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 FloatTy = llvm::Type::getFloatTy(LLVMContext);
107 DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
108 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
109 PointerAlignInBytes =
110 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
112 C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
114 C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
115 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
116 IntPtrTy = llvm::IntegerType::get(LLVMContext,
117 C.getTargetInfo().getMaxPointerWidth());
118 Int8PtrTy = Int8Ty->getPointerTo(0);
119 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
120 AllocaInt8PtrTy = Int8Ty->getPointerTo(
121 M.getDataLayout().getAllocaAddrSpace());
122 ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
124 RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
125 BuiltinCC = getTargetCodeGenInfo().getABIInfo().getBuiltinCC();
130 createOpenCLRuntime();
132 createOpenMPRuntime();
136 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
137 if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
138 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
139 TBAA.reset(new CodeGenTBAA(Context, TheModule, CodeGenOpts, getLangOpts(),
140 getCXXABI().getMangleContext()));
142 // If debug info or coverage generation is enabled, create the CGDebugInfo
144 if (CodeGenOpts.getDebugInfo() != codegenoptions::NoDebugInfo ||
145 CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)
146 DebugInfo.reset(new CGDebugInfo(*this));
148 Block.GlobalUniqueCount = 0;
150 if (C.getLangOpts().ObjC1)
151 ObjCData.reset(new ObjCEntrypoints());
153 if (CodeGenOpts.hasProfileClangUse()) {
154 auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
155 CodeGenOpts.ProfileInstrumentUsePath);
156 if (auto E = ReaderOrErr.takeError()) {
157 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
158 "Could not read profile %0: %1");
159 llvm::handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EI) {
160 getDiags().Report(DiagID) << CodeGenOpts.ProfileInstrumentUsePath
164 PGOReader = std::move(ReaderOrErr.get());
167 // If coverage mapping generation is enabled, create the
168 // CoverageMappingModuleGen object.
169 if (CodeGenOpts.CoverageMapping)
170 CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
173 CodeGenModule::~CodeGenModule() {}
175 void CodeGenModule::createObjCRuntime() {
176 // This is just isGNUFamily(), but we want to force implementors of
177 // new ABIs to decide how best to do this.
178 switch (LangOpts.ObjCRuntime.getKind()) {
179 case ObjCRuntime::GNUstep:
180 case ObjCRuntime::GCC:
181 case ObjCRuntime::ObjFW:
182 ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
185 case ObjCRuntime::FragileMacOSX:
186 case ObjCRuntime::MacOSX:
187 case ObjCRuntime::iOS:
188 case ObjCRuntime::WatchOS:
189 ObjCRuntime.reset(CreateMacObjCRuntime(*this));
192 llvm_unreachable("bad runtime kind");
195 void CodeGenModule::createOpenCLRuntime() {
196 OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
199 void CodeGenModule::createOpenMPRuntime() {
200 // Select a specialized code generation class based on the target, if any.
201 // If it does not exist use the default implementation.
202 switch (getTriple().getArch()) {
203 case llvm::Triple::nvptx:
204 case llvm::Triple::nvptx64:
205 assert(getLangOpts().OpenMPIsDevice &&
206 "OpenMP NVPTX is only prepared to deal with device code.");
207 OpenMPRuntime.reset(new CGOpenMPRuntimeNVPTX(*this));
210 OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
215 void CodeGenModule::createCUDARuntime() {
216 CUDARuntime.reset(CreateNVCUDARuntime(*this));
219 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
220 Replacements[Name] = C;
223 void CodeGenModule::applyReplacements() {
224 for (auto &I : Replacements) {
225 StringRef MangledName = I.first();
226 llvm::Constant *Replacement = I.second;
227 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
230 auto *OldF = cast<llvm::Function>(Entry);
231 auto *NewF = dyn_cast<llvm::Function>(Replacement);
233 if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
234 NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
236 auto *CE = cast<llvm::ConstantExpr>(Replacement);
237 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
238 CE->getOpcode() == llvm::Instruction::GetElementPtr);
239 NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
243 // Replace old with new, but keep the old order.
244 OldF->replaceAllUsesWith(Replacement);
246 NewF->removeFromParent();
247 OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
250 OldF->eraseFromParent();
254 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
255 GlobalValReplacements.push_back(std::make_pair(GV, C));
258 void CodeGenModule::applyGlobalValReplacements() {
259 for (auto &I : GlobalValReplacements) {
260 llvm::GlobalValue *GV = I.first;
261 llvm::Constant *C = I.second;
263 GV->replaceAllUsesWith(C);
264 GV->eraseFromParent();
268 // This is only used in aliases that we created and we know they have a
270 static const llvm::GlobalObject *getAliasedGlobal(
271 const llvm::GlobalIndirectSymbol &GIS) {
272 llvm::SmallPtrSet<const llvm::GlobalIndirectSymbol*, 4> Visited;
273 const llvm::Constant *C = &GIS;
275 C = C->stripPointerCasts();
276 if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
278 // stripPointerCasts will not walk over weak aliases.
279 auto *GIS2 = dyn_cast<llvm::GlobalIndirectSymbol>(C);
282 if (!Visited.insert(GIS2).second)
284 C = GIS2->getIndirectSymbol();
288 void CodeGenModule::checkAliases() {
289 // Check if the constructed aliases are well formed. It is really unfortunate
290 // that we have to do this in CodeGen, but we only construct mangled names
291 // and aliases during codegen.
293 DiagnosticsEngine &Diags = getDiags();
294 for (const GlobalDecl &GD : Aliases) {
295 const auto *D = cast<ValueDecl>(GD.getDecl());
296 SourceLocation Location;
297 bool IsIFunc = D->hasAttr<IFuncAttr>();
298 if (const Attr *A = D->getDefiningAttr())
299 Location = A->getLocation();
301 llvm_unreachable("Not an alias or ifunc?");
302 StringRef MangledName = getMangledName(GD);
303 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
304 auto *Alias = cast<llvm::GlobalIndirectSymbol>(Entry);
305 const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
308 Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
309 } else if (GV->isDeclaration()) {
311 Diags.Report(Location, diag::err_alias_to_undefined)
312 << IsIFunc << IsIFunc;
313 } else if (IsIFunc) {
314 // Check resolver function type.
315 llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(
316 GV->getType()->getPointerElementType());
318 if (!FTy->getReturnType()->isPointerTy())
319 Diags.Report(Location, diag::err_ifunc_resolver_return);
320 if (FTy->getNumParams())
321 Diags.Report(Location, diag::err_ifunc_resolver_params);
324 llvm::Constant *Aliasee = Alias->getIndirectSymbol();
325 llvm::GlobalValue *AliaseeGV;
326 if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
327 AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
329 AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
331 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
332 StringRef AliasSection = SA->getName();
333 if (AliasSection != AliaseeGV->getSection())
334 Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
335 << AliasSection << IsIFunc << IsIFunc;
338 // We have to handle alias to weak aliases in here. LLVM itself disallows
339 // this since the object semantics would not match the IL one. For
340 // compatibility with gcc we implement it by just pointing the alias
341 // to its aliasee's aliasee. We also warn, since the user is probably
342 // expecting the link to be weak.
343 if (auto GA = dyn_cast<llvm::GlobalIndirectSymbol>(AliaseeGV)) {
344 if (GA->isInterposable()) {
345 Diags.Report(Location, diag::warn_alias_to_weak_alias)
346 << GV->getName() << GA->getName() << IsIFunc;
347 Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
348 GA->getIndirectSymbol(), Alias->getType());
349 Alias->setIndirectSymbol(Aliasee);
356 for (const GlobalDecl &GD : Aliases) {
357 StringRef MangledName = getMangledName(GD);
358 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
359 auto *Alias = dyn_cast<llvm::GlobalIndirectSymbol>(Entry);
360 Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
361 Alias->eraseFromParent();
365 void CodeGenModule::clear() {
366 DeferredDeclsToEmit.clear();
368 OpenMPRuntime->clear();
371 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
372 StringRef MainFile) {
373 if (!hasDiagnostics())
375 if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
376 if (MainFile.empty())
377 MainFile = "<stdin>";
378 Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
381 Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
384 Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
388 void CodeGenModule::Release() {
390 EmitVTablesOpportunistically();
391 applyGlobalValReplacements();
394 EmitCXXGlobalInitFunc();
395 EmitCXXGlobalDtorFunc();
396 EmitCXXThreadLocalInitFunc();
398 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
399 AddGlobalCtor(ObjCInitFunction);
400 if (Context.getLangOpts().CUDA && !Context.getLangOpts().CUDAIsDevice &&
402 if (llvm::Function *CudaCtorFunction = CUDARuntime->makeModuleCtorFunction())
403 AddGlobalCtor(CudaCtorFunction);
404 if (llvm::Function *CudaDtorFunction = CUDARuntime->makeModuleDtorFunction())
405 AddGlobalDtor(CudaDtorFunction);
408 if (llvm::Function *OpenMPRegistrationFunction =
409 OpenMPRuntime->emitRegistrationFunction()) {
410 auto ComdatKey = OpenMPRegistrationFunction->hasComdat() ?
411 OpenMPRegistrationFunction : nullptr;
412 AddGlobalCtor(OpenMPRegistrationFunction, 0, ComdatKey);
415 getModule().setProfileSummary(PGOReader->getSummary().getMD(VMContext));
416 if (PGOStats.hasDiagnostics())
417 PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
419 EmitCtorList(GlobalCtors, "llvm.global_ctors");
420 EmitCtorList(GlobalDtors, "llvm.global_dtors");
421 EmitGlobalAnnotations();
422 EmitStaticExternCAliases();
423 EmitDeferredUnusedCoverageMappings();
425 CoverageMapping->emit();
426 if (CodeGenOpts.SanitizeCfiCrossDso) {
427 CodeGenFunction(*this).EmitCfiCheckFail();
428 CodeGenFunction(*this).EmitCfiCheckStub();
430 emitAtAvailableLinkGuard();
435 if (CodeGenOpts.Autolink &&
436 (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
437 EmitModuleLinkOptions();
440 // Record mregparm value now so it is visible through rest of codegen.
441 if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
442 getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
443 CodeGenOpts.NumRegisterParameters);
445 if (CodeGenOpts.DwarfVersion) {
446 // We actually want the latest version when there are conflicts.
447 // We can change from Warning to Latest if such mode is supported.
448 getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version",
449 CodeGenOpts.DwarfVersion);
451 if (CodeGenOpts.EmitCodeView) {
452 // Indicate that we want CodeView in the metadata.
453 getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
455 if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
456 // We don't support LTO with 2 with different StrictVTablePointers
457 // FIXME: we could support it by stripping all the information introduced
458 // by StrictVTablePointers.
460 getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
462 llvm::Metadata *Ops[2] = {
463 llvm::MDString::get(VMContext, "StrictVTablePointers"),
464 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
465 llvm::Type::getInt32Ty(VMContext), 1))};
467 getModule().addModuleFlag(llvm::Module::Require,
468 "StrictVTablePointersRequirement",
469 llvm::MDNode::get(VMContext, Ops));
472 // We support a single version in the linked module. The LLVM
473 // parser will drop debug info with a different version number
474 // (and warn about it, too).
475 getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
476 llvm::DEBUG_METADATA_VERSION);
478 // We need to record the widths of enums and wchar_t, so that we can generate
479 // the correct build attributes in the ARM backend. wchar_size is also used by
480 // TargetLibraryInfo.
481 uint64_t WCharWidth =
482 Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
483 getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
485 llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
486 if ( Arch == llvm::Triple::arm
487 || Arch == llvm::Triple::armeb
488 || Arch == llvm::Triple::thumb
489 || Arch == llvm::Triple::thumbeb) {
490 // The minimum width of an enum in bytes
491 uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
492 getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
495 if (CodeGenOpts.SanitizeCfiCrossDso) {
496 // Indicate that we want cross-DSO control flow integrity checks.
497 getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
500 if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
501 // Indicate whether __nvvm_reflect should be configured to flush denormal
502 // floating point values to 0. (This corresponds to its "__CUDA_FTZ"
504 getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
505 LangOpts.CUDADeviceFlushDenormalsToZero ? 1 : 0);
508 // Emit OpenCL specific module metadata: OpenCL/SPIR version.
509 if (LangOpts.OpenCL) {
510 EmitOpenCLMetadata();
511 // Emit SPIR version.
512 if (getTriple().getArch() == llvm::Triple::spir ||
513 getTriple().getArch() == llvm::Triple::spir64) {
514 // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
515 // opencl.spir.version named metadata.
516 llvm::Metadata *SPIRVerElts[] = {
517 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
518 Int32Ty, LangOpts.OpenCLVersion / 100)),
519 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
520 Int32Ty, (LangOpts.OpenCLVersion / 100 > 1) ? 0 : 2))};
521 llvm::NamedMDNode *SPIRVerMD =
522 TheModule.getOrInsertNamedMetadata("opencl.spir.version");
523 llvm::LLVMContext &Ctx = TheModule.getContext();
524 SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
528 if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
529 assert(PLevel < 3 && "Invalid PIC Level");
530 getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
531 if (Context.getLangOpts().PIE)
532 getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
535 SimplifyPersonality();
537 if (getCodeGenOpts().EmitDeclMetadata)
540 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
544 DebugInfo->finalize();
546 EmitVersionIdentMetadata();
548 EmitTargetMetadata();
551 void CodeGenModule::EmitOpenCLMetadata() {
552 // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
553 // opencl.ocl.version named metadata node.
554 llvm::Metadata *OCLVerElts[] = {
555 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
556 Int32Ty, LangOpts.OpenCLVersion / 100)),
557 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
558 Int32Ty, (LangOpts.OpenCLVersion % 100) / 10))};
559 llvm::NamedMDNode *OCLVerMD =
560 TheModule.getOrInsertNamedMetadata("opencl.ocl.version");
561 llvm::LLVMContext &Ctx = TheModule.getContext();
562 OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
565 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
566 // Make sure that this type is translated.
567 Types.UpdateCompletedType(TD);
570 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
571 // Make sure that this type is translated.
572 Types.RefreshTypeCacheForClass(RD);
575 llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
578 return TBAA->getTypeInfo(QTy);
581 TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
582 // Pointee values may have incomplete types, but they shall never be
584 if (AccessType->isIncompleteType())
585 return TBAAAccessInfo::getIncompleteInfo();
587 uint64_t Size = Context.getTypeSizeInChars(AccessType).getQuantity();
588 return TBAAAccessInfo(getTBAATypeInfo(AccessType), Size);
592 CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
594 return TBAAAccessInfo();
595 return TBAA->getVTablePtrAccessInfo(VTablePtrType);
598 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
601 return TBAA->getTBAAStructInfo(QTy);
604 llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
607 return TBAA->getBaseTypeInfo(QTy);
610 llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
613 return TBAA->getAccessTagInfo(Info);
616 TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
617 TBAAAccessInfo TargetInfo) {
619 return TBAAAccessInfo();
620 return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
624 CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
625 TBAAAccessInfo InfoB) {
627 return TBAAAccessInfo();
628 return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
631 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
632 TBAAAccessInfo TBAAInfo) {
633 if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
634 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
637 void CodeGenModule::DecorateInstructionWithInvariantGroup(
638 llvm::Instruction *I, const CXXRecordDecl *RD) {
639 I->setMetadata(llvm::LLVMContext::MD_invariant_group,
640 llvm::MDNode::get(getLLVMContext(), {}));
643 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
644 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
645 getDiags().Report(Context.getFullLoc(loc), diagID) << message;
648 /// ErrorUnsupported - Print out an error that codegen doesn't support the
649 /// specified stmt yet.
650 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
651 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
652 "cannot compile this %0 yet");
653 std::string Msg = Type;
654 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID)
655 << Msg << S->getSourceRange();
658 /// ErrorUnsupported - Print out an error that codegen doesn't support the
659 /// specified decl yet.
660 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
661 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
662 "cannot compile this %0 yet");
663 std::string Msg = Type;
664 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
667 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
668 return llvm::ConstantInt::get(SizeTy, size.getQuantity());
671 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
673 ForDefinition_t IsForDefinition) const {
674 // Internal definitions always have default visibility.
675 if (GV->hasLocalLinkage()) {
676 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
680 // Set visibility for definitions.
681 LinkageInfo LV = D->getLinkageAndVisibility();
682 if (LV.isVisibilityExplicit() ||
683 (IsForDefinition && !GV->hasAvailableExternallyLinkage()))
684 GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
687 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
688 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
689 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
690 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
691 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
692 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
695 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(
696 CodeGenOptions::TLSModel M) {
698 case CodeGenOptions::GeneralDynamicTLSModel:
699 return llvm::GlobalVariable::GeneralDynamicTLSModel;
700 case CodeGenOptions::LocalDynamicTLSModel:
701 return llvm::GlobalVariable::LocalDynamicTLSModel;
702 case CodeGenOptions::InitialExecTLSModel:
703 return llvm::GlobalVariable::InitialExecTLSModel;
704 case CodeGenOptions::LocalExecTLSModel:
705 return llvm::GlobalVariable::LocalExecTLSModel;
707 llvm_unreachable("Invalid TLS model!");
710 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
711 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
713 llvm::GlobalValue::ThreadLocalMode TLM;
714 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel());
716 // Override the TLS model if it is explicitly specified.
717 if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
718 TLM = GetLLVMTLSModel(Attr->getModel());
721 GV->setThreadLocalMode(TLM);
724 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
725 GlobalDecl CanonicalGD = GD.getCanonicalDecl();
727 // Some ABIs don't have constructor variants. Make sure that base and
728 // complete constructors get mangled the same.
