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 = LangOpts.Sanitize.Mask &
2243  (SanitizerKind::Address | SanitizerKind::KernelAddress |
2244  SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress);
2245  if (!EnabledAsanMask)
2246  return false;
2247  const auto &SanitizerBL = getContext().getSanitizerBlacklist();
2248  if (SanitizerBL.isBlacklistedGlobal(EnabledAsanMask, GV->getName(), Category))
2249  return true;
2250  if (SanitizerBL.isBlacklistedLocation(EnabledAsanMask, Loc, Category))
2251  return true;
2252  // Check global type.
2253  if (!Ty.isNull()) {
2254  // Drill down the array types: if global variable of a fixed type is
2255  // blacklisted, we also don't instrument arrays of them.
2256  while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
2257  Ty = AT->getElementType();
2259  // We allow to blacklist only record types (classes, structs etc.)
2260  if (Ty->isRecordType()) {
2261  std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
2262  if (SanitizerBL.isBlacklistedType(EnabledAsanMask, TypeStr, Category))
2263  return true;
2264  }
2265  }
2266  return false;
2267 }
2268 
2269 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
2270  StringRef Category) const {
2271  const auto &XRayFilter = getContext().getXRayFilter();
2272  using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
2273  auto Attr = ImbueAttr::NONE;
2274  if (Loc.isValid())
2275  Attr = XRayFilter.shouldImbueLocation(Loc, Category);
2276  if (Attr == ImbueAttr::NONE)
2277  Attr = XRayFilter.shouldImbueFunction(Fn->getName());
2278  switch (Attr) {
2279  case ImbueAttr::NONE:
2280  return false;
2281  case ImbueAttr::ALWAYS:
2282  Fn->addFnAttr("function-instrument", "xray-always");
2283  break;
2284  case ImbueAttr::ALWAYS_ARG1:
2285  Fn->addFnAttr("function-instrument", "xray-always");
2286  Fn->addFnAttr("xray-log-args", "1");
2287  break;
2288  case ImbueAttr::NEVER:
2289  Fn->addFnAttr("function-instrument", "xray-never");
2290  break;
2291  }
2292  return true;
2293 }
2294 
2295 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
2296  // Never defer when EmitAllDecls is specified.
2297  if (LangOpts.EmitAllDecls)
2298  return true;
2299 
2300  if (CodeGenOpts.KeepStaticConsts) {
2301  const auto *VD = dyn_cast<VarDecl>(Global);
2302  if (VD && VD->getType().isConstQualified() &&
2303  VD->getStorageDuration() == SD_Static)
2304  return true;
2305  }
2306 
2307  return getContext().DeclMustBeEmitted(Global);
2308 }
2309 
2310 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
2311  if (const auto *FD = dyn_cast<FunctionDecl>(Global))
2313  // Implicit template instantiations may change linkage if they are later
2314  // explicitly instantiated, so they should not be emitted eagerly.
2315  return false;
2316  if (const auto *VD = dyn_cast<VarDecl>(Global))
2317  if (Context.getInlineVariableDefinitionKind(VD) ==
2319  // A definition of an inline constexpr static data member may change
2320  // linkage later if it's redeclared outside the class.
2321  return false;
2322  // If OpenMP is enabled and threadprivates must be generated like TLS, delay
2323  // codegen for global variables, because they may be marked as threadprivate.
2324  if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
2325  getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
2326  !isTypeConstant(Global->getType(), false) &&
2327  !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
2328  return false;
2329 
2330  return true;
2331 }
2332 
2334  const CXXUuidofExpr* E) {
2335  // Sema has verified that IIDSource has a __declspec(uuid()), and that its
2336  // well-formed.
2337  StringRef Uuid = E->getUuidStr();
2338  std::string Name = "_GUID_" + Uuid.lower();
2339  std::replace(Name.begin(), Name.end(), '-', '_');
2340 
2341  // The UUID descriptor should be pointer aligned.
2343 
2344  // Look for an existing global.
2345  if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
2346  return ConstantAddress(GV, Alignment);
2347 
2348  llvm::Constant *Init = EmitUuidofInitializer(Uuid);
2349  assert(Init && "failed to initialize as constant");
2350 
2351  auto *GV = new llvm::GlobalVariable(
2352  getModule(), Init->getType(),
2353  /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
2354  if (supportsCOMDAT())
2355  GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
2356  setDSOLocal(GV);
2357  return ConstantAddress(GV, Alignment);
2358 }
2359 
2361  const AliasAttr *AA = VD->getAttr<AliasAttr>();
2362  assert(AA && "No alias?");
2363 
2364  CharUnits Alignment = getContext().getDeclAlign(VD);
2365  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
2366 
2367  // See if there is already something with the target's name in the module.
2368  llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
2369  if (Entry) {
2370  unsigned AS = getContext().getTargetAddressSpace(VD->getType());
2371  auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
2372  return ConstantAddress(Ptr, Alignment);
2373  }
2374 
2375  llvm::Constant *Aliasee;
2376  if (isa<llvm::FunctionType>(DeclTy))
2377  Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
2378  GlobalDecl(cast<FunctionDecl>(VD)),
2379  /*ForVTable=*/false);
2380  else
2381  Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
2382  llvm::PointerType::getUnqual(DeclTy),
2383  nullptr);
2384 
2385  auto *F = cast<llvm::GlobalValue>(Aliasee);
2386  F->setLinkage(llvm::Function::ExternalWeakLinkage);
2387  WeakRefReferences.insert(F);
2388 
2389  return ConstantAddress(Aliasee, Alignment);
2390 }
2391 
2393  const auto *Global = cast<ValueDecl>(GD.getDecl());
2394 
2395  // Weak references don't produce any output by themselves.
2396  if (Global->hasAttr<WeakRefAttr>())
2397  return;
2398 
2399  // If this is an alias definition (which otherwise looks like a declaration)
2400  // emit it now.
2401  if (Global->hasAttr<AliasAttr>())
2402  return EmitAliasDefinition(GD);
2403 
2404  // IFunc like an alias whose value is resolved at runtime by calling resolver.
2405  if (Global->hasAttr<IFuncAttr>())
2406  return emitIFuncDefinition(GD);
2407 
2408  // If this is a cpu_dispatch multiversion function, emit the resolver.
2409  if (Global->hasAttr<CPUDispatchAttr>())
2410  return emitCPUDispatchDefinition(GD);
2411 
2412  // If this is CUDA, be selective about which declarations we emit.
2413  if (LangOpts.CUDA) {
2414  if (LangOpts.CUDAIsDevice) {
2415  if (!Global->hasAttr<CUDADeviceAttr>() &&
2416  !Global->hasAttr<CUDAGlobalAttr>() &&
2417  !Global->hasAttr<CUDAConstantAttr>() &&
2418  !Global->hasAttr<CUDASharedAttr>())
2419  return;
2420  } else {
2421  // We need to emit host-side 'shadows' for all global
2422  // device-side variables because the CUDA runtime needs their
2423  // size and host-side address in order to provide access to
2424  // their device-side incarnations.
2425 
2426  // So device-only functions are the only things we skip.
2427  if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
2428  Global->hasAttr<CUDADeviceAttr>())
2429  return;
2430 
2431  assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
2432  "Expected Variable or Function");
2433  }
2434  }
2435 
2436  if (LangOpts.OpenMP) {
2437  // If this is OpenMP device, check if it is legal to emit this global
2438  // normally.
2439  if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
2440  return;
2441  if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
2442  if (MustBeEmitted(Global))
2444  return;
2445  } else if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) {
2446  if (MustBeEmitted(Global))
2447  EmitOMPDeclareMapper(DMD);
2448  return;
2449  }
2450  }
2451 
2452  // Ignore declarations, they will be emitted on their first use.
2453  if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
2454  // Forward declarations are emitted lazily on first use.
2455  if (!FD->doesThisDeclarationHaveABody()) {
2457  return;
2458 
2459  StringRef MangledName = getMangledName(GD);
2460 
2461  // Compute the function info and LLVM type.
2463  llvm::Type *Ty = getTypes().GetFunctionType(FI);
2464 
2465  GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
2466  /*DontDefer=*/false);
2467  return;
2468  }
2469  } else {
2470  const auto *VD = cast<VarDecl>(Global);
2471  assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
2472  if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
2473  !Context.isMSStaticDataMemberInlineDefinition(VD)) {
2474  if (LangOpts.OpenMP) {
2475  // Emit declaration of the must-be-emitted declare target variable.
2477  OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
2478  bool UnifiedMemoryEnabled =
2479  getOpenMPRuntime().hasRequiresUnifiedSharedMemory();
2480  if (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2481  !UnifiedMemoryEnabled) {
2482  (void)GetAddrOfGlobalVar(VD);
2483  } else {
2484  assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2485  (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2486  UnifiedMemoryEnabled)) &&
2487  "Link clause or to clause with unified memory expected.");
2488  (void)getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2489  }
2490 
2491  return;
2492  }
2493  }
2494  // If this declaration may have caused an inline variable definition to
2495  // change linkage, make sure that it's emitted.
2496  if (Context.getInlineVariableDefinitionKind(VD) ==
2498  GetAddrOfGlobalVar(VD);
2499  return;
2500  }
2501  }
2502 
2503  // Defer code generation to first use when possible, e.g. if this is an inline
2504  // function. If the global must always be emitted, do it eagerly if possible
2505  // to benefit from cache locality.
2506  if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
2507  // Emit the definition if it can't be deferred.
2508  EmitGlobalDefinition(GD);
2509  return;
2510  }
2511 
2512  // If we're deferring emission of a C++ variable with an
2513  // initializer, remember the order in which it appeared in the file.
2514  if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
2515  cast<VarDecl>(Global)->hasInit()) {
2516  DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
2517  CXXGlobalInits.push_back(nullptr);
2518  }
2519 
2520  StringRef MangledName = getMangledName(GD);
2521  if (GetGlobalValue(MangledName) != nullptr) {
2522  // The value has already been used and should therefore be emitted.
2523  addDeferredDeclToEmit(GD);
2524  } else if (MustBeEmitted(Global)) {
2525  // The value must be emitted, but cannot be emitted eagerly.
2526  assert(!MayBeEmittedEagerly(Global));
2527  addDeferredDeclToEmit(GD);
2528  } else {
2529  // Otherwise, remember that we saw a deferred decl with this name. The
2530  // first use of the mangled name will cause it to move into
2531  // DeferredDeclsToEmit.
2532  DeferredDecls[MangledName] = GD;
2533  }
2534 }
2535 
2536 // Check if T is a class type with a destructor that's not dllimport.
2538  if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
2539  if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
2540  if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
2541  return true;
2542 
2543  return false;
2544 }
2545 
2546 namespace {
2547  struct FunctionIsDirectlyRecursive
2548  : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> {
2549  const StringRef Name;
2550  const Builtin::Context &BI;
2551  FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C)
2552  : Name(N), BI(C) {}
2553 
2554  bool VisitCallExpr(const CallExpr *E) {
2555  const FunctionDecl *FD = E->getDirectCallee();
2556  if (!FD)
2557  return false;
2558  AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
2559  if (Attr && Name == Attr->getLabel())
2560  return true;
2561  unsigned BuiltinID = FD->getBuiltinID();
2562  if (!BuiltinID || !BI.isLibFunction(BuiltinID))
2563  return false;
2564  StringRef BuiltinName = BI.getName(BuiltinID);
2565  if (BuiltinName.startswith("__builtin_") &&
2566  Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
2567  return true;
2568  }
2569  return false;
2570  }
2571 
2572  bool VisitStmt(const Stmt *S) {
2573  for (const Stmt *Child : S->children())
2574  if (Child && this->Visit(Child))
2575  return true;
2576  return false;
2577  }
2578  };
2579 
2580  // Make sure we're not referencing non-imported vars or functions.
2581  struct DLLImportFunctionVisitor
2582  : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
2583  bool SafeToInline = true;
2584 
2585  bool shouldVisitImplicitCode() const { return true; }
2586 
2587  bool VisitVarDecl(VarDecl *VD) {
2588  if (VD->getTLSKind()) {
2589  // A thread-local variable cannot be imported.
2590  SafeToInline = false;
2591  return SafeToInline;
2592  }
2593 
2594  // A variable definition might imply a destructor call.
2595  if (VD->isThisDeclarationADefinition())
2596  SafeToInline = !HasNonDllImportDtor(VD->getType());
2597 
2598  return SafeToInline;
2599  }
2600 
2601  bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
2602  if (const auto *D = E->getTemporary()->getDestructor())
2603  SafeToInline = D->hasAttr<DLLImportAttr>();
2604  return SafeToInline;
2605  }
2606 
2607  bool VisitDeclRefExpr(DeclRefExpr *E) {
2608  ValueDecl *VD = E->getDecl();
2609  if (isa<FunctionDecl>(VD))
2610  SafeToInline = VD->hasAttr<DLLImportAttr>();
2611  else if (VarDecl *V = dyn_cast<VarDecl>(VD))
2612  SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
2613  return SafeToInline;
2614  }
2615 
2616  bool VisitCXXConstructExpr(CXXConstructExpr *E) {
2617  SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
2618  return SafeToInline;
2619  }
2620 
2621  bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
2622  CXXMethodDecl *M = E->getMethodDecl();
2623  if (!M) {
2624  // Call through a pointer to member function. This is safe to inline.
2625  SafeToInline = true;
2626  } else {
2627  SafeToInline = M->hasAttr<DLLImportAttr>();
2628  }
2629  return SafeToInline;
2630  }
2631 
2632  bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
2633  SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
2634  return SafeToInline;
2635  }
2636 
2637  bool VisitCXXNewExpr(CXXNewExpr *E) {
2638  SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
2639  return SafeToInline;
2640  }
2641  };
2642 }
2643 
2644 // isTriviallyRecursive - Check if this function calls another
2645 // decl that, because of the asm attribute or the other decl being a builtin,
2646 // ends up pointing to itself.
2647 bool
2648 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
2649  StringRef Name;
2650  if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
2651  // asm labels are a special kind of mangling we have to support.
2652  AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
2653  if (!Attr)
2654  return false;
2655  Name = Attr->getLabel();
2656  } else {
2657  Name = FD->getName();
2658  }
2659 
2660  FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
2661  const Stmt *Body = FD->getBody();
2662  return Body ? Walker.Visit(Body) : false;
2663 }
2664 
2665 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
2666  if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
2667  return true;
2668  const auto *F = cast<FunctionDecl>(GD.getDecl());
2669  if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
2670  return false;
2671 
2672  if (F->hasAttr<DLLImportAttr>()) {
2673  // Check whether it would be safe to inline this dllimport function.
2674  DLLImportFunctionVisitor Visitor;
2675  Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
2676  if (!Visitor.SafeToInline)
2677  return false;
2678 
2679  if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
2680  // Implicit destructor invocations aren't captured in the AST, so the
2681  // check above can't see them. Check for them manually here.
