1 //===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
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 coordinates the per-module state used while generating code.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "CodeGenModule.h"
15 #include "CGDebugInfo.h"
16 #include "CodeGenFunction.h"
17 #include "CodeGenTBAA.h"
18 #include "CGCall.h"
19 #include "CGCUDARuntime.h"
20 #include "CGCXXABI.h"
21 #include "CGObjCRuntime.h"
22 #include "CGOpenCLRuntime.h"
23 #include "TargetInfo.h"
24 #include "clang/Frontend/CodeGenOptions.h"
25 #include "clang/AST/ASTContext.h"
26 #include "clang/AST/CharUnits.h"
27 #include "clang/AST/DeclObjC.h"
28 #include "clang/AST/DeclCXX.h"
29 #include "clang/AST/DeclTemplate.h"
30 #include "clang/AST/Mangle.h"
31 #include "clang/AST/RecordLayout.h"
32 #include "clang/AST/RecursiveASTVisitor.h"
33 #include "clang/Basic/Builtins.h"
34 #include "clang/Basic/Diagnostic.h"
35 #include "clang/Basic/SourceManager.h"
36 #include "clang/Basic/TargetInfo.h"
37 #include "clang/Basic/ConvertUTF.h"
38 #include "llvm/CallingConv.h"
39 #include "llvm/Module.h"
40 #include "llvm/Intrinsics.h"
41 #include "llvm/LLVMContext.h"
42 #include "llvm/ADT/APSInt.h"
43 #include "llvm/ADT/Triple.h"
44 #include "llvm/Target/Mangler.h"
45 #include "llvm/Target/TargetData.h"
46 #include "llvm/Support/CallSite.h"
47 #include "llvm/Support/ErrorHandling.h"
48 using namespace clang;
49 using namespace CodeGen;
50
51 static const char AnnotationSection[] = "llvm.metadata";
52
createCXXABI(CodeGenModule & CGM)53 static CGCXXABI &createCXXABI(CodeGenModule &CGM) {
54 switch (CGM.getContext().getTargetInfo().getCXXABI()) {
55 case CXXABI_ARM: return *CreateARMCXXABI(CGM);
56 case CXXABI_Itanium: return *CreateItaniumCXXABI(CGM);
57 case CXXABI_Microsoft: return *CreateMicrosoftCXXABI(CGM);
58 }
59
60 llvm_unreachable("invalid C++ ABI kind");
61 }
62
63
CodeGenModule(ASTContext & C,const CodeGenOptions & CGO,llvm::Module & M,const llvm::TargetData & TD,DiagnosticsEngine & diags)64 CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO,
65 llvm::Module &M, const llvm::TargetData &TD,
66 DiagnosticsEngine &diags)
67 : Context(C), LangOpts(C.getLangOpts()), CodeGenOpts(CGO), TheModule(M),
68 TheTargetData(TD), TheTargetCodeGenInfo(0), Diags(diags),
69 ABI(createCXXABI(*this)),
70 Types(*this),
71 TBAA(0),
72 VTables(*this), ObjCRuntime(0), OpenCLRuntime(0), CUDARuntime(0),
73 DebugInfo(0), ARCData(0), NoObjCARCExceptionsMetadata(0),
74 RRData(0), CFConstantStringClassRef(0),
75 ConstantStringClassRef(0), NSConstantStringType(0),
76 VMContext(M.getContext()),
77 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0),
78 BlockObjectAssign(0), BlockObjectDispose(0),
79 BlockDescriptorType(0), GenericBlockLiteralType(0) {
80
81 // Initialize the type cache.
82 llvm::LLVMContext &LLVMContext = M.getContext();
83 VoidTy = llvm::Type::getVoidTy(LLVMContext);
84 Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
85 Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
86 Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
87 Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
88 FloatTy = llvm::Type::getFloatTy(LLVMContext);
89 DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
90 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
91 PointerAlignInBytes =
92 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
93 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
94 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits);
95 Int8PtrTy = Int8Ty->getPointerTo(0);
96 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
97
98 if (LangOpts.ObjC1)
99 createObjCRuntime();
100 if (LangOpts.OpenCL)
101 createOpenCLRuntime();
102 if (LangOpts.CUDA)
103 createCUDARuntime();
104
105 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
106 if (LangOpts.ThreadSanitizer ||
107 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
108 TBAA = new CodeGenTBAA(Context, VMContext, CodeGenOpts, getLangOpts(),
109 ABI.getMangleContext());
110
111 // If debug info or coverage generation is enabled, create the CGDebugInfo
112 // object.
113 if (CodeGenOpts.DebugInfo != CodeGenOptions::NoDebugInfo ||
114 CodeGenOpts.EmitGcovArcs ||
115 CodeGenOpts.EmitGcovNotes)
116 DebugInfo = new CGDebugInfo(*this);
117
118 Block.GlobalUniqueCount = 0;
119
120 if (C.getLangOpts().ObjCAutoRefCount)
121 ARCData = new ARCEntrypoints();
122 RRData = new RREntrypoints();
123 }
124
~CodeGenModule()125 CodeGenModule::~CodeGenModule() {
126 delete ObjCRuntime;
127 delete OpenCLRuntime;
128 delete CUDARuntime;
129 delete TheTargetCodeGenInfo;
130 delete &ABI;
131 delete TBAA;
132 delete DebugInfo;
133 delete ARCData;
134 delete RRData;
135 }
136
createObjCRuntime()137 void CodeGenModule::createObjCRuntime() {
138 // This is just isGNUFamily(), but we want to force implementors of
139 // new ABIs to decide how best to do this.
140 switch (LangOpts.ObjCRuntime.getKind()) {
141 case ObjCRuntime::GNUstep:
142 case ObjCRuntime::GCC:
143 case ObjCRuntime::ObjFW:
144 ObjCRuntime = CreateGNUObjCRuntime(*this);
145 return;
146
147 case ObjCRuntime::FragileMacOSX:
148 case ObjCRuntime::MacOSX:
149 case ObjCRuntime::iOS:
150 ObjCRuntime = CreateMacObjCRuntime(*this);
151 return;
152 }
153 llvm_unreachable("bad runtime kind");
154 }
155
createOpenCLRuntime()156 void CodeGenModule::createOpenCLRuntime() {
157 OpenCLRuntime = new CGOpenCLRuntime(*this);
158 }
159
createCUDARuntime()160 void CodeGenModule::createCUDARuntime() {
161 CUDARuntime = CreateNVCUDARuntime(*this);
162 }
163
Release()164 void CodeGenModule::Release() {
165 EmitDeferred();
166 EmitCXXGlobalInitFunc();
167 EmitCXXGlobalDtorFunc();
168 if (ObjCRuntime)
169 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
170 AddGlobalCtor(ObjCInitFunction);
171 EmitCtorList(GlobalCtors, "llvm.global_ctors");
172 EmitCtorList(GlobalDtors, "llvm.global_dtors");
173 EmitGlobalAnnotations();
174 EmitLLVMUsed();
175
176 SimplifyPersonality();
177
178 if (getCodeGenOpts().EmitDeclMetadata)
179 EmitDeclMetadata();
180
181 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
182 EmitCoverageFile();
183
184 if (DebugInfo)
185 DebugInfo->finalize();
186 }
187
UpdateCompletedType(const TagDecl * TD)188 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
189 // Make sure that this type is translated.
190 Types.UpdateCompletedType(TD);
191 }
192
getTBAAInfo(QualType QTy)193 llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) {
194 if (!TBAA)
195 return 0;
196 return TBAA->getTBAAInfo(QTy);
197 }
198
getTBAAInfoForVTablePtr()199 llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() {
200 if (!TBAA)
201 return 0;
202 return TBAA->getTBAAInfoForVTablePtr();
203 }
204
DecorateInstruction(llvm::Instruction * Inst,llvm::MDNode * TBAAInfo)205 void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
206 llvm::MDNode *TBAAInfo) {
207 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo);
208 }
209
isTargetDarwin() const210 bool CodeGenModule::isTargetDarwin() const {
211 return getContext().getTargetInfo().getTriple().isOSDarwin();
212 }
213
Error(SourceLocation loc,StringRef error)214 void CodeGenModule::Error(SourceLocation loc, StringRef error) {
215 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error);
216 getDiags().Report(Context.getFullLoc(loc), diagID);
217 }
218
219 /// ErrorUnsupported - Print out an error that codegen doesn't support the
220 /// specified stmt yet.
ErrorUnsupported(const Stmt * S,const char * Type,bool OmitOnError)221 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type,
222 bool OmitOnError) {
223 if (OmitOnError && getDiags().hasErrorOccurred())
224 return;
225 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
226 "cannot compile this %0 yet");
227 std::string Msg = Type;
228 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID)
229 << Msg << S->getSourceRange();
230 }
231
232 /// ErrorUnsupported - Print out an error that codegen doesn't support the
233 /// specified decl yet.
ErrorUnsupported(const Decl * D,const char * Type,bool OmitOnError)234 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type,
235 bool OmitOnError) {
236 if (OmitOnError && getDiags().hasErrorOccurred())
237 return;
238 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
239 "cannot compile this %0 yet");
240 std::string Msg = Type;
241 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
242 }
243
getSize(CharUnits size)244 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
245 return llvm::ConstantInt::get(SizeTy, size.getQuantity());
246 }
247
setGlobalVisibility(llvm::GlobalValue * GV,const NamedDecl * D) const248 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
249 const NamedDecl *D) const {
250 // Internal definitions always have default visibility.
251 if (GV->hasLocalLinkage()) {
252 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
253 return;
254 }
255
256 // Set visibility for definitions.
257 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility();
258 if (LV.visibilityExplicit() || !GV->hasAvailableExternallyLinkage())
259 GV->setVisibility(GetLLVMVisibility(LV.visibility()));
260 }
261
GetLLVMTLSModel(StringRef S)262 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
263 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
264 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
265 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
266 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
267 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
268 }
269
GetLLVMTLSModel(CodeGenOptions::TLSModel M)270 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(
271 CodeGenOptions::TLSModel M) {
272 switch (M) {
273 case CodeGenOptions::GeneralDynamicTLSModel:
274 return llvm::GlobalVariable::GeneralDynamicTLSModel;
275 case CodeGenOptions::LocalDynamicTLSModel:
276 return llvm::GlobalVariable::LocalDynamicTLSModel;
277 case CodeGenOptions::InitialExecTLSModel:
278 return llvm::GlobalVariable::InitialExecTLSModel;
279 case CodeGenOptions::LocalExecTLSModel:
280 return llvm::GlobalVariable::LocalExecTLSModel;
281 }
282 llvm_unreachable("Invalid TLS model!");
283 }
284
setTLSMode(llvm::GlobalVariable * GV,const VarDecl & D) const285 void CodeGenModule::setTLSMode(llvm::GlobalVariable *GV,
286 const VarDecl &D) const {
287 assert(D.isThreadSpecified() && "setting TLS mode on non-TLS var!");
288
289 llvm::GlobalVariable::ThreadLocalMode TLM;
290 TLM = GetLLVMTLSModel(CodeGenOpts.DefaultTLSModel);
291
292 // Override the TLS model if it is explicitly specified.
293 if (D.hasAttr<TLSModelAttr>()) {
294 const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>();
295 TLM = GetLLVMTLSModel(Attr->getModel());
296 }
297
298 GV->setThreadLocalMode(TLM);
299 }
300
301 /// Set the symbol visibility of type information (vtable and RTTI)
302 /// associated with the given type.
setTypeVisibility(llvm::GlobalValue * GV,const CXXRecordDecl * RD,TypeVisibilityKind TVK) const303 void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV,
304 const CXXRecordDecl *RD,
305 TypeVisibilityKind TVK) const {
306 setGlobalVisibility(GV, RD);
307
308 if (!CodeGenOpts.HiddenWeakVTables)
309 return;
310
311 // We never want to drop the visibility for RTTI names.
312 if (TVK == TVK_ForRTTIName)
313 return;
314
315 // We want to drop the visibility to hidden for weak type symbols.
316 // This isn't possible if there might be unresolved references
317 // elsewhere that rely on this symbol being visible.
318
319 // This should be kept roughly in sync with setThunkVisibility
320 // in CGVTables.cpp.
321
322 // Preconditions.
323 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage ||
324 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility)
325 return;
326
327 // Don't override an explicit visibility attribute.
328 if (RD->getExplicitVisibility())
329 return;
330
331 switch (RD->getTemplateSpecializationKind()) {
332 // We have to disable the optimization if this is an EI definition
333 // because there might be EI declarations in other shared objects.
334 case TSK_ExplicitInstantiationDefinition:
335 case TSK_ExplicitInstantiationDeclaration:
336 return;
337
338 // Every use of a non-template class's type information has to emit it.
339 case TSK_Undeclared:
340 break;
341
342 // In theory, implicit instantiations can ignore the possibility of
343 // an explicit instantiation declaration because there necessarily
344 // must be an EI definition somewhere with default visibility. In
345 // practice, it's possible to have an explicit instantiation for
346 // an arbitrary template class, and linkers aren't necessarily able
347 // to deal with mixed-visibility symbols.