729 if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
730 if (!getTarget().getCXXABI().hasConstructorVariants()) {
731 CXXCtorType OrigCtorType = GD.getCtorType();
732 assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
733 if (OrigCtorType == Ctor_Base)
734 CanonicalGD = GlobalDecl(CD, Ctor_Complete);
738 auto FoundName = MangledDeclNames.find(CanonicalGD);
739 if (FoundName != MangledDeclNames.end())
740 return FoundName->second;
742 const auto *ND = cast<NamedDecl>(GD.getDecl());
743 SmallString<256> Buffer;
745 if (getCXXABI().getMangleContext().shouldMangleDeclName(ND)) {
746 llvm::raw_svector_ostream Out(Buffer);
747 if (const auto *D = dyn_cast<CXXConstructorDecl>(ND))
748 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out);
749 else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND))
750 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out);
752 getCXXABI().getMangleContext().mangleName(ND, Out);
755 IdentifierInfo *II = ND->getIdentifier();
756 assert(II && "Attempt to mangle unnamed decl.");
757 const auto *FD = dyn_cast<FunctionDecl>(ND);
760 FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
761 llvm::raw_svector_ostream Out(Buffer);
762 Out << "__regcall3__" << II->getName();
769 // Keep the first result in the case of a mangling collision.
770 auto Result = Manglings.insert(std::make_pair(Str, GD));
771 return MangledDeclNames[CanonicalGD] = Result.first->first();
774 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
775 const BlockDecl *BD) {
776 MangleContext &MangleCtx = getCXXABI().getMangleContext();
777 const Decl *D = GD.getDecl();
779 SmallString<256> Buffer;
780 llvm::raw_svector_ostream Out(Buffer);
782 MangleCtx.mangleGlobalBlock(BD,
783 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
784 else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
785 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
786 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
787 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
789 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
791 auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
792 return Result.first->first();
795 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
796 return getModule().getNamedValue(Name);
799 /// AddGlobalCtor - Add a function to the list that will be called before
801 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
802 llvm::Constant *AssociatedData) {
803 // FIXME: Type coercion of void()* types.
804 GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData));
807 /// AddGlobalDtor - Add a function to the list that will be called
808 /// when the module is unloaded.
809 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority) {
810 // FIXME: Type coercion of void()* types.
811 GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
814 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
815 if (Fns.empty()) return;
817 // Ctor function type is void()*.
818 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
819 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy);
821 // Get the type of a ctor entry, { i32, void ()*, i8* }.
822 llvm::StructType *CtorStructTy = llvm::StructType::get(
823 Int32Ty, llvm::PointerType::getUnqual(CtorFTy), VoidPtrTy);
825 // Construct the constructor and destructor arrays.
826 ConstantInitBuilder builder(*this);
827 auto ctors = builder.beginArray(CtorStructTy);
828 for (const auto &I : Fns) {
829 auto ctor = ctors.beginStruct(CtorStructTy);
830 ctor.addInt(Int32Ty, I.Priority);
831 ctor.add(llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy));
832 if (I.AssociatedData)
833 ctor.add(llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy));
835 ctor.addNullPointer(VoidPtrTy);
836 ctor.finishAndAddTo(ctors);
840 ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
842 llvm::GlobalValue::AppendingLinkage);
844 // The LTO linker doesn't seem to like it when we set an alignment
845 // on appending variables. Take it off as a workaround.
846 list->setAlignment(0);
851 llvm::GlobalValue::LinkageTypes
852 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
853 const auto *D = cast<FunctionDecl>(GD.getDecl());
855 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
857 if (isa<CXXDestructorDecl>(D) &&
858 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
860 // Destructor variants in the Microsoft C++ ABI are always internal or
861 // linkonce_odr thunks emitted on an as-needed basis.
862 return Linkage == GVA_Internal ? llvm::GlobalValue::InternalLinkage
863 : llvm::GlobalValue::LinkOnceODRLinkage;
866 if (isa<CXXConstructorDecl>(D) &&
867 cast<CXXConstructorDecl>(D)->isInheritingConstructor() &&
868 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
869 // Our approach to inheriting constructors is fundamentally different from
870 // that used by the MS ABI, so keep our inheriting constructor thunks
871 // internal rather than trying to pick an unambiguous mangling for them.
872 return llvm::GlobalValue::InternalLinkage;
875 return getLLVMLinkageForDeclarator(D, Linkage, /*isConstantVariable=*/false);
878 void CodeGenModule::setFunctionDLLStorageClass(GlobalDecl GD, llvm::Function *F) {
879 const auto *FD = cast<FunctionDecl>(GD.getDecl());
881 if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(FD)) {
882 if (getCXXABI().useThunkForDtorVariant(Dtor, GD.getDtorType())) {
883 // Don't dllexport/import destructor thunks.
884 F->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
889 if (FD->hasAttr<DLLImportAttr>())
890 F->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
891 else if (FD->hasAttr<DLLExportAttr>())
892 F->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
894 F->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
897 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
898 llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
899 if (!MDS) return nullptr;
901 return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
904 void CodeGenModule::setFunctionDefinitionAttributes(const FunctionDecl *D,
906 setNonAliasAttributes(D, F);
909 void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
910 const CGFunctionInfo &Info,
912 unsigned CallingConv;
913 llvm::AttributeList PAL;
914 ConstructAttributeList(F->getName(), Info, D, PAL, CallingConv, false);
915 F->setAttributes(PAL);
916 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
919 /// Determines whether the language options require us to model
920 /// unwind exceptions. We treat -fexceptions as mandating this
921 /// except under the fragile ObjC ABI with only ObjC exceptions
922 /// enabled. This means, for example, that C with -fexceptions
924 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
925 // If exceptions are completely disabled, obviously this is false.
926 if (!LangOpts.Exceptions) return false;
928 // If C++ exceptions are enabled, this is true.
929 if (LangOpts.CXXExceptions) return true;
931 // If ObjC exceptions are enabled, this depends on the ABI.
932 if (LangOpts.ObjCExceptions) {
933 return LangOpts.ObjCRuntime.hasUnwindExceptions();
939 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
943 if (CodeGenOpts.UnwindTables)
944 B.addAttribute(llvm::Attribute::UWTable);
946 if (!hasUnwindExceptions(LangOpts))
947 B.addAttribute(llvm::Attribute::NoUnwind);
949 if (LangOpts.getStackProtector() == LangOptions::SSPOn)
950 B.addAttribute(llvm::Attribute::StackProtect);
951 else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
952 B.addAttribute(llvm::Attribute::StackProtectStrong);
953 else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
954 B.addAttribute(llvm::Attribute::StackProtectReq);
957 // If we don't have a declaration to control inlining, the function isn't
958 // explicitly marked as alwaysinline for semantic reasons, and inlining is
959 // disabled, mark the function as noinline.
960 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
961 CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
962 B.addAttribute(llvm::Attribute::NoInline);
964 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
968 // Track whether we need to add the optnone LLVM attribute,
969 // starting with the default for this optimization level.
970 bool ShouldAddOptNone =
971 !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
972 // We can't add optnone in the following cases, it won't pass the verifier.
973 ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
974 ShouldAddOptNone &= !F->hasFnAttribute(llvm::Attribute::AlwaysInline);
975 ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
977 if (ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) {
978 B.addAttribute(llvm::Attribute::OptimizeNone);
980 // OptimizeNone implies noinline; we should not be inlining such functions.
981 B.addAttribute(llvm::Attribute::NoInline);
982 assert(!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
983 "OptimizeNone and AlwaysInline on same function!");
985 // We still need to handle naked functions even though optnone subsumes
986 // much of their semantics.
987 if (D->hasAttr<NakedAttr>())
988 B.addAttribute(llvm::Attribute::Naked);
990 // OptimizeNone wins over OptimizeForSize and MinSize.
991 F->removeFnAttr(llvm::Attribute::OptimizeForSize);
992 F->removeFnAttr(llvm::Attribute::MinSize);
993 } else if (D->hasAttr<NakedAttr>()) {
994 // Naked implies noinline: we should not be inlining such functions.
995 B.addAttribute(llvm::Attribute::Naked);
996 B.addAttribute(llvm::Attribute::NoInline);
997 } else if (D->hasAttr<NoDuplicateAttr>()) {
998 B.addAttribute(llvm::Attribute::NoDuplicate);
999 } else if (D->hasAttr<NoInlineAttr>()) {
1000 B.addAttribute(llvm::Attribute::NoInline);
1001 } else if (D->hasAttr<AlwaysInlineAttr>() &&
1002 !F->hasFnAttribute(llvm::Attribute::NoInline)) {
1003 // (noinline wins over always_inline, and we can't specify both in IR)
1004 B.addAttribute(llvm::Attribute::AlwaysInline);
1005 } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
1006 // If we're not inlining, then force everything that isn't always_inline to
1007 // carry an explicit noinline attribute.
1008 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
1009 B.addAttribute(llvm::Attribute::NoInline);
1011 // Otherwise, propagate the inline hint attribute and potentially use its
1012 // absence to mark things as noinline.
1013 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
1014 if (any_of(FD->redecls(), [&](const FunctionDecl *Redecl) {
1015 return Redecl->isInlineSpecified();
1017 B.addAttribute(llvm::Attribute::InlineHint);
1018 } else if (CodeGenOpts.getInlining() ==
1019 CodeGenOptions::OnlyHintInlining &&
1021 !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1022 B.addAttribute(llvm::Attribute::NoInline);
1027 // Add other optimization related attributes if we are optimizing this
1029 if (!D->hasAttr<OptimizeNoneAttr>()) {
1030 if (D->hasAttr<ColdAttr>()) {
1031 if (!ShouldAddOptNone)
1032 B.addAttribute(llvm::Attribute::OptimizeForSize);
1033 B.addAttribute(llvm::Attribute::Cold);
1036 if (D->hasAttr<MinSizeAttr>())
1037 B.addAttribute(llvm::Attribute::MinSize);
1040 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1042 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
1044 F->setAlignment(alignment);
1046 // Some C++ ABIs require 2-byte alignment for member functions, in order to
1047 // reserve a bit for differentiating between virtual and non-virtual member
1048 // functions. If the current target's C++ ABI requires this and this is a
1049 // member function, set its alignment accordingly.
1050 if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
1051 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
1055 // In the cross-dso CFI mode, we want !type attributes on definitions only.
1056 if (CodeGenOpts.SanitizeCfiCrossDso)
1057 if (auto *FD = dyn_cast<FunctionDecl>(D))
1058 CreateFunctionTypeMetadata(FD, F);
1061 void CodeGenModule::SetCommonAttributes(const Decl *D,
1062 llvm::GlobalValue *GV) {
1063 if (const auto *ND = dyn_cast_or_null<NamedDecl>(D))
1064 setGlobalVisibility(GV, ND, ForDefinition);
1066 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1068 if (D && D->hasAttr<UsedAttr>())
1072 void CodeGenModule::setAliasAttributes(const Decl *D,
1073 llvm::GlobalValue *GV) {
1074 SetCommonAttributes(D, GV);
1076 // Process the dllexport attribute based on whether the original definition
1077 // (not necessarily the aliasee) was exported.
1078 if (D->hasAttr<DLLExportAttr>())
1079 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
1082 void CodeGenModule::setNonAliasAttributes(const Decl *D,
1083 llvm::GlobalObject *GO) {
1084 SetCommonAttributes(D, GO);
1087 if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
1088 if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
1089 GV->addAttribute("bss-section", SA->getName());
1090 if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
1091 GV->addAttribute("data-section", SA->getName());
1092 if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
1093 GV->addAttribute("rodata-section", SA->getName());
1096 if (auto *F = dyn_cast<llvm::Function>(GO)) {
1097 if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
1098 if (!D->getAttr<SectionAttr>())
1099 F->addFnAttr("implicit-section-name", SA->getName());
1102 if (const SectionAttr *SA = D->getAttr<SectionAttr>())
1103 GO->setSection(SA->getName());
1106 getTargetCodeGenInfo().setTargetAttributes(D, GO, *this, ForDefinition);
1109 void CodeGenModule::SetInternalFunctionAttributes(const Decl *D,
1111 const CGFunctionInfo &FI) {
1112 SetLLVMFunctionAttributes(D, FI, F);
1113 SetLLVMFunctionAttributesForDefinition(D, F);
1115 F->setLinkage(llvm::Function::InternalLinkage);
1117 setNonAliasAttributes(D, F);
1120 static void setLinkageForGV(llvm::GlobalValue *GV,
1121 const NamedDecl *ND) {
1122 // Set linkage and visibility in case we never see a definition.
1123 LinkageInfo LV = ND->getLinkageAndVisibility();
1124 if (!isExternallyVisible(LV.getLinkage())) {
1125 // Don't set internal linkage on declarations.
1127 if (ND->hasAttr<DLLImportAttr>()) {
1128 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
1129 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
1130 } else if (ND->hasAttr<DLLExportAttr>()) {
1131 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
1132 } else if (ND->hasAttr<WeakAttr>() || ND->isWeakImported()) {
1133 // "extern_weak" is overloaded in LLVM; we probably should have
1134 // separate linkage types for this.
1135 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
1140 void CodeGenModule::CreateFunctionTypeMetadata(const FunctionDecl *FD,
1141 llvm::Function *F) {
1142 // Only if we are checking indirect calls.
1143 if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
1146 // Non-static class methods are handled via vtable pointer checks elsewhere.
1147 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
1150 // Additionally, if building with cross-DSO support...
1151 if (CodeGenOpts.SanitizeCfiCrossDso) {
1152 // Skip available_externally functions. They won't be codegen'ed in the
1153 // current module anyway.
1154 if (getContext().GetGVALinkageForFunction(FD) == GVA_AvailableExternally)
1158 llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
1159 F->addTypeMetadata(0, MD);
1160 F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
1162 // Emit a hash-based bit set entry for cross-DSO calls.
1163 if (CodeGenOpts.SanitizeCfiCrossDso)
1164 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
1165 F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
1168 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
1169 bool IsIncompleteFunction,
1171 ForDefinition_t IsForDefinition) {
1173 if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) {
1174 // If this is an intrinsic function, set the function's attributes
1175 // to the intrinsic's attributes.
1176 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID));
1180 const auto *FD = cast<FunctionDecl>(GD.getDecl());
1182 if (!IsIncompleteFunction) {
1183 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F);
1184 // Setup target-specific attributes.
1185 if (!IsForDefinition)
1186 getTargetCodeGenInfo().setTargetAttributes(FD, F, *this,
1190 // Add the Returned attribute for "this", except for iOS 5 and earlier
1191 // where substantial code, including the libstdc++ dylib, was compiled with
1192 // GCC and does not actually return "this".
1193 if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
1194 !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
1195 assert(!F->arg_empty() &&
1196 F->arg_begin()->getType()
1197 ->canLosslesslyBitCastTo(F->getReturnType()) &&
1198 "unexpected this return");
1199 F->addAttribute(1, llvm::Attribute::Returned);
1202 // Only a few attributes are set on declarations; these may later be
1203 // overridden by a definition.
1205 setLinkageForGV(F, FD);
1206 setGlobalVisibility(F, FD, NotForDefinition);
1208 if (FD->getAttr<PragmaClangTextSectionAttr>()) {
1209 F->addFnAttr("implicit-section-name");
1212 if (const SectionAttr *SA = FD->getAttr<SectionAttr>())
1213 F->setSection(SA->getName());
1215 if (FD->isReplaceableGlobalAllocationFunction()) {
1216 // A replaceable global allocation function does not act like a builtin by
1217 // default, only if it is invoked by a new-expression or delete-expression.
1218 F->addAttribute(llvm::AttributeList::FunctionIndex,
1219 llvm::Attribute::NoBuiltin);
1221 // A sane operator new returns a non-aliasing pointer.
1222 // FIXME: Also add NonNull attribute to the return value
1223 // for the non-nothrow forms?
1224 auto Kind = FD->getDeclName().getCXXOverloadedOperator();
1225 if (getCodeGenOpts().AssumeSaneOperatorNew &&
1226 (Kind == OO_New || Kind == OO_Array_New))
1227 F->addAttribute(llvm::AttributeList::ReturnIndex,
1228 llvm::Attribute::NoAlias);
1231 if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
1232 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1233 else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
1234 if (MD->isVirtual())
1235 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1237 // Don't emit entries for function declarations in the cross-DSO mode. This
1238 // is handled with better precision by the receiving DSO.
1239 if (!CodeGenOpts.SanitizeCfiCrossDso)
1240 CreateFunctionTypeMetadata(FD, F);
1242 if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
1243 getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
1246 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
1247 assert(!GV->isDeclaration() &&
1248 "Only globals with definition can force usage.");
1249 LLVMUsed.emplace_back(GV);
1252 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
1253 assert(!GV->isDeclaration() &&
1254 "Only globals with definition can force usage.");
1255 LLVMCompilerUsed.emplace_back(GV);
1258 static void emitUsed(CodeGenModule &CGM, StringRef Name,
1259 std::vector<llvm::WeakTrackingVH> &List) {
1260 // Don't create llvm.used if there is no need.
1264 // Convert List to what ConstantArray needs.
