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"
16 #include "CGCUDARuntime.h"
19 #include "CGDebugInfo.h"
20 #include "CGObjCRuntime.h"
21 #include "CGOpenCLRuntime.h"
22 #include "CGOpenMPRuntime.h"
23 #include "CGOpenMPRuntimeNVPTX.h"
24 #include "CodeGenFunction.h"
25 #include "CodeGenPGO.h"
26 #include "ConstantEmitter.h"
27 #include "CoverageMappingGen.h"
28 #include "TargetInfo.h"
29 #include "clang/AST/ASTContext.h"
30 #include "clang/AST/CharUnits.h"
31 #include "clang/AST/DeclCXX.h"
32 #include "clang/AST/DeclObjC.h"
33 #include "clang/AST/DeclTemplate.h"
34 #include "clang/AST/Mangle.h"
35 #include "clang/AST/RecordLayout.h"
36 #include "clang/AST/RecursiveASTVisitor.h"
37 #include "clang/Basic/Builtins.h"
38 #include "clang/Basic/CharInfo.h"
39 #include "clang/Basic/Diagnostic.h"
40 #include "clang/Basic/Module.h"
41 #include "clang/Basic/SourceManager.h"
42 #include "clang/Basic/TargetInfo.h"
43 #include "clang/Basic/Version.h"
44 #include "clang/CodeGen/ConstantInitBuilder.h"
45 #include "clang/Frontend/CodeGenOptions.h"
46 #include "clang/Sema/SemaDiagnostic.h"
47 #include "llvm/ADT/Triple.h"
48 #include "llvm/Analysis/TargetLibraryInfo.h"
49 #include "llvm/IR/CallSite.h"
50 #include "llvm/IR/CallingConv.h"
51 #include "llvm/IR/DataLayout.h"
52 #include "llvm/IR/Intrinsics.h"
53 #include "llvm/IR/LLVMContext.h"
54 #include "llvm/IR/Module.h"
55 #include "llvm/ProfileData/InstrProfReader.h"
56 #include "llvm/Support/ConvertUTF.h"
57 #include "llvm/Support/ErrorHandling.h"
58 #include "llvm/Support/MD5.h"
60 using namespace clang;
61 using namespace CodeGen;
63 static llvm::cl::opt<bool> LimitedCoverage(
64 "limited-coverage-experimental", llvm::cl::ZeroOrMore, llvm::cl::Hidden,
65 llvm::cl::desc("Emit limited coverage mapping information (experimental)"),
66 llvm::cl::init(false));
68 static const char AnnotationSection[] = "llvm.metadata";
70 static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
71 switch (CGM.getTarget().getCXXABI().getKind()) {
72 case TargetCXXABI::GenericAArch64:
73 case TargetCXXABI::GenericARM:
74 case TargetCXXABI::iOS:
75 case TargetCXXABI::iOS64:
76 case TargetCXXABI::WatchOS:
77 case TargetCXXABI::GenericMIPS:
78 case TargetCXXABI::GenericItanium:
79 case TargetCXXABI::WebAssembly:
80 return CreateItaniumCXXABI(CGM);
81 case TargetCXXABI::Microsoft:
82 return CreateMicrosoftCXXABI(CGM);
85 llvm_unreachable("invalid C++ ABI kind");
88 CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
89 const PreprocessorOptions &PPO,
90 const CodeGenOptions &CGO, llvm::Module &M,
91 DiagnosticsEngine &diags,
92 CoverageSourceInfo *CoverageInfo)
93 : Context(C), LangOpts(C.getLangOpts()), HeaderSearchOpts(HSO),
94 PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
95 Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
96 VMContext(M.getContext()), Types(*this), VTables(*this),
97 SanitizerMD(new SanitizerMetadata(*this)) {
99 // Initialize the type cache.
100 llvm::LLVMContext &LLVMContext = M.getContext();
101 VoidTy = llvm::Type::getVoidTy(LLVMContext);
102 Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
103 Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
104 Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
105 Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
106 HalfTy = llvm::Type::getHalfTy(LLVMContext);
107 FloatTy = llvm::Type::getFloatTy(LLVMContext);
108 DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
109 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
110 PointerAlignInBytes =
111 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
113 C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
115 C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
116 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
117 IntPtrTy = llvm::IntegerType::get(LLVMContext,
118 C.getTargetInfo().getMaxPointerWidth());
119 Int8PtrTy = Int8Ty->getPointerTo(0);
120 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
121 AllocaInt8PtrTy = Int8Ty->getPointerTo(
122 M.getDataLayout().getAllocaAddrSpace());
123 ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
125 RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
126 BuiltinCC = getTargetCodeGenInfo().getABIInfo().getBuiltinCC();
131 createOpenCLRuntime();
133 createOpenMPRuntime();
137 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
138 if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
139 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
140 TBAA.reset(new CodeGenTBAA(Context, TheModule, CodeGenOpts, getLangOpts(),
141 getCXXABI().getMangleContext()));
143 // If debug info or coverage generation is enabled, create the CGDebugInfo
145 if (CodeGenOpts.getDebugInfo() != codegenoptions::NoDebugInfo ||
146 CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)
147 DebugInfo.reset(new CGDebugInfo(*this));
149 Block.GlobalUniqueCount = 0;
151 if (C.getLangOpts().ObjC1)
152 ObjCData.reset(new ObjCEntrypoints());
154 if (CodeGenOpts.hasProfileClangUse()) {
155 auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
156 CodeGenOpts.ProfileInstrumentUsePath);
157 if (auto E = ReaderOrErr.takeError()) {
158 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
159 "Could not read profile %0: %1");
160 llvm::handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EI) {
161 getDiags().Report(DiagID) << CodeGenOpts.ProfileInstrumentUsePath
165 PGOReader = std::move(ReaderOrErr.get());
168 // If coverage mapping generation is enabled, create the
169 // CoverageMappingModuleGen object.
170 if (CodeGenOpts.CoverageMapping)
171 CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
174 CodeGenModule::~CodeGenModule() {}
176 void CodeGenModule::createObjCRuntime() {
177 // This is just isGNUFamily(), but we want to force implementors of
178 // new ABIs to decide how best to do this.
179 switch (LangOpts.ObjCRuntime.getKind()) {
180 case ObjCRuntime::GNUstep:
181 case ObjCRuntime::GCC:
182 case ObjCRuntime::ObjFW:
183 ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
186 case ObjCRuntime::FragileMacOSX:
187 case ObjCRuntime::MacOSX:
188 case ObjCRuntime::iOS:
189 case ObjCRuntime::WatchOS:
190 ObjCRuntime.reset(CreateMacObjCRuntime(*this));
193 llvm_unreachable("bad runtime kind");
196 void CodeGenModule::createOpenCLRuntime() {
197 OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
200 void CodeGenModule::createOpenMPRuntime() {
201 // Select a specialized code generation class based on the target, if any.
202 // If it does not exist use the default implementation.
203 switch (getTriple().getArch()) {
204 case llvm::Triple::nvptx:
205 case llvm::Triple::nvptx64:
206 assert(getLangOpts().OpenMPIsDevice &&
207 "OpenMP NVPTX is only prepared to deal with device code.");
208 OpenMPRuntime.reset(new CGOpenMPRuntimeNVPTX(*this));
211 if (LangOpts.OpenMPSimd)
212 OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
214 OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
219 void CodeGenModule::createCUDARuntime() {
220 CUDARuntime.reset(CreateNVCUDARuntime(*this));
223 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
224 Replacements[Name] = C;
227 void CodeGenModule::applyReplacements() {
228 for (auto &I : Replacements) {
229 StringRef MangledName = I.first();
230 llvm::Constant *Replacement = I.second;
231 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
234 auto *OldF = cast<llvm::Function>(Entry);
235 auto *NewF = dyn_cast<llvm::Function>(Replacement);
237 if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
238 NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
240 auto *CE = cast<llvm::ConstantExpr>(Replacement);
241 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
242 CE->getOpcode() == llvm::Instruction::GetElementPtr);
243 NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
247 // Replace old with new, but keep the old order.
248 OldF->replaceAllUsesWith(Replacement);
250 NewF->removeFromParent();
251 OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
254 OldF->eraseFromParent();
258 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
259 GlobalValReplacements.push_back(std::make_pair(GV, C));
262 void CodeGenModule::applyGlobalValReplacements() {
263 for (auto &I : GlobalValReplacements) {
264 llvm::GlobalValue *GV = I.first;
265 llvm::Constant *C = I.second;
267 GV->replaceAllUsesWith(C);
268 GV->eraseFromParent();
272 // This is only used in aliases that we created and we know they have a
274 static const llvm::GlobalObject *getAliasedGlobal(
275 const llvm::GlobalIndirectSymbol &GIS) {
276 llvm::SmallPtrSet<const llvm::GlobalIndirectSymbol*, 4> Visited;
277 const llvm::Constant *C = &GIS;
279 C = C->stripPointerCasts();
280 if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
282 // stripPointerCasts will not walk over weak aliases.
283 auto *GIS2 = dyn_cast<llvm::GlobalIndirectSymbol>(C);
286 if (!Visited.insert(GIS2).second)
288 C = GIS2->getIndirectSymbol();
292 void CodeGenModule::checkAliases() {
293 // Check if the constructed aliases are well formed. It is really unfortunate
294 // that we have to do this in CodeGen, but we only construct mangled names
295 // and aliases during codegen.
297 DiagnosticsEngine &Diags = getDiags();
298 for (const GlobalDecl &GD : Aliases) {
299 const auto *D = cast<ValueDecl>(GD.getDecl());
300 SourceLocation Location;
301 bool IsIFunc = D->hasAttr<IFuncAttr>();
302 if (const Attr *A = D->getDefiningAttr())
303 Location = A->getLocation();
305 llvm_unreachable("Not an alias or ifunc?");
306 StringRef MangledName = getMangledName(GD);
307 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
308 auto *Alias = cast<llvm::GlobalIndirectSymbol>(Entry);
309 const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
312 Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
313 } else if (GV->isDeclaration()) {
315 Diags.Report(Location, diag::err_alias_to_undefined)
316 << IsIFunc << IsIFunc;
317 } else if (IsIFunc) {
318 // Check resolver function type.
319 llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(
320 GV->getType()->getPointerElementType());
322 if (!FTy->getReturnType()->isPointerTy())
323 Diags.Report(Location, diag::err_ifunc_resolver_return);
324 if (FTy->getNumParams())
325 Diags.Report(Location, diag::err_ifunc_resolver_params);
328 llvm::Constant *Aliasee = Alias->getIndirectSymbol();
329 llvm::GlobalValue *AliaseeGV;
330 if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
331 AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
333 AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
335 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
336 StringRef AliasSection = SA->getName();
337 if (AliasSection != AliaseeGV->getSection())
338 Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
339 << AliasSection << IsIFunc << IsIFunc;
342 // We have to handle alias to weak aliases in here. LLVM itself disallows
343 // this since the object semantics would not match the IL one. For
344 // compatibility with gcc we implement it by just pointing the alias
345 // to its aliasee's aliasee. We also warn, since the user is probably
346 // expecting the link to be weak.
347 if (auto GA = dyn_cast<llvm::GlobalIndirectSymbol>(AliaseeGV)) {
348 if (GA->isInterposable()) {
349 Diags.Report(Location, diag::warn_alias_to_weak_alias)
350 << GV->getName() << GA->getName() << IsIFunc;
351 Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
352 GA->getIndirectSymbol(), Alias->getType());
353 Alias->setIndirectSymbol(Aliasee);
360 for (const GlobalDecl &GD : Aliases) {
361 StringRef MangledName = getMangledName(GD);
362 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
363 auto *Alias = dyn_cast<llvm::GlobalIndirectSymbol>(Entry);
364 Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
365 Alias->eraseFromParent();
369 void CodeGenModule::clear() {
370 DeferredDeclsToEmit.clear();
372 OpenMPRuntime->clear();
375 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
376 StringRef MainFile) {
377 if (!hasDiagnostics())
379 if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
380 if (MainFile.empty())
381 MainFile = "<stdin>";
382 Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
385 Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
388 Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
392 void CodeGenModule::Release() {
394 EmitVTablesOpportunistically();
395 applyGlobalValReplacements();
398 EmitCXXGlobalInitFunc();
399 EmitCXXGlobalDtorFunc();
400 EmitCXXThreadLocalInitFunc();
402 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
403 AddGlobalCtor(ObjCInitFunction);
404 if (Context.getLangOpts().CUDA && !Context.getLangOpts().CUDAIsDevice &&
406 if (llvm::Function *CudaCtorFunction = CUDARuntime->makeModuleCtorFunction())
407 AddGlobalCtor(CudaCtorFunction);
408 if (llvm::Function *CudaDtorFunction = CUDARuntime->makeModuleDtorFunction())
409 AddGlobalDtor(CudaDtorFunction);
412 if (llvm::Function *OpenMPRegistrationFunction =
413 OpenMPRuntime->emitRegistrationFunction()) {
414 auto ComdatKey = OpenMPRegistrationFunction->hasComdat() ?
415 OpenMPRegistrationFunction : nullptr;
416 AddGlobalCtor(OpenMPRegistrationFunction, 0, ComdatKey);
419 getModule().setProfileSummary(PGOReader->getSummary().getMD(VMContext));
420 if (PGOStats.hasDiagnostics())
421 PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
423 EmitCtorList(GlobalCtors, "llvm.global_ctors");
424 EmitCtorList(GlobalDtors, "llvm.global_dtors");
425 EmitGlobalAnnotations();
426 EmitStaticExternCAliases();
427 EmitDeferredUnusedCoverageMappings();
429 CoverageMapping->emit();
430 if (CodeGenOpts.SanitizeCfiCrossDso) {
431 CodeGenFunction(*this).EmitCfiCheckFail();
432 CodeGenFunction(*this).EmitCfiCheckStub();
434 emitAtAvailableLinkGuard();
439 if (CodeGenOpts.Autolink &&
440 (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
441 EmitModuleLinkOptions();
444 // Record mregparm value now so it is visible through rest of codegen.
445 if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
446 getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
447 CodeGenOpts.NumRegisterParameters);
449 if (CodeGenOpts.DwarfVersion) {
450 // We actually want the latest version when there are conflicts.
451 // We can change from Warning to Latest if such mode is supported.
452 getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version",
453 CodeGenOpts.DwarfVersion);
455 if (CodeGenOpts.EmitCodeView) {
456 // Indicate that we want CodeView in the metadata.
457 getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
459 if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
460 // We don't support LTO with 2 with different StrictVTablePointers
461 // FIXME: we could support it by stripping all the information introduced
462 // by StrictVTablePointers.
464 getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
466 llvm::Metadata *Ops[2] = {
467 llvm::MDString::get(VMContext, "StrictVTablePointers"),
468 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
469 llvm::Type::getInt32Ty(VMContext), 1))};
471 getModule().addModuleFlag(llvm::Module::Require,
472 "StrictVTablePointersRequirement",
473 llvm::MDNode::get(VMContext, Ops));
476 // We support a single version in the linked module. The LLVM
477 // parser will drop debug info with a different version number
478 // (and warn about it, too).
479 getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
480 llvm::DEBUG_METADATA_VERSION);
482 // We need to record the widths of enums and wchar_t, so that we can generate
483 // the correct build attributes in the ARM backend. wchar_size is also used by
484 // TargetLibraryInfo.
485 uint64_t WCharWidth =
486 Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
487 getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
489 llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
490 if ( Arch == llvm::Triple::arm
491 || Arch == llvm::Triple::armeb
492 || Arch == llvm::Triple::thumb
493 || Arch == llvm::Triple::thumbeb) {
494 // The minimum width of an enum in bytes
495 uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
496 getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
499 if (CodeGenOpts.SanitizeCfiCrossDso) {
500 // Indicate that we want cross-DSO control flow integrity checks.
501 getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
504 if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
505 // Indicate whether __nvvm_reflect should be configured to flush denormal
506 // floating point values to 0. (This corresponds to its "__CUDA_FTZ"
508 getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
509 LangOpts.CUDADeviceFlushDenormalsToZero ? 1 : 0);
512 // Emit OpenCL specific module metadata: OpenCL/SPIR version.
513 if (LangOpts.OpenCL) {
514 EmitOpenCLMetadata();
515 // Emit SPIR version.
516 if (getTriple().getArch() == llvm::Triple::spir ||
517 getTriple().getArch() == llvm::Triple::spir64) {
518 // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
519 // opencl.spir.version named metadata.
520 llvm::Metadata *SPIRVerElts[] = {
521 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
522 Int32Ty, LangOpts.OpenCLVersion / 100)),
523 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
524 Int32Ty, (LangOpts.OpenCLVersion / 100 > 1) ? 0 : 2))};
525 llvm::NamedMDNode *SPIRVerMD =
526 TheModule.getOrInsertNamedMetadata("opencl.spir.version");
527 llvm::LLVMContext &Ctx = TheModule.getContext();
528 SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
532 if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
533 assert(PLevel < 3 && "Invalid PIC Level");
534 getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
535 if (Context.getLangOpts().PIE)
536 getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
539 SimplifyPersonality();
541 if (getCodeGenOpts().EmitDeclMetadata)
544 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
548 DebugInfo->finalize();
550 EmitVersionIdentMetadata();
552 EmitTargetMetadata();
555 void CodeGenModule::EmitOpenCLMetadata() {
556 // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
557 // opencl.ocl.version named metadata node.
558 llvm::Metadata *OCLVerElts[] = {
559 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
560 Int32Ty, LangOpts.OpenCLVersion / 100)),
561 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
562 Int32Ty, (LangOpts.OpenCLVersion % 100) / 10))};
563 llvm::NamedMDNode *OCLVerMD =
564 TheModule.getOrInsertNamedMetadata("opencl.ocl.version");
565 llvm::LLVMContext &Ctx = TheModule.getContext();
566 OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
569 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
570 // Make sure that this type is translated.
571 Types.UpdateCompletedType(TD);
574 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
575 // Make sure that this type is translated.