2682  for (const Decl *Member : Dtor->getParent()->decls())
2683  if (isa<FieldDecl>(Member))
2684  if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
2685  return false;
2686  for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
2687  if (HasNonDllImportDtor(B.getType()))
2688  return false;
2689  }
2690  }
2691 
2692  // PR9614. Avoid cases where the source code is lying to us. An available
2693  // externally function should have an equivalent function somewhere else,
2694  // but a function that calls itself is clearly not equivalent to the real
2695  // implementation.
2696  // This happens in glibc's btowc and in some configure checks.
2697  return !isTriviallyRecursive(F);
2698 }
2699 
2700 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
2701  return CodeGenOpts.OptimizationLevel > 0;
2702 }
2703 
2704 void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
2705  llvm::GlobalValue *GV) {
2706  const auto *FD = cast<FunctionDecl>(GD.getDecl());
2707 
2708  if (FD->isCPUSpecificMultiVersion()) {
2709  auto *Spec = FD->getAttr<CPUSpecificAttr>();
2710  for (unsigned I = 0; I < Spec->cpus_size(); ++I)
2711  EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
2712  // Requires multiple emits.
2713  } else
2714  EmitGlobalFunctionDefinition(GD, GV);
2715 }
2716 
2717 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
2718  const auto *D = cast<ValueDecl>(GD.getDecl());
2719 
2720  PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
2721  Context.getSourceManager(),
2722  "Generating code for declaration");
2723 
2724  if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
2725  // At -O0, don't generate IR for functions with available_externally
2726  // linkage.
2727  if (!shouldEmitFunction(GD))
2728  return;
2729 
2730  llvm::TimeTraceScope TimeScope("CodeGen Function", [&]() {
2731  std::string Name;
2732  llvm::raw_string_ostream OS(Name);
2733  FD->getNameForDiagnostic(OS, getContext().getPrintingPolicy(),
2734  /*Qualified=*/true);
2735  return Name;
2736  });
2737 
2738  if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
2739  // Make sure to emit the definition(s) before we emit the thunks.
2740  // This is necessary for the generation of certain thunks.
2741  if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
2742  ABI->emitCXXStructor(GD);
2743  else if (FD->isMultiVersion())
2744  EmitMultiVersionFunctionDefinition(GD, GV);
2745  else
2746  EmitGlobalFunctionDefinition(GD, GV);
2747 
2748  if (Method->isVirtual())
2749  getVTables().EmitThunks(GD);
2750 
2751  return;
2752  }
2753 
2754  if (FD->isMultiVersion())
2755  return EmitMultiVersionFunctionDefinition(GD, GV);
2756  return EmitGlobalFunctionDefinition(GD, GV);
2757  }
2758 
2759  if (const auto *VD = dyn_cast<VarDecl>(D))
2760  return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
2761 
2762  llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
2763 }
2764 
2765 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
2766  llvm::Function *NewFn);
2767 
2768 static unsigned
2771  unsigned Priority = 0;
2772  for (StringRef Feat : RO.Conditions.Features)
2773  Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
2774 
2775  if (!RO.Conditions.Architecture.empty())
2776  Priority = std::max(
2778  return Priority;
2779 }
2780 
2781 void CodeGenModule::emitMultiVersionFunctions() {
2782  for (GlobalDecl GD : MultiVersionFuncs) {
2784  const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2786  FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
2787  GlobalDecl CurGD{
2788  (CurFD->isDefined() ? CurFD->getDefinition() : CurFD)};
2789  StringRef MangledName = getMangledName(CurGD);
2790  llvm::Constant *Func = GetGlobalValue(MangledName);
2791  if (!Func) {
2792  if (CurFD->isDefined()) {
2793  EmitGlobalFunctionDefinition(CurGD, nullptr);
2794  Func = GetGlobalValue(MangledName);
2795  } else {
2796  const CGFunctionInfo &FI =
2798  llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
2799  Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
2800  /*DontDefer=*/false, ForDefinition);
2801  }
2802  assert(Func && "This should have just been created");
2803  }
2804 
2805  const auto *TA = CurFD->getAttr<TargetAttr>();
2807  TA->getAddedFeatures(Feats);
2808 
2809  Options.emplace_back(cast<llvm::Function>(Func),
2810  TA->getArchitecture(), Feats);
2811  });
2812 
2813  llvm::Function *ResolverFunc;
2814  const TargetInfo &TI = getTarget();
2815 
2816  if (TI.supportsIFunc() || FD->isTargetMultiVersion())
2817  ResolverFunc = cast<llvm::Function>(
2818  GetGlobalValue((getMangledName(GD) + ".resolver").str()));
2819  else
2820  ResolverFunc = cast<llvm::Function>(GetGlobalValue(getMangledName(GD)));
2821 
2822  if (supportsCOMDAT())
2823  ResolverFunc->setComdat(
2824  getModule().getOrInsertComdat(ResolverFunc->getName()));
2825 
2826  llvm::stable_sort(
2827  Options, [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
2829  return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
2830  });
2831  CodeGenFunction CGF(*this);
2832  CGF.EmitMultiVersionResolver(ResolverFunc, Options);
2833  }
2834 }
2835 
2836 void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
2837  const auto *FD = cast<FunctionDecl>(GD.getDecl());
2838  assert(FD && "Not a FunctionDecl?");
2839  const auto *DD = FD->getAttr<CPUDispatchAttr>();
2840  assert(DD && "Not a cpu_dispatch Function?");
2841  llvm::Type *DeclTy = getTypes().ConvertType(FD->getType());
2842 
2843  if (const auto *CXXFD = dyn_cast<CXXMethodDecl>(FD)) {
2844  const CGFunctionInfo &FInfo = getTypes().arrangeCXXMethodDeclaration(CXXFD);
2845  DeclTy = getTypes().GetFunctionType(FInfo);
2846  }
2847 
2848  StringRef ResolverName = getMangledName(GD);
2849 
2850  llvm::Type *ResolverType;
2851  GlobalDecl ResolverGD;
2852  if (getTarget().supportsIFunc())
2853  ResolverType = llvm::FunctionType::get(
2854  llvm::PointerType::get(DeclTy,
2855  Context.getTargetAddressSpace(FD->getType())),
2856  false);
2857  else {
2858  ResolverType = DeclTy;
2859  ResolverGD = GD;
2860  }
2861 
2862  auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
2863  ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
2864 
2866  const TargetInfo &Target = getTarget();
2867  unsigned Index = 0;
2868  for (const IdentifierInfo *II : DD->cpus()) {
2869  // Get the name of the target function so we can look it up/create it.
2870  std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
2871  getCPUSpecificMangling(*this, II->getName());
2872 
2873  llvm::Constant *Func = GetGlobalValue(MangledName);
2874 
2875  if (!Func) {
2876  GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
2877  if (ExistingDecl.getDecl() &&
2878  ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
2879  EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
2880  Func = GetGlobalValue(MangledName);
2881  } else {
2882  if (!ExistingDecl.getDecl())
2883  ExistingDecl = GD.getWithMultiVersionIndex(Index);
2884 
2885  Func = GetOrCreateLLVMFunction(
2886  MangledName, DeclTy, ExistingDecl,
2887  /*ForVTable=*/false, /*DontDefer=*/true,
2888  /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
2889  }
2890  }
2891 
2893  Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
2894  llvm::transform(Features, Features.begin(),
2895  [](StringRef Str) { return Str.substr(1); });
2896  Features.erase(std::remove_if(
2897  Features.begin(), Features.end(), [&Target](StringRef Feat) {
2898  return !Target.validateCpuSupports(Feat);
2899  }), Features.end());
2900  Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
2901  ++Index;
2902  }
2903 
2904  llvm::sort(
2905  Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
2909  });
2910 
2911  // If the list contains multiple 'default' versions, such as when it contains
2912  // 'pentium' and 'generic', don't emit the call to the generic one (since we
2913  // always run on at least a 'pentium'). We do this by deleting the 'least
2914  // advanced' (read, lowest mangling letter).
2915  while (Options.size() > 1 &&
2917  (Options.end() - 2)->Conditions.Features) == 0) {
2918  StringRef LHSName = (Options.end() - 2)->Function->getName();
2919  StringRef RHSName = (Options.end() - 1)->Function->getName();
2920  if (LHSName.compare(RHSName) < 0)
2921  Options.erase(Options.end() - 2);
2922  else
2923  Options.erase(Options.end() - 1);
2924  }
2925 
2926  CodeGenFunction CGF(*this);
2927  CGF.EmitMultiVersionResolver(ResolverFunc, Options);
2928 }
2929 
2930 /// If a dispatcher for the specified mangled name is not in the module, create
2931 /// and return an llvm Function with the specified type.
2932 llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(
2933  GlobalDecl GD, llvm::Type *DeclTy, const FunctionDecl *FD) {
2934  std::string MangledName =
2935  getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
2936 
2937  // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
2938  // a separate resolver).
2939  std::string ResolverName = MangledName;
2940  if (getTarget().supportsIFunc())
2941  ResolverName += ".ifunc";
2942  else if (FD->isTargetMultiVersion())
2943  ResolverName += ".resolver";
2944 
2945  // If this already exists, just return that one.
2946  if (llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName))
2947  return ResolverGV;
2948 
2949  // Since this is the first time we've created this IFunc, make sure
2950  // that we put this multiversioned function into the list to be
2951  // replaced later if necessary (target multiversioning only).
2953  MultiVersionFuncs.push_back(GD);
2954 
2955  if (getTarget().supportsIFunc()) {
2956  llvm::Type *ResolverType = llvm::FunctionType::get(
2957  llvm::PointerType::get(
2958  DeclTy, getContext().getTargetAddressSpace(FD->getType())),
2959  false);
2960  llvm::Constant *Resolver = GetOrCreateLLVMFunction(
2961  MangledName + ".resolver", ResolverType, GlobalDecl{},
2962  /*ForVTable=*/false);
2963  llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
2964  DeclTy, 0, llvm::Function::ExternalLinkage, "", Resolver, &getModule());
2965  GIF->setName(ResolverName);
2966  SetCommonAttributes(FD, GIF);
2967 
2968  return GIF;
2969  }
2970 
2971  llvm::Constant *Resolver = GetOrCreateLLVMFunction(
2972  ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
2973  assert(isa<llvm::GlobalValue>(Resolver) &&
2974  "Resolver should be created for the first time");
2975  SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
2976  return Resolver;
2977 }
2978 
2979 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
2980 /// module, create and return an llvm Function with the specified type. If there
2981 /// is something in the module with the specified name, return it potentially
2982 /// bitcasted to the right type.
2983 ///
2984 /// If D is non-null, it specifies a decl that correspond to this. This is used
2985 /// to set the attributes on the function when it is first created.
2986 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
2987  StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
2988  bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
2989  ForDefinition_t IsForDefinition) {
2990  const Decl *D = GD.getDecl();
2991 
2992  // Any attempts to use a MultiVersion function should result in retrieving
2993  // the iFunc instead. Name Mangling will handle the rest of the changes.
2994  if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
2995  // For the device mark the function as one that should be emitted.
2996  if (getLangOpts().OpenMPIsDevice && OpenMPRuntime &&
2997  !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
2998  !DontDefer && !IsForDefinition) {
2999  if (const FunctionDecl *FDDef = FD->getDefinition()) {
3000  GlobalDecl GDDef;
3001  if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
3002  GDDef = GlobalDecl(CD, GD.getCtorType());
3003  else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
3004  GDDef = GlobalDecl(DD, GD.getDtorType());
3005  else
3006  GDDef = GlobalDecl(FDDef);
3007  EmitGlobal(GDDef);
3008  }
3009  }
3010 
3011  if (FD->isMultiVersion()) {
3012  const auto *TA = FD->getAttr<TargetAttr>();
3013  if (TA && TA->isDefaultVersion())
3014  UpdateMultiVersionNames(GD, FD);
3015  if (!IsForDefinition)
3016  return GetOrCreateMultiVersionResolver(GD, Ty, FD);
3017  }
3018  }
3019 
3020  // Lookup the entry, lazily creating it if necessary.
3021  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3022  if (Entry) {
3023  if (WeakRefReferences.erase(Entry)) {
3024  const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
3025  if (FD && !FD->hasAttr<WeakAttr>())
3026  Entry->setLinkage(llvm::Function::ExternalLinkage);
3027  }
3028 
3029  // Handle dropped DLL attributes.
3030  if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>()) {
3031  Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3032  setDSOLocal(Entry);
3033  }
3034 
3035  // If there are two attempts to define the same mangled name, issue an
3036  // error.
3037  if (IsForDefinition && !Entry->isDeclaration()) {
3038  GlobalDecl OtherGD;
3039  // Check that GD is not yet in DiagnosedConflictingDefinitions is required
3040  // to make sure that we issue an error only once.
3041  if (lookupRepresentativeDecl(MangledName, OtherGD) &&
3042  (GD.getCanonicalDecl().getDecl() !=
3043  OtherGD.getCanonicalDecl().getDecl()) &&
3044  DiagnosedConflictingDefinitions.insert(GD).second) {
3045  getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3046  << MangledName;
3047  getDiags().Report(OtherGD.getDecl()->getLocation(),
3048  diag::note_previous_definition);
3049  }
3050  }
3051 
3052  if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
3053  (Entry->getType()->getElementType() == Ty)) {
3054  return Entry;
3055  }
3056 
3057  // Make sure the result is of the correct type.
3058  // (If function is requested for a definition, we always need to create a new
3059  // function, not just return a bitcast.)
3060  if (!IsForDefinition)
3061  return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
3062  }
3063 
3064  // This function doesn't have a complete type (for example, the return
3065  // type is an incomplete struct). Use a fake type instead, and make
3066  // sure not to try to set attributes.
3067  bool IsIncompleteFunction = false;
3068 
3069  llvm::FunctionType *FTy;
3070  if (isa<llvm::FunctionType>(Ty)) {
3071  FTy = cast<llvm::FunctionType>(Ty);
3072  } else {
3073  FTy = llvm::FunctionType::get(VoidTy, false);
3074  IsIncompleteFunction = true;
3075  }
3076 
3077  llvm::Function *F =
3079  Entry ? StringRef() : MangledName, &getModule());
3080 
3081  // If we already created a function with the same mangled name (but different
3082  // type) before, take its name and add it to the list of functions to be
3083  // replaced with F at the end of CodeGen.
3084  //
3085  // This happens if there is a prototype for a function (e.g. "int f()") and
3086  // then a definition of a different type (e.g. "int f(int x)").
3087  if (Entry) {
3088  F->takeName(Entry);
3089 
3090  // This might be an implementation of a function without a prototype, in
3091  // which case, try to do special replacement of calls which match the new
3092  // prototype. The really key thing here is that we also potentially drop
3093  // arguments from the call site so as to make a direct call, which makes the
3094  // inliner happier and suppresses a number of optimizer warnings (!) about
3095  // dropping arguments.
