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 "CGOpenMPRuntimeAMDGCN.h"
23#include "CGOpenMPRuntimeNVPTX.h"
24#include "CodeGenFunction.h"
25#include "CodeGenPGO.h"
26#include "ConstantEmitter.h"
27#include "CoverageMappingGen.h"
28#include "TargetInfo.h"
29#include "clang/AST/ASTContext.h"
30#include "clang/AST/CharUnits.h"
31#include "clang/AST/DeclCXX.h"
32#include "clang/AST/DeclObjC.h"
33#include "clang/AST/DeclTemplate.h"
34#include "clang/AST/Mangle.h"
35#include "clang/AST/RecordLayout.h"
36#include "clang/AST/RecursiveASTVisitor.h"
37#include "clang/AST/StmtVisitor.h"
38#include "clang/Basic/Builtins.h"
39#include "clang/Basic/CharInfo.h"
40#include "clang/Basic/CodeGenOptions.h"
41#include "clang/Basic/Diagnostic.h"
42#include "clang/Basic/FileManager.h"
43#include "clang/Basic/Module.h"
44#include "clang/Basic/SourceManager.h"
45#include "clang/Basic/TargetInfo.h"
46#include "clang/Basic/Version.h"
47#include "clang/CodeGen/ConstantInitBuilder.h"
48#include "clang/Frontend/FrontendDiagnostic.h"
49#include "llvm/ADT/StringSwitch.h"
50#include "llvm/ADT/Triple.h"
51#include "llvm/Analysis/TargetLibraryInfo.h"
52#include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
53#include "llvm/IR/CallingConv.h"
54#include "llvm/IR/DataLayout.h"
55#include "llvm/IR/Intrinsics.h"
56#include "llvm/IR/LLVMContext.h"
57#include "llvm/IR/Module.h"
58#include "llvm/IR/ProfileSummary.h"
59#include "llvm/ProfileData/InstrProfReader.h"
60#include "llvm/Support/CodeGen.h"
61#include "llvm/Support/CommandLine.h"
62#include "llvm/Support/ConvertUTF.h"
63#include "llvm/Support/ErrorHandling.h"
64#include "llvm/Support/MD5.h"
65#include "llvm/Support/TimeProfiler.h"
66
67using namespace clang;
68using namespace CodeGen;
69
70static llvm::cl::opt<bool> LimitedCoverage(
71    "limited-coverage-experimental", llvm::cl::ZeroOrMore, llvm::cl::Hidden,
72    llvm::cl::desc("Emit limited coverage mapping information (experimental)"),
73    llvm::cl::init(false));
74
75static const char AnnotationSection[] = "llvm.metadata";
76
77static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
78  switch (CGM.getContext().getCXXABIKind()) {
79  case TargetCXXABI::AppleARM64:
80  case TargetCXXABI::Fuchsia:
81  case TargetCXXABI::GenericAArch64:
82  case TargetCXXABI::GenericARM:
83  case TargetCXXABI::iOS:
84  case TargetCXXABI::WatchOS:
85  case TargetCXXABI::GenericMIPS:
86  case TargetCXXABI::GenericItanium:
87  case TargetCXXABI::WebAssembly:
88  case TargetCXXABI::XL:
89    return CreateItaniumCXXABI(CGM);
90  case TargetCXXABI::Microsoft:
91    return CreateMicrosoftCXXABI(CGM);
92  }
93
94  llvm_unreachable("invalid C++ ABI kind");
95}
96
97CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
98                             const PreprocessorOptions &PPO,
99                             const CodeGenOptions &CGO, llvm::Module &M,
100                             DiagnosticsEngine &diags,
101                             CoverageSourceInfo *CoverageInfo)
102    : Context(C), LangOpts(C.getLangOpts()), HeaderSearchOpts(HSO),
103      PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
104      Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
105      VMContext(M.getContext()), Types(*this), VTables(*this),
106      SanitizerMD(new SanitizerMetadata(*this)) {
107
108  // Initialize the type cache.
109  llvm::LLVMContext &LLVMContext = M.getContext();
110  VoidTy = llvm::Type::getVoidTy(LLVMContext);
111  Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
112  Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
113  Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
114  Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
115  HalfTy = llvm::Type::getHalfTy(LLVMContext);
116  BFloatTy = llvm::Type::getBFloatTy(LLVMContext);
117  FloatTy = llvm::Type::getFloatTy(LLVMContext);
118  DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
119  PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
120  PointerAlignInBytes =
121    C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
122  SizeSizeInBytes =
123    C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
124  IntAlignInBytes =
125    C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
126  CharTy =
127    llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getCharWidth());
128  IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
129  IntPtrTy = llvm::IntegerType::get(LLVMContext,
130    C.getTargetInfo().getMaxPointerWidth());
131  Int8PtrTy = Int8Ty->getPointerTo(0);
132  Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
133  AllocaInt8PtrTy = Int8Ty->getPointerTo(
134      M.getDataLayout().getAllocaAddrSpace());
135  ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
136
137  RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
138
139  if (LangOpts.ObjC)
140    createObjCRuntime();
141  if (LangOpts.OpenCL)
142    createOpenCLRuntime();
143  if (LangOpts.OpenMP)
144    createOpenMPRuntime();
145  if (LangOpts.CUDA)
146    createCUDARuntime();
147
148  // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
149  if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
150      (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
151    TBAA.reset(new CodeGenTBAA(Context, TheModule, CodeGenOpts, getLangOpts(),
152                               getCXXABI().getMangleContext()));
153
154  // If debug info or coverage generation is enabled, create the CGDebugInfo
155  // object.
156  if (CodeGenOpts.getDebugInfo() != codegenoptions::NoDebugInfo ||
157      CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)
158    DebugInfo.reset(new CGDebugInfo(*this));
159
160  Block.GlobalUniqueCount = 0;
161
162  if (C.getLangOpts().ObjC)
163    ObjCData.reset(new ObjCEntrypoints());
164
165  if (CodeGenOpts.hasProfileClangUse()) {
166    auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
167        CodeGenOpts.ProfileInstrumentUsePath, CodeGenOpts.ProfileRemappingFile);
168    if (auto E = ReaderOrErr.takeError()) {
169      unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
170                                              "Could not read profile %0: %1");
171      llvm::handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EI) {
172        getDiags().Report(DiagID) << CodeGenOpts.ProfileInstrumentUsePath
173                                  << EI.message();
174      });
175    } else
176      PGOReader = std::move(ReaderOrErr.get());
177  }
178
179  // If coverage mapping generation is enabled, create the
180  // CoverageMappingModuleGen object.
181  if (CodeGenOpts.CoverageMapping)
182    CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
183
184  // Generate the module name hash here if needed.
185  if (CodeGenOpts.UniqueInternalLinkageNames &&
186      !getModule().getSourceFileName().empty()) {
187    std::string Path = getModule().getSourceFileName();
188    // Check if a path substitution is needed from the MacroPrefixMap.
189    for (const auto &Entry : PPO.MacroPrefixMap)
190      if (Path.rfind(Entry.first, 0) != std::string::npos) {
191        Path = Entry.second + Path.substr(Entry.first.size());
192        break;
193      }
194    llvm::MD5 Md5;
195    Md5.update(Path);
196    llvm::MD5::MD5Result R;
197    Md5.final(R);
198    SmallString<32> Str;
199    llvm::MD5::stringifyResult(R, Str);
200    // Convert MD5hash to Decimal. Demangler suffixes can either contain
201    // numbers or characters but not both.
202    llvm::APInt IntHash(128, Str.str(), 16);
203    // Prepend "__uniq" before the hash for tools like profilers to understand
204    // that this symbol is of internal linkage type.  The "__uniq" is the
205    // pre-determined prefix that is used to tell tools that this symbol was
206    // created with -funique-internal-linakge-symbols and the tools can strip or
207    // keep the prefix as needed.
208    ModuleNameHash = (Twine(".__uniq.") +
209        Twine(IntHash.toString(/* Radix = */ 10, /* Signed = */false))).str();
210  }
211}
212
213CodeGenModule::~CodeGenModule() {}
214
215void CodeGenModule::createObjCRuntime() {
216  // This is just isGNUFamily(), but we want to force implementors of
217  // new ABIs to decide how best to do this.
218  switch (LangOpts.ObjCRuntime.getKind()) {
219  case ObjCRuntime::GNUstep:
220  case ObjCRuntime::GCC:
221  case ObjCRuntime::ObjFW:
222    ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
223    return;
224
225  case ObjCRuntime::FragileMacOSX:
226  case ObjCRuntime::MacOSX:
227  case ObjCRuntime::iOS:
228  case ObjCRuntime::WatchOS:
229    ObjCRuntime.reset(CreateMacObjCRuntime(*this));
230    return;
231  }
232  llvm_unreachable("bad runtime kind");
233}
234
235void CodeGenModule::createOpenCLRuntime() {
236  OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
237}
238
239void CodeGenModule::createOpenMPRuntime() {
240  // Select a specialized code generation class based on the target, if any.
241  // If it does not exist use the default implementation.
242  switch (getTriple().getArch()) {
243  case llvm::Triple::nvptx:
244  case llvm::Triple::nvptx64:
245    assert(getLangOpts().OpenMPIsDevice &&
246           "OpenMP NVPTX is only prepared to deal with device code.");
247    OpenMPRuntime.reset(new CGOpenMPRuntimeNVPTX(*this));
248    break;
249  case llvm::Triple::amdgcn:
250    assert(getLangOpts().OpenMPIsDevice &&
251           "OpenMP AMDGCN is only prepared to deal with device code.");
252    OpenMPRuntime.reset(new CGOpenMPRuntimeAMDGCN(*this));
253    break;
254  default:
255    if (LangOpts.OpenMPSimd)
256      OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
257    else
258      OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
259    break;
260  }
261}
262
263void CodeGenModule::createCUDARuntime() {
264  CUDARuntime.reset(CreateNVCUDARuntime(*this));
265}
266
267void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
268  Replacements[Name] = C;
269}
270
271void CodeGenModule::applyReplacements() {
272  for (auto &I : Replacements) {
273    StringRef MangledName = I.first();
274    llvm::Constant *Replacement = I.second;
275    llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
276    if (!Entry)
277      continue;
278    auto *OldF = cast<llvm::Function>(Entry);
279    auto *NewF = dyn_cast<llvm::Function>(Replacement);
280    if (!NewF) {
281      if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
282        NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
283      } else {
284        auto *CE = cast<llvm::ConstantExpr>(Replacement);
285        assert(CE->getOpcode() == llvm::Instruction::BitCast ||
286               CE->getOpcode() == llvm::Instruction::GetElementPtr);
287        NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
288      }
289    }
290
291    // Replace old with new, but keep the old order.
292    OldF->replaceAllUsesWith(Replacement);
293    if (NewF) {
294      NewF->removeFromParent();
295      OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
296                                                       NewF);
297    }
298    OldF->eraseFromParent();
299  }
300}
301
302void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
303  GlobalValReplacements.push_back(std::make_pair(GV, C));
304}
305
306void CodeGenModule::applyGlobalValReplacements() {
307  for (auto &I : GlobalValReplacements) {
308    llvm::GlobalValue *GV = I.first;
309    llvm::Constant *C = I.second;
310
311    GV->replaceAllUsesWith(C);
312    GV->eraseFromParent();
313  }
314}
315
316// This is only used in aliases that we created and we know they have a
317// linear structure.
318static const llvm::GlobalObject *getAliasedGlobal(
319    const llvm::GlobalIndirectSymbol &GIS) {
320  llvm::SmallPtrSet<const llvm::GlobalIndirectSymbol*, 4> Visited;
321  const llvm::Constant *C = &GIS;
322  for (;;) {
323    C = C->stripPointerCasts();
324    if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
325      return GO;
326    // stripPointerCasts will not walk over weak aliases.
327    auto *GIS2 = dyn_cast<llvm::GlobalIndirectSymbol>(C);
328    if (!GIS2)
329      return nullptr;
330    if (!Visited.insert(GIS2).second)
331      return nullptr;
332    C = GIS2->getIndirectSymbol();
333  }
334}
335
336void CodeGenModule::checkAliases() {
337  // Check if the constructed aliases are well formed. It is really unfortunate
338  // that we have to do this in CodeGen, but we only construct mangled names
339  // and aliases during codegen.
340  bool Error = false;
341  DiagnosticsEngine &Diags = getDiags();
342  for (const GlobalDecl &GD : Aliases) {
343    const auto *D = cast<ValueDecl>(GD.getDecl());
344    SourceLocation Location;
345    bool IsIFunc = D->hasAttr<IFuncAttr>();
346    if (const Attr *A = D->getDefiningAttr())
347      Location = A->getLocation();
348    else
349      llvm_unreachable("Not an alias or ifunc?");
350    StringRef MangledName = getMangledName(GD);
351    llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
352    auto *Alias  = cast<llvm::GlobalIndirectSymbol>(Entry);
353    const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
354    if (!GV) {
355      Error = true;
356      Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
357    } else if (GV->isDeclaration()) {
358      Error = true;
359      Diags.Report(Location, diag::err_alias_to_undefined)
360          << IsIFunc << IsIFunc;
361    } else if (IsIFunc) {
362      // Check resolver function type.
363      llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(
364          GV->getType()->getPointerElementType());
365      assert(FTy);
366      if (!FTy->getReturnType()->isPointerTy())
367        Diags.Report(Location, diag::err_ifunc_resolver_return);
368    }
369
370    llvm::Constant *Aliasee = Alias->getIndirectSymbol();
371    llvm::GlobalValue *AliaseeGV;
372    if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
373      AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
374    else
375      AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
376
377    if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
378      StringRef AliasSection = SA->getName();
379      if (AliasSection != AliaseeGV->getSection())
380        Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
381            << AliasSection << IsIFunc << IsIFunc;
382    }
383
384    // We have to handle alias to weak aliases in here. LLVM itself disallows
385    // this since the object semantics would not match the IL one. For
386    // compatibility with gcc we implement it by just pointing the alias
387    // to its aliasee's aliasee. We also warn, since the user is probably
388    // expecting the link to be weak.
389    if (auto GA = dyn_cast<llvm::GlobalIndirectSymbol>(AliaseeGV)) {
390      if (GA->isInterposable()) {
391        Diags.Report(Location, diag::warn_alias_to_weak_alias)
392            << GV->getName() << GA->getName() << IsIFunc;
393        Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
394            GA->getIndirectSymbol(), Alias->getType());
395        Alias->setIndirectSymbol(Aliasee);
396      }
397    }
398  }
399  if (!Error)
400    return;
401
402  for (const GlobalDecl &GD : Aliases) {
403    StringRef MangledName = getMangledName(GD);
404    llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
405    auto *Alias = cast<llvm::GlobalIndirectSymbol>(Entry);
406    Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
407    Alias->eraseFromParent();
408  }
409}
410
411void CodeGenModule::clear() {
412  DeferredDeclsToEmit.clear();
413  if (OpenMPRuntime)
414    OpenMPRuntime->clear();
415}
416
417void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
418                                       StringRef MainFile) {
419  if (!hasDiagnostics())
420    return;
421  if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
422    if (MainFile.empty())
423      MainFile = "<stdin>";
424    Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
425  } else {
426    if (Mismatched > 0)
427      Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
428
429    if (Missing > 0)
430      Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
431  }
432}
433
434static void setVisibilityFromDLLStorageClass(const clang::LangOptions &LO,
435                                             llvm::Module &M) {
436  if (!LO.VisibilityFromDLLStorageClass)
437    return;
438
439  llvm::GlobalValue::VisibilityTypes DLLExportVisibility =
440      CodeGenModule::GetLLVMVisibility(LO.getDLLExportVisibility());
441  llvm::GlobalValue::VisibilityTypes NoDLLStorageClassVisibility =
442      CodeGenModule::GetLLVMVisibility(LO.getNoDLLStorageClassVisibility());
443  llvm::GlobalValue::VisibilityTypes ExternDeclDLLImportVisibility =
444      CodeGenModule::GetLLVMVisibility(LO.getExternDeclDLLImportVisibility());
445  llvm::GlobalValue::VisibilityTypes ExternDeclNoDLLStorageClassVisibility =
446      CodeGenModule::GetLLVMVisibility(
447          LO.getExternDeclNoDLLStorageClassVisibility());
448
449  for (llvm::GlobalValue &GV : M.global_values()) {
450    if (GV.hasAppendingLinkage() || GV.hasLocalLinkage())
451      continue;
452
453    // Reset DSO locality before setting the visibility. This removes
454    // any effects that visibility options and annotations may have
455    // had on the DSO locality. Setting the visibility will implicitly set
456    // appropriate globals to DSO Local; however, this will be pessimistic
457    // w.r.t. to the normal compiler IRGen.
458    GV.setDSOLocal(false);
459
460    if (GV.isDeclarationForLinker()) {
461      GV.setVisibility(GV.getDLLStorageClass() ==
462                               llvm::GlobalValue::DLLImportStorageClass
463                           ? ExternDeclDLLImportVisibility
464                           : ExternDeclNoDLLStorageClassVisibility);
465    } else {
466      GV.setVisibility(GV.getDLLStorageClass() ==
467                               llvm::GlobalValue::DLLExportStorageClass
468                           ? DLLExportVisibility
469                           : NoDLLStorageClassVisibility);
470    }
471
472    GV.setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
473  }
474}
475
476void CodeGenModule::Release() {
477  EmitDeferred();
478  EmitVTablesOpportunistically();
479  applyGlobalValReplacements();
480  applyReplacements();
481  checkAliases();
482  emitMultiVersionFunctions();
483  EmitCXXGlobalInitFunc();
484  EmitCXXGlobalCleanUpFunc();
485  registerGlobalDtorsWithAtExit();
486  EmitCXXThreadLocalInitFunc();
487  if (ObjCRuntime)
488    if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
489      AddGlobalCtor(ObjCInitFunction);
490  if (Context.getLangOpts().CUDA && CUDARuntime) {
491    if (llvm::Function *CudaCtorFunction = CUDARuntime->finalizeModule())
492      AddGlobalCtor(CudaCtorFunction);
493  }
494  if (OpenMPRuntime) {
495    if (llvm::Function *OpenMPRequiresDirectiveRegFun =
496            OpenMPRuntime->emitRequiresDirectiveRegFun()) {
497      AddGlobalCtor(OpenMPRequiresDirectiveRegFun, 0);
498    }
499    OpenMPRuntime->createOffloadEntriesAndInfoMetadata();
500    OpenMPRuntime->clear();
501  }
502  if (PGOReader) {
503    getModule().setProfileSummary(
504        PGOReader->getSummary(/* UseCS */ false).getMD(VMContext),
505        llvm::ProfileSummary::PSK_Instr);
506    if (PGOStats.hasDiagnostics())
507      PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
508  }
509  EmitCtorList(GlobalCtors, "llvm.global_ctors");
510  EmitCtorList(GlobalDtors, "llvm.global_dtors");
511  EmitGlobalAnnotations();
512  EmitStaticExternCAliases();
513  EmitDeferredUnusedCoverageMappings();
514  CodeGenPGO(*this).setValueProfilingFlag(getModule());
515  if (CoverageMapping)
516    CoverageMapping->emit();
517  if (CodeGenOpts.SanitizeCfiCrossDso) {
518    CodeGenFunction(*this).EmitCfiCheckFail();
519    CodeGenFunction(*this).EmitCfiCheckStub();
520  }
521  emitAtAvailableLinkGuard();
522  if (Context.getTargetInfo().getTriple().isWasm() &&
523      !Context.getTargetInfo().getTriple().isOSEmscripten()) {
524    EmitMainVoidAlias();
525  }
526  emitLLVMUsed();
527  if (SanStats)
528    SanStats->finish();
529
530  if (CodeGenOpts.Autolink &&
531      (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
532    EmitModuleLinkOptions();
533  }
534
535  // On ELF we pass the dependent library specifiers directly to the linker
536  // without manipulating them. This is in contrast to other platforms where
537  // they are mapped to a specific linker option by the compiler. This
538  // difference is a result of the greater variety of ELF linkers and the fact
539  // that ELF linkers tend to handle libraries in a more complicated fashion
540  // than on other platforms. This forces us to defer handling the dependent
541  // libs to the linker.