1265 SmallVector<llvm::Constant*, 8> UsedArray;
1266 UsedArray.resize(List.size());
1267 for (unsigned i = 0, e = List.size(); i != e; ++i) {
1269 llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
1270 cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
1273 if (UsedArray.empty())
1275 llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
1277 auto *GV = new llvm::GlobalVariable(
1278 CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
1279 llvm::ConstantArray::get(ATy, UsedArray), Name);
1281 GV->setSection("llvm.metadata");
1284 void CodeGenModule::emitLLVMUsed() {
1285 emitUsed(*this, "llvm.used", LLVMUsed);
1286 emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
1289 void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
1290 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
1291 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1294 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
1295 llvm::SmallString<32> Opt;
1296 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
1297 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
1298 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1301 void CodeGenModule::AddDependentLib(StringRef Lib) {
1302 llvm::SmallString<24> Opt;
1303 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
1304 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
1305 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1308 /// \brief Add link options implied by the given module, including modules
1309 /// it depends on, using a postorder walk.
1310 static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
1311 SmallVectorImpl<llvm::MDNode *> &Metadata,
1312 llvm::SmallPtrSet<Module *, 16> &Visited) {
1313 // Import this module's parent.
1314 if (Mod->Parent && Visited.insert(Mod->Parent).second) {
1315 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
1318 // Import this module's dependencies.
1319 for (unsigned I = Mod->Imports.size(); I > 0; --I) {
1320 if (Visited.insert(Mod->Imports[I - 1]).second)
1321 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited);
1324 // Add linker options to link against the libraries/frameworks
1325 // described by this module.
1326 llvm::LLVMContext &Context = CGM.getLLVMContext();
1327 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) {
1328 // Link against a framework. Frameworks are currently Darwin only, so we
1329 // don't to ask TargetCodeGenInfo for the spelling of the linker option.
1330 if (Mod->LinkLibraries[I-1].IsFramework) {
1331 llvm::Metadata *Args[2] = {
1332 llvm::MDString::get(Context, "-framework"),
1333 llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library)};
1335 Metadata.push_back(llvm::MDNode::get(Context, Args));
1339 // Link against a library.
1340 llvm::SmallString<24> Opt;
1341 CGM.getTargetCodeGenInfo().getDependentLibraryOption(
1342 Mod->LinkLibraries[I-1].Library, Opt);
1343 auto *OptString = llvm::MDString::get(Context, Opt);
1344 Metadata.push_back(llvm::MDNode::get(Context, OptString));
1348 void CodeGenModule::EmitModuleLinkOptions() {
1349 // Collect the set of all of the modules we want to visit to emit link
1350 // options, which is essentially the imported modules and all of their
1351 // non-explicit child modules.
1352 llvm::SetVector<clang::Module *> LinkModules;
1353 llvm::SmallPtrSet<clang::Module *, 16> Visited;
1354 SmallVector<clang::Module *, 16> Stack;
1356 // Seed the stack with imported modules.
1357 for (Module *M : ImportedModules) {
1358 // Do not add any link flags when an implementation TU of a module imports
1359 // a header of that same module.
1360 if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
1361 !getLangOpts().isCompilingModule())
1363 if (Visited.insert(M).second)
1367 // Find all of the modules to import, making a little effort to prune
1368 // non-leaf modules.
1369 while (!Stack.empty()) {
1370 clang::Module *Mod = Stack.pop_back_val();
1372 bool AnyChildren = false;
1374 // Visit the submodules of this module.
1375 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
1376 SubEnd = Mod->submodule_end();
1377 Sub != SubEnd; ++Sub) {
1378 // Skip explicit children; they need to be explicitly imported to be
1380 if ((*Sub)->IsExplicit)
1383 if (Visited.insert(*Sub).second) {
1384 Stack.push_back(*Sub);
1389 // We didn't find any children, so add this module to the list of
1390 // modules to link against.
1392 LinkModules.insert(Mod);
1396 // Add link options for all of the imported modules in reverse topological
1397 // order. We don't do anything to try to order import link flags with respect
1398 // to linker options inserted by things like #pragma comment().
1399 SmallVector<llvm::MDNode *, 16> MetadataArgs;
1401 for (Module *M : LinkModules)
1402 if (Visited.insert(M).second)
1403 addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
1404 std::reverse(MetadataArgs.begin(), MetadataArgs.end());
1405 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
1407 // Add the linker options metadata flag.
1408 auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
1409 for (auto *MD : LinkerOptionsMetadata)
1410 NMD->addOperand(MD);
1413 void CodeGenModule::EmitDeferred() {
1414 // Emit code for any potentially referenced deferred decls. Since a
1415 // previously unused static decl may become used during the generation of code
1416 // for a static function, iterate until no changes are made.
1418 if (!DeferredVTables.empty()) {
1419 EmitDeferredVTables();
1421 // Emitting a vtable doesn't directly cause more vtables to
1422 // become deferred, although it can cause functions to be
1423 // emitted that then need those vtables.
1424 assert(DeferredVTables.empty());
1427 // Stop if we're out of both deferred vtables and deferred declarations.
1428 if (DeferredDeclsToEmit.empty())
1431 // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
1432 // work, it will not interfere with this.
1433 std::vector<GlobalDecl> CurDeclsToEmit;
1434 CurDeclsToEmit.swap(DeferredDeclsToEmit);
1436 for (GlobalDecl &D : CurDeclsToEmit) {
1437 // We should call GetAddrOfGlobal with IsForDefinition set to true in order
1438 // to get GlobalValue with exactly the type we need, not something that
1439 // might had been created for another decl with the same mangled name but
1441 llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
1442 GetAddrOfGlobal(D, ForDefinition));
1444 // In case of different address spaces, we may still get a cast, even with
1445 // IsForDefinition equal to true. Query mangled names table to get
1448 GV = GetGlobalValue(getMangledName(D));
1450 // Make sure GetGlobalValue returned non-null.
1453 // Check to see if we've already emitted this. This is necessary
1454 // for a couple of reasons: first, decls can end up in the
1455 // deferred-decls queue multiple times, and second, decls can end
1456 // up with definitions in unusual ways (e.g. by an extern inline
1457 // function acquiring a strong function redefinition). Just
1458 // ignore these cases.
1459 if (!GV->isDeclaration())
1462 // Otherwise, emit the definition and move on to the next one.
1463 EmitGlobalDefinition(D, GV);
1465 // If we found out that we need to emit more decls, do that recursively.
1466 // This has the advantage that the decls are emitted in a DFS and related
1467 // ones are close together, which is convenient for testing.
1468 if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
1470 assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
1475 void CodeGenModule::EmitVTablesOpportunistically() {
1476 // Try to emit external vtables as available_externally if they have emitted
1477 // all inlined virtual functions. It runs after EmitDeferred() and therefore
1478 // is not allowed to create new references to things that need to be emitted
1479 // lazily. Note that it also uses fact that we eagerly emitting RTTI.
1481 assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
1482 && "Only emit opportunistic vtables with optimizations");
1484 for (const CXXRecordDecl *RD : OpportunisticVTables) {
1485 assert(getVTables().isVTableExternal(RD) &&
1486 "This queue should only contain external vtables");
1487 if (getCXXABI().canSpeculativelyEmitVTable(RD))
1488 VTables.GenerateClassData(RD);
1490 OpportunisticVTables.clear();
1493 void CodeGenModule::EmitGlobalAnnotations() {
1494 if (Annotations.empty())
1497 // Create a new global variable for the ConstantStruct in the Module.
1498 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
1499 Annotations[0]->getType(), Annotations.size()), Annotations);
1500 auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
1501 llvm::GlobalValue::AppendingLinkage,
1502 Array, "llvm.global.annotations");
1503 gv->setSection(AnnotationSection);
1506 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
1507 llvm::Constant *&AStr = AnnotationStrings[Str];
1511 // Not found yet, create a new global.
1512 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
1514 new llvm::GlobalVariable(getModule(), s->getType(), true,
1515 llvm::GlobalValue::PrivateLinkage, s, ".str");
1516 gv->setSection(AnnotationSection);
1517 gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1522 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
1523 SourceManager &SM = getContext().getSourceManager();
1524 PresumedLoc PLoc = SM.getPresumedLoc(Loc);
1526 return EmitAnnotationString(PLoc.getFilename());
1527 return EmitAnnotationString(SM.getBufferName(Loc));
1530 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
1531 SourceManager &SM = getContext().getSourceManager();
1532 PresumedLoc PLoc = SM.getPresumedLoc(L);
1533 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
1534 SM.getExpansionLineNumber(L);
1535 return llvm::ConstantInt::get(Int32Ty, LineNo);
1538 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
1539 const AnnotateAttr *AA,
1541 // Get the globals for file name, annotation, and the line number.
1542 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
1543 *UnitGV = EmitAnnotationUnit(L),
1544 *LineNoCst = EmitAnnotationLineNo(L);
1546 // Create the ConstantStruct for the global annotation.
1547 llvm::Constant *Fields[4] = {
1548 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy),
1549 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
1550 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
1553 return llvm::ConstantStruct::getAnon(Fields);
1556 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
1557 llvm::GlobalValue *GV) {
1558 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
1559 // Get the struct elements for these annotations.
1560 for (const auto *I : D->specific_attrs<AnnotateAttr>())
1561 Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
1564 bool CodeGenModule::isInSanitizerBlacklist(SanitizerMask Kind,
1566 SourceLocation Loc) const {
1567 const auto &SanitizerBL = getContext().getSanitizerBlacklist();
1568 // Blacklist by function name.
1569 if (SanitizerBL.isBlacklistedFunction(Kind, Fn->getName()))
1571 // Blacklist by location.
1573 return SanitizerBL.isBlacklistedLocation(Kind, Loc);
1574 // If location is unknown, this may be a compiler-generated function. Assume
1575 // it's located in the main file.
1576 auto &SM = Context.getSourceManager();
1577 if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1578 return SanitizerBL.isBlacklistedFile(Kind, MainFile->getName());
1583 bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
1584 SourceLocation Loc, QualType Ty,
1585 StringRef Category) const {
1586 // For now globals can be blacklisted only in ASan and KASan.
1587 const SanitizerMask EnabledAsanMask = LangOpts.Sanitize.Mask &
1588 (SanitizerKind::Address | SanitizerKind::KernelAddress | SanitizerKind::HWAddress);
1589 if (!EnabledAsanMask)
1591 const auto &SanitizerBL = getContext().getSanitizerBlacklist();
1592 if (SanitizerBL.isBlacklistedGlobal(EnabledAsanMask, GV->getName(), Category))
1594 if (SanitizerBL.isBlacklistedLocation(EnabledAsanMask, Loc, Category))
1596 // Check global type.
1598 // Drill down the array types: if global variable of a fixed type is
1599 // blacklisted, we also don't instrument arrays of them.
1600 while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
1601 Ty = AT->getElementType();
1602 Ty = Ty.getCanonicalType().getUnqualifiedType();
1603 // We allow to blacklist only record types (classes, structs etc.)
1604 if (Ty->isRecordType()) {
1605 std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
1606 if (SanitizerBL.isBlacklistedType(EnabledAsanMask, TypeStr, Category))
1613 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
1614 StringRef Category) const {
1615 if (!LangOpts.XRayInstrument)
1617 const auto &XRayFilter = getContext().getXRayFilter();
1618 using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
1619 auto Attr = XRayFunctionFilter::ImbueAttribute::NONE;
1621 Attr = XRayFilter.shouldImbueLocation(Loc, Category);
1622 if (Attr == ImbueAttr::NONE)
1623 Attr = XRayFilter.shouldImbueFunction(Fn->getName());
1625 case ImbueAttr::NONE:
1627 case ImbueAttr::ALWAYS:
1628 Fn->addFnAttr("function-instrument", "xray-always");
1630 case ImbueAttr::ALWAYS_ARG1:
1631 Fn->addFnAttr("function-instrument", "xray-always");
1632 Fn->addFnAttr("xray-log-args", "1");
1634 case ImbueAttr::NEVER:
1635 Fn->addFnAttr("function-instrument", "xray-never");
1641 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
1642 // Never defer when EmitAllDecls is specified.
1643 if (LangOpts.EmitAllDecls)
1646 return getContext().DeclMustBeEmitted(Global);
1649 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
1650 if (const auto *FD = dyn_cast<FunctionDecl>(Global))
1651 if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
1652 // Implicit template instantiations may change linkage if they are later
1653 // explicitly instantiated, so they should not be emitted eagerly.
1655 if (const auto *VD = dyn_cast<VarDecl>(Global))
1656 if (Context.getInlineVariableDefinitionKind(VD) ==
1657 ASTContext::InlineVariableDefinitionKind::WeakUnknown)
1658 // A definition of an inline constexpr static data member may change
1659 // linkage later if it's redeclared outside the class.
1661 // If OpenMP is enabled and threadprivates must be generated like TLS, delay
1662 // codegen for global variables, because they may be marked as threadprivate.
1663 if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
1664 getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global))
1670 ConstantAddress CodeGenModule::GetAddrOfUuidDescriptor(
1671 const CXXUuidofExpr* E) {
1672 // Sema has verified that IIDSource has a __declspec(uuid()), and that its
1674 StringRef Uuid = E->getUuidStr();
1675 std::string Name = "_GUID_" + Uuid.lower();
1676 std::replace(Name.begin(), Name.end(), '-', '_');
1678 // The UUID descriptor should be pointer aligned.
1679 CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
1681 // Look for an existing global.
1682 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
1683 return ConstantAddress(GV, Alignment);
1685 llvm::Constant *Init = EmitUuidofInitializer(Uuid);
1686 assert(Init && "failed to initialize as constant");
1688 auto *GV = new llvm::GlobalVariable(
1689 getModule(), Init->getType(),
1690 /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
1691 if (supportsCOMDAT())
1692 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
1693 return ConstantAddress(GV, Alignment);
1696 ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
1697 const AliasAttr *AA = VD->getAttr<AliasAttr>();
1698 assert(AA && "No alias?");
1700 CharUnits Alignment = getContext().getDeclAlign(VD);
1701 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
1703 // See if there is already something with the target's name in the module.
1704 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
1706 unsigned AS = getContext().getTargetAddressSpace(VD->getType());
1707 auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
1708 return ConstantAddress(Ptr, Alignment);
1711 llvm::Constant *Aliasee;
1712 if (isa<llvm::FunctionType>(DeclTy))
1713 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
1714 GlobalDecl(cast<FunctionDecl>(VD)),
1715 /*ForVTable=*/false);
1717 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
1718 llvm::PointerType::getUnqual(DeclTy),
1721 auto *F = cast<llvm::GlobalValue>(Aliasee);
1722 F->setLinkage(llvm::Function::ExternalWeakLinkage);
1723 WeakRefReferences.insert(F);
1725 return ConstantAddress(Aliasee, Alignment);
1728 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
1729 const auto *Global = cast<ValueDecl>(GD.getDecl());
1731 // Weak references don't produce any output by themselves.
1732 if (Global->hasAttr<WeakRefAttr>())
1735 // If this is an alias definition (which otherwise looks like a declaration)
1737 if (Global->hasAttr<AliasAttr>())
1738 return EmitAliasDefinition(GD);
1740 // IFunc like an alias whose value is resolved at runtime by calling resolver.
1741 if (Global->hasAttr<IFuncAttr>())
1742 return emitIFuncDefinition(GD);
1744 // If this is CUDA, be selective about which declarations we emit.
1745 if (LangOpts.CUDA) {
1746 if (LangOpts.CUDAIsDevice) {
1747 if (!Global->hasAttr<CUDADeviceAttr>() &&
1748 !Global->hasAttr<CUDAGlobalAttr>() &&
1749 !Global->hasAttr<CUDAConstantAttr>() &&
1750 !Global->hasAttr<CUDASharedAttr>())
1753 // We need to emit host-side 'shadows' for all global
1754 // device-side variables because the CUDA runtime needs their
1755 // size and host-side address in order to provide access to
1756 // their device-side incarnations.
1758 // So device-only functions are the only things we skip.
1759 if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
1760 Global->hasAttr<CUDADeviceAttr>())
1763 assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
1764 "Expected Variable or Function");
1768 if (LangOpts.OpenMP) {
1769 // If this is OpenMP device, check if it is legal to emit this global
1771 if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
1773 if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
1774 if (MustBeEmitted(Global))
1775 EmitOMPDeclareReduction(DRD);
1780 // Ignore declarations, they will be emitted on their first use.
1781 if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
1782 // Forward declarations are emitted lazily on first use.
1783 if (!FD->doesThisDeclarationHaveABody()) {
1784 if (!FD->doesDeclarationForceExternallyVisibleDefinition())
1787 StringRef MangledName = getMangledName(GD);
1789 // Compute the function info and LLVM type.
1790 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
1791 llvm::Type *Ty = getTypes().GetFunctionType(FI);
1793 GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
1794 /*DontDefer=*/false);
1798 const auto *VD = cast<VarDecl>(Global);
1799 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
1800 // We need to emit device-side global CUDA variables even if a
1801 // variable does not have a definition -- we still need to define
1802 // host-side shadow for it.
1803 bool MustEmitForCuda = LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
1804 !VD->hasDefinition() &&
1805 (VD->hasAttr<CUDAConstantAttr>() ||
1806 VD->hasAttr<CUDADeviceAttr>());
1807 if (!MustEmitForCuda &&
1808 VD->isThisDeclarationADefinition() != VarDecl::Definition &&
1809 !Context.isMSStaticDataMemberInlineDefinition(VD)) {
1810 // If this declaration may have caused an inline variable definition to
1811 // change linkage, make sure that it's emitted.
1812 if (Context.getInlineVariableDefinitionKind(VD) ==
1813 ASTContext::InlineVariableDefinitionKind::Strong)
1814 GetAddrOfGlobalVar(VD);
1819 // Defer code generation to first use when possible, e.g. if this is an inline
1820 // function. If the global must always be emitted, do it eagerly if possible
1821 // to benefit from cache locality.