576 Types.RefreshTypeCacheForClass(RD);
579 llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
582 return TBAA->getTypeInfo(QTy);
585 TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
586 // Pointee values may have incomplete types, but they shall never be
588 if (AccessType->isIncompleteType())
589 return TBAAAccessInfo::getIncompleteInfo();
591 uint64_t Size = Context.getTypeSizeInChars(AccessType).getQuantity();
592 return TBAAAccessInfo(getTBAATypeInfo(AccessType), Size);
596 CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
598 return TBAAAccessInfo();
599 return TBAA->getVTablePtrAccessInfo(VTablePtrType);
602 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
605 return TBAA->getTBAAStructInfo(QTy);
608 llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
611 return TBAA->getBaseTypeInfo(QTy);
614 llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
617 return TBAA->getAccessTagInfo(Info);
620 TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
621 TBAAAccessInfo TargetInfo) {
623 return TBAAAccessInfo();
624 return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
628 CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
629 TBAAAccessInfo InfoB) {
631 return TBAAAccessInfo();
632 return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
635 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
636 TBAAAccessInfo TBAAInfo) {
637 if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
638 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
641 void CodeGenModule::DecorateInstructionWithInvariantGroup(
642 llvm::Instruction *I, const CXXRecordDecl *RD) {
643 I->setMetadata(llvm::LLVMContext::MD_invariant_group,
644 llvm::MDNode::get(getLLVMContext(), {}));
647 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
648 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
649 getDiags().Report(Context.getFullLoc(loc), diagID) << message;
652 /// ErrorUnsupported - Print out an error that codegen doesn't support the
653 /// specified stmt yet.
654 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
655 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
656 "cannot compile this %0 yet");
657 std::string Msg = Type;
658 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID)
659 << Msg << S->getSourceRange();
662 /// ErrorUnsupported - Print out an error that codegen doesn't support the
663 /// specified decl yet.
664 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
665 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
666 "cannot compile this %0 yet");
667 std::string Msg = Type;
668 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
671 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
672 return llvm::ConstantInt::get(SizeTy, size.getQuantity());
675 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
677 ForDefinition_t IsForDefinition) const {
678 // Internal definitions always have default visibility.
679 if (GV->hasLocalLinkage()) {
680 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
684 // Set visibility for definitions.
685 LinkageInfo LV = D->getLinkageAndVisibility();
686 if (LV.isVisibilityExplicit() ||
687 (IsForDefinition && !GV->hasAvailableExternallyLinkage()))
688 GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
691 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
692 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
693 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
694 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
695 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
696 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
699 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(
700 CodeGenOptions::TLSModel M) {
702 case CodeGenOptions::GeneralDynamicTLSModel:
703 return llvm::GlobalVariable::GeneralDynamicTLSModel;
704 case CodeGenOptions::LocalDynamicTLSModel:
705 return llvm::GlobalVariable::LocalDynamicTLSModel;
706 case CodeGenOptions::InitialExecTLSModel:
707 return llvm::GlobalVariable::InitialExecTLSModel;
708 case CodeGenOptions::LocalExecTLSModel:
709 return llvm::GlobalVariable::LocalExecTLSModel;
711 llvm_unreachable("Invalid TLS model!");
714 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
715 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
717 llvm::GlobalValue::ThreadLocalMode TLM;
718 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel());
720 // Override the TLS model if it is explicitly specified.
721 if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
722 TLM = GetLLVMTLSModel(Attr->getModel());
725 GV->setThreadLocalMode(TLM);
728 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
729 GlobalDecl CanonicalGD = GD.getCanonicalDecl();
731 // Some ABIs don't have constructor variants. Make sure that base and
732 // complete constructors get mangled the same.
733 if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
734 if (!getTarget().getCXXABI().hasConstructorVariants()) {
735 CXXCtorType OrigCtorType = GD.getCtorType();
736 assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
737 if (OrigCtorType == Ctor_Base)
738 CanonicalGD = GlobalDecl(CD, Ctor_Complete);
742 auto FoundName = MangledDeclNames.find(CanonicalGD);
743 if (FoundName != MangledDeclNames.end())
744 return FoundName->second;
746 const auto *ND = cast<NamedDecl>(GD.getDecl());
747 SmallString<256> Buffer;
749 if (getCXXABI().getMangleContext().shouldMangleDeclName(ND)) {
750 llvm::raw_svector_ostream Out(Buffer);
751 if (const auto *D = dyn_cast<CXXConstructorDecl>(ND))
752 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out);
753 else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND))
754 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out);
756 getCXXABI().getMangleContext().mangleName(ND, Out);
759 IdentifierInfo *II = ND->getIdentifier();
760 assert(II && "Attempt to mangle unnamed decl.");
761 const auto *FD = dyn_cast<FunctionDecl>(ND);
764 FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
765 llvm::raw_svector_ostream Out(Buffer);
766 Out << "__regcall3__" << II->getName();
773 // Keep the first result in the case of a mangling collision.
774 auto Result = Manglings.insert(std::make_pair(Str, GD));
775 return MangledDeclNames[CanonicalGD] = Result.first->first();
778 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
779 const BlockDecl *BD) {
780 MangleContext &MangleCtx = getCXXABI().getMangleContext();
781 const Decl *D = GD.getDecl();
783 SmallString<256> Buffer;
784 llvm::raw_svector_ostream Out(Buffer);
786 MangleCtx.mangleGlobalBlock(BD,
787 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
788 else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
789 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
790 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
791 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
793 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
795 auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
796 return Result.first->first();
799 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
800 return getModule().getNamedValue(Name);
803 /// AddGlobalCtor - Add a function to the list that will be called before
805 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
806 llvm::Constant *AssociatedData) {
807 // FIXME: Type coercion of void()* types.
808 GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData));
811 /// AddGlobalDtor - Add a function to the list that will be called
812 /// when the module is unloaded.
813 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority) {
814 // FIXME: Type coercion of void()* types.
815 GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
818 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
819 if (Fns.empty()) return;
821 // Ctor function type is void()*.
822 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
823 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy);
825 // Get the type of a ctor entry, { i32, void ()*, i8* }.
826 llvm::StructType *CtorStructTy = llvm::StructType::get(
827 Int32Ty, llvm::PointerType::getUnqual(CtorFTy), VoidPtrTy);
829 // Construct the constructor and destructor arrays.
830 ConstantInitBuilder builder(*this);
831 auto ctors = builder.beginArray(CtorStructTy);
832 for (const auto &I : Fns) {
833 auto ctor = ctors.beginStruct(CtorStructTy);
834 ctor.addInt(Int32Ty, I.Priority);
835 ctor.add(llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy));
836 if (I.AssociatedData)
837 ctor.add(llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy));
839 ctor.addNullPointer(VoidPtrTy);
840 ctor.finishAndAddTo(ctors);
844 ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
846 llvm::GlobalValue::AppendingLinkage);
848 // The LTO linker doesn't seem to like it when we set an alignment
849 // on appending variables. Take it off as a workaround.
850 list->setAlignment(0);
855 llvm::GlobalValue::LinkageTypes
856 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
857 const auto *D = cast<FunctionDecl>(GD.getDecl());
859 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
861 if (isa<CXXDestructorDecl>(D) &&
862 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
864 // Destructor variants in the Microsoft C++ ABI are always internal or
865 // linkonce_odr thunks emitted on an as-needed basis.
866 return Linkage == GVA_Internal ? llvm::GlobalValue::InternalLinkage
867 : llvm::GlobalValue::LinkOnceODRLinkage;
870 if (isa<CXXConstructorDecl>(D) &&
871 cast<CXXConstructorDecl>(D)->isInheritingConstructor() &&
872 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
873 // Our approach to inheriting constructors is fundamentally different from
874 // that used by the MS ABI, so keep our inheriting constructor thunks
875 // internal rather than trying to pick an unambiguous mangling for them.
876 return llvm::GlobalValue::InternalLinkage;
879 return getLLVMLinkageForDeclarator(D, Linkage, /*isConstantVariable=*/false);
882 void CodeGenModule::setFunctionDLLStorageClass(GlobalDecl GD, llvm::Function *F) {
883 const auto *FD = cast<FunctionDecl>(GD.getDecl());
885 if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(FD)) {
886 if (getCXXABI().useThunkForDtorVariant(Dtor, GD.getDtorType())) {
887 // Don't dllexport/import destructor thunks.
888 F->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
893 if (FD->hasAttr<DLLImportAttr>())
894 F->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
895 else if (FD->hasAttr<DLLExportAttr>())
896 F->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
898 F->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
901 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
902 llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
903 if (!MDS) return nullptr;
905 return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
908 void CodeGenModule::setFunctionDefinitionAttributes(const FunctionDecl *D,
910 setNonAliasAttributes(D, F);
913 void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
914 const CGFunctionInfo &Info,
916 unsigned CallingConv;
917 llvm::AttributeList PAL;
918 ConstructAttributeList(F->getName(), Info, D, PAL, CallingConv, false);
919 F->setAttributes(PAL);
920 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
923 /// Determines whether the language options require us to model
924 /// unwind exceptions. We treat -fexceptions as mandating this
925 /// except under the fragile ObjC ABI with only ObjC exceptions
926 /// enabled. This means, for example, that C with -fexceptions
928 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
929 // If exceptions are completely disabled, obviously this is false.
930 if (!LangOpts.Exceptions) return false;
932 // If C++ exceptions are enabled, this is true.
933 if (LangOpts.CXXExceptions) return true;
935 // If ObjC exceptions are enabled, this depends on the ABI.
936 if (LangOpts.ObjCExceptions) {
937 return LangOpts.ObjCRuntime.hasUnwindExceptions();
943 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
947 if (CodeGenOpts.UnwindTables)
948 B.addAttribute(llvm::Attribute::UWTable);
950 if (!hasUnwindExceptions(LangOpts))
951 B.addAttribute(llvm::Attribute::NoUnwind);
953 if (LangOpts.getStackProtector() == LangOptions::SSPOn)
954 B.addAttribute(llvm::Attribute::StackProtect);
955 else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
956 B.addAttribute(llvm::Attribute::StackProtectStrong);
957 else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
958 B.addAttribute(llvm::Attribute::StackProtectReq);
961 // If we don't have a declaration to control inlining, the function isn't
962 // explicitly marked as alwaysinline for semantic reasons, and inlining is
963 // disabled, mark the function as noinline.
964 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
965 CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
966 B.addAttribute(llvm::Attribute::NoInline);
968 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
972 // Track whether we need to add the optnone LLVM attribute,
973 // starting with the default for this optimization level.
974 bool ShouldAddOptNone =
975 !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
976 // We can't add optnone in the following cases, it won't pass the verifier.
977 ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
978 ShouldAddOptNone &= !F->hasFnAttribute(llvm::Attribute::AlwaysInline);
979 ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
981 if (ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) {
982 B.addAttribute(llvm::Attribute::OptimizeNone);
984 // OptimizeNone implies noinline; we should not be inlining such functions.
985 B.addAttribute(llvm::Attribute::NoInline);
986 assert(!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
987 "OptimizeNone and AlwaysInline on same function!");
989 // We still need to handle naked functions even though optnone subsumes
990 // much of their semantics.
991 if (D->hasAttr<NakedAttr>())
992 B.addAttribute(llvm::Attribute::Naked);
994 // OptimizeNone wins over OptimizeForSize and MinSize.
995 F->removeFnAttr(llvm::Attribute::OptimizeForSize);
996 F->removeFnAttr(llvm::Attribute::MinSize);
997 } else if (D->hasAttr<NakedAttr>()) {
998 // Naked implies noinline: we should not be inlining such functions.
999 B.addAttribute(llvm::Attribute::Naked);
1000 B.addAttribute(llvm::Attribute::NoInline);
1001 } else if (D->hasAttr<NoDuplicateAttr>()) {
1002 B.addAttribute(llvm::Attribute::NoDuplicate);
1003 } else if (D->hasAttr<NoInlineAttr>()) {
1004 B.addAttribute(llvm::Attribute::NoInline);
1005 } else if (D->hasAttr<AlwaysInlineAttr>() &&
1006 !F->hasFnAttribute(llvm::Attribute::NoInline)) {
1007 // (noinline wins over always_inline, and we can't specify both in IR)
1008 B.addAttribute(llvm::Attribute::AlwaysInline);
1009 } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
1010 // If we're not inlining, then force everything that isn't always_inline to
1011 // carry an explicit noinline attribute.
1012 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
1013 B.addAttribute(llvm::Attribute::NoInline);
1015 // Otherwise, propagate the inline hint attribute and potentially use its
1016 // absence to mark things as noinline.
1017 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
1018 if (any_of(FD->redecls(), [&](const FunctionDecl *Redecl) {
1019 return Redecl->isInlineSpecified();
1021 B.addAttribute(llvm::Attribute::InlineHint);
1022 } else if (CodeGenOpts.getInlining() ==
1023 CodeGenOptions::OnlyHintInlining &&
1025 !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1026 B.addAttribute(llvm::Attribute::NoInline);
1031 // Add other optimization related attributes if we are optimizing this
1033 if (!D->hasAttr<OptimizeNoneAttr>()) {
1034 if (D->hasAttr<ColdAttr>()) {
1035 if (!ShouldAddOptNone)
1036 B.addAttribute(llvm::Attribute::OptimizeForSize);
1037 B.addAttribute(llvm::Attribute::Cold);
1040 if (D->hasAttr<MinSizeAttr>())
1041 B.addAttribute(llvm::Attribute::MinSize);
1044 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1046 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
1048 F->setAlignment(alignment);
1050 // Some C++ ABIs require 2-byte alignment for member functions, in order to
1051 // reserve a bit for differentiating between virtual and non-virtual member
1052 // functions. If the current target's C++ ABI requires this and this is a
1053 // member function, set its alignment accordingly.
1054 if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
1055 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
1059 // In the cross-dso CFI mode, we want !type attributes on definitions only.
1060 if (CodeGenOpts.SanitizeCfiCrossDso)
1061 if (auto *FD = dyn_cast<FunctionDecl>(D))
1062 CreateFunctionTypeMetadata(FD, F);
1065 void CodeGenModule::SetCommonAttributes(const Decl *D,
1066 llvm::GlobalValue *GV) {
1067 if (const auto *ND = dyn_cast_or_null<NamedDecl>(D))
1068 setGlobalVisibility(GV, ND, ForDefinition);
1070 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1072 if (D && D->hasAttr<UsedAttr>())
1076 void CodeGenModule::setAliasAttributes(const Decl *D,
1077 llvm::GlobalValue *GV) {
1078 SetCommonAttributes(D, GV);
1080 // Process the dllexport attribute based on whether the original definition
1081 // (not necessarily the aliasee) was exported.
1082 if (D->hasAttr<DLLExportAttr>())
1083 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
1086 void CodeGenModule::setNonAliasAttributes(const Decl *D,
1087 llvm::GlobalObject *GO) {
1088 SetCommonAttributes(D, GO);
1091 if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
1092 if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
1093 GV->addAttribute("bss-section", SA->getName());
1094 if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
1095 GV->addAttribute("data-section", SA->getName());
1096 if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
1097 GV->addAttribute("rodata-section", SA->getName());
1100 if (auto *F = dyn_cast<llvm::Function>(GO)) {
1101 if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
1102 if (!D->getAttr<SectionAttr>())
1103 F->addFnAttr("implicit-section-name", SA->getName());
1106 if (const SectionAttr *SA = D->getAttr<SectionAttr>())
1107 GO->setSection(SA->getName());
1110 getTargetCodeGenInfo().setTargetAttributes(D, GO, *this, ForDefinition);
1113 void CodeGenModule::SetInternalFunctionAttributes(const Decl *D,
1115 const CGFunctionInfo &FI) {
1116 SetLLVMFunctionAttributes(D, FI, F);
1117 SetLLVMFunctionAttributesForDefinition(D, F);
1119 F->setLinkage(llvm::Function::InternalLinkage);
1121 setNonAliasAttributes(D, F);
1124 static void setLinkageForGV(llvm::GlobalValue *GV,
1125 const NamedDecl *ND) {
1126 // Set linkage and visibility in case we never see a definition.
1127 LinkageInfo LV = ND->getLinkageAndVisibility();
1128 if (!isExternallyVisible(LV.getLinkage())) {
1129 // Don't set internal linkage on declarations.
1131 if (ND->hasAttr<DLLImportAttr>()) {
1132 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
1133 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
1134 } else if (ND->hasAttr<DLLExportAttr>()) {
1135 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
1136 } else if (ND->hasAttr<WeakAttr>() || ND->isWeakImported()) {
1137 // "extern_weak" is overloaded in LLVM; we probably should have
1138 // separate linkage types for this.
1139 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
1144 void CodeGenModule::CreateFunctionTypeMetadata(const FunctionDecl *FD,
1145 llvm::Function *F) {
1146 // Only if we are checking indirect calls.
1147 if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
1150 // Non-static class methods are handled via vtable pointer checks elsewhere.
1151 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
1154 // Additionally, if building with cross-DSO support...
1155 if (CodeGenOpts.SanitizeCfiCrossDso) {
1156 // Skip available_externally functions. They won't be codegen'ed in the
1157 // current module anyway.
1158 if (getContext().GetGVALinkageForFunction(FD) == GVA_AvailableExternally)
1162 llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
1163 F->addTypeMetadata(0, MD);
1164 F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
1166 // Emit a hash-based bit set entry for cross-DSO calls.
1167 if (CodeGenOpts.SanitizeCfiCrossDso)
1168 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
1169 F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
1172 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
1173 bool IsIncompleteFunction,
1175 ForDefinition_t IsForDefinition) {
1177 if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) {
1178 // If this is an intrinsic function, set the function's attributes
1179 // to the intrinsic's attributes.
1180 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID));
1184 const auto *FD = cast<FunctionDecl>(GD.getDecl());
1186 if (!IsIncompleteFunction) {
1187 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F);
1188 // Setup target-specific attributes.