3096  if (!Entry->use_empty()) {
3098  Entry->removeDeadConstantUsers();
3099  }
3100 
3101  llvm::Constant *BC = llvm::ConstantExpr::getBitCast(
3102  F, Entry->getType()->getElementType()->getPointerTo());
3103  addGlobalValReplacement(Entry, BC);
3104  }
3105 
3106  assert(F->getName() == MangledName && "name was uniqued!");
3107  if (D)
3108  SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
3109  if (ExtraAttrs.hasAttributes(llvm::AttributeList::FunctionIndex)) {
3110  llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex);
3111  F->addAttributes(llvm::AttributeList::FunctionIndex, B);
3112  }
3113 
3114  if (!DontDefer) {
3115  // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
3116  // each other bottoming out with the base dtor. Therefore we emit non-base
3117  // dtors on usage, even if there is no dtor definition in the TU.
3118  if (D && isa<CXXDestructorDecl>(D) &&
3119  getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
3120  GD.getDtorType()))
3121  addDeferredDeclToEmit(GD);
3122 
3123  // This is the first use or definition of a mangled name. If there is a
3124  // deferred decl with this name, remember that we need to emit it at the end
3125  // of the file.
3126  auto DDI = DeferredDecls.find(MangledName);
3127  if (DDI != DeferredDecls.end()) {
3128  // Move the potentially referenced deferred decl to the
3129  // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
3130  // don't need it anymore).
3131  addDeferredDeclToEmit(DDI->second);
3132  DeferredDecls.erase(DDI);
3133 
3134  // Otherwise, there are cases we have to worry about where we're
3135  // using a declaration for which we must emit a definition but where
3136  // we might not find a top-level definition:
3137  // - member functions defined inline in their classes
3138  // - friend functions defined inline in some class
3139  // - special member functions with implicit definitions
3140  // If we ever change our AST traversal to walk into class methods,
3141  // this will be unnecessary.
3142  //
3143  // We also don't emit a definition for a function if it's going to be an
3144  // entry in a vtable, unless it's already marked as used.
3145  } else if (getLangOpts().CPlusPlus && D) {
3146  // Look for a declaration that's lexically in a record.
3147  for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
3148  FD = FD->getPreviousDecl()) {
3149  if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
3150  if (FD->doesThisDeclarationHaveABody()) {
3151  addDeferredDeclToEmit(GD.getWithDecl(FD));
3152  break;
3153  }
3154  }
3155  }
3156  }
3157  }
3158 
3159  // Make sure the result is of the requested type.
3160  if (!IsIncompleteFunction) {
3161  assert(F->getType()->getElementType() == Ty);
3162  return F;
3163  }
3164 
3165  llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
3166  return llvm::ConstantExpr::getBitCast(F, PTy);
3167 }
3168 
3169 /// GetAddrOfFunction - Return the address of the given function. If Ty is
3170 /// non-null, then this function will use the specified type if it has to
3171 /// create it (this occurs when we see a definition of the function).
3173  llvm::Type *Ty,
3174  bool ForVTable,
3175  bool DontDefer,
3176  ForDefinition_t IsForDefinition) {
3177  // If there was no specific requested type, just convert it now.
3178  if (!Ty) {
3179  const auto *FD = cast<FunctionDecl>(GD.getDecl());
3180  Ty = getTypes().ConvertType(FD->getType());
3181  }
3182 
3183  // Devirtualized destructor calls may come through here instead of via
3184  // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
3185  // of the complete destructor when necessary.
3186  if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
3187  if (getTarget().getCXXABI().isMicrosoft() &&
3188  GD.getDtorType() == Dtor_Complete &&
3189  DD->getParent()->getNumVBases() == 0)
3190  GD = GlobalDecl(DD, Dtor_Base);
3191  }
3192 
3193  StringRef MangledName = getMangledName(GD);
3194  return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
3195  /*IsThunk=*/false, llvm::AttributeList(),
3196  IsForDefinition);
3197 }
3198 
3199 static const FunctionDecl *
3200 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
3203 
3204  IdentifierInfo &CII = C.Idents.get(Name);
3205  for (const auto &Result : DC->lookup(&CII))
3206  if (const auto FD = dyn_cast<FunctionDecl>(Result))
3207  return FD;
3208 
3209  if (!C.getLangOpts().CPlusPlus)
3210  return nullptr;
3211 
3212  // Demangle the premangled name from getTerminateFn()
3213  IdentifierInfo &CXXII =
3214  (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
3215  ? C.Idents.get("terminate")
3216  : C.Idents.get(Name);
3217 
3218  for (const auto &N : {"__cxxabiv1", "std"}) {
3219  IdentifierInfo &NS = C.Idents.get(N);
3220  for (const auto &Result : DC->lookup(&NS)) {
3221  NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
3222  if (auto LSD = dyn_cast<LinkageSpecDecl>(Result))
3223  for (const auto &Result : LSD->lookup(&NS))
3224  if ((ND = dyn_cast<NamespaceDecl>(Result)))
3225  break;
3226 
3227  if (ND)
3228  for (const auto &Result : ND->lookup(&CXXII))
3229  if (const auto *FD = dyn_cast<FunctionDecl>(Result))
3230  return FD;
3231  }
3232  }
3233 
3234  return nullptr;
3235 }
3236 
3237 /// CreateRuntimeFunction - Create a new runtime function with the specified
3238 /// type and name.
3239 llvm::FunctionCallee
3240 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
3241  llvm::AttributeList ExtraAttrs,
3242  bool Local) {
3243  llvm::Constant *C =
3244  GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
3245  /*DontDefer=*/false, /*IsThunk=*/false,
3246  ExtraAttrs);
3247 
3248  if (auto *F = dyn_cast<llvm::Function>(C)) {
3249  if (F->empty()) {
3250  F->setCallingConv(getRuntimeCC());
3251 
3252  // In Windows Itanium environments, try to mark runtime functions
3253  // dllimport. For Mingw and MSVC, don't. We don't really know if the user
3254  // will link their standard library statically or dynamically. Marking
3255  // functions imported when they are not imported can cause linker errors
3256  // and warnings.
3257  if (!Local && getTriple().isWindowsItaniumEnvironment() &&
3258  !getCodeGenOpts().LTOVisibilityPublicStd) {
3259  const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
3260  if (!FD || FD->hasAttr<DLLImportAttr>()) {
3261  F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
3262  F->setLinkage(llvm::GlobalValue::ExternalLinkage);
3263  }
3264  }
3265  setDSOLocal(F);
3266  }
3267  }
3268 
3269  return {FTy, C};
3270 }
3271 
3272 /// isTypeConstant - Determine whether an object of this type can be emitted
3273 /// as a constant.
3274 ///
3275 /// If ExcludeCtor is true, the duration when the object's constructor runs
3276 /// will not be considered. The caller will need to verify that the object is
3277 /// not written to during its construction.
3278 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
3279  if (!Ty.isConstant(Context) && !Ty->isReferenceType())
3280  return false;
3281 
3282  if (Context.getLangOpts().CPlusPlus) {
3283  if (const CXXRecordDecl *Record
3284  = Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
3285  return ExcludeCtor && !Record->hasMutableFields() &&
3286  Record->hasTrivialDestructor();
3287  }
3288 
3289  return true;
3290 }
3291 
3292 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
3293 /// create and return an llvm GlobalVariable with the specified type. If there
3294 /// is something in the module with the specified name, return it potentially
3295 /// bitcasted to the right type.
3296 ///
3297 /// If D is non-null, it specifies a decl that correspond to this. This is used
3298 /// to set the attributes on the global when it is first created.
3299 ///
3300 /// If IsForDefinition is true, it is guaranteed that an actual global with
3301 /// type Ty will be returned, not conversion of a variable with the same
3302 /// mangled name but some other type.
3303 llvm::Constant *
3304 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
3305  llvm::PointerType *Ty,
3306  const VarDecl *D,
3307  ForDefinition_t IsForDefinition) {
3308  // Lookup the entry, lazily creating it if necessary.
3309  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3310  if (Entry) {
3311  if (WeakRefReferences.erase(Entry)) {
3312  if (D && !D->hasAttr<WeakAttr>())
3313  Entry->setLinkage(llvm::Function::ExternalLinkage);
3314  }
3315 
3316  // Handle dropped DLL attributes.
3317  if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
3318  Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3319 
3320  if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
3321  getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
3322 
3323  if (Entry->getType() == Ty)
3324  return Entry;
3325 
3326  // If there are two attempts to define the same mangled name, issue an
3327  // error.
3328  if (IsForDefinition && !Entry->isDeclaration()) {
3329  GlobalDecl OtherGD;
3330  const VarDecl *OtherD;
3331 
3332  // Check that D is not yet in DiagnosedConflictingDefinitions is required
3333  // to make sure that we issue an error only once.
3334  if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
3335  (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
3336  (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
3337  OtherD->hasInit() &&
3338  DiagnosedConflictingDefinitions.insert(D).second) {
3339  getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3340  << MangledName;
3341  getDiags().Report(OtherGD.getDecl()->getLocation(),
3342  diag::note_previous_definition);
3343  }
3344  }
3345 
3346  // Make sure the result is of the correct type.
3347  if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace())
3348  return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty);
3349 
3350  // (If global is requested for a definition, we always need to create a new
3351  // global, not just return a bitcast.)
3352  if (!IsForDefinition)
3353  return llvm::ConstantExpr::getBitCast(Entry, Ty);
3354  }
3355 
3356  auto AddrSpace = GetGlobalVarAddressSpace(D);
3357  auto TargetAddrSpace = getContext().getTargetAddressSpace(AddrSpace);
3358 
3359  auto *GV = new llvm::GlobalVariable(
3360  getModule(), Ty->getElementType(), false,
3361  llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr,
3362  llvm::GlobalVariable::NotThreadLocal, TargetAddrSpace);
3363 
3364  // If we already created a global with the same mangled name (but different
3365  // type) before, take its name and remove it from its parent.
3366  if (Entry) {
3367  GV->takeName(Entry);
3368 
3369  if (!Entry->use_empty()) {
3370  llvm::Constant *NewPtrForOldDecl =
3371  llvm::ConstantExpr::getBitCast(GV, Entry->getType());
3372  Entry->replaceAllUsesWith(NewPtrForOldDecl);
3373  }
3374 
3375  Entry->eraseFromParent();
3376  }
3377 
3378  // This is the first use or definition of a mangled name. If there is a
3379  // deferred decl with this name, remember that we need to emit it at the end
3380  // of the file.
3381  auto DDI = DeferredDecls.find(MangledName);
3382  if (DDI != DeferredDecls.end()) {
3383  // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
3384  // list, and remove it from DeferredDecls (since we don't need it anymore).
3385  addDeferredDeclToEmit(DDI->second);
3386  DeferredDecls.erase(DDI);
3387  }
3388 
3389  // Handle things which are present even on external declarations.
3390  if (D) {
3391  if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
3392  getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
3393 
3394  // FIXME: This code is overly simple and should be merged with other global
3395  // handling.
3396  GV->setConstant(isTypeConstant(D->getType(), false));
3397 
3398  GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
3399 
3400  setLinkageForGV(GV, D);
3401 
3402  if (D->getTLSKind()) {
3403  if (D->getTLSKind() == VarDecl::TLS_Dynamic)
3404  CXXThreadLocals.push_back(D);
3405  setTLSMode(GV, *D);
3406  }
3407 
3408  setGVProperties(GV, D);
3409 
3410  // If required by the ABI, treat declarations of static data members with
3411  // inline initializers as definitions.
3412  if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
3413  EmitGlobalVarDefinition(D);
3414  }
3415 
3416  // Emit section information for extern variables.
3417  if (D->hasExternalStorage()) {
3418  if (const SectionAttr *SA = D->getAttr<SectionAttr>())
3419  GV->setSection(SA->getName());
3420  }
3421 
3422  // Handle XCore specific ABI requirements.
3423  if (getTriple().getArch() == llvm::Triple::xcore &&
3425  D->getType().isConstant(Context) &&
3427  GV->setSection(".cp.rodata");
3428 
3429  // Check if we a have a const declaration with an initializer, we may be
3430  // able to emit it as available_externally to expose it's value to the
3431  // optimizer.
3432  if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
3433  D->getType().isConstQualified() && !GV->hasInitializer() &&
3434  !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
3435  const auto *Record =
3436  Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
3437  bool HasMutableFields = Record && Record->hasMutableFields();
3438  if (!HasMutableFields) {
3439  const VarDecl *InitDecl;
3440  const Expr *InitExpr = D->getAnyInitializer(InitDecl);
3441  if (InitExpr) {
3442  ConstantEmitter emitter(*this);
3443  llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
3444  if (Init) {
3445  auto *InitType = Init->getType();
3446  if (GV->getType()->getElementType() != InitType) {
3447  // The type of the initializer does not match the definition.
3448  // This happens when an initializer has a different type from
3449  // the type of the global (because of padding at the end of a
3450  // structure for instance).
3451  GV->setName(StringRef());
3452  // Make a new global with the correct type, this is now guaranteed
3453  // to work.
3454  auto *NewGV = cast<llvm::GlobalVariable>(
3455  GetAddrOfGlobalVar(D, InitType, IsForDefinition));
3456 
3457  // Erase the old global, since it is no longer used.
3458  GV->eraseFromParent();
3459  GV = NewGV;
3460  } else {
3461  GV->setInitializer(Init);
3462  GV->setConstant(true);
3463  GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
3464  }
3465  emitter.finalize(GV);
3466  }
3467  }
3468  }
3469  }
3470  }
3471 
3472  LangAS ExpectedAS =
3473  D ? D->getType().getAddressSpace()
3474  : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
3475  assert(getContext().getTargetAddressSpace(ExpectedAS) ==
3476  Ty->getPointerAddressSpace());
3477  if (AddrSpace != ExpectedAS)
3478  return getTargetCodeGenInfo().performAddrSpaceCast(*this, GV, AddrSpace,
3479  ExpectedAS, Ty);
3480 
3481  if (GV->isDeclaration())
3482  getTargetCodeGenInfo().setTargetAttributes(D, GV, *this);
3483 
3484  return GV;
3485 }
3486 
3487 llvm::Constant *
3489  ForDefinition_t IsForDefinition) {
3490  const Decl *D = GD.getDecl();
3491  if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
3492  return getAddrOfCXXStructor(GD, /*FnInfo=*/nullptr, /*FnType=*/nullptr,
3493  /*DontDefer=*/false, IsForDefinition);
3494  else if (isa<CXXMethodDecl>(D)) {
3495  auto FInfo = &getTypes().arrangeCXXMethodDeclaration(
3496  cast<CXXMethodDecl>(D));
3497  auto Ty = getTypes().GetFunctionType(*FInfo);
3498  return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
3499  IsForDefinition);
3500  } else if (isa<FunctionDecl>(D)) {
3502  llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
3503  return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
3504  IsForDefinition);
3505  } else
3506  return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr,
3507  IsForDefinition);
3508 }
3509 
3511  StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
3512  unsigned Alignment) {
3513  llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
3514  llvm::GlobalVariable *OldGV = nullptr;
3515 
3516  if (GV) {
3517  // Check if the variable has the right type.
3518  if (GV->getType()->getElementType() == Ty)
3519  return GV;
3520 
3521  // Because C++ name mangling, the only way we can end up with an already
3522  // existing global with the same name is if it has been declared extern "C".
