaceDecl>(R->getDeclContext());
436 ND && !IsInStd; ND = dyn_cast<NamespaceDecl>(ND->getParent())) {
437 if (SemaRef.getStdNamespace()->InEnclosingNamespaceSetOf(ND))
438 IsInStd = true;
439 }
440
441 if (IsInStd && llvm::StringSwitch<bool>(R->getName())
442 .Cases("basic_string", "deque", "forward_list", true)
443 .Cases("list", "map", "multimap", "multiset", true)
444 .Cases("priority_queue", "queue", "set", "stack", true)
445 .Cases("unordered_map", "unordered_set", "vector", true)
446 .Default(false)) {
447 InitSeq.InitializeFrom(
448 SemaRef, Entity,
449 InitializationKind::CreateValue(Loc, Loc, Loc, true),
450 MultiExprArg(), /*TopLevelOfInitList=*/false,
451 TreatUnavailableAsInvalid);
452 // Emit a warning for this. System header warnings aren't shown
453 // by default, but people working on system headers should see it.
454 if (!VerifyOnly) {
455 SemaRef.Diag(CtorDecl->getLocation(),
456 diag::warn_invalid_initializer_from_system_header);
457 if (Entity.getKind() == InitializedEntity::EK_Member)
458 SemaRef.Diag(Entity.getDecl()->getLocation(),
459 diag::note_used_in_initialization_here);
460 else if (Entity.getKind() == InitializedEntity::EK_ArrayElement)
461 SemaRef.Diag(Loc, diag::note_used_in_initialization_here);
462 }
463 }
464 }
465 }
466 if (!InitSeq) {
467 if (!VerifyOnly) {
468 InitSeq.Diagnose(SemaRef, Entity, Kind, SubInit);
469 if (Entity.getKind() == InitializedEntity::EK_Member)
470 SemaRef.Diag(Entity.getDecl()->getLocation(),
471 diag::note_in_omitted_aggregate_initializer)
472 << /*field*/1 << Entity.getDecl();
473 else if (Entity.getKind() == InitializedEntity::EK_ArrayElement)
474 SemaRef.Diag(Loc, diag::note_in_omitted_aggregate_initializer)
475 << /*array element*/0 << Entity.getElementIndex();
476 }
477 return ExprError();
478 }
479
480 return VerifyOnly ? ExprResult(static_cast<Expr *>(nullptr))
481 : InitSeq.Perform(SemaRef, Entity, Kind, SubInit);
482 }
483
CheckEmptyInitializable(const InitializedEntity & Entity,SourceLocation Loc)484 void InitListChecker::CheckEmptyInitializable(const InitializedEntity &Entity,
485 SourceLocation Loc) {
486 assert(VerifyOnly &&
487 "CheckEmptyInitializable is only inteded for verification mode.");
488 if (PerformEmptyInit(SemaRef, Loc, Entity, /*VerifyOnly*/true,
489 TreatUnavailableAsInvalid).isInvalid())
490 hadError = true;
491 }
492
FillInEmptyInitForBase(unsigned Init,const CXXBaseSpecifier & Base,const InitializedEntity & ParentEntity,InitListExpr * ILE,bool & RequiresSecondPass,bool FillWithNoInit)493 void InitListChecker::FillInEmptyInitForBase(
494 unsigned Init, const CXXBaseSpecifier &Base,
495 const InitializedEntity &ParentEntity, InitListExpr *ILE,
496 bool &RequiresSecondPass, bool FillWithNoInit) {
497 assert(Init < ILE->getNumInits() && "should have been expanded");
498
499 InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
500 SemaRef.Context, &Base, false, &ParentEntity);
501
502 if (!ILE->getInit(Init)) {
503 ExprResult BaseInit =
504 FillWithNoInit ? new (SemaRef.Context) NoInitExpr(Base.getType())
505 : PerformEmptyInit(SemaRef, ILE->getLocEnd(), BaseEntity,
506 /*VerifyOnly*/ false,
507 TreatUnavailableAsInvalid);
508 if (BaseInit.isInvalid()) {
509 hadError = true;
510 return;
511 }
512
513 ILE->setInit(Init, BaseInit.getAs<Expr>());
514 } else if (InitListExpr *InnerILE =
515 dyn_cast<InitListExpr>(ILE->getInit(Init))) {
516 FillInEmptyInitializations(BaseEntity, InnerILE,
517 RequiresSecondPass, FillWithNoInit);
518 } else if (DesignatedInitUpdateExpr *InnerDIUE =
519 dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init))) {
520 FillInEmptyInitializations(BaseEntity, InnerDIUE->getUpdater(),
521 RequiresSecondPass, /*FillWithNoInit =*/true);
522 }
523 }
524
FillInEmptyInitForField(unsigned Init,FieldDecl * Field,const InitializedEntity & ParentEntity,InitListExpr * ILE,bool & RequiresSecondPass,bool FillWithNoInit)525 void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field,
526 const InitializedEntity &ParentEntity,
527 InitListExpr *ILE,
528 bool &RequiresSecondPass,
529 bool FillWithNoInit) {
530 SourceLocation Loc = ILE->getLocEnd();
531 unsigned NumInits = ILE->getNumInits();
532 InitializedEntity MemberEntity
533 = InitializedEntity::InitializeMember(Field, &ParentEntity);
534
535 if (const RecordType *RType = ILE->getType()->getAs<RecordType>())
536 if (!RType->getDecl()->isUnion())
537 assert(Init < NumInits && "This ILE should have been expanded");
538
539 if (Init >= NumInits || !ILE->getInit(Init)) {
540 if (FillWithNoInit) {
541 Expr *Filler = new (SemaRef.Context) NoInitExpr(Field->getType());
542 if (Init < NumInits)
543 ILE->setInit(Init, Filler);
544 else
545 ILE->updateInit(SemaRef.Context, Init, Filler);
546 return;
547 }
548 // C++1y [dcl.init.aggr]p7:
549 // If there are fewer initializer-clauses in the list than there are
550 // members in the aggregate, then each member not explicitly initialized
551 // shall be initialized from its brace-or-equal-initializer [...]
552 if (Field->hasInClassInitializer()) {
553 ExprResult DIE = SemaRef.BuildCXXDefaultInitExpr(Loc, Field);
554 if (DIE.isInvalid()) {
555 hadError = true;
556 return;
557 }
558 if (Init < NumInits)
559 ILE->setInit(Init, DIE.get());
560 else {
561 ILE->updateInit(SemaRef.Context, Init, DIE.get());
562 RequiresSecondPass = true;
563 }
564 return;
565 }
566
567 if (Field->getType()->isReferenceType()) {
568 // C++ [dcl.init.aggr]p9:
569 // If an incomplete or empty initializer-list leaves a
570 // member of reference type uninitialized, the program is
571 // ill-formed.
572 SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized)
573 << Field->getType()
574 << ILE->getSyntacticForm()->getSourceRange();
575 SemaRef.Diag(Field->getLocation(),
576 diag::note_uninit_reference_member);
577 hadError = true;
578 return;
579 }
580
581 ExprResult MemberInit = PerformEmptyInit(SemaRef, Loc, MemberEntity,
582 /*VerifyOnly*/false,
583 TreatUnavailableAsInvalid);
584 if (MemberInit.isInvalid()) {
585 hadError = true;
586 return;
587 }
588
589 if (hadError) {
590 // Do nothing
591 } else if (Init < NumInits) {
592 ILE->setInit(Init, MemberInit.getAs<Expr>());
593 } else if (!isa<ImplicitValueInitExpr>(MemberInit.get())) {
594 // Empty initialization requires a constructor call, so
595 // extend the initializer list to include the constructor
596 // call and make a note that we'll need to take another pass
597 // through the initializer list.
598 ILE->updateInit(SemaRef.Context, Init, MemberInit.getAs<Expr>());
599 RequiresSecondPass = true;
600 }
601 } else if (InitListExpr *InnerILE
602 = dyn_cast<InitListExpr>(ILE->getInit(Init)))
603 FillInEmptyInitializations(MemberEntity, InnerILE,
604 RequiresSecondPass, FillWithNoInit);
605 else if (DesignatedInitUpdateExpr *InnerDIUE
606 = dyn_cast<DesignatedInitUpdateExpr>(ILE->getInit(Init)))
607 FillInEmptyInitializations(MemberEntity, InnerDIUE->getUpdater(),
608 RequiresSecondPass, /*FillWithNoInit =*/ true);
609 }
610
611 /// Recursively replaces NULL values within the given initializer list
612 /// with expressions that perform value-initialization of the
613 /// appropriate type.
614 void
FillInEmptyInitializations(const InitializedEntity & Entity,InitListExpr * ILE,bool & RequiresSecondPass,bool FillWithNoInit)615 InitListChecker::FillInEmptyInitializations(const InitializedEntity &Entity,
616 InitListExpr *ILE,
617 bool &RequiresSecondPass,
618 bool FillWithNoInit) {
619 assert((ILE->getType() != SemaRef.Context.VoidTy) &&
620 "Should not have void type");
621
622 if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) {
623 const RecordDecl *RDecl = RType->getDecl();
624 if (RDecl->isUnion() && ILE->getInitializedFieldInUnion())
625 FillInEmptyInitForField(0, ILE->getInitializedFieldInUnion(),
626 Entity, ILE, RequiresSecondPass, FillWithNoInit);
627 else if (RDecl->isUnion() && isa<CXXRecordDecl>(RDecl) &&
628 cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) {
629 for (auto *Field : RDecl->fields()) {
630 if (Field->hasInClassInitializer()) {
631 FillInEmptyInitForField(0, Field, Entity, ILE, RequiresSecondPass,
632 FillWithNoInit);
633 break;
634 }
635 }
636 } else {
637 // The fields beyond ILE->getNumInits() are default initialized, so in
638 // order to leave them uninitialized, the ILE is expanded and the extra
639 // fields are then filled with NoInitExpr.
640 unsigned NumElems = numStructUnionElements(ILE->getType());
641 if (RDecl->hasFlexibleArrayMember())
642 ++NumElems;
643 if (ILE->getNumInits() < NumElems)
644 ILE->resizeInits(SemaRef.Context, NumElems);
645
646 unsigned Init = 0;
647
648 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RDecl)) {
649 for (auto &Base : CXXRD->bases()) {
650 if (hadError)
651 return;
652
653 FillInEmptyInitForBase(Init, Base, Entity, ILE, RequiresSecondPass,
654 FillWithNoInit);
655 ++Init;
656 }
657 }
658
659 for (auto *Field : RDecl->fields()) {
660 if (Field->isUnnamedBitfield())
661 continue;
662
663 if (hadError)
664 return;
665
666 FillInEmptyInitForField(Init, Field, Entity, ILE, RequiresSecondPass,
667 FillWithNoInit);
668 if (hadError)
669 return;
670
671 ++Init;
672
673 // Only look at the first initialization of a union.
674 if (RDecl->isUnion())
675 break;
676 }
677 }
678
679 return;
680 }
681
682 QualType ElementType;
683
684 InitializedEntity ElementEntity = Entity;
685 unsigned NumInits = ILE->getNumInits();
686 unsigned NumElements = NumInits;
687 if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) {
688 ElementType = AType->getElementType();
689 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType))
690 NumElements = CAType->getSize().getZExtValue();
691 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
692 0, Entity);
693 } else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) {
694 ElementType = VType->getElementType();
695 NumElements = VType->getNumElements();
696 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context,
697 0, Entity);
698 } else
699 ElementType = ILE->getType();
700
701 for (unsigned Init = 0; Init != NumElements; ++Init) {
702 if (hadError)
703 return;
704
705 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement ||
706 ElementEntity.getKind() == InitializedEntity::EK_VectorElement)
707 ElementEntity.setElementIndex(Init);
708
709 Expr *InitExpr = (Init < NumInits ? ILE->getInit(Init) : nullptr);
710 if (!InitExpr && Init < NumInits && ILE->hasArrayFiller())
711 ILE->setInit(Init, ILE->getArrayFiller());
712 else if (!InitExpr && !ILE->hasArrayFiller()) {
713 Expr *Filler = nullptr;
714
715 if (FillWithNoInit)
716 Filler = new (SemaRef.Context) NoInitExpr(ElementType);
717 else {
718 ExprResult ElementInit = PerformEmptyInit(SemaRef, ILE->getLocEnd(),
719 ElementEntity,
720 /*VerifyOnly*/false,
721 TreatUnavailableAsInvalid);
722 if (ElementInit.isInvalid()) {
723 hadError = true;
724 return;
725 }
726
727 Filler = ElementInit.getAs<Expr>();
728 }
729
730 if (hadError) {
731 // Do nothing
732 } else if (Init < NumInits) {
733 // For arrays, just set the expression used for value-initialization
734 // of the "holes" in the array.
735 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement)
736 ILE->setArrayFiller(Filler);
737 else
738 ILE->setInit(Init, Filler);
739 } else {
740 // For arrays, just set the expression used for value-initialization
741 // of the rest of elements and exit.
742 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) {
743 ILE->setArrayFiller(Filler);
744 return;
745 }
746
747 if (!isa<ImplicitValueInitExpr>(Filler) && !isa<NoInitExpr>(Filler)) {
748 // Empty initialization requires a constructor call, so
749 // extend the initializer list to include the constructor
750 // call and make a note that we'll need to take another pass
751 // through the initializer list.
752 ILE->updateInit(SemaRef.Context, Init, Filler);
753 RequiresSecondPass = true;
754 }
755 }
756 } else if (InitListExpr *InnerILE
757 = dyn_cast_or_null<InitListExpr>(InitExpr))
758 FillInEmptyInitializations(ElementEntity, InnerILE, RequiresSecondPass,
759 FillWithNoInit);
760 else if (DesignatedInitUpdateExpr *InnerDIUE
761 = dyn_cast_or_null<DesignatedInitUpdateExpr>(InitExpr))
762 FillInEmptyInitializations(ElementEntity, InnerDIUE->getUpdater(),
763 RequiresSecondPass, /*FillWithNoInit =*/ true);
764 }
765 }
766
InitListChecker(Sema & S,const InitializedEntity & Entity,InitListExpr * IL,QualType & T,bool VerifyOnly,bool TreatUnavailableAsInvalid)767 InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
768 InitListExpr *IL, QualType &T,
769 bool VerifyOnly,
770 bool TreatUnavailableAsInvalid)
771 : SemaRef(S), VerifyOnly(VerifyOnly),
772 TreatUnavailableAsInvalid(TreatUnavailableAsInvalid) {
773 // FIXME: Check that IL isn't already the semantic form of some other
774 // InitListExpr. If it is, we'd create a broken AST.
775
776 hadError = false;
777
778 FullyStructuredList =
779 getStructuredSubobjectInit(IL, 0, T, nullptr, 0, IL->getSourceRange());
780 CheckExplicitInitList(Entity, IL, T, FullyStructuredList,
781 /*TopLevelObject=*/true);
782
783 if (!hadError && !VerifyOnly) {
784 bool RequiresSecondPass = false;
785 FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass);
786 if (RequiresSecondPass && !hadError)
787 FillInEmptyInitializations(Entity, FullyStructuredList,
788 RequiresSecondPass);
789 }
790 }
791
numArrayElements(QualType DeclType)792 int InitListChecker::numArrayElements(QualType DeclType) {
793 // FIXME: use a proper constant
794 int maxElements = 0x7FFFFFFF;
795 if (const ConstantArrayType *CAT =
796 SemaRef.Context.getAsConstantArrayType(DeclType)) {
797 maxElements = static_cast<int>(CAT->getSize().getZExtValue());
798 }
799 return maxElements;
800 }
801
numStructUnionElements(QualType DeclType)802 int InitListChecker::numStructUnionElements(QualType DeclType) {
803 RecordDecl *structDecl = DeclType->getAs<RecordType>()->getDecl();
804 int InitializableMembers = 0;
805 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(structDecl))
806 InitializableMembers += CXXRD->getNumBases();
807 for (const auto *Field : structDecl->fields())
808 if (!Field->isUnnamedBitfield())
809 ++InitializableMembers;
810
811 if (structDecl->isUnion())
812 return std::min(InitializableMembers, 1);
813 return InitializableMembers - structDecl->hasFlexibleArrayMember();
814 }
815
816 /// Check whether the range of the initializer \p ParentIList from element
817 /// \p Index onwards can be used to initialize an object of type \p T. Update
818 /// \p Index to indicate how many elements of the list were consumed.
819 ///
820 /// This also fills in \p StructuredList, from element \p StructuredIndex
821 /// onwards, with the fully-braced, desugared form of the initialization.
CheckImplicitInitList(const InitializedEntity & Entity,InitListExpr * ParentIList,QualType T,unsigned & Index,InitListExpr * StructuredList,unsigned & StructuredIndex)822 void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity,
823 InitListExpr *ParentIList,
824 QualType T, unsigned &Index,
825 InitListExpr *StructuredList,
826 unsigned &StructuredIndex) {
827 int maxElements = 0;
828
829 if (T->isArrayType())
830 maxElements = numArrayElements(T);
831 else if (T->isRecordType())
832 maxElements = numStructUnionElements(T);
833 else if (T->isVectorType())
834 maxElements = T->getAs<VectorType>()->getNumElements();
835 else
836 llvm_unreachable("CheckImplicitInitList(): Illegal type");
837
838 if (maxElements == 0) {
839 if (!VerifyOnly)
840 SemaRef.Diag(ParentIList->getInit(Index)->getLocStart(),
841 diag::err_implicit_empty_initializer);
842 ++Index;
843 hadError = true;
844 return;
845 }
846
847 // Build a structured initializer list corresponding to this subobject.
848 InitListExpr *StructuredSubobjectInitList
849 = getStructuredSubobjectInit(ParentIList, Index, T, StructuredList,
850 StructuredIndex,
851 SourceRange(ParentIList->getInit(Index)->getLocStart(),
852 ParentIList->getSourceRange().getEnd()));
853 unsigned StructuredSubobjectInitIndex = 0;
854
855 // Check the element types and build the structural subobject.
856 unsigned StartIndex = Index;
857 CheckListElementTypes(Entity, ParentIList, T,
858 /*SubobjectIsDesignatorContext=*/false, Index,
859 StructuredSubobjectInitList,
860 StructuredSubobjectInitIndex);
861
862 if (!VerifyOnly) {
863 StructuredSubobjectInitList->setType(T);
864
865 unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1);
866 // Update the structured sub-object initializer so that it's ending
867 // range corresponds with the end of the last initializer it used.
868 if (EndIndex < ParentIList->getNumInits() &&
869 ParentIList->getInit(EndIndex)) {
870 SourceLocation EndLoc
871 = ParentIList->getInit(EndIndex)->getSourceRange().getEnd();
872 StructuredSubobjectInitList->setRBraceLoc(EndLoc);
873 }
874
875 // Complain about missing braces.
876 if (T->isArrayType() || T->isRecordType()) {
877 SemaRef.Diag(StructuredSubobjectInitList->getLocStart(),
878 diag::warn_missing_braces)
879 << StructuredSubobjectInitList->getSourceRange()
880 << FixItHint::CreateInsertion(
881 StructuredSubobjectInitList->getLocStart(), "{")
882 << FixItHint::CreateInsertion(
883 SemaRef.getLocForEndOfToken(
884 StructuredSubobjectInitList->getLocEnd()),
885 "}");
886 }
887 }
888 }
889
890 /// Warn that \p Entity was of scalar type and was initialized by a
891 /// single-element braced initializer list.
warnBracedScalarInit(Sema & S,const InitializedEntity & Entity,SourceRange Braces)892 static void warnBracedScalarInit(Sema &S, const InitializedEntity &Entity,
893 SourceRange Braces) {
894 // Don't warn during template instantiation. If the initialization was
895 // non-dependent, we warned during the initial parse; otherwise, the
896 // type might not be scalar in some uses of the template.
897 if (!S.ActiveTemplateInstantiations.empty())
898 return;
899
900 unsigned DiagID = 0;
901
902 switch (Entity.getKind()) {
903 case InitializedEntity::EK_VectorElement:
904 case InitializedEntity::EK_ComplexElement:
905 case InitializedEntity::EK_ArrayElement:
906 case InitializedEntity::EK_Parameter:
907 case InitializedEntity::EK_Parameter_CF_Audited:
908 case InitializedEntity::EK_Result:
909 // Extra braces here are suspicious.
910 DiagID = diag::warn_braces_around_scalar_init;
911 break;
912
913 case InitializedEntity::EK_Member:
914 // Warn on aggregate initialization but not on ctor init list or
915 // default member initializer.
916 if (Entity.getParent())
917 DiagID = diag::warn_braces_around_scalar_init;
918 break;
919
920 case InitializedEntity::EK_Variable:
921 case InitializedEntity::EK_LambdaCapture:
922 // No warning, might be direct-list-initialization.
923 // FIXME: Should we warn for copy-list-initialization in these cases?
924 break;
925
926 case InitializedEntity::EK_New:
927 case InitializedEntity::EK_Temporary:
928 case InitializedEntity::EK_CompoundLiteralInit:
929 // No warning, braces are part of the syntax of the underlying construct.
930 break;
931
932 case InitializedEntity::EK_RelatedResult:
933 // No warning, we already warned when initializing the result.
934 break;
935
936 case InitializedEntity::EK_Exception:
937 case InitializedEntity::EK_Base:
938 case InitializedEntity::EK_Delegating:
939 case InitializedEntity::EK_BlockElement:
940 llvm_unreachable("unexpected braced scalar init");
941 }
942
943 if (DiagID) {
944 S.Diag(Braces.getBegin(), DiagID)
945 << Braces
946 << FixItHint::CreateRemoval(Braces.getBegin())
947 << FixItHint::CreateRemoval(Braces.getEnd());
948 }
949 }
950
951 /// Check whether the initializer \p IList (that was written with explicit
952 /// braces) can be used to initialize an object of type \p T.
953 ///
954 /// This also fills in \p StructuredList with the fully-braced, desugared
955 /// form of the initialization.
CheckExplicitInitList(const InitializedEntity & Entity,InitListExpr * IList,QualType & T,InitListExpr * StructuredList,bool TopLevelObject)956 void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity,
957 InitListExpr *IList, QualType &T,
958 InitListExpr *StructuredList,
959 bool TopLevelObject) {
960 if (!VerifyOnly) {
961 SyntacticToSemantic[IList] = StructuredList;
962 StructuredList->setSyntacticForm(IList);
963 }
964
965 unsigned Index = 0, StructuredIndex = 0;
966 CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true,
967 Index, StructuredList, StructuredIndex, TopLevelObject);
968 if (!VerifyOnly) {
969 QualType ExprTy = T;
970 if (!ExprTy->isArrayType())
971 ExprTy = ExprTy.getNonLValueExprType(SemaRef.Context);
972 IList->setType(ExprTy);
973 StructuredList->setType(ExprTy);
974 }
975 if (hadError)
976 return;
977
978 if (Index < IList->getNumInits()) {
979 // We have leftover initializers
980 if (VerifyOnly) {
981 if (SemaRef.getLangOpts().CPlusPlus ||
982 (SemaRef.getLangOpts().OpenCL &&
983 IList->getType()->isVectorType())) {
984 hadError = true;
985 }
986 return;
987 }
988
989 if (StructuredIndex == 1 &&
990 IsStringInit(StructuredList->getInit(0), T, SemaRef.Context) ==
991 SIF_None) {
992 unsigned DK = diag::ext_excess_initializers_in_char_array_initializer;
993 if (SemaRef.getLangOpts().CPlusPlus) {
994 DK = diag::err_excess_initializers_in_char_array_initializer;
995 hadError = true;
996 }
997 // Special-case
998 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK)
999 << IList->getInit(Index)->getSourceRange();
1000 } else if (!T->isIncompleteType()) {
1001 // Don't complain for incomplete types, since we'll get an error
1002 // elsewhere
1003 QualType CurrentObjectType = StructuredList->getType();
1004 int initKind =
1005 CurrentObjectType->isArrayType()? 0 :
1006 CurrentObjectType->isVectorType()? 1 :
1007 CurrentObjectType->isScalarType()? 2 :
1008 CurrentObjectType->isUnionType()? 3 :
1009 4;
1010
1011 unsigned DK = diag::ext_excess_initializers;
1012 if (SemaRef.getLangOpts().CPlusPlus) {
1013 DK = diag::err_excess_initializers;
1014 hadError = true;
1015 }
1016 if (SemaRef.getLangOpts().OpenCL && initKind == 1) {
1017 DK = diag::err_excess_initializers;
1018 hadError = true;
1019 }
1020
1021 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK)
1022 << initKind << IList->getInit(Index)->getSourceRange();
1023 }
1024 }
1025
1026 if (!VerifyOnly && T->isScalarType() &&
1027 IList->getNumInits() == 1 && !isa<InitListExpr>(IList->getInit(0)))
1028 warnBracedScalarInit(SemaRef, Entity, IList->getSourceRange());
1029 }
1030
CheckListElementTypes(const InitializedEntity & Entity,InitListExpr * IList,QualType & DeclType,bool SubobjectIsDesignatorContext,unsigned & Index,InitListExpr * StructuredList,unsigned & StructuredIndex,bool TopLevelObject)1031 void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity,
1032 InitListExpr *IList,
1033 QualType &DeclType,
1034 bool SubobjectIsDesignatorContext,
1035 unsigned &Index,
1036 InitListExpr *StructuredList,
1037 unsigned &StructuredIndex,
1038 bool TopLevelObject) {
1039 if (DeclType->isAnyComplexType() && SubobjectIsDesignatorContext) {
1040 // Explicitly braced initializer for complex type can be real+imaginary
1041 // parts.
1042 CheckComplexType(Entity, IList, DeclType, Index,
1043 StructuredList, StructuredIndex);
1044 } else if (DeclType->isScalarType()) {
1045 CheckScalarType(Entity, IList, DeclType, Index,
1046 StructuredList, StructuredIndex);
1047 } else if (DeclType->isVectorType()) {
1048 CheckVectorType(Entity, IList, DeclType, Index,
1049 StructuredList, StructuredIndex);
1050 } else if (DeclType->isRecordType()) {
1051 assert(DeclType->isAggregateType() &&
1052 "non-aggregate records should be handed in CheckSubElementType");
1053 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl();
1054 auto Bases =
1055 CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
1056 CXXRecordDecl::base_class_iterator());
1057 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
1058 Bases = CXXRD->bases();
1059 CheckStructUnionTypes(Entity, IList, DeclType, Bases, RD->field_begin(),
1060 SubobjectIsDesignatorContext, Index, StructuredList,
1061 StructuredIndex, TopLevelObject);
1062 } else if (DeclType->isArrayType()) {
1063 llvm::APSInt Zero(
1064 SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()),
1065 false);
1066 CheckArrayType(Entity, IList, DeclType, Zero,
1067 SubobjectIsDesignatorContext, Index,
1068 StructuredList, StructuredIndex);
1069 } else if (DeclType->isVoidType() || DeclType->isFunctionType()) {
1070 // This type is invalid, issue a diagnostic.
1071 ++Index;
1072 if (!VerifyOnly)
1073 SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type)
1074 << DeclType;
1075 hadError = true;
1076 } else if (DeclType->isReferenceType()) {
1077 CheckReferenceType(Entity, IList, DeclType, Index,
1078 StructuredList, StructuredIndex);
1079 } else if (DeclType->isObjCObjectType()) {
1080 if (!VerifyOnly)
1081 SemaRef.Diag(IList->getLocStart(), diag::err_init_objc_class)
1082 << DeclType;
1083 hadError = true;
1084 } else {
1085 if (!VerifyOnly)
1086 SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type)
1087 << DeclType;
1088 hadError = true;
1089 }
1090 }
1091
CheckSubElementType(const InitializedEntity & Entity,InitListExpr * IList,QualType ElemType,unsigned & Index,InitListExpr * StructuredList,unsigned & StructuredIndex)1092 void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
1093 InitListExpr *IList,
1094 QualType ElemType,
1095 unsigned &Index,
1096 InitListExpr *StructuredList,
1097 unsigned &StructuredIndex) {
1098 Expr *expr = IList->getInit(Index);
1099
1100 if (ElemType->isReferenceType())
1101 return CheckReferenceType(Entity, IList, ElemType, Index,
1102 StructuredList, StructuredIndex);
1103
1104 if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) {
1105 if (SubInitList->getNumInits() == 1 &&
1106 IsStringInit(SubInitList->getInit(0), ElemType, SemaRef.Context) ==
1107 SIF_None) {
1108 expr = SubInitList->getInit(0);
1109 } else if (!SemaRef.getLangOpts().CPlusPlus) {
1110 InitListExpr *InnerStructuredList
1111 = getStructuredSubobjectInit(IList, Index, ElemType,
1112 StructuredList, StructuredIndex,
1113 SubInitList->getSourceRange(), true);
1114 CheckExplicitInitList(Entity, SubInitList, ElemType,
1115 InnerStructuredList);
1116
1117 if (!hadError && !VerifyOnly) {
1118 bool RequiresSecondPass = false;
1119 FillInEmptyInitializations(Entity, InnerStructuredList,
1120 RequiresSecondPass);
1121 if (RequiresSecondPass && !hadError)
1122 FillInEmptyInitializations(Entity, InnerStructuredList,
1123 RequiresSecondPass);
1124 }
1125 ++StructuredIndex;
1126 ++Index;
1127 return;
1128 }
1129 // C++ initialization is handled later.
1130 } else if (isa<ImplicitValueInitExpr>(expr)) {
1131 // This happens during template instantiation when we see an InitListExpr
1132 // that we've already checked once.
1133 assert(SemaRef.Context.hasSameType(expr->getType(), ElemType) &&
1134 "found implicit initialization for the wrong type");
1135 if (!VerifyOnly)
1136 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1137 ++Index;
1138 return;
1139 }
1140
1141 if (SemaRef.getLangOpts().CPlusPlus) {
1142 // C++ [dcl.init.aggr]p2:
1143 // Each member is copy-initialized from the corresponding
1144 // initializer-clause.
1145
1146 // FIXME: Better EqualLoc?
1147 InitializationKind Kind =
1148 InitializationKind::CreateCopy(expr->getLocStart(), SourceLocation());
1149 InitializationSequence Seq(SemaRef, Entity, Kind, expr,
1150 /*TopLevelOfInitList*/ true);
1151
1152 // C++14 [dcl.init.aggr]p13:
1153 // If the assignment-expression can initialize a member, the member is
1154 // initialized. Otherwise [...] brace elision is assumed
1155 //
1156 // Brace elision is never performed if the element is not an
1157 // assignment-expression.
1158 if (Seq || isa<InitListExpr>(expr)) {
1159 if (!VerifyOnly) {
1160 ExprResult Result =
1161 Seq.Perform(SemaRef, Entity, Kind, expr);
1162 if (Result.isInvalid())
1163 hadError = true;
1164
1165 UpdateStructuredListElement(StructuredList, StructuredIndex,
1166 Result.getAs<Expr>());
1167 } else if (!Seq)
1168 hadError = true;
1169 ++Index;
1170 return;
1171 }
1172
1173 // Fall through for subaggregate initialization
1174 } else if (ElemType->isScalarType() || ElemType->isAtomicType()) {
1175 // FIXME: Need to handle atomic aggregate types with implicit init lists.
1176 return CheckScalarType(Entity, IList, ElemType, Index,
1177 StructuredList, StructuredIndex);
1178 } else if (const ArrayType *arrayType =
1179 SemaRef.Context.getAsArrayType(ElemType)) {
1180 // arrayType can be incomplete if we're initializing a flexible
1181 // array member. There's nothing we can do with the completed
1182 // type here, though.
1183
1184 if (IsStringInit(expr, arrayType, SemaRef.Context) == SIF_None) {
1185 if (!VerifyOnly) {
1186 CheckStringInit(expr, ElemType, arrayType, SemaRef);
1187 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1188 }
1189 ++Index;
1190 return;
1191 }
1192
1193 // Fall through for subaggregate initialization.
1194
1195 } else {
1196 assert((ElemType->isRecordType() || ElemType->isVectorType() ||
1197 ElemType->isClkEventT()) && "Unexpected type");
1198
1199 // C99 6.7.8p13:
1200 //
1201 // The initializer for a structure or union object that has
1202 // automatic storage duration shall be either an initializer
1203 // list as described below, or a single expression that has
1204 // compatible structure or union type. In the latter case, the
1205 // initial value of the object, including unnamed members, is
1206 // that of the expression.
1207 ExprResult ExprRes = expr;
1208 if (SemaRef.CheckSingleAssignmentConstraints(
1209 ElemType, ExprRes, !VerifyOnly) != Sema::Incompatible) {
1210 if (ExprRes.isInvalid())
1211 hadError = true;
1212 else {
1213 ExprRes = SemaRef.DefaultFunctionArrayLvalueConversion(ExprRes.get());
1214 if (ExprRes.isInvalid())
1215 hadError = true;
1216 }
1217 UpdateStructuredListElement(StructuredList, StructuredIndex,
1218 ExprRes.getAs<Expr>());
1219 ++Index;
1220 return;
1221 }
1222 ExprRes.get();
1223 // Fall through for subaggregate initialization
1224 }
1225
1226 // C++ [dcl.init.aggr]p12:
1227 //
1228 // [...] Otherwise, if the member is itself a non-empty
1229 // subaggregate, brace elision is assumed and the initializer is
1230 // considered for the initialization of the first member of
1231 // the subaggregate.
1232 if (!SemaRef.getLangOpts().OpenCL &&
1233 (ElemType->isAggregateType() || ElemType->isVectorType())) {
1234 CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList,
1235 StructuredIndex);
1236 ++StructuredIndex;
1237 } else {
1238 if (!VerifyOnly) {
1239 // We cannot initialize this element, so let
1240 // PerformCopyInitialization produce the appropriate diagnostic.
1241 SemaRef.PerformCopyInitialization(Entity, SourceLocation(), expr,
1242 /*TopLevelOfInitList=*/true);
1243 }
1244 hadError = true;
1245 ++Index;
1246 ++StructuredIndex;
1247 }
1248 }
1249
CheckComplexType(const InitializedEntity & Entity,InitListExpr * IList,QualType DeclType,unsigned & Index,InitListExpr * StructuredList,unsigned & StructuredIndex)1250 void InitListChecker::CheckComplexType(const InitializedEntity &Entity,
1251 InitListExpr *IList, QualType DeclType,
1252 unsigned &Index,
1253 InitListExpr *StructuredList,
1254 unsigned &StructuredIndex) {
1255 assert(Index == 0 && "Index in explicit init list must be zero");
1256
1257 // As an extension, clang supports complex initializers, which initialize
1258 // a complex number component-wise. When an explicit initializer list for
1259 // a complex number contains two two initializers, this extension kicks in:
1260 // it exepcts the initializer list to contain two elements convertible to
1261 // the element type of the complex type. The first element initializes
1262 // the real part, and the second element intitializes the imaginary part.
1263
1264 if (IList->getNumInits() != 2)
1265 return CheckScalarType(Entity, IList, DeclType, Index, StructuredList,
1266 StructuredIndex);
1267
1268 // This is an extension in C. (The builtin _Complex type does not exist
1269 // in the C++ standard.)
1270 if (!SemaRef.getLangOpts().CPlusPlus && !VerifyOnly)
1271 SemaRef.Diag(IList->getLocStart(), diag::ext_complex_component_init)
1272 << IList->getSourceRange();
1273
1274 // Initialize the complex number.
1275 QualType elementType = DeclType->getAs<ComplexType>()->getElementType();
1276 InitializedEntity ElementEntity =
1277 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1278
1279 for (unsigned i = 0; i < 2; ++i) {
1280 ElementEntity.setElementIndex(Index);
1281 CheckSubElementType(ElementEntity, IList, elementType, Index,
1282 StructuredList, StructuredIndex);
1283 }
1284 }
1285
CheckScalarType(const InitializedEntity & Entity,InitListExpr * IList,QualType DeclType,unsigned & Index,InitListExpr * StructuredList,unsigned & StructuredIndex)1286 void InitListChecker::CheckScalarType(const InitializedEntity &Entity,
1287 InitListExpr *IList, QualType DeclType,
1288 unsigned &Index,
1289 InitListExpr *StructuredList,
1290 unsigned &StructuredIndex) {
1291 if (Index >= IList->getNumInits()) {
1292 if (!VerifyOnly)
1293 SemaRef.Diag(IList->getLocStart(),
1294 SemaRef.getLangOpts().CPlusPlus11 ?
1295 diag::warn_cxx98_compat_empty_scalar_initializer :
1296 diag::err_empty_scalar_initializer)
1297 << IList->getSourceRange();
1298 hadError = !SemaRef.getLangOpts().CPlusPlus11;
1299 ++Index;
1300 ++StructuredIndex;
1301 return;
1302 }
1303
1304 Expr *expr = IList->getInit(Index);
1305 if (InitListExpr *SubIList = dyn_cast<InitListExpr>(expr)) {
1306 // FIXME: This is invalid, and accepting it causes overload resolution
1307 // to pick the wrong overload in some corner cases.
1308 if (!VerifyOnly)
1309 SemaRef.Diag(SubIList->getLocStart(),
1310 diag::ext_many_braces_around_scalar_init)
1311 << SubIList->getSourceRange();
1312
1313 CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList,
1314 StructuredIndex);
1315 return;
1316 } else if (isa<DesignatedInitExpr>(expr)) {
1317 if (!VerifyOnly)
1318 SemaRef.Diag(expr->getLocStart(),
1319 diag::err_designator_for_scalar_init)
1320 << DeclType << expr->getSourceRange();
1321 hadError = true;
1322 ++Index;
1323 ++StructuredIndex;
1324 return;
1325 }
1326
1327 if (VerifyOnly) {
1328 if (!SemaRef.CanPerformCopyInitialization(Entity,expr))
1329 hadError = true;
1330 ++Index;
1331 return;
1332 }
1333
1334 ExprResult Result =
1335 SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), expr,
1336 /*TopLevelOfInitList=*/true);
1337
1338 Expr *ResultExpr = nullptr;
1339
1340 if (Result.isInvalid())
1341 hadError = true; // types weren't compatible.
1342 else {
1343 ResultExpr = Result.getAs<Expr>();
1344
1345 if (ResultExpr != expr) {
1346 // The type was promoted, update initializer list.
1347 IList->setInit(Index, ResultExpr);
1348 }
1349 }
1350 if (hadError)
1351 ++StructuredIndex;
1352 else
1353 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr);
1354 ++Index;
1355 }
1356
CheckReferenceType(const InitializedEntity & Entity,InitListExpr * IList,QualType DeclType,unsigned & Index,InitListExpr * StructuredList,unsigned & StructuredIndex)1357 void InitListChecker::CheckReferenceType(const InitializedEntity &Entity,
1358 InitListExpr *IList, QualType DeclType,
1359 unsigned &Index,
1360 InitListExpr *StructuredList,
1361 unsigned &StructuredIndex) {
1362 if (Index >= IList->getNumInits()) {
1363 // FIXME: It would be wonderful if we could point at the actual member. In
1364 // general, it would be useful to pass location information down the stack,
1365 // so that we know the location (or decl) of the "current object" being
1366 // initialized.