1189 if (!IsForDefinition)
1190 getTargetCodeGenInfo().setTargetAttributes(FD, F, *this,
1194 // Add the Returned attribute for "this", except for iOS 5 and earlier
1195 // where substantial code, including the libstdc++ dylib, was compiled with
1196 // GCC and does not actually return "this".
1197 if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
1198 !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
1199 assert(!F->arg_empty() &&
1200 F->arg_begin()->getType()
1201 ->canLosslesslyBitCastTo(F->getReturnType()) &&
1202 "unexpected this return");
1203 F->addAttribute(1, llvm::Attribute::Returned);
1206 // Only a few attributes are set on declarations; these may later be
1207 // overridden by a definition.
1209 setLinkageForGV(F, FD);
1210 setGlobalVisibility(F, FD, NotForDefinition);
1212 if (FD->getAttr<PragmaClangTextSectionAttr>()) {
1213 F->addFnAttr("implicit-section-name");
1216 if (const SectionAttr *SA = FD->getAttr<SectionAttr>())
1217 F->setSection(SA->getName());
1219 if (FD->isReplaceableGlobalAllocationFunction()) {
1220 // A replaceable global allocation function does not act like a builtin by
1221 // default, only if it is invoked by a new-expression or delete-expression.
1222 F->addAttribute(llvm::AttributeList::FunctionIndex,
1223 llvm::Attribute::NoBuiltin);
1225 // A sane operator new returns a non-aliasing pointer.
1226 // FIXME: Also add NonNull attribute to the return value
1227 // for the non-nothrow forms?
1228 auto Kind = FD->getDeclName().getCXXOverloadedOperator();
1229 if (getCodeGenOpts().AssumeSaneOperatorNew &&
1230 (Kind == OO_New || Kind == OO_Array_New))
1231 F->addAttribute(llvm::AttributeList::ReturnIndex,
1232 llvm::Attribute::NoAlias);
1235 if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
1236 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1237 else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
1238 if (MD->isVirtual())
1239 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1241 // Don't emit entries for function declarations in the cross-DSO mode. This
1242 // is handled with better precision by the receiving DSO.
1243 if (!CodeGenOpts.SanitizeCfiCrossDso)
1244 CreateFunctionTypeMetadata(FD, F);
1246 if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
1247 getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
1250 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
1251 assert(!GV->isDeclaration() &&
1252 "Only globals with definition can force usage.");
1253 LLVMUsed.emplace_back(GV);
1256 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
1257 assert(!GV->isDeclaration() &&
1258 "Only globals with definition can force usage.");
1259 LLVMCompilerUsed.emplace_back(GV);
1262 static void emitUsed(CodeGenModule &CGM, StringRef Name,
1263 std::vector<llvm::WeakTrackingVH> &List) {
1264 // Don't create llvm.used if there is no need.
1268 // Convert List to what ConstantArray needs.
1269 SmallVector<llvm::Constant*, 8> UsedArray;
1270 UsedArray.resize(List.size());
1271 for (unsigned i = 0, e = List.size(); i != e; ++i) {
1273 llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
1274 cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
1277 if (UsedArray.empty())
1279 llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
1281 auto *GV = new llvm::GlobalVariable(
1282 CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
1283 llvm::ConstantArray::get(ATy, UsedArray), Name);
1285 GV->setSection("llvm.metadata");
1288 void CodeGenModule::emitLLVMUsed() {
1289 emitUsed(*this, "llvm.used", LLVMUsed);
1290 emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
1293 void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
1294 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
1295 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1298 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
1299 llvm::SmallString<32> Opt;
1300 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
1301 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
1302 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1305 void CodeGenModule::AddDependentLib(StringRef Lib) {
1306 llvm::SmallString<24> Opt;
1307 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
1308 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
1309 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1312 /// \brief Add link options implied by the given module, including modules
1313 /// it depends on, using a postorder walk.
1314 static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
1315 SmallVectorImpl<llvm::MDNode *> &Metadata,
1316 llvm::SmallPtrSet<Module *, 16> &Visited) {
1317 // Import this module's parent.
1318 if (Mod->Parent && Visited.insert(Mod->Parent).second) {
1319 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
1322 // Import this module's dependencies.
1323 for (unsigned I = Mod->Imports.size(); I > 0; --I) {
1324 if (Visited.insert(Mod->Imports[I - 1]).second)
1325 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited);
1328 // Add linker options to link against the libraries/frameworks
1329 // described by this module.
1330 llvm::LLVMContext &Context = CGM.getLLVMContext();
1331 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) {
1332 // Link against a framework. Frameworks are currently Darwin only, so we
1333 // don't to ask TargetCodeGenInfo for the spelling of the linker option.
1334 if (Mod->LinkLibraries[I-1].IsFramework) {
1335 llvm::Metadata *Args[2] = {
1336 llvm::MDString::get(Context, "-framework"),
1337 llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library)};
1339 Metadata.push_back(llvm::MDNode::get(Context, Args));
1343 // Link against a library.
1344 llvm::SmallString<24> Opt;
1345 CGM.getTargetCodeGenInfo().getDependentLibraryOption(
1346 Mod->LinkLibraries[I-1].Library, Opt);
1347 auto *OptString = llvm::MDString::get(Context, Opt);
1348 Metadata.push_back(llvm::MDNode::get(Context, OptString));
1352 void CodeGenModule::EmitModuleLinkOptions() {
1353 // Collect the set of all of the modules we want to visit to emit link
1354 // options, which is essentially the imported modules and all of their
1355 // non-explicit child modules.
1356 llvm::SetVector<clang::Module *> LinkModules;
1357 llvm::SmallPtrSet<clang::Module *, 16> Visited;
1358 SmallVector<clang::Module *, 16> Stack;
1360 // Seed the stack with imported modules.
1361 for (Module *M : ImportedModules) {
1362 // Do not add any link flags when an implementation TU of a module imports
1363 // a header of that same module.
1364 if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
1365 !getLangOpts().isCompilingModule())
1367 if (Visited.insert(M).second)
1371 // Find all of the modules to import, making a little effort to prune
1372 // non-leaf modules.
1373 while (!Stack.empty()) {
1374 clang::Module *Mod = Stack.pop_back_val();
1376 bool AnyChildren = false;
1378 // Visit the submodules of this module.
1379 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
1380 SubEnd = Mod->submodule_end();
1381 Sub != SubEnd; ++Sub) {
1382 // Skip explicit children; they need to be explicitly imported to be
1384 if ((*Sub)->IsExplicit)
1387 if (Visited.insert(*Sub).second) {
1388 Stack.push_back(*Sub);
1393 // We didn't find any children, so add this module to the list of
1394 // modules to link against.
1396 LinkModules.insert(Mod);
1400 // Add link options for all of the imported modules in reverse topological
1401 // order. We don't do anything to try to order import link flags with respect
1402 // to linker options inserted by things like #pragma comment().
1403 SmallVector<llvm::MDNode *, 16> MetadataArgs;
1405 for (Module *M : LinkModules)
1406 if (Visited.insert(M).second)
1407 addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
1408 std::reverse(MetadataArgs.begin(), MetadataArgs.end());
1409 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
1411 // Add the linker options metadata flag.
1412 auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
1413 for (auto *MD : LinkerOptionsMetadata)
1414 NMD->addOperand(MD);
1417 void CodeGenModule::EmitDeferred() {
1418 // Emit code for any potentially referenced deferred decls. Since a
1419 // previously unused static decl may become used during the generation of code
1420 // for a static function, iterate until no changes are made.
1422 if (!DeferredVTables.empty()) {
1423 EmitDeferredVTables();
1425 // Emitting a vtable doesn't directly cause more vtables to
1426 // become deferred, although it can cause functions to be
1427 // emitted that then need those vtables.
1428 assert(DeferredVTables.empty());
1431 // Stop if we're out of both deferred vtables and deferred declarations.
1432 if (DeferredDeclsToEmit.empty())
1435 // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
1436 // work, it will not interfere with this.
1437 std::vector<GlobalDecl> CurDeclsToEmit;
1438 CurDeclsToEmit.swap(DeferredDeclsToEmit);
1440 for (GlobalDecl &D : CurDeclsToEmit) {
1441 // We should call GetAddrOfGlobal with IsForDefinition set to true in order
1442 // to get GlobalValue with exactly the type we need, not something that
1443 // might had been created for another decl with the same mangled name but
1445 llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
1446 GetAddrOfGlobal(D, ForDefinition));
1448 // In case of different address spaces, we may still get a cast, even with
1449 // IsForDefinition equal to true. Query mangled names table to get
1452 GV = GetGlobalValue(getMangledName(D));
1454 // Make sure GetGlobalValue returned non-null.
1457 // Check to see if we've already emitted this. This is necessary
1458 // for a couple of reasons: first, decls can end up in the
1459 // deferred-decls queue multiple times, and second, decls can end
1460 // up with definitions in unusual ways (e.g. by an extern inline
1461 // function acquiring a strong function redefinition). Just
1462 // ignore these cases.
1463 if (!GV->isDeclaration())
1466 // Otherwise, emit the definition and move on to the next one.
1467 EmitGlobalDefinition(D, GV);
1469 // If we found out that we need to emit more decls, do that recursively.
1470 // This has the advantage that the decls are emitted in a DFS and related
1471 // ones are close together, which is convenient for testing.
1472 if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
1474 assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
1479 void CodeGenModule::EmitVTablesOpportunistically() {
1480 // Try to emit external vtables as available_externally if they have emitted
1481 // all inlined virtual functions. It runs after EmitDeferred() and therefore
1482 // is not allowed to create new references to things that need to be emitted
1483 // lazily. Note that it also uses fact that we eagerly emitting RTTI.
1485 assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
1486 && "Only emit opportunistic vtables with optimizations");
1488 for (const CXXRecordDecl *RD : OpportunisticVTables) {
1489 assert(getVTables().isVTableExternal(RD) &&
1490 "This queue should only contain external vtables");
1491 if (getCXXABI().canSpeculativelyEmitVTable(RD))
1492 VTables.GenerateClassData(RD);
1494 OpportunisticVTables.clear();
1497 void CodeGenModule::EmitGlobalAnnotations() {
1498 if (Annotations.empty())
1501 // Create a new global variable for the ConstantStruct in the Module.
1502 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
1503 Annotations[0]->getType(), Annotations.size()), Annotations);
1504 auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
1505 llvm::GlobalValue::AppendingLinkage,
1506 Array, "llvm.global.annotations");
1507 gv->setSection(AnnotationSection);
1510 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
1511 llvm::Constant *&AStr = AnnotationStrings[Str];
1515 // Not found yet, create a new global.
1516 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
1518 new llvm::GlobalVariable(getModule(), s->getType(), true,
1519 llvm::GlobalValue::PrivateLinkage, s, ".str");
1520 gv->setSection(AnnotationSection);
1521 gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1526 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
1527 SourceManager &SM = getContext().getSourceManager();
1528 PresumedLoc PLoc = SM.getPresumedLoc(Loc);
1530 return EmitAnnotationString(PLoc.getFilename());
1531 return EmitAnnotationString(SM.getBufferName(Loc));
1534 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
1535 SourceManager &SM = getContext().getSourceManager();
1536 PresumedLoc PLoc = SM.getPresumedLoc(L);
1537 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
1538 SM.getExpansionLineNumber(L);
1539 return llvm::ConstantInt::get(Int32Ty, LineNo);
1542 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
1543 const AnnotateAttr *AA,
1545 // Get the globals for file name, annotation, and the line number.
1546 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
1547 *UnitGV = EmitAnnotationUnit(L),
1548 *LineNoCst = EmitAnnotationLineNo(L);
1550 // Create the ConstantStruct for the global annotation.
1551 llvm::Constant *Fields[4] = {
1552 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy),
1553 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
1554 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
1557 return llvm::ConstantStruct::getAnon(Fields);
1560 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
1561 llvm::GlobalValue *GV) {
1562 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
1563 // Get the struct elements for these annotations.
1564 for (const auto *I : D->specific_attrs<AnnotateAttr>())
1565 Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
1568 bool CodeGenModule::isInSanitizerBlacklist(SanitizerMask Kind,
1570 SourceLocation Loc) const {
1571 const auto &SanitizerBL = getContext().getSanitizerBlacklist();
1572 // Blacklist by function name.
1573 if (SanitizerBL.isBlacklistedFunction(Kind, Fn->getName()))
1575 // Blacklist by location.
1577 return SanitizerBL.isBlacklistedLocation(Kind, Loc);
1578 // If location is unknown, this may be a compiler-generated function. Assume
1579 // it's located in the main file.
1580 auto &SM = Context.getSourceManager();
1581 if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1582 return SanitizerBL.isBlacklistedFile(Kind, MainFile->getName());
1587 bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
1588 SourceLocation Loc, QualType Ty,
1589 StringRef Category) const {
1590 // For now globals can be blacklisted only in ASan and KASan.
1591 const SanitizerMask EnabledAsanMask = LangOpts.Sanitize.Mask &
1592 (SanitizerKind::Address | SanitizerKind::KernelAddress | SanitizerKind::HWAddress);
1593 if (!EnabledAsanMask)
1595 const auto &SanitizerBL = getContext().getSanitizerBlacklist();
1596 if (SanitizerBL.isBlacklistedGlobal(EnabledAsanMask, GV->getName(), Category))
1598 if (SanitizerBL.isBlacklistedLocation(EnabledAsanMask, Loc, Category))
1600 // Check global type.
1602 // Drill down the array types: if global variable of a fixed type is
1603 // blacklisted, we also don't instrument arrays of them.
1604 while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
1605 Ty = AT->getElementType();
1606 Ty = Ty.getCanonicalType().getUnqualifiedType();
1607 // We allow to blacklist only record types (classes, structs etc.)
1608 if (Ty->isRecordType()) {
1609 std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
1610 if (SanitizerBL.isBlacklistedType(EnabledAsanMask, TypeStr, Category))
1617 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
1618 StringRef Category) const {
1619 if (!LangOpts.XRayInstrument)
1621 const auto &XRayFilter = getContext().getXRayFilter();
1622 using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
1623 auto Attr = XRayFunctionFilter::ImbueAttribute::NONE;
1625 Attr = XRayFilter.shouldImbueLocation(Loc, Category);
1626 if (Attr == ImbueAttr::NONE)
1627 Attr = XRayFilter.shouldImbueFunction(Fn->getName());
1629 case ImbueAttr::NONE:
1631 case ImbueAttr::ALWAYS:
1632 Fn->addFnAttr("function-instrument", "xray-always");
1634 case ImbueAttr::ALWAYS_ARG1:
1635 Fn->addFnAttr("function-instrument", "xray-always");
1636 Fn->addFnAttr("xray-log-args", "1");
1638 case ImbueAttr::NEVER:
1639 Fn->addFnAttr("function-instrument", "xray-never");
1645 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
1646 // Never defer when EmitAllDecls is specified.
1647 if (LangOpts.EmitAllDecls)
1650 return getContext().DeclMustBeEmitted(Global);
1653 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
1654 if (const auto *FD = dyn_cast<FunctionDecl>(Global))
1655 if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
1656 // Implicit template instantiations may change linkage if they are later
1657 // explicitly instantiated, so they should not be emitted eagerly.
1659 if (const auto *VD = dyn_cast<VarDecl>(Global))
1660 if (Context.getInlineVariableDefinitionKind(VD) ==
1661 ASTContext::InlineVariableDefinitionKind::WeakUnknown)
1662 // A definition of an inline constexpr static data member may change
1663 // linkage later if it's redeclared outside the class.
1665 // If OpenMP is enabled and threadprivates must be generated like TLS, delay
1666 // codegen for global variables, because they may be marked as threadprivate.
1667 if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
1668 getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global))
1674 ConstantAddress CodeGenModule::GetAddrOfUuidDescriptor(
1675 const CXXUuidofExpr* E) {
1676 // Sema has verified that IIDSource has a __declspec(uuid()), and that its
1678 StringRef Uuid = E->getUuidStr();
1679 std::string Name = "_GUID_" + Uuid.lower();
1680 std::replace(Name.begin(), Name.end(), '-', '_');
1682 // The UUID descriptor should be pointer aligned.
1683 CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
1685 // Look for an existing global.
1686 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
1687 return ConstantAddress(GV, Alignment);
1689 llvm::Constant *Init = EmitUuidofInitializer(Uuid);
1690 assert(Init && "failed to initialize as constant");
1692 auto *GV = new llvm::GlobalVariable(
1693 getModule(), Init->getType(),
1694 /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
1695 if (supportsCOMDAT())
1696 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
1697 return ConstantAddress(GV, Alignment);
1700 ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
1701 const AliasAttr *AA = VD->getAttr<AliasAttr>();
1702 assert(AA && "No alias?");
1704 CharUnits Alignment = getContext().getDeclAlign(VD);
1705 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
1707 // See if there is already something with the target's name in the module.
1708 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
1710 unsigned AS = getContext().getTargetAddressSpace(VD->getType());
1711 auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
1712 return ConstantAddress(Ptr, Alignment);
1715 llvm::Constant *Aliasee;
1716 if (isa<llvm::FunctionType>(DeclTy))
1717 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
1718 GlobalDecl(cast<FunctionDecl>(VD)),
1719 /*ForVTable=*/false);
1721 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
1722 llvm::PointerType::getUnqual(DeclTy),
1725 auto *F = cast<llvm::GlobalValue>(Aliasee);
1726 F->setLinkage(llvm::Function::ExternalWeakLinkage);
1727 WeakRefReferences.insert(F);
1729 return ConstantAddress(Aliasee, Alignment);
1732 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
1733 const auto *Global = cast<ValueDecl>(GD.getDecl());
1735 // Weak references don't produce any output by themselves.
1736 if (Global->hasAttr<WeakRefAttr>())
1739 // If this is an alias definition (which otherwise looks like a declaration)
1741 if (Global->hasAttr<AliasAttr>())
1742 return EmitAliasDefinition(GD);
1744 // IFunc like an alias whose value is resolved at runtime by calling resolver.