3523  assert(GV->isDeclaration() && "Declaration has wrong type!");
3524  OldGV = GV;
3525  }
3526 
3527  // Create a new variable.
3528  GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
3529  Linkage, nullptr, Name);
3530 
3531  if (OldGV) {
3532  // Replace occurrences of the old variable if needed.
3533  GV->takeName(OldGV);
3534 
3535  if (!OldGV->use_empty()) {
3536  llvm::Constant *NewPtrForOldDecl =
3537  llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
3538  OldGV->replaceAllUsesWith(NewPtrForOldDecl);
3539  }
3540 
3541  OldGV->eraseFromParent();
3542  }
3543 
3544  if (supportsCOMDAT() && GV->isWeakForLinker() &&
3545  !GV->hasAvailableExternallyLinkage())
3546  GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3547 
3548  GV->setAlignment(Alignment);
3549 
3550  return GV;
3551 }
3552 
3553 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
3554 /// given global variable. If Ty is non-null and if the global doesn't exist,
3555 /// then it will be created with the specified type instead of whatever the
3556 /// normal requested type would be. If IsForDefinition is true, it is guaranteed
3557 /// that an actual global with type Ty will be returned, not conversion of a
3558 /// variable with the same mangled name but some other type.
3560  llvm::Type *Ty,
3561  ForDefinition_t IsForDefinition) {
3562  assert(D->hasGlobalStorage() && "Not a global variable");
3563  QualType ASTTy = D->getType();
3564  if (!Ty)
3565  Ty = getTypes().ConvertTypeForMem(ASTTy);
3566 
3567  llvm::PointerType *PTy =
3568  llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
3569 
3570  StringRef MangledName = getMangledName(D);
3571  return GetOrCreateLLVMGlobal(MangledName, PTy, D, IsForDefinition);
3572 }
3573 
3574 /// CreateRuntimeVariable - Create a new runtime global variable with the
3575 /// specified type and name.
3576 llvm::Constant *
3578  StringRef Name) {
3579  auto *Ret =
3580  GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), nullptr);
3581  setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
3582  return Ret;
3583 }
3584 
3586  assert(!D->getInit() && "Cannot emit definite definitions here!");
3587 
3588  StringRef MangledName = getMangledName(D);
3589  llvm::GlobalValue *GV = GetGlobalValue(MangledName);
3590 
3591  // We already have a definition, not declaration, with the same mangled name.
3592  // Emitting of declaration is not required (and actually overwrites emitted
3593  // definition).
3594  if (GV && !GV->isDeclaration())
3595  return;
3596 
3597  // If we have not seen a reference to this variable yet, place it into the
3598  // deferred declarations table to be emitted if needed later.
3599  if (!MustBeEmitted(D) && !GV) {
3600  DeferredDecls[MangledName] = D;
3601  return;
3602  }
3603 
3604  // The tentative definition is the only definition.
3605  EmitGlobalVarDefinition(D);
3606 }
3607 
3609  return Context.toCharUnitsFromBits(
3610  getDataLayout().getTypeStoreSizeInBits(Ty));
3611 }
3612 
3614  LangAS AddrSpace = LangAS::Default;
3615  if (LangOpts.OpenCL) {
3616  AddrSpace = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
3617  assert(AddrSpace == LangAS::opencl_global ||
3618  AddrSpace == LangAS::opencl_constant ||
3619  AddrSpace == LangAS::opencl_local ||
3620  AddrSpace >= LangAS::FirstTargetAddressSpace);
3621  return AddrSpace;
3622  }
3623 
3624  if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
3625  if (D && D->hasAttr<CUDAConstantAttr>())
3626  return LangAS::cuda_constant;
3627  else if (D && D->hasAttr<CUDASharedAttr>())
3628  return LangAS::cuda_shared;
3629  else if (D && D->hasAttr<CUDADeviceAttr>())
3630  return LangAS::cuda_device;
3631  else if (D && D->getType().isConstQualified())
3632  return LangAS::cuda_constant;
3633  else
3634  return LangAS::cuda_device;
3635  }
3636 
3637  if (LangOpts.OpenMP) {
3638  LangAS AS;
3639  if (OpenMPRuntime->hasAllocateAttributeForGlobalVar(D, AS))
3640  return AS;
3641  }
3643 }
3644 
3646  // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
3647  if (LangOpts.OpenCL)
3648  return LangAS::opencl_constant;
3649  if (auto AS = getTarget().getConstantAddressSpace())
3650  return AS.getValue();
3651  return LangAS::Default;
3652 }
3653 
3654 // In address space agnostic languages, string literals are in default address
3655 // space in AST. However, certain targets (e.g. amdgcn) request them to be
3656 // emitted in constant address space in LLVM IR. To be consistent with other
3657 // parts of AST, string literal global variables in constant address space
3658 // need to be casted to default address space before being put into address
3659 // map and referenced by other part of CodeGen.
3660 // In OpenCL, string literals are in constant address space in AST, therefore
3661 // they should not be casted to default address space.
3662 static llvm::Constant *
3664  llvm::GlobalVariable *GV) {
3665  llvm::Constant *Cast = GV;
3666  if (!CGM.getLangOpts().OpenCL) {
3667  if (auto AS = CGM.getTarget().getConstantAddressSpace()) {
3668  if (AS != LangAS::Default)
3670  CGM, GV, AS.getValue(), LangAS::Default,
3671  GV->getValueType()->getPointerTo(
3673  }
3674  }
3675  return Cast;
3676 }
3677 
3678 template<typename SomeDecl>
3680  llvm::GlobalValue *GV) {
3681  if (!getLangOpts().CPlusPlus)
3682  return;
3683 
3684  // Must have 'used' attribute, or else inline assembly can't rely on
3685  // the name existing.
3686  if (!D->template hasAttr<UsedAttr>())
3687  return;
3688 
3689  // Must have internal linkage and an ordinary name.
3690  if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage)
3691  return;
3692 
3693  // Must be in an extern "C" context. Entities declared directly within
3694  // a record are not extern "C" even if the record is in such a context.
3695  const SomeDecl *First = D->getFirstDecl();
3696  if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
3697  return;
3698 
3699  // OK, this is an internal linkage entity inside an extern "C" linkage
3700  // specification. Make a note of that so we can give it the "expected"
3701  // mangled name if nothing else is using that name.
3702  std::pair<StaticExternCMap::iterator, bool> R =
3703  StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
3704 
3705  // If we have multiple internal linkage entities with the same name
3706  // in extern "C" regions, none of them gets that name.
3707  if (!R.second)
3708  R.first->second = nullptr;
3709 }
3710 
3711 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
3712  if (!CGM.supportsCOMDAT())
3713  return false;
3714 
3715  if (D.hasAttr<SelectAnyAttr>())
3716  return true;
3717 
3719  if (auto *VD = dyn_cast<VarDecl>(&D))
3720  Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
3721  else
3722  Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
3723 
3724  switch (Linkage) {
3725  case GVA_Internal:
3727  case GVA_StrongExternal:
3728  return false;
3729  case GVA_DiscardableODR:
3730  case GVA_StrongODR:
3731  return true;
3732  }
3733  llvm_unreachable("No such linkage");
3734 }
3735 
3737  llvm::GlobalObject &GO) {
3738  if (!shouldBeInCOMDAT(*this, D))
3739  return;
3740  GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
3741 }
3742 
3743 /// Pass IsTentative as true if you want to create a tentative definition.
3744 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
3745  bool IsTentative) {
3746  // OpenCL global variables of sampler type are translated to function calls,
3747  // therefore no need to be translated.
3748  QualType ASTTy = D->getType();
3749  if (getLangOpts().OpenCL && ASTTy->isSamplerT())
3750  return;
3751 
3752  // If this is OpenMP device, check if it is legal to emit this global
3753  // normally.
3754  if (LangOpts.OpenMPIsDevice && OpenMPRuntime &&
3755  OpenMPRuntime->emitTargetGlobalVariable(D))
3756  return;
3757 
3758  llvm::Constant *Init = nullptr;
3760  bool NeedsGlobalCtor = false;
3761  bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor();
3762 
3763  const VarDecl *InitDecl;
3764  const Expr *InitExpr = D->getAnyInitializer(InitDecl);
3765 
3766  Optional<ConstantEmitter> emitter;
3767 
3768  // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
3769  // as part of their declaration." Sema has already checked for
3770  // error cases, so we just need to set Init to UndefValue.
3771  bool IsCUDASharedVar =
3772  getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
3773  // Shadows of initialized device-side global variables are also left
3774  // undefined.
3775  bool IsCUDAShadowVar =
3776  !getLangOpts().CUDAIsDevice &&
3777  (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
3778  D->hasAttr<CUDASharedAttr>());
3779  if (getLangOpts().CUDA && (IsCUDASharedVar || IsCUDAShadowVar))
3780  Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
3781  else if (!InitExpr) {
3782  // This is a tentative definition; tentative definitions are
3783  // implicitly initialized with { 0 }.
3784  //
3785  // Note that tentative definitions are only emitted at the end of
3786  // a translation unit, so they should never have incomplete
3787  // type. In addition, EmitTentativeDefinition makes sure that we
3788  // never attempt to emit a tentative definition if a real one
3789  // exists. A use may still exists, however, so we still may need
3790  // to do a RAUW.
3791  assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
3792  Init = EmitNullConstant(D->getType());
3793  } else {
3794  initializedGlobalDecl = GlobalDecl(D);
3795  emitter.emplace(*this);
3796  Init = emitter->tryEmitForInitializer(*InitDecl);
3797 
3798  if (!Init) {
3799  QualType T = InitExpr->getType();
3800  if (D->getType()->isReferenceType())
3801  T = D->getType();
3802 
3803  if (getLangOpts().CPlusPlus) {
3804  Init = EmitNullConstant(T);
3805  NeedsGlobalCtor = true;
3806  } else {
3807  ErrorUnsupported(D, "static initializer");
3808  Init = llvm::UndefValue::get(getTypes().ConvertType(T));
3809  }
3810  } else {
3811  // We don't need an initializer, so remove the entry for the delayed
3812  // initializer position (just in case this entry was delayed) if we
3813  // also don't need to register a destructor.
3814  if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
3815  DelayedCXXInitPosition.erase(D);
3816  }
3817  }
3818 
3819  llvm::Type* InitType = Init->getType();
3820  llvm::Constant *Entry =
3821  GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
3822 
3823  // Strip off a bitcast if we got one back.
3824  if (auto *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
3825  assert(CE->getOpcode() == llvm::Instruction::BitCast ||
3826  CE->getOpcode() == llvm::Instruction::AddrSpaceCast ||
3827  // All zero index gep.
3828  CE->getOpcode() == llvm::Instruction::GetElementPtr);
3829  Entry = CE->getOperand(0);
3830  }
3831 
3832  // Entry is now either a Function or GlobalVariable.
3833  auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
3834 
3835  // We have a definition after a declaration with the wrong type.
3836  // We must make a new GlobalVariable* and update everything that used OldGV
3837  // (a declaration or tentative definition) with the new GlobalVariable*
3838  // (which will be a definition).
3839  //
3840  // This happens if there is a prototype for a global (e.g.
3841  // "extern int x[];") and then a definition of a different type (e.g.
3842  // "int x[10];"). This also happens when an initializer has a different type
3843  // from the type of the global (this happens with unions).
3844  if (!GV || GV->getType()->getElementType() != InitType ||
3845  GV->getType()->getAddressSpace() !=
3847 
3848  // Move the old entry aside so that we'll create a new one.
3849  Entry->setName(StringRef());
3850 
3851  // Make a new global with the correct type, this is now guaranteed to work.
3852  GV = cast<llvm::GlobalVariable>(
3853  GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative)));
3854 
3855  // Replace all uses of the old global with the new global
3856  llvm::Constant *NewPtrForOldDecl =
3857  llvm::ConstantExpr::getBitCast(GV, Entry->getType());
3858  Entry->replaceAllUsesWith(NewPtrForOldDecl);
3859 
3860  // Erase the old global, since it is no longer used.
3861  cast<llvm::GlobalValue>(Entry)->eraseFromParent();
3862  }
3863 
3865 
3866  if (D->hasAttr<AnnotateAttr>())
3867  AddGlobalAnnotations(D, GV);
3868 
3869  // Set the llvm linkage type as appropriate.
3870  llvm::GlobalValue::LinkageTypes Linkage =
3871  getLLVMLinkageVarDefinition(D, GV->isConstant());
3872 
3873  // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
3874  // the device. [...]"
3875  // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
3876  // __device__, declares a variable that: [...]
3877  // Is accessible from all the threads within the grid and from the host
3878  // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
3879  // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
3880  if (GV && LangOpts.CUDA) {
3881  if (LangOpts.CUDAIsDevice) {
3882  if (Linkage != llvm::GlobalValue::InternalLinkage &&
3883  (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()))
3884  GV->setExternallyInitialized(true);
3885  } else {
3886  // Host-side shadows of external declarations of device-side
3887  // global variables become internal definitions. These have to
3888  // be internal in order to prevent name conflicts with global
3889  // host variables with the same name in a different TUs.
3890  if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()) {
3892 
3893  // Shadow variables and their properties must be registered
3894  // with CUDA runtime.
3895  unsigned Flags = 0;
3896  if (!D->hasDefinition())
3898  if (D->hasAttr<CUDAConstantAttr>())
3900  // Extern global variables will be registered in the TU where they are
3901  // defined.
3902  if (!D->hasExternalStorage())
3903  getCUDARuntime().registerDeviceVar(D, *GV, Flags);
3904  } else if (D->hasAttr<CUDASharedAttr>())
3905  // __shared__ variables are odd. Shadows do get created, but
3906  // they are not registered with the CUDA runtime, so they
3907  // can't really be used to access their device-side
3908  // counterparts. It's not clear yet whether it's nvcc's bug or
3909  // a feature, but we've got to do the same for compatibility.
3911  }
3912  }
3913 
3914  GV->setInitializer(Init);
3915  if (emitter) emitter->finalize(GV);
3916 
3917  // If it is safe to mark the global 'constant', do so now.
3918  GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
3919  isTypeConstant(D->getType(), true));
3920 
3921  // If it is in a read-only section, mark it 'constant'.
3922  if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
3923  const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
3924  if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
3925  GV->setConstant(true);
3926  }
3927 
3928  GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
3929 
3930 
3931  // On Darwin, if the normal linkage of a C++ thread_local variable is
3932  // LinkOnce or Weak, we keep the normal linkage to prevent multiple
3933  // copies within a linkage unit; otherwise, the backing variable has
3934  // internal linkage and all accesses should just be calls to the
3935  // Itanium-specified entry point, which has the normal linkage of the
3936  // variable. This is to preserve the ability to change the implementation
3937  // behind the scenes.
3938  if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic &&
3939  Context.getTargetInfo().getTriple().isOSDarwin() &&
3940  !llvm::GlobalVariable::isLinkOnceLinkage(Linkage) &&
3941  !llvm::GlobalVariable::isWeakLinkage(Linkage))
3943 
3944  GV->setLinkage(Linkage);
3945  if (D->hasAttr<DLLImportAttr>())
3946  GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
3947  else if (D->hasAttr<DLLExportAttr>())
3948  GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
3949  else
3950  GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
3951 
3952  if (Linkage == llvm::GlobalVariable::CommonLinkage) {
3953  // common vars aren't constant even if declared const.
