clang  9.0.0svn
CodeGenModule.cpp
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1 //===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This coordinates the per-module state used while generating code.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "CodeGenModule.h"
14 #include "CGBlocks.h"
15 #include "CGCUDARuntime.h"
16 #include "CGCXXABI.h"
17 #include "CGCall.h"
18 #include "CGDebugInfo.h"
19 #include "CGObjCRuntime.h"
20 #include "CGOpenCLRuntime.h"
21 #include "CGOpenMPRuntime.h"
22 #include "CGOpenMPRuntimeNVPTX.h"
23 #include "CodeGenFunction.h"
24 #include "CodeGenPGO.h"
25 #include "ConstantEmitter.h"
26 #include "CoverageMappingGen.h"
27 #include "TargetInfo.h"
28 #include "clang/AST/ASTContext.h"
29 #include "clang/AST/CharUnits.h"
30 #include "clang/AST/DeclCXX.h"
31 #include "clang/AST/DeclObjC.h"
32 #include "clang/AST/DeclTemplate.h"
33 #include "clang/AST/Mangle.h"
34 #include "clang/AST/RecordLayout.h"
36 #include "clang/AST/StmtVisitor.h"
37 #include "clang/Basic/Builtins.h"
38 #include "clang/Basic/CharInfo.h"
40 #include "clang/Basic/Diagnostic.h"
41 #include "clang/Basic/Module.h"
43 #include "clang/Basic/TargetInfo.h"
44 #include "clang/Basic/Version.h"
47 #include "llvm/ADT/StringSwitch.h"
48 #include "llvm/ADT/Triple.h"
49 #include "llvm/Analysis/TargetLibraryInfo.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/IR/ProfileSummary.h"
56 #include "llvm/ProfileData/InstrProfReader.h"
57 #include "llvm/Support/CodeGen.h"
58 #include "llvm/Support/ConvertUTF.h"
59 #include "llvm/Support/ErrorHandling.h"
60 #include "llvm/Support/MD5.h"
61 #include "llvm/Support/TimeProfiler.h"
62 
63 using namespace clang;
64 using namespace CodeGen;
65 
66 static llvm::cl::opt<bool> LimitedCoverage(
67  "limited-coverage-experimental", llvm::cl::ZeroOrMore, llvm::cl::Hidden,
68  llvm::cl::desc("Emit limited coverage mapping information (experimental)"),
69  llvm::cl::init(false));
70 
71 static const char AnnotationSection[] = "llvm.metadata";
72 
74  switch (CGM.getTarget().getCXXABI().getKind()) {
77  case TargetCXXABI::iOS:
83  return CreateItaniumCXXABI(CGM);
85  return CreateMicrosoftCXXABI(CGM);
86  }
87 
88  llvm_unreachable("invalid C++ ABI kind");
89 }
90 
91 CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
92  const PreprocessorOptions &PPO,
93  const CodeGenOptions &CGO, llvm::Module &M,
94  DiagnosticsEngine &diags,
95  CoverageSourceInfo *CoverageInfo)
96  : Context(C), LangOpts(C.getLangOpts()), HeaderSearchOpts(HSO),
97  PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
98  Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
99  VMContext(M.getContext()), Types(*this), VTables(*this),
100  SanitizerMD(new SanitizerMetadata(*this)) {
101 
102  // Initialize the type cache.
103  llvm::LLVMContext &LLVMContext = M.getContext();
104  VoidTy = llvm::Type::getVoidTy(LLVMContext);
105  Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
106  Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
107  Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
108  Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
109  HalfTy = llvm::Type::getHalfTy(LLVMContext);
110  FloatTy = llvm::Type::getFloatTy(LLVMContext);
111  DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
114  C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
118  C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
119  IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
120  IntPtrTy = llvm::IntegerType::get(LLVMContext,
122  Int8PtrTy = Int8Ty->getPointerTo(0);
123  Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
124  AllocaInt8PtrTy = Int8Ty->getPointerTo(
125  M.getDataLayout().getAllocaAddrSpace());
127 
129 
130  if (LangOpts.ObjC)
131  createObjCRuntime();
132  if (LangOpts.OpenCL)
133  createOpenCLRuntime();
134  if (LangOpts.OpenMP)
135  createOpenMPRuntime();
136  if (LangOpts.CUDA)
137  createCUDARuntime();
138 
139  // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
140  if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
141  (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
142  TBAA.reset(new CodeGenTBAA(Context, TheModule, CodeGenOpts, getLangOpts(),
143  getCXXABI().getMangleContext()));
144 
145  // If debug info or coverage generation is enabled, create the CGDebugInfo
146  // object.
147  if (CodeGenOpts.getDebugInfo() != codegenoptions::NoDebugInfo ||
148  CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)
149  DebugInfo.reset(new CGDebugInfo(*this));
150 
151  Block.GlobalUniqueCount = 0;
152 
153  if (C.getLangOpts().ObjC)
154  ObjCData.reset(new ObjCEntrypoints());
155 
156  if (CodeGenOpts.hasProfileClangUse()) {
157  auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
158  CodeGenOpts.ProfileInstrumentUsePath, CodeGenOpts.ProfileRemappingFile);
159  if (auto E = ReaderOrErr.takeError()) {
160  unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
161  "Could not read profile %0: %1");
162  llvm::handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EI) {
163  getDiags().Report(DiagID) << CodeGenOpts.ProfileInstrumentUsePath
164  << EI.message();
165  });
166  } else
167  PGOReader = std::move(ReaderOrErr.get());
168  }
169 
170  // If coverage mapping generation is enabled, create the
171  // CoverageMappingModuleGen object.
172  if (CodeGenOpts.CoverageMapping)
173  CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
174 }
175 
177 
178 void CodeGenModule::createObjCRuntime() {
179  // This is just isGNUFamily(), but we want to force implementors of
180  // new ABIs to decide how best to do this.
181  switch (LangOpts.ObjCRuntime.getKind()) {
183  case ObjCRuntime::GCC:
184  case ObjCRuntime::ObjFW:
185  ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
186  return;
187 
189  case ObjCRuntime::MacOSX:
190  case ObjCRuntime::iOS:
192  ObjCRuntime.reset(CreateMacObjCRuntime(*this));
193  return;
194  }
195  llvm_unreachable("bad runtime kind");
196 }
197 
198 void CodeGenModule::createOpenCLRuntime() {
199  OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
200 }
201 
202 void CodeGenModule::createOpenMPRuntime() {
203  // Select a specialized code generation class based on the target, if any.
204  // If it does not exist use the default implementation.
205  switch (getTriple().getArch()) {
206  case llvm::Triple::nvptx:
207  case llvm::Triple::nvptx64:
208  assert(getLangOpts().OpenMPIsDevice &&
209  "OpenMP NVPTX is only prepared to deal with device code.");
210  OpenMPRuntime.reset(new CGOpenMPRuntimeNVPTX(*this));
211  break;
212  default:
213  if (LangOpts.OpenMPSimd)
214  OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
215  else
216  OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
217  break;
218  }
219 }
220 
221 void CodeGenModule::createCUDARuntime() {
222  CUDARuntime.reset(CreateNVCUDARuntime(*this));
223 }
224 
225 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
226  Replacements[Name] = C;
227 }
228 
229 void CodeGenModule::applyReplacements() {
230  for (auto &I : Replacements) {
231  StringRef MangledName = I.first();
232  llvm::Constant *Replacement = I.second;
233  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
234  if (!Entry)
235  continue;
236  auto *OldF = cast<llvm::Function>(Entry);
237  auto *NewF = dyn_cast<llvm::Function>(Replacement);
238  if (!NewF) {
239  if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
240  NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
241  } else {
242  auto *CE = cast<llvm::ConstantExpr>(Replacement);
243  assert(CE->getOpcode() == llvm::Instruction::BitCast ||
244  CE->getOpcode() == llvm::Instruction::GetElementPtr);
245  NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
246  }
247  }
248 
249  // Replace old with new, but keep the old order.
250  OldF->replaceAllUsesWith(Replacement);
251  if (NewF) {
252  NewF->removeFromParent();
253  OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
254  NewF);
255  }
256  OldF->eraseFromParent();
257  }
258 }
259 
260 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
261  GlobalValReplacements.push_back(std::make_pair(GV, C));
262 }
263 
264 void CodeGenModule::applyGlobalValReplacements() {
265  for (auto &I : GlobalValReplacements) {
266  llvm::GlobalValue *GV = I.first;
267  llvm::Constant *C = I.second;
268 
269  GV->replaceAllUsesWith(C);
270  GV->eraseFromParent();
271  }
272 }
273 
274 // This is only used in aliases that we created and we know they have a
275 // linear structure.
276 static const llvm::GlobalObject *getAliasedGlobal(
277  const llvm::GlobalIndirectSymbol &GIS) {
278  llvm::SmallPtrSet<const llvm::GlobalIndirectSymbol*, 4> Visited;
279  const llvm::Constant *C = &GIS;
280  for (;;) {
281  C = C->stripPointerCasts();
282  if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
283  return GO;
284  // stripPointerCasts will not walk over weak aliases.
285  auto *GIS2 = dyn_cast<llvm::GlobalIndirectSymbol>(C);
286  if (!GIS2)
287  return nullptr;
288  if (!Visited.insert(GIS2).second)
289  return nullptr;
290  C = GIS2->getIndirectSymbol();
291  }
292 }
293 
294 void CodeGenModule::checkAliases() {
295  // Check if the constructed aliases are well formed. It is really unfortunate
296  // that we have to do this in CodeGen, but we only construct mangled names
297  // and aliases during codegen.
298  bool Error = false;
299  DiagnosticsEngine &Diags = getDiags();
300  for (const GlobalDecl &GD : Aliases) {
301  const auto *D = cast<ValueDecl>(GD.getDecl());
302  SourceLocation Location;
303  bool IsIFunc = D->hasAttr<IFuncAttr>();
304  if (const Attr *A = D->getDefiningAttr())
305  Location = A->getLocation();
306  else
307  llvm_unreachable("Not an alias or ifunc?");
308  StringRef MangledName = getMangledName(GD);
309  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
310  auto *Alias = cast<llvm::GlobalIndirectSymbol>(Entry);
311  const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
312  if (!GV) {
313  Error = true;
314  Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
315  } else if (GV->isDeclaration()) {
316  Error = true;
317  Diags.Report(Location, diag::err_alias_to_undefined)
318  << IsIFunc << IsIFunc;
319  } else if (IsIFunc) {
320  // Check resolver function type.
321  llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(
322  GV->getType()->getPointerElementType());
323  assert(FTy);
324  if (!FTy->getReturnType()->isPointerTy())
325  Diags.Report(Location, diag::err_ifunc_resolver_return);
326  }
327 
328  llvm::Constant *Aliasee = Alias->getIndirectSymbol();
329  llvm::GlobalValue *AliaseeGV;
330  if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
331  AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
332  else
333  AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
334 
335  if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
336  StringRef AliasSection = SA->getName();
337  if (AliasSection != AliaseeGV->getSection())
338  Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
339  << AliasSection << IsIFunc << IsIFunc;
340  }
341 
342  // We have to handle alias to weak aliases in here. LLVM itself disallows
343  // this since the object semantics would not match the IL one. For
344  // compatibility with gcc we implement it by just pointing the alias
345  // to its aliasee's aliasee. We also warn, since the user is probably
346  // expecting the link to be weak.
347  if (auto GA = dyn_cast<llvm::GlobalIndirectSymbol>(AliaseeGV)) {
348  if (GA->isInterposable()) {
349  Diags.Report(Location, diag::warn_alias_to_weak_alias)
350  << GV->getName() << GA->getName() << IsIFunc;
351  Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
352  GA->getIndirectSymbol(), Alias->getType());
353  Alias->setIndirectSymbol(Aliasee);
354  }
355  }
356  }
357  if (!Error)
358  return;
359 
360  for (const GlobalDecl &GD : Aliases) {
361  StringRef MangledName = getMangledName(GD);
362  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
363  auto *Alias = dyn_cast<llvm::GlobalIndirectSymbol>(Entry);
364  Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
365  Alias->eraseFromParent();
366  }
367 }
368 
370  DeferredDeclsToEmit.clear();
371  if (OpenMPRuntime)
372  OpenMPRuntime->clear();
373 }
374 
376  StringRef MainFile) {
377  if (!hasDiagnostics())
378  return;
379  if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
380  if (MainFile.empty())
381  MainFile = "<stdin>";
382  Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
383  } else {
384  if (Mismatched > 0)
385  Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
386 
387  if (Missing > 0)
388  Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
389  }
390 }
391 
393  EmitDeferred();
394  EmitVTablesOpportunistically();
395  applyGlobalValReplacements();
396  applyReplacements();
397  checkAliases();
398  emitMultiVersionFunctions();
399  EmitCXXGlobalInitFunc();
400  EmitCXXGlobalDtorFunc();
401  registerGlobalDtorsWithAtExit();
402  EmitCXXThreadLocalInitFunc();
403  if (ObjCRuntime)
404  if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
405  AddGlobalCtor(ObjCInitFunction);
406  if (Context.getLangOpts().CUDA && !Context.getLangOpts().CUDAIsDevice &&
407  CUDARuntime) {
408  if (llvm::Function *CudaCtorFunction =
409  CUDARuntime->makeModuleCtorFunction())
410  AddGlobalCtor(CudaCtorFunction);
411  }
412  if (OpenMPRuntime) {
413  if (llvm::Function *OpenMPRequiresDirectiveRegFun =
414  OpenMPRuntime->emitRequiresDirectiveRegFun()) {
415  AddGlobalCtor(OpenMPRequiresDirectiveRegFun, 0);
416  }
417  if (llvm::Function *OpenMPRegistrationFunction =
418  OpenMPRuntime->emitRegistrationFunction()) {
419  auto ComdatKey = OpenMPRegistrationFunction->hasComdat() ?
420  OpenMPRegistrationFunction : nullptr;
421  AddGlobalCtor(OpenMPRegistrationFunction, 0, ComdatKey);
422  }
423  OpenMPRuntime->clear();
424  }
425  if (PGOReader) {
426  getModule().setProfileSummary(
427  PGOReader->getSummary(/* UseCS */ false).getMD(VMContext),
428  llvm::ProfileSummary::PSK_Instr);
429  if (PGOStats.hasDiagnostics())
430  PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
431  }
432  EmitCtorList(GlobalCtors, "llvm.global_ctors");
433  EmitCtorList(GlobalDtors, "llvm.global_dtors");
435  EmitStaticExternCAliases();
437  if (CoverageMapping)
438  CoverageMapping->emit();
439  if (CodeGenOpts.SanitizeCfiCrossDso) {
442  }
443  emitAtAvailableLinkGuard();
444  emitLLVMUsed();
445  if (SanStats)
446  SanStats->finish();
447 
448  if (CodeGenOpts.Autolink &&
449  (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
450  EmitModuleLinkOptions();
451  }
452 
453  // On ELF we pass the dependent library specifiers directly to the linker
454  // without manipulating them. This is in contrast to other platforms where
455  // they are mapped to a specific linker option by the compiler. This
456  // difference is a result of the greater variety of ELF linkers and the fact
457  // that ELF linkers tend to handle libraries in a more complicated fashion
458  // than on other platforms. This forces us to defer handling the dependent
459  // libs to the linker.
460  //
461  // CUDA/HIP device and host libraries are different. Currently there is no
462  // way to differentiate dependent libraries for host or device. Existing
463  // usage of #pragma comment(lib, *) is intended for host libraries on
464  // Windows. Therefore emit llvm.dependent-libraries only for host.
465  if (!ELFDependentLibraries.empty() && !Context.getLangOpts().CUDAIsDevice) {
466  auto *NMD = getModule().getOrInsertNamedMetadata("llvm.dependent-libraries");
467  for (auto *MD : ELFDependentLibraries)
468  NMD->addOperand(MD);
469  }
470 
471  // Record mregparm value now so it is visible through rest of codegen.
472  if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
473  getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
474  CodeGenOpts.NumRegisterParameters);
475 
476  if (CodeGenOpts.DwarfVersion) {
477  // We actually want the latest version when there are conflicts.
478  // We can change from Warning to Latest if such mode is supported.
479  getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version",
480  CodeGenOpts.DwarfVersion);
481  }
482  if (CodeGenOpts.EmitCodeView) {
483  // Indicate that we want CodeView in the metadata.
484  getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
485  }
486  if (CodeGenOpts.CodeViewGHash) {
487  getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
488  }
489  if (CodeGenOpts.ControlFlowGuard) {
490  // We want function ID tables for Control Flow Guard.
491  getModule().addModuleFlag(llvm::Module::Warning, "cfguardtable", 1);
492  }
493  if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
494  // We don't support LTO with 2 with different StrictVTablePointers
495  // FIXME: we could support it by stripping all the information introduced
496  // by StrictVTablePointers.
497 
498  getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
499 
500  llvm::Metadata *Ops[2] = {
501  llvm::MDString::get(VMContext, "StrictVTablePointers"),
502  llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
503  llvm::Type::getInt32Ty(VMContext), 1))};
504 
505  getModule().addModuleFlag(llvm::Module::Require,
506  "StrictVTablePointersRequirement",
507  llvm::MDNode::get(VMContext, Ops));
508  }
509  if (DebugInfo)
510  // We support a single version in the linked module. The LLVM
511  // parser will drop debug info with a different version number
512  // (and warn about it, too).
513  getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
514  llvm::DEBUG_METADATA_VERSION);
515 
516  // We need to record the widths of enums and wchar_t, so that we can generate
517  // the correct build attributes in the ARM backend. wchar_size is also used by
518  // TargetLibraryInfo.
519  uint64_t WCharWidth =
520  Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
521  getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
522 
523  llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
524  if ( Arch == llvm::Triple::arm
525  || Arch == llvm::Triple::armeb
526  || Arch == llvm::Triple::thumb
527  || Arch == llvm::Triple::thumbeb) {
528  // The minimum width of an enum in bytes
529  uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
530  getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
531  }
532 
533  if (CodeGenOpts.SanitizeCfiCrossDso) {
534  // Indicate that we want cross-DSO control flow integrity checks.
535  getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
536  }
537 
538  if (CodeGenOpts.CFProtectionReturn &&
540  // Indicate that we want to instrument return control flow protection.
541  getModule().addModuleFlag(llvm::Module::Override, "cf-protection-return",
542  1);
543  }
544 
545  if (CodeGenOpts.CFProtectionBranch &&
547  // Indicate that we want to instrument branch control flow protection.
548  getModule().addModuleFlag(llvm::Module::Override, "cf-protection-branch",
549  1);
550  }
551 
552  if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
553  // Indicate whether __nvvm_reflect should be configured to flush denormal
554  // floating point values to 0. (This corresponds to its "__CUDA_FTZ"
555  // property.)
556  getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
557  CodeGenOpts.FlushDenorm ? 1 : 0);
558  }
559 
560  // Emit OpenCL specific module metadata: OpenCL/SPIR version.
561  if (LangOpts.OpenCL) {
562  EmitOpenCLMetadata();
563  // Emit SPIR version.
564  if (getTriple().isSPIR()) {
565  // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
566  // opencl.spir.version named metadata.
567  // C++ is backwards compatible with OpenCL v2.0.
568  auto Version = LangOpts.OpenCLCPlusPlus ? 200 : LangOpts.OpenCLVersion;
569  llvm::Metadata *SPIRVerElts[] = {
570  llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
571  Int32Ty, Version / 100)),
572  llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
573  Int32Ty, (Version / 100 > 1) ? 0 : 2))};
574  llvm::NamedMDNode *SPIRVerMD =
575  TheModule.getOrInsertNamedMetadata("opencl.spir.version");
576  llvm::LLVMContext &Ctx = TheModule.getContext();
577  SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
578  }
579  }
580 
581  if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
582  assert(PLevel < 3 && "Invalid PIC Level");
583  getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
584  if (Context.getLangOpts().PIE)
585  getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
586  }
587 
588  if (getCodeGenOpts().CodeModel.size() > 0) {
589  unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
590  .Case("tiny", llvm::CodeModel::Tiny)
591  .Case("small", llvm::CodeModel::Small)
592  .Case("kernel", llvm::CodeModel::Kernel)
593  .Case("medium", llvm::CodeModel::Medium)
594  .Case("large", llvm::CodeModel::Large)
595  .Default(~0u);
596  if (CM != ~0u) {
597  llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
598  getModule().setCodeModel(codeModel);
599  }
600  }
601 
602  if (CodeGenOpts.NoPLT)
603  getModule().setRtLibUseGOT();
604 
605  SimplifyPersonality();
606 
607  if (getCodeGenOpts().EmitDeclMetadata)
608  EmitDeclMetadata();
609 
610  if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
611  EmitCoverageFile();
612 
613  if (DebugInfo)
614  DebugInfo->finalize();
615 
616  if (getCodeGenOpts().EmitVersionIdentMetadata)
617  EmitVersionIdentMetadata();
618 
619  if (!getCodeGenOpts().RecordCommandLine.empty())
620  EmitCommandLineMetadata();
621 
622  EmitTargetMetadata();
623 }
624 
625 void CodeGenModule::EmitOpenCLMetadata() {
626  // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
627  // opencl.ocl.version named metadata node.
628  // C++ is backwards compatible with OpenCL v2.0.
629  // FIXME: We might need to add CXX version at some point too?
630  auto Version = LangOpts.OpenCLCPlusPlus ? 200 : LangOpts.OpenCLVersion;
631  llvm::Metadata *OCLVerElts[] = {
632  llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
633  Int32Ty, Version / 100)),
634  llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
635  Int32Ty, (Version % 100) / 10))};
636  llvm::NamedMDNode *OCLVerMD =
637  TheModule.getOrInsertNamedMetadata("opencl.ocl.version");
638  llvm::LLVMContext &Ctx = TheModule.getContext();
639  OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
640 }
641 
643  // Make sure that this type is translated.
644  Types.UpdateCompletedType(TD);
645 }
646 
648  // Make sure that this type is translated.
649  Types.RefreshTypeCacheForClass(RD);
650 }
651 
653  if (!TBAA)
654  return nullptr;
655  return TBAA->getTypeInfo(QTy);
656 }
657 
659  if (!TBAA)
660  return TBAAAccessInfo();
661  return TBAA->getAccessInfo(AccessType);
662 }
663 
666  if (!TBAA)
667  return TBAAAccessInfo();
668  return TBAA->getVTablePtrAccessInfo(VTablePtrType);
669 }
670 
672  if (!TBAA)
673  return nullptr;
674  return TBAA->getTBAAStructInfo(QTy);
675 }
676 
678  if (!TBAA)
679  return nullptr;
680  return TBAA->getBaseTypeInfo(QTy);
681 }
682 
684  if (!TBAA)
685  return nullptr;
686  return TBAA->getAccessTagInfo(Info);
687 }
688 
691  if (!TBAA)
692  return TBAAAccessInfo();
693  return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
694 }
695 
698  TBAAAccessInfo InfoB) {
699  if (!TBAA)
700  return TBAAAccessInfo();
701  return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
702 }
703 
706  TBAAAccessInfo SrcInfo) {
707  if (!TBAA)
708  return TBAAAccessInfo();
709  return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
710 }
711 
712 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
713  TBAAAccessInfo TBAAInfo) {
714  if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
715  Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
716 }
717 
719  llvm::Instruction *I, const CXXRecordDecl *RD) {
720  I->setMetadata(llvm::LLVMContext::MD_invariant_group,
721  llvm::MDNode::get(getLLVMContext(), {}));
722 }
723 
724 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
725  unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
726  getDiags().Report(Context.getFullLoc(loc), diagID) << message;
727 }
728 
729 /// ErrorUnsupported - Print out an error that codegen doesn't support the
730 /// specified stmt yet.
731 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
733  "cannot compile this %0 yet");
734  std::string Msg = Type;
735  getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID)
736  << Msg << S->getSourceRange();
737 }
738 
739 /// ErrorUnsupported - Print out an error that codegen doesn't support the
740 /// specified decl yet.
741 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
743  "cannot compile this %0 yet");
744  std::string Msg = Type;
745  getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
746 }
747 
748 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
749  return llvm::ConstantInt::get(SizeTy, size.getQuantity());
750 }
751 
752 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
753  const NamedDecl *D) const {
754  if (GV->hasDLLImportStorageClass())
755  return;
756  // Internal definitions always have default visibility.
757  if (GV->hasLocalLinkage()) {
758  GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
759  return;
760  }
761  if (!D)
762  return;
763  // Set visibility for definitions, and for declarations if requested globally
764  // or set explicitly.