542  //
543  // CUDA/HIP device and host libraries are different. Currently there is no
544  // way to differentiate dependent libraries for host or device. Existing
545  // usage of #pragma comment(lib, *) is intended for host libraries on
546  // Windows. Therefore emit llvm.dependent-libraries only for host.
547  if (!ELFDependentLibraries.empty() && !Context.getLangOpts().CUDAIsDevice) {
548    auto *NMD = getModule().getOrInsertNamedMetadata("llvm.dependent-libraries");
549    for (auto *MD : ELFDependentLibraries)
550      NMD->addOperand(MD);
551  }
552
553  // Record mregparm value now so it is visible through rest of codegen.
554  if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
555    getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
556                              CodeGenOpts.NumRegisterParameters);
557
558  if (CodeGenOpts.DwarfVersion) {
559    getModule().addModuleFlag(llvm::Module::Max, "Dwarf Version",
560                              CodeGenOpts.DwarfVersion);
561  }
562
563  if (CodeGenOpts.Dwarf64)
564    getModule().addModuleFlag(llvm::Module::Max, "DWARF64", 1);
565
566  if (Context.getLangOpts().SemanticInterposition)
567    // Require various optimization to respect semantic interposition.
568    getModule().setSemanticInterposition(1);
569
570  if (CodeGenOpts.EmitCodeView) {
571    // Indicate that we want CodeView in the metadata.
572    getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
573  }
574  if (CodeGenOpts.CodeViewGHash) {
575    getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
576  }
577  if (CodeGenOpts.ControlFlowGuard) {
578    // Function ID tables and checks for Control Flow Guard (cfguard=2).
579    getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 2);
580  } else if (CodeGenOpts.ControlFlowGuardNoChecks) {
581    // Function ID tables for Control Flow Guard (cfguard=1).
582    getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 1);
583  }
584  if (CodeGenOpts.EHContGuard) {
585    // Function ID tables for EH Continuation Guard.
586    getModule().addModuleFlag(llvm::Module::Warning, "ehcontguard", 1);
587  }
588  if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
589    // We don't support LTO with 2 with different StrictVTablePointers
590    // FIXME: we could support it by stripping all the information introduced
591    // by StrictVTablePointers.
592
593    getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
594
595    llvm::Metadata *Ops[2] = {
596              llvm::MDString::get(VMContext, "StrictVTablePointers"),
597              llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
598                  llvm::Type::getInt32Ty(VMContext), 1))};
599
600    getModule().addModuleFlag(llvm::Module::Require,
601                              "StrictVTablePointersRequirement",
602                              llvm::MDNode::get(VMContext, Ops));
603  }
604  if (getModuleDebugInfo())
605    // We support a single version in the linked module. The LLVM
606    // parser will drop debug info with a different version number
607    // (and warn about it, too).
608    getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
609                              llvm::DEBUG_METADATA_VERSION);
610
611  // We need to record the widths of enums and wchar_t, so that we can generate
612  // the correct build attributes in the ARM backend. wchar_size is also used by
613  // TargetLibraryInfo.
614  uint64_t WCharWidth =
615      Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
616  getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
617
618  llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
619  if (   Arch == llvm::Triple::arm
620      || Arch == llvm::Triple::armeb
621      || Arch == llvm::Triple::thumb
622      || Arch == llvm::Triple::thumbeb) {
623    // The minimum width of an enum in bytes
624    uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
625    getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
626  }
627
628  if (Arch == llvm::Triple::riscv32 || Arch == llvm::Triple::riscv64) {
629    StringRef ABIStr = Target.getABI();
630    llvm::LLVMContext &Ctx = TheModule.getContext();
631    getModule().addModuleFlag(llvm::Module::Error, "target-abi",
632                              llvm::MDString::get(Ctx, ABIStr));
633  }
634
635  if (CodeGenOpts.SanitizeCfiCrossDso) {
636    // Indicate that we want cross-DSO control flow integrity checks.
637    getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
638  }
639
640  if (CodeGenOpts.WholeProgramVTables) {
641    // Indicate whether VFE was enabled for this module, so that the
642    // vcall_visibility metadata added under whole program vtables is handled
643    // appropriately in the optimizer.
644    getModule().addModuleFlag(llvm::Module::Error, "Virtual Function Elim",
645                              CodeGenOpts.VirtualFunctionElimination);
646  }
647
648  if (LangOpts.Sanitize.has(SanitizerKind::CFIICall)) {
649    getModule().addModuleFlag(llvm::Module::Override,
650                              "CFI Canonical Jump Tables",
651                              CodeGenOpts.SanitizeCfiCanonicalJumpTables);
652  }
653
654  if (CodeGenOpts.CFProtectionReturn &&
655      Target.checkCFProtectionReturnSupported(getDiags())) {
656    // Indicate that we want to instrument return control flow protection.
657    getModule().addModuleFlag(llvm::Module::Override, "cf-protection-return",
658                              1);
659  }
660
661  if (CodeGenOpts.CFProtectionBranch &&
662      Target.checkCFProtectionBranchSupported(getDiags())) {
663    // Indicate that we want to instrument branch control flow protection.
664    getModule().addModuleFlag(llvm::Module::Override, "cf-protection-branch",
665                              1);
666  }
667
668  if (Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_32 ||
669      Arch == llvm::Triple::aarch64_be) {
670    getModule().addModuleFlag(llvm::Module::Error,
671                              "branch-target-enforcement",
672                              LangOpts.BranchTargetEnforcement);
673
674    getModule().addModuleFlag(llvm::Module::Error, "sign-return-address",
675                              LangOpts.hasSignReturnAddress());
676
677    getModule().addModuleFlag(llvm::Module::Error, "sign-return-address-all",
678                              LangOpts.isSignReturnAddressScopeAll());
679
680    getModule().addModuleFlag(llvm::Module::Error,
681                              "sign-return-address-with-bkey",
682                              !LangOpts.isSignReturnAddressWithAKey());
683  }
684
685  if (!CodeGenOpts.MemoryProfileOutput.empty()) {
686    llvm::LLVMContext &Ctx = TheModule.getContext();
687    getModule().addModuleFlag(
688        llvm::Module::Error, "MemProfProfileFilename",
689        llvm::MDString::get(Ctx, CodeGenOpts.MemoryProfileOutput));
690  }
691
692  if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
693    // Indicate whether __nvvm_reflect should be configured to flush denormal
694    // floating point values to 0.  (This corresponds to its "__CUDA_FTZ"
695    // property.)
696    getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
697                              CodeGenOpts.FP32DenormalMode.Output !=
698                                  llvm::DenormalMode::IEEE);
699  }
700
701  if (LangOpts.EHAsynch)
702    getModule().addModuleFlag(llvm::Module::Warning, "eh-asynch", 1);
703
704  // Emit OpenCL specific module metadata: OpenCL/SPIR version.
705  if (LangOpts.OpenCL) {
706    EmitOpenCLMetadata();
707    // Emit SPIR version.
708    if (getTriple().isSPIR()) {
709      // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
710      // opencl.spir.version named metadata.
711      // C++ is backwards compatible with OpenCL v2.0.
712      auto Version = LangOpts.OpenCLCPlusPlus ? 200 : LangOpts.OpenCLVersion;
713      llvm::Metadata *SPIRVerElts[] = {
714          llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
715              Int32Ty, Version / 100)),
716          llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
717              Int32Ty, (Version / 100 > 1) ? 0 : 2))};
718      llvm::NamedMDNode *SPIRVerMD =
719          TheModule.getOrInsertNamedMetadata("opencl.spir.version");
720      llvm::LLVMContext &Ctx = TheModule.getContext();
721      SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
722    }
723  }
724
725  if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
726    assert(PLevel < 3 && "Invalid PIC Level");
727    getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
728    if (Context.getLangOpts().PIE)
729      getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
730  }
731
732  if (getCodeGenOpts().CodeModel.size() > 0) {
733    unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
734                  .Case("tiny", llvm::CodeModel::Tiny)
735                  .Case("small", llvm::CodeModel::Small)
736                  .Case("kernel", llvm::CodeModel::Kernel)
737                  .Case("medium", llvm::CodeModel::Medium)
738                  .Case("large", llvm::CodeModel::Large)
739                  .Default(~0u);
740    if (CM != ~0u) {
741      llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
742      getModule().setCodeModel(codeModel);
743    }
744  }
745
746  if (CodeGenOpts.NoPLT)
747    getModule().setRtLibUseGOT();
748  if (CodeGenOpts.UnwindTables)
749    getModule().setUwtable();
750
751  switch (CodeGenOpts.getFramePointer()) {
752  case CodeGenOptions::FramePointerKind::None:
753    // 0 ("none") is the default.
754    break;
755  case CodeGenOptions::FramePointerKind::NonLeaf:
756    getModule().setFramePointer(llvm::FramePointerKind::NonLeaf);
757    break;
758  case CodeGenOptions::FramePointerKind::All:
759    getModule().setFramePointer(llvm::FramePointerKind::All);
760    break;
761  }
762
763  SimplifyPersonality();
764
765  if (getCodeGenOpts().EmitDeclMetadata)
766    EmitDeclMetadata();
767
768  if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
769    EmitCoverageFile();
770
771  if (CGDebugInfo *DI = getModuleDebugInfo())
772    DI->finalize();
773
774  if (getCodeGenOpts().EmitVersionIdentMetadata)
775    EmitVersionIdentMetadata();
776
777  if (!getCodeGenOpts().RecordCommandLine.empty())
778    EmitCommandLineMetadata();
779
780  if (!getCodeGenOpts().StackProtectorGuard.empty())
781    getModule().setStackProtectorGuard(getCodeGenOpts().StackProtectorGuard);
782  if (!getCodeGenOpts().StackProtectorGuardReg.empty())
783    getModule().setStackProtectorGuardReg(
784        getCodeGenOpts().StackProtectorGuardReg);
785  if (getCodeGenOpts().StackProtectorGuardOffset != INT_MAX)
786    getModule().setStackProtectorGuardOffset(
787        getCodeGenOpts().StackProtectorGuardOffset);
788
789  getTargetCodeGenInfo().emitTargetMetadata(*this, MangledDeclNames);
790
791  EmitBackendOptionsMetadata(getCodeGenOpts());
792
793  // Set visibility from DLL storage class
794  // We do this at the end of LLVM IR generation; after any operation
795  // that might affect the DLL storage class or the visibility, and
796  // before anything that might act on these.
797  setVisibilityFromDLLStorageClass(LangOpts, getModule());
798}
799
800void CodeGenModule::EmitOpenCLMetadata() {
801  // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
802  // opencl.ocl.version named metadata node.
803  // C++ is backwards compatible with OpenCL v2.0.
804  // FIXME: We might need to add CXX version at some point too?
805  auto Version = LangOpts.OpenCLCPlusPlus ? 200 : LangOpts.OpenCLVersion;
806  llvm::Metadata *OCLVerElts[] = {
807      llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
808          Int32Ty, Version / 100)),
809      llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
810          Int32Ty, (Version % 100) / 10))};
811  llvm::NamedMDNode *OCLVerMD =
812      TheModule.getOrInsertNamedMetadata("opencl.ocl.version");
813  llvm::LLVMContext &Ctx = TheModule.getContext();
814  OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
815}
816
817void CodeGenModule::EmitBackendOptionsMetadata(
818    const CodeGenOptions CodeGenOpts) {
819  switch (getTriple().getArch()) {
820  default:
821    break;
822  case llvm::Triple::riscv32:
823  case llvm::Triple::riscv64:
824    getModule().addModuleFlag(llvm::Module::Error, "SmallDataLimit",
825                              CodeGenOpts.SmallDataLimit);
826    break;
827  }
828}
829
830void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
831  // Make sure that this type is translated.
832  Types.UpdateCompletedType(TD);
833}
834
835void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
836  // Make sure that this type is translated.
837  Types.RefreshTypeCacheForClass(RD);
838}
839
840llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
841  if (!TBAA)
842    return nullptr;
843  return TBAA->getTypeInfo(QTy);
844}
845
846TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
847  if (!TBAA)
848    return TBAAAccessInfo();
849  if (getLangOpts().CUDAIsDevice) {
850    // As CUDA builtin surface/texture types are replaced, skip generating TBAA
851    // access info.
852    if (AccessType->isCUDADeviceBuiltinSurfaceType()) {
853      if (getTargetCodeGenInfo().getCUDADeviceBuiltinSurfaceDeviceType() !=
854          nullptr)
855        return TBAAAccessInfo();
856    } else if (AccessType->isCUDADeviceBuiltinTextureType()) {
857      if (getTargetCodeGenInfo().getCUDADeviceBuiltinTextureDeviceType() !=
858          nullptr)
859        return TBAAAccessInfo();
860    }
861  }
862  return TBAA->getAccessInfo(AccessType);
863}
864
865TBAAAccessInfo
866CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
867  if (!TBAA)
868    return TBAAAccessInfo();
869  return TBAA->getVTablePtrAccessInfo(VTablePtrType);
870}
871
872llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
873  if (!TBAA)
874    return nullptr;
875  return TBAA->getTBAAStructInfo(QTy);
876}
877
878llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
879  if (!TBAA)
880    return nullptr;
881  return TBAA->getBaseTypeInfo(QTy);
882}
883
884llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
885  if (!TBAA)
886    return nullptr;
887  return TBAA->getAccessTagInfo(Info);
888}
889
890TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
891                                                   TBAAAccessInfo TargetInfo) {
892  if (!TBAA)
893    return TBAAAccessInfo();
894  return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
895}
896
897TBAAAccessInfo
898CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
899                                                   TBAAAccessInfo InfoB) {
900  if (!TBAA)
901    return TBAAAccessInfo();
902  return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
903}
904
905TBAAAccessInfo
906CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
907                                              TBAAAccessInfo SrcInfo) {
908  if (!TBAA)
909    return TBAAAccessInfo();
910  return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
911}
912
913void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
914                                                TBAAAccessInfo TBAAInfo) {
915  if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
916    Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
917}
918
919void CodeGenModule::DecorateInstructionWithInvariantGroup(
920    llvm::Instruction *I, const CXXRecordDecl *RD) {
921  I->setMetadata(llvm::LLVMContext::MD_invariant_group,
922                 llvm::MDNode::get(getLLVMContext(), {}));
923}
924
925void CodeGenModule::Error(SourceLocation loc, StringRef message) {
926  unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
927  getDiags().Report(Context.getFullLoc(loc), diagID) << message;
928}
929
930/// ErrorUnsupported - Print out an error that codegen doesn't support the
931/// specified stmt yet.
932void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
933  unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
934                                               "cannot compile this %0 yet");
935  std::string Msg = Type;
936  getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID)
937      << Msg << S->getSourceRange();
938}
939
940/// ErrorUnsupported - Print out an error that codegen doesn't support the
941/// specified decl yet.
942void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
943  unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
944                                               "cannot compile this %0 yet");
945  std::string Msg = Type;
946  getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
947}
948
949llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
950  return llvm::ConstantInt::get(SizeTy, size.getQuantity());
951}
952
953void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
954                                        const NamedDecl *D) const {
955  if (GV->hasDLLImportStorageClass())
956    return;
957  // Internal definitions always have default visibility.
958  if (GV->hasLocalLinkage()) {
959    GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
960    return;
961  }
962  if (!D)
963    return;
964  // Set visibility for definitions, and for declarations if requested globally
965  // or set explicitly.
966  LinkageInfo LV = D->getLinkageAndVisibility();
967  if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
968      !GV->isDeclarationForLinker())
969    GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
970}
971
972static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
973                                 llvm::GlobalValue *GV) {
974  if (GV->hasLocalLinkage())
975    return true;
976
977  if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
978    return true;
979
980  // DLLImport explicitly marks the GV as external.
981  if (GV->hasDLLImportStorageClass())
982    return false;
983
984  const llvm::Triple &TT = CGM.getTriple();
985  if (TT.isWindowsGNUEnvironment()) {
986    // In MinGW, variables without DLLImport can still be automatically
987    // imported from a DLL by the linker; don't mark variables that
988    // potentially could come from another DLL as DSO local.
989    if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
990        !GV->isThreadLocal())
991      return false;
992  }
993
994  // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
995  // remain unresolved in the link, they can be resolved to zero, which is
996  // outside the current DSO.
997  if (TT.isOSBinFormatCOFF() && GV->hasExternalWeakLinkage())
998    return false;
999
1000  // Every other GV is local on COFF.
1001  // Make an exception for windows OS in the triple: Some firmware builds use
1002  // *-win32-macho triples. This (accidentally?) produced windows relocations
1003  // without GOT tables in older clang versions; Keep this behaviour.
1004  // FIXME: even thread local variables?
1005  if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
1006    return true;
1007
1008  // Only handle COFF and ELF for now.
1009  if (!TT.isOSBinFormatELF())
1010    return false;
1011
1012  // If this is not an executable, don't assume anything is local.
1013  const auto &CGOpts = CGM.getCodeGenOpts();
1014  llvm::Reloc::Model RM = CGOpts.RelocationModel;
1015  const auto &LOpts = CGM.getLangOpts();
1016  if (RM != llvm::Reloc::Static && !LOpts.PIE) {
1017    // On ELF, if -fno-semantic-interposition is specified and the target
1018    // supports local aliases, there will be neither CC1
1019    // -fsemantic-interposition nor -fhalf-no-semantic-interposition. Set
1020    // dso_local on the function if using a local alias is preferable (can avoid
1021    // PLT indirection).