348 case TSK_ExplicitSpecialization:
349 case TSK_ImplicitInstantiation:
350 if (!CodeGenOpts.HiddenWeakTemplateVTables)
351 return;
352 break;
353 }
354
355 // If there's a key function, there may be translation units
356 // that don't have the key function's definition. But ignore
357 // this if we're emitting RTTI under -fno-rtti.
358 if (!(TVK != TVK_ForRTTI) || LangOpts.RTTI) {
359 if (Context.getKeyFunction(RD))
360 return;
361 }
362
363 // Otherwise, drop the visibility to hidden.
364 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
365 GV->setUnnamedAddr(true);
366 }
367
getMangledName(GlobalDecl GD)368 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
369 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
370
371 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()];
372 if (!Str.empty())
373 return Str;
374
375 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) {
376 IdentifierInfo *II = ND->getIdentifier();
377 assert(II && "Attempt to mangle unnamed decl.");
378
379 Str = II->getName();
380 return Str;
381 }
382
383 SmallString<256> Buffer;
384 llvm::raw_svector_ostream Out(Buffer);
385 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND))
386 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out);
387 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND))
388 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out);
389 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND))
390 getCXXABI().getMangleContext().mangleBlock(BD, Out,
391 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()));
392 else
393 getCXXABI().getMangleContext().mangleName(ND, Out);
394
395 // Allocate space for the mangled name.
396 Out.flush();
397 size_t Length = Buffer.size();
398 char *Name = MangledNamesAllocator.Allocate<char>(Length);
399 std::copy(Buffer.begin(), Buffer.end(), Name);
400
401 Str = StringRef(Name, Length);
402
403 return Str;
404 }
405
getBlockMangledName(GlobalDecl GD,MangleBuffer & Buffer,const BlockDecl * BD)406 void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer,
407 const BlockDecl *BD) {
408 MangleContext &MangleCtx = getCXXABI().getMangleContext();
409 const Decl *D = GD.getDecl();
410 llvm::raw_svector_ostream Out(Buffer.getBuffer());
411 if (D == 0)
412 MangleCtx.mangleGlobalBlock(BD,
413 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
414 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D))
415 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
416 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D))
417 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
418 else
419 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
420 }
421
GetGlobalValue(StringRef Name)422 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
423 return getModule().getNamedValue(Name);
424 }
425
426 /// AddGlobalCtor - Add a function to the list that will be called before
427 /// main() runs.
AddGlobalCtor(llvm::Function * Ctor,int Priority)428 void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) {
429 // FIXME: Type coercion of void()* types.
430 GlobalCtors.push_back(std::make_pair(Ctor, Priority));
431 }
432
433 /// AddGlobalDtor - Add a function to the list that will be called
434 /// when the module is unloaded.
AddGlobalDtor(llvm::Function * Dtor,int Priority)435 void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) {
436 // FIXME: Type coercion of void()* types.
437 GlobalDtors.push_back(std::make_pair(Dtor, Priority));
438 }
439
EmitCtorList(const CtorList & Fns,const char * GlobalName)440 void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) {
441 // Ctor function type is void()*.
442 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
443 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy);
444
445 // Get the type of a ctor entry, { i32, void ()* }.
446 llvm::StructType *CtorStructTy =
447 llvm::StructType::get(Int32Ty, llvm::PointerType::getUnqual(CtorFTy), NULL);
448
449 // Construct the constructor and destructor arrays.
450 SmallVector<llvm::Constant*, 8> Ctors;
451 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
452 llvm::Constant *S[] = {
453 llvm::ConstantInt::get(Int32Ty, I->second, false),
454 llvm::ConstantExpr::getBitCast(I->first, CtorPFTy)
455 };
456 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S));
457 }
458
459 if (!Ctors.empty()) {
460 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size());
461 new llvm::GlobalVariable(TheModule, AT, false,
462 llvm::GlobalValue::AppendingLinkage,
463 llvm::ConstantArray::get(AT, Ctors),
464 GlobalName);
465 }
466 }
467
468 llvm::GlobalValue::LinkageTypes
getFunctionLinkage(const FunctionDecl * D)469 CodeGenModule::getFunctionLinkage(const FunctionDecl *D) {
470 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
471
472 if (Linkage == GVA_Internal)
473 return llvm::Function::InternalLinkage;
474
475 if (D->hasAttr<DLLExportAttr>())
476 return llvm::Function::DLLExportLinkage;
477
478 if (D->hasAttr<WeakAttr>())
479 return llvm::Function::WeakAnyLinkage;
480
481 // In C99 mode, 'inline' functions are guaranteed to have a strong
482 // definition somewhere else, so we can use available_externally linkage.
483 if (Linkage == GVA_C99Inline)
484 return llvm::Function::AvailableExternallyLinkage;
485
486 // Note that Apple's kernel linker doesn't support symbol
487 // coalescing, so we need to avoid linkonce and weak linkages there.
488 // Normally, this means we just map to internal, but for explicit
489 // instantiations we'll map to external.
490
491 // In C++, the compiler has to emit a definition in every translation unit
492 // that references the function. We should use linkonce_odr because
493 // a) if all references in this translation unit are optimized away, we
494 // don't need to codegen it. b) if the function persists, it needs to be
495 // merged with other definitions. c) C++ has the ODR, so we know the
496 // definition is dependable.
497 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation)
498 return !Context.getLangOpts().AppleKext
499 ? llvm::Function::LinkOnceODRLinkage
500 : llvm::Function::InternalLinkage;
501
502 // An explicit instantiation of a template has weak linkage, since
503 // explicit instantiations can occur in multiple translation units
504 // and must all be equivalent. However, we are not allowed to
505 // throw away these explicit instantiations.
506 if (Linkage == GVA_ExplicitTemplateInstantiation)
507 return !Context.getLangOpts().AppleKext
508 ? llvm::Function::WeakODRLinkage
509 : llvm::Function::ExternalLinkage;
510
511 // Otherwise, we have strong external linkage.
512 assert(Linkage == GVA_StrongExternal);
513 return llvm::Function::ExternalLinkage;
514 }
515
516
517 /// SetFunctionDefinitionAttributes - Set attributes for a global.
518 ///
519 /// FIXME: This is currently only done for aliases and functions, but not for
520 /// variables (these details are set in EmitGlobalVarDefinition for variables).
SetFunctionDefinitionAttributes(const FunctionDecl * D,llvm::GlobalValue * GV)521 void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D,
522 llvm::GlobalValue *GV) {
523 SetCommonAttributes(D, GV);
524 }
525
SetLLVMFunctionAttributes(const Decl * D,const CGFunctionInfo & Info,llvm::Function * F)526 void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
527 const CGFunctionInfo &Info,
528 llvm::Function *F) {
529 unsigned CallingConv;
530 AttributeListType AttributeList;
531 ConstructAttributeList(Info, D, AttributeList, CallingConv);
532 F->setAttributes(llvm::AttrListPtr::get(AttributeList));
533 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
534 }
535
536 /// Determines whether the language options require us to model
537 /// unwind exceptions. We treat -fexceptions as mandating this
538 /// except under the fragile ObjC ABI with only ObjC exceptions
539 /// enabled. This means, for example, that C with -fexceptions
540 /// enables this.
hasUnwindExceptions(const LangOptions & LangOpts)541 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
542 // If exceptions are completely disabled, obviously this is false.
543 if (!LangOpts.Exceptions) return false;
544
545 // If C++ exceptions are enabled, this is true.
546 if (LangOpts.CXXExceptions) return true;
547
548 // If ObjC exceptions are enabled, this depends on the ABI.
549 if (LangOpts.ObjCExceptions) {
550 return LangOpts.ObjCRuntime.hasUnwindExceptions();
551 }
552
553 return true;
554 }
555
SetLLVMFunctionAttributesForDefinition(const Decl * D,llvm::Function * F)556 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
557 llvm::Function *F) {
558 if (CodeGenOpts.UnwindTables)
559 F->setHasUWTable();
560
561 if (!hasUnwindExceptions(LangOpts))
562 F->addFnAttr(llvm::Attribute::NoUnwind);
563
564 if (D->hasAttr<NakedAttr>()) {
565 // Naked implies noinline: we should not be inlining such functions.
566 F->addFnAttr(llvm::Attribute::Naked);
567 F->addFnAttr(llvm::Attribute::NoInline);
568 }
569
570 if (D->hasAttr<NoInlineAttr>())
571 F->addFnAttr(llvm::Attribute::NoInline);
572
573 // (noinline wins over always_inline, and we can't specify both in IR)
574 if ((D->hasAttr<AlwaysInlineAttr>() || D->hasAttr<ForceInlineAttr>()) &&
575 !F->hasFnAttr(llvm::Attribute::NoInline))
576 F->addFnAttr(llvm::Attribute::AlwaysInline);
577
578 // FIXME: Communicate hot and cold attributes to LLVM more directly.
579 if (D->hasAttr<ColdAttr>())
580 F->addFnAttr(llvm::Attribute::OptimizeForSize);
581
582 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
583 F->setUnnamedAddr(true);
584
585 if (LangOpts.getStackProtector() == LangOptions::SSPOn)
586 F->addFnAttr(llvm::Attribute::StackProtect);
587 else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
588 F->addFnAttr(llvm::Attribute::StackProtectReq);
589
590 if (LangOpts.AddressSanitizer) {
591 // When AddressSanitizer is enabled, set AddressSafety attribute
592 // unless __attribute__((no_address_safety_analysis)) is used.
593 if (!D->hasAttr<NoAddressSafetyAnalysisAttr>())
594 F->addFnAttr(llvm::Attribute::AddressSafety);
595 }
596
597 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
598 if (alignment)
599 F->setAlignment(alignment);
600
601 // C++ ABI requires 2-byte alignment for member functions.
602 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
603 F->setAlignment(2);
604 }
605
SetCommonAttributes(const Decl * D,llvm::GlobalValue * GV)606 void CodeGenModule::SetCommonAttributes(const Decl *D,
607 llvm::GlobalValue *GV) {
608 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
609 setGlobalVisibility(GV, ND);
610 else
611 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
612
613 if (D->hasAttr<UsedAttr>())
614 AddUsedGlobal(GV);
615
616 if (const SectionAttr *SA = D->getAttr<SectionAttr>())
617 GV->setSection(SA->getName());
618
619 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this);
620 }
621
SetInternalFunctionAttributes(const Decl * D,llvm::Function * F,const CGFunctionInfo & FI)622 void CodeGenModule::SetInternalFunctionAttributes(const Decl *D,
623 llvm::Function *F,
624 const CGFunctionInfo &FI) {
625 SetLLVMFunctionAttributes(D, FI, F);
626 SetLLVMFunctionAttributesForDefinition(D, F);
627
628 F->setLinkage(llvm::Function::InternalLinkage);
629
630 SetCommonAttributes(D, F);
631 }
632
SetFunctionAttributes(GlobalDecl GD,llvm::Function * F,bool IsIncompleteFunction)633 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD,
634 llvm::Function *F,
635 bool IsIncompleteFunction) {
636 if (unsigned IID = F->getIntrinsicID()) {
637 // If this is an intrinsic function, set the function's attributes
638 // to the intrinsic's attributes.
639 F->setAttributes(llvm::Intrinsic::getAttributes((llvm::Intrinsic::ID)IID));
640 return;
641 }
642
643 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
644
645 if (!IsIncompleteFunction)
646 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F);
647
648 // Only a few attributes are set on declarations; these may later be
649 // overridden by a definition.
650
651 if (FD->hasAttr<DLLImportAttr>()) {
652 F->setLinkage(llvm::Function::DLLImportLinkage);
653 } else if (FD->hasAttr<WeakAttr>() ||
654 FD->isWeakImported()) {
655 // "extern_weak" is overloaded in LLVM; we probably should have
656 // separate linkage types for this.
657 F->setLinkage(llvm::Function::ExternalWeakLinkage);
658 } else {
659 F->setLinkage(llvm::Function::ExternalLinkage);
660
661 NamedDecl::LinkageInfo LV = FD->getLinkageAndVisibility();
662 if (LV.linkage() == ExternalLinkage && LV.visibilityExplicit()) {
663 F->setVisibility(GetLLVMVisibility(LV.visibility()));
664 }
665 }
666
667 if (const SectionAttr *SA = FD->getAttr<SectionAttr>())
668 F->setSection(SA->getName());
669 }
670
AddUsedGlobal(llvm::GlobalValue * GV)671 void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) {
672 assert(!GV->isDeclaration() &&
673 "Only globals with definition can force usage.");
674 LLVMUsed.push_back(GV);
675 }
676
EmitLLVMUsed()677 void CodeGenModule::EmitLLVMUsed() {
678 // Don't create llvm.used if there is no need.
679 if (LLVMUsed.empty())
680 return;
681
682 // Convert LLVMUsed to what ConstantArray needs.