766  if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
767  !GV->isDeclarationForLinker())
768  GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
769 }
770 
771 static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
772  llvm::GlobalValue *GV) {
773  if (GV->hasLocalLinkage())
774  return true;
775 
776  if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
777  return true;
778 
779  // DLLImport explicitly marks the GV as external.
780  if (GV->hasDLLImportStorageClass())
781  return false;
782 
783  const llvm::Triple &TT = CGM.getTriple();
784  if (TT.isWindowsGNUEnvironment()) {
785  // In MinGW, variables without DLLImport can still be automatically
786  // imported from a DLL by the linker; don't mark variables that
787  // potentially could come from another DLL as DSO local.
788  if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
789  !GV->isThreadLocal())
790  return false;
791  }
792 
793  // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
794  // remain unresolved in the link, they can be resolved to zero, which is
795  // outside the current DSO.
796  if (TT.isOSBinFormatCOFF() && GV->hasExternalWeakLinkage())
797  return false;
798 
799  // Every other GV is local on COFF.
800  // Make an exception for windows OS in the triple: Some firmware builds use
801  // *-win32-macho triples. This (accidentally?) produced windows relocations
802  // without GOT tables in older clang versions; Keep this behaviour.
803  // FIXME: even thread local variables?
804  if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
805  return true;
806 
807  // Only handle COFF and ELF for now.
808  if (!TT.isOSBinFormatELF())
809  return false;
810 
811  // If this is not an executable, don't assume anything is local.
812  const auto &CGOpts = CGM.getCodeGenOpts();
813  llvm::Reloc::Model RM = CGOpts.RelocationModel;
814  const auto &LOpts = CGM.getLangOpts();
815  if (RM != llvm::Reloc::Static && !LOpts.PIE && !LOpts.OpenMPIsDevice)
816  return false;
817 
818  // A definition cannot be preempted from an executable.
819  if (!GV->isDeclarationForLinker())
820  return true;
821 
822  // Most PIC code sequences that assume that a symbol is local cannot produce a
823  // 0 if it turns out the symbol is undefined. While this is ABI and relocation
824  // depended, it seems worth it to handle it here.
825  if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
826  return false;
827 
828  // PPC has no copy relocations and cannot use a plt entry as a symbol address.
829  llvm::Triple::ArchType Arch = TT.getArch();
830  if (Arch == llvm::Triple::ppc || Arch == llvm::Triple::ppc64 ||
831  Arch == llvm::Triple::ppc64le)
832  return false;
833 
834  // If we can use copy relocations we can assume it is local.
835  if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
836  if (!Var->isThreadLocal() &&
837  (RM == llvm::Reloc::Static || CGOpts.PIECopyRelocations))
838  return true;
839 
840  // If we can use a plt entry as the symbol address we can assume it
841  // is local.
842  // FIXME: This should work for PIE, but the gold linker doesn't support it.
843  if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
844  return true;
845 
846  // Otherwise don't assue it is local.
847  return false;
848 }
849 
850 void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
851  GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
852 }
853 
854 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
855  GlobalDecl GD) const {
856  const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
857  // C++ destructors have a few C++ ABI specific special cases.
858  if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
860  return;
861  }
862  setDLLImportDLLExport(GV, D);
863 }
864 
865 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
866  const NamedDecl *D) const {
867  if (D && D->isExternallyVisible()) {
868  if (D->hasAttr<DLLImportAttr>())
869  GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
870  else if (D->hasAttr<DLLExportAttr>() && !GV->isDeclarationForLinker())
871  GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
872  }
873 }
874 
875 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
876  GlobalDecl GD) const {
877  setDLLImportDLLExport(GV, GD);
878  setGVPropertiesAux(GV, dyn_cast<NamedDecl>(GD.getDecl()));
879 }
880 
881 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
882  const NamedDecl *D) const {
883  setDLLImportDLLExport(GV, D);
884  setGVPropertiesAux(GV, D);
885 }
886 
887 void CodeGenModule::setGVPropertiesAux(llvm::GlobalValue *GV,
888  const NamedDecl *D) const {
889  setGlobalVisibility(GV, D);
890  setDSOLocal(GV);
891  GV->setPartition(CodeGenOpts.SymbolPartition);
892 }
893 
894 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
895  return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
896  .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
897  .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
898  .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
899  .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
900 }
901 
902 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(
904  switch (M) {
906  return llvm::GlobalVariable::GeneralDynamicTLSModel;
908  return llvm::GlobalVariable::LocalDynamicTLSModel;
910  return llvm::GlobalVariable::InitialExecTLSModel;
912  return llvm::GlobalVariable::LocalExecTLSModel;
913  }
914  llvm_unreachable("Invalid TLS model!");
915 }
916 
917 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
918  assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
919 
920  llvm::GlobalValue::ThreadLocalMode TLM;
921  TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel());
922 
923  // Override the TLS model if it is explicitly specified.
924  if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
925  TLM = GetLLVMTLSModel(Attr->getModel());
926  }
927 
928  GV->setThreadLocalMode(TLM);
929 }
930 
931 static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
932  StringRef Name) {
933  const TargetInfo &Target = CGM.getTarget();
934  return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
935 }
936 
938  const CPUSpecificAttr *Attr,
939  unsigned CPUIndex,
940  raw_ostream &Out) {
941  // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
942  // supported.
943  if (Attr)
944  Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
945  else if (CGM.getTarget().supportsIFunc())
946  Out << ".resolver";
947 }
948 
949 static void AppendTargetMangling(const CodeGenModule &CGM,
950  const TargetAttr *Attr, raw_ostream &Out) {
951  if (Attr->isDefaultVersion())
952  return;
953 
954  Out << '.';
955  const TargetInfo &Target = CGM.getTarget();
956  TargetAttr::ParsedTargetAttr Info =
957  Attr->parse([&Target](StringRef LHS, StringRef RHS) {
958  // Multiversioning doesn't allow "no-${feature}", so we can
959  // only have "+" prefixes here.
960  assert(LHS.startswith("+") && RHS.startswith("+") &&
961  "Features should always have a prefix.");
962  return Target.multiVersionSortPriority(LHS.substr(1)) >
963  Target.multiVersionSortPriority(RHS.substr(1));
964  });
965 
966  bool IsFirst = true;
967 
968  if (!Info.Architecture.empty()) {
969  IsFirst = false;
970  Out << "arch_" << Info.Architecture;
971  }
972 
973  for (StringRef Feat : Info.Features) {
974  if (!IsFirst)
975  Out << '_';
976  IsFirst = false;
977  Out << Feat.substr(1);
978  }
979 }
980 
981 static std::string getMangledNameImpl(const CodeGenModule &CGM, GlobalDecl GD,
982  const NamedDecl *ND,
983  bool OmitMultiVersionMangling = false) {
984  SmallString<256> Buffer;
985  llvm::raw_svector_ostream Out(Buffer);
987  if (MC.shouldMangleDeclName(ND)) {
988  llvm::raw_svector_ostream Out(Buffer);
989  if (const auto *D = dyn_cast<CXXConstructorDecl>(ND))
990  MC.mangleCXXCtor(D, GD.getCtorType(), Out);
991  else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND))
992  MC.mangleCXXDtor(D, GD.getDtorType(), Out);
993  else
994  MC.mangleName(ND, Out);
995  } else {
996  IdentifierInfo *II = ND->getIdentifier();
997  assert(II && "Attempt to mangle unnamed decl.");
998  const auto *FD = dyn_cast<FunctionDecl>(ND);
999 
1000  if (FD &&
1001  FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
1002  llvm::raw_svector_ostream Out(Buffer);
1003  Out << "__regcall3__" << II->getName();
1004  } else {
1005  Out << II->getName();
1006  }
1007  }
1008 
1009  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
1010  if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
1011  switch (FD->getMultiVersionKind()) {
1015  FD->getAttr<CPUSpecificAttr>(),
1016  GD.getMultiVersionIndex(), Out);
1017  break;
1019  AppendTargetMangling(CGM, FD->getAttr<TargetAttr>(), Out);
1020  break;
1022  llvm_unreachable("None multiversion type isn't valid here");
1023  }
1024  }
1025 
1026  return Out.str();
1027 }
1028 
1029 void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
1030  const FunctionDecl *FD) {
1031  if (!FD->isMultiVersion())
1032  return;
1033 
1034  // Get the name of what this would be without the 'target' attribute. This
1035  // allows us to lookup the version that was emitted when this wasn't a
1036  // multiversion function.
1037  std::string NonTargetName =
1038  getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
1039  GlobalDecl OtherGD;
1040  if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
1041  assert(OtherGD.getCanonicalDecl()
1042  .getDecl()
1043  ->getAsFunction()
1044  ->isMultiVersion() &&
1045  "Other GD should now be a multiversioned function");
1046  // OtherFD is the version of this function that was mangled BEFORE
1047  // becoming a MultiVersion function. It potentially needs to be updated.
1048  const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
1049  .getDecl()
1050  ->getAsFunction()
1051  ->getMostRecentDecl();
1052  std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
1053  // This is so that if the initial version was already the 'default'
1054  // version, we don't try to update it.
1055  if (OtherName != NonTargetName) {
1056  // Remove instead of erase, since others may have stored the StringRef
1057  // to this.
1058  const auto ExistingRecord = Manglings.find(NonTargetName);
1059  if (ExistingRecord != std::end(Manglings))
1060  Manglings.remove(&(*ExistingRecord));
1061  auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
1062  MangledDeclNames[OtherGD.getCanonicalDecl()] = Result.first->first();
1063  if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
1064  Entry->setName(OtherName);
1065  }
1066  }
1067 }
1068 
1070  GlobalDecl CanonicalGD = GD.getCanonicalDecl();
1071 
1072  // Some ABIs don't have constructor variants. Make sure that base and
1073  // complete constructors get mangled the same.
1074  if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
1076  CXXCtorType OrigCtorType = GD.getCtorType();
1077  assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
1078  if (OrigCtorType == Ctor_Base)
1079  CanonicalGD = GlobalDecl(CD, Ctor_Complete);
1080  }
1081  }
1082 
1083  auto FoundName = MangledDeclNames.find(CanonicalGD);
1084  if (FoundName != MangledDeclNames.end())
1085  return FoundName->second;
1086 
1087  // Keep the first result in the case of a mangling collision.
1088  const auto *ND = cast<NamedDecl>(GD.getDecl());
1089  std::string MangledName = getMangledNameImpl(*this, GD, ND);
1090 
1091  // Adjust kernel stub mangling as we may need to be able to differentiate
1092  // them from the kernel itself (e.g., for HIP).
1093  if (auto *FD = dyn_cast<FunctionDecl>(GD.getDecl()))
1094  if (!getLangOpts().CUDAIsDevice && FD->hasAttr<CUDAGlobalAttr>())
1095  MangledName = getCUDARuntime().getDeviceStubName(MangledName);
1096 
1097  auto Result = Manglings.insert(std::make_pair(MangledName, GD));
1098  return MangledDeclNames[CanonicalGD] = Result.first->first();
1099 }
1100 
1102  const BlockDecl *BD) {
1103  MangleContext &MangleCtx = getCXXABI().getMangleContext();
1104  const Decl *D = GD.getDecl();
1105 
1106  SmallString<256> Buffer;
1107  llvm::raw_svector_ostream Out(Buffer);
1108  if (!D)
1109  MangleCtx.mangleGlobalBlock(BD,
1110  dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
1111  else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
1112  MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
1113  else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
1114  MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
1115  else
1116  MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
1117 
1118  auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
1119  return Result.first->first();
1120 }
1121 
1122 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
1123  return getModule().getNamedValue(Name);
1124 }
1125 
1126 /// AddGlobalCtor - Add a function to the list that will be called before
1127 /// main() runs.
1128 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
1129  llvm::Constant *AssociatedData) {
1130  // FIXME: Type coercion of void()* types.
1131  GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData));
1132 }
1133 
1134 /// AddGlobalDtor - Add a function to the list that will be called
1135 /// when the module is unloaded.
1136 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority) {
1137  if (CodeGenOpts.RegisterGlobalDtorsWithAtExit) {
1138  DtorsUsingAtExit[Priority].push_back(Dtor);
1139  return;
1140  }
1141 
1142  // FIXME: Type coercion of void()* types.
1143  GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
1144 }
1145 
1146 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
1147  if (Fns.empty()) return;
1148 
1149  // Ctor function type is void()*.
1150  llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
1151  llvm::Type *CtorPFTy = llvm::PointerType::get(CtorFTy,
1152  TheModule.getDataLayout().getProgramAddressSpace());
1153 
1154  // Get the type of a ctor entry, { i32, void ()*, i8* }.
1155  llvm::StructType *CtorStructTy = llvm::StructType::get(
1156  Int32Ty, CtorPFTy, VoidPtrTy);
1157 
1158  // Construct the constructor and destructor arrays.
1159  ConstantInitBuilder builder(*this);
1160  auto ctors = builder.beginArray(CtorStructTy);
1161  for (const auto &I : Fns) {
1162  auto ctor = ctors.beginStruct(CtorStructTy);
1163  ctor.addInt(Int32Ty, I.Priority);
1164  ctor.add(llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy));
1165  if (I.AssociatedData)
1166  ctor.add(llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy));
1167  else
1168  ctor.addNullPointer(VoidPtrTy);
1169  ctor.finishAndAddTo(ctors);
1170  }
1171 
1172  auto list =
1173  ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
1174  /*constant*/ false,
1175  llvm::GlobalValue::AppendingLinkage);
1176 
1177  // The LTO linker doesn't seem to like it when we set an alignment
1178  // on appending variables. Take it off as a workaround.
1179  list->setAlignment(0);
1180 
1181  Fns.clear();
1182 }
1183 
1184 llvm::GlobalValue::LinkageTypes
1186  const auto *D = cast<FunctionDecl>(GD.getDecl());
1187 
1189 
1190  if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
1191  return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
1192 
1193  if (isa<CXXConstructorDecl>(D) &&
1194  cast<CXXConstructorDecl>(D)->isInheritingConstructor() &&
1195  Context.getTargetInfo().getCXXABI().isMicrosoft()) {
1196  // Our approach to inheriting constructors is fundamentally different from
1197  // that used by the MS ABI, so keep our inheriting constructor thunks
1198  // internal rather than trying to pick an unambiguous mangling for them.
1200  }
1201 
1202  return getLLVMLinkageForDeclarator(D, Linkage, /*IsConstantVariable=*/false);
1203 }
1204 
1205 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
1206  llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
1207  if (!MDS) return nullptr;
1208 
1209  return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
1210 }
1211 
1213  const CGFunctionInfo &Info,
1214  llvm::Function *F) {
1215  unsigned CallingConv;
1216  llvm::AttributeList PAL;
1217  ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv, false);
1218  F->setAttributes(PAL);
1219  F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
1220 }
1221 
1222 static void removeImageAccessQualifier(std::string& TyName) {
1223  std::string ReadOnlyQual("__read_only");
1224  std::string::size_type ReadOnlyPos = TyName.find(ReadOnlyQual);
1225  if (ReadOnlyPos != std::string::npos)
1226  // "+ 1" for the space after access qualifier.
1227  TyName.erase(ReadOnlyPos, ReadOnlyQual.size() + 1);
1228  else {
1229  std::string WriteOnlyQual("__write_only");
1230  std::string::size_type WriteOnlyPos = TyName.find(WriteOnlyQual);
1231  if (WriteOnlyPos != std::string::npos)
1232  TyName.erase(WriteOnlyPos, WriteOnlyQual.size() + 1);
1233  else {
1234  std::string ReadWriteQual("__read_write");
1235  std::string::size_type ReadWritePos = TyName.find(ReadWriteQual);
1236  if (ReadWritePos != std::string::npos)
1237  TyName.erase(ReadWritePos, ReadWriteQual.size() + 1);
1238  }
1239  }
1240 }
1241 
1242 // Returns the address space id that should be produced to the
1243 // kernel_arg_addr_space metadata. This is always fixed to the ids
1244 // as specified in the SPIR 2.0 specification in order to differentiate
1245 // for example in clGetKernelArgInfo() implementation between the address
1246 // spaces with targets without unique mapping to the OpenCL address spaces
1247 // (basically all single AS CPUs).
1248 static unsigned ArgInfoAddressSpace(LangAS AS) {
1249  switch (AS) {
1250  case LangAS::opencl_global: return 1;
1251  case LangAS::opencl_constant: return 2;
1252  case LangAS::opencl_local: return 3;
1253  case LangAS::opencl_generic: return 4; // Not in SPIR 2.0 specs.
1254  default:
1255  return 0; // Assume private.
1256  }
1257 }
1258 
1259 void CodeGenModule::GenOpenCLArgMetadata(llvm::Function *Fn,
1260  const FunctionDecl *FD,
1261  CodeGenFunction *CGF) {
1262  assert(((FD && CGF) || (!FD && !CGF)) &&
1263  "Incorrect use - FD and CGF should either be both null or not!");
1264  // Create MDNodes that represent the kernel arg metadata.
1265  // Each MDNode is a list in the form of "key", N number of values which is
1266  // the same number of values as their are kernel arguments.
1267 
1268  const PrintingPolicy &Policy = Context.getPrintingPolicy();
1269 
1270  // MDNode for the kernel argument address space qualifiers.
1271  SmallVector<llvm::Metadata *, 8> addressQuals;
1272 
1273  // MDNode for the kernel argument access qualifiers (images only).
1275 
1276  // MDNode for the kernel argument type names.
1277  SmallVector<llvm::Metadata *, 8> argTypeNames;
1278 
1279  // MDNode for the kernel argument base type names.
1280  SmallVector<llvm::Metadata *, 8> argBaseTypeNames;
1281 
1282  // MDNode for the kernel argument type qualifiers.
1283  SmallVector<llvm::Metadata *, 8> argTypeQuals;
1284 
1285  // MDNode for the kernel argument names.
1287 
1288  if (FD && CGF)
1289  for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
1290  const ParmVarDecl *parm = FD->getParamDecl(i);
1291  QualType ty = parm->getType();
1292  std::string typeQuals;
1293 
1294  if (ty->isPointerType()) {
1295  QualType pointeeTy = ty->getPointeeType();
1296 
1297  // Get address qualifier.
1298  addressQuals.push_back(
1299  llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(
1300  ArgInfoAddressSpace(pointeeTy.getAddressSpace()))));
1301 
1302  // Get argument type name.
1303  std::string typeName =
1304  pointeeTy.getUnqualifiedType().getAsString(Policy) + "*";
1305 
1306  // Turn "unsigned type" to "utype"
1307  std::string::size_type pos = typeName.find("unsigned");
1308  if (pointeeTy.isCanonical() && pos != std::string::npos)
1309  typeName.erase(pos + 1, 8);
1310 
1311  argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
1312 
1313  std::string baseTypeName =
1315  Policy) +
1316  "*";
1317 
1318  // Turn "unsigned type" to "utype"
1319  pos = baseTypeName.find("unsigned");
1320  if (pos != std::string::npos)
1321  baseTypeName.erase(pos + 1, 8);
1322 
1323  argBaseTypeNames.push_back(
1324  llvm::MDString::get(VMContext, baseTypeName));
1325 
1326  // Get argument type qualifiers:
1327  if (ty.isRestrictQualified())
1328  typeQuals = "restrict";
1329  if (pointeeTy.isConstQualified() ||
1330  (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
1331  typeQuals += typeQuals.empty() ? "const" : " const";
1332  if (pointeeTy.isVolatileQualified())
1333  typeQuals += typeQuals.empty() ? "volatile" : " volatile";
1334  } else {
1335  uint32_t AddrSpc = 0;
1336  bool isPipe = ty->isPipeType();
1337  if (ty->isImageType() || isPipe)
1339 
1340  addressQuals.push_back(
1341  llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(AddrSpc)));
1342 
1343  // Get argument type name.
1344  std::string typeName;
1345  if (isPipe)
1346  typeName = ty.getCanonicalType()
1347  ->getAs<PipeType>()
1348  ->getElementType()
1349  .getAsString(Policy);
1350  else
1351  typeName = ty.getUnqualifiedType().getAsString(Policy);
1352 
1353  // Turn "unsigned type" to "utype"
1354  std::string::size_type pos = typeName.find("unsigned");
1355  if (ty.isCanonical() && pos != std::string::npos)
1356  typeName.erase(pos + 1, 8);
1357 
1358  std::string baseTypeName;
1359  if (isPipe)
1360  baseTypeName = ty.getCanonicalType()
1361  ->getAs<PipeType>()
1362  ->getElementType()
1363  .getCanonicalType()
1364  .getAsString(Policy);
1365  else
1366  baseTypeName =
1368 
1369  // Remove access qualifiers on images
1370  // (as they are inseparable from type in clang implementation,
1371  // but OpenCL spec provides a special query to get access qualifier
1372  // via clGetKernelArgInfo with CL_KERNEL_ARG_ACCESS_QUALIFIER):
1373  if (ty->isImageType()) {
1374  removeImageAccessQualifier(typeName);
1375  removeImageAccessQualifier(baseTypeName);
1376  }
1377 
1378  argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
1379 
1380  // Turn "unsigned type" to "utype"
1381  pos = baseTypeName.find("unsigned");
1382  if (pos != std::string::npos)
1383  baseTypeName.erase(pos + 1, 8);
1384 
1385  argBaseTypeNames.push_back(
1386  llvm::MDString::get(VMContext, baseTypeName));
1387 
1388  if (isPipe)
1389  typeQuals = "pipe";
1390  }
1391 
1392  argTypeQuals.push_back(llvm::MDString::get(VMContext, typeQuals));
1393 
1394  // Get image and pipe access qualifier:
1395  if (ty->isImageType() || ty->isPipeType()) {
1396  const Decl *PDecl = parm;
1397  if (auto *TD = dyn_cast<TypedefType>(ty))
1398  PDecl = TD->getDecl();
1399  const OpenCLAccessAttr *A = PDecl->getAttr<OpenCLAccessAttr>();
1400  if (A && A->isWriteOnly())
1401  accessQuals.push_back(llvm::MDString::get(VMContext, "write_only"));
1402  else if (A && A->isReadWrite())
1403  accessQuals.push_back(llvm::MDString::get(VMContext, "read_write"));
1404  else
1405  accessQuals.push_back(llvm::MDString::get(VMContext, "read_only"));
1406  } else
1407  accessQuals.push_back(llvm::MDString::get(VMContext, "none"));
1408 
1409  // Get argument name.
1410  argNames.push_back(llvm::MDString::get(VMContext, parm->getName()));
1411  }
1412 
1413  Fn->setMetadata("kernel_arg_addr_space",
1414  llvm::MDNode::get(VMContext, addressQuals));
1415  Fn->setMetadata("kernel_arg_access_qual",
1416  llvm::MDNode::get(VMContext, accessQuals));
1417  Fn->setMetadata("kernel_arg_type",
1418  llvm::MDNode::get(VMContext, argTypeNames));
1419  Fn->setMetadata("kernel_arg_base_type",
1420  llvm::MDNode::get(VMContext, argBaseTypeNames));
1421  Fn->setMetadata("kernel_arg_type_qual",
1422  llvm::MDNode::get(VMContext, argTypeQuals));
1423  if (getCodeGenOpts().EmitOpenCLArgMetadata)
1424  Fn->setMetadata("kernel_arg_name",
1425  llvm::MDNode::get(VMContext, argNames));
1426 }
1427 
1428 /// Determines whether the language options require us to model
1429 /// unwind exceptions. We treat -fexceptions as mandating this
1430 /// except under the fragile ObjC ABI with only ObjC exceptions
1431 /// enabled. This means, for example, that C with -fexceptions
1432 /// enables this.
1433 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
1434  // If exceptions are completely disabled, obviously this is false.
1435  if (!LangOpts.Exceptions) return false;
1436 
1437  // If C++ exceptions are enabled, this is true.
1438  if (LangOpts.CXXExceptions) return true;
1439 
1440  // If ObjC exceptions are enabled, this depends on the ABI.
1441  if (LangOpts.ObjCExceptions) {
1442  return LangOpts.ObjCRuntime.hasUnwindExceptions();
1443  }
1444 
1445  return true;
1446 }
1447 
1449  const CXXMethodDecl *MD) {
1450  // Check that the type metadata can ever actually be used by a call.
1451  if (!CGM.getCodeGenOpts().LTOUnit ||
1452  !CGM.HasHiddenLTOVisibility(MD->getParent()))
1453  return false;
1454 
1455  // Only functions whose address can be taken with a member function pointer
1456  // need this sort of type metadata.