1022    if (!(isa<llvm::Function>(GV) && GV->canBenefitFromLocalAlias()))
1023      return false;
1024    return !(CGM.getLangOpts().SemanticInterposition ||
1025             CGM.getLangOpts().HalfNoSemanticInterposition);
1026  }
1027
1028  // A definition cannot be preempted from an executable.
1029  if (!GV->isDeclarationForLinker())
1030    return true;
1031
1032  // Most PIC code sequences that assume that a symbol is local cannot produce a
1033  // 0 if it turns out the symbol is undefined. While this is ABI and relocation
1034  // depended, it seems worth it to handle it here.
1035  if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
1036    return false;
1037
1038  // PowerPC64 prefers TOC indirection to avoid copy relocations.
1039  if (TT.isPPC64())
1040    return false;
1041
1042  if (CGOpts.DirectAccessExternalData) {
1043    // If -fdirect-access-external-data (default for -fno-pic), set dso_local
1044    // for non-thread-local variables. If the symbol is not defined in the
1045    // executable, a copy relocation will be needed at link time. dso_local is
1046    // excluded for thread-local variables because they generally don't support
1047    // copy relocations.
1048    if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
1049      if (!Var->isThreadLocal())
1050        return true;
1051
1052    // -fno-pic sets dso_local on a function declaration to allow direct
1053    // accesses when taking its address (similar to a data symbol). If the
1054    // function is not defined in the executable, a canonical PLT entry will be
1055    // needed at link time. -fno-direct-access-external-data can avoid the
1056    // canonical PLT entry. We don't generalize this condition to -fpie/-fpic as
1057    // it could just cause trouble without providing perceptible benefits.
1058    if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
1059      return true;
1060  }
1061
1062  // If we can use copy relocations we can assume it is local.
1063
1064  // Otherwise don't assume it is local.
1065  return false;
1066}
1067
1068void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
1069  GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
1070}
1071
1072void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1073                                          GlobalDecl GD) const {
1074  const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
1075  // C++ destructors have a few C++ ABI specific special cases.
1076  if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
1077    getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
1078    return;
1079  }
1080  setDLLImportDLLExport(GV, D);
1081}
1082
1083void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1084                                          const NamedDecl *D) const {
1085  if (D && D->isExternallyVisible()) {
1086    if (D->hasAttr<DLLImportAttr>())
1087      GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
1088    else if (D->hasAttr<DLLExportAttr>() && !GV->isDeclarationForLinker())
1089      GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
1090  }
1091}
1092
1093void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1094                                    GlobalDecl GD) const {
1095  setDLLImportDLLExport(GV, GD);
1096  setGVPropertiesAux(GV, dyn_cast<NamedDecl>(GD.getDecl()));
1097}
1098
1099void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1100                                    const NamedDecl *D) const {
1101  setDLLImportDLLExport(GV, D);
1102  setGVPropertiesAux(GV, D);
1103}
1104
1105void CodeGenModule::setGVPropertiesAux(llvm::GlobalValue *GV,
1106                                       const NamedDecl *D) const {
1107  setGlobalVisibility(GV, D);
1108  setDSOLocal(GV);
1109  GV->setPartition(CodeGenOpts.SymbolPartition);
1110}
1111
1112static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
1113  return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
1114      .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
1115      .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
1116      .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
1117      .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
1118}
1119
1120llvm::GlobalVariable::ThreadLocalMode
1121CodeGenModule::GetDefaultLLVMTLSModel() const {
1122  switch (CodeGenOpts.getDefaultTLSModel()) {
1123  case CodeGenOptions::GeneralDynamicTLSModel:
1124    return llvm::GlobalVariable::GeneralDynamicTLSModel;
1125  case CodeGenOptions::LocalDynamicTLSModel:
1126    return llvm::GlobalVariable::LocalDynamicTLSModel;
1127  case CodeGenOptions::InitialExecTLSModel:
1128    return llvm::GlobalVariable::InitialExecTLSModel;
1129  case CodeGenOptions::LocalExecTLSModel:
1130    return llvm::GlobalVariable::LocalExecTLSModel;
1131  }
1132  llvm_unreachable("Invalid TLS model!");
1133}
1134
1135void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
1136  assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
1137
1138  llvm::GlobalValue::ThreadLocalMode TLM;
1139  TLM = GetDefaultLLVMTLSModel();
1140
1141  // Override the TLS model if it is explicitly specified.
1142  if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
1143    TLM = GetLLVMTLSModel(Attr->getModel());
1144  }
1145
1146  GV->setThreadLocalMode(TLM);
1147}
1148
1149static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
1150                                          StringRef Name) {
1151  const TargetInfo &Target = CGM.getTarget();
1152  return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
1153}
1154
1155static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
1156                                                 const CPUSpecificAttr *Attr,
1157                                                 unsigned CPUIndex,
1158                                                 raw_ostream &Out) {
1159  // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
1160  // supported.
1161  if (Attr)
1162    Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
1163  else if (CGM.getTarget().supportsIFunc())
1164    Out << ".resolver";
1165}
1166
1167static void AppendTargetMangling(const CodeGenModule &CGM,
1168                                 const TargetAttr *Attr, raw_ostream &Out) {
1169  if (Attr->isDefaultVersion())
1170    return;
1171
1172  Out << '.';
1173  const TargetInfo &Target = CGM.getTarget();
1174  ParsedTargetAttr Info =
1175      Attr->parse([&Target](StringRef LHS, StringRef RHS) {
1176        // Multiversioning doesn't allow "no-${feature}", so we can
1177        // only have "+" prefixes here.
1178        assert(LHS.startswith("+") && RHS.startswith("+") &&
1179               "Features should always have a prefix.");
1180        return Target.multiVersionSortPriority(LHS.substr(1)) >
1181               Target.multiVersionSortPriority(RHS.substr(1));
1182      });
1183
1184  bool IsFirst = true;
1185
1186  if (!Info.Architecture.empty()) {
1187    IsFirst = false;
1188    Out << "arch_" << Info.Architecture;
1189  }
1190
1191  for (StringRef Feat : Info.Features) {
1192    if (!IsFirst)
1193      Out << '_';
1194    IsFirst = false;
1195    Out << Feat.substr(1);
1196  }
1197}
1198
1199// Returns true if GD is a function decl with internal linkage and
1200// needs a unique suffix after the mangled name.
1201static bool isUniqueInternalLinkageDecl(GlobalDecl GD,
1202                                        CodeGenModule &CGM) {
1203  const Decl *D = GD.getDecl();
1204  return !CGM.getModuleNameHash().empty() && isa<FunctionDecl>(D) &&
1205         (CGM.getFunctionLinkage(GD) == llvm::GlobalValue::InternalLinkage);
1206}
1207
1208static std::string getMangledNameImpl(CodeGenModule &CGM, GlobalDecl GD,
1209                                      const NamedDecl *ND,
1210                                      bool OmitMultiVersionMangling = false) {
1211  SmallString<256> Buffer;
1212  llvm::raw_svector_ostream Out(Buffer);
1213  MangleContext &MC = CGM.getCXXABI().getMangleContext();
1214  if (!CGM.getModuleNameHash().empty())
1215    MC.needsUniqueInternalLinkageNames();
1216  bool ShouldMangle = MC.shouldMangleDeclName(ND);
1217  if (ShouldMangle)
1218    MC.mangleName(GD.getWithDecl(ND), Out);
1219  else {
1220    IdentifierInfo *II = ND->getIdentifier();
1221    assert(II && "Attempt to mangle unnamed decl.");
1222    const auto *FD = dyn_cast<FunctionDecl>(ND);
1223
1224    if (FD &&
1225        FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
1226      Out << "__regcall3__" << II->getName();
1227    } else if (FD && FD->hasAttr<CUDAGlobalAttr>() &&
1228               GD.getKernelReferenceKind() == KernelReferenceKind::Stub) {
1229      Out << "__device_stub__" << II->getName();
1230    } else {
1231      Out << II->getName();
1232    }
1233  }
1234
1235  // Check if the module name hash should be appended for internal linkage
1236  // symbols.   This should come before multi-version target suffixes are
1237  // appended. This is to keep the name and module hash suffix of the
1238  // internal linkage function together.  The unique suffix should only be
1239  // added when name mangling is done to make sure that the final name can
1240  // be properly demangled.  For example, for C functions without prototypes,
1241  // name mangling is not done and the unique suffix should not be appeneded
1242  // then.
1243  if (ShouldMangle && isUniqueInternalLinkageDecl(GD, CGM)) {
1244    assert(CGM.getCodeGenOpts().UniqueInternalLinkageNames &&
1245           "Hash computed when not explicitly requested");
1246    Out << CGM.getModuleNameHash();
1247  }
1248
1249  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
1250    if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
1251      switch (FD->getMultiVersionKind()) {
1252      case MultiVersionKind::CPUDispatch:
1253      case MultiVersionKind::CPUSpecific:
1254        AppendCPUSpecificCPUDispatchMangling(CGM,
1255                                             FD->getAttr<CPUSpecificAttr>(),
1256                                             GD.getMultiVersionIndex(), Out);
1257        break;
1258      case MultiVersionKind::Target:
1259        AppendTargetMangling(CGM, FD->getAttr<TargetAttr>(), Out);
1260        break;
1261      case MultiVersionKind::None:
1262        llvm_unreachable("None multiversion type isn't valid here");
1263      }
1264    }
1265
1266  // Make unique name for device side static file-scope variable for HIP.
1267  if (CGM.getContext().shouldExternalizeStaticVar(ND) &&
1268      CGM.getLangOpts().GPURelocatableDeviceCode &&
1269      CGM.getLangOpts().CUDAIsDevice && !CGM.getLangOpts().CUID.empty())
1270    CGM.printPostfixForExternalizedStaticVar(Out);
1271  return std::string(Out.str());
1272}
1273
1274void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
1275                                            const FunctionDecl *FD) {
1276  if (!FD->isMultiVersion())
1277    return;
1278
1279  // Get the name of what this would be without the 'target' attribute.  This
1280  // allows us to lookup the version that was emitted when this wasn't a
1281  // multiversion function.
1282  std::string NonTargetName =
1283      getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
1284  GlobalDecl OtherGD;
1285  if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
1286    assert(OtherGD.getCanonicalDecl()
1287               .getDecl()
1288               ->getAsFunction()
1289               ->isMultiVersion() &&
1290           "Other GD should now be a multiversioned function");
1291    // OtherFD is the version of this function that was mangled BEFORE
1292    // becoming a MultiVersion function.  It potentially needs to be updated.
1293    const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
1294                                      .getDecl()
1295                                      ->getAsFunction()
1296                                      ->getMostRecentDecl();
1297    std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
1298    // This is so that if the initial version was already the 'default'
1299    // version, we don't try to update it.
1300    if (OtherName != NonTargetName) {
1301      // Remove instead of erase, since others may have stored the StringRef
1302      // to this.
1303      const auto ExistingRecord = Manglings.find(NonTargetName);
1304      if (ExistingRecord != std::end(Manglings))
1305        Manglings.remove(&(*ExistingRecord));
1306      auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
1307      MangledDeclNames[OtherGD.getCanonicalDecl()] = Result.first->first();
1308      if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
1309        Entry->setName(OtherName);
1310    }
1311  }
1312}
1313
1314StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
1315  GlobalDecl CanonicalGD = GD.getCanonicalDecl();
1316
1317  // Some ABIs don't have constructor variants.  Make sure that base and
1318  // complete constructors get mangled the same.
1319  if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
1320    if (!getTarget().getCXXABI().hasConstructorVariants()) {
1321      CXXCtorType OrigCtorType = GD.getCtorType();
1322      assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
1323      if (OrigCtorType == Ctor_Base)
1324        CanonicalGD = GlobalDecl(CD, Ctor_Complete);
1325    }
1326  }
1327
1328  // In CUDA/HIP device compilation with -fgpu-rdc, the mangled name of a
1329  // static device variable depends on whether the variable is referenced by
1330  // a host or device host function. Therefore the mangled name cannot be
1331  // cached.
1332  if (!LangOpts.CUDAIsDevice ||
1333      !getContext().mayExternalizeStaticVar(GD.getDecl())) {
1334    auto FoundName = MangledDeclNames.find(CanonicalGD);
1335    if (FoundName != MangledDeclNames.end())
1336      return FoundName->second;
1337  }
1338
1339  // Keep the first result in the case of a mangling collision.
1340  const auto *ND = cast<NamedDecl>(GD.getDecl());
1341  std::string MangledName = getMangledNameImpl(*this, GD, ND);
1342
1343  // Ensure either we have different ABIs between host and device compilations,
1344  // says host compilation following MSVC ABI but device compilation follows
1345  // Itanium C++ ABI or, if they follow the same ABI, kernel names after
1346  // mangling should be the same after name stubbing. The later checking is
1347  // very important as the device kernel name being mangled in host-compilation
1348  // is used to resolve the device binaries to be executed. Inconsistent naming
1349  // result in undefined behavior. Even though we cannot check that naming
1350  // directly between host- and device-compilations, the host- and
1351  // device-mangling in host compilation could help catching certain ones.
1352  assert(!isa<FunctionDecl>(ND) || !ND->hasAttr<CUDAGlobalAttr>() ||
1353         getLangOpts().CUDAIsDevice ||
1354         (getContext().getAuxTargetInfo() &&
1355          (getContext().getAuxTargetInfo()->getCXXABI() !=
1356           getContext().getTargetInfo().getCXXABI())) ||
1357         getCUDARuntime().getDeviceSideName(ND) ==
1358             getMangledNameImpl(
1359                 *this,
1360                 GD.getWithKernelReferenceKind(KernelReferenceKind::Kernel),
1361                 ND));
1362
1363  auto Result = Manglings.insert(std::make_pair(MangledName, GD));
1364  return MangledDeclNames[CanonicalGD] = Result.first->first();
1365}
1366
1367StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
1368                                             const BlockDecl *BD) {
1369  MangleContext &MangleCtx = getCXXABI().getMangleContext();
1370  const Decl *D = GD.getDecl();
1371
1372  SmallString<256> Buffer;
1373  llvm::raw_svector_ostream Out(Buffer);
1374  if (!D)
1375    MangleCtx.mangleGlobalBlock(BD,
1376      dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
1377  else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
1378    MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
1379  else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
1380    MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
1381  else
1382    MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
1383
1384  auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
1385  return Result.first->first();
1386}
1387
1388llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
1389  return getModule().getNamedValue(Name);
1390}
1391
1392/// AddGlobalCtor - Add a function to the list that will be called before
1393/// main() runs.
1394void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
1395                                  llvm::Constant *AssociatedData) {
1396  // FIXME: Type coercion of void()* types.
1397  GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData));
1398}
1399
1400/// AddGlobalDtor - Add a function to the list that will be called
1401/// when the module is unloaded.
1402void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority,
1403                                  bool IsDtorAttrFunc) {
1404  if (CodeGenOpts.RegisterGlobalDtorsWithAtExit &&
1405      (!getContext().getTargetInfo().getTriple().isOSAIX() || IsDtorAttrFunc)) {
1406    DtorsUsingAtExit[Priority].push_back(Dtor);
1407    return;
1408  }
1409
1410  // FIXME: Type coercion of void()* types.
1411  GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
1412}
1413
1414void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
1415  if (Fns.empty()) return;
1416
1417  // Ctor function type is void()*.
1418  llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
1419  llvm::Type *CtorPFTy = llvm::PointerType::get(CtorFTy,
1420      TheModule.getDataLayout().getProgramAddressSpace());
1421
1422  // Get the type of a ctor entry, { i32, void ()*, i8* }.
1423  llvm::StructType *CtorStructTy = llvm::StructType::get(
1424      Int32Ty, CtorPFTy, VoidPtrTy);
1425
1426  // Construct the constructor and destructor arrays.
1427  ConstantInitBuilder builder(*this);
1428  auto ctors = builder.beginArray(CtorStructTy);
1429  for (const auto &I : Fns) {
1430    auto ctor = ctors.beginStruct(CtorStructTy);
1431    ctor.addInt(Int32Ty, I.Priority);
1432    ctor.add(llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy));
1433    if (I.AssociatedData)
1434      ctor.add(llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy));
1435    else
1436      ctor.addNullPointer(VoidPtrTy);
1437    ctor.finishAndAddTo(ctors);
1438  }
1439
1440  auto list =
1441    ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
1442                                /*constant*/ false,
1443                                llvm::GlobalValue::AppendingLinkage);
1444
1445  // The LTO linker doesn't seem to like it when we set an alignment
1446  // on appending variables.  Take it off as a workaround.
1447  list->setAlignment(llvm::None);
1448
1449  Fns.clear();
1450}
1451
1452llvm::GlobalValue::LinkageTypes
1453CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
1454  const auto *D = cast<FunctionDecl>(GD.getDecl());
1455
1456  GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
1457
1458  if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
1459    return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
1460
1461  if (isa<CXXConstructorDecl>(D) &&
1462      cast<CXXConstructorDecl>(D)->isInheritingConstructor() &&
1463      Context.getTargetInfo().getCXXABI().isMicrosoft()) {
1464    // Our approach to inheriting constructors is fundamentally different from
1465    // that used by the MS ABI, so keep our inheriting constructor thunks
1466    // internal rather than trying to pick an unambiguous mangling for them.
1467    return llvm::GlobalValue::InternalLinkage;
1468  }
1469
1470  return getLLVMLinkageForDeclarator(D, Linkage, /*IsConstantVariable=*/false);
1471}
1472
1473llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
1474  llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
1475  if (!MDS) return nullptr;
1476
1477  return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
1478}
1479
1480void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
1481                                              const CGFunctionInfo &Info,
1482                                              llvm::Function *F, bool IsThunk) {
1483  unsigned CallingConv;
1484  llvm::AttributeList PAL;
1485  ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv,
1486                         /*AttrOnCallSite=*/false, IsThunk);
1487  F->setAttributes(PAL);
1488  F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
1489}
1490
1491static void removeImageAccessQualifier(std::string& TyName) {
1492  std::string ReadOnlyQual("__read_only");
1493  std::string::size_type ReadOnlyPos = TyName.find(ReadOnlyQual);
1494  if (ReadOnlyPos != std::string::npos)
1495    // "+ 1" for the space after access qualifier.
