1 //===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This coordinates the per-module state used while generating code.
12 //===----------------------------------------------------------------------===//
14 #include "CodeGenModule.h"
15 #include "CGCUDARuntime.h"
18 #include "CGDebugInfo.h"
19 #include "CGObjCRuntime.h"
20 #include "CGOpenCLRuntime.h"
21 #include "CGOpenMPRuntime.h"
22 #include "CodeGenFunction.h"
23 #include "CodeGenPGO.h"
24 #include "CodeGenTBAA.h"
25 #include "TargetInfo.h"
26 #include "clang/AST/ASTContext.h"
27 #include "clang/AST/CharUnits.h"
28 #include "clang/AST/DeclCXX.h"
29 #include "clang/AST/DeclObjC.h"
30 #include "clang/AST/DeclTemplate.h"
31 #include "clang/AST/Mangle.h"
32 #include "clang/AST/RecordLayout.h"
33 #include "clang/AST/RecursiveASTVisitor.h"
34 #include "clang/Basic/Builtins.h"
35 #include "clang/Basic/CharInfo.h"
36 #include "clang/Basic/Diagnostic.h"
37 #include "clang/Basic/Module.h"
38 #include "clang/Basic/SourceManager.h"
39 #include "clang/Basic/TargetInfo.h"
40 #include "clang/Basic/Version.h"
41 #include "clang/Frontend/CodeGenOptions.h"
42 #include "clang/Sema/SemaDiagnostic.h"
43 #include "llvm/ADT/APSInt.h"
44 #include "llvm/ADT/Triple.h"
45 #include "llvm/IR/CallSite.h"
46 #include "llvm/IR/CallingConv.h"
47 #include "llvm/IR/DataLayout.h"
48 #include "llvm/IR/Intrinsics.h"
49 #include "llvm/IR/LLVMContext.h"
50 #include "llvm/IR/Module.h"
51 #include "llvm/ProfileData/InstrProfReader.h"
52 #include "llvm/Support/ConvertUTF.h"
53 #include "llvm/Support/ErrorHandling.h"
55 using namespace clang;
56 using namespace CodeGen;
58 static const char AnnotationSection[] = "llvm.metadata";
60 static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
61 switch (CGM.getTarget().getCXXABI().getKind()) {
62 case TargetCXXABI::GenericAArch64:
63 case TargetCXXABI::GenericARM:
64 case TargetCXXABI::iOS:
65 case TargetCXXABI::iOS64:
66 case TargetCXXABI::GenericItanium:
67 return CreateItaniumCXXABI(CGM);
68 case TargetCXXABI::Microsoft:
69 return CreateMicrosoftCXXABI(CGM);
72 llvm_unreachable("invalid C++ ABI kind");
75 CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO,
76 llvm::Module &M, const llvm::DataLayout &TD,
77 DiagnosticsEngine &diags)
78 : Context(C), LangOpts(C.getLangOpts()), CodeGenOpts(CGO), TheModule(M),
79 Diags(diags), TheDataLayout(TD), Target(C.getTargetInfo()),
80 ABI(createCXXABI(*this)), VMContext(M.getContext()), TBAA(nullptr),
81 TheTargetCodeGenInfo(nullptr), Types(*this), VTables(*this),
82 ObjCRuntime(nullptr), OpenCLRuntime(nullptr), OpenMPRuntime(nullptr),
83 CUDARuntime(nullptr), DebugInfo(nullptr), ARCData(nullptr),
84 NoObjCARCExceptionsMetadata(nullptr), RRData(nullptr), PGOReader(nullptr),
85 CFConstantStringClassRef(nullptr), ConstantStringClassRef(nullptr),
86 NSConstantStringType(nullptr), NSConcreteGlobalBlock(nullptr),
87 NSConcreteStackBlock(nullptr), BlockObjectAssign(nullptr),
88 BlockObjectDispose(nullptr), BlockDescriptorType(nullptr),
89 GenericBlockLiteralType(nullptr), LifetimeStartFn(nullptr),
90 LifetimeEndFn(nullptr), SanitizerBL(llvm::SpecialCaseList::createOrDie(
91 CGO.SanitizerBlacklistFile)) {
93 // Initialize the type cache.
94 llvm::LLVMContext &LLVMContext = M.getContext();
95 VoidTy = llvm::Type::getVoidTy(LLVMContext);
96 Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
97 Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
98 Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
99 Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
100 FloatTy = llvm::Type::getFloatTy(LLVMContext);
101 DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
102 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
103 PointerAlignInBytes =
104 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
105 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
106 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits);
107 Int8PtrTy = Int8Ty->getPointerTo(0);
108 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
110 RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
115 createOpenCLRuntime();
117 createOpenMPRuntime();
121 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
122 if (LangOpts.Sanitize.Thread ||
123 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
124 TBAA = new CodeGenTBAA(Context, VMContext, CodeGenOpts, getLangOpts(),
125 getCXXABI().getMangleContext());
127 // If debug info or coverage generation is enabled, create the CGDebugInfo
129 if (CodeGenOpts.getDebugInfo() != CodeGenOptions::NoDebugInfo ||
130 CodeGenOpts.EmitGcovArcs ||
131 CodeGenOpts.EmitGcovNotes)
132 DebugInfo = new CGDebugInfo(*this);
134 Block.GlobalUniqueCount = 0;
136 if (C.getLangOpts().ObjCAutoRefCount)
137 ARCData = new ARCEntrypoints();
138 RRData = new RREntrypoints();
140 if (!CodeGenOpts.InstrProfileInput.empty()) {
141 if (std::error_code EC = llvm::IndexedInstrProfReader::create(
142 CodeGenOpts.InstrProfileInput, PGOReader)) {
143 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
144 "Could not read profile: %0");
145 getDiags().Report(DiagID) << EC.message();
150 CodeGenModule::~CodeGenModule() {
152 delete OpenCLRuntime;
153 delete OpenMPRuntime;
155 delete TheTargetCodeGenInfo;
162 void CodeGenModule::createObjCRuntime() {
163 // This is just isGNUFamily(), but we want to force implementors of
164 // new ABIs to decide how best to do this.
165 switch (LangOpts.ObjCRuntime.getKind()) {
166 case ObjCRuntime::GNUstep:
167 case ObjCRuntime::GCC:
168 case ObjCRuntime::ObjFW:
169 ObjCRuntime = CreateGNUObjCRuntime(*this);
172 case ObjCRuntime::FragileMacOSX:
173 case ObjCRuntime::MacOSX:
174 case ObjCRuntime::iOS:
175 ObjCRuntime = CreateMacObjCRuntime(*this);
178 llvm_unreachable("bad runtime kind");
181 void CodeGenModule::createOpenCLRuntime() {
182 OpenCLRuntime = new CGOpenCLRuntime(*this);
185 void CodeGenModule::createOpenMPRuntime() {
186 OpenMPRuntime = new CGOpenMPRuntime(*this);
189 void CodeGenModule::createCUDARuntime() {
190 CUDARuntime = CreateNVCUDARuntime(*this);
193 void CodeGenModule::applyReplacements() {
194 for (ReplacementsTy::iterator I = Replacements.begin(),
195 E = Replacements.end();
197 StringRef MangledName = I->first();
198 llvm::Constant *Replacement = I->second;
199 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
202 auto *OldF = cast<llvm::Function>(Entry);
203 auto *NewF = dyn_cast<llvm::Function>(Replacement);
205 if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
206 NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
208 auto *CE = cast<llvm::ConstantExpr>(Replacement);
209 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
210 CE->getOpcode() == llvm::Instruction::GetElementPtr);
211 NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
215 // Replace old with new, but keep the old order.
216 OldF->replaceAllUsesWith(Replacement);
218 NewF->removeFromParent();
219 OldF->getParent()->getFunctionList().insertAfter(OldF, NewF);
221 OldF->eraseFromParent();
225 // This is only used in aliases that we created and we know they have a
227 static const llvm::GlobalObject *getAliasedGlobal(const llvm::GlobalAlias &GA) {
228 llvm::SmallPtrSet<const llvm::GlobalAlias*, 4> Visited;
229 const llvm::Constant *C = &GA;
231 C = C->stripPointerCasts();
232 if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
234 // stripPointerCasts will not walk over weak aliases.
235 auto *GA2 = dyn_cast<llvm::GlobalAlias>(C);
238 if (!Visited.insert(GA2))
240 C = GA2->getAliasee();
244 void CodeGenModule::checkAliases() {
245 // Check if the constructed aliases are well formed. It is really unfortunate
246 // that we have to do this in CodeGen, but we only construct mangled names
247 // and aliases during codegen.
249 DiagnosticsEngine &Diags = getDiags();
250 for (std::vector<GlobalDecl>::iterator I = Aliases.begin(),
251 E = Aliases.end(); I != E; ++I) {
252 const GlobalDecl &GD = *I;
253 const auto *D = cast<ValueDecl>(GD.getDecl());
254 const AliasAttr *AA = D->getAttr<AliasAttr>();
255 StringRef MangledName = getMangledName(GD);
256 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
257 auto *Alias = cast<llvm::GlobalAlias>(Entry);
258 const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
261 Diags.Report(AA->getLocation(), diag::err_cyclic_alias);
262 } else if (GV->isDeclaration()) {
264 Diags.Report(AA->getLocation(), diag::err_alias_to_undefined);
267 llvm::Constant *Aliasee = Alias->getAliasee();
268 llvm::GlobalValue *AliaseeGV;
269 if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
270 AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
272 AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
274 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
275 StringRef AliasSection = SA->getName();
276 if (AliasSection != AliaseeGV->getSection())
277 Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
281 // We have to handle alias to weak aliases in here. LLVM itself disallows
282 // this since the object semantics would not match the IL one. For
283 // compatibility with gcc we implement it by just pointing the alias
284 // to its aliasee's aliasee. We also warn, since the user is probably
285 // expecting the link to be weak.
286 if (auto GA = dyn_cast<llvm::GlobalAlias>(AliaseeGV)) {
287 if (GA->mayBeOverridden()) {
288 Diags.Report(AA->getLocation(), diag::warn_alias_to_weak_alias)
289 << GV->getName() << GA->getName();
290 Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
291 GA->getAliasee(), Alias->getType());
292 Alias->setAliasee(Aliasee);
299 for (std::vector<GlobalDecl>::iterator I = Aliases.begin(),
300 E = Aliases.end(); I != E; ++I) {
301 const GlobalDecl &GD = *I;
302 StringRef MangledName = getMangledName(GD);
303 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
304 auto *Alias = cast<llvm::GlobalAlias>(Entry);
305 Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
306 Alias->eraseFromParent();
310 void CodeGenModule::clear() {
311 DeferredDeclsToEmit.clear();
314 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
315 StringRef MainFile) {
316 if (!hasDiagnostics())
318 if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
319 if (MainFile.empty())
320 MainFile = "<stdin>";
321 Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
323 Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Missing
327 void CodeGenModule::Release() {
331 EmitCXXGlobalInitFunc();
332 EmitCXXGlobalDtorFunc();
333 EmitCXXThreadLocalInitFunc();
335 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
336 AddGlobalCtor(ObjCInitFunction);
337 if (getCodeGenOpts().ProfileInstrGenerate)
338 if (llvm::Function *PGOInit = CodeGenPGO::emitInitialization(*this))
339 AddGlobalCtor(PGOInit, 0);
340 if (PGOReader && PGOStats.hasDiagnostics())
341 PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
342 EmitCtorList(GlobalCtors, "llvm.global_ctors");
343 EmitCtorList(GlobalDtors, "llvm.global_dtors");
344 EmitGlobalAnnotations();
345 EmitStaticExternCAliases();
348 if (CodeGenOpts.Autolink &&
349 (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
350 EmitModuleLinkOptions();
352 if (CodeGenOpts.DwarfVersion)
353 // We actually want the latest version when there are conflicts.
354 // We can change from Warning to Latest if such mode is supported.
355 getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version",
356 CodeGenOpts.DwarfVersion);
358 // We support a single version in the linked module. The LLVM
359 // parser will drop debug info with a different version number
360 // (and warn about it, too).
361 getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
362 llvm::DEBUG_METADATA_VERSION);
364 // We need to record the widths of enums and wchar_t, so that we can generate
365 // the correct build attributes in the ARM backend.
366 llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
367 if ( Arch == llvm::Triple::arm
368 || Arch == llvm::Triple::armeb
369 || Arch == llvm::Triple::thumb
370 || Arch == llvm::Triple::thumbeb) {
371 // Width of wchar_t in bytes
372 uint64_t WCharWidth =
373 Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
374 getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
376 // The minimum width of an enum in bytes
377 uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
378 getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
381 SimplifyPersonality();
383 if (getCodeGenOpts().EmitDeclMetadata)
386 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
390 DebugInfo->finalize();
392 EmitVersionIdentMetadata();
394 EmitTargetMetadata();
397 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
398 // Make sure that this type is translated.
399 Types.UpdateCompletedType(TD);
402 llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) {
405 return TBAA->getTBAAInfo(QTy);
408 llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() {
411 return TBAA->getTBAAInfoForVTablePtr();
414 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
417 return TBAA->getTBAAStructInfo(QTy);
420 llvm::MDNode *CodeGenModule::getTBAAStructTypeInfo(QualType QTy) {
423 return TBAA->getTBAAStructTypeInfo(QTy);
426 llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy,
427 llvm::MDNode *AccessN,
431 return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O);
434 /// Decorate the instruction with a TBAA tag. For both scalar TBAA
435 /// and struct-path aware TBAA, the tag has the same format:
436 /// base type, access type and offset.