1457  return !MD->isStatic() && !MD->isVirtual() && !isa<CXXConstructorDecl>(MD) &&
1458  !isa<CXXDestructorDecl>(MD);
1459 }
1460 
1461 std::vector<const CXXRecordDecl *>
1463  llvm::SetVector<const CXXRecordDecl *> MostBases;
1464 
1465  std::function<void (const CXXRecordDecl *)> CollectMostBases;
1466  CollectMostBases = [&](const CXXRecordDecl *RD) {
1467  if (RD->getNumBases() == 0)
1468  MostBases.insert(RD);
1469  for (const CXXBaseSpecifier &B : RD->bases())
1470  CollectMostBases(B.getType()->getAsCXXRecordDecl());
1471  };
1472  CollectMostBases(RD);
1473  return MostBases.takeVector();
1474 }
1475 
1477  llvm::Function *F) {
1478  llvm::AttrBuilder B;
1479 
1480  if (CodeGenOpts.UnwindTables)
1481  B.addAttribute(llvm::Attribute::UWTable);
1482 
1483  if (!hasUnwindExceptions(LangOpts))
1484  B.addAttribute(llvm::Attribute::NoUnwind);
1485 
1486  if (!D || !D->hasAttr<NoStackProtectorAttr>()) {
1487  if (LangOpts.getStackProtector() == LangOptions::SSPOn)
1488  B.addAttribute(llvm::Attribute::StackProtect);
1489  else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
1490  B.addAttribute(llvm::Attribute::StackProtectStrong);
1491  else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
1492  B.addAttribute(llvm::Attribute::StackProtectReq);
1493  }
1494 
1495  if (!D) {
1496  // If we don't have a declaration to control inlining, the function isn't
1497  // explicitly marked as alwaysinline for semantic reasons, and inlining is
1498  // disabled, mark the function as noinline.
1499  if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
1500  CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
1501  B.addAttribute(llvm::Attribute::NoInline);
1502 
1503  F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1504  return;
1505  }
1506 
1507  // Track whether we need to add the optnone LLVM attribute,
1508  // starting with the default for this optimization level.
1509  bool ShouldAddOptNone =
1510  !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
1511  // We can't add optnone in the following cases, it won't pass the verifier.
1512  ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
1513  ShouldAddOptNone &= !F->hasFnAttribute(llvm::Attribute::AlwaysInline);
1514  ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
1515 
1516  if (ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) {
1517  B.addAttribute(llvm::Attribute::OptimizeNone);
1518 
1519  // OptimizeNone implies noinline; we should not be inlining such functions.
1520  B.addAttribute(llvm::Attribute::NoInline);
1521  assert(!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
1522  "OptimizeNone and AlwaysInline on same function!");
1523 
1524  // We still need to handle naked functions even though optnone subsumes
1525  // much of their semantics.
1526  if (D->hasAttr<NakedAttr>())
1527  B.addAttribute(llvm::Attribute::Naked);
1528 
1529  // OptimizeNone wins over OptimizeForSize and MinSize.
1530  F->removeFnAttr(llvm::Attribute::OptimizeForSize);
1531  F->removeFnAttr(llvm::Attribute::MinSize);
1532  } else if (D->hasAttr<NakedAttr>()) {
1533  // Naked implies noinline: we should not be inlining such functions.
1534  B.addAttribute(llvm::Attribute::Naked);
1535  B.addAttribute(llvm::Attribute::NoInline);
1536  } else if (D->hasAttr<NoDuplicateAttr>()) {
1537  B.addAttribute(llvm::Attribute::NoDuplicate);
1538  } else if (D->hasAttr<NoInlineAttr>()) {
1539  B.addAttribute(llvm::Attribute::NoInline);
1540  } else if (D->hasAttr<AlwaysInlineAttr>() &&
1541  !F->hasFnAttribute(llvm::Attribute::NoInline)) {
1542  // (noinline wins over always_inline, and we can't specify both in IR)
1543  B.addAttribute(llvm::Attribute::AlwaysInline);
1544  } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
1545  // If we're not inlining, then force everything that isn't always_inline to
1546  // carry an explicit noinline attribute.
1547  if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
1548  B.addAttribute(llvm::Attribute::NoInline);
1549  } else {
1550  // Otherwise, propagate the inline hint attribute and potentially use its
1551  // absence to mark things as noinline.
1552  if (auto *FD = dyn_cast<FunctionDecl>(D)) {
1553  // Search function and template pattern redeclarations for inline.
1554  auto CheckForInline = [](const FunctionDecl *FD) {
1555  auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
1556  return Redecl->isInlineSpecified();
1557  };
1558  if (any_of(FD->redecls(), CheckRedeclForInline))
1559  return true;
1560  const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
1561  if (!Pattern)
1562  return false;
1563  return any_of(Pattern->redecls(), CheckRedeclForInline);
1564  };
1565  if (CheckForInline(FD)) {
1566  B.addAttribute(llvm::Attribute::InlineHint);
1567  } else if (CodeGenOpts.getInlining() ==
1569  !FD->isInlined() &&
1570  !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1571  B.addAttribute(llvm::Attribute::NoInline);
1572  }
1573  }
1574  }
1575 
1576  // Add other optimization related attributes if we are optimizing this
1577  // function.
1578  if (!D->hasAttr<OptimizeNoneAttr>()) {
1579  if (D->hasAttr<ColdAttr>()) {
1580  if (!ShouldAddOptNone)
1581  B.addAttribute(llvm::Attribute::OptimizeForSize);
1582  B.addAttribute(llvm::Attribute::Cold);
1583  }
1584 
1585  if (D->hasAttr<MinSizeAttr>())
1586  B.addAttribute(llvm::Attribute::MinSize);
1587  }
1588 
1589  F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1590 
1591  unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
1592  if (alignment)
1593  F->setAlignment(alignment);
1594 
1595  if (!D->hasAttr<AlignedAttr>())
1596  if (LangOpts.FunctionAlignment)
1597  F->setAlignment(1 << LangOpts.FunctionAlignment);
1598 
1599  // Some C++ ABIs require 2-byte alignment for member functions, in order to
1600  // reserve a bit for differentiating between virtual and non-virtual member
1601  // functions. If the current target's C++ ABI requires this and this is a
1602  // member function, set its alignment accordingly.
1603  if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
1604  if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
1605  F->setAlignment(2);
1606  }
1607 
1608  // In the cross-dso CFI mode, we want !type attributes on definitions only.
1609  if (CodeGenOpts.SanitizeCfiCrossDso)
1610  if (auto *FD = dyn_cast<FunctionDecl>(D))
1612 
1613  // Emit type metadata on member functions for member function pointer checks.
1614  // These are only ever necessary on definitions; we're guaranteed that the
1615  // definition will be present in the LTO unit as a result of LTO visibility.
1616  auto *MD = dyn_cast<CXXMethodDecl>(D);
1617  if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
1618  for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
1619  llvm::Metadata *Id =
1621  MD->getType(), Context.getRecordType(Base).getTypePtr()));
1622  F->addTypeMetadata(0, Id);
1623  }
1624  }
1625 }
1626 
1627 void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
1628  const Decl *D = GD.getDecl();
1629  if (dyn_cast_or_null<NamedDecl>(D))
1630  setGVProperties(GV, GD);
1631  else
1632  GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1633 
1634  if (D && D->hasAttr<UsedAttr>())
1635  addUsedGlobal(GV);
1636 
1637  if (CodeGenOpts.KeepStaticConsts && D && isa<VarDecl>(D)) {
1638  const auto *VD = cast<VarDecl>(D);
1639  if (VD->getType().isConstQualified() &&
1640  VD->getStorageDuration() == SD_Static)
1641  addUsedGlobal(GV);
1642  }
1643 }
1644 
1645 bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
1646  llvm::AttrBuilder &Attrs) {
1647  // Add target-cpu and target-features attributes to functions. If
1648  // we have a decl for the function and it has a target attribute then
1649  // parse that and add it to the feature set.
1650  StringRef TargetCPU = getTarget().getTargetOpts().CPU;
1651  std::vector<std::string> Features;
1652  const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
1653  FD = FD ? FD->getMostRecentDecl() : FD;
1654  const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
1655  const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
1656  bool AddedAttr = false;
1657  if (TD || SD) {
1658  llvm::StringMap<bool> FeatureMap;
1659  getFunctionFeatureMap(FeatureMap, GD);
1660 
1661  // Produce the canonical string for this set of features.
1662  for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
1663  Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
1664 
1665  // Now add the target-cpu and target-features to the function.
1666  // While we populated the feature map above, we still need to
1667  // get and parse the target attribute so we can get the cpu for
1668  // the function.
1669  if (TD) {
1670  TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
1671  if (ParsedAttr.Architecture != "" &&
1672  getTarget().isValidCPUName(ParsedAttr.Architecture))
1673  TargetCPU = ParsedAttr.Architecture;
1674  }
1675  } else {
1676  // Otherwise just add the existing target cpu and target features to the
1677  // function.
1678  Features = getTarget().getTargetOpts().Features;
1679  }
1680 
1681  if (TargetCPU != "") {
1682  Attrs.addAttribute("target-cpu", TargetCPU);
1683  AddedAttr = true;
1684  }
1685  if (!Features.empty()) {
1686  llvm::sort(Features);
1687  Attrs.addAttribute("target-features", llvm::join(Features, ","));
1688  AddedAttr = true;
1689  }
1690 
1691  return AddedAttr;
1692 }
1693 
1694 void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
1695  llvm::GlobalObject *GO) {
1696  const Decl *D = GD.getDecl();
1697  SetCommonAttributes(GD, GO);
1698 
1699  if (D) {
1700  if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
1701  if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
1702  GV->addAttribute("bss-section", SA->getName());
1703  if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
1704  GV->addAttribute("data-section", SA->getName());
1705  if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
1706  GV->addAttribute("rodata-section", SA->getName());
1707  }
1708 
1709  if (auto *F = dyn_cast<llvm::Function>(GO)) {
1710  if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
1711  if (!D->getAttr<SectionAttr>())
1712  F->addFnAttr("implicit-section-name", SA->getName());
1713 
1714  llvm::AttrBuilder Attrs;
1715  if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
1716  // We know that GetCPUAndFeaturesAttributes will always have the
1717  // newest set, since it has the newest possible FunctionDecl, so the
1718  // new ones should replace the old.
1719  F->removeFnAttr("target-cpu");
1720  F->removeFnAttr("target-features");
1721  F->addAttributes(llvm::AttributeList::FunctionIndex, Attrs);
1722  }
1723  }
1724 
1725  if (const auto *CSA = D->getAttr<CodeSegAttr>())
1726  GO->setSection(CSA->getName());
1727  else if (const auto *SA = D->getAttr<SectionAttr>())
1728  GO->setSection(SA->getName());
1729  }
1730 
1731  getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
1732 }
1733 
1735  llvm::Function *F,
1736  const CGFunctionInfo &FI) {
1737  const Decl *D = GD.getDecl();
1738  SetLLVMFunctionAttributes(GD, FI, F);
1740 
1741  F->setLinkage(llvm::Function::InternalLinkage);
1742 
1743  setNonAliasAttributes(GD, F);
1744 }
1745 
1746 static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
1747  // Set linkage and visibility in case we never see a definition.
1749  // Don't set internal linkage on declarations.
1750  // "extern_weak" is overloaded in LLVM; we probably should have
1751  // separate linkage types for this.
1752  if (isExternallyVisible(LV.getLinkage()) &&
1753  (ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
1754  GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
1755 }
1756 
1758  llvm::Function *F) {
1759  // Only if we are checking indirect calls.
1760  if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
1761  return;
1762 
1763  // Non-static class methods are handled via vtable or member function pointer
1764  // checks elsewhere.
1765  if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
1766  return;
1767 
1768  // Additionally, if building with cross-DSO support...
1769  if (CodeGenOpts.SanitizeCfiCrossDso) {
1770  // Skip available_externally functions. They won't be codegen'ed in the
1771  // current module anyway.
1773  return;
1774  }
1775 
1776  llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
1777  F->addTypeMetadata(0, MD);
1778  F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
1779 
1780  // Emit a hash-based bit set entry for cross-DSO calls.
1781  if (CodeGenOpts.SanitizeCfiCrossDso)
1782  if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
1783  F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
1784 }
1785 
1786 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
1787  bool IsIncompleteFunction,
1788  bool IsThunk) {
1789 
1790  if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) {
1791  // If this is an intrinsic function, set the function's attributes
1792  // to the intrinsic's attributes.
1793  F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID));
1794  return;
1795  }
1796 
1797  const auto *FD = cast<FunctionDecl>(GD.getDecl());
1798 
1799  if (!IsIncompleteFunction)
1800  SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F);
1801 
1802  // Add the Returned attribute for "this", except for iOS 5 and earlier
1803  // where substantial code, including the libstdc++ dylib, was compiled with
1804  // GCC and does not actually return "this".
1805  if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
1806  !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
1807  assert(!F->arg_empty() &&
1808  F->arg_begin()->getType()
1809  ->canLosslesslyBitCastTo(F->getReturnType()) &&
1810  "unexpected this return");
1811  F->addAttribute(1, llvm::Attribute::Returned);
1812  }
1813 
1814  // Only a few attributes are set on declarations; these may later be
1815  // overridden by a definition.
1816 
1817  setLinkageForGV(F, FD);
1818  setGVProperties(F, FD);
1819 
1820  // Setup target-specific attributes.
1821  if (!IsIncompleteFunction && F->isDeclaration())
1822  getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
1823 
1824  if (const auto *CSA = FD->getAttr<CodeSegAttr>())
1825  F->setSection(CSA->getName());
1826  else if (const auto *SA = FD->getAttr<SectionAttr>())
1827  F->setSection(SA->getName());
1828 
1830  // A replaceable global allocation function does not act like a builtin by
1831  // default, only if it is invoked by a new-expression or delete-expression.
1832  F->addAttribute(llvm::AttributeList::FunctionIndex,
1833  llvm::Attribute::NoBuiltin);
1834 
1835  // A sane operator new returns a non-aliasing pointer.
1836  // FIXME: Also add NonNull attribute to the return value
1837  // for the non-nothrow forms?
1838  auto Kind = FD->getDeclName().getCXXOverloadedOperator();
1839  if (getCodeGenOpts().AssumeSaneOperatorNew &&
1840  (Kind == OO_New || Kind == OO_Array_New))
1841  F->addAttribute(llvm::AttributeList::ReturnIndex,
1842  llvm::Attribute::NoAlias);
1843  }
1844 
1845  if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
1846  F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1847  else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
1848  if (MD->isVirtual())
1849  F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1850 
1851  // Don't emit entries for function declarations in the cross-DSO mode. This
1852  // is handled with better precision by the receiving DSO.
1853  if (!CodeGenOpts.SanitizeCfiCrossDso)
1855 
1856  if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
1857  getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
1858 
1859  if (const auto *CB = FD->getAttr<CallbackAttr>()) {
1860  // Annotate the callback behavior as metadata:
1861  // - The callback callee (as argument number).
1862  // - The callback payloads (as argument numbers).
1863  llvm::LLVMContext &Ctx = F->getContext();
1864  llvm::MDBuilder MDB(Ctx);
1865 
1866  // The payload indices are all but the first one in the encoding. The first
1867  // identifies the callback callee.
1868  int CalleeIdx = *CB->encoding_begin();
1869  ArrayRef<int> PayloadIndices(CB->encoding_begin() + 1, CB->encoding_end());
1870  F->addMetadata(llvm::LLVMContext::MD_callback,
1871  *llvm::MDNode::get(Ctx, {MDB.createCallbackEncoding(
1872  CalleeIdx, PayloadIndices,
1873  /* VarArgsArePassed */ false)}));
1874  }
1875 }
1876 
1877 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
1878  assert(!GV->isDeclaration() &&
1879  "Only globals with definition can force usage.");
1880  LLVMUsed.emplace_back(GV);
1881 }
1882 
1883 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
1884  assert(!GV->isDeclaration() &&
1885  "Only globals with definition can force usage.");
1886  LLVMCompilerUsed.emplace_back(GV);
1887 }
1888 
1889 static void emitUsed(CodeGenModule &CGM, StringRef Name,
1890  std::vector<llvm::WeakTrackingVH> &List) {
1891  // Don't create llvm.used if there is no need.
1892  if (List.empty())
1893  return;
1894 
1895  // Convert List to what ConstantArray needs.
1897  UsedArray.resize(List.size());
1898  for (unsigned i = 0, e = List.size(); i != e; ++i) {
1899  UsedArray[i] =
1900  llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
1901  cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
1902  }
1903 
1904  if (UsedArray.empty())
1905  return;
1906  llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
1907 
1908  auto *GV = new llvm::GlobalVariable(
1909  CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
1910  llvm::ConstantArray::get(ATy, UsedArray), Name);
1911 
1912  GV->setSection("llvm.metadata");
1913 }
1914 
1915 void CodeGenModule::emitLLVMUsed() {
1916  emitUsed(*this, "llvm.used", LLVMUsed);
1917  emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
1918 }
1919 
1921  auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
1922  LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1923 }
1924 
1925 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
1927  getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
1928  auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
1929  LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1930 }
1931 
1932 void CodeGenModule::AddDependentLib(StringRef Lib) {
1933  auto &C = getLLVMContext();
1934  if (getTarget().getTriple().isOSBinFormatELF()) {
1935  ELFDependentLibraries.push_back(
1936  llvm::MDNode::get(C, llvm::MDString::get(C, Lib)));
1937  return;
1938  }
1939 
1942  auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
1943  LinkerOptionsMetadata.push_back(llvm::MDNode::get(C, MDOpts));
1944 }
1945 
1946 /// Add link options implied by the given module, including modules
1947 /// it depends on, using a postorder walk.
1950  llvm::SmallPtrSet<Module *, 16> &Visited) {
1951  // Import this module's parent.
1952  if (Mod->Parent && Visited.insert(Mod->Parent).second) {
1953  addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
1954  }
1955 
1956  // Import this module's dependencies.
1957  for (unsigned I = Mod->Imports.size(); I > 0; --I) {
1958  if (Visited.insert(Mod->Imports[I - 1]).second)
1959  addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited);
1960  }
1961 
1962  // Add linker options to link against the libraries/frameworks
1963  // described by this module.
1964  llvm::LLVMContext &Context = CGM.getLLVMContext();
1965  bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
1966 
1967  // For modules that use export_as for linking, use that module
1968  // name instead.
1969  if (Mod->UseExportAsModuleLinkName)
1970  return;
1971 
1972  for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) {
1973  // Link against a framework. Frameworks are currently Darwin only, so we
1974  // don't to ask TargetCodeGenInfo for the spelling of the linker option.
1975  if (Mod->LinkLibraries[I-1].IsFramework) {
1976  llvm::Metadata *Args[2] = {
1977  llvm::MDString::get(Context, "-framework"),
1978  llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library)};
1979 
1980  Metadata.push_back(llvm::MDNode::get(Context, Args));
1981  continue;
1982  }
1983 
1984  // Link against a library.
1985  if (IsELF) {
1986  llvm::Metadata *Args[2] = {
1987  llvm::MDString::get(Context, "lib"),
1988  llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library),
1989  };
1990  Metadata.push_back(llvm::MDNode::get(Context, Args));
1991  } else {
1994  Mod->LinkLibraries[I - 1].Library, Opt);
1995  auto *OptString = llvm::MDString::get(Context, Opt);
1996  Metadata.push_back(llvm::MDNode::get(Context, OptString));
1997  }
1998  }
1999 }
2000 
2001 void CodeGenModule::EmitModuleLinkOptions() {
2002  // Collect the set of all of the modules we want to visit to emit link
2003  // options, which is essentially the imported modules and all of their
2004  // non-explicit child modules.
2005  llvm::SetVector<clang::Module *> LinkModules;
2006  llvm::SmallPtrSet<clang::Module *, 16> Visited;
2008 
2009  // Seed the stack with imported modules.
2010  for (Module *M : ImportedModules) {
2011  // Do not add any link flags when an implementation TU of a module imports
2012  // a header of that same module.
2013  if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
2015  continue;
2016  if (Visited.insert(M).second)
2017  Stack.push_back(M);
2018  }
2019 
2020  // Find all of the modules to import, making a little effort to prune
2021  // non-leaf modules.
2022  while (!Stack.empty()) {
2023  clang::Module *Mod = Stack.pop_back_val();
2024 
2025  bool AnyChildren = false;
2026 
2027  // Visit the submodules of this module.
2028  for (const auto &SM : Mod->submodules()) {
2029  // Skip explicit children; they need to be explicitly imported to be
2030  // linked against.
2031  if (SM->IsExplicit)
2032  continue;
2033 
2034  if (Visited.insert(SM).second) {
2035  Stack.push_back(SM);
2036  AnyChildren = true;
2037  }
2038  }
2039 
2040  // We didn't find any children, so add this module to the list of
2041  // modules to link against.
2042  if (!AnyChildren) {
2043  LinkModules.insert(Mod);
2044  }
2045  }
2046 
2047  // Add link options for all of the imported modules in reverse topological
2048  // order. We don't do anything to try to order import link flags with respect
2049  // to linker options inserted by things like #pragma comment().
2050  SmallVector<llvm::MDNode *, 16> MetadataArgs;
2051  Visited.clear();
2052  for (Module *M : LinkModules)
2053  if (Visited.insert(M).second)
2054  addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
2055  std::reverse(MetadataArgs.begin(), MetadataArgs.end());
2056  LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
2057 
2058  // Add the linker options metadata flag.
2059  auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
2060  for (auto *MD : LinkerOptionsMetadata)
2061  NMD->addOperand(MD);
2062 }
2063 
2064 void CodeGenModule::EmitDeferred() {
2065  // Emit deferred declare target declarations.
2066  if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
2067  getOpenMPRuntime().emitDeferredTargetDecls();
2068 
2069  // Emit code for any potentially referenced deferred decls. Since a
2070  // previously unused static decl may become used during the generation of code
2071  // for a static function, iterate until no changes are made.
2072 
2073  if (!DeferredVTables.empty()) {
2074  EmitDeferredVTables();
2075 
2076  // Emitting a vtable doesn't directly cause more vtables to
2077  // become deferred, although it can cause functions to be
2078  // emitted that then need those vtables.
2079  assert(DeferredVTables.empty());
2080  }
2081 
2082  // Stop if we're out of both deferred vtables and deferred declarations.
2083  if (DeferredDeclsToEmit.empty())
2084  return;
2085 
2086  // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
2087  // work, it will not interfere with this.
2088  std::vector<GlobalDecl> CurDeclsToEmit;
2089  CurDeclsToEmit.swap(DeferredDeclsToEmit);
2090 
2091  for (GlobalDecl &D : CurDeclsToEmit) {
2092  // We should call GetAddrOfGlobal with IsForDefinition set to true in order
2093  // to get GlobalValue with exactly the type we need, not something that
2094  // might had been created for another decl with the same mangled name but
2095  // different type.
2096  llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
2098 
2099  // In case of different address spaces, we may still get a cast, even with
2100  // IsForDefinition equal to true. Query mangled names table to get
2101  // GlobalValue.
2102  if (!GV)
2103  GV = GetGlobalValue(getMangledName(D));
2104 
2105  // Make sure GetGlobalValue returned non-null.
2106  assert(GV);
2107 
2108  // Check to see if we've already emitted this. This is necessary
2109  // for a couple of reasons: first, decls can end up in the
2110  // deferred-decls queue multiple times, and second, decls can end
2111  // up with definitions in unusual ways (e.g. by an extern inline
2112  // function acquiring a strong function redefinition). Just
2113  // ignore these cases.
2114  if (!GV->isDeclaration())
2115  continue;
2116 
2117  // Otherwise, emit the definition and move on to the next one.
2118  EmitGlobalDefinition(D, GV);
2119 
2120  // If we found out that we need to emit more decls, do that recursively.
2121  // This has the advantage that the decls are emitted in a DFS and related
2122  // ones are close together, which is convenient for testing.
2123  if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
2124  EmitDeferred();
2125  assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
2126  }
2127  }
2128 }
2129 
2130 void CodeGenModule::EmitVTablesOpportunistically() {
2131  // Try to emit external vtables as available_externally if they have emitted
2132  // all inlined virtual functions. It runs after EmitDeferred() and therefore
2133  // is not allowed to create new references to things that need to be emitted
2134  // lazily. Note that it also uses fact that we eagerly emitting RTTI.
2135 
2136  assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
2137  && "Only emit opportunistic vtables with optimizations");
2138 
2139  for (const CXXRecordDecl *RD : OpportunisticVTables) {
2140  assert(getVTables().isVTableExternal(RD) &&
2141  "This queue should only contain external vtables");
2142  if (getCXXABI().canSpeculativelyEmitVTable(RD))
2143  VTables.GenerateClassData(RD);
2144  }
2145  OpportunisticVTables.clear();
2146 }
2147 
2149  if (Annotations.empty())
2150  return;
2151 
2152  // Create a new global variable for the ConstantStruct in the Module.