1496    TyName.erase(ReadOnlyPos, ReadOnlyQual.size() + 1);
1497  else {
1498    std::string WriteOnlyQual("__write_only");
1499    std::string::size_type WriteOnlyPos = TyName.find(WriteOnlyQual);
1500    if (WriteOnlyPos != std::string::npos)
1501      TyName.erase(WriteOnlyPos, WriteOnlyQual.size() + 1);
1502    else {
1503      std::string ReadWriteQual("__read_write");
1504      std::string::size_type ReadWritePos = TyName.find(ReadWriteQual);
1505      if (ReadWritePos != std::string::npos)
1506        TyName.erase(ReadWritePos, ReadWriteQual.size() + 1);
1507    }
1508  }
1509}
1510
1511// Returns the address space id that should be produced to the
1512// kernel_arg_addr_space metadata. This is always fixed to the ids
1513// as specified in the SPIR 2.0 specification in order to differentiate
1514// for example in clGetKernelArgInfo() implementation between the address
1515// spaces with targets without unique mapping to the OpenCL address spaces
1516// (basically all single AS CPUs).
1517static unsigned ArgInfoAddressSpace(LangAS AS) {
1518  switch (AS) {
1519  case LangAS::opencl_global:
1520    return 1;
1521  case LangAS::opencl_constant:
1522    return 2;
1523  case LangAS::opencl_local:
1524    return 3;
1525  case LangAS::opencl_generic:
1526    return 4; // Not in SPIR 2.0 specs.
1527  case LangAS::opencl_global_device:
1528    return 5;
1529  case LangAS::opencl_global_host:
1530    return 6;
1531  default:
1532    return 0; // Assume private.
1533  }
1534}
1535
1536void CodeGenModule::GenOpenCLArgMetadata(llvm::Function *Fn,
1537                                         const FunctionDecl *FD,
1538                                         CodeGenFunction *CGF) {
1539  assert(((FD && CGF) || (!FD && !CGF)) &&
1540         "Incorrect use - FD and CGF should either be both null or not!");
1541  // Create MDNodes that represent the kernel arg metadata.
1542  // Each MDNode is a list in the form of "key", N number of values which is
1543  // the same number of values as their are kernel arguments.
1544
1545  const PrintingPolicy &Policy = Context.getPrintingPolicy();
1546
1547  // MDNode for the kernel argument address space qualifiers.
1548  SmallVector<llvm::Metadata *, 8> addressQuals;
1549
1550  // MDNode for the kernel argument access qualifiers (images only).
1551  SmallVector<llvm::Metadata *, 8> accessQuals;
1552
1553  // MDNode for the kernel argument type names.
1554  SmallVector<llvm::Metadata *, 8> argTypeNames;
1555
1556  // MDNode for the kernel argument base type names.
1557  SmallVector<llvm::Metadata *, 8> argBaseTypeNames;
1558
1559  // MDNode for the kernel argument type qualifiers.
1560  SmallVector<llvm::Metadata *, 8> argTypeQuals;
1561
1562  // MDNode for the kernel argument names.
1563  SmallVector<llvm::Metadata *, 8> argNames;
1564
1565  if (FD && CGF)
1566    for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
1567      const ParmVarDecl *parm = FD->getParamDecl(i);
1568      QualType ty = parm->getType();
1569      std::string typeQuals;
1570
1571      // Get image and pipe access qualifier:
1572      if (ty->isImageType() || ty->isPipeType()) {
1573        const Decl *PDecl = parm;
1574        if (auto *TD = dyn_cast<TypedefType>(ty))
1575          PDecl = TD->getDecl();
1576        const OpenCLAccessAttr *A = PDecl->getAttr<OpenCLAccessAttr>();
1577        if (A && A->isWriteOnly())
1578          accessQuals.push_back(llvm::MDString::get(VMContext, "write_only"));
1579        else if (A && A->isReadWrite())
1580          accessQuals.push_back(llvm::MDString::get(VMContext, "read_write"));
1581        else
1582          accessQuals.push_back(llvm::MDString::get(VMContext, "read_only"));
1583      } else
1584        accessQuals.push_back(llvm::MDString::get(VMContext, "none"));
1585
1586      // Get argument name.
1587      argNames.push_back(llvm::MDString::get(VMContext, parm->getName()));
1588
1589      auto getTypeSpelling = [&](QualType Ty) {
1590        auto typeName = Ty.getUnqualifiedType().getAsString(Policy);
1591
1592        if (Ty.isCanonical()) {
1593          StringRef typeNameRef = typeName;
1594          // Turn "unsigned type" to "utype"
1595          if (typeNameRef.consume_front("unsigned "))
1596            return std::string("u") + typeNameRef.str();
1597          if (typeNameRef.consume_front("signed "))
1598            return typeNameRef.str();
1599        }
1600
1601        return typeName;
1602      };
1603
1604      if (ty->isPointerType()) {
1605        QualType pointeeTy = ty->getPointeeType();
1606
1607        // Get address qualifier.
1608        addressQuals.push_back(
1609            llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(
1610                ArgInfoAddressSpace(pointeeTy.getAddressSpace()))));
1611
1612        // Get argument type name.
1613        std::string typeName = getTypeSpelling(pointeeTy) + "*";
1614        std::string baseTypeName =
1615            getTypeSpelling(pointeeTy.getCanonicalType()) + "*";
1616        argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
1617        argBaseTypeNames.push_back(
1618            llvm::MDString::get(VMContext, baseTypeName));
1619
1620        // Get argument type qualifiers:
1621        if (ty.isRestrictQualified())
1622          typeQuals = "restrict";
1623        if (pointeeTy.isConstQualified() ||
1624            (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
1625          typeQuals += typeQuals.empty() ? "const" : " const";
1626        if (pointeeTy.isVolatileQualified())
1627          typeQuals += typeQuals.empty() ? "volatile" : " volatile";
1628      } else {
1629        uint32_t AddrSpc = 0;
1630        bool isPipe = ty->isPipeType();
1631        if (ty->isImageType() || isPipe)
1632          AddrSpc = ArgInfoAddressSpace(LangAS::opencl_global);
1633
1634        addressQuals.push_back(
1635            llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(AddrSpc)));
1636
1637        // Get argument type name.
1638        ty = isPipe ? ty->castAs<PipeType>()->getElementType() : ty;
1639        std::string typeName = getTypeSpelling(ty);
1640        std::string baseTypeName = getTypeSpelling(ty.getCanonicalType());
1641
1642        // Remove access qualifiers on images
1643        // (as they are inseparable from type in clang implementation,
1644        // but OpenCL spec provides a special query to get access qualifier
1645        // via clGetKernelArgInfo with CL_KERNEL_ARG_ACCESS_QUALIFIER):
1646        if (ty->isImageType()) {
1647          removeImageAccessQualifier(typeName);
1648          removeImageAccessQualifier(baseTypeName);
1649        }
1650
1651        argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
1652        argBaseTypeNames.push_back(
1653            llvm::MDString::get(VMContext, baseTypeName));
1654
1655        if (isPipe)
1656          typeQuals = "pipe";
1657      }
1658      argTypeQuals.push_back(llvm::MDString::get(VMContext, typeQuals));
1659    }
1660
1661  Fn->setMetadata("kernel_arg_addr_space",
1662                  llvm::MDNode::get(VMContext, addressQuals));
1663  Fn->setMetadata("kernel_arg_access_qual",
1664                  llvm::MDNode::get(VMContext, accessQuals));
1665  Fn->setMetadata("kernel_arg_type",
1666                  llvm::MDNode::get(VMContext, argTypeNames));
1667  Fn->setMetadata("kernel_arg_base_type",
1668                  llvm::MDNode::get(VMContext, argBaseTypeNames));
1669  Fn->setMetadata("kernel_arg_type_qual",
1670                  llvm::MDNode::get(VMContext, argTypeQuals));
1671  if (getCodeGenOpts().EmitOpenCLArgMetadata)
1672    Fn->setMetadata("kernel_arg_name",
1673                    llvm::MDNode::get(VMContext, argNames));
1674}
1675
1676/// Determines whether the language options require us to model
1677/// unwind exceptions.  We treat -fexceptions as mandating this
1678/// except under the fragile ObjC ABI with only ObjC exceptions
1679/// enabled.  This means, for example, that C with -fexceptions
1680/// enables this.
1681static bool hasUnwindExceptions(const LangOptions &LangOpts) {
1682  // If exceptions are completely disabled, obviously this is false.
1683  if (!LangOpts.Exceptions) return false;
1684
1685  // If C++ exceptions are enabled, this is true.
1686  if (LangOpts.CXXExceptions) return true;
1687
1688  // If ObjC exceptions are enabled, this depends on the ABI.
1689  if (LangOpts.ObjCExceptions) {
1690    return LangOpts.ObjCRuntime.hasUnwindExceptions();
1691  }
1692
1693  return true;
1694}
1695
1696static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM,
1697                                                      const CXXMethodDecl *MD) {
1698  // Check that the type metadata can ever actually be used by a call.
1699  if (!CGM.getCodeGenOpts().LTOUnit ||
1700      !CGM.HasHiddenLTOVisibility(MD->getParent()))
1701    return false;
1702
1703  // Only functions whose address can be taken with a member function pointer
1704  // need this sort of type metadata.
1705  return !MD->isStatic() && !MD->isVirtual() && !isa<CXXConstructorDecl>(MD) &&
1706         !isa<CXXDestructorDecl>(MD);
1707}
1708
1709std::vector<const CXXRecordDecl *>
1710CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
1711  llvm::SetVector<const CXXRecordDecl *> MostBases;
1712
1713  std::function<void (const CXXRecordDecl *)> CollectMostBases;
1714  CollectMostBases = [&](const CXXRecordDecl *RD) {
1715    if (RD->getNumBases() == 0)
1716      MostBases.insert(RD);
1717    for (const CXXBaseSpecifier &B : RD->bases())
1718      CollectMostBases(B.getType()->getAsCXXRecordDecl());
1719  };
1720  CollectMostBases(RD);
1721  return MostBases.takeVector();
1722}
1723
1724void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
1725                                                           llvm::Function *F) {
1726  llvm::AttrBuilder B;
1727
1728  if (CodeGenOpts.UnwindTables)
1729    B.addAttribute(llvm::Attribute::UWTable);
1730
1731  if (CodeGenOpts.StackClashProtector)
1732    B.addAttribute("probe-stack", "inline-asm");
1733
1734  if (!hasUnwindExceptions(LangOpts))
1735    B.addAttribute(llvm::Attribute::NoUnwind);
1736
1737  if (!D || !D->hasAttr<NoStackProtectorAttr>()) {
1738    if (LangOpts.getStackProtector() == LangOptions::SSPOn)
1739      B.addAttribute(llvm::Attribute::StackProtect);
1740    else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
1741      B.addAttribute(llvm::Attribute::StackProtectStrong);
1742    else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
1743      B.addAttribute(llvm::Attribute::StackProtectReq);
1744  }
1745
1746  if (!D) {
1747    // If we don't have a declaration to control inlining, the function isn't
1748    // explicitly marked as alwaysinline for semantic reasons, and inlining is
1749    // disabled, mark the function as noinline.
1750    if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
1751        CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
1752      B.addAttribute(llvm::Attribute::NoInline);
1753
1754    F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1755    return;
1756  }
1757
1758  // Track whether we need to add the optnone LLVM attribute,
1759  // starting with the default for this optimization level.
1760  bool ShouldAddOptNone =
1761      !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
1762  // We can't add optnone in the following cases, it won't pass the verifier.
1763  ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
1764  ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
1765
1766  // Add optnone, but do so only if the function isn't always_inline.
1767  if ((ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) &&
1768      !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1769    B.addAttribute(llvm::Attribute::OptimizeNone);
1770
1771    // OptimizeNone implies noinline; we should not be inlining such functions.
1772    B.addAttribute(llvm::Attribute::NoInline);
1773
1774    // We still need to handle naked functions even though optnone subsumes
1775    // much of their semantics.
1776    if (D->hasAttr<NakedAttr>())
1777      B.addAttribute(llvm::Attribute::Naked);
1778
1779    // OptimizeNone wins over OptimizeForSize and MinSize.
1780    F->removeFnAttr(llvm::Attribute::OptimizeForSize);
1781    F->removeFnAttr(llvm::Attribute::MinSize);
1782  } else if (D->hasAttr<NakedAttr>()) {
1783    // Naked implies noinline: we should not be inlining such functions.
1784    B.addAttribute(llvm::Attribute::Naked);
1785    B.addAttribute(llvm::Attribute::NoInline);
1786  } else if (D->hasAttr<NoDuplicateAttr>()) {
1787    B.addAttribute(llvm::Attribute::NoDuplicate);
1788  } else if (D->hasAttr<NoInlineAttr>() && !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1789    // Add noinline if the function isn't always_inline.
1790    B.addAttribute(llvm::Attribute::NoInline);
1791  } else if (D->hasAttr<AlwaysInlineAttr>() &&
1792             !F->hasFnAttribute(llvm::Attribute::NoInline)) {
1793    // (noinline wins over always_inline, and we can't specify both in IR)
1794    B.addAttribute(llvm::Attribute::AlwaysInline);
1795  } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
1796    // If we're not inlining, then force everything that isn't always_inline to
1797    // carry an explicit noinline attribute.
1798    if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
1799      B.addAttribute(llvm::Attribute::NoInline);
1800  } else {
1801    // Otherwise, propagate the inline hint attribute and potentially use its
1802    // absence to mark things as noinline.
1803    if (auto *FD = dyn_cast<FunctionDecl>(D)) {
1804      // Search function and template pattern redeclarations for inline.
1805      auto CheckForInline = [](const FunctionDecl *FD) {
1806        auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
1807          return Redecl->isInlineSpecified();
1808        };
1809        if (any_of(FD->redecls(), CheckRedeclForInline))
1810          return true;
1811        const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
1812        if (!Pattern)
1813          return false;
1814        return any_of(Pattern->redecls(), CheckRedeclForInline);
1815      };
1816      if (CheckForInline(FD)) {
1817        B.addAttribute(llvm::Attribute::InlineHint);
1818      } else if (CodeGenOpts.getInlining() ==
1819                     CodeGenOptions::OnlyHintInlining &&
1820                 !FD->isInlined() &&
1821                 !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1822        B.addAttribute(llvm::Attribute::NoInline);
1823      }
1824    }
1825  }
1826
1827  // Add other optimization related attributes if we are optimizing this
1828  // function.
1829  if (!D->hasAttr<OptimizeNoneAttr>()) {
1830    if (D->hasAttr<ColdAttr>()) {
1831      if (!ShouldAddOptNone)
1832        B.addAttribute(llvm::Attribute::OptimizeForSize);
1833      B.addAttribute(llvm::Attribute::Cold);
1834    }
1835    if (D->hasAttr<HotAttr>())
1836      B.addAttribute(llvm::Attribute::Hot);
1837    if (D->hasAttr<MinSizeAttr>())
1838      B.addAttribute(llvm::Attribute::MinSize);
1839  }
1840
1841  F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1842
1843  unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
1844  if (alignment)
1845    F->setAlignment(llvm::Align(alignment));
1846
1847  if (!D->hasAttr<AlignedAttr>())
1848    if (LangOpts.FunctionAlignment)
1849      F->setAlignment(llvm::Align(1ull << LangOpts.FunctionAlignment));
1850
1851  // Some C++ ABIs require 2-byte alignment for member functions, in order to
1852  // reserve a bit for differentiating between virtual and non-virtual member
1853  // functions. If the current target's C++ ABI requires this and this is a
1854  // member function, set its alignment accordingly.
1855  if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
1856    if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
1857      F->setAlignment(llvm::Align(2));
1858  }
1859
1860  // In the cross-dso CFI mode with canonical jump tables, we want !type
1861  // attributes on definitions only.
1862  if (CodeGenOpts.SanitizeCfiCrossDso &&
1863      CodeGenOpts.SanitizeCfiCanonicalJumpTables) {
1864    if (auto *FD = dyn_cast<FunctionDecl>(D)) {
1865      // Skip available_externally functions. They won't be codegen'ed in the
1866      // current module anyway.
1867      if (getContext().GetGVALinkageForFunction(FD) != GVA_AvailableExternally)
1868        CreateFunctionTypeMetadataForIcall(FD, F);
1869    }
1870  }
1871
1872  // Emit type metadata on member functions for member function pointer checks.
1873  // These are only ever necessary on definitions; we're guaranteed that the
1874  // definition will be present in the LTO unit as a result of LTO visibility.
1875  auto *MD = dyn_cast<CXXMethodDecl>(D);
1876  if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
1877    for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
1878      llvm::Metadata *Id =
1879          CreateMetadataIdentifierForType(Context.getMemberPointerType(
1880              MD->getType(), Context.getRecordType(Base).getTypePtr()));
1881      F->addTypeMetadata(0, Id);
1882    }
1883  }
1884}
1885
1886void CodeGenModule::setLLVMFunctionFEnvAttributes(const FunctionDecl *D,
1887                                                  llvm::Function *F) {
1888  if (D->hasAttr<StrictFPAttr>()) {
1889    llvm::AttrBuilder FuncAttrs;
1890    FuncAttrs.addAttribute("strictfp");
1891    F->addAttributes(llvm::AttributeList::FunctionIndex, FuncAttrs);
1892  }
1893}
1894
1895void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
1896  const Decl *D = GD.getDecl();
1897  if (dyn_cast_or_null<NamedDecl>(D))
1898    setGVProperties(GV, GD);
1899  else
1900    GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1901
1902  if (D && D->hasAttr<UsedAttr>())
1903    addUsedOrCompilerUsedGlobal(GV);
1904
1905  if (CodeGenOpts.KeepStaticConsts && D && isa<VarDecl>(D)) {
1906    const auto *VD = cast<VarDecl>(D);
1907    if (VD->getType().isConstQualified() &&
1908        VD->getStorageDuration() == SD_Static)
1909      addUsedOrCompilerUsedGlobal(GV);
1910  }
1911}
1912
1913bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
1914                                                llvm::AttrBuilder &Attrs) {
1915  // Add target-cpu and target-features attributes to functions. If
1916  // we have a decl for the function and it has a target attribute then
1917  // parse that and add it to the feature set.
1918  StringRef TargetCPU = getTarget().getTargetOpts().CPU;
1919  StringRef TuneCPU = getTarget().getTargetOpts().TuneCPU;
1920  std::vector<std::string> Features;
1921  const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
1922  FD = FD ? FD->getMostRecentDecl() : FD;
1923  const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
1924  const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
1925  bool AddedAttr = false;
1926  if (TD || SD) {
1927    llvm::StringMap<bool> FeatureMap;
1928    getContext().getFunctionFeatureMap(FeatureMap, GD);
1929
1930    // Produce the canonical string for this set of features.
1931    for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
1932      Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
1933
1934    // Now add the target-cpu and target-features to the function.
1935    // While we populated the feature map above, we still need to
1936    // get and parse the target attribute so we can get the cpu for
1937    // the function.
1938    if (TD) {
1939      ParsedTargetAttr ParsedAttr = TD->parse();
1940      if (!ParsedAttr.Architecture.empty() &&
1941          getTarget().isValidCPUName(ParsedAttr.Architecture)) {
1942        TargetCPU = ParsedAttr.Architecture;
1943        TuneCPU = ""; // Clear the tune CPU.
1944      }
1945      if (!ParsedAttr.Tune.empty() &&
1946          getTarget().isValidCPUName(ParsedAttr.Tune))
1947        TuneCPU = ParsedAttr.Tune;
1948    }
1949  } else {
1950    // Otherwise just add the existing target cpu and target features to the
1951    // function.