437 /// When ConvertTypeToTag is true, we create a tag based on the scalar type.
438 void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
439 llvm::MDNode *TBAAInfo,
440 bool ConvertTypeToTag) {
441 if (ConvertTypeToTag && TBAA)
442 Inst->setMetadata(llvm::LLVMContext::MD_tbaa,
443 TBAA->getTBAAScalarTagInfo(TBAAInfo));
445 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo);
448 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
449 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
450 getDiags().Report(Context.getFullLoc(loc), diagID) << message;
453 /// ErrorUnsupported - Print out an error that codegen doesn't support the
454 /// specified stmt yet.
455 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
456 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
457 "cannot compile this %0 yet");
458 std::string Msg = Type;
459 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID)
460 << Msg << S->getSourceRange();
463 /// ErrorUnsupported - Print out an error that codegen doesn't support the
464 /// specified decl yet.
465 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
466 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
467 "cannot compile this %0 yet");
468 std::string Msg = Type;
469 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
472 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
473 return llvm::ConstantInt::get(SizeTy, size.getQuantity());
476 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
477 const NamedDecl *D) const {
478 // Internal definitions always have default visibility.
479 if (GV->hasLocalLinkage()) {
480 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
484 // Set visibility for definitions.
485 LinkageInfo LV = D->getLinkageAndVisibility();
486 if (LV.isVisibilityExplicit() || !GV->hasAvailableExternallyLinkage())
487 GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
490 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
491 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
492 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
493 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
494 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
495 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
498 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(
499 CodeGenOptions::TLSModel M) {
501 case CodeGenOptions::GeneralDynamicTLSModel:
502 return llvm::GlobalVariable::GeneralDynamicTLSModel;
503 case CodeGenOptions::LocalDynamicTLSModel:
504 return llvm::GlobalVariable::LocalDynamicTLSModel;
505 case CodeGenOptions::InitialExecTLSModel:
506 return llvm::GlobalVariable::InitialExecTLSModel;
507 case CodeGenOptions::LocalExecTLSModel:
508 return llvm::GlobalVariable::LocalExecTLSModel;
510 llvm_unreachable("Invalid TLS model!");
513 void CodeGenModule::setTLSMode(llvm::GlobalVariable *GV,
514 const VarDecl &D) const {
515 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
517 llvm::GlobalVariable::ThreadLocalMode TLM;
518 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel());
520 // Override the TLS model if it is explicitly specified.
521 if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
522 TLM = GetLLVMTLSModel(Attr->getModel());
525 GV->setThreadLocalMode(TLM);
528 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
529 StringRef &FoundStr = MangledDeclNames[GD.getCanonicalDecl()];
530 if (!FoundStr.empty())
533 const auto *ND = cast<NamedDecl>(GD.getDecl());
534 SmallString<256> Buffer;
536 if (getCXXABI().getMangleContext().shouldMangleDeclName(ND)) {
537 llvm::raw_svector_ostream Out(Buffer);
538 if (const auto *D = dyn_cast<CXXConstructorDecl>(ND))
539 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out);
540 else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND))
541 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out);
543 getCXXABI().getMangleContext().mangleName(ND, Out);
546 IdentifierInfo *II = ND->getIdentifier();
547 assert(II && "Attempt to mangle unnamed decl.");
551 auto &Mangled = Manglings.GetOrCreateValue(Str);
553 return FoundStr = Mangled.first();
556 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
557 const BlockDecl *BD) {
558 MangleContext &MangleCtx = getCXXABI().getMangleContext();
559 const Decl *D = GD.getDecl();
561 SmallString<256> Buffer;
562 llvm::raw_svector_ostream Out(Buffer);
564 MangleCtx.mangleGlobalBlock(BD,
565 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
566 else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
567 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
568 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
569 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
571 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
573 auto &Mangled = Manglings.GetOrCreateValue(Out.str());
575 return Mangled.first();
578 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
579 return getModule().getNamedValue(Name);
582 /// AddGlobalCtor - Add a function to the list that will be called before
584 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
585 llvm::Constant *AssociatedData) {
586 // FIXME: Type coercion of void()* types.
587 GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData));
590 /// AddGlobalDtor - Add a function to the list that will be called
591 /// when the module is unloaded.
592 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority) {
593 // FIXME: Type coercion of void()* types.
594 GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
597 void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) {
598 // Ctor function type is void()*.
599 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
600 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy);
602 // Get the type of a ctor entry, { i32, void ()*, i8* }.
603 llvm::StructType *CtorStructTy = llvm::StructType::get(
604 Int32Ty, llvm::PointerType::getUnqual(CtorFTy), VoidPtrTy, NULL);
606 // Construct the constructor and destructor arrays.
607 SmallVector<llvm::Constant*, 8> Ctors;
608 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
609 llvm::Constant *S[] = {
610 llvm::ConstantInt::get(Int32Ty, I->Priority, false),
611 llvm::ConstantExpr::getBitCast(I->Initializer, CtorPFTy),
613 ? llvm::ConstantExpr::getBitCast(I->AssociatedData, VoidPtrTy)
614 : llvm::Constant::getNullValue(VoidPtrTy))
616 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S));
619 if (!Ctors.empty()) {
620 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size());
621 new llvm::GlobalVariable(TheModule, AT, false,
622 llvm::GlobalValue::AppendingLinkage,
623 llvm::ConstantArray::get(AT, Ctors),
628 llvm::GlobalValue::LinkageTypes
629 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
630 const auto *D = cast<FunctionDecl>(GD.getDecl());
632 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
634 if (isa<CXXDestructorDecl>(D) &&
635 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
637 // Destructor variants in the Microsoft C++ ABI are always internal or
638 // linkonce_odr thunks emitted on an as-needed basis.
639 return Linkage == GVA_Internal ? llvm::GlobalValue::InternalLinkage
640 : llvm::GlobalValue::LinkOnceODRLinkage;
643 return getLLVMLinkageForDeclarator(D, Linkage, /*isConstantVariable=*/false);
646 void CodeGenModule::setFunctionDefinitionAttributes(const FunctionDecl *D,
648 setNonAliasAttributes(D, F);
651 void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
652 const CGFunctionInfo &Info,
654 unsigned CallingConv;
655 AttributeListType AttributeList;
656 ConstructAttributeList(Info, D, AttributeList, CallingConv, false);
657 F->setAttributes(llvm::AttributeSet::get(getLLVMContext(), AttributeList));
658 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
661 /// Determines whether the language options require us to model
662 /// unwind exceptions. We treat -fexceptions as mandating this
663 /// except under the fragile ObjC ABI with only ObjC exceptions
664 /// enabled. This means, for example, that C with -fexceptions
666 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
667 // If exceptions are completely disabled, obviously this is false.
668 if (!LangOpts.Exceptions) return false;
670 // If C++ exceptions are enabled, this is true.
671 if (LangOpts.CXXExceptions) return true;
673 // If ObjC exceptions are enabled, this depends on the ABI.
674 if (LangOpts.ObjCExceptions) {
675 return LangOpts.ObjCRuntime.hasUnwindExceptions();
681 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
685 if (CodeGenOpts.UnwindTables)
686 B.addAttribute(llvm::Attribute::UWTable);
688 if (!hasUnwindExceptions(LangOpts))
689 B.addAttribute(llvm::Attribute::NoUnwind);
691 if (D->hasAttr<NakedAttr>()) {
692 // Naked implies noinline: we should not be inlining such functions.
693 B.addAttribute(llvm::Attribute::Naked);
694 B.addAttribute(llvm::Attribute::NoInline);
695 } else if (D->hasAttr<OptimizeNoneAttr>()) {
696 // OptimizeNone implies noinline; we should not be inlining such functions.
697 B.addAttribute(llvm::Attribute::OptimizeNone);
698 B.addAttribute(llvm::Attribute::NoInline);
699 } else if (D->hasAttr<NoDuplicateAttr>()) {
700 B.addAttribute(llvm::Attribute::NoDuplicate);
701 } else if (D->hasAttr<NoInlineAttr>()) {
702 B.addAttribute(llvm::Attribute::NoInline);
703 } else if (D->hasAttr<AlwaysInlineAttr>() &&
704 !F->getAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex,
705 llvm::Attribute::NoInline)) {
706 // (noinline wins over always_inline, and we can't specify both in IR)
707 B.addAttribute(llvm::Attribute::AlwaysInline);
710 if (D->hasAttr<ColdAttr>()) {
711 B.addAttribute(llvm::Attribute::OptimizeForSize);
712 B.addAttribute(llvm::Attribute::Cold);
715 if (D->hasAttr<MinSizeAttr>())
716 B.addAttribute(llvm::Attribute::MinSize);
718 if (D->hasAttr<OptimizeNoneAttr>()) {
719 // OptimizeNone wins over OptimizeForSize and MinSize.
720 B.removeAttribute(llvm::Attribute::OptimizeForSize);
721 B.removeAttribute(llvm::Attribute::MinSize);
724 if (LangOpts.getStackProtector() == LangOptions::SSPOn)
725 B.addAttribute(llvm::Attribute::StackProtect);
726 else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
727 B.addAttribute(llvm::Attribute::StackProtectStrong);
728 else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
729 B.addAttribute(llvm::Attribute::StackProtectReq);
731 // Add sanitizer attributes if function is not blacklisted.
732 if (!SanitizerBL.isIn(*F)) {
733 // When AddressSanitizer is enabled, set SanitizeAddress attribute
734 // unless __attribute__((no_sanitize_address)) is used.
735 if (LangOpts.Sanitize.Address && !D->hasAttr<NoSanitizeAddressAttr>())
736 B.addAttribute(llvm::Attribute::SanitizeAddress);
737 // Same for ThreadSanitizer and __attribute__((no_sanitize_thread))
738 if (LangOpts.Sanitize.Thread && !D->hasAttr<NoSanitizeThreadAttr>())
739 B.addAttribute(llvm::Attribute::SanitizeThread);
740 // Same for MemorySanitizer and __attribute__((no_sanitize_memory))
741 if (LangOpts.Sanitize.Memory && !D->hasAttr<NoSanitizeMemoryAttr>())
742 B.addAttribute(llvm::Attribute::SanitizeMemory);
745 F->addAttributes(llvm::AttributeSet::FunctionIndex,
746 llvm::AttributeSet::get(
747 F->getContext(), llvm::AttributeSet::FunctionIndex, B));
749 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
750 F->setUnnamedAddr(true);
751 else if (const auto *MD = dyn_cast<CXXMethodDecl>(D))
753 F->setUnnamedAddr(true);
755 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
757 F->setAlignment(alignment);
759 // C++ ABI requires 2-byte alignment for member functions.
760 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
764 void CodeGenModule::SetCommonAttributes(const Decl *D,
765 llvm::GlobalValue *GV) {
766 if (const auto *ND = dyn_cast<NamedDecl>(D))
767 setGlobalVisibility(GV, ND);
769 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
771 if (D->hasAttr<UsedAttr>())
775 void CodeGenModule::setNonAliasAttributes(const Decl *D,
776 llvm::GlobalObject *GO) {
777 SetCommonAttributes(D, GO);
779 if (const SectionAttr *SA = D->getAttr<SectionAttr>())
780 GO->setSection(SA->getName());
782 getTargetCodeGenInfo().SetTargetAttributes(D, GO, *this);
785 void CodeGenModule::SetInternalFunctionAttributes(const Decl *D,
787 const CGFunctionInfo &FI) {
788 SetLLVMFunctionAttributes(D, FI, F);
789 SetLLVMFunctionAttributesForDefinition(D, F);
791 F->setLinkage(llvm::Function::InternalLinkage);
793 setNonAliasAttributes(D, F);
796 static void setLinkageAndVisibilityForGV(llvm::GlobalValue *GV,
797 const NamedDecl *ND) {
798 // Set linkage and visibility in case we never see a definition.
799 LinkageInfo LV = ND->getLinkageAndVisibility();
800 if (LV.getLinkage() != ExternalLinkage) {
801 // Don't set internal linkage on declarations.
803 if (ND->hasAttr<DLLImportAttr>()) {
804 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
805 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
806 } else if (ND->hasAttr<DLLExportAttr>()) {
807 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
808 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
809 } else if (ND->hasAttr<WeakAttr>() || ND->isWeakImported()) {
810 // "extern_weak" is overloaded in LLVM; we probably should have
811 // separate linkage types for this.
812 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
815 // Set visibility on a declaration only if it's explicit.
816 if (LV.isVisibilityExplicit())
817 GV->setVisibility(CodeGenModule::GetLLVMVisibility(LV.getVisibility()));
821 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD,
823 bool IsIncompleteFunction) {
824 if (unsigned IID = F->getIntrinsicID()) {
825 // If this is an intrinsic function, set the function's attributes
826 // to the intrinsic's attributes.
827 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(),
828 (llvm::Intrinsic::ID)IID));
832 const auto *FD = cast<FunctionDecl>(GD.getDecl());
834 if (!IsIncompleteFunction)
835 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F);
837 // Add the Returned attribute for "this", except for iOS 5 and earlier
838 // where substantial code, including the libstdc++ dylib, was compiled with
839 // GCC and does not actually return "this".