683 SmallVector<llvm::Constant*, 8> UsedArray;
684 UsedArray.resize(LLVMUsed.size());
685 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) {
686 UsedArray[i] =
687 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]),
688 Int8PtrTy);
689 }
690
691 if (UsedArray.empty())
692 return;
693 llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size());
694
695 llvm::GlobalVariable *GV =
696 new llvm::GlobalVariable(getModule(), ATy, false,
697 llvm::GlobalValue::AppendingLinkage,
698 llvm::ConstantArray::get(ATy, UsedArray),
699 "llvm.used");
700
701 GV->setSection("llvm.metadata");
702 }
703
EmitDeferred()704 void CodeGenModule::EmitDeferred() {
705 // Emit code for any potentially referenced deferred decls. Since a
706 // previously unused static decl may become used during the generation of code
707 // for a static function, iterate until no changes are made.
708
709 while (!DeferredDeclsToEmit.empty() || !DeferredVTables.empty()) {
710 if (!DeferredVTables.empty()) {
711 const CXXRecordDecl *RD = DeferredVTables.back();
712 DeferredVTables.pop_back();
713 getCXXABI().EmitVTables(RD);
714 continue;
715 }
716
717 GlobalDecl D = DeferredDeclsToEmit.back();
718 DeferredDeclsToEmit.pop_back();
719
720 // Check to see if we've already emitted this. This is necessary
721 // for a couple of reasons: first, decls can end up in the
722 // deferred-decls queue multiple times, and second, decls can end
723 // up with definitions in unusual ways (e.g. by an extern inline
724 // function acquiring a strong function redefinition). Just
725 // ignore these cases.
726 //
727 // TODO: That said, looking this up multiple times is very wasteful.
728 StringRef Name = getMangledName(D);
729 llvm::GlobalValue *CGRef = GetGlobalValue(Name);
730 assert(CGRef && "Deferred decl wasn't referenced?");
731
732 if (!CGRef->isDeclaration())
733 continue;
734
735 // GlobalAlias::isDeclaration() defers to the aliasee, but for our
736 // purposes an alias counts as a definition.
737 if (isa<llvm::GlobalAlias>(CGRef))
738 continue;
739
740 // Otherwise, emit the definition and move on to the next one.
741 EmitGlobalDefinition(D);
742 }
743 }
744
EmitGlobalAnnotations()745 void CodeGenModule::EmitGlobalAnnotations() {
746 if (Annotations.empty())
747 return;
748
749 // Create a new global variable for the ConstantStruct in the Module.
750 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
751 Annotations[0]->getType(), Annotations.size()), Annotations);
752 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(),
753 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array,
754 "llvm.global.annotations");
755 gv->setSection(AnnotationSection);
756 }
757
EmitAnnotationString(llvm::StringRef Str)758 llvm::Constant *CodeGenModule::EmitAnnotationString(llvm::StringRef Str) {
759 llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str);
760 if (i != AnnotationStrings.end())
761 return i->second;
762
763 // Not found yet, create a new global.
764 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
765 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(),
766 true, llvm::GlobalValue::PrivateLinkage, s, ".str");
767 gv->setSection(AnnotationSection);
768 gv->setUnnamedAddr(true);
769 AnnotationStrings[Str] = gv;
770 return gv;
771 }
772
EmitAnnotationUnit(SourceLocation Loc)773 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
774 SourceManager &SM = getContext().getSourceManager();
775 PresumedLoc PLoc = SM.getPresumedLoc(Loc);
776 if (PLoc.isValid())
777 return EmitAnnotationString(PLoc.getFilename());
778 return EmitAnnotationString(SM.getBufferName(Loc));
779 }
780
EmitAnnotationLineNo(SourceLocation L)781 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
782 SourceManager &SM = getContext().getSourceManager();
783 PresumedLoc PLoc = SM.getPresumedLoc(L);
784 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
785 SM.getExpansionLineNumber(L);
786 return llvm::ConstantInt::get(Int32Ty, LineNo);
787 }
788
EmitAnnotateAttr(llvm::GlobalValue * GV,const AnnotateAttr * AA,SourceLocation L)789 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
790 const AnnotateAttr *AA,
791 SourceLocation L) {
792 // Get the globals for file name, annotation, and the line number.
793 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
794 *UnitGV = EmitAnnotationUnit(L),
795 *LineNoCst = EmitAnnotationLineNo(L);
796
797 // Create the ConstantStruct for the global annotation.
798 llvm::Constant *Fields[4] = {
799 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy),
800 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
801 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
802 LineNoCst
803 };
804 return llvm::ConstantStruct::getAnon(Fields);
805 }
806
AddGlobalAnnotations(const ValueDecl * D,llvm::GlobalValue * GV)807 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
808 llvm::GlobalValue *GV) {
809 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
810 // Get the struct elements for these annotations.
811 for (specific_attr_iterator<AnnotateAttr>
812 ai = D->specific_attr_begin<AnnotateAttr>(),
813 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai)
814 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation()));
815 }
816
MayDeferGeneration(const ValueDecl * Global)817 bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) {
818 // Never defer when EmitAllDecls is specified.
819 if (LangOpts.EmitAllDecls)
820 return false;
821
822 return !getContext().DeclMustBeEmitted(Global);
823 }
824
GetWeakRefReference(const ValueDecl * VD)825 llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
826 const AliasAttr *AA = VD->getAttr<AliasAttr>();
827 assert(AA && "No alias?");
828
829 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
830
831 // See if there is already something with the target's name in the module.
832 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
833
834 llvm::Constant *Aliasee;
835 if (isa<llvm::FunctionType>(DeclTy))
836 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(),
837 /*ForVTable=*/false);
838 else
839 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
840 llvm::PointerType::getUnqual(DeclTy), 0);
841 if (!Entry) {
842 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee);
843 F->setLinkage(llvm::Function::ExternalWeakLinkage);
844 WeakRefReferences.insert(F);
845 }
846
847 return Aliasee;
848 }
849
EmitGlobal(GlobalDecl GD)850 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
851 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl());
852
853 // Weak references don't produce any output by themselves.
854 if (Global->hasAttr<WeakRefAttr>())
855 return;
856
857 // If this is an alias definition (which otherwise looks like a declaration)
858 // emit it now.
859 if (Global->hasAttr<AliasAttr>())
860 return EmitAliasDefinition(GD);
861
862 // If this is CUDA, be selective about which declarations we emit.
863 if (LangOpts.CUDA) {
864 if (CodeGenOpts.CUDAIsDevice) {
865 if (!Global->hasAttr<CUDADeviceAttr>() &&
866 !Global->hasAttr<CUDAGlobalAttr>() &&
867 !Global->hasAttr<CUDAConstantAttr>() &&
868 !Global->hasAttr<CUDASharedAttr>())
869 return;
870 } else {
871 if (!Global->hasAttr<CUDAHostAttr>() && (
872 Global->hasAttr<CUDADeviceAttr>() ||
873 Global->hasAttr<CUDAConstantAttr>() ||
874 Global->hasAttr<CUDASharedAttr>()))
875 return;
876 }
877 }
878
879 // Ignore declarations, they will be emitted on their first use.
880 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
881 // Forward declarations are emitted lazily on first use.
882 if (!FD->doesThisDeclarationHaveABody()) {
883 if (!FD->doesDeclarationForceExternallyVisibleDefinition())
884 return;
885
886 const FunctionDecl *InlineDefinition = 0;
887 FD->getBody(InlineDefinition);
888
889 StringRef MangledName = getMangledName(GD);
890 DeferredDecls.erase(MangledName);
891 EmitGlobalDefinition(InlineDefinition);
892 return;
893 }
894 } else {
895 const VarDecl *VD = cast<VarDecl>(Global);
896 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
897
898 if (VD->isThisDeclarationADefinition() != VarDecl::Definition)
899 return;
900 }
901
902 // Defer code generation when possible if this is a static definition, inline
903 // function etc. These we only want to emit if they are used.
904 if (!MayDeferGeneration(Global)) {
905 // Emit the definition if it can't be deferred.
906 EmitGlobalDefinition(GD);
907 return;
908 }
909
910 // If we're deferring emission of a C++ variable with an
911 // initializer, remember the order in which it appeared in the file.
912 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
913 cast<VarDecl>(Global)->hasInit()) {
914 DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
915 CXXGlobalInits.push_back(0);
916 }
917
918 // If the value has already been used, add it directly to the
919 // DeferredDeclsToEmit list.
920 StringRef MangledName = getMangledName(GD);
921 if (GetGlobalValue(MangledName))
922 DeferredDeclsToEmit.push_back(GD);
923 else {
924 // Otherwise, remember that we saw a deferred decl with this name. The
925 // first use of the mangled name will cause it to move into
926 // DeferredDeclsToEmit.
927 DeferredDecls[MangledName] = GD;
928 }
929 }
930
931 namespace {
932 struct FunctionIsDirectlyRecursive :
933 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> {
934 const StringRef Name;
935 const Builtin::Context &BI;
936 bool Result;
FunctionIsDirectlyRecursive__anona5e95aa10111::FunctionIsDirectlyRecursive937 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) :
938 Name(N), BI(C), Result(false) {
939 }
940 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base;
941
TraverseCallExpr__anona5e95aa10111::FunctionIsDirectlyRecursive942 bool TraverseCallExpr(CallExpr *E) {
943 const FunctionDecl *FD = E->getDirectCallee();
944 if (!FD)
945 return true;
946 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
947 if (Attr && Name == Attr->getLabel()) {
948 Result = true;
949 return false;
950 }
951 unsigned BuiltinID = FD->getBuiltinID();
952 if (!BuiltinID)
953 return true;
954 StringRef BuiltinName = BI.GetName(BuiltinID);
955 if (BuiltinName.startswith("__builtin_") &&
956 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
957 Result = true;
958 return false;
959 }
960 return true;
961 }
962 };
963 }
964
965 // isTriviallyRecursive - Check if this function calls another
966 // decl that, because of the asm attribute or the other decl being a builtin,
967 // ends up pointing to itself.
968 bool
isTriviallyRecursive(const FunctionDecl * FD)969 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
970 StringRef Name;
971 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
972 // asm labels are a special kind of mangling we have to support.
973 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
974 if (!Attr)
975 return false;
976 Name = Attr->getLabel();
977 } else {
978 Name = FD->getName();
979 }
980
981 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
982 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD));
983 return Walker.Result;
984 }
985
986 bool
shouldEmitFunction(const FunctionDecl * F)987 CodeGenModule::shouldEmitFunction(const FunctionDecl *F) {
988 if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage)
989 return true;
990 if (CodeGenOpts.OptimizationLevel == 0 &&
991 !F->hasAttr<AlwaysInlineAttr>() && !F->hasAttr<ForceInlineAttr>())
992 return false;
993 // PR9614. Avoid cases where the source code is lying to us. An available
994 // externally function should have an equivalent function somewhere else,
995 // but a function that calls itself is clearly not equivalent to the real
996 // implementation.
997 // This happens in glibc's btowc and in some configure checks.
998 return !isTriviallyRecursive(F);
999 }
1000
EmitGlobalDefinition(GlobalDecl GD)1001 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) {
1002 const ValueDecl *D = cast<ValueDecl>(GD.getDecl());
1003
1004 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
1005 Context.getSourceManager(),
1006 "Generating code for declaration");
1007
1008 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
1009 // At -O0, don't generate IR for functions with available_externally
1010 // linkage.
1011 if (!shouldEmitFunction(Function))
1012 return;
1013
1014 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
1015 // Make sure to emit the definition(s) before we emit the thunks.
1016 // This is necessary for the generation of certain thunks.
1017 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method))
1018 EmitCXXConstructor(CD, GD.getCtorType());
1019 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method))
1020 EmitCXXDestructor(DD, GD.getDtorType());
1021 else
1022 EmitGlobalFunctionDefinition(GD);
1023
1024 if (Method->isVirtual())
1025 getVTables().EmitThunks(GD);
1026
1027 return;
1028 }
1029
1030 return EmitGlobalFunctionDefinition(GD);
1031 }
1032
1033 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
1034 return EmitGlobalVarDefinition(VD);
1035
1036 llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
1037 }
1038
1039 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
1040 /// module, create and return an llvm Function with the specified type. If there
1041 /// is something in the module with the specified name, return it potentially
1042 /// bitcasted to the right type.
1043 ///
1044 /// If D is non-null, it specifies a decl that correspond to this. This is used
1045 /// to set the attributes on the function when it is first created.
1046 llvm::Constant *
GetOrCreateLLVMFunction(StringRef MangledName,llvm::Type * Ty,GlobalDecl D,bool ForVTable,llvm::Attributes ExtraAttrs)1047 CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName,
1048 llvm::Type *Ty,
1049 GlobalDecl D, bool ForVTable,
1050 llvm::Attributes ExtraAttrs) {
1051 // Lookup the entry, lazily creating it if necessary.
1052 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
1053 if (Entry) {
1054 if (WeakRefReferences.erase(Entry)) {
1055 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl());
1056 if (FD && !FD->hasAttr<WeakAttr>())
1057 Entry->setLinkage(llvm::Function::ExternalLinkage);
1058 }
1059
1060 if (Entry->getType()->getElementType() == Ty)
1061 return Entry;
1062
1063 // Make sure the result is of the correct type.
1064 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
1065 }
1066
1067 // This function doesn't have a complete type (for example, the return
1068 // type is an incomplete struct). Use a fake type instead, and make
1069 // sure not to try to set attributes.