3954  GV->setConstant(false);
3955  // Tentative definition of global variables may be initialized with
3956  // non-zero null pointers. In this case they should have weak linkage
3957  // since common linkage must have zero initializer and must not have
3958  // explicit section therefore cannot have non-zero initial value.
3959  if (!GV->getInitializer()->isNullValue())
3960  GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
3961  }
3962 
3963  setNonAliasAttributes(D, GV);
3964 
3965  if (D->getTLSKind() && !GV->isThreadLocal()) {
3966  if (D->getTLSKind() == VarDecl::TLS_Dynamic)
3967  CXXThreadLocals.push_back(D);
3968  setTLSMode(GV, *D);
3969  }
3970 
3971  maybeSetTrivialComdat(*D, *GV);
3972 
3973  // Emit the initializer function if necessary.
3974  if (NeedsGlobalCtor || NeedsGlobalDtor)
3975  EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
3976 
3977  SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor);
3978 
3979  // Emit global variable debug information.
3980  if (CGDebugInfo *DI = getModuleDebugInfo())
3981  if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
3982  DI->EmitGlobalVariable(GV, D);
3983 }
3984 
3985 static bool isVarDeclStrongDefinition(const ASTContext &Context,
3986  CodeGenModule &CGM, const VarDecl *D,
3987  bool NoCommon) {
3988  // Don't give variables common linkage if -fno-common was specified unless it
3989  // was overridden by a NoCommon attribute.
3990  if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
3991  return true;
3992 
3993  // C11 6.9.2/2:
3994  // A declaration of an identifier for an object that has file scope without
3995  // an initializer, and without a storage-class specifier or with the
3996  // storage-class specifier static, constitutes a tentative definition.
3997  if (D->getInit() || D->hasExternalStorage())
3998  return true;
3999 
4000  // A variable cannot be both common and exist in a section.
4001  if (D->hasAttr<SectionAttr>())
4002  return true;
4003 
4004  // A variable cannot be both common and exist in a section.
4005  // We don't try to determine which is the right section in the front-end.
4006  // If no specialized section name is applicable, it will resort to default.
4007  if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
4008  D->hasAttr<PragmaClangDataSectionAttr>() ||
4009  D->hasAttr<PragmaClangRodataSectionAttr>())
4010  return true;
4011 
4012  // Thread local vars aren't considered common linkage.
4013  if (D->getTLSKind())
4014  return true;
4015 
4016  // Tentative definitions marked with WeakImportAttr are true definitions.
4017  if (D->hasAttr<WeakImportAttr>())
4018  return true;
4019 
4020  // A variable cannot be both common and exist in a comdat.
4021  if (shouldBeInCOMDAT(CGM, *D))
4022  return true;
4023 
4024  // Declarations with a required alignment do not have common linkage in MSVC
4025  // mode.
4026  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
4027  if (D->hasAttr<AlignedAttr>())
4028  return true;
4029  QualType VarType = D->getType();
4030  if (Context.isAlignmentRequired(VarType))
4031  return true;
4032 
4033  if (const auto *RT = VarType->getAs<RecordType>()) {
4034  const RecordDecl *RD = RT->getDecl();
4035  for (const FieldDecl *FD : RD->fields()) {
4036  if (FD->isBitField())
4037  continue;
4038  if (FD->hasAttr<AlignedAttr>())
4039  return true;
4040  if (Context.isAlignmentRequired(FD->getType()))
4041  return true;
4042  }
4043  }
4044  }
4045 
4046  // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
4047  // common symbols, so symbols with greater alignment requirements cannot be
4048  // common.
4049  // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
4050  // alignments for common symbols via the aligncomm directive, so this
4051  // restriction only applies to MSVC environments.
4052  if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
4053  Context.getTypeAlignIfKnown(D->getType()) >
4054  Context.toBits(CharUnits::fromQuantity(32)))
4055  return true;
4056 
4057  return false;
4058 }
4059 
4060 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
4061  const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) {
4062  if (Linkage == GVA_Internal)
4064 
4065  if (D->hasAttr<WeakAttr>()) {
4066  if (IsConstantVariable)
4067  return llvm::GlobalVariable::WeakODRLinkage;
4068  else
4069  return llvm::GlobalVariable::WeakAnyLinkage;
4070  }
4071 
4072  if (const auto *FD = D->getAsFunction())
4073  if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
4074  return llvm::GlobalVariable::LinkOnceAnyLinkage;
4075 
4076  // We are guaranteed to have a strong definition somewhere else,
4077  // so we can use available_externally linkage.
4078  if (Linkage == GVA_AvailableExternally)
4079  return llvm::GlobalValue::AvailableExternallyLinkage;
4080 
4081  // Note that Apple's kernel linker doesn't support symbol
4082  // coalescing, so we need to avoid linkonce and weak linkages there.
4083  // Normally, this means we just map to internal, but for explicit
4084  // instantiations we'll map to external.
4085 
4086  // In C++, the compiler has to emit a definition in every translation unit
4087  // that references the function. We should use linkonce_odr because
4088  // a) if all references in this translation unit are optimized away, we
4089  // don't need to codegen it. b) if the function persists, it needs to be
4090  // merged with other definitions. c) C++ has the ODR, so we know the
4091  // definition is dependable.
4092  if (Linkage == GVA_DiscardableODR)
4093  return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
4095 
4096  // An explicit instantiation of a template has weak linkage, since
4097  // explicit instantiations can occur in multiple translation units
4098  // and must all be equivalent. However, we are not allowed to
4099  // throw away these explicit instantiations.
4100  //
4101  // We don't currently support CUDA device code spread out across multiple TUs,
4102  // so say that CUDA templates are either external (for kernels) or internal.
4103  // This lets llvm perform aggressive inter-procedural optimizations.
4104  if (Linkage == GVA_StrongODR) {
4105  if (Context.getLangOpts().AppleKext)
4107  if (Context.getLangOpts().CUDA && Context.getLangOpts().CUDAIsDevice)
4108  return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
4110  return llvm::Function::WeakODRLinkage;
4111  }
4112 
4113  // C++ doesn't have tentative definitions and thus cannot have common
4114  // linkage.
4115  if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
4116  !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
4117  CodeGenOpts.NoCommon))
4118  return llvm::GlobalVariable::CommonLinkage;
4119 
4120  // selectany symbols are externally visible, so use weak instead of
4121  // linkonce. MSVC optimizes away references to const selectany globals, so
4122  // all definitions should be the same and ODR linkage should be used.
4123  // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
4124  if (D->hasAttr<SelectAnyAttr>())
4125  return llvm::GlobalVariable::WeakODRLinkage;
4126 
4127  // Otherwise, we have strong external linkage.
4128  assert(Linkage == GVA_StrongExternal);
4130 }
4131 
4132 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition(
4133  const VarDecl *VD, bool IsConstant) {
4135  return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant);
4136 }
4137 
4138 /// Replace the uses of a function that was declared with a non-proto type.
4139 /// We want to silently drop extra arguments from call sites
4140 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
4141  llvm::Function *newFn) {
4142  // Fast path.
4143  if (old->use_empty()) return;
4144 
4145  llvm::Type *newRetTy = newFn->getReturnType();
4148 
4149  for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
4150  ui != ue; ) {
4151  llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
4152  llvm::User *user = use->getUser();
4153 
4154  // Recognize and replace uses of bitcasts. Most calls to
4155  // unprototyped functions will use bitcasts.
4156  if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
4157  if (bitcast->getOpcode() == llvm::Instruction::BitCast)
4158  replaceUsesOfNonProtoConstant(bitcast, newFn);
4159  continue;
4160  }
4161 
4162  // Recognize calls to the function.
4163  llvm::CallBase *callSite = dyn_cast<llvm::CallBase>(user);
4164  if (!callSite) continue;
4165  if (!callSite->isCallee(&*use))
4166  continue;
4167 
4168  // If the return types don't match exactly, then we can't
4169  // transform this call unless it's dead.
4170  if (callSite->getType() != newRetTy && !callSite->use_empty())
4171  continue;
4172 
4173  // Get the call site's attribute list.
4175  llvm::AttributeList oldAttrs = callSite->getAttributes();
4176 
4177  // If the function was passed too few arguments, don't transform.
4178  unsigned newNumArgs = newFn->arg_size();
4179  if (callSite->arg_size() < newNumArgs)
4180  continue;
4181 
4182  // If extra arguments were passed, we silently drop them.
4183  // If any of the types mismatch, we don't transform.
4184  unsigned argNo = 0;
4185  bool dontTransform = false;
4186  for (llvm::Argument &A : newFn->args()) {
4187  if (callSite->getArgOperand(argNo)->getType() != A.getType()) {
4188  dontTransform = true;
4189  break;
4190  }
4191 
4192  // Add any parameter attributes.
4193  newArgAttrs.push_back(oldAttrs.getParamAttributes(argNo));
4194  argNo++;
4195  }
4196  if (dontTransform)
4197  continue;
4198 
4199  // Okay, we can transform this. Create the new call instruction and copy
4200  // over the required information.
4201  newArgs.append(callSite->arg_begin(), callSite->arg_begin() + argNo);
4202 
4203  // Copy over any operand bundles.
4204  callSite->getOperandBundlesAsDefs(newBundles);
4205 
4206  llvm::CallBase *newCall;
4207  if (dyn_cast<llvm::CallInst>(callSite)) {
4208  newCall =
4209  llvm::CallInst::Create(newFn, newArgs, newBundles, "", callSite);
4210  } else {
4211  auto *oldInvoke = cast<llvm::InvokeInst>(callSite);
4212  newCall = llvm::InvokeInst::Create(newFn, oldInvoke->getNormalDest(),
4213  oldInvoke->getUnwindDest(), newArgs,
4214  newBundles, "", callSite);
4215  }
4216  newArgs.clear(); // for the next iteration
4217 
4218  if (!newCall->getType()->isVoidTy())
4219  newCall->takeName(callSite);
4220  newCall->setAttributes(llvm::AttributeList::get(
4221  newFn->getContext(), oldAttrs.getFnAttributes(),
4222  oldAttrs.getRetAttributes(), newArgAttrs));
4223  newCall->setCallingConv(callSite->getCallingConv());
4224 
4225  // Finally, remove the old call, replacing any uses with the new one.
4226  if (!callSite->use_empty())
4227  callSite->replaceAllUsesWith(newCall);
4228 
4229  // Copy debug location attached to CI.
4230  if (callSite->getDebugLoc())
4231  newCall->setDebugLoc(callSite->getDebugLoc());
4232 
4233  callSite->eraseFromParent();
4234  }
4235 }
4236 
4237 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
4238 /// implement a function with no prototype, e.g. "int foo() {}". If there are
4239 /// existing call uses of the old function in the module, this adjusts them to
4240 /// call the new function directly.
4241 ///
4242 /// This is not just a cleanup: the always_inline pass requires direct calls to
4243 /// functions to be able to inline them. If there is a bitcast in the way, it
4244 /// won't inline them. Instcombine normally deletes these calls, but it isn't
4245 /// run at -O0.
4246 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
4247  llvm::Function *NewFn) {
4248  // If we're redefining a global as a function, don't transform it.
4249  if (!isa<llvm::Function>(Old)) return;
4250 
4251  replaceUsesOfNonProtoConstant(Old, NewFn);
4252 }
4253 
4255  auto DK = VD->isThisDeclarationADefinition();
4256  if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
4257  return;
4258 
4260  // If we have a definition, this might be a deferred decl. If the
4261  // instantiation is explicit, make sure we emit it at the end.
4263  GetAddrOfGlobalVar(VD);
4264 
4265  EmitTopLevelDecl(VD);
4266 }
4267 
4268 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
4269  llvm::GlobalValue *GV) {
4270  const auto *D = cast<FunctionDecl>(GD.getDecl());
4271 
4272  // Compute the function info and LLVM type.
4274  llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4275 
4276  // Get or create the prototype for the function.
4277  if (!GV || (GV->getType()->getElementType() != Ty))
4278  GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
4279  /*DontDefer=*/true,
4280  ForDefinition));
4281 
4282  // Already emitted.
4283  if (!GV->isDeclaration())
4284  return;
4285 
4286  // We need to set linkage and visibility on the function before
4287  // generating code for it because various parts of IR generation
4288  // want to propagate this information down (e.g. to local static
4289  // declarations).
4290  auto *Fn = cast<llvm::Function>(GV);
4291  setFunctionLinkage(GD, Fn);
4292 
4293  // FIXME: this is redundant with part of setFunctionDefinitionAttributes
4294  setGVProperties(Fn, GD);
4295 
4297 
4298 
4299  maybeSetTrivialComdat(*D, *Fn);
4300 
4301  CodeGenFunction(*this).GenerateCode(D, Fn, FI);
4302 
4303  setNonAliasAttributes(GD, Fn);
4305 
4306  if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
4307  AddGlobalCtor(Fn, CA->getPriority());
4308  if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
4309  AddGlobalDtor(Fn, DA->getPriority());
4310  if (D->hasAttr<AnnotateAttr>())
4311  AddGlobalAnnotations(D, Fn);
4312 }
4313 
4314 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
4315  const auto *D = cast<ValueDecl>(GD.getDecl());
4316  const AliasAttr *AA = D->getAttr<AliasAttr>();
4317  assert(AA && "Not an alias?");
4318 
4319  StringRef MangledName = getMangledName(GD);
4320 
4321  if (AA->getAliasee() == MangledName) {
4322  Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4323  return;
4324  }
4325 
4326  // If there is a definition in the module, then it wins over the alias.
4327  // This is dubious, but allow it to be safe. Just ignore the alias.
4328  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4329  if (Entry && !Entry->isDeclaration())
4330  return;
4331 
4332  Aliases.push_back(GD);
4333 
4334  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4335 
4336  // Create a reference to the named value. This ensures that it is emitted
4337  // if a deferred decl.
4338  llvm::Constant *Aliasee;
4339  if (isa<llvm::FunctionType>(DeclTy))
4340  Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
4341  /*ForVTable=*/false);
4342  else
4343  Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
4344  llvm::PointerType::getUnqual(DeclTy),
4345  /*D=*/nullptr);
4346 
4347  // Create the new alias itself, but don't set a name yet.
4348  auto *GA = llvm::GlobalAlias::create(
4349  DeclTy, 0, llvm::Function::ExternalLinkage, "", Aliasee, &getModule());
4350 
4351  if (Entry) {
4352  if (GA->getAliasee() == Entry) {
4353  Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4354  return;
4355  }
4356 
4357  assert(Entry->isDeclaration());
4358 
4359  // If there is a declaration in the module, then we had an extern followed
4360  // by the alias, as in:
4361  // extern int test6();
4362  // ...
4363  // int test6() __attribute__((alias("test7")));
4364  //
4365  // Remove it and replace uses of it with the alias.