1367 if (!VerifyOnly)
1368 SemaRef.Diag(IList->getLocStart(),
1369 diag::err_init_reference_member_uninitialized)
1370 << DeclType
1371 << IList->getSourceRange();
1372 hadError = true;
1373 ++Index;
1374 ++StructuredIndex;
1375 return;
1376 }
1377
1378 Expr *expr = IList->getInit(Index);
1379 if (isa<InitListExpr>(expr) && !SemaRef.getLangOpts().CPlusPlus11) {
1380 if (!VerifyOnly)
1381 SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list)
1382 << DeclType << IList->getSourceRange();
1383 hadError = true;
1384 ++Index;
1385 ++StructuredIndex;
1386 return;
1387 }
1388
1389 if (VerifyOnly) {
1390 if (!SemaRef.CanPerformCopyInitialization(Entity,expr))
1391 hadError = true;
1392 ++Index;
1393 return;
1394 }
1395
1396 ExprResult Result =
1397 SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), expr,
1398 /*TopLevelOfInitList=*/true);
1399
1400 if (Result.isInvalid())
1401 hadError = true;
1402
1403 expr = Result.getAs<Expr>();
1404 IList->setInit(Index, expr);
1405
1406 if (hadError)
1407 ++StructuredIndex;
1408 else
1409 UpdateStructuredListElement(StructuredList, StructuredIndex, expr);
1410 ++Index;
1411 }
1412
CheckVectorType(const InitializedEntity & Entity,InitListExpr * IList,QualType DeclType,unsigned & Index,InitListExpr * StructuredList,unsigned & StructuredIndex)1413 void InitListChecker::CheckVectorType(const InitializedEntity &Entity,
1414 InitListExpr *IList, QualType DeclType,
1415 unsigned &Index,
1416 InitListExpr *StructuredList,
1417 unsigned &StructuredIndex) {
1418 const VectorType *VT = DeclType->getAs<VectorType>();
1419 unsigned maxElements = VT->getNumElements();
1420 unsigned numEltsInit = 0;
1421 QualType elementType = VT->getElementType();
1422
1423 if (Index >= IList->getNumInits()) {
1424 // Make sure the element type can be value-initialized.
1425 if (VerifyOnly)
1426 CheckEmptyInitializable(
1427 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity),
1428 IList->getLocEnd());
1429 return;
1430 }
1431
1432 if (!SemaRef.getLangOpts().OpenCL) {
1433 // If the initializing element is a vector, try to copy-initialize
1434 // instead of breaking it apart (which is doomed to failure anyway).
1435 Expr *Init = IList->getInit(Index);
1436 if (!isa<InitListExpr>(Init) && Init->getType()->isVectorType()) {
1437 if (VerifyOnly) {
1438 if (!SemaRef.CanPerformCopyInitialization(Entity, Init))
1439 hadError = true;
1440 ++Index;
1441 return;
1442 }
1443
1444 ExprResult Result =
1445 SemaRef.PerformCopyInitialization(Entity, Init->getLocStart(), Init,
1446 /*TopLevelOfInitList=*/true);
1447
1448 Expr *ResultExpr = nullptr;
1449 if (Result.isInvalid())
1450 hadError = true; // types weren't compatible.
1451 else {
1452 ResultExpr = Result.getAs<Expr>();
1453
1454 if (ResultExpr != Init) {
1455 // The type was promoted, update initializer list.
1456 IList->setInit(Index, ResultExpr);
1457 }
1458 }
1459 if (hadError)
1460 ++StructuredIndex;
1461 else
1462 UpdateStructuredListElement(StructuredList, StructuredIndex,
1463 ResultExpr);
1464 ++Index;
1465 return;
1466 }
1467
1468 InitializedEntity ElementEntity =
1469 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1470
1471 for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) {
1472 // Don't attempt to go past the end of the init list
1473 if (Index >= IList->getNumInits()) {
1474 if (VerifyOnly)
1475 CheckEmptyInitializable(ElementEntity, IList->getLocEnd());
1476 break;
1477 }
1478
1479 ElementEntity.setElementIndex(Index);
1480 CheckSubElementType(ElementEntity, IList, elementType, Index,
1481 StructuredList, StructuredIndex);
1482 }
1483
1484 if (VerifyOnly)
1485 return;
1486
1487 bool isBigEndian = SemaRef.Context.getTargetInfo().isBigEndian();
1488 const VectorType *T = Entity.getType()->getAs<VectorType>();
1489 if (isBigEndian && (T->getVectorKind() == VectorType::NeonVector ||
1490 T->getVectorKind() == VectorType::NeonPolyVector)) {
1491 // The ability to use vector initializer lists is a GNU vector extension
1492 // and is unrelated to the NEON intrinsics in arm_neon.h. On little
1493 // endian machines it works fine, however on big endian machines it
1494 // exhibits surprising behaviour:
1495 //
1496 // uint32x2_t x = {42, 64};
1497 // return vget_lane_u32(x, 0); // Will return 64.
1498 //
1499 // Because of this, explicitly call out that it is non-portable.
1500 //
1501 SemaRef.Diag(IList->getLocStart(),
1502 diag::warn_neon_vector_initializer_non_portable);
1503
1504 const char *typeCode;
1505 unsigned typeSize = SemaRef.Context.getTypeSize(elementType);
1506
1507 if (elementType->isFloatingType())
1508 typeCode = "f";
1509 else if (elementType->isSignedIntegerType())
1510 typeCode = "s";
1511 else if (elementType->isUnsignedIntegerType())
1512 typeCode = "u";
1513 else
1514 llvm_unreachable("Invalid element type!");
1515
1516 SemaRef.Diag(IList->getLocStart(),
1517 SemaRef.Context.getTypeSize(VT) > 64 ?
1518 diag::note_neon_vector_initializer_non_portable_q :
1519 diag::note_neon_vector_initializer_non_portable)
1520 << typeCode << typeSize;
1521 }
1522
1523 return;
1524 }
1525
1526 InitializedEntity ElementEntity =
1527 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
1528
1529 // OpenCL initializers allows vectors to be constructed from vectors.
1530 for (unsigned i = 0; i < maxElements; ++i) {
1531 // Don't attempt to go past the end of the init list
1532 if (Index >= IList->getNumInits())
1533 break;
1534
1535 ElementEntity.setElementIndex(Index);
1536
1537 QualType IType = IList->getInit(Index)->getType();
1538 if (!IType->isVectorType()) {
1539 CheckSubElementType(ElementEntity, IList, elementType, Index,
1540 StructuredList, StructuredIndex);
1541 ++numEltsInit;
1542 } else {
1543 QualType VecType;
1544 const VectorType *IVT = IType->getAs<VectorType>();
1545 unsigned numIElts = IVT->getNumElements();
1546
1547 if (IType->isExtVectorType())
1548 VecType = SemaRef.Context.getExtVectorType(elementType, numIElts);
1549 else
1550 VecType = SemaRef.Context.getVectorType(elementType, numIElts,
1551 IVT->getVectorKind());
1552 CheckSubElementType(ElementEntity, IList, VecType, Index,
1553 StructuredList, StructuredIndex);
1554 numEltsInit += numIElts;
1555 }
1556 }
1557
1558 // OpenCL requires all elements to be initialized.
1559 if (numEltsInit != maxElements) {
1560 if (!VerifyOnly)
1561 SemaRef.Diag(IList->getLocStart(),
1562 diag::err_vector_incorrect_num_initializers)
1563 << (numEltsInit < maxElements) << maxElements << numEltsInit;
1564 hadError = true;
1565 }
1566 }
1567
CheckArrayType(const InitializedEntity & Entity,InitListExpr * IList,QualType & DeclType,llvm::APSInt elementIndex,bool SubobjectIsDesignatorContext,unsigned & Index,InitListExpr * StructuredList,unsigned & StructuredIndex)1568 void InitListChecker::CheckArrayType(const InitializedEntity &Entity,
1569 InitListExpr *IList, QualType &DeclType,
1570 llvm::APSInt elementIndex,
1571 bool SubobjectIsDesignatorContext,
1572 unsigned &Index,
1573 InitListExpr *StructuredList,
1574 unsigned &StructuredIndex) {
1575 const ArrayType *arrayType = SemaRef.Context.getAsArrayType(DeclType);
1576
1577 // Check for the special-case of initializing an array with a string.
1578 if (Index < IList->getNumInits()) {
1579 if (IsStringInit(IList->getInit(Index), arrayType, SemaRef.Context) ==
1580 SIF_None) {
1581 // We place the string literal directly into the resulting
1582 // initializer list. This is the only place where the structure
1583 // of the structured initializer list doesn't match exactly,
1584 // because doing so would involve allocating one character
1585 // constant for each string.
1586 if (!VerifyOnly) {
1587 CheckStringInit(IList->getInit(Index), DeclType, arrayType, SemaRef);
1588 UpdateStructuredListElement(StructuredList, StructuredIndex,
1589 IList->getInit(Index));
1590 StructuredList->resizeInits(SemaRef.Context, StructuredIndex);
1591 }
1592 ++Index;
1593 return;
1594 }
1595 }
1596 if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(arrayType)) {
1597 // Check for VLAs; in standard C it would be possible to check this
1598 // earlier, but I don't know where clang accepts VLAs (gcc accepts
1599 // them in all sorts of strange places).
1600 if (!VerifyOnly)
1601 SemaRef.Diag(VAT->getSizeExpr()->getLocStart(),
1602 diag::err_variable_object_no_init)
1603 << VAT->getSizeExpr()->getSourceRange();
1604 hadError = true;
1605 ++Index;
1606 ++StructuredIndex;
1607 return;
1608 }
1609
1610 // We might know the maximum number of elements in advance.
1611 llvm::APSInt maxElements(elementIndex.getBitWidth(),
1612 elementIndex.isUnsigned());
1613 bool maxElementsKnown = false;
1614 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(arrayType)) {
1615 maxElements = CAT->getSize();
1616 elementIndex = elementIndex.extOrTrunc(maxElements.getBitWidth());
1617 elementIndex.setIsUnsigned(maxElements.isUnsigned());
1618 maxElementsKnown = true;
1619 }
1620
1621 QualType elementType = arrayType->getElementType();
1622 while (Index < IList->getNumInits()) {
1623 Expr *Init = IList->getInit(Index);
1624 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
1625 // If we're not the subobject that matches up with the '{' for
1626 // the designator, we shouldn't be handling the
1627 // designator. Return immediately.
1628 if (!SubobjectIsDesignatorContext)
1629 return;
1630
1631 // Handle this designated initializer. elementIndex will be
1632 // updated to be the next array element we'll initialize.
1633 if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
1634 DeclType, nullptr, &elementIndex, Index,
1635 StructuredList, StructuredIndex, true,
1636 false)) {
1637 hadError = true;
1638 continue;
1639 }
1640
1641 if (elementIndex.getBitWidth() > maxElements.getBitWidth())
1642 maxElements = maxElements.extend(elementIndex.getBitWidth());
1643 else if (elementIndex.getBitWidth() < maxElements.getBitWidth())
1644 elementIndex = elementIndex.extend(maxElements.getBitWidth());
1645 elementIndex.setIsUnsigned(maxElements.isUnsigned());
1646
1647 // If the array is of incomplete type, keep track of the number of
1648 // elements in the initializer.
1649 if (!maxElementsKnown && elementIndex > maxElements)
1650 maxElements = elementIndex;
1651
1652 continue;
1653 }
1654
1655 // If we know the maximum number of elements, and we've already
1656 // hit it, stop consuming elements in the initializer list.
1657 if (maxElementsKnown && elementIndex == maxElements)
1658 break;
1659
1660 InitializedEntity ElementEntity =
1661 InitializedEntity::InitializeElement(SemaRef.Context, StructuredIndex,
1662 Entity);
1663 // Check this element.
1664 CheckSubElementType(ElementEntity, IList, elementType, Index,
1665 StructuredList, StructuredIndex);
1666 ++elementIndex;
1667
1668 // If the array is of incomplete type, keep track of the number of
1669 // elements in the initializer.
1670 if (!maxElementsKnown && elementIndex > maxElements)
1671 maxElements = elementIndex;
1672 }
1673 if (!hadError && DeclType->isIncompleteArrayType() && !VerifyOnly) {
1674 // If this is an incomplete array type, the actual type needs to
1675 // be calculated here.
1676 llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned());
1677 if (maxElements == Zero) {
1678 // Sizing an array implicitly to zero is not allowed by ISO C,
1679 // but is supported by GNU.
1680 SemaRef.Diag(IList->getLocStart(),
1681 diag::ext_typecheck_zero_array_size);
1682 }
1683
1684 DeclType = SemaRef.Context.getConstantArrayType(elementType, maxElements,
1685 ArrayType::Normal, 0);
1686 }
1687 if (!hadError && VerifyOnly) {
1688 // Check if there are any members of the array that get value-initialized.
1689 // If so, check if doing that is possible.
1690 // FIXME: This needs to detect holes left by designated initializers too.
1691 if (maxElementsKnown && elementIndex < maxElements)
1692 CheckEmptyInitializable(InitializedEntity::InitializeElement(
1693 SemaRef.Context, 0, Entity),
1694 IList->getLocEnd());
1695 }
1696 }
1697
CheckFlexibleArrayInit(const InitializedEntity & Entity,Expr * InitExpr,FieldDecl * Field,bool TopLevelObject)1698 bool InitListChecker::CheckFlexibleArrayInit(const InitializedEntity &Entity,
1699 Expr *InitExpr,
1700 FieldDecl *Field,
1701 bool TopLevelObject) {
1702 // Handle GNU flexible array initializers.
1703 unsigned FlexArrayDiag;
1704 if (isa<InitListExpr>(InitExpr) &&
1705 cast<InitListExpr>(InitExpr)->getNumInits() == 0) {
1706 // Empty flexible array init always allowed as an extension
1707 FlexArrayDiag = diag::ext_flexible_array_init;
1708 } else if (SemaRef.getLangOpts().CPlusPlus) {
1709 // Disallow flexible array init in C++; it is not required for gcc
1710 // compatibility, and it needs work to IRGen correctly in general.
1711 FlexArrayDiag = diag::err_flexible_array_init;
1712 } else if (!TopLevelObject) {
1713 // Disallow flexible array init on non-top-level object
1714 FlexArrayDiag = diag::err_flexible_array_init;
1715 } else if (Entity.getKind() != InitializedEntity::EK_Variable) {
1716 // Disallow flexible array init on anything which is not a variable.
1717 FlexArrayDiag = diag::err_flexible_array_init;
1718 } else if (cast<VarDecl>(Entity.getDecl())->hasLocalStorage()) {
1719 // Disallow flexible array init on local variables.
1720 FlexArrayDiag = diag::err_flexible_array_init;
1721 } else {
1722 // Allow other cases.
1723 FlexArrayDiag = diag::ext_flexible_array_init;
1724 }
1725
1726 if (!VerifyOnly) {
1727 SemaRef.Diag(InitExpr->getLocStart(),
1728 FlexArrayDiag)
1729 << InitExpr->getLocStart();
1730 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
1731 << Field;
1732 }
1733
1734 return FlexArrayDiag != diag::ext_flexible_array_init;
1735 }
1736
CheckStructUnionTypes(const InitializedEntity & Entity,InitListExpr * IList,QualType DeclType,CXXRecordDecl::base_class_range Bases,RecordDecl::field_iterator Field,bool SubobjectIsDesignatorContext,unsigned & Index,InitListExpr * StructuredList,unsigned & StructuredIndex,bool TopLevelObject)1737 void InitListChecker::CheckStructUnionTypes(
1738 const InitializedEntity &Entity, InitListExpr *IList, QualType DeclType,
1739 CXXRecordDecl::base_class_range Bases, RecordDecl::field_iterator Field,
1740 bool SubobjectIsDesignatorContext, unsigned &Index,
1741 InitListExpr *StructuredList, unsigned &StructuredIndex,
1742 bool TopLevelObject) {
1743 RecordDecl *structDecl = DeclType->getAs<RecordType>()->getDecl();
1744
1745 // If the record is invalid, some of it's members are invalid. To avoid
1746 // confusion, we forgo checking the intializer for the entire record.
1747 if (structDecl->isInvalidDecl()) {
1748 // Assume it was supposed to consume a single initializer.
1749 ++Index;
1750 hadError = true;
1751 return;
1752 }
1753
1754 if (DeclType->isUnionType() && IList->getNumInits() == 0) {
1755 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl();
1756
1757 // If there's a default initializer, use it.
1758 if (isa<CXXRecordDecl>(RD) && cast<CXXRecordDecl>(RD)->hasInClassInitializer()) {
1759 if (VerifyOnly)
1760 return;
1761 for (RecordDecl::field_iterator FieldEnd = RD->field_end();
1762 Field != FieldEnd; ++Field) {
1763 if (Field->hasInClassInitializer()) {
1764 StructuredList->setInitializedFieldInUnion(*Field);
1765 // FIXME: Actually build a CXXDefaultInitExpr?
1766 return;
1767 }
1768 }
1769 }
1770
1771 // Value-initialize the first member of the union that isn't an unnamed
1772 // bitfield.
1773 for (RecordDecl::field_iterator FieldEnd = RD->field_end();
1774 Field != FieldEnd; ++Field) {
1775 if (!Field->isUnnamedBitfield()) {
1776 if (VerifyOnly)
1777 CheckEmptyInitializable(
1778 InitializedEntity::InitializeMember(*Field, &Entity),
1779 IList->getLocEnd());
1780 else
1781 StructuredList->setInitializedFieldInUnion(*Field);
1782 break;
1783 }
1784 }
1785 return;
1786 }
1787
1788 bool InitializedSomething = false;
1789
1790 // If we have any base classes, they are initialized prior to the fields.
1791 for (auto &Base : Bases) {
1792 Expr *Init = Index < IList->getNumInits() ? IList->getInit(Index) : nullptr;
1793 SourceLocation InitLoc = Init ? Init->getLocStart() : IList->getLocEnd();
1794
1795 // Designated inits always initialize fields, so if we see one, all
1796 // remaining base classes have no explicit initializer.
1797 if (Init && isa<DesignatedInitExpr>(Init))
1798 Init = nullptr;
1799
1800 InitializedEntity BaseEntity = InitializedEntity::InitializeBase(
1801 SemaRef.Context, &Base, false, &Entity);
1802 if (Init) {
1803 CheckSubElementType(BaseEntity, IList, Base.getType(), Index,
1804 StructuredList, StructuredIndex);
1805 InitializedSomething = true;
1806 } else if (VerifyOnly) {
1807 CheckEmptyInitializable(BaseEntity, InitLoc);
1808 }
1809 }
1810
1811 // If structDecl is a forward declaration, this loop won't do
1812 // anything except look at designated initializers; That's okay,
1813 // because an error should get printed out elsewhere. It might be
1814 // worthwhile to skip over the rest of the initializer, though.
1815 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl();
1816 RecordDecl::field_iterator FieldEnd = RD->field_end();
1817 bool CheckForMissingFields = true;
1818 while (Index < IList->getNumInits()) {
1819 Expr *Init = IList->getInit(Index);
1820
1821 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) {
1822 // If we're not the subobject that matches up with the '{' for
1823 // the designator, we shouldn't be handling the
1824 // designator. Return immediately.
1825 if (!SubobjectIsDesignatorContext)
1826 return;
1827
1828 // Handle this designated initializer. Field will be updated to
1829 // the next field that we'll be initializing.
1830 if (CheckDesignatedInitializer(Entity, IList, DIE, 0,
1831 DeclType, &Field, nullptr, Index,
1832 StructuredList, StructuredIndex,
1833 true, TopLevelObject))
1834 hadError = true;
1835
1836 InitializedSomething = true;
1837
1838 // Disable check for missing fields when designators are used.
1839 // This matches gcc behaviour.
1840 CheckForMissingFields = false;
1841 continue;
1842 }
1843
1844 if (Field == FieldEnd) {
1845 // We've run out of fields. We're done.
1846 break;
1847 }
1848
1849 // We've already initialized a member of a union. We're done.
1850 if (InitializedSomething && DeclType->isUnionType())
1851 break;
1852
1853 // If we've hit the flexible array member at the end, we're done.
1854 if (Field->getType()->isIncompleteArrayType())
1855 break;
1856
1857 if (Field->isUnnamedBitfield()) {
1858 // Don't initialize unnamed bitfields, e.g. "int : 20;"
1859 ++Field;
1860 continue;
1861 }
1862
1863 // Make sure we can use this declaration.
1864 bool InvalidUse;
1865 if (VerifyOnly)
1866 InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
1867 else
1868 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field,
1869 IList->getInit(Index)->getLocStart());
1870 if (InvalidUse) {
1871 ++Index;
1872 ++Field;
1873 hadError = true;
1874 continue;
1875 }
1876
1877 InitializedEntity MemberEntity =
1878 InitializedEntity::InitializeMember(*Field, &Entity);
1879 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
1880 StructuredList, StructuredIndex);
1881 InitializedSomething = true;
1882
1883 if (DeclType->isUnionType() && !VerifyOnly) {
1884 // Initialize the first field within the union.
1885 StructuredList->setInitializedFieldInUnion(*Field);
1886 }
1887
1888 ++Field;
1889 }
1890
1891 // Emit warnings for missing struct field initializers.
1892 if (!VerifyOnly && InitializedSomething && CheckForMissingFields &&
1893 Field != FieldEnd && !Field->getType()->isIncompleteArrayType() &&
1894 !DeclType->isUnionType()) {
1895 // It is possible we have one or more unnamed bitfields remaining.
1896 // Find first (if any) named field and emit warning.
1897 for (RecordDecl::field_iterator it = Field, end = RD->field_end();
1898 it != end; ++it) {
1899 if (!it->isUnnamedBitfield() && !it->hasInClassInitializer()) {
1900 SemaRef.Diag(IList->getSourceRange().getEnd(),
1901 diag::warn_missing_field_initializers) << *it;
1902 break;
1903 }
1904 }
1905 }
1906
1907 // Check that any remaining fields can be value-initialized.
1908 if (VerifyOnly && Field != FieldEnd && !DeclType->isUnionType() &&
1909 !Field->getType()->isIncompleteArrayType()) {
1910 // FIXME: Should check for holes left by designated initializers too.
1911 for (; Field != FieldEnd && !hadError; ++Field) {
1912 if (!Field->isUnnamedBitfield() && !Field->hasInClassInitializer())
1913 CheckEmptyInitializable(
1914 InitializedEntity::InitializeMember(*Field, &Entity),
1915 IList->getLocEnd());
1916 }
1917 }
1918
1919 if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() ||
1920 Index >= IList->getNumInits())
1921 return;
1922
1923 if (CheckFlexibleArrayInit(Entity, IList->getInit(Index), *Field,
1924 TopLevelObject)) {
1925 hadError = true;
1926 ++Index;
1927 return;
1928 }
1929
1930 InitializedEntity MemberEntity =
1931 InitializedEntity::InitializeMember(*Field, &Entity);
1932
1933 if (isa<InitListExpr>(IList->getInit(Index)))
1934 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
1935 StructuredList, StructuredIndex);
1936 else
1937 CheckImplicitInitList(MemberEntity, IList, Field->getType(), Index,
1938 StructuredList, StructuredIndex);
1939 }
1940
1941 /// \brief Expand a field designator that refers to a member of an
1942 /// anonymous struct or union into a series of field designators that
1943 /// refers to the field within the appropriate subobject.
1944 ///
ExpandAnonymousFieldDesignator(Sema & SemaRef,DesignatedInitExpr * DIE,unsigned DesigIdx,IndirectFieldDecl * IndirectField)1945 static void ExpandAnonymousFieldDesignator(Sema &SemaRef,
1946 DesignatedInitExpr *DIE,
1947 unsigned DesigIdx,
1948 IndirectFieldDecl *IndirectField) {
1949 typedef DesignatedInitExpr::Designator Designator;
1950
1951 // Build the replacement designators.
1952 SmallVector<Designator, 4> Replacements;
1953 for (IndirectFieldDecl::chain_iterator PI = IndirectField->chain_begin(),
1954 PE = IndirectField->chain_end(); PI != PE; ++PI) {
1955 if (PI + 1 == PE)
1956 Replacements.push_back(Designator((IdentifierInfo *)nullptr,
1957 DIE->getDesignator(DesigIdx)->getDotLoc(),
1958 DIE->getDesignator(DesigIdx)->getFieldLoc()));
1959 else
1960 Replacements.push_back(Designator((IdentifierInfo *)nullptr,
1961 SourceLocation(), SourceLocation()));
1962 assert(isa<FieldDecl>(*PI));
1963 Replacements.back().setField(cast<FieldDecl>(*PI));
1964 }
1965
1966 // Expand the current designator into the set of replacement
1967 // designators, so we have a full subobject path down to where the
1968 // member of the anonymous struct/union is actually stored.
1969 DIE->ExpandDesignator(SemaRef.Context, DesigIdx, &Replacements[0],
1970 &Replacements[0] + Replacements.size());
1971 }
1972
CloneDesignatedInitExpr(Sema & SemaRef,DesignatedInitExpr * DIE)1973 static DesignatedInitExpr *CloneDesignatedInitExpr(Sema &SemaRef,
1974 DesignatedInitExpr *DIE) {
1975 unsigned NumIndexExprs = DIE->getNumSubExprs() - 1;
1976 SmallVector<Expr*, 4> IndexExprs(NumIndexExprs);
1977 for (unsigned I = 0; I < NumIndexExprs; ++I)
1978 IndexExprs[I] = DIE->getSubExpr(I + 1);
1979 return DesignatedInitExpr::Create(SemaRef.Context, DIE->designators(),
1980 IndexExprs,
1981 DIE->getEqualOrColonLoc(),
1982 DIE->usesGNUSyntax(), DIE->getInit());
1983 }
1984
1985 namespace {
1986
1987 // Callback to only accept typo corrections that are for field members of
1988 // the given struct or union.
1989 class FieldInitializerValidatorCCC : public CorrectionCandidateCallback {
1990 public:
FieldInitializerValidatorCCC(RecordDecl * RD)1991 explicit FieldInitializerValidatorCCC(RecordDecl *RD)
1992 : Record(RD) {}
1993
ValidateCandidate(const TypoCorrection & candidate)1994 bool ValidateCandidate(const TypoCorrection &candidate) override {
1995 FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>();
1996 return FD && FD->getDeclContext()->getRedeclContext()->Equals(Record);
1997 }
1998
1999 private:
2000 RecordDecl *Record;
2001 };
2002
2003 } // end anonymous namespace
2004
2005 /// @brief Check the well-formedness of a C99 designated initializer.
2006 ///
2007 /// Determines whether the designated initializer @p DIE, which
2008 /// resides at the given @p Index within the initializer list @p
2009 /// IList, is well-formed for a current object of type @p DeclType
2010 /// (C99 6.7.8). The actual subobject that this designator refers to
2011 /// within the current subobject is returned in either
2012 /// @p NextField or @p NextElementIndex (whichever is appropriate).
2013 ///
2014 /// @param IList The initializer list in which this designated
2015 /// initializer occurs.
2016 ///
2017 /// @param DIE The designated initializer expression.
2018 ///
2019 /// @param DesigIdx The index of the current designator.
2020 ///
2021 /// @param CurrentObjectType The type of the "current object" (C99 6.7.8p17),
2022 /// into which the designation in @p DIE should refer.
2023 ///
2024 /// @param NextField If non-NULL and the first designator in @p DIE is
2025 /// a field, this will be set to the field declaration corresponding
2026 /// to the field named by the designator.
2027 ///
2028 /// @param NextElementIndex If non-NULL and the first designator in @p
2029 /// DIE is an array designator or GNU array-range designator, this
2030 /// will be set to the last index initialized by this designator.
2031 ///
2032 /// @param Index Index into @p IList where the designated initializer
2033 /// @p DIE occurs.
2034 ///
2035 /// @param StructuredList The initializer list expression that
2036 /// describes all of the subobject initializers in the order they'll
2037 /// actually be initialized.
2038 ///
2039 /// @returns true if there was an error, false otherwise.
2040 bool
CheckDesignatedInitializer(const InitializedEntity & Entity,InitListExpr * IList,DesignatedInitExpr * DIE,unsigned DesigIdx,QualType & CurrentObjectType,RecordDecl::field_iterator * NextField,llvm::APSInt * NextElementIndex,unsigned & Index,InitListExpr * StructuredList,unsigned & StructuredIndex,bool FinishSubobjectInit,bool TopLevelObject)2041 InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity,
2042 InitListExpr *IList,
2043 DesignatedInitExpr *DIE,
2044 unsigned DesigIdx,
2045 QualType &CurrentObjectType,
2046 RecordDecl::field_iterator *NextField,
2047 llvm::APSInt *NextElementIndex,
2048 unsigned &Index,
2049 InitListExpr *StructuredList,
2050 unsigned &StructuredIndex,
2051 bool FinishSubobjectInit,
2052 bool TopLevelObject) {
2053 if (DesigIdx == DIE->size()) {
2054 // Check the actual initialization for the designated object type.
2055 bool prevHadError = hadError;
2056
2057 // Temporarily remove the designator expression from the
2058 // initializer list that the child calls see, so that we don't try
2059 // to re-process the designator.
2060 unsigned OldIndex = Index;
2061 IList->setInit(OldIndex, DIE->getInit());
2062
2063 CheckSubElementType(Entity, IList, CurrentObjectType, Index,
2064 StructuredList, StructuredIndex);
2065
2066 // Restore the designated initializer expression in the syntactic
2067 // form of the initializer list.
2068 if (IList->getInit(OldIndex) != DIE->getInit())
2069 DIE->setInit(IList->getInit(OldIndex));
2070 IList->setInit(OldIndex, DIE);
2071
2072 return hadError && !prevHadError;
2073 }
2074
2075 DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx);
2076 bool IsFirstDesignator = (DesigIdx == 0);
2077 if (!VerifyOnly) {
2078 assert((IsFirstDesignator || StructuredList) &&
2079 "Need a non-designated initializer list to start from");
2080
2081 // Determine the structural initializer list that corresponds to the
2082 // current subobject.
2083 if (IsFirstDesignator)
2084 StructuredList = SyntacticToSemantic.lookup(IList);
2085 else {
2086 Expr *ExistingInit = StructuredIndex < StructuredList->getNumInits() ?
2087 StructuredList->getInit(StructuredIndex) : nullptr;
2088 if (!ExistingInit && StructuredList->hasArrayFiller())
2089 ExistingInit = StructuredList->getArrayFiller();
2090
2091 if (!ExistingInit)
2092 StructuredList =
2093 getStructuredSubobjectInit(IList, Index, CurrentObjectType,
2094 StructuredList, StructuredIndex,
2095 SourceRange(D->getLocStart(),
2096 DIE->getLocEnd()));
2097 else if (InitListExpr *Result = dyn_cast<InitListExpr>(ExistingInit))
2098 StructuredList = Result;
2099 else {
2100 if (DesignatedInitUpdateExpr *E =
2101 dyn_cast<DesignatedInitUpdateExpr>(ExistingInit))
2102 StructuredList = E->getUpdater();
2103 else {
2104 DesignatedInitUpdateExpr *DIUE =
2105 new (SemaRef.Context) DesignatedInitUpdateExpr(SemaRef.Context,
2106 D->getLocStart(), ExistingInit,
2107 DIE->getLocEnd());
2108 StructuredList->updateInit(SemaRef.Context, StructuredIndex, DIUE);
2109 StructuredList = DIUE->getUpdater();
2110 }
2111
2112 // We need to check on source range validity because the previous
2113 // initializer does not have to be an explicit initializer. e.g.,
2114 //
2115 // struct P { int a, b; };
2116 // struct PP { struct P p } l = { { .a = 2 }, .p.b = 3 };
2117 //
2118 // There is an overwrite taking place because the first braced initializer
2119 // list "{ .a = 2 }" already provides value for .p.b (which is zero).
2120 if (ExistingInit->getSourceRange().isValid()) {
2121 // We are creating an initializer list that initializes the
2122 // subobjects of the current object, but there was already an
2123 // initialization that completely initialized the current
2124 // subobject, e.g., by a compound literal:
2125 //
2126 // struct X { int a, b; };
2127 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
2128 //
2129 // Here, xs[0].a == 0 and xs[0].b == 3, since the second,
2130 // designated initializer re-initializes the whole
2131 // subobject [0], overwriting previous initializers.
2132 SemaRef.Diag(D->getLocStart(),
2133 diag::warn_subobject_initializer_overrides)
2134 << SourceRange(D->getLocStart(), DIE->getLocEnd());
2135
2136 SemaRef.Diag(ExistingInit->getLocStart(),
2137 diag::note_previous_initializer)
2138 << /*FIXME:has side effects=*/0
2139 << ExistingInit->getSourceRange();
2140 }
2141 }
2142 }
2143 assert(StructuredList && "Expected a structured initializer list");
2144 }
2145
2146 if (D->isFieldDesignator()) {
2147 // C99 6.7.8p7:
2148 //
2149 // If a designator has the form
2150 //
2151 // . identifier
2152 //
2153 // then the current object (defined below) shall have
2154 // structure or union type and the identifier shall be the
2155 // name of a member of that type.
2156 const RecordType *RT = CurrentObjectType->getAs<RecordType>();
2157 if (!RT) {
2158 SourceLocation Loc = D->getDotLoc();
2159 if (Loc.isInvalid())
2160 Loc = D->getFieldLoc();
2161 if (!VerifyOnly)
2162 SemaRef.Diag(Loc, diag::err_field_designator_non_aggr)
2163 << SemaRef.getLangOpts().CPlusPlus << CurrentObjectType;
2164 ++Index;
2165 return true;
2166 }
2167
2168 FieldDecl *KnownField = D->getField();
2169 if (!KnownField) {
2170 IdentifierInfo *FieldName = D->getFieldName();
2171 DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName);
2172 for (NamedDecl *ND : Lookup) {
2173 if (auto *FD = dyn_cast<FieldDecl>(ND)) {
2174 KnownField = FD;
2175 break;
2176 }
2177 if (auto *IFD = dyn_cast<IndirectFieldDecl>(ND)) {
2178 // In verify mode, don't modify the original.
2179 if (VerifyOnly)
2180 DIE = CloneDesignatedInitExpr(SemaRef, DIE);
2181 ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IFD);
2182 D = DIE->getDesignator(DesigIdx);
2183 KnownField = cast<FieldDecl>(*IFD->chain_begin());
2184 break;
2185 }
2186 }
2187 if (!KnownField) {
2188 if (VerifyOnly) {
2189 ++Index;
2190 return true; // No typo correction when just trying this out.
2191 }
2192
2193 // Name lookup found something, but it wasn't a field.
2194 if (!Lookup.empty()) {
2195 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield)
2196 << FieldName;
2197 SemaRef.Diag(Lookup.front()->getLocation(),
2198 diag::note_field_designator_found);
2199 ++Index;
2200 return true;
2201 }
2202
2203 // Name lookup didn't find anything.
2204 // Determine whether this was a typo for another field name.
2205 if (TypoCorrection Corrected = SemaRef.CorrectTypo(
2206 DeclarationNameInfo(FieldName, D->getFieldLoc()),
2207 Sema::LookupMemberName, /*Scope=*/nullptr, /*SS=*/nullptr,
2208 llvm::make_unique<FieldInitializerValidatorCCC>(RT->getDecl()),
2209 Sema::CTK_ErrorRecovery, RT->getDecl())) {
2210 SemaRef.diagnoseTypo(
2211 Corrected,
2212 SemaRef.PDiag(diag::err_field_designator_unknown_suggest)
2213 << FieldName << CurrentObjectType);
2214 KnownField = Corrected.getCorrectionDeclAs<FieldDecl>();
2215 hadError = true;
2216 } else {
2217 // Typo correction didn't find anything.
2218 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown)
2219 << FieldName << CurrentObjectType;
2220 ++Index;
2221 return true;
2222 }
2223 }
2224 }
2225
2226 unsigned FieldIndex = 0;
2227 for (auto *FI : RT->getDecl()->fields()) {
2228 if (FI->isUnnamedBitfield())
2229 continue;
2230 if (declaresSameEntity(KnownField, FI)) {
2231 KnownField = FI;
2232 break;
2233 }
2234 ++FieldIndex;
2235 }
2236
2237 RecordDecl::field_iterator Field =
2238 RecordDecl::field_iterator(DeclContext::decl_iterator(KnownField));
2239
2240 // All of the fields of a union are located at the same place in
2241 // the initializer list.
2242 if (RT->getDecl()->isUnion()) {
2243 FieldIndex = 0;
2244 if (!VerifyOnly) {
2245 FieldDecl *CurrentField = StructuredList->getInitializedFieldInUnion();
2246 if (CurrentField && !declaresSameEntity(CurrentField, *Field)) {
2247 assert(StructuredList->getNumInits() == 1
2248 && "A union should never have more than one initializer!");
2249
2250 // We're about to throw away an initializer, emit warning.
2251 SemaRef.Diag(D->getFieldLoc(),
2252 diag::warn_initializer_overrides)
2253 << D->getSourceRange();
2254 Expr *ExistingInit = StructuredList->getInit(0);
2255 SemaRef.Diag(ExistingInit->getLocStart(),
2256 diag::note_previous_initializer)
2257 << /*FIXME:has side effects=*/0
2258 << ExistingInit->getSourceRange();
2259
2260 // remove existing initializer
2261 StructuredList->resizeInits(SemaRef.Context, 0);
2262 StructuredList->setInitializedFieldInUnion(nullptr);
2263 }
2264
2265 StructuredList->setInitializedFieldInUnion(*Field);
2266 }
2267 }
2268
2269 // Make sure we can use this declaration.
2270 bool InvalidUse;
2271 if (VerifyOnly)
2272 InvalidUse = !SemaRef.CanUseDecl(*Field, TreatUnavailableAsInvalid);
2273 else
2274 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc());
2275 if (InvalidUse) {
2276 ++Index;
2277 return true;
2278 }
2279
2280 if (!VerifyOnly) {
2281 // Update the designator with the field declaration.
2282 D->setField(*Field);
2283
2284 // Make sure that our non-designated initializer list has space
2285 // for a subobject corresponding to this field.
2286 if (FieldIndex >= StructuredList->getNumInits())
2287 StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1);
2288 }
2289
2290 // This designator names a flexible array member.
2291 if (Field->getType()->isIncompleteArrayType()) {
2292 bool Invalid = false;
2293 if ((DesigIdx + 1) != DIE->size()) {
2294 // We can't designate an object within the flexible array
2295 // member (because GCC doesn't allow it).
2296 if (!VerifyOnly) {
2297 DesignatedInitExpr::Designator *NextD
2298 = DIE->getDesignator(DesigIdx + 1);
2299 SemaRef.Diag(NextD->getLocStart(),
2300 diag::err_designator_into_flexible_array_member)
2301 << SourceRange(NextD->getLocStart(),
2302 DIE->getLocEnd());
2303 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2304 << *Field;
2305 }
2306 Invalid = true;
2307 }
2308
2309 if (!hadError && !isa<InitListExpr>(DIE->getInit()) &&
2310 !isa<StringLiteral>(DIE->getInit())) {
2311 // The initializer is not an initializer list.
2312 if (!VerifyOnly) {
2313 SemaRef.Diag(DIE->getInit()->getLocStart(),
2314 diag::err_flexible_array_init_needs_braces)
2315 << DIE->getInit()->getSourceRange();
2316 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member)
2317 << *Field;
2318 }
2319 Invalid = true;
2320 }
2321
2322 // Check GNU flexible array initializer.
2323 if (!Invalid && CheckFlexibleArrayInit(Entity, DIE->getInit(), *Field,
2324 TopLevelObject))
2325 Invalid = true;
2326
2327 if (Invalid) {
2328 ++Index;
2329 return true;
2330 }
2331
2332 // Initialize the array.