840 if (getCXXABI().HasThisReturn(GD) &&
841 !(getTarget().getTriple().isiOS() &&
842 getTarget().getTriple().isOSVersionLT(6))) {
843 assert(!F->arg_empty() &&
844 F->arg_begin()->getType()
845 ->canLosslesslyBitCastTo(F->getReturnType()) &&
846 "unexpected this return");
847 F->addAttribute(1, llvm::Attribute::Returned);
850 // Only a few attributes are set on declarations; these may later be
851 // overridden by a definition.
853 setLinkageAndVisibilityForGV(F, FD);
855 if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(FD)) {
856 if (getCXXABI().useThunkForDtorVariant(Dtor, GD.getDtorType())) {
857 // Don't dllexport/import destructor thunks.
858 F->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
862 if (const SectionAttr *SA = FD->getAttr<SectionAttr>())
863 F->setSection(SA->getName());
865 // A replaceable global allocation function does not act like a builtin by
866 // default, only if it is invoked by a new-expression or delete-expression.
867 if (FD->isReplaceableGlobalAllocationFunction())
868 F->addAttribute(llvm::AttributeSet::FunctionIndex,
869 llvm::Attribute::NoBuiltin);
872 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
873 assert(!GV->isDeclaration() &&
874 "Only globals with definition can force usage.");
875 LLVMUsed.push_back(GV);
878 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
879 assert(!GV->isDeclaration() &&
880 "Only globals with definition can force usage.");
881 LLVMCompilerUsed.push_back(GV);
884 static void emitUsed(CodeGenModule &CGM, StringRef Name,
885 std::vector<llvm::WeakVH> &List) {
886 // Don't create llvm.used if there is no need.
890 // Convert List to what ConstantArray needs.
891 SmallVector<llvm::Constant*, 8> UsedArray;
892 UsedArray.resize(List.size());
893 for (unsigned i = 0, e = List.size(); i != e; ++i) {
895 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*List[i]),
899 if (UsedArray.empty())
901 llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
903 auto *GV = new llvm::GlobalVariable(
904 CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
905 llvm::ConstantArray::get(ATy, UsedArray), Name);
907 GV->setSection("llvm.metadata");
910 void CodeGenModule::emitLLVMUsed() {
911 emitUsed(*this, "llvm.used", LLVMUsed);
912 emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
915 void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
916 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
917 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
920 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
921 llvm::SmallString<32> Opt;
922 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
923 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
924 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
927 void CodeGenModule::AddDependentLib(StringRef Lib) {
928 llvm::SmallString<24> Opt;
929 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
930 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
931 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
934 /// \brief Add link options implied by the given module, including modules
935 /// it depends on, using a postorder walk.
936 static void addLinkOptionsPostorder(CodeGenModule &CGM,
938 SmallVectorImpl<llvm::Value *> &Metadata,
939 llvm::SmallPtrSet<Module *, 16> &Visited) {
940 // Import this module's parent.
941 if (Mod->Parent && Visited.insert(Mod->Parent)) {
942 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
945 // Import this module's dependencies.
946 for (unsigned I = Mod->Imports.size(); I > 0; --I) {
947 if (Visited.insert(Mod->Imports[I-1]))
948 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited);
951 // Add linker options to link against the libraries/frameworks
952 // described by this module.
953 llvm::LLVMContext &Context = CGM.getLLVMContext();
954 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) {
955 // Link against a framework. Frameworks are currently Darwin only, so we
956 // don't to ask TargetCodeGenInfo for the spelling of the linker option.
957 if (Mod->LinkLibraries[I-1].IsFramework) {
958 llvm::Value *Args[2] = {
959 llvm::MDString::get(Context, "-framework"),
960 llvm::MDString::get(Context, Mod->LinkLibraries[I-1].Library)
963 Metadata.push_back(llvm::MDNode::get(Context, Args));
967 // Link against a library.
968 llvm::SmallString<24> Opt;
969 CGM.getTargetCodeGenInfo().getDependentLibraryOption(
970 Mod->LinkLibraries[I-1].Library, Opt);
971 llvm::Value *OptString = llvm::MDString::get(Context, Opt);
972 Metadata.push_back(llvm::MDNode::get(Context, OptString));
976 void CodeGenModule::EmitModuleLinkOptions() {
977 // Collect the set of all of the modules we want to visit to emit link
978 // options, which is essentially the imported modules and all of their
979 // non-explicit child modules.
980 llvm::SetVector<clang::Module *> LinkModules;
981 llvm::SmallPtrSet<clang::Module *, 16> Visited;
982 SmallVector<clang::Module *, 16> Stack;
984 // Seed the stack with imported modules.
985 for (llvm::SetVector<clang::Module *>::iterator M = ImportedModules.begin(),
986 MEnd = ImportedModules.end();
988 if (Visited.insert(*M))
992 // Find all of the modules to import, making a little effort to prune
994 while (!Stack.empty()) {
995 clang::Module *Mod = Stack.pop_back_val();
997 bool AnyChildren = false;
999 // Visit the submodules of this module.
1000 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
1001 SubEnd = Mod->submodule_end();
1002 Sub != SubEnd; ++Sub) {
1003 // Skip explicit children; they need to be explicitly imported to be
1005 if ((*Sub)->IsExplicit)
1008 if (Visited.insert(*Sub)) {
1009 Stack.push_back(*Sub);
1014 // We didn't find any children, so add this module to the list of
1015 // modules to link against.
1017 LinkModules.insert(Mod);
1021 // Add link options for all of the imported modules in reverse topological
1022 // order. We don't do anything to try to order import link flags with respect
1023 // to linker options inserted by things like #pragma comment().
1024 SmallVector<llvm::Value *, 16> MetadataArgs;
1026 for (llvm::SetVector<clang::Module *>::iterator M = LinkModules.begin(),
1027 MEnd = LinkModules.end();
1029 if (Visited.insert(*M))
1030 addLinkOptionsPostorder(*this, *M, MetadataArgs, Visited);
1032 std::reverse(MetadataArgs.begin(), MetadataArgs.end());
1033 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
1035 // Add the linker options metadata flag.
1036 getModule().addModuleFlag(llvm::Module::AppendUnique, "Linker Options",
1037 llvm::MDNode::get(getLLVMContext(),
1038 LinkerOptionsMetadata));
1041 void CodeGenModule::EmitDeferred() {
1042 // Emit code for any potentially referenced deferred decls. Since a
1043 // previously unused static decl may become used during the generation of code
1044 // for a static function, iterate until no changes are made.
1047 if (!DeferredVTables.empty()) {
1048 EmitDeferredVTables();
1050 // Emitting a v-table doesn't directly cause more v-tables to
1051 // become deferred, although it can cause functions to be
1052 // emitted that then need those v-tables.
1053 assert(DeferredVTables.empty());
1056 // Stop if we're out of both deferred v-tables and deferred declarations.
1057 if (DeferredDeclsToEmit.empty()) break;
1059 DeferredGlobal &G = DeferredDeclsToEmit.back();
1060 GlobalDecl D = G.GD;
1061 llvm::GlobalValue *GV = G.GV;
1062 DeferredDeclsToEmit.pop_back();
1064 assert(GV == GetGlobalValue(getMangledName(D)));
1065 // Check to see if we've already emitted this. This is necessary
1066 // for a couple of reasons: first, decls can end up in the
1067 // deferred-decls queue multiple times, and second, decls can end
1068 // up with definitions in unusual ways (e.g. by an extern inline
1069 // function acquiring a strong function redefinition). Just
1070 // ignore these cases.
1071 if(!GV->isDeclaration())
1074 // Otherwise, emit the definition and move on to the next one.
1075 EmitGlobalDefinition(D, GV);
1079 void CodeGenModule::EmitGlobalAnnotations() {
1080 if (Annotations.empty())
1083 // Create a new global variable for the ConstantStruct in the Module.
1084 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
1085 Annotations[0]->getType(), Annotations.size()), Annotations);
1086 auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
1087 llvm::GlobalValue::AppendingLinkage,
1088 Array, "llvm.global.annotations");
1089 gv->setSection(AnnotationSection);
1092 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
1093 llvm::Constant *&AStr = AnnotationStrings[Str];
1097 // Not found yet, create a new global.
1098 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
1100 new llvm::GlobalVariable(getModule(), s->getType(), true,
1101 llvm::GlobalValue::PrivateLinkage, s, ".str");
1102 gv->setSection(AnnotationSection);
1103 gv->setUnnamedAddr(true);
1108 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
1109 SourceManager &SM = getContext().getSourceManager();
1110 PresumedLoc PLoc = SM.getPresumedLoc(Loc);
1112 return EmitAnnotationString(PLoc.getFilename());
1113 return EmitAnnotationString(SM.getBufferName(Loc));
1116 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
1117 SourceManager &SM = getContext().getSourceManager();
1118 PresumedLoc PLoc = SM.getPresumedLoc(L);
1119 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
1120 SM.getExpansionLineNumber(L);
1121 return llvm::ConstantInt::get(Int32Ty, LineNo);
1124 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
1125 const AnnotateAttr *AA,
1127 // Get the globals for file name, annotation, and the line number.
1128 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
1129 *UnitGV = EmitAnnotationUnit(L),
1130 *LineNoCst = EmitAnnotationLineNo(L);
1132 // Create the ConstantStruct for the global annotation.
1133 llvm::Constant *Fields[4] = {
1134 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy),
1135 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
1136 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
1139 return llvm::ConstantStruct::getAnon(Fields);
1142 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
1143 llvm::GlobalValue *GV) {
1144 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
1145 // Get the struct elements for these annotations.
1146 for (const auto *I : D->specific_attrs<AnnotateAttr>())
1147 Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
1150 bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) {
1151 // Never defer when EmitAllDecls is specified.
1152 if (LangOpts.EmitAllDecls)
1155 return !getContext().DeclMustBeEmitted(Global);
1158 llvm::Constant *CodeGenModule::GetAddrOfUuidDescriptor(
1159 const CXXUuidofExpr* E) {
1160 // Sema has verified that IIDSource has a __declspec(uuid()), and that its
1162 StringRef Uuid = E->getUuidAsStringRef(Context);
1163 std::string Name = "_GUID_" + Uuid.lower();
1164 std::replace(Name.begin(), Name.end(), '-', '_');
1166 // Look for an existing global.
1167 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
1170 llvm::Constant *Init = EmitUuidofInitializer(Uuid, E->getType());
1171 assert(Init && "failed to initialize as constant");
1173 auto *GV = new llvm::GlobalVariable(
1174 getModule(), Init->getType(),
1175 /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
1179 llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
1180 const AliasAttr *AA = VD->getAttr<AliasAttr>();
1181 assert(AA && "No alias?");
1183 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
1185 // See if there is already something with the target's name in the module.
1186 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
1188 unsigned AS = getContext().getTargetAddressSpace(VD->getType());
1189 return llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
1192 llvm::Constant *Aliasee;
1193 if (isa<llvm::FunctionType>(DeclTy))
1194 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
1195 GlobalDecl(cast<FunctionDecl>(VD)),
1196 /*ForVTable=*/false);
1198 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
1199 llvm::PointerType::getUnqual(DeclTy),
1202 auto *F = cast<llvm::GlobalValue>(Aliasee);
1203 F->setLinkage(llvm::Function::ExternalWeakLinkage);
1204 WeakRefReferences.insert(F);
1209 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
1210 const auto *Global = cast<ValueDecl>(GD.getDecl());
1212 // Weak references don't produce any output by themselves.
1213 if (Global->hasAttr<WeakRefAttr>())
1216 // If this is an alias definition (which otherwise looks like a declaration)
1218 if (Global->hasAttr<AliasAttr>())
1219 return EmitAliasDefinition(GD);
1221 // If this is CUDA, be selective about which declarations we emit.
1222 if (LangOpts.CUDA) {
1223 if (CodeGenOpts.CUDAIsDevice) {
1224 if (!Global->hasAttr<CUDADeviceAttr>() &&
1225 !Global->hasAttr<CUDAGlobalAttr>() &&
1226 !Global->hasAttr<CUDAConstantAttr>() &&
1227 !Global->hasAttr<CUDASharedAttr>())
1230 if (!Global->hasAttr<CUDAHostAttr>() && (
1231 Global->hasAttr<CUDADeviceAttr>() ||
1232 Global->hasAttr<CUDAConstantAttr>() ||
1233 Global->hasAttr<CUDASharedAttr>()))
1238 // Ignore declarations, they will be emitted on their first use.
1239 if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
1240 // Forward declarations are emitted lazily on first use.
1241 if (!FD->doesThisDeclarationHaveABody()) {
1242 if (!FD->doesDeclarationForceExternallyVisibleDefinition())
1245 StringRef MangledName = getMangledName(GD);
1247 // Compute the function info and LLVM type.
1248 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
1249 llvm::Type *Ty = getTypes().GetFunctionType(FI);
1251 GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
1252 /*DontDefer=*/false);
1256 const auto *VD = cast<VarDecl>(Global);
1257 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
1259 if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
1260 !Context.isMSStaticDataMemberInlineDefinition(VD))
1264 // Defer code generation when possible if this is a static definition, inline
1265 // function etc. These we only want to emit if they are used.
1266 if (!MayDeferGeneration(Global)) {
1267 // Emit the definition if it can't be deferred.
1268 EmitGlobalDefinition(GD);
1272 // If we're deferring emission of a C++ variable with an
1273 // initializer, remember the order in which it appeared in the file.