4366  GA->takeName(Entry);
4367 
4368  Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
4369  Entry->getType()));
4370  Entry->eraseFromParent();
4371  } else {
4372  GA->setName(MangledName);
4373  }
4374 
4375  // Set attributes which are particular to an alias; this is a
4376  // specialization of the attributes which may be set on a global
4377  // variable/function.
4378  if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
4379  D->isWeakImported()) {
4380  GA->setLinkage(llvm::Function::WeakAnyLinkage);
4381  }
4382 
4383  if (const auto *VD = dyn_cast<VarDecl>(D))
4384  if (VD->getTLSKind())
4385  setTLSMode(GA, *VD);
4386 
4387  SetCommonAttributes(GD, GA);
4388 }
4389 
4390 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
4391  const auto *D = cast<ValueDecl>(GD.getDecl());
4392  const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
4393  assert(IFA && "Not an ifunc?");
4394 
4395  StringRef MangledName = getMangledName(GD);
4396 
4397  if (IFA->getResolver() == MangledName) {
4398  Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4399  return;
4400  }
4401 
4402  // Report an error if some definition overrides ifunc.
4403  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4404  if (Entry && !Entry->isDeclaration()) {
4405  GlobalDecl OtherGD;
4406  if (lookupRepresentativeDecl(MangledName, OtherGD) &&
4407  DiagnosedConflictingDefinitions.insert(GD).second) {
4408  Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
4409  << MangledName;
4410  Diags.Report(OtherGD.getDecl()->getLocation(),
4411  diag::note_previous_definition);
4412  }
4413  return;
4414  }
4415 
4416  Aliases.push_back(GD);
4417 
4418  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4419  llvm::Constant *Resolver =
4420  GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD,
4421  /*ForVTable=*/false);
4422  llvm::GlobalIFunc *GIF =
4424  "", Resolver, &getModule());
4425  if (Entry) {
4426  if (GIF->getResolver() == Entry) {
4427  Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4428  return;
4429  }
4430  assert(Entry->isDeclaration());
4431 
4432  // If there is a declaration in the module, then we had an extern followed
4433  // by the ifunc, as in:
4434  // extern int test();
4435  // ...
4436  // int test() __attribute__((ifunc("resolver")));
4437  //
4438  // Remove it and replace uses of it with the ifunc.
4439  GIF->takeName(Entry);
4440 
4441  Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
4442  Entry->getType()));
4443  Entry->eraseFromParent();
4444  } else
4445  GIF->setName(MangledName);
4446 
4447  SetCommonAttributes(GD, GIF);
4448 }
4449 
4450 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
4451  ArrayRef<llvm::Type*> Tys) {
4452  return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
4453  Tys);
4454 }
4455 
4456 static llvm::StringMapEntry<llvm::GlobalVariable *> &
4457 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
4458  const StringLiteral *Literal, bool TargetIsLSB,
4459  bool &IsUTF16, unsigned &StringLength) {
4460  StringRef String = Literal->getString();
4461  unsigned NumBytes = String.size();
4462 
4463  // Check for simple case.
4464  if (!Literal->containsNonAsciiOrNull()) {
4465  StringLength = NumBytes;
4466  return *Map.insert(std::make_pair(String, nullptr)).first;
4467  }
4468 
4469  // Otherwise, convert the UTF8 literals into a string of shorts.
4470  IsUTF16 = true;
4471 
4472  SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
4473  const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
4474  llvm::UTF16 *ToPtr = &ToBuf[0];
4475 
4476  (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
4477  ToPtr + NumBytes, llvm::strictConversion);
4478 
4479  // ConvertUTF8toUTF16 returns the length in ToPtr.
4480  StringLength = ToPtr - &ToBuf[0];
4481 
4482  // Add an explicit null.
4483  *ToPtr = 0;
4484  return *Map.insert(std::make_pair(
4485  StringRef(reinterpret_cast<const char *>(ToBuf.data()),
4486  (StringLength + 1) * 2),
4487  nullptr)).first;
4488 }
4489 
4492  unsigned StringLength = 0;
4493  bool isUTF16 = false;
4494  llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
4495  GetConstantCFStringEntry(CFConstantStringMap, Literal,
4496  getDataLayout().isLittleEndian(), isUTF16,
4497  StringLength);
4498 
4499  if (auto *C = Entry.second)
4500  return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment()));
4501 
4502  llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
4503  llvm::Constant *Zeros[] = { Zero, Zero };
4504 
4505  const ASTContext &Context = getContext();
4506  const llvm::Triple &Triple = getTriple();
4507 
4508  const auto CFRuntime = getLangOpts().CFRuntime;
4509  const bool IsSwiftABI =
4510  static_cast<unsigned>(CFRuntime) >=
4511  static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
4512  const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
4513 
4514  // If we don't already have it, get __CFConstantStringClassReference.
4515  if (!CFConstantStringClassRef) {
4516  const char *CFConstantStringClassName = "__CFConstantStringClassReference";
4518  Ty = llvm::ArrayType::get(Ty, 0);
4519 
4520  switch (CFRuntime) {
4521  default: break;
4522  case LangOptions::CoreFoundationABI::Swift: LLVM_FALLTHROUGH;
4524  CFConstantStringClassName =
4525  Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
4526  : "$s10Foundation19_NSCFConstantStringCN";
4527  Ty = IntPtrTy;
4528  break;
4530  CFConstantStringClassName =
4531  Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
4532  : "$S10Foundation19_NSCFConstantStringCN";
4533  Ty = IntPtrTy;
4534  break;
4536  CFConstantStringClassName =
4537  Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
4538  : "__T010Foundation19_NSCFConstantStringCN";
4539  Ty = IntPtrTy;
4540  break;
4541  }
4542 
4543  llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
4544 
4545  if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
4546  llvm::GlobalValue *GV = nullptr;
4547 
4548  if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
4549  IdentifierInfo &II = Context.Idents.get(GV->getName());
4550  TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
4552 
4553  const VarDecl *VD = nullptr;
4554  for (const auto &Result : DC->lookup(&II))
4555  if ((VD = dyn_cast<VarDecl>(Result)))
4556  break;
4557 
4558  if (Triple.isOSBinFormatELF()) {
4559  if (!VD)
4560  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
4561  } else {
4562  GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
4563  if (!VD || !VD->hasAttr<DLLExportAttr>())
4564  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
4565  else
4566  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
4567  }
4568 
4569  setDSOLocal(GV);
4570  }
4571  }
4572 
4573  // Decay array -> ptr
4574  CFConstantStringClassRef =
4575  IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty)
4576  : llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros);
4577  }
4578 
4579  QualType CFTy = Context.getCFConstantStringType();
4580 
4581  auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
4582 
4583  ConstantInitBuilder Builder(*this);
4584  auto Fields = Builder.beginStruct(STy);
4585 
4586  // Class pointer.
4587  Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
4588 
4589  // Flags.
4590  if (IsSwiftABI) {
4591  Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
4592  Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
4593  } else {
4594  Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
4595  }
4596 
4597  // String pointer.
4598  llvm::Constant *C = nullptr;
4599  if (isUTF16) {
4600  auto Arr = llvm::makeArrayRef(
4601  reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
4602  Entry.first().size() / 2);
4603  C = llvm::ConstantDataArray::get(VMContext, Arr);
4604  } else {
4605  C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
4606  }
4607 
4608  // Note: -fwritable-strings doesn't make the backing store strings of
4609  // CFStrings writable. (See <rdar://problem/10657500>)
4610  auto *GV =
4611  new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
4612  llvm::GlobalValue::PrivateLinkage, C, ".str");
4613  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4614  // Don't enforce the target's minimum global alignment, since the only use
4615  // of the string is via this class initializer.
4616  CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
4617  : Context.getTypeAlignInChars(Context.CharTy);
4618  GV->setAlignment(Align.getQuantity());
4619 
4620  // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
4621  // Without it LLVM can merge the string with a non unnamed_addr one during
4622  // LTO. Doing that changes the section it ends in, which surprises ld64.
4623  if (Triple.isOSBinFormatMachO())
4624  GV->setSection(isUTF16 ? "__TEXT,__ustring"
4625  : "__TEXT,__cstring,cstring_literals");
4626  // Make sure the literal ends up in .rodata to allow for safe ICF and for
4627  // the static linker to adjust permissions to read-only later on.
4628  else if (Triple.isOSBinFormatELF())
4629  GV->setSection(".rodata");
4630 
4631  // String.
4632  llvm::Constant *Str =
4633  llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
4634 
4635  if (isUTF16)
4636  // Cast the UTF16 string to the correct type.
4637  Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
4638  Fields.add(Str);
4639 
4640  // String length.
4641  llvm::IntegerType *LengthTy =
4642  llvm::IntegerType::get(getModule().getContext(),
4643  Context.getTargetInfo().getLongWidth());
4644  if (IsSwiftABI) {
4645  if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
4647  LengthTy = Int32Ty;
4648  else
4649  LengthTy = IntPtrTy;
4650  }
4651  Fields.addInt(LengthTy, StringLength);
4652 
4653  CharUnits Alignment = getPointerAlign();
4654 
4655  // The struct.
4656  GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
4657  /*isConstant=*/false,
4658  llvm::GlobalVariable::PrivateLinkage);
4659  GV->addAttribute("objc_arc_inert");
4660  switch (Triple.getObjectFormat()) {
4661  case llvm::Triple::UnknownObjectFormat:
4662  llvm_unreachable("unknown file format");
4663  case llvm::Triple::XCOFF:
4664  llvm_unreachable("XCOFF is not yet implemented");
4665  case llvm::Triple::COFF:
4666  case llvm::Triple::ELF:
4667  case llvm::Triple::Wasm:
4668  GV->setSection("cfstring");
4669  break;
4670  case llvm::Triple::MachO:
4671  GV->setSection("__DATA,__cfstring");
4672  break;
4673  }
4674  Entry.second = GV;
4675 
4676  return ConstantAddress(GV, Alignment);
4677 }
4678 
4680  return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
4681 }
4682 
4684  if (ObjCFastEnumerationStateType.isNull()) {
4685  RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
4686  D->startDefinition();
4687 
4688  QualType FieldTypes[] = {
4689  Context.UnsignedLongTy,
4690  Context.getPointerType(Context.getObjCIdType()),
4691  Context.getPointerType(Context.UnsignedLongTy),
4692  Context.getConstantArrayType(Context.UnsignedLongTy,
4693  llvm::APInt(32, 5), ArrayType::Normal, 0)
4694  };
4695 
4696  for (size_t i = 0; i < 4; ++i) {
4697  FieldDecl *Field = FieldDecl::Create(Context,
4698  D,
4699  SourceLocation(),
4700  SourceLocation(), nullptr,
4701  FieldTypes[i], /*TInfo=*/nullptr,
4702  /*BitWidth=*/nullptr,
4703  /*Mutable=*/false,
4704  ICIS_NoInit);
4705  Field->setAccess(AS_public);
4706  D->addDecl(Field);
4707  }
4708 
4709  D->completeDefinition();
4710  ObjCFastEnumerationStateType = Context.getTagDeclType(D);
4711  }
4712 
4713  return ObjCFastEnumerationStateType;
4714 }
4715 
4716 llvm::Constant *
4718  assert(!E->getType()->isPointerType() && "Strings are always arrays");
4719 
4720  // Don't emit it as the address of the string, emit the string data itself
4721  // as an inline array.
4722  if (E->getCharByteWidth() == 1) {
4723  SmallString<64> Str(E->getString());
4724 
4725  // Resize the string to the right size, which is indicated by its type.
4726  const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
4727  Str.resize(CAT->getSize().getZExtValue());
4728  return llvm::ConstantDataArray::getString(VMContext, Str, false);
4729  }
4730 
4731  auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
4732  llvm::Type *ElemTy = AType->getElementType();
4733  unsigned NumElements = AType->getNumElements();
4734 
4735  // Wide strings have either 2-byte or 4-byte elements.
4736  if (ElemTy->getPrimitiveSizeInBits() == 16) {
4737  SmallVector<uint16_t, 32> Elements;
4738  Elements.reserve(NumElements);
4739 
4740  for(unsigned i = 0, e = E->getLength(); i != e; ++i)
4741  Elements.push_back(E->getCodeUnit(i));
4742  Elements.resize(NumElements);
4743  return llvm::ConstantDataArray::get(VMContext, Elements);
4744  }
4745 
4746  assert(ElemTy->getPrimitiveSizeInBits() == 32);
4747  SmallVector<uint32_t, 32> Elements;
4748  Elements.reserve(NumElements);
4749 
4750  for(unsigned i = 0, e = E->getLength(); i != e; ++i)
4751  Elements.push_back(E->getCodeUnit(i));
4752  Elements.resize(NumElements);
4753  return llvm::ConstantDataArray::get(VMContext, Elements);
4754 }
4755 
4756 static llvm::GlobalVariable *
4757 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
4758  CodeGenModule &CGM, StringRef GlobalName,
4759  CharUnits Alignment) {
4760  unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
4762 
4763  llvm::Module &M = CGM.getModule();
4764  // Create a global variable for this string
4765  auto *GV = new llvm::GlobalVariable(
4766  M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
4767  nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
4768  GV->setAlignment(Alignment.getQuantity());
4769  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4770  if (GV->isWeakForLinker()) {
4771  assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
4772  GV->setComdat(M.getOrInsertComdat(GV->getName()));
4773  }
4774  CGM.setDSOLocal(GV);
4775 
4776  return GV;
4777 }
4778 
4779 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
4780 /// constant array for the given string literal.
4783  StringRef Name) {
4785 
4786  llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
4787  llvm::GlobalVariable **Entry = nullptr;
4788  if (!LangOpts.WritableStrings) {
4789  Entry = &ConstantStringMap[C];
4790  if (auto GV = *Entry) {
4791  if (Alignment.getQuantity() > GV->getAlignment())
4792  GV->setAlignment(Alignment.getQuantity());
4794  Alignment);
4795  }
4796  }
4797 
4798  SmallString<256> MangledNameBuffer;
4799  StringRef GlobalVariableName;
4800  llvm::GlobalValue::LinkageTypes LT;
4801 
4802  // Mangle the string literal if that's how the ABI merges duplicate strings.
4803  // Don't do it if they are writable, since we don't want writes in one TU to
4804  // affect strings in another.
4805  if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
4806  !LangOpts.WritableStrings) {
4807  llvm::raw_svector_ostream Out(MangledNameBuffer);
4809  LT = llvm::GlobalValue::LinkOnceODRLinkage;
4810  GlobalVariableName = MangledNameBuffer;
4811  } else {
4812  LT = llvm::GlobalValue::PrivateLinkage;
4813  GlobalVariableName = Name;
4814  }
4815 
4816  auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
4817  if (Entry)
4818  *Entry = GV;
4819 
4820  SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>",
4821  QualType());
4822 
4824  Alignment);
4825 }
4826 
4827 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
4828 /// array for the given ObjCEncodeExpr node.
4831  std::string Str;
4833 
4834  return GetAddrOfConstantCString(Str);
4835 }
4836 
4837 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
4838 /// the literal and a terminating '\0' character.
4839 /// The result has pointer to array type.