2333 bool prevHadError = hadError;
2334 unsigned newStructuredIndex = FieldIndex;
2335 unsigned OldIndex = Index;
2336 IList->setInit(Index, DIE->getInit());
2337
2338 InitializedEntity MemberEntity =
2339 InitializedEntity::InitializeMember(*Field, &Entity);
2340 CheckSubElementType(MemberEntity, IList, Field->getType(), Index,
2341 StructuredList, newStructuredIndex);
2342
2343 IList->setInit(OldIndex, DIE);
2344 if (hadError && !prevHadError) {
2345 ++Field;
2346 ++FieldIndex;
2347 if (NextField)
2348 *NextField = Field;
2349 StructuredIndex = FieldIndex;
2350 return true;
2351 }
2352 } else {
2353 // Recurse to check later designated subobjects.
2354 QualType FieldType = Field->getType();
2355 unsigned newStructuredIndex = FieldIndex;
2356
2357 InitializedEntity MemberEntity =
2358 InitializedEntity::InitializeMember(*Field, &Entity);
2359 if (CheckDesignatedInitializer(MemberEntity, IList, DIE, DesigIdx + 1,
2360 FieldType, nullptr, nullptr, Index,
2361 StructuredList, newStructuredIndex,
2362 FinishSubobjectInit, false))
2363 return true;
2364 }
2365
2366 // Find the position of the next field to be initialized in this
2367 // subobject.
2368 ++Field;
2369 ++FieldIndex;
2370
2371 // If this the first designator, our caller will continue checking
2372 // the rest of this struct/class/union subobject.
2373 if (IsFirstDesignator) {
2374 if (NextField)
2375 *NextField = Field;
2376 StructuredIndex = FieldIndex;
2377 return false;
2378 }
2379
2380 if (!FinishSubobjectInit)
2381 return false;
2382
2383 // We've already initialized something in the union; we're done.
2384 if (RT->getDecl()->isUnion())
2385 return hadError;
2386
2387 // Check the remaining fields within this class/struct/union subobject.
2388 bool prevHadError = hadError;
2389
2390 auto NoBases =
2391 CXXRecordDecl::base_class_range(CXXRecordDecl::base_class_iterator(),
2392 CXXRecordDecl::base_class_iterator());
2393 CheckStructUnionTypes(Entity, IList, CurrentObjectType, NoBases, Field,
2394 false, Index, StructuredList, FieldIndex);
2395 return hadError && !prevHadError;
2396 }
2397
2398 // C99 6.7.8p6:
2399 //
2400 // If a designator has the form
2401 //
2402 // [ constant-expression ]
2403 //
2404 // then the current object (defined below) shall have array
2405 // type and the expression shall be an integer constant
2406 // expression. If the array is of unknown size, any
2407 // nonnegative value is valid.
2408 //
2409 // Additionally, cope with the GNU extension that permits
2410 // designators of the form
2411 //
2412 // [ constant-expression ... constant-expression ]
2413 const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType);
2414 if (!AT) {
2415 if (!VerifyOnly)
2416 SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array)
2417 << CurrentObjectType;
2418 ++Index;
2419 return true;
2420 }
2421
2422 Expr *IndexExpr = nullptr;
2423 llvm::APSInt DesignatedStartIndex, DesignatedEndIndex;
2424 if (D->isArrayDesignator()) {
2425 IndexExpr = DIE->getArrayIndex(*D);
2426 DesignatedStartIndex = IndexExpr->EvaluateKnownConstInt(SemaRef.Context);
2427 DesignatedEndIndex = DesignatedStartIndex;
2428 } else {
2429 assert(D->isArrayRangeDesignator() && "Need array-range designator");
2430
2431 DesignatedStartIndex =
2432 DIE->getArrayRangeStart(*D)->EvaluateKnownConstInt(SemaRef.Context);
2433 DesignatedEndIndex =
2434 DIE->getArrayRangeEnd(*D)->EvaluateKnownConstInt(SemaRef.Context);
2435 IndexExpr = DIE->getArrayRangeEnd(*D);
2436
2437 // Codegen can't handle evaluating array range designators that have side
2438 // effects, because we replicate the AST value for each initialized element.
2439 // As such, set the sawArrayRangeDesignator() bit if we initialize multiple
2440 // elements with something that has a side effect, so codegen can emit an
2441 // "error unsupported" error instead of miscompiling the app.
2442 if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&&
2443 DIE->getInit()->HasSideEffects(SemaRef.Context) && !VerifyOnly)
2444 FullyStructuredList->sawArrayRangeDesignator();
2445 }
2446
2447 if (isa<ConstantArrayType>(AT)) {
2448 llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false);
2449 DesignatedStartIndex
2450 = DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth());
2451 DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned());
2452 DesignatedEndIndex
2453 = DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth());
2454 DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned());
2455 if (DesignatedEndIndex >= MaxElements) {
2456 if (!VerifyOnly)
2457 SemaRef.Diag(IndexExpr->getLocStart(),
2458 diag::err_array_designator_too_large)
2459 << DesignatedEndIndex.toString(10) << MaxElements.toString(10)
2460 << IndexExpr->getSourceRange();
2461 ++Index;
2462 return true;
2463 }
2464 } else {
2465 unsigned DesignatedIndexBitWidth =
2466 ConstantArrayType::getMaxSizeBits(SemaRef.Context);
2467 DesignatedStartIndex =
2468 DesignatedStartIndex.extOrTrunc(DesignatedIndexBitWidth);
2469 DesignatedEndIndex =
2470 DesignatedEndIndex.extOrTrunc(DesignatedIndexBitWidth);
2471 DesignatedStartIndex.setIsUnsigned(true);
2472 DesignatedEndIndex.setIsUnsigned(true);
2473 }
2474
2475 if (!VerifyOnly && StructuredList->isStringLiteralInit()) {
2476 // We're modifying a string literal init; we have to decompose the string
2477 // so we can modify the individual characters.
2478 ASTContext &Context = SemaRef.Context;
2479 Expr *SubExpr = StructuredList->getInit(0)->IgnoreParens();
2480
2481 // Compute the character type
2482 QualType CharTy = AT->getElementType();
2483
2484 // Compute the type of the integer literals.
2485 QualType PromotedCharTy = CharTy;
2486 if (CharTy->isPromotableIntegerType())
2487 PromotedCharTy = Context.getPromotedIntegerType(CharTy);
2488 unsigned PromotedCharTyWidth = Context.getTypeSize(PromotedCharTy);
2489
2490 if (StringLiteral *SL = dyn_cast<StringLiteral>(SubExpr)) {
2491 // Get the length of the string.
2492 uint64_t StrLen = SL->getLength();
2493 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
2494 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
2495 StructuredList->resizeInits(Context, StrLen);
2496
2497 // Build a literal for each character in the string, and put them into
2498 // the init list.
2499 for (unsigned i = 0, e = StrLen; i != e; ++i) {
2500 llvm::APInt CodeUnit(PromotedCharTyWidth, SL->getCodeUnit(i));
2501 Expr *Init = new (Context) IntegerLiteral(
2502 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
2503 if (CharTy != PromotedCharTy)
2504 Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast,
2505 Init, nullptr, VK_RValue);
2506 StructuredList->updateInit(Context, i, Init);
2507 }
2508 } else {
2509 ObjCEncodeExpr *E = cast<ObjCEncodeExpr>(SubExpr);
2510 std::string Str;
2511 Context.getObjCEncodingForType(E->getEncodedType(), Str);
2512
2513 // Get the length of the string.
2514 uint64_t StrLen = Str.size();
2515 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen))
2516 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue();
2517 StructuredList->resizeInits(Context, StrLen);
2518
2519 // Build a literal for each character in the string, and put them into
2520 // the init list.
2521 for (unsigned i = 0, e = StrLen; i != e; ++i) {
2522 llvm::APInt CodeUnit(PromotedCharTyWidth, Str[i]);
2523 Expr *Init = new (Context) IntegerLiteral(
2524 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc());
2525 if (CharTy != PromotedCharTy)
2526 Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast,
2527 Init, nullptr, VK_RValue);
2528 StructuredList->updateInit(Context, i, Init);
2529 }
2530 }
2531 }
2532
2533 // Make sure that our non-designated initializer list has space
2534 // for a subobject corresponding to this array element.
2535 if (!VerifyOnly &&
2536 DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits())
2537 StructuredList->resizeInits(SemaRef.Context,
2538 DesignatedEndIndex.getZExtValue() + 1);
2539
2540 // Repeatedly perform subobject initializations in the range
2541 // [DesignatedStartIndex, DesignatedEndIndex].
2542
2543 // Move to the next designator
2544 unsigned ElementIndex = DesignatedStartIndex.getZExtValue();
2545 unsigned OldIndex = Index;
2546
2547 InitializedEntity ElementEntity =
2548 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity);
2549
2550 while (DesignatedStartIndex <= DesignatedEndIndex) {
2551 // Recurse to check later designated subobjects.
2552 QualType ElementType = AT->getElementType();
2553 Index = OldIndex;
2554
2555 ElementEntity.setElementIndex(ElementIndex);
2556 if (CheckDesignatedInitializer(
2557 ElementEntity, IList, DIE, DesigIdx + 1, ElementType, nullptr,
2558 nullptr, Index, StructuredList, ElementIndex,
2559 FinishSubobjectInit && (DesignatedStartIndex == DesignatedEndIndex),
2560 false))
2561 return true;
2562
2563 // Move to the next index in the array that we'll be initializing.
2564 ++DesignatedStartIndex;
2565 ElementIndex = DesignatedStartIndex.getZExtValue();
2566 }
2567
2568 // If this the first designator, our caller will continue checking
2569 // the rest of this array subobject.
2570 if (IsFirstDesignator) {
2571 if (NextElementIndex)
2572 *NextElementIndex = DesignatedStartIndex;
2573 StructuredIndex = ElementIndex;
2574 return false;
2575 }
2576
2577 if (!FinishSubobjectInit)
2578 return false;
2579
2580 // Check the remaining elements within this array subobject.
2581 bool prevHadError = hadError;
2582 CheckArrayType(Entity, IList, CurrentObjectType, DesignatedStartIndex,
2583 /*SubobjectIsDesignatorContext=*/false, Index,
2584 StructuredList, ElementIndex);
2585 return hadError && !prevHadError;
2586 }
2587
2588 // Get the structured initializer list for a subobject of type
2589 // @p CurrentObjectType.
2590 InitListExpr *
getStructuredSubobjectInit(InitListExpr * IList,unsigned Index,QualType CurrentObjectType,InitListExpr * StructuredList,unsigned StructuredIndex,SourceRange InitRange,bool IsFullyOverwritten)2591 InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index,
2592 QualType CurrentObjectType,
2593 InitListExpr *StructuredList,
2594 unsigned StructuredIndex,
2595 SourceRange InitRange,
2596 bool IsFullyOverwritten) {
2597 if (VerifyOnly)
2598 return nullptr; // No structured list in verification-only mode.
2599 Expr *ExistingInit = nullptr;
2600 if (!StructuredList)
2601 ExistingInit = SyntacticToSemantic.lookup(IList);
2602 else if (StructuredIndex < StructuredList->getNumInits())
2603 ExistingInit = StructuredList->getInit(StructuredIndex);
2604
2605 if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit))
2606 // There might have already been initializers for subobjects of the current
2607 // object, but a subsequent initializer list will overwrite the entirety
2608 // of the current object. (See DR 253 and C99 6.7.8p21). e.g.,
2609 //
2610 // struct P { char x[6]; };
2611 // struct P l = { .x[2] = 'x', .x = { [0] = 'f' } };
2612 //
2613 // The first designated initializer is ignored, and l.x is just "f".
2614 if (!IsFullyOverwritten)
2615 return Result;
2616
2617 if (ExistingInit) {
2618 // We are creating an initializer list that initializes the
2619 // subobjects of the current object, but there was already an
2620 // initialization that completely initialized the current
2621 // subobject, e.g., by a compound literal:
2622 //
2623 // struct X { int a, b; };
2624 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 };
2625 //
2626 // Here, xs[0].a == 0 and xs[0].b == 3, since the second,
2627 // designated initializer re-initializes the whole
2628 // subobject [0], overwriting previous initializers.
2629 SemaRef.Diag(InitRange.getBegin(),
2630 diag::warn_subobject_initializer_overrides)
2631 << InitRange;
2632 SemaRef.Diag(ExistingInit->getLocStart(),
2633 diag::note_previous_initializer)
2634 << /*FIXME:has side effects=*/0
2635 << ExistingInit->getSourceRange();
2636 }
2637
2638 InitListExpr *Result
2639 = new (SemaRef.Context) InitListExpr(SemaRef.Context,
2640 InitRange.getBegin(), None,
2641 InitRange.getEnd());
2642
2643 QualType ResultType = CurrentObjectType;
2644 if (!ResultType->isArrayType())
2645 ResultType = ResultType.getNonLValueExprType(SemaRef.Context);
2646 Result->setType(ResultType);
2647
2648 // Pre-allocate storage for the structured initializer list.
2649 unsigned NumElements = 0;
2650 unsigned NumInits = 0;
2651 bool GotNumInits = false;
2652 if (!StructuredList) {
2653 NumInits = IList->getNumInits();
2654 GotNumInits = true;
2655 } else if (Index < IList->getNumInits()) {
2656 if (InitListExpr *SubList = dyn_cast<InitListExpr>(IList->getInit(Index))) {
2657 NumInits = SubList->getNumInits();
2658 GotNumInits = true;
2659 }
2660 }
2661
2662 if (const ArrayType *AType
2663 = SemaRef.Context.getAsArrayType(CurrentObjectType)) {
2664 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) {
2665 NumElements = CAType->getSize().getZExtValue();
2666 // Simple heuristic so that we don't allocate a very large
2667 // initializer with many empty entries at the end.
2668 if (GotNumInits && NumElements > NumInits)
2669 NumElements = 0;
2670 }
2671 } else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>())
2672 NumElements = VType->getNumElements();
2673 else if (const RecordType *RType = CurrentObjectType->getAs<RecordType>()) {
2674 RecordDecl *RDecl = RType->getDecl();
2675 if (RDecl->isUnion())
2676 NumElements = 1;
2677 else
2678 NumElements = std::distance(RDecl->field_begin(), RDecl->field_end());
2679 }
2680
2681 Result->reserveInits(SemaRef.Context, NumElements);
2682
2683 // Link this new initializer list into the structured initializer
2684 // lists.
2685 if (StructuredList)
2686 StructuredList->updateInit(SemaRef.Context, StructuredIndex, Result);
2687 else {
2688 Result->setSyntacticForm(IList);
2689 SyntacticToSemantic[IList] = Result;
2690 }
2691
2692 return Result;
2693 }
2694
2695 /// Update the initializer at index @p StructuredIndex within the
2696 /// structured initializer list to the value @p expr.
UpdateStructuredListElement(InitListExpr * StructuredList,unsigned & StructuredIndex,Expr * expr)2697 void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList,
2698 unsigned &StructuredIndex,
2699 Expr *expr) {
2700 // No structured initializer list to update
2701 if (!StructuredList)
2702 return;
2703
2704 if (Expr *PrevInit = StructuredList->updateInit(SemaRef.Context,
2705 StructuredIndex, expr)) {
2706 // This initializer overwrites a previous initializer. Warn.
2707 // We need to check on source range validity because the previous
2708 // initializer does not have to be an explicit initializer.
2709 // struct P { int a, b; };
2710 // struct PP { struct P p } l = { { .a = 2 }, .p.b = 3 };
2711 // There is an overwrite taking place because the first braced initializer
2712 // list "{ .a = 2 }' already provides value for .p.b (which is zero).
2713 if (PrevInit->getSourceRange().isValid()) {
2714 SemaRef.Diag(expr->getLocStart(),
2715 diag::warn_initializer_overrides)
2716 << expr->getSourceRange();
2717
2718 SemaRef.Diag(PrevInit->getLocStart(),
2719 diag::note_previous_initializer)
2720 << /*FIXME:has side effects=*/0
2721 << PrevInit->getSourceRange();
2722 }
2723 }
2724
2725 ++StructuredIndex;
2726 }
2727
2728 /// Check that the given Index expression is a valid array designator
2729 /// value. This is essentially just a wrapper around
2730 /// VerifyIntegerConstantExpression that also checks for negative values
2731 /// and produces a reasonable diagnostic if there is a
2732 /// failure. Returns the index expression, possibly with an implicit cast
2733 /// added, on success. If everything went okay, Value will receive the
2734 /// value of the constant expression.
2735 static ExprResult
CheckArrayDesignatorExpr(Sema & S,Expr * Index,llvm::APSInt & Value)2736 CheckArrayDesignatorExpr(Sema &S, Expr *Index, llvm::APSInt &Value) {
2737 SourceLocation Loc = Index->getLocStart();
2738
2739 // Make sure this is an integer constant expression.
2740 ExprResult Result = S.VerifyIntegerConstantExpression(Index, &Value);
2741 if (Result.isInvalid())
2742 return Result;
2743
2744 if (Value.isSigned() && Value.isNegative())
2745 return S.Diag(Loc, diag::err_array_designator_negative)
2746 << Value.toString(10) << Index->getSourceRange();
2747
2748 Value.setIsUnsigned(true);
2749 return Result;
2750 }
2751
ActOnDesignatedInitializer(Designation & Desig,SourceLocation Loc,bool GNUSyntax,ExprResult Init)2752 ExprResult Sema::ActOnDesignatedInitializer(Designation &Desig,
2753 SourceLocation Loc,
2754 bool GNUSyntax,
2755 ExprResult Init) {
2756 typedef DesignatedInitExpr::Designator ASTDesignator;
2757
2758 bool Invalid = false;
2759 SmallVector<ASTDesignator, 32> Designators;
2760 SmallVector<Expr *, 32> InitExpressions;
2761
2762 // Build designators and check array designator expressions.
2763 for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) {
2764 const Designator &D = Desig.getDesignator(Idx);
2765 switch (D.getKind()) {
2766 case Designator::FieldDesignator:
2767 Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(),
2768 D.getFieldLoc()));
2769 break;
2770
2771 case Designator::ArrayDesignator: {
2772 Expr *Index = static_cast<Expr *>(D.getArrayIndex());
2773 llvm::APSInt IndexValue;
2774 if (!Index->isTypeDependent() && !Index->isValueDependent())
2775 Index = CheckArrayDesignatorExpr(*this, Index, IndexValue).get();
2776 if (!Index)
2777 Invalid = true;
2778 else {
2779 Designators.push_back(ASTDesignator(InitExpressions.size(),
2780 D.getLBracketLoc(),
2781 D.getRBracketLoc()));
2782 InitExpressions.push_back(Index);
2783 }
2784 break;
2785 }
2786
2787 case Designator::ArrayRangeDesignator: {
2788 Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart());
2789 Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd());
2790 llvm::APSInt StartValue;
2791 llvm::APSInt EndValue;
2792 bool StartDependent = StartIndex->isTypeDependent() ||
2793 StartIndex->isValueDependent();
2794 bool EndDependent = EndIndex->isTypeDependent() ||
2795 EndIndex->isValueDependent();
2796 if (!StartDependent)
2797 StartIndex =
2798 CheckArrayDesignatorExpr(*this, StartIndex, StartValue).get();
2799 if (!EndDependent)
2800 EndIndex = CheckArrayDesignatorExpr(*this, EndIndex, EndValue).get();
2801
2802 if (!StartIndex || !EndIndex)
2803 Invalid = true;
2804 else {
2805 // Make sure we're comparing values with the same bit width.
2806 if (StartDependent || EndDependent) {
2807 // Nothing to compute.
2808 } else if (StartValue.getBitWidth() > EndValue.getBitWidth())
2809 EndValue = EndValue.extend(StartValue.getBitWidth());
2810 else if (StartValue.getBitWidth() < EndValue.getBitWidth())
2811 StartValue = StartValue.extend(EndValue.getBitWidth());
2812
2813 if (!StartDependent && !EndDependent && EndValue < StartValue) {
2814 Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range)
2815 << StartValue.toString(10) << EndValue.toString(10)
2816 << StartIndex->getSourceRange() << EndIndex->getSourceRange();
2817 Invalid = true;
2818 } else {
2819 Designators.push_back(ASTDesignator(InitExpressions.size(),
2820 D.getLBracketLoc(),
2821 D.getEllipsisLoc(),
2822 D.getRBracketLoc()));
2823 InitExpressions.push_back(StartIndex);
2824 InitExpressions.push_back(EndIndex);
2825 }
2826 }
2827 break;
2828 }
2829 }
2830 }
2831
2832 if (Invalid || Init.isInvalid())
2833 return ExprError();
2834
2835 // Clear out the expressions within the designation.
2836 Desig.ClearExprs(*this);
2837
2838 DesignatedInitExpr *DIE
2839 = DesignatedInitExpr::Create(Context,
2840 Designators,
2841 InitExpressions, Loc, GNUSyntax,
2842 Init.getAs<Expr>());
2843
2844 if (!getLangOpts().C99)
2845 Diag(DIE->getLocStart(), diag::ext_designated_init)
2846 << DIE->getSourceRange();
2847
2848 return DIE;
2849 }
2850
2851 //===----------------------------------------------------------------------===//
2852 // Initialization entity
2853 //===----------------------------------------------------------------------===//
2854
InitializedEntity(ASTContext & Context,unsigned Index,const InitializedEntity & Parent)2855 InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index,
2856 const InitializedEntity &Parent)
2857 : Parent(&Parent), Index(Index)
2858 {
2859 if (const ArrayType *AT = Context.getAsArrayType(Parent.getType())) {
2860 Kind = EK_ArrayElement;
2861 Type = AT->getElementType();
2862 } else if (const VectorType *VT = Parent.getType()->getAs<VectorType>()) {
2863 Kind = EK_VectorElement;
2864 Type = VT->getElementType();
2865 } else {
2866 const ComplexType *CT = Parent.getType()->getAs<ComplexType>();
2867 assert(CT && "Unexpected type");
2868 Kind = EK_ComplexElement;
2869 Type = CT->getElementType();
2870 }
2871 }
2872
2873 InitializedEntity
InitializeBase(ASTContext & Context,const CXXBaseSpecifier * Base,bool IsInheritedVirtualBase,const InitializedEntity * Parent)2874 InitializedEntity::InitializeBase(ASTContext &Context,
2875 const CXXBaseSpecifier *Base,
2876 bool IsInheritedVirtualBase,
2877 const InitializedEntity *Parent) {
2878 InitializedEntity Result;
2879 Result.Kind = EK_Base;
2880 Result.Parent = Parent;
2881 Result.Base = reinterpret_cast<uintptr_t>(Base);
2882 if (IsInheritedVirtualBase)
2883 Result.Base |= 0x01;
2884
2885 Result.Type = Base->getType();
2886 return Result;
2887 }
2888
getName() const2889 DeclarationName InitializedEntity::getName() const {
2890 switch (getKind()) {
2891 case EK_Parameter:
2892 case EK_Parameter_CF_Audited: {
2893 ParmVarDecl *D = reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1);
2894 return (D ? D->getDeclName() : DeclarationName());
2895 }
2896
2897 case EK_Variable:
2898 case EK_Member:
2899 return VariableOrMember->getDeclName();
2900
2901 case EK_LambdaCapture:
2902 return DeclarationName(Capture.VarID);
2903
2904 case EK_Result:
2905 case EK_Exception:
2906 case EK_New:
2907 case EK_Temporary:
2908 case EK_Base:
2909 case EK_Delegating:
2910 case EK_ArrayElement:
2911 case EK_VectorElement:
2912 case EK_ComplexElement:
2913 case EK_BlockElement:
2914 case EK_CompoundLiteralInit:
2915 case EK_RelatedResult:
2916 return DeclarationName();
2917 }
2918
2919 llvm_unreachable("Invalid EntityKind!");
2920 }
2921
getDecl() const2922 DeclaratorDecl *InitializedEntity::getDecl() const {
2923 switch (getKind()) {
2924 case EK_Variable:
2925 case EK_Member:
2926 return VariableOrMember;
2927
2928 case EK_Parameter:
2929 case EK_Parameter_CF_Audited:
2930 return reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1);
2931
2932 case EK_Result:
2933 case EK_Exception:
2934 case EK_New:
2935 case EK_Temporary:
2936 case EK_Base:
2937 case EK_Delegating:
2938 case EK_ArrayElement:
2939 case EK_VectorElement:
2940 case EK_ComplexElement:
2941 case EK_BlockElement:
2942 case EK_LambdaCapture:
2943 case EK_CompoundLiteralInit:
2944 case EK_RelatedResult:
2945 return nullptr;
2946 }
2947
2948 llvm_unreachable("Invalid EntityKind!");
2949 }
2950
allowsNRVO() const2951 bool InitializedEntity::allowsNRVO() const {
2952 switch (getKind()) {
2953 case EK_Result:
2954 case EK_Exception:
2955 return LocAndNRVO.NRVO;
2956
2957 case EK_Variable:
2958 case EK_Parameter:
2959 case EK_Parameter_CF_Audited:
2960 case EK_Member:
2961 case EK_New:
2962 case EK_Temporary:
2963 case EK_CompoundLiteralInit:
2964 case EK_Base:
2965 case EK_Delegating:
2966 case EK_ArrayElement:
2967 case EK_VectorElement:
2968 case EK_ComplexElement:
2969 case EK_BlockElement:
2970 case EK_LambdaCapture:
2971 case EK_RelatedResult:
2972 break;
2973 }
2974
2975 return false;
2976 }
2977
dumpImpl(raw_ostream & OS) const2978 unsigned InitializedEntity::dumpImpl(raw_ostream &OS) const {
2979 assert(getParent() != this);
2980 unsigned Depth = getParent() ? getParent()->dumpImpl(OS) : 0;
2981 for (unsigned I = 0; I != Depth; ++I)
2982 OS << "`-";
2983
2984 switch (getKind()) {
2985 case EK_Variable: OS << "Variable"; break;
2986 case EK_Parameter: OS << "Parameter"; break;
2987 case EK_Parameter_CF_Audited: OS << "CF audited function Parameter";
2988 break;
2989 case EK_Result: OS << "Result"; break;
2990 case EK_Exception: OS << "Exception"; break;
2991 case EK_Member: OS << "Member"; break;
2992 case EK_New: OS << "New"; break;
2993 case EK_Temporary: OS << "Temporary"; break;
2994 case EK_CompoundLiteralInit: OS << "CompoundLiteral";break;
2995 case EK_RelatedResult: OS << "RelatedResult"; break;
2996 case EK_Base: OS << "Base"; break;
2997 case EK_Delegating: OS << "Delegating"; break;
2998 case EK_ArrayElement: OS << "ArrayElement " << Index; break;
2999 case EK_VectorElement: OS << "VectorElement " << Index; break;
3000 case EK_ComplexElement: OS << "ComplexElement " << Index; break;
3001 case EK_BlockElement: OS << "Block"; break;
3002 case EK_LambdaCapture:
3003 OS << "LambdaCapture ";
3004 OS << DeclarationName(Capture.VarID);
3005 break;
3006 }
3007
3008 if (Decl *D = getDecl()) {
3009 OS << " ";
3010 cast<NamedDecl>(D)->printQualifiedName(OS);
3011 }
3012
3013 OS << " '" << getType().getAsString() << "'\n";
3014
3015 return Depth + 1;
3016 }
3017
dump() const3018 LLVM_DUMP_METHOD void InitializedEntity::dump() const {
3019 dumpImpl(llvm::errs());
3020 }
3021
3022 //===----------------------------------------------------------------------===//
3023 // Initialization sequence
3024 //===----------------------------------------------------------------------===//
3025
Destroy()3026 void InitializationSequence::Step::Destroy() {
3027 switch (Kind) {
3028 case SK_ResolveAddressOfOverloadedFunction:
3029 case SK_CastDerivedToBaseRValue:
3030 case SK_CastDerivedToBaseXValue:
3031 case SK_CastDerivedToBaseLValue:
3032 case SK_BindReference:
3033 case SK_BindReferenceToTemporary:
3034 case SK_ExtraneousCopyToTemporary:
3035 case SK_UserConversion:
3036 case SK_QualificationConversionRValue:
3037 case SK_QualificationConversionXValue:
3038 case SK_QualificationConversionLValue:
3039 case SK_AtomicConversion:
3040 case SK_LValueToRValue:
3041 case SK_ListInitialization:
3042 case SK_UnwrapInitList:
3043 case SK_RewrapInitList:
3044 case SK_ConstructorInitialization:
3045 case SK_ConstructorInitializationFromList:
3046 case SK_ZeroInitialization:
3047 case SK_CAssignment:
3048 case SK_StringInit:
3049 case SK_ObjCObjectConversion:
3050 case SK_ArrayInit:
3051 case SK_ParenthesizedArrayInit:
3052 case SK_PassByIndirectCopyRestore:
3053 case SK_PassByIndirectRestore:
3054 case SK_ProduceObjCObject:
3055 case SK_StdInitializerList:
3056 case SK_StdInitializerListConstructorCall:
3057 case SK_OCLSamplerInit:
3058 case SK_OCLZeroEvent:
3059 break;
3060
3061 case SK_ConversionSequence:
3062 case SK_ConversionSequenceNoNarrowing:
3063 delete ICS;
3064 }
3065 }
3066
isDirectReferenceBinding() const3067 bool InitializationSequence::isDirectReferenceBinding() const {
3068 return !Steps.empty() && Steps.back().Kind == SK_BindReference;
3069 }
3070
isAmbiguous() const3071 bool InitializationSequence::isAmbiguous() const {
3072 if (!Failed())
3073 return false;
3074
3075 switch (getFailureKind()) {
3076 case FK_TooManyInitsForReference:
3077 case FK_ArrayNeedsInitList:
3078 case FK_ArrayNeedsInitListOrStringLiteral:
3079 case FK_ArrayNeedsInitListOrWideStringLiteral:
3080 case FK_NarrowStringIntoWideCharArray:
3081 case FK_WideStringIntoCharArray:
3082 case FK_IncompatWideStringIntoWideChar:
3083 case FK_AddressOfOverloadFailed: // FIXME: Could do better
3084 case FK_NonConstLValueReferenceBindingToTemporary:
3085 case FK_NonConstLValueReferenceBindingToUnrelated:
3086 case FK_RValueReferenceBindingToLValue:
3087 case FK_ReferenceInitDropsQualifiers:
3088 case FK_ReferenceInitFailed:
3089 case FK_ConversionFailed:
3090 case FK_ConversionFromPropertyFailed:
3091 case FK_TooManyInitsForScalar:
3092 case FK_ReferenceBindingToInitList:
3093 case FK_InitListBadDestinationType:
3094 case FK_DefaultInitOfConst:
3095 case FK_Incomplete:
3096 case FK_ArrayTypeMismatch:
3097 case FK_NonConstantArrayInit:
3098 case FK_ListInitializationFailed:
3099 case FK_VariableLengthArrayHasInitializer:
3100 case FK_PlaceholderType:
3101 case FK_ExplicitConstructor:
3102 case FK_AddressOfUnaddressableFunction:
3103 return false;
3104
3105 case FK_ReferenceInitOverloadFailed:
3106 case FK_UserConversionOverloadFailed:
3107 case FK_ConstructorOverloadFailed:
3108 case FK_ListConstructorOverloadFailed:
3109 return FailedOverloadResult == OR_Ambiguous;
3110 }
3111
3112 llvm_unreachable("Invalid EntityKind!");
3113 }
3114
isConstructorInitialization() const3115 bool InitializationSequence::isConstructorInitialization() const {
3116 return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization;
3117 }
3118
3119 void
3120 InitializationSequence
AddAddressOverloadResolutionStep(FunctionDecl * Function,DeclAccessPair Found,bool HadMultipleCandidates)3121 ::AddAddressOverloadResolutionStep(FunctionDecl *Function,
3122 DeclAccessPair Found,
3123 bool HadMultipleCandidates) {
3124 Step S;
3125 S.Kind = SK_ResolveAddressOfOverloadedFunction;
3126 S.Type = Function->getType();
3127 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3128 S.Function.Function = Function;
3129 S.Function.FoundDecl = Found;
3130 Steps.push_back(S);
3131 }
3132
AddDerivedToBaseCastStep(QualType BaseType,ExprValueKind VK)3133 void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType,
3134 ExprValueKind VK) {
3135 Step S;
3136 switch (VK) {
3137 case VK_RValue: S.Kind = SK_CastDerivedToBaseRValue; break;
3138 case VK_XValue: S.Kind = SK_CastDerivedToBaseXValue; break;
3139 case VK_LValue: S.Kind = SK_CastDerivedToBaseLValue; break;
3140 }
3141 S.Type = BaseType;
3142 Steps.push_back(S);
3143 }
3144
AddReferenceBindingStep(QualType T,bool BindingTemporary)3145 void InitializationSequence::AddReferenceBindingStep(QualType T,
3146 bool BindingTemporary) {
3147 Step S;
3148 S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference;
3149 S.Type = T;
3150 Steps.push_back(S);
3151 }
3152
AddExtraneousCopyToTemporary(QualType T)3153 void InitializationSequence::AddExtraneousCopyToTemporary(QualType T) {
3154 Step S;
3155 S.Kind = SK_ExtraneousCopyToTemporary;
3156 S.Type = T;
3157 Steps.push_back(S);
3158 }
3159
3160 void
AddUserConversionStep(FunctionDecl * Function,DeclAccessPair FoundDecl,QualType T,bool HadMultipleCandidates)3161 InitializationSequence::AddUserConversionStep(FunctionDecl *Function,
3162 DeclAccessPair FoundDecl,
3163 QualType T,
3164 bool HadMultipleCandidates) {
3165 Step S;
3166 S.Kind = SK_UserConversion;
3167 S.Type = T;
3168 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3169 S.Function.Function = Function;
3170 S.Function.FoundDecl = FoundDecl;
3171 Steps.push_back(S);
3172 }
3173
AddQualificationConversionStep(QualType Ty,ExprValueKind VK)3174 void InitializationSequence::AddQualificationConversionStep(QualType Ty,
3175 ExprValueKind VK) {
3176 Step S;
3177 S.Kind = SK_QualificationConversionRValue; // work around a gcc warning
3178 switch (VK) {
3179 case VK_RValue:
3180 S.Kind = SK_QualificationConversionRValue;
3181 break;
3182 case VK_XValue:
3183 S.Kind = SK_QualificationConversionXValue;
3184 break;
3185 case VK_LValue:
3186 S.Kind = SK_QualificationConversionLValue;
3187 break;
3188 }
3189 S.Type = Ty;
3190 Steps.push_back(S);
3191 }
3192
AddAtomicConversionStep(QualType Ty)3193 void InitializationSequence::AddAtomicConversionStep(QualType Ty) {
3194 Step S;
3195 S.Kind = SK_AtomicConversion;
3196 S.Type = Ty;
3197 Steps.push_back(S);
3198 }
3199
AddLValueToRValueStep(QualType Ty)3200 void InitializationSequence::AddLValueToRValueStep(QualType Ty) {
3201 assert(!Ty.hasQualifiers() && "rvalues may not have qualifiers");
3202
3203 Step S;
3204 S.Kind = SK_LValueToRValue;
3205 S.Type = Ty;
3206 Steps.push_back(S);
3207 }
3208
AddConversionSequenceStep(const ImplicitConversionSequence & ICS,QualType T,bool TopLevelOfInitList)3209 void InitializationSequence::AddConversionSequenceStep(
3210 const ImplicitConversionSequence &ICS, QualType T,
3211 bool TopLevelOfInitList) {
3212 Step S;
3213 S.Kind = TopLevelOfInitList ? SK_ConversionSequenceNoNarrowing
3214 : SK_ConversionSequence;
3215 S.Type = T;
3216 S.ICS = new ImplicitConversionSequence(ICS);
3217 Steps.push_back(S);
3218 }
3219
AddListInitializationStep(QualType T)3220 void InitializationSequence::AddListInitializationStep(QualType T) {
3221 Step S;
3222 S.Kind = SK_ListInitialization;
3223 S.Type = T;
3224 Steps.push_back(S);
3225 }
3226
AddConstructorInitializationStep(DeclAccessPair FoundDecl,CXXConstructorDecl * Constructor,QualType T,bool HadMultipleCandidates,bool FromInitList,bool AsInitList)3227 void InitializationSequence::AddConstructorInitializationStep(
3228 DeclAccessPair FoundDecl, CXXConstructorDecl *Constructor, QualType T,
3229 bool HadMultipleCandidates, bool FromInitList, bool AsInitList) {
3230 Step S;
3231 S.Kind = FromInitList ? AsInitList ? SK_StdInitializerListConstructorCall
3232 : SK_ConstructorInitializationFromList
3233 : SK_ConstructorInitialization;
3234 S.Type = T;
3235 S.Function.HadMultipleCandidates = HadMultipleCandidates;
3236 S.Function.Function = Constructor;
3237 S.Function.FoundDecl = FoundDecl;
3238 Steps.push_back(S);
3239 }
3240
AddZeroInitializationStep(QualType T)3241 void InitializationSequence::AddZeroInitializationStep(QualType T) {
3242 Step S;
3243 S.Kind = SK_ZeroInitialization;
3244 S.Type = T;
3245 Steps.push_back(S);
3246 }
3247
AddCAssignmentStep(QualType T)3248 void InitializationSequence::AddCAssignmentStep(QualType T) {
3249 Step S;
3250 S.Kind = SK_CAssignment;
3251 S.Type = T;
3252 Steps.push_back(S);
3253 }
3254
AddStringInitStep(QualType T)3255 void InitializationSequence::AddStringInitStep(QualType T) {
3256 Step S;
3257 S.Kind = SK_StringInit;
3258 S.Type = T;
3259 Steps.push_back(S);
3260 }
3261
AddObjCObjectConversionStep(QualType T)3262 void InitializationSequence::AddObjCObjectConversionStep(QualType T) {
3263 Step S;
3264 S.Kind = SK_ObjCObjectConversion;
3265 S.Type = T;
3266 Steps.push_back(S);
3267 }
3268
AddArrayInitStep(QualType T)3269 void InitializationSequence::AddArrayInitStep(QualType T) {
3270 Step S;
3271 S.Kind = SK_ArrayInit;
3272 S.Type = T;
3273 Steps.push_back(S);
3274 }
3275
AddParenthesizedArrayInitStep(QualType T)3276 void InitializationSequence::AddParenthesizedArrayInitStep(QualType T) {
3277 Step S;
3278 S.Kind = SK_ParenthesizedArrayInit;
3279 S.Type = T;
3280 Steps.push_back(S);
3281 }
3282
AddPassByIndirectCopyRestoreStep(QualType type,bool shouldCopy)3283 void InitializationSequence::AddPassByIndirectCopyRestoreStep(QualType type,
3284 bool shouldCopy) {
3285 Step s;
3286 s.Kind = (shouldCopy ? SK_PassByIndirectCopyRestore
3287 : SK_PassByIndirectRestore);
3288 s.Type = type;
3289 Steps.push_back(s);
3290 }
3291
AddProduceObjCObjectStep(QualType T)3292 void InitializationSequence::AddProduceObjCObjectStep(QualType T) {
3293 Step S;
3294 S.Kind = SK_ProduceObjCObject;
3295 S.Type = T;
3296 Steps.push_back(S);
3297 }
3298
AddStdInitializerListConstructionStep(QualType T)3299 void InitializationSequence::AddStdInitializerListConstructionStep(QualType T) {
3300 Step S;
3301 S.Kind = SK_StdInitializerList;
3302 S.Type = T;
3303 Steps.push_back(S);
3304 }
3305
AddOCLSamplerInitStep(QualType T)3306 void InitializationSequence::AddOCLSamplerInitStep(QualType T) {
3307 Step S;
3308 S.Kind = SK_OCLSamplerInit;
3309 S.Type = T;
3310 Steps.push_back(S);
3311 }
3312
AddOCLZeroEventStep(QualType T)3313 void InitializationSequence::AddOCLZeroEventStep(QualType T) {
3314 Step S;
3315 S.Kind = SK_OCLZeroEvent;
3316 S.Type = T;
3317 Steps.push_back(S);
3318 }
3319
RewrapReferenceInitList(QualType T,InitListExpr * Syntactic)3320 void InitializationSequence::RewrapReferenceInitList(QualType T,
3321 InitListExpr *Syntactic) {
3322 assert(Syntactic->getNumInits() == 1 &&
3323 "Can only rewrap trivial init lists.");
3324 Step S;
3325 S.Kind = SK_UnwrapInitList;
3326 S.Type = Syntactic->getInit(0)->getType();
3327 Steps.insert(Steps.begin(), S);
3328
3329 S.Kind = SK_RewrapInitList;
3330 S.Type = T;
3331 S.WrappingSyntacticList = Syntactic;
3332 Steps.push_back(S);
3333 }
3334
SetOverloadFailure(FailureKind Failure,OverloadingResult Result)3335 void InitializationSequence::SetOverloadFailure(FailureKind Failure,
3336 OverloadingResult Result) {
3337 setSequenceKind(FailedSequence);
3338 this->Failure = Failure;
3339 this->FailedOverloadResult = Result;
3340 }
3341
3342 //===----------------------------------------------------------------------===//
3343 // Attempt initialization
3344 //===----------------------------------------------------------------------===//
3345
3346 /// Tries to add a zero initializer. Returns true if that worked.