1745 if (Global->hasAttr<IFuncAttr>())
1746 return emitIFuncDefinition(GD);
1748 // If this is CUDA, be selective about which declarations we emit.
1749 if (LangOpts.CUDA) {
1750 if (LangOpts.CUDAIsDevice) {
1751 if (!Global->hasAttr<CUDADeviceAttr>() &&
1752 !Global->hasAttr<CUDAGlobalAttr>() &&
1753 !Global->hasAttr<CUDAConstantAttr>() &&
1754 !Global->hasAttr<CUDASharedAttr>())
1757 // We need to emit host-side 'shadows' for all global
1758 // device-side variables because the CUDA runtime needs their
1759 // size and host-side address in order to provide access to
1760 // their device-side incarnations.
1762 // So device-only functions are the only things we skip.
1763 if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
1764 Global->hasAttr<CUDADeviceAttr>())
1767 assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
1768 "Expected Variable or Function");
1772 if (LangOpts.OpenMP) {
1773 // If this is OpenMP device, check if it is legal to emit this global
1775 if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
1777 if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
1778 if (MustBeEmitted(Global))
1779 EmitOMPDeclareReduction(DRD);
1784 // Ignore declarations, they will be emitted on their first use.
1785 if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
1786 // Forward declarations are emitted lazily on first use.
1787 if (!FD->doesThisDeclarationHaveABody()) {
1788 if (!FD->doesDeclarationForceExternallyVisibleDefinition())
1791 StringRef MangledName = getMangledName(GD);
1793 // Compute the function info and LLVM type.
1794 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
1795 llvm::Type *Ty = getTypes().GetFunctionType(FI);
1797 GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
1798 /*DontDefer=*/false);
1802 const auto *VD = cast<VarDecl>(Global);
1803 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
1804 // We need to emit device-side global CUDA variables even if a
1805 // variable does not have a definition -- we still need to define
1806 // host-side shadow for it.
1807 bool MustEmitForCuda = LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
1808 !VD->hasDefinition() &&
1809 (VD->hasAttr<CUDAConstantAttr>() ||
1810 VD->hasAttr<CUDADeviceAttr>());
1811 if (!MustEmitForCuda &&
1812 VD->isThisDeclarationADefinition() != VarDecl::Definition &&
1813 !Context.isMSStaticDataMemberInlineDefinition(VD)) {
1814 // If this declaration may have caused an inline variable definition to
1815 // change linkage, make sure that it's emitted.
1816 if (Context.getInlineVariableDefinitionKind(VD) ==
1817 ASTContext::InlineVariableDefinitionKind::Strong)
1818 GetAddrOfGlobalVar(VD);
1823 // Defer code generation to first use when possible, e.g. if this is an inline
1824 // function. If the global must always be emitted, do it eagerly if possible
1825 // to benefit from cache locality.
1826 if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
1827 // Emit the definition if it can't be deferred.
1828 EmitGlobalDefinition(GD);
1832 // If we're deferring emission of a C++ variable with an
1833 // initializer, remember the order in which it appeared in the file.
1834 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
1835 cast<VarDecl>(Global)->hasInit()) {
1836 DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
1837 CXXGlobalInits.push_back(nullptr);
1840 StringRef MangledName = getMangledName(GD);
1841 if (GetGlobalValue(MangledName) != nullptr) {
1842 // The value has already been used and should therefore be emitted.
1843 addDeferredDeclToEmit(GD);
1844 } else if (MustBeEmitted(Global)) {
1845 // The value must be emitted, but cannot be emitted eagerly.
1846 assert(!MayBeEmittedEagerly(Global));
1847 addDeferredDeclToEmit(GD);
1849 // Otherwise, remember that we saw a deferred decl with this name. The
1850 // first use of the mangled name will cause it to move into
1851 // DeferredDeclsToEmit.
1852 DeferredDecls[MangledName] = GD;
1856 // Check if T is a class type with a destructor that's not dllimport.
1857 static bool HasNonDllImportDtor(QualType T) {
1858 if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
1859 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1860 if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
1867 struct FunctionIsDirectlyRecursive :
1868 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> {
1869 const StringRef Name;
1870 const Builtin::Context &BI;
1872 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) :
1873 Name(N), BI(C), Result(false) {
1875 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base;
1877 bool TraverseCallExpr(CallExpr *E) {
1878 const FunctionDecl *FD = E->getDirectCallee();
1881 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
1882 if (Attr && Name == Attr->getLabel()) {
1886 unsigned BuiltinID = FD->getBuiltinID();
1887 if (!BuiltinID || !BI.isLibFunction(BuiltinID))
1889 StringRef BuiltinName = BI.getName(BuiltinID);
1890 if (BuiltinName.startswith("__builtin_") &&
1891 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
1899 // Make sure we're not referencing non-imported vars or functions.
1900 struct DLLImportFunctionVisitor
1901 : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
1902 bool SafeToInline = true;
1904 bool shouldVisitImplicitCode() const { return true; }
1906 bool VisitVarDecl(VarDecl *VD) {
1907 if (VD->getTLSKind()) {
1908 // A thread-local variable cannot be imported.
1909 SafeToInline = false;
1910 return SafeToInline;
1913 // A variable definition might imply a destructor call.
1914 if (VD->isThisDeclarationADefinition())
1915 SafeToInline = !HasNonDllImportDtor(VD->getType());
1917 return SafeToInline;
1920 bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
1921 if (const auto *D = E->getTemporary()->getDestructor())
1922 SafeToInline = D->hasAttr<DLLImportAttr>();
1923 return SafeToInline;
1926 bool VisitDeclRefExpr(DeclRefExpr *E) {
1927 ValueDecl *VD = E->getDecl();
1928 if (isa<FunctionDecl>(VD))
1929 SafeToInline = VD->hasAttr<DLLImportAttr>();
1930 else if (VarDecl *V = dyn_cast<VarDecl>(VD))
1931 SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
1932 return SafeToInline;
1935 bool VisitCXXConstructExpr(CXXConstructExpr *E) {
1936 SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
1937 return SafeToInline;
1940 bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
1941 CXXMethodDecl *M = E->getMethodDecl();
1943 // Call through a pointer to member function. This is safe to inline.
1944 SafeToInline = true;
1946 SafeToInline = M->hasAttr<DLLImportAttr>();
1948 return SafeToInline;
1951 bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
1952 SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
1953 return SafeToInline;
1956 bool VisitCXXNewExpr(CXXNewExpr *E) {
1957 SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
1958 return SafeToInline;
1963 // isTriviallyRecursive - Check if this function calls another
1964 // decl that, because of the asm attribute or the other decl being a builtin,
1965 // ends up pointing to itself.
1967 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
1969 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
1970 // asm labels are a special kind of mangling we have to support.
1971 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
1974 Name = Attr->getLabel();
1976 Name = FD->getName();
1979 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
1980 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD));
1981 return Walker.Result;
1984 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
1985 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
1987 const auto *F = cast<FunctionDecl>(GD.getDecl());
1988 if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
1991 if (F->hasAttr<DLLImportAttr>()) {
1992 // Check whether it would be safe to inline this dllimport function.
1993 DLLImportFunctionVisitor Visitor;
1994 Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
1995 if (!Visitor.SafeToInline)
1998 if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
1999 // Implicit destructor invocations aren't captured in the AST, so the
2000 // check above can't see them. Check for them manually here.
2001 for (const Decl *Member : Dtor->getParent()->decls())
2002 if (isa<FieldDecl>(Member))
2003 if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
2005 for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
2006 if (HasNonDllImportDtor(B.getType()))
2011 // PR9614. Avoid cases where the source code is lying to us. An available
2012 // externally function should have an equivalent function somewhere else,
2013 // but a function that calls itself is clearly not equivalent to the real
2015 // This happens in glibc's btowc and in some configure checks.
2016 return !isTriviallyRecursive(F);
2019 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
2020 return CodeGenOpts.OptimizationLevel > 0;
2023 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
2024 const auto *D = cast<ValueDecl>(GD.getDecl());
2026 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
2027 Context.getSourceManager(),
2028 "Generating code for declaration");
2030 if (isa<FunctionDecl>(D)) {
2031 // At -O0, don't generate IR for functions with available_externally
2033 if (!shouldEmitFunction(GD))
2036 if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
2037 // Make sure to emit the definition(s) before we emit the thunks.
2038 // This is necessary for the generation of certain thunks.
2039 if (const auto *CD = dyn_cast<CXXConstructorDecl>(Method))
2040 ABI->emitCXXStructor(CD, getFromCtorType(GD.getCtorType()));
2041 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(Method))
2042 ABI->emitCXXStructor(DD, getFromDtorType(GD.getDtorType()));
2044 EmitGlobalFunctionDefinition(GD, GV);
2046 if (Method->isVirtual())
2047 getVTables().EmitThunks(GD);
2052 return EmitGlobalFunctionDefinition(GD, GV);
2055 if (const auto *VD = dyn_cast<VarDecl>(D))
2056 return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
2058 llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
2061 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
2062 llvm::Function *NewFn);
2064 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
2065 /// module, create and return an llvm Function with the specified type. If there
2066 /// is something in the module with the specified name, return it potentially
2067 /// bitcasted to the right type.
2069 /// If D is non-null, it specifies a decl that correspond to this. This is used
2070 /// to set the attributes on the function when it is first created.
2071 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
2072 StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
2073 bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
2074 ForDefinition_t IsForDefinition) {
2075 const Decl *D = GD.getDecl();
2077 // Lookup the entry, lazily creating it if necessary.
2078 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
2080 if (WeakRefReferences.erase(Entry)) {
2081 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
2082 if (FD && !FD->hasAttr<WeakAttr>())
2083 Entry->setLinkage(llvm::Function::ExternalLinkage);
2086 // Handle dropped DLL attributes.
2087 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
2088 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
2090 // If there are two attempts to define the same mangled name, issue an
2092 if (IsForDefinition && !Entry->isDeclaration()) {
2094 // Check that GD is not yet in DiagnosedConflictingDefinitions is required
2095 // to make sure that we issue an error only once.
2096 if (lookupRepresentativeDecl(MangledName, OtherGD) &&
2097 (GD.getCanonicalDecl().getDecl() !=
2098 OtherGD.getCanonicalDecl().getDecl()) &&
2099 DiagnosedConflictingDefinitions.insert(GD).second) {
2100 getDiags().Report(D->getLocation(),
2101 diag::err_duplicate_mangled_name);
2102 getDiags().Report(OtherGD.getDecl()->getLocation(),
2103 diag::note_previous_definition);
2107 if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
2108 (Entry->getType()->getElementType() == Ty)) {
2112 // Make sure the result is of the correct type.
2113 // (If function is requested for a definition, we always need to create a new
2114 // function, not just return a bitcast.)
2115 if (!IsForDefinition)
2116 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
2119 // This function doesn't have a complete type (for example, the return
2120 // type is an incomplete struct). Use a fake type instead, and make
2121 // sure not to try to set attributes.
2122 bool IsIncompleteFunction = false;
2124 llvm::FunctionType *FTy;
2125 if (isa<llvm::FunctionType>(Ty)) {
2126 FTy = cast<llvm::FunctionType>(Ty);
2128 FTy = llvm::FunctionType::get(VoidTy, false);
2129 IsIncompleteFunction = true;
2133 llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
2134 Entry ? StringRef() : MangledName, &getModule());
2136 // If we already created a function with the same mangled name (but different
2137 // type) before, take its name and add it to the list of functions to be
2138 // replaced with F at the end of CodeGen.
2140 // This happens if there is a prototype for a function (e.g. "int f()") and
2141 // then a definition of a different type (e.g. "int f(int x)").
2145 // This might be an implementation of a function without a prototype, in
2146 // which case, try to do special replacement of calls which match the new
2147 // prototype. The really key thing here is that we also potentially drop
2148 // arguments from the call site so as to make a direct call, which makes the
2149 // inliner happier and suppresses a number of optimizer warnings (!) about
2150 // dropping arguments.
2151 if (!Entry->use_empty()) {
2152 ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
2153 Entry->removeDeadConstantUsers();
2156 llvm::Constant *BC = llvm::ConstantExpr::getBitCast(
2157 F, Entry->getType()->getElementType()->getPointerTo());
2158 addGlobalValReplacement(Entry, BC);
2161 assert(F->getName() == MangledName && "name was uniqued!");
2163 SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk,
2165 if (ExtraAttrs.hasAttributes(llvm::AttributeList::FunctionIndex)) {
2166 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex);
2167 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
2171 // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
2172 // each other bottoming out with the base dtor. Therefore we emit non-base
2173 // dtors on usage, even if there is no dtor definition in the TU.
2174 if (D && isa<CXXDestructorDecl>(D) &&
2175 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
2177 addDeferredDeclToEmit(GD);
2179 // This is the first use or definition of a mangled name. If there is a
2180 // deferred decl with this name, remember that we need to emit it at the end
2182 auto DDI = DeferredDecls.find(MangledName);
2183 if (DDI != DeferredDecls.end()) {
2184 // Move the potentially referenced deferred decl to the
2185 // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
2186 // don't need it anymore).
2187 addDeferredDeclToEmit(DDI->second);
2188 DeferredDecls.erase(DDI);
2190 // Otherwise, there are cases we have to worry about where we're
2191 // using a declaration for which we must emit a definition but where
2192 // we might not find a top-level definition:
2193 // - member functions defined inline in their classes
2194 // - friend functions defined inline in some class
2195 // - special member functions with implicit definitions
2196 // If we ever change our AST traversal to walk into class methods,
2197 // this will be unnecessary.
2199 // We also don't emit a definition for a function if it's going to be an
2200 // entry in a vtable, unless it's already marked as used.
2201 } else if (getLangOpts().CPlusPlus && D) {
2202 // Look for a declaration that's lexically in a record.
2203 for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
2204 FD = FD->getPreviousDecl()) {
2205 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
2206 if (FD->doesThisDeclarationHaveABody()) {
2207 addDeferredDeclToEmit(GD.getWithDecl(FD));
2215 // Make sure the result is of the requested type.
2216 if (!IsIncompleteFunction) {
2217 assert(F->getType()->getElementType() == Ty);
2221 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
2222 return llvm::ConstantExpr::getBitCast(F, PTy);
2225 /// GetAddrOfFunction - Return the address of the given function. If Ty is
2226 /// non-null, then this function will use the specified type if it has to
2227 /// create it (this occurs when we see a definition of the function).
2228 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
2232 ForDefinition_t IsForDefinition) {
2233 // If there was no specific requested type, just convert it now.
2235 const auto *FD = cast<FunctionDecl>(GD.getDecl());
2236 auto CanonTy = Context.getCanonicalType(FD->getType());
2237 Ty = getTypes().ConvertFunctionType(CanonTy, FD);
2240 StringRef MangledName = getMangledName(GD);
2241 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
2242 /*IsThunk=*/false, llvm::AttributeList(),
2246 static const FunctionDecl *
2247 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
2248 TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
2249 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
2251 IdentifierInfo &CII = C.Idents.get(Name);
2252 for (const auto &Result : DC->lookup(&CII))
2253 if (const auto FD = dyn_cast<FunctionDecl>(Result))
2256 if (!C.getLangOpts().CPlusPlus)
2259 // Demangle the premangled name from getTerminateFn()
2260 IdentifierInfo &CXXII =
2261 (Name == "_ZSt9terminatev" || Name == "\01?terminate@@YAXXZ")
2262 ? C.Idents.get("terminate")
2263 : C.Idents.get(Name);
2265 for (const auto &N : {"__cxxabiv1", "std"}) {
2266 IdentifierInfo &NS = C.Idents.get(N);
2267 for (const auto &Result : DC->lookup(&NS)) {
2268 NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
2269 if (auto LSD = dyn_cast<LinkageSpecDecl>(Result))
2270 for (const auto &Result : LSD->lookup(&NS))
2271 if ((ND = dyn_cast<NamespaceDecl>(Result)))
2275 for (const auto &Result : ND->lookup(&CXXII))
2276 if (const auto *FD = dyn_cast<FunctionDecl>(Result))
2284 /// CreateRuntimeFunction - Create a new runtime function with the specified
2287 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
2288 llvm::AttributeList ExtraAttrs,
2291 GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
2292 /*DontDefer=*/false, /*IsThunk=*/false,
2295 if (auto *F = dyn_cast<llvm::Function>(C)) {
2297 F->setCallingConv(getRuntimeCC());
2299 if (!Local && getTriple().isOSBinFormatCOFF() &&
2300 !getCodeGenOpts().LTOVisibilityPublicStd &&
2301 !getTriple().isWindowsGNUEnvironment()) {
2302 const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
2303 if (!FD || FD->hasAttr<DLLImportAttr>()) {
2304 F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2305 F->setLinkage(llvm::GlobalValue::ExternalLinkage);
2314 /// CreateBuiltinFunction - Create a new builtin function with the specified
2317 CodeGenModule::CreateBuiltinFunction(llvm::FunctionType *FTy, StringRef Name,
2318 llvm::AttributeList ExtraAttrs) {
2320 GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
2321 /*DontDefer=*/false, /*IsThunk=*/false, ExtraAttrs);
2322 if (auto *F = dyn_cast<llvm::Function>(C))
2324 F->setCallingConv(getBuiltinCC());
2328 /// isTypeConstant - Determine whether an object of this type can be emitted
2331 /// If ExcludeCtor is true, the duration when the object's constructor runs
2332 /// will not be considered. The caller will need to verify that the object is
2333 /// not written to during its construction.
2334 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
2335 if (!Ty.isConstant(Context) && !Ty->isReferenceType())
2338 if (Context.getLangOpts().CPlusPlus) {
2339 if (const CXXRecordDecl *Record
2340 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
2341 return ExcludeCtor && !Record->hasMutableFields() &&
2342 Record->hasTrivialDestructor();
2348 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
2349 /// create and return an llvm GlobalVariable with the specified type. If there
2350 /// is something in the module with the specified name, return it potentially
2351 /// bitcasted to the right type.
2353 /// If D is non-null, it specifies a decl that correspond to this. This is used
2354 /// to set the attributes on the global when it is first created.