4841  const std::string &Str, const char *GlobalName) {
4842  StringRef StrWithNull(Str.c_str(), Str.size() + 1);
4843  CharUnits Alignment =
4845 
4846  llvm::Constant *C =
4847  llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
4848 
4849  // Don't share any string literals if strings aren't constant.
4850  llvm::GlobalVariable **Entry = nullptr;
4851  if (!LangOpts.WritableStrings) {
4852  Entry = &ConstantStringMap[C];
4853  if (auto GV = *Entry) {
4854  if (Alignment.getQuantity() > GV->getAlignment())
4855  GV->setAlignment(Alignment.getQuantity());
4857  Alignment);
4858  }
4859  }
4860 
4861  // Get the default prefix if a name wasn't specified.
4862  if (!GlobalName)
4863  GlobalName = ".str";
4864  // Create a global variable for this.
4865  auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
4866  GlobalName, Alignment);
4867  if (Entry)
4868  *Entry = GV;
4869 
4871  Alignment);
4872 }
4873 
4875  const MaterializeTemporaryExpr *E, const Expr *Init) {
4876  assert((E->getStorageDuration() == SD_Static ||
4877  E->getStorageDuration() == SD_Thread) && "not a global temporary");
4878  const auto *VD = cast<VarDecl>(E->getExtendingDecl());
4879 
4880  // If we're not materializing a subobject of the temporary, keep the
4881  // cv-qualifiers from the type of the MaterializeTemporaryExpr.
4882  QualType MaterializedType = Init->getType();
4883  if (Init == E->GetTemporaryExpr())
4884  MaterializedType = E->getType();
4885 
4886  CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
4887 
4888  if (llvm::Constant *Slot = MaterializedGlobalTemporaryMap[E])
4889  return ConstantAddress(Slot, Align);
4890 
4891  // FIXME: If an externally-visible declaration extends multiple temporaries,
4892  // we need to give each temporary the same name in every translation unit (and
4893  // we also need to make the temporaries externally-visible).
4894  SmallString<256> Name;
4895  llvm::raw_svector_ostream Out(Name);
4897  VD, E->getManglingNumber(), Out);
4898 
4899  APValue *Value = nullptr;
4900  if (E->getStorageDuration() == SD_Static) {
4901  // We might have a cached constant initializer for this temporary. Note
4902  // that this might have a different value from the value computed by
4903  // evaluating the initializer if the surrounding constant expression
4904  // modifies the temporary.
4905  Value = getContext().getMaterializedTemporaryValue(E, false);
4906  if (Value && Value->isAbsent())
4907  Value = nullptr;
4908  }
4909 
4910  // Try evaluating it now, it might have a constant initializer.
4911  Expr::EvalResult EvalResult;
4912  if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
4913  !EvalResult.hasSideEffects())
4914  Value = &EvalResult.Val;
4915 
4916  LangAS AddrSpace =
4917  VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace();
4918 
4919  Optional<ConstantEmitter> emitter;
4920  llvm::Constant *InitialValue = nullptr;
4921  bool Constant = false;
4922  llvm::Type *Type;
4923  if (Value) {
4924  // The temporary has a constant initializer, use it.
4925  emitter.emplace(*this);
4926  InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
4927  MaterializedType);
4928  Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value);
4929  Type = InitialValue->getType();
4930  } else {
4931  // No initializer, the initialization will be provided when we
4932  // initialize the declaration which performed lifetime extension.
4933  Type = getTypes().ConvertTypeForMem(MaterializedType);
4934  }
4935 
4936  // Create a global variable for this lifetime-extended temporary.
4937  llvm::GlobalValue::LinkageTypes Linkage =
4938  getLLVMLinkageVarDefinition(VD, Constant);
4939  if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
4940  const VarDecl *InitVD;
4941  if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
4942  isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
4943  // Temporaries defined inside a class get linkonce_odr linkage because the
4944  // class can be defined in multiple translation units.
4945  Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
4946  } else {
4947  // There is no need for this temporary to have external linkage if the
4948  // VarDecl has external linkage.
4950  }
4951  }
4952  auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
4953  auto *GV = new llvm::GlobalVariable(
4954  getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
4955  /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
4956  if (emitter) emitter->finalize(GV);
4957  setGVProperties(GV, VD);
4958  GV->setAlignment(Align.getQuantity());
4959  if (supportsCOMDAT() && GV->isWeakForLinker())
4960  GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
4961  if (VD->getTLSKind())
4962  setTLSMode(GV, *VD);
4963  llvm::Constant *CV = GV;
4964  if (AddrSpace != LangAS::Default)
4966  *this, GV, AddrSpace, LangAS::Default,
4967  Type->getPointerTo(
4968  getContext().getTargetAddressSpace(LangAS::Default)));
4969  MaterializedGlobalTemporaryMap[E] = CV;
4970  return ConstantAddress(CV, Align);
4971 }
4972 
4973 /// EmitObjCPropertyImplementations - Emit information for synthesized
4974 /// properties for an implementation.
4975 void CodeGenModule::EmitObjCPropertyImplementations(const
4977  for (const auto *PID : D->property_impls()) {
4978  // Dynamic is just for type-checking.
4979  if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
4980  ObjCPropertyDecl *PD = PID->getPropertyDecl();
4981 
4982  // Determine which methods need to be implemented, some may have
4983  // been overridden. Note that ::isPropertyAccessor is not the method
4984  // we want, that just indicates if the decl came from a
4985  // property. What we want to know is if the method is defined in
4986  // this implementation.
4987  if (!D->getInstanceMethod(PD->getGetterName()))
4989  const_cast<ObjCImplementationDecl *>(D), PID);
4990  if (!PD->isReadOnly() &&
4991  !D->getInstanceMethod(PD->getSetterName()))
4993  const_cast<ObjCImplementationDecl *>(D), PID);
4994  }
4995  }
4996 }
4997 
4999  const ObjCInterfaceDecl *iface = impl->getClassInterface();
5000  for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
5001  ivar; ivar = ivar->getNextIvar())
5002  if (ivar->getType().isDestructedType())
5003  return true;
5004 
5005  return false;
5006 }
5007 
5010  CodeGenFunction CGF(CGM);
5012  E = D->init_end(); B != E; ++B) {
5013  CXXCtorInitializer *CtorInitExp = *B;
5014  Expr *Init = CtorInitExp->getInit();
5015  if (!CGF.isTrivialInitializer(Init))
5016  return false;
5017  }
5018  return true;
5019 }
5020 
5021 /// EmitObjCIvarInitializations - Emit information for ivar initialization
5022 /// for an implementation.
5023 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
5024  // We might need a .cxx_destruct even if we don't have any ivar initializers.
5025  if (needsDestructMethod(D)) {
5026  IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
5027  Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
5028  ObjCMethodDecl *DTORMethod =
5030  cxxSelector, getContext().VoidTy, nullptr, D,
5031  /*isInstance=*/true, /*isVariadic=*/false,
5032  /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true,
5033  /*isDefined=*/false, ObjCMethodDecl::Required);
5034  D->addInstanceMethod(DTORMethod);
5035  CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
5036  D->setHasDestructors(true);
5037  }
5038 
5039  // If the implementation doesn't have any ivar initializers, we don't need
5040  // a .cxx_construct.
5041  if (D->getNumIvarInitializers() == 0 ||
5042  AllTrivialInitializers(*this, D))
5043  return;
5044 
5045  IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
5046  Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
5047  // The constructor returns 'self'.
5049  D->getLocation(),
5050  D->getLocation(),
5051  cxxSelector,
5053  nullptr, D, /*isInstance=*/true,
5054  /*isVariadic=*/false,
5055  /*isPropertyAccessor=*/true,
5056  /*isImplicitlyDeclared=*/true,
5057  /*isDefined=*/false,
5059  D->addInstanceMethod(CTORMethod);
5060  CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
5061  D->setHasNonZeroConstructors(true);
5062 }
5063 
5064 // EmitLinkageSpec - Emit all declarations in a linkage spec.
5065 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
5066  if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
5068  ErrorUnsupported(LSD, "linkage spec");
5069  return;
5070  }
5071 
5072  EmitDeclContext(LSD);
5073 }
5074 
5075 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
5076  for (auto *I : DC->decls()) {
5077  // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
5078  // are themselves considered "top-level", so EmitTopLevelDecl on an
5079  // ObjCImplDecl does not recursively visit them. We need to do that in
5080  // case they're nested inside another construct (LinkageSpecDecl /
5081  // ExportDecl) that does stop them from being considered "top-level".
5082  if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
5083  for (auto *M : OID->methods())
5084  EmitTopLevelDecl(M);
5085  }
5086 
5087  EmitTopLevelDecl(I);
5088  }
5089 }
5090 
5091 /// EmitTopLevelDecl - Emit code for a single top level declaration.
5093  // Ignore dependent declarations.
5094  if (D->isTemplated())
5095  return;
5096 
5097  switch (D->getKind()) {
5098  case Decl::CXXConversion:
5099  case Decl::CXXMethod:
5100  case Decl::Function:
5101  EmitGlobal(cast<FunctionDecl>(D));
5102  // Always provide some coverage mapping
5103  // even for the functions that aren't emitted.
5105  break;
5106 
5107  case Decl::CXXDeductionGuide:
5108  // Function-like, but does not result in code emission.
5109  break;
5110 
5111  case Decl::Var:
5112  case Decl::Decomposition:
5113  case Decl::VarTemplateSpecialization:
5114  EmitGlobal(cast<VarDecl>(D));
5115  if (auto *DD = dyn_cast<DecompositionDecl>(D))
5116  for (auto *B : DD->bindings())
5117  if (auto *HD = B->getHoldingVar())
5118  EmitGlobal(HD);
5119  break;
5120 
5121  // Indirect fields from global anonymous structs and unions can be
5122  // ignored; only the actual variable requires IR gen support.
5123  case Decl::IndirectField:
5124  break;
5125 
5126  // C++ Decls
5127  case Decl::Namespace:
5128  EmitDeclContext(cast<NamespaceDecl>(D));
5129  break;
5130  case Decl::ClassTemplateSpecialization: {
5131  const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
5132  if (DebugInfo &&
5133  Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition &&
5134  Spec->hasDefinition())
5135  DebugInfo->completeTemplateDefinition(*Spec);
5136  } LLVM_FALLTHROUGH;
5137  case Decl::CXXRecord:
5138  if (DebugInfo) {
5139  if (auto *ES = D->getASTContext().getExternalSource())
5140  if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
5141  DebugInfo->completeUnusedClass(cast<CXXRecordDecl>(*D));
5142  }
5143  // Emit any static data members, they may be definitions.
5144  for (auto *I : cast<CXXRecordDecl>(D)->decls())
5145  if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
5146  EmitTopLevelDecl(I);
5147  break;
5148  // No code generation needed.
5149  case Decl::UsingShadow:
5150  case Decl::ClassTemplate:
5151  case Decl::VarTemplate:
5152  case Decl::VarTemplatePartialSpecialization:
5153  case Decl::FunctionTemplate:
5154  case Decl::TypeAliasTemplate:
5155  case Decl::Block:
5156  case Decl::Empty:
5157  case Decl::Binding:
5158  break;
5159  case Decl::Using: // using X; [C++]
5160  if (CGDebugInfo *DI = getModuleDebugInfo())
5161  DI->EmitUsingDecl(cast<UsingDecl>(*D));
5162  return;
5163  case Decl::NamespaceAlias:
5164  if (CGDebugInfo *DI = getModuleDebugInfo())
5165  DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
5166  return;
5167  case Decl::UsingDirective: // using namespace X; [C++]
5168  if (CGDebugInfo *DI = getModuleDebugInfo())
5169  DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
5170  return;
5171  case Decl::CXXConstructor:
5172  getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
5173  break;
5174  case Decl::CXXDestructor:
5175  getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
5176  break;
5177 
5178  case Decl::StaticAssert:
5179  // Nothing to do.
5180  break;
5181 
5182  // Objective-C Decls
5183 
5184  // Forward declarations, no (immediate) code generation.
5185  case Decl::ObjCInterface:
5186  case Decl::ObjCCategory:
5187  break;
5188 
5189  case Decl::ObjCProtocol: {
5190  auto *Proto = cast<ObjCProtocolDecl>(D);
5191  if (Proto->isThisDeclarationADefinition())
5192  ObjCRuntime->GenerateProtocol(Proto);
5193  break;
5194  }
5195 
5196  case Decl::ObjCCategoryImpl:
5197  // Categories have properties but don't support synthesize so we
5198  // can ignore them here.
5199  ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
5200  break;
5201 
5202  case Decl::ObjCImplementation: {
5203  auto *OMD = cast<ObjCImplementationDecl>(D);
5204  EmitObjCPropertyImplementations(OMD);
5205  EmitObjCIvarInitializations(OMD);
5206  ObjCRuntime->GenerateClass(OMD);
5207  // Emit global variable debug information.
5208  if (CGDebugInfo *DI = getModuleDebugInfo())
5209  if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
5210  DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
5211  OMD->getClassInterface()), OMD->getLocation());
5212  break;
5213  }
5214  case Decl::ObjCMethod: {
5215  auto *OMD = cast<ObjCMethodDecl>(D);
5216  // If this is not a prototype, emit the body.
5217  if (OMD->getBody())
5218  CodeGenFunction(*this).GenerateObjCMethod(OMD);
5219  break;
5220  }
5221  case Decl::ObjCCompatibleAlias:
5222  ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
5223  break;
5224 
5225  case Decl::PragmaComment: {
5226  const auto *PCD = cast<PragmaCommentDecl>(D);
5227  switch (PCD->getCommentKind()) {
5228  case PCK_Unknown:
5229  llvm_unreachable("unexpected pragma comment kind");
5230  case PCK_Linker:
5231  AppendLinkerOptions(PCD->getArg());
5232  break;
5233  case PCK_Lib:
5234  AddDependentLib(PCD->getArg());
5235  break;
5236  case PCK_Compiler:
5237  case PCK_ExeStr:
5238  case PCK_User:
5239  break; // We ignore all of these.
5240  }
5241  break;
5242  }
5243 
5244  case Decl::PragmaDetectMismatch: {
5245  const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
5246  AddDetectMismatch(PDMD->getName(), PDMD->getValue());
5247  break;
5248  }
5249 
5250  case Decl::LinkageSpec:
5251  EmitLinkageSpec(cast<LinkageSpecDecl>(D));
5252  break;
5253 
5254  case Decl::FileScopeAsm: {
5255  // File-scope asm is ignored during device-side CUDA compilation.
5256  if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
5257  break;
5258  // File-scope asm is ignored during device-side OpenMP compilation.
5259  if (LangOpts.OpenMPIsDevice)
5260  break;
5261  auto *AD = cast<FileScopeAsmDecl>(D);
5262  getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
5263  break;
5264  }
5265 
5266  case Decl::Import: {
5267  auto *Import = cast<ImportDecl>(D);
5268 
5269  // If we've already imported this module, we're done.
5270  if (!ImportedModules.insert(Import->getImportedModule()))
5271  break;
5272 
5273  // Emit debug information for direct imports.