1070 bool IsIncompleteFunction = false;
1071
1072 llvm::FunctionType *FTy;
1073 if (isa<llvm::FunctionType>(Ty)) {
1074 FTy = cast<llvm::FunctionType>(Ty);
1075 } else {
1076 FTy = llvm::FunctionType::get(VoidTy, false);
1077 IsIncompleteFunction = true;
1078 }
1079
1080 llvm::Function *F = llvm::Function::Create(FTy,
1081 llvm::Function::ExternalLinkage,
1082 MangledName, &getModule());
1083 assert(F->getName() == MangledName && "name was uniqued!");
1084 if (D.getDecl())
1085 SetFunctionAttributes(D, F, IsIncompleteFunction);
1086 if (ExtraAttrs != llvm::Attribute::None)
1087 F->addFnAttr(ExtraAttrs);
1088
1089 // This is the first use or definition of a mangled name. If there is a
1090 // deferred decl with this name, remember that we need to emit it at the end
1091 // of the file.
1092 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName);
1093 if (DDI != DeferredDecls.end()) {
1094 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
1095 // list, and remove it from DeferredDecls (since we don't need it anymore).
1096 DeferredDeclsToEmit.push_back(DDI->second);
1097 DeferredDecls.erase(DDI);
1098
1099 // Otherwise, there are cases we have to worry about where we're
1100 // using a declaration for which we must emit a definition but where
1101 // we might not find a top-level definition:
1102 // - member functions defined inline in their classes
1103 // - friend functions defined inline in some class
1104 // - special member functions with implicit definitions
1105 // If we ever change our AST traversal to walk into class methods,
1106 // this will be unnecessary.
1107 //
1108 // We also don't emit a definition for a function if it's going to be an entry
1109 // in a vtable, unless it's already marked as used.
1110 } else if (getLangOpts().CPlusPlus && D.getDecl()) {
1111 // Look for a declaration that's lexically in a record.
1112 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl());
1113 FD = FD->getMostRecentDecl();
1114 do {
1115 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
1116 if (FD->isImplicit() && !ForVTable) {
1117 assert(FD->isUsed() && "Sema didn't mark implicit function as used!");
1118 DeferredDeclsToEmit.push_back(D.getWithDecl(FD));
1119 break;
1120 } else if (FD->doesThisDeclarationHaveABody()) {
1121 DeferredDeclsToEmit.push_back(D.getWithDecl(FD));
1122 break;
1123 }
1124 }
1125 FD = FD->getPreviousDecl();
1126 } while (FD);
1127 }
1128
1129 // Make sure the result is of the requested type.
1130 if (!IsIncompleteFunction) {
1131 assert(F->getType()->getElementType() == Ty);
1132 return F;
1133 }
1134
1135 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
1136 return llvm::ConstantExpr::getBitCast(F, PTy);
1137 }
1138
1139 /// GetAddrOfFunction - Return the address of the given function. If Ty is
1140 /// non-null, then this function will use the specified type if it has to
1141 /// create it (this occurs when we see a definition of the function).
GetAddrOfFunction(GlobalDecl GD,llvm::Type * Ty,bool ForVTable)1142 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
1143 llvm::Type *Ty,
1144 bool ForVTable) {
1145 // If there was no specific requested type, just convert it now.
1146 if (!Ty)
1147 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType());
1148
1149 StringRef MangledName = getMangledName(GD);
1150 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable);
1151 }
1152
1153 /// CreateRuntimeFunction - Create a new runtime function with the specified
1154 /// type and name.
1155 llvm::Constant *
CreateRuntimeFunction(llvm::FunctionType * FTy,StringRef Name,llvm::Attributes ExtraAttrs)1156 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy,
1157 StringRef Name,
1158 llvm::Attributes ExtraAttrs) {
1159 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
1160 ExtraAttrs);
1161 }
1162
1163 /// isTypeConstant - Determine whether an object of this type can be emitted
1164 /// as a constant.
1165 ///
1166 /// If ExcludeCtor is true, the duration when the object's constructor runs
1167 /// will not be considered. The caller will need to verify that the object is
1168 /// not written to during its construction.
isTypeConstant(QualType Ty,bool ExcludeCtor)1169 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
1170 if (!Ty.isConstant(Context) && !Ty->isReferenceType())
1171 return false;
1172
1173 if (Context.getLangOpts().CPlusPlus) {
1174 if (const CXXRecordDecl *Record
1175 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
1176 return ExcludeCtor && !Record->hasMutableFields() &&
1177 Record->hasTrivialDestructor();
1178 }
1179
1180 return true;
1181 }
1182
1183 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
1184 /// create and return an llvm GlobalVariable with the specified type. If there
1185 /// is something in the module with the specified name, return it potentially
1186 /// bitcasted to the right type.
1187 ///
1188 /// If D is non-null, it specifies a decl that correspond to this. This is used
1189 /// to set the attributes on the global when it is first created.
1190 llvm::Constant *
GetOrCreateLLVMGlobal(StringRef MangledName,llvm::PointerType * Ty,const VarDecl * D,bool UnnamedAddr)1191 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
1192 llvm::PointerType *Ty,
1193 const VarDecl *D,
1194 bool UnnamedAddr) {
1195 // Lookup the entry, lazily creating it if necessary.
1196 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
1197 if (Entry) {
1198 if (WeakRefReferences.erase(Entry)) {
1199 if (D && !D->hasAttr<WeakAttr>())
1200 Entry->setLinkage(llvm::Function::ExternalLinkage);
1201 }
1202
1203 if (UnnamedAddr)
1204 Entry->setUnnamedAddr(true);
1205
1206 if (Entry->getType() == Ty)
1207 return Entry;
1208
1209 // Make sure the result is of the correct type.
1210 return llvm::ConstantExpr::getBitCast(Entry, Ty);
1211 }
1212
1213 // This is the first use or definition of a mangled name. If there is a
1214 // deferred decl with this name, remember that we need to emit it at the end
1215 // of the file.
1216 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName);
1217 if (DDI != DeferredDecls.end()) {
1218 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
1219 // list, and remove it from DeferredDecls (since we don't need it anymore).
1220 DeferredDeclsToEmit.push_back(DDI->second);
1221 DeferredDecls.erase(DDI);
1222 }
1223
1224 unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace());
1225 llvm::GlobalVariable *GV =
1226 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false,
1227 llvm::GlobalValue::ExternalLinkage,
1228 0, MangledName, 0,
1229 llvm::GlobalVariable::NotThreadLocal, AddrSpace);
1230
1231 // Handle things which are present even on external declarations.
1232 if (D) {
1233 // FIXME: This code is overly simple and should be merged with other global
1234 // handling.
1235 GV->setConstant(isTypeConstant(D->getType(), false));
1236
1237 // Set linkage and visibility in case we never see a definition.
1238 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility();
1239 if (LV.linkage() != ExternalLinkage) {
1240 // Don't set internal linkage on declarations.
1241 } else {
1242 if (D->hasAttr<DLLImportAttr>())
1243 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage);
1244 else if (D->hasAttr<WeakAttr>() || D->isWeakImported())
1245 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
1246
1247 // Set visibility on a declaration only if it's explicit.
1248 if (LV.visibilityExplicit())
1249 GV->setVisibility(GetLLVMVisibility(LV.visibility()));
1250 }
1251
1252 if (D->isThreadSpecified())
1253 setTLSMode(GV, *D);
1254 }
1255
1256 if (AddrSpace != Ty->getAddressSpace())
1257 return llvm::ConstantExpr::getBitCast(GV, Ty);
1258 else
1259 return GV;
1260 }
1261
1262
1263 llvm::GlobalVariable *
CreateOrReplaceCXXRuntimeVariable(StringRef Name,llvm::Type * Ty,llvm::GlobalValue::LinkageTypes Linkage)1264 CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name,
1265 llvm::Type *Ty,
1266 llvm::GlobalValue::LinkageTypes Linkage) {
1267 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
1268 llvm::GlobalVariable *OldGV = 0;
1269
1270
1271 if (GV) {
1272 // Check if the variable has the right type.
1273 if (GV->getType()->getElementType() == Ty)
1274 return GV;
1275
1276 // Because C++ name mangling, the only way we can end up with an already
1277 // existing global with the same name is if it has been declared extern "C".
1278 assert(GV->isDeclaration() && "Declaration has wrong type!");
1279 OldGV = GV;
1280 }
1281
1282 // Create a new variable.
1283 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
1284 Linkage, 0, Name);
1285
1286 if (OldGV) {
1287 // Replace occurrences of the old variable if needed.
1288 GV->takeName(OldGV);
1289
1290 if (!OldGV->use_empty()) {
1291 llvm::Constant *NewPtrForOldDecl =
1292 llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
1293 OldGV->replaceAllUsesWith(NewPtrForOldDecl);
1294 }
1295
1296 OldGV->eraseFromParent();
1297 }
1298
1299 return GV;
1300 }
1301
1302 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
1303 /// given global variable. If Ty is non-null and if the global doesn't exist,
1304 /// then it will be created with the specified type instead of whatever the
1305 /// normal requested type would be.
GetAddrOfGlobalVar(const VarDecl * D,llvm::Type * Ty)1306 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
1307 llvm::Type *Ty) {
1308 assert(D->hasGlobalStorage() && "Not a global variable");
1309 QualType ASTTy = D->getType();
1310 if (Ty == 0)
1311 Ty = getTypes().ConvertTypeForMem(ASTTy);
1312
1313 llvm::PointerType *PTy =
1314 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
1315
1316 StringRef MangledName = getMangledName(D);
1317 return GetOrCreateLLVMGlobal(MangledName, PTy, D);
1318 }
1319
1320 /// CreateRuntimeVariable - Create a new runtime global variable with the
1321 /// specified type and name.
1322 llvm::Constant *
CreateRuntimeVariable(llvm::Type * Ty,StringRef Name)1323 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
1324 StringRef Name) {
1325 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0,
1326 true);
1327 }
1328
EmitTentativeDefinition(const VarDecl * D)1329 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
1330 assert(!D->getInit() && "Cannot emit definite definitions here!");
1331
1332 if (MayDeferGeneration(D)) {
1333 // If we have not seen a reference to this variable yet, place it
1334 // into the deferred declarations table to be emitted if needed
1335 // later.
1336 StringRef MangledName = getMangledName(D);
1337 if (!GetGlobalValue(MangledName)) {
1338 DeferredDecls[MangledName] = D;
1339 return;
1340 }
1341 }
1342
1343 // The tentative definition is the only definition.
1344 EmitGlobalVarDefinition(D);
1345 }
1346
EmitVTable(CXXRecordDecl * Class,bool DefinitionRequired)1347 void CodeGenModule::EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired) {
1348 if (DefinitionRequired)
1349 getCXXABI().EmitVTables(Class);
1350 }
1351
1352 llvm::GlobalVariable::LinkageTypes
getVTableLinkage(const CXXRecordDecl * RD)1353 CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) {
1354 if (RD->getLinkage() != ExternalLinkage)
1355 return llvm::GlobalVariable::InternalLinkage;
1356
1357 if (const CXXMethodDecl *KeyFunction
1358 = RD->getASTContext().getKeyFunction(RD)) {
1359 // If this class has a key function, use that to determine the linkage of
1360 // the vtable.
1361 const FunctionDecl *Def = 0;
1362 if (KeyFunction->hasBody(Def))
1363 KeyFunction = cast<CXXMethodDecl>(Def);
1364
1365 switch (KeyFunction->getTemplateSpecializationKind()) {
1366 case TSK_Undeclared:
1367 case TSK_ExplicitSpecialization:
1368 // When compiling with optimizations turned on, we emit all vtables,
1369 // even if the key function is not defined in the current translation
1370 // unit. If this is the case, use available_externally linkage.
1371 if (!Def && CodeGenOpts.OptimizationLevel)
1372 return llvm::GlobalVariable::AvailableExternallyLinkage;
1373
1374 if (KeyFunction->isInlined())
1375 return !Context.getLangOpts().AppleKext ?
1376 llvm::GlobalVariable::LinkOnceODRLinkage :
1377 llvm::Function::InternalLinkage;
1378
1379 return llvm::GlobalVariable::ExternalLinkage;
1380
1381 case TSK_ImplicitInstantiation:
1382 return !Context.getLangOpts().AppleKext ?
1383 llvm::GlobalVariable::LinkOnceODRLinkage :
1384 llvm::Function::InternalLinkage;
1385
1386 case TSK_ExplicitInstantiationDefinition:
1387 return !Context.getLangOpts().AppleKext ?
1388 llvm::GlobalVariable::WeakODRLinkage :
1389 llvm::Function::InternalLinkage;
1390
1391 case TSK_ExplicitInstantiationDeclaration:
1392 // FIXME: Use available_externally linkage. However, this currently
1393 // breaks LLVM's build due to undefined symbols.
1394 // return llvm::GlobalVariable::AvailableExternallyLinkage;
1395 return !Context.getLangOpts().AppleKext ?
1396 llvm::GlobalVariable::LinkOnceODRLinkage :
1397 llvm::Function::InternalLinkage;
1398 }
1399 }
1400
1401 if (Context.getLangOpts().AppleKext)
1402 return llvm::Function::InternalLinkage;
1403
1404 switch (RD->getTemplateSpecializationKind()) {
1405 case TSK_Undeclared:
1406 case TSK_ExplicitSpecialization:
1407 case TSK_ImplicitInstantiation:
1408 // FIXME: Use available_externally linkage. However, this currently
1409 // breaks LLVM's build due to undefined symbols.