2356 /// If IsForDefinition is true, it is guranteed that an actual global with
2357 /// type Ty will be returned, not conversion of a variable with the same
2358 /// mangled name but some other type.
2360 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
2361 llvm::PointerType *Ty,
2363 ForDefinition_t IsForDefinition) {
2364 // Lookup the entry, lazily creating it if necessary.
2365 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
2367 if (WeakRefReferences.erase(Entry)) {
2368 if (D && !D->hasAttr<WeakAttr>())
2369 Entry->setLinkage(llvm::Function::ExternalLinkage);
2372 // Handle dropped DLL attributes.
2373 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
2374 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
2376 if (Entry->getType() == Ty)
2379 // If there are two attempts to define the same mangled name, issue an
2381 if (IsForDefinition && !Entry->isDeclaration()) {
2383 const VarDecl *OtherD;
2385 // Check that D is not yet in DiagnosedConflictingDefinitions is required
2386 // to make sure that we issue an error only once.
2387 if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
2388 (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
2389 (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
2390 OtherD->hasInit() &&
2391 DiagnosedConflictingDefinitions.insert(D).second) {
2392 getDiags().Report(D->getLocation(),
2393 diag::err_duplicate_mangled_name);
2394 getDiags().Report(OtherGD.getDecl()->getLocation(),
2395 diag::note_previous_definition);
2399 // Make sure the result is of the correct type.
2400 if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace())
2401 return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty);
2403 // (If global is requested for a definition, we always need to create a new
2404 // global, not just return a bitcast.)
2405 if (!IsForDefinition)
2406 return llvm::ConstantExpr::getBitCast(Entry, Ty);
2409 auto AddrSpace = GetGlobalVarAddressSpace(D);
2410 auto TargetAddrSpace = getContext().getTargetAddressSpace(AddrSpace);
2412 auto *GV = new llvm::GlobalVariable(
2413 getModule(), Ty->getElementType(), false,
2414 llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr,
2415 llvm::GlobalVariable::NotThreadLocal, TargetAddrSpace);
2417 // If we already created a global with the same mangled name (but different
2418 // type) before, take its name and remove it from its parent.
2420 GV->takeName(Entry);
2422 if (!Entry->use_empty()) {
2423 llvm::Constant *NewPtrForOldDecl =
2424 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
2425 Entry->replaceAllUsesWith(NewPtrForOldDecl);
2428 Entry->eraseFromParent();
2431 // This is the first use or definition of a mangled name. If there is a
2432 // deferred decl with this name, remember that we need to emit it at the end
2434 auto DDI = DeferredDecls.find(MangledName);
2435 if (DDI != DeferredDecls.end()) {
2436 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
2437 // list, and remove it from DeferredDecls (since we don't need it anymore).
2438 addDeferredDeclToEmit(DDI->second);
2439 DeferredDecls.erase(DDI);
2442 // Handle things which are present even on external declarations.
2444 // FIXME: This code is overly simple and should be merged with other global
2446 GV->setConstant(isTypeConstant(D->getType(), false));
2448 GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
2450 setLinkageForGV(GV, D);
2451 setGlobalVisibility(GV, D, NotForDefinition);
2453 if (D->getTLSKind()) {
2454 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
2455 CXXThreadLocals.push_back(D);
2459 // If required by the ABI, treat declarations of static data members with
2460 // inline initializers as definitions.
2461 if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
2462 EmitGlobalVarDefinition(D);
2465 // Emit section information for extern variables.
2466 if (D->hasExternalStorage()) {
2467 if (const SectionAttr *SA = D->getAttr<SectionAttr>())
2468 GV->setSection(SA->getName());
2471 // Handle XCore specific ABI requirements.
2472 if (getTriple().getArch() == llvm::Triple::xcore &&
2473 D->getLanguageLinkage() == CLanguageLinkage &&
2474 D->getType().isConstant(Context) &&
2475 isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
2476 GV->setSection(".cp.rodata");
2478 // Check if we a have a const declaration with an initializer, we may be
2479 // able to emit it as available_externally to expose it's value to the
2481 if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
2482 D->getType().isConstQualified() && !GV->hasInitializer() &&
2483 !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
2484 const auto *Record =
2485 Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
2486 bool HasMutableFields = Record && Record->hasMutableFields();
2487 if (!HasMutableFields) {
2488 const VarDecl *InitDecl;
2489 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
2491 ConstantEmitter emitter(*this);
2492 llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
2494 auto *InitType = Init->getType();
2495 if (GV->getType()->getElementType() != InitType) {
2496 // The type of the initializer does not match the definition.
2497 // This happens when an initializer has a different type from
2498 // the type of the global (because of padding at the end of a
2499 // structure for instance).
2500 GV->setName(StringRef());
2501 // Make a new global with the correct type, this is now guaranteed
2503 auto *NewGV = cast<llvm::GlobalVariable>(
2504 GetAddrOfGlobalVar(D, InitType, IsForDefinition));
2506 // Erase the old global, since it is no longer used.
2507 cast<llvm::GlobalValue>(GV)->eraseFromParent();
2510 GV->setInitializer(Init);
2511 GV->setConstant(true);
2512 GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
2514 emitter.finalize(GV);
2522 D ? D->getType().getAddressSpace()
2523 : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
2524 assert(getContext().getTargetAddressSpace(ExpectedAS) ==
2525 Ty->getPointerAddressSpace());
2526 if (AddrSpace != ExpectedAS)
2527 return getTargetCodeGenInfo().performAddrSpaceCast(*this, GV, AddrSpace,
2534 CodeGenModule::GetAddrOfGlobal(GlobalDecl GD,
2535 ForDefinition_t IsForDefinition) {
2536 const Decl *D = GD.getDecl();
2537 if (isa<CXXConstructorDecl>(D))
2538 return getAddrOfCXXStructor(cast<CXXConstructorDecl>(D),
2539 getFromCtorType(GD.getCtorType()),
2540 /*FnInfo=*/nullptr, /*FnType=*/nullptr,
2541 /*DontDefer=*/false, IsForDefinition);
2542 else if (isa<CXXDestructorDecl>(D))
2543 return getAddrOfCXXStructor(cast<CXXDestructorDecl>(D),
2544 getFromDtorType(GD.getDtorType()),
2545 /*FnInfo=*/nullptr, /*FnType=*/nullptr,
2546 /*DontDefer=*/false, IsForDefinition);
2547 else if (isa<CXXMethodDecl>(D)) {
2548 auto FInfo = &getTypes().arrangeCXXMethodDeclaration(
2549 cast<CXXMethodDecl>(D));
2550 auto Ty = getTypes().GetFunctionType(*FInfo);
2551 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
2553 } else if (isa<FunctionDecl>(D)) {
2554 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
2555 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
2556 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
2559 return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr,
2563 llvm::GlobalVariable *
2564 CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name,
2566 llvm::GlobalValue::LinkageTypes Linkage) {
2567 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
2568 llvm::GlobalVariable *OldGV = nullptr;
2571 // Check if the variable has the right type.
2572 if (GV->getType()->getElementType() == Ty)
2575 // Because C++ name mangling, the only way we can end up with an already
2576 // existing global with the same name is if it has been declared extern "C".
2577 assert(GV->isDeclaration() && "Declaration has wrong type!");
2581 // Create a new variable.
2582 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
2583 Linkage, nullptr, Name);
2586 // Replace occurrences of the old variable if needed.
2587 GV->takeName(OldGV);
2589 if (!OldGV->use_empty()) {
2590 llvm::Constant *NewPtrForOldDecl =
2591 llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
2592 OldGV->replaceAllUsesWith(NewPtrForOldDecl);
2595 OldGV->eraseFromParent();
2598 if (supportsCOMDAT() && GV->isWeakForLinker() &&
2599 !GV->hasAvailableExternallyLinkage())
2600 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
2605 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
2606 /// given global variable. If Ty is non-null and if the global doesn't exist,
2607 /// then it will be created with the specified type instead of whatever the
2608 /// normal requested type would be. If IsForDefinition is true, it is guranteed
2609 /// that an actual global with type Ty will be returned, not conversion of a
2610 /// variable with the same mangled name but some other type.
2611 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
2613 ForDefinition_t IsForDefinition) {
2614 assert(D->hasGlobalStorage() && "Not a global variable");
2615 QualType ASTTy = D->getType();
2617 Ty = getTypes().ConvertTypeForMem(ASTTy);
2619 llvm::PointerType *PTy =
2620 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
2622 StringRef MangledName = getMangledName(D);
2623 return GetOrCreateLLVMGlobal(MangledName, PTy, D, IsForDefinition);
2626 /// CreateRuntimeVariable - Create a new runtime global variable with the
2627 /// specified type and name.
2629 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
2631 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), nullptr);
2634 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
2635 assert(!D->getInit() && "Cannot emit definite definitions here!");
2637 StringRef MangledName = getMangledName(D);
2638 llvm::GlobalValue *GV = GetGlobalValue(MangledName);
2640 // We already have a definition, not declaration, with the same mangled name.
2641 // Emitting of declaration is not required (and actually overwrites emitted
2643 if (GV && !GV->isDeclaration())
2646 // If we have not seen a reference to this variable yet, place it into the
2647 // deferred declarations table to be emitted if needed later.
2648 if (!MustBeEmitted(D) && !GV) {
2649 DeferredDecls[MangledName] = D;
2653 // The tentative definition is the only definition.
2654 EmitGlobalVarDefinition(D);
2657 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
2658 return Context.toCharUnitsFromBits(
2659 getDataLayout().getTypeStoreSizeInBits(Ty));
2662 LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
2663 LangAS AddrSpace = LangAS::Default;
2664 if (LangOpts.OpenCL) {
2665 AddrSpace = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
2666 assert(AddrSpace == LangAS::opencl_global ||
2667 AddrSpace == LangAS::opencl_constant ||
2668 AddrSpace == LangAS::opencl_local ||
2669 AddrSpace >= LangAS::FirstTargetAddressSpace);
2673 if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
2674 if (D && D->hasAttr<CUDAConstantAttr>())
2675 return LangAS::cuda_constant;
2676 else if (D && D->hasAttr<CUDASharedAttr>())
2677 return LangAS::cuda_shared;
2679 return LangAS::cuda_device;
2682 return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
2685 template<typename SomeDecl>
2686 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
2687 llvm::GlobalValue *GV) {
2688 if (!getLangOpts().CPlusPlus)
2691 // Must have 'used' attribute, or else inline assembly can't rely on
2692 // the name existing.
2693 if (!D->template hasAttr<UsedAttr>())
2696 // Must have internal linkage and an ordinary name.
2697 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage)
2700 // Must be in an extern "C" context. Entities declared directly within
2701 // a record are not extern "C" even if the record is in such a context.
2702 const SomeDecl *First = D->getFirstDecl();
2703 if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
2706 // OK, this is an internal linkage entity inside an extern "C" linkage
2707 // specification. Make a note of that so we can give it the "expected"
2708 // mangled name if nothing else is using that name.
2709 std::pair<StaticExternCMap::iterator, bool> R =
2710 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
2712 // If we have multiple internal linkage entities with the same name
2713 // in extern "C" regions, none of them gets that name.
2715 R.first->second = nullptr;
2718 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
2719 if (!CGM.supportsCOMDAT())
2722 if (D.hasAttr<SelectAnyAttr>())
2726 if (auto *VD = dyn_cast<VarDecl>(&D))
2727 Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
2729 Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
2733 case GVA_AvailableExternally:
2734 case GVA_StrongExternal:
2736 case GVA_DiscardableODR:
2740 llvm_unreachable("No such linkage");
2743 void CodeGenModule::maybeSetTrivialComdat(const Decl &D,
2744 llvm::GlobalObject &GO) {
2745 if (!shouldBeInCOMDAT(*this, D))
2747 GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
2750 /// Pass IsTentative as true if you want to create a tentative definition.
2751 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
2753 // OpenCL global variables of sampler type are translated to function calls,
2754 // therefore no need to be translated.
2755 QualType ASTTy = D->getType();
2756 if (getLangOpts().OpenCL && ASTTy->isSamplerT())
2759 llvm::Constant *Init = nullptr;
2760 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
2761 bool NeedsGlobalCtor = false;
2762 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor();
2764 const VarDecl *InitDecl;
2765 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
2767 Optional<ConstantEmitter> emitter;
2769 // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
2770 // as part of their declaration." Sema has already checked for
2771 // error cases, so we just need to set Init to UndefValue.
2772 if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
2773 D->hasAttr<CUDASharedAttr>())
2774 Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
2775 else if (!InitExpr) {
2776 // This is a tentative definition; tentative definitions are
2777 // implicitly initialized with { 0 }.
2779 // Note that tentative definitions are only emitted at the end of
2780 // a translation unit, so they should never have incomplete
2781 // type. In addition, EmitTentativeDefinition makes sure that we
2782 // never attempt to emit a tentative definition if a real one
2783 // exists. A use may still exists, however, so we still may need
2785 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
2786 Init = EmitNullConstant(D->getType());
2788 initializedGlobalDecl = GlobalDecl(D);
2789 emitter.emplace(*this);
2790 Init = emitter->tryEmitForInitializer(*InitDecl);
2793 QualType T = InitExpr->getType();
2794 if (D->getType()->isReferenceType())
2797 if (getLangOpts().CPlusPlus) {
2798 Init = EmitNullConstant(T);
2799 NeedsGlobalCtor = true;
2801 ErrorUnsupported(D, "static initializer");
2802 Init = llvm::UndefValue::get(getTypes().ConvertType(T));
2805 // We don't need an initializer, so remove the entry for the delayed
2806 // initializer position (just in case this entry was delayed) if we
2807 // also don't need to register a destructor.
2808 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
2809 DelayedCXXInitPosition.erase(D);
2813 llvm::Type* InitType = Init->getType();
2814 llvm::Constant *Entry =
2815 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
2817 // Strip off a bitcast if we got one back.
2818 if (auto *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
2819 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
2820 CE->getOpcode() == llvm::Instruction::AddrSpaceCast ||
2821 // All zero index gep.
2822 CE->getOpcode() == llvm::Instruction::GetElementPtr);
2823 Entry = CE->getOperand(0);
2826 // Entry is now either a Function or GlobalVariable.
2827 auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
2829 // We have a definition after a declaration with the wrong type.
2830 // We must make a new GlobalVariable* and update everything that used OldGV
2831 // (a declaration or tentative definition) with the new GlobalVariable*
2832 // (which will be a definition).
2834 // This happens if there is a prototype for a global (e.g.
2835 // "extern int x[];") and then a definition of a different type (e.g.
2836 // "int x[10];"). This also happens when an initializer has a different type
2837 // from the type of the global (this happens with unions).
2838 if (!GV || GV->getType()->getElementType() != InitType ||
2839 GV->getType()->getAddressSpace() !=
2840 getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
2842 // Move the old entry aside so that we'll create a new one.
2843 Entry->setName(StringRef());
2845 // Make a new global with the correct type, this is now guaranteed to work.
2846 GV = cast<llvm::GlobalVariable>(
2847 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative)));
2849 // Replace all uses of the old global with the new global
2850 llvm::Constant *NewPtrForOldDecl =
2851 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
2852 Entry->replaceAllUsesWith(NewPtrForOldDecl);
2854 // Erase the old global, since it is no longer used.
2855 cast<llvm::GlobalValue>(Entry)->eraseFromParent();
2858 MaybeHandleStaticInExternC(D, GV);
2860 if (D->hasAttr<AnnotateAttr>())
2861 AddGlobalAnnotations(D, GV);
2863 // Set the llvm linkage type as appropriate.
2864 llvm::GlobalValue::LinkageTypes Linkage =
2865 getLLVMLinkageVarDefinition(D, GV->isConstant());
2867 // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
2868 // the device. [...]"
2869 // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
2870 // __device__, declares a variable that: [...]
2871 // Is accessible from all the threads within the grid and from the host
2872 // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
2873 // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
2874 if (GV && LangOpts.CUDA) {
2875 if (LangOpts.CUDAIsDevice) {
2876 if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>())
2877 GV->setExternallyInitialized(true);
2879 // Host-side shadows of external declarations of device-side
2880 // global variables become internal definitions. These have to
2881 // be internal in order to prevent name conflicts with global
2882 // host variables with the same name in a different TUs.
2883 if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()) {
2884 Linkage = llvm::GlobalValue::InternalLinkage;
2886 // Shadow variables and their properties must be registered
2887 // with CUDA runtime.
2889 if (!D->hasDefinition())
2890 Flags |= CGCUDARuntime::ExternDeviceVar;
2891 if (D->hasAttr<CUDAConstantAttr>())
2892 Flags |= CGCUDARuntime::ConstantDeviceVar;
2893 getCUDARuntime().registerDeviceVar(*GV, Flags);
2894 } else if (D->hasAttr<CUDASharedAttr>())
2895 // __shared__ variables are odd. Shadows do get created, but
2896 // they are not registered with the CUDA runtime, so they
2897 // can't really be used to access their device-side
2898 // counterparts. It's not clear yet whether it's nvcc's bug or
2899 // a feature, but we've got to do the same for compatibility.
2900 Linkage = llvm::GlobalValue::InternalLinkage;
2904 GV->setInitializer(Init);
2905 if (emitter) emitter->finalize(GV);
2907 // If it is safe to mark the global 'constant', do so now.
2908 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
2909 isTypeConstant(D->getType(), true));
2911 // If it is in a read-only section, mark it 'constant'.
2912 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
2913 const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
2914 if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
2915 GV->setConstant(true);
2918 GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
2921 // On Darwin, if the normal linkage of a C++ thread_local variable is
2922 // LinkOnce or Weak, we keep the normal linkage to prevent multiple
2923 // copies within a linkage unit; otherwise, the backing variable has
2924 // internal linkage and all accesses should just be calls to the
2925 // Itanium-specified entry point, which has the normal linkage of the
2926 // variable. This is to preserve the ability to change the implementation
2927 // behind the scenes.