2153  llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
2154  Annotations[0]->getType(), Annotations.size()), Annotations);
2155  auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
2156  llvm::GlobalValue::AppendingLinkage,
2157  Array, "llvm.global.annotations");
2158  gv->setSection(AnnotationSection);
2159 }
2160 
2161 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
2162  llvm::Constant *&AStr = AnnotationStrings[Str];
2163  if (AStr)
2164  return AStr;
2165 
2166  // Not found yet, create a new global.
2167  llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
2168  auto *gv =
2169  new llvm::GlobalVariable(getModule(), s->getType(), true,
2170  llvm::GlobalValue::PrivateLinkage, s, ".str");
2171  gv->setSection(AnnotationSection);
2172  gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2173  AStr = gv;
2174  return gv;
2175 }
2176 
2179  PresumedLoc PLoc = SM.getPresumedLoc(Loc);
2180  if (PLoc.isValid())
2181  return EmitAnnotationString(PLoc.getFilename());
2182  return EmitAnnotationString(SM.getBufferName(Loc));
2183 }
2184 
2187  PresumedLoc PLoc = SM.getPresumedLoc(L);
2188  unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
2189  SM.getExpansionLineNumber(L);
2190  return llvm::ConstantInt::get(Int32Ty, LineNo);
2191 }
2192 
2193 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
2194  const AnnotateAttr *AA,
2195  SourceLocation L) {
2196  // Get the globals for file name, annotation, and the line number.
2197  llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
2198  *UnitGV = EmitAnnotationUnit(L),
2199  *LineNoCst = EmitAnnotationLineNo(L);
2200 
2201  // Create the ConstantStruct for the global annotation.
2202  llvm::Constant *Fields[4] = {
2203  llvm::ConstantExpr::getBitCast(GV, Int8PtrTy),
2204  llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
2205  llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
2206  LineNoCst
2207  };
2208  return llvm::ConstantStruct::getAnon(Fields);
2209 }
2210 
2212  llvm::GlobalValue *GV) {
2213  assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
2214  // Get the struct elements for these annotations.
2215  for (const auto *I : D->specific_attrs<AnnotateAttr>())
2216  Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
2217 }
2218 
2220  llvm::Function *Fn,
2221  SourceLocation Loc) const {
2222  const auto &SanitizerBL = getContext().getSanitizerBlacklist();
2223  // Blacklist by function name.
2224  if (SanitizerBL.isBlacklistedFunction(Kind, Fn->getName()))
2225  return true;
2226  // Blacklist by location.
2227  if (Loc.isValid())
2228  return SanitizerBL.isBlacklistedLocation(Kind, Loc);
2229  // If location is unknown, this may be a compiler-generated function. Assume
2230  // it's located in the main file.
2231  auto &SM = Context.getSourceManager();
2232  if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
2233  return SanitizerBL.isBlacklistedFile(Kind, MainFile->getName());
2234  }
2235  return false;
2236 }
2237 
2238 bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
2239  SourceLocation Loc, QualType Ty,
2240  StringRef Category) const {
2241  // For now globals can be blacklisted only in ASan and KASan.
2242  const SanitizerMask EnabledAsanMask =
2243  LangOpts.Sanitize.Mask &
2244  (SanitizerKind::Address | SanitizerKind::KernelAddress |
2245  SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress |
2246  SanitizerKind::MemTag);
2247  if (!EnabledAsanMask)
2248  return false;
2249  const auto &SanitizerBL = getContext().getSanitizerBlacklist();
2250  if (SanitizerBL.isBlacklistedGlobal(EnabledAsanMask, GV->getName(), Category))
2251  return true;
2252  if (SanitizerBL.isBlacklistedLocation(EnabledAsanMask, Loc, Category))
2253  return true;
2254  // Check global type.
2255  if (!Ty.isNull()) {
2256  // Drill down the array types: if global variable of a fixed type is
2257  // blacklisted, we also don't instrument arrays of them.
2258  while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
2259  Ty = AT->getElementType();
2261  // We allow to blacklist only record types (classes, structs etc.)
2262  if (Ty->isRecordType()) {
2263  std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
2264  if (SanitizerBL.isBlacklistedType(EnabledAsanMask, TypeStr, Category))
2265  return true;
2266  }
2267  }
2268  return false;
2269 }
2270 
2271 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
2272  StringRef Category) const {
2273  const auto &XRayFilter = getContext().getXRayFilter();
2274  using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
2275  auto Attr = ImbueAttr::NONE;
2276  if (Loc.isValid())
2277  Attr = XRayFilter.shouldImbueLocation(Loc, Category);
2278  if (Attr == ImbueAttr::NONE)
2279  Attr = XRayFilter.shouldImbueFunction(Fn->getName());
2280  switch (Attr) {
2281  case ImbueAttr::NONE:
2282  return false;
2283  case ImbueAttr::ALWAYS:
2284  Fn->addFnAttr("function-instrument", "xray-always");
2285  break;
2286  case ImbueAttr::ALWAYS_ARG1:
2287  Fn->addFnAttr("function-instrument", "xray-always");
2288  Fn->addFnAttr("xray-log-args", "1");
2289  break;
2290  case ImbueAttr::NEVER:
2291  Fn->addFnAttr("function-instrument", "xray-never");
2292  break;
2293  }
2294  return true;
2295 }
2296 
2297 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
2298  // Never defer when EmitAllDecls is specified.
2299  if (LangOpts.EmitAllDecls)
2300  return true;
2301 
2302  if (CodeGenOpts.KeepStaticConsts) {
2303  const auto *VD = dyn_cast<VarDecl>(Global);
2304  if (VD && VD->getType().isConstQualified() &&
2305  VD->getStorageDuration() == SD_Static)
2306  return true;
2307  }
2308 
2309  return getContext().DeclMustBeEmitted(Global);
2310 }
2311 
2312 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
2313  if (const auto *FD = dyn_cast<FunctionDecl>(Global))
2315  // Implicit template instantiations may change linkage if they are later
2316  // explicitly instantiated, so they should not be emitted eagerly.
2317  return false;
2318  if (const auto *VD = dyn_cast<VarDecl>(Global))
2319  if (Context.getInlineVariableDefinitionKind(VD) ==
2321  // A definition of an inline constexpr static data member may change
2322  // linkage later if it's redeclared outside the class.
2323  return false;
2324  // If OpenMP is enabled and threadprivates must be generated like TLS, delay
2325  // codegen for global variables, because they may be marked as threadprivate.
2326  if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
2327  getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
2328  !isTypeConstant(Global->getType(), false) &&
2329  !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
2330  return false;
2331 
2332  return true;
2333 }
2334 
2336  const CXXUuidofExpr* E) {
2337  // Sema has verified that IIDSource has a __declspec(uuid()), and that its
2338  // well-formed.
2339  StringRef Uuid = E->getUuidStr();
2340  std::string Name = "_GUID_" + Uuid.lower();
2341  std::replace(Name.begin(), Name.end(), '-', '_');
2342 
2343  // The UUID descriptor should be pointer aligned.
2345 
2346  // Look for an existing global.
2347  if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
2348  return ConstantAddress(GV, Alignment);
2349 
2350  llvm::Constant *Init = EmitUuidofInitializer(Uuid);
2351  assert(Init && "failed to initialize as constant");
2352 
2353  auto *GV = new llvm::GlobalVariable(
2354  getModule(), Init->getType(),
2355  /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
2356  if (supportsCOMDAT())
2357  GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
2358  setDSOLocal(GV);
2359  return ConstantAddress(GV, Alignment);
2360 }
2361 
2363  const AliasAttr *AA = VD->getAttr<AliasAttr>();
2364  assert(AA && "No alias?");
2365 
2366  CharUnits Alignment = getContext().getDeclAlign(VD);
2367  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
2368 
2369  // See if there is already something with the target's name in the module.
2370  llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
2371  if (Entry) {
2372  unsigned AS = getContext().getTargetAddressSpace(VD->getType());
2373  auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
2374  return ConstantAddress(Ptr, Alignment);
2375  }
2376 
2377  llvm::Constant *Aliasee;
2378  if (isa<llvm::FunctionType>(DeclTy))
2379  Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
2380  GlobalDecl(cast<FunctionDecl>(VD)),
2381  /*ForVTable=*/false);
2382  else
2383  Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
2384  llvm::PointerType::getUnqual(DeclTy),
2385  nullptr);
2386 
2387  auto *F = cast<llvm::GlobalValue>(Aliasee);
2388  F->setLinkage(llvm::Function::ExternalWeakLinkage);
2389  WeakRefReferences.insert(F);
2390 
2391  return ConstantAddress(Aliasee, Alignment);
2392 }
2393 
2395  const auto *Global = cast<ValueDecl>(GD.getDecl());
2396 
2397  // Weak references don't produce any output by themselves.
2398  if (Global->hasAttr<WeakRefAttr>())
2399  return;
2400 
2401  // If this is an alias definition (which otherwise looks like a declaration)
2402  // emit it now.
2403  if (Global->hasAttr<AliasAttr>())
2404  return EmitAliasDefinition(GD);
2405 
2406  // IFunc like an alias whose value is resolved at runtime by calling resolver.
2407  if (Global->hasAttr<IFuncAttr>())
2408  return emitIFuncDefinition(GD);
2409 
2410  // If this is a cpu_dispatch multiversion function, emit the resolver.
2411  if (Global->hasAttr<CPUDispatchAttr>())
2412  return emitCPUDispatchDefinition(GD);
2413 
2414  // If this is CUDA, be selective about which declarations we emit.
2415  if (LangOpts.CUDA) {
2416  if (LangOpts.CUDAIsDevice) {
2417  if (!Global->hasAttr<CUDADeviceAttr>() &&
2418  !Global->hasAttr<CUDAGlobalAttr>() &&
2419  !Global->hasAttr<CUDAConstantAttr>() &&
2420  !Global->hasAttr<CUDASharedAttr>() &&
2421  !(LangOpts.HIP && Global->hasAttr<HIPPinnedShadowAttr>()))
2422  return;
2423  } else {
2424  // We need to emit host-side 'shadows' for all global
2425  // device-side variables because the CUDA runtime needs their
2426  // size and host-side address in order to provide access to
2427  // their device-side incarnations.
2428 
2429  // So device-only functions are the only things we skip.
2430  if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
2431  Global->hasAttr<CUDADeviceAttr>())
2432  return;
2433 
2434  assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
2435  "Expected Variable or Function");
2436  }
2437  }
2438 
2439  if (LangOpts.OpenMP) {
2440  // If this is OpenMP device, check if it is legal to emit this global
2441  // normally.
2442  if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
2443  return;
2444  if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
2445  if (MustBeEmitted(Global))
2447  return;
2448  } else if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) {
2449  if (MustBeEmitted(Global))
2450  EmitOMPDeclareMapper(DMD);
2451  return;
2452  }
2453  }
2454 
2455  // Ignore declarations, they will be emitted on their first use.
2456  if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
2457  // Forward declarations are emitted lazily on first use.
2458  if (!FD->doesThisDeclarationHaveABody()) {
2460  return;
2461 
2462  StringRef MangledName = getMangledName(GD);
2463 
2464  // Compute the function info and LLVM type.
2466  llvm::Type *Ty = getTypes().GetFunctionType(FI);
2467 
2468  GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
2469  /*DontDefer=*/false);
2470  return;
2471  }
2472  } else {
2473  const auto *VD = cast<VarDecl>(Global);
2474  assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
2475  if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
2476  !Context.isMSStaticDataMemberInlineDefinition(VD)) {
2477  if (LangOpts.OpenMP) {
2478  // Emit declaration of the must-be-emitted declare target variable.
2480  OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
2481  bool UnifiedMemoryEnabled =
2482  getOpenMPRuntime().hasRequiresUnifiedSharedMemory();
2483  if (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2484  !UnifiedMemoryEnabled) {
2485  (void)GetAddrOfGlobalVar(VD);
2486  } else {
2487  assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2488  (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2489  UnifiedMemoryEnabled)) &&
2490  "Link clause or to clause with unified memory expected.");
2491  (void)getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2492  }
2493 
2494  return;
2495  }
2496  }
2497  // If this declaration may have caused an inline variable definition to
2498  // change linkage, make sure that it's emitted.
2499  if (Context.getInlineVariableDefinitionKind(VD) ==
2501  GetAddrOfGlobalVar(VD);
2502  return;
2503  }
2504  }
2505 
2506  // Defer code generation to first use when possible, e.g. if this is an inline
2507  // function. If the global must always be emitted, do it eagerly if possible
2508  // to benefit from cache locality.
2509  if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
2510  // Emit the definition if it can't be deferred.
2511  EmitGlobalDefinition(GD);
2512  return;
2513  }
2514 
2515  // If we're deferring emission of a C++ variable with an
2516  // initializer, remember the order in which it appeared in the file.
2517  if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
2518  cast<VarDecl>(Global)->hasInit()) {
2519  DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
2520  CXXGlobalInits.push_back(nullptr);
2521  }
2522 
2523  StringRef MangledName = getMangledName(GD);
2524  if (GetGlobalValue(MangledName) != nullptr) {
2525  // The value has already been used and should therefore be emitted.
2526  addDeferredDeclToEmit(GD);
2527  } else if (MustBeEmitted(Global)) {
2528  // The value must be emitted, but cannot be emitted eagerly.
2529  assert(!MayBeEmittedEagerly(Global));
2530  addDeferredDeclToEmit(GD);
2531  } else {
2532  // Otherwise, remember that we saw a deferred decl with this name. The
2533  // first use of the mangled name will cause it to move into
2534  // DeferredDeclsToEmit.
2535  DeferredDecls[MangledName] = GD;
2536  }
2537 }
2538 
2539 // Check if T is a class type with a destructor that's not dllimport.
2541  if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
2542  if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
2543  if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
2544  return true;
2545 
2546  return false;
2547 }
2548 
2549 namespace {
2550  struct FunctionIsDirectlyRecursive
2551  : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> {
2552  const StringRef Name;
2553  const Builtin::Context &BI;
2554  FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C)
2555  : Name(N), BI(C) {}
2556 
2557  bool VisitCallExpr(const CallExpr *E) {
2558  const FunctionDecl *FD = E->getDirectCallee();
2559  if (!FD)
2560  return false;
2561  AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
2562  if (Attr && Name == Attr->getLabel())
2563  return true;
2564  unsigned BuiltinID = FD->getBuiltinID();
2565  if (!BuiltinID || !BI.isLibFunction(BuiltinID))
2566  return false;
2567  StringRef BuiltinName = BI.getName(BuiltinID);
2568  if (BuiltinName.startswith("__builtin_") &&
2569  Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
2570  return true;
2571  }
2572  return false;
2573  }
2574 
2575  bool VisitStmt(const Stmt *S) {
2576  for (const Stmt *Child : S->children())
2577  if (Child && this->Visit(Child))
2578  return true;
2579  return false;
2580  }
2581  };
2582 
2583  // Make sure we're not referencing non-imported vars or functions.
2584  struct DLLImportFunctionVisitor
2585  : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
2586  bool SafeToInline = true;
2587 
2588  bool shouldVisitImplicitCode() const { return true; }
2589 
2590  bool VisitVarDecl(VarDecl *VD) {
2591  if (VD->getTLSKind()) {
2592  // A thread-local variable cannot be imported.
2593  SafeToInline = false;
2594  return SafeToInline;
2595  }
2596 
2597  // A variable definition might imply a destructor call.
2598  if (VD->isThisDeclarationADefinition())
2599  SafeToInline = !HasNonDllImportDtor(VD->getType());
2600 
2601  return SafeToInline;
2602  }
2603 
2604  bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
2605  if (const auto *D = E->getTemporary()->getDestructor())
2606  SafeToInline = D->hasAttr<DLLImportAttr>();
2607  return SafeToInline;
2608  }
2609 
2610  bool VisitDeclRefExpr(DeclRefExpr *E) {
2611  ValueDecl *VD = E->getDecl();
2612  if (isa<FunctionDecl>(VD))
2613  SafeToInline = VD->hasAttr<DLLImportAttr>();
2614  else if (VarDecl *V = dyn_cast<VarDecl>(VD))
2615  SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
2616  return SafeToInline;
2617  }
2618 
2619  bool VisitCXXConstructExpr(CXXConstructExpr *E) {
2620  SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
2621  return SafeToInline;
2622  }
2623 
2624  bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
2625  CXXMethodDecl *M = E->getMethodDecl();
2626  if (!M) {
2627  // Call through a pointer to member function. This is safe to inline.
2628  SafeToInline = true;
2629  } else {
2630  SafeToInline = M->hasAttr<DLLImportAttr>();
2631  }
2632  return SafeToInline;
2633  }
2634 
2635  bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
2636  SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
2637  return SafeToInline;
2638  }
2639 
2640  bool VisitCXXNewExpr(CXXNewExpr *E) {
2641  SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
2642  return SafeToInline;
2643  }
2644  };
2645 }
2646 
2647 // isTriviallyRecursive - Check if this function calls another
2648 // decl that, because of the asm attribute or the other decl being a builtin,
2649 // ends up pointing to itself.
2650 bool
2651 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
2652  StringRef Name;
2653  if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
2654  // asm labels are a special kind of mangling we have to support.
2655  AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
2656  if (!Attr)
2657  return false;
2658  Name = Attr->getLabel();
2659  } else {
2660  Name = FD->getName();
2661  }
2662 
2663  FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
2664  const Stmt *Body = FD->getBody();
2665  return Body ? Walker.Visit(Body) : false;
2666 }
2667 
2668 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
2669  if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
2670  return true;
2671  const auto *F = cast<FunctionDecl>(GD.getDecl());
2672  if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
2673  return false;
2674 
2675  if (F->hasAttr<DLLImportAttr>()) {
2676  // Check whether it would be safe to inline this dllimport function.
2677  DLLImportFunctionVisitor Visitor;
2678  Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
2679  if (!Visitor.SafeToInline)
2680  return false;
2681 
2682  if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
2683  // Implicit destructor invocations aren't captured in the AST, so the
2684  // check above can't see them. Check for them manually here.
2685  for (const Decl *Member : Dtor->getParent()->decls())
2686  if (isa<FieldDecl>(Member))
2687  if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
2688  return false;
2689  for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
2690  if (HasNonDllImportDtor(B.getType()))
2691  return false;
2692  }
2693  }
2694 
2695  // PR9614. Avoid cases where the source code is lying to us. An available
2696  // externally function should have an equivalent function somewhere else,
2697  // but a function that calls itself is clearly not equivalent to the real
2698  // implementation.
2699  // This happens in glibc's btowc and in some configure checks.
2700  return !isTriviallyRecursive(F);
2701 }
2702 
2703 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
2704  return CodeGenOpts.OptimizationLevel > 0;
2705 }
2706 
2707 void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
2708  llvm::GlobalValue *GV) {
2709  const auto *FD = cast<FunctionDecl>(GD.getDecl());
2710 
2711  if (FD->isCPUSpecificMultiVersion()) {
2712  auto *Spec = FD->getAttr<CPUSpecificAttr>();
2713  for (unsigned I = 0; I < Spec->cpus_size(); ++I)
2714  EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
2715  // Requires multiple emits.
2716  } else
2717  EmitGlobalFunctionDefinition(GD, GV);
2718 }
2719 
2720 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
2721  const auto *D = cast<ValueDecl>(GD.getDecl());
2722 
2723  PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
2724  Context.getSourceManager(),
2725  "Generating code for declaration");
2726 
2727  if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
2728  // At -O0, don't generate IR for functions with available_externally
2729  // linkage.
2730  if (!shouldEmitFunction(GD))
2731  return;
2732 
2733  llvm::TimeTraceScope TimeScope("CodeGen Function", [&]() {
2734  std::string Name;
2735  llvm::raw_string_ostream OS(Name);
2736  FD->getNameForDiagnostic(OS, getContext().getPrintingPolicy(),
2737  /*Qualified=*/true);
2738  return Name;
2739  });
2740 
2741  if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
2742  // Make sure to emit the definition(s) before we emit the thunks.
2743  // This is necessary for the generation of certain thunks.
2744  if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
2745  ABI->emitCXXStructor(GD);
2746  else if (FD->isMultiVersion())
2747  EmitMultiVersionFunctionDefinition(GD, GV);
2748  else
2749  EmitGlobalFunctionDefinition(GD, GV);
2750 
2751  if (Method->isVirtual())
2752  getVTables().EmitThunks(GD);
2753 
2754  return;
2755  }
2756 
2757  if (FD->isMultiVersion())
2758  return EmitMultiVersionFunctionDefinition(GD, GV);
2759  return EmitGlobalFunctionDefinition(GD, GV);
2760  }
2761 
2762  if (const auto *VD = dyn_cast<VarDecl>(D))
2763  return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
2764 
2765  llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
2766 }
2767 
2768 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
2769  llvm::Function *NewFn);
2770 
2771 static unsigned
2774  unsigned Priority = 0;
2775  for (StringRef Feat : RO.Conditions.Features)
2776  Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
2777 
2778  if (!RO.Conditions.Architecture.empty())
2779  Priority = std::max(
2781  return Priority;
2782 }
2783 
2784 void CodeGenModule::emitMultiVersionFunctions() {
2785  for (GlobalDecl GD : MultiVersionFuncs) {
2787  const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2789  FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
2790  GlobalDecl CurGD{
2791  (CurFD->isDefined() ? CurFD->getDefinition() : CurFD)};
2792  StringRef MangledName = getMangledName(CurGD);
2793  llvm::Constant *Func = GetGlobalValue(MangledName);
2794  if (!Func) {
2795  if (CurFD->isDefined()) {
2796  EmitGlobalFunctionDefinition(CurGD, nullptr);
2797  Func = GetGlobalValue(MangledName);
2798  } else {
2799  const CGFunctionInfo &FI =
2801  llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
2802  Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
2803  /*DontDefer=*/false, ForDefinition);
2804  }
2805  assert(Func && "This should have just been created");
2806  }
2807 
2808  const auto *TA = CurFD->getAttr<TargetAttr>();
2810  TA->getAddedFeatures(Feats);
2811 
2812  Options.emplace_back(cast<llvm::Function>(Func),
2813  TA->getArchitecture(), Feats);
2814  });
2815 
2816  llvm::Function *ResolverFunc;
2817  const TargetInfo &TI = getTarget();
2818 
2819  if (TI.supportsIFunc() || FD->isTargetMultiVersion())
2820  ResolverFunc = cast<llvm::Function>(
2821  GetGlobalValue((getMangledName(GD) + ".resolver").str()));
2822  else
2823  ResolverFunc = cast<llvm::Function>(GetGlobalValue(getMangledName(GD)));
2824 
2825  if (supportsCOMDAT())
2826  ResolverFunc->setComdat(
2827  getModule().getOrInsertComdat(ResolverFunc->getName()));
2828 
2829  llvm::stable_sort(
2830  Options, [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
2832  return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
2833  });
2834  CodeGenFunction CGF(*this);
2835  CGF.EmitMultiVersionResolver(ResolverFunc, Options);
2836  }
2837 }
2838 
2839 void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
2840  const auto *FD = cast<FunctionDecl>(GD.getDecl());
2841  assert(FD && "Not a FunctionDecl?");
2842  const auto *DD = FD->getAttr<CPUDispatchAttr>();
2843  assert(DD && "Not a cpu_dispatch Function?");
2844  llvm::Type *DeclTy = getTypes().ConvertType(FD->getType());
2845 
2846  if (const auto *CXXFD = dyn_cast<CXXMethodDecl>(FD)) {
2847  const CGFunctionInfo &FInfo = getTypes().arrangeCXXMethodDeclaration(CXXFD);
2848  DeclTy = getTypes().GetFunctionType(FInfo);
2849  }
2850 
2851  StringRef ResolverName = getMangledName(GD);
2852 
2853  llvm::Type *ResolverType;
2854  GlobalDecl ResolverGD;
2855  if (getTarget().supportsIFunc())
2856  ResolverType = llvm::FunctionType::get(
2857  llvm::PointerType::get(DeclTy,
2858  Context.getTargetAddressSpace(FD->getType())),
2859  false);
2860  else {
2861  ResolverType = DeclTy;
2862  ResolverGD = GD;
2863  }
2864 
2865  auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
2866  ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
2867 
2869  const TargetInfo &Target = getTarget();
2870  unsigned Index = 0;
2871  for (const IdentifierInfo *II : DD->cpus()) {
2872  // Get the name of the target function so we can look it up/create it.