1274 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
1275 cast<VarDecl>(Global)->hasInit()) {
1276 DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
1277 CXXGlobalInits.push_back(nullptr);
1280 // If the value has already been used, add it directly to the
1281 // DeferredDeclsToEmit list.
1282 StringRef MangledName = getMangledName(GD);
1283 if (llvm::GlobalValue *GV = GetGlobalValue(MangledName))
1284 addDeferredDeclToEmit(GV, GD);
1286 // Otherwise, remember that we saw a deferred decl with this name. The
1287 // first use of the mangled name will cause it to move into
1288 // DeferredDeclsToEmit.
1289 DeferredDecls[MangledName] = GD;
1294 struct FunctionIsDirectlyRecursive :
1295 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> {
1296 const StringRef Name;
1297 const Builtin::Context &BI;
1299 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) :
1300 Name(N), BI(C), Result(false) {
1302 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base;
1304 bool TraverseCallExpr(CallExpr *E) {
1305 const FunctionDecl *FD = E->getDirectCallee();
1308 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
1309 if (Attr && Name == Attr->getLabel()) {
1313 unsigned BuiltinID = FD->getBuiltinID();
1316 StringRef BuiltinName = BI.GetName(BuiltinID);
1317 if (BuiltinName.startswith("__builtin_") &&
1318 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
1327 // isTriviallyRecursive - Check if this function calls another
1328 // decl that, because of the asm attribute or the other decl being a builtin,
1329 // ends up pointing to itself.
1331 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
1333 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
1334 // asm labels are a special kind of mangling we have to support.
1335 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
1338 Name = Attr->getLabel();
1340 Name = FD->getName();
1343 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
1344 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD));
1345 return Walker.Result;
1349 CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
1350 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
1352 const auto *F = cast<FunctionDecl>(GD.getDecl());
1353 if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
1355 // PR9614. Avoid cases where the source code is lying to us. An available
1356 // externally function should have an equivalent function somewhere else,
1357 // but a function that calls itself is clearly not equivalent to the real
1359 // This happens in glibc's btowc and in some configure checks.
1360 return !isTriviallyRecursive(F);
1363 /// If the type for the method's class was generated by
1364 /// CGDebugInfo::createContextChain(), the cache contains only a
1365 /// limited DIType without any declarations. Since EmitFunctionStart()
1366 /// needs to find the canonical declaration for each method, we need
1367 /// to construct the complete type prior to emitting the method.
1368 void CodeGenModule::CompleteDIClassType(const CXXMethodDecl* D) {
1369 if (!D->isInstance())
1372 if (CGDebugInfo *DI = getModuleDebugInfo())
1373 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) {
1374 const auto *ThisPtr = cast<PointerType>(D->getThisType(getContext()));
1375 DI->getOrCreateRecordType(ThisPtr->getPointeeType(), D->getLocation());
1379 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
1380 const auto *D = cast<ValueDecl>(GD.getDecl());
1382 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
1383 Context.getSourceManager(),
1384 "Generating code for declaration");
1386 if (isa<FunctionDecl>(D)) {
1387 // At -O0, don't generate IR for functions with available_externally
1389 if (!shouldEmitFunction(GD))
1392 if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
1393 CompleteDIClassType(Method);
1394 // Make sure to emit the definition(s) before we emit the thunks.
1395 // This is necessary for the generation of certain thunks.
1396 if (const auto *CD = dyn_cast<CXXConstructorDecl>(Method))
1397 EmitCXXConstructor(CD, GD.getCtorType());
1398 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(Method))
1399 EmitCXXDestructor(DD, GD.getDtorType());
1401 EmitGlobalFunctionDefinition(GD, GV);
1403 if (Method->isVirtual())
1404 getVTables().EmitThunks(GD);
1409 return EmitGlobalFunctionDefinition(GD, GV);
1412 if (const auto *VD = dyn_cast<VarDecl>(D))
1413 return EmitGlobalVarDefinition(VD);
1415 llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
1418 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
1419 /// module, create and return an llvm Function with the specified type. If there
1420 /// is something in the module with the specified name, return it potentially
1421 /// bitcasted to the right type.
1423 /// If D is non-null, it specifies a decl that correspond to this. This is used
1424 /// to set the attributes on the function when it is first created.
1426 CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName,
1428 GlobalDecl GD, bool ForVTable,
1430 llvm::AttributeSet ExtraAttrs) {
1431 const Decl *D = GD.getDecl();
1433 // Lookup the entry, lazily creating it if necessary.
1434 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
1436 if (WeakRefReferences.erase(Entry)) {
1437 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
1438 if (FD && !FD->hasAttr<WeakAttr>())
1439 Entry->setLinkage(llvm::Function::ExternalLinkage);
1442 if (Entry->getType()->getElementType() == Ty)
1445 // Make sure the result is of the correct type.
1446 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
1449 // This function doesn't have a complete type (for example, the return
1450 // type is an incomplete struct). Use a fake type instead, and make
1451 // sure not to try to set attributes.
1452 bool IsIncompleteFunction = false;
1454 llvm::FunctionType *FTy;
1455 if (isa<llvm::FunctionType>(Ty)) {
1456 FTy = cast<llvm::FunctionType>(Ty);
1458 FTy = llvm::FunctionType::get(VoidTy, false);
1459 IsIncompleteFunction = true;
1462 llvm::Function *F = llvm::Function::Create(FTy,
1463 llvm::Function::ExternalLinkage,
1464 MangledName, &getModule());
1465 assert(F->getName() == MangledName && "name was uniqued!");
1467 SetFunctionAttributes(GD, F, IsIncompleteFunction);
1468 if (ExtraAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) {
1469 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeSet::FunctionIndex);
1470 F->addAttributes(llvm::AttributeSet::FunctionIndex,
1471 llvm::AttributeSet::get(VMContext,
1472 llvm::AttributeSet::FunctionIndex,
1477 // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
1478 // each other bottoming out with the base dtor. Therefore we emit non-base
1479 // dtors on usage, even if there is no dtor definition in the TU.
1480 if (D && isa<CXXDestructorDecl>(D) &&
1481 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
1483 addDeferredDeclToEmit(F, GD);
1485 // This is the first use or definition of a mangled name. If there is a
1486 // deferred decl with this name, remember that we need to emit it at the end
1488 auto DDI = DeferredDecls.find(MangledName);
1489 if (DDI != DeferredDecls.end()) {
1490 // Move the potentially referenced deferred decl to the
1491 // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
1492 // don't need it anymore).
1493 addDeferredDeclToEmit(F, DDI->second);
1494 DeferredDecls.erase(DDI);
1496 // Otherwise, if this is a sized deallocation function, emit a weak
1498 // for it at the end of the translation unit.
1499 } else if (D && cast<FunctionDecl>(D)
1500 ->getCorrespondingUnsizedGlobalDeallocationFunction()) {
1501 addDeferredDeclToEmit(F, GD);
1503 // Otherwise, there are cases we have to worry about where we're
1504 // using a declaration for which we must emit a definition but where
1505 // we might not find a top-level definition:
1506 // - member functions defined inline in their classes
1507 // - friend functions defined inline in some class
1508 // - special member functions with implicit definitions
1509 // If we ever change our AST traversal to walk into class methods,
1510 // this will be unnecessary.
1512 // We also don't emit a definition for a function if it's going to be an
1514 // in a vtable, unless it's already marked as used.
1515 } else if (getLangOpts().CPlusPlus && D) {
1516 // Look for a declaration that's lexically in a record.
1517 const auto *FD = cast<FunctionDecl>(D);
1518 FD = FD->getMostRecentDecl();
1520 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
1521 if (FD->isImplicit() && !ForVTable) {
1522 assert(FD->isUsed() &&
1523 "Sema didn't mark implicit function as used!");
1524 addDeferredDeclToEmit(F, GD.getWithDecl(FD));
1526 } else if (FD->doesThisDeclarationHaveABody()) {
1527 addDeferredDeclToEmit(F, GD.getWithDecl(FD));
1531 FD = FD->getPreviousDecl();
1536 // Make sure the result is of the requested type.
1537 if (!IsIncompleteFunction) {
1538 assert(F->getType()->getElementType() == Ty);
1542 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
1543 return llvm::ConstantExpr::getBitCast(F, PTy);
1546 /// GetAddrOfFunction - Return the address of the given function. If Ty is
1547 /// non-null, then this function will use the specified type if it has to
1548 /// create it (this occurs when we see a definition of the function).
1549 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
1553 // If there was no specific requested type, just convert it now.
1555 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType());
1557 StringRef MangledName = getMangledName(GD);
1558 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer);
1561 /// CreateRuntimeFunction - Create a new runtime function with the specified
1564 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy,
1566 llvm::AttributeSet ExtraAttrs) {
1568 GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
1569 /*DontDefer=*/false, ExtraAttrs);
1570 if (auto *F = dyn_cast<llvm::Function>(C))
1572 F->setCallingConv(getRuntimeCC());
1576 /// isTypeConstant - Determine whether an object of this type can be emitted
1579 /// If ExcludeCtor is true, the duration when the object's constructor runs
1580 /// will not be considered. The caller will need to verify that the object is
1581 /// not written to during its construction.
1582 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
1583 if (!Ty.isConstant(Context) && !Ty->isReferenceType())
1586 if (Context.getLangOpts().CPlusPlus) {
1587 if (const CXXRecordDecl *Record
1588 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
1589 return ExcludeCtor && !Record->hasMutableFields() &&
1590 Record->hasTrivialDestructor();
1596 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
1597 /// create and return an llvm GlobalVariable with the specified type. If there
1598 /// is something in the module with the specified name, return it potentially
1599 /// bitcasted to the right type.
1601 /// If D is non-null, it specifies a decl that correspond to this. This is used
1602 /// to set the attributes on the global when it is first created.
1604 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
1605 llvm::PointerType *Ty,
1607 // Lookup the entry, lazily creating it if necessary.
1608 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
1610 if (WeakRefReferences.erase(Entry)) {
1611 if (D && !D->hasAttr<WeakAttr>())
1612 Entry->setLinkage(llvm::Function::ExternalLinkage);
1615 if (Entry->getType() == Ty)
1618 // Make sure the result is of the correct type.
1619 if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace())
1620 return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty);
1622 return llvm::ConstantExpr::getBitCast(Entry, Ty);
1625 unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace());
1626 auto *GV = new llvm::GlobalVariable(
1627 getModule(), Ty->getElementType(), false,
1628 llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr,
1629 llvm::GlobalVariable::NotThreadLocal, AddrSpace);
1631 // This is the first use or definition of a mangled name. If there is a
1632 // deferred decl with this name, remember that we need to emit it at the end
1634 auto DDI = DeferredDecls.find(MangledName);
1635 if (DDI != DeferredDecls.end()) {
1636 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
1637 // list, and remove it from DeferredDecls (since we don't need it anymore).
1638 addDeferredDeclToEmit(GV, DDI->second);
1639 DeferredDecls.erase(DDI);
1642 // Handle things which are present even on external declarations.
1644 // FIXME: This code is overly simple and should be merged with other global
1646 GV->setConstant(isTypeConstant(D->getType(), false));
1648 setLinkageAndVisibilityForGV(GV, D);
1650 if (D->getTLSKind()) {
1651 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
1652 CXXThreadLocals.push_back(std::make_pair(D, GV));
1656 // If required by the ABI, treat declarations of static data members with
1657 // inline initializers as definitions.
1658 if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
1659 EmitGlobalVarDefinition(D);
1662 // Handle XCore specific ABI requirements.
1663 if (getTarget().getTriple().getArch() == llvm::Triple::xcore &&
1664 D->getLanguageLinkage() == CLanguageLinkage &&
1665 D->getType().isConstant(Context) &&
1666 isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
1667 GV->setSection(".cp.rodata");
1670 if (AddrSpace != Ty->getAddressSpace())
1671 return llvm::ConstantExpr::getAddrSpaceCast(GV, Ty);
1677 llvm::GlobalVariable *
1678 CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name,
1680 llvm::GlobalValue::LinkageTypes Linkage) {
1681 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
1682 llvm::GlobalVariable *OldGV = nullptr;
1685 // Check if the variable has the right type.
1686 if (GV->getType()->getElementType() == Ty)
1689 // Because C++ name mangling, the only way we can end up with an already
1690 // existing global with the same name is if it has been declared extern "C".
1691 assert(GV->isDeclaration() && "Declaration has wrong type!");
1695 // Create a new variable.
1696 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
1697 Linkage, nullptr, Name);
1700 // Replace occurrences of the old variable if needed.
1701 GV->takeName(OldGV);
1703 if (!OldGV->use_empty()) {
1704 llvm::Constant *NewPtrForOldDecl =
1705 llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
1706 OldGV->replaceAllUsesWith(NewPtrForOldDecl);
1709 OldGV->eraseFromParent();
1715 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
1716 /// given global variable. If Ty is non-null and if the global doesn't exist,
1717 /// then it will be created with the specified type instead of whatever the
1718 /// normal requested type would be.
1719 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
1721 assert(D->hasGlobalStorage() && "Not a global variable");
1722 QualType ASTTy = D->getType();
1724 Ty = getTypes().ConvertTypeForMem(ASTTy);
1726 llvm::PointerType *PTy =
1727 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
1729 StringRef MangledName = getMangledName(D);
1730 return GetOrCreateLLVMGlobal(MangledName, PTy, D);
1733 /// CreateRuntimeVariable - Create a new runtime global variable with the
1734 /// specified type and name.