1952    Features = getTarget().getTargetOpts().Features;
1953  }
1954
1955  if (!TargetCPU.empty()) {
1956    Attrs.addAttribute("target-cpu", TargetCPU);
1957    AddedAttr = true;
1958  }
1959  if (!TuneCPU.empty()) {
1960    Attrs.addAttribute("tune-cpu", TuneCPU);
1961    AddedAttr = true;
1962  }
1963  if (!Features.empty()) {
1964    llvm::sort(Features);
1965    Attrs.addAttribute("target-features", llvm::join(Features, ","));
1966    AddedAttr = true;
1967  }
1968
1969  return AddedAttr;
1970}
1971
1972void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
1973                                          llvm::GlobalObject *GO) {
1974  const Decl *D = GD.getDecl();
1975  SetCommonAttributes(GD, GO);
1976
1977  if (D) {
1978    if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
1979      if (D->hasAttr<RetainAttr>())
1980        addUsedGlobal(GV);
1981      if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
1982        GV->addAttribute("bss-section", SA->getName());
1983      if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
1984        GV->addAttribute("data-section", SA->getName());
1985      if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
1986        GV->addAttribute("rodata-section", SA->getName());
1987      if (auto *SA = D->getAttr<PragmaClangRelroSectionAttr>())
1988        GV->addAttribute("relro-section", SA->getName());
1989    }
1990
1991    if (auto *F = dyn_cast<llvm::Function>(GO)) {
1992      if (D->hasAttr<RetainAttr>())
1993        addUsedGlobal(F);
1994      if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
1995        if (!D->getAttr<SectionAttr>())
1996          F->addFnAttr("implicit-section-name", SA->getName());
1997
1998      llvm::AttrBuilder Attrs;
1999      if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
2000        // We know that GetCPUAndFeaturesAttributes will always have the
2001        // newest set, since it has the newest possible FunctionDecl, so the
2002        // new ones should replace the old.
2003        llvm::AttrBuilder RemoveAttrs;
2004        RemoveAttrs.addAttribute("target-cpu");
2005        RemoveAttrs.addAttribute("target-features");
2006        RemoveAttrs.addAttribute("tune-cpu");
2007        F->removeAttributes(llvm::AttributeList::FunctionIndex, RemoveAttrs);
2008        F->addAttributes(llvm::AttributeList::FunctionIndex, Attrs);
2009      }
2010    }
2011
2012    if (const auto *CSA = D->getAttr<CodeSegAttr>())
2013      GO->setSection(CSA->getName());
2014    else if (const auto *SA = D->getAttr<SectionAttr>())
2015      GO->setSection(SA->getName());
2016  }
2017
2018  getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
2019}
2020
2021void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
2022                                                  llvm::Function *F,
2023                                                  const CGFunctionInfo &FI) {
2024  const Decl *D = GD.getDecl();
2025  SetLLVMFunctionAttributes(GD, FI, F, /*IsThunk=*/false);
2026  SetLLVMFunctionAttributesForDefinition(D, F);
2027
2028  F->setLinkage(llvm::Function::InternalLinkage);
2029
2030  setNonAliasAttributes(GD, F);
2031}
2032
2033static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
2034  // Set linkage and visibility in case we never see a definition.
2035  LinkageInfo LV = ND->getLinkageAndVisibility();
2036  // Don't set internal linkage on declarations.
2037  // "extern_weak" is overloaded in LLVM; we probably should have
2038  // separate linkage types for this.
2039  if (isExternallyVisible(LV.getLinkage()) &&
2040      (ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
2041    GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2042}
2043
2044void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
2045                                                       llvm::Function *F) {
2046  // Only if we are checking indirect calls.
2047  if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
2048    return;
2049
2050  // Non-static class methods are handled via vtable or member function pointer
2051  // checks elsewhere.
2052  if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
2053    return;
2054
2055  llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
2056  F->addTypeMetadata(0, MD);
2057  F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
2058
2059  // Emit a hash-based bit set entry for cross-DSO calls.
2060  if (CodeGenOpts.SanitizeCfiCrossDso)
2061    if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
2062      F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
2063}
2064
2065void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
2066                                          bool IsIncompleteFunction,
2067                                          bool IsThunk) {
2068
2069  if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) {
2070    // If this is an intrinsic function, set the function's attributes
2071    // to the intrinsic's attributes.
2072    F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID));
2073    return;
2074  }
2075
2076  const auto *FD = cast<FunctionDecl>(GD.getDecl());
2077
2078  if (!IsIncompleteFunction)
2079    SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F,
2080                              IsThunk);
2081
2082  // Add the Returned attribute for "this", except for iOS 5 and earlier
2083  // where substantial code, including the libstdc++ dylib, was compiled with
2084  // GCC and does not actually return "this".
2085  if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
2086      !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
2087    assert(!F->arg_empty() &&
2088           F->arg_begin()->getType()
2089             ->canLosslesslyBitCastTo(F->getReturnType()) &&
2090           "unexpected this return");
2091    F->addAttribute(1, llvm::Attribute::Returned);
2092  }
2093
2094  // Only a few attributes are set on declarations; these may later be
2095  // overridden by a definition.
2096
2097  setLinkageForGV(F, FD);
2098  setGVProperties(F, FD);
2099
2100  // Setup target-specific attributes.
2101  if (!IsIncompleteFunction && F->isDeclaration())
2102    getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
2103
2104  if (const auto *CSA = FD->getAttr<CodeSegAttr>())
2105    F->setSection(CSA->getName());
2106  else if (const auto *SA = FD->getAttr<SectionAttr>())
2107     F->setSection(SA->getName());
2108
2109  // If we plan on emitting this inline builtin, we can't treat it as a builtin.
2110  if (FD->isInlineBuiltinDeclaration()) {
2111    const FunctionDecl *FDBody;
2112    bool HasBody = FD->hasBody(FDBody);
2113    (void)HasBody;
2114    assert(HasBody && "Inline builtin declarations should always have an "
2115                      "available body!");
2116    if (shouldEmitFunction(FDBody))
2117      F->addAttribute(llvm::AttributeList::FunctionIndex,
2118                      llvm::Attribute::NoBuiltin);
2119  }
2120
2121  if (FD->isReplaceableGlobalAllocationFunction()) {
2122    // A replaceable global allocation function does not act like a builtin by
2123    // default, only if it is invoked by a new-expression or delete-expression.
2124    F->addAttribute(llvm::AttributeList::FunctionIndex,
2125                    llvm::Attribute::NoBuiltin);
2126  }
2127
2128  if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
2129    F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2130  else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
2131    if (MD->isVirtual())
2132      F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2133
2134  // Don't emit entries for function declarations in the cross-DSO mode. This
2135  // is handled with better precision by the receiving DSO. But if jump tables
2136  // are non-canonical then we need type metadata in order to produce the local
2137  // jump table.
2138  if (!CodeGenOpts.SanitizeCfiCrossDso ||
2139      !CodeGenOpts.SanitizeCfiCanonicalJumpTables)
2140    CreateFunctionTypeMetadataForIcall(FD, F);
2141
2142  if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
2143    getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
2144
2145  if (const auto *CB = FD->getAttr<CallbackAttr>()) {
2146    // Annotate the callback behavior as metadata:
2147    //  - The callback callee (as argument number).
2148    //  - The callback payloads (as argument numbers).
2149    llvm::LLVMContext &Ctx = F->getContext();
2150    llvm::MDBuilder MDB(Ctx);
2151
2152    // The payload indices are all but the first one in the encoding. The first
2153    // identifies the callback callee.
2154    int CalleeIdx = *CB->encoding_begin();
2155    ArrayRef<int> PayloadIndices(CB->encoding_begin() + 1, CB->encoding_end());
2156    F->addMetadata(llvm::LLVMContext::MD_callback,
2157                   *llvm::MDNode::get(Ctx, {MDB.createCallbackEncoding(
2158                                               CalleeIdx, PayloadIndices,
2159                                               /* VarArgsArePassed */ false)}));
2160  }
2161}
2162
2163void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
2164  assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
2165         "Only globals with definition can force usage.");
2166  LLVMUsed.emplace_back(GV);
2167}
2168
2169void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
2170  assert(!GV->isDeclaration() &&
2171         "Only globals with definition can force usage.");
2172  LLVMCompilerUsed.emplace_back(GV);
2173}
2174
2175void CodeGenModule::addUsedOrCompilerUsedGlobal(llvm::GlobalValue *GV) {
2176  assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
2177         "Only globals with definition can force usage.");
2178  if (getTriple().isOSBinFormatELF())
2179    LLVMCompilerUsed.emplace_back(GV);
2180  else
2181    LLVMUsed.emplace_back(GV);
2182}
2183
2184static void emitUsed(CodeGenModule &CGM, StringRef Name,
2185                     std::vector<llvm::WeakTrackingVH> &List) {
2186  // Don't create llvm.used if there is no need.
2187  if (List.empty())
2188    return;
2189
2190  // Convert List to what ConstantArray needs.
2191  SmallVector<llvm::Constant*, 8> UsedArray;
2192  UsedArray.resize(List.size());
2193  for (unsigned i = 0, e = List.size(); i != e; ++i) {
2194    UsedArray[i] =
2195        llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
2196            cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
2197  }
2198
2199  if (UsedArray.empty())
2200    return;
2201  llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
2202
2203  auto *GV = new llvm::GlobalVariable(
2204      CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
2205      llvm::ConstantArray::get(ATy, UsedArray), Name);
2206
2207  GV->setSection("llvm.metadata");
2208}
2209
2210void CodeGenModule::emitLLVMUsed() {
2211  emitUsed(*this, "llvm.used", LLVMUsed);
2212  emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
2213}
2214
2215void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
2216  auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
2217  LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
2218}
2219
2220void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
2221  llvm::SmallString<32> Opt;
2222  getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
2223  if (Opt.empty())
2224    return;
2225  auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
2226  LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
2227}
2228
2229void CodeGenModule::AddDependentLib(StringRef Lib) {
2230  auto &C = getLLVMContext();
2231  if (getTarget().getTriple().isOSBinFormatELF()) {
2232      ELFDependentLibraries.push_back(
2233        llvm::MDNode::get(C, llvm::MDString::get(C, Lib)));
2234    return;
2235  }
2236
2237  llvm::SmallString<24> Opt;
2238  getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
2239  auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
2240  LinkerOptionsMetadata.push_back(llvm::MDNode::get(C, MDOpts));
2241}
2242
2243/// Add link options implied by the given module, including modules
2244/// it depends on, using a postorder walk.
2245static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
2246                                    SmallVectorImpl<llvm::MDNode *> &Metadata,
2247                                    llvm::SmallPtrSet<Module *, 16> &Visited) {
2248  // Import this module's parent.
2249  if (Mod->Parent && Visited.insert(Mod->Parent).second) {
2250    addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
2251  }
2252
2253  // Import this module's dependencies.
2254  for (unsigned I = Mod->Imports.size(); I > 0; --I) {
2255    if (Visited.insert(Mod->Imports[I - 1]).second)
2256      addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited);
2257  }
2258
2259  // Add linker options to link against the libraries/frameworks
2260  // described by this module.
2261  llvm::LLVMContext &Context = CGM.getLLVMContext();
2262  bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
2263
2264  // For modules that use export_as for linking, use that module
2265  // name instead.
2266  if (Mod->UseExportAsModuleLinkName)
2267    return;
2268
2269  for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) {
2270    // Link against a framework.  Frameworks are currently Darwin only, so we
2271    // don't to ask TargetCodeGenInfo for the spelling of the linker option.
2272    if (Mod->LinkLibraries[I-1].IsFramework) {
2273      llvm::Metadata *Args[2] = {
2274          llvm::MDString::get(Context, "-framework"),
2275          llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library)};
2276
2277      Metadata.push_back(llvm::MDNode::get(Context, Args));
2278      continue;
2279    }
2280
2281    // Link against a library.
2282    if (IsELF) {
2283      llvm::Metadata *Args[2] = {
2284          llvm::MDString::get(Context, "lib"),
2285          llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library),
2286      };
2287      Metadata.push_back(llvm::MDNode::get(Context, Args));
2288    } else {
2289      llvm::SmallString<24> Opt;
2290      CGM.getTargetCodeGenInfo().getDependentLibraryOption(
2291          Mod->LinkLibraries[I - 1].Library, Opt);
2292      auto *OptString = llvm::MDString::get(Context, Opt);
2293      Metadata.push_back(llvm::MDNode::get(Context, OptString));
2294    }
2295  }
2296}
2297
2298void CodeGenModule::EmitModuleLinkOptions() {
2299  // Collect the set of all of the modules we want to visit to emit link
2300  // options, which is essentially the imported modules and all of their
2301  // non-explicit child modules.
2302  llvm::SetVector<clang::Module *> LinkModules;
2303  llvm::SmallPtrSet<clang::Module *, 16> Visited;
2304  SmallVector<clang::Module *, 16> Stack;
2305
2306  // Seed the stack with imported modules.
2307  for (Module *M : ImportedModules) {
2308    // Do not add any link flags when an implementation TU of a module imports
2309    // a header of that same module.
2310    if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
2311        !getLangOpts().isCompilingModule())
2312      continue;
2313    if (Visited.insert(M).second)
2314      Stack.push_back(M);
2315  }
2316
2317  // Find all of the modules to import, making a little effort to prune
2318  // non-leaf modules.
2319  while (!Stack.empty()) {
2320    clang::Module *Mod = Stack.pop_back_val();
2321
2322    bool AnyChildren = false;
2323
2324    // Visit the submodules of this module.
2325    for (const auto &SM : Mod->submodules()) {
2326      // Skip explicit children; they need to be explicitly imported to be
2327      // linked against.
2328      if (SM->IsExplicit)
2329        continue;
2330
2331      if (Visited.insert(SM).second) {
2332        Stack.push_back(SM);
2333        AnyChildren = true;
2334      }
2335    }
2336
2337    // We didn't find any children, so add this module to the list of
2338    // modules to link against.
2339    if (!AnyChildren) {
2340      LinkModules.insert(Mod);
2341    }
2342  }
2343
2344  // Add link options for all of the imported modules in reverse topological
2345  // order.  We don't do anything to try to order import link flags with respect
2346  // to linker options inserted by things like #pragma comment().
2347  SmallVector<llvm::MDNode *, 16> MetadataArgs;
2348  Visited.clear();
2349  for (Module *M : LinkModules)
2350    if (Visited.insert(M).second)
2351      addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
2352  std::reverse(MetadataArgs.begin(), MetadataArgs.end());
2353  LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
2354
2355  // Add the linker options metadata flag.
2356  auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
2357  for (auto *MD : LinkerOptionsMetadata)
2358    NMD->addOperand(MD);
2359}
2360
2361void CodeGenModule::EmitDeferred() {
2362  // Emit deferred declare target declarations.
2363  if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
2364    getOpenMPRuntime().emitDeferredTargetDecls();
2365
2366  // Emit code for any potentially referenced deferred decls.  Since a
2367  // previously unused static decl may become used during the generation of code
2368  // for a static function, iterate until no changes are made.
2369
2370  if (!DeferredVTables.empty()) {
2371    EmitDeferredVTables();
2372
2373    // Emitting a vtable doesn't directly cause more vtables to
2374    // become deferred, although it can cause functions to be
2375    // emitted that then need those vtables.
2376    assert(DeferredVTables.empty());
2377  }
2378
2379  // Emit CUDA/HIP static device variables referenced by host code only.
2380  // Note we should not clear CUDADeviceVarODRUsedByHost since it is still
2381  // needed for further handling.
2382  if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
2383    for (const auto *V : getContext().CUDADeviceVarODRUsedByHost)
2384      DeferredDeclsToEmit.push_back(V);
2385
2386  // Stop if we're out of both deferred vtables and deferred declarations.
2387  if (DeferredDeclsToEmit.empty())
2388    return;
2389
2390  // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
2391  // work, it will not interfere with this.
2392  std::vector<GlobalDecl> CurDeclsToEmit;
2393  CurDeclsToEmit.swap(DeferredDeclsToEmit);
2394
2395  for (GlobalDecl &D : CurDeclsToEmit) {
2396    // We should call GetAddrOfGlobal with IsForDefinition set to true in order
2397    // to get GlobalValue with exactly the type we need, not something that
2398    // might had been created for another decl with the same mangled name but
2399    // different type.
2400    llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
2401        GetAddrOfGlobal(D, ForDefinition));
2402
2403    // In case of different address spaces, we may still get a cast, even with
2404    // IsForDefinition equal to true. Query mangled names table to get
2405    // GlobalValue.
2406    if (!GV)
2407      GV = GetGlobalValue(getMangledName(D));
2408
2409    // Make sure GetGlobalValue returned non-null.
2410    assert(GV);
2411
2412    // Check to see if we've already emitted this.  This is necessary
2413    // for a couple of reasons: first, decls can end up in the
2414    // deferred-decls queue multiple times, and second, decls can end
2415    // up with definitions in unusual ways (e.g. by an extern inline
2416    // function acquiring a strong function redefinition).  Just
2417    // ignore these cases.
2418    if (!GV->isDeclaration())
2419      continue;
2420
2421    // If this is OpenMP, check if it is legal to emit this global normally.
2422    if (LangOpts.OpenMP && OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(D))
2423      continue;
2424
2425    // Otherwise, emit the definition and move on to the next one.
2426    EmitGlobalDefinition(D, GV);
2427
2428    // If we found out that we need to emit more decls, do that recursively.
2429    // This has the advantage that the decls are emitted in a DFS and related
2430    // ones are close together, which is convenient for testing.
2431    if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
2432      EmitDeferred();
2433      assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
2434    }
2435  }
2436}
2437
2438void CodeGenModule::EmitVTablesOpportunistically() {
2439  // Try to emit external vtables as available_externally if they have emitted
2440  // all inlined virtual functions.  It runs after EmitDeferred() and therefore
2441  // is not allowed to create new references to things that need to be emitted
2442  // lazily. Note that it also uses fact that we eagerly emitting RTTI.
2443
2444  assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
2445         && "Only emit opportunistic vtables with optimizations");
2446
2447  for (const CXXRecordDecl *RD : OpportunisticVTables) {
2448    assert(getVTables().isVTableExternal(RD) &&
2449           "This queue should only contain external vtables");
2450    if (getCXXABI().canSpeculativelyEmitVTable(RD))
2451      VTables.GenerateClassData(RD);
2452  }
2453  OpportunisticVTables.clear();
2454}
2455
2456void CodeGenModule::EmitGlobalAnnotations() {
2457  if (Annotations.empty())
2458    return;
2459
2460  // Create a new global variable for the ConstantStruct in the Module.