1410 // return llvm::GlobalVariable::AvailableExternallyLinkage;
1411 case TSK_ExplicitInstantiationDeclaration:
1412 return llvm::GlobalVariable::LinkOnceODRLinkage;
1413
1414 case TSK_ExplicitInstantiationDefinition:
1415 return llvm::GlobalVariable::WeakODRLinkage;
1416 }
1417
1418 llvm_unreachable("Invalid TemplateSpecializationKind!");
1419 }
1420
GetTargetTypeStoreSize(llvm::Type * Ty) const1421 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
1422 return Context.toCharUnitsFromBits(
1423 TheTargetData.getTypeStoreSizeInBits(Ty));
1424 }
1425
1426 llvm::Constant *
MaybeEmitGlobalStdInitializerListInitializer(const VarDecl * D,const Expr * rawInit)1427 CodeGenModule::MaybeEmitGlobalStdInitializerListInitializer(const VarDecl *D,
1428 const Expr *rawInit) {
1429 ArrayRef<ExprWithCleanups::CleanupObject> cleanups;
1430 if (const ExprWithCleanups *withCleanups =
1431 dyn_cast<ExprWithCleanups>(rawInit)) {
1432 cleanups = withCleanups->getObjects();
1433 rawInit = withCleanups->getSubExpr();
1434 }
1435
1436 const InitListExpr *init = dyn_cast<InitListExpr>(rawInit);
1437 if (!init || !init->initializesStdInitializerList() ||
1438 init->getNumInits() == 0)
1439 return 0;
1440
1441 ASTContext &ctx = getContext();
1442 unsigned numInits = init->getNumInits();
1443 // FIXME: This check is here because we would otherwise silently miscompile
1444 // nested global std::initializer_lists. Better would be to have a real
1445 // implementation.
1446 for (unsigned i = 0; i < numInits; ++i) {
1447 const InitListExpr *inner = dyn_cast<InitListExpr>(init->getInit(i));
1448 if (inner && inner->initializesStdInitializerList()) {
1449 ErrorUnsupported(inner, "nested global std::initializer_list");
1450 return 0;
1451 }
1452 }
1453
1454 // Synthesize a fake VarDecl for the array and initialize that.
1455 QualType elementType = init->getInit(0)->getType();
1456 llvm::APInt numElements(ctx.getTypeSize(ctx.getSizeType()), numInits);
1457 QualType arrayType = ctx.getConstantArrayType(elementType, numElements,
1458 ArrayType::Normal, 0);
1459
1460 IdentifierInfo *name = &ctx.Idents.get(D->getNameAsString() + "__initlist");
1461 TypeSourceInfo *sourceInfo = ctx.getTrivialTypeSourceInfo(
1462 arrayType, D->getLocation());
1463 VarDecl *backingArray = VarDecl::Create(ctx, const_cast<DeclContext*>(
1464 D->getDeclContext()),
1465 D->getLocStart(), D->getLocation(),
1466 name, arrayType, sourceInfo,
1467 SC_Static, SC_Static);
1468
1469 // Now clone the InitListExpr to initialize the array instead.
1470 // Incredible hack: we want to use the existing InitListExpr here, so we need
1471 // to tell it that it no longer initializes a std::initializer_list.
1472 ArrayRef<Expr*> Inits(const_cast<InitListExpr*>(init)->getInits(),
1473 init->getNumInits());
1474 Expr *arrayInit = new (ctx) InitListExpr(ctx, init->getLBraceLoc(), Inits,
1475 init->getRBraceLoc());
1476 arrayInit->setType(arrayType);
1477
1478 if (!cleanups.empty())
1479 arrayInit = ExprWithCleanups::Create(ctx, arrayInit, cleanups);
1480
1481 backingArray->setInit(arrayInit);
1482
1483 // Emit the definition of the array.
1484 EmitGlobalVarDefinition(backingArray);
1485
1486 // Inspect the initializer list to validate it and determine its type.
1487 // FIXME: doing this every time is probably inefficient; caching would be nice
1488 RecordDecl *record = init->getType()->castAs<RecordType>()->getDecl();
1489 RecordDecl::field_iterator field = record->field_begin();
1490 if (field == record->field_end()) {
1491 ErrorUnsupported(D, "weird std::initializer_list");
1492 return 0;
1493 }
1494 QualType elementPtr = ctx.getPointerType(elementType.withConst());
1495 // Start pointer.
1496 if (!ctx.hasSameType(field->getType(), elementPtr)) {
1497 ErrorUnsupported(D, "weird std::initializer_list");
1498 return 0;
1499 }
1500 ++field;
1501 if (field == record->field_end()) {
1502 ErrorUnsupported(D, "weird std::initializer_list");
1503 return 0;
1504 }
1505 bool isStartEnd = false;
1506 if (ctx.hasSameType(field->getType(), elementPtr)) {
1507 // End pointer.
1508 isStartEnd = true;
1509 } else if(!ctx.hasSameType(field->getType(), ctx.getSizeType())) {
1510 ErrorUnsupported(D, "weird std::initializer_list");
1511 return 0;
1512 }
1513
1514 // Now build an APValue representing the std::initializer_list.
1515 APValue initListValue(APValue::UninitStruct(), 0, 2);
1516 APValue &startField = initListValue.getStructField(0);
1517 APValue::LValuePathEntry startOffsetPathEntry;
1518 startOffsetPathEntry.ArrayIndex = 0;
1519 startField = APValue(APValue::LValueBase(backingArray),
1520 CharUnits::fromQuantity(0),
1521 llvm::makeArrayRef(startOffsetPathEntry),
1522 /*IsOnePastTheEnd=*/false, 0);
1523
1524 if (isStartEnd) {
1525 APValue &endField = initListValue.getStructField(1);
1526 APValue::LValuePathEntry endOffsetPathEntry;
1527 endOffsetPathEntry.ArrayIndex = numInits;
1528 endField = APValue(APValue::LValueBase(backingArray),
1529 ctx.getTypeSizeInChars(elementType) * numInits,
1530 llvm::makeArrayRef(endOffsetPathEntry),
1531 /*IsOnePastTheEnd=*/true, 0);
1532 } else {
1533 APValue &sizeField = initListValue.getStructField(1);
1534 sizeField = APValue(llvm::APSInt(numElements));
1535 }
1536
1537 // Emit the constant for the initializer_list.
1538 llvm::Constant *llvmInit =
1539 EmitConstantValueForMemory(initListValue, D->getType());
1540 assert(llvmInit && "failed to initialize as constant");
1541 return llvmInit;
1542 }
1543
GetGlobalVarAddressSpace(const VarDecl * D,unsigned AddrSpace)1544 unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D,
1545 unsigned AddrSpace) {
1546 if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) {
1547 if (D->hasAttr<CUDAConstantAttr>())
1548 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_constant);
1549 else if (D->hasAttr<CUDASharedAttr>())
1550 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_shared);
1551 else
1552 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_device);
1553 }
1554
1555 return AddrSpace;
1556 }
1557
EmitGlobalVarDefinition(const VarDecl * D)1558 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
1559 llvm::Constant *Init = 0;
1560 QualType ASTTy = D->getType();
1561 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
1562 bool NeedsGlobalCtor = false;
1563 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor();
1564
1565 const VarDecl *InitDecl;
1566 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
1567
1568 if (!InitExpr) {
1569 // This is a tentative definition; tentative definitions are
1570 // implicitly initialized with { 0 }.
1571 //
1572 // Note that tentative definitions are only emitted at the end of
1573 // a translation unit, so they should never have incomplete
1574 // type. In addition, EmitTentativeDefinition makes sure that we
1575 // never attempt to emit a tentative definition if a real one
1576 // exists. A use may still exists, however, so we still may need
1577 // to do a RAUW.
1578 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
1579 Init = EmitNullConstant(D->getType());
1580 } else {
1581 // If this is a std::initializer_list, emit the special initializer.
1582 Init = MaybeEmitGlobalStdInitializerListInitializer(D, InitExpr);
1583 // An empty init list will perform zero-initialization, which happens
1584 // to be exactly what we want.
1585 // FIXME: It does so in a global constructor, which is *not* what we
1586 // want.
1587
1588 if (!Init) {
1589 initializedGlobalDecl = GlobalDecl(D);
1590 Init = EmitConstantInit(*InitDecl);
1591 }
1592 if (!Init) {
1593 QualType T = InitExpr->getType();
1594 if (D->getType()->isReferenceType())
1595 T = D->getType();
1596
1597 if (getLangOpts().CPlusPlus) {
1598 Init = EmitNullConstant(T);
1599 NeedsGlobalCtor = true;
1600 } else {
1601 ErrorUnsupported(D, "static initializer");
1602 Init = llvm::UndefValue::get(getTypes().ConvertType(T));
1603 }
1604 } else {
1605 // We don't need an initializer, so remove the entry for the delayed
1606 // initializer position (just in case this entry was delayed) if we
1607 // also don't need to register a destructor.
1608 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
1609 DelayedCXXInitPosition.erase(D);
1610 }
1611 }
1612
1613 llvm::Type* InitType = Init->getType();
1614 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType);
1615
1616 // Strip off a bitcast if we got one back.
1617 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
1618 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
1619 // all zero index gep.
1620 CE->getOpcode() == llvm::Instruction::GetElementPtr);
1621 Entry = CE->getOperand(0);
1622 }
1623
1624 // Entry is now either a Function or GlobalVariable.
1625 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry);
1626
1627 // We have a definition after a declaration with the wrong type.
1628 // We must make a new GlobalVariable* and update everything that used OldGV
1629 // (a declaration or tentative definition) with the new GlobalVariable*
1630 // (which will be a definition).
1631 //
1632 // This happens if there is a prototype for a global (e.g.
1633 // "extern int x[];") and then a definition of a different type (e.g.
1634 // "int x[10];"). This also happens when an initializer has a different type
1635 // from the type of the global (this happens with unions).
1636 if (GV == 0 ||
1637 GV->getType()->getElementType() != InitType ||
1638 GV->getType()->getAddressSpace() !=
1639 GetGlobalVarAddressSpace(D, getContext().getTargetAddressSpace(ASTTy))) {
1640
1641 // Move the old entry aside so that we'll create a new one.
1642 Entry->setName(StringRef());
1643
1644 // Make a new global with the correct type, this is now guaranteed to work.
1645 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType));
1646
1647 // Replace all uses of the old global with the new global
1648 llvm::Constant *NewPtrForOldDecl =
1649 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
1650 Entry->replaceAllUsesWith(NewPtrForOldDecl);
1651
1652 // Erase the old global, since it is no longer used.
1653 cast<llvm::GlobalValue>(Entry)->eraseFromParent();
1654 }
1655
1656 if (D->hasAttr<AnnotateAttr>())
1657 AddGlobalAnnotations(D, GV);
1658
1659 GV->setInitializer(Init);
1660
1661 // If it is safe to mark the global 'constant', do so now.
1662 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
1663 isTypeConstant(D->getType(), true));
1664
1665 GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
1666
1667 // Set the llvm linkage type as appropriate.
1668 llvm::GlobalValue::LinkageTypes Linkage =
1669 GetLLVMLinkageVarDefinition(D, GV);
1670 GV->setLinkage(Linkage);
1671 if (Linkage == llvm::GlobalVariable::CommonLinkage)
1672 // common vars aren't constant even if declared const.
1673 GV->setConstant(false);
1674
1675 SetCommonAttributes(D, GV);
1676
1677 // Emit the initializer function if necessary.
1678 if (NeedsGlobalCtor || NeedsGlobalDtor)
1679 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
1680
1681 // If we are compiling with ASan, add metadata indicating dynamically
1682 // initialized globals.
1683 if (LangOpts.AddressSanitizer && NeedsGlobalCtor) {
1684 llvm::Module &M = getModule();
1685
1686 llvm::NamedMDNode *DynamicInitializers =
1687 M.getOrInsertNamedMetadata("llvm.asan.dynamically_initialized_globals");
1688 llvm::Value *GlobalToAdd[] = { GV };
1689 llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalToAdd);
1690 DynamicInitializers->addOperand(ThisGlobal);
1691 }
1692
1693 // Emit global variable debug information.