1736 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
1738 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), nullptr);
1741 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
1742 assert(!D->getInit() && "Cannot emit definite definitions here!");
1744 if (MayDeferGeneration(D)) {
1745 // If we have not seen a reference to this variable yet, place it
1746 // into the deferred declarations table to be emitted if needed
1748 StringRef MangledName = getMangledName(D);
1749 if (!GetGlobalValue(MangledName)) {
1750 DeferredDecls[MangledName] = D;
1755 // The tentative definition is the only definition.
1756 EmitGlobalVarDefinition(D);
1759 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
1760 return Context.toCharUnitsFromBits(
1761 TheDataLayout.getTypeStoreSizeInBits(Ty));
1764 unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D,
1765 unsigned AddrSpace) {
1766 if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) {
1767 if (D->hasAttr<CUDAConstantAttr>())
1768 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_constant);
1769 else if (D->hasAttr<CUDASharedAttr>())
1770 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_shared);
1772 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_device);
1778 template<typename SomeDecl>
1779 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
1780 llvm::GlobalValue *GV) {
1781 if (!getLangOpts().CPlusPlus)
1784 // Must have 'used' attribute, or else inline assembly can't rely on
1785 // the name existing.
1786 if (!D->template hasAttr<UsedAttr>())
1789 // Must have internal linkage and an ordinary name.
1790 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage)
1793 // Must be in an extern "C" context. Entities declared directly within
1794 // a record are not extern "C" even if the record is in such a context.
1795 const SomeDecl *First = D->getFirstDecl();
1796 if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
1799 // OK, this is an internal linkage entity inside an extern "C" linkage
1800 // specification. Make a note of that so we can give it the "expected"
1801 // mangled name if nothing else is using that name.
1802 std::pair<StaticExternCMap::iterator, bool> R =
1803 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
1805 // If we have multiple internal linkage entities with the same name
1806 // in extern "C" regions, none of them gets that name.
1808 R.first->second = nullptr;
1811 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
1812 llvm::Constant *Init = nullptr;
1813 QualType ASTTy = D->getType();
1814 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
1815 bool NeedsGlobalCtor = false;
1816 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor();
1818 const VarDecl *InitDecl;
1819 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
1822 // This is a tentative definition; tentative definitions are
1823 // implicitly initialized with { 0 }.
1825 // Note that tentative definitions are only emitted at the end of
1826 // a translation unit, so they should never have incomplete
1827 // type. In addition, EmitTentativeDefinition makes sure that we
1828 // never attempt to emit a tentative definition if a real one
1829 // exists. A use may still exists, however, so we still may need
1831 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
1832 Init = EmitNullConstant(D->getType());
1834 initializedGlobalDecl = GlobalDecl(D);
1835 Init = EmitConstantInit(*InitDecl);
1838 QualType T = InitExpr->getType();
1839 if (D->getType()->isReferenceType())
1842 if (getLangOpts().CPlusPlus) {
1843 Init = EmitNullConstant(T);
1844 NeedsGlobalCtor = true;
1846 ErrorUnsupported(D, "static initializer");
1847 Init = llvm::UndefValue::get(getTypes().ConvertType(T));
1850 // We don't need an initializer, so remove the entry for the delayed
1851 // initializer position (just in case this entry was delayed) if we
1852 // also don't need to register a destructor.
1853 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
1854 DelayedCXXInitPosition.erase(D);
1858 llvm::Type* InitType = Init->getType();
1859 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType);
1861 // Strip off a bitcast if we got one back.
1862 if (auto *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
1863 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
1864 CE->getOpcode() == llvm::Instruction::AddrSpaceCast ||
1865 // All zero index gep.
1866 CE->getOpcode() == llvm::Instruction::GetElementPtr);
1867 Entry = CE->getOperand(0);
1870 // Entry is now either a Function or GlobalVariable.
1871 auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
1873 // We have a definition after a declaration with the wrong type.
1874 // We must make a new GlobalVariable* and update everything that used OldGV
1875 // (a declaration or tentative definition) with the new GlobalVariable*
1876 // (which will be a definition).
1878 // This happens if there is a prototype for a global (e.g.
1879 // "extern int x[];") and then a definition of a different type (e.g.
1880 // "int x[10];"). This also happens when an initializer has a different type
1881 // from the type of the global (this happens with unions).
1883 GV->getType()->getElementType() != InitType ||
1884 GV->getType()->getAddressSpace() !=
1885 GetGlobalVarAddressSpace(D, getContext().getTargetAddressSpace(ASTTy))) {
1887 // Move the old entry aside so that we'll create a new one.
1888 Entry->setName(StringRef());
1890 // Make a new global with the correct type, this is now guaranteed to work.
1891 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType));
1893 // Replace all uses of the old global with the new global
1894 llvm::Constant *NewPtrForOldDecl =
1895 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
1896 Entry->replaceAllUsesWith(NewPtrForOldDecl);
1898 // Erase the old global, since it is no longer used.
1899 cast<llvm::GlobalValue>(Entry)->eraseFromParent();
1902 MaybeHandleStaticInExternC(D, GV);
1904 if (D->hasAttr<AnnotateAttr>())
1905 AddGlobalAnnotations(D, GV);
1907 GV->setInitializer(Init);
1909 // If it is safe to mark the global 'constant', do so now.
1910 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
1911 isTypeConstant(D->getType(), true));
1913 GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
1915 // Set the llvm linkage type as appropriate.
1916 llvm::GlobalValue::LinkageTypes Linkage =
1917 getLLVMLinkageVarDefinition(D, GV->isConstant());
1919 // On Darwin, the backing variable for a C++11 thread_local variable always
1920 // has internal linkage; all accesses should just be calls to the
1921 // Itanium-specified entry point, which has the normal linkage of the
1923 if (const auto *VD = dyn_cast<VarDecl>(D))
1924 if (!VD->isStaticLocal() && VD->getTLSKind() == VarDecl::TLS_Dynamic &&
1925 Context.getTargetInfo().getTriple().isMacOSX())
1926 Linkage = llvm::GlobalValue::InternalLinkage;
1928 GV->setLinkage(Linkage);
1929 if (D->hasAttr<DLLImportAttr>())
1930 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
1931 else if (D->hasAttr<DLLExportAttr>())
1932 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
1934 if (Linkage == llvm::GlobalVariable::CommonLinkage)
1935 // common vars aren't constant even if declared const.
1936 GV->setConstant(false);
1938 setNonAliasAttributes(D, GV);
1940 // Emit the initializer function if necessary.
1941 if (NeedsGlobalCtor || NeedsGlobalDtor)
1942 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
1944 reportGlobalToASan(GV, *D, NeedsGlobalCtor);
1946 // Emit global variable debug information.
1947 if (CGDebugInfo *DI = getModuleDebugInfo())
1948 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo)
1949 DI->EmitGlobalVariable(GV, D);
1952 void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV,
1953 SourceLocation Loc, StringRef Name,
1954 bool IsDynInit, bool IsBlacklisted) {
1955 if (!LangOpts.Sanitize.Address)
1957 IsDynInit &= !SanitizerBL.isIn(*GV, "init");
1958 IsBlacklisted |= SanitizerBL.isIn(*GV);
1960 llvm::GlobalVariable *LocDescr = nullptr;
1961 llvm::GlobalVariable *GlobalName = nullptr;
1962 if (!IsBlacklisted) {
1963 // Don't generate source location and global name if it is blacklisted -
1964 // it won't be instrumented anyway.
1965 PresumedLoc PLoc = Context.getSourceManager().getPresumedLoc(Loc);
1966 if (PLoc.isValid()) {
1967 llvm::Constant *LocData[] = {
1968 GetAddrOfConstantCString(PLoc.getFilename()),
1969 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
1971 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
1974 auto LocStruct = llvm::ConstantStruct::getAnon(LocData);
1975 LocDescr = new llvm::GlobalVariable(TheModule, LocStruct->getType(), true,
1976 llvm::GlobalValue::PrivateLinkage,
1977 LocStruct, ".asan_loc_descr");
1978 LocDescr->setUnnamedAddr(true);
1979 // Add LocDescr to llvm.compiler.used, so that it won't be removed by
1980 // the optimizer before the ASan instrumentation pass.
1981 addCompilerUsedGlobal(LocDescr);
1983 if (!Name.empty()) {
1984 GlobalName = GetAddrOfConstantCString(Name);
1985 // GlobalName shouldn't be removed by the optimizer.
1986 addCompilerUsedGlobal(GlobalName);
1990 llvm::Value *GlobalMetadata[] = {
1991 GV, LocDescr, GlobalName,
1992 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsDynInit),
1993 llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsBlacklisted)};
1995 llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalMetadata);
1996 llvm::NamedMDNode *AsanGlobals =
1997 TheModule.getOrInsertNamedMetadata("llvm.asan.globals");
1998 AsanGlobals->addOperand(ThisGlobal);
2001 void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV,
2002 const VarDecl &D, bool IsDynInit) {
2003 if (!LangOpts.Sanitize.Address)
2005 std::string QualName;
2006 llvm::raw_string_ostream OS(QualName);
2007 D.printQualifiedName(OS);
2008 reportGlobalToASan(GV, D.getLocation(), OS.str(), IsDynInit);
2011 void CodeGenModule::disableSanitizerForGlobal(llvm::GlobalVariable *GV) {
2012 // For now, just make sure the global is not modified by the ASan
2014 if (LangOpts.Sanitize.Address)
2015 reportGlobalToASan(GV, SourceLocation(), "", false, true);
2018 static bool isVarDeclStrongDefinition(const VarDecl *D, bool NoCommon) {
2019 // Don't give variables common linkage if -fno-common was specified unless it
2020 // was overridden by a NoCommon attribute.
2021 if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
2025 // A declaration of an identifier for an object that has file scope without
2026 // an initializer, and without a storage-class specifier or with the
2027 // storage-class specifier static, constitutes a tentative definition.
2028 if (D->getInit() || D->hasExternalStorage())
2031 // A variable cannot be both common and exist in a section.
2032 if (D->hasAttr<SectionAttr>())
2035 // Thread local vars aren't considered common linkage.
2036 if (D->getTLSKind())
2039 // Tentative definitions marked with WeakImportAttr are true definitions.
2040 if (D->hasAttr<WeakImportAttr>())
2046 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
2047 const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) {
2048 if (Linkage == GVA_Internal)
2049 return llvm::Function::InternalLinkage;
2051 if (D->hasAttr<WeakAttr>()) {
2052 if (IsConstantVariable)
2053 return llvm::GlobalVariable::WeakODRLinkage;
2055 return llvm::GlobalVariable::WeakAnyLinkage;
2058 // We are guaranteed to have a strong definition somewhere else,
2059 // so we can use available_externally linkage.
2060 if (Linkage == GVA_AvailableExternally)
2061 return llvm::Function::AvailableExternallyLinkage;
2063 // Note that Apple's kernel linker doesn't support symbol
2064 // coalescing, so we need to avoid linkonce and weak linkages there.
2065 // Normally, this means we just map to internal, but for explicit
2066 // instantiations we'll map to external.
2068 // In C++, the compiler has to emit a definition in every translation unit
2069 // that references the function. We should use linkonce_odr because
2070 // a) if all references in this translation unit are optimized away, we
2071 // don't need to codegen it. b) if the function persists, it needs to be
2072 // merged with other definitions. c) C++ has the ODR, so we know the
2073 // definition is dependable.
2074 if (Linkage == GVA_DiscardableODR)
2075 return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
2076 : llvm::Function::InternalLinkage;
2078 // An explicit instantiation of a template has weak linkage, since
2079 // explicit instantiations can occur in multiple translation units
2080 // and must all be equivalent. However, we are not allowed to
2081 // throw away these explicit instantiations.
2082 if (Linkage == GVA_StrongODR)
2083 return !Context.getLangOpts().AppleKext ? llvm::Function::WeakODRLinkage
2084 : llvm::Function::ExternalLinkage;
2086 // C++ doesn't have tentative definitions and thus cannot have common
2088 if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
2089 !isVarDeclStrongDefinition(cast<VarDecl>(D), CodeGenOpts.NoCommon))
2090 return llvm::GlobalVariable::CommonLinkage;
2092 // selectany symbols are externally visible, so use weak instead of
2093 // linkonce. MSVC optimizes away references to const selectany globals, so
2094 // all definitions should be the same and ODR linkage should be used.
2095 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
2096 if (D->hasAttr<SelectAnyAttr>())
2097 return llvm::GlobalVariable::WeakODRLinkage;
2099 // Otherwise, we have strong external linkage.
2100 assert(Linkage == GVA_StrongExternal);
2101 return llvm::GlobalVariable::ExternalLinkage;
2104 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition(
2105 const VarDecl *VD, bool IsConstant) {
2106 GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
2107 return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant);
2110 /// Replace the uses of a function that was declared with a non-proto type.
2111 /// We want to silently drop extra arguments from call sites
2112 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
2113 llvm::Function *newFn) {
2115 if (old->use_empty()) return;
2117 llvm::Type *newRetTy = newFn->getReturnType();
2118 SmallVector<llvm::Value*, 4> newArgs;
2120 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
2122 llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
2123 llvm::User *user = use->getUser();
2125 // Recognize and replace uses of bitcasts. Most calls to
2126 // unprototyped functions will use bitcasts.