2461  llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
2462    Annotations[0]->getType(), Annotations.size()), Annotations);
2463  auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
2464                                      llvm::GlobalValue::AppendingLinkage,
2465                                      Array, "llvm.global.annotations");
2466  gv->setSection(AnnotationSection);
2467}
2468
2469llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
2470  llvm::Constant *&AStr = AnnotationStrings[Str];
2471  if (AStr)
2472    return AStr;
2473
2474  // Not found yet, create a new global.
2475  llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
2476  auto *gv =
2477      new llvm::GlobalVariable(getModule(), s->getType(), true,
2478                               llvm::GlobalValue::PrivateLinkage, s, ".str");
2479  gv->setSection(AnnotationSection);
2480  gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2481  AStr = gv;
2482  return gv;
2483}
2484
2485llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
2486  SourceManager &SM = getContext().getSourceManager();
2487  PresumedLoc PLoc = SM.getPresumedLoc(Loc);
2488  if (PLoc.isValid())
2489    return EmitAnnotationString(PLoc.getFilename());
2490  return EmitAnnotationString(SM.getBufferName(Loc));
2491}
2492
2493llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
2494  SourceManager &SM = getContext().getSourceManager();
2495  PresumedLoc PLoc = SM.getPresumedLoc(L);
2496  unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
2497    SM.getExpansionLineNumber(L);
2498  return llvm::ConstantInt::get(Int32Ty, LineNo);
2499}
2500
2501llvm::Constant *CodeGenModule::EmitAnnotationArgs(const AnnotateAttr *Attr) {
2502  ArrayRef<Expr *> Exprs = {Attr->args_begin(), Attr->args_size()};
2503  if (Exprs.empty())
2504    return llvm::ConstantPointerNull::get(Int8PtrTy);
2505
2506  llvm::FoldingSetNodeID ID;
2507  for (Expr *E : Exprs) {
2508    ID.Add(cast<clang::ConstantExpr>(E)->getAPValueResult());
2509  }
2510  llvm::Constant *&Lookup = AnnotationArgs[ID.ComputeHash()];
2511  if (Lookup)
2512    return Lookup;
2513
2514  llvm::SmallVector<llvm::Constant *, 4> LLVMArgs;
2515  LLVMArgs.reserve(Exprs.size());
2516  ConstantEmitter ConstEmiter(*this);
2517  llvm::transform(Exprs, std::back_inserter(LLVMArgs), [&](const Expr *E) {
2518    const auto *CE = cast<clang::ConstantExpr>(E);
2519    return ConstEmiter.emitAbstract(CE->getBeginLoc(), CE->getAPValueResult(),
2520                                    CE->getType());
2521  });
2522  auto *Struct = llvm::ConstantStruct::getAnon(LLVMArgs);
2523  auto *GV = new llvm::GlobalVariable(getModule(), Struct->getType(), true,
2524                                      llvm::GlobalValue::PrivateLinkage, Struct,
2525                                      ".args");
2526  GV->setSection(AnnotationSection);
2527  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2528  auto *Bitcasted = llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);
2529
2530  Lookup = Bitcasted;
2531  return Bitcasted;
2532}
2533
2534llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
2535                                                const AnnotateAttr *AA,
2536                                                SourceLocation L) {
2537  // Get the globals for file name, annotation, and the line number.
2538  llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
2539                 *UnitGV = EmitAnnotationUnit(L),
2540                 *LineNoCst = EmitAnnotationLineNo(L),
2541                 *Args = EmitAnnotationArgs(AA);
2542
2543  llvm::Constant *ASZeroGV = GV;
2544  if (GV->getAddressSpace() != 0) {
2545    ASZeroGV = llvm::ConstantExpr::getAddrSpaceCast(
2546                   GV, GV->getValueType()->getPointerTo(0));
2547  }
2548
2549  // Create the ConstantStruct for the global annotation.
2550  llvm::Constant *Fields[] = {
2551      llvm::ConstantExpr::getBitCast(ASZeroGV, Int8PtrTy),
2552      llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
2553      llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
2554      LineNoCst,
2555      Args,
2556  };
2557  return llvm::ConstantStruct::getAnon(Fields);
2558}
2559
2560void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
2561                                         llvm::GlobalValue *GV) {
2562  assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
2563  // Get the struct elements for these annotations.
2564  for (const auto *I : D->specific_attrs<AnnotateAttr>())
2565    Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
2566}
2567
2568bool CodeGenModule::isInNoSanitizeList(SanitizerMask Kind, llvm::Function *Fn,
2569                                       SourceLocation Loc) const {
2570  const auto &NoSanitizeL = getContext().getNoSanitizeList();
2571  // NoSanitize by function name.
2572  if (NoSanitizeL.containsFunction(Kind, Fn->getName()))
2573    return true;
2574  // NoSanitize by location.
2575  if (Loc.isValid())
2576    return NoSanitizeL.containsLocation(Kind, Loc);
2577  // If location is unknown, this may be a compiler-generated function. Assume
2578  // it's located in the main file.
2579  auto &SM = Context.getSourceManager();
2580  if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
2581    return NoSanitizeL.containsFile(Kind, MainFile->getName());
2582  }
2583  return false;
2584}
2585
2586bool CodeGenModule::isInNoSanitizeList(llvm::GlobalVariable *GV,
2587                                       SourceLocation Loc, QualType Ty,
2588                                       StringRef Category) const {
2589  // For now globals can be ignored only in ASan and KASan.
2590  const SanitizerMask EnabledAsanMask =
2591      LangOpts.Sanitize.Mask &
2592      (SanitizerKind::Address | SanitizerKind::KernelAddress |
2593       SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress |
2594       SanitizerKind::MemTag);
2595  if (!EnabledAsanMask)
2596    return false;
2597  const auto &NoSanitizeL = getContext().getNoSanitizeList();
2598  if (NoSanitizeL.containsGlobal(EnabledAsanMask, GV->getName(), Category))
2599    return true;
2600  if (NoSanitizeL.containsLocation(EnabledAsanMask, Loc, Category))
2601    return true;
2602  // Check global type.
2603  if (!Ty.isNull()) {
2604    // Drill down the array types: if global variable of a fixed type is
2605    // not sanitized, we also don't instrument arrays of them.
2606    while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
2607      Ty = AT->getElementType();
2608    Ty = Ty.getCanonicalType().getUnqualifiedType();
2609    // Only record types (classes, structs etc.) are ignored.
2610    if (Ty->isRecordType()) {
2611      std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
2612      if (NoSanitizeL.containsType(EnabledAsanMask, TypeStr, Category))
2613        return true;
2614    }
2615  }
2616  return false;
2617}
2618
2619bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
2620                                   StringRef Category) const {
2621  const auto &XRayFilter = getContext().getXRayFilter();
2622  using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
2623  auto Attr = ImbueAttr::NONE;
2624  if (Loc.isValid())
2625    Attr = XRayFilter.shouldImbueLocation(Loc, Category);
2626  if (Attr == ImbueAttr::NONE)
2627    Attr = XRayFilter.shouldImbueFunction(Fn->getName());
2628  switch (Attr) {
2629  case ImbueAttr::NONE:
2630    return false;
2631  case ImbueAttr::ALWAYS:
2632    Fn->addFnAttr("function-instrument", "xray-always");
2633    break;
2634  case ImbueAttr::ALWAYS_ARG1:
2635    Fn->addFnAttr("function-instrument", "xray-always");
2636    Fn->addFnAttr("xray-log-args", "1");
2637    break;
2638  case ImbueAttr::NEVER:
2639    Fn->addFnAttr("function-instrument", "xray-never");
2640    break;
2641  }
2642  return true;
2643}
2644
2645bool CodeGenModule::isProfileInstrExcluded(llvm::Function *Fn,
2646                                           SourceLocation Loc) const {
2647  const auto &ProfileList = getContext().getProfileList();
2648  // If the profile list is empty, then instrument everything.
2649  if (ProfileList.isEmpty())
2650    return false;
2651  CodeGenOptions::ProfileInstrKind Kind = getCodeGenOpts().getProfileInstr();
2652  // First, check the function name.
2653  Optional<bool> V = ProfileList.isFunctionExcluded(Fn->getName(), Kind);
2654  if (V.hasValue())
2655    return *V;
2656  // Next, check the source location.
2657  if (Loc.isValid()) {
2658    Optional<bool> V = ProfileList.isLocationExcluded(Loc, Kind);
2659    if (V.hasValue())
2660      return *V;
2661  }
2662  // If location is unknown, this may be a compiler-generated function. Assume
2663  // it's located in the main file.
2664  auto &SM = Context.getSourceManager();
2665  if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
2666    Optional<bool> V = ProfileList.isFileExcluded(MainFile->getName(), Kind);
2667    if (V.hasValue())
2668      return *V;
2669  }
2670  return ProfileList.getDefault();
2671}
2672
2673bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
2674  // Never defer when EmitAllDecls is specified.
2675  if (LangOpts.EmitAllDecls)
2676    return true;
2677
2678  if (CodeGenOpts.KeepStaticConsts) {
2679    const auto *VD = dyn_cast<VarDecl>(Global);
2680    if (VD && VD->getType().isConstQualified() &&
2681        VD->getStorageDuration() == SD_Static)
2682      return true;
2683  }
2684
2685  return getContext().DeclMustBeEmitted(Global);
2686}
2687
2688bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
2689  // In OpenMP 5.0 variables and function may be marked as
2690  // device_type(host/nohost) and we should not emit them eagerly unless we sure
2691  // that they must be emitted on the host/device. To be sure we need to have
2692  // seen a declare target with an explicit mentioning of the function, we know
2693  // we have if the level of the declare target attribute is -1. Note that we
2694  // check somewhere else if we should emit this at all.
2695  if (LangOpts.OpenMP >= 50 && !LangOpts.OpenMPSimd) {
2696    llvm::Optional<OMPDeclareTargetDeclAttr *> ActiveAttr =
2697        OMPDeclareTargetDeclAttr::getActiveAttr(Global);
2698    if (!ActiveAttr || (*ActiveAttr)->getLevel() != (unsigned)-1)
2699      return false;
2700  }
2701
2702  if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
2703    if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
2704      // Implicit template instantiations may change linkage if they are later
2705      // explicitly instantiated, so they should not be emitted eagerly.
2706      return false;
2707  }
2708  if (const auto *VD = dyn_cast<VarDecl>(Global))
2709    if (Context.getInlineVariableDefinitionKind(VD) ==
2710        ASTContext::InlineVariableDefinitionKind::WeakUnknown)
2711      // A definition of an inline constexpr static data member may change
2712      // linkage later if it's redeclared outside the class.
2713      return false;
2714  // If OpenMP is enabled and threadprivates must be generated like TLS, delay
2715  // codegen for global variables, because they may be marked as threadprivate.
2716  if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
2717      getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
2718      !isTypeConstant(Global->getType(), false) &&
2719      !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
2720    return false;
2721
2722  return true;
2723}
2724
2725ConstantAddress CodeGenModule::GetAddrOfMSGuidDecl(const MSGuidDecl *GD) {
2726  StringRef Name = getMangledName(GD);
2727
2728  // The UUID descriptor should be pointer aligned.
2729  CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
2730
2731  // Look for an existing global.
2732  if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
2733    return ConstantAddress(GV, Alignment);
2734
2735  ConstantEmitter Emitter(*this);
2736  llvm::Constant *Init;
2737
2738  APValue &V = GD->getAsAPValue();
2739  if (!V.isAbsent()) {
2740    // If possible, emit the APValue version of the initializer. In particular,
2741    // this gets the type of the constant right.
2742    Init = Emitter.emitForInitializer(
2743        GD->getAsAPValue(), GD->getType().getAddressSpace(), GD->getType());
2744  } else {
2745    // As a fallback, directly construct the constant.
2746    // FIXME: This may get padding wrong under esoteric struct layout rules.
2747    // MSVC appears to create a complete type 'struct __s_GUID' that it
2748    // presumably uses to represent these constants.
2749    MSGuidDecl::Parts Parts = GD->getParts();
2750    llvm::Constant *Fields[4] = {
2751        llvm::ConstantInt::get(Int32Ty, Parts.Part1),
2752        llvm::ConstantInt::get(Int16Ty, Parts.Part2),
2753        llvm::ConstantInt::get(Int16Ty, Parts.Part3),
2754        llvm::ConstantDataArray::getRaw(
2755            StringRef(reinterpret_cast<char *>(Parts.Part4And5), 8), 8,
2756            Int8Ty)};
2757    Init = llvm::ConstantStruct::getAnon(Fields);
2758  }
2759
2760  auto *GV = new llvm::GlobalVariable(
2761      getModule(), Init->getType(),
2762      /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
2763  if (supportsCOMDAT())
2764    GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
2765  setDSOLocal(GV);
2766
2767  llvm::Constant *Addr = GV;
2768  if (!V.isAbsent()) {
2769    Emitter.finalize(GV);
2770  } else {
2771    llvm::Type *Ty = getTypes().ConvertTypeForMem(GD->getType());
2772    Addr = llvm::ConstantExpr::getBitCast(
2773        GV, Ty->getPointerTo(GV->getAddressSpace()));
2774  }
2775  return ConstantAddress(Addr, Alignment);
2776}
2777
2778ConstantAddress CodeGenModule::GetAddrOfTemplateParamObject(
2779    const TemplateParamObjectDecl *TPO) {
2780  StringRef Name = getMangledName(TPO);
2781  CharUnits Alignment = getNaturalTypeAlignment(TPO->getType());
2782
2783  if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
2784    return ConstantAddress(GV, Alignment);
2785
2786  ConstantEmitter Emitter(*this);
2787  llvm::Constant *Init = Emitter.emitForInitializer(
2788        TPO->getValue(), TPO->getType().getAddressSpace(), TPO->getType());
2789
2790  if (!Init) {
2791    ErrorUnsupported(TPO, "template parameter object");
2792    return ConstantAddress::invalid();
2793  }
2794
2795  auto *GV = new llvm::GlobalVariable(
2796      getModule(), Init->getType(),
2797      /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
2798  if (supportsCOMDAT())
2799    GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
2800  Emitter.finalize(GV);
2801
2802  return ConstantAddress(GV, Alignment);
2803}
2804
2805ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
2806  const AliasAttr *AA = VD->getAttr<AliasAttr>();
2807  assert(AA && "No alias?");
2808
2809  CharUnits Alignment = getContext().getDeclAlign(VD);
2810  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
2811
2812  // See if there is already something with the target's name in the module.
2813  llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
2814  if (Entry) {
2815    unsigned AS = getContext().getTargetAddressSpace(VD->getType());
2816    auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
2817    return ConstantAddress(Ptr, Alignment);
2818  }
2819
2820  llvm::Constant *Aliasee;
2821  if (isa<llvm::FunctionType>(DeclTy))
2822    Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
2823                                      GlobalDecl(cast<FunctionDecl>(VD)),
2824                                      /*ForVTable=*/false);
2825  else
2826    Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, 0, nullptr);
2827
2828  auto *F = cast<llvm::GlobalValue>(Aliasee);
2829  F->setLinkage(llvm::Function::ExternalWeakLinkage);
2830  WeakRefReferences.insert(F);
2831
2832  return ConstantAddress(Aliasee, Alignment);
2833}
2834
2835void CodeGenModule::EmitGlobal(GlobalDecl GD) {
2836  const auto *Global = cast<ValueDecl>(GD.getDecl());
2837
2838  // Weak references don't produce any output by themselves.
2839  if (Global->hasAttr<WeakRefAttr>())
2840    return;
2841
2842  // If this is an alias definition (which otherwise looks like a declaration)
2843  // emit it now.
2844  if (Global->hasAttr<AliasAttr>())
2845    return EmitAliasDefinition(GD);
2846
2847  // IFunc like an alias whose value is resolved at runtime by calling resolver.
2848  if (Global->hasAttr<IFuncAttr>())
2849    return emitIFuncDefinition(GD);
2850
2851  // If this is a cpu_dispatch multiversion function, emit the resolver.
2852  if (Global->hasAttr<CPUDispatchAttr>())
2853    return emitCPUDispatchDefinition(GD);
2854
2855  // If this is CUDA, be selective about which declarations we emit.
2856  if (LangOpts.CUDA) {
2857    if (LangOpts.CUDAIsDevice) {
2858      if (!Global->hasAttr<CUDADeviceAttr>() &&
2859          !Global->hasAttr<CUDAGlobalAttr>() &&
2860          !Global->hasAttr<CUDAConstantAttr>() &&
2861          !Global->hasAttr<CUDASharedAttr>() &&
2862          !Global->getType()->isCUDADeviceBuiltinSurfaceType() &&
2863          !Global->getType()->isCUDADeviceBuiltinTextureType())
2864        return;
2865    } else {
2866      // We need to emit host-side 'shadows' for all global
2867      // device-side variables because the CUDA runtime needs their
2868      // size and host-side address in order to provide access to
2869      // their device-side incarnations.
2870
2871      // So device-only functions are the only things we skip.
2872      if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
2873          Global->hasAttr<CUDADeviceAttr>())
2874        return;
2875
2876      assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
2877             "Expected Variable or Function");
2878    }
2879  }
2880
2881  if (LangOpts.OpenMP) {
2882    // If this is OpenMP, check if it is legal to emit this global normally.
2883    if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
2884      return;
2885    if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
2886      if (MustBeEmitted(Global))
2887        EmitOMPDeclareReduction(DRD);
2888      return;
2889    } else if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) {
2890      if (MustBeEmitted(Global))
2891        EmitOMPDeclareMapper(DMD);
2892      return;
2893    }
2894  }
2895
2896  // Ignore declarations, they will be emitted on their first use.
2897  if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
2898    // Forward declarations are emitted lazily on first use.
2899    if (!FD->doesThisDeclarationHaveABody()) {
2900      if (!FD->doesDeclarationForceExternallyVisibleDefinition())
2901        return;
2902
2903      StringRef MangledName = getMangledName(GD);
2904
2905      // Compute the function info and LLVM type.
2906      const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
2907      llvm::Type *Ty = getTypes().GetFunctionType(FI);
2908
2909      GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
2910                              /*DontDefer=*/false);
2911      return;
2912    }
2913  } else {
2914    const auto *VD = cast<VarDecl>(Global);
2915    assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
2916    if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
2917        !Context.isMSStaticDataMemberInlineDefinition(VD)) {
2918      if (LangOpts.OpenMP) {
2919        // Emit declaration of the must-be-emitted declare target variable.