1822 if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
1823 // Emit the definition if it can't be deferred.
1824 EmitGlobalDefinition(GD);
1828 // If we're deferring emission of a C++ variable with an
1829 // initializer, remember the order in which it appeared in the file.
1830 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
1831 cast<VarDecl>(Global)->hasInit()) {
1832 DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
1833 CXXGlobalInits.push_back(nullptr);
1836 StringRef MangledName = getMangledName(GD);
1837 if (GetGlobalValue(MangledName) != nullptr) {
1838 // The value has already been used and should therefore be emitted.
1839 addDeferredDeclToEmit(GD);
1840 } else if (MustBeEmitted(Global)) {
1841 // The value must be emitted, but cannot be emitted eagerly.
1842 assert(!MayBeEmittedEagerly(Global));
1843 addDeferredDeclToEmit(GD);
1845 // Otherwise, remember that we saw a deferred decl with this name. The
1846 // first use of the mangled name will cause it to move into
1847 // DeferredDeclsToEmit.
1848 DeferredDecls[MangledName] = GD;
1852 // Check if T is a class type with a destructor that's not dllimport.
1853 static bool HasNonDllImportDtor(QualType T) {
1854 if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
1855 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1856 if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
1863 struct FunctionIsDirectlyRecursive :
1864 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> {
1865 const StringRef Name;
1866 const Builtin::Context &BI;
1868 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) :
1869 Name(N), BI(C), Result(false) {
1871 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base;
1873 bool TraverseCallExpr(CallExpr *E) {
1874 const FunctionDecl *FD = E->getDirectCallee();
1877 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
1878 if (Attr && Name == Attr->getLabel()) {
1882 unsigned BuiltinID = FD->getBuiltinID();
1883 if (!BuiltinID || !BI.isLibFunction(BuiltinID))
1885 StringRef BuiltinName = BI.getName(BuiltinID);
1886 if (BuiltinName.startswith("__builtin_") &&
1887 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
1895 // Make sure we're not referencing non-imported vars or functions.
1896 struct DLLImportFunctionVisitor
1897 : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
1898 bool SafeToInline = true;
1900 bool shouldVisitImplicitCode() const { return true; }
1902 bool VisitVarDecl(VarDecl *VD) {
1903 if (VD->getTLSKind()) {
1904 // A thread-local variable cannot be imported.
1905 SafeToInline = false;
1906 return SafeToInline;
1909 // A variable definition might imply a destructor call.
1910 if (VD->isThisDeclarationADefinition())
1911 SafeToInline = !HasNonDllImportDtor(VD->getType());
1913 return SafeToInline;
1916 bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
1917 if (const auto *D = E->getTemporary()->getDestructor())
1918 SafeToInline = D->hasAttr<DLLImportAttr>();
1919 return SafeToInline;
1922 bool VisitDeclRefExpr(DeclRefExpr *E) {
1923 ValueDecl *VD = E->getDecl();
1924 if (isa<FunctionDecl>(VD))
1925 SafeToInline = VD->hasAttr<DLLImportAttr>();
1926 else if (VarDecl *V = dyn_cast<VarDecl>(VD))
1927 SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
1928 return SafeToInline;
1931 bool VisitCXXConstructExpr(CXXConstructExpr *E) {
1932 SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
1933 return SafeToInline;
1936 bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
1937 CXXMethodDecl *M = E->getMethodDecl();
1939 // Call through a pointer to member function. This is safe to inline.
1940 SafeToInline = true;
1942 SafeToInline = M->hasAttr<DLLImportAttr>();
1944 return SafeToInline;
1947 bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
1948 SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
1949 return SafeToInline;
1952 bool VisitCXXNewExpr(CXXNewExpr *E) {
1953 SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
1954 return SafeToInline;
1959 // isTriviallyRecursive - Check if this function calls another
1960 // decl that, because of the asm attribute or the other decl being a builtin,
1961 // ends up pointing to itself.
1963 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
1965 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
1966 // asm labels are a special kind of mangling we have to support.
1967 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
1970 Name = Attr->getLabel();
1972 Name = FD->getName();
1975 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
1976 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD));
1977 return Walker.Result;
1980 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
1981 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
1983 const auto *F = cast<FunctionDecl>(GD.getDecl());
1984 if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
1987 if (F->hasAttr<DLLImportAttr>()) {
1988 // Check whether it would be safe to inline this dllimport function.
1989 DLLImportFunctionVisitor Visitor;
1990 Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
1991 if (!Visitor.SafeToInline)
1994 if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
1995 // Implicit destructor invocations aren't captured in the AST, so the
1996 // check above can't see them. Check for them manually here.
1997 for (const Decl *Member : Dtor->getParent()->decls())
1998 if (isa<FieldDecl>(Member))
1999 if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
2001 for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
2002 if (HasNonDllImportDtor(B.getType()))
2007 // PR9614. Avoid cases where the source code is lying to us. An available
2008 // externally function should have an equivalent function somewhere else,
2009 // but a function that calls itself is clearly not equivalent to the real
2011 // This happens in glibc's btowc and in some configure checks.
2012 return !isTriviallyRecursive(F);
2015 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
2016 return CodeGenOpts.OptimizationLevel > 0;
2019 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
2020 const auto *D = cast<ValueDecl>(GD.getDecl());
2022 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
2023 Context.getSourceManager(),
2024 "Generating code for declaration");
2026 if (isa<FunctionDecl>(D)) {
2027 // At -O0, don't generate IR for functions with available_externally
2029 if (!shouldEmitFunction(GD))
2032 if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
2033 // Make sure to emit the definition(s) before we emit the thunks.
2034 // This is necessary for the generation of certain thunks.
2035 if (const auto *CD = dyn_cast<CXXConstructorDecl>(Method))
2036 ABI->emitCXXStructor(CD, getFromCtorType(GD.getCtorType()));
2037 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(Method))
2038 ABI->emitCXXStructor(DD, getFromDtorType(GD.getDtorType()));
2040 EmitGlobalFunctionDefinition(GD, GV);
2042 if (Method->isVirtual())
2043 getVTables().EmitThunks(GD);
2048 return EmitGlobalFunctionDefinition(GD, GV);
2051 if (const auto *VD = dyn_cast<VarDecl>(D))
2052 return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
2054 llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
2057 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
2058 llvm::Function *NewFn);
2060 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
2061 /// module, create and return an llvm Function with the specified type. If there
2062 /// is something in the module with the specified name, return it potentially
2063 /// bitcasted to the right type.
2065 /// If D is non-null, it specifies a decl that correspond to this. This is used
2066 /// to set the attributes on the function when it is first created.
2067 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
2068 StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
2069 bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
2070 ForDefinition_t IsForDefinition) {
2071 const Decl *D = GD.getDecl();
2073 // Lookup the entry, lazily creating it if necessary.
2074 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
2076 if (WeakRefReferences.erase(Entry)) {
2077 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
2078 if (FD && !FD->hasAttr<WeakAttr>())
2079 Entry->setLinkage(llvm::Function::ExternalLinkage);
2082 // Handle dropped DLL attributes.
2083 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
2084 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
2086 // If there are two attempts to define the same mangled name, issue an
2088 if (IsForDefinition && !Entry->isDeclaration()) {
2090 // Check that GD is not yet in DiagnosedConflictingDefinitions is required
2091 // to make sure that we issue an error only once.
2092 if (lookupRepresentativeDecl(MangledName, OtherGD) &&
2093 (GD.getCanonicalDecl().getDecl() !=
2094 OtherGD.getCanonicalDecl().getDecl()) &&
2095 DiagnosedConflictingDefinitions.insert(GD).second) {
2096 getDiags().Report(D->getLocation(),
2097 diag::err_duplicate_mangled_name);
2098 getDiags().Report(OtherGD.getDecl()->getLocation(),
2099 diag::note_previous_definition);
2103 if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
2104 (Entry->getType()->getElementType() == Ty)) {
2108 // Make sure the result is of the correct type.
2109 // (If function is requested for a definition, we always need to create a new
2110 // function, not just return a bitcast.)
2111 if (!IsForDefinition)
2112 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
2115 // This function doesn't have a complete type (for example, the return
2116 // type is an incomplete struct). Use a fake type instead, and make
2117 // sure not to try to set attributes.
2118 bool IsIncompleteFunction = false;
2120 llvm::FunctionType *FTy;
2121 if (isa<llvm::FunctionType>(Ty)) {
2122 FTy = cast<llvm::FunctionType>(Ty);
2124 FTy = llvm::FunctionType::get(VoidTy, false);
2125 IsIncompleteFunction = true;
2129 llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
2130 Entry ? StringRef() : MangledName, &getModule());
2132 // If we already created a function with the same mangled name (but different
2133 // type) before, take its name and add it to the list of functions to be
2134 // replaced with F at the end of CodeGen.
2136 // This happens if there is a prototype for a function (e.g. "int f()") and
2137 // then a definition of a different type (e.g. "int f(int x)").
2141 // This might be an implementation of a function without a prototype, in
2142 // which case, try to do special replacement of calls which match the new
2143 // prototype. The really key thing here is that we also potentially drop
2144 // arguments from the call site so as to make a direct call, which makes the
2145 // inliner happier and suppresses a number of optimizer warnings (!) about
2146 // dropping arguments.
2147 if (!Entry->use_empty()) {
2148 ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
2149 Entry->removeDeadConstantUsers();
2152 llvm::Constant *BC = llvm::ConstantExpr::getBitCast(
2153 F, Entry->getType()->getElementType()->getPointerTo());
2154 addGlobalValReplacement(Entry, BC);
2157 assert(F->getName() == MangledName && "name was uniqued!");
2159 SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk,
2161 if (ExtraAttrs.hasAttributes(llvm::AttributeList::FunctionIndex)) {
2162 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex);
2163 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
2167 // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
2168 // each other bottoming out with the base dtor. Therefore we emit non-base
2169 // dtors on usage, even if there is no dtor definition in the TU.
2170 if (D && isa<CXXDestructorDecl>(D) &&
2171 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
2173 addDeferredDeclToEmit(GD);
2175 // This is the first use or definition of a mangled name. If there is a
2176 // deferred decl with this name, remember that we need to emit it at the end
2178 auto DDI = DeferredDecls.find(MangledName);
2179 if (DDI != DeferredDecls.end()) {
2180 // Move the potentially referenced deferred decl to the
2181 // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
2182 // don't need it anymore).
2183 addDeferredDeclToEmit(DDI->second);
2184 DeferredDecls.erase(DDI);
2186 // Otherwise, there are cases we have to worry about where we're
2187 // using a declaration for which we must emit a definition but where
2188 // we might not find a top-level definition:
2189 // - member functions defined inline in their classes
2190 // - friend functions defined inline in some class
2191 // - special member functions with implicit definitions
2192 // If we ever change our AST traversal to walk into class methods,
2193 // this will be unnecessary.
2195 // We also don't emit a definition for a function if it's going to be an
2196 // entry in a vtable, unless it's already marked as used.
2197 } else if (getLangOpts().CPlusPlus && D) {
2198 // Look for a declaration that's lexically in a record.
2199 for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
2200 FD = FD->getPreviousDecl()) {
2201 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
2202 if (FD->doesThisDeclarationHaveABody()) {
2203 addDeferredDeclToEmit(GD.getWithDecl(FD));
2211 // Make sure the result is of the requested type.
2212 if (!IsIncompleteFunction) {
2213 assert(F->getType()->getElementType() == Ty);
2217 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
2218 return llvm::ConstantExpr::getBitCast(F, PTy);
2221 /// GetAddrOfFunction - Return the address of the given function. If Ty is
2222 /// non-null, then this function will use the specified type if it has to
2223 /// create it (this occurs when we see a definition of the function).
2224 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
2228 ForDefinition_t IsForDefinition) {
2229 // If there was no specific requested type, just convert it now.
2231 const auto *FD = cast<FunctionDecl>(GD.getDecl());
2232 auto CanonTy = Context.getCanonicalType(FD->getType());
2233 Ty = getTypes().ConvertFunctionType(CanonTy, FD);
2236 StringRef MangledName = getMangledName(GD);
2237 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
2238 /*IsThunk=*/false, llvm::AttributeList(),
2242 static const FunctionDecl *
2243 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
2244 TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
2245 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
2247 IdentifierInfo &CII = C.Idents.get(Name);
2248 for (const auto &Result : DC->lookup(&CII))
2249 if (const auto FD = dyn_cast<FunctionDecl>(Result))
2252 if (!C.getLangOpts().CPlusPlus)
2255 // Demangle the premangled name from getTerminateFn()
2256 IdentifierInfo &CXXII =
2257 (Name == "_ZSt9terminatev" || Name == "\01?terminate@@YAXXZ")
2258 ? C.Idents.get("terminate")
2259 : C.Idents.get(Name);
2261 for (const auto &N : {"__cxxabiv1", "std"}) {
2262 IdentifierInfo &NS = C.Idents.get(N);
2263 for (const auto &Result : DC->lookup(&NS)) {
2264 NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
2265 if (auto LSD = dyn_cast<LinkageSpecDecl>(Result))
2266 for (const auto &Result : LSD->lookup(&NS))
2267 if ((ND = dyn_cast<NamespaceDecl>(Result)))
2271 for (const auto &Result : ND->lookup(&CXXII))
2272 if (const auto *FD = dyn_cast<FunctionDecl>(Result))
2280 /// CreateRuntimeFunction - Create a new runtime function with the specified
2283 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
2284 llvm::AttributeList ExtraAttrs,
2287 GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
2288 /*DontDefer=*/false, /*IsThunk=*/false,
2291 if (auto *F = dyn_cast<llvm::Function>(C)) {
2293 F->setCallingConv(getRuntimeCC());
2295 if (!Local && getTriple().isOSBinFormatCOFF() &&
2296 !getCodeGenOpts().LTOVisibilityPublicStd &&
2297 !getTriple().isWindowsGNUEnvironment()) {
2298 const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
2299 if (!FD || FD->hasAttr<DLLImportAttr>()) {
2300 F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2301 F->setLinkage(llvm::GlobalValue::ExternalLinkage);
2310 /// CreateBuiltinFunction - Create a new builtin function with the specified
2313 CodeGenModule::CreateBuiltinFunction(llvm::FunctionType *FTy, StringRef Name,
2314 llvm::AttributeList ExtraAttrs) {
2316 GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
2317 /*DontDefer=*/false, /*IsThunk=*/false, ExtraAttrs);
2318 if (auto *F = dyn_cast<llvm::Function>(C))
2320 F->setCallingConv(getBuiltinCC());
2324 /// isTypeConstant - Determine whether an object of this type can be emitted
2327 /// If ExcludeCtor is true, the duration when the object's constructor runs
2328 /// will not be considered. The caller will need to verify that the object is
2329 /// not written to during its construction.
2330 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
2331 if (!Ty.isConstant(Context) && !Ty->isReferenceType())
2334 if (Context.getLangOpts().CPlusPlus) {
2335 if (const CXXRecordDecl *Record
2336 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
2337 return ExcludeCtor && !Record->hasMutableFields() &&
2338 Record->hasTrivialDestructor();
2344 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
2345 /// create and return an llvm GlobalVariable with the specified type. If there
2346 /// is something in the module with the specified name, return it potentially
2347 /// bitcasted to the right type.
2349 /// If D is non-null, it specifies a decl that correspond to this. This is used
2350 /// to set the attributes on the global when it is first created.
2352 /// If IsForDefinition is true, it is guranteed that an actual global with
2353 /// type Ty will be returned, not conversion of a variable with the same
2354 /// mangled name but some other type.
2356 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
2357 llvm::PointerType *Ty,
2359 ForDefinition_t IsForDefinition) {
2360 // Lookup the entry, lazily creating it if necessary.
2361 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
2363 if (WeakRefReferences.erase(Entry)) {
2364 if (D && !D->hasAttr<WeakAttr>())
2365 Entry->setLinkage(llvm::Function::ExternalLinkage);
2368 // Handle dropped DLL attributes.
2369 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
2370 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
2372 if (Entry->getType() == Ty)
2375 // If there are two attempts to define the same mangled name, issue an
2377 if (IsForDefinition && !Entry->isDeclaration()) {
2379 const VarDecl *OtherD;
2381 // Check that D is not yet in DiagnosedConflictingDefinitions is required
2382 // to make sure that we issue an error only once.
2383 if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
2384 (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
2385 (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
2386 OtherD->hasInit() &&
2387 DiagnosedConflictingDefinitions.insert(D).second) {
2388 getDiags().Report(D->getLocation(),
2389 diag::err_duplicate_mangled_name);
2390 getDiags().Report(OtherGD.getDecl()->getLocation(),
2391 diag::note_previous_definition);
2395 // Make sure the result is of the correct type.
2396 if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace())
2397 return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty);
2399 // (If global is requested for a definition, we always need to create a new
2400 // global, not just return a bitcast.)
2401 if (!IsForDefinition)
2402 return llvm::ConstantExpr::getBitCast(Entry, Ty);
2405 auto AddrSpace = GetGlobalVarAddressSpace(D);
2406 auto TargetAddrSpace = getContext().getTargetAddressSpace(AddrSpace);
2408 auto *GV = new llvm::GlobalVariable(
2409 getModule(), Ty->getElementType(), false,
2410 llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr,
2411 llvm::GlobalVariable::NotThreadLocal, TargetAddrSpace);
2413 // If we already created a global with the same mangled name (but different
2414 // type) before, take its name and remove it from its parent.