2127 if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
2128 if (bitcast->getOpcode() == llvm::Instruction::BitCast)
2129 replaceUsesOfNonProtoConstant(bitcast, newFn);
2133 // Recognize calls to the function.
2134 llvm::CallSite callSite(user);
2135 if (!callSite) continue;
2136 if (!callSite.isCallee(&*use)) continue;
2138 // If the return types don't match exactly, then we can't
2139 // transform this call unless it's dead.
2140 if (callSite->getType() != newRetTy && !callSite->use_empty())
2143 // Get the call site's attribute list.
2144 SmallVector<llvm::AttributeSet, 8> newAttrs;
2145 llvm::AttributeSet oldAttrs = callSite.getAttributes();
2147 // Collect any return attributes from the call.
2148 if (oldAttrs.hasAttributes(llvm::AttributeSet::ReturnIndex))
2150 llvm::AttributeSet::get(newFn->getContext(),
2151 oldAttrs.getRetAttributes()));
2153 // If the function was passed too few arguments, don't transform.
2154 unsigned newNumArgs = newFn->arg_size();
2155 if (callSite.arg_size() < newNumArgs) continue;
2157 // If extra arguments were passed, we silently drop them.
2158 // If any of the types mismatch, we don't transform.
2160 bool dontTransform = false;
2161 for (llvm::Function::arg_iterator ai = newFn->arg_begin(),
2162 ae = newFn->arg_end(); ai != ae; ++ai, ++argNo) {
2163 if (callSite.getArgument(argNo)->getType() != ai->getType()) {
2164 dontTransform = true;
2168 // Add any parameter attributes.
2169 if (oldAttrs.hasAttributes(argNo + 1))
2172 AttributeSet::get(newFn->getContext(),
2173 oldAttrs.getParamAttributes(argNo + 1)));
2178 if (oldAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex))
2179 newAttrs.push_back(llvm::AttributeSet::get(newFn->getContext(),
2180 oldAttrs.getFnAttributes()));
2182 // Okay, we can transform this. Create the new call instruction and copy
2183 // over the required information.
2184 newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo);
2186 llvm::CallSite newCall;
2187 if (callSite.isCall()) {
2188 newCall = llvm::CallInst::Create(newFn, newArgs, "",
2189 callSite.getInstruction());
2191 auto *oldInvoke = cast<llvm::InvokeInst>(callSite.getInstruction());
2192 newCall = llvm::InvokeInst::Create(newFn,
2193 oldInvoke->getNormalDest(),
2194 oldInvoke->getUnwindDest(),
2196 callSite.getInstruction());
2198 newArgs.clear(); // for the next iteration
2200 if (!newCall->getType()->isVoidTy())
2201 newCall->takeName(callSite.getInstruction());
2202 newCall.setAttributes(
2203 llvm::AttributeSet::get(newFn->getContext(), newAttrs));
2204 newCall.setCallingConv(callSite.getCallingConv());
2206 // Finally, remove the old call, replacing any uses with the new one.
2207 if (!callSite->use_empty())
2208 callSite->replaceAllUsesWith(newCall.getInstruction());
2210 // Copy debug location attached to CI.
2211 if (!callSite->getDebugLoc().isUnknown())
2212 newCall->setDebugLoc(callSite->getDebugLoc());
2213 callSite->eraseFromParent();
2217 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
2218 /// implement a function with no prototype, e.g. "int foo() {}". If there are
2219 /// existing call uses of the old function in the module, this adjusts them to
2220 /// call the new function directly.
2222 /// This is not just a cleanup: the always_inline pass requires direct calls to
2223 /// functions to be able to inline them. If there is a bitcast in the way, it
2224 /// won't inline them. Instcombine normally deletes these calls, but it isn't
2226 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
2227 llvm::Function *NewFn) {
2228 // If we're redefining a global as a function, don't transform it.
2229 if (!isa<llvm::Function>(Old)) return;
2231 replaceUsesOfNonProtoConstant(Old, NewFn);
2234 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
2235 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
2236 // If we have a definition, this might be a deferred decl. If the
2237 // instantiation is explicit, make sure we emit it at the end.
2238 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
2239 GetAddrOfGlobalVar(VD);
2241 EmitTopLevelDecl(VD);
2244 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
2245 llvm::GlobalValue *GV) {
2246 const auto *D = cast<FunctionDecl>(GD.getDecl());
2248 // Compute the function info and LLVM type.
2249 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
2250 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
2252 // Get or create the prototype for the function.
2255 GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer*/ true);
2257 // Strip off a bitcast if we got one back.
2258 if (auto *CE = dyn_cast<llvm::ConstantExpr>(C)) {
2259 assert(CE->getOpcode() == llvm::Instruction::BitCast);
2260 GV = cast<llvm::GlobalValue>(CE->getOperand(0));
2262 GV = cast<llvm::GlobalValue>(C);
2266 if (!GV->isDeclaration()) {
2267 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name);
2271 if (GV->getType()->getElementType() != Ty) {
2272 // If the types mismatch then we have to rewrite the definition.
2273 assert(GV->isDeclaration() && "Shouldn't replace non-declaration");
2275 // F is the Function* for the one with the wrong type, we must make a new
2276 // Function* and update everything that used F (a declaration) with the new
2277 // Function* (which will be a definition).
2279 // This happens if there is a prototype for a function
2280 // (e.g. "int f()") and then a definition of a different type
2281 // (e.g. "int f(int x)"). Move the old function aside so that it
2282 // doesn't interfere with GetAddrOfFunction.
2283 GV->setName(StringRef());
2284 auto *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty));
2286 // This might be an implementation of a function without a
2287 // prototype, in which case, try to do special replacement of
2288 // calls which match the new prototype. The really key thing here
2289 // is that we also potentially drop arguments from the call site
2290 // so as to make a direct call, which makes the inliner happier
2291 // and suppresses a number of optimizer warnings (!) about
2292 // dropping arguments.
2293 if (!GV->use_empty()) {
2294 ReplaceUsesOfNonProtoTypeWithRealFunction(GV, NewFn);
2295 GV->removeDeadConstantUsers();
2298 // Replace uses of F with the Function we will endow with a body.
2299 if (!GV->use_empty()) {
2300 llvm::Constant *NewPtrForOldDecl =
2301 llvm::ConstantExpr::getBitCast(NewFn, GV->getType());
2302 GV->replaceAllUsesWith(NewPtrForOldDecl);
2305 // Ok, delete the old function now, which is dead.
2306 GV->eraseFromParent();
2311 // We need to set linkage and visibility on the function before
2312 // generating code for it because various parts of IR generation
2313 // want to propagate this information down (e.g. to local static
2315 auto *Fn = cast<llvm::Function>(GV);
2316 setFunctionLinkage(GD, Fn);
2318 // FIXME: this is redundant with part of setFunctionDefinitionAttributes
2319 setGlobalVisibility(Fn, D);
2321 MaybeHandleStaticInExternC(D, Fn);
2323 CodeGenFunction(*this).GenerateCode(D, Fn, FI);
2325 setFunctionDefinitionAttributes(D, Fn);
2326 SetLLVMFunctionAttributesForDefinition(D, Fn);
2328 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
2329 AddGlobalCtor(Fn, CA->getPriority());
2330 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
2331 AddGlobalDtor(Fn, DA->getPriority());
2332 if (D->hasAttr<AnnotateAttr>())
2333 AddGlobalAnnotations(D, Fn);
2336 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
2337 const auto *D = cast<ValueDecl>(GD.getDecl());
2338 const AliasAttr *AA = D->getAttr<AliasAttr>();
2339 assert(AA && "Not an alias?");
2341 StringRef MangledName = getMangledName(GD);
2343 // If there is a definition in the module, then it wins over the alias.
2344 // This is dubious, but allow it to be safe. Just ignore the alias.
2345 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
2346 if (Entry && !Entry->isDeclaration())
2349 Aliases.push_back(GD);
2351 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
2353 // Create a reference to the named value. This ensures that it is emitted
2354 // if a deferred decl.
2355 llvm::Constant *Aliasee;
2356 if (isa<llvm::FunctionType>(DeclTy))
2357 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
2358 /*ForVTable=*/false);
2360 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
2361 llvm::PointerType::getUnqual(DeclTy),
2364 // Create the new alias itself, but don't set a name yet.
2365 auto *GA = llvm::GlobalAlias::create(
2366 cast<llvm::PointerType>(Aliasee->getType())->getElementType(), 0,
2367 llvm::Function::ExternalLinkage, "", Aliasee, &getModule());
2370 if (GA->getAliasee() == Entry) {
2371 Diags.Report(AA->getLocation(), diag::err_cyclic_alias);
2375 assert(Entry->isDeclaration());
2377 // If there is a declaration in the module, then we had an extern followed
2378 // by the alias, as in:
2379 // extern int test6();
2381 // int test6() __attribute__((alias("test7")));
2383 // Remove it and replace uses of it with the alias.
2384 GA->takeName(Entry);
2386 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
2388 Entry->eraseFromParent();
2390 GA->setName(MangledName);
2393 // Set attributes which are particular to an alias; this is a
2394 // specialization of the attributes which may be set on a global
2395 // variable/function.
2396 if (D->hasAttr<DLLExportAttr>()) {
2397 if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
2398 // The dllexport attribute is ignored for undefined symbols.
2400 GA->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2402 GA->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2404 } else if (D->hasAttr<WeakAttr>() ||
2405 D->hasAttr<WeakRefAttr>() ||
2406 D->isWeakImported()) {
2407 GA->setLinkage(llvm::Function::WeakAnyLinkage);
2410 SetCommonAttributes(D, GA);
2413 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
2414 ArrayRef<llvm::Type*> Tys) {
2415 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
2419 static llvm::StringMapEntry<llvm::Constant*> &
2420 GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map,
2421 const StringLiteral *Literal,
2424 unsigned &StringLength) {
2425 StringRef String = Literal->getString();
2426 unsigned NumBytes = String.size();
2428 // Check for simple case.
2429 if (!Literal->containsNonAsciiOrNull()) {
2430 StringLength = NumBytes;
2431 return Map.GetOrCreateValue(String);
2434 // Otherwise, convert the UTF8 literals into a string of shorts.
2437 SmallVector<UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
2438 const UTF8 *FromPtr = (const UTF8 *)String.data();
2439 UTF16 *ToPtr = &ToBuf[0];
2441 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes,
2442 &ToPtr, ToPtr + NumBytes,
2445 // ConvertUTF8toUTF16 returns the length in ToPtr.
2446 StringLength = ToPtr - &ToBuf[0];
2448 // Add an explicit null.
2451 GetOrCreateValue(StringRef(reinterpret_cast<const char *>(ToBuf.data()),
2452 (StringLength + 1) * 2));
2455 static llvm::StringMapEntry<llvm::Constant*> &
2456 GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map,
2457 const StringLiteral *Literal,
2458 unsigned &StringLength) {
2459 StringRef String = Literal->getString();
2460 StringLength = String.size();
2461 return Map.GetOrCreateValue(String);
2465 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
2466 unsigned StringLength = 0;
2467 bool isUTF16 = false;
2468 llvm::StringMapEntry<llvm::Constant*> &Entry =
2469 GetConstantCFStringEntry(CFConstantStringMap, Literal,
2470 getDataLayout().isLittleEndian(),
2471 isUTF16, StringLength);
2473 if (llvm::Constant *C = Entry.getValue())
2476 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
2477 llvm::Constant *Zeros[] = { Zero, Zero };
2480 // If we don't already have it, get __CFConstantStringClassReference.
2481 if (!CFConstantStringClassRef) {
2482 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
2483 Ty = llvm::ArrayType::get(Ty, 0);
2484 llvm::Constant *GV = CreateRuntimeVariable(Ty,
2485 "__CFConstantStringClassReference");
2486 // Decay array -> ptr
2487 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
2488 CFConstantStringClassRef = V;
2491 V = CFConstantStringClassRef;
2493 QualType CFTy = getContext().getCFConstantStringType();
2495 auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
2497 llvm::Constant *Fields[4];
2500 Fields[0] = cast<llvm::ConstantExpr>(V);
2503 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy);
2504 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) :
2505 llvm::ConstantInt::get(Ty, 0x07C8);
2508 llvm::Constant *C = nullptr;
2510 ArrayRef<uint16_t> Arr =
2511 llvm::makeArrayRef<uint16_t>(reinterpret_cast<uint16_t*>(
2512 const_cast<char *>(Entry.getKey().data())),
2513 Entry.getKey().size() / 2);
2514 C = llvm::ConstantDataArray::get(VMContext, Arr);
2516 C = llvm::ConstantDataArray::getString(VMContext, Entry.getKey());
2519 // Note: -fwritable-strings doesn't make the backing store strings of
2520 // CFStrings writable. (See <rdar://problem/10657500>)
2522 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
2523 llvm::GlobalValue::PrivateLinkage, C, ".str");
2524 GV->setUnnamedAddr(true);
2525 // Don't enforce the target's minimum global alignment, since the only use
2526 // of the string is via this class initializer.
2527 // FIXME: We set the section explicitly to avoid a bug in ld64 224.1. Without
2528 // it LLVM can merge the string with a non unnamed_addr one during LTO. Doing
2529 // that changes the section it ends in, which surprises ld64.