2873  std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
2874  getCPUSpecificMangling(*this, II->getName());
2875 
2876  llvm::Constant *Func = GetGlobalValue(MangledName);
2877 
2878  if (!Func) {
2879  GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
2880  if (ExistingDecl.getDecl() &&
2881  ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
2882  EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
2883  Func = GetGlobalValue(MangledName);
2884  } else {
2885  if (!ExistingDecl.getDecl())
2886  ExistingDecl = GD.getWithMultiVersionIndex(Index);
2887 
2888  Func = GetOrCreateLLVMFunction(
2889  MangledName, DeclTy, ExistingDecl,
2890  /*ForVTable=*/false, /*DontDefer=*/true,
2891  /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
2892  }
2893  }
2894 
2896  Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
2897  llvm::transform(Features, Features.begin(),
2898  [](StringRef Str) { return Str.substr(1); });
2899  Features.erase(std::remove_if(
2900  Features.begin(), Features.end(), [&Target](StringRef Feat) {
2901  return !Target.validateCpuSupports(Feat);
2902  }), Features.end());
2903  Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
2904  ++Index;
2905  }
2906 
2907  llvm::sort(
2908  Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
2912  });
2913 
2914  // If the list contains multiple 'default' versions, such as when it contains
2915  // 'pentium' and 'generic', don't emit the call to the generic one (since we
2916  // always run on at least a 'pentium'). We do this by deleting the 'least
2917  // advanced' (read, lowest mangling letter).
2918  while (Options.size() > 1 &&
2920  (Options.end() - 2)->Conditions.Features) == 0) {
2921  StringRef LHSName = (Options.end() - 2)->Function->getName();
2922  StringRef RHSName = (Options.end() - 1)->Function->getName();
2923  if (LHSName.compare(RHSName) < 0)
2924  Options.erase(Options.end() - 2);
2925  else
2926  Options.erase(Options.end() - 1);
2927  }
2928 
2929  CodeGenFunction CGF(*this);
2930  CGF.EmitMultiVersionResolver(ResolverFunc, Options);
2931 }
2932 
2933 /// If a dispatcher for the specified mangled name is not in the module, create
2934 /// and return an llvm Function with the specified type.
2935 llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(
2936  GlobalDecl GD, llvm::Type *DeclTy, const FunctionDecl *FD) {
2937  std::string MangledName =
2938  getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
2939 
2940  // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
2941  // a separate resolver).
2942  std::string ResolverName = MangledName;
2943  if (getTarget().supportsIFunc())
2944  ResolverName += ".ifunc";
2945  else if (FD->isTargetMultiVersion())
2946  ResolverName += ".resolver";
2947 
2948  // If this already exists, just return that one.
2949  if (llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName))
2950  return ResolverGV;
2951 
2952  // Since this is the first time we've created this IFunc, make sure
2953  // that we put this multiversioned function into the list to be
2954  // replaced later if necessary (target multiversioning only).
2956  MultiVersionFuncs.push_back(GD);
2957 
2958  if (getTarget().supportsIFunc()) {
2959  llvm::Type *ResolverType = llvm::FunctionType::get(
2960  llvm::PointerType::get(
2961  DeclTy, getContext().getTargetAddressSpace(FD->getType())),
2962  false);
2963  llvm::Constant *Resolver = GetOrCreateLLVMFunction(
2964  MangledName + ".resolver", ResolverType, GlobalDecl{},
2965  /*ForVTable=*/false);
2966  llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
2967  DeclTy, 0, llvm::Function::ExternalLinkage, "", Resolver, &getModule());
2968  GIF->setName(ResolverName);
2969  SetCommonAttributes(FD, GIF);
2970 
2971  return GIF;
2972  }
2973 
2974  llvm::Constant *Resolver = GetOrCreateLLVMFunction(
2975  ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
2976  assert(isa<llvm::GlobalValue>(Resolver) &&
2977  "Resolver should be created for the first time");
2978  SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
2979  return Resolver;
2980 }
2981 
2982 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
2983 /// module, create and return an llvm Function with the specified type. If there
2984 /// is something in the module with the specified name, return it potentially
2985 /// bitcasted to the right type.
2986 ///
2987 /// If D is non-null, it specifies a decl that correspond to this. This is used
2988 /// to set the attributes on the function when it is first created.
2989 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
2990  StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
2991  bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
2992  ForDefinition_t IsForDefinition) {
2993  const Decl *D = GD.getDecl();
2994 
2995  // Any attempts to use a MultiVersion function should result in retrieving
2996  // the iFunc instead. Name Mangling will handle the rest of the changes.
2997  if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
2998  // For the device mark the function as one that should be emitted.
2999  if (getLangOpts().OpenMPIsDevice && OpenMPRuntime &&
3000  !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
3001  !DontDefer && !IsForDefinition) {
3002  if (const FunctionDecl *FDDef = FD->getDefinition()) {
3003  GlobalDecl GDDef;
3004  if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
3005  GDDef = GlobalDecl(CD, GD.getCtorType());
3006  else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
3007  GDDef = GlobalDecl(DD, GD.getDtorType());
3008  else
3009  GDDef = GlobalDecl(FDDef);
3010  EmitGlobal(GDDef);
3011  }
3012  }
3013 
3014  if (FD->isMultiVersion()) {
3015  const auto *TA = FD->getAttr<TargetAttr>();
3016  if (TA && TA->isDefaultVersion())
3017  UpdateMultiVersionNames(GD, FD);
3018  if (!IsForDefinition)
3019  return GetOrCreateMultiVersionResolver(GD, Ty, FD);
3020  }
3021  }
3022 
3023  // Lookup the entry, lazily creating it if necessary.
3024  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3025  if (Entry) {
3026  if (WeakRefReferences.erase(Entry)) {
3027  const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
3028  if (FD && !FD->hasAttr<WeakAttr>())
3029  Entry->setLinkage(llvm::Function::ExternalLinkage);
3030  }
3031 
3032  // Handle dropped DLL attributes.
3033  if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>()) {
3034  Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3035  setDSOLocal(Entry);
3036  }
3037 
3038  // If there are two attempts to define the same mangled name, issue an
3039  // error.
3040  if (IsForDefinition && !Entry->isDeclaration()) {
3041  GlobalDecl OtherGD;
3042  // Check that GD is not yet in DiagnosedConflictingDefinitions is required
3043  // to make sure that we issue an error only once.
3044  if (lookupRepresentativeDecl(MangledName, OtherGD) &&
3045  (GD.getCanonicalDecl().getDecl() !=
3046  OtherGD.getCanonicalDecl().getDecl()) &&
3047  DiagnosedConflictingDefinitions.insert(GD).second) {
3048  getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3049  << MangledName;
3050  getDiags().Report(OtherGD.getDecl()->getLocation(),
3051  diag::note_previous_definition);
3052  }
3053  }
3054 
3055  if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
3056  (Entry->getType()->getElementType() == Ty)) {
3057  return Entry;
3058  }
3059 
3060  // Make sure the result is of the correct type.
3061  // (If function is requested for a definition, we always need to create a new
3062  // function, not just return a bitcast.)
3063  if (!IsForDefinition)
3064  return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
3065  }
3066 
3067  // This function doesn't have a complete type (for example, the return
3068  // type is an incomplete struct). Use a fake type instead, and make
3069  // sure not to try to set attributes.
3070  bool IsIncompleteFunction = false;
3071 
3072  llvm::FunctionType *FTy;
3073  if (isa<llvm::FunctionType>(Ty)) {
3074  FTy = cast<llvm::FunctionType>(Ty);
3075  } else {
3076  FTy = llvm::FunctionType::get(VoidTy, false);
3077  IsIncompleteFunction = true;
3078  }
3079 
3080  llvm::Function *F =
3082  Entry ? StringRef() : MangledName, &getModule());
3083 
3084  // If we already created a function with the same mangled name (but different
3085  // type) before, take its name and add it to the list of functions to be
3086  // replaced with F at the end of CodeGen.
3087  //
3088  // This happens if there is a prototype for a function (e.g. "int f()") and
3089  // then a definition of a different type (e.g. "int f(int x)").
3090  if (Entry) {
3091  F->takeName(Entry);
3092 
3093  // This might be an implementation of a function without a prototype, in
3094  // which case, try to do special replacement of calls which match the new
3095  // prototype. The really key thing here is that we also potentially drop
3096  // arguments from the call site so as to make a direct call, which makes the
3097  // inliner happier and suppresses a number of optimizer warnings (!) about
3098  // dropping arguments.
3099  if (!Entry->use_empty()) {
3101  Entry->removeDeadConstantUsers();
3102  }
3103 
3104  llvm::Constant *BC = llvm::ConstantExpr::getBitCast(
3105  F, Entry->getType()->getElementType()->getPointerTo());
3106  addGlobalValReplacement(Entry, BC);
3107  }
3108 
3109  assert(F->getName() == MangledName && "name was uniqued!");
3110  if (D)
3111  SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
3112  if (ExtraAttrs.hasAttributes(llvm::AttributeList::FunctionIndex)) {
3113  llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex);
3114  F->addAttributes(llvm::AttributeList::FunctionIndex, B);
3115  }
3116 
3117  if (!DontDefer) {
3118  // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
3119  // each other bottoming out with the base dtor. Therefore we emit non-base
3120  // dtors on usage, even if there is no dtor definition in the TU.
3121  if (D && isa<CXXDestructorDecl>(D) &&
3122  getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
3123  GD.getDtorType()))
3124  addDeferredDeclToEmit(GD);
3125 
3126  // This is the first use or definition of a mangled name. If there is a
3127  // deferred decl with this name, remember that we need to emit it at the end
3128  // of the file.
3129  auto DDI = DeferredDecls.find(MangledName);
3130  if (DDI != DeferredDecls.end()) {
3131  // Move the potentially referenced deferred decl to the
3132  // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
3133  // don't need it anymore).
3134  addDeferredDeclToEmit(DDI->second);
3135  DeferredDecls.erase(DDI);
3136 
3137  // Otherwise, there are cases we have to worry about where we're
3138  // using a declaration for which we must emit a definition but where
3139  // we might not find a top-level definition:
3140  // - member functions defined inline in their classes
3141  // - friend functions defined inline in some class
3142  // - special member functions with implicit definitions
3143  // If we ever change our AST traversal to walk into class methods,
3144  // this will be unnecessary.
3145  //
3146  // We also don't emit a definition for a function if it's going to be an
3147  // entry in a vtable, unless it's already marked as used.
3148  } else if (getLangOpts().CPlusPlus && D) {
3149  // Look for a declaration that's lexically in a record.
3150  for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
3151  FD = FD->getPreviousDecl()) {
3152  if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
3153  if (FD->doesThisDeclarationHaveABody()) {
3154  addDeferredDeclToEmit(GD.getWithDecl(FD));
3155  break;
3156  }
3157  }
3158  }
3159  }
3160  }
3161 
3162  // Make sure the result is of the requested type.
3163  if (!IsIncompleteFunction) {
3164  assert(F->getType()->getElementType() == Ty);
3165  return F;
3166  }
3167 
3168  llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
3169  return llvm::ConstantExpr::getBitCast(F, PTy);
3170 }
3171 
3172 /// GetAddrOfFunction - Return the address of the given function. If Ty is
3173 /// non-null, then this function will use the specified type if it has to
3174 /// create it (this occurs when we see a definition of the function).
3176  llvm::Type *Ty,
3177  bool ForVTable,
3178  bool DontDefer,
3179  ForDefinition_t IsForDefinition) {
3180  // If there was no specific requested type, just convert it now.
3181  if (!Ty) {
3182  const auto *FD = cast<FunctionDecl>(GD.getDecl());
3183  Ty = getTypes().ConvertType(FD->getType());
3184  }
3185 
3186  // Devirtualized destructor calls may come through here instead of via
3187  // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
3188  // of the complete destructor when necessary.
3189  if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
3190  if (getTarget().getCXXABI().isMicrosoft() &&
3191  GD.getDtorType() == Dtor_Complete &&
3192  DD->getParent()->getNumVBases() == 0)
3193  GD = GlobalDecl(DD, Dtor_Base);
3194  }
3195 
3196  StringRef MangledName = getMangledName(GD);
3197  return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
3198  /*IsThunk=*/false, llvm::AttributeList(),
3199  IsForDefinition);
3200 }
3201 
3202 static const FunctionDecl *
3203 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
3206 
3207  IdentifierInfo &CII = C.Idents.get(Name);
3208  for (const auto &Result : DC->lookup(&CII))
3209  if (const auto FD = dyn_cast<FunctionDecl>(Result))
3210  return FD;
3211 
3212  if (!C.getLangOpts().CPlusPlus)
3213  return nullptr;
3214 
3215  // Demangle the premangled name from getTerminateFn()
3216  IdentifierInfo &CXXII =
3217  (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
3218  ? C.Idents.get("terminate")
3219  : C.Idents.get(Name);
3220 
3221  for (const auto &N : {"__cxxabiv1", "std"}) {
3222  IdentifierInfo &NS = C.Idents.get(N);
3223  for (const auto &Result : DC->lookup(&NS)) {
3224  NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
3225  if (auto LSD = dyn_cast<LinkageSpecDecl>(Result))
3226  for (const auto &Result : LSD->lookup(&NS))
3227  if ((ND = dyn_cast<NamespaceDecl>(Result)))
3228  break;
3229 
3230  if (ND)
3231  for (const auto &Result : ND->lookup(&CXXII))
3232  if (const auto *FD = dyn_cast<FunctionDecl>(Result))
3233  return FD;
3234  }
3235  }
3236 
3237  return nullptr;
3238 }
3239 
3240 /// CreateRuntimeFunction - Create a new runtime function with the specified
3241 /// type and name.
3242 llvm::FunctionCallee
3243 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
3244  llvm::AttributeList ExtraAttrs,
3245  bool Local) {
3246  llvm::Constant *C =
3247  GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
3248  /*DontDefer=*/false, /*IsThunk=*/false,
3249  ExtraAttrs);
3250 
3251  if (auto *F = dyn_cast<llvm::Function>(C)) {
3252  if (F->empty()) {
3253  F->setCallingConv(getRuntimeCC());
3254 
3255  // In Windows Itanium environments, try to mark runtime functions
3256  // dllimport. For Mingw and MSVC, don't. We don't really know if the user
3257  // will link their standard library statically or dynamically. Marking
3258  // functions imported when they are not imported can cause linker errors
3259  // and warnings.
3260  if (!Local && getTriple().isWindowsItaniumEnvironment() &&
3261  !getCodeGenOpts().LTOVisibilityPublicStd) {
3262  const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
3263  if (!FD || FD->hasAttr<DLLImportAttr>()) {
3264  F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
3265  F->setLinkage(llvm::GlobalValue::ExternalLinkage);
3266  }
3267  }
3268  setDSOLocal(F);
3269  }
3270  }
3271 
3272  return {FTy, C};
3273 }
3274 
3275 /// isTypeConstant - Determine whether an object of this type can be emitted
3276 /// as a constant.
3277 ///
3278 /// If ExcludeCtor is true, the duration when the object's constructor runs
3279 /// will not be considered. The caller will need to verify that the object is
3280 /// not written to during its construction.
3281 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
3282  if (!Ty.isConstant(Context) && !Ty->isReferenceType())
3283  return false;
3284 
3285  if (Context.getLangOpts().CPlusPlus) {
3286  if (const CXXRecordDecl *Record
3287  = Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
3288  return ExcludeCtor && !Record->hasMutableFields() &&
3289  Record->hasTrivialDestructor();
3290  }
3291 
3292  return true;
3293 }
3294 
3295 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
3296 /// create and return an llvm GlobalVariable with the specified type. If there
3297 /// is something in the module with the specified name, return it potentially
3298 /// bitcasted to the right type.
3299 ///
3300 /// If D is non-null, it specifies a decl that correspond to this. This is used
3301 /// to set the attributes on the global when it is first created.
3302 ///
3303 /// If IsForDefinition is true, it is guaranteed that an actual global with
3304 /// type Ty will be returned, not conversion of a variable with the same
3305 /// mangled name but some other type.
3306 llvm::Constant *
3307 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
3308  llvm::PointerType *Ty,
3309  const VarDecl *D,
3310  ForDefinition_t IsForDefinition) {
3311  // Lookup the entry, lazily creating it if necessary.
3312  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3313  if (Entry) {
3314  if (WeakRefReferences.erase(Entry)) {
3315  if (D && !D->hasAttr<WeakAttr>())
3316  Entry->setLinkage(llvm::Function::ExternalLinkage);
3317  }
3318 
3319  // Handle dropped DLL attributes.
3320  if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
3321  Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3322 
3323  if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
3324  getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
3325 
3326  if (Entry->getType() == Ty)
3327  return Entry;
3328 
3329  // If there are two attempts to define the same mangled name, issue an
3330  // error.
3331  if (IsForDefinition && !Entry->isDeclaration()) {
3332  GlobalDecl OtherGD;
3333  const VarDecl *OtherD;
3334 
3335  // Check that D is not yet in DiagnosedConflictingDefinitions is required
3336  // to make sure that we issue an error only once.
3337  if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
3338  (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
3339  (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
3340  OtherD->hasInit() &&
3341  DiagnosedConflictingDefinitions.insert(D).second) {
3342  getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3343  << MangledName;
3344  getDiags().Report(OtherGD.getDecl()->getLocation(),
3345  diag::note_previous_definition);
3346  }
3347  }
3348 
3349  // Make sure the result is of the correct type.
3350  if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace())
3351  return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty);
3352 
3353  // (If global is requested for a definition, we always need to create a new
3354  // global, not just return a bitcast.)
3355  if (!IsForDefinition)
3356  return llvm::ConstantExpr::getBitCast(Entry, Ty);
3357  }
3358 
3359  auto AddrSpace = GetGlobalVarAddressSpace(D);
3360  auto TargetAddrSpace = getContext().getTargetAddressSpace(AddrSpace);
3361 
3362  auto *GV = new llvm::GlobalVariable(
3363  getModule(), Ty->getElementType(), false,
3364  llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr,
3365  llvm::GlobalVariable::NotThreadLocal, TargetAddrSpace);
3366 
3367  // If we already created a global with the same mangled name (but different
3368  // type) before, take its name and remove it from its parent.
3369  if (Entry) {
3370  GV->takeName(Entry);
3371 
3372  if (!Entry->use_empty()) {
3373  llvm::Constant *NewPtrForOldDecl =
3374  llvm::ConstantExpr::getBitCast(GV, Entry->getType());
3375  Entry->replaceAllUsesWith(NewPtrForOldDecl);
3376  }
3377 
3378  Entry->eraseFromParent();
3379  }
3380 
3381  // This is the first use or definition of a mangled name. If there is a
3382  // deferred decl with this name, remember that we need to emit it at the end
3383  // of the file.
3384  auto DDI = DeferredDecls.find(MangledName);
3385  if (DDI != DeferredDecls.end()) {
3386  // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
3387  // list, and remove it from DeferredDecls (since we don't need it anymore).
3388  addDeferredDeclToEmit(DDI->second);
3389  DeferredDecls.erase(DDI);
3390  }
3391 
3392  // Handle things which are present even on external declarations.
3393  if (D) {
3394  if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
3395  getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
3396 
3397  // FIXME: This code is overly simple and should be merged with other global
3398  // handling.
3399  GV->setConstant(isTypeConstant(D->getType(), false));
3400 
3401  GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
3402 
3403  setLinkageForGV(GV, D);
3404 
3405  if (D->getTLSKind()) {
3406  if (D->getTLSKind() == VarDecl::TLS_Dynamic)
3407  CXXThreadLocals.push_back(D);
3408  setTLSMode(GV, *D);
3409  }
3410 
3411  setGVProperties(GV, D);
3412 
3413  // If required by the ABI, treat declarations of static data members with
3414  // inline initializers as definitions.
3415  if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
3416  EmitGlobalVarDefinition(D);
3417  }
3418 
3419  // Emit section information for extern variables.
3420  if (D->hasExternalStorage()) {
3421  if (const SectionAttr *SA = D->getAttr<SectionAttr>())
3422  GV->setSection(SA->getName());
3423  }
3424 
3425  // Handle XCore specific ABI requirements.
3426  if (getTriple().getArch() == llvm::Triple::xcore &&
3428  D->getType().isConstant(Context) &&
3430  GV->setSection(".cp.rodata");
3431 
3432  // Check if we a have a const declaration with an initializer, we may be
3433  // able to emit it as available_externally to expose it's value to the
3434  // optimizer.
3435  if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
3436  D->getType().isConstQualified() && !GV->hasInitializer() &&
3437  !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
3438  const auto *Record =
3439  Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
3440  bool HasMutableFields = Record && Record->hasMutableFields();
3441  if (!HasMutableFields) {
3442  const VarDecl *InitDecl;
3443  const Expr *InitExpr = D->getAnyInitializer(InitDecl);
3444  if (InitExpr) {
3445  ConstantEmitter emitter(*this);
3446  llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
3447  if (Init) {
3448  auto *InitType = Init->getType();
3449  if (GV->getType()->getElementType() != InitType) {
3450  // The type of the initializer does not match the definition.
3451  // This happens when an initializer has a different type from
3452  // the type of the global (because of padding at the end of a
3453  // structure for instance).
3454  GV->setName(StringRef());
3455  // Make a new global with the correct type, this is now guaranteed
3456  // to work.
3457  auto *NewGV = cast<llvm::GlobalVariable>(
3458  GetAddrOfGlobalVar(D, InitType, IsForDefinition));
3459 
3460  // Erase the old global, since it is no longer used.
3461  GV->eraseFromParent();
3462  GV = NewGV;
3463  } else {
3464  GV->setInitializer(Init);
3465  GV->setConstant(true);
3466  GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
3467  }
3468  emitter.finalize(GV);
3469  }
3470  }
3471  }
3472  }
3473  }
3474 
3475  LangAS ExpectedAS =
3476  D ? D->getType().getAddressSpace()
3477  : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
3478  assert(getContext().getTargetAddressSpace(ExpectedAS) ==
3479  Ty->getPointerAddressSpace());
3480  if (AddrSpace != ExpectedAS)
3481  return getTargetCodeGenInfo().performAddrSpaceCast(*this, GV, AddrSpace,
3482  ExpectedAS, Ty);
3483 
3484  if (GV->isDeclaration())
3485  getTargetCodeGenInfo().setTargetAttributes(D, GV, *this);
3486 
3487  return GV;
3488 }
3489 
3490 llvm::Constant *
3492  ForDefinition_t IsForDefinition) {
3493  const Decl *D = GD.getDecl();
3494  if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
3495  return getAddrOfCXXStructor(GD, /*FnInfo=*/nullptr, /*FnType=*/nullptr,
3496  /*DontDefer=*/false, IsForDefinition);
3497  else if (isa<CXXMethodDecl>(D)) {
3498  auto FInfo = &getTypes().arrangeCXXMethodDeclaration(
3499  cast<CXXMethodDecl>(D));
3500  auto Ty = getTypes().GetFunctionType(*FInfo);
3501  return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
3502  IsForDefinition);
3503  } else if (isa<FunctionDecl>(D)) {
3505  llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
3506  return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
3507  IsForDefinition);
3508  } else
3509  return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr,
3510  IsForDefinition);
3511 }
3512 
3514  StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
3515  unsigned Alignment) {
3516  llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
3517  llvm::GlobalVariable *OldGV = nullptr;
3518 
3519  if (GV) {
3520  // Check if the variable has the right type.
3521  if (GV->getType()->getElementType() == Ty)
3522  return GV;
3523 
3524  // Because C++ name mangling, the only way we can end up with an already
3525  // existing global with the same name is if it has been declared extern "C".
3526  assert(GV->isDeclaration() && "Declaration has wrong type!");
3527  OldGV = GV;
3528  }
3529 
3530  // Create a new variable.
3531  GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
3532  Linkage, nullptr, Name);
3533 
3534  if (OldGV) {
3535  // Replace occurrences of the old variable if needed.
3536  GV->takeName(OldGV);
3537 
3538  if (!OldGV->use_empty()) {
3539  llvm::Constant *NewPtrForOldDecl =
3540  llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
3541  OldGV->replaceAllUsesWith(NewPtrForOldDecl);
3542  }
3543 
3544  OldGV->eraseFromParent();
3545  }
3546 
3547  if (supportsCOMDAT() && GV->isWeakForLinker() &&
3548  !GV->hasAvailableExternallyLinkage())
3549  GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3550 
3551  GV->setAlignment(Alignment);
3552 
3553  return GV;
3554 }
3555 
3556 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
3557 /// given global variable. If Ty is non-null and if the global doesn't exist,
3558 /// then it will be created with the specified type instead of whatever the
3559 /// normal requested type would be. If IsForDefinition is true, it is guaranteed
3560 /// that an actual global with type Ty will be returned, not conversion of a
3561 /// variable with the same mangled name but some other type.