2928 if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic &&
2929 Context.getTargetInfo().getTriple().isOSDarwin() &&
2930 !llvm::GlobalVariable::isLinkOnceLinkage(Linkage) &&
2931 !llvm::GlobalVariable::isWeakLinkage(Linkage))
2932 Linkage = llvm::GlobalValue::InternalLinkage;
2934 GV->setLinkage(Linkage);
2935 if (D->hasAttr<DLLImportAttr>())
2936 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
2937 else if (D->hasAttr<DLLExportAttr>())
2938 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
2940 GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
2942 if (Linkage == llvm::GlobalVariable::CommonLinkage) {
2943 // common vars aren't constant even if declared const.
2944 GV->setConstant(false);
2945 // Tentative definition of global variables may be initialized with
2946 // non-zero null pointers. In this case they should have weak linkage
2947 // since common linkage must have zero initializer and must not have
2948 // explicit section therefore cannot have non-zero initial value.
2949 if (!GV->getInitializer()->isNullValue())
2950 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
2953 setNonAliasAttributes(D, GV);
2955 if (D->getTLSKind() && !GV->isThreadLocal()) {
2956 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
2957 CXXThreadLocals.push_back(D);
2961 maybeSetTrivialComdat(*D, *GV);
2963 // Emit the initializer function if necessary.
2964 if (NeedsGlobalCtor || NeedsGlobalDtor)
2965 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
2967 SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor);
2969 // Emit global variable debug information.
2970 if (CGDebugInfo *DI = getModuleDebugInfo())
2971 if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
2972 DI->EmitGlobalVariable(GV, D);
2975 static bool isVarDeclStrongDefinition(const ASTContext &Context,
2976 CodeGenModule &CGM, const VarDecl *D,
2978 // Don't give variables common linkage if -fno-common was specified unless it
2979 // was overridden by a NoCommon attribute.
2980 if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
2984 // A declaration of an identifier for an object that has file scope without
2985 // an initializer, and without a storage-class specifier or with the
2986 // storage-class specifier static, constitutes a tentative definition.
2987 if (D->getInit() || D->hasExternalStorage())
2990 // A variable cannot be both common and exist in a section.
2991 if (D->hasAttr<SectionAttr>())
2994 // A variable cannot be both common and exist in a section.
2995 // We dont try to determine which is the right section in the front-end.
2996 // If no specialized section name is applicable, it will resort to default.
2997 if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
2998 D->hasAttr<PragmaClangDataSectionAttr>() ||
2999 D->hasAttr<PragmaClangRodataSectionAttr>())
3002 // Thread local vars aren't considered common linkage.
3003 if (D->getTLSKind())
3006 // Tentative definitions marked with WeakImportAttr are true definitions.
3007 if (D->hasAttr<WeakImportAttr>())
3010 // A variable cannot be both common and exist in a comdat.
3011 if (shouldBeInCOMDAT(CGM, *D))
3014 // Declarations with a required alignment do not have common linkage in MSVC
3016 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
3017 if (D->hasAttr<AlignedAttr>())
3019 QualType VarType = D->getType();
3020 if (Context.isAlignmentRequired(VarType))
3023 if (const auto *RT = VarType->getAs<RecordType>()) {
3024 const RecordDecl *RD = RT->getDecl();
3025 for (const FieldDecl *FD : RD->fields()) {
3026 if (FD->isBitField())
3028 if (FD->hasAttr<AlignedAttr>())
3030 if (Context.isAlignmentRequired(FD->getType()))
3039 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
3040 const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) {
3041 if (Linkage == GVA_Internal)
3042 return llvm::Function::InternalLinkage;
3044 if (D->hasAttr<WeakAttr>()) {
3045 if (IsConstantVariable)
3046 return llvm::GlobalVariable::WeakODRLinkage;
3048 return llvm::GlobalVariable::WeakAnyLinkage;
3051 // We are guaranteed to have a strong definition somewhere else,
3052 // so we can use available_externally linkage.
3053 if (Linkage == GVA_AvailableExternally)
3054 return llvm::GlobalValue::AvailableExternallyLinkage;
3056 // Note that Apple's kernel linker doesn't support symbol
3057 // coalescing, so we need to avoid linkonce and weak linkages there.
3058 // Normally, this means we just map to internal, but for explicit
3059 // instantiations we'll map to external.
3061 // In C++, the compiler has to emit a definition in every translation unit
3062 // that references the function. We should use linkonce_odr because
3063 // a) if all references in this translation unit are optimized away, we
3064 // don't need to codegen it. b) if the function persists, it needs to be
3065 // merged with other definitions. c) C++ has the ODR, so we know the
3066 // definition is dependable.
3067 if (Linkage == GVA_DiscardableODR)
3068 return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
3069 : llvm::Function::InternalLinkage;
3071 // An explicit instantiation of a template has weak linkage, since
3072 // explicit instantiations can occur in multiple translation units
3073 // and must all be equivalent. However, we are not allowed to
3074 // throw away these explicit instantiations.
3076 // We don't currently support CUDA device code spread out across multiple TUs,
3077 // so say that CUDA templates are either external (for kernels) or internal.
3078 // This lets llvm perform aggressive inter-procedural optimizations.
3079 if (Linkage == GVA_StrongODR) {
3080 if (Context.getLangOpts().AppleKext)
3081 return llvm::Function::ExternalLinkage;
3082 if (Context.getLangOpts().CUDA && Context.getLangOpts().CUDAIsDevice)
3083 return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
3084 : llvm::Function::InternalLinkage;
3085 return llvm::Function::WeakODRLinkage;
3088 // C++ doesn't have tentative definitions and thus cannot have common
3090 if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
3091 !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
3092 CodeGenOpts.NoCommon))
3093 return llvm::GlobalVariable::CommonLinkage;
3095 // selectany symbols are externally visible, so use weak instead of
3096 // linkonce. MSVC optimizes away references to const selectany globals, so
3097 // all definitions should be the same and ODR linkage should be used.
3098 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
3099 if (D->hasAttr<SelectAnyAttr>())
3100 return llvm::GlobalVariable::WeakODRLinkage;
3102 // Otherwise, we have strong external linkage.
3103 assert(Linkage == GVA_StrongExternal);
3104 return llvm::GlobalVariable::ExternalLinkage;
3107 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition(
3108 const VarDecl *VD, bool IsConstant) {
3109 GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
3110 return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant);
3113 /// Replace the uses of a function that was declared with a non-proto type.
3114 /// We want to silently drop extra arguments from call sites
3115 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
3116 llvm::Function *newFn) {
3118 if (old->use_empty()) return;
3120 llvm::Type *newRetTy = newFn->getReturnType();
3121 SmallVector<llvm::Value*, 4> newArgs;
3122 SmallVector<llvm::OperandBundleDef, 1> newBundles;
3124 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
3126 llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
3127 llvm::User *user = use->getUser();
3129 // Recognize and replace uses of bitcasts. Most calls to
3130 // unprototyped functions will use bitcasts.
3131 if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
3132 if (bitcast->getOpcode() == llvm::Instruction::BitCast)
3133 replaceUsesOfNonProtoConstant(bitcast, newFn);
3137 // Recognize calls to the function.
3138 llvm::CallSite callSite(user);
3139 if (!callSite) continue;
3140 if (!callSite.isCallee(&*use)) continue;
3142 // If the return types don't match exactly, then we can't
3143 // transform this call unless it's dead.
3144 if (callSite->getType() != newRetTy && !callSite->use_empty())
3147 // Get the call site's attribute list.
3148 SmallVector<llvm::AttributeSet, 8> newArgAttrs;
3149 llvm::AttributeList oldAttrs = callSite.getAttributes();
3151 // If the function was passed too few arguments, don't transform.
3152 unsigned newNumArgs = newFn->arg_size();
3153 if (callSite.arg_size() < newNumArgs) continue;
3155 // If extra arguments were passed, we silently drop them.
3156 // If any of the types mismatch, we don't transform.
3158 bool dontTransform = false;
3159 for (llvm::Argument &A : newFn->args()) {
3160 if (callSite.getArgument(argNo)->getType() != A.getType()) {
3161 dontTransform = true;
3165 // Add any parameter attributes.
3166 newArgAttrs.push_back(oldAttrs.getParamAttributes(argNo));
3172 // Okay, we can transform this. Create the new call instruction and copy
3173 // over the required information.
3174 newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo);
3176 // Copy over any operand bundles.
3177 callSite.getOperandBundlesAsDefs(newBundles);
3179 llvm::CallSite newCall;
3180 if (callSite.isCall()) {
3181 newCall = llvm::CallInst::Create(newFn, newArgs, newBundles, "",
3182 callSite.getInstruction());
3184 auto *oldInvoke = cast<llvm::InvokeInst>(callSite.getInstruction());
3185 newCall = llvm::InvokeInst::Create(newFn,
3186 oldInvoke->getNormalDest(),
3187 oldInvoke->getUnwindDest(),
3188 newArgs, newBundles, "",
3189 callSite.getInstruction());
3191 newArgs.clear(); // for the next iteration
3193 if (!newCall->getType()->isVoidTy())
3194 newCall->takeName(callSite.getInstruction());
3195 newCall.setAttributes(llvm::AttributeList::get(
3196 newFn->getContext(), oldAttrs.getFnAttributes(),
3197 oldAttrs.getRetAttributes(), newArgAttrs));
3198 newCall.setCallingConv(callSite.getCallingConv());
3200 // Finally, remove the old call, replacing any uses with the new one.
3201 if (!callSite->use_empty())
3202 callSite->replaceAllUsesWith(newCall.getInstruction());
3204 // Copy debug location attached to CI.
3205 if (callSite->getDebugLoc())
3206 newCall->setDebugLoc(callSite->getDebugLoc());
3208 callSite->eraseFromParent();
3212 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
3213 /// implement a function with no prototype, e.g. "int foo() {}". If there are
3214 /// existing call uses of the old function in the module, this adjusts them to
3215 /// call the new function directly.
3217 /// This is not just a cleanup: the always_inline pass requires direct calls to
3218 /// functions to be able to inline them. If there is a bitcast in the way, it
3219 /// won't inline them. Instcombine normally deletes these calls, but it isn't
3221 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
3222 llvm::Function *NewFn) {
3223 // If we're redefining a global as a function, don't transform it.
3224 if (!isa<llvm::Function>(Old)) return;
3226 replaceUsesOfNonProtoConstant(Old, NewFn);
3229 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
3230 auto DK = VD->isThisDeclarationADefinition();
3231 if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
3234 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
3235 // If we have a definition, this might be a deferred decl. If the
3236 // instantiation is explicit, make sure we emit it at the end.
3237 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
3238 GetAddrOfGlobalVar(VD);
3240 EmitTopLevelDecl(VD);
3243 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
3244 llvm::GlobalValue *GV) {
3245 const auto *D = cast<FunctionDecl>(GD.getDecl());
3247 // Compute the function info and LLVM type.
3248 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
3249 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
3251 // Get or create the prototype for the function.
3252 if (!GV || (GV->getType()->getElementType() != Ty))
3253 GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
3258 if (!GV->isDeclaration())
3261 // We need to set linkage and visibility on the function before
3262 // generating code for it because various parts of IR generation
3263 // want to propagate this information down (e.g. to local static
3265 auto *Fn = cast<llvm::Function>(GV);
3266 setFunctionLinkage(GD, Fn);
3267 setFunctionDLLStorageClass(GD, Fn);
3269 // FIXME: this is redundant with part of setFunctionDefinitionAttributes
3270 setGlobalVisibility(Fn, D, ForDefinition);
3272 MaybeHandleStaticInExternC(D, Fn);
3274 maybeSetTrivialComdat(*D, *Fn);
3276 CodeGenFunction(*this).GenerateCode(D, Fn, FI);
3278 setFunctionDefinitionAttributes(D, Fn);
3279 SetLLVMFunctionAttributesForDefinition(D, Fn);
3281 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
3282 AddGlobalCtor(Fn, CA->getPriority());
3283 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
3284 AddGlobalDtor(Fn, DA->getPriority());
3285 if (D->hasAttr<AnnotateAttr>())
3286 AddGlobalAnnotations(D, Fn);
3289 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
3290 const auto *D = cast<ValueDecl>(GD.getDecl());
3291 const AliasAttr *AA = D->getAttr<AliasAttr>();
3292 assert(AA && "Not an alias?");
3294 StringRef MangledName = getMangledName(GD);
3296 if (AA->getAliasee() == MangledName) {
3297 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
3301 // If there is a definition in the module, then it wins over the alias.
3302 // This is dubious, but allow it to be safe. Just ignore the alias.
3303 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3304 if (Entry && !Entry->isDeclaration())
3307 Aliases.push_back(GD);
3309 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
3311 // Create a reference to the named value. This ensures that it is emitted
3312 // if a deferred decl.
3313 llvm::Constant *Aliasee;
3314 if (isa<llvm::FunctionType>(DeclTy))
3315 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
3316 /*ForVTable=*/false);
3318 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
3319 llvm::PointerType::getUnqual(DeclTy),
3322 // Create the new alias itself, but don't set a name yet.
3323 auto *GA = llvm::GlobalAlias::create(
3324 DeclTy, 0, llvm::Function::ExternalLinkage, "", Aliasee, &getModule());
3327 if (GA->getAliasee() == Entry) {
3328 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
3332 assert(Entry->isDeclaration());
3334 // If there is a declaration in the module, then we had an extern followed
3335 // by the alias, as in:
3336 // extern int test6();
3338 // int test6() __attribute__((alias("test7")));
3340 // Remove it and replace uses of it with the alias.
3341 GA->takeName(Entry);
3343 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
3345 Entry->eraseFromParent();
3347 GA->setName(MangledName);
3350 // Set attributes which are particular to an alias; this is a
3351 // specialization of the attributes which may be set on a global
3352 // variable/function.
3353 if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
3354 D->isWeakImported()) {
3355 GA->setLinkage(llvm::Function::WeakAnyLinkage);
3358 if (const auto *VD = dyn_cast<VarDecl>(D))
3359 if (VD->getTLSKind())
3360 setTLSMode(GA, *VD);
3362 setAliasAttributes(D, GA);
3365 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
3366 const auto *D = cast<ValueDecl>(GD.getDecl());
3367 const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
3368 assert(IFA && "Not an ifunc?");
3370 StringRef MangledName = getMangledName(GD);
3372 if (IFA->getResolver() == MangledName) {
3373 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
3377 // Report an error if some definition overrides ifunc.
3378 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3379 if (Entry && !Entry->isDeclaration()) {
3381 if (lookupRepresentativeDecl(MangledName, OtherGD) &&
3382 DiagnosedConflictingDefinitions.insert(GD).second) {
3383 Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name);
3384 Diags.Report(OtherGD.getDecl()->getLocation(),
3385 diag::note_previous_definition);
3390 Aliases.push_back(GD);
3392 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
3393 llvm::Constant *Resolver =
3394 GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD,
3395 /*ForVTable=*/false);
3396 llvm::GlobalIFunc *GIF =
3397 llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage,
3398 "", Resolver, &getModule());
3400 if (GIF->getResolver() == Entry) {
3401 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
3404 assert(Entry->isDeclaration());
3406 // If there is a declaration in the module, then we had an extern followed
3407 // by the ifunc, as in:
3408 // extern int test();
3410 // int test() __attribute__((ifunc("resolver")));
3412 // Remove it and replace uses of it with the ifunc.
3413 GIF->takeName(Entry);
3415 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
3417 Entry->eraseFromParent();
3419 GIF->setName(MangledName);
3421 SetCommonAttributes(D, GIF);
3424 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
3425 ArrayRef<llvm::Type*> Tys) {
3426 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
3430 static llvm::StringMapEntry<llvm::GlobalVariable *> &
3431 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
3432 const StringLiteral *Literal, bool TargetIsLSB,
3433 bool &IsUTF16, unsigned &StringLength) {
3434 StringRef String = Literal->getString();
3435 unsigned NumBytes = String.size();
3437 // Check for simple case.
3438 if (!Literal->containsNonAsciiOrNull()) {
3439 StringLength = NumBytes;
3440 return *Map.insert(std::make_pair(String, nullptr)).first;
3443 // Otherwise, convert the UTF8 literals into a string of shorts.
3446 SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
3447 const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
3448 llvm::UTF16 *ToPtr = &ToBuf[0];
3450 (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
3451 ToPtr + NumBytes, llvm::strictConversion);
3453 // ConvertUTF8toUTF16 returns the length in ToPtr.
3454 StringLength = ToPtr - &ToBuf[0];
3456 // Add an explicit null.
3458 return *Map.insert(std::make_pair(
3459 StringRef(reinterpret_cast<const char *>(ToBuf.data()),
3460 (StringLength + 1) * 2),
3465 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
3466 unsigned StringLength = 0;
3467 bool isUTF16 = false;
3468 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
3469 GetConstantCFStringEntry(CFConstantStringMap, Literal,
3470 getDataLayout().isLittleEndian(), isUTF16,
3473 if (auto *C = Entry.second)
3474 return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment()));
3476 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
3477 llvm::Constant *Zeros[] = { Zero, Zero };
3479 // If we don't already have it, get __CFConstantStringClassReference.