2531 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy);
2532 GV->setAlignment(Align.getQuantity());
2533 GV->setSection("__TEXT,__ustring");
2535 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy);
2536 GV->setAlignment(Align.getQuantity());
2537 GV->setSection("__TEXT,__cstring,cstring_literals");
2541 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
2544 // Cast the UTF16 string to the correct type.
2545 Fields[2] = llvm::ConstantExpr::getBitCast(Fields[2], Int8PtrTy);
2548 Ty = getTypes().ConvertType(getContext().LongTy);
2549 Fields[3] = llvm::ConstantInt::get(Ty, StringLength);
2552 C = llvm::ConstantStruct::get(STy, Fields);
2553 GV = new llvm::GlobalVariable(getModule(), C->getType(), true,
2554 llvm::GlobalVariable::PrivateLinkage, C,
2555 "_unnamed_cfstring_");
2556 GV->setSection("__DATA,__cfstring");
2563 CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) {
2564 unsigned StringLength = 0;
2565 llvm::StringMapEntry<llvm::Constant*> &Entry =
2566 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength);
2568 if (llvm::Constant *C = Entry.getValue())
2571 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
2572 llvm::Constant *Zeros[] = { Zero, Zero };
2574 // If we don't already have it, get _NSConstantStringClassReference.
2575 if (!ConstantStringClassRef) {
2576 std::string StringClass(getLangOpts().ObjCConstantStringClass);
2577 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
2579 if (LangOpts.ObjCRuntime.isNonFragile()) {
2581 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString"
2582 : "OBJC_CLASS_$_" + StringClass;
2583 GV = getObjCRuntime().GetClassGlobal(str);
2584 // Make sure the result is of the correct type.
2585 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
2586 V = llvm::ConstantExpr::getBitCast(GV, PTy);
2587 ConstantStringClassRef = V;
2590 StringClass.empty() ? "_NSConstantStringClassReference"
2591 : "_" + StringClass + "ClassReference";
2592 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0);
2593 GV = CreateRuntimeVariable(PTy, str);
2594 // Decay array -> ptr
2595 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
2596 ConstantStringClassRef = V;
2600 V = ConstantStringClassRef;
2602 if (!NSConstantStringType) {
2603 // Construct the type for a constant NSString.
2604 RecordDecl *D = Context.buildImplicitRecord("__builtin_NSString");
2605 D->startDefinition();
2607 QualType FieldTypes[3];
2610 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst());
2612 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst());
2613 // unsigned int length;
2614 FieldTypes[2] = Context.UnsignedIntTy;
2617 for (unsigned i = 0; i < 3; ++i) {
2618 FieldDecl *Field = FieldDecl::Create(Context, D,
2620 SourceLocation(), nullptr,
2621 FieldTypes[i], /*TInfo=*/nullptr,
2622 /*BitWidth=*/nullptr,
2625 Field->setAccess(AS_public);
2629 D->completeDefinition();
2630 QualType NSTy = Context.getTagDeclType(D);
2631 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy));
2634 llvm::Constant *Fields[3];
2637 Fields[0] = cast<llvm::ConstantExpr>(V);
2641 llvm::ConstantDataArray::getString(VMContext, Entry.getKey());
2643 llvm::GlobalValue::LinkageTypes Linkage;
2645 Linkage = llvm::GlobalValue::PrivateLinkage;
2646 isConstant = !LangOpts.WritableStrings;
2648 auto *GV = new llvm::GlobalVariable(getModule(), C->getType(), isConstant,
2649 Linkage, C, ".str");
2650 GV->setUnnamedAddr(true);
2651 // Don't enforce the target's minimum global alignment, since the only use
2652 // of the string is via this class initializer.
2653 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy);
2654 GV->setAlignment(Align.getQuantity());
2655 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
2658 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy);
2659 Fields[2] = llvm::ConstantInt::get(Ty, StringLength);
2662 C = llvm::ConstantStruct::get(NSConstantStringType, Fields);
2663 GV = new llvm::GlobalVariable(getModule(), C->getType(), true,
2664 llvm::GlobalVariable::PrivateLinkage, C,
2665 "_unnamed_nsstring_");
2666 const char *NSStringSection = "__OBJC,__cstring_object,regular,no_dead_strip";
2667 const char *NSStringNonFragileABISection =
2668 "__DATA,__objc_stringobj,regular,no_dead_strip";
2669 // FIXME. Fix section.
2670 GV->setSection(LangOpts.ObjCRuntime.isNonFragile()
2671 ? NSStringNonFragileABISection
2678 QualType CodeGenModule::getObjCFastEnumerationStateType() {
2679 if (ObjCFastEnumerationStateType.isNull()) {
2680 RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
2681 D->startDefinition();
2683 QualType FieldTypes[] = {
2684 Context.UnsignedLongTy,
2685 Context.getPointerType(Context.getObjCIdType()),
2686 Context.getPointerType(Context.UnsignedLongTy),
2687 Context.getConstantArrayType(Context.UnsignedLongTy,
2688 llvm::APInt(32, 5), ArrayType::Normal, 0)
2691 for (size_t i = 0; i < 4; ++i) {
2692 FieldDecl *Field = FieldDecl::Create(Context,
2695 SourceLocation(), nullptr,
2696 FieldTypes[i], /*TInfo=*/nullptr,
2697 /*BitWidth=*/nullptr,
2700 Field->setAccess(AS_public);
2704 D->completeDefinition();
2705 ObjCFastEnumerationStateType = Context.getTagDeclType(D);
2708 return ObjCFastEnumerationStateType;
2712 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
2713 assert(!E->getType()->isPointerType() && "Strings are always arrays");
2715 // Don't emit it as the address of the string, emit the string data itself
2716 // as an inline array.
2717 if (E->getCharByteWidth() == 1) {
2718 SmallString<64> Str(E->getString());
2720 // Resize the string to the right size, which is indicated by its type.
2721 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
2722 Str.resize(CAT->getSize().getZExtValue());
2723 return llvm::ConstantDataArray::getString(VMContext, Str, false);
2726 auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
2727 llvm::Type *ElemTy = AType->getElementType();
2728 unsigned NumElements = AType->getNumElements();
2730 // Wide strings have either 2-byte or 4-byte elements.
2731 if (ElemTy->getPrimitiveSizeInBits() == 16) {
2732 SmallVector<uint16_t, 32> Elements;
2733 Elements.reserve(NumElements);
2735 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
2736 Elements.push_back(E->getCodeUnit(i));
2737 Elements.resize(NumElements);
2738 return llvm::ConstantDataArray::get(VMContext, Elements);
2741 assert(ElemTy->getPrimitiveSizeInBits() == 32);
2742 SmallVector<uint32_t, 32> Elements;
2743 Elements.reserve(NumElements);
2745 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
2746 Elements.push_back(E->getCodeUnit(i));
2747 Elements.resize(NumElements);
2748 return llvm::ConstantDataArray::get(VMContext, Elements);
2751 static llvm::GlobalVariable *
2752 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
2753 CodeGenModule &CGM, StringRef GlobalName,
2754 unsigned Alignment) {
2755 // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
2756 unsigned AddrSpace = 0;
2757 if (CGM.getLangOpts().OpenCL)
2758 AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_constant);
2760 // Create a global variable for this string
2761 auto *GV = new llvm::GlobalVariable(
2762 CGM.getModule(), C->getType(), !CGM.getLangOpts().WritableStrings, LT, C,
2763 GlobalName, nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
2764 GV->setAlignment(Alignment);
2765 GV->setUnnamedAddr(true);
2769 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
2770 /// constant array for the given string literal.
2771 llvm::GlobalVariable *
2772 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) {
2774 getContext().getAlignOfGlobalVarInChars(S->getType()).getQuantity();
2776 llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
2777 llvm::GlobalVariable **Entry = nullptr;
2778 if (!LangOpts.WritableStrings) {
2779 Entry = &ConstantStringMap[C];
2780 if (auto GV = *Entry) {
2781 if (Alignment > GV->getAlignment())
2782 GV->setAlignment(Alignment);
2787 SmallString<256> MangledNameBuffer;
2788 StringRef GlobalVariableName;
2789 llvm::GlobalValue::LinkageTypes LT;
2791 // Mangle the string literal if the ABI allows for it. However, we cannot
2792 // do this if we are compiling with ASan or -fwritable-strings because they
2793 // rely on strings having normal linkage.
2794 if (!LangOpts.WritableStrings && !LangOpts.Sanitize.Address &&
2795 getCXXABI().getMangleContext().shouldMangleStringLiteral(S)) {
2796 llvm::raw_svector_ostream Out(MangledNameBuffer);
2797 getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
2800 LT = llvm::GlobalValue::LinkOnceODRLinkage;
2801 GlobalVariableName = MangledNameBuffer;
2803 LT = llvm::GlobalValue::PrivateLinkage;
2804 GlobalVariableName = ".str";
2807 auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
2811 reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>");
2815 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
2816 /// array for the given ObjCEncodeExpr node.
2817 llvm::GlobalVariable *
2818 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
2820 getContext().getObjCEncodingForType(E->getEncodedType(), Str);
2822 return GetAddrOfConstantCString(Str);
2825 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
2826 /// the literal and a terminating '\0' character.
2827 /// The result has pointer to array type.
2828 llvm::GlobalVariable *CodeGenModule::GetAddrOfConstantCString(
2829 const std::string &Str, const char *GlobalName, unsigned Alignment) {
2830 StringRef StrWithNull(Str.c_str(), Str.size() + 1);
2831 if (Alignment == 0) {
2832 Alignment = getContext()
2833 .getAlignOfGlobalVarInChars(getContext().CharTy)
2838 llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
2840 // Don't share any string literals if strings aren't constant.
2841 llvm::GlobalVariable **Entry = nullptr;
2842 if (!LangOpts.WritableStrings) {
2843 Entry = &ConstantStringMap[C];
2844 if (auto GV = *Entry) {
2845 if (Alignment > GV->getAlignment())
2846 GV->setAlignment(Alignment);
2851 // Get the default prefix if a name wasn't specified.
2853 GlobalName = ".str";
2854 // Create a global variable for this.
2855 auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
2856 GlobalName, Alignment);
2862 llvm::Constant *CodeGenModule::GetAddrOfGlobalTemporary(
2863 const MaterializeTemporaryExpr *E, const Expr *Init) {
2864 assert((E->getStorageDuration() == SD_Static ||
2865 E->getStorageDuration() == SD_Thread) && "not a global temporary");
2866 const auto *VD = cast<VarDecl>(E->getExtendingDecl());
2868 // If we're not materializing a subobject of the temporary, keep the
2869 // cv-qualifiers from the type of the MaterializeTemporaryExpr.
2870 QualType MaterializedType = Init->getType();
2871 if (Init == E->GetTemporaryExpr())
2872 MaterializedType = E->getType();
2874 llvm::Constant *&Slot = MaterializedGlobalTemporaryMap[E];
2878 // FIXME: If an externally-visible declaration extends multiple temporaries,
2879 // we need to give each temporary the same name in every translation unit (and
2880 // we also need to make the temporaries externally-visible).
2881 SmallString<256> Name;
2882 llvm::raw_svector_ostream Out(Name);
2883 getCXXABI().getMangleContext().mangleReferenceTemporary(
2884 VD, E->getManglingNumber(), Out);
2887 APValue *Value = nullptr;
2888 if (E->getStorageDuration() == SD_Static) {
2889 // We might have a cached constant initializer for this temporary. Note
2890 // that this might have a different value from the value computed by
2891 // evaluating the initializer if the surrounding constant expression
2892 // modifies the temporary.
2893 Value = getContext().getMaterializedTemporaryValue(E, false);
2894 if (Value && Value->isUninit())
2898 // Try evaluating it now, it might have a constant initializer.
2899 Expr::EvalResult EvalResult;
2900 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
2901 !EvalResult.hasSideEffects())
2902 Value = &EvalResult.Val;
2904 llvm::Constant *InitialValue = nullptr;
2905 bool Constant = false;
2908 // The temporary has a constant initializer, use it.
2909 InitialValue = EmitConstantValue(*Value, MaterializedType, nullptr);
2910 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value);
2911 Type = InitialValue->getType();
2913 // No initializer, the initialization will be provided when we
2914 // initialize the declaration which performed lifetime extension.
2915 Type = getTypes().ConvertTypeForMem(MaterializedType);
2918 // Create a global variable for this lifetime-extended temporary.
2919 llvm::GlobalValue::LinkageTypes Linkage =
2920 getLLVMLinkageVarDefinition(VD, Constant);
2921 // There is no need for this temporary to have global linkage if the global
2922 // variable has external linkage.
2923 if (Linkage == llvm::GlobalVariable::ExternalLinkage)
2924 Linkage = llvm::GlobalVariable::PrivateLinkage;
2925 unsigned AddrSpace = GetGlobalVarAddressSpace(
2926 VD, getContext().getTargetAddressSpace(MaterializedType));
2927 auto *GV = new llvm::GlobalVariable(
2928 getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
2929 /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal,
2931 setGlobalVisibility(GV, VD);
2933 getContext().getTypeAlignInChars(MaterializedType).getQuantity());
2934 if (VD->getTLSKind())
2935 setTLSMode(GV, *VD);
2940 /// EmitObjCPropertyImplementations - Emit information for synthesized
2941 /// properties for an implementation.
2942 void CodeGenModule::EmitObjCPropertyImplementations(const
2943 ObjCImplementationDecl *D) {
2944 for (const auto *PID : D->property_impls()) {
2945 // Dynamic is just for type-checking.