2920        if (llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
2921                OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
2922          bool UnifiedMemoryEnabled =
2923              getOpenMPRuntime().hasRequiresUnifiedSharedMemory();
2924          if (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2925              !UnifiedMemoryEnabled) {
2926            (void)GetAddrOfGlobalVar(VD);
2927          } else {
2928            assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2929                    (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2930                     UnifiedMemoryEnabled)) &&
2931                   "Link clause or to clause with unified memory expected.");
2932            (void)getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2933          }
2934
2935          return;
2936        }
2937      }
2938      // If this declaration may have caused an inline variable definition to
2939      // change linkage, make sure that it's emitted.
2940      if (Context.getInlineVariableDefinitionKind(VD) ==
2941          ASTContext::InlineVariableDefinitionKind::Strong)
2942        GetAddrOfGlobalVar(VD);
2943      return;
2944    }
2945  }
2946
2947  // Defer code generation to first use when possible, e.g. if this is an inline
2948  // function. If the global must always be emitted, do it eagerly if possible
2949  // to benefit from cache locality.
2950  if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
2951    // Emit the definition if it can't be deferred.
2952    EmitGlobalDefinition(GD);
2953    return;
2954  }
2955
2956  // If we're deferring emission of a C++ variable with an
2957  // initializer, remember the order in which it appeared in the file.
2958  if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
2959      cast<VarDecl>(Global)->hasInit()) {
2960    DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
2961    CXXGlobalInits.push_back(nullptr);
2962  }
2963
2964  StringRef MangledName = getMangledName(GD);
2965  if (GetGlobalValue(MangledName) != nullptr) {
2966    // The value has already been used and should therefore be emitted.
2967    addDeferredDeclToEmit(GD);
2968  } else if (MustBeEmitted(Global)) {
2969    // The value must be emitted, but cannot be emitted eagerly.
2970    assert(!MayBeEmittedEagerly(Global));
2971    addDeferredDeclToEmit(GD);
2972  } else {
2973    // Otherwise, remember that we saw a deferred decl with this name.  The
2974    // first use of the mangled name will cause it to move into
2975    // DeferredDeclsToEmit.
2976    DeferredDecls[MangledName] = GD;
2977  }
2978}
2979
2980// Check if T is a class type with a destructor that's not dllimport.
2981static bool HasNonDllImportDtor(QualType T) {
2982  if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
2983    if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
2984      if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
2985        return true;
2986
2987  return false;
2988}
2989
2990namespace {
2991  struct FunctionIsDirectlyRecursive
2992      : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> {
2993    const StringRef Name;
2994    const Builtin::Context &BI;
2995    FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C)
2996        : Name(N), BI(C) {}
2997
2998    bool VisitCallExpr(const CallExpr *E) {
2999      const FunctionDecl *FD = E->getDirectCallee();
3000      if (!FD)
3001        return false;
3002      AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
3003      if (Attr && Name == Attr->getLabel())
3004        return true;
3005      unsigned BuiltinID = FD->getBuiltinID();
3006      if (!BuiltinID || !BI.isLibFunction(BuiltinID))
3007        return false;
3008      StringRef BuiltinName = BI.getName(BuiltinID);
3009      if (BuiltinName.startswith("__builtin_") &&
3010          Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
3011        return true;
3012      }
3013      return false;
3014    }
3015
3016    bool VisitStmt(const Stmt *S) {
3017      for (const Stmt *Child : S->children())
3018        if (Child && this->Visit(Child))
3019          return true;
3020      return false;
3021    }
3022  };
3023
3024  // Make sure we're not referencing non-imported vars or functions.
3025  struct DLLImportFunctionVisitor
3026      : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
3027    bool SafeToInline = true;
3028
3029    bool shouldVisitImplicitCode() const { return true; }
3030
3031    bool VisitVarDecl(VarDecl *VD) {
3032      if (VD->getTLSKind()) {
3033        // A thread-local variable cannot be imported.
3034        SafeToInline = false;
3035        return SafeToInline;
3036      }
3037
3038      // A variable definition might imply a destructor call.
3039      if (VD->isThisDeclarationADefinition())
3040        SafeToInline = !HasNonDllImportDtor(VD->getType());
3041
3042      return SafeToInline;
3043    }
3044
3045    bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
3046      if (const auto *D = E->getTemporary()->getDestructor())
3047        SafeToInline = D->hasAttr<DLLImportAttr>();
3048      return SafeToInline;
3049    }
3050
3051    bool VisitDeclRefExpr(DeclRefExpr *E) {
3052      ValueDecl *VD = E->getDecl();
3053      if (isa<FunctionDecl>(VD))
3054        SafeToInline = VD->hasAttr<DLLImportAttr>();
3055      else if (VarDecl *V = dyn_cast<VarDecl>(VD))
3056        SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
3057      return SafeToInline;
3058    }
3059
3060    bool VisitCXXConstructExpr(CXXConstructExpr *E) {
3061      SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
3062      return SafeToInline;
3063    }
3064
3065    bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3066      CXXMethodDecl *M = E->getMethodDecl();
3067      if (!M) {
3068        // Call through a pointer to member function. This is safe to inline.
3069        SafeToInline = true;
3070      } else {
3071        SafeToInline = M->hasAttr<DLLImportAttr>();
3072      }
3073      return SafeToInline;
3074    }
3075
3076    bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
3077      SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
3078      return SafeToInline;
3079    }
3080
3081    bool VisitCXXNewExpr(CXXNewExpr *E) {
3082      SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
3083      return SafeToInline;
3084    }
3085  };
3086}
3087
3088// isTriviallyRecursive - Check if this function calls another
3089// decl that, because of the asm attribute or the other decl being a builtin,
3090// ends up pointing to itself.
3091bool
3092CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
3093  StringRef Name;
3094  if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
3095    // asm labels are a special kind of mangling we have to support.
3096    AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
3097    if (!Attr)
3098      return false;
3099    Name = Attr->getLabel();
3100  } else {
3101    Name = FD->getName();
3102  }
3103
3104  FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
3105  const Stmt *Body = FD->getBody();
3106  return Body ? Walker.Visit(Body) : false;
3107}
3108
3109bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
3110  if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
3111    return true;
3112  const auto *F = cast<FunctionDecl>(GD.getDecl());
3113  if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
3114    return false;
3115
3116  if (F->hasAttr<DLLImportAttr>() && !F->hasAttr<AlwaysInlineAttr>()) {
3117    // Check whether it would be safe to inline this dllimport function.
3118    DLLImportFunctionVisitor Visitor;
3119    Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
3120    if (!Visitor.SafeToInline)
3121      return false;
3122
3123    if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
3124      // Implicit destructor invocations aren't captured in the AST, so the
3125      // check above can't see them. Check for them manually here.
3126      for (const Decl *Member : Dtor->getParent()->decls())
3127        if (isa<FieldDecl>(Member))
3128          if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
3129            return false;
3130      for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
3131        if (HasNonDllImportDtor(B.getType()))
3132          return false;
3133    }
3134  }
3135
3136  // PR9614. Avoid cases where the source code is lying to us. An available
3137  // externally function should have an equivalent function somewhere else,
3138  // but a function that calls itself through asm label/`__builtin_` trickery is
3139  // clearly not equivalent to the real implementation.
3140  // This happens in glibc's btowc and in some configure checks.
3141  return !isTriviallyRecursive(F);
3142}
3143
3144bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
3145  return CodeGenOpts.OptimizationLevel > 0;
3146}
3147
3148void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
3149                                                       llvm::GlobalValue *GV) {
3150  const auto *FD = cast<FunctionDecl>(GD.getDecl());
3151
3152  if (FD->isCPUSpecificMultiVersion()) {
3153    auto *Spec = FD->getAttr<CPUSpecificAttr>();
3154    for (unsigned I = 0; I < Spec->cpus_size(); ++I)
3155      EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
3156    // Requires multiple emits.
3157  } else
3158    EmitGlobalFunctionDefinition(GD, GV);
3159}
3160
3161void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
3162  const auto *D = cast<ValueDecl>(GD.getDecl());
3163
3164  PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
3165                                 Context.getSourceManager(),
3166                                 "Generating code for declaration");
3167
3168  if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
3169    // At -O0, don't generate IR for functions with available_externally
3170    // linkage.
3171    if (!shouldEmitFunction(GD))
3172      return;
3173
3174    llvm::TimeTraceScope TimeScope("CodeGen Function", [&]() {
3175      std::string Name;
3176      llvm::raw_string_ostream OS(Name);
3177      FD->getNameForDiagnostic(OS, getContext().getPrintingPolicy(),
3178                               /*Qualified=*/true);
3179      return Name;
3180    });
3181
3182    if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
3183      // Make sure to emit the definition(s) before we emit the thunks.
3184      // This is necessary for the generation of certain thunks.
3185      if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
3186        ABI->emitCXXStructor(GD);
3187      else if (FD->isMultiVersion())
3188        EmitMultiVersionFunctionDefinition(GD, GV);
3189      else
3190        EmitGlobalFunctionDefinition(GD, GV);
3191
3192      if (Method->isVirtual())
3193        getVTables().EmitThunks(GD);
3194
3195      return;
3196    }
3197
3198    if (FD->isMultiVersion())
3199      return EmitMultiVersionFunctionDefinition(GD, GV);
3200    return EmitGlobalFunctionDefinition(GD, GV);
3201  }
3202
3203  if (const auto *VD = dyn_cast<VarDecl>(D))
3204    return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
3205
3206  llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
3207}
3208
3209static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
3210                                                      llvm::Function *NewFn);
3211
3212static unsigned
3213TargetMVPriority(const TargetInfo &TI,
3214                 const CodeGenFunction::MultiVersionResolverOption &RO) {
3215  unsigned Priority = 0;
3216  for (StringRef Feat : RO.Conditions.Features)
3217    Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
3218
3219  if (!RO.Conditions.Architecture.empty())
3220    Priority = std::max(
3221        Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
3222  return Priority;
3223}
3224
3225void CodeGenModule::emitMultiVersionFunctions() {
3226  std::vector<GlobalDecl> MVFuncsToEmit;
3227  MultiVersionFuncs.swap(MVFuncsToEmit);
3228  for (GlobalDecl GD : MVFuncsToEmit) {
3229    SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
3230    const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
3231    getContext().forEachMultiversionedFunctionVersion(
3232        FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
3233          GlobalDecl CurGD{
3234              (CurFD->isDefined() ? CurFD->getDefinition() : CurFD)};
3235          StringRef MangledName = getMangledName(CurGD);
3236          llvm::Constant *Func = GetGlobalValue(MangledName);
3237          if (!Func) {
3238            if (CurFD->isDefined()) {
3239              EmitGlobalFunctionDefinition(CurGD, nullptr);
3240              Func = GetGlobalValue(MangledName);
3241            } else {
3242              const CGFunctionInfo &FI =
3243                  getTypes().arrangeGlobalDeclaration(GD);
3244              llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
3245              Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
3246                                       /*DontDefer=*/false, ForDefinition);
3247            }
3248            assert(Func && "This should have just been created");
3249          }
3250
3251          const auto *TA = CurFD->getAttr<TargetAttr>();
3252          llvm::SmallVector<StringRef, 8> Feats;
3253          TA->getAddedFeatures(Feats);
3254
3255          Options.emplace_back(cast<llvm::Function>(Func),
3256                               TA->getArchitecture(), Feats);
3257        });
3258
3259    llvm::Function *ResolverFunc;
3260    const TargetInfo &TI = getTarget();
3261
3262    if (TI.supportsIFunc() || FD->isTargetMultiVersion()) {
3263      ResolverFunc = cast<llvm::Function>(
3264          GetGlobalValue((getMangledName(GD) + ".resolver").str()));
3265      ResolverFunc->setLinkage(llvm::Function::WeakODRLinkage);
3266    } else {
3267      ResolverFunc = cast<llvm::Function>(GetGlobalValue(getMangledName(GD)));
3268    }
3269
3270    if (supportsCOMDAT())
3271      ResolverFunc->setComdat(
3272          getModule().getOrInsertComdat(ResolverFunc->getName()));
3273
3274    llvm::stable_sort(
3275        Options, [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
3276                       const CodeGenFunction::MultiVersionResolverOption &RHS) {
3277          return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
3278        });
3279    CodeGenFunction CGF(*this);
3280    CGF.EmitMultiVersionResolver(ResolverFunc, Options);
3281  }
3282
3283  // Ensure that any additions to the deferred decls list caused by emitting a
3284  // variant are emitted.  This can happen when the variant itself is inline and
3285  // calls a function without linkage.
3286  if (!MVFuncsToEmit.empty())
3287    EmitDeferred();
3288
3289  // Ensure that any additions to the multiversion funcs list from either the
3290  // deferred decls or the multiversion functions themselves are emitted.
3291  if (!MultiVersionFuncs.empty())
3292    emitMultiVersionFunctions();
3293}
3294
3295void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
3296  const auto *FD = cast<FunctionDecl>(GD.getDecl());
3297  assert(FD && "Not a FunctionDecl?");
3298  const auto *DD = FD->getAttr<CPUDispatchAttr>();
3299  assert(DD && "Not a cpu_dispatch Function?");
3300  llvm::Type *DeclTy = getTypes().ConvertType(FD->getType());
3301
3302  if (const auto *CXXFD = dyn_cast<CXXMethodDecl>(FD)) {
3303    const CGFunctionInfo &FInfo = getTypes().arrangeCXXMethodDeclaration(CXXFD);
3304    DeclTy = getTypes().GetFunctionType(FInfo);
3305  }
3306
3307  StringRef ResolverName = getMangledName(GD);
3308
3309  llvm::Type *ResolverType;
3310  GlobalDecl ResolverGD;
3311  if (getTarget().supportsIFunc())
3312    ResolverType = llvm::FunctionType::get(
3313        llvm::PointerType::get(DeclTy,
3314                               Context.getTargetAddressSpace(FD->getType())),
3315        false);
3316  else {
3317    ResolverType = DeclTy;
3318    ResolverGD = GD;
3319  }
3320
3321  auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
3322      ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
3323  ResolverFunc->setLinkage(llvm::Function::WeakODRLinkage);
3324  if (supportsCOMDAT())
3325    ResolverFunc->setComdat(
3326        getModule().getOrInsertComdat(ResolverFunc->getName()));
3327
3328  SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
3329  const TargetInfo &Target = getTarget();
3330  unsigned Index = 0;
3331  for (const IdentifierInfo *II : DD->cpus()) {
3332    // Get the name of the target function so we can look it up/create it.
3333    std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
3334                              getCPUSpecificMangling(*this, II->getName());
3335
3336    llvm::Constant *Func = GetGlobalValue(MangledName);
3337
3338    if (!Func) {
3339      GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
3340      if (ExistingDecl.getDecl() &&
3341          ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
3342        EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
3343        Func = GetGlobalValue(MangledName);
3344      } else {
3345        if (!ExistingDecl.getDecl())
3346          ExistingDecl = GD.getWithMultiVersionIndex(Index);
3347
3348      Func = GetOrCreateLLVMFunction(
3349          MangledName, DeclTy, ExistingDecl,
3350          /*ForVTable=*/false, /*DontDefer=*/true,
3351          /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
3352      }
3353    }
3354
3355    llvm::SmallVector<StringRef, 32> Features;
3356    Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
3357    llvm::transform(Features, Features.begin(),
3358                    [](StringRef Str) { return Str.substr(1); });
3359    Features.erase(std::remove_if(
3360        Features.begin(), Features.end(), [&Target](StringRef Feat) {
3361          return !Target.validateCpuSupports(Feat);
3362        }), Features.end());
3363    Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
3364    ++Index;
3365  }
3366
3367  llvm::stable_sort(
3368      Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
3369                  const CodeGenFunction::MultiVersionResolverOption &RHS) {
3370        return CodeGenFunction::GetX86CpuSupportsMask(LHS.Conditions.Features) >
3371               CodeGenFunction::GetX86CpuSupportsMask(RHS.Conditions.Features);
3372      });
3373
3374  // If the list contains multiple 'default' versions, such as when it contains
3375  // 'pentium' and 'generic', don't emit the call to the generic one (since we
3376  // always run on at least a 'pentium'). We do this by deleting the 'least
3377  // advanced' (read, lowest mangling letter).
3378  while (Options.size() > 1 &&
3379         CodeGenFunction::GetX86CpuSupportsMask(
3380             (Options.end() - 2)->Conditions.Features) == 0) {
3381    StringRef LHSName = (Options.end() - 2)->Function->getName();
3382    StringRef RHSName = (Options.end() - 1)->Function->getName();
3383    if (LHSName.compare(RHSName) < 0)
3384      Options.erase(Options.end() - 2);
3385    else
3386      Options.erase(Options.end() - 1);
3387  }
3388
3389  CodeGenFunction CGF(*this);
3390  CGF.EmitMultiVersionResolver(ResolverFunc, Options);
3391
3392  if (getTarget().supportsIFunc()) {
3393    std::string AliasName = getMangledNameImpl(
3394        *this, GD, FD, /*OmitMultiVersionMangling=*/true);
3395    llvm::Constant *AliasFunc = GetGlobalValue(AliasName);
3396    if (!AliasFunc) {
3397      auto *IFunc = cast<llvm::GlobalIFunc>(GetOrCreateLLVMFunction(
3398          AliasName, DeclTy, GD, /*ForVTable=*/false, /*DontDefer=*/true,
3399          /*IsThunk=*/false, llvm::AttributeList(), NotForDefinition));
3400      auto *GA = llvm::GlobalAlias::create(
3401         DeclTy, 0, getFunctionLinkage(GD), AliasName, IFunc, &getModule());
3402      GA->setLinkage(llvm::Function::WeakODRLinkage);
3403      SetCommonAttributes(GD, GA);
3404    }
3405  }
3406}
3407
3408/// If a dispatcher for the specified mangled name is not in the module, create
3409/// and return an llvm Function with the specified type.
3410llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(
3411    GlobalDecl GD, llvm::Type *DeclTy, const FunctionDecl *FD) {
3412  std::string MangledName =
3413      getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
3414
3415  // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
3416  // a separate resolver).
3417  std::string ResolverName = MangledName;
3418  if (getTarget().supportsIFunc())
3419    ResolverName += ".ifunc";
3420  else if (FD->isTargetMultiVersion())
3421    ResolverName += ".resolver";
3422
3423  // If this already exists, just return that one.
3424  if (llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName))
3425    return ResolverGV;
3426
3427  // Since this is the first time we've created this IFunc, make sure
3428  // that we put this multiversioned function into the list to be
3429  // replaced later if necessary (target multiversioning only).