3563  llvm::Type *Ty,
3564  ForDefinition_t IsForDefinition) {
3565  assert(D->hasGlobalStorage() && "Not a global variable");
3566  QualType ASTTy = D->getType();
3567  if (!Ty)
3568  Ty = getTypes().ConvertTypeForMem(ASTTy);
3569 
3570  llvm::PointerType *PTy =
3571  llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
3572 
3573  StringRef MangledName = getMangledName(D);
3574  return GetOrCreateLLVMGlobal(MangledName, PTy, D, IsForDefinition);
3575 }
3576 
3577 /// CreateRuntimeVariable - Create a new runtime global variable with the
3578 /// specified type and name.
3579 llvm::Constant *
3581  StringRef Name) {
3582  auto PtrTy =
3583  getContext().getLangOpts().OpenCL
3584  ? llvm::PointerType::get(
3585  Ty, getContext().getTargetAddressSpace(LangAS::opencl_global))
3586  : llvm::PointerType::getUnqual(Ty);
3587  auto *Ret = GetOrCreateLLVMGlobal(Name, PtrTy, nullptr);
3588  setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
3589  return Ret;
3590 }
3591 
3593  assert(!D->getInit() && "Cannot emit definite definitions here!");
3594 
3595  StringRef MangledName = getMangledName(D);
3596  llvm::GlobalValue *GV = GetGlobalValue(MangledName);
3597 
3598  // We already have a definition, not declaration, with the same mangled name.
3599  // Emitting of declaration is not required (and actually overwrites emitted
3600  // definition).
3601  if (GV && !GV->isDeclaration())
3602  return;
3603 
3604  // If we have not seen a reference to this variable yet, place it into the
3605  // deferred declarations table to be emitted if needed later.
3606  if (!MustBeEmitted(D) && !GV) {
3607  DeferredDecls[MangledName] = D;
3608  return;
3609  }
3610 
3611  // The tentative definition is the only definition.
3612  EmitGlobalVarDefinition(D);
3613 }
3614 
3616  return Context.toCharUnitsFromBits(
3617  getDataLayout().getTypeStoreSizeInBits(Ty));
3618 }
3619 
3621  LangAS AddrSpace = LangAS::Default;
3622  if (LangOpts.OpenCL) {
3623  AddrSpace = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
3624  assert(AddrSpace == LangAS::opencl_global ||
3625  AddrSpace == LangAS::opencl_constant ||
3626  AddrSpace == LangAS::opencl_local ||
3627  AddrSpace >= LangAS::FirstTargetAddressSpace);
3628  return AddrSpace;
3629  }
3630 
3631  if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
3632  if (D && D->hasAttr<CUDAConstantAttr>())
3633  return LangAS::cuda_constant;
3634  else if (D && D->hasAttr<CUDASharedAttr>())
3635  return LangAS::cuda_shared;
3636  else if (D && D->hasAttr<CUDADeviceAttr>())
3637  return LangAS::cuda_device;
3638  else if (D && D->getType().isConstQualified())
3639  return LangAS::cuda_constant;
3640  else
3641  return LangAS::cuda_device;
3642  }
3643 
3644  if (LangOpts.OpenMP) {
3645  LangAS AS;
3646  if (OpenMPRuntime->hasAllocateAttributeForGlobalVar(D, AS))
3647  return AS;
3648  }
3650 }
3651 
3653  // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
3654  if (LangOpts.OpenCL)
3655  return LangAS::opencl_constant;
3656  if (auto AS = getTarget().getConstantAddressSpace())
3657  return AS.getValue();
3658  return LangAS::Default;
3659 }
3660 
3661 // In address space agnostic languages, string literals are in default address
3662 // space in AST. However, certain targets (e.g. amdgcn) request them to be
3663 // emitted in constant address space in LLVM IR. To be consistent with other
3664 // parts of AST, string literal global variables in constant address space
3665 // need to be casted to default address space before being put into address
3666 // map and referenced by other part of CodeGen.
3667 // In OpenCL, string literals are in constant address space in AST, therefore
3668 // they should not be casted to default address space.
3669 static llvm::Constant *
3671  llvm::GlobalVariable *GV) {
3672  llvm::Constant *Cast = GV;
3673  if (!CGM.getLangOpts().OpenCL) {
3674  if (auto AS = CGM.getTarget().getConstantAddressSpace()) {
3675  if (AS != LangAS::Default)
3677  CGM, GV, AS.getValue(), LangAS::Default,
3678  GV->getValueType()->getPointerTo(
3680  }
3681  }
3682  return Cast;
3683 }
3684 
3685 template<typename SomeDecl>
3687  llvm::GlobalValue *GV) {
3688  if (!getLangOpts().CPlusPlus)
3689  return;
3690 
3691  // Must have 'used' attribute, or else inline assembly can't rely on
3692  // the name existing.
3693  if (!D->template hasAttr<UsedAttr>())
3694  return;
3695 
3696  // Must have internal linkage and an ordinary name.
3697  if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage)
3698  return;
3699 
3700  // Must be in an extern "C" context. Entities declared directly within
3701  // a record are not extern "C" even if the record is in such a context.
3702  const SomeDecl *First = D->getFirstDecl();
3703  if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
3704  return;
3705 
3706  // OK, this is an internal linkage entity inside an extern "C" linkage
3707  // specification. Make a note of that so we can give it the "expected"
3708  // mangled name if nothing else is using that name.
3709  std::pair<StaticExternCMap::iterator, bool> R =
3710  StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
3711 
3712  // If we have multiple internal linkage entities with the same name
3713  // in extern "C" regions, none of them gets that name.
3714  if (!R.second)
3715  R.first->second = nullptr;
3716 }
3717 
3718 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
3719  if (!CGM.supportsCOMDAT())
3720  return false;
3721 
3722  // Do not set COMDAT attribute for CUDA/HIP stub functions to prevent
3723  // them being "merged" by the COMDAT Folding linker optimization.
3724  if (D.hasAttr<CUDAGlobalAttr>())
3725  return false;
3726 
3727  if (D.hasAttr<SelectAnyAttr>())
3728  return true;
3729 
3731  if (auto *VD = dyn_cast<VarDecl>(&D))
3732  Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
3733  else
3734  Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
3735 
3736  switch (Linkage) {
3737  case GVA_Internal:
3739  case GVA_StrongExternal:
3740  return false;
3741  case GVA_DiscardableODR:
3742  case GVA_StrongODR:
3743  return true;
3744  }
3745  llvm_unreachable("No such linkage");
3746 }
3747 
3749  llvm::GlobalObject &GO) {
3750  if (!shouldBeInCOMDAT(*this, D))
3751  return;
3752  GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
3753 }
3754 
3755 /// Pass IsTentative as true if you want to create a tentative definition.
3756 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
3757  bool IsTentative) {
3758  // OpenCL global variables of sampler type are translated to function calls,
3759  // therefore no need to be translated.
3760  QualType ASTTy = D->getType();
3761  if (getLangOpts().OpenCL && ASTTy->isSamplerT())
3762  return;
3763 
3764  // If this is OpenMP device, check if it is legal to emit this global
3765  // normally.
3766  if (LangOpts.OpenMPIsDevice && OpenMPRuntime &&
3767  OpenMPRuntime->emitTargetGlobalVariable(D))
3768  return;
3769 
3770  llvm::Constant *Init = nullptr;
3772  bool NeedsGlobalCtor = false;
3773  bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor();
3774 
3775  const VarDecl *InitDecl;
3776  const Expr *InitExpr = D->getAnyInitializer(InitDecl);
3777 
3778  Optional<ConstantEmitter> emitter;
3779 
3780  // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
3781  // as part of their declaration." Sema has already checked for
3782  // error cases, so we just need to set Init to UndefValue.
3783  bool IsCUDASharedVar =
3784  getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
3785  // Shadows of initialized device-side global variables are also left
3786  // undefined.
3787  bool IsCUDAShadowVar =
3788  !getLangOpts().CUDAIsDevice &&
3789  (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
3790  D->hasAttr<CUDASharedAttr>());
3791  // HIP pinned shadow of initialized host-side global variables are also
3792  // left undefined.
3793  bool IsHIPPinnedShadowVar =
3794  getLangOpts().CUDAIsDevice && D->hasAttr<HIPPinnedShadowAttr>();
3795  if (getLangOpts().CUDA &&
3796  (IsCUDASharedVar || IsCUDAShadowVar || IsHIPPinnedShadowVar))
3797  Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
3798  else if (!InitExpr) {
3799  // This is a tentative definition; tentative definitions are
3800  // implicitly initialized with { 0 }.
3801  //
3802  // Note that tentative definitions are only emitted at the end of
3803  // a translation unit, so they should never have incomplete
3804  // type. In addition, EmitTentativeDefinition makes sure that we
3805  // never attempt to emit a tentative definition if a real one
3806  // exists. A use may still exists, however, so we still may need
3807  // to do a RAUW.
3808  assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
3809  Init = EmitNullConstant(D->getType());
3810  } else {
3811  initializedGlobalDecl = GlobalDecl(D);
3812  emitter.emplace(*this);
3813  Init = emitter->tryEmitForInitializer(*InitDecl);
3814 
3815  if (!Init) {
3816  QualType T = InitExpr->getType();
3817  if (D->getType()->isReferenceType())
3818  T = D->getType();
3819 
3820  if (getLangOpts().CPlusPlus) {
3821  Init = EmitNullConstant(T);
3822  NeedsGlobalCtor = true;
3823  } else {
3824  ErrorUnsupported(D, "static initializer");
3825  Init = llvm::UndefValue::get(getTypes().ConvertType(T));
3826  }
3827  } else {
3828  // We don't need an initializer, so remove the entry for the delayed
3829  // initializer position (just in case this entry was delayed) if we
3830  // also don't need to register a destructor.
3831  if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
3832  DelayedCXXInitPosition.erase(D);
3833  }
3834  }
3835 
3836  llvm::Type* InitType = Init->getType();
3837  llvm::Constant *Entry =
3838  GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
3839 
3840  // Strip off a bitcast if we got one back.
3841  if (auto *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
3842  assert(CE->getOpcode() == llvm::Instruction::BitCast ||
3843  CE->getOpcode() == llvm::Instruction::AddrSpaceCast ||
3844  // All zero index gep.
3845  CE->getOpcode() == llvm::Instruction::GetElementPtr);
3846  Entry = CE->getOperand(0);
3847  }
3848 
3849  // Entry is now either a Function or GlobalVariable.
3850  auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
3851 
3852  // We have a definition after a declaration with the wrong type.
3853  // We must make a new GlobalVariable* and update everything that used OldGV
3854  // (a declaration or tentative definition) with the new GlobalVariable*
3855  // (which will be a definition).
3856  //
3857  // This happens if there is a prototype for a global (e.g.
3858  // "extern int x[];") and then a definition of a different type (e.g.
3859  // "int x[10];"). This also happens when an initializer has a different type
3860  // from the type of the global (this happens with unions).
3861  if (!GV || GV->getType()->getElementType() != InitType ||
3862  GV->getType()->getAddressSpace() !=
3864 
3865  // Move the old entry aside so that we'll create a new one.
3866  Entry->setName(StringRef());
3867 
3868  // Make a new global with the correct type, this is now guaranteed to work.
3869  GV = cast<llvm::GlobalVariable>(
3870  GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative)));
3871 
3872  // Replace all uses of the old global with the new global
3873  llvm::Constant *NewPtrForOldDecl =
3874  llvm::ConstantExpr::getBitCast(GV, Entry->getType());
3875  Entry->replaceAllUsesWith(NewPtrForOldDecl);
3876 
3877  // Erase the old global, since it is no longer used.
3878  cast<llvm::GlobalValue>(Entry)->eraseFromParent();
3879  }
3880 
3882 
3883  if (D->hasAttr<AnnotateAttr>())
3884  AddGlobalAnnotations(D, GV);
3885 
3886  // Set the llvm linkage type as appropriate.
3887  llvm::GlobalValue::LinkageTypes Linkage =
3888  getLLVMLinkageVarDefinition(D, GV->isConstant());
3889 
3890  // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
3891  // the device. [...]"
3892  // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
3893  // __device__, declares a variable that: [...]
3894  // Is accessible from all the threads within the grid and from the host
3895  // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
3896  // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
3897  if (GV && LangOpts.CUDA) {
3898  if (LangOpts.CUDAIsDevice) {
3899  if (Linkage != llvm::GlobalValue::InternalLinkage &&
3900  (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()))
3901  GV->setExternallyInitialized(true);
3902  } else {
3903  // Host-side shadows of external declarations of device-side
3904  // global variables become internal definitions. These have to
3905  // be internal in order to prevent name conflicts with global
3906  // host variables with the same name in a different TUs.
3907  if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
3908  D->hasAttr<HIPPinnedShadowAttr>()) {
3910 
3911  // Shadow variables and their properties must be registered
3912  // with CUDA runtime.
3913  unsigned Flags = 0;
3914  if (!D->hasDefinition())
3916  if (D->hasAttr<CUDAConstantAttr>())
3918  // Extern global variables will be registered in the TU where they are
3919  // defined.
3920  if (!D->hasExternalStorage())
3921  getCUDARuntime().registerDeviceVar(D, *GV, Flags);
3922  } else if (D->hasAttr<CUDASharedAttr>())
3923  // __shared__ variables are odd. Shadows do get created, but
3924  // they are not registered with the CUDA runtime, so they
3925  // can't really be used to access their device-side
3926  // counterparts. It's not clear yet whether it's nvcc's bug or
3927  // a feature, but we've got to do the same for compatibility.
3929  }
3930  }
3931 
3932  if (!IsHIPPinnedShadowVar)
3933  GV->setInitializer(Init);
3934  if (emitter) emitter->finalize(GV);
3935 
3936  // If it is safe to mark the global 'constant', do so now.
3937  GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
3938  isTypeConstant(D->getType(), true));
3939 
3940  // If it is in a read-only section, mark it 'constant'.
3941  if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
3942  const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
3943  if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
3944  GV->setConstant(true);
3945  }
3946 
3947  GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
3948 
3949 
3950  // On Darwin, if the normal linkage of a C++ thread_local variable is
3951  // LinkOnce or Weak, we keep the normal linkage to prevent multiple
3952  // copies within a linkage unit; otherwise, the backing variable has
3953  // internal linkage and all accesses should just be calls to the
3954  // Itanium-specified entry point, which has the normal linkage of the
3955  // variable. This is to preserve the ability to change the implementation
3956  // behind the scenes.
3957  if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic &&
3958  Context.getTargetInfo().getTriple().isOSDarwin() &&
3959  !llvm::GlobalVariable::isLinkOnceLinkage(Linkage) &&
3960  !llvm::GlobalVariable::isWeakLinkage(Linkage))
3962 
3963  GV->setLinkage(Linkage);
3964  if (D->hasAttr<DLLImportAttr>())
3965  GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
3966  else if (D->hasAttr<DLLExportAttr>())
3967  GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
3968  else
3969  GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
3970 
3971  if (Linkage == llvm::GlobalVariable::CommonLinkage) {
3972  // common vars aren't constant even if declared const.
3973  GV->setConstant(false);
3974  // Tentative definition of global variables may be initialized with
3975  // non-zero null pointers. In this case they should have weak linkage
3976  // since common linkage must have zero initializer and must not have
3977  // explicit section therefore cannot have non-zero initial value.
3978  if (!GV->getInitializer()->isNullValue())
3979  GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
3980  }
3981 
3982  setNonAliasAttributes(D, GV);
3983 
3984  if (D->getTLSKind() && !GV->isThreadLocal()) {
3985  if (D->getTLSKind() == VarDecl::TLS_Dynamic)
3986  CXXThreadLocals.push_back(D);
3987  setTLSMode(GV, *D);
3988  }
3989 
3990  maybeSetTrivialComdat(*D, *GV);
3991 
3992  // Emit the initializer function if necessary.
3993  if (NeedsGlobalCtor || NeedsGlobalDtor)
3994  EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
3995 
3996  SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor);
3997 
3998  // Emit global variable debug information.
3999  if (CGDebugInfo *DI = getModuleDebugInfo())
4000  if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
4001  DI->EmitGlobalVariable(GV, D);
4002 }
4003 
4004 static bool isVarDeclStrongDefinition(const ASTContext &Context,
4005  CodeGenModule &CGM, const VarDecl *D,
4006  bool NoCommon) {
4007  // Don't give variables common linkage if -fno-common was specified unless it
4008  // was overridden by a NoCommon attribute.
4009  if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
4010  return true;
4011 
4012  // C11 6.9.2/2:
4013  // A declaration of an identifier for an object that has file scope without
4014  // an initializer, and without a storage-class specifier or with the
4015  // storage-class specifier static, constitutes a tentative definition.
4016  if (D->getInit() || D->hasExternalStorage())
4017  return true;
4018 
4019  // A variable cannot be both common and exist in a section.
4020  if (D->hasAttr<SectionAttr>())
4021  return true;
4022 
4023  // A variable cannot be both common and exist in a section.
4024  // We don't try to determine which is the right section in the front-end.
4025  // If no specialized section name is applicable, it will resort to default.
4026  if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
4027  D->hasAttr<PragmaClangDataSectionAttr>() ||
4028  D->hasAttr<PragmaClangRodataSectionAttr>())
4029  return true;
4030 
4031  // Thread local vars aren't considered common linkage.
4032  if (D->getTLSKind())
4033  return true;
4034 
4035  // Tentative definitions marked with WeakImportAttr are true definitions.
4036  if (D->hasAttr<WeakImportAttr>())
4037  return true;
4038 
4039  // A variable cannot be both common and exist in a comdat.
4040  if (shouldBeInCOMDAT(CGM, *D))
4041  return true;
4042 
4043  // Declarations with a required alignment do not have common linkage in MSVC
4044  // mode.
4045  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
4046  if (D->hasAttr<AlignedAttr>())
4047  return true;
4048  QualType VarType = D->getType();
4049  if (Context.isAlignmentRequired(VarType))
4050  return true;
4051 
4052  if (const auto *RT = VarType->getAs<RecordType>()) {
4053  const RecordDecl *RD = RT->getDecl();
4054  for (const FieldDecl *FD : RD->fields()) {
4055  if (FD->isBitField())
4056  continue;
4057  if (FD->hasAttr<AlignedAttr>())
4058  return true;
4059  if (Context.isAlignmentRequired(FD->getType()))
4060  return true;
4061  }
4062  }
4063  }
4064 
4065  // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
4066  // common symbols, so symbols with greater alignment requirements cannot be
4067  // common.
4068  // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
4069  // alignments for common symbols via the aligncomm directive, so this
4070  // restriction only applies to MSVC environments.
4071  if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
4072  Context.getTypeAlignIfKnown(D->getType()) >
4073  Context.toBits(CharUnits::fromQuantity(32)))
4074  return true;
4075 
4076  return false;
4077 }
4078 
4079 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
4080  const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) {
4081  if (Linkage == GVA_Internal)
4083 
4084  if (D->hasAttr<WeakAttr>()) {
4085  if (IsConstantVariable)
4086  return llvm::GlobalVariable::WeakODRLinkage;
4087  else
4088  return llvm::GlobalVariable::WeakAnyLinkage;
4089  }
4090 
4091  if (const auto *FD = D->getAsFunction())
4092  if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
4093  return llvm::GlobalVariable::LinkOnceAnyLinkage;
4094 
4095  // We are guaranteed to have a strong definition somewhere else,
4096  // so we can use available_externally linkage.
4097  if (Linkage == GVA_AvailableExternally)
4098  return llvm::GlobalValue::AvailableExternallyLinkage;
4099 
4100  // Note that Apple's kernel linker doesn't support symbol
4101  // coalescing, so we need to avoid linkonce and weak linkages there.
4102  // Normally, this means we just map to internal, but for explicit
4103  // instantiations we'll map to external.
4104 
4105  // In C++, the compiler has to emit a definition in every translation unit
4106  // that references the function. We should use linkonce_odr because
4107  // a) if all references in this translation unit are optimized away, we
4108  // don't need to codegen it. b) if the function persists, it needs to be
4109  // merged with other definitions. c) C++ has the ODR, so we know the
4110  // definition is dependable.
4111  if (Linkage == GVA_DiscardableODR)
4112  return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
4114 
4115  // An explicit instantiation of a template has weak linkage, since
4116  // explicit instantiations can occur in multiple translation units
4117  // and must all be equivalent. However, we are not allowed to
4118  // throw away these explicit instantiations.
4119  //
4120  // We don't currently support CUDA device code spread out across multiple TUs,
4121  // so say that CUDA templates are either external (for kernels) or internal.
4122  // This lets llvm perform aggressive inter-procedural optimizations.
4123  if (Linkage == GVA_StrongODR) {
4124  if (Context.getLangOpts().AppleKext)
4126  if (Context.getLangOpts().CUDA && Context.getLangOpts().CUDAIsDevice)
4127  return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
4129  return llvm::Function::WeakODRLinkage;
4130  }
4131 
4132  // C++ doesn't have tentative definitions and thus cannot have common
4133  // linkage.
4134  if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
4135  !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
4136  CodeGenOpts.NoCommon))
4137  return llvm::GlobalVariable::CommonLinkage;
4138 
4139  // selectany symbols are externally visible, so use weak instead of
4140  // linkonce. MSVC optimizes away references to const selectany globals, so
4141  // all definitions should be the same and ODR linkage should be used.
4142  // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
4143  if (D->hasAttr<SelectAnyAttr>())
4144  return llvm::GlobalVariable::WeakODRLinkage;
4145 
4146  // Otherwise, we have strong external linkage.
4147  assert(Linkage == GVA_StrongExternal);
4149 }
4150 
4151 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition(
4152  const VarDecl *VD, bool IsConstant) {
4154  return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant);
4155 }
4156 
4157 /// Replace the uses of a function that was declared with a non-proto type.
4158 /// We want to silently drop extra arguments from call sites
4159 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
4160  llvm::Function *newFn) {
4161  // Fast path.
4162  if (old->use_empty()) return;
4163 
4164  llvm::Type *newRetTy = newFn->getReturnType();
4167 
4168  for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
4169  ui != ue; ) {
4170  llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
4171  llvm::User *user = use->getUser();
4172 
4173  // Recognize and replace uses of bitcasts. Most calls to
4174  // unprototyped functions will use bitcasts.
4175  if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
4176  if (bitcast->getOpcode() == llvm::Instruction::BitCast)
4177  replaceUsesOfNonProtoConstant(bitcast, newFn);
4178  continue;
4179  }
4180 
4181  // Recognize calls to the function.
4182  llvm::CallBase *callSite = dyn_cast<llvm::CallBase>(user);
4183  if (!callSite) continue;
4184  if (!callSite->isCallee(&*use))
4185  continue;
4186 
4187  // If the return types don't match exactly, then we can't
4188  // transform this call unless it's dead.
4189  if (callSite->getType() != newRetTy && !callSite->use_empty())
4190  continue;
4191 
4192  // Get the call site's attribute list.
4194  llvm::AttributeList oldAttrs = callSite->getAttributes();
4195 
4196  // If the function was passed too few arguments, don't transform.
4197  unsigned newNumArgs = newFn->arg_size();
4198  if (callSite->arg_size() < newNumArgs)
4199  continue;
4200 
4201  // If extra arguments were passed, we silently drop them.
4202  // If any of the types mismatch, we don't transform.
4203  unsigned argNo = 0;
4204  bool dontTransform = false;
4205  for (llvm::Argument &A : newFn->args()) {
4206  if (callSite->getArgOperand(argNo)->getType() != A.getType()) {
4207  dontTransform = true;
4208  break;
4209  }
4210 
4211  // Add any parameter attributes.
4212  newArgAttrs.push_back(oldAttrs.getParamAttributes(argNo));
4213  argNo++;
4214  }
4215  if (dontTransform)
4216  continue;
4217 
4218  // Okay, we can transform this. Create the new call instruction and copy
4219  // over the required information.
4220  newArgs.append(callSite->arg_begin(), callSite->arg_begin() + argNo);
4221 
4222  // Copy over any operand bundles.