5274  if (!Import->getImportedOwningModule()) {
5275  if (CGDebugInfo *DI = getModuleDebugInfo())
5276  DI->EmitImportDecl(*Import);
5277  }
5278 
5279  // Find all of the submodules and emit the module initializers.
5280  llvm::SmallPtrSet<clang::Module *, 16> Visited;
5282  Visited.insert(Import->getImportedModule());
5283  Stack.push_back(Import->getImportedModule());
5284 
5285  while (!Stack.empty()) {
5286  clang::Module *Mod = Stack.pop_back_val();
5287  if (!EmittedModuleInitializers.insert(Mod).second)
5288  continue;
5289 
5290  for (auto *D : Context.getModuleInitializers(Mod))
5291  EmitTopLevelDecl(D);
5292 
5293  // Visit the submodules of this module.
5295  SubEnd = Mod->submodule_end();
5296  Sub != SubEnd; ++Sub) {
5297  // Skip explicit children; they need to be explicitly imported to emit
5298  // the initializers.
5299  if ((*Sub)->IsExplicit)
5300  continue;
5301 
5302  if (Visited.insert(*Sub).second)
5303  Stack.push_back(*Sub);
5304  }
5305  }
5306  break;
5307  }
5308 
5309  case Decl::Export:
5310  EmitDeclContext(cast<ExportDecl>(D));
5311  break;
5312 
5313  case Decl::OMPThreadPrivate:
5314  EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
5315  break;
5316 
5317  case Decl::OMPAllocate:
5318  break;
5319 
5320  case Decl::OMPDeclareReduction:
5321  EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
5322  break;
5323 
5324  case Decl::OMPDeclareMapper:
5325  EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D));
5326  break;
5327 
5328  case Decl::OMPRequires:
5329  EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
5330  break;
5331 
5332  default:
5333  // Make sure we handled everything we should, every other kind is a
5334  // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
5335  // function. Need to recode Decl::Kind to do that easily.
5336  assert(isa<TypeDecl>(D) && "Unsupported decl kind");
5337  break;
5338  }
5339 }
5340 
5342  // Do we need to generate coverage mapping?
5343  if (!CodeGenOpts.CoverageMapping)
5344  return;
5345  switch (D->getKind()) {
5346  case Decl::CXXConversion:
5347  case Decl::CXXMethod:
5348  case Decl::Function:
5349  case Decl::ObjCMethod:
5350  case Decl::CXXConstructor:
5351  case Decl::CXXDestructor: {
5352  if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
5353  return;
5355  if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
5356  return;
5357  auto I = DeferredEmptyCoverageMappingDecls.find(D);
5358  if (I == DeferredEmptyCoverageMappingDecls.end())
5359  DeferredEmptyCoverageMappingDecls[D] = true;
5360  break;
5361  }
5362  default:
5363  break;
5364  };
5365 }
5366 
5368  // Do we need to generate coverage mapping?
5369  if (!CodeGenOpts.CoverageMapping)
5370  return;
5371  if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
5372  if (Fn->isTemplateInstantiation())
5373  ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
5374  }
5375  auto I = DeferredEmptyCoverageMappingDecls.find(D);
5376  if (I == DeferredEmptyCoverageMappingDecls.end())
5377  DeferredEmptyCoverageMappingDecls[D] = false;
5378  else
5379  I->second = false;
5380 }
5381 
5383  // We call takeVector() here to avoid use-after-free.
5384  // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
5385  // we deserialize function bodies to emit coverage info for them, and that
5386  // deserializes more declarations. How should we handle that case?
5387  for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
5388  if (!Entry.second)
5389  continue;
5390  const Decl *D = Entry.first;
5391  switch (D->getKind()) {
5392  case Decl::CXXConversion:
5393  case Decl::CXXMethod:
5394  case Decl::Function:
5395  case Decl::ObjCMethod: {
5396  CodeGenPGO PGO(*this);
5397  GlobalDecl GD(cast<FunctionDecl>(D));
5399  getFunctionLinkage(GD));
5400  break;
5401  }
5402  case Decl::CXXConstructor: {
5403  CodeGenPGO PGO(*this);
5404  GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
5406  getFunctionLinkage(GD));
5407  break;
5408  }
5409  case Decl::CXXDestructor: {
5410  CodeGenPGO PGO(*this);
5411  GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
5413  getFunctionLinkage(GD));
5414  break;
5415  }
5416  default:
5417  break;
5418  };
5419  }
5420 }
5421 
5422 /// Turns the given pointer into a constant.
5423 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
5424  const void *Ptr) {
5425  uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
5426  llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
5427  return llvm::ConstantInt::get(i64, PtrInt);
5428 }
5429 
5431  llvm::NamedMDNode *&GlobalMetadata,
5432  GlobalDecl D,
5433  llvm::GlobalValue *Addr) {
5434  if (!GlobalMetadata)
5435  GlobalMetadata =
5436  CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
5437 
5438  // TODO: should we report variant information for ctors/dtors?
5439  llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
5440  llvm::ConstantAsMetadata::get(GetPointerConstant(
5441  CGM.getLLVMContext(), D.getDecl()))};
5442  GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
5443 }
5444 
5445 /// For each function which is declared within an extern "C" region and marked
5446 /// as 'used', but has internal linkage, create an alias from the unmangled
5447 /// name to the mangled name if possible. People expect to be able to refer
5448 /// to such functions with an unmangled name from inline assembly within the
5449 /// same translation unit.
5450 void CodeGenModule::EmitStaticExternCAliases() {
5451  if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
5452  return;
5453  for (auto &I : StaticExternCValues) {
5454  IdentifierInfo *Name = I.first;
5455  llvm::GlobalValue *Val = I.second;
5456  if (Val && !getModule().getNamedValue(Name->getName()))
5458  }
5459 }
5460 
5461 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
5462  GlobalDecl &Result) const {
5463  auto Res = Manglings.find(MangledName);
5464  if (Res == Manglings.end())
5465  return false;
5466  Result = Res->getValue();
5467  return true;
5468 }
5469 
5470 /// Emits metadata nodes associating all the global values in the
5471 /// current module with the Decls they came from. This is useful for
5472 /// projects using IR gen as a subroutine.
5473 ///
5474 /// Since there's currently no way to associate an MDNode directly
5475 /// with an llvm::GlobalValue, we create a global named metadata
5476 /// with the name 'clang.global.decl.ptrs'.
5477 void CodeGenModule::EmitDeclMetadata() {
5478  llvm::NamedMDNode *GlobalMetadata = nullptr;
5479 
5480  for (auto &I : MangledDeclNames) {
5481  llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
5482  // Some mangled names don't necessarily have an associated GlobalValue
5483  // in this module, e.g. if we mangled it for DebugInfo.
5484  if (Addr)
5485  EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
5486  }
5487 }
5488 
5489 /// Emits metadata nodes for all the local variables in the current
5490 /// function.
5491 void CodeGenFunction::EmitDeclMetadata() {
5492  if (LocalDeclMap.empty()) return;
5493 
5494  llvm::LLVMContext &Context = getLLVMContext();
5495 
5496  // Find the unique metadata ID for this name.
5497  unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
5498 
5499  llvm::NamedMDNode *GlobalMetadata = nullptr;
5500 
5501  for (auto &I : LocalDeclMap) {
5502  const Decl *D = I.first;
5503  llvm::Value *Addr = I.second.getPointer();
5504  if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
5506  Alloca->setMetadata(
5507  DeclPtrKind, llvm::MDNode::get(
5508  Context, llvm::ValueAsMetadata::getConstant(DAddr)));
5509  } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
5510  GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
5511  EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
5512  }
5513  }
5514 }
5515 
5516 void CodeGenModule::EmitVersionIdentMetadata() {
5517  llvm::NamedMDNode *IdentMetadata =
5518  TheModule.getOrInsertNamedMetadata("llvm.ident");
5519  std::string Version = getClangFullVersion();
5520  llvm::LLVMContext &Ctx = TheModule.getContext();
5521 
5522  llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
5523  IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
5524 }
5525 
5526 void CodeGenModule::EmitCommandLineMetadata() {
5527  llvm::NamedMDNode *CommandLineMetadata =
5528  TheModule.getOrInsertNamedMetadata("llvm.commandline");
5529  std::string CommandLine = getCodeGenOpts().RecordCommandLine;
5530  llvm::LLVMContext &Ctx = TheModule.getContext();
5531 
5532  llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
5533  CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
5534 }
5535 
5536 void CodeGenModule::EmitTargetMetadata() {
5537  // Warning, new MangledDeclNames may be appended within this loop.
5538  // We rely on MapVector insertions adding new elements to the end
5539  // of the container.
5540  // FIXME: Move this loop into the one target that needs it, and only
5541  // loop over those declarations for which we couldn't emit the target
5542  // metadata when we emitted the declaration.
5543  for (unsigned I = 0; I != MangledDeclNames.size(); ++I) {
5544  auto Val = *(MangledDeclNames.begin() + I);
5545  const Decl *D = Val.first.getDecl()->getMostRecentDecl();
5546  llvm::GlobalValue *GV = GetGlobalValue(Val.second);
5547  getTargetCodeGenInfo().emitTargetMD(D, GV, *this);
5548  }
5549 }
5550 
5551 void CodeGenModule::EmitCoverageFile() {
5552  if (getCodeGenOpts().CoverageDataFile.empty() &&
5554  return;
5555 
5556  llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
5557  if (!CUNode)
5558  return;
5559 
5560  llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
5561  llvm::LLVMContext &Ctx = TheModule.getContext();
5562  auto *CoverageDataFile =
5563  llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
5564  auto *CoverageNotesFile =
5565  llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
5566  for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
5567  llvm::MDNode *CU = CUNode->getOperand(i);
5568  llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
5569  GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
5570  }
5571 }
5572 
5573 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid) {
5574  // Sema has checked that all uuid strings are of the form
5575  // "12345678-1234-1234-1234-1234567890ab".
5576  assert(Uuid.size() == 36);
5577  for (unsigned i = 0; i < 36; ++i) {
5578  if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-');
5579  else assert(isHexDigit(Uuid[i]));
5580  }
5581 
5582  // The starts of all bytes of Field3 in Uuid. Field 3 is "1234-1234567890ab".
5583  const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 };
5584 
5585  llvm::Constant *Field3[8];
5586  for (unsigned Idx = 0; Idx < 8; ++Idx)
5587  Field3[Idx] = llvm::ConstantInt::get(
5588  Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16);
5589 
5590  llvm::Constant *Fields[4] = {
5591  llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16),
5592  llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16),
5593  llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16),
5594  llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3)
5595  };
5596 
5597  return llvm::ConstantStruct::getAnon(Fields);
5598 }
5599 
5601  bool ForEH) {
5602  // Return a bogus pointer if RTTI is disabled, unless it's for EH.
5603  // FIXME: should we even be calling this method if RTTI is disabled
5604  // and it's not for EH?
5605  if ((!ForEH && !getLangOpts().RTTI) || getLangOpts().CUDAIsDevice)
5606  return llvm::Constant::getNullValue(Int8PtrTy);
5607 
5608  if (ForEH && Ty->isObjCObjectPointerType() &&
5609  LangOpts.ObjCRuntime.isGNUFamily())
5610  return ObjCRuntime->GetEHType(Ty);
5611 
5612  return getCXXABI().getAddrOfRTTIDescriptor(Ty);
5613 }
5614 
5616  // Do not emit threadprivates in simd-only mode.
5617  if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
5618  return;
5619  for (auto RefExpr : D->varlists()) {
5620  auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
5621  bool PerformInit =
5622  VD->getAnyInitializer() &&
5623  !VD->getAnyInitializer()->isConstantInitializer(getContext(),
5624  /*ForRef=*/false);
5625 
5627  if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
5628  VD, Addr, RefExpr->getBeginLoc(), PerformInit))
5629  CXXGlobalInits.push_back(InitFunction);
5630  }
5631 }
5632 
5633 llvm::Metadata *
5634 CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
5635  StringRef Suffix) {
5636  llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
5637  if (InternalId)
5638  return InternalId;
5639 
5640  if (isExternallyVisible(T->getLinkage())) {
5641  std::string OutName;
5642  llvm::raw_string_ostream Out(OutName);
5644  Out << Suffix;
5645 
5646  InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
5647  } else {
5648  InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
5650  }
5651 
5652  return InternalId;
5653 }
5654 
5656  return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
5657 }
5658 
5659 llvm::Metadata *
5661  return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
5662 }
5663 
5664 // Generalize pointer types to a void pointer with the qualifiers of the
5665 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
5666 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
5667 // 'void *'.
5669  if (!Ty->isPointerType())
5670  return Ty;
5671 
5672  return Ctx.getPointerType(
5674  Ty->getPointeeType().getCVRQualifiers()));
5675 }
5676 
5677 // Apply type generalization to a FunctionType's return and argument types
5679  if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
5680  SmallVector<QualType, 8> GeneralizedParams;
5681  for (auto &Param : FnType->param_types())
5682  GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
5683 
5684  return Ctx.getFunctionType(
5685  GeneralizeType(Ctx, FnType->getReturnType()),
5686  GeneralizedParams, FnType->getExtProtoInfo());
5687  }
5688 
5689  if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
5690  return Ctx.getFunctionNoProtoType(
5691  GeneralizeType(Ctx, FnType->getReturnType()));
5692 
5693  llvm_unreachable("Encountered unknown FunctionType");
5694 }
5695 
5697  return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
5698  GeneralizedMetadataIdMap, ".generalized");
5699 }
5700 
5701 /// Returns whether this module needs the "all-vtables" type identifier.
5703  // Returns true if at least one of vtable-based CFI checkers is enabled and
5704  // is not in the trapping mode.
5705  return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
5706  !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
5707  (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
5708  !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
5709  (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
5710  !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
5711  (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
5712  !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
5713 }
5714 
5715 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
5716  CharUnits Offset,
5717  const CXXRecordDecl *RD) {
5718  llvm::Metadata *MD =
5720  VTable->addTypeMetadata(Offset.getQuantity(), MD);
5721 
5722  if (CodeGenOpts.SanitizeCfiCrossDso)
5723  if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
5724  VTable->addTypeMetadata(Offset.getQuantity(),
5725  llvm::ConstantAsMetadata::get(CrossDsoTypeId));
5726 
5727  if (NeedAllVtablesTypeId()) {
5728  llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
5729  VTable->addTypeMetadata(Offset.getQuantity(), MD);
5730  }
5731 }
5732 
5733 TargetAttr::ParsedTargetAttr CodeGenModule::filterFunctionTargetAttrs(const TargetAttr *TD) {
5734  assert(TD != nullptr);
5735  TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
5736 
5737  ParsedAttr.Features.erase(
5738  llvm::remove_if(ParsedAttr.Features,
5739  [&](const std::string &Feat) {
5740  return !Target.isValidFeatureName(
5741  StringRef{Feat}.substr(1));
5742  }),
5743  ParsedAttr.Features.end());
5744  return ParsedAttr;
5745 }
5746 
5747 
5748 // Fills in the supplied string map with the set of target features for the