2416 GV->takeName(Entry);
2418 if (!Entry->use_empty()) {
2419 llvm::Constant *NewPtrForOldDecl =
2420 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
2421 Entry->replaceAllUsesWith(NewPtrForOldDecl);
2424 Entry->eraseFromParent();
2427 // This is the first use or definition of a mangled name. If there is a
2428 // deferred decl with this name, remember that we need to emit it at the end
2430 auto DDI = DeferredDecls.find(MangledName);
2431 if (DDI != DeferredDecls.end()) {
2432 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
2433 // list, and remove it from DeferredDecls (since we don't need it anymore).
2434 addDeferredDeclToEmit(DDI->second);
2435 DeferredDecls.erase(DDI);
2438 // Handle things which are present even on external declarations.
2440 // FIXME: This code is overly simple and should be merged with other global
2442 GV->setConstant(isTypeConstant(D->getType(), false));
2444 GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
2446 setLinkageForGV(GV, D);
2447 setGlobalVisibility(GV, D, NotForDefinition);
2449 if (D->getTLSKind()) {
2450 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
2451 CXXThreadLocals.push_back(D);
2455 // If required by the ABI, treat declarations of static data members with
2456 // inline initializers as definitions.
2457 if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
2458 EmitGlobalVarDefinition(D);
2461 // Emit section information for extern variables.
2462 if (D->hasExternalStorage()) {
2463 if (const SectionAttr *SA = D->getAttr<SectionAttr>())
2464 GV->setSection(SA->getName());
2467 // Handle XCore specific ABI requirements.
2468 if (getTriple().getArch() == llvm::Triple::xcore &&
2469 D->getLanguageLinkage() == CLanguageLinkage &&
2470 D->getType().isConstant(Context) &&
2471 isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
2472 GV->setSection(".cp.rodata");
2474 // Check if we a have a const declaration with an initializer, we may be
2475 // able to emit it as available_externally to expose it's value to the
2477 if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
2478 D->getType().isConstQualified() && !GV->hasInitializer() &&
2479 !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
2480 const auto *Record =
2481 Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
2482 bool HasMutableFields = Record && Record->hasMutableFields();
2483 if (!HasMutableFields) {
2484 const VarDecl *InitDecl;
2485 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
2487 ConstantEmitter emitter(*this);
2488 llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
2490 auto *InitType = Init->getType();
2491 if (GV->getType()->getElementType() != InitType) {
2492 // The type of the initializer does not match the definition.
2493 // This happens when an initializer has a different type from
2494 // the type of the global (because of padding at the end of a
2495 // structure for instance).
2496 GV->setName(StringRef());
2497 // Make a new global with the correct type, this is now guaranteed
2499 auto *NewGV = cast<llvm::GlobalVariable>(
2500 GetAddrOfGlobalVar(D, InitType, IsForDefinition));
2502 // Erase the old global, since it is no longer used.
2503 cast<llvm::GlobalValue>(GV)->eraseFromParent();
2506 GV->setInitializer(Init);
2507 GV->setConstant(true);
2508 GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
2510 emitter.finalize(GV);
2518 D ? D->getType().getAddressSpace()
2519 : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
2520 assert(getContext().getTargetAddressSpace(ExpectedAS) ==
2521 Ty->getPointerAddressSpace());
2522 if (AddrSpace != ExpectedAS)
2523 return getTargetCodeGenInfo().performAddrSpaceCast(*this, GV, AddrSpace,
2530 CodeGenModule::GetAddrOfGlobal(GlobalDecl GD,
2531 ForDefinition_t IsForDefinition) {
2532 const Decl *D = GD.getDecl();
2533 if (isa<CXXConstructorDecl>(D))
2534 return getAddrOfCXXStructor(cast<CXXConstructorDecl>(D),
2535 getFromCtorType(GD.getCtorType()),
2536 /*FnInfo=*/nullptr, /*FnType=*/nullptr,
2537 /*DontDefer=*/false, IsForDefinition);
2538 else if (isa<CXXDestructorDecl>(D))
2539 return getAddrOfCXXStructor(cast<CXXDestructorDecl>(D),
2540 getFromDtorType(GD.getDtorType()),
2541 /*FnInfo=*/nullptr, /*FnType=*/nullptr,
2542 /*DontDefer=*/false, IsForDefinition);
2543 else if (isa<CXXMethodDecl>(D)) {
2544 auto FInfo = &getTypes().arrangeCXXMethodDeclaration(
2545 cast<CXXMethodDecl>(D));
2546 auto Ty = getTypes().GetFunctionType(*FInfo);
2547 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
2549 } else if (isa<FunctionDecl>(D)) {
2550 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
2551 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
2552 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
2555 return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr,
2559 llvm::GlobalVariable *
2560 CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name,
2562 llvm::GlobalValue::LinkageTypes Linkage) {
2563 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
2564 llvm::GlobalVariable *OldGV = nullptr;
2567 // Check if the variable has the right type.
2568 if (GV->getType()->getElementType() == Ty)
2571 // Because C++ name mangling, the only way we can end up with an already
2572 // existing global with the same name is if it has been declared extern "C".
2573 assert(GV->isDeclaration() && "Declaration has wrong type!");
2577 // Create a new variable.
2578 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
2579 Linkage, nullptr, Name);
2582 // Replace occurrences of the old variable if needed.
2583 GV->takeName(OldGV);
2585 if (!OldGV->use_empty()) {
2586 llvm::Constant *NewPtrForOldDecl =
2587 llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
2588 OldGV->replaceAllUsesWith(NewPtrForOldDecl);
2591 OldGV->eraseFromParent();
2594 if (supportsCOMDAT() && GV->isWeakForLinker() &&
2595 !GV->hasAvailableExternallyLinkage())
2596 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
2601 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
2602 /// given global variable. If Ty is non-null and if the global doesn't exist,
2603 /// then it will be created with the specified type instead of whatever the
2604 /// normal requested type would be. If IsForDefinition is true, it is guranteed
2605 /// that an actual global with type Ty will be returned, not conversion of a
2606 /// variable with the same mangled name but some other type.
2607 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
2609 ForDefinition_t IsForDefinition) {
2610 assert(D->hasGlobalStorage() && "Not a global variable");
2611 QualType ASTTy = D->getType();
2613 Ty = getTypes().ConvertTypeForMem(ASTTy);
2615 llvm::PointerType *PTy =
2616 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
2618 StringRef MangledName = getMangledName(D);
2619 return GetOrCreateLLVMGlobal(MangledName, PTy, D, IsForDefinition);
2622 /// CreateRuntimeVariable - Create a new runtime global variable with the
2623 /// specified type and name.
2625 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
2627 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), nullptr);
2630 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
2631 assert(!D->getInit() && "Cannot emit definite definitions here!");
2633 StringRef MangledName = getMangledName(D);
2634 llvm::GlobalValue *GV = GetGlobalValue(MangledName);
2636 // We already have a definition, not declaration, with the same mangled name.
2637 // Emitting of declaration is not required (and actually overwrites emitted
2639 if (GV && !GV->isDeclaration())
2642 // If we have not seen a reference to this variable yet, place it into the
2643 // deferred declarations table to be emitted if needed later.
2644 if (!MustBeEmitted(D) && !GV) {
2645 DeferredDecls[MangledName] = D;
2649 // The tentative definition is the only definition.
2650 EmitGlobalVarDefinition(D);
2653 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
2654 return Context.toCharUnitsFromBits(
2655 getDataLayout().getTypeStoreSizeInBits(Ty));
2658 LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
2659 LangAS AddrSpace = LangAS::Default;
2660 if (LangOpts.OpenCL) {
2661 AddrSpace = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
2662 assert(AddrSpace == LangAS::opencl_global ||
2663 AddrSpace == LangAS::opencl_constant ||
2664 AddrSpace == LangAS::opencl_local ||
2665 AddrSpace >= LangAS::FirstTargetAddressSpace);
2669 if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
2670 if (D && D->hasAttr<CUDAConstantAttr>())
2671 return LangAS::cuda_constant;
2672 else if (D && D->hasAttr<CUDASharedAttr>())
2673 return LangAS::cuda_shared;
2675 return LangAS::cuda_device;
2678 return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
2681 template<typename SomeDecl>
2682 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
2683 llvm::GlobalValue *GV) {
2684 if (!getLangOpts().CPlusPlus)
2687 // Must have 'used' attribute, or else inline assembly can't rely on
2688 // the name existing.
2689 if (!D->template hasAttr<UsedAttr>())
2692 // Must have internal linkage and an ordinary name.
2693 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage)
2696 // Must be in an extern "C" context. Entities declared directly within
2697 // a record are not extern "C" even if the record is in such a context.
2698 const SomeDecl *First = D->getFirstDecl();
2699 if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
2702 // OK, this is an internal linkage entity inside an extern "C" linkage
2703 // specification. Make a note of that so we can give it the "expected"
2704 // mangled name if nothing else is using that name.
2705 std::pair<StaticExternCMap::iterator, bool> R =
2706 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
2708 // If we have multiple internal linkage entities with the same name
2709 // in extern "C" regions, none of them gets that name.
2711 R.first->second = nullptr;
2714 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
2715 if (!CGM.supportsCOMDAT())
2718 if (D.hasAttr<SelectAnyAttr>())
2722 if (auto *VD = dyn_cast<VarDecl>(&D))
2723 Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
2725 Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
2729 case GVA_AvailableExternally:
2730 case GVA_StrongExternal:
2732 case GVA_DiscardableODR:
2736 llvm_unreachable("No such linkage");
2739 void CodeGenModule::maybeSetTrivialComdat(const Decl &D,
2740 llvm::GlobalObject &GO) {
2741 if (!shouldBeInCOMDAT(*this, D))
2743 GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
2746 /// Pass IsTentative as true if you want to create a tentative definition.
2747 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
2749 // OpenCL global variables of sampler type are translated to function calls,
2750 // therefore no need to be translated.
2751 QualType ASTTy = D->getType();
2752 if (getLangOpts().OpenCL && ASTTy->isSamplerT())
2755 llvm::Constant *Init = nullptr;
2756 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
2757 bool NeedsGlobalCtor = false;
2758 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor();
2760 const VarDecl *InitDecl;
2761 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
2763 Optional<ConstantEmitter> emitter;
2765 // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
2766 // as part of their declaration." Sema has already checked for
2767 // error cases, so we just need to set Init to UndefValue.
2768 if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
2769 D->hasAttr<CUDASharedAttr>())
2770 Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
2771 else if (!InitExpr) {
2772 // This is a tentative definition; tentative definitions are
2773 // implicitly initialized with { 0 }.
2775 // Note that tentative definitions are only emitted at the end of
2776 // a translation unit, so they should never have incomplete
2777 // type. In addition, EmitTentativeDefinition makes sure that we
2778 // never attempt to emit a tentative definition if a real one
2779 // exists. A use may still exists, however, so we still may need
2781 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
2782 Init = EmitNullConstant(D->getType());
2784 initializedGlobalDecl = GlobalDecl(D);
2785 emitter.emplace(*this);
2786 Init = emitter->tryEmitForInitializer(*InitDecl);
2789 QualType T = InitExpr->getType();
2790 if (D->getType()->isReferenceType())
2793 if (getLangOpts().CPlusPlus) {
2794 Init = EmitNullConstant(T);
2795 NeedsGlobalCtor = true;
2797 ErrorUnsupported(D, "static initializer");
2798 Init = llvm::UndefValue::get(getTypes().ConvertType(T));
2801 // We don't need an initializer, so remove the entry for the delayed
2802 // initializer position (just in case this entry was delayed) if we
2803 // also don't need to register a destructor.
2804 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
2805 DelayedCXXInitPosition.erase(D);
2809 llvm::Type* InitType = Init->getType();
2810 llvm::Constant *Entry =
2811 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
2813 // Strip off a bitcast if we got one back.
2814 if (auto *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
2815 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
2816 CE->getOpcode() == llvm::Instruction::AddrSpaceCast ||
2817 // All zero index gep.
2818 CE->getOpcode() == llvm::Instruction::GetElementPtr);
2819 Entry = CE->getOperand(0);
2822 // Entry is now either a Function or GlobalVariable.
2823 auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
2825 // We have a definition after a declaration with the wrong type.
2826 // We must make a new GlobalVariable* and update everything that used OldGV
2827 // (a declaration or tentative definition) with the new GlobalVariable*
2828 // (which will be a definition).
2830 // This happens if there is a prototype for a global (e.g.
2831 // "extern int x[];") and then a definition of a different type (e.g.
2832 // "int x[10];"). This also happens when an initializer has a different type
2833 // from the type of the global (this happens with unions).
2834 if (!GV || GV->getType()->getElementType() != InitType ||
2835 GV->getType()->getAddressSpace() !=
2836 getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
2838 // Move the old entry aside so that we'll create a new one.
2839 Entry->setName(StringRef());
2841 // Make a new global with the correct type, this is now guaranteed to work.
2842 GV = cast<llvm::GlobalVariable>(
2843 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative)));
2845 // Replace all uses of the old global with the new global
2846 llvm::Constant *NewPtrForOldDecl =
2847 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
2848 Entry->replaceAllUsesWith(NewPtrForOldDecl);
2850 // Erase the old global, since it is no longer used.
2851 cast<llvm::GlobalValue>(Entry)->eraseFromParent();
2854 MaybeHandleStaticInExternC(D, GV);
2856 if (D->hasAttr<AnnotateAttr>())
2857 AddGlobalAnnotations(D, GV);
2859 // Set the llvm linkage type as appropriate.
2860 llvm::GlobalValue::LinkageTypes Linkage =
2861 getLLVMLinkageVarDefinition(D, GV->isConstant());
2863 // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
2864 // the device. [...]"
2865 // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
2866 // __device__, declares a variable that: [...]
2867 // Is accessible from all the threads within the grid and from the host
2868 // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
2869 // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
2870 if (GV && LangOpts.CUDA) {
2871 if (LangOpts.CUDAIsDevice) {
2872 if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>())
2873 GV->setExternallyInitialized(true);
2875 // Host-side shadows of external declarations of device-side
2876 // global variables become internal definitions. These have to
2877 // be internal in order to prevent name conflicts with global
2878 // host variables with the same name in a different TUs.
2879 if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()) {
2880 Linkage = llvm::GlobalValue::InternalLinkage;
2882 // Shadow variables and their properties must be registered
2883 // with CUDA runtime.
2885 if (!D->hasDefinition())
2886 Flags |= CGCUDARuntime::ExternDeviceVar;
2887 if (D->hasAttr<CUDAConstantAttr>())
2888 Flags |= CGCUDARuntime::ConstantDeviceVar;
2889 getCUDARuntime().registerDeviceVar(*GV, Flags);
2890 } else if (D->hasAttr<CUDASharedAttr>())
2891 // __shared__ variables are odd. Shadows do get created, but
2892 // they are not registered with the CUDA runtime, so they
2893 // can't really be used to access their device-side
2894 // counterparts. It's not clear yet whether it's nvcc's bug or
2895 // a feature, but we've got to do the same for compatibility.
2896 Linkage = llvm::GlobalValue::InternalLinkage;
2900 GV->setInitializer(Init);
2901 if (emitter) emitter->finalize(GV);
2903 // If it is safe to mark the global 'constant', do so now.
2904 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
2905 isTypeConstant(D->getType(), true));
2907 // If it is in a read-only section, mark it 'constant'.
2908 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
2909 const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
2910 if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
2911 GV->setConstant(true);
2914 GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
2917 // On Darwin, if the normal linkage of a C++ thread_local variable is
2918 // LinkOnce or Weak, we keep the normal linkage to prevent multiple
2919 // copies within a linkage unit; otherwise, the backing variable has
2920 // internal linkage and all accesses should just be calls to the
2921 // Itanium-specified entry point, which has the normal linkage of the
2922 // variable. This is to preserve the ability to change the implementation
2923 // behind the scenes.
2924 if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic &&
2925 Context.getTargetInfo().getTriple().isOSDarwin() &&
2926 !llvm::GlobalVariable::isLinkOnceLinkage(Linkage) &&
2927 !llvm::GlobalVariable::isWeakLinkage(Linkage))
2928 Linkage = llvm::GlobalValue::InternalLinkage;
2930 GV->setLinkage(Linkage);
2931 if (D->hasAttr<DLLImportAttr>())
2932 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
2933 else if (D->hasAttr<DLLExportAttr>())
2934 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
2936 GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
2938 if (Linkage == llvm::GlobalVariable::CommonLinkage) {
2939 // common vars aren't constant even if declared const.
2940 GV->setConstant(false);
2941 // Tentative definition of global variables may be initialized with
2942 // non-zero null pointers. In this case they should have weak linkage
2943 // since common linkage must have zero initializer and must not have
2944 // explicit section therefore cannot have non-zero initial value.
2945 if (!GV->getInitializer()->isNullValue())
2946 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
2949 setNonAliasAttributes(D, GV);
2951 if (D->getTLSKind() && !GV->isThreadLocal()) {
2952 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
2953 CXXThreadLocals.push_back(D);
2957 maybeSetTrivialComdat(*D, *GV);
2959 // Emit the initializer function if necessary.
2960 if (NeedsGlobalCtor || NeedsGlobalDtor)
2961 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
2963 SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor);
2965 // Emit global variable debug information.
2966 if (CGDebugInfo *DI = getModuleDebugInfo())
2967 if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
2968 DI->EmitGlobalVariable(GV, D);
2971 static bool isVarDeclStrongDefinition(const ASTContext &Context,
2972 CodeGenModule &CGM, const VarDecl *D,
2974 // Don't give variables common linkage if -fno-common was specified unless it
2975 // was overridden by a NoCommon attribute.