4223  callSite->getOperandBundlesAsDefs(newBundles);
4224 
4225  llvm::CallBase *newCall;
4226  if (dyn_cast<llvm::CallInst>(callSite)) {
4227  newCall =
4228  llvm::CallInst::Create(newFn, newArgs, newBundles, "", callSite);
4229  } else {
4230  auto *oldInvoke = cast<llvm::InvokeInst>(callSite);
4231  newCall = llvm::InvokeInst::Create(newFn, oldInvoke->getNormalDest(),
4232  oldInvoke->getUnwindDest(), newArgs,
4233  newBundles, "", callSite);
4234  }
4235  newArgs.clear(); // for the next iteration
4236 
4237  if (!newCall->getType()->isVoidTy())
4238  newCall->takeName(callSite);
4239  newCall->setAttributes(llvm::AttributeList::get(
4240  newFn->getContext(), oldAttrs.getFnAttributes(),
4241  oldAttrs.getRetAttributes(), newArgAttrs));
4242  newCall->setCallingConv(callSite->getCallingConv());
4243 
4244  // Finally, remove the old call, replacing any uses with the new one.
4245  if (!callSite->use_empty())
4246  callSite->replaceAllUsesWith(newCall);
4247 
4248  // Copy debug location attached to CI.
4249  if (callSite->getDebugLoc())
4250  newCall->setDebugLoc(callSite->getDebugLoc());
4251 
4252  callSite->eraseFromParent();
4253  }
4254 }
4255 
4256 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
4257 /// implement a function with no prototype, e.g. "int foo() {}". If there are
4258 /// existing call uses of the old function in the module, this adjusts them to
4259 /// call the new function directly.
4260 ///
4261 /// This is not just a cleanup: the always_inline pass requires direct calls to
4262 /// functions to be able to inline them. If there is a bitcast in the way, it
4263 /// won't inline them. Instcombine normally deletes these calls, but it isn't
4264 /// run at -O0.
4265 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
4266  llvm::Function *NewFn) {
4267  // If we're redefining a global as a function, don't transform it.
4268  if (!isa<llvm::Function>(Old)) return;
4269 
4270  replaceUsesOfNonProtoConstant(Old, NewFn);
4271 }
4272 
4274  auto DK = VD->isThisDeclarationADefinition();
4275  if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
4276  return;
4277 
4279  // If we have a definition, this might be a deferred decl. If the
4280  // instantiation is explicit, make sure we emit it at the end.
4282  GetAddrOfGlobalVar(VD);
4283 
4284  EmitTopLevelDecl(VD);
4285 }
4286 
4287 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
4288  llvm::GlobalValue *GV) {
4289  const auto *D = cast<FunctionDecl>(GD.getDecl());
4290 
4291  // Compute the function info and LLVM type.
4293  llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4294 
4295  // Get or create the prototype for the function.
4296  if (!GV || (GV->getType()->getElementType() != Ty))
4297  GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
4298  /*DontDefer=*/true,
4299  ForDefinition));
4300 
4301  // Already emitted.
4302  if (!GV->isDeclaration())
4303  return;
4304 
4305  // We need to set linkage and visibility on the function before
4306  // generating code for it because various parts of IR generation
4307  // want to propagate this information down (e.g. to local static
4308  // declarations).
4309  auto *Fn = cast<llvm::Function>(GV);
4310  setFunctionLinkage(GD, Fn);
4311 
4312  // FIXME: this is redundant with part of setFunctionDefinitionAttributes
4313  setGVProperties(Fn, GD);
4314 
4316 
4317 
4318  maybeSetTrivialComdat(*D, *Fn);
4319 
4320  CodeGenFunction(*this).GenerateCode(D, Fn, FI);
4321 
4322  setNonAliasAttributes(GD, Fn);
4324 
4325  if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
4326  AddGlobalCtor(Fn, CA->getPriority());
4327  if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
4328  AddGlobalDtor(Fn, DA->getPriority());
4329  if (D->hasAttr<AnnotateAttr>())
4330  AddGlobalAnnotations(D, Fn);
4331 }
4332 
4333 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
4334  const auto *D = cast<ValueDecl>(GD.getDecl());
4335  const AliasAttr *AA = D->getAttr<AliasAttr>();
4336  assert(AA && "Not an alias?");
4337 
4338  StringRef MangledName = getMangledName(GD);
4339 
4340  if (AA->getAliasee() == MangledName) {
4341  Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4342  return;
4343  }
4344 
4345  // If there is a definition in the module, then it wins over the alias.
4346  // This is dubious, but allow it to be safe. Just ignore the alias.
4347  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4348  if (Entry && !Entry->isDeclaration())
4349  return;
4350 
4351  Aliases.push_back(GD);
4352 
4353  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4354 
4355  // Create a reference to the named value. This ensures that it is emitted
4356  // if a deferred decl.
4357  llvm::Constant *Aliasee;
4358  if (isa<llvm::FunctionType>(DeclTy))
4359  Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
4360  /*ForVTable=*/false);
4361  else
4362  Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
4363  llvm::PointerType::getUnqual(DeclTy),
4364  /*D=*/nullptr);
4365 
4366  // Create the new alias itself, but don't set a name yet.
4367  auto *GA = llvm::GlobalAlias::create(
4368  DeclTy, 0, llvm::Function::ExternalLinkage, "", Aliasee, &getModule());
4369 
4370  if (Entry) {
4371  if (GA->getAliasee() == Entry) {
4372  Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4373  return;
4374  }
4375 
4376  assert(Entry->isDeclaration());
4377 
4378  // If there is a declaration in the module, then we had an extern followed
4379  // by the alias, as in:
4380  // extern int test6();
4381  // ...
4382  // int test6() __attribute__((alias("test7")));
4383  //
4384  // Remove it and replace uses of it with the alias.
4385  GA->takeName(Entry);
4386 
4387  Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
4388  Entry->getType()));
4389  Entry->eraseFromParent();
4390  } else {
4391  GA->setName(MangledName);
4392  }
4393 
4394  // Set attributes which are particular to an alias; this is a
4395  // specialization of the attributes which may be set on a global
4396  // variable/function.
4397  if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
4398  D->isWeakImported()) {
4399  GA->setLinkage(llvm::Function::WeakAnyLinkage);
4400  }
4401 
4402  if (const auto *VD = dyn_cast<VarDecl>(D))
4403  if (VD->getTLSKind())
4404  setTLSMode(GA, *VD);
4405 
4406  SetCommonAttributes(GD, GA);
4407 }
4408 
4409 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
4410  const auto *D = cast<ValueDecl>(GD.getDecl());
4411  const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
4412  assert(IFA && "Not an ifunc?");
4413 
4414  StringRef MangledName = getMangledName(GD);
4415 
4416  if (IFA->getResolver() == MangledName) {
4417  Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4418  return;
4419  }
4420 
4421  // Report an error if some definition overrides ifunc.
4422  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4423  if (Entry && !Entry->isDeclaration()) {
4424  GlobalDecl OtherGD;
4425  if (lookupRepresentativeDecl(MangledName, OtherGD) &&
4426  DiagnosedConflictingDefinitions.insert(GD).second) {
4427  Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
4428  << MangledName;
4429  Diags.Report(OtherGD.getDecl()->getLocation(),
4430  diag::note_previous_definition);
4431  }
4432  return;
4433  }
4434 
4435  Aliases.push_back(GD);
4436 
4437  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4438  llvm::Constant *Resolver =
4439  GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD,
4440  /*ForVTable=*/false);
4441  llvm::GlobalIFunc *GIF =
4443  "", Resolver, &getModule());
4444  if (Entry) {
4445  if (GIF->getResolver() == Entry) {
4446  Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4447  return;
4448  }
4449  assert(Entry->isDeclaration());
4450 
4451  // If there is a declaration in the module, then we had an extern followed
4452  // by the ifunc, as in:
4453  // extern int test();
4454  // ...
4455  // int test() __attribute__((ifunc("resolver")));
4456  //
4457  // Remove it and replace uses of it with the ifunc.
4458  GIF->takeName(Entry);
4459 
4460  Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
4461  Entry->getType()));
4462  Entry->eraseFromParent();
4463  } else
4464  GIF->setName(MangledName);
4465 
4466  SetCommonAttributes(GD, GIF);
4467 }
4468 
4469 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
4470  ArrayRef<llvm::Type*> Tys) {
4471  return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
4472  Tys);
4473 }
4474 
4475 static llvm::StringMapEntry<llvm::GlobalVariable *> &
4476 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
4477  const StringLiteral *Literal, bool TargetIsLSB,
4478  bool &IsUTF16, unsigned &StringLength) {
4479  StringRef String = Literal->getString();
4480  unsigned NumBytes = String.size();
4481 
4482  // Check for simple case.
4483  if (!Literal->containsNonAsciiOrNull()) {
4484  StringLength = NumBytes;
4485  return *Map.insert(std::make_pair(String, nullptr)).first;
4486  }
4487 
4488  // Otherwise, convert the UTF8 literals into a string of shorts.
4489  IsUTF16 = true;
4490 
4491  SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
4492  const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
4493  llvm::UTF16 *ToPtr = &ToBuf[0];
4494 
4495  (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
4496  ToPtr + NumBytes, llvm::strictConversion);
4497 
4498  // ConvertUTF8toUTF16 returns the length in ToPtr.
4499  StringLength = ToPtr - &ToBuf[0];
4500 
4501  // Add an explicit null.
4502  *ToPtr = 0;
4503  return *Map.insert(std::make_pair(
4504  StringRef(reinterpret_cast<const char *>(ToBuf.data()),
4505  (StringLength + 1) * 2),
4506  nullptr)).first;
4507 }
4508 
4511  unsigned StringLength = 0;
4512  bool isUTF16 = false;
4513  llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
4514  GetConstantCFStringEntry(CFConstantStringMap, Literal,
4515  getDataLayout().isLittleEndian(), isUTF16,
4516  StringLength);
4517 
4518  if (auto *C = Entry.second)
4519  return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment()));
4520 
4521  llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
4522  llvm::Constant *Zeros[] = { Zero, Zero };
4523 
4524  const ASTContext &Context = getContext();
4525  const llvm::Triple &Triple = getTriple();
4526 
4527  const auto CFRuntime = getLangOpts().CFRuntime;
4528  const bool IsSwiftABI =
4529  static_cast<unsigned>(CFRuntime) >=
4530  static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
4531  const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
4532 
4533  // If we don't already have it, get __CFConstantStringClassReference.
4534  if (!CFConstantStringClassRef) {
4535  const char *CFConstantStringClassName = "__CFConstantStringClassReference";
4537  Ty = llvm::ArrayType::get(Ty, 0);
4538 
4539  switch (CFRuntime) {
4540  default: break;
4541  case LangOptions::CoreFoundationABI::Swift: LLVM_FALLTHROUGH;
4543  CFConstantStringClassName =
4544  Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
4545  : "$s10Foundation19_NSCFConstantStringCN";
4546  Ty = IntPtrTy;
4547  break;
4549  CFConstantStringClassName =
4550  Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
4551  : "$S10Foundation19_NSCFConstantStringCN";
4552  Ty = IntPtrTy;
4553  break;
4555  CFConstantStringClassName =
4556  Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
4557  : "__T010Foundation19_NSCFConstantStringCN";
4558  Ty = IntPtrTy;
4559  break;
4560  }
4561 
4562  llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
4563 
4564  if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
4565  llvm::GlobalValue *GV = nullptr;
4566 
4567  if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
4568  IdentifierInfo &II = Context.Idents.get(GV->getName());
4569  TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
4571 
4572  const VarDecl *VD = nullptr;
4573  for (const auto &Result : DC->lookup(&II))
4574  if ((VD = dyn_cast<VarDecl>(Result)))
4575  break;
4576 
4577  if (Triple.isOSBinFormatELF()) {
4578  if (!VD)
4579  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
4580  } else {
4581  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
4582  if (!VD || !VD->hasAttr<DLLExportAttr>())
4583  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
4584  else
4585  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
4586  }
4587 
4588  setDSOLocal(GV);
4589  }
4590  }
4591 
4592  // Decay array -> ptr
4593  CFConstantStringClassRef =
4594  IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty)
4595  : llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros);
4596  }
4597 
4598  QualType CFTy = Context.getCFConstantStringType();
4599 
4600  auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
4601 
4602  ConstantInitBuilder Builder(*this);
4603  auto Fields = Builder.beginStruct(STy);
4604 
4605  // Class pointer.
4606  Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
4607 
4608  // Flags.
4609  if (IsSwiftABI) {
4610  Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
4611  Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
4612  } else {
4613  Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
4614  }
4615 
4616  // String pointer.
4617  llvm::Constant *C = nullptr;
4618  if (isUTF16) {
4619  auto Arr = llvm::makeArrayRef(
4620  reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
4621  Entry.first().size() / 2);
4622  C = llvm::ConstantDataArray::get(VMContext, Arr);
4623  } else {
4624  C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
4625  }
4626 
4627  // Note: -fwritable-strings doesn't make the backing store strings of
4628  // CFStrings writable. (See <rdar://problem/10657500>)
4629  auto *GV =
4630  new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
4631  llvm::GlobalValue::PrivateLinkage, C, ".str");
4632  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4633  // Don't enforce the target's minimum global alignment, since the only use
4634  // of the string is via this class initializer.
4635  CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
4636  : Context.getTypeAlignInChars(Context.CharTy);
4637  GV->setAlignment(Align.getQuantity());
4638 
4639  // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
4640  // Without it LLVM can merge the string with a non unnamed_addr one during
4641  // LTO. Doing that changes the section it ends in, which surprises ld64.
4642  if (Triple.isOSBinFormatMachO())
4643  GV->setSection(isUTF16 ? "__TEXT,__ustring"
4644  : "__TEXT,__cstring,cstring_literals");
4645  // Make sure the literal ends up in .rodata to allow for safe ICF and for
4646  // the static linker to adjust permissions to read-only later on.
4647  else if (Triple.isOSBinFormatELF())
4648  GV->setSection(".rodata");
4649 
4650  // String.
4651  llvm::Constant *Str =
4652  llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
4653 
4654  if (isUTF16)
4655  // Cast the UTF16 string to the correct type.
4656  Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
4657  Fields.add(Str);
4658 
4659  // String length.
4660  llvm::IntegerType *LengthTy =
4661  llvm::IntegerType::get(getModule().getContext(),
4662  Context.getTargetInfo().getLongWidth());
4663  if (IsSwiftABI) {
4664  if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
4666  LengthTy = Int32Ty;
4667  else
4668  LengthTy = IntPtrTy;
4669  }
4670  Fields.addInt(LengthTy, StringLength);
4671 
4672  CharUnits Alignment = getPointerAlign();
4673 
4674  // The struct.
4675  GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
4676  /*isConstant=*/false,
4677  llvm::GlobalVariable::PrivateLinkage);
4678  GV->addAttribute("objc_arc_inert");
4679  switch (Triple.getObjectFormat()) {
4680  case llvm::Triple::UnknownObjectFormat:
4681  llvm_unreachable("unknown file format");
4682  case llvm::Triple::XCOFF:
4683  llvm_unreachable("XCOFF is not yet implemented");
4684  case llvm::Triple::COFF:
4685  case llvm::Triple::ELF:
4686  case llvm::Triple::Wasm:
4687  GV->setSection("cfstring");
4688  break;
4689  case llvm::Triple::MachO:
4690  GV->setSection("__DATA,__cfstring");
4691  break;
4692  }
4693  Entry.second = GV;
4694 
4695  return ConstantAddress(GV, Alignment);
4696 }
4697 
4699  return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
4700 }
4701 
4703  if (ObjCFastEnumerationStateType.isNull()) {
4704  RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
4705  D->startDefinition();
4706 
4707  QualType FieldTypes[] = {
4708  Context.UnsignedLongTy,
4709  Context.getPointerType(Context.getObjCIdType()),
4710  Context.getPointerType(Context.UnsignedLongTy),
4711  Context.getConstantArrayType(Context.UnsignedLongTy,
4712  llvm::APInt(32, 5), ArrayType::Normal, 0)
4713  };
4714 
4715  for (size_t i = 0; i < 4; ++i) {
4716  FieldDecl *Field = FieldDecl::Create(Context,
4717  D,
4718  SourceLocation(),
4719  SourceLocation(), nullptr,
4720  FieldTypes[i], /*TInfo=*/nullptr,
4721  /*BitWidth=*/nullptr,
4722  /*Mutable=*/false,
4723  ICIS_NoInit);
4724  Field->setAccess(AS_public);
4725  D->addDecl(Field);
4726  }
4727 
4728  D->completeDefinition();
4729  ObjCFastEnumerationStateType = Context.getTagDeclType(D);
4730  }
4731 
4732  return ObjCFastEnumerationStateType;
4733 }
4734 
4735 llvm::Constant *
4737  assert(!E->getType()->isPointerType() && "Strings are always arrays");
4738 
4739  // Don't emit it as the address of the string, emit the string data itself
4740  // as an inline array.
4741  if (E->getCharByteWidth() == 1) {
4742  SmallString<64> Str(E->getString());
4743 
4744  // Resize the string to the right size, which is indicated by its type.
4745  const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
4746  Str.resize(CAT->getSize().getZExtValue());
4747  return llvm::ConstantDataArray::getString(VMContext, Str, false);
4748  }
4749 
4750  auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
4751  llvm::Type *ElemTy = AType->getElementType();
4752  unsigned NumElements = AType->getNumElements();
4753 
4754  // Wide strings have either 2-byte or 4-byte elements.
4755  if (ElemTy->getPrimitiveSizeInBits() == 16) {
4756  SmallVector<uint16_t, 32> Elements;
4757  Elements.reserve(NumElements);
4758 
4759  for(unsigned i = 0, e = E->getLength(); i != e; ++i)
4760  Elements.push_back(E->getCodeUnit(i));
4761  Elements.resize(NumElements);
4762  return llvm::ConstantDataArray::get(VMContext, Elements);
4763  }
4764 
4765  assert(ElemTy->getPrimitiveSizeInBits() == 32);
4766  SmallVector<uint32_t, 32> Elements;
4767  Elements.reserve(NumElements);
4768 
4769  for(unsigned i = 0, e = E->getLength(); i != e; ++i)
4770  Elements.push_back(E->getCodeUnit(i));
4771  Elements.resize(NumElements);
4772  return llvm::ConstantDataArray::get(VMContext, Elements);
4773 }
4774 
4775 static llvm::GlobalVariable *
4776 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
4777  CodeGenModule &CGM, StringRef GlobalName,
4778  CharUnits Alignment) {
4779  unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
4781 
4782  llvm::Module &M = CGM.getModule();
4783  // Create a global variable for this string
4784  auto *GV = new llvm::GlobalVariable(
4785  M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
4786  nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
4787  GV->setAlignment(Alignment.getQuantity());
4788  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4789  if (GV->isWeakForLinker()) {
4790  assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
4791  GV->setComdat(M.getOrInsertComdat(GV->getName()));
4792  }
4793  CGM.setDSOLocal(GV);
4794 
4795  return GV;
4796 }
4797 
4798 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
4799 /// constant array for the given string literal.
4802  StringRef Name) {
4804 
4805  llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
4806  llvm::GlobalVariable **Entry = nullptr;
4807  if (!LangOpts.WritableStrings) {
4808  Entry = &ConstantStringMap[C];
4809  if (auto GV = *Entry) {
4810  if (Alignment.getQuantity() > GV->getAlignment())
4811  GV->setAlignment(Alignment.getQuantity());
4813  Alignment);
4814  }
4815  }
4816 
4817  SmallString<256> MangledNameBuffer;
4818  StringRef GlobalVariableName;
4819  llvm::GlobalValue::LinkageTypes LT;
4820 
4821  // Mangle the string literal if that's how the ABI merges duplicate strings.
4822  // Don't do it if they are writable, since we don't want writes in one TU to
4823  // affect strings in another.
4824  if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
4825  !LangOpts.WritableStrings) {
4826  llvm::raw_svector_ostream Out(MangledNameBuffer);
4828  LT = llvm::GlobalValue::LinkOnceODRLinkage;
4829  GlobalVariableName = MangledNameBuffer;
4830  } else {
4831  LT = llvm::GlobalValue::PrivateLinkage;
4832  GlobalVariableName = Name;
4833  }
4834 
4835  auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
4836  if (Entry)
4837  *Entry = GV;
4838 
4839  SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>",
4840  QualType());
4841 
4843  Alignment);
4844 }
4845 
4846 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
4847 /// array for the given ObjCEncodeExpr node.
4850  std::string Str;
4852 
4853  return GetAddrOfConstantCString(Str);
4854 }
4855 
4856 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
4857 /// the literal and a terminating '\0' character.
4858 /// The result has pointer to array type.
4860  const std::string &Str, const char *GlobalName) {
4861  StringRef StrWithNull(Str.c_str(), Str.size() + 1);
4862  CharUnits Alignment =
4864 
4865  llvm::Constant *C =
4866  llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
4867 
4868  // Don't share any string literals if strings aren't constant.
4869  llvm::GlobalVariable **Entry = nullptr;
4870  if (!LangOpts.WritableStrings) {
4871  Entry = &ConstantStringMap[C];
4872  if (auto GV = *Entry) {
4873  if (Alignment.getQuantity() > GV->getAlignment())
4874  GV->setAlignment(Alignment.getQuantity());
4876  Alignment);
4877  }
4878  }
4879 
4880  // Get the default prefix if a name wasn't specified.
4881  if (!GlobalName)
4882  GlobalName = ".str";
4883  // Create a global variable for this.
4884  auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
4885  GlobalName, Alignment);
4886  if (Entry)
4887  *Entry = GV;
4888 
4890  Alignment);
4891 }
4892 
4894  const MaterializeTemporaryExpr *E, const Expr *Init) {
4895  assert((E->getStorageDuration() == SD_Static ||
4896  E->getStorageDuration() == SD_Thread) && "not a global temporary");
4897  const auto *VD = cast<VarDecl>(E->getExtendingDecl());
4898 
4899  // If we're not materializing a subobject of the temporary, keep the
4900  // cv-qualifiers from the type of the MaterializeTemporaryExpr.
4901  QualType MaterializedType = Init->getType();
4902  if (Init == E->GetTemporaryExpr())
4903  MaterializedType = E->getType();
4904 
4905  CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
4906 
4907  if (llvm::Constant *Slot = MaterializedGlobalTemporaryMap[E])
4908  return ConstantAddress(Slot, Align);
4909 
4910  // FIXME: If an externally-visible declaration extends multiple temporaries,
4911  // we need to give each temporary the same name in every translation unit (and
4912  // we also need to make the temporaries externally-visible).
4913  SmallString<256> Name;
4914  llvm::raw_svector_ostream Out(Name);
4916  VD, E->getManglingNumber(), Out);
4917 
4918  APValue *Value = nullptr;
4919  if (E->getStorageDuration() == SD_Static) {
4920  // We might have a cached constant initializer for this temporary. Note
4921  // that this might have a different value from the value computed by
4922  // evaluating the initializer if the surrounding constant expression
4923  // modifies the temporary.
4924  Value = getContext().getMaterializedTemporaryValue(E, false);
4925  if (Value && Value->isAbsent())
4926  Value = nullptr;
4927  }
4928 
4929  // Try evaluating it now, it might have a constant initializer.
4930  Expr::EvalResult EvalResult;
4931  if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
4932  !EvalResult.hasSideEffects())
4933  Value = &EvalResult.Val;
4934 
4935  LangAS AddrSpace =
4936  VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace();
4937 
4938  Optional<ConstantEmitter> emitter;
4939  llvm::Constant *InitialValue = nullptr;
4940  bool Constant = false;
4941  llvm::Type *Type;
4942  if (Value) {
4943  // The temporary has a constant initializer, use it.
4944  emitter.emplace(*this);
4945  InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
4946  MaterializedType);
4947  Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value);
4948  Type = InitialValue->getType();
4949  } else {
4950  // No initializer, the initialization will be provided when we
4951  // initialize the declaration which performed lifetime extension.
4952  Type = getTypes().ConvertTypeForMem(MaterializedType);
4953  }
4954 
4955  // Create a global variable for this lifetime-extended temporary.
4956  llvm::GlobalValue::LinkageTypes Linkage =
4957  getLLVMLinkageVarDefinition(VD, Constant);
4958  if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
4959  const VarDecl *InitVD;
4960  if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
4961  isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
4962  // Temporaries defined inside a class get linkonce_odr linkage because the
4963  // class can be defined in multiple translation units.
4964  Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
4965  } else {
4966  // There is no need for this temporary to have external linkage if the
4967  // VarDecl has external linkage.
4969  }
4970  }
4971  auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
4972  auto *GV = new llvm::GlobalVariable(
4973  getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
4974  /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
4975  if (emitter) emitter->finalize(GV);
4976  setGVProperties(GV, VD);
4977  GV->setAlignment(Align.getQuantity());
4978  if (supportsCOMDAT() && GV->isWeakForLinker())
4979  GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
4980  if (VD->getTLSKind())
4981  setTLSMode(GV, *VD);
4982  llvm::Constant *CV = GV;
4983  if (AddrSpace != LangAS::Default)
4985  *this, GV, AddrSpace, LangAS::Default,
4986  Type->getPointerTo(
4987  getContext().getTargetAddressSpace(LangAS::Default)));
4988  MaterializedGlobalTemporaryMap[E] = CV;
4989  return ConstantAddress(CV, Align);
4990 }
4991 
4992 /// EmitObjCPropertyImplementations - Emit information for synthesized
4993 /// properties for an implementation.