3430  if (!FD->isCPUDispatchMultiVersion() && !FD->isCPUSpecificMultiVersion())
3431    MultiVersionFuncs.push_back(GD);
3432
3433  if (getTarget().supportsIFunc()) {
3434    llvm::Type *ResolverType = llvm::FunctionType::get(
3435        llvm::PointerType::get(
3436            DeclTy, getContext().getTargetAddressSpace(FD->getType())),
3437        false);
3438    llvm::Constant *Resolver = GetOrCreateLLVMFunction(
3439        MangledName + ".resolver", ResolverType, GlobalDecl{},
3440        /*ForVTable=*/false);
3441    llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
3442        DeclTy, 0, llvm::Function::WeakODRLinkage, "", Resolver, &getModule());
3443    GIF->setName(ResolverName);
3444    SetCommonAttributes(FD, GIF);
3445
3446    return GIF;
3447  }
3448
3449  llvm::Constant *Resolver = GetOrCreateLLVMFunction(
3450      ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
3451  assert(isa<llvm::GlobalValue>(Resolver) &&
3452         "Resolver should be created for the first time");
3453  SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
3454  return Resolver;
3455}
3456
3457/// GetOrCreateLLVMFunction - If the specified mangled name is not in the
3458/// module, create and return an llvm Function with the specified type. If there
3459/// is something in the module with the specified name, return it potentially
3460/// bitcasted to the right type.
3461///
3462/// If D is non-null, it specifies a decl that correspond to this.  This is used
3463/// to set the attributes on the function when it is first created.
3464llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
3465    StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
3466    bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
3467    ForDefinition_t IsForDefinition) {
3468  const Decl *D = GD.getDecl();
3469
3470  // Any attempts to use a MultiVersion function should result in retrieving
3471  // the iFunc instead. Name Mangling will handle the rest of the changes.
3472  if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
3473    // For the device mark the function as one that should be emitted.
3474    if (getLangOpts().OpenMPIsDevice && OpenMPRuntime &&
3475        !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
3476        !DontDefer && !IsForDefinition) {
3477      if (const FunctionDecl *FDDef = FD->getDefinition()) {
3478        GlobalDecl GDDef;
3479        if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
3480          GDDef = GlobalDecl(CD, GD.getCtorType());
3481        else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
3482          GDDef = GlobalDecl(DD, GD.getDtorType());
3483        else
3484          GDDef = GlobalDecl(FDDef);
3485        EmitGlobal(GDDef);
3486      }
3487    }
3488
3489    if (FD->isMultiVersion()) {
3490      if (FD->hasAttr<TargetAttr>())
3491        UpdateMultiVersionNames(GD, FD);
3492      if (!IsForDefinition)
3493        return GetOrCreateMultiVersionResolver(GD, Ty, FD);
3494    }
3495  }
3496
3497  // Lookup the entry, lazily creating it if necessary.
3498  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3499  if (Entry) {
3500    if (WeakRefReferences.erase(Entry)) {
3501      const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
3502      if (FD && !FD->hasAttr<WeakAttr>())
3503        Entry->setLinkage(llvm::Function::ExternalLinkage);
3504    }
3505
3506    // Handle dropped DLL attributes.
3507    if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>()) {
3508      Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3509      setDSOLocal(Entry);
3510    }
3511
3512    // If there are two attempts to define the same mangled name, issue an
3513    // error.
3514    if (IsForDefinition && !Entry->isDeclaration()) {
3515      GlobalDecl OtherGD;
3516      // Check that GD is not yet in DiagnosedConflictingDefinitions is required
3517      // to make sure that we issue an error only once.
3518      if (lookupRepresentativeDecl(MangledName, OtherGD) &&
3519          (GD.getCanonicalDecl().getDecl() !=
3520           OtherGD.getCanonicalDecl().getDecl()) &&
3521          DiagnosedConflictingDefinitions.insert(GD).second) {
3522        getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3523            << MangledName;
3524        getDiags().Report(OtherGD.getDecl()->getLocation(),
3525                          diag::note_previous_definition);
3526      }
3527    }
3528
3529    if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
3530        (Entry->getValueType() == Ty)) {
3531      return Entry;
3532    }
3533
3534    // Make sure the result is of the correct type.
3535    // (If function is requested for a definition, we always need to create a new
3536    // function, not just return a bitcast.)
3537    if (!IsForDefinition)
3538      return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
3539  }
3540
3541  // This function doesn't have a complete type (for example, the return
3542  // type is an incomplete struct). Use a fake type instead, and make
3543  // sure not to try to set attributes.
3544  bool IsIncompleteFunction = false;
3545
3546  llvm::FunctionType *FTy;
3547  if (isa<llvm::FunctionType>(Ty)) {
3548    FTy = cast<llvm::FunctionType>(Ty);
3549  } else {
3550    FTy = llvm::FunctionType::get(VoidTy, false);
3551    IsIncompleteFunction = true;
3552  }
3553
3554  llvm::Function *F =
3555      llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
3556                             Entry ? StringRef() : MangledName, &getModule());
3557
3558  // If we already created a function with the same mangled name (but different
3559  // type) before, take its name and add it to the list of functions to be
3560  // replaced with F at the end of CodeGen.
3561  //
3562  // This happens if there is a prototype for a function (e.g. "int f()") and
3563  // then a definition of a different type (e.g. "int f(int x)").
3564  if (Entry) {
3565    F->takeName(Entry);
3566
3567    // This might be an implementation of a function without a prototype, in
3568    // which case, try to do special replacement of calls which match the new
3569    // prototype.  The really key thing here is that we also potentially drop
3570    // arguments from the call site so as to make a direct call, which makes the
3571    // inliner happier and suppresses a number of optimizer warnings (!) about
3572    // dropping arguments.
3573    if (!Entry->use_empty()) {
3574      ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
3575      Entry->removeDeadConstantUsers();
3576    }
3577
3578    llvm::Constant *BC = llvm::ConstantExpr::getBitCast(
3579        F, Entry->getValueType()->getPointerTo());
3580    addGlobalValReplacement(Entry, BC);
3581  }
3582
3583  assert(F->getName() == MangledName && "name was uniqued!");
3584  if (D)
3585    SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
3586  if (ExtraAttrs.hasAttributes(llvm::AttributeList::FunctionIndex)) {
3587    llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex);
3588    F->addAttributes(llvm::AttributeList::FunctionIndex, B);
3589  }
3590
3591  if (!DontDefer) {
3592    // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
3593    // each other bottoming out with the base dtor.  Therefore we emit non-base
3594    // dtors on usage, even if there is no dtor definition in the TU.
3595    if (D && isa<CXXDestructorDecl>(D) &&
3596        getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
3597                                           GD.getDtorType()))
3598      addDeferredDeclToEmit(GD);
3599
3600    // This is the first use or definition of a mangled name.  If there is a
3601    // deferred decl with this name, remember that we need to emit it at the end
3602    // of the file.
3603    auto DDI = DeferredDecls.find(MangledName);
3604    if (DDI != DeferredDecls.end()) {
3605      // Move the potentially referenced deferred decl to the
3606      // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
3607      // don't need it anymore).
3608      addDeferredDeclToEmit(DDI->second);
3609      DeferredDecls.erase(DDI);
3610
3611      // Otherwise, there are cases we have to worry about where we're
3612      // using a declaration for which we must emit a definition but where
3613      // we might not find a top-level definition:
3614      //   - member functions defined inline in their classes
3615      //   - friend functions defined inline in some class
3616      //   - special member functions with implicit definitions
3617      // If we ever change our AST traversal to walk into class methods,
3618      // this will be unnecessary.
3619      //
3620      // We also don't emit a definition for a function if it's going to be an
3621      // entry in a vtable, unless it's already marked as used.
3622    } else if (getLangOpts().CPlusPlus && D) {
3623      // Look for a declaration that's lexically in a record.
3624      for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
3625           FD = FD->getPreviousDecl()) {
3626        if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
3627          if (FD->doesThisDeclarationHaveABody()) {
3628            addDeferredDeclToEmit(GD.getWithDecl(FD));
3629            break;
3630          }
3631        }
3632      }
3633    }
3634  }
3635
3636  // Make sure the result is of the requested type.
3637  if (!IsIncompleteFunction) {
3638    assert(F->getFunctionType() == Ty);
3639    return F;
3640  }
3641
3642  llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
3643  return llvm::ConstantExpr::getBitCast(F, PTy);
3644}
3645
3646/// GetAddrOfFunction - Return the address of the given function.  If Ty is
3647/// non-null, then this function will use the specified type if it has to
3648/// create it (this occurs when we see a definition of the function).
3649llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
3650                                                 llvm::Type *Ty,
3651                                                 bool ForVTable,
3652                                                 bool DontDefer,
3653                                              ForDefinition_t IsForDefinition) {
3654  assert(!cast<FunctionDecl>(GD.getDecl())->isConsteval() &&
3655         "consteval function should never be emitted");
3656  // If there was no specific requested type, just convert it now.
3657  if (!Ty) {
3658    const auto *FD = cast<FunctionDecl>(GD.getDecl());
3659    Ty = getTypes().ConvertType(FD->getType());
3660  }
3661
3662  // Devirtualized destructor calls may come through here instead of via
3663  // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
3664  // of the complete destructor when necessary.
3665  if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
3666    if (getTarget().getCXXABI().isMicrosoft() &&
3667        GD.getDtorType() == Dtor_Complete &&
3668        DD->getParent()->getNumVBases() == 0)
3669      GD = GlobalDecl(DD, Dtor_Base);
3670  }
3671
3672  StringRef MangledName = getMangledName(GD);
3673  auto *F = GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
3674                                    /*IsThunk=*/false, llvm::AttributeList(),
3675                                    IsForDefinition);
3676  // Returns kernel handle for HIP kernel stub function.
3677  if (LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
3678      cast<FunctionDecl>(GD.getDecl())->hasAttr<CUDAGlobalAttr>()) {
3679    auto *Handle = getCUDARuntime().getKernelHandle(
3680        cast<llvm::Function>(F->stripPointerCasts()), GD);
3681    if (IsForDefinition)
3682      return F;
3683    return llvm::ConstantExpr::getBitCast(Handle, Ty->getPointerTo());
3684  }
3685  return F;
3686}
3687
3688static const FunctionDecl *
3689GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
3690  TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
3691  DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
3692
3693  IdentifierInfo &CII = C.Idents.get(Name);
3694  for (const auto *Result : DC->lookup(&CII))
3695    if (const auto *FD = dyn_cast<FunctionDecl>(Result))
3696      return FD;
3697
3698  if (!C.getLangOpts().CPlusPlus)
3699    return nullptr;
3700
3701  // Demangle the premangled name from getTerminateFn()
3702  IdentifierInfo &CXXII =
3703      (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
3704          ? C.Idents.get("terminate")
3705          : C.Idents.get(Name);
3706
3707  for (const auto &N : {"__cxxabiv1", "std"}) {
3708    IdentifierInfo &NS = C.Idents.get(N);
3709    for (const auto *Result : DC->lookup(&NS)) {
3710      const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
3711      if (auto *LSD = dyn_cast<LinkageSpecDecl>(Result))
3712        for (const auto *Result : LSD->lookup(&NS))
3713          if ((ND = dyn_cast<NamespaceDecl>(Result)))
3714            break;
3715
3716      if (ND)
3717        for (const auto *Result : ND->lookup(&CXXII))
3718          if (const auto *FD = dyn_cast<FunctionDecl>(Result))
3719            return FD;
3720    }
3721  }
3722
3723  return nullptr;
3724}
3725
3726/// CreateRuntimeFunction - Create a new runtime function with the specified
3727/// type and name.
3728llvm::FunctionCallee
3729CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
3730                                     llvm::AttributeList ExtraAttrs, bool Local,
3731                                     bool AssumeConvergent) {
3732  if (AssumeConvergent) {
3733    ExtraAttrs =
3734        ExtraAttrs.addAttribute(VMContext, llvm::AttributeList::FunctionIndex,
3735                                llvm::Attribute::Convergent);
3736  }
3737
3738  llvm::Constant *C =
3739      GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
3740                              /*DontDefer=*/false, /*IsThunk=*/false,
3741                              ExtraAttrs);
3742
3743  if (auto *F = dyn_cast<llvm::Function>(C)) {
3744    if (F->empty()) {
3745      F->setCallingConv(getRuntimeCC());
3746
3747      // In Windows Itanium environments, try to mark runtime functions
3748      // dllimport. For Mingw and MSVC, don't. We don't really know if the user
3749      // will link their standard library statically or dynamically. Marking
3750      // functions imported when they are not imported can cause linker errors
3751      // and warnings.
3752      if (!Local && getTriple().isWindowsItaniumEnvironment() &&
3753          !getCodeGenOpts().LTOVisibilityPublicStd) {
3754        const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
3755        if (!FD || FD->hasAttr<DLLImportAttr>()) {
3756          F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
3757          F->setLinkage(llvm::GlobalValue::ExternalLinkage);
3758        }
3759      }
3760      setDSOLocal(F);
3761    }
3762  }
3763
3764  return {FTy, C};
3765}
3766
3767/// isTypeConstant - Determine whether an object of this type can be emitted
3768/// as a constant.
3769///
3770/// If ExcludeCtor is true, the duration when the object's constructor runs
3771/// will not be considered. The caller will need to verify that the object is
3772/// not written to during its construction.
3773bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
3774  if (!Ty.isConstant(Context) && !Ty->isReferenceType())
3775    return false;
3776
3777  if (Context.getLangOpts().CPlusPlus) {
3778    if (const CXXRecordDecl *Record
3779          = Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
3780      return ExcludeCtor && !Record->hasMutableFields() &&
3781             Record->hasTrivialDestructor();
3782  }
3783
3784  return true;
3785}
3786
3787/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
3788/// create and return an llvm GlobalVariable with the specified type and address
3789/// space. If there is something in the module with the specified name, return
3790/// it potentially bitcasted to the right type.
3791///
3792/// If D is non-null, it specifies a decl that correspond to this.  This is used
3793/// to set the attributes on the global when it is first created.
3794///
3795/// If IsForDefinition is true, it is guaranteed that an actual global with
3796/// type Ty will be returned, not conversion of a variable with the same
3797/// mangled name but some other type.
3798llvm::Constant *
3799CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, llvm::Type *Ty,
3800                                     unsigned AddrSpace, const VarDecl *D,
3801                                     ForDefinition_t IsForDefinition) {
3802  // Lookup the entry, lazily creating it if necessary.
3803  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3804  if (Entry) {
3805    if (WeakRefReferences.erase(Entry)) {
3806      if (D && !D->hasAttr<WeakAttr>())
3807        Entry->setLinkage(llvm::Function::ExternalLinkage);
3808    }
3809
3810    // Handle dropped DLL attributes.
3811    if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
3812      Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3813
3814    if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
3815      getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
3816
3817    if (Entry->getValueType() == Ty && Entry->getAddressSpace() == AddrSpace)
3818      return Entry;
3819
3820    // If there are two attempts to define the same mangled name, issue an
3821    // error.
3822    if (IsForDefinition && !Entry->isDeclaration()) {
3823      GlobalDecl OtherGD;
3824      const VarDecl *OtherD;
3825
3826      // Check that D is not yet in DiagnosedConflictingDefinitions is required
3827      // to make sure that we issue an error only once.
3828      if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
3829          (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
3830          (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
3831          OtherD->hasInit() &&
3832          DiagnosedConflictingDefinitions.insert(D).second) {
3833        getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3834            << MangledName;
3835        getDiags().Report(OtherGD.getDecl()->getLocation(),
3836                          diag::note_previous_definition);
3837      }
3838    }
3839
3840    // Make sure the result is of the correct type.
3841    if (Entry->getType()->getAddressSpace() != AddrSpace) {
3842      return llvm::ConstantExpr::getAddrSpaceCast(Entry,
3843                                                  Ty->getPointerTo(AddrSpace));
3844    }
3845
3846    // (If global is requested for a definition, we always need to create a new
3847    // global, not just return a bitcast.)
3848    if (!IsForDefinition)
3849      return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo(AddrSpace));
3850  }
3851
3852  auto DAddrSpace = GetGlobalVarAddressSpace(D);
3853  auto TargetAddrSpace = getContext().getTargetAddressSpace(DAddrSpace);
3854
3855  auto *GV = new llvm::GlobalVariable(
3856      getModule(), Ty, false, llvm::GlobalValue::ExternalLinkage, nullptr,
3857      MangledName, nullptr, llvm::GlobalVariable::NotThreadLocal,
3858      TargetAddrSpace);
3859
3860  // If we already created a global with the same mangled name (but different
3861  // type) before, take its name and remove it from its parent.
3862  if (Entry) {
3863    GV->takeName(Entry);
3864
3865    if (!Entry->use_empty()) {
3866      llvm::Constant *NewPtrForOldDecl =
3867          llvm::ConstantExpr::getBitCast(GV, Entry->getType());
3868      Entry->replaceAllUsesWith(NewPtrForOldDecl);
3869    }
3870
3871    Entry->eraseFromParent();
3872  }
3873
3874  // This is the first use or definition of a mangled name.  If there is a
3875  // deferred decl with this name, remember that we need to emit it at the end
3876  // of the file.
3877  auto DDI = DeferredDecls.find(MangledName);
3878  if (DDI != DeferredDecls.end()) {
3879    // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
3880    // list, and remove it from DeferredDecls (since we don't need it anymore).
3881    addDeferredDeclToEmit(DDI->second);
3882    DeferredDecls.erase(DDI);
3883  }
3884
3885  // Handle things which are present even on external declarations.
3886  if (D) {
3887    if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
3888      getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
3889
3890    // FIXME: This code is overly simple and should be merged with other global
3891    // handling.
3892    GV->setConstant(isTypeConstant(D->getType(), false));
3893
3894    GV->setAlignment(getContext().getDeclAlign(D).getAsAlign());
3895
3896    setLinkageForGV(GV, D);
3897
3898    if (D->getTLSKind()) {
3899      if (D->getTLSKind() == VarDecl::TLS_Dynamic)
3900        CXXThreadLocals.push_back(D);
3901      setTLSMode(GV, *D);
3902    }
3903
3904    setGVProperties(GV, D);
3905
3906    // If required by the ABI, treat declarations of static data members with
3907    // inline initializers as definitions.
3908    if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
3909      EmitGlobalVarDefinition(D);
3910    }
3911
3912    // Emit section information for extern variables.
3913    if (D->hasExternalStorage()) {
3914      if (const SectionAttr *SA = D->getAttr<SectionAttr>())
3915        GV->setSection(SA->getName());
3916    }
3917
3918    // Handle XCore specific ABI requirements.
3919    if (getTriple().getArch() == llvm::Triple::xcore &&
3920        D->getLanguageLinkage() == CLanguageLinkage &&
3921        D->getType().isConstant(Context) &&
3922        isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
3923      GV->setSection(".cp.rodata");
3924
3925    // Check if we a have a const declaration with an initializer, we may be
3926    // able to emit it as available_externally to expose it's value to the
3927    // optimizer.
3928    if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
3929        D->getType().isConstQualified() && !GV->hasInitializer() &&
3930        !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
3931      const auto *Record =
3932          Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
3933      bool HasMutableFields = Record && Record