3347 static bool
maybeRecoverWithZeroInitialization(Sema & S,InitializationSequence & Sequence,const InitializedEntity & Entity)3348 maybeRecoverWithZeroInitialization(Sema &S, InitializationSequence &Sequence,
3349 const InitializedEntity &Entity) {
3350 if (Entity.getKind() != InitializedEntity::EK_Variable)
3351 return false;
3352
3353 VarDecl *VD = cast<VarDecl>(Entity.getDecl());
3354 if (VD->getInit() || VD->getLocEnd().isMacroID())
3355 return false;
3356
3357 QualType VariableTy = VD->getType().getCanonicalType();
3358 SourceLocation Loc = S.getLocForEndOfToken(VD->getLocEnd());
3359 std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc);
3360 if (!Init.empty()) {
3361 Sequence.AddZeroInitializationStep(Entity.getType());
3362 Sequence.SetZeroInitializationFixit(Init, Loc);
3363 return true;
3364 }
3365 return false;
3366 }
3367
MaybeProduceObjCObject(Sema & S,InitializationSequence & Sequence,const InitializedEntity & Entity)3368 static void MaybeProduceObjCObject(Sema &S,
3369 InitializationSequence &Sequence,
3370 const InitializedEntity &Entity) {
3371 if (!S.getLangOpts().ObjCAutoRefCount) return;
3372
3373 /// When initializing a parameter, produce the value if it's marked
3374 /// __attribute__((ns_consumed)).
3375 if (Entity.isParameterKind()) {
3376 if (!Entity.isParameterConsumed())
3377 return;
3378
3379 assert(Entity.getType()->isObjCRetainableType() &&
3380 "consuming an object of unretainable type?");
3381 Sequence.AddProduceObjCObjectStep(Entity.getType());
3382
3383 /// When initializing a return value, if the return type is a
3384 /// retainable type, then returns need to immediately retain the
3385 /// object. If an autorelease is required, it will be done at the
3386 /// last instant.
3387 } else if (Entity.getKind() == InitializedEntity::EK_Result) {
3388 if (!Entity.getType()->isObjCRetainableType())
3389 return;
3390
3391 Sequence.AddProduceObjCObjectStep(Entity.getType());
3392 }
3393 }
3394
3395 static void TryListInitialization(Sema &S,
3396 const InitializedEntity &Entity,
3397 const InitializationKind &Kind,
3398 InitListExpr *InitList,
3399 InitializationSequence &Sequence,
3400 bool TreatUnavailableAsInvalid);
3401
3402 /// \brief When initializing from init list via constructor, handle
3403 /// initialization of an object of type std::initializer_list<T>.
3404 ///
3405 /// \return true if we have handled initialization of an object of type
3406 /// std::initializer_list<T>, false otherwise.
TryInitializerListConstruction(Sema & S,InitListExpr * List,QualType DestType,InitializationSequence & Sequence,bool TreatUnavailableAsInvalid)3407 static bool TryInitializerListConstruction(Sema &S,
3408 InitListExpr *List,
3409 QualType DestType,
3410 InitializationSequence &Sequence,
3411 bool TreatUnavailableAsInvalid) {
3412 QualType E;
3413 if (!S.isStdInitializerList(DestType, &E))
3414 return false;
3415
3416 if (!S.isCompleteType(List->getExprLoc(), E)) {
3417 Sequence.setIncompleteTypeFailure(E);
3418 return true;
3419 }
3420
3421 // Try initializing a temporary array from the init list.
3422 QualType ArrayType = S.Context.getConstantArrayType(
3423 E.withConst(), llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
3424 List->getNumInits()),
3425 clang::ArrayType::Normal, 0);
3426 InitializedEntity HiddenArray =
3427 InitializedEntity::InitializeTemporary(ArrayType);
3428 InitializationKind Kind =
3429 InitializationKind::CreateDirectList(List->getExprLoc());
3430 TryListInitialization(S, HiddenArray, Kind, List, Sequence,
3431 TreatUnavailableAsInvalid);
3432 if (Sequence)
3433 Sequence.AddStdInitializerListConstructionStep(DestType);
3434 return true;
3435 }
3436
3437 static OverloadingResult
ResolveConstructorOverload(Sema & S,SourceLocation DeclLoc,MultiExprArg Args,OverloadCandidateSet & CandidateSet,DeclContext::lookup_result Ctors,OverloadCandidateSet::iterator & Best,bool CopyInitializing,bool AllowExplicit,bool OnlyListConstructors,bool IsListInit)3438 ResolveConstructorOverload(Sema &S, SourceLocation DeclLoc,
3439 MultiExprArg Args,
3440 OverloadCandidateSet &CandidateSet,
3441 DeclContext::lookup_result Ctors,
3442 OverloadCandidateSet::iterator &Best,
3443 bool CopyInitializing, bool AllowExplicit,
3444 bool OnlyListConstructors, bool IsListInit) {
3445 CandidateSet.clear();
3446
3447 for (NamedDecl *D : Ctors) {
3448 auto Info = getConstructorInfo(D);
3449 if (!Info.Constructor)
3450 continue;
3451
3452 bool SuppressUserConversions = false;
3453
3454 if (!Info.ConstructorTmpl) {
3455 // C++11 [over.best.ics]p4:
3456 // ... and the constructor or user-defined conversion function is a
3457 // candidate by
3458 // - 13.3.1.3, when the argument is the temporary in the second step
3459 // of a class copy-initialization, or
3460 // - 13.3.1.4, 13.3.1.5, or 13.3.1.6 (in all cases),
3461 // user-defined conversion sequences are not considered.
3462 // FIXME: This breaks backward compatibility, e.g. PR12117. As a
3463 // temporary fix, let's re-instate the third bullet above until
3464 // there is a resolution in the standard, i.e.,
3465 // - 13.3.1.7 when the initializer list has exactly one element that is
3466 // itself an initializer list and a conversion to some class X or
3467 // reference to (possibly cv-qualified) X is considered for the first
3468 // parameter of a constructor of X.
3469 if ((CopyInitializing ||
3470 (IsListInit && Args.size() == 1 && isa<InitListExpr>(Args[0]))) &&
3471 Info.Constructor->isCopyOrMoveConstructor())
3472 SuppressUserConversions = true;
3473 }
3474
3475 if (!Info.Constructor->isInvalidDecl() &&
3476 (AllowExplicit || !Info.Constructor->isExplicit()) &&
3477 (!OnlyListConstructors || S.isInitListConstructor(Info.Constructor))) {
3478 if (Info.ConstructorTmpl)
3479 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3480 /*ExplicitArgs*/ nullptr, Args,
3481 CandidateSet, SuppressUserConversions);
3482 else {
3483 // C++ [over.match.copy]p1:
3484 // - When initializing a temporary to be bound to the first parameter
3485 // of a constructor that takes a reference to possibly cv-qualified
3486 // T as its first argument, called with a single argument in the
3487 // context of direct-initialization, explicit conversion functions
3488 // are also considered.
3489 bool AllowExplicitConv = AllowExplicit && !CopyInitializing &&
3490 Args.size() == 1 &&
3491 Info.Constructor->isCopyOrMoveConstructor();
3492 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl, Args,
3493 CandidateSet, SuppressUserConversions,
3494 /*PartialOverloading=*/false,
3495 /*AllowExplicit=*/AllowExplicitConv);
3496 }
3497 }
3498 }
3499
3500 // Perform overload resolution and return the result.
3501 return CandidateSet.BestViableFunction(S, DeclLoc, Best);
3502 }
3503
3504 /// \brief Attempt initialization by constructor (C++ [dcl.init]), which
3505 /// enumerates the constructors of the initialized entity and performs overload
3506 /// resolution to select the best.
3507 /// \param IsListInit Is this list-initialization?
3508 /// \param IsInitListCopy Is this non-list-initialization resulting from a
3509 /// list-initialization from {x} where x is the same
3510 /// type as the entity?
TryConstructorInitialization(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,MultiExprArg Args,QualType DestType,InitializationSequence & Sequence,bool IsListInit=false,bool IsInitListCopy=false)3511 static void TryConstructorInitialization(Sema &S,
3512 const InitializedEntity &Entity,
3513 const InitializationKind &Kind,
3514 MultiExprArg Args, QualType DestType,
3515 InitializationSequence &Sequence,
3516 bool IsListInit = false,
3517 bool IsInitListCopy = false) {
3518 assert((!IsListInit || (Args.size() == 1 && isa<InitListExpr>(Args[0]))) &&
3519 "IsListInit must come with a single initializer list argument.");
3520
3521 // The type we're constructing needs to be complete.
3522 if (!S.isCompleteType(Kind.getLocation(), DestType)) {
3523 Sequence.setIncompleteTypeFailure(DestType);
3524 return;
3525 }
3526
3527 const RecordType *DestRecordType = DestType->getAs<RecordType>();
3528 assert(DestRecordType && "Constructor initialization requires record type");
3529 CXXRecordDecl *DestRecordDecl
3530 = cast<CXXRecordDecl>(DestRecordType->getDecl());
3531
3532 // Build the candidate set directly in the initialization sequence
3533 // structure, so that it will persist if we fail.
3534 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
3535
3536 // Determine whether we are allowed to call explicit constructors or
3537 // explicit conversion operators.
3538 bool AllowExplicit = Kind.AllowExplicit() || IsListInit;
3539 bool CopyInitialization = Kind.getKind() == InitializationKind::IK_Copy;
3540
3541 // - Otherwise, if T is a class type, constructors are considered. The
3542 // applicable constructors are enumerated, and the best one is chosen
3543 // through overload resolution.
3544 DeclContext::lookup_result Ctors = S.LookupConstructors(DestRecordDecl);
3545
3546 OverloadingResult Result = OR_No_Viable_Function;
3547 OverloadCandidateSet::iterator Best;
3548 bool AsInitializerList = false;
3549
3550 // C++11 [over.match.list]p1, per DR1467:
3551 // When objects of non-aggregate type T are list-initialized, such that
3552 // 8.5.4 [dcl.init.list] specifies that overload resolution is performed
3553 // according to the rules in this section, overload resolution selects
3554 // the constructor in two phases:
3555 //
3556 // - Initially, the candidate functions are the initializer-list
3557 // constructors of the class T and the argument list consists of the
3558 // initializer list as a single argument.
3559 if (IsListInit) {
3560 InitListExpr *ILE = cast<InitListExpr>(Args[0]);
3561 AsInitializerList = true;
3562
3563 // If the initializer list has no elements and T has a default constructor,
3564 // the first phase is omitted.
3565 if (ILE->getNumInits() != 0 || !DestRecordDecl->hasDefaultConstructor())
3566 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args,
3567 CandidateSet, Ctors, Best,
3568 CopyInitialization, AllowExplicit,
3569 /*OnlyListConstructor=*/true,
3570 IsListInit);
3571
3572 // Time to unwrap the init list.
3573 Args = MultiExprArg(ILE->getInits(), ILE->getNumInits());
3574 }
3575
3576 // C++11 [over.match.list]p1:
3577 // - If no viable initializer-list constructor is found, overload resolution
3578 // is performed again, where the candidate functions are all the
3579 // constructors of the class T and the argument list consists of the
3580 // elements of the initializer list.
3581 if (Result == OR_No_Viable_Function) {
3582 AsInitializerList = false;
3583 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args,
3584 CandidateSet, Ctors, Best,
3585 CopyInitialization, AllowExplicit,
3586 /*OnlyListConstructors=*/false,
3587 IsListInit);
3588 }
3589 if (Result) {
3590 Sequence.SetOverloadFailure(IsListInit ?
3591 InitializationSequence::FK_ListConstructorOverloadFailed :
3592 InitializationSequence::FK_ConstructorOverloadFailed,
3593 Result);
3594 return;
3595 }
3596
3597 // C++11 [dcl.init]p6:
3598 // If a program calls for the default initialization of an object
3599 // of a const-qualified type T, T shall be a class type with a
3600 // user-provided default constructor.
3601 // C++ core issue 253 proposal:
3602 // If the implicit default constructor initializes all subobjects, no
3603 // initializer should be required.
3604 // The 253 proposal is for example needed to process libstdc++ headers in 5.x.
3605 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
3606 if (Kind.getKind() == InitializationKind::IK_Default &&
3607 Entity.getType().isConstQualified()) {
3608 if (!CtorDecl->getParent()->allowConstDefaultInit()) {
3609 if (!maybeRecoverWithZeroInitialization(S, Sequence, Entity))
3610 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
3611 return;
3612 }
3613 }
3614
3615 // C++11 [over.match.list]p1:
3616 // In copy-list-initialization, if an explicit constructor is chosen, the
3617 // initializer is ill-formed.
3618 if (IsListInit && !Kind.AllowExplicit() && CtorDecl->isExplicit()) {
3619 Sequence.SetFailed(InitializationSequence::FK_ExplicitConstructor);
3620 return;
3621 }
3622
3623 // Add the constructor initialization step. Any cv-qualification conversion is
3624 // subsumed by the initialization.
3625 bool HadMultipleCandidates = (CandidateSet.size() > 1);
3626 Sequence.AddConstructorInitializationStep(
3627 Best->FoundDecl, CtorDecl, DestType, HadMultipleCandidates,
3628 IsListInit | IsInitListCopy, AsInitializerList);
3629 }
3630
3631 static bool
ResolveOverloadedFunctionForReferenceBinding(Sema & S,Expr * Initializer,QualType & SourceType,QualType & UnqualifiedSourceType,QualType UnqualifiedTargetType,InitializationSequence & Sequence)3632 ResolveOverloadedFunctionForReferenceBinding(Sema &S,
3633 Expr *Initializer,
3634 QualType &SourceType,
3635 QualType &UnqualifiedSourceType,
3636 QualType UnqualifiedTargetType,
3637 InitializationSequence &Sequence) {
3638 if (S.Context.getCanonicalType(UnqualifiedSourceType) ==
3639 S.Context.OverloadTy) {
3640 DeclAccessPair Found;
3641 bool HadMultipleCandidates = false;
3642 if (FunctionDecl *Fn
3643 = S.ResolveAddressOfOverloadedFunction(Initializer,
3644 UnqualifiedTargetType,
3645 false, Found,
3646 &HadMultipleCandidates)) {
3647 Sequence.AddAddressOverloadResolutionStep(Fn, Found,
3648 HadMultipleCandidates);
3649 SourceType = Fn->getType();
3650 UnqualifiedSourceType = SourceType.getUnqualifiedType();
3651 } else if (!UnqualifiedTargetType->isRecordType()) {
3652 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
3653 return true;
3654 }
3655 }
3656 return false;
3657 }
3658
3659 static void TryReferenceInitializationCore(Sema &S,
3660 const InitializedEntity &Entity,
3661 const InitializationKind &Kind,
3662 Expr *Initializer,
3663 QualType cv1T1, QualType T1,
3664 Qualifiers T1Quals,
3665 QualType cv2T2, QualType T2,
3666 Qualifiers T2Quals,
3667 InitializationSequence &Sequence);
3668
3669 static void TryValueInitialization(Sema &S,
3670 const InitializedEntity &Entity,
3671 const InitializationKind &Kind,
3672 InitializationSequence &Sequence,
3673 InitListExpr *InitList = nullptr);
3674
3675 /// \brief Attempt list initialization of a reference.
TryReferenceListInitialization(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,InitListExpr * InitList,InitializationSequence & Sequence,bool TreatUnavailableAsInvalid)3676 static void TryReferenceListInitialization(Sema &S,
3677 const InitializedEntity &Entity,
3678 const InitializationKind &Kind,
3679 InitListExpr *InitList,
3680 InitializationSequence &Sequence,
3681 bool TreatUnavailableAsInvalid) {
3682 // First, catch C++03 where this isn't possible.
3683 if (!S.getLangOpts().CPlusPlus11) {
3684 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
3685 return;
3686 }
3687 // Can't reference initialize a compound literal.
3688 if (Entity.getKind() == InitializedEntity::EK_CompoundLiteralInit) {
3689 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList);
3690 return;
3691 }
3692
3693 QualType DestType = Entity.getType();
3694 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType();
3695 Qualifiers T1Quals;
3696 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
3697
3698 // Reference initialization via an initializer list works thus:
3699 // If the initializer list consists of a single element that is
3700 // reference-related to the referenced type, bind directly to that element
3701 // (possibly creating temporaries).
3702 // Otherwise, initialize a temporary with the initializer list and
3703 // bind to that.
3704 if (InitList->getNumInits() == 1) {
3705 Expr *Initializer = InitList->getInit(0);
3706 QualType cv2T2 = Initializer->getType();
3707 Qualifiers T2Quals;
3708 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);
3709
3710 // If this fails, creating a temporary wouldn't work either.
3711 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
3712 T1, Sequence))
3713 return;
3714
3715 SourceLocation DeclLoc = Initializer->getLocStart();
3716 bool dummy1, dummy2, dummy3;
3717 Sema::ReferenceCompareResult RefRelationship
3718 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, dummy1,
3719 dummy2, dummy3);
3720 if (RefRelationship >= Sema::Ref_Related) {
3721 // Try to bind the reference here.
3722 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
3723 T1Quals, cv2T2, T2, T2Quals, Sequence);
3724 if (Sequence)
3725 Sequence.RewrapReferenceInitList(cv1T1, InitList);
3726 return;
3727 }
3728
3729 // Update the initializer if we've resolved an overloaded function.
3730 if (Sequence.step_begin() != Sequence.step_end())
3731 Sequence.RewrapReferenceInitList(cv1T1, InitList);
3732 }
3733
3734 // Not reference-related. Create a temporary and bind to that.
3735 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1);
3736
3737 TryListInitialization(S, TempEntity, Kind, InitList, Sequence,
3738 TreatUnavailableAsInvalid);
3739 if (Sequence) {
3740 if (DestType->isRValueReferenceType() ||
3741 (T1Quals.hasConst() && !T1Quals.hasVolatile()))
3742 Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true);
3743 else
3744 Sequence.SetFailed(
3745 InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary);
3746 }
3747 }
3748
3749 /// \brief Attempt list initialization (C++0x [dcl.init.list])
TryListInitialization(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,InitListExpr * InitList,InitializationSequence & Sequence,bool TreatUnavailableAsInvalid)3750 static void TryListInitialization(Sema &S,
3751 const InitializedEntity &Entity,
3752 const InitializationKind &Kind,
3753 InitListExpr *InitList,
3754 InitializationSequence &Sequence,
3755 bool TreatUnavailableAsInvalid) {
3756 QualType DestType = Entity.getType();
3757
3758 // C++ doesn't allow scalar initialization with more than one argument.
3759 // But C99 complex numbers are scalars and it makes sense there.
3760 if (S.getLangOpts().CPlusPlus && DestType->isScalarType() &&
3761 !DestType->isAnyComplexType() && InitList->getNumInits() > 1) {
3762 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar);
3763 return;
3764 }
3765 if (DestType->isReferenceType()) {
3766 TryReferenceListInitialization(S, Entity, Kind, InitList, Sequence,
3767 TreatUnavailableAsInvalid);
3768 return;
3769 }
3770
3771 if (DestType->isRecordType() &&
3772 !S.isCompleteType(InitList->getLocStart(), DestType)) {
3773 Sequence.setIncompleteTypeFailure(DestType);
3774 return;
3775 }
3776
3777 // C++11 [dcl.init.list]p3, per DR1467:
3778 // - If T is a class type and the initializer list has a single element of
3779 // type cv U, where U is T or a class derived from T, the object is
3780 // initialized from that element (by copy-initialization for
3781 // copy-list-initialization, or by direct-initialization for
3782 // direct-list-initialization).
3783 // - Otherwise, if T is a character array and the initializer list has a
3784 // single element that is an appropriately-typed string literal
3785 // (8.5.2 [dcl.init.string]), initialization is performed as described
3786 // in that section.
3787 // - Otherwise, if T is an aggregate, [...] (continue below).
3788 if (S.getLangOpts().CPlusPlus11 && InitList->getNumInits() == 1) {
3789 if (DestType->isRecordType()) {
3790 QualType InitType = InitList->getInit(0)->getType();
3791 if (S.Context.hasSameUnqualifiedType(InitType, DestType) ||
3792 S.IsDerivedFrom(InitList->getLocStart(), InitType, DestType)) {
3793 Expr *InitAsExpr = InitList->getInit(0);
3794 TryConstructorInitialization(S, Entity, Kind, InitAsExpr, DestType,
3795 Sequence, /*InitListSyntax*/ false,
3796 /*IsInitListCopy*/ true);
3797 return;
3798 }
3799 }
3800 if (const ArrayType *DestAT = S.Context.getAsArrayType(DestType)) {
3801 Expr *SubInit[1] = {InitList->getInit(0)};
3802 if (!isa<VariableArrayType>(DestAT) &&
3803 IsStringInit(SubInit[0], DestAT, S.Context) == SIF_None) {
3804 InitializationKind SubKind =
3805 Kind.getKind() == InitializationKind::IK_DirectList
3806 ? InitializationKind::CreateDirect(Kind.getLocation(),
3807 InitList->getLBraceLoc(),
3808 InitList->getRBraceLoc())
3809 : Kind;
3810 Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
3811 /*TopLevelOfInitList*/ true,
3812 TreatUnavailableAsInvalid);
3813
3814 // TryStringLiteralInitialization() (in InitializeFrom()) will fail if
3815 // the element is not an appropriately-typed string literal, in which
3816 // case we should proceed as in C++11 (below).
3817 if (Sequence) {
3818 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
3819 return;
3820 }
3821 }
3822 }
3823 }
3824
3825 // C++11 [dcl.init.list]p3:
3826 // - If T is an aggregate, aggregate initialization is performed.
3827 if ((DestType->isRecordType() && !DestType->isAggregateType()) ||
3828 (S.getLangOpts().CPlusPlus11 &&
3829 S.isStdInitializerList(DestType, nullptr))) {
3830 if (S.getLangOpts().CPlusPlus11) {
3831 // - Otherwise, if the initializer list has no elements and T is a
3832 // class type with a default constructor, the object is
3833 // value-initialized.
3834 if (InitList->getNumInits() == 0) {
3835 CXXRecordDecl *RD = DestType->getAsCXXRecordDecl();
3836 if (RD->hasDefaultConstructor()) {
3837 TryValueInitialization(S, Entity, Kind, Sequence, InitList);
3838 return;
3839 }
3840 }
3841
3842 // - Otherwise, if T is a specialization of std::initializer_list<E>,
3843 // an initializer_list object constructed [...]
3844 if (TryInitializerListConstruction(S, InitList, DestType, Sequence,
3845 TreatUnavailableAsInvalid))
3846 return;
3847
3848 // - Otherwise, if T is a class type, constructors are considered.
3849 Expr *InitListAsExpr = InitList;
3850 TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType,
3851 Sequence, /*InitListSyntax*/ true);
3852 } else
3853 Sequence.SetFailed(InitializationSequence::FK_InitListBadDestinationType);
3854 return;
3855 }
3856
3857 if (S.getLangOpts().CPlusPlus && !DestType->isAggregateType() &&
3858 InitList->getNumInits() == 1) {
3859 Expr *E = InitList->getInit(0);
3860
3861 // - Otherwise, if T is an enumeration with a fixed underlying type,
3862 // the initializer-list has a single element v, and the initialization
3863 // is direct-list-initialization, the object is initialized with the
3864 // value T(v); if a narrowing conversion is required to convert v to
3865 // the underlying type of T, the program is ill-formed.
3866 auto *ET = DestType->getAs<EnumType>();
3867 if (S.getLangOpts().CPlusPlus1z &&
3868 Kind.getKind() == InitializationKind::IK_DirectList &&
3869 ET && ET->getDecl()->isFixed() &&
3870 !S.Context.hasSameUnqualifiedType(E->getType(), DestType) &&
3871 (E->getType()->isIntegralOrEnumerationType() ||
3872 E->getType()->isFloatingType())) {
3873 // There are two ways that T(v) can work when T is an enumeration type.
3874 // If there is either an implicit conversion sequence from v to T or
3875 // a conversion function that can convert from v to T, then we use that.
3876 // Otherwise, if v is of integral, enumeration, or floating-point type,
3877 // it is converted to the enumeration type via its underlying type.
3878 // There is no overlap possible between these two cases (except when the
3879 // source value is already of the destination type), and the first
3880 // case is handled by the general case for single-element lists below.
3881 ImplicitConversionSequence ICS;
3882 ICS.setStandard();
3883 ICS.Standard.setAsIdentityConversion();
3884 // If E is of a floating-point type, then the conversion is ill-formed
3885 // due to narrowing, but go through the motions in order to produce the
3886 // right diagnostic.
3887 ICS.Standard.Second = E->getType()->isFloatingType()
3888 ? ICK_Floating_Integral
3889 : ICK_Integral_Conversion;
3890 ICS.Standard.setFromType(E->getType());
3891 ICS.Standard.setToType(0, E->getType());
3892 ICS.Standard.setToType(1, DestType);
3893 ICS.Standard.setToType(2, DestType);
3894 Sequence.AddConversionSequenceStep(ICS, ICS.Standard.getToType(2),
3895 /*TopLevelOfInitList*/true);
3896 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
3897 return;
3898 }
3899
3900 // - Otherwise, if the initializer list has a single element of type E
3901 // [...references are handled above...], the object or reference is
3902 // initialized from that element (by copy-initialization for
3903 // copy-list-initialization, or by direct-initialization for
3904 // direct-list-initialization); if a narrowing conversion is required
3905 // to convert the element to T, the program is ill-formed.
3906 //
3907 // Per core-24034, this is direct-initialization if we were performing
3908 // direct-list-initialization and copy-initialization otherwise.
3909 // We can't use InitListChecker for this, because it always performs
3910 // copy-initialization. This only matters if we might use an 'explicit'
3911 // conversion operator, so we only need to handle the cases where the source
3912 // is of record type.
3913 if (InitList->getInit(0)->getType()->isRecordType()) {
3914 InitializationKind SubKind =
3915 Kind.getKind() == InitializationKind::IK_DirectList
3916 ? InitializationKind::CreateDirect(Kind.getLocation(),
3917 InitList->getLBraceLoc(),
3918 InitList->getRBraceLoc())
3919 : Kind;
3920 Expr *SubInit[1] = { InitList->getInit(0) };
3921 Sequence.InitializeFrom(S, Entity, SubKind, SubInit,
3922 /*TopLevelOfInitList*/true,
3923 TreatUnavailableAsInvalid);
3924 if (Sequence)
3925 Sequence.RewrapReferenceInitList(Entity.getType(), InitList);
3926 return;
3927 }
3928 }
3929
3930 InitListChecker CheckInitList(S, Entity, InitList,
3931 DestType, /*VerifyOnly=*/true, TreatUnavailableAsInvalid);
3932 if (CheckInitList.HadError()) {
3933 Sequence.SetFailed(InitializationSequence::FK_ListInitializationFailed);
3934 return;
3935 }
3936
3937 // Add the list initialization step with the built init list.
3938 Sequence.AddListInitializationStep(DestType);
3939 }
3940
3941 /// \brief Try a reference initialization that involves calling a conversion
3942 /// function.
TryRefInitWithConversionFunction(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,Expr * Initializer,bool AllowRValues,InitializationSequence & Sequence)3943 static OverloadingResult TryRefInitWithConversionFunction(Sema &S,
3944 const InitializedEntity &Entity,
3945 const InitializationKind &Kind,
3946 Expr *Initializer,
3947 bool AllowRValues,
3948 InitializationSequence &Sequence) {
3949 QualType DestType = Entity.getType();
3950 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType();
3951 QualType T1 = cv1T1.getUnqualifiedType();
3952 QualType cv2T2 = Initializer->getType();
3953 QualType T2 = cv2T2.getUnqualifiedType();
3954
3955 bool DerivedToBase;
3956 bool ObjCConversion;
3957 bool ObjCLifetimeConversion;
3958 assert(!S.CompareReferenceRelationship(Initializer->getLocStart(),
3959 T1, T2, DerivedToBase,
3960 ObjCConversion,
3961 ObjCLifetimeConversion) &&
3962 "Must have incompatible references when binding via conversion");
3963 (void)DerivedToBase;
3964 (void)ObjCConversion;
3965 (void)ObjCLifetimeConversion;
3966
3967 // Build the candidate set directly in the initialization sequence
3968 // structure, so that it will persist if we fail.
3969 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
3970 CandidateSet.clear();
3971
3972 // Determine whether we are allowed to call explicit constructors or
3973 // explicit conversion operators.
3974 bool AllowExplicit = Kind.AllowExplicit();
3975 bool AllowExplicitConvs = Kind.allowExplicitConversionFunctionsInRefBinding();
3976
3977 const RecordType *T1RecordType = nullptr;
3978 if (AllowRValues && (T1RecordType = T1->getAs<RecordType>()) &&
3979 S.isCompleteType(Kind.getLocation(), T1)) {
3980 // The type we're converting to is a class type. Enumerate its constructors
3981 // to see if there is a suitable conversion.
3982 CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl());
3983
3984 for (NamedDecl *D : S.LookupConstructors(T1RecordDecl)) {
3985 auto Info = getConstructorInfo(D);
3986 if (!Info.Constructor)
3987 continue;
3988
3989 if (!Info.Constructor->isInvalidDecl() &&
3990 Info.Constructor->isConvertingConstructor(AllowExplicit)) {
3991 if (Info.ConstructorTmpl)
3992 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
3993 /*ExplicitArgs*/ nullptr,
3994 Initializer, CandidateSet,
3995 /*SuppressUserConversions=*/true);
3996 else
3997 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
3998 Initializer, CandidateSet,
3999 /*SuppressUserConversions=*/true);
4000 }
4001 }
4002 }
4003 if (T1RecordType && T1RecordType->getDecl()->isInvalidDecl())
4004 return OR_No_Viable_Function;
4005
4006 const RecordType *T2RecordType = nullptr;
4007 if ((T2RecordType = T2->getAs<RecordType>()) &&
4008 S.isCompleteType(Kind.getLocation(), T2)) {
4009 // The type we're converting from is a class type, enumerate its conversion
4010 // functions.
4011 CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl());
4012
4013 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions();
4014 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4015 NamedDecl *D = *I;
4016 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4017 if (isa<UsingShadowDecl>(D))
4018 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4019
4020 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
4021 CXXConversionDecl *Conv;
4022 if (ConvTemplate)
4023 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4024 else
4025 Conv = cast<CXXConversionDecl>(D);
4026
4027 // If the conversion function doesn't return a reference type,
4028 // it can't be considered for this conversion unless we're allowed to
4029 // consider rvalues.
4030 // FIXME: Do we need to make sure that we only consider conversion
4031 // candidates with reference-compatible results? That might be needed to
4032 // break recursion.
4033 if ((AllowExplicitConvs || !Conv->isExplicit()) &&
4034 (AllowRValues || Conv->getConversionType()->isLValueReferenceType())){
4035 if (ConvTemplate)
4036 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(),
4037 ActingDC, Initializer,
4038 DestType, CandidateSet,
4039 /*AllowObjCConversionOnExplicit=*/
4040 false);
4041 else
4042 S.AddConversionCandidate(Conv, I.getPair(), ActingDC,
4043 Initializer, DestType, CandidateSet,
4044 /*AllowObjCConversionOnExplicit=*/false);
4045 }
4046 }
4047 }
4048 if (T2RecordType && T2RecordType->getDecl()->isInvalidDecl())
4049 return OR_No_Viable_Function;
4050
4051 SourceLocation DeclLoc = Initializer->getLocStart();
4052
4053 // Perform overload resolution. If it fails, return the failed result.
4054 OverloadCandidateSet::iterator Best;
4055 if (OverloadingResult Result
4056 = CandidateSet.BestViableFunction(S, DeclLoc, Best, true))
4057 return Result;
4058
4059 FunctionDecl *Function = Best->Function;
4060 // This is the overload that will be used for this initialization step if we
4061 // use this initialization. Mark it as referenced.
4062 Function->setReferenced();
4063
4064 // Compute the returned type of the conversion.
4065 if (isa<CXXConversionDecl>(Function))
4066 T2 = Function->getReturnType();
4067 else
4068 T2 = cv1T1;
4069
4070 // Add the user-defined conversion step.
4071 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4072 Sequence.AddUserConversionStep(Function, Best->FoundDecl,
4073 T2.getNonLValueExprType(S.Context),
4074 HadMultipleCandidates);
4075
4076 // Determine whether we need to perform derived-to-base or
4077 // cv-qualification adjustments.
4078 ExprValueKind VK = VK_RValue;
4079 if (T2->isLValueReferenceType())
4080 VK = VK_LValue;
4081 else if (const RValueReferenceType *RRef = T2->getAs<RValueReferenceType>())
4082 VK = RRef->getPointeeType()->isFunctionType() ? VK_LValue : VK_XValue;
4083
4084 bool NewDerivedToBase = false;
4085 bool NewObjCConversion = false;
4086 bool NewObjCLifetimeConversion = false;
4087 Sema::ReferenceCompareResult NewRefRelationship
4088 = S.CompareReferenceRelationship(DeclLoc, T1,
4089 T2.getNonLValueExprType(S.Context),
4090 NewDerivedToBase, NewObjCConversion,
4091 NewObjCLifetimeConversion);
4092 if (NewRefRelationship == Sema::Ref_Incompatible) {
4093 // If the type we've converted to is not reference-related to the
4094 // type we're looking for, then there is another conversion step
4095 // we need to perform to produce a temporary of the right type
4096 // that we'll be binding to.
4097 ImplicitConversionSequence ICS;
4098 ICS.setStandard();
4099 ICS.Standard = Best->FinalConversion;
4100 T2 = ICS.Standard.getToType(2);
4101 Sequence.AddConversionSequenceStep(ICS, T2);
4102 } else if (NewDerivedToBase)
4103 Sequence.AddDerivedToBaseCastStep(
4104 S.Context.getQualifiedType(T1,
4105 T2.getNonReferenceType().getQualifiers()),
4106 VK);
4107 else if (NewObjCConversion)
4108 Sequence.AddObjCObjectConversionStep(
4109 S.Context.getQualifiedType(T1,
4110 T2.getNonReferenceType().getQualifiers()));
4111
4112 if (cv1T1.getQualifiers() != T2.getNonReferenceType().getQualifiers())
4113 Sequence.AddQualificationConversionStep(cv1T1, VK);
4114
4115 Sequence.AddReferenceBindingStep(cv1T1, !T2->isReferenceType());
4116 return OR_Success;
4117 }
4118
4119 static void CheckCXX98CompatAccessibleCopy(Sema &S,
4120 const InitializedEntity &Entity,
4121 Expr *CurInitExpr);
4122
4123 /// \brief Attempt reference initialization (C++0x [dcl.init.ref])
TryReferenceInitialization(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,Expr * Initializer,InitializationSequence & Sequence)4124 static void TryReferenceInitialization(Sema &S,
4125 const InitializedEntity &Entity,
4126 const InitializationKind &Kind,
4127 Expr *Initializer,
4128 InitializationSequence &Sequence) {
4129 QualType DestType = Entity.getType();
4130 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType();
4131 Qualifiers T1Quals;
4132 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals);
4133 QualType cv2T2 = Initializer->getType();
4134 Qualifiers T2Quals;
4135 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals);
4136
4137 // If the initializer is the address of an overloaded function, try
4138 // to resolve the overloaded function. If all goes well, T2 is the
4139 // type of the resulting function.
4140 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2,
4141 T1, Sequence))
4142 return;
4143
4144 // Delegate everything else to a subfunction.
4145 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1,
4146 T1Quals, cv2T2, T2, T2Quals, Sequence);
4147 }
4148
4149 /// Converts the target of reference initialization so that it has the
4150 /// appropriate qualifiers and value kind.
4151 ///
4152 /// In this case, 'x' is an 'int' lvalue, but it needs to be 'const int'.
4153 /// \code
4154 /// int x;
4155 /// const int &r = x;
4156 /// \endcode
4157 ///
4158 /// In this case the reference is binding to a bitfield lvalue, which isn't
4159 /// valid. Perform a load to create a lifetime-extended temporary instead.
4160 /// \code
4161 /// const int &r = someStruct.bitfield;
4162 /// \endcode
4163 static ExprValueKind
convertQualifiersAndValueKindIfNecessary(Sema & S,InitializationSequence & Sequence,Expr * Initializer,QualType cv1T1,Qualifiers T1Quals,Qualifiers T2Quals,bool IsLValueRef)4164 convertQualifiersAndValueKindIfNecessary(Sema &S,
4165 InitializationSequence &Sequence,
4166 Expr *Initializer,
4167 QualType cv1T1,
4168 Qualifiers T1Quals,
4169 Qualifiers T2Quals,
4170 bool IsLValueRef) {
4171 bool IsNonAddressableType = Initializer->refersToBitField() ||
4172 Initializer->refersToVectorElement();
4173
4174 if (IsNonAddressableType) {
4175 // C++11 [dcl.init.ref]p5: [...] Otherwise, the reference shall be an
4176 // lvalue reference to a non-volatile const type, or the reference shall be
4177 // an rvalue reference.
4178 //
4179 // If not, we can't make a temporary and bind to that. Give up and allow the
4180 // error to be diagnosed later.
4181 if (IsLValueRef && (!T1Quals.hasConst() || T1Quals.hasVolatile())) {
4182 assert(Initializer->isGLValue());
4183 return Initializer->getValueKind();
4184 }
4185
4186 // Force a load so we can materialize a temporary.