3480 if (!CFConstantStringClassRef) {
3481 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
3482 Ty = llvm::ArrayType::get(Ty, 0);
3483 llvm::Constant *GV =
3484 CreateRuntimeVariable(Ty, "__CFConstantStringClassReference");
3486 if (getTriple().isOSBinFormatCOFF()) {
3487 IdentifierInfo &II = getContext().Idents.get(GV->getName());
3488 TranslationUnitDecl *TUDecl = getContext().getTranslationUnitDecl();
3489 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
3490 llvm::GlobalValue *CGV = cast<llvm::GlobalValue>(GV);
3492 const VarDecl *VD = nullptr;
3493 for (const auto &Result : DC->lookup(&II))
3494 if ((VD = dyn_cast<VarDecl>(Result)))
3497 if (!VD || !VD->hasAttr<DLLExportAttr>()) {
3498 CGV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
3499 CGV->setLinkage(llvm::GlobalValue::ExternalLinkage);
3501 CGV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
3502 CGV->setLinkage(llvm::GlobalValue::ExternalLinkage);
3506 // Decay array -> ptr
3507 CFConstantStringClassRef =
3508 llvm::ConstantExpr::getGetElementPtr(Ty, GV, Zeros);
3511 QualType CFTy = getContext().getCFConstantStringType();
3513 auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
3515 ConstantInitBuilder Builder(*this);
3516 auto Fields = Builder.beginStruct(STy);
3519 Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
3522 Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
3525 llvm::Constant *C = nullptr;
3527 auto Arr = llvm::makeArrayRef(
3528 reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
3529 Entry.first().size() / 2);
3530 C = llvm::ConstantDataArray::get(VMContext, Arr);
3532 C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
3535 // Note: -fwritable-strings doesn't make the backing store strings of
3536 // CFStrings writable. (See <rdar://problem/10657500>)
3538 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
3539 llvm::GlobalValue::PrivateLinkage, C, ".str");
3540 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3541 // Don't enforce the target's minimum global alignment, since the only use
3542 // of the string is via this class initializer.
3543 CharUnits Align = isUTF16
3544 ? getContext().getTypeAlignInChars(getContext().ShortTy)
3545 : getContext().getTypeAlignInChars(getContext().CharTy);
3546 GV->setAlignment(Align.getQuantity());
3548 // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
3549 // Without it LLVM can merge the string with a non unnamed_addr one during
3550 // LTO. Doing that changes the section it ends in, which surprises ld64.
3551 if (getTriple().isOSBinFormatMachO())
3552 GV->setSection(isUTF16 ? "__TEXT,__ustring"
3553 : "__TEXT,__cstring,cstring_literals");
3556 llvm::Constant *Str =
3557 llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
3560 // Cast the UTF16 string to the correct type.
3561 Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
3565 auto Ty = getTypes().ConvertType(getContext().LongTy);
3566 Fields.addInt(cast<llvm::IntegerType>(Ty), StringLength);
3568 CharUnits Alignment = getPointerAlign();
3571 GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
3572 /*isConstant=*/false,
3573 llvm::GlobalVariable::PrivateLinkage);
3574 switch (getTriple().getObjectFormat()) {
3575 case llvm::Triple::UnknownObjectFormat:
3576 llvm_unreachable("unknown file format");
3577 case llvm::Triple::COFF:
3578 case llvm::Triple::ELF:
3579 case llvm::Triple::Wasm:
3580 GV->setSection("cfstring");
3582 case llvm::Triple::MachO:
3583 GV->setSection("__DATA,__cfstring");
3588 return ConstantAddress(GV, Alignment);
3591 bool CodeGenModule::getExpressionLocationsEnabled() const {
3592 return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
3595 QualType CodeGenModule::getObjCFastEnumerationStateType() {
3596 if (ObjCFastEnumerationStateType.isNull()) {
3597 RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
3598 D->startDefinition();
3600 QualType FieldTypes[] = {
3601 Context.UnsignedLongTy,
3602 Context.getPointerType(Context.getObjCIdType()),
3603 Context.getPointerType(Context.UnsignedLongTy),
3604 Context.getConstantArrayType(Context.UnsignedLongTy,
3605 llvm::APInt(32, 5), ArrayType::Normal, 0)
3608 for (size_t i = 0; i < 4; ++i) {
3609 FieldDecl *Field = FieldDecl::Create(Context,
3612 SourceLocation(), nullptr,
3613 FieldTypes[i], /*TInfo=*/nullptr,
3614 /*BitWidth=*/nullptr,
3617 Field->setAccess(AS_public);
3621 D->completeDefinition();
3622 ObjCFastEnumerationStateType = Context.getTagDeclType(D);
3625 return ObjCFastEnumerationStateType;
3629 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
3630 assert(!E->getType()->isPointerType() && "Strings are always arrays");
3632 // Don't emit it as the address of the string, emit the string data itself
3633 // as an inline array.
3634 if (E->getCharByteWidth() == 1) {
3635 SmallString<64> Str(E->getString());
3637 // Resize the string to the right size, which is indicated by its type.
3638 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
3639 Str.resize(CAT->getSize().getZExtValue());
3640 return llvm::ConstantDataArray::getString(VMContext, Str, false);
3643 auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
3644 llvm::Type *ElemTy = AType->getElementType();
3645 unsigned NumElements = AType->getNumElements();
3647 // Wide strings have either 2-byte or 4-byte elements.
3648 if (ElemTy->getPrimitiveSizeInBits() == 16) {
3649 SmallVector<uint16_t, 32> Elements;
3650 Elements.reserve(NumElements);
3652 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
3653 Elements.push_back(E->getCodeUnit(i));
3654 Elements.resize(NumElements);
3655 return llvm::ConstantDataArray::get(VMContext, Elements);
3658 assert(ElemTy->getPrimitiveSizeInBits() == 32);
3659 SmallVector<uint32_t, 32> Elements;
3660 Elements.reserve(NumElements);
3662 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
3663 Elements.push_back(E->getCodeUnit(i));
3664 Elements.resize(NumElements);
3665 return llvm::ConstantDataArray::get(VMContext, Elements);
3668 static llvm::GlobalVariable *
3669 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
3670 CodeGenModule &CGM, StringRef GlobalName,
3671 CharUnits Alignment) {
3672 // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
3673 unsigned AddrSpace = 0;
3674 if (CGM.getLangOpts().OpenCL)
3675 AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_constant);
3677 llvm::Module &M = CGM.getModule();
3678 // Create a global variable for this string
3679 auto *GV = new llvm::GlobalVariable(
3680 M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
3681 nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
3682 GV->setAlignment(Alignment.getQuantity());
3683 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3684 if (GV->isWeakForLinker()) {
3685 assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
3686 GV->setComdat(M.getOrInsertComdat(GV->getName()));
3692 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
3693 /// constant array for the given string literal.
3695 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
3697 CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType());
3699 llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
3700 llvm::GlobalVariable **Entry = nullptr;
3701 if (!LangOpts.WritableStrings) {
3702 Entry = &ConstantStringMap[C];
3703 if (auto GV = *Entry) {
3704 if (Alignment.getQuantity() > GV->getAlignment())
3705 GV->setAlignment(Alignment.getQuantity());
3706 return ConstantAddress(GV, Alignment);
3710 SmallString<256> MangledNameBuffer;
3711 StringRef GlobalVariableName;
3712 llvm::GlobalValue::LinkageTypes LT;
3714 // Mangle the string literal if the ABI allows for it. However, we cannot
3715 // do this if we are compiling with ASan or -fwritable-strings because they
3716 // rely on strings having normal linkage.
3717 if (!LangOpts.WritableStrings &&
3718 !LangOpts.Sanitize.has(SanitizerKind::Address) &&
3719 getCXXABI().getMangleContext().shouldMangleStringLiteral(S)) {
3720 llvm::raw_svector_ostream Out(MangledNameBuffer);
3721 getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
3723 LT = llvm::GlobalValue::LinkOnceODRLinkage;
3724 GlobalVariableName = MangledNameBuffer;
3726 LT = llvm::GlobalValue::PrivateLinkage;
3727 GlobalVariableName = Name;
3730 auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
3734 SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>",
3736 return ConstantAddress(GV, Alignment);
3739 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
3740 /// array for the given ObjCEncodeExpr node.
3742 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
3744 getContext().getObjCEncodingForType(E->getEncodedType(), Str);
3746 return GetAddrOfConstantCString(Str);
3749 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
3750 /// the literal and a terminating '\0' character.
3751 /// The result has pointer to array type.
3752 ConstantAddress CodeGenModule::GetAddrOfConstantCString(
3753 const std::string &Str, const char *GlobalName) {
3754 StringRef StrWithNull(Str.c_str(), Str.size() + 1);
3755 CharUnits Alignment =
3756 getContext().getAlignOfGlobalVarInChars(getContext().CharTy);
3759 llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
3761 // Don't share any string literals if strings aren't constant.
3762 llvm::GlobalVariable **Entry = nullptr;
3763 if (!LangOpts.WritableStrings) {
3764 Entry = &ConstantStringMap[C];
3765 if (auto GV = *Entry) {
3766 if (Alignment.getQuantity() > GV->getAlignment())
3767 GV->setAlignment(Alignment.getQuantity());
3768 return ConstantAddress(GV, Alignment);
3772 // Get the default prefix if a name wasn't specified.
3774 GlobalName = ".str";
3775 // Create a global variable for this.
3776 auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
3777 GlobalName, Alignment);
3780 return ConstantAddress(GV, Alignment);
3783 ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
3784 const MaterializeTemporaryExpr *E, const Expr *Init) {
3785 assert((E->getStorageDuration() == SD_Static ||
3786 E->getStorageDuration() == SD_Thread) && "not a global temporary");
3787 const auto *VD = cast<VarDecl>(E->getExtendingDecl());
3789 // If we're not materializing a subobject of the temporary, keep the
3790 // cv-qualifiers from the type of the MaterializeTemporaryExpr.
3791 QualType MaterializedType = Init->getType();
3792 if (Init == E->GetTemporaryExpr())
3793 MaterializedType = E->getType();
3795 CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
3797 if (llvm::Constant *Slot = MaterializedGlobalTemporaryMap[E])
3798 return ConstantAddress(Slot, Align);
3800 // FIXME: If an externally-visible declaration extends multiple temporaries,
3801 // we need to give each temporary the same name in every translation unit (and
3802 // we also need to make the temporaries externally-visible).
3803 SmallString<256> Name;
3804 llvm::raw_svector_ostream Out(Name);
3805 getCXXABI().getMangleContext().mangleReferenceTemporary(
3806 VD, E->getManglingNumber(), Out);
3808 APValue *Value = nullptr;
3809 if (E->getStorageDuration() == SD_Static) {
3810 // We might have a cached constant initializer for this temporary. Note
3811 // that this might have a different value from the value computed by
3812 // evaluating the initializer if the surrounding constant expression
3813 // modifies the temporary.
3814 Value = getContext().getMaterializedTemporaryValue(E, false);
3815 if (Value && Value->isUninit())
3819 // Try evaluating it now, it might have a constant initializer.
3820 Expr::EvalResult EvalResult;
3821 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
3822 !EvalResult.hasSideEffects())
3823 Value = &EvalResult.Val;
3826 VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace();
3828 Optional<ConstantEmitter> emitter;
3829 llvm::Constant *InitialValue = nullptr;
3830 bool Constant = false;
3833 // The temporary has a constant initializer, use it.
3834 emitter.emplace(*this);
3835 InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
3837 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value);
3838 Type = InitialValue->getType();
3840 // No initializer, the initialization will be provided when we
3841 // initialize the declaration which performed lifetime extension.
3842 Type = getTypes().ConvertTypeForMem(MaterializedType);
3845 // Create a global variable for this lifetime-extended temporary.
3846 llvm::GlobalValue::LinkageTypes Linkage =
3847 getLLVMLinkageVarDefinition(VD, Constant);
3848 if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
3849 const VarDecl *InitVD;
3850 if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
3851 isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
3852 // Temporaries defined inside a class get linkonce_odr linkage because the
3853 // class can be defined in multipe translation units.
3854 Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
3856 // There is no need for this temporary to have external linkage if the
3857 // VarDecl has external linkage.
3858 Linkage = llvm::GlobalVariable::InternalLinkage;
3861 auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
3862 auto *GV = new llvm::GlobalVariable(
3863 getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
3864 /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
3865 if (emitter) emitter->finalize(GV);
3866 setGlobalVisibility(GV, VD, ForDefinition);
3867 GV->setAlignment(Align.getQuantity());
3868 if (supportsCOMDAT() && GV->isWeakForLinker())
3869 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3870 if (VD->getTLSKind())
3871 setTLSMode(GV, *VD);
3872 llvm::Constant *CV = GV;
3873 if (AddrSpace != LangAS::Default)
3874 CV = getTargetCodeGenInfo().performAddrSpaceCast(
3875 *this, GV, AddrSpace, LangAS::Default,
3877 getContext().getTargetAddressSpace(LangAS::Default)));
3878 MaterializedGlobalTemporaryMap[E] = CV;
3879 return ConstantAddress(CV, Align);
3882 /// EmitObjCPropertyImplementations - Emit information for synthesized
3883 /// properties for an implementation.
3884 void CodeGenModule::EmitObjCPropertyImplementations(const
3885 ObjCImplementationDecl *D) {
3886 for (const auto *PID : D->property_impls()) {
3887 // Dynamic is just for type-checking.
3888 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
3889 ObjCPropertyDecl *PD = PID->getPropertyDecl();
3891 // Determine which methods need to be implemented, some may have
3892 // been overridden. Note that ::isPropertyAccessor is not the method
3893 // we want, that just indicates if the decl came from a
3894 // property. What we want to know is if the method is defined in
3895 // this implementation.
3896 if (!D->getInstanceMethod(PD->getGetterName()))
3897 CodeGenFunction(*this).GenerateObjCGetter(
3898 const_cast<ObjCImplementationDecl *>(D), PID);
3899 if (!PD->isReadOnly() &&
3900 !D->getInstanceMethod(PD->getSetterName()))
3901 CodeGenFunction(*this).GenerateObjCSetter(
3902 const_cast<ObjCImplementationDecl *>(D), PID);
3907 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
3908 const ObjCInterfaceDecl *iface = impl->getClassInterface();
3909 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
3910 ivar; ivar = ivar->getNextIvar())
3911 if (ivar->getType().isDestructedType())
3917 static bool AllTrivialInitializers(CodeGenModule &CGM,
3918 ObjCImplementationDecl *D) {
3919 CodeGenFunction CGF(CGM);
3920 for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
3921 E = D->init_end(); B != E; ++B) {
3922 CXXCtorInitializer *CtorInitExp = *B;
3923 Expr *Init = CtorInitExp->getInit();
3924 if (!CGF.isTrivialInitializer(Init))
3930 /// EmitObjCIvarInitializations - Emit information for ivar initialization
3931 /// for an implementation.
3932 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
3933 // We might need a .cxx_destruct even if we don't have any ivar initializers.
3934 if (needsDestructMethod(D)) {
3935 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
3936 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
3937 ObjCMethodDecl *DTORMethod =
3938 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(),
3939 cxxSelector, getContext().VoidTy, nullptr, D,
3940 /*isInstance=*/true, /*isVariadic=*/false,
3941 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true,
3942 /*isDefined=*/false, ObjCMethodDecl::Required);
3943 D->addInstanceMethod(DTORMethod);
3944 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
3945 D->setHasDestructors(true);
3948 // If the implementation doesn't have any ivar initializers, we don't need
3949 // a .cxx_construct.
3950 if (D->getNumIvarInitializers() == 0 ||
3951 AllTrivialInitializers(*this, D))
3954 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
3955 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
3956 // The constructor returns 'self'.
3957 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(),
3961 getContext().getObjCIdType(),
3962 nullptr, D, /*isInstance=*/true,
3963 /*isVariadic=*/false,
3964 /*isPropertyAccessor=*/true,
3965 /*isImplicitlyDeclared=*/true,
3966 /*isDefined=*/false,
3967 ObjCMethodDecl::Required);
3968 D->addInstanceMethod(CTORMethod);
3969 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
3970 D->setHasNonZeroConstructors(true);
3973 // EmitLinkageSpec - Emit all declarations in a linkage spec.
3974 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
3975 if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
3976 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
3977 ErrorUnsupported(LSD, "linkage spec");
3981 EmitDeclContext(LSD);
3984 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
3985 for (auto *I : DC->decls()) {
3986 // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
3987 // are themselves considered "top-level", so EmitTopLevelDecl on an
3988 // ObjCImplDecl does not recursively visit them. We need to do that in
3989 // case they're nested inside another construct (LinkageSpecDecl /
3990 // ExportDecl) that does stop them from being considered "top-level".
3991 if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
3992 for (auto *M : OID->methods())
3993 EmitTopLevelDecl(M);
3996 EmitTopLevelDecl(I);
4000 /// EmitTopLevelDecl - Emit code for a single top level declaration.
4001 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
4002 // Ignore dependent declarations.
4003 if (D->isTemplated())
4006 switch (D->getKind()) {
4007 case Decl::CXXConversion:
4008 case Decl::CXXMethod:
4009 case Decl::Function:
4010 EmitGlobal(cast<FunctionDecl>(D));
4011 // Always provide some coverage mapping
4012 // even for the functions that aren't emitted.
4013 AddDeferredUnusedCoverageMapping(D);
4016 case Decl::CXXDeductionGuide:
4017 // Function-like, but does not result in code emission.
4021 case Decl::Decomposition:
4022 case Decl::VarTemplateSpecialization:
4023 EmitGlobal(cast<VarDecl>(D));
4024 if (auto *DD = dyn_cast<DecompositionDecl>(D))
4025 for (auto *B : DD->bindings())
4026 if (auto *HD = B->getHoldingVar())
4030 // Indirect fields from global anonymous structs and unions can be
4031 // ignored; only the actual variable requires IR gen support.
4032 case Decl::IndirectField:
4036 case Decl::Namespace:
4037 EmitDeclContext(cast<NamespaceDecl>(D));
4039 case Decl::ClassTemplateSpecialization: {
4040 const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
4042 Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition &&
4043 Spec->hasDefinition())
4044 DebugInfo->completeTemplateDefinition(*Spec);
4046 case Decl::CXXRecord:
4048 if (auto *ES = D->getASTContext().getExternalSource())
4049 if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
4050 DebugInfo->completeUnusedClass(cast<CXXRecordDecl>(*D));
4052 // Emit any static data members, they may be definitions.
4053 for (auto *I : cast<CXXRecordDecl>(D)->decls())
4054 if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
4055 EmitTopLevelDecl(I);
4057 // No code generation needed.