2976 if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
2980 // A declaration of an identifier for an object that has file scope without
2981 // an initializer, and without a storage-class specifier or with the
2982 // storage-class specifier static, constitutes a tentative definition.
2983 if (D->getInit() || D->hasExternalStorage())
2986 // A variable cannot be both common and exist in a section.
2987 if (D->hasAttr<SectionAttr>())
2990 // A variable cannot be both common and exist in a section.
2991 // We dont try to determine which is the right section in the front-end.
2992 // If no specialized section name is applicable, it will resort to default.
2993 if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
2994 D->hasAttr<PragmaClangDataSectionAttr>() ||
2995 D->hasAttr<PragmaClangRodataSectionAttr>())
2998 // Thread local vars aren't considered common linkage.
2999 if (D->getTLSKind())
3002 // Tentative definitions marked with WeakImportAttr are true definitions.
3003 if (D->hasAttr<WeakImportAttr>())
3006 // A variable cannot be both common and exist in a comdat.
3007 if (shouldBeInCOMDAT(CGM, *D))
3010 // Declarations with a required alignment do not have common linkage in MSVC
3012 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
3013 if (D->hasAttr<AlignedAttr>())
3015 QualType VarType = D->getType();
3016 if (Context.isAlignmentRequired(VarType))
3019 if (const auto *RT = VarType->getAs<RecordType>()) {
3020 const RecordDecl *RD = RT->getDecl();
3021 for (const FieldDecl *FD : RD->fields()) {
3022 if (FD->isBitField())
3024 if (FD->hasAttr<AlignedAttr>())
3026 if (Context.isAlignmentRequired(FD->getType()))
3035 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
3036 const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) {
3037 if (Linkage == GVA_Internal)
3038 return llvm::Function::InternalLinkage;
3040 if (D->hasAttr<WeakAttr>()) {
3041 if (IsConstantVariable)
3042 return llvm::GlobalVariable::WeakODRLinkage;
3044 return llvm::GlobalVariable::WeakAnyLinkage;
3047 // We are guaranteed to have a strong definition somewhere else,
3048 // so we can use available_externally linkage.
3049 if (Linkage == GVA_AvailableExternally)
3050 return llvm::GlobalValue::AvailableExternallyLinkage;
3052 // Note that Apple's kernel linker doesn't support symbol
3053 // coalescing, so we need to avoid linkonce and weak linkages there.
3054 // Normally, this means we just map to internal, but for explicit
3055 // instantiations we'll map to external.
3057 // In C++, the compiler has to emit a definition in every translation unit
3058 // that references the function. We should use linkonce_odr because
3059 // a) if all references in this translation unit are optimized away, we
3060 // don't need to codegen it. b) if the function persists, it needs to be
3061 // merged with other definitions. c) C++ has the ODR, so we know the
3062 // definition is dependable.
3063 if (Linkage == GVA_DiscardableODR)
3064 return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
3065 : llvm::Function::InternalLinkage;
3067 // An explicit instantiation of a template has weak linkage, since
3068 // explicit instantiations can occur in multiple translation units
3069 // and must all be equivalent. However, we are not allowed to
3070 // throw away these explicit instantiations.
3072 // We don't currently support CUDA device code spread out across multiple TUs,
3073 // so say that CUDA templates are either external (for kernels) or internal.
3074 // This lets llvm perform aggressive inter-procedural optimizations.
3075 if (Linkage == GVA_StrongODR) {
3076 if (Context.getLangOpts().AppleKext)
3077 return llvm::Function::ExternalLinkage;
3078 if (Context.getLangOpts().CUDA && Context.getLangOpts().CUDAIsDevice)
3079 return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
3080 : llvm::Function::InternalLinkage;
3081 return llvm::Function::WeakODRLinkage;
3084 // C++ doesn't have tentative definitions and thus cannot have common
3086 if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
3087 !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
3088 CodeGenOpts.NoCommon))
3089 return llvm::GlobalVariable::CommonLinkage;
3091 // selectany symbols are externally visible, so use weak instead of
3092 // linkonce. MSVC optimizes away references to const selectany globals, so
3093 // all definitions should be the same and ODR linkage should be used.
3094 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
3095 if (D->hasAttr<SelectAnyAttr>())
3096 return llvm::GlobalVariable::WeakODRLinkage;
3098 // Otherwise, we have strong external linkage.
3099 assert(Linkage == GVA_StrongExternal);
3100 return llvm::GlobalVariable::ExternalLinkage;
3103 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition(
3104 const VarDecl *VD, bool IsConstant) {
3105 GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
3106 return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant);
3109 /// Replace the uses of a function that was declared with a non-proto type.
3110 /// We want to silently drop extra arguments from call sites
3111 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
3112 llvm::Function *newFn) {
3114 if (old->use_empty()) return;
3116 llvm::Type *newRetTy = newFn->getReturnType();
3117 SmallVector<llvm::Value*, 4> newArgs;
3118 SmallVector<llvm::OperandBundleDef, 1> newBundles;
3120 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
3122 llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
3123 llvm::User *user = use->getUser();
3125 // Recognize and replace uses of bitcasts. Most calls to
3126 // unprototyped functions will use bitcasts.
3127 if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
3128 if (bitcast->getOpcode() == llvm::Instruction::BitCast)
3129 replaceUsesOfNonProtoConstant(bitcast, newFn);
3133 // Recognize calls to the function.
3134 llvm::CallSite callSite(user);
3135 if (!callSite) continue;
3136 if (!callSite.isCallee(&*use)) continue;
3138 // If the return types don't match exactly, then we can't
3139 // transform this call unless it's dead.
3140 if (callSite->getType() != newRetTy && !callSite->use_empty())
3143 // Get the call site's attribute list.
3144 SmallVector<llvm::AttributeSet, 8> newArgAttrs;
3145 llvm::AttributeList oldAttrs = callSite.getAttributes();
3147 // If the function was passed too few arguments, don't transform.
3148 unsigned newNumArgs = newFn->arg_size();
3149 if (callSite.arg_size() < newNumArgs) continue;
3151 // If extra arguments were passed, we silently drop them.
3152 // If any of the types mismatch, we don't transform.
3154 bool dontTransform = false;
3155 for (llvm::Argument &A : newFn->args()) {
3156 if (callSite.getArgument(argNo)->getType() != A.getType()) {
3157 dontTransform = true;
3161 // Add any parameter attributes.
3162 newArgAttrs.push_back(oldAttrs.getParamAttributes(argNo));
3168 // Okay, we can transform this. Create the new call instruction and copy
3169 // over the required information.
3170 newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo);
3172 // Copy over any operand bundles.
3173 callSite.getOperandBundlesAsDefs(newBundles);
3175 llvm::CallSite newCall;
3176 if (callSite.isCall()) {
3177 newCall = llvm::CallInst::Create(newFn, newArgs, newBundles, "",
3178 callSite.getInstruction());
3180 auto *oldInvoke = cast<llvm::InvokeInst>(callSite.getInstruction());
3181 newCall = llvm::InvokeInst::Create(newFn,
3182 oldInvoke->getNormalDest(),
3183 oldInvoke->getUnwindDest(),
3184 newArgs, newBundles, "",
3185 callSite.getInstruction());
3187 newArgs.clear(); // for the next iteration
3189 if (!newCall->getType()->isVoidTy())
3190 newCall->takeName(callSite.getInstruction());
3191 newCall.setAttributes(llvm::AttributeList::get(
3192 newFn->getContext(), oldAttrs.getFnAttributes(),
3193 oldAttrs.getRetAttributes(), newArgAttrs));
3194 newCall.setCallingConv(callSite.getCallingConv());
3196 // Finally, remove the old call, replacing any uses with the new one.
3197 if (!callSite->use_empty())
3198 callSite->replaceAllUsesWith(newCall.getInstruction());
3200 // Copy debug location attached to CI.
3201 if (callSite->getDebugLoc())
3202 newCall->setDebugLoc(callSite->getDebugLoc());
3204 callSite->eraseFromParent();
3208 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
3209 /// implement a function with no prototype, e.g. "int foo() {}". If there are
3210 /// existing call uses of the old function in the module, this adjusts them to
3211 /// call the new function directly.
3213 /// This is not just a cleanup: the always_inline pass requires direct calls to
3214 /// functions to be able to inline them. If there is a bitcast in the way, it
3215 /// won't inline them. Instcombine normally deletes these calls, but it isn't
3217 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
3218 llvm::Function *NewFn) {
3219 // If we're redefining a global as a function, don't transform it.
3220 if (!isa<llvm::Function>(Old)) return;
3222 replaceUsesOfNonProtoConstant(Old, NewFn);
3225 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
3226 auto DK = VD->isThisDeclarationADefinition();
3227 if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
3230 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
3231 // If we have a definition, this might be a deferred decl. If the
3232 // instantiation is explicit, make sure we emit it at the end.
3233 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
3234 GetAddrOfGlobalVar(VD);
3236 EmitTopLevelDecl(VD);
3239 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
3240 llvm::GlobalValue *GV) {
3241 const auto *D = cast<FunctionDecl>(GD.getDecl());
3243 // Compute the function info and LLVM type.
3244 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
3245 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
3247 // Get or create the prototype for the function.
3248 if (!GV || (GV->getType()->getElementType() != Ty))
3249 GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
3254 if (!GV->isDeclaration())
3257 // We need to set linkage and visibility on the function before
3258 // generating code for it because various parts of IR generation
3259 // want to propagate this information down (e.g. to local static
3261 auto *Fn = cast<llvm::Function>(GV);
3262 setFunctionLinkage(GD, Fn);
3263 setFunctionDLLStorageClass(GD, Fn);
3265 // FIXME: this is redundant with part of setFunctionDefinitionAttributes
3266 setGlobalVisibility(Fn, D, ForDefinition);
3268 MaybeHandleStaticInExternC(D, Fn);
3270 maybeSetTrivialComdat(*D, *Fn);
3272 CodeGenFunction(*this).GenerateCode(D, Fn, FI);
3274 setFunctionDefinitionAttributes(D, Fn);
3275 SetLLVMFunctionAttributesForDefinition(D, Fn);
3277 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
3278 AddGlobalCtor(Fn, CA->getPriority());
3279 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
3280 AddGlobalDtor(Fn, DA->getPriority());
3281 if (D->hasAttr<AnnotateAttr>())
3282 AddGlobalAnnotations(D, Fn);
3285 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
3286 const auto *D = cast<ValueDecl>(GD.getDecl());
3287 const AliasAttr *AA = D->getAttr<AliasAttr>();
3288 assert(AA && "Not an alias?");
3290 StringRef MangledName = getMangledName(GD);
3292 if (AA->getAliasee() == MangledName) {
3293 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
3297 // If there is a definition in the module, then it wins over the alias.
3298 // This is dubious, but allow it to be safe. Just ignore the alias.
3299 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3300 if (Entry && !Entry->isDeclaration())
3303 Aliases.push_back(GD);
3305 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
3307 // Create a reference to the named value. This ensures that it is emitted
3308 // if a deferred decl.
3309 llvm::Constant *Aliasee;
3310 if (isa<llvm::FunctionType>(DeclTy))
3311 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
3312 /*ForVTable=*/false);
3314 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
3315 llvm::PointerType::getUnqual(DeclTy),
3318 // Create the new alias itself, but don't set a name yet.
3319 auto *GA = llvm::GlobalAlias::create(
3320 DeclTy, 0, llvm::Function::ExternalLinkage, "", Aliasee, &getModule());
3323 if (GA->getAliasee() == Entry) {
3324 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
3328 assert(Entry->isDeclaration());
3330 // If there is a declaration in the module, then we had an extern followed
3331 // by the alias, as in:
3332 // extern int test6();
3334 // int test6() __attribute__((alias("test7")));
3336 // Remove it and replace uses of it with the alias.
3337 GA->takeName(Entry);
3339 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
3341 Entry->eraseFromParent();
3343 GA->setName(MangledName);
3346 // Set attributes which are particular to an alias; this is a
3347 // specialization of the attributes which may be set on a global
3348 // variable/function.
3349 if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
3350 D->isWeakImported()) {
3351 GA->setLinkage(llvm::Function::WeakAnyLinkage);
3354 if (const auto *VD = dyn_cast<VarDecl>(D))
3355 if (VD->getTLSKind())
3356 setTLSMode(GA, *VD);
3358 setAliasAttributes(D, GA);
3361 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
3362 const auto *D = cast<ValueDecl>(GD.getDecl());
3363 const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
3364 assert(IFA && "Not an ifunc?");
3366 StringRef MangledName = getMangledName(GD);
3368 if (IFA->getResolver() == MangledName) {
3369 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
3373 // Report an error if some definition overrides ifunc.
3374 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3375 if (Entry && !Entry->isDeclaration()) {
3377 if (lookupRepresentativeDecl(MangledName, OtherGD) &&
3378 DiagnosedConflictingDefinitions.insert(GD).second) {
3379 Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name);
3380 Diags.Report(OtherGD.getDecl()->getLocation(),
3381 diag::note_previous_definition);
3386 Aliases.push_back(GD);
3388 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
3389 llvm::Constant *Resolver =
3390 GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD,
3391 /*ForVTable=*/false);
3392 llvm::GlobalIFunc *GIF =
3393 llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage,
3394 "", Resolver, &getModule());
3396 if (GIF->getResolver() == Entry) {
3397 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
3400 assert(Entry->isDeclaration());
3402 // If there is a declaration in the module, then we had an extern followed
3403 // by the ifunc, as in:
3404 // extern int test();
3406 // int test() __attribute__((ifunc("resolver")));
3408 // Remove it and replace uses of it with the ifunc.
3409 GIF->takeName(Entry);
3411 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
3413 Entry->eraseFromParent();
3415 GIF->setName(MangledName);
3417 SetCommonAttributes(D, GIF);
3420 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
3421 ArrayRef<llvm::Type*> Tys) {
3422 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
3426 static llvm::StringMapEntry<llvm::GlobalVariable *> &
3427 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
3428 const StringLiteral *Literal, bool TargetIsLSB,
3429 bool &IsUTF16, unsigned &StringLength) {
3430 StringRef String = Literal->getString();
3431 unsigned NumBytes = String.size();
3433 // Check for simple case.
3434 if (!Literal->containsNonAsciiOrNull()) {
3435 StringLength = NumBytes;
3436 return *Map.insert(std::make_pair(String, nullptr)).first;
3439 // Otherwise, convert the UTF8 literals into a string of shorts.
3442 SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
3443 const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
3444 llvm::UTF16 *ToPtr = &ToBuf[0];
3446 (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
3447 ToPtr + NumBytes, llvm::strictConversion);
3449 // ConvertUTF8toUTF16 returns the length in ToPtr.
3450 StringLength = ToPtr - &ToBuf[0];
3452 // Add an explicit null.
3454 return *Map.insert(std::make_pair(
3455 StringRef(reinterpret_cast<const char *>(ToBuf.data()),
3456 (StringLength + 1) * 2),
3461 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
3462 unsigned StringLength = 0;
3463 bool isUTF16 = false;
3464 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
3465 GetConstantCFStringEntry(CFConstantStringMap, Literal,
3466 getDataLayout().isLittleEndian(), isUTF16,
3469 if (auto *C = Entry.second)
3470 return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment()));
3472 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
3473 llvm::Constant *Zeros[] = { Zero, Zero };
3475 // If we don't already have it, get __CFConstantStringClassReference.
3476 if (!CFConstantStringClassRef) {
3477 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
3478 Ty = llvm::ArrayType::get(Ty, 0);
3479 llvm::Constant *GV =
3480 CreateRuntimeVariable(Ty, "__CFConstantStringClassReference");
3482 if (getTriple().isOSBinFormatCOFF()) {
3483 IdentifierInfo &II = getContext().Idents.get(GV->getName());
3484 TranslationUnitDecl *TUDecl = getContext().getTranslationUnitDecl();
3485 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
3486 llvm::GlobalValue *CGV = cast<llvm::GlobalValue>(GV);
3488 const VarDecl *VD = nullptr;
3489 for (const auto &Result : DC->lookup(&II))
3490 if ((VD = dyn_cast<VarDecl>(Result)))
3493 if (!VD || !VD->hasAttr<DLLExportAttr>()) {
3494 CGV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
3495 CGV->setLinkage(llvm::GlobalValue::ExternalLinkage);
3497 CGV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
3498 CGV->setLinkage(llvm::GlobalValue::ExternalLinkage);
3502 // Decay array -> ptr
3503 CFConstantStringClassRef =
3504 llvm::ConstantExpr::getGetElementPtr(Ty, GV, Zeros);
3507 QualType CFTy = getContext().getCFConstantStringType();
3509 auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
3511 ConstantInitBuilder Builder(*this);
3512 auto Fields = Builder.beginStruct(STy);
3515 Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
3518 Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
3521 llvm::Constant *C = nullptr;
3523 auto Arr = llvm::makeArrayRef(
3524 reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
3525 Entry.first().size() / 2);
3526 C = llvm::ConstantDataArray::get(VMContext, Arr);
3528 C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
3531 // Note: -fwritable-strings doesn't make the backing store strings of
3532 // CFStrings writable. (See <rdar://problem/10657500>)
3534 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
3535 llvm::GlobalValue::PrivateLinkage, C, ".str");
3536 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3537 // Don't enforce the target's minimum global alignment, since the only use
3538 // of the string is via this class initializer.