1694 if (CGDebugInfo *DI = getModuleDebugInfo())
1695 if (getCodeGenOpts().DebugInfo >= CodeGenOptions::LimitedDebugInfo)
1696 DI->EmitGlobalVariable(GV, D);
1697 }
1698
1699 llvm::GlobalValue::LinkageTypes
GetLLVMLinkageVarDefinition(const VarDecl * D,llvm::GlobalVariable * GV)1700 CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D,
1701 llvm::GlobalVariable *GV) {
1702 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D);
1703 if (Linkage == GVA_Internal)
1704 return llvm::Function::InternalLinkage;
1705 else if (D->hasAttr<DLLImportAttr>())
1706 return llvm::Function::DLLImportLinkage;
1707 else if (D->hasAttr<DLLExportAttr>())
1708 return llvm::Function::DLLExportLinkage;
1709 else if (D->hasAttr<WeakAttr>()) {
1710 if (GV->isConstant())
1711 return llvm::GlobalVariable::WeakODRLinkage;
1712 else
1713 return llvm::GlobalVariable::WeakAnyLinkage;
1714 } else if (Linkage == GVA_TemplateInstantiation ||
1715 Linkage == GVA_ExplicitTemplateInstantiation)
1716 return llvm::GlobalVariable::WeakODRLinkage;
1717 else if (!getLangOpts().CPlusPlus &&
1718 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) ||
1719 D->getAttr<CommonAttr>()) &&
1720 !D->hasExternalStorage() && !D->getInit() &&
1721 !D->getAttr<SectionAttr>() && !D->isThreadSpecified() &&
1722 !D->getAttr<WeakImportAttr>()) {
1723 // Thread local vars aren't considered common linkage.
1724 return llvm::GlobalVariable::CommonLinkage;
1725 }
1726 return llvm::GlobalVariable::ExternalLinkage;
1727 }
1728
1729 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
1730 /// implement a function with no prototype, e.g. "int foo() {}". If there are
1731 /// existing call uses of the old function in the module, this adjusts them to
1732 /// call the new function directly.
1733 ///
1734 /// This is not just a cleanup: the always_inline pass requires direct calls to
1735 /// functions to be able to inline them. If there is a bitcast in the way, it
1736 /// won't inline them. Instcombine normally deletes these calls, but it isn't
1737 /// run at -O0.
ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue * Old,llvm::Function * NewFn)1738 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
1739 llvm::Function *NewFn) {
1740 // If we're redefining a global as a function, don't transform it.
1741 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old);
1742 if (OldFn == 0) return;
1743
1744 llvm::Type *NewRetTy = NewFn->getReturnType();
1745 SmallVector<llvm::Value*, 4> ArgList;
1746
1747 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end();
1748 UI != E; ) {
1749 // TODO: Do invokes ever occur in C code? If so, we should handle them too.
1750 llvm::Value::use_iterator I = UI++; // Increment before the CI is erased.
1751 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*I);
1752 if (!CI) continue; // FIXME: when we allow Invoke, just do CallSite CS(*I)
1753 llvm::CallSite CS(CI);
1754 if (!CI || !CS.isCallee(I)) continue;
1755
1756 // If the return types don't match exactly, and if the call isn't dead, then
1757 // we can't transform this call.
1758 if (CI->getType() != NewRetTy && !CI->use_empty())
1759 continue;
1760
1761 // Get the attribute list.
1762 llvm::SmallVector<llvm::AttributeWithIndex, 8> AttrVec;
1763 llvm::AttrListPtr AttrList = CI->getAttributes();
1764
1765 // Get any return attributes.
1766 llvm::Attributes RAttrs = AttrList.getRetAttributes();
1767
1768 // Add the return attributes.
1769 if (RAttrs)
1770 AttrVec.push_back(llvm::AttributeWithIndex::get(0, RAttrs));
1771
1772 // If the function was passed too few arguments, don't transform. If extra
1773 // arguments were passed, we silently drop them. If any of the types
1774 // mismatch, we don't transform.
1775 unsigned ArgNo = 0;
1776 bool DontTransform = false;
1777 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(),
1778 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) {
1779 if (CS.arg_size() == ArgNo ||
1780 CS.getArgument(ArgNo)->getType() != AI->getType()) {
1781 DontTransform = true;
1782 break;
1783 }
1784
1785 // Add any parameter attributes.
1786 if (llvm::Attributes PAttrs = AttrList.getParamAttributes(ArgNo + 1))
1787 AttrVec.push_back(llvm::AttributeWithIndex::get(ArgNo + 1, PAttrs));
1788 }
1789 if (DontTransform)
1790 continue;
1791
1792 if (llvm::Attributes FnAttrs = AttrList.getFnAttributes())
1793 AttrVec.push_back(llvm::AttributeWithIndex::get(~0, FnAttrs));
1794
1795 // Okay, we can transform this. Create the new call instruction and copy
1796 // over the required information.
1797 ArgList.append(CS.arg_begin(), CS.arg_begin() + ArgNo);
1798 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList, "", CI);
1799 ArgList.clear();
1800 if (!NewCall->getType()->isVoidTy())
1801 NewCall->takeName(CI);
1802 NewCall->setAttributes(llvm::AttrListPtr::get(AttrVec));
1803 NewCall->setCallingConv(CI->getCallingConv());
1804
1805 // Finally, remove the old call, replacing any uses with the new one.
1806 if (!CI->use_empty())
1807 CI->replaceAllUsesWith(NewCall);
1808
1809 // Copy debug location attached to CI.
1810 if (!CI->getDebugLoc().isUnknown())
1811 NewCall->setDebugLoc(CI->getDebugLoc());
1812 CI->eraseFromParent();
1813 }
1814 }
1815
HandleCXXStaticMemberVarInstantiation(VarDecl * VD)1816 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
1817 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
1818 // If we have a definition, this might be a deferred decl. If the
1819 // instantiation is explicit, make sure we emit it at the end.
1820 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
1821 GetAddrOfGlobalVar(VD);
1822 }
1823
EmitGlobalFunctionDefinition(GlobalDecl GD)1824 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) {
1825 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl());
1826
1827 // Compute the function info and LLVM type.
1828 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
1829 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
1830
1831 // Get or create the prototype for the function.
1832 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty);
1833
1834 // Strip off a bitcast if we got one back.
1835 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
1836 assert(CE->getOpcode() == llvm::Instruction::BitCast);
1837 Entry = CE->getOperand(0);
1838 }
1839
1840
1841 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) {
1842 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry);
1843
1844 // If the types mismatch then we have to rewrite the definition.
1845 assert(OldFn->isDeclaration() &&
1846 "Shouldn't replace non-declaration");
1847
1848 // F is the Function* for the one with the wrong type, we must make a new
1849 // Function* and update everything that used F (a declaration) with the new
1850 // Function* (which will be a definition).
1851 //
1852 // This happens if there is a prototype for a function
1853 // (e.g. "int f()") and then a definition of a different type
1854 // (e.g. "int f(int x)"). Move the old function aside so that it
1855 // doesn't interfere with GetAddrOfFunction.
1856 OldFn->setName(StringRef());
1857 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty));
1858
1859 // If this is an implementation of a function without a prototype, try to
1860 // replace any existing uses of the function (which may be calls) with uses
1861 // of the new function
1862 if (D->getType()->isFunctionNoProtoType()) {
1863 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn);
1864 OldFn->removeDeadConstantUsers();
1865 }
1866
1867 // Replace uses of F with the Function we will endow with a body.
1868 if (!Entry->use_empty()) {
1869 llvm::Constant *NewPtrForOldDecl =
1870 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType());
1871 Entry->replaceAllUsesWith(NewPtrForOldDecl);
1872 }
1873
1874 // Ok, delete the old function now, which is dead.
1875 OldFn->eraseFromParent();
1876
1877 Entry = NewFn;
1878 }
1879
1880 // We need to set linkage and visibility on the function before
1881 // generating code for it because various parts of IR generation
1882 // want to propagate this information down (e.g. to local static
1883 // declarations).
1884 llvm::Function *Fn = cast<llvm::Function>(Entry);
1885 setFunctionLinkage(D, Fn);
1886
1887 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes
1888 setGlobalVisibility(Fn, D);
1889
1890 CodeGenFunction(*this).GenerateCode(D, Fn, FI);
1891
1892 SetFunctionDefinitionAttributes(D, Fn);
1893 SetLLVMFunctionAttributesForDefinition(D, Fn);
1894
1895 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
1896 AddGlobalCtor(Fn, CA->getPriority());
1897 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
1898 AddGlobalDtor(Fn, DA->getPriority());
1899 if (D->hasAttr<AnnotateAttr>())
1900 AddGlobalAnnotations(D, Fn);
1901 }
1902
EmitAliasDefinition(GlobalDecl GD)1903 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
1904 const ValueDecl *D = cast<ValueDecl>(GD.getDecl());
1905 const AliasAttr *AA = D->getAttr<AliasAttr>();
1906 assert(AA && "Not an alias?");
1907
1908 StringRef MangledName = getMangledName(GD);
1909
1910 // If there is a definition in the module, then it wins over the alias.
1911 // This is dubious, but allow it to be safe. Just ignore the alias.
1912 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
1913 if (Entry && !Entry->isDeclaration())
1914 return;
1915
1916 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
1917
1918 // Create a reference to the named value. This ensures that it is emitted
1919 // if a deferred decl.
1920 llvm::Constant *Aliasee;
1921 if (isa<llvm::FunctionType>(DeclTy))
1922 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(),
1923 /*ForVTable=*/false);
1924 else
1925 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
1926 llvm::PointerType::getUnqual(DeclTy), 0);
1927
1928 // Create the new alias itself, but don't set a name yet.
1929 llvm::GlobalValue *GA =
1930 new llvm::GlobalAlias(Aliasee->getType(),
1931 llvm::Function::ExternalLinkage,
1932 "", Aliasee, &getModule());
1933
1934 if (Entry) {
1935 assert(Entry->isDeclaration());
1936
1937 // If there is a declaration in the module, then we had an extern followed
1938 // by the alias, as in:
1939 // extern int test6();
1940 // ...
1941 // int test6() __attribute__((alias("test7")));
1942 //
1943 // Remove it and replace uses of it with the alias.
1944 GA->takeName(Entry);
1945
1946 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
1947 Entry->getType()));
1948 Entry->eraseFromParent();
1949 } else {
1950 GA->setName(MangledName);
1951 }
1952
1953 // Set attributes which are particular to an alias; this is a
1954 // specialization of the attributes which may be set on a global
1955 // variable/function.
1956 if (D->hasAttr<DLLExportAttr>()) {
1957 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
1958 // The dllexport attribute is ignored for undefined symbols.
1959 if (FD->hasBody())
1960 GA->setLinkage(llvm::Function::DLLExportLinkage);
1961 } else {
1962 GA->setLinkage(llvm::Function::DLLExportLinkage);
1963 }
1964 } else if (D->hasAttr<WeakAttr>() ||
1965 D->hasAttr<WeakRefAttr>() ||
1966 D->isWeakImported()) {
1967 GA->setLinkage(llvm::Function::WeakAnyLinkage);
1968 }
1969
1970 SetCommonAttributes(D, GA);
1971 }
1972
getIntrinsic(unsigned IID,ArrayRef<llvm::Type * > Tys)1973 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
1974 ArrayRef<llvm::Type*> Tys) {
1975 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
1976 Tys);
1977 }
1978
1979 static llvm::StringMapEntry<llvm::Constant*> &
GetConstantCFStringEntry(llvm::StringMap<llvm::Constant * > & Map,const StringLiteral * Literal,bool TargetIsLSB,bool & IsUTF16,unsigned & StringLength)1980 GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map,
1981 const StringLiteral *Literal,
1982 bool TargetIsLSB,
1983 bool &IsUTF16,
1984 unsigned &StringLength) {
1985 StringRef String = Literal->getString();
1986 unsigned NumBytes = String.size();
1987
1988 // Check for simple case.
1989 if (!Literal->containsNonAsciiOrNull()) {
1990 StringLength = NumBytes;
1991 return Map.GetOrCreateValue(String);
1992 }
1993
1994 // Otherwise, convert the UTF8 literals into a string of shorts.
1995 IsUTF16 = true;
1996
1997 SmallVector<UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
1998 const UTF8 *FromPtr = (const UTF8 *)String.data();
1999 UTF16 *ToPtr = &ToBuf[0];
2000
2001 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes,
2002 &ToPtr, ToPtr + NumBytes,
2003 strictConversion);
2004
2005 // ConvertUTF8toUTF16 returns the length in ToPtr.
2006 StringLength = ToPtr - &ToBuf[0];
2007
2008 // Add an explicit null.
2009 *ToPtr = 0;
2010 return Map.
2011 GetOrCreateValue(StringRef(reinterpret_cast<const char *>(ToBuf.data()),
2012 (StringLength + 1) * 2));
2013 }
2014
2015 static llvm::StringMapEntry<llvm::Constant*> &
GetConstantStringEntry(llvm::StringMap<llvm::Constant * > & Map,const StringLiteral * Literal,unsigned & StringLength)2016 GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map,
2017 const StringLiteral *Literal,
2018 unsigned &StringLength) {
2019 StringRef String = Literal->getString();
2020 StringLength = String.size();
2021 return Map.GetOrCreateValue(String);
2022 }
2023
2024 llvm::Constant *
GetAddrOfConstantCFString(const StringLiteral * Literal)2025 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
2026 unsigned StringLength = 0;
2027 bool isUTF16 = false;
2028 llvm::StringMapEntry<llvm::Constant*> &Entry =
2029 GetConstantCFStringEntry(CFConstantStringMap, Literal,
2030 getTargetData().isLittleEndian(),
2031 isUTF16, StringLength);
2032
2033 if (llvm::Constant *C = Entry.getValue())
2034 return C;
2035
2036 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
2037 llvm::Constant *Zeros[] = { Zero, Zero };
2038
2039 // If we don't already have it, get __CFConstantStringClassReference.