4994 void CodeGenModule::EmitObjCPropertyImplementations(const
4996  for (const auto *PID : D->property_impls()) {
4997  // Dynamic is just for type-checking.
4998  if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
4999  ObjCPropertyDecl *PD = PID->getPropertyDecl();
5000 
5001  // Determine which methods need to be implemented, some may have
5002  // been overridden. Note that ::isPropertyAccessor is not the method
5003  // we want, that just indicates if the decl came from a
5004  // property. What we want to know is if the method is defined in
5005  // this implementation.
5006  if (!D->getInstanceMethod(PD->getGetterName()))
5008  const_cast<ObjCImplementationDecl *>(D), PID);
5009  if (!PD->isReadOnly() &&
5010  !D->getInstanceMethod(PD->getSetterName()))
5012  const_cast<ObjCImplementationDecl *>(D), PID);
5013  }
5014  }
5015 }
5016 
5018  const ObjCInterfaceDecl *iface = impl->getClassInterface();
5019  for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
5020  ivar; ivar = ivar->getNextIvar())
5021  if (ivar->getType().isDestructedType())
5022  return true;
5023 
5024  return false;
5025 }
5026 
5029  CodeGenFunction CGF(CGM);
5031  E = D->init_end(); B != E; ++B) {
5032  CXXCtorInitializer *CtorInitExp = *B;
5033  Expr *Init = CtorInitExp->getInit();
5034  if (!CGF.isTrivialInitializer(Init))
5035  return false;
5036  }
5037  return true;
5038 }
5039 
5040 /// EmitObjCIvarInitializations - Emit information for ivar initialization
5041 /// for an implementation.
5042 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
5043  // We might need a .cxx_destruct even if we don't have any ivar initializers.
5044  if (needsDestructMethod(D)) {
5045  IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
5046  Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
5047  ObjCMethodDecl *DTORMethod =
5049  cxxSelector, getContext().VoidTy, nullptr, D,
5050  /*isInstance=*/true, /*isVariadic=*/false,
5051  /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true,
5052  /*isDefined=*/false, ObjCMethodDecl::Required);
5053  D->addInstanceMethod(DTORMethod);
5054  CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
5055  D->setHasDestructors(true);
5056  }
5057 
5058  // If the implementation doesn't have any ivar initializers, we don't need
5059  // a .cxx_construct.
5060  if (D->getNumIvarInitializers() == 0 ||
5061  AllTrivialInitializers(*this, D))
5062  return;
5063 
5064  IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
5065  Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
5066  // The constructor returns 'self'.
5068  D->getLocation(),
5069  D->getLocation(),
5070  cxxSelector,
5072  nullptr, D, /*isInstance=*/true,
5073  /*isVariadic=*/false,
5074  /*isPropertyAccessor=*/true,
5075  /*isImplicitlyDeclared=*/true,
5076  /*isDefined=*/false,
5078  D->addInstanceMethod(CTORMethod);
5079  CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
5080  D->setHasNonZeroConstructors(true);
5081 }
5082 
5083 // EmitLinkageSpec - Emit all declarations in a linkage spec.
5084 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
5085  if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
5087  ErrorUnsupported(LSD, "linkage spec");
5088  return;
5089  }
5090 
5091  EmitDeclContext(LSD);
5092 }
5093 
5094 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
5095  for (auto *I : DC->decls()) {
5096  // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
5097  // are themselves considered "top-level", so EmitTopLevelDecl on an
5098  // ObjCImplDecl does not recursively visit them. We need to do that in
5099  // case they're nested inside another construct (LinkageSpecDecl /
5100  // ExportDecl) that does stop them from being considered "top-level".
5101  if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
5102  for (auto *M : OID->methods())
5103  EmitTopLevelDecl(M);
5104  }
5105 
5106  EmitTopLevelDecl(I);
5107  }
5108 }
5109 
5110 /// EmitTopLevelDecl - Emit code for a single top level declaration.
5112  // Ignore dependent declarations.
5113  if (D->isTemplated())
5114  return;
5115 
5116  switch (D->getKind()) {
5117  case Decl::CXXConversion:
5118  case Decl::CXXMethod:
5119  case Decl::Function:
5120  EmitGlobal(cast<FunctionDecl>(D));
5121  // Always provide some coverage mapping
5122  // even for the functions that aren't emitted.
5124  break;
5125 
5126  case Decl::CXXDeductionGuide:
5127  // Function-like, but does not result in code emission.
5128  break;
5129 
5130  case Decl::Var:
5131  case Decl::Decomposition:
5132  case Decl::VarTemplateSpecialization:
5133  EmitGlobal(cast<VarDecl>(D));
5134  if (auto *DD = dyn_cast<DecompositionDecl>(D))
5135  for (auto *B : DD->bindings())
5136  if (auto *HD = B->getHoldingVar())
5137  EmitGlobal(HD);
5138  break;
5139 
5140  // Indirect fields from global anonymous structs and unions can be
5141  // ignored; only the actual variable requires IR gen support.
5142  case Decl::IndirectField:
5143  break;
5144 
5145  // C++ Decls
5146  case Decl::Namespace:
5147  EmitDeclContext(cast<NamespaceDecl>(D));
5148  break;
5149  case Decl::ClassTemplateSpecialization: {
5150  const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
5151  if (DebugInfo &&
5152  Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition &&
5153  Spec->hasDefinition())
5154  DebugInfo->completeTemplateDefinition(*Spec);
5155  } LLVM_FALLTHROUGH;
5156  case Decl::CXXRecord:
5157  if (DebugInfo) {
5158  if (auto *ES = D->getASTContext().getExternalSource())
5159  if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
5160  DebugInfo->completeUnusedClass(cast<CXXRecordDecl>(*D));
5161  }
5162  // Emit any static data members, they may be definitions.
5163  for (auto *I : cast<CXXRecordDecl>(D)->decls())
5164  if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
5165  EmitTopLevelDecl(I);
5166  break;
5167  // No code generation needed.
5168  case Decl::UsingShadow:
5169  case Decl::ClassTemplate:
5170  case Decl::VarTemplate:
5171  case Decl::Concept:
5172  case Decl::VarTemplatePartialSpecialization:
5173  case Decl::FunctionTemplate:
5174  case Decl::TypeAliasTemplate:
5175  case Decl::Block:
5176  case Decl::Empty:
5177  case Decl::Binding:
5178  break;
5179  case Decl::Using: // using X; [C++]
5180  if (CGDebugInfo *DI = getModuleDebugInfo())
5181  DI->EmitUsingDecl(cast<UsingDecl>(*D));
5182  return;
5183  case Decl::NamespaceAlias:
5184  if (CGDebugInfo *DI = getModuleDebugInfo())
5185  DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
5186  return;
5187  case Decl::UsingDirective: // using namespace X; [C++]
5188  if (CGDebugInfo *DI = getModuleDebugInfo())
5189  DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
5190  return;
5191  case Decl::CXXConstructor:
5192  getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
5193  break;
5194  case Decl::CXXDestructor:
5195  getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
5196  break;
5197 
5198  case Decl::StaticAssert:
5199  // Nothing to do.
5200  break;
5201 
5202  // Objective-C Decls
5203 
5204  // Forward declarations, no (immediate) code generation.
5205  case Decl::ObjCInterface:
5206  case Decl::ObjCCategory:
5207  break;
5208 
5209  case Decl::ObjCProtocol: {
5210  auto *Proto = cast<ObjCProtocolDecl>(D);
5211  if (Proto->isThisDeclarationADefinition())
5212  ObjCRuntime->GenerateProtocol(Proto);
5213  break;
5214  }
5215 
5216  case Decl::ObjCCategoryImpl:
5217  // Categories have properties but don't support synthesize so we
5218  // can ignore them here.
5219  ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
5220  break;
5221 
5222  case Decl::ObjCImplementation: {
5223  auto *OMD = cast<ObjCImplementationDecl>(D);
5224  EmitObjCPropertyImplementations(OMD);
5225  EmitObjCIvarInitializations(OMD);
5226  ObjCRuntime->GenerateClass(OMD);
5227  // Emit global variable debug information.
5228  if (CGDebugInfo *DI = getModuleDebugInfo())
5229  if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
5230  DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
5231  OMD->getClassInterface()), OMD->getLocation());
5232  break;
5233  }
5234  case Decl::ObjCMethod: {
5235  auto *OMD = cast<ObjCMethodDecl>(D);
5236  // If this is not a prototype, emit the body.
5237  if (OMD->getBody())
5238  CodeGenFunction(*this).GenerateObjCMethod(OMD);
5239  break;
5240  }
5241  case Decl::ObjCCompatibleAlias:
5242  ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
5243  break;
5244 
5245  case Decl::PragmaComment: {
5246  const auto *PCD = cast<PragmaCommentDecl>(D);
5247  switch (PCD->getCommentKind()) {
5248  case PCK_Unknown:
5249  llvm_unreachable("unexpected pragma comment kind");
5250  case PCK_Linker:
5251  AppendLinkerOptions(PCD->getArg());
5252  break;
5253  case PCK_Lib:
5254  AddDependentLib(PCD->getArg());
5255  break;
5256  case PCK_Compiler:
5257  case PCK_ExeStr:
5258  case PCK_User:
5259  break; // We ignore all of these.
5260  }
5261  break;
5262  }
5263 
5264  case Decl::PragmaDetectMismatch: {
5265  const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
5266  AddDetectMismatch(PDMD->getName(), PDMD->getValue());
5267  break;
5268  }
5269 
5270  case Decl::LinkageSpec:
5271  EmitLinkageSpec(cast<LinkageSpecDecl>(D));
5272  break;
5273 
5274  case Decl::FileScopeAsm: {
5275  // File-scope asm is ignored during device-side CUDA compilation.
5276  if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
5277  break;
5278  // File-scope asm is ignored during device-side OpenMP compilation.
5279  if (LangOpts.OpenMPIsDevice)
5280  break;
5281  auto *AD = cast<FileScopeAsmDecl>(D);
5282  getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
5283  break;
5284  }
5285 
5286  case Decl::Import: {
5287  auto *Import = cast<ImportDecl>(D);
5288 
5289  // If we've already imported this module, we're done.
5290  if (!ImportedModules.insert(Import->getImportedModule()))
5291  break;
5292 
5293  // Emit debug information for direct imports.
5294  if (!Import->getImportedOwningModule()) {
5295  if (CGDebugInfo *DI = getModuleDebugInfo())
5296  DI->EmitImportDecl(*Import);
5297  }
5298 
5299  // Find all of the submodules and emit the module initializers.
5300  llvm::SmallPtrSet<clang::Module *, 16> Visited;
5302  Visited.insert(Import->getImportedModule());
5303  Stack.push_back(Import->getImportedModule());
5304 
5305  while (!Stack.empty()) {
5306  clang::Module *Mod = Stack.pop_back_val();
5307  if (!EmittedModuleInitializers.insert(Mod).second)
5308  continue;
5309 
5310  for (auto *D : Context.getModuleInitializers(Mod))
5311  EmitTopLevelDecl(D);
5312 
5313  // Visit the submodules of this module.
5315  SubEnd = Mod->submodule_end();
5316  Sub != SubEnd; ++Sub) {
5317  // Skip explicit children; they need to be explicitly imported to emit
5318  // the initializers.
5319  if ((*Sub)->IsExplicit)
5320  continue;
5321 
5322  if (Visited.insert(*Sub).second)
5323  Stack.push_back(*Sub);
5324  }
5325  }
5326  break;
5327  }
5328 
5329  case Decl::Export:
5330  EmitDeclContext(cast<ExportDecl>(D));
5331  break;
5332 
5333  case Decl::OMPThreadPrivate:
5334  EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
5335  break;
5336 
5337  case Decl::OMPAllocate:
5338  break;
5339 
5340  case Decl::OMPDeclareReduction:
5341  EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
5342  break;
5343 
5344  case Decl::OMPDeclareMapper:
5345  EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D));
5346  break;
5347 
5348  case Decl::OMPRequires:
5349  EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
5350  break;
5351 
5352  default:
5353  // Make sure we handled everything we should, every other kind is a
5354  // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
5355  // function. Need to recode Decl::Kind to do that easily.
5356  assert(isa<TypeDecl>(D) && "Unsupported decl kind");
5357  break;
5358  }
5359 }
5360 
5362  // Do we need to generate coverage mapping?
5363  if (!CodeGenOpts.CoverageMapping)
5364  return;
5365  switch (D->getKind()) {
5366  case Decl::CXXConversion:
5367  case Decl::CXXMethod:
5368  case Decl::Function:
5369  case Decl::ObjCMethod:
5370  case Decl::CXXConstructor:
5371  case Decl::CXXDestructor: {
5372  if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
5373  return;
5375  if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
5376  return;
5377  auto I = DeferredEmptyCoverageMappingDecls.find(D);
5378  if (I == DeferredEmptyCoverageMappingDecls.end())
5379  DeferredEmptyCoverageMappingDecls[D] = true;
5380  break;
5381  }
5382  default:
5383  break;
5384  };
5385 }
5386 
5388  // Do we need to generate coverage mapping?
5389  if (!CodeGenOpts.CoverageMapping)
5390  return;
5391  if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
5392  if (Fn->isTemplateInstantiation())
5393  ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
5394  }
5395  auto I = DeferredEmptyCoverageMappingDecls.find(D);
5396  if (I == DeferredEmptyCoverageMappingDecls.end())
5397  DeferredEmptyCoverageMappingDecls[D] = false;
5398  else
5399  I->second = false;
5400 }
5401 
5403  // We call takeVector() here to avoid use-after-free.
5404  // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
5405  // we deserialize function bodies to emit coverage info for them, and that
5406  // deserializes more declarations. How should we handle that case?
5407  for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
5408  if (!Entry.second)
5409  continue;
5410  const Decl *D = Entry.first;
5411  switch (D->getKind()) {
5412  case Decl::CXXConversion:
5413  case Decl::CXXMethod:
5414  case Decl::Function:
5415  case Decl::ObjCMethod: {
5416  CodeGenPGO PGO(*this);
5417  GlobalDecl GD(cast<FunctionDecl>(D));
5419  getFunctionLinkage(GD));
5420  break;
5421  }
5422  case Decl::CXXConstructor: {
5423  CodeGenPGO PGO(*this);
5424  GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
5426  getFunctionLinkage(GD));
5427  break;
5428  }
5429  case Decl::CXXDestructor: {
5430  CodeGenPGO PGO(*this);
5431  GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
5433  getFunctionLinkage(GD));
5434  break;
5435  }
5436  default:
5437  break;
5438  };
5439  }
5440 }
5441 
5442 /// Turns the given pointer into a constant.
5443 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
5444  const void *Ptr) {
5445  uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
5446  llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
5447  return llvm::ConstantInt::get(i64, PtrInt);
5448 }
5449 
5451  llvm::NamedMDNode *&GlobalMetadata,
5452  GlobalDecl D,
5453  llvm::GlobalValue *Addr) {
5454  if (!GlobalMetadata)
5455  GlobalMetadata =
5456  CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
5457 
5458  // TODO: should we report variant information for ctors/dtors?
5459  llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
5460  llvm::ConstantAsMetadata::get(GetPointerConstant(
5461  CGM.getLLVMContext(), D.getDecl()))};
5462  GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
5463 }
5464 
5465 /// For each function which is declared within an extern "C" region and marked
5466 /// as 'used', but has internal linkage, create an alias from the unmangled
5467 /// name to the mangled name if possible. People expect to be able to refer
5468 /// to such functions with an unmangled name from inline assembly within the
5469 /// same translation unit.
5470 void CodeGenModule::EmitStaticExternCAliases() {
5471  if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
5472  return;
5473  for (auto &I : StaticExternCValues) {
5474  IdentifierInfo *Name = I.first;
5475  llvm::GlobalValue *Val = I.second;
5476  if (Val && !getModule().getNamedValue(Name->getName()))
5478  }
5479 }
5480 
5481 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
5482  GlobalDecl &Result) const {
5483  auto Res = Manglings.find(MangledName);
5484  if (Res == Manglings.end())
5485  return false;
5486  Result = Res->getValue();
5487  return true;
5488 }
5489 
5490 /// Emits metadata nodes associating all the global values in the
5491 /// current module with the Decls they came from. This is useful for
5492 /// projects using IR gen as a subroutine.
5493 ///
5494 /// Since there's currently no way to associate an MDNode directly
5495 /// with an llvm::GlobalValue, we create a global named metadata
5496 /// with the name 'clang.global.decl.ptrs'.
5497 void CodeGenModule::EmitDeclMetadata() {
5498  llvm::NamedMDNode *GlobalMetadata = nullptr;
5499 
5500  for (auto &I : MangledDeclNames) {
5501  llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
5502  // Some mangled names don't necessarily have an associated GlobalValue
5503  // in this module, e.g. if we mangled it for DebugInfo.
5504  if (Addr)
5505  EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
5506  }
5507 }
5508 
5509 /// Emits metadata nodes for all the local variables in the current
5510 /// function.
5511 void CodeGenFunction::EmitDeclMetadata() {
5512  if (LocalDeclMap.empty()) return;
5513 
5514  llvm::LLVMContext &Context = getLLVMContext();
5515 
5516  // Find the unique metadata ID for this name.
5517  unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
5518 
5519  llvm::NamedMDNode *GlobalMetadata = nullptr;
5520 
5521  for (auto &I : LocalDeclMap) {
5522  const Decl *D = I.first;
5523  llvm::Value *Addr = I.second.getPointer();
5524  if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
5526  Alloca->setMetadata(
5527  DeclPtrKind, llvm::MDNode::get(
5528  Context, llvm::ValueAsMetadata::getConstant(DAddr)));
5529  } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
5530  GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
5531  EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
5532  }
5533  }
5534 }
5535 
5536 void CodeGenModule::EmitVersionIdentMetadata() {
5537  llvm::NamedMDNode *IdentMetadata =
5538  TheModule.getOrInsertNamedMetadata("llvm.ident");
5539  std::string Version = getClangFullVersion();
5540  llvm::LLVMContext &Ctx = TheModule.getContext();
5541 
5542  llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
5543  IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
5544 }
5545 
5546 void CodeGenModule::EmitCommandLineMetadata() {
5547  llvm::NamedMDNode *CommandLineMetadata =
5548  TheModule.getOrInsertNamedMetadata("llvm.commandline");
5549  std::string CommandLine = getCodeGenOpts().RecordCommandLine;
5550  llvm::LLVMContext &Ctx = TheModule.getContext();
5551 
5552  llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
5553  CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
5554 }
5555 
5556 void CodeGenModule::EmitTargetMetadata() {
5557  // Warning, new MangledDeclNames may be appended within this loop.
5558  // We rely on MapVector insertions adding new elements to the end
5559  // of the container.
5560  // FIXME: Move this loop into the one target that needs it, and only
5561  // loop over those declarations for which we couldn't emit the target
5562  // metadata when we emitted the declaration.
5563  for (unsigned I = 0; I != MangledDeclNames.size(); ++I) {
5564  auto Val = *(MangledDeclNames.begin() + I);
5565  const Decl *D = Val.first.getDecl()->getMostRecentDecl();
5566  llvm::GlobalValue *GV = GetGlobalValue(Val.second);
5567  getTargetCodeGenInfo().emitTargetMD(D, GV, *this);
5568  }
5569 }
5570 
5571 void CodeGenModule::EmitCoverageFile() {
5572  if (getCodeGenOpts().CoverageDataFile.empty() &&
5574  return;
5575 
5576  llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
5577  if (!CUNode)
5578  return;
5579 
5580  llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
5581  llvm::LLVMContext &Ctx = TheModule.getContext();
5582  auto *CoverageDataFile =
5583  llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
5584  auto *CoverageNotesFile =
5585  llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
5586  for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
5587  llvm::MDNode *CU = CUNode->getOperand(i);
5588  llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
5589  GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
5590  }
5591 }
5592 
5593 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid) {
5594  // Sema has checked that all uuid strings are of the form
5595  // "12345678-1234-1234-1234-1234567890ab".
5596  assert(Uuid.size() == 36);
5597  for (unsigned i = 0; i < 36; ++i) {
5598  if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-');
5599  else assert(isHexDigit(Uuid[i]));
5600  }
5601 
5602  // The starts of all bytes of Field3 in Uuid. Field 3 is "1234-1234567890ab".
5603  const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 };
5604 
5605  llvm::Constant *Field3[8];
5606  for (unsigned Idx = 0; Idx < 8; ++Idx)
5607  Field3[Idx] = llvm::ConstantInt::get(
5608  Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16);
5609 
5610  llvm::Constant *Fields[4] = {
5611  llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16),
5612  llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16),
5613  llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16),
5614  llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3)
5615  };
5616 
5617  return llvm::ConstantStruct::getAnon(Fields);
5618 }
5619 
5621  bool ForEH) {
5622  // Return a bogus pointer if RTTI is disabled, unless it's for EH.
5623  // FIXME: should we even be calling this method if RTTI is disabled
5624  // and it's not for EH?
5625  if ((!ForEH && !getLangOpts().RTTI) || getLangOpts().CUDAIsDevice)
5626  return llvm::Constant::getNullValue(Int8PtrTy);
5627 
5628  if (ForEH && Ty->isObjCObjectPointerType() &&
5629  LangOpts.ObjCRuntime.isGNUFamily())
5630  return ObjCRuntime->GetEHType(Ty);
5631 
5632  return getCXXABI().getAddrOfRTTIDescriptor(Ty);
5633 }
5634 
5636  // Do not emit threadprivates in simd-only mode.
5637  if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
5638  return;
5639  for (auto RefExpr : D->varlists()) {
5640  auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
5641  bool PerformInit =
5642  VD->getAnyInitializer() &&
5643  !VD->getAnyInitializer()->isConstantInitializer(getContext(),
5644  /*ForRef=*/false);
5645 
5647  if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
5648  VD, Addr, RefExpr->getBeginLoc(), PerformInit))
5649  CXXGlobalInits.push_back(InitFunction);
5650  }
5651 }
5652 
5653 llvm::Metadata *
5654 CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
5655  StringRef Suffix) {
5656  llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
5657  if (InternalId)
5658  return InternalId;
5659 
5660  if (isExternallyVisible(T->getLinkage())) {
5661  std::string OutName;
5662  llvm::raw_string_ostream Out(OutName);
5664  Out << Suffix;
5665 
5666  InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
5667  } else {
5668  InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
5670  }
5671 
5672  return InternalId;
5673 }
5674 
5676  return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
5677 }
5678 
5679 llvm::Metadata *
5681  return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
5682 }
5683 
5684 // Generalize pointer types to a void pointer with the qualifiers of the
5685 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
5686 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
5687 // 'void *'.
5689  if (!Ty->isPointerType())
5690  return Ty;
5691 
5692  return Ctx.getPointerType(
5694  Ty->getPointeeType().getCVRQualifiers()));
5695 }
5696 
5697 // Apply type generalization to a FunctionType's return and argument types
5699  if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
5700  SmallVector<QualType, 8> GeneralizedParams;
5701  for (auto &Param : FnType->param_types())
5702  GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
5703 
5704  return Ctx.getFunctionType(
5705  GeneralizeType(Ctx, FnType->getReturnType()),
5706  GeneralizedParams, FnType->getExtProtoInfo());
5707  }
5708 
5709  if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
5710  return Ctx.getFunctionNoProtoType(
5711  GeneralizeType(Ctx, FnType->getReturnType()));
5712 
5713  llvm_unreachable("Encountered unknown FunctionType");
5714 }
5715 
5717  return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
5718  GeneralizedMetadataIdMap, ".generalized");
5719 }
5720 
5721 /// Returns whether this module needs the "all-vtables" type identifier.
5723  // Returns true if at least one of vtable-based CFI checkers is enabled and
5724  // is not in the trapping mode.
5725  return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
5726  !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
5727  (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
5728  !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
5729  (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
5730  !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
5731  (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
5732  !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
5733 }
5734 
5735 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
5736  CharUnits Offset,
5737  const CXXRecordDecl *RD) {
5738  llvm::Metadata *MD =
5740  VTable->addTypeMetadata(Offset.getQuantity(), MD);
5741 
5742  if (CodeGenOpts.SanitizeCfiCrossDso)
5743  if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
5744  VTable->addTypeMetadata(Offset.getQuantity(),