3539 CharUnits Align = isUTF16
3540 ? getContext().getTypeAlignInChars(getContext().ShortTy)
3541 : getContext().getTypeAlignInChars(getContext().CharTy);
3542 GV->setAlignment(Align.getQuantity());
3544 // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
3545 // Without it LLVM can merge the string with a non unnamed_addr one during
3546 // LTO. Doing that changes the section it ends in, which surprises ld64.
3547 if (getTriple().isOSBinFormatMachO())
3548 GV->setSection(isUTF16 ? "__TEXT,__ustring"
3549 : "__TEXT,__cstring,cstring_literals");
3552 llvm::Constant *Str =
3553 llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
3556 // Cast the UTF16 string to the correct type.
3557 Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
3561 auto Ty = getTypes().ConvertType(getContext().LongTy);
3562 Fields.addInt(cast<llvm::IntegerType>(Ty), StringLength);
3564 CharUnits Alignment = getPointerAlign();
3567 GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
3568 /*isConstant=*/false,
3569 llvm::GlobalVariable::PrivateLinkage);
3570 switch (getTriple().getObjectFormat()) {
3571 case llvm::Triple::UnknownObjectFormat:
3572 llvm_unreachable("unknown file format");
3573 case llvm::Triple::COFF:
3574 case llvm::Triple::ELF:
3575 case llvm::Triple::Wasm:
3576 GV->setSection("cfstring");
3578 case llvm::Triple::MachO:
3579 GV->setSection("__DATA,__cfstring");
3584 return ConstantAddress(GV, Alignment);
3587 bool CodeGenModule::getExpressionLocationsEnabled() const {
3588 return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
3591 QualType CodeGenModule::getObjCFastEnumerationStateType() {
3592 if (ObjCFastEnumerationStateType.isNull()) {
3593 RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
3594 D->startDefinition();
3596 QualType FieldTypes[] = {
3597 Context.UnsignedLongTy,
3598 Context.getPointerType(Context.getObjCIdType()),
3599 Context.getPointerType(Context.UnsignedLongTy),
3600 Context.getConstantArrayType(Context.UnsignedLongTy,
3601 llvm::APInt(32, 5), ArrayType::Normal, 0)
3604 for (size_t i = 0; i < 4; ++i) {
3605 FieldDecl *Field = FieldDecl::Create(Context,
3608 SourceLocation(), nullptr,
3609 FieldTypes[i], /*TInfo=*/nullptr,
3610 /*BitWidth=*/nullptr,
3613 Field->setAccess(AS_public);
3617 D->completeDefinition();
3618 ObjCFastEnumerationStateType = Context.getTagDeclType(D);
3621 return ObjCFastEnumerationStateType;
3625 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
3626 assert(!E->getType()->isPointerType() && "Strings are always arrays");
3628 // Don't emit it as the address of the string, emit the string data itself
3629 // as an inline array.
3630 if (E->getCharByteWidth() == 1) {
3631 SmallString<64> Str(E->getString());
3633 // Resize the string to the right size, which is indicated by its type.
3634 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
3635 Str.resize(CAT->getSize().getZExtValue());
3636 return llvm::ConstantDataArray::getString(VMContext, Str, false);
3639 auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
3640 llvm::Type *ElemTy = AType->getElementType();
3641 unsigned NumElements = AType->getNumElements();
3643 // Wide strings have either 2-byte or 4-byte elements.
3644 if (ElemTy->getPrimitiveSizeInBits() == 16) {
3645 SmallVector<uint16_t, 32> Elements;
3646 Elements.reserve(NumElements);
3648 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
3649 Elements.push_back(E->getCodeUnit(i));
3650 Elements.resize(NumElements);
3651 return llvm::ConstantDataArray::get(VMContext, Elements);
3654 assert(ElemTy->getPrimitiveSizeInBits() == 32);
3655 SmallVector<uint32_t, 32> Elements;
3656 Elements.reserve(NumElements);
3658 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
3659 Elements.push_back(E->getCodeUnit(i));
3660 Elements.resize(NumElements);
3661 return llvm::ConstantDataArray::get(VMContext, Elements);
3664 static llvm::GlobalVariable *
3665 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
3666 CodeGenModule &CGM, StringRef GlobalName,
3667 CharUnits Alignment) {
3668 // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
3669 unsigned AddrSpace = 0;
3670 if (CGM.getLangOpts().OpenCL)
3671 AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_constant);
3673 llvm::Module &M = CGM.getModule();
3674 // Create a global variable for this string
3675 auto *GV = new llvm::GlobalVariable(
3676 M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
3677 nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
3678 GV->setAlignment(Alignment.getQuantity());
3679 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3680 if (GV->isWeakForLinker()) {
3681 assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
3682 GV->setComdat(M.getOrInsertComdat(GV->getName()));
3688 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
3689 /// constant array for the given string literal.
3691 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
3693 CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType());
3695 llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
3696 llvm::GlobalVariable **Entry = nullptr;
3697 if (!LangOpts.WritableStrings) {
3698 Entry = &ConstantStringMap[C];
3699 if (auto GV = *Entry) {
3700 if (Alignment.getQuantity() > GV->getAlignment())
3701 GV->setAlignment(Alignment.getQuantity());
3702 return ConstantAddress(GV, Alignment);
3706 SmallString<256> MangledNameBuffer;
3707 StringRef GlobalVariableName;
3708 llvm::GlobalValue::LinkageTypes LT;
3710 // Mangle the string literal if the ABI allows for it. However, we cannot
3711 // do this if we are compiling with ASan or -fwritable-strings because they
3712 // rely on strings having normal linkage.
3713 if (!LangOpts.WritableStrings &&
3714 !LangOpts.Sanitize.has(SanitizerKind::Address) &&
3715 getCXXABI().getMangleContext().shouldMangleStringLiteral(S)) {
3716 llvm::raw_svector_ostream Out(MangledNameBuffer);
3717 getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
3719 LT = llvm::GlobalValue::LinkOnceODRLinkage;
3720 GlobalVariableName = MangledNameBuffer;
3722 LT = llvm::GlobalValue::PrivateLinkage;
3723 GlobalVariableName = Name;
3726 auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
3730 SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>",
3732 return ConstantAddress(GV, Alignment);
3735 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
3736 /// array for the given ObjCEncodeExpr node.
3738 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
3740 getContext().getObjCEncodingForType(E->getEncodedType(), Str);
3742 return GetAddrOfConstantCString(Str);
3745 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
3746 /// the literal and a terminating '\0' character.
3747 /// The result has pointer to array type.
3748 ConstantAddress CodeGenModule::GetAddrOfConstantCString(
3749 const std::string &Str, const char *GlobalName) {
3750 StringRef StrWithNull(Str.c_str(), Str.size() + 1);
3751 CharUnits Alignment =
3752 getContext().getAlignOfGlobalVarInChars(getContext().CharTy);
3755 llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
3757 // Don't share any string literals if strings aren't constant.
3758 llvm::GlobalVariable **Entry = nullptr;
3759 if (!LangOpts.WritableStrings) {
3760 Entry = &ConstantStringMap[C];
3761 if (auto GV = *Entry) {
3762 if (Alignment.getQuantity() > GV->getAlignment())
3763 GV->setAlignment(Alignment.getQuantity());
3764 return ConstantAddress(GV, Alignment);
3768 // Get the default prefix if a name wasn't specified.
3770 GlobalName = ".str";
3771 // Create a global variable for this.
3772 auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
3773 GlobalName, Alignment);
3776 return ConstantAddress(GV, Alignment);
3779 ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
3780 const MaterializeTemporaryExpr *E, const Expr *Init) {
3781 assert((E->getStorageDuration() == SD_Static ||
3782 E->getStorageDuration() == SD_Thread) && "not a global temporary");
3783 const auto *VD = cast<VarDecl>(E->getExtendingDecl());
3785 // If we're not materializing a subobject of the temporary, keep the
3786 // cv-qualifiers from the type of the MaterializeTemporaryExpr.
3787 QualType MaterializedType = Init->getType();
3788 if (Init == E->GetTemporaryExpr())
3789 MaterializedType = E->getType();
3791 CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
3793 if (llvm::Constant *Slot = MaterializedGlobalTemporaryMap[E])
3794 return ConstantAddress(Slot, Align);
3796 // FIXME: If an externally-visible declaration extends multiple temporaries,
3797 // we need to give each temporary the same name in every translation unit (and
3798 // we also need to make the temporaries externally-visible).
3799 SmallString<256> Name;
3800 llvm::raw_svector_ostream Out(Name);
3801 getCXXABI().getMangleContext().mangleReferenceTemporary(
3802 VD, E->getManglingNumber(), Out);
3804 APValue *Value = nullptr;
3805 if (E->getStorageDuration() == SD_Static) {
3806 // We might have a cached constant initializer for this temporary. Note
3807 // that this might have a different value from the value computed by
3808 // evaluating the initializer if the surrounding constant expression
3809 // modifies the temporary.
3810 Value = getContext().getMaterializedTemporaryValue(E, false);
3811 if (Value && Value->isUninit())
3815 // Try evaluating it now, it might have a constant initializer.
3816 Expr::EvalResult EvalResult;
3817 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
3818 !EvalResult.hasSideEffects())
3819 Value = &EvalResult.Val;
3822 VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace();
3824 Optional<ConstantEmitter> emitter;
3825 llvm::Constant *InitialValue = nullptr;
3826 bool Constant = false;
3829 // The temporary has a constant initializer, use it.
3830 emitter.emplace(*this);
3831 InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
3833 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value);
3834 Type = InitialValue->getType();
3836 // No initializer, the initialization will be provided when we
3837 // initialize the declaration which performed lifetime extension.
3838 Type = getTypes().ConvertTypeForMem(MaterializedType);
3841 // Create a global variable for this lifetime-extended temporary.
3842 llvm::GlobalValue::LinkageTypes Linkage =
3843 getLLVMLinkageVarDefinition(VD, Constant);
3844 if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
3845 const VarDecl *InitVD;
3846 if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
3847 isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
3848 // Temporaries defined inside a class get linkonce_odr linkage because the
3849 // class can be defined in multipe translation units.
3850 Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
3852 // There is no need for this temporary to have external linkage if the
3853 // VarDecl has external linkage.
3854 Linkage = llvm::GlobalVariable::InternalLinkage;
3857 auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
3858 auto *GV = new llvm::GlobalVariable(
3859 getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
3860 /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
3861 if (emitter) emitter->finalize(GV);
3862 setGlobalVisibility(GV, VD, ForDefinition);
3863 GV->setAlignment(Align.getQuantity());
3864 if (supportsCOMDAT() && GV->isWeakForLinker())
3865 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3866 if (VD->getTLSKind())
3867 setTLSMode(GV, *VD);
3868 llvm::Constant *CV = GV;
3869 if (AddrSpace != LangAS::Default)
3870 CV = getTargetCodeGenInfo().performAddrSpaceCast(
3871 *this, GV, AddrSpace, LangAS::Default,
3873 getContext().getTargetAddressSpace(LangAS::Default)));
3874 MaterializedGlobalTemporaryMap[E] = CV;
3875 return ConstantAddress(CV, Align);
3878 /// EmitObjCPropertyImplementations - Emit information for synthesized
3879 /// properties for an implementation.
3880 void CodeGenModule::EmitObjCPropertyImplementations(const
3881 ObjCImplementationDecl *D) {
3882 for (const auto *PID : D->property_impls()) {
3883 // Dynamic is just for type-checking.
3884 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
3885 ObjCPropertyDecl *PD = PID->getPropertyDecl();
3887 // Determine which methods need to be implemented, some may have
3888 // been overridden. Note that ::isPropertyAccessor is not the method
3889 // we want, that just indicates if the decl came from a
3890 // property. What we want to know is if the method is defined in
3891 // this implementation.
3892 if (!D->getInstanceMethod(PD->getGetterName()))
3893 CodeGenFunction(*this).GenerateObjCGetter(
3894 const_cast<ObjCImplementationDecl *>(D), PID);
3895 if (!PD->isReadOnly() &&
3896 !D->getInstanceMethod(PD->getSetterName()))
3897 CodeGenFunction(*this).GenerateObjCSetter(
3898 const_cast<ObjCImplementationDecl *>(D), PID);
3903 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
3904 const ObjCInterfaceDecl *iface = impl->getClassInterface();
3905 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
3906 ivar; ivar = ivar->getNextIvar())
3907 if (ivar->getType().isDestructedType())
3913 static bool AllTrivialInitializers(CodeGenModule &CGM,
3914 ObjCImplementationDecl *D) {
3915 CodeGenFunction CGF(CGM);
3916 for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
3917 E = D->init_end(); B != E; ++B) {
3918 CXXCtorInitializer *CtorInitExp = *B;
3919 Expr *Init = CtorInitExp->getInit();
3920 if (!CGF.isTrivialInitializer(Init))
3926 /// EmitObjCIvarInitializations - Emit information for ivar initialization
3927 /// for an implementation.
3928 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
3929 // We might need a .cxx_destruct even if we don't have any ivar initializers.
3930 if (needsDestructMethod(D)) {
3931 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
3932 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
3933 ObjCMethodDecl *DTORMethod =
3934 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(),
3935 cxxSelector, getContext().VoidTy, nullptr, D,
3936 /*isInstance=*/true, /*isVariadic=*/false,
3937 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true,
3938 /*isDefined=*/false, ObjCMethodDecl::Required);
3939 D->addInstanceMethod(DTORMethod);
3940 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
3941 D->setHasDestructors(true);
3944 // If the implementation doesn't have any ivar initializers, we don't need
3945 // a .cxx_construct.
3946 if (D->getNumIvarInitializers() == 0 ||
3947 AllTrivialInitializers(*this, D))
3950 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
3951 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
3952 // The constructor returns 'self'.
3953 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(),
3957 getContext().getObjCIdType(),
3958 nullptr, D, /*isInstance=*/true,
3959 /*isVariadic=*/false,
3960 /*isPropertyAccessor=*/true,
3961 /*isImplicitlyDeclared=*/true,
3962 /*isDefined=*/false,
3963 ObjCMethodDecl::Required);
3964 D->addInstanceMethod(CTORMethod);
3965 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
3966 D->setHasNonZeroConstructors(true);
3969 // EmitLinkageSpec - Emit all declarations in a linkage spec.
3970 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
3971 if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
3972 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
3973 ErrorUnsupported(LSD, "linkage spec");
3977 EmitDeclContext(LSD);
3980 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
3981 for (auto *I : DC->decls()) {
3982 // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
3983 // are themselves considered "top-level", so EmitTopLevelDecl on an
3984 // ObjCImplDecl does not recursively visit them. We need to do that in
3985 // case they're nested inside another construct (LinkageSpecDecl /
3986 // ExportDecl) that does stop them from being considered "top-level".
3987 if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
3988 for (auto *M : OID->methods())
3989 EmitTopLevelDecl(M);
3992 EmitTopLevelDecl(I);
3996 /// EmitTopLevelDecl - Emit code for a single top level declaration.
3997 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
3998 // Ignore dependent declarations.
3999 if (D->getDeclContext() && D->getDeclContext()->isDependentContext())
4002 switch (D->getKind()) {
4003 case Decl::CXXConversion:
4004 case Decl::CXXMethod:
4005 case Decl::Function:
4006 // Skip function templates
4007 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
4008 cast<FunctionDecl>(D)->isLateTemplateParsed())
4011 EmitGlobal(cast<FunctionDecl>(D));
4012 // Always provide some coverage mapping
4013 // even for the functions that aren't emitted.
4014 AddDeferredUnusedCoverageMapping(D);
4017 case Decl::CXXDeductionGuide:
4018 // Function-like, but does not result in code emission.
4022 case Decl::Decomposition:
4023 // Skip variable templates
4024 if (cast<VarDecl>(D)->getDescribedVarTemplate())
4027 case Decl::VarTemplateSpecialization:
4028 EmitGlobal(cast<VarDecl>(D));
4029 if (auto *DD = dyn_cast<DecompositionDecl>(D))
4030 for (auto *B : DD->bindings())
4031 if (auto *HD = B->getHoldingVar())
4035 // Indirect fields from global anonymous structs and unions can be
4036 // ignored; only the actual variable requires IR gen support.
4037 case Decl::IndirectField:
4041 case Decl::Namespace:
4042 EmitDeclContext(cast<NamespaceDecl>(D));
4044 case Decl::ClassTemplateSpecialization: {
4045 const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
4047 Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition &&
4048 Spec->hasDefinition())
4049 DebugInfo->completeTemplateDefinition(*Spec);
4051 case Decl::CXXRecord:
4053 if (auto *ES = D->getASTContext().getExternalSource())
4054 if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
4055 DebugInfo->completeUnusedClass(cast<CXXRecordDecl>(*D));
4057 // Emit any static data members, they may be definitions.
4058 for (auto *I : cast<CXXRecordDecl>(D)->decls())
4059 if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
4060 EmitTopLevelDecl(I);
4062 // No code generation needed.
4063 case Decl::UsingShadow:
4064 case Decl::ClassTemplate:
4065 case Decl::VarTemplate:
4066 case Decl::VarTemplatePartialSpecialization:
4067 case Decl::FunctionTemplate:
4068 case Decl::TypeAliasTemplate:
4072 case Decl::Using: // using X; [C++]
4073 if (CGDebugInfo *DI = getModuleDebugInfo())
4074 DI->EmitUsingDecl(cast<UsingDecl>(*D));
4076 case Decl::NamespaceAlias:
4077 if (CGDebugInfo *DI = getModuleDebugInfo())
4078 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
4080 case Decl::UsingDirective: // using namespace X; [C++]
4081 if (CGDebugInfo *DI = getModuleDebugInfo())
4082 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
4084 case Decl::CXXConstructor:
4085 // Skip function templates
4086 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
4087 cast<FunctionDecl>(D)->isLateTemplateParsed())
4090 getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
4092 case Decl::CXXDestructor:
4093 if (cast<FunctionDecl>(D)->isLateTemplateParsed())
4095 getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
4098 case Decl::StaticAssert:
4102 // Objective-C Decls
4104 // Forward declarations, no (immediate) code generation.