2040 if (!CFConstantStringClassRef) {
2041 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
2042 Ty = llvm::ArrayType::get(Ty, 0);
2043 llvm::Constant *GV = CreateRuntimeVariable(Ty,
2044 "__CFConstantStringClassReference");
2045 // Decay array -> ptr
2046 CFConstantStringClassRef =
2047 llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
2048 }
2049
2050 QualType CFTy = getContext().getCFConstantStringType();
2051
2052 llvm::StructType *STy =
2053 cast<llvm::StructType>(getTypes().ConvertType(CFTy));
2054
2055 llvm::Constant *Fields[4];
2056
2057 // Class pointer.
2058 Fields[0] = CFConstantStringClassRef;
2059
2060 // Flags.
2061 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy);
2062 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) :
2063 llvm::ConstantInt::get(Ty, 0x07C8);
2064
2065 // String pointer.
2066 llvm::Constant *C = 0;
2067 if (isUTF16) {
2068 ArrayRef<uint16_t> Arr =
2069 llvm::makeArrayRef<uint16_t>((uint16_t*)Entry.getKey().data(),
2070 Entry.getKey().size() / 2);
2071 C = llvm::ConstantDataArray::get(VMContext, Arr);
2072 } else {
2073 C = llvm::ConstantDataArray::getString(VMContext, Entry.getKey());
2074 }
2075
2076 llvm::GlobalValue::LinkageTypes Linkage;
2077 if (isUTF16)
2078 // FIXME: why do utf strings get "_" labels instead of "L" labels?
2079 Linkage = llvm::GlobalValue::InternalLinkage;
2080 else
2081 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error
2082 // when using private linkage. It is not clear if this is a bug in ld
2083 // or a reasonable new restriction.
2084 Linkage = llvm::GlobalValue::LinkerPrivateLinkage;
2085
2086 // Note: -fwritable-strings doesn't make the backing store strings of
2087 // CFStrings writable. (See <rdar://problem/10657500>)
2088 llvm::GlobalVariable *GV =
2089 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
2090 Linkage, C, ".str");
2091 GV->setUnnamedAddr(true);
2092 if (isUTF16) {
2093 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy);
2094 GV->setAlignment(Align.getQuantity());
2095 } else {
2096 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy);
2097 GV->setAlignment(Align.getQuantity());
2098 }
2099
2100 // String.
2101 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
2102
2103 if (isUTF16)
2104 // Cast the UTF16 string to the correct type.
2105 Fields[2] = llvm::ConstantExpr::getBitCast(Fields[2], Int8PtrTy);
2106
2107 // String length.
2108 Ty = getTypes().ConvertType(getContext().LongTy);
2109 Fields[3] = llvm::ConstantInt::get(Ty, StringLength);
2110
2111 // The struct.
2112 C = llvm::ConstantStruct::get(STy, Fields);
2113 GV = new llvm::GlobalVariable(getModule(), C->getType(), true,
2114 llvm::GlobalVariable::PrivateLinkage, C,
2115 "_unnamed_cfstring_");
2116 if (const char *Sect = getContext().getTargetInfo().getCFStringSection())
2117 GV->setSection(Sect);
2118 Entry.setValue(GV);
2119
2120 return GV;
2121 }
2122
2123 static RecordDecl *
CreateRecordDecl(const ASTContext & Ctx,RecordDecl::TagKind TK,DeclContext * DC,IdentifierInfo * Id)2124 CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK,
2125 DeclContext *DC, IdentifierInfo *Id) {
2126 SourceLocation Loc;
2127 if (Ctx.getLangOpts().CPlusPlus)
2128 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id);
2129 else
2130 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id);
2131 }
2132
2133 llvm::Constant *
GetAddrOfConstantString(const StringLiteral * Literal)2134 CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) {
2135 unsigned StringLength = 0;
2136 llvm::StringMapEntry<llvm::Constant*> &Entry =
2137 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength);
2138
2139 if (llvm::Constant *C = Entry.getValue())
2140 return C;
2141
2142 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
2143 llvm::Constant *Zeros[] = { Zero, Zero };
2144
2145 // If we don't already have it, get _NSConstantStringClassReference.
2146 if (!ConstantStringClassRef) {
2147 std::string StringClass(getLangOpts().ObjCConstantStringClass);
2148 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
2149 llvm::Constant *GV;
2150 if (LangOpts.ObjCRuntime.isNonFragile()) {
2151 std::string str =
2152 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString"
2153 : "OBJC_CLASS_$_" + StringClass;
2154 GV = getObjCRuntime().GetClassGlobal(str);
2155 // Make sure the result is of the correct type.
2156 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
2157 ConstantStringClassRef =
2158 llvm::ConstantExpr::getBitCast(GV, PTy);
2159 } else {
2160 std::string str =
2161 StringClass.empty() ? "_NSConstantStringClassReference"
2162 : "_" + StringClass + "ClassReference";
2163 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0);
2164 GV = CreateRuntimeVariable(PTy, str);
2165 // Decay array -> ptr
2166 ConstantStringClassRef =
2167 llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
2168 }
2169 }
2170
2171 if (!NSConstantStringType) {
2172 // Construct the type for a constant NSString.
2173 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct,
2174 Context.getTranslationUnitDecl(),
2175 &Context.Idents.get("__builtin_NSString"));
2176 D->startDefinition();
2177
2178 QualType FieldTypes[3];
2179
2180 // const int *isa;
2181 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst());
2182 // const char *str;
2183 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst());
2184 // unsigned int length;
2185 FieldTypes[2] = Context.UnsignedIntTy;
2186
2187 // Create fields
2188 for (unsigned i = 0; i < 3; ++i) {
2189 FieldDecl *Field = FieldDecl::Create(Context, D,
2190 SourceLocation(),
2191 SourceLocation(), 0,
2192 FieldTypes[i], /*TInfo=*/0,
2193 /*BitWidth=*/0,
2194 /*Mutable=*/false,
2195 ICIS_NoInit);
2196 Field->setAccess(AS_public);
2197 D->addDecl(Field);
2198 }
2199
2200 D->completeDefinition();
2201 QualType NSTy = Context.getTagDeclType(D);
2202 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy));
2203 }
2204
2205 llvm::Constant *Fields[3];
2206
2207 // Class pointer.
2208 Fields[0] = ConstantStringClassRef;
2209
2210 // String pointer.
2211 llvm::Constant *C =
2212 llvm::ConstantDataArray::getString(VMContext, Entry.getKey());
2213
2214 llvm::GlobalValue::LinkageTypes Linkage;
2215 bool isConstant;
2216 Linkage = llvm::GlobalValue::PrivateLinkage;
2217 isConstant = !LangOpts.WritableStrings;
2218
2219 llvm::GlobalVariable *GV =
2220 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C,
2221 ".str");
2222 GV->setUnnamedAddr(true);
2223 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy);
2224 GV->setAlignment(Align.getQuantity());
2225 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
2226
2227 // String length.
2228 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy);
2229 Fields[2] = llvm::ConstantInt::get(Ty, StringLength);
2230
2231 // The struct.
2232 C = llvm::ConstantStruct::get(NSConstantStringType, Fields);
2233 GV = new llvm::GlobalVariable(getModule(), C->getType(), true,
2234 llvm::GlobalVariable::PrivateLinkage, C,
2235 "_unnamed_nsstring_");
2236 // FIXME. Fix section.
2237 if (const char *Sect =
2238 LangOpts.ObjCRuntime.isNonFragile()
2239 ? getContext().getTargetInfo().getNSStringNonFragileABISection()
2240 : getContext().getTargetInfo().getNSStringSection())
2241 GV->setSection(Sect);
2242 Entry.setValue(GV);
2243
2244 return GV;
2245 }
2246
getObjCFastEnumerationStateType()2247 QualType CodeGenModule::getObjCFastEnumerationStateType() {
2248 if (ObjCFastEnumerationStateType.isNull()) {
2249 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct,
2250 Context.getTranslationUnitDecl(),
2251 &Context.Idents.get("__objcFastEnumerationState"));
2252 D->startDefinition();
2253
2254 QualType FieldTypes[] = {
2255 Context.UnsignedLongTy,
2256 Context.getPointerType(Context.getObjCIdType()),
2257 Context.getPointerType(Context.UnsignedLongTy),
2258 Context.getConstantArrayType(Context.UnsignedLongTy,
2259 llvm::APInt(32, 5), ArrayType::Normal, 0)
2260 };
2261
2262 for (size_t i = 0; i < 4; ++i) {
2263 FieldDecl *Field = FieldDecl::Create(Context,
2264 D,
2265 SourceLocation(),
2266 SourceLocation(), 0,
2267 FieldTypes[i], /*TInfo=*/0,
2268 /*BitWidth=*/0,
2269 /*Mutable=*/false,
2270 ICIS_NoInit);
2271 Field->setAccess(AS_public);
2272 D->addDecl(Field);
2273 }
2274
2275 D->completeDefinition();
2276 ObjCFastEnumerationStateType = Context.getTagDeclType(D);
2277 }
2278
2279 return ObjCFastEnumerationStateType;
2280 }
2281
2282 llvm::Constant *
GetConstantArrayFromStringLiteral(const StringLiteral * E)2283 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
2284 assert(!E->getType()->isPointerType() && "Strings are always arrays");
2285
2286 // Don't emit it as the address of the string, emit the string data itself
2287 // as an inline array.
2288 if (E->getCharByteWidth() == 1) {
2289 SmallString<64> Str(E->getString());
2290
2291 // Resize the string to the right size, which is indicated by its type.
2292 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
2293 Str.resize(CAT->getSize().getZExtValue());
2294 return llvm::ConstantDataArray::getString(VMContext, Str, false);
2295 }
2296
2297 llvm::ArrayType *AType =
2298 cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
2299 llvm::Type *ElemTy = AType->getElementType();
2300 unsigned NumElements = AType->getNumElements();
2301
2302 // Wide strings have either 2-byte or 4-byte elements.
2303 if (ElemTy->getPrimitiveSizeInBits() == 16) {
2304 SmallVector<uint16_t, 32> Elements;
2305 Elements.reserve(NumElements);
2306
2307 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
2308 Elements.push_back(E->getCodeUnit(i));
2309 Elements.resize(NumElements);
2310 return llvm::ConstantDataArray::get(VMContext, Elements);
2311 }
2312
2313 assert(ElemTy->getPrimitiveSizeInBits() == 32);
2314 SmallVector<uint32_t, 32> Elements;
2315 Elements.reserve(NumElements);
2316
2317 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
2318 Elements.push_back(E->getCodeUnit(i));
2319 Elements.resize(NumElements);
2320 return llvm::ConstantDataArray::get(VMContext, Elements);
2321 }
2322
2323 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
2324 /// constant array for the given string literal.
2325 llvm::Constant *
GetAddrOfConstantStringFromLiteral(const StringLiteral * S)2326 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) {
2327 CharUnits Align = getContext().getTypeAlignInChars(S->getType());
2328 if (S->isAscii() || S->isUTF8()) {
2329 SmallString<64> Str(S->getString());
2330
2331 // Resize the string to the right size, which is indicated by its type.
2332 const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType());
2333 Str.resize(CAT->getSize().getZExtValue());
2334 return GetAddrOfConstantString(Str, /*GlobalName*/ 0, Align.getQuantity());
2335 }
2336
2337 // FIXME: the following does not memoize wide strings.
2338 llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
2339 llvm::GlobalVariable *GV =
2340 new llvm::GlobalVariable(getModule(),C->getType(),
2341 !LangOpts.WritableStrings,
2342 llvm::GlobalValue::PrivateLinkage,
2343 C,".str");
2344
2345 GV->setAlignment(Align.getQuantity());
2346 GV->setUnnamedAddr(true);
2347 return GV;
2348 }
2349
2350 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
2351 /// array for the given ObjCEncodeExpr node.
2352 llvm::Constant *
GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr * E)2353 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
2354 std::string Str;
2355 getContext().getObjCEncodingForType(E->getEncodedType(), Str);
2356
2357 return GetAddrOfConstantCString(Str);
2358 }
2359
2360
2361 /// GenerateWritableString -- Creates storage for a string literal.
GenerateStringLiteral(StringRef str,bool constant,CodeGenModule & CGM,const char * GlobalName,unsigned Alignment)2362 static llvm::GlobalVariable *GenerateStringLiteral(StringRef str,
2363 bool constant,
2364 CodeGenModule &CGM,
2365 const char *GlobalName,
2366 unsigned Alignment) {
2367 // Create Constant for this string literal. Don't add a '\0'.
2368 llvm::Constant *C =
2369 llvm::ConstantDataArray::getString(CGM.getLLVMContext(), str, false);
2370
2371 // Create a global variable for this string
2372 llvm::GlobalVariable *GV =
2373 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant,
2374 llvm::GlobalValue::PrivateLinkage,
2375 C, GlobalName);
2376 GV->setAlignment(Alignment);
2377 GV->setUnnamedAddr(true);
2378 return GV;
2379 }
2380
2381 /// GetAddrOfConstantString - Returns a pointer to a character array
2382 /// containing the literal. This contents are exactly that of the
2383 /// given string, i.e. it will not be null terminated automatically;
2384 /// see GetAddrOfConstantCString. Note that whether the result is
2385 /// actually a pointer to an LLVM constant depends on
2386 /// Feature.WriteableStrings.