4187 Sequence.AddLValueToRValueStep(cv1T1.getUnqualifiedType());
4188 return VK_RValue;
4189 }
4190
4191 if (T1Quals != T2Quals) {
4192 Sequence.AddQualificationConversionStep(cv1T1,
4193 Initializer->getValueKind());
4194 }
4195
4196 return Initializer->getValueKind();
4197 }
4198
4199 /// \brief Reference initialization without resolving overloaded functions.
TryReferenceInitializationCore(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,Expr * Initializer,QualType cv1T1,QualType T1,Qualifiers T1Quals,QualType cv2T2,QualType T2,Qualifiers T2Quals,InitializationSequence & Sequence)4200 static void TryReferenceInitializationCore(Sema &S,
4201 const InitializedEntity &Entity,
4202 const InitializationKind &Kind,
4203 Expr *Initializer,
4204 QualType cv1T1, QualType T1,
4205 Qualifiers T1Quals,
4206 QualType cv2T2, QualType T2,
4207 Qualifiers T2Quals,
4208 InitializationSequence &Sequence) {
4209 QualType DestType = Entity.getType();
4210 SourceLocation DeclLoc = Initializer->getLocStart();
4211 // Compute some basic properties of the types and the initializer.
4212 bool isLValueRef = DestType->isLValueReferenceType();
4213 bool isRValueRef = !isLValueRef;
4214 bool DerivedToBase = false;
4215 bool ObjCConversion = false;
4216 bool ObjCLifetimeConversion = false;
4217 Expr::Classification InitCategory = Initializer->Classify(S.Context);
4218 Sema::ReferenceCompareResult RefRelationship
4219 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, DerivedToBase,
4220 ObjCConversion, ObjCLifetimeConversion);
4221
4222 // C++0x [dcl.init.ref]p5:
4223 // A reference to type "cv1 T1" is initialized by an expression of type
4224 // "cv2 T2" as follows:
4225 //
4226 // - If the reference is an lvalue reference and the initializer
4227 // expression
4228 // Note the analogous bullet points for rvalue refs to functions. Because
4229 // there are no function rvalues in C++, rvalue refs to functions are treated
4230 // like lvalue refs.
4231 OverloadingResult ConvOvlResult = OR_Success;
4232 bool T1Function = T1->isFunctionType();
4233 if (isLValueRef || T1Function) {
4234 if (InitCategory.isLValue() &&
4235 (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification ||
4236 (Kind.isCStyleOrFunctionalCast() &&
4237 RefRelationship == Sema::Ref_Related))) {
4238 // - is an lvalue (but is not a bit-field), and "cv1 T1" is
4239 // reference-compatible with "cv2 T2," or
4240 //
4241 // Per C++ [over.best.ics]p2, we don't diagnose whether the lvalue is a
4242 // bit-field when we're determining whether the reference initialization
4243 // can occur. However, we do pay attention to whether it is a bit-field
4244 // to decide whether we're actually binding to a temporary created from
4245 // the bit-field.
4246 if (DerivedToBase)
4247 Sequence.AddDerivedToBaseCastStep(
4248 S.Context.getQualifiedType(T1, T2Quals),
4249 VK_LValue);
4250 else if (ObjCConversion)
4251 Sequence.AddObjCObjectConversionStep(
4252 S.Context.getQualifiedType(T1, T2Quals));
4253
4254 ExprValueKind ValueKind =
4255 convertQualifiersAndValueKindIfNecessary(S, Sequence, Initializer,
4256 cv1T1, T1Quals, T2Quals,
4257 isLValueRef);
4258 Sequence.AddReferenceBindingStep(cv1T1, ValueKind == VK_RValue);
4259 return;
4260 }
4261
4262 // - has a class type (i.e., T2 is a class type), where T1 is not
4263 // reference-related to T2, and can be implicitly converted to an
4264 // lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible
4265 // with "cv3 T3" (this conversion is selected by enumerating the
4266 // applicable conversion functions (13.3.1.6) and choosing the best
4267 // one through overload resolution (13.3)),
4268 // If we have an rvalue ref to function type here, the rhs must be
4269 // an rvalue. DR1287 removed the "implicitly" here.
4270 if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType() &&
4271 (isLValueRef || InitCategory.isRValue())) {
4272 ConvOvlResult = TryRefInitWithConversionFunction(
4273 S, Entity, Kind, Initializer, /*AllowRValues*/isRValueRef, Sequence);
4274 if (ConvOvlResult == OR_Success)
4275 return;
4276 if (ConvOvlResult != OR_No_Viable_Function)
4277 Sequence.SetOverloadFailure(
4278 InitializationSequence::FK_ReferenceInitOverloadFailed,
4279 ConvOvlResult);
4280 }
4281 }
4282
4283 // - Otherwise, the reference shall be an lvalue reference to a
4284 // non-volatile const type (i.e., cv1 shall be const), or the reference
4285 // shall be an rvalue reference.
4286 if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile())) {
4287 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
4288 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
4289 else if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
4290 Sequence.SetOverloadFailure(
4291 InitializationSequence::FK_ReferenceInitOverloadFailed,
4292 ConvOvlResult);
4293 else
4294 Sequence.SetFailed(InitCategory.isLValue()
4295 ? (RefRelationship == Sema::Ref_Related
4296 ? InitializationSequence::FK_ReferenceInitDropsQualifiers
4297 : InitializationSequence::FK_NonConstLValueReferenceBindingToUnrelated)
4298 : InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary);
4299
4300 return;
4301 }
4302
4303 // - If the initializer expression
4304 // - is an xvalue, class prvalue, array prvalue, or function lvalue and
4305 // "cv1 T1" is reference-compatible with "cv2 T2"
4306 // Note: functions are handled below.
4307 if (!T1Function &&
4308 (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification ||
4309 (Kind.isCStyleOrFunctionalCast() &&
4310 RefRelationship == Sema::Ref_Related)) &&
4311 (InitCategory.isXValue() ||
4312 (InitCategory.isPRValue() && T2->isRecordType()) ||
4313 (InitCategory.isPRValue() && T2->isArrayType()))) {
4314 ExprValueKind ValueKind = InitCategory.isXValue()? VK_XValue : VK_RValue;
4315 if (InitCategory.isPRValue() && T2->isRecordType()) {
4316 // The corresponding bullet in C++03 [dcl.init.ref]p5 gives the
4317 // compiler the freedom to perform a copy here or bind to the
4318 // object, while C++0x requires that we bind directly to the
4319 // object. Hence, we always bind to the object without making an
4320 // extra copy. However, in C++03 requires that we check for the
4321 // presence of a suitable copy constructor:
4322 //
4323 // The constructor that would be used to make the copy shall
4324 // be callable whether or not the copy is actually done.
4325 if (!S.getLangOpts().CPlusPlus11 && !S.getLangOpts().MicrosoftExt)
4326 Sequence.AddExtraneousCopyToTemporary(cv2T2);
4327 else if (S.getLangOpts().CPlusPlus11)
4328 CheckCXX98CompatAccessibleCopy(S, Entity, Initializer);
4329 }
4330
4331 if (DerivedToBase)
4332 Sequence.AddDerivedToBaseCastStep(S.Context.getQualifiedType(T1, T2Quals),
4333 ValueKind);
4334 else if (ObjCConversion)
4335 Sequence.AddObjCObjectConversionStep(
4336 S.Context.getQualifiedType(T1, T2Quals));
4337
4338 ValueKind = convertQualifiersAndValueKindIfNecessary(S, Sequence,
4339 Initializer, cv1T1,
4340 T1Quals, T2Quals,
4341 isLValueRef);
4342
4343 Sequence.AddReferenceBindingStep(cv1T1, ValueKind == VK_RValue);
4344 return;
4345 }
4346
4347 // - has a class type (i.e., T2 is a class type), where T1 is not
4348 // reference-related to T2, and can be implicitly converted to an
4349 // xvalue, class prvalue, or function lvalue of type "cv3 T3",
4350 // where "cv1 T1" is reference-compatible with "cv3 T3",
4351 //
4352 // DR1287 removes the "implicitly" here.
4353 if (T2->isRecordType()) {
4354 if (RefRelationship == Sema::Ref_Incompatible) {
4355 ConvOvlResult = TryRefInitWithConversionFunction(
4356 S, Entity, Kind, Initializer, /*AllowRValues*/true, Sequence);
4357 if (ConvOvlResult)
4358 Sequence.SetOverloadFailure(
4359 InitializationSequence::FK_ReferenceInitOverloadFailed,
4360 ConvOvlResult);
4361
4362 return;
4363 }
4364
4365 if ((RefRelationship == Sema::Ref_Compatible ||
4366 RefRelationship == Sema::Ref_Compatible_With_Added_Qualification) &&
4367 isRValueRef && InitCategory.isLValue()) {
4368 Sequence.SetFailed(
4369 InitializationSequence::FK_RValueReferenceBindingToLValue);
4370 return;
4371 }
4372
4373 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
4374 return;
4375 }
4376
4377 // - Otherwise, a temporary of type "cv1 T1" is created and initialized
4378 // from the initializer expression using the rules for a non-reference
4379 // copy-initialization (8.5). The reference is then bound to the
4380 // temporary. [...]
4381
4382 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1);
4383
4384 // FIXME: Why do we use an implicit conversion here rather than trying
4385 // copy-initialization?
4386 ImplicitConversionSequence ICS
4387 = S.TryImplicitConversion(Initializer, TempEntity.getType(),
4388 /*SuppressUserConversions=*/false,
4389 /*AllowExplicit=*/false,
4390 /*FIXME:InOverloadResolution=*/false,
4391 /*CStyle=*/Kind.isCStyleOrFunctionalCast(),
4392 /*AllowObjCWritebackConversion=*/false);
4393
4394 if (ICS.isBad()) {
4395 // FIXME: Use the conversion function set stored in ICS to turn
4396 // this into an overloading ambiguity diagnostic. However, we need
4397 // to keep that set as an OverloadCandidateSet rather than as some
4398 // other kind of set.
4399 if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty())
4400 Sequence.SetOverloadFailure(
4401 InitializationSequence::FK_ReferenceInitOverloadFailed,
4402 ConvOvlResult);
4403 else if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy)
4404 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
4405 else
4406 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed);
4407 return;
4408 } else {
4409 Sequence.AddConversionSequenceStep(ICS, TempEntity.getType());
4410 }
4411
4412 // [...] If T1 is reference-related to T2, cv1 must be the
4413 // same cv-qualification as, or greater cv-qualification
4414 // than, cv2; otherwise, the program is ill-formed.
4415 unsigned T1CVRQuals = T1Quals.getCVRQualifiers();
4416 unsigned T2CVRQuals = T2Quals.getCVRQualifiers();
4417 if (RefRelationship == Sema::Ref_Related &&
4418 (T1CVRQuals | T2CVRQuals) != T1CVRQuals) {
4419 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers);
4420 return;
4421 }
4422
4423 // [...] If T1 is reference-related to T2 and the reference is an rvalue
4424 // reference, the initializer expression shall not be an lvalue.
4425 if (RefRelationship >= Sema::Ref_Related && !isLValueRef &&
4426 InitCategory.isLValue()) {
4427 Sequence.SetFailed(
4428 InitializationSequence::FK_RValueReferenceBindingToLValue);
4429 return;
4430 }
4431
4432 Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true);
4433 }
4434
4435 /// \brief Attempt character array initialization from a string literal
4436 /// (C++ [dcl.init.string], C99 6.7.8).
TryStringLiteralInitialization(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,Expr * Initializer,InitializationSequence & Sequence)4437 static void TryStringLiteralInitialization(Sema &S,
4438 const InitializedEntity &Entity,
4439 const InitializationKind &Kind,
4440 Expr *Initializer,
4441 InitializationSequence &Sequence) {
4442 Sequence.AddStringInitStep(Entity.getType());
4443 }
4444
4445 /// \brief Attempt value initialization (C++ [dcl.init]p7).
TryValueInitialization(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,InitializationSequence & Sequence,InitListExpr * InitList)4446 static void TryValueInitialization(Sema &S,
4447 const InitializedEntity &Entity,
4448 const InitializationKind &Kind,
4449 InitializationSequence &Sequence,
4450 InitListExpr *InitList) {
4451 assert((!InitList || InitList->getNumInits() == 0) &&
4452 "Shouldn't use value-init for non-empty init lists");
4453
4454 // C++98 [dcl.init]p5, C++11 [dcl.init]p7:
4455 //
4456 // To value-initialize an object of type T means:
4457 QualType T = Entity.getType();
4458
4459 // -- if T is an array type, then each element is value-initialized;
4460 T = S.Context.getBaseElementType(T);
4461
4462 if (const RecordType *RT = T->getAs<RecordType>()) {
4463 if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
4464 bool NeedZeroInitialization = true;
4465 if (!S.getLangOpts().CPlusPlus11) {
4466 // C++98:
4467 // -- if T is a class type (clause 9) with a user-declared constructor
4468 // (12.1), then the default constructor for T is called (and the
4469 // initialization is ill-formed if T has no accessible default
4470 // constructor);
4471 if (ClassDecl->hasUserDeclaredConstructor())
4472 NeedZeroInitialization = false;
4473 } else {
4474 // C++11:
4475 // -- if T is a class type (clause 9) with either no default constructor
4476 // (12.1 [class.ctor]) or a default constructor that is user-provided
4477 // or deleted, then the object is default-initialized;
4478 CXXConstructorDecl *CD = S.LookupDefaultConstructor(ClassDecl);
4479 if (!CD || !CD->getCanonicalDecl()->isDefaulted() || CD->isDeleted())
4480 NeedZeroInitialization = false;
4481 }
4482
4483 // -- if T is a (possibly cv-qualified) non-union class type without a
4484 // user-provided or deleted default constructor, then the object is
4485 // zero-initialized and, if T has a non-trivial default constructor,
4486 // default-initialized;
4487 // The 'non-union' here was removed by DR1502. The 'non-trivial default
4488 // constructor' part was removed by DR1507.
4489 if (NeedZeroInitialization)
4490 Sequence.AddZeroInitializationStep(Entity.getType());
4491
4492 // C++03:
4493 // -- if T is a non-union class type without a user-declared constructor,
4494 // then every non-static data member and base class component of T is
4495 // value-initialized;
4496 // [...] A program that calls for [...] value-initialization of an
4497 // entity of reference type is ill-formed.
4498 //
4499 // C++11 doesn't need this handling, because value-initialization does not
4500 // occur recursively there, and the implicit default constructor is
4501 // defined as deleted in the problematic cases.
4502 if (!S.getLangOpts().CPlusPlus11 &&
4503 ClassDecl->hasUninitializedReferenceMember()) {
4504 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForReference);
4505 return;
4506 }
4507
4508 // If this is list-value-initialization, pass the empty init list on when
4509 // building the constructor call. This affects the semantics of a few
4510 // things (such as whether an explicit default constructor can be called).
4511 Expr *InitListAsExpr = InitList;
4512 MultiExprArg Args(&InitListAsExpr, InitList ? 1 : 0);
4513 bool InitListSyntax = InitList;
4514
4515 return TryConstructorInitialization(S, Entity, Kind, Args, T, Sequence,
4516 InitListSyntax);
4517 }
4518 }
4519
4520 Sequence.AddZeroInitializationStep(Entity.getType());
4521 }
4522
4523 /// \brief Attempt default initialization (C++ [dcl.init]p6).
TryDefaultInitialization(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,InitializationSequence & Sequence)4524 static void TryDefaultInitialization(Sema &S,
4525 const InitializedEntity &Entity,
4526 const InitializationKind &Kind,
4527 InitializationSequence &Sequence) {
4528 assert(Kind.getKind() == InitializationKind::IK_Default);
4529
4530 // C++ [dcl.init]p6:
4531 // To default-initialize an object of type T means:
4532 // - if T is an array type, each element is default-initialized;
4533 QualType DestType = S.Context.getBaseElementType(Entity.getType());
4534
4535 // - if T is a (possibly cv-qualified) class type (Clause 9), the default
4536 // constructor for T is called (and the initialization is ill-formed if
4537 // T has no accessible default constructor);
4538 if (DestType->isRecordType() && S.getLangOpts().CPlusPlus) {
4539 TryConstructorInitialization(S, Entity, Kind, None, DestType, Sequence);
4540 return;
4541 }
4542
4543 // - otherwise, no initialization is performed.
4544
4545 // If a program calls for the default initialization of an object of
4546 // a const-qualified type T, T shall be a class type with a user-provided
4547 // default constructor.
4548 if (DestType.isConstQualified() && S.getLangOpts().CPlusPlus) {
4549 if (!maybeRecoverWithZeroInitialization(S, Sequence, Entity))
4550 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst);
4551 return;
4552 }
4553
4554 // If the destination type has a lifetime property, zero-initialize it.
4555 if (DestType.getQualifiers().hasObjCLifetime()) {
4556 Sequence.AddZeroInitializationStep(Entity.getType());
4557 return;
4558 }
4559 }
4560
4561 /// \brief Attempt a user-defined conversion between two types (C++ [dcl.init]),
4562 /// which enumerates all conversion functions and performs overload resolution
4563 /// to select the best.
TryUserDefinedConversion(Sema & S,QualType DestType,const InitializationKind & Kind,Expr * Initializer,InitializationSequence & Sequence,bool TopLevelOfInitList)4564 static void TryUserDefinedConversion(Sema &S,
4565 QualType DestType,
4566 const InitializationKind &Kind,
4567 Expr *Initializer,
4568 InitializationSequence &Sequence,
4569 bool TopLevelOfInitList) {
4570 assert(!DestType->isReferenceType() && "References are handled elsewhere");
4571 QualType SourceType = Initializer->getType();
4572 assert((DestType->isRecordType() || SourceType->isRecordType()) &&
4573 "Must have a class type to perform a user-defined conversion");
4574
4575 // Build the candidate set directly in the initialization sequence
4576 // structure, so that it will persist if we fail.
4577 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet();
4578 CandidateSet.clear();
4579
4580 // Determine whether we are allowed to call explicit constructors or
4581 // explicit conversion operators.
4582 bool AllowExplicit = Kind.AllowExplicit();
4583
4584 if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) {
4585 // The type we're converting to is a class type. Enumerate its constructors
4586 // to see if there is a suitable conversion.
4587 CXXRecordDecl *DestRecordDecl
4588 = cast<CXXRecordDecl>(DestRecordType->getDecl());
4589
4590 // Try to complete the type we're converting to.
4591 if (S.isCompleteType(Kind.getLocation(), DestType)) {
4592 DeclContext::lookup_result R = S.LookupConstructors(DestRecordDecl);
4593 // The container holding the constructors can under certain conditions
4594 // be changed while iterating. To be safe we copy the lookup results
4595 // to a new container.
4596 SmallVector<NamedDecl*, 8> CopyOfCon(R.begin(), R.end());
4597 for (SmallVectorImpl<NamedDecl *>::iterator
4598 Con = CopyOfCon.begin(), ConEnd = CopyOfCon.end();
4599 Con != ConEnd; ++Con) {
4600 NamedDecl *D = *Con;
4601 auto Info = getConstructorInfo(D);
4602 if (!Info.Constructor)
4603 continue;
4604
4605 if (!Info.Constructor->isInvalidDecl() &&
4606 Info.Constructor->isConvertingConstructor(AllowExplicit)) {
4607 if (Info.ConstructorTmpl)
4608 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
4609 /*ExplicitArgs*/ nullptr,
4610 Initializer, CandidateSet,
4611 /*SuppressUserConversions=*/true);
4612 else
4613 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
4614 Initializer, CandidateSet,
4615 /*SuppressUserConversions=*/true);
4616 }
4617 }
4618 }
4619 }
4620
4621 SourceLocation DeclLoc = Initializer->getLocStart();
4622
4623 if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) {
4624 // The type we're converting from is a class type, enumerate its conversion
4625 // functions.
4626
4627 // We can only enumerate the conversion functions for a complete type; if
4628 // the type isn't complete, simply skip this step.
4629 if (S.isCompleteType(DeclLoc, SourceType)) {
4630 CXXRecordDecl *SourceRecordDecl
4631 = cast<CXXRecordDecl>(SourceRecordType->getDecl());
4632
4633 const auto &Conversions =
4634 SourceRecordDecl->getVisibleConversionFunctions();
4635 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) {
4636 NamedDecl *D = *I;
4637 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext());
4638 if (isa<UsingShadowDecl>(D))
4639 D = cast<UsingShadowDecl>(D)->getTargetDecl();
4640
4641 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D);
4642 CXXConversionDecl *Conv;
4643 if (ConvTemplate)
4644 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl());
4645 else
4646 Conv = cast<CXXConversionDecl>(D);
4647
4648 if (AllowExplicit || !Conv->isExplicit()) {
4649 if (ConvTemplate)
4650 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(),
4651 ActingDC, Initializer, DestType,
4652 CandidateSet, AllowExplicit);
4653 else
4654 S.AddConversionCandidate(Conv, I.getPair(), ActingDC,
4655 Initializer, DestType, CandidateSet,
4656 AllowExplicit);
4657 }
4658 }
4659 }
4660 }
4661
4662 // Perform overload resolution. If it fails, return the failed result.
4663 OverloadCandidateSet::iterator Best;
4664 if (OverloadingResult Result
4665 = CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) {
4666 Sequence.SetOverloadFailure(
4667 InitializationSequence::FK_UserConversionOverloadFailed,
4668 Result);
4669 return;
4670 }
4671
4672 FunctionDecl *Function = Best->Function;
4673 Function->setReferenced();
4674 bool HadMultipleCandidates = (CandidateSet.size() > 1);
4675
4676 if (isa<CXXConstructorDecl>(Function)) {
4677 // Add the user-defined conversion step. Any cv-qualification conversion is
4678 // subsumed by the initialization. Per DR5, the created temporary is of the
4679 // cv-unqualified type of the destination.
4680 Sequence.AddUserConversionStep(Function, Best->FoundDecl,
4681 DestType.getUnqualifiedType(),
4682 HadMultipleCandidates);
4683 return;
4684 }
4685
4686 // Add the user-defined conversion step that calls the conversion function.
4687 QualType ConvType = Function->getCallResultType();
4688 if (ConvType->getAs<RecordType>()) {
4689 // If we're converting to a class type, there may be an copy of
4690 // the resulting temporary object (possible to create an object of
4691 // a base class type). That copy is not a separate conversion, so
4692 // we just make a note of the actual destination type (possibly a
4693 // base class of the type returned by the conversion function) and
4694 // let the user-defined conversion step handle the conversion.
4695 Sequence.AddUserConversionStep(Function, Best->FoundDecl, DestType,
4696 HadMultipleCandidates);
4697 return;
4698 }
4699
4700 Sequence.AddUserConversionStep(Function, Best->FoundDecl, ConvType,
4701 HadMultipleCandidates);
4702
4703 // If the conversion following the call to the conversion function
4704 // is interesting, add it as a separate step.
4705 if (Best->FinalConversion.First || Best->FinalConversion.Second ||
4706 Best->FinalConversion.Third) {
4707 ImplicitConversionSequence ICS;
4708 ICS.setStandard();
4709 ICS.Standard = Best->FinalConversion;
4710 Sequence.AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);
4711 }
4712 }
4713
4714 /// An egregious hack for compatibility with libstdc++-4.2: in <tr1/hashtable>,
4715 /// a function with a pointer return type contains a 'return false;' statement.
4716 /// In C++11, 'false' is not a null pointer, so this breaks the build of any
4717 /// code using that header.
4718 ///
4719 /// Work around this by treating 'return false;' as zero-initializing the result
4720 /// if it's used in a pointer-returning function in a system header.
isLibstdcxxPointerReturnFalseHack(Sema & S,const InitializedEntity & Entity,const Expr * Init)4721 static bool isLibstdcxxPointerReturnFalseHack(Sema &S,
4722 const InitializedEntity &Entity,
4723 const Expr *Init) {
4724 return S.getLangOpts().CPlusPlus11 &&
4725 Entity.getKind() == InitializedEntity::EK_Result &&
4726 Entity.getType()->isPointerType() &&
4727 isa<CXXBoolLiteralExpr>(Init) &&
4728 !cast<CXXBoolLiteralExpr>(Init)->getValue() &&
4729 S.getSourceManager().isInSystemHeader(Init->getExprLoc());
4730 }
4731
4732 /// The non-zero enum values here are indexes into diagnostic alternatives.
4733 enum InvalidICRKind { IIK_okay, IIK_nonlocal, IIK_nonscalar };
4734
4735 /// Determines whether this expression is an acceptable ICR source.
isInvalidICRSource(ASTContext & C,Expr * e,bool isAddressOf,bool & isWeakAccess)4736 static InvalidICRKind isInvalidICRSource(ASTContext &C, Expr *e,
4737 bool isAddressOf, bool &isWeakAccess) {
4738 // Skip parens.
4739 e = e->IgnoreParens();
4740
4741 // Skip address-of nodes.
4742 if (UnaryOperator *op = dyn_cast<UnaryOperator>(e)) {
4743 if (op->getOpcode() == UO_AddrOf)
4744 return isInvalidICRSource(C, op->getSubExpr(), /*addressof*/ true,
4745 isWeakAccess);
4746
4747 // Skip certain casts.
4748 } else if (CastExpr *ce = dyn_cast<CastExpr>(e)) {
4749 switch (ce->getCastKind()) {
4750 case CK_Dependent:
4751 case CK_BitCast:
4752 case CK_LValueBitCast:
4753 case CK_NoOp:
4754 return isInvalidICRSource(C, ce->getSubExpr(), isAddressOf, isWeakAccess);
4755
4756 case CK_ArrayToPointerDecay:
4757 return IIK_nonscalar;
4758
4759 case CK_NullToPointer:
4760 return IIK_okay;
4761
4762 default:
4763 break;
4764 }
4765
4766 // If we have a declaration reference, it had better be a local variable.
4767 } else if (isa<DeclRefExpr>(e)) {
4768 // set isWeakAccess to true, to mean that there will be an implicit
4769 // load which requires a cleanup.
4770 if (e->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
4771 isWeakAccess = true;
4772
4773 if (!isAddressOf) return IIK_nonlocal;
4774
4775 VarDecl *var = dyn_cast<VarDecl>(cast<DeclRefExpr>(e)->getDecl());
4776 if (!var) return IIK_nonlocal;
4777
4778 return (var->hasLocalStorage() ? IIK_okay : IIK_nonlocal);
4779
4780 // If we have a conditional operator, check both sides.
4781 } else if (ConditionalOperator *cond = dyn_cast<ConditionalOperator>(e)) {
4782 if (InvalidICRKind iik = isInvalidICRSource(C, cond->getLHS(), isAddressOf,
4783 isWeakAccess))
4784 return iik;
4785
4786 return isInvalidICRSource(C, cond->getRHS(), isAddressOf, isWeakAccess);
4787
4788 // These are never scalar.
4789 } else if (isa<ArraySubscriptExpr>(e)) {
4790 return IIK_nonscalar;
4791
4792 // Otherwise, it needs to be a null pointer constant.
4793 } else {
4794 return (e->isNullPointerConstant(C, Expr::NPC_ValueDependentIsNull)
4795 ? IIK_okay : IIK_nonlocal);
4796 }
4797
4798 return IIK_nonlocal;
4799 }
4800
4801 /// Check whether the given expression is a valid operand for an
4802 /// indirect copy/restore.
checkIndirectCopyRestoreSource(Sema & S,Expr * src)4803 static void checkIndirectCopyRestoreSource(Sema &S, Expr *src) {
4804 assert(src->isRValue());
4805 bool isWeakAccess = false;
4806 InvalidICRKind iik = isInvalidICRSource(S.Context, src, false, isWeakAccess);
4807 // If isWeakAccess to true, there will be an implicit
4808 // load which requires a cleanup.
4809 if (S.getLangOpts().ObjCAutoRefCount && isWeakAccess)
4810 S.Cleanup.setExprNeedsCleanups(true);
4811
4812 if (iik == IIK_okay) return;
4813
4814 S.Diag(src->getExprLoc(), diag::err_arc_nonlocal_writeback)
4815 << ((unsigned) iik - 1) // shift index into diagnostic explanations
4816 << src->getSourceRange();
4817 }
4818
4819 /// \brief Determine whether we have compatible array types for the
4820 /// purposes of GNU by-copy array initialization.
hasCompatibleArrayTypes(ASTContext & Context,const ArrayType * Dest,const ArrayType * Source)4821 static bool hasCompatibleArrayTypes(ASTContext &Context, const ArrayType *Dest,
4822 const ArrayType *Source) {
4823 // If the source and destination array types are equivalent, we're
4824 // done.
4825 if (Context.hasSameType(QualType(Dest, 0), QualType(Source, 0)))
4826 return true;
4827
4828 // Make sure that the element types are the same.
4829 if (!Context.hasSameType(Dest->getElementType(), Source->getElementType()))
4830 return false;
4831
4832 // The only mismatch we allow is when the destination is an
4833 // incomplete array type and the source is a constant array type.
4834 return Source->isConstantArrayType() && Dest->isIncompleteArrayType();
4835 }
4836
tryObjCWritebackConversion(Sema & S,InitializationSequence & Sequence,const InitializedEntity & Entity,Expr * Initializer)4837 static bool tryObjCWritebackConversion(Sema &S,
4838 InitializationSequence &Sequence,
4839 const InitializedEntity &Entity,
4840 Expr *Initializer) {
4841 bool ArrayDecay = false;
4842 QualType ArgType = Initializer->getType();
4843 QualType ArgPointee;
4844 if (const ArrayType *ArgArrayType = S.Context.getAsArrayType(ArgType)) {
4845 ArrayDecay = true;
4846 ArgPointee = ArgArrayType->getElementType();
4847 ArgType = S.Context.getPointerType(ArgPointee);
4848 }
4849
4850 // Handle write-back conversion.
4851 QualType ConvertedArgType;
4852 if (!S.isObjCWritebackConversion(ArgType, Entity.getType(),
4853 ConvertedArgType))
4854 return false;
4855
4856 // We should copy unless we're passing to an argument explicitly
4857 // marked 'out'.
4858 bool ShouldCopy = true;
4859 if (ParmVarDecl *param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
4860 ShouldCopy = (param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);
4861
4862 // Do we need an lvalue conversion?
4863 if (ArrayDecay || Initializer->isGLValue()) {
4864 ImplicitConversionSequence ICS;
4865 ICS.setStandard();
4866 ICS.Standard.setAsIdentityConversion();
4867
4868 QualType ResultType;
4869 if (ArrayDecay) {
4870 ICS.Standard.First = ICK_Array_To_Pointer;
4871 ResultType = S.Context.getPointerType(ArgPointee);
4872 } else {
4873 ICS.Standard.First = ICK_Lvalue_To_Rvalue;
4874 ResultType = Initializer->getType().getNonLValueExprType(S.Context);
4875 }
4876
4877 Sequence.AddConversionSequenceStep(ICS, ResultType);
4878 }
4879
4880 Sequence.AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy);
4881 return true;
4882 }
4883
TryOCLSamplerInitialization(Sema & S,InitializationSequence & Sequence,QualType DestType,Expr * Initializer)4884 static bool TryOCLSamplerInitialization(Sema &S,
4885 InitializationSequence &Sequence,
4886 QualType DestType,
4887 Expr *Initializer) {
4888 if (!S.getLangOpts().OpenCL || !DestType->isSamplerT() ||
4889 !Initializer->isIntegerConstantExpr(S.getASTContext()))
4890 return false;
4891
4892 Sequence.AddOCLSamplerInitStep(DestType);
4893 return true;
4894 }
4895
4896 //
4897 // OpenCL 1.2 spec, s6.12.10
4898 //
4899 // The event argument can also be used to associate the
4900 // async_work_group_copy with a previous async copy allowing
4901 // an event to be shared by multiple async copies; otherwise
4902 // event should be zero.
4903 //
TryOCLZeroEventInitialization(Sema & S,InitializationSequence & Sequence,QualType DestType,Expr * Initializer)4904 static bool TryOCLZeroEventInitialization(Sema &S,
4905 InitializationSequence &Sequence,
4906 QualType DestType,
4907 Expr *Initializer) {
4908 if (!S.getLangOpts().OpenCL || !DestType->isEventT() ||
4909 !Initializer->isIntegerConstantExpr(S.getASTContext()) ||
4910 (Initializer->EvaluateKnownConstInt(S.getASTContext()) != 0))
4911 return false;
4912
4913 Sequence.AddOCLZeroEventStep(DestType);
4914 return true;
4915 }
4916
InitializationSequence(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,MultiExprArg Args,bool TopLevelOfInitList,bool TreatUnavailableAsInvalid)4917 InitializationSequence::InitializationSequence(Sema &S,
4918 const InitializedEntity &Entity,
4919 const InitializationKind &Kind,
4920 MultiExprArg Args,
4921 bool TopLevelOfInitList,
4922 bool TreatUnavailableAsInvalid)
4923 : FailedCandidateSet(Kind.getLocation(), OverloadCandidateSet::CSK_Normal) {
4924 InitializeFrom(S, Entity, Kind, Args, TopLevelOfInitList,
4925 TreatUnavailableAsInvalid);
4926 }
4927
4928 /// Tries to get a FunctionDecl out of `E`. If it succeeds and we can take the
4929 /// address of that function, this returns true. Otherwise, it returns false.
isExprAnUnaddressableFunction(Sema & S,const Expr * E)4930 static bool isExprAnUnaddressableFunction(Sema &S, const Expr *E) {
4931 auto *DRE = dyn_cast<DeclRefExpr>(E);
4932 if (!DRE || !isa<FunctionDecl>(DRE->getDecl()))
4933 return false;
4934
4935 return !S.checkAddressOfFunctionIsAvailable(
4936 cast<FunctionDecl>(DRE->getDecl()));
4937 }
4938
InitializeFrom(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,MultiExprArg Args,bool TopLevelOfInitList,bool TreatUnavailableAsInvalid)4939 void InitializationSequence::InitializeFrom(Sema &S,
4940 const InitializedEntity &Entity,
4941 const InitializationKind &Kind,
4942 MultiExprArg Args,
4943 bool TopLevelOfInitList,
4944 bool TreatUnavailableAsInvalid) {
4945 ASTContext &Context = S.Context;
4946
4947 // Eliminate non-overload placeholder types in the arguments. We
4948 // need to do this before checking whether types are dependent
4949 // because lowering a pseudo-object expression might well give us
4950 // something of dependent type.
4951 for (unsigned I = 0, E = Args.size(); I != E; ++I)
4952 if (Args[I]->getType()->isNonOverloadPlaceholderType()) {
4953 // FIXME: should we be doing this here?
4954 ExprResult result = S.CheckPlaceholderExpr(Args[I]);
4955 if (result.isInvalid()) {
4956 SetFailed(FK_PlaceholderType);
4957 return;
4958 }
4959 Args[I] = result.get();
4960 }
4961
4962 // C++0x [dcl.init]p16:
4963 // The semantics of initializers are as follows. The destination type is
4964 // the type of the object or reference being initialized and the source
4965 // type is the type of the initializer expression. The source type is not
4966 // defined when the initializer is a braced-init-list or when it is a
4967 // parenthesized list of expressions.
4968 QualType DestType = Entity.getType();
4969
4970 if (DestType->isDependentType() ||
4971 Expr::hasAnyTypeDependentArguments(Args)) {
4972 SequenceKind = DependentSequence;
4973 return;
4974 }
4975
4976 // Almost everything is a normal sequence.
4977 setSequenceKind(NormalSequence);
4978
4979 QualType SourceType;
4980 Expr *Initializer = nullptr;
4981 if (Args.size() == 1) {
4982 Initializer = Args[0];
4983 if (S.getLangOpts().ObjC1) {
4984 if (S.CheckObjCBridgeRelatedConversions(Initializer->getLocStart(),
4985 DestType, Initializer->getType(),
4986 Initializer) ||
4987 S.ConversionToObjCStringLiteralCheck(DestType, Initializer))
4988 Args[0] = Initializer;
4989 }
4990 if (!isa<InitListExpr>(Initializer))
4991 SourceType = Initializer->getType();
4992 }
4993
4994 // - If the initializer is a (non-parenthesized) braced-init-list, the
4995 // object is list-initialized (8.5.4).
4996 if (Kind.getKind() != InitializationKind::IK_Direct) {
4997 if (InitListExpr *InitList = dyn_cast_or_null<InitListExpr>(Initializer)) {
4998 TryListInitialization(S, Entity, Kind, InitList, *this,
4999 TreatUnavailableAsInvalid);
5000 return;
5001 }
5002 }
5003
5004 // - If the destination type is a reference type, see 8.5.3.
5005 if (DestType->isReferenceType()) {
5006 // C++0x [dcl.init.ref]p1:
5007 // A variable declared to be a T& or T&&, that is, "reference to type T"
5008 // (8.3.2), shall be initialized by an object, or function, of type T or
5009 // by an object that can be converted into a T.
5010 // (Therefore, multiple arguments are not permitted.)
5011 if (Args.size() != 1)
5012 SetFailed(FK_TooManyInitsForReference);
5013 else
5014 TryReferenceInitialization(S, Entity, Kind, Args[0], *this);
5015 return;
5016 }
5017
5018 // - If the initializer is (), the object is value-initialized.
5019 if (Kind.getKind() == InitializationKind::IK_Value ||
5020 (Kind.getKind() == InitializationKind::IK_Direct && Args.empty())) {
5021 TryValueInitialization(S, Entity, Kind, *this);
5022 return;
5023 }
5024
5025 // Handle default initialization.
5026 if (Kind.getKind() == InitializationKind::IK_Default) {
5027 TryDefaultInitialization(S, Entity, Kind, *this);
5028 return;
5029 }
5030
5031 // - If the destination type is an array of characters, an array of
5032 // char16_t, an array of char32_t, or an array of wchar_t, and the
5033 // initializer is a string literal, see 8.5.2.
5034 // - Otherwise, if the destination type is an array, the program is
5035 // ill-formed.
5036 if (const ArrayType *DestAT = Context.getAsArrayType(DestType)) {
5037 if (Initializer && isa<VariableArrayType>(DestAT)) {
5038 SetFailed(FK_VariableLengthArrayHasInitializer);
5039 return;
5040 }
5041
5042 if (Initializer) {
5043 switch (IsStringInit(Initializer, DestAT, Context)) {
5044 case SIF_None:
5045 TryStringLiteralInitialization(S, Entity, Kind, Initializer, *this);
5046 return;
5047 case SIF_NarrowStringIntoWideChar:
5048 SetFailed(FK_NarrowStringIntoWideCharArray);
5049 return;
5050 case SIF_WideStringIntoChar:
5051 SetFailed(FK_WideStringIntoCharArray);
5052 return;
5053 case SIF_IncompatWideStringIntoWideChar:
5054 SetFailed(FK_IncompatWideStringIntoWideChar);
5055 return;
5056 case SIF_Other:
5057 break;
5058 }
5059 }
5060
5061 // Note: as an GNU C extension, we allow initialization of an
5062 // array from a compound literal that creates an array of the same
5063 // type, so long as the initializer has no side effects.
5064 if (!S.getLangOpts().CPlusPlus && Initializer &&
5065 isa<CompoundLiteralExpr>(Initializer->IgnoreParens()) &&
5066 Initializer->getType()->isArrayType()) {
5067 const ArrayType *SourceAT
5068 = Context.getAsArrayType(Initializer->getType());
5069 if (!hasCompatibleArrayTypes(S.Context, DestAT, SourceAT))
5070 SetFailed(FK_ArrayTypeMismatch);
5071 else if (Initializer->HasSideEffects(S.Context))
5072 SetFailed(FK_NonConstantArrayInit);
5073 else {
5074 AddArrayInitStep(DestType);
5075 }
5076 }
5077 // Note: as a GNU C++ extension, we allow list-initialization of a
5078 // class member of array type from a parenthesized initializer list.