4105 case Decl::ObjCInterface:
4106 case Decl::ObjCCategory:
4109 case Decl::ObjCProtocol: {
4110 auto *Proto = cast<ObjCProtocolDecl>(D);
4111 if (Proto->isThisDeclarationADefinition())
4112 ObjCRuntime->GenerateProtocol(Proto);
4116 case Decl::ObjCCategoryImpl:
4117 // Categories have properties but don't support synthesize so we
4118 // can ignore them here.
4119 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
4122 case Decl::ObjCImplementation: {
4123 auto *OMD = cast<ObjCImplementationDecl>(D);
4124 EmitObjCPropertyImplementations(OMD);
4125 EmitObjCIvarInitializations(OMD);
4126 ObjCRuntime->GenerateClass(OMD);
4127 // Emit global variable debug information.
4128 if (CGDebugInfo *DI = getModuleDebugInfo())
4129 if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
4130 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
4131 OMD->getClassInterface()), OMD->getLocation());
4134 case Decl::ObjCMethod: {
4135 auto *OMD = cast<ObjCMethodDecl>(D);
4136 // If this is not a prototype, emit the body.
4138 CodeGenFunction(*this).GenerateObjCMethod(OMD);
4141 case Decl::ObjCCompatibleAlias:
4142 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
4145 case Decl::PragmaComment: {
4146 const auto *PCD = cast<PragmaCommentDecl>(D);
4147 switch (PCD->getCommentKind()) {
4149 llvm_unreachable("unexpected pragma comment kind");
4151 AppendLinkerOptions(PCD->getArg());
4154 AddDependentLib(PCD->getArg());
4159 break; // We ignore all of these.
4164 case Decl::PragmaDetectMismatch: {
4165 const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
4166 AddDetectMismatch(PDMD->getName(), PDMD->getValue());
4170 case Decl::LinkageSpec:
4171 EmitLinkageSpec(cast<LinkageSpecDecl>(D));
4174 case Decl::FileScopeAsm: {
4175 // File-scope asm is ignored during device-side CUDA compilation.
4176 if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
4178 // File-scope asm is ignored during device-side OpenMP compilation.
4179 if (LangOpts.OpenMPIsDevice)
4181 auto *AD = cast<FileScopeAsmDecl>(D);
4182 getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
4186 case Decl::Import: {
4187 auto *Import = cast<ImportDecl>(D);
4189 // If we've already imported this module, we're done.
4190 if (!ImportedModules.insert(Import->getImportedModule()))
4193 // Emit debug information for direct imports.
4194 if (!Import->getImportedOwningModule()) {
4195 if (CGDebugInfo *DI = getModuleDebugInfo())
4196 DI->EmitImportDecl(*Import);
4199 // Find all of the submodules and emit the module initializers.
4200 llvm::SmallPtrSet<clang::Module *, 16> Visited;
4201 SmallVector<clang::Module *, 16> Stack;
4202 Visited.insert(Import->getImportedModule());
4203 Stack.push_back(Import->getImportedModule());
4205 while (!Stack.empty()) {
4206 clang::Module *Mod = Stack.pop_back_val();
4207 if (!EmittedModuleInitializers.insert(Mod).second)
4210 for (auto *D : Context.getModuleInitializers(Mod))
4211 EmitTopLevelDecl(D);
4213 // Visit the submodules of this module.
4214 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
4215 SubEnd = Mod->submodule_end();
4216 Sub != SubEnd; ++Sub) {
4217 // Skip explicit children; they need to be explicitly imported to emit
4218 // the initializers.
4219 if ((*Sub)->IsExplicit)
4222 if (Visited.insert(*Sub).second)
4223 Stack.push_back(*Sub);
4230 EmitDeclContext(cast<ExportDecl>(D));
4233 case Decl::OMPThreadPrivate:
4234 EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
4237 case Decl::OMPDeclareReduction:
4238 EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
4242 // Make sure we handled everything we should, every other kind is a
4243 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
4244 // function. Need to recode Decl::Kind to do that easily.
4245 assert(isa<TypeDecl>(D) && "Unsupported decl kind");
4250 void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
4251 // Do we need to generate coverage mapping?
4252 if (!CodeGenOpts.CoverageMapping)
4254 switch (D->getKind()) {
4255 case Decl::CXXConversion:
4256 case Decl::CXXMethod:
4257 case Decl::Function:
4258 case Decl::ObjCMethod:
4259 case Decl::CXXConstructor:
4260 case Decl::CXXDestructor: {
4261 if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
4263 SourceManager &SM = getContext().getSourceManager();
4264 if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getLocStart()))
4266 auto I = DeferredEmptyCoverageMappingDecls.find(D);
4267 if (I == DeferredEmptyCoverageMappingDecls.end())
4268 DeferredEmptyCoverageMappingDecls[D] = true;
4276 void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
4277 // Do we need to generate coverage mapping?
4278 if (!CodeGenOpts.CoverageMapping)
4280 if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
4281 if (Fn->isTemplateInstantiation())
4282 ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
4284 auto I = DeferredEmptyCoverageMappingDecls.find(D);
4285 if (I == DeferredEmptyCoverageMappingDecls.end())
4286 DeferredEmptyCoverageMappingDecls[D] = false;
4291 void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
4292 for (const auto &Entry : DeferredEmptyCoverageMappingDecls) {
4295 const Decl *D = Entry.first;
4296 switch (D->getKind()) {
4297 case Decl::CXXConversion:
4298 case Decl::CXXMethod:
4299 case Decl::Function:
4300 case Decl::ObjCMethod: {
4301 CodeGenPGO PGO(*this);
4302 GlobalDecl GD(cast<FunctionDecl>(D));
4303 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
4304 getFunctionLinkage(GD));
4307 case Decl::CXXConstructor: {
4308 CodeGenPGO PGO(*this);
4309 GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
4310 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
4311 getFunctionLinkage(GD));
4314 case Decl::CXXDestructor: {
4315 CodeGenPGO PGO(*this);
4316 GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
4317 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
4318 getFunctionLinkage(GD));
4327 /// Turns the given pointer into a constant.
4328 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
4330 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
4331 llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
4332 return llvm::ConstantInt::get(i64, PtrInt);
4335 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
4336 llvm::NamedMDNode *&GlobalMetadata,
4338 llvm::GlobalValue *Addr) {
4339 if (!GlobalMetadata)
4341 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
4343 // TODO: should we report variant information for ctors/dtors?
4344 llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
4345 llvm::ConstantAsMetadata::get(GetPointerConstant(
4346 CGM.getLLVMContext(), D.getDecl()))};
4347 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
4350 /// For each function which is declared within an extern "C" region and marked
4351 /// as 'used', but has internal linkage, create an alias from the unmangled
4352 /// name to the mangled name if possible. People expect to be able to refer
4353 /// to such functions with an unmangled name from inline assembly within the
4354 /// same translation unit.
4355 void CodeGenModule::EmitStaticExternCAliases() {
4356 // Don't do anything if we're generating CUDA device code -- the NVPTX
4357 // assembly target doesn't support aliases.
4358 if (Context.getTargetInfo().getTriple().isNVPTX())
4360 for (auto &I : StaticExternCValues) {
4361 IdentifierInfo *Name = I.first;
4362 llvm::GlobalValue *Val = I.second;
4363 if (Val && !getModule().getNamedValue(Name->getName()))
4364 addUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
4368 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
4369 GlobalDecl &Result) const {
4370 auto Res = Manglings.find(MangledName);
4371 if (Res == Manglings.end())
4373 Result = Res->getValue();
4377 /// Emits metadata nodes associating all the global values in the
4378 /// current module with the Decls they came from. This is useful for
4379 /// projects using IR gen as a subroutine.
4381 /// Since there's currently no way to associate an MDNode directly
4382 /// with an llvm::GlobalValue, we create a global named metadata
4383 /// with the name 'clang.global.decl.ptrs'.
4384 void CodeGenModule::EmitDeclMetadata() {
4385 llvm::NamedMDNode *GlobalMetadata = nullptr;
4387 for (auto &I : MangledDeclNames) {
4388 llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
4389 // Some mangled names don't necessarily have an associated GlobalValue
4390 // in this module, e.g. if we mangled it for DebugInfo.
4392 EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
4396 /// Emits metadata nodes for all the local variables in the current
4398 void CodeGenFunction::EmitDeclMetadata() {
4399 if (LocalDeclMap.empty()) return;
4401 llvm::LLVMContext &Context = getLLVMContext();
4403 // Find the unique metadata ID for this name.
4404 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
4406 llvm::NamedMDNode *GlobalMetadata = nullptr;
4408 for (auto &I : LocalDeclMap) {
4409 const Decl *D = I.first;
4410 llvm::Value *Addr = I.second.getPointer();
4411 if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
4412 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
4413 Alloca->setMetadata(
4414 DeclPtrKind, llvm::MDNode::get(
4415 Context, llvm::ValueAsMetadata::getConstant(DAddr)));
4416 } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
4417 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
4418 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
4423 void CodeGenModule::EmitVersionIdentMetadata() {
4424 llvm::NamedMDNode *IdentMetadata =
4425 TheModule.getOrInsertNamedMetadata("llvm.ident");
4426 std::string Version = getClangFullVersion();
4427 llvm::LLVMContext &Ctx = TheModule.getContext();
4429 llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
4430 IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
4433 void CodeGenModule::EmitTargetMetadata() {
4434 // Warning, new MangledDeclNames may be appended within this loop.
4435 // We rely on MapVector insertions adding new elements to the end
4436 // of the container.
4437 // FIXME: Move this loop into the one target that needs it, and only
4438 // loop over those declarations for which we couldn't emit the target
4439 // metadata when we emitted the declaration.
4440 for (unsigned I = 0; I != MangledDeclNames.size(); ++I) {
4441 auto Val = *(MangledDeclNames.begin() + I);
4442 const Decl *D = Val.first.getDecl()->getMostRecentDecl();
4443 llvm::GlobalValue *GV = GetGlobalValue(Val.second);
4444 getTargetCodeGenInfo().emitTargetMD(D, GV, *this);
4448 void CodeGenModule::EmitCoverageFile() {
4449 if (getCodeGenOpts().CoverageDataFile.empty() &&
4450 getCodeGenOpts().CoverageNotesFile.empty())
4453 llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
4457 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
4458 llvm::LLVMContext &Ctx = TheModule.getContext();
4459 auto *CoverageDataFile =
4460 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
4461 auto *CoverageNotesFile =
4462 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
4463 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
4464 llvm::MDNode *CU = CUNode->getOperand(i);
4465 llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
4466 GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
4470 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid) {
4471 // Sema has checked that all uuid strings are of the form
4472 // "12345678-1234-1234-1234-1234567890ab".
4473 assert(Uuid.size() == 36);
4474 for (unsigned i = 0; i < 36; ++i) {
4475 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-');
4476 else assert(isHexDigit(Uuid[i]));
4479 // The starts of all bytes of Field3 in Uuid. Field 3 is "1234-1234567890ab".
4480 const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 };
4482 llvm::Constant *Field3[8];
4483 for (unsigned Idx = 0; Idx < 8; ++Idx)
4484 Field3[Idx] = llvm::ConstantInt::get(
4485 Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16);
4487 llvm::Constant *Fields[4] = {
4488 llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16),
4489 llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16),
4490 llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16),
4491 llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3)
4494 return llvm::ConstantStruct::getAnon(Fields);
4497 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
4499 // Return a bogus pointer if RTTI is disabled, unless it's for EH.
4500 // FIXME: should we even be calling this method if RTTI is disabled
4501 // and it's not for EH?
4502 if (!ForEH && !getLangOpts().RTTI)
4503 return llvm::Constant::getNullValue(Int8PtrTy);
4505 if (ForEH && Ty->isObjCObjectPointerType() &&
4506 LangOpts.ObjCRuntime.isGNUFamily())
4507 return ObjCRuntime->GetEHType(Ty);
4509 return getCXXABI().getAddrOfRTTIDescriptor(Ty);
4512 void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
4513 for (auto RefExpr : D->varlists()) {
4514 auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
4516 VD->getAnyInitializer() &&
4517 !VD->getAnyInitializer()->isConstantInitializer(getContext(),
4520 Address Addr(GetAddrOfGlobalVar(VD), getContext().getDeclAlign(VD));
4521 if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
4522 VD, Addr, RefExpr->getLocStart(), PerformInit))
4523 CXXGlobalInits.push_back(InitFunction);
4527 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
4528 llvm::Metadata *&InternalId = MetadataIdMap[T.getCanonicalType()];
4532 if (isExternallyVisible(T->getLinkage())) {
4533 std::string OutName;
4534 llvm::raw_string_ostream Out(OutName);
4535 getCXXABI().getMangleContext().mangleTypeName(T, Out);
4537 InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
4539 InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
4540 llvm::ArrayRef<llvm::Metadata *>());
4546 // Generalize pointer types to a void pointer with the qualifiers of the
4547 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
4548 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
4550 static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
4551 if (!Ty->isPointerType())
4554 return Ctx.getPointerType(
4555 QualType(Ctx.VoidTy).withCVRQualifiers(
4556 Ty->getPointeeType().getCVRQualifiers()));
4559 // Apply type generalization to a FunctionType's return and argument types
4560 static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
4561 if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
4562 SmallVector<QualType, 8> GeneralizedParams;
4563 for (auto &Param : FnType->param_types())
4564 GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
4566 return Ctx.getFunctionType(
4567 GeneralizeType(Ctx, FnType->getReturnType()),
4568 GeneralizedParams, FnType->getExtProtoInfo());
4571 if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
4572 return Ctx.getFunctionNoProtoType(
4573 GeneralizeType(Ctx, FnType->getReturnType()));
4575 llvm_unreachable("Encountered unknown FunctionType");
4578 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
4579 T = GeneralizeFunctionType(getContext(), T);
4581 llvm::Metadata *&InternalId = GeneralizedMetadataIdMap[T.getCanonicalType()];
4585 if (isExternallyVisible(T->getLinkage())) {
4586 std::string OutName;
4587 llvm::raw_string_ostream Out(OutName);
4588 getCXXABI().getMangleContext().mangleTypeName(T, Out);
4589 Out << ".generalized";
4591 InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
4593 InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
4594 llvm::ArrayRef<llvm::Metadata *>());
4600 /// Returns whether this module needs the "all-vtables" type identifier.
4601 bool CodeGenModule::NeedAllVtablesTypeId() const {
4602 // Returns true if at least one of vtable-based CFI checkers is enabled and
4603 // is not in the trapping mode.
4604 return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
4605 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
4606 (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
4607 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
4608 (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
4609 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
4610 (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
4611 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
4614 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
4616 const CXXRecordDecl *RD) {
4617 llvm::Metadata *MD =
4618 CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
4619 VTable->addTypeMetadata(Offset.getQuantity(), MD);
4621 if (CodeGenOpts.SanitizeCfiCrossDso)
4622 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
4623 VTable->addTypeMetadata(Offset.getQuantity(),
4624 llvm::ConstantAsMetadata::get(CrossDsoTypeId));
4626 if (NeedAllVtablesTypeId()) {
4627 llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
4628 VTable->addTypeMetadata(Offset.getQuantity(), MD);
4632 // Fills in the supplied string map with the set of target features for the
4633 // passed in function.
4634 void CodeGenModule::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
4635 const FunctionDecl *FD) {
4636 StringRef TargetCPU = Target.getTargetOpts().CPU;
4637 if (const auto *TD = FD->getAttr<TargetAttr>()) {
4638 // If we have a TargetAttr build up the feature map based on that.
4639 TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
4641 ParsedAttr.Features.erase(
4642 llvm::remove_if(ParsedAttr.Features,
4643 [&](const std::string &Feat) {
4644 return !Target.isValidFeatureName(
4645 StringRef{Feat}.substr(1));
4647 ParsedAttr.Features.end());
4649 // Make a copy of the features as passed on the command line into the
4650 // beginning of the additional features from the function to override.
4651 ParsedAttr.Features.insert(ParsedAttr.Features.begin(),
4652 Target.getTargetOpts().FeaturesAsWritten.begin(),
4653 Target.getTargetOpts().FeaturesAsWritten.end());
4655 if (ParsedAttr.Architecture != "" &&
4656 Target.isValidCPUName(ParsedAttr.Architecture))
4657 TargetCPU = ParsedAttr.Architecture;
4659 // Now populate the feature map, first with the TargetCPU which is either
4660 // the default or a new one from the target attribute string. Then we'll use
4661 // the passed in features (FeaturesAsWritten) along with the new ones from
4663 Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU,
4664 ParsedAttr.Features);
4666 Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU,
4667 Target.getTargetOpts().Features);
4671 llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
4673 SanStats = llvm::make_unique<llvm::SanitizerStatReport>(&getModule());
4678 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
4679 CodeGenFunction &CGF) {
4680 llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
4681 auto SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
4682 auto FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
4683 return CGF.Builder.CreateCall(CreateRuntimeFunction(FTy,
4684 "__translate_sampler_initializer"),