2946 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
2947 ObjCPropertyDecl *PD = PID->getPropertyDecl();
2949 // Determine which methods need to be implemented, some may have
2950 // been overridden. Note that ::isPropertyAccessor is not the method
2951 // we want, that just indicates if the decl came from a
2952 // property. What we want to know is if the method is defined in
2953 // this implementation.
2954 if (!D->getInstanceMethod(PD->getGetterName()))
2955 CodeGenFunction(*this).GenerateObjCGetter(
2956 const_cast<ObjCImplementationDecl *>(D), PID);
2957 if (!PD->isReadOnly() &&
2958 !D->getInstanceMethod(PD->getSetterName()))
2959 CodeGenFunction(*this).GenerateObjCSetter(
2960 const_cast<ObjCImplementationDecl *>(D), PID);
2965 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
2966 const ObjCInterfaceDecl *iface = impl->getClassInterface();
2967 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
2968 ivar; ivar = ivar->getNextIvar())
2969 if (ivar->getType().isDestructedType())
2975 /// EmitObjCIvarInitializations - Emit information for ivar initialization
2976 /// for an implementation.
2977 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
2978 // We might need a .cxx_destruct even if we don't have any ivar initializers.
2979 if (needsDestructMethod(D)) {
2980 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
2981 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
2982 ObjCMethodDecl *DTORMethod =
2983 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(),
2984 cxxSelector, getContext().VoidTy, nullptr, D,
2985 /*isInstance=*/true, /*isVariadic=*/false,
2986 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true,
2987 /*isDefined=*/false, ObjCMethodDecl::Required);
2988 D->addInstanceMethod(DTORMethod);
2989 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
2990 D->setHasDestructors(true);
2993 // If the implementation doesn't have any ivar initializers, we don't need
2994 // a .cxx_construct.
2995 if (D->getNumIvarInitializers() == 0)
2998 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
2999 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
3000 // The constructor returns 'self'.
3001 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(),
3005 getContext().getObjCIdType(),
3006 nullptr, D, /*isInstance=*/true,
3007 /*isVariadic=*/false,
3008 /*isPropertyAccessor=*/true,
3009 /*isImplicitlyDeclared=*/true,
3010 /*isDefined=*/false,
3011 ObjCMethodDecl::Required);
3012 D->addInstanceMethod(CTORMethod);
3013 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
3014 D->setHasNonZeroConstructors(true);
3017 /// EmitNamespace - Emit all declarations in a namespace.
3018 void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) {
3019 for (auto *I : ND->decls()) {
3020 if (const auto *VD = dyn_cast<VarDecl>(I))
3021 if (VD->getTemplateSpecializationKind() != TSK_ExplicitSpecialization &&
3022 VD->getTemplateSpecializationKind() != TSK_Undeclared)
3024 EmitTopLevelDecl(I);
3028 // EmitLinkageSpec - Emit all declarations in a linkage spec.
3029 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
3030 if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
3031 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
3032 ErrorUnsupported(LSD, "linkage spec");
3036 for (auto *I : LSD->decls()) {
3037 // Meta-data for ObjC class includes references to implemented methods.
3038 // Generate class's method definitions first.
3039 if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
3040 for (auto *M : OID->methods())
3041 EmitTopLevelDecl(M);
3043 EmitTopLevelDecl(I);
3047 /// EmitTopLevelDecl - Emit code for a single top level declaration.
3048 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
3049 // Ignore dependent declarations.
3050 if (D->getDeclContext() && D->getDeclContext()->isDependentContext())
3053 switch (D->getKind()) {
3054 case Decl::CXXConversion:
3055 case Decl::CXXMethod:
3056 case Decl::Function:
3057 // Skip function templates
3058 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
3059 cast<FunctionDecl>(D)->isLateTemplateParsed())
3062 EmitGlobal(cast<FunctionDecl>(D));
3066 // Skip variable templates
3067 if (cast<VarDecl>(D)->getDescribedVarTemplate())
3069 case Decl::VarTemplateSpecialization:
3070 EmitGlobal(cast<VarDecl>(D));
3073 // Indirect fields from global anonymous structs and unions can be
3074 // ignored; only the actual variable requires IR gen support.
3075 case Decl::IndirectField:
3079 case Decl::Namespace:
3080 EmitNamespace(cast<NamespaceDecl>(D));
3082 // No code generation needed.
3083 case Decl::UsingShadow:
3084 case Decl::ClassTemplate:
3085 case Decl::VarTemplate:
3086 case Decl::VarTemplatePartialSpecialization:
3087 case Decl::FunctionTemplate:
3088 case Decl::TypeAliasTemplate:
3092 case Decl::Using: // using X; [C++]
3093 if (CGDebugInfo *DI = getModuleDebugInfo())
3094 DI->EmitUsingDecl(cast<UsingDecl>(*D));
3096 case Decl::NamespaceAlias:
3097 if (CGDebugInfo *DI = getModuleDebugInfo())
3098 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
3100 case Decl::UsingDirective: // using namespace X; [C++]
3101 if (CGDebugInfo *DI = getModuleDebugInfo())
3102 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
3104 case Decl::CXXConstructor:
3105 // Skip function templates
3106 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
3107 cast<FunctionDecl>(D)->isLateTemplateParsed())
3110 getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
3112 case Decl::CXXDestructor:
3113 if (cast<FunctionDecl>(D)->isLateTemplateParsed())
3115 getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
3118 case Decl::StaticAssert:
3122 // Objective-C Decls
3124 // Forward declarations, no (immediate) code generation.
3125 case Decl::ObjCInterface:
3126 case Decl::ObjCCategory:
3129 case Decl::ObjCProtocol: {
3130 auto *Proto = cast<ObjCProtocolDecl>(D);
3131 if (Proto->isThisDeclarationADefinition())
3132 ObjCRuntime->GenerateProtocol(Proto);
3136 case Decl::ObjCCategoryImpl:
3137 // Categories have properties but don't support synthesize so we
3138 // can ignore them here.
3139 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
3142 case Decl::ObjCImplementation: {
3143 auto *OMD = cast<ObjCImplementationDecl>(D);
3144 EmitObjCPropertyImplementations(OMD);
3145 EmitObjCIvarInitializations(OMD);
3146 ObjCRuntime->GenerateClass(OMD);
3147 // Emit global variable debug information.
3148 if (CGDebugInfo *DI = getModuleDebugInfo())
3149 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo)
3150 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
3151 OMD->getClassInterface()), OMD->getLocation());
3154 case Decl::ObjCMethod: {
3155 auto *OMD = cast<ObjCMethodDecl>(D);
3156 // If this is not a prototype, emit the body.
3158 CodeGenFunction(*this).GenerateObjCMethod(OMD);
3161 case Decl::ObjCCompatibleAlias:
3162 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
3165 case Decl::LinkageSpec:
3166 EmitLinkageSpec(cast<LinkageSpecDecl>(D));
3169 case Decl::FileScopeAsm: {
3170 auto *AD = cast<FileScopeAsmDecl>(D);
3171 StringRef AsmString = AD->getAsmString()->getString();
3173 const std::string &S = getModule().getModuleInlineAsm();
3175 getModule().setModuleInlineAsm(AsmString);
3176 else if (S.end()[-1] == '\n')
3177 getModule().setModuleInlineAsm(S + AsmString.str());
3179 getModule().setModuleInlineAsm(S + '\n' + AsmString.str());
3183 case Decl::Import: {
3184 auto *Import = cast<ImportDecl>(D);
3186 // Ignore import declarations that come from imported modules.
3187 if (clang::Module *Owner = Import->getOwningModule()) {
3188 if (getLangOpts().CurrentModule.empty() ||
3189 Owner->getTopLevelModule()->Name == getLangOpts().CurrentModule)
3193 ImportedModules.insert(Import->getImportedModule());
3197 case Decl::ClassTemplateSpecialization: {
3198 const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
3200 Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition)
3201 DebugInfo->completeTemplateDefinition(*Spec);
3205 // Make sure we handled everything we should, every other kind is a
3206 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
3207 // function. Need to recode Decl::Kind to do that easily.
3208 assert(isa<TypeDecl>(D) && "Unsupported decl kind");
3212 /// Turns the given pointer into a constant.
3213 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
3215 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
3216 llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
3217 return llvm::ConstantInt::get(i64, PtrInt);
3220 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
3221 llvm::NamedMDNode *&GlobalMetadata,
3223 llvm::GlobalValue *Addr) {
3224 if (!GlobalMetadata)
3226 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
3228 // TODO: should we report variant information for ctors/dtors?
3229 llvm::Value *Ops[] = {
3231 GetPointerConstant(CGM.getLLVMContext(), D.getDecl())
3233 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
3236 /// For each function which is declared within an extern "C" region and marked
3237 /// as 'used', but has internal linkage, create an alias from the unmangled
3238 /// name to the mangled name if possible. People expect to be able to refer
3239 /// to such functions with an unmangled name from inline assembly within the
3240 /// same translation unit.
3241 void CodeGenModule::EmitStaticExternCAliases() {
3242 for (StaticExternCMap::iterator I = StaticExternCValues.begin(),
3243 E = StaticExternCValues.end();
3245 IdentifierInfo *Name = I->first;
3246 llvm::GlobalValue *Val = I->second;
3247 if (Val && !getModule().getNamedValue(Name->getName()))
3248 addUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
3252 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
3253 GlobalDecl &Result) const {
3254 auto Res = Manglings.find(MangledName);
3255 if (Res == Manglings.end())
3257 Result = Res->getValue();
3261 /// Emits metadata nodes associating all the global values in the
3262 /// current module with the Decls they came from. This is useful for
3263 /// projects using IR gen as a subroutine.
3265 /// Since there's currently no way to associate an MDNode directly
3266 /// with an llvm::GlobalValue, we create a global named metadata
3267 /// with the name 'clang.global.decl.ptrs'.
3268 void CodeGenModule::EmitDeclMetadata() {
3269 llvm::NamedMDNode *GlobalMetadata = nullptr;
3271 // StaticLocalDeclMap
3272 for (auto &I : MangledDeclNames) {
3273 llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
3274 EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
3278 /// Emits metadata nodes for all the local variables in the current
3280 void CodeGenFunction::EmitDeclMetadata() {
3281 if (LocalDeclMap.empty()) return;
3283 llvm::LLVMContext &Context = getLLVMContext();
3285 // Find the unique metadata ID for this name.
3286 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
3288 llvm::NamedMDNode *GlobalMetadata = nullptr;
3290 for (auto &I : LocalDeclMap) {
3291 const Decl *D = I.first;
3292 llvm::Value *Addr = I.second;
3293 if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
3294 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
3295 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr));
3296 } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
3297 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
3298 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
3303 void CodeGenModule::EmitVersionIdentMetadata() {
3304 llvm::NamedMDNode *IdentMetadata =
3305 TheModule.getOrInsertNamedMetadata("llvm.ident");
3306 std::string Version = getClangFullVersion();
3307 llvm::LLVMContext &Ctx = TheModule.getContext();
3309 llvm::Value *IdentNode[] = {
3310 llvm::MDString::get(Ctx, Version)
3312 IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
3315 void CodeGenModule::EmitTargetMetadata() {
3316 for (auto &I : MangledDeclNames) {
3317 const Decl *D = I.first.getDecl()->getMostRecentDecl();
3318 llvm::GlobalValue *GV = GetGlobalValue(I.second);
3319 getTargetCodeGenInfo().emitTargetMD(D, GV, *this);
3323 void CodeGenModule::EmitCoverageFile() {
3324 if (!getCodeGenOpts().CoverageFile.empty()) {
3325 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) {
3326 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
3327 llvm::LLVMContext &Ctx = TheModule.getContext();
3328 llvm::MDString *CoverageFile =
3329 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile);
3330 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
3331 llvm::MDNode *CU = CUNode->getOperand(i);
3332 llvm::Value *node[] = { CoverageFile, CU };
3333 llvm::MDNode *N = llvm::MDNode::get(Ctx, node);
3334 GCov->addOperand(N);
3340 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid,
3341 QualType GuidType) {
3342 // Sema has checked that all uuid strings are of the form
3343 // "12345678-1234-1234-1234-1234567890ab".
3344 assert(Uuid.size() == 36);
3345 for (unsigned i = 0; i < 36; ++i) {
3346 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-');
3347 else assert(isHexDigit(Uuid[i]));
3350 const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 };
3352 llvm::Constant *Field3[8];
3353 for (unsigned Idx = 0; Idx < 8; ++Idx)
3354 Field3[Idx] = llvm::ConstantInt::get(
3355 Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16);
3357 llvm::Constant *Fields[4] = {
3358 llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16),
3359 llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16),
3360 llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16),
3361 llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3)
3364 return llvm::ConstantStruct::getAnon(Fields);
3367 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
3369 // Return a bogus pointer if RTTI is disabled, unless it's for EH.
3370 // FIXME: should we even be calling this method if RTTI is disabled
3371 // and it's not for EH?
3372 if (!ForEH && !getLangOpts().RTTI)
3373 return llvm::Constant::getNullValue(Int8PtrTy);
3375 if (ForEH && Ty->isObjCObjectPointerType() &&
3376 LangOpts.ObjCRuntime.isGNUFamily())
3377 return ObjCRuntime->GetEHType(Ty);
3379 return getCXXABI().getAddrOfRTTIDescriptor(Ty);