5079 else if (S.getLangOpts().CPlusPlus &&
5080 Entity.getKind() == InitializedEntity::EK_Member &&
5081 Initializer && isa<InitListExpr>(Initializer)) {
5082 TryListInitialization(S, Entity, Kind, cast<InitListExpr>(Initializer),
5083 *this, TreatUnavailableAsInvalid);
5084 AddParenthesizedArrayInitStep(DestType);
5085 } else if (DestAT->getElementType()->isCharType())
5086 SetFailed(FK_ArrayNeedsInitListOrStringLiteral);
5087 else if (IsWideCharCompatible(DestAT->getElementType(), Context))
5088 SetFailed(FK_ArrayNeedsInitListOrWideStringLiteral);
5089 else
5090 SetFailed(FK_ArrayNeedsInitList);
5091
5092 return;
5093 }
5094
5095 // Determine whether we should consider writeback conversions for
5096 // Objective-C ARC.
5097 bool allowObjCWritebackConversion = S.getLangOpts().ObjCAutoRefCount &&
5098 Entity.isParameterKind();
5099
5100 // We're at the end of the line for C: it's either a write-back conversion
5101 // or it's a C assignment. There's no need to check anything else.
5102 if (!S.getLangOpts().CPlusPlus) {
5103 // If allowed, check whether this is an Objective-C writeback conversion.
5104 if (allowObjCWritebackConversion &&
5105 tryObjCWritebackConversion(S, *this, Entity, Initializer)) {
5106 return;
5107 }
5108
5109 if (TryOCLSamplerInitialization(S, *this, DestType, Initializer))
5110 return;
5111
5112 if (TryOCLZeroEventInitialization(S, *this, DestType, Initializer))
5113 return;
5114
5115 // Handle initialization in C
5116 AddCAssignmentStep(DestType);
5117 MaybeProduceObjCObject(S, *this, Entity);
5118 return;
5119 }
5120
5121 assert(S.getLangOpts().CPlusPlus);
5122
5123 // - If the destination type is a (possibly cv-qualified) class type:
5124 if (DestType->isRecordType()) {
5125 // - If the initialization is direct-initialization, or if it is
5126 // copy-initialization where the cv-unqualified version of the
5127 // source type is the same class as, or a derived class of, the
5128 // class of the destination, constructors are considered. [...]
5129 if (Kind.getKind() == InitializationKind::IK_Direct ||
5130 (Kind.getKind() == InitializationKind::IK_Copy &&
5131 (Context.hasSameUnqualifiedType(SourceType, DestType) ||
5132 S.IsDerivedFrom(Initializer->getLocStart(), SourceType, DestType))))
5133 TryConstructorInitialization(S, Entity, Kind, Args,
5134 DestType, *this);
5135 // - Otherwise (i.e., for the remaining copy-initialization cases),
5136 // user-defined conversion sequences that can convert from the source
5137 // type to the destination type or (when a conversion function is
5138 // used) to a derived class thereof are enumerated as described in
5139 // 13.3.1.4, and the best one is chosen through overload resolution
5140 // (13.3).
5141 else
5142 TryUserDefinedConversion(S, DestType, Kind, Initializer, *this,
5143 TopLevelOfInitList);
5144 return;
5145 }
5146
5147 if (Args.size() > 1) {
5148 SetFailed(FK_TooManyInitsForScalar);
5149 return;
5150 }
5151 assert(Args.size() == 1 && "Zero-argument case handled above");
5152
5153 // - Otherwise, if the source type is a (possibly cv-qualified) class
5154 // type, conversion functions are considered.
5155 if (!SourceType.isNull() && SourceType->isRecordType()) {
5156 // For a conversion to _Atomic(T) from either T or a class type derived
5157 // from T, initialize the T object then convert to _Atomic type.
5158 bool NeedAtomicConversion = false;
5159 if (const AtomicType *Atomic = DestType->getAs<AtomicType>()) {
5160 if (Context.hasSameUnqualifiedType(SourceType, Atomic->getValueType()) ||
5161 S.IsDerivedFrom(Initializer->getLocStart(), SourceType,
5162 Atomic->getValueType())) {
5163 DestType = Atomic->getValueType();
5164 NeedAtomicConversion = true;
5165 }
5166 }
5167
5168 TryUserDefinedConversion(S, DestType, Kind, Initializer, *this,
5169 TopLevelOfInitList);
5170 MaybeProduceObjCObject(S, *this, Entity);
5171 if (!Failed() && NeedAtomicConversion)
5172 AddAtomicConversionStep(Entity.getType());
5173 return;
5174 }
5175
5176 // - Otherwise, the initial value of the object being initialized is the
5177 // (possibly converted) value of the initializer expression. Standard
5178 // conversions (Clause 4) will be used, if necessary, to convert the
5179 // initializer expression to the cv-unqualified version of the
5180 // destination type; no user-defined conversions are considered.
5181
5182 ImplicitConversionSequence ICS
5183 = S.TryImplicitConversion(Initializer, DestType,
5184 /*SuppressUserConversions*/true,
5185 /*AllowExplicitConversions*/ false,
5186 /*InOverloadResolution*/ false,
5187 /*CStyle=*/Kind.isCStyleOrFunctionalCast(),
5188 allowObjCWritebackConversion);
5189
5190 if (ICS.isStandard() &&
5191 ICS.Standard.Second == ICK_Writeback_Conversion) {
5192 // Objective-C ARC writeback conversion.
5193
5194 // We should copy unless we're passing to an argument explicitly
5195 // marked 'out'.
5196 bool ShouldCopy = true;
5197 if (ParmVarDecl *Param = cast_or_null<ParmVarDecl>(Entity.getDecl()))
5198 ShouldCopy = (Param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out);
5199
5200 // If there was an lvalue adjustment, add it as a separate conversion.
5201 if (ICS.Standard.First == ICK_Array_To_Pointer ||
5202 ICS.Standard.First == ICK_Lvalue_To_Rvalue) {
5203 ImplicitConversionSequence LvalueICS;
5204 LvalueICS.setStandard();
5205 LvalueICS.Standard.setAsIdentityConversion();
5206 LvalueICS.Standard.setAllToTypes(ICS.Standard.getToType(0));
5207 LvalueICS.Standard.First = ICS.Standard.First;
5208 AddConversionSequenceStep(LvalueICS, ICS.Standard.getToType(0));
5209 }
5210
5211 AddPassByIndirectCopyRestoreStep(DestType, ShouldCopy);
5212 } else if (ICS.isBad()) {
5213 DeclAccessPair dap;
5214 if (isLibstdcxxPointerReturnFalseHack(S, Entity, Initializer)) {
5215 AddZeroInitializationStep(Entity.getType());
5216 } else if (Initializer->getType() == Context.OverloadTy &&
5217 !S.ResolveAddressOfOverloadedFunction(Initializer, DestType,
5218 false, dap))
5219 SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
5220 else if (Initializer->getType()->isFunctionType() &&
5221 isExprAnUnaddressableFunction(S, Initializer))
5222 SetFailed(InitializationSequence::FK_AddressOfUnaddressableFunction);
5223 else
5224 SetFailed(InitializationSequence::FK_ConversionFailed);
5225 } else {
5226 AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList);
5227
5228 MaybeProduceObjCObject(S, *this, Entity);
5229 }
5230 }
5231
~InitializationSequence()5232 InitializationSequence::~InitializationSequence() {
5233 for (auto &S : Steps)
5234 S.Destroy();
5235 }
5236
5237 //===----------------------------------------------------------------------===//
5238 // Perform initialization
5239 //===----------------------------------------------------------------------===//
5240 static Sema::AssignmentAction
getAssignmentAction(const InitializedEntity & Entity,bool Diagnose=false)5241 getAssignmentAction(const InitializedEntity &Entity, bool Diagnose = false) {
5242 switch(Entity.getKind()) {
5243 case InitializedEntity::EK_Variable:
5244 case InitializedEntity::EK_New:
5245 case InitializedEntity::EK_Exception:
5246 case InitializedEntity::EK_Base:
5247 case InitializedEntity::EK_Delegating:
5248 return Sema::AA_Initializing;
5249
5250 case InitializedEntity::EK_Parameter:
5251 if (Entity.getDecl() &&
5252 isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext()))
5253 return Sema::AA_Sending;
5254
5255 return Sema::AA_Passing;
5256
5257 case InitializedEntity::EK_Parameter_CF_Audited:
5258 if (Entity.getDecl() &&
5259 isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext()))
5260 return Sema::AA_Sending;
5261
5262 return !Diagnose ? Sema::AA_Passing : Sema::AA_Passing_CFAudited;
5263
5264 case InitializedEntity::EK_Result:
5265 return Sema::AA_Returning;
5266
5267 case InitializedEntity::EK_Temporary:
5268 case InitializedEntity::EK_RelatedResult:
5269 // FIXME: Can we tell apart casting vs. converting?
5270 return Sema::AA_Casting;
5271
5272 case InitializedEntity::EK_Member:
5273 case InitializedEntity::EK_ArrayElement:
5274 case InitializedEntity::EK_VectorElement:
5275 case InitializedEntity::EK_ComplexElement:
5276 case InitializedEntity::EK_BlockElement:
5277 case InitializedEntity::EK_LambdaCapture:
5278 case InitializedEntity::EK_CompoundLiteralInit:
5279 return Sema::AA_Initializing;
5280 }
5281
5282 llvm_unreachable("Invalid EntityKind!");
5283 }
5284
5285 /// \brief Whether we should bind a created object as a temporary when
5286 /// initializing the given entity.
shouldBindAsTemporary(const InitializedEntity & Entity)5287 static bool shouldBindAsTemporary(const InitializedEntity &Entity) {
5288 switch (Entity.getKind()) {
5289 case InitializedEntity::EK_ArrayElement:
5290 case InitializedEntity::EK_Member:
5291 case InitializedEntity::EK_Result:
5292 case InitializedEntity::EK_New:
5293 case InitializedEntity::EK_Variable:
5294 case InitializedEntity::EK_Base:
5295 case InitializedEntity::EK_Delegating:
5296 case InitializedEntity::EK_VectorElement:
5297 case InitializedEntity::EK_ComplexElement:
5298 case InitializedEntity::EK_Exception:
5299 case InitializedEntity::EK_BlockElement:
5300 case InitializedEntity::EK_LambdaCapture:
5301 case InitializedEntity::EK_CompoundLiteralInit:
5302 return false;
5303
5304 case InitializedEntity::EK_Parameter:
5305 case InitializedEntity::EK_Parameter_CF_Audited:
5306 case InitializedEntity::EK_Temporary:
5307 case InitializedEntity::EK_RelatedResult:
5308 return true;
5309 }
5310
5311 llvm_unreachable("missed an InitializedEntity kind?");
5312 }
5313
5314 /// \brief Whether the given entity, when initialized with an object
5315 /// created for that initialization, requires destruction.
shouldDestroyTemporary(const InitializedEntity & Entity)5316 static bool shouldDestroyTemporary(const InitializedEntity &Entity) {
5317 switch (Entity.getKind()) {
5318 case InitializedEntity::EK_Result:
5319 case InitializedEntity::EK_New:
5320 case InitializedEntity::EK_Base:
5321 case InitializedEntity::EK_Delegating:
5322 case InitializedEntity::EK_VectorElement:
5323 case InitializedEntity::EK_ComplexElement:
5324 case InitializedEntity::EK_BlockElement:
5325 case InitializedEntity::EK_LambdaCapture:
5326 return false;
5327
5328 case InitializedEntity::EK_Member:
5329 case InitializedEntity::EK_Variable:
5330 case InitializedEntity::EK_Parameter:
5331 case InitializedEntity::EK_Parameter_CF_Audited:
5332 case InitializedEntity::EK_Temporary:
5333 case InitializedEntity::EK_ArrayElement:
5334 case InitializedEntity::EK_Exception:
5335 case InitializedEntity::EK_CompoundLiteralInit:
5336 case InitializedEntity::EK_RelatedResult:
5337 return true;
5338 }
5339
5340 llvm_unreachable("missed an InitializedEntity kind?");
5341 }
5342
5343 /// \brief Look for copy and move constructors and constructor templates, for
5344 /// copying an object via direct-initialization (per C++11 [dcl.init]p16).
LookupCopyAndMoveConstructors(Sema & S,OverloadCandidateSet & CandidateSet,CXXRecordDecl * Class,Expr * CurInitExpr)5345 static void LookupCopyAndMoveConstructors(Sema &S,
5346 OverloadCandidateSet &CandidateSet,
5347 CXXRecordDecl *Class,
5348 Expr *CurInitExpr) {
5349 DeclContext::lookup_result R = S.LookupConstructors(Class);
5350 // The container holding the constructors can under certain conditions
5351 // be changed while iterating (e.g. because of deserialization).
5352 // To be safe we copy the lookup results to a new container.
5353 SmallVector<NamedDecl*, 16> Ctors(R.begin(), R.end());
5354 for (SmallVectorImpl<NamedDecl *>::iterator
5355 CI = Ctors.begin(), CE = Ctors.end(); CI != CE; ++CI) {
5356 NamedDecl *D = *CI;
5357 auto Info = getConstructorInfo(D);
5358 if (!Info.Constructor)
5359 continue;
5360
5361 if (!Info.ConstructorTmpl) {
5362 // Handle copy/move constructors, only.
5363 if (Info.Constructor->isInvalidDecl() ||
5364 !Info.Constructor->isCopyOrMoveConstructor() ||
5365 !Info.Constructor->isConvertingConstructor(/*AllowExplicit=*/true))
5366 continue;
5367
5368 S.AddOverloadCandidate(Info.Constructor, Info.FoundDecl,
5369 CurInitExpr, CandidateSet);
5370 continue;
5371 }
5372
5373 // Handle constructor templates.
5374 if (Info.ConstructorTmpl->isInvalidDecl())
5375 continue;
5376
5377 if (!Info.Constructor->isConvertingConstructor(/*AllowExplicit=*/true))
5378 continue;
5379
5380 // FIXME: Do we need to limit this to copy-constructor-like
5381 // candidates?
5382 S.AddTemplateOverloadCandidate(Info.ConstructorTmpl, Info.FoundDecl,
5383 nullptr, CurInitExpr, CandidateSet, true);
5384 }
5385 }
5386
5387 /// \brief Get the location at which initialization diagnostics should appear.
getInitializationLoc(const InitializedEntity & Entity,Expr * Initializer)5388 static SourceLocation getInitializationLoc(const InitializedEntity &Entity,
5389 Expr *Initializer) {
5390 switch (Entity.getKind()) {
5391 case InitializedEntity::EK_Result:
5392 return Entity.getReturnLoc();
5393
5394 case InitializedEntity::EK_Exception:
5395 return Entity.getThrowLoc();
5396
5397 case InitializedEntity::EK_Variable:
5398 return Entity.getDecl()->getLocation();
5399
5400 case InitializedEntity::EK_LambdaCapture:
5401 return Entity.getCaptureLoc();
5402
5403 case InitializedEntity::EK_ArrayElement:
5404 case InitializedEntity::EK_Member:
5405 case InitializedEntity::EK_Parameter:
5406 case InitializedEntity::EK_Parameter_CF_Audited:
5407 case InitializedEntity::EK_Temporary:
5408 case InitializedEntity::EK_New:
5409 case InitializedEntity::EK_Base:
5410 case InitializedEntity::EK_Delegating:
5411 case InitializedEntity::EK_VectorElement:
5412 case InitializedEntity::EK_ComplexElement:
5413 case InitializedEntity::EK_BlockElement:
5414 case InitializedEntity::EK_CompoundLiteralInit:
5415 case InitializedEntity::EK_RelatedResult:
5416 return Initializer->getLocStart();
5417 }
5418 llvm_unreachable("missed an InitializedEntity kind?");
5419 }
5420
5421 /// \brief Make a (potentially elidable) temporary copy of the object
5422 /// provided by the given initializer by calling the appropriate copy
5423 /// constructor.
5424 ///
5425 /// \param S The Sema object used for type-checking.
5426 ///
5427 /// \param T The type of the temporary object, which must either be
5428 /// the type of the initializer expression or a superclass thereof.
5429 ///
5430 /// \param Entity The entity being initialized.
5431 ///
5432 /// \param CurInit The initializer expression.
5433 ///
5434 /// \param IsExtraneousCopy Whether this is an "extraneous" copy that
5435 /// is permitted in C++03 (but not C++0x) when binding a reference to
5436 /// an rvalue.
5437 ///
5438 /// \returns An expression that copies the initializer expression into
5439 /// a temporary object, or an error expression if a copy could not be
5440 /// created.
CopyObject(Sema & S,QualType T,const InitializedEntity & Entity,ExprResult CurInit,bool IsExtraneousCopy)5441 static ExprResult CopyObject(Sema &S,
5442 QualType T,
5443 const InitializedEntity &Entity,
5444 ExprResult CurInit,
5445 bool IsExtraneousCopy) {
5446 if (CurInit.isInvalid())
5447 return CurInit;
5448 // Determine which class type we're copying to.
5449 Expr *CurInitExpr = (Expr *)CurInit.get();
5450 CXXRecordDecl *Class = nullptr;
5451 if (const RecordType *Record = T->getAs<RecordType>())
5452 Class = cast<CXXRecordDecl>(Record->getDecl());
5453 if (!Class)
5454 return CurInit;
5455
5456 // C++0x [class.copy]p32:
5457 // When certain criteria are met, an implementation is allowed to
5458 // omit the copy/move construction of a class object, even if the
5459 // copy/move constructor and/or destructor for the object have
5460 // side effects. [...]
5461 // - when a temporary class object that has not been bound to a
5462 // reference (12.2) would be copied/moved to a class object
5463 // with the same cv-unqualified type, the copy/move operation
5464 // can be omitted by constructing the temporary object
5465 // directly into the target of the omitted copy/move
5466 //
5467 // Note that the other three bullets are handled elsewhere. Copy
5468 // elision for return statements and throw expressions are handled as part
5469 // of constructor initialization, while copy elision for exception handlers
5470 // is handled by the run-time.
5471 bool Elidable = CurInitExpr->isTemporaryObject(S.Context, Class);
5472 SourceLocation Loc = getInitializationLoc(Entity, CurInit.get());
5473
5474 // Make sure that the type we are copying is complete.
5475 if (S.RequireCompleteType(Loc, T, diag::err_temp_copy_incomplete))
5476 return CurInit;
5477
5478 // Perform overload resolution using the class's copy/move constructors.
5479 // Only consider constructors and constructor templates. Per
5480 // C++0x [dcl.init]p16, second bullet to class types, this initialization
5481 // is direct-initialization.
5482 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5483 LookupCopyAndMoveConstructors(S, CandidateSet, Class, CurInitExpr);
5484
5485 bool HadMultipleCandidates = (CandidateSet.size() > 1);
5486
5487 OverloadCandidateSet::iterator Best;
5488 switch (CandidateSet.BestViableFunction(S, Loc, Best)) {
5489 case OR_Success:
5490 break;
5491
5492 case OR_No_Viable_Function:
5493 S.Diag(Loc, IsExtraneousCopy && !S.isSFINAEContext()
5494 ? diag::ext_rvalue_to_reference_temp_copy_no_viable
5495 : diag::err_temp_copy_no_viable)
5496 << (int)Entity.getKind() << CurInitExpr->getType()
5497 << CurInitExpr->getSourceRange();
5498 CandidateSet.NoteCandidates(S, OCD_AllCandidates, CurInitExpr);
5499 if (!IsExtraneousCopy || S.isSFINAEContext())
5500 return ExprError();
5501 return CurInit;
5502
5503 case OR_Ambiguous:
5504 S.Diag(Loc, diag::err_temp_copy_ambiguous)
5505 << (int)Entity.getKind() << CurInitExpr->getType()
5506 << CurInitExpr->getSourceRange();
5507 CandidateSet.NoteCandidates(S, OCD_ViableCandidates, CurInitExpr);
5508 return ExprError();
5509
5510 case OR_Deleted:
5511 S.Diag(Loc, diag::err_temp_copy_deleted)
5512 << (int)Entity.getKind() << CurInitExpr->getType()
5513 << CurInitExpr->getSourceRange();
5514 S.NoteDeletedFunction(Best->Function);
5515 return ExprError();
5516 }
5517
5518 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function);
5519 SmallVector<Expr*, 8> ConstructorArgs;
5520 CurInit.get(); // Ownership transferred into MultiExprArg, below.
5521
5522 S.CheckConstructorAccess(Loc, Constructor, Best->FoundDecl, Entity,
5523 IsExtraneousCopy);
5524
5525 if (IsExtraneousCopy) {
5526 // If this is a totally extraneous copy for C++03 reference
5527 // binding purposes, just return the original initialization
5528 // expression. We don't generate an (elided) copy operation here
5529 // because doing so would require us to pass down a flag to avoid
5530 // infinite recursion, where each step adds another extraneous,
5531 // elidable copy.
5532
5533 // Instantiate the default arguments of any extra parameters in
5534 // the selected copy constructor, as if we were going to create a
5535 // proper call to the copy constructor.
5536 for (unsigned I = 1, N = Constructor->getNumParams(); I != N; ++I) {
5537 ParmVarDecl *Parm = Constructor->getParamDecl(I);
5538 if (S.RequireCompleteType(Loc, Parm->getType(),
5539 diag::err_call_incomplete_argument))
5540 break;
5541
5542 // Build the default argument expression; we don't actually care
5543 // if this succeeds or not, because this routine will complain
5544 // if there was a problem.
5545 S.BuildCXXDefaultArgExpr(Loc, Constructor, Parm);
5546 }
5547
5548 return CurInitExpr;
5549 }
5550
5551 // Determine the arguments required to actually perform the
5552 // constructor call (we might have derived-to-base conversions, or
5553 // the copy constructor may have default arguments).
5554 if (S.CompleteConstructorCall(Constructor, CurInitExpr, Loc, ConstructorArgs))
5555 return ExprError();
5556
5557 // Actually perform the constructor call.
5558 CurInit = S.BuildCXXConstructExpr(Loc, T, Best->FoundDecl, Constructor,
5559 Elidable,
5560 ConstructorArgs,
5561 HadMultipleCandidates,
5562 /*ListInit*/ false,
5563 /*StdInitListInit*/ false,
5564 /*ZeroInit*/ false,
5565 CXXConstructExpr::CK_Complete,
5566 SourceRange());
5567
5568 // If we're supposed to bind temporaries, do so.
5569 if (!CurInit.isInvalid() && shouldBindAsTemporary(Entity))
5570 CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>());
5571 return CurInit;
5572 }
5573
5574 /// \brief Check whether elidable copy construction for binding a reference to
5575 /// a temporary would have succeeded if we were building in C++98 mode, for
5576 /// -Wc++98-compat.
CheckCXX98CompatAccessibleCopy(Sema & S,const InitializedEntity & Entity,Expr * CurInitExpr)5577 static void CheckCXX98CompatAccessibleCopy(Sema &S,
5578 const InitializedEntity &Entity,
5579 Expr *CurInitExpr) {
5580 assert(S.getLangOpts().CPlusPlus11);
5581
5582 const RecordType *Record = CurInitExpr->getType()->getAs<RecordType>();
5583 if (!Record)
5584 return;
5585
5586 SourceLocation Loc = getInitializationLoc(Entity, CurInitExpr);
5587 if (S.Diags.isIgnored(diag::warn_cxx98_compat_temp_copy, Loc))
5588 return;
5589
5590 // Find constructors which would have been considered.
5591 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal);
5592 LookupCopyAndMoveConstructors(
5593 S, CandidateSet, cast<CXXRecordDecl>(Record->getDecl()), CurInitExpr);
5594
5595 // Perform overload resolution.
5596 OverloadCandidateSet::iterator Best;
5597 OverloadingResult OR = CandidateSet.BestViableFunction(S, Loc, Best);
5598
5599 PartialDiagnostic Diag = S.PDiag(diag::warn_cxx98_compat_temp_copy)
5600 << OR << (int)Entity.getKind() << CurInitExpr->getType()
5601 << CurInitExpr->getSourceRange();
5602
5603 switch (OR) {
5604 case OR_Success:
5605 S.CheckConstructorAccess(Loc, cast<CXXConstructorDecl>(Best->Function),
5606 Best->FoundDecl, Entity, Diag);
5607 // FIXME: Check default arguments as far as that's possible.
5608 break;
5609
5610 case OR_No_Viable_Function:
5611 S.Diag(Loc, Diag);
5612 CandidateSet.NoteCandidates(S, OCD_AllCandidates, CurInitExpr);
5613 break;
5614
5615 case OR_Ambiguous:
5616 S.Diag(Loc, Diag);
5617 CandidateSet.NoteCandidates(S, OCD_ViableCandidates, CurInitExpr);
5618 break;
5619
5620 case OR_Deleted:
5621 S.Diag(Loc, Diag);
5622 S.NoteDeletedFunction(Best->Function);
5623 break;
5624 }
5625 }
5626
PrintInitLocationNote(Sema & S,const InitializedEntity & Entity)5627 void InitializationSequence::PrintInitLocationNote(Sema &S,
5628 const InitializedEntity &Entity) {
5629 if (Entity.isParameterKind() && Entity.getDecl()) {
5630 if (Entity.getDecl()->getLocation().isInvalid())
5631 return;
5632
5633 if (Entity.getDecl()->getDeclName())
5634 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_named_here)
5635 << Entity.getDecl()->getDeclName();
5636 else
5637 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_here);
5638 }
5639 else if (Entity.getKind() == InitializedEntity::EK_RelatedResult &&
5640 Entity.getMethodDecl())
5641 S.Diag(Entity.getMethodDecl()->getLocation(),
5642 diag::note_method_return_type_change)
5643 << Entity.getMethodDecl()->getDeclName();
5644 }
5645
isReferenceBinding(const InitializationSequence::Step & s)5646 static bool isReferenceBinding(const InitializationSequence::Step &s) {
5647 return s.Kind == InitializationSequence::SK_BindReference ||
5648 s.Kind == InitializationSequence::SK_BindReferenceToTemporary;
5649 }
5650
5651 /// Returns true if the parameters describe a constructor initialization of
5652 /// an explicit temporary object, e.g. "Point(x, y)".
isExplicitTemporary(const InitializedEntity & Entity,const InitializationKind & Kind,unsigned NumArgs)5653 static bool isExplicitTemporary(const InitializedEntity &Entity,
5654 const InitializationKind &Kind,
5655 unsigned NumArgs) {
5656 switch (Entity.getKind()) {
5657 case InitializedEntity::EK_Temporary:
5658 case InitializedEntity::EK_CompoundLiteralInit:
5659 case InitializedEntity::EK_RelatedResult:
5660 break;
5661 default:
5662 return false;
5663 }
5664
5665 switch (Kind.getKind()) {
5666 case InitializationKind::IK_DirectList:
5667 return true;
5668 // FIXME: Hack to work around cast weirdness.
5669 case InitializationKind::IK_Direct:
5670 case InitializationKind::IK_Value:
5671 return NumArgs != 1;
5672 default:
5673 return false;
5674 }
5675 }
5676
5677 static ExprResult
PerformConstructorInitialization(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,MultiExprArg Args,const InitializationSequence::Step & Step,bool & ConstructorInitRequiresZeroInit,bool IsListInitialization,bool IsStdInitListInitialization,SourceLocation LBraceLoc,SourceLocation RBraceLoc)5678 PerformConstructorInitialization(Sema &S,
5679 const InitializedEntity &Entity,
5680 const InitializationKind &Kind,
5681 MultiExprArg Args,
5682 const InitializationSequence::Step& Step,
5683 bool &ConstructorInitRequiresZeroInit,
5684 bool IsListInitialization,
5685 bool IsStdInitListInitialization,
5686 SourceLocation LBraceLoc,
5687 SourceLocation RBraceLoc) {
5688 unsigned NumArgs = Args.size();
5689 CXXConstructorDecl *Constructor
5690 = cast<CXXConstructorDecl>(Step.Function.Function);
5691 bool HadMultipleCandidates = Step.Function.HadMultipleCandidates;
5692
5693 // Build a call to the selected constructor.
5694 SmallVector<Expr*, 8> ConstructorArgs;
5695 SourceLocation Loc = (Kind.isCopyInit() && Kind.getEqualLoc().isValid())
5696 ? Kind.getEqualLoc()
5697 : Kind.getLocation();
5698
5699 if (Kind.getKind() == InitializationKind::IK_Default) {
5700 // Force even a trivial, implicit default constructor to be
5701 // semantically checked. We do this explicitly because we don't build
5702 // the definition for completely trivial constructors.
5703 assert(Constructor->getParent() && "No parent class for constructor.");
5704 if (Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
5705 Constructor->isTrivial() && !Constructor->isUsed(false))
5706 S.DefineImplicitDefaultConstructor(Loc, Constructor);
5707 }
5708
5709 ExprResult CurInit((Expr *)nullptr);
5710
5711 // C++ [over.match.copy]p1:
5712 // - When initializing a temporary to be bound to the first parameter
5713 // of a constructor that takes a reference to possibly cv-qualified
5714 // T as its first argument, called with a single argument in the
5715 // context of direct-initialization, explicit conversion functions
5716 // are also considered.
5717 bool AllowExplicitConv = Kind.AllowExplicit() && !Kind.isCopyInit() &&
5718 Args.size() == 1 &&
5719 Constructor->isCopyOrMoveConstructor();
5720
5721 // Determine the arguments required to actually perform the constructor
5722 // call.
5723 if (S.CompleteConstructorCall(Constructor, Args,
5724 Loc, ConstructorArgs,
5725 AllowExplicitConv,
5726 IsListInitialization))
5727 return ExprError();
5728
5729
5730 if (isExplicitTemporary(Entity, Kind, NumArgs)) {
5731 // An explicitly-constructed temporary, e.g., X(1, 2).
5732 if (S.DiagnoseUseOfDecl(Constructor, Loc))
5733 return ExprError();
5734
5735 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo();
5736 if (!TSInfo)
5737 TSInfo = S.Context.getTrivialTypeSourceInfo(Entity.getType(), Loc);
5738 SourceRange ParenOrBraceRange =
5739 (Kind.getKind() == InitializationKind::IK_DirectList)
5740 ? SourceRange(LBraceLoc, RBraceLoc)
5741 : Kind.getParenRange();
5742
5743 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(
5744 Step.Function.FoundDecl.getDecl())) {
5745 Constructor = S.findInheritingConstructor(Loc, Constructor, Shadow);
5746 if (S.DiagnoseUseOfDecl(Constructor, Loc))
5747 return ExprError();
5748 }
5749 S.MarkFunctionReferenced(Loc, Constructor);
5750
5751 CurInit = new (S.Context) CXXTemporaryObjectExpr(
5752 S.Context, Constructor, TSInfo,
5753 ConstructorArgs, ParenOrBraceRange, HadMultipleCandidates,
5754 IsListInitialization, IsStdInitListInitialization,
5755 ConstructorInitRequiresZeroInit);
5756 } else {
5757 CXXConstructExpr::ConstructionKind ConstructKind =
5758 CXXConstructExpr::CK_Complete;
5759
5760 if (Entity.getKind() == InitializedEntity::EK_Base) {
5761 ConstructKind = Entity.getBaseSpecifier()->isVirtual() ?
5762 CXXConstructExpr::CK_VirtualBase :
5763 CXXConstructExpr::CK_NonVirtualBase;
5764 } else if (Entity.getKind() == InitializedEntity::EK_Delegating) {
5765 ConstructKind = CXXConstructExpr::CK_Delegating;
5766 }
5767
5768 // Only get the parenthesis or brace range if it is a list initialization or
5769 // direct construction.
5770 SourceRange ParenOrBraceRange;
5771 if (IsListInitialization)
5772 ParenOrBraceRange = SourceRange(LBraceLoc, RBraceLoc);
5773 else if (Kind.getKind() == InitializationKind::IK_Direct)
5774 ParenOrBraceRange = Kind.getParenRange();
5775
5776 // If the entity allows NRVO, mark the construction as elidable
5777 // unconditionally.
5778 if (Entity.allowsNRVO())
5779 CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(),
5780 Step.Function.FoundDecl,
5781 Constructor, /*Elidable=*/true,
5782 ConstructorArgs,
5783 HadMultipleCandidates,
5784 IsListInitialization,
5785 IsStdInitListInitialization,
5786 ConstructorInitRequiresZeroInit,
5787 ConstructKind,
5788 ParenOrBraceRange);
5789 else
5790 CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(),
5791 Step.Function.FoundDecl,
5792 Constructor,
5793 ConstructorArgs,
5794 HadMultipleCandidates,
5795 IsListInitialization,
5796 IsStdInitListInitialization,
5797 ConstructorInitRequiresZeroInit,
5798 ConstructKind,
5799 ParenOrBraceRange);
5800 }
5801 if (CurInit.isInvalid())
5802 return ExprError();
5803
5804 // Only check access if all of that succeeded.
5805 S.CheckConstructorAccess(Loc, Constructor, Step.Function.FoundDecl, Entity);
5806 if (S.DiagnoseUseOfDecl(Step.Function.FoundDecl, Loc))
5807 return ExprError();
5808
5809 if (shouldBindAsTemporary(Entity))
5810 CurInit = S.MaybeBindToTemporary(CurInit.get());
5811
5812 return CurInit;
5813 }
5814
5815 /// Determine whether the specified InitializedEntity definitely has a lifetime
5816 /// longer than the current full-expression. Conservatively returns false if
5817 /// it's unclear.
5818 static bool
InitializedEntityOutlivesFullExpression(const InitializedEntity & Entity)5819 InitializedEntityOutlivesFullExpression(const InitializedEntity &Entity) {
5820 const InitializedEntity *Top = &Entity;
5821 while (Top->getParent())
5822 Top = Top->getParent();
5823
5824 switch (Top->getKind()) {
5825 case InitializedEntity::EK_Variable:
5826 case InitializedEntity::EK_Result:
5827 case InitializedEntity::EK_Exception:
5828 case InitializedEntity::EK_Member:
5829 case InitializedEntity::EK_New:
5830 case InitializedEntity::EK_Base:
5831 case InitializedEntity::EK_Delegating:
5832 return true;
5833
5834 case InitializedEntity::EK_ArrayElement:
5835 case InitializedEntity::EK_VectorElement:
5836 case InitializedEntity::EK_BlockElement:
5837 case InitializedEntity::EK_ComplexElement:
5838 // Could not determine what the full initialization is. Assume it might not
5839 // outlive the full-expression.
5840 return false;
5841
5842 case InitializedEntity::EK_Parameter:
5843 case InitializedEntity::EK_Parameter_CF_Audited:
5844 case InitializedEntity::EK_Temporary:
5845 case InitializedEntity::EK_LambdaCapture:
5846 case InitializedEntity::EK_CompoundLiteralInit:
5847 case InitializedEntity::EK_RelatedResult:
5848 // The entity being initialized might not outlive the full-expression.
5849 return false;
5850 }
5851
5852 llvm_unreachable("unknown entity kind");
5853 }
5854
5855 /// Determine the declaration which an initialized entity ultimately refers to,
5856 /// for the purpose of lifetime-extending a temporary bound to a reference in
5857 /// the initialization of \p Entity.
getEntityForTemporaryLifetimeExtension(const InitializedEntity * Entity,const InitializedEntity * FallbackDecl=nullptr)5858 static const InitializedEntity *getEntityForTemporaryLifetimeExtension(
5859 const InitializedEntity *Entity,
5860 const InitializedEntity *FallbackDecl = nullptr) {
5861 // C++11 [class.temporary]p5:
5862 switch (Entity->getKind()) {
5863 case InitializedEntity::EK_Variable:
5864 // The temporary [...] persists for the lifetime of the reference
5865 return Entity;
5866
5867 case InitializedEntity::EK_Member:
5868 // For subobjects, we look at the complete object.
5869 if (Entity->getParent())
5870 return getEntityForTemporaryLifetimeExtension(Entity->getParent(),
5871 Entity);
5872
5873 // except:
5874 // -- A temporary bound to a reference member in a constructor's
5875 // ctor-initializer persists until the constructor exits.
5876 return Entity;
5877
5878 case InitializedEntity::EK_Parameter:
5879 case InitializedEntity::EK_Parameter_CF_Audited:
5880 // -- A temporary bound to a reference parameter in a function call
5881 // persists until the completion of the full-expression containing
5882 // the call.
5883 case InitializedEntity::EK_Result:
5884 // -- The lifetime of a temporary bound to the returned value in a
5885 // function return statement is not extended; the temporary is
5886 // destroyed at the end of the full-expression in the return statement.
5887 case InitializedEntity::EK_New:
5888 // -- A temporary bound to a reference in a new-initializer persists
5889 // until the completion of the full-expression containing the
5890 // new-initializer.
5891 return nullptr;
5892
5893 case InitializedEntity::EK_Temporary:
5894 case InitializedEntity::EK_CompoundLiteralInit:
5895 case InitializedEntity::EK_RelatedResult:
5896 // We don't yet know the storage duration of the surrounding temporary.
5897 // Assume it's got full-expression duration for now, it will patch up our
5898 // storage duration if that's not correct.
5899 return nullptr;
5900
5901 case InitializedEntity::EK_ArrayElement:
5902 // For subobjects, we look at the complete object.
5903 return getEntityForTemporaryLifetimeExtension(Entity->getParent(),
5904 FallbackDecl);
5905
5906 case InitializedEntity::EK_Base:
5907 // For subobjects, we look at the complete object.
5908 if (Entity->getParent())
5909 return getEntityForTemporaryLifetimeExtension(Entity->getParent(),
5910 Entity);
5911 // Fall through.
5912 case InitializedEntity::EK_Delegating:
5913 // We can reach this case for aggregate initialization in a constructor:
5914 // struct A { int &&r; };
5915 // struct B : A { B() : A{0} {} };
5916 // In this case, use the innermost field decl as the context.
5917 return FallbackDecl;
5918
5919 case InitializedEntity::EK_BlockElement:
5920 case InitializedEntity::EK_LambdaCapture:
5921 case InitializedEntity::EK_Exception:
5922 case InitializedEntity::EK_VectorElement:
5923 case InitializedEntity::EK_ComplexElement:
5924 return nullptr;
5925 }
5926 llvm_unreachable("unknown entity kind");
5927 }
5928
5929 static void performLifetimeExtension(Expr *Init,
5930 const InitializedEntity *ExtendingEntity);
5931
5932 /// Update a glvalue expression that is used as the initializer of a reference
5933 /// to note that its lifetime is extended.
5934 /// \return \c true if any temporary had its lifetime extended.
5935 static bool
performReferenceExtension(Expr * Init,const InitializedEntity * ExtendingEntity)5936 performReferenceExtension(Expr *Init,
5937 const InitializedEntity *ExtendingEntity) {
5938 // Walk past any constructs which we can lifetime-extend across.
5939 Expr *Old;
5940 do {
5941 Old = Init;
5942
5943 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
5944 if (ILE->getNumInits() == 1 && ILE->isGLValue()) {
5945 // This is just redundant braces around an initializer. Step over it.
5946 Init = ILE->getInit(0);
5947 }
5948 }
5949
5950 // Step over any subobject adjustments; we may have a materialized
5951 // temporary inside them.