4058 case Decl::UsingShadow:
4059 case Decl::ClassTemplate:
4060 case Decl::VarTemplate:
4061 case Decl::VarTemplatePartialSpecialization:
4062 case Decl::FunctionTemplate:
4063 case Decl::TypeAliasTemplate:
4067 case Decl::Using: // using X; [C++]
4068 if (CGDebugInfo *DI = getModuleDebugInfo())
4069 DI->EmitUsingDecl(cast<UsingDecl>(*D));
4071 case Decl::NamespaceAlias:
4072 if (CGDebugInfo *DI = getModuleDebugInfo())
4073 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
4075 case Decl::UsingDirective: // using namespace X; [C++]
4076 if (CGDebugInfo *DI = getModuleDebugInfo())
4077 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
4079 case Decl::CXXConstructor:
4080 getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
4082 case Decl::CXXDestructor:
4083 getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
4086 case Decl::StaticAssert:
4090 // Objective-C Decls
4092 // Forward declarations, no (immediate) code generation.
4093 case Decl::ObjCInterface:
4094 case Decl::ObjCCategory:
4097 case Decl::ObjCProtocol: {
4098 auto *Proto = cast<ObjCProtocolDecl>(D);
4099 if (Proto->isThisDeclarationADefinition())
4100 ObjCRuntime->GenerateProtocol(Proto);
4104 case Decl::ObjCCategoryImpl:
4105 // Categories have properties but don't support synthesize so we
4106 // can ignore them here.
4107 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
4110 case Decl::ObjCImplementation: {
4111 auto *OMD = cast<ObjCImplementationDecl>(D);
4112 EmitObjCPropertyImplementations(OMD);
4113 EmitObjCIvarInitializations(OMD);
4114 ObjCRuntime->GenerateClass(OMD);
4115 // Emit global variable debug information.
4116 if (CGDebugInfo *DI = getModuleDebugInfo())
4117 if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
4118 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
4119 OMD->getClassInterface()), OMD->getLocation());
4122 case Decl::ObjCMethod: {
4123 auto *OMD = cast<ObjCMethodDecl>(D);
4124 // If this is not a prototype, emit the body.
4126 CodeGenFunction(*this).GenerateObjCMethod(OMD);
4129 case Decl::ObjCCompatibleAlias:
4130 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
4133 case Decl::PragmaComment: {
4134 const auto *PCD = cast<PragmaCommentDecl>(D);
4135 switch (PCD->getCommentKind()) {
4137 llvm_unreachable("unexpected pragma comment kind");
4139 AppendLinkerOptions(PCD->getArg());
4142 AddDependentLib(PCD->getArg());
4147 break; // We ignore all of these.
4152 case Decl::PragmaDetectMismatch: {
4153 const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
4154 AddDetectMismatch(PDMD->getName(), PDMD->getValue());
4158 case Decl::LinkageSpec:
4159 EmitLinkageSpec(cast<LinkageSpecDecl>(D));
4162 case Decl::FileScopeAsm: {
4163 // File-scope asm is ignored during device-side CUDA compilation.
4164 if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
4166 // File-scope asm is ignored during device-side OpenMP compilation.
4167 if (LangOpts.OpenMPIsDevice)
4169 auto *AD = cast<FileScopeAsmDecl>(D);
4170 getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
4174 case Decl::Import: {
4175 auto *Import = cast<ImportDecl>(D);
4177 // If we've already imported this module, we're done.
4178 if (!ImportedModules.insert(Import->getImportedModule()))
4181 // Emit debug information for direct imports.
4182 if (!Import->getImportedOwningModule()) {
4183 if (CGDebugInfo *DI = getModuleDebugInfo())
4184 DI->EmitImportDecl(*Import);
4187 // Find all of the submodules and emit the module initializers.
4188 llvm::SmallPtrSet<clang::Module *, 16> Visited;
4189 SmallVector<clang::Module *, 16> Stack;
4190 Visited.insert(Import->getImportedModule());
4191 Stack.push_back(Import->getImportedModule());
4193 while (!Stack.empty()) {
4194 clang::Module *Mod = Stack.pop_back_val();
4195 if (!EmittedModuleInitializers.insert(Mod).second)
4198 for (auto *D : Context.getModuleInitializers(Mod))
4199 EmitTopLevelDecl(D);
4201 // Visit the submodules of this module.
4202 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
4203 SubEnd = Mod->submodule_end();
4204 Sub != SubEnd; ++Sub) {
4205 // Skip explicit children; they need to be explicitly imported to emit
4206 // the initializers.
4207 if ((*Sub)->IsExplicit)
4210 if (Visited.insert(*Sub).second)
4211 Stack.push_back(*Sub);
4218 EmitDeclContext(cast<ExportDecl>(D));
4221 case Decl::OMPThreadPrivate:
4222 EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
4225 case Decl::OMPDeclareReduction:
4226 EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
4230 // Make sure we handled everything we should, every other kind is a
4231 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
4232 // function. Need to recode Decl::Kind to do that easily.
4233 assert(isa<TypeDecl>(D) && "Unsupported decl kind");
4238 void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
4239 // Do we need to generate coverage mapping?
4240 if (!CodeGenOpts.CoverageMapping)
4242 switch (D->getKind()) {
4243 case Decl::CXXConversion:
4244 case Decl::CXXMethod:
4245 case Decl::Function:
4246 case Decl::ObjCMethod:
4247 case Decl::CXXConstructor:
4248 case Decl::CXXDestructor: {
4249 if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
4251 SourceManager &SM = getContext().getSourceManager();
4252 if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getLocStart()))
4254 auto I = DeferredEmptyCoverageMappingDecls.find(D);
4255 if (I == DeferredEmptyCoverageMappingDecls.end())
4256 DeferredEmptyCoverageMappingDecls[D] = true;
4264 void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
4265 // Do we need to generate coverage mapping?
4266 if (!CodeGenOpts.CoverageMapping)
4268 if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
4269 if (Fn->isTemplateInstantiation())
4270 ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
4272 auto I = DeferredEmptyCoverageMappingDecls.find(D);
4273 if (I == DeferredEmptyCoverageMappingDecls.end())
4274 DeferredEmptyCoverageMappingDecls[D] = false;
4279 void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
4280 // We call takeVector() here to avoid use-after-free.
4281 // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
4282 // we deserialize function bodies to emit coverage info for them, and that
4283 // deserializes more declarations. How should we handle that case?
4284 for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
4287 const Decl *D = Entry.first;
4288 switch (D->getKind()) {
4289 case Decl::CXXConversion:
4290 case Decl::CXXMethod:
4291 case Decl::Function:
4292 case Decl::ObjCMethod: {
4293 CodeGenPGO PGO(*this);
4294 GlobalDecl GD(cast<FunctionDecl>(D));
4295 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
4296 getFunctionLinkage(GD));
4299 case Decl::CXXConstructor: {
4300 CodeGenPGO PGO(*this);
4301 GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
4302 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
4303 getFunctionLinkage(GD));
4306 case Decl::CXXDestructor: {
4307 CodeGenPGO PGO(*this);
4308 GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
4309 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
4310 getFunctionLinkage(GD));
4319 /// Turns the given pointer into a constant.
4320 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
4322 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
4323 llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
4324 return llvm::ConstantInt::get(i64, PtrInt);
4327 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
4328 llvm::NamedMDNode *&GlobalMetadata,
4330 llvm::GlobalValue *Addr) {
4331 if (!GlobalMetadata)
4333 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
4335 // TODO: should we report variant information for ctors/dtors?
4336 llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
4337 llvm::ConstantAsMetadata::get(GetPointerConstant(
4338 CGM.getLLVMContext(), D.getDecl()))};
4339 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
4342 /// For each function which is declared within an extern "C" region and marked
4343 /// as 'used', but has internal linkage, create an alias from the unmangled
4344 /// name to the mangled name if possible. People expect to be able to refer
4345 /// to such functions with an unmangled name from inline assembly within the
4346 /// same translation unit.
4347 void CodeGenModule::EmitStaticExternCAliases() {
4348 // Don't do anything if we're generating CUDA device code -- the NVPTX
4349 // assembly target doesn't support aliases.
4350 if (Context.getTargetInfo().getTriple().isNVPTX())
4352 for (auto &I : StaticExternCValues) {
4353 IdentifierInfo *Name = I.first;
4354 llvm::GlobalValue *Val = I.second;
4355 if (Val && !getModule().getNamedValue(Name->getName()))
4356 addUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
4360 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
4361 GlobalDecl &Result) const {
4362 auto Res = Manglings.find(MangledName);
4363 if (Res == Manglings.end())
4365 Result = Res->getValue();
4369 /// Emits metadata nodes associating all the global values in the
4370 /// current module with the Decls they came from. This is useful for
4371 /// projects using IR gen as a subroutine.
4373 /// Since there's currently no way to associate an MDNode directly
4374 /// with an llvm::GlobalValue, we create a global named metadata
4375 /// with the name 'clang.global.decl.ptrs'.
4376 void CodeGenModule::EmitDeclMetadata() {
4377 llvm::NamedMDNode *GlobalMetadata = nullptr;
4379 for (auto &I : MangledDeclNames) {
4380 llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
4381 // Some mangled names don't necessarily have an associated GlobalValue
4382 // in this module, e.g. if we mangled it for DebugInfo.
4384 EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
4388 /// Emits metadata nodes for all the local variables in the current
4390 void CodeGenFunction::EmitDeclMetadata() {
4391 if (LocalDeclMap.empty()) return;
4393 llvm::LLVMContext &Context = getLLVMContext();
4395 // Find the unique metadata ID for this name.
4396 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
4398 llvm::NamedMDNode *GlobalMetadata = nullptr;
4400 for (auto &I : LocalDeclMap) {
4401 const Decl *D = I.first;
4402 llvm::Value *Addr = I.second.getPointer();
4403 if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
4404 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
4405 Alloca->setMetadata(
4406 DeclPtrKind, llvm::MDNode::get(
4407 Context, llvm::ValueAsMetadata::getConstant(DAddr)));
4408 } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
4409 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
4410 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
4415 void CodeGenModule::EmitVersionIdentMetadata() {
4416 llvm::NamedMDNode *IdentMetadata =
4417 TheModule.getOrInsertNamedMetadata("llvm.ident");
4418 std::string Version = getClangFullVersion();
4419 llvm::LLVMContext &Ctx = TheModule.getContext();
4421 llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
4422 IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
4425 void CodeGenModule::EmitTargetMetadata() {
4426 // Warning, new MangledDeclNames may be appended within this loop.
4427 // We rely on MapVector insertions adding new elements to the end
4428 // of the container.
4429 // FIXME: Move this loop into the one target that needs it, and only
4430 // loop over those declarations for which we couldn't emit the target
4431 // metadata when we emitted the declaration.
4432 for (unsigned I = 0; I != MangledDeclNames.size(); ++I) {
4433 auto Val = *(MangledDeclNames.begin() + I);
4434 const Decl *D = Val.first.getDecl()->getMostRecentDecl();
4435 llvm::GlobalValue *GV = GetGlobalValue(Val.second);
4436 getTargetCodeGenInfo().emitTargetMD(D, GV, *this);
4440 void CodeGenModule::EmitCoverageFile() {
4441 if (getCodeGenOpts().CoverageDataFile.empty() &&
4442 getCodeGenOpts().CoverageNotesFile.empty())
4445 llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
4449 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
4450 llvm::LLVMContext &Ctx = TheModule.getContext();
4451 auto *CoverageDataFile =
4452 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
4453 auto *CoverageNotesFile =
4454 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
4455 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
4456 llvm::MDNode *CU = CUNode->getOperand(i);
4457 llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
4458 GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
4462 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid) {
4463 // Sema has checked that all uuid strings are of the form
4464 // "12345678-1234-1234-1234-1234567890ab".
4465 assert(Uuid.size() == 36);
4466 for (unsigned i = 0; i < 36; ++i) {
4467 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-');
4468 else assert(isHexDigit(Uuid[i]));
4471 // The starts of all bytes of Field3 in Uuid. Field 3 is "1234-1234567890ab".
4472 const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 };
4474 llvm::Constant *Field3[8];
4475 for (unsigned Idx = 0; Idx < 8; ++Idx)
4476 Field3[Idx] = llvm::ConstantInt::get(
4477 Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16);
4479 llvm::Constant *Fields[4] = {
4480 llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16),
4481 llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16),
4482 llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16),
4483 llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3)
4486 return llvm::ConstantStruct::getAnon(Fields);
4489 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
4491 // Return a bogus pointer if RTTI is disabled, unless it's for EH.
4492 // FIXME: should we even be calling this method if RTTI is disabled
4493 // and it's not for EH?
4494 if (!ForEH && !getLangOpts().RTTI)
4495 return llvm::Constant::getNullValue(Int8PtrTy);
4497 if (ForEH && Ty->isObjCObjectPointerType() &&
4498 LangOpts.ObjCRuntime.isGNUFamily())
4499 return ObjCRuntime->GetEHType(Ty);
4501 return getCXXABI().getAddrOfRTTIDescriptor(Ty);
4504 void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
4505 // Do not emit threadprivates in simd-only mode.
4506 if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
4508 for (auto RefExpr : D->varlists()) {
4509 auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
4511 VD->getAnyInitializer() &&
4512 !VD->getAnyInitializer()->isConstantInitializer(getContext(),
4515 Address Addr(GetAddrOfGlobalVar(VD), getContext().getDeclAlign(VD));
4516 if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
4517 VD, Addr, RefExpr->getLocStart(), PerformInit))
4518 CXXGlobalInits.push_back(InitFunction);
4522 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
4523 llvm::Metadata *&InternalId = MetadataIdMap[T.getCanonicalType()];
4527 if (isExternallyVisible(T->getLinkage())) {
4528 std::string OutName;
4529 llvm::raw_string_ostream Out(OutName);
4530 getCXXABI().getMangleContext().mangleTypeName(T, Out);
4532 InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
4534 InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
4535 llvm::ArrayRef<llvm::Metadata *>());
4541 // Generalize pointer types to a void pointer with the qualifiers of the
4542 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
4543 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
4545 static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
4546 if (!Ty->isPointerType())
4549 return Ctx.getPointerType(
4550 QualType(Ctx.VoidTy).withCVRQualifiers(
4551 Ty->getPointeeType().getCVRQualifiers()));
4554 // Apply type generalization to a FunctionType's return and argument types
4555 static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
4556 if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
4557 SmallVector<QualType, 8> GeneralizedParams;
4558 for (auto &Param : FnType->param_types())
4559 GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
4561 return Ctx.getFunctionType(
4562 GeneralizeType(Ctx, FnType->getReturnType()),
4563 GeneralizedParams, FnType->getExtProtoInfo());
4566 if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
4567 return Ctx.getFunctionNoProtoType(
4568 GeneralizeType(Ctx, FnType->getReturnType()));
4570 llvm_unreachable("Encountered unknown FunctionType");
4573 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
4574 T = GeneralizeFunctionType(getContext(), T);
4576 llvm::Metadata *&InternalId = GeneralizedMetadataIdMap[T.getCanonicalType()];
4580 if (isExternallyVisible(T->getLinkage())) {
4581 std::string OutName;
4582 llvm::raw_string_ostream Out(OutName);
4583 getCXXABI().getMangleContext().mangleTypeName(T, Out);
4584 Out << ".generalized";
4586 InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
4588 InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
4589 llvm::ArrayRef<llvm::Metadata *>());
4595 /// Returns whether this module needs the "all-vtables" type identifier.
4596 bool CodeGenModule::NeedAllVtablesTypeId() const {
4597 // Returns true if at least one of vtable-based CFI checkers is enabled and
4598 // is not in the trapping mode.
4599 return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
4600 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
4601 (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
4602 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
4603 (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
4604 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
4605 (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
4606 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
4609 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
4611 const CXXRecordDecl *RD) {
4612 llvm::Metadata *MD =
4613 CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
4614 VTable->addTypeMetadata(Offset.getQuantity(), MD);
4616 if (CodeGenOpts.SanitizeCfiCrossDso)
4617 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
4618 VTable->addTypeMetadata(Offset.getQuantity(),
4619 llvm::ConstantAsMetadata::get(CrossDsoTypeId));
4621 if (NeedAllVtablesTypeId()) {
4622 llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
4623 VTable->addTypeMetadata(Offset.getQuantity(), MD);
4627 // Fills in the supplied string map with the set of target features for the
4628 // passed in function.
4629 void CodeGenModule::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
4630 const FunctionDecl *FD) {
4631 StringRef TargetCPU = Target.getTargetOpts().CPU;
4632 if (const auto *TD = FD->getAttr<TargetAttr>()) {
4633 // If we have a TargetAttr build up the feature map based on that.
4634 TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
4636 ParsedAttr.Features.erase(
4637 llvm::remove_if(ParsedAttr.Features,
4638 [&](const std::string &Feat) {
4639 return !Target.isValidFeatureName(
4640 StringRef{Feat}.substr(1));
4642 ParsedAttr.Features.end());
4644 // Make a copy of the features as passed on the command line into the
4645 // beginning of the additional features from the function to override.
4646 ParsedAttr.Features.insert(ParsedAttr.Features.begin(),
4647 Target.getTargetOpts().FeaturesAsWritten.begin(),
4648 Target.getTargetOpts().FeaturesAsWritten.end());
4650 if (ParsedAttr.Architecture != "" &&
4651 Target.isValidCPUName(ParsedAttr.Architecture))
4652 TargetCPU = ParsedAttr.Architecture;
4654 // Now populate the feature map, first with the TargetCPU which is either
4655 // the default or a new one from the target attribute string. Then we'll use
4656 // the passed in features (FeaturesAsWritten) along with the new ones from
4658 Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU,
4659 ParsedAttr.Features);
4661 Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU,
4662 Target.getTargetOpts().Features);
4666 llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
4668 SanStats = llvm::make_unique<llvm::SanitizerStatReport>(&getModule());
4673 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
4674 CodeGenFunction &CGF) {
4675 llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
4676 auto SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
4677 auto FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
4678 return CGF.Builder.CreateCall(CreateRuntimeFunction(FTy,
4679 "__translate_sampler_initializer"),