2387 ///
2388 /// The result has pointer to array type.
GetAddrOfConstantString(StringRef Str,const char * GlobalName,unsigned Alignment)2389 llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str,
2390 const char *GlobalName,
2391 unsigned Alignment) {
2392 // Get the default prefix if a name wasn't specified.
2393 if (!GlobalName)
2394 GlobalName = ".str";
2395
2396 // Don't share any string literals if strings aren't constant.
2397 if (LangOpts.WritableStrings)
2398 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment);
2399
2400 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
2401 ConstantStringMap.GetOrCreateValue(Str);
2402
2403 if (llvm::GlobalVariable *GV = Entry.getValue()) {
2404 if (Alignment > GV->getAlignment()) {
2405 GV->setAlignment(Alignment);
2406 }
2407 return GV;
2408 }
2409
2410 // Create a global variable for this.
2411 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName,
2412 Alignment);
2413 Entry.setValue(GV);
2414 return GV;
2415 }
2416
2417 /// GetAddrOfConstantCString - Returns a pointer to a character
2418 /// array containing the literal and a terminating '\0'
2419 /// character. The result has pointer to array type.
GetAddrOfConstantCString(const std::string & Str,const char * GlobalName,unsigned Alignment)2420 llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str,
2421 const char *GlobalName,
2422 unsigned Alignment) {
2423 StringRef StrWithNull(Str.c_str(), Str.size() + 1);
2424 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment);
2425 }
2426
2427 /// EmitObjCPropertyImplementations - Emit information for synthesized
2428 /// properties for an implementation.
EmitObjCPropertyImplementations(const ObjCImplementationDecl * D)2429 void CodeGenModule::EmitObjCPropertyImplementations(const
2430 ObjCImplementationDecl *D) {
2431 for (ObjCImplementationDecl::propimpl_iterator
2432 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) {
2433 ObjCPropertyImplDecl *PID = *i;
2434
2435 // Dynamic is just for type-checking.
2436 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
2437 ObjCPropertyDecl *PD = PID->getPropertyDecl();
2438
2439 // Determine which methods need to be implemented, some may have
2440 // been overridden. Note that ::isSynthesized is not the method
2441 // we want, that just indicates if the decl came from a
2442 // property. What we want to know is if the method is defined in
2443 // this implementation.
2444 if (!D->getInstanceMethod(PD->getGetterName()))
2445 CodeGenFunction(*this).GenerateObjCGetter(
2446 const_cast<ObjCImplementationDecl *>(D), PID);
2447 if (!PD->isReadOnly() &&
2448 !D->getInstanceMethod(PD->getSetterName()))
2449 CodeGenFunction(*this).GenerateObjCSetter(
2450 const_cast<ObjCImplementationDecl *>(D), PID);
2451 }
2452 }
2453 }
2454
needsDestructMethod(ObjCImplementationDecl * impl)2455 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
2456 const ObjCInterfaceDecl *iface = impl->getClassInterface();
2457 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
2458 ivar; ivar = ivar->getNextIvar())
2459 if (ivar->getType().isDestructedType())
2460 return true;
2461
2462 return false;
2463 }
2464
2465 /// EmitObjCIvarInitializations - Emit information for ivar initialization
2466 /// for an implementation.
EmitObjCIvarInitializations(ObjCImplementationDecl * D)2467 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
2468 // We might need a .cxx_destruct even if we don't have any ivar initializers.
2469 if (needsDestructMethod(D)) {
2470 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
2471 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
2472 ObjCMethodDecl *DTORMethod =
2473 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(),
2474 cxxSelector, getContext().VoidTy, 0, D,
2475 /*isInstance=*/true, /*isVariadic=*/false,
2476 /*isSynthesized=*/true, /*isImplicitlyDeclared=*/true,
2477 /*isDefined=*/false, ObjCMethodDecl::Required);
2478 D->addInstanceMethod(DTORMethod);
2479 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
2480 D->setHasCXXStructors(true);
2481 }
2482
2483 // If the implementation doesn't have any ivar initializers, we don't need
2484 // a .cxx_construct.
2485 if (D->getNumIvarInitializers() == 0)
2486 return;
2487
2488 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
2489 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
2490 // The constructor returns 'self'.
2491 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(),
2492 D->getLocation(),
2493 D->getLocation(),
2494 cxxSelector,
2495 getContext().getObjCIdType(), 0,
2496 D, /*isInstance=*/true,
2497 /*isVariadic=*/false,
2498 /*isSynthesized=*/true,
2499 /*isImplicitlyDeclared=*/true,
2500 /*isDefined=*/false,
2501 ObjCMethodDecl::Required);
2502 D->addInstanceMethod(CTORMethod);
2503 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
2504 D->setHasCXXStructors(true);
2505 }
2506
2507 /// EmitNamespace - Emit all declarations in a namespace.
EmitNamespace(const NamespaceDecl * ND)2508 void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) {
2509 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end();
2510 I != E; ++I)
2511 EmitTopLevelDecl(*I);
2512 }
2513
2514 // EmitLinkageSpec - Emit all declarations in a linkage spec.
EmitLinkageSpec(const LinkageSpecDecl * LSD)2515 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
2516 if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
2517 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
2518 ErrorUnsupported(LSD, "linkage spec");
2519 return;
2520 }
2521
2522 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end();
2523 I != E; ++I)
2524 EmitTopLevelDecl(*I);
2525 }
2526
2527 /// EmitTopLevelDecl - Emit code for a single top level declaration.
EmitTopLevelDecl(Decl * D)2528 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
2529 // If an error has occurred, stop code generation, but continue
2530 // parsing and semantic analysis (to ensure all warnings and errors
2531 // are emitted).
2532 if (Diags.hasErrorOccurred())
2533 return;
2534
2535 // Ignore dependent declarations.
2536 if (D->getDeclContext() && D->getDeclContext()->isDependentContext())
2537 return;
2538
2539 switch (D->getKind()) {
2540 case Decl::CXXConversion:
2541 case Decl::CXXMethod:
2542 case Decl::Function:
2543 // Skip function templates
2544 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
2545 cast<FunctionDecl>(D)->isLateTemplateParsed())
2546 return;
2547
2548 EmitGlobal(cast<FunctionDecl>(D));
2549 break;
2550
2551 case Decl::Var:
2552 EmitGlobal(cast<VarDecl>(D));
2553 break;
2554
2555 // Indirect fields from global anonymous structs and unions can be
2556 // ignored; only the actual variable requires IR gen support.
2557 case Decl::IndirectField:
2558 break;
2559
2560 // C++ Decls
2561 case Decl::Namespace:
2562 EmitNamespace(cast<NamespaceDecl>(D));
2563 break;
2564 // No code generation needed.
2565 case Decl::UsingShadow:
2566 case Decl::Using:
2567 case Decl::UsingDirective:
2568 case Decl::ClassTemplate:
2569 case Decl::FunctionTemplate:
2570 case Decl::TypeAliasTemplate:
2571 case Decl::NamespaceAlias:
2572 case Decl::Block:
2573 case Decl::Import:
2574 break;
2575 case Decl::CXXConstructor:
2576 // Skip function templates
2577 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
2578 cast<FunctionDecl>(D)->isLateTemplateParsed())
2579 return;
2580
2581 EmitCXXConstructors(cast<CXXConstructorDecl>(D));
2582 break;
2583 case Decl::CXXDestructor:
2584 if (cast<FunctionDecl>(D)->isLateTemplateParsed())
2585 return;
2586 EmitCXXDestructors(cast<CXXDestructorDecl>(D));
2587 break;
2588
2589 case Decl::StaticAssert:
2590 // Nothing to do.
2591 break;
2592
2593 // Objective-C Decls
2594
2595 // Forward declarations, no (immediate) code generation.
2596 case Decl::ObjCInterface:
2597 case Decl::ObjCCategory:
2598 break;
2599
2600 case Decl::ObjCProtocol: {
2601 ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D);
2602 if (Proto->isThisDeclarationADefinition())
2603 ObjCRuntime->GenerateProtocol(Proto);
2604 break;
2605 }
2606
2607 case Decl::ObjCCategoryImpl:
2608 // Categories have properties but don't support synthesize so we
2609 // can ignore them here.
2610 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
2611 break;
2612
2613 case Decl::ObjCImplementation: {
2614 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D);
2615 EmitObjCPropertyImplementations(OMD);
2616 EmitObjCIvarInitializations(OMD);
2617 ObjCRuntime->GenerateClass(OMD);
2618 // Emit global variable debug information.
2619 if (CGDebugInfo *DI = getModuleDebugInfo())
2620 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(OMD->getClassInterface()),
2621 OMD->getLocation());
2622
2623 break;
2624 }
2625 case Decl::ObjCMethod: {
2626 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D);
2627 // If this is not a prototype, emit the body.
2628 if (OMD->getBody())
2629 CodeGenFunction(*this).GenerateObjCMethod(OMD);
2630 break;
2631 }
2632 case Decl::ObjCCompatibleAlias:
2633 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
2634 break;
2635
2636 case Decl::LinkageSpec:
2637 EmitLinkageSpec(cast<LinkageSpecDecl>(D));
2638 break;
2639
2640 case Decl::FileScopeAsm: {
2641 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D);
2642 StringRef AsmString = AD->getAsmString()->getString();
2643
2644 const std::string &S = getModule().getModuleInlineAsm();
2645 if (S.empty())
2646 getModule().setModuleInlineAsm(AsmString);
2647 else if (S.end()[-1] == '\n')
2648 getModule().setModuleInlineAsm(S + AsmString.str());
2649 else
2650 getModule().setModuleInlineAsm(S + '\n' + AsmString.str());
2651 break;
2652 }
2653
2654 default:
2655 // Make sure we handled everything we should, every other kind is a
2656 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
2657 // function. Need to recode Decl::Kind to do that easily.
2658 assert(isa<TypeDecl>(D) && "Unsupported decl kind");
2659 }
2660 }
2661
2662 /// Turns the given pointer into a constant.
GetPointerConstant(llvm::LLVMContext & Context,const void * Ptr)2663 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
2664 const void *Ptr) {
2665 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
2666 llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
2667 return llvm::ConstantInt::get(i64, PtrInt);
2668 }
2669
EmitGlobalDeclMetadata(CodeGenModule & CGM,llvm::NamedMDNode * & GlobalMetadata,GlobalDecl D,llvm::GlobalValue * Addr)2670 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
2671 llvm::NamedMDNode *&GlobalMetadata,
2672 GlobalDecl D,
2673 llvm::GlobalValue *Addr) {
2674 if (!GlobalMetadata)
2675 GlobalMetadata =
2676 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
2677
2678 // TODO: should we report variant information for ctors/dtors?
2679 llvm::Value *Ops[] = {
2680 Addr,
2681 GetPointerConstant(CGM.getLLVMContext(), D.getDecl())
2682 };
2683 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2684 }
2685
2686 /// Emits metadata nodes associating all the global values in the
2687 /// current module with the Decls they came from. This is useful for
2688 /// projects using IR gen as a subroutine.
2689 ///
2690 /// Since there's currently no way to associate an MDNode directly
2691 /// with an llvm::GlobalValue, we create a global named metadata
2692 /// with the name 'clang.global.decl.ptrs'.
EmitDeclMetadata()2693 void CodeGenModule::EmitDeclMetadata() {
2694 llvm::NamedMDNode *GlobalMetadata = 0;
2695
2696 // StaticLocalDeclMap
2697 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator
2698 I = MangledDeclNames.begin(), E = MangledDeclNames.end();
2699 I != E; ++I) {
2700 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second);
2701 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr);
2702 }
2703 }
2704
2705 /// Emits metadata nodes for all the local variables in the current
2706 /// function.
EmitDeclMetadata()2707 void CodeGenFunction::EmitDeclMetadata() {
2708 if (LocalDeclMap.empty()) return;
2709
2710 llvm::LLVMContext &Context = getLLVMContext();
2711
2712 // Find the unique metadata ID for this name.
2713 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
2714
2715 llvm::NamedMDNode *GlobalMetadata = 0;
2716
2717 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator
2718 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) {
2719 const Decl *D = I->first;
2720 llvm::Value *Addr = I->second;
2721
2722 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
2723 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
2724 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr));
2725 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
2726 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
2727 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
2728 }
2729 }
2730 }
2731
EmitCoverageFile()2732 void CodeGenModule::EmitCoverageFile() {
2733 if (!getCodeGenOpts().CoverageFile.empty()) {
2734 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) {
2735 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
2736 llvm::LLVMContext &Ctx = TheModule.getContext();
2737 llvm::MDString *CoverageFile =
2738 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile);
2739 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
2740 llvm::MDNode *CU = CUNode->getOperand(i);
2741 llvm::Value *node[] = { CoverageFile, CU };
2742 llvm::MDNode *N = llvm::MDNode::get(Ctx, node);
2743 GCov->addOperand(N);
2744 }
2745 }
2746 }
2747 }
2748