5952 SmallVector<const Expr *, 2> CommaLHSs;
5953 SmallVector<SubobjectAdjustment, 2> Adjustments;
5954 Init = const_cast<Expr *>(
5955 Init->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments));
5956
5957 // Per current approach for DR1376, look through casts to reference type
5958 // when performing lifetime extension.
5959 if (CastExpr *CE = dyn_cast<CastExpr>(Init))
5960 if (CE->getSubExpr()->isGLValue())
5961 Init = CE->getSubExpr();
5962
5963 // FIXME: Per DR1213, subscripting on an array temporary produces an xvalue.
5964 // It's unclear if binding a reference to that xvalue extends the array
5965 // temporary.
5966 } while (Init != Old);
5967
5968 if (MaterializeTemporaryExpr *ME = dyn_cast<MaterializeTemporaryExpr>(Init)) {
5969 // Update the storage duration of the materialized temporary.
5970 // FIXME: Rebuild the expression instead of mutating it.
5971 ME->setExtendingDecl(ExtendingEntity->getDecl(),
5972 ExtendingEntity->allocateManglingNumber());
5973 performLifetimeExtension(ME->GetTemporaryExpr(), ExtendingEntity);
5974 return true;
5975 }
5976
5977 return false;
5978 }
5979
5980 /// Update a prvalue expression that is going to be materialized as a
5981 /// lifetime-extended temporary.
performLifetimeExtension(Expr * Init,const InitializedEntity * ExtendingEntity)5982 static void performLifetimeExtension(Expr *Init,
5983 const InitializedEntity *ExtendingEntity) {
5984 // Dig out the expression which constructs the extended temporary.
5985 SmallVector<const Expr *, 2> CommaLHSs;
5986 SmallVector<SubobjectAdjustment, 2> Adjustments;
5987 Init = const_cast<Expr *>(
5988 Init->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments));
5989
5990 if (CXXBindTemporaryExpr *BTE = dyn_cast<CXXBindTemporaryExpr>(Init))
5991 Init = BTE->getSubExpr();
5992
5993 if (CXXStdInitializerListExpr *ILE =
5994 dyn_cast<CXXStdInitializerListExpr>(Init)) {
5995 performReferenceExtension(ILE->getSubExpr(), ExtendingEntity);
5996 return;
5997 }
5998
5999 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
6000 if (ILE->getType()->isArrayType()) {
6001 for (unsigned I = 0, N = ILE->getNumInits(); I != N; ++I)
6002 performLifetimeExtension(ILE->getInit(I), ExtendingEntity);
6003 return;
6004 }
6005
6006 if (CXXRecordDecl *RD = ILE->getType()->getAsCXXRecordDecl()) {
6007 assert(RD->isAggregate() && "aggregate init on non-aggregate");
6008
6009 // If we lifetime-extend a braced initializer which is initializing an
6010 // aggregate, and that aggregate contains reference members which are
6011 // bound to temporaries, those temporaries are also lifetime-extended.
6012 if (RD->isUnion() && ILE->getInitializedFieldInUnion() &&
6013 ILE->getInitializedFieldInUnion()->getType()->isReferenceType())
6014 performReferenceExtension(ILE->getInit(0), ExtendingEntity);
6015 else {
6016 unsigned Index = 0;
6017 for (const auto *I : RD->fields()) {
6018 if (Index >= ILE->getNumInits())
6019 break;
6020 if (I->isUnnamedBitfield())
6021 continue;
6022 Expr *SubInit = ILE->getInit(Index);
6023 if (I->getType()->isReferenceType())
6024 performReferenceExtension(SubInit, ExtendingEntity);
6025 else if (isa<InitListExpr>(SubInit) ||
6026 isa<CXXStdInitializerListExpr>(SubInit))
6027 // This may be either aggregate-initialization of a member or
6028 // initialization of a std::initializer_list object. Either way,
6029 // we should recursively lifetime-extend that initializer.
6030 performLifetimeExtension(SubInit, ExtendingEntity);
6031 ++Index;
6032 }
6033 }
6034 }
6035 }
6036 }
6037
warnOnLifetimeExtension(Sema & S,const InitializedEntity & Entity,const Expr * Init,bool IsInitializerList,const ValueDecl * ExtendingDecl)6038 static void warnOnLifetimeExtension(Sema &S, const InitializedEntity &Entity,
6039 const Expr *Init, bool IsInitializerList,
6040 const ValueDecl *ExtendingDecl) {
6041 // Warn if a field lifetime-extends a temporary.
6042 if (isa<FieldDecl>(ExtendingDecl)) {
6043 if (IsInitializerList) {
6044 S.Diag(Init->getExprLoc(), diag::warn_dangling_std_initializer_list)
6045 << /*at end of constructor*/true;
6046 return;
6047 }
6048
6049 bool IsSubobjectMember = false;
6050 for (const InitializedEntity *Ent = Entity.getParent(); Ent;
6051 Ent = Ent->getParent()) {
6052 if (Ent->getKind() != InitializedEntity::EK_Base) {
6053 IsSubobjectMember = true;
6054 break;
6055 }
6056 }
6057 S.Diag(Init->getExprLoc(),
6058 diag::warn_bind_ref_member_to_temporary)
6059 << ExtendingDecl << Init->getSourceRange()
6060 << IsSubobjectMember << IsInitializerList;
6061 if (IsSubobjectMember)
6062 S.Diag(ExtendingDecl->getLocation(),
6063 diag::note_ref_subobject_of_member_declared_here);
6064 else
6065 S.Diag(ExtendingDecl->getLocation(),
6066 diag::note_ref_or_ptr_member_declared_here)
6067 << /*is pointer*/false;
6068 }
6069 }
6070
6071 static void DiagnoseNarrowingInInitList(Sema &S,
6072 const ImplicitConversionSequence &ICS,
6073 QualType PreNarrowingType,
6074 QualType EntityType,
6075 const Expr *PostInit);
6076
6077 /// Provide warnings when std::move is used on construction.
CheckMoveOnConstruction(Sema & S,const Expr * InitExpr,bool IsReturnStmt)6078 static void CheckMoveOnConstruction(Sema &S, const Expr *InitExpr,
6079 bool IsReturnStmt) {
6080 if (!InitExpr)
6081 return;
6082
6083 if (!S.ActiveTemplateInstantiations.empty())
6084 return;
6085
6086 QualType DestType = InitExpr->getType();
6087 if (!DestType->isRecordType())
6088 return;
6089
6090 unsigned DiagID = 0;
6091 if (IsReturnStmt) {
6092 const CXXConstructExpr *CCE =
6093 dyn_cast<CXXConstructExpr>(InitExpr->IgnoreParens());
6094 if (!CCE || CCE->getNumArgs() != 1)
6095 return;
6096
6097 if (!CCE->getConstructor()->isCopyOrMoveConstructor())
6098 return;
6099
6100 InitExpr = CCE->getArg(0)->IgnoreImpCasts();
6101 }
6102
6103 // Find the std::move call and get the argument.
6104 const CallExpr *CE = dyn_cast<CallExpr>(InitExpr->IgnoreParens());
6105 if (!CE || CE->getNumArgs() != 1)
6106 return;
6107
6108 const FunctionDecl *MoveFunction = CE->getDirectCallee();
6109 if (!MoveFunction || !MoveFunction->isInStdNamespace() ||
6110 !MoveFunction->getIdentifier() ||
6111 !MoveFunction->getIdentifier()->isStr("move"))
6112 return;
6113
6114 const Expr *Arg = CE->getArg(0)->IgnoreImplicit();
6115
6116 if (IsReturnStmt) {
6117 const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg->IgnoreParenImpCasts());
6118 if (!DRE || DRE->refersToEnclosingVariableOrCapture())
6119 return;
6120
6121 const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl());
6122 if (!VD || !VD->hasLocalStorage())
6123 return;
6124
6125 QualType SourceType = VD->getType();
6126 if (!SourceType->isRecordType())
6127 return;
6128
6129 if (!S.Context.hasSameUnqualifiedType(DestType, SourceType)) {
6130 return;
6131 }
6132
6133 // If we're returning a function parameter, copy elision
6134 // is not possible.
6135 if (isa<ParmVarDecl>(VD))
6136 DiagID = diag::warn_redundant_move_on_return;
6137 else
6138 DiagID = diag::warn_pessimizing_move_on_return;
6139 } else {
6140 DiagID = diag::warn_pessimizing_move_on_initialization;
6141 const Expr *ArgStripped = Arg->IgnoreImplicit()->IgnoreParens();
6142 if (!ArgStripped->isRValue() || !ArgStripped->getType()->isRecordType())
6143 return;
6144 }
6145
6146 S.Diag(CE->getLocStart(), DiagID);
6147
6148 // Get all the locations for a fix-it. Don't emit the fix-it if any location
6149 // is within a macro.
6150 SourceLocation CallBegin = CE->getCallee()->getLocStart();
6151 if (CallBegin.isMacroID())
6152 return;
6153 SourceLocation RParen = CE->getRParenLoc();
6154 if (RParen.isMacroID())
6155 return;
6156 SourceLocation LParen;
6157 SourceLocation ArgLoc = Arg->getLocStart();
6158
6159 // Special testing for the argument location. Since the fix-it needs the
6160 // location right before the argument, the argument location can be in a
6161 // macro only if it is at the beginning of the macro.
6162 while (ArgLoc.isMacroID() &&
6163 S.getSourceManager().isAtStartOfImmediateMacroExpansion(ArgLoc)) {
6164 ArgLoc = S.getSourceManager().getImmediateExpansionRange(ArgLoc).first;
6165 }
6166
6167 if (LParen.isMacroID())
6168 return;
6169
6170 LParen = ArgLoc.getLocWithOffset(-1);
6171
6172 S.Diag(CE->getLocStart(), diag::note_remove_move)
6173 << FixItHint::CreateRemoval(SourceRange(CallBegin, LParen))
6174 << FixItHint::CreateRemoval(SourceRange(RParen, RParen));
6175 }
6176
CheckForNullPointerDereference(Sema & S,const Expr * E)6177 static void CheckForNullPointerDereference(Sema &S, const Expr *E) {
6178 // Check to see if we are dereferencing a null pointer. If so, this is
6179 // undefined behavior, so warn about it. This only handles the pattern
6180 // "*null", which is a very syntactic check.
6181 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParenCasts()))
6182 if (UO->getOpcode() == UO_Deref &&
6183 UO->getSubExpr()->IgnoreParenCasts()->
6184 isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull)) {
6185 S.DiagRuntimeBehavior(UO->getOperatorLoc(), UO,
6186 S.PDiag(diag::warn_binding_null_to_reference)
6187 << UO->getSubExpr()->getSourceRange());
6188 }
6189 }
6190
6191 MaterializeTemporaryExpr *
CreateMaterializeTemporaryExpr(QualType T,Expr * Temporary,bool BoundToLvalueReference)6192 Sema::CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary,
6193 bool BoundToLvalueReference) {
6194 auto MTE = new (Context)
6195 MaterializeTemporaryExpr(T, Temporary, BoundToLvalueReference);
6196
6197 // Order an ExprWithCleanups for lifetime marks.
6198 //
6199 // TODO: It'll be good to have a single place to check the access of the
6200 // destructor and generate ExprWithCleanups for various uses. Currently these
6201 // are done in both CreateMaterializeTemporaryExpr and MaybeBindToTemporary,
6202 // but there may be a chance to merge them.
6203 Cleanup.setExprNeedsCleanups(false);
6204 return MTE;
6205 }
6206
6207 ExprResult
Perform(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,MultiExprArg Args,QualType * ResultType)6208 InitializationSequence::Perform(Sema &S,
6209 const InitializedEntity &Entity,
6210 const InitializationKind &Kind,
6211 MultiExprArg Args,
6212 QualType *ResultType) {
6213 if (Failed()) {
6214 Diagnose(S, Entity, Kind, Args);
6215 return ExprError();
6216 }
6217 if (!ZeroInitializationFixit.empty()) {
6218 unsigned DiagID = diag::err_default_init_const;
6219 if (Decl *D = Entity.getDecl())
6220 if (S.getLangOpts().MSVCCompat && D->hasAttr<SelectAnyAttr>())
6221 DiagID = diag::ext_default_init_const;
6222
6223 // The initialization would have succeeded with this fixit. Since the fixit
6224 // is on the error, we need to build a valid AST in this case, so this isn't
6225 // handled in the Failed() branch above.
6226 QualType DestType = Entity.getType();
6227 S.Diag(Kind.getLocation(), DiagID)
6228 << DestType << (bool)DestType->getAs<RecordType>()
6229 << FixItHint::CreateInsertion(ZeroInitializationFixitLoc,
6230 ZeroInitializationFixit);
6231 }
6232
6233 if (getKind() == DependentSequence) {
6234 // If the declaration is a non-dependent, incomplete array type
6235 // that has an initializer, then its type will be completed once
6236 // the initializer is instantiated.
6237 if (ResultType && !Entity.getType()->isDependentType() &&
6238 Args.size() == 1) {
6239 QualType DeclType = Entity.getType();
6240 if (const IncompleteArrayType *ArrayT
6241 = S.Context.getAsIncompleteArrayType(DeclType)) {
6242 // FIXME: We don't currently have the ability to accurately
6243 // compute the length of an initializer list without
6244 // performing full type-checking of the initializer list
6245 // (since we have to determine where braces are implicitly
6246 // introduced and such). So, we fall back to making the array
6247 // type a dependently-sized array type with no specified
6248 // bound.
6249 if (isa<InitListExpr>((Expr *)Args[0])) {
6250 SourceRange Brackets;
6251
6252 // Scavange the location of the brackets from the entity, if we can.
6253 if (DeclaratorDecl *DD = Entity.getDecl()) {
6254 if (TypeSourceInfo *TInfo = DD->getTypeSourceInfo()) {
6255 TypeLoc TL = TInfo->getTypeLoc();
6256 if (IncompleteArrayTypeLoc ArrayLoc =
6257 TL.getAs<IncompleteArrayTypeLoc>())
6258 Brackets = ArrayLoc.getBracketsRange();
6259 }
6260 }
6261
6262 *ResultType
6263 = S.Context.getDependentSizedArrayType(ArrayT->getElementType(),
6264 /*NumElts=*/nullptr,
6265 ArrayT->getSizeModifier(),
6266 ArrayT->getIndexTypeCVRQualifiers(),
6267 Brackets);
6268 }
6269
6270 }
6271 }
6272 if (Kind.getKind() == InitializationKind::IK_Direct &&
6273 !Kind.isExplicitCast()) {
6274 // Rebuild the ParenListExpr.
6275 SourceRange ParenRange = Kind.getParenRange();
6276 return S.ActOnParenListExpr(ParenRange.getBegin(), ParenRange.getEnd(),
6277 Args);
6278 }
6279 assert(Kind.getKind() == InitializationKind::IK_Copy ||
6280 Kind.isExplicitCast() ||
6281 Kind.getKind() == InitializationKind::IK_DirectList);
6282 return ExprResult(Args[0]);
6283 }
6284
6285 // No steps means no initialization.
6286 if (Steps.empty())
6287 return ExprResult((Expr *)nullptr);
6288
6289 if (S.getLangOpts().CPlusPlus11 && Entity.getType()->isReferenceType() &&
6290 Args.size() == 1 && isa<InitListExpr>(Args[0]) &&
6291 !Entity.isParameterKind()) {
6292 // Produce a C++98 compatibility warning if we are initializing a reference
6293 // from an initializer list. For parameters, we produce a better warning
6294 // elsewhere.
6295 Expr *Init = Args[0];
6296 S.Diag(Init->getLocStart(), diag::warn_cxx98_compat_reference_list_init)
6297 << Init->getSourceRange();
6298 }
6299
6300 // Diagnose cases where we initialize a pointer to an array temporary, and the
6301 // pointer obviously outlives the temporary.
6302 if (Args.size() == 1 && Args[0]->getType()->isArrayType() &&
6303 Entity.getType()->isPointerType() &&
6304 InitializedEntityOutlivesFullExpression(Entity)) {
6305 Expr *Init = Args[0];
6306 Expr::LValueClassification Kind = Init->ClassifyLValue(S.Context);
6307 if (Kind == Expr::LV_ClassTemporary || Kind == Expr::LV_ArrayTemporary)
6308 S.Diag(Init->getLocStart(), diag::warn_temporary_array_to_pointer_decay)
6309 << Init->getSourceRange();
6310 }
6311
6312 QualType DestType = Entity.getType().getNonReferenceType();
6313 // FIXME: Ugly hack around the fact that Entity.getType() is not
6314 // the same as Entity.getDecl()->getType() in cases involving type merging,
6315 // and we want latter when it makes sense.
6316 if (ResultType)
6317 *ResultType = Entity.getDecl() ? Entity.getDecl()->getType() :
6318 Entity.getType();
6319
6320 ExprResult CurInit((Expr *)nullptr);
6321
6322 // For initialization steps that start with a single initializer,
6323 // grab the only argument out the Args and place it into the "current"
6324 // initializer.
6325 switch (Steps.front().Kind) {
6326 case SK_ResolveAddressOfOverloadedFunction:
6327 case SK_CastDerivedToBaseRValue:
6328 case SK_CastDerivedToBaseXValue:
6329 case SK_CastDerivedToBaseLValue:
6330 case SK_BindReference:
6331 case SK_BindReferenceToTemporary:
6332 case SK_ExtraneousCopyToTemporary:
6333 case SK_UserConversion:
6334 case SK_QualificationConversionLValue:
6335 case SK_QualificationConversionXValue:
6336 case SK_QualificationConversionRValue:
6337 case SK_AtomicConversion:
6338 case SK_LValueToRValue:
6339 case SK_ConversionSequence:
6340 case SK_ConversionSequenceNoNarrowing:
6341 case SK_ListInitialization:
6342 case SK_UnwrapInitList:
6343 case SK_RewrapInitList:
6344 case SK_CAssignment:
6345 case SK_StringInit:
6346 case SK_ObjCObjectConversion:
6347 case SK_ArrayInit:
6348 case SK_ParenthesizedArrayInit:
6349 case SK_PassByIndirectCopyRestore:
6350 case SK_PassByIndirectRestore:
6351 case SK_ProduceObjCObject:
6352 case SK_StdInitializerList:
6353 case SK_OCLSamplerInit:
6354 case SK_OCLZeroEvent: {
6355 assert(Args.size() == 1);
6356 CurInit = Args[0];
6357 if (!CurInit.get()) return ExprError();
6358 break;
6359 }
6360
6361 case SK_ConstructorInitialization:
6362 case SK_ConstructorInitializationFromList:
6363 case SK_StdInitializerListConstructorCall:
6364 case SK_ZeroInitialization:
6365 break;
6366 }
6367
6368 // Walk through the computed steps for the initialization sequence,
6369 // performing the specified conversions along the way.
6370 bool ConstructorInitRequiresZeroInit = false;
6371 for (step_iterator Step = step_begin(), StepEnd = step_end();
6372 Step != StepEnd; ++Step) {
6373 if (CurInit.isInvalid())
6374 return ExprError();
6375
6376 QualType SourceType = CurInit.get() ? CurInit.get()->getType() : QualType();
6377
6378 switch (Step->Kind) {
6379 case SK_ResolveAddressOfOverloadedFunction:
6380 // Overload resolution determined which function invoke; update the
6381 // initializer to reflect that choice.
6382 S.CheckAddressOfMemberAccess(CurInit.get(), Step->Function.FoundDecl);
6383 if (S.DiagnoseUseOfDecl(Step->Function.FoundDecl, Kind.getLocation()))
6384 return ExprError();
6385 CurInit = S.FixOverloadedFunctionReference(CurInit,
6386 Step->Function.FoundDecl,
6387 Step->Function.Function);
6388 break;
6389
6390 case SK_CastDerivedToBaseRValue:
6391 case SK_CastDerivedToBaseXValue:
6392 case SK_CastDerivedToBaseLValue: {
6393 // We have a derived-to-base cast that produces either an rvalue or an
6394 // lvalue. Perform that cast.
6395
6396 CXXCastPath BasePath;
6397
6398 // Casts to inaccessible base classes are allowed with C-style casts.
6399 bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast();
6400 if (S.CheckDerivedToBaseConversion(SourceType, Step->Type,
6401 CurInit.get()->getLocStart(),
6402 CurInit.get()->getSourceRange(),
6403 &BasePath, IgnoreBaseAccess))
6404 return ExprError();
6405
6406 ExprValueKind VK =
6407 Step->Kind == SK_CastDerivedToBaseLValue ?
6408 VK_LValue :
6409 (Step->Kind == SK_CastDerivedToBaseXValue ?
6410 VK_XValue :
6411 VK_RValue);
6412 CurInit =
6413 ImplicitCastExpr::Create(S.Context, Step->Type, CK_DerivedToBase,
6414 CurInit.get(), &BasePath, VK);
6415 break;
6416 }
6417
6418 case SK_BindReference:
6419 // References cannot bind to bit-fields (C++ [dcl.init.ref]p5).
6420 if (CurInit.get()->refersToBitField()) {
6421 // We don't necessarily have an unambiguous source bit-field.
6422 FieldDecl *BitField = CurInit.get()->getSourceBitField();
6423 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield)
6424 << Entity.getType().isVolatileQualified()
6425 << (BitField ? BitField->getDeclName() : DeclarationName())
6426 << (BitField != nullptr)
6427 << CurInit.get()->getSourceRange();
6428 if (BitField)
6429 S.Diag(BitField->getLocation(), diag::note_bitfield_decl);
6430
6431 return ExprError();
6432 }
6433
6434 if (CurInit.get()->refersToVectorElement()) {
6435 // References cannot bind to vector elements.
6436 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_vector_element)
6437 << Entity.getType().isVolatileQualified()
6438 << CurInit.get()->getSourceRange();
6439 PrintInitLocationNote(S, Entity);
6440 return ExprError();
6441 }
6442
6443 // Reference binding does not have any corresponding ASTs.
6444
6445 // Check exception specifications
6446 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
6447 return ExprError();
6448
6449 // Even though we didn't materialize a temporary, the binding may still
6450 // extend the lifetime of a temporary. This happens if we bind a reference
6451 // to the result of a cast to reference type.
6452 if (const InitializedEntity *ExtendingEntity =
6453 getEntityForTemporaryLifetimeExtension(&Entity))
6454 if (performReferenceExtension(CurInit.get(), ExtendingEntity))
6455 warnOnLifetimeExtension(S, Entity, CurInit.get(),
6456 /*IsInitializerList=*/false,
6457 ExtendingEntity->getDecl());
6458
6459 CheckForNullPointerDereference(S, CurInit.get());
6460 break;
6461
6462 case SK_BindReferenceToTemporary: {
6463 // Make sure the "temporary" is actually an rvalue.
6464 assert(CurInit.get()->isRValue() && "not a temporary");
6465
6466 // Check exception specifications
6467 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType))
6468 return ExprError();
6469
6470 // Materialize the temporary into memory.
6471 MaterializeTemporaryExpr *MTE = S.CreateMaterializeTemporaryExpr(
6472 Entity.getType().getNonReferenceType(), CurInit.get(),
6473 Entity.getType()->isLValueReferenceType());
6474
6475 // Maybe lifetime-extend the temporary's subobjects to match the
6476 // entity's lifetime.
6477 if (const InitializedEntity *ExtendingEntity =
6478 getEntityForTemporaryLifetimeExtension(&Entity))
6479 if (performReferenceExtension(MTE, ExtendingEntity))
6480 warnOnLifetimeExtension(S, Entity, CurInit.get(), /*IsInitializerList=*/false,
6481 ExtendingEntity->getDecl());
6482
6483 // If we're binding to an Objective-C object that has lifetime, we
6484 // need cleanups. Likewise if we're extending this temporary to automatic
6485 // storage duration -- we need to register its cleanup during the
6486 // full-expression's cleanups.
6487 if ((S.getLangOpts().ObjCAutoRefCount &&
6488 MTE->getType()->isObjCLifetimeType()) ||
6489 (MTE->getStorageDuration() == SD_Automatic &&
6490 MTE->getType().isDestructedType()))
6491 S.Cleanup.setExprNeedsCleanups(true);
6492
6493 CurInit = MTE;
6494 break;
6495 }
6496
6497 case SK_ExtraneousCopyToTemporary:
6498 CurInit = CopyObject(S, Step->Type, Entity, CurInit,
6499 /*IsExtraneousCopy=*/true);
6500 break;
6501
6502 case SK_UserConversion: {
6503 // We have a user-defined conversion that invokes either a constructor
6504 // or a conversion function.
6505 CastKind CastKind;
6506 bool IsCopy = false;
6507 FunctionDecl *Fn = Step->Function.Function;
6508 DeclAccessPair FoundFn = Step->Function.FoundDecl;
6509 bool HadMultipleCandidates = Step->Function.HadMultipleCandidates;
6510 bool CreatedObject = false;
6511 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Fn)) {
6512 // Build a call to the selected constructor.
6513 SmallVector<Expr*, 8> ConstructorArgs;
6514 SourceLocation Loc = CurInit.get()->getLocStart();
6515 CurInit.get(); // Ownership transferred into MultiExprArg, below.
6516
6517 // Determine the arguments required to actually perform the constructor
6518 // call.
6519 Expr *Arg = CurInit.get();
6520 if (S.CompleteConstructorCall(Constructor,
6521 MultiExprArg(&Arg, 1),
6522 Loc, ConstructorArgs))
6523 return ExprError();
6524
6525 // Build an expression that constructs a temporary.
6526 CurInit = S.BuildCXXConstructExpr(Loc, Step->Type,
6527 FoundFn, Constructor,
6528 ConstructorArgs,
6529 HadMultipleCandidates,
6530 /*ListInit*/ false,
6531 /*StdInitListInit*/ false,
6532 /*ZeroInit*/ false,
6533 CXXConstructExpr::CK_Complete,
6534 SourceRange());
6535 if (CurInit.isInvalid())
6536 return ExprError();
6537
6538 S.CheckConstructorAccess(Kind.getLocation(), Constructor, FoundFn,
6539 Entity);
6540 if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()))
6541 return ExprError();
6542
6543 CastKind = CK_ConstructorConversion;
6544 QualType Class = S.Context.getTypeDeclType(Constructor->getParent());
6545 if (S.Context.hasSameUnqualifiedType(SourceType, Class) ||
6546 S.IsDerivedFrom(Loc, SourceType, Class))
6547 IsCopy = true;
6548
6549 CreatedObject = true;
6550 } else {
6551 // Build a call to the conversion function.
6552 CXXConversionDecl *Conversion = cast<CXXConversionDecl>(Fn);
6553 S.CheckMemberOperatorAccess(Kind.getLocation(), CurInit.get(), nullptr,
6554 FoundFn);
6555 if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()))
6556 return ExprError();
6557
6558 // FIXME: Should we move this initialization into a separate
6559 // derived-to-base conversion? I believe the answer is "no", because
6560 // we don't want to turn off access control here for c-style casts.
6561 ExprResult CurInitExprRes =
6562 S.PerformObjectArgumentInitialization(CurInit.get(),
6563 /*Qualifier=*/nullptr,
6564 FoundFn, Conversion);
6565 if(CurInitExprRes.isInvalid())
6566 return ExprError();
6567 CurInit = CurInitExprRes;
6568
6569 // Build the actual call to the conversion function.
6570 CurInit = S.BuildCXXMemberCallExpr(CurInit.get(), FoundFn, Conversion,
6571 HadMultipleCandidates);
6572 if (CurInit.isInvalid() || !CurInit.get())
6573 return ExprError();
6574
6575 CastKind = CK_UserDefinedConversion;
6576
6577 CreatedObject = Conversion->getReturnType()->isRecordType();
6578 }
6579
6580 bool RequiresCopy = !IsCopy && !isReferenceBinding(Steps.back());
6581 bool MaybeBindToTemp = RequiresCopy || shouldBindAsTemporary(Entity);
6582
6583 if (!MaybeBindToTemp && CreatedObject && shouldDestroyTemporary(Entity)) {
6584 QualType T = CurInit.get()->getType();
6585 if (const RecordType *Record = T->getAs<RecordType>()) {
6586 CXXDestructorDecl *Destructor
6587 = S.LookupDestructor(cast<CXXRecordDecl>(Record->getDecl()));
6588 S.CheckDestructorAccess(CurInit.get()->getLocStart(), Destructor,
6589 S.PDiag(diag::err_access_dtor_temp) << T);
6590 S.MarkFunctionReferenced(CurInit.get()->getLocStart(), Destructor);
6591 if (S.DiagnoseUseOfDecl(Destructor, CurInit.get()->getLocStart()))
6592 return ExprError();
6593 }
6594 }
6595
6596 CurInit = ImplicitCastExpr::Create(S.Context, CurInit.get()->getType(),
6597 CastKind, CurInit.get(), nullptr,
6598 CurInit.get()->getValueKind());
6599 if (MaybeBindToTemp)
6600 CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>());
6601 if (RequiresCopy)
6602 CurInit = CopyObject(S, Entity.getType().getNonReferenceType(), Entity,
6603 CurInit, /*IsExtraneousCopy=*/false);
6604 break;
6605 }
6606
6607 case SK_QualificationConversionLValue:
6608 case SK_QualificationConversionXValue:
6609 case SK_QualificationConversionRValue: {
6610 // Perform a qualification conversion; these can never go wrong.
6611 ExprValueKind VK =
6612 Step->Kind == SK_QualificationConversionLValue ?
6613 VK_LValue :
6614 (Step->Kind == SK_QualificationConversionXValue ?
6615 VK_XValue :
6616 VK_RValue);
6617 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type, CK_NoOp, VK);
6618 break;
6619 }
6620
6621 case SK_AtomicConversion: {
6622 assert(CurInit.get()->isRValue() && "cannot convert glvalue to atomic");
6623 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
6624 CK_NonAtomicToAtomic, VK_RValue);
6625 break;
6626 }
6627
6628 case SK_LValueToRValue: {
6629 assert(CurInit.get()->isGLValue() && "cannot load from a prvalue");
6630 CurInit = ImplicitCastExpr::Create(S.Context, Step->Type,
6631 CK_LValueToRValue, CurInit.get(),
6632 /*BasePath=*/nullptr, VK_RValue);
6633 break;
6634 }
6635
6636 case SK_ConversionSequence:
6637 case SK_ConversionSequenceNoNarrowing: {
6638 Sema::CheckedConversionKind CCK
6639 = Kind.isCStyleCast()? Sema::CCK_CStyleCast
6640 : Kind.isFunctionalCast()? Sema::CCK_FunctionalCast
6641 : Kind.isExplicitCast()? Sema::CCK_OtherCast
6642 : Sema::CCK_ImplicitConversion;
6643 ExprResult CurInitExprRes =
6644 S.PerformImplicitConversion(CurInit.get(), Step->Type, *Step->ICS,
6645 getAssignmentAction(Entity), CCK);
6646 if (CurInitExprRes.isInvalid())
6647 return ExprError();
6648 CurInit = CurInitExprRes;
6649
6650 if (Step->Kind == SK_ConversionSequenceNoNarrowing &&
6651 S.getLangOpts().CPlusPlus && !CurInit.get()->isValueDependent())
6652 DiagnoseNarrowingInInitList(S, *Step->ICS, SourceType, Entity.getType(),
6653 CurInit.get());
6654 break;
6655 }
6656
6657 case SK_ListInitialization: {
6658 InitListExpr *InitList = cast<InitListExpr>(CurInit.get());
6659 // If we're not initializing the top-level entity, we need to create an
6660 // InitializeTemporary entity for our target type.
6661 QualType Ty = Step->Type;
6662 bool IsTemporary = !S.Context.hasSameType(Entity.getType(), Ty);
6663 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(Ty);
6664 InitializedEntity InitEntity = IsTemporary ? TempEntity : Entity;
6665 InitListChecker PerformInitList(S, InitEntity,
6666 InitList, Ty, /*VerifyOnly=*/false,
6667 /*TreatUnavailableAsInvalid=*/false);
6668 if (PerformInitList.HadError())
6669 return ExprError();
6670
6671 // Hack: We must update *ResultType if available in order to set the
6672 // bounds of arrays, e.g. in 'int ar[] = {1, 2, 3};'.
6673 // Worst case: 'const int (&arref)[] = {1, 2, 3};'.
6674 if (ResultType &&
6675 ResultType->getNonReferenceType()->isIncompleteArrayType()) {
6676 if ((*ResultType)->isRValueReferenceType())
6677 Ty = S.Context.getRValueReferenceType(Ty);
6678 else if ((*ResultType)->isLValueReferenceType())
6679 Ty = S.Context.getLValueReferenceType(Ty,
6680 (*ResultType)->getAs<LValueReferenceType>()->isSpelledAsLValue());
6681 *ResultType = Ty;
6682 }
6683
6684 InitListExpr *StructuredInitList =
6685 PerformInitList.getFullyStructuredList();
6686 CurInit.get();
6687 CurInit = shouldBindAsTemporary(InitEntity)
6688 ? S.MaybeBindToTemporary(StructuredInitList)
6689 : StructuredInitList;
6690 break;
6691 }
6692
6693 case SK_ConstructorInitializationFromList: {
6694 // When an initializer list is passed for a parameter of type "reference
6695 // to object", we don't get an EK_Temporary entity, but instead an
6696 // EK_Parameter entity with reference type.
6697 // FIXME: This is a hack. What we really should do is create a user
6698 // conversion step for this case, but this makes it considerably more
6699 // complicated. For now, this will do.
6700 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(
6701 Entity.getType().getNonReferenceType());
6702 bool UseTemporary = Entity.getType()->isReferenceType();
6703 assert(Args.size() == 1 && "expected a single argument for list init");
6704 InitListExpr *InitList = cast<InitListExpr>(Args[0]);
6705 S.Diag(InitList->getExprLoc(), diag::warn_cxx98_compat_ctor_list_init)
6706 << InitList->getSourceRange();
6707 MultiExprArg Arg(InitList->getInits(), InitList->getNumInits());
6708 CurInit = PerformConstructorInitialization(S, UseTemporary ? TempEntity :
6709 Entity,
6710 Kind, Arg, *Step,
6711 ConstructorInitRequiresZeroInit,
6712 /*IsListInitialization*/true,
6713 /*IsStdInitListInit*/false,
6714 InitList->getLBraceLoc(),
6715 InitList->getRBraceLoc());
6716 break;
6717 }
6718
6719 case SK_UnwrapInitList:
6720 CurInit = cast<InitListExpr>(CurInit.get())->getInit(0);
6721 break;
6722
6723 case SK_RewrapInitList: {
6724 Expr *E = CurInit.get();
6725 InitListExpr *Syntactic = Step->WrappingSyntacticList;
6726 InitListExpr *ILE = new (S.Context) InitListExpr(S.Context,
6727 Syntactic->getLBraceLoc(), E, Syntactic->getRBraceLoc());
6728 ILE->setSyntacticForm(Syntactic);
6729 ILE->setType(E->getType());
6730 ILE->setValueKind(E->getValueKind());
6731 CurInit = ILE;
6732 break;
6733 }
6734
6735 case SK_ConstructorInitialization:
6736 case SK_StdInitializerListConstructorCall: {
6737 // When an initializer list is passed for a parameter of type "reference
6738 // to object", we don't get an EK_Temporary entity, but instead an
6739 // EK_Parameter entity with reference type.
6740 // FIXME: This is a hack. What we really should do is create a user
6741 // conversion step for this case, but this makes it considerably more
6742 // complicated. For now, this will do.
6743 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(
6744 Entity.getType().getNonReferenceType());
6745 bool UseTemporary = Entity.getType()->isReferenceType();
6746 bool IsStdInitListInit =
6747 Step->Kind == SK_StdInitializerListConstructorCall;
6748 CurInit = PerformConstructorInitialization(
6749 S, UseTemporary ? TempEntity : Entity, Kind, Args, *Step,
6750 ConstructorInitRequiresZeroInit,
6751 /*IsListInitialization*/IsStdInitListInit,
6752 /*IsStdInitListInitialization*/IsStdInitListInit,
6753 /*LBraceLoc*/SourceLocation(),
6754 /*RBraceLoc*/SourceLocation());
6755 break;
6756 }
6757
6758 case SK_ZeroInitialization: {
6759 step_iterator NextStep = Step;
6760 ++NextStep;
6761 if (NextStep != StepEnd &&
6762 (NextStep->Kind == SK_ConstructorInitialization ||
6763 NextStep->Kind == SK_ConstructorInitializationFromList)) {
6764 // The need for zero-initialization is recorded directly into
6765 // the call to the object's constructor within the next step.
6766 ConstructorInitRequiresZeroInit = true;
6767 } else if (Kind.getKind() == InitializationKind::IK_Value &&
6768 S.getLangOpts().CPlusPlus &&
6769 !Kind.isImplicitValueInit()) {
6770 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo();
6771 if (!TSInfo)
6772 TSInfo = S.Context.getTrivialTypeSourceInfo(Step->Type,
6773 Kind.getRange().getBegin());
6774
6775 CurInit = new (S.Context) CXXScalarValueInitExpr(
6776 TSInfo->getType().getNonLValueExprType(S.Context), TSInfo,
6777 Kind.getRange().getEnd());
6778 } else {
6779 CurInit = new (S.Context) ImplicitValueInitExpr(Step->Type);
6780 }
6781 break;
6782 }
6783
6784 case SK_CAssignment: {
6785 QualType SourceType = CurInit.get()->getType();
6786 // Save off the initial CurInit in case we need to emit a diagnostic
6787 ExprResult InitialCurInit = CurInit;
6788 ExprResult Result = CurInit;
6789 Sema::AssignConvertType ConvTy =
6790 S.CheckSingleAssignmentConstraints(Step->Type, Result, true,
6791 Entity.getKind() == InitializedEntity::EK_Parameter_CF_Audited);
6792 if (Result.isInvalid())
6793 return ExprError();
6794 CurInit = Result;
6795
6796 // If this is a call, allow conversion to a transparent union.
6797 ExprResult CurInitExprRes = CurInit;
6798 if (ConvTy != Sema::Compatible &&
6799 Entity.isParameterKind() &&
6800 S.CheckTransparentUnionArgumentConstraints(Step->Type, CurInitExprRes)
6801 == Sema::Compatible)
6802 ConvTy = Sema::Compatible;
6803 if (CurInitExprRes.isInvalid())
6804 return ExprError();
6805 CurInit = CurInitExprRes;
6806
6807 bool Complained;
6808 if (S.DiagnoseAssignmentResult(ConvTy, Kind.getLocation(),
6809 Step->Type, SourceType,
6810 InitialCurInit.get(),
6811 getAssignmentAction(Entity, true),
6812 &Complained)) {
6813 PrintInitLocationNote(S, Entity);
6814 return ExprError();
6815 } else if (Complained)
6816 PrintInitLocationNote(S, Entity);
6817 break;
6818 }
6819
6820 case SK_StringInit: {
6821 QualType Ty = Step->Type;
6822 CheckStringInit(CurInit.get(), ResultType ? *ResultType : Ty,
6823 S.Context.getAsArrayType(Ty), S);
6824 break;
6825 }
6826
6827 case SK_ObjCObjectConversion:
6828 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
6829 CK_ObjCObjectLValueCast,
6830 CurInit.get()->getValueKind());
6831 break;
6832
6833 case SK_ArrayInit:
6834 // Okay: we checked everything before creating this step. Note that
6835 // this is a GNU extension.
6836 S.Diag(Kind.getLocation(), diag::ext_array_init_copy)
6837 << Step->Type << CurInit.get()->getType()
6838 << CurInit.get()->getSourceRange();
6839
6840 // If the destination type is an incomplete array type, update the
6841 // type accordingly.
6842 if (ResultType) {
6843 if (const IncompleteArrayType *IncompleteDest
6844 = S.Context.getAsIncompleteArrayType(Step->Type)) {
6845 if (const ConstantArrayType *ConstantSource
6846 = S.Context.getAsConstantArrayType(CurInit.get()->getType())) {
6847 *ResultType = S.Context.getConstantArrayType(
6848 IncompleteDest->getElementType(),
6849 ConstantSource->getSize(),
6850 ArrayType::Normal, 0);
6851 }
6852 }
6853 }
6854 break;
6855
6856 case SK_ParenthesizedArrayInit:
6857 // Okay: we checked everything before creating this step. Note that
6858 // this is a GNU extension.
6859 S.Diag(Kind.getLocation(), diag::ext_array_init_parens)
6860 << CurInit.get()->getSourceRange();
6861 break;
6862
6863 case SK_PassByIndirectCopyRestore:
6864 case SK_PassByIndirectRestore:
6865 checkIndirectCopyRestoreSource(S, CurInit.get());
6866 CurInit = new (S.Context) ObjCIndirectCopyRestoreExpr(
6867 CurInit.get(), Step->Type,
6868 Step->Kind == SK_PassByIndirectCopyRestore);
6869 break;
6870
6871 case SK_ProduceObjCObject:
6872 CurInit =
6873 ImplicitCastExpr::Create(S.Context, Step->Type, CK_ARCProduceObject,
6874 CurInit.get(), nullptr, VK_RValue);
6875 break;
6876
6877 case SK_StdInitializerList: {
6878 S.Diag(CurInit.get()->getExprLoc(),
6879 diag::warn_cxx98_compat_initializer_list_init)
6880 << CurInit.get()->getSourceRange();
6881
6882 // Materialize the temporary into memory.
6883 MaterializeTemporaryExpr *MTE = S.CreateMaterializeTemporaryExpr(
6884 CurInit.get()->getType(), CurInit.get(),
6885 /*BoundToLvalueReference=*/false);
6886
6887 // Maybe lifetime-extend the array temporary's subobjects to match the
6888 // entity's lifetime.
6889 if (const InitializedEntity *ExtendingEntity =
6890 getEntityForTemporaryLifetimeExtension(&Entity))
6891 if (performReferenceExtension(MTE, ExtendingEntity))
6892 warnOnLifetimeExtension(S, Entity, CurInit.get(),
6893 /*IsInitializerList=*/true,
6894 ExtendingEntity->getDecl());
6895
6896 // Wrap it in a construction of a std::initializer_list<T>.
6897 CurInit = new (S.Context) CXXStdInitializerListExpr(Step->Type, MTE);
6898
6899 // Bind the result, in case the library has given initializer_list a
6900 // non-trivial destructor.
6901 if (shouldBindAsTemporary(Entity))
6902 CurInit = S.MaybeBindToTemporary(CurInit.get());
6903 break;
6904 }
6905
6906 case SK_OCLSamplerInit: {
6907 assert(Step->Type->isSamplerT() &&
6908 "Sampler initialization on non-sampler type.");
6909
6910 QualType SourceType = CurInit.get()->getType();
6911
6912 if (Entity.isParameterKind()) {
6913 if (!SourceType->isSamplerT())
6914 S.Diag(Kind.getLocation(), diag::err_sampler_argument_required)
6915 << SourceType;
6916 } else if (Entity.getKind() != InitializedEntity::EK_Variable) {
6917 llvm_unreachable("Invalid EntityKind!");
6918 }
6919
6920 break;
6921 }
6922 case SK_OCLZeroEvent: {
6923 assert(Step->Type->isEventT() &&
6924 "Event initialization on non-event type.");
6925
6926 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type,
6927 CK_ZeroToOCLEvent,
6928 CurInit.get()->getValueKind());
6929 break;
6930 }
6931 }
6932 }
6933
6934 // Diagnose non-fatal problems with the completed initialization.
6935 if (Entity.getKind() == InitializedEntity::EK_Member &&
6936 cast<FieldDecl>(Entity.getDecl())->isBitField())
6937 S.CheckBitFieldInitialization(Kind.getLocation(),
6938 cast<FieldDecl>(Entity.getDecl()),
6939 CurInit.get());
6940
6941 // Check for std::move on construction.
6942 if (const Expr *E = CurInit.get()) {
6943 CheckMoveOnConstruction(S, E,
6944 Entity.getKind() == InitializedEntity::EK_Result);
6945 }
6946
6947 return CurInit;
6948 }
6949
6950 /// Somewhere within T there is an uninitialized reference subobject.
6951 /// Dig it out and diagnose it.
DiagnoseUninitializedReference(Sema & S,SourceLocation Loc,QualType T)6952 static bool DiagnoseUninitializedReference(Sema &S, SourceLocation Loc,
6953 QualType T) {
6954 if (T->isReferenceType()) {
6955 S.Diag(Loc, diag::err_reference_without_init)
6956 << T.getNonReferenceType();
6957 return true;
6958 }
6959
6960 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
6961 if (!RD || !RD->hasUninitializedReferenceMember())
6962 return false;
6963
6964 for (const auto *FI : RD->fields()) {
6965 if (FI->isUnnamedBitfield())
6966 continue;
6967
6968 if (DiagnoseUninitializedReference(S, FI->getLocation(), FI->getType())) {
6969 S.Diag(Loc, diag::note_value_initialization_here) << RD;
6970 return true;
6971 }
6972 }
6973
6974 for (const auto &BI : RD->bases()) {
6975 if (DiagnoseUninitializedReference(S, BI.getLocStart(), BI.getType())) {
6976 S.Diag(Loc, diag::note_value_initialization_here) << RD;
6977 return true;
6978 }
6979 }
6980
6981 return false;
6982 }
6983
6984
6985 //===----------------------------------------------------------------------===//
6986 // Diagnose initialization failures
6987 //===----------------------------------------------------------------------===//
6988
6989 /// Emit notes associated with an initialization that failed due to a
6990 /// "simple" conversion failure.
emitBadConversionNotes(Sema & S,const InitializedEntity & entity,Expr * op)6991 static void emitBadConversionNotes(Sema &S, const InitializedEntity &entity,
6992 Expr *op) {
6993 QualType destType = entity.getType();
6994 if (destType.getNonReferenceType()->isObjCObjectPointerType() &&
6995 op->getType()->isObjCObjectPointerType()) {
6996
6997 // Emit a possible note about the conversion failing because the
6998 // operand is a message send with a related result type.
6999 S.EmitRelatedResultTypeNote(op);
7000
7001 // Emit a possible note about a return failing because we're
7002 // expecting a related result type.
7003 if (entity.getKind() == InitializedEntity::EK_Result)
7004 S.EmitRelatedResultTypeNoteForReturn(destType);
7005 }
7006 }
7007
diagnoseListInit(Sema & S,const InitializedEntity & Entity,InitListExpr * InitList)7008 static void diagnoseListInit(Sema &S, const InitializedEntity &Entity,
7009 InitListExpr *InitList) {
7010 QualType DestType = Entity.getType();
7011
7012 QualType E;
7013 if (S.getLangOpts().CPlusPlus11 && S.isStdInitializerList(DestType, &E)) {
7014 QualType ArrayType = S.Context.getConstantArrayType(
7015 E.withConst(),
7016 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()),
7017 InitList->getNumInits()),
7018 clang::ArrayType::Normal, 0);
7019 InitializedEntity HiddenArray =
7020 InitializedEntity::InitializeTemporary(ArrayType);
7021 return diagnoseListInit(S, HiddenArray, InitList);
7022 }
7023
7024 if (DestType->isReferenceType()) {
7025 // A list-initialization failure for a reference means that we tried to
7026 // create a temporary of the inner type (per [dcl.init.list]p3.6) and the
7027 // inner initialization failed.
7028 QualType T = DestType->getAs<ReferenceType>()->getPointeeType();
7029 diagnoseListInit(S, InitializedEntity::InitializeTemporary(T), InitList);
7030 SourceLocation Loc = InitList->getLocStart();
7031 if (auto *D = Entity.getDecl())
7032 Loc = D->getLocation();
7033 S.Diag(Loc, diag::note_in_reference_temporary_list_initializer) << T;
7034 return;
7035 }
7036
7037 InitListChecker DiagnoseInitList(S, Entity, InitList, DestType,
7038 /*VerifyOnly=*/false,
7039 /*TreatUnavailableAsInvalid=*/false);
7040 assert(DiagnoseInitList.HadError() &&
7041 "Inconsistent init list check result.");
7042 }
7043
Diagnose(Sema & S,const InitializedEntity & Entity,const InitializationKind & Kind,ArrayRef<Expr * > Args)7044 bool InitializationSequence::Diagnose(Sema &S,
7045 const InitializedEntity &Entity,
7046 const InitializationKind &Kind,
7047 ArrayRef<Expr *> Args) {
7048 if (!Failed())
7049 return false;
7050
7051 QualType DestType = Entity.getType();
7052 switch (Failure) {
7053 case FK_TooManyInitsForReference:
7054 // FIXME: Customize for the initialized entity?
7055 if (Args.empty()) {
7056 // Dig out the reference subobject which is uninitialized and diagnose it.
7057 // If this is value-initialization, this could be nested some way within
7058 // the target type.
7059 assert(Kind.getKind() == InitializationKind::IK_Value ||
7060 DestType->isReferenceType());
7061 bool Diagnosed =
7062 DiagnoseUninitializedReference(S, Kind.getLocation(), DestType);
7063 assert(Diagnosed && "couldn't find uninitialized reference to diagnose");
7064 (void)Diagnosed;
7065 } else // FIXME: diagnostic below could be better!
7066 S.Diag(Kind.getLocation(), diag::err_reference_has_multiple_inits)
7067 << SourceRange(Args.front()->getLocStart(), Args.back()->getLocEnd());
7068 break;
7069
7070 case FK_ArrayNeedsInitList:
7071 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 0;
7072 break;
7073 case FK_ArrayNeedsInitListOrStringLiteral:
7074 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 1;
7075 break;
7076 case FK_ArrayNeedsInitListOrWideStringLiteral:
7077 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 2;
7078 break;
7079 case FK_NarrowStringIntoWideCharArray:
7080 S.Diag(Kind.getLocation(), diag::err_array_init_narrow_string_into_wchar);
7081 break;
7082 case FK_WideStringIntoCharArray:
7083 S.Diag(Kind.getLocation(), diag::err_array_init_wide_string_into_char);
7084 break;
7085 case FK_IncompatWideStringIntoWideChar:
7086 S.Diag(Kind.getLocation(),
7087 diag::err_array_init_incompat_wide_string_into_wchar);
7088 break;
7089 case FK_ArrayTypeMismatch:
7090 case FK_NonConstantArrayInit:
7091 S.Diag(Kind.getLocation(),
7092 (Failure == FK_ArrayTypeMismatch
7093 ? diag::err_array_init_different_type
7094 : diag::err_array_init_non_constant_array))
7095 << DestType.getNonReferenceType()
7096 << Args[0]->getType()
7097 << Args[0]->getSourceRange();
7098 break;
7099
7100 case FK_VariableLengthArrayHasInitializer:
7101 S.Diag(Kind.getLocation(), diag::err_variable_object_no_init)
7102 << Args[0]->getSourceRange();
7103 break;
7104
7105 case FK_AddressOfOverloadFailed: {
7106 DeclAccessPair Found;
7107 S.ResolveAddressOfOverloadedFunction(Args[0],
7108 DestType.getNonReferenceType(),
7109 true,
7110 Found);
7111 break;
7112 }
7113
7114 case FK_AddressOfUnaddressableFunction: {
7115 auto *FD = cast<FunctionDecl>(cast<DeclRefExpr>(Args[0])->getDecl());
7116 S.checkAddressOfFunctionIsAvailable(FD, /*Complain=*/true,
7117 Args[0]->getLocStart());
7118 break;
7119 }
7120
7121 case FK_ReferenceInitOverloadFailed:
7122 case FK_UserConversionOverloadFailed:
7123 switch (FailedOverloadResult) {
7124 case OR_Ambiguous:
7125 if (Failure == FK_UserConversionOverloadFailed)
7126 S.Diag(Kind.getLocation(), diag::err_typecheck_ambiguous_condition)
7127 << Args[0]->getType() << DestType
7128 << Args[0]->getSourceRange();
7129 else
7130 S.Diag(Kind.getLocation(), diag::err_ref_init_ambiguous)
7131 << DestType << Args[0]->getType()
7132 << Args[0]->getSourceRange();
7133
7134 FailedCandidateSet.NoteCandidates(S, OCD_ViableCandidates, Args);
7135 break;
7136
7137 case OR_No_Viable_Function:
7138 if (!S.RequireCompleteType(Kind.getLocation(),
7139 DestType.getNonReferenceType(),
7140 diag::err_typecheck_nonviable_condition_incomplete,
7141 Args[0]->getType(), Args[0]->getSourceRange()))
7142 S.Diag(Kind.getLocation(), diag::err_typecheck_nonviable_condition)
7143 << (Entity.getKind() == InitializedEntity::EK_Result)
7144 << Args[0]->getType() << Args[0]->getSourceRange()
7145 << DestType.getNonReferenceType();
7146
7147 FailedCandidateSet.NoteCandidates(S, OCD_AllCandidates, Args);
7148 break;
7149
7150 case OR_Deleted: {
7151 S.Diag(Kind.getLocation(), diag::err_typecheck_deleted_function)
7152 << Args[0]->getType() << DestType.getNonReferenceType()
7153 << Args[0]->getSourceRange();
7154 OverloadCandidateSet::iterator Best;
7155 OverloadingResult Ovl
7156 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best,
7157 true);
7158 if (Ovl == OR_Deleted) {
7159 S.NoteDeletedFunction(Best->Function);
7160 } else {
7161 llvm_unreachable("Inconsistent overload resolution?");
7162 }
7163 break;
7164 }
7165
7166 case OR_Success:
7167 llvm_unreachable("Conversion did not fail!");
7168 }
7169 break;
7170
7171 case FK_NonConstLValueReferenceBindingToTemporary:
7172 if (isa<InitListExpr>(Args[0])) {
7173 S.Diag(Kind.getLocation(),
7174 diag::err_lvalue_reference_bind_to_initlist)
7175 << DestType.getNonReferenceType().isVolatileQualified()
7176 << DestType.getNonReferenceType()
7177 << Args[0]->getSourceRange();
7178 break;
7179 }
7180 // Intentional fallthrough
7181
7182 case FK_NonConstLValueReferenceBindingToUnrelated:
7183 S.Diag(Kind.getLocation(),
7184 Failure == FK_NonConstLValueReferenceBindingToTemporary
7185 ? diag::err_lvalue_reference_bind_to_temporary
7186 : diag::err_lvalue_reference_bind_to_unrelated)
7187 << DestType.getNonReferenceType().isVolatileQualified()
7188 << DestType.getNonReferenceType()
7189 << Args[0]->getType()
7190 << Args[0]->getSourceRange();
7191 break;
7192
7193 case FK_RValueReferenceBindingToLValue:
7194 S.Diag(Kind.getLocation(), diag::err_lvalue_to_rvalue_ref)
7195 << DestType.getNonReferenceType() << Args[0]->getType()
7196 << Args[0]->getSourceRange();
7197 break;
7198
7199 case FK_ReferenceInitDropsQualifiers: {
7200 QualType SourceType = Args[0]->getType();
7201 QualType NonRefType = DestType.getNonReferenceType();
7202 Qualifiers DroppedQualifiers =
7203 SourceType.getQualifiers() - NonRefType.getQualifiers();
7204
7205 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals)
7206 << SourceType
7207 << NonRefType
7208 << DroppedQualifiers.getCVRQualifiers()
7209 << Args[0]->getSourceRange();
7210 break;
7211 }
7212
7213 case FK_ReferenceInitFailed:
7214 S.Diag(Kind.getLocation(), diag::err_reference_bind_failed)
7215 << DestType.getNonReferenceType()
7216 << Args[0]->isLValue()
7217 << Args[0]->getType()
7218 << Args[0]->getSourceRange();
7219 emitBadConversionNotes(S, Entity, Args[0]);
7220 break;
7221
7222 case FK_ConversionFailed: {
7223 QualType FromType = Args[0]->getType();
7224 PartialDiagnostic PDiag = S.PDiag(diag::err_init_conversion_failed)
7225 << (int)Entity.getKind()
7226 << DestType
7227 << Args[0]->isLValue()
7228 << FromType
7229 << Args[0]->getSourceRange();
7230 S.HandleFunctionTypeMismatch(PDiag, FromType, DestType);
7231 S.Diag(Kind.getLocation(), PDiag);
7232 emitBadConversionNotes(S, Entity, Args[0]);
7233 break;
7234 }
7235
7236 case FK_ConversionFromPropertyFailed:
7237 // No-op. This error has already been reported.
7238 break;
7239
7240 case FK_TooManyInitsForScalar: {
7241 SourceRange R;
7242
7243 auto *InitList = dyn_cast<InitListExpr>(Args[0]);
7244 if (InitList && InitList->getNumInits() >= 1) {
7245 R = SourceRange(InitList->getInit(0)->getLocEnd(), InitList->getLocEnd());
7246 } else {
7247 assert(Args.size() > 1 && "Expected multiple initializers!");
7248 R = SourceRange(Args.front()->getLocEnd(), Args.back()->getLocEnd());
7249 }
7250
7251 R.setBegin(S.getLocForEndOfToken(R.getBegin()));
7252 if (Kind.isCStyleOrFunctionalCast())
7253 S.Diag(Kind.getLocation(), diag::err_builtin_func_cast_more_than_one_arg)
7254 << R;
7255 else
7256 S.Diag(Kind.getLocation(), diag::err_excess_initializers)
7257 << /*scalar=*/2 << R;
7258 break;
7259 }
7260
7261 case FK_ReferenceBindingToInitList:
7262 S.Diag(Kind.getLocation(), diag::err_reference_bind_init_list)
7263 << DestType.getNonReferenceType() << Args[0]->getSourceRange();
7264 break;
7265
7266 case FK_InitListBadDestinationType:
7267 S.Diag(Kind.getLocation(), diag::err_init_list_bad_dest_type)
7268 << (DestType->isRecordType()) << DestType << Args[0]->getSourceRange();
7269 break;
7270
7271 case FK_ListConstructorOverloadFailed:
7272 case FK_ConstructorOverloadFailed: {
7273 SourceRange ArgsRange;
7274 if (Args.size())
7275 ArgsRange = SourceRange(Args.front()->getLocStart(),
7276 Args.back()->getLocEnd());
7277
7278 if (Failure == FK_ListConstructorOverloadFailed) {
7279 assert(Args.size() == 1 &&
7280 "List construction from other than 1 argument.");
7281 InitListExpr *InitList = cast<InitListExpr>(Args[0]);
7282 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
7283 }
7284
7285 // FIXME: Using "DestType" for the entity we're printing is probably
7286 // bad.
7287 switch (FailedOverloadResult) {
7288 case OR_Ambiguous:
7289 S.Diag(Kind.getLocation(), diag::err_ovl_ambiguous_init)
7290 << DestType << ArgsRange;
7291 FailedCandidateSet.NoteCandidates(S, OCD_ViableCandidates, Args);
7292 break;
7293
7294 case OR_No_Viable_Function:
7295 if (Kind.getKind() == InitializationKind::IK_Default &&
7296 (Entity.getKind() == InitializedEntity::EK_Base ||
7297 Entity.getKind() == InitializedEntity::EK_Member) &&
7298 isa<CXXConstructorDecl>(S.CurContext)) {
7299 // This is implicit default initialization of a member or
7300 // base within a constructor. If no viable function was
7301 // found, notify the user that they need to explicitly
7302 // initialize this base/member.
7303 CXXConstructorDecl *Constructor
7304 = cast<CXXConstructorDecl>(S.CurContext);
7305 const CXXRecordDecl *InheritedFrom = nullptr;
7306 if (auto Inherited = Constructor->getInheritedConstructor())
7307 InheritedFrom = Inherited.getShadowDecl()->getNominatedBaseClass();
7308 if (Entity.getKind() == InitializedEntity::EK_Base) {
7309 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor)
7310 << (InheritedFrom ? 2 : Constructor->isImplicit() ? 1 : 0)
7311 << S.Context.getTypeDeclType(Constructor->getParent())
7312 << /*base=*/0
7313 << Entity.getType()
7314 << InheritedFrom;
7315
7316 RecordDecl *BaseDecl
7317 = Entity.getBaseSpecifier()->getType()->getAs<RecordType>()
7318 ->getDecl();
7319 S.Diag(BaseDecl->getLocation(), diag::note_previous_decl)
7320 << S.Context.getTagDeclType(BaseDecl);
7321 } else {
7322 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor)
7323 << (InheritedFrom ? 2 : Constructor->isImplicit() ? 1 : 0)
7324 << S.Context.getTypeDeclType(Constructor->getParent())
7325 << /*member=*/1
7326 << Entity.getName()
7327 << InheritedFrom;
7328 S.Diag(Entity.getDecl()->getLocation(),
7329 diag::note_member_declared_at);
7330
7331 if (const RecordType *Record
7332 = Entity.getType()->getAs<RecordType>())
7333 S.Diag(Record->getDecl()->getLocation(),
7334 diag::note_previous_decl)
7335 << S.Context.getTagDeclType(Record->getDecl());
7336 }
7337 break;
7338 }
7339
7340 S.Diag(Kind.getLocation(), diag::err_ovl_no_viable_function_in_init)
7341 << DestType << ArgsRange;
7342 FailedCandidateSet.NoteCandidates(S, OCD_AllCandidates, Args);
7343 break;
7344
7345 case OR_Deleted: {
7346 OverloadCandidateSet::iterator Best;
7347 OverloadingResult Ovl
7348 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
7349 if (Ovl != OR_Deleted) {
7350 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
7351 << true << DestType << ArgsRange;
7352 llvm_unreachable("Inconsistent overload resolution?");
7353 break;
7354 }
7355
7356 // If this is a defaulted or implicitly-declared function, then
7357 // it was implicitly deleted. Make it clear that the deletion was
7358 // implicit.
7359 if (S.isImplicitlyDeleted(Best->Function))
7360 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_special_init)
7361 << S.getSpecialMember(cast<CXXMethodDecl>(Best->Function))
7362 << DestType << ArgsRange;
7363 else
7364 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init)
7365 << true << DestType << ArgsRange;
7366
7367 S.NoteDeletedFunction(Best->Function);
7368 break;
7369 }
7370
7371 case OR_Success:
7372 llvm_unreachable("Conversion did not fail!");
7373 }
7374 }
7375 break;
7376
7377 case FK_DefaultInitOfConst:
7378 if (Entity.getKind() == InitializedEntity::EK_Member &&
7379 isa<CXXConstructorDecl>(S.CurContext)) {
7380 // This is implicit default-initialization of a const member in
7381 // a constructor. Complain that it needs to be explicitly
7382 // initialized.
7383 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(S.CurContext);
7384 S.Diag(Kind.getLocation(), diag::err_uninitialized_member_in_ctor)
7385 << (Constructor->getInheritedConstructor() ? 2 :
7386 Constructor->isImplicit() ? 1 : 0)
7387 << S.Context.getTypeDeclType(Constructor->getParent())
7388 << /*const=*/1
7389 << Entity.getName();
7390 S.Diag(Entity.getDecl()->getLocation(), diag::note_previous_decl)
7391 << Entity.getName();
7392 } else {
7393 S.Diag(Kind.getLocation(), diag::err_default_init_const)
7394 << DestType << (bool)DestType->getAs<RecordType>();
7395 }
7396 break;
7397
7398 case FK_Incomplete:
7399 S.RequireCompleteType(Kind.getLocation(), FailedIncompleteType,
7400 diag::err_init_incomplete_type);
7401 break;
7402
7403 case FK_ListInitializationFailed: {
7404 // Run the init list checker again to emit diagnostics.
7405 InitListExpr *InitList = cast<InitListExpr>(Args[0]);
7406 diagnoseListInit(S, Entity, InitList);
7407 break;
7408 }
7409
7410 case FK_PlaceholderType: {
7411 // FIXME: Already diagnosed!
7412 break;
7413 }
7414
7415 case FK_ExplicitConstructor: {
7416 S.Diag(Kind.getLocation(), diag::err_selected_explicit_constructor)
7417 << Args[0]->getSourceRange();
7418 OverloadCandidateSet::iterator Best;
7419 OverloadingResult Ovl
7420 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best);
7421 (void)Ovl;
7422 assert(Ovl == OR_Success && "Inconsistent overload resolution");
7423 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function);
7424 S.Diag(CtorDecl->getLocation(), diag::note_constructor_declared_here);
7425 break;
7426 }
7427 }
7428
7429 PrintInitLocationNote(S, Entity);
7430 return true;
7431 }
7432
dump(raw_ostream & OS) const7433 void InitializationSequence::dump(raw_ostream &OS) const {
7434 switch (SequenceKind) {
7435 case FailedSequence: {
7436 OS << "Failed sequence: ";
7437 switch (Failure) {
7438 case FK_TooManyInitsForReference:
7439 OS << "too many initializers for reference";
7440 break;
7441
7442 case FK_ArrayNeedsInitList:
7443 OS << "array requires initializer list";
7444 break;
7445
7446 case FK_AddressOfUnaddressableFunction:
7447 OS << "address of unaddressable function was taken";
7448 break;
7449
7450 case FK_ArrayNeedsInitListOrStringLiteral:
7451 OS << "array requires initializer list or string literal";
7452 break;
7453
7454 case FK_ArrayNeedsInitListOrWideStringLiteral:
7455 OS << "array requires initializer list or wide string literal";
7456 break;
7457
7458 case FK_NarrowStringIntoWideCharArray:
7459 OS << "narrow string into wide char array";
7460 break;
7461
7462 case FK_WideStringIntoCharArray:
7463 OS << "wide string into char array";
7464 break;
7465
7466 case FK_IncompatWideStringIntoWideChar:
7467 OS << "incompatible wide string into wide char array";
7468 break;
7469
7470 case FK_ArrayTypeMismatch:
7471 OS << "array type mismatch";
7472 break;
7473
7474 case FK_NonConstantArrayInit:
7475 OS << "non-constant array initializer";
7476 break;
7477
7478 case FK_AddressOfOverloadFailed:
7479 OS << "address of overloaded function failed";
7480 break;
7481
7482 case FK_ReferenceInitOverloadFailed:
7483 OS << "overload resolution for reference initialization failed";
7484 break;
7485
7486 case FK_NonConstLValueReferenceBindingToTemporary:
7487 OS << "non-const lvalue reference bound to temporary";
7488 break;
7489
7490 case FK_NonConstLValueReferenceBindingToUnrelated:
7491 OS << "non-const lvalue reference bound to unrelated type";
7492 break;
7493
7494 case FK_RValueReferenceBindingToLValue:
7495 OS << "rvalue reference bound to an lvalue";
7496 break;
7497
7498 case FK_ReferenceInitDropsQualifiers:
7499 OS << "reference initialization drops qualifiers";
7500 break;
7501
7502 case FK_ReferenceInitFailed:
7503 OS << "reference initialization failed";
7504 break;
7505
7506 case FK_ConversionFailed:
7507 OS << "conversion failed";
7508 break;
7509
7510 case FK_ConversionFromPropertyFailed:
7511 OS << "conversion from property failed";
7512 break;
7513
7514 case FK_TooManyInitsForScalar:
7515 OS << "too many initializers for scalar";
7516 break;
7517
7518 case FK_ReferenceBindingToInitList:
7519 OS << "referencing binding to initializer list";
7520 break;
7521
7522 case FK_InitListBadDestinationType:
7523 OS << "initializer list for non-aggregate, non-scalar type";
7524 break;
7525
7526 case FK_UserConversionOverloadFailed:
7527 OS << "overloading failed for user-defined conversion";
7528 break;
7529
7530 case FK_ConstructorOverloadFailed:
7531 OS << "constructor overloading failed";
7532 break;
7533
7534 case FK_DefaultInitOfConst:
7535 OS << "default initialization of a const variable";
7536 break;
7537
7538 case FK_Incomplete:
7539 OS << "initialization of incomplete type";
7540 break;
7541
7542 case FK_ListInitializationFailed:
7543 OS << "list initialization checker failure";
7544 break;
7545
7546 case FK_VariableLengthArrayHasInitializer:
7547 OS << "variable length array has an initializer";
7548 break;
7549
7550 case FK_PlaceholderType:
7551 OS << "initializer expression isn't contextually valid";
7552 break;
7553
7554 case FK_ListConstructorOverloadFailed:
7555 OS << "list constructor overloading failed";
7556 break;
7557
7558 case FK_ExplicitConstructor:
7559 OS << "list copy initialization chose explicit constructor";
7560 break;
7561 }
7562 OS << '\n';
7563 return;
7564 }
7565
7566 case DependentSequence:
7567 OS << "Dependent sequence\n";
7568 return;
7569
7570 case NormalSequence:
7571 OS << "Normal sequence: ";
7572 break;
7573 }
7574
7575 for (step_iterator S = step_begin(), SEnd = step_end(); S != SEnd; ++S) {
7576 if (S != step_begin()) {
7577 OS << " -> ";
7578 }
7579
7580 switch (S->Kind) {
7581 case SK_ResolveAddressOfOverloadedFunction:
7582 OS << "resolve address of overloaded function";
7583 break;
7584
7585 case SK_CastDerivedToBaseRValue:
7586 OS << "derived-to-base case (rvalue" << S->Type.getAsString() << ")";
7587 break;
7588
7589 case SK_CastDerivedToBaseXValue:
7590 OS << "derived-to-base case (xvalue" << S->Type.getAsString() << ")";
7591 break;
7592
7593 case SK_CastDerivedToBaseLValue:
7594 OS << "derived-to-base case (lvalue" << S->Type.getAsString() << ")";
7595 break;
7596
7597 case SK_BindReference:
7598 OS << "bind reference to lvalue";
7599 break;
7600
7601 case SK_BindReferenceToTemporary:
7602 OS << "bind reference to a temporary";
7603 break;
7604
7605 case SK_ExtraneousCopyToTemporary:
7606 OS << "extraneous C++03 copy to temporary";
7607 break;
7608
7609 case SK_UserConversion:
7610 OS << "user-defined conversion via " << *S->Function.Function;
7611 break;
7612
7613 case SK_QualificationConversionRValue:
7614 OS << "qualification conversion (rvalue)";
7615 break;
7616
7617 case SK_QualificationConversionXValue:
7618 OS << "qualification conversion (xvalue)";
7619 break;
7620
7621 case SK_QualificationConversionLValue:
7622 OS << "qualification conversion (lvalue)";
7623 break;
7624
7625 case SK_AtomicConversion:
7626 OS << "non-atomic-to-atomic conversion";
7627 break;
7628
7629 case SK_LValueToRValue:
7630 OS << "load (lvalue to rvalue)";
7631 break;
7632
7633 case SK_ConversionSequence:
7634 OS << "implicit conversion sequence (";
7635 S->ICS->dump(); // FIXME: use OS
7636 OS << ")";
7637 break;
7638
7639 case SK_ConversionSequenceNoNarrowing:
7640 OS << "implicit conversion sequence with narrowing prohibited (";
7641 S->ICS->dump(); // FIXME: use OS
7642 OS << ")";
7643 break;
7644
7645 case SK_ListInitialization:
7646 OS << "list aggregate initialization";
7647 break;
7648
7649 case SK_UnwrapInitList:
7650 OS << "unwrap reference initializer list";
7651 break;
7652
7653 case SK_RewrapInitList:
7654 OS << "rewrap reference initializer list";
7655 break;
7656
7657 case SK_ConstructorInitialization:
7658 OS << "constructor initialization";
7659 break;
7660
7661 case SK_ConstructorInitializationFromList:
7662 OS << "list initialization via constructor";
7663 break;
7664
7665 case SK_ZeroInitialization:
7666 OS << "zero initialization";
7667 break;
7668
7669 case SK_CAssignment:
7670 OS << "C assignment";
7671 break;
7672
7673 case SK_StringInit:
7674 OS << "string initialization";
7675 break;
7676
7677 case SK_ObjCObjectConversion:
7678 OS << "Objective-C object conversion";
7679 break;
7680
7681 case SK_ArrayInit:
7682 OS << "array initialization";
7683 break;
7684
7685 case SK_ParenthesizedArrayInit:
7686 OS << "parenthesized array initialization";
7687 break;
7688
7689 case SK_PassByIndirectCopyRestore:
7690 OS << "pass by indirect copy and restore";
7691 break;
7692
7693 case SK_PassByIndirectRestore:
7694 OS << "pass by indirect restore";
7695 break;
7696
7697 case SK_ProduceObjCObject:
7698 OS << "Objective-C object retension";
7699 break;
7700
7701 case SK_StdInitializerList:
7702 OS << "std::initializer_list from initializer list";
7703 break;
7704
7705 case SK_StdInitializerListConstructorCall:
7706 OS << "list initialization from std::initializer_list";
7707 break;
7708
7709 case SK_OCLSamplerInit:
7710 OS << "OpenCL sampler_t from integer constant";
7711 break;
7712
7713 case SK_OCLZeroEvent:
7714 OS << "OpenCL event_t from zero";
7715 break;
7716 }
7717
7718 OS << " [" << S->Type.getAsString() << ']';
7719 }
7720
7721 OS << '\n';
7722 }
7723
dump() const7724 void InitializationSequence::dump() const {
7725 dump(llvm::errs());
7726 }
7727
DiagnoseNarrowingInInitList(Sema & S,const ImplicitConversionSequence & ICS,QualType PreNarrowingType,QualType EntityType,const Expr * PostInit)7728 static void DiagnoseNarrowingInInitList(Sema &S,
7729 const ImplicitConversionSequence &ICS,
7730 QualType PreNarrowingType,
7731 QualType EntityType,
7732 const Expr *PostInit) {
7733 const StandardConversionSequence *SCS = nullptr;
7734 switch (ICS.getKind()) {
7735 case ImplicitConversionSequence::StandardConversion:
7736 SCS = &ICS.Standard;
7737 break;
7738 case ImplicitConversionSequence::UserDefinedConversion:
7739 SCS = &ICS.UserDefined.After;
7740 break;
7741 case ImplicitConversionSequence::AmbiguousConversion:
7742 case ImplicitConversionSequence::EllipsisConversion:
7743 case ImplicitConversionSequence::BadConversion:
7744 return;
7745 }
7746
7747 // C++11 [dcl.init.list]p7: Check whether this is a narrowing conversion.
7748 APValue ConstantValue;
7749 QualType ConstantType;
7750 switch (SCS->getNarrowingKind(S.Context, PostInit, ConstantValue,
7751 ConstantType)) {
7752 case NK_Not_Narrowing:
7753 // No narrowing occurred.
7754 return;
7755
7756 case NK_Type_Narrowing:
7757 // This was a floating-to-integer conversion, which is always considered a
7758 // narrowing conversion even if the value is a constant and can be
7759 // represented exactly as an integer.
7760 S.Diag(PostInit->getLocStart(),
7761 (S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11)
7762 ? diag::warn_init_list_type_narrowing
7763 : diag::ext_init_list_type_narrowing)
7764 << PostInit->getSourceRange()
7765 << PreNarrowingType.getLocalUnqualifiedType()
7766 << EntityType.getLocalUnqualifiedType();
7767 break;
7768
7769 case NK_Constant_Narrowing:
7770 // A constant value was narrowed.
7771 S.Diag(PostInit->getLocStart(),
7772 (S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11)
7773 ? diag::warn_init_list_constant_narrowing
7774 : diag::ext_init_list_constant_narrowing)
7775 << PostInit->getSourceRange()
7776 << ConstantValue.getAsString(S.getASTContext(), ConstantType)
7777 << EntityType.getLocalUnqualifiedType();
7778 break;
7779
7780 case NK_Variable_Narrowing:
7781 // A variable's value may have been narrowed.
7782 S.Diag(PostInit->getLocStart(),
7783 (S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11)
7784 ? diag::warn_init_list_variable_narrowing
7785 : diag::ext_init_list_variable_narrowing)
7786 << PostInit->getSourceRange()
7787 << PreNarrowingType.getLocalUnqualifiedType()
7788 << EntityType.getLocalUnqualifiedType();
7789 break;
7790 }
7791
7792 SmallString<128> StaticCast;
7793 llvm::raw_svector_ostream OS(StaticCast);
7794 OS << "static_cast<";
7795 if (const TypedefType *TT = EntityType->getAs<TypedefType>()) {
7796 // It's important to use the typedef's name if there is one so that the
7797 // fixit doesn't break code using types like int64_t.
7798 //
7799 // FIXME: This will break if the typedef requires qualification. But
7800 // getQualifiedNameAsString() includes non-machine-parsable components.
7801 OS << *TT->getDecl();
7802 } else if (const BuiltinType *BT = EntityType->getAs<BuiltinType>())
7803 OS << BT->getName(S.getLangOpts());
7804 else {
7805 // Oops, we didn't find the actual type of the variable. Don't emit a fixit
7806 // with a broken cast.
7807 return;
7808 }
7809 OS << ">(";
7810 S.Diag(PostInit->getLocStart(), diag::note_init_list_narrowing_silence)
7811 << PostInit->getSourceRange()
7812 << FixItHint::CreateInsertion(PostInit->getLocStart(), OS.str())
7813 << FixItHint::CreateInsertion(
7814 S.getLocForEndOfToken(PostInit->getLocEnd()), ")");
7815 }
7816
7817 //===----------------------------------------------------------------------===//
7818 // Initialization helper functions
7819 //===----------------------------------------------------------------------===//
7820 bool
CanPerformCopyInitialization(const InitializedEntity & Entity,ExprResult Init)7821 Sema::CanPerformCopyInitialization(const InitializedEntity &Entity,
7822 ExprResult Init) {
7823 if (Init.isInvalid())
7824 return false;
7825
7826 Expr *InitE = Init.get();
7827 assert(InitE && "No initialization expression");
7828
7829 InitializationKind Kind
7830 = InitializationKind::CreateCopy(InitE->getLocStart(), SourceLocation());
7831 InitializationSequence Seq(*this, Entity, Kind, InitE);
7832 return !Seq.Failed();
7833 }
7834
7835 ExprResult
PerformCopyInitialization(const InitializedEntity & Entity,SourceLocation EqualLoc,ExprResult Init,bool TopLevelOfInitList,bool AllowExplicit)7836 Sema::PerformCopyInitialization(const InitializedEntity &Entity,
7837 SourceLocation EqualLoc,
7838 ExprResult Init,
7839 bool TopLevelOfInitList,
7840 bool AllowExplicit) {
7841 if (Init.isInvalid())
7842 return ExprError();
7843
7844 Expr *InitE = Init.get();
7845 assert(InitE && "No initialization expression?");
7846
7847 if (EqualLoc.isInvalid())
7848 EqualLoc = InitE->getLocStart();
7849
7850 InitializationKind Kind = InitializationKind::CreateCopy(InitE->getLocStart(),
7851 EqualLoc,
7852 AllowExplicit);
7853 InitializationSequence Seq(*this, Entity, Kind, InitE, TopLevelOfInitList);
7854
7855 ExprResult Result = Seq.Perform(*this, Entity, Kind, InitE);
7856
7857 return Result;
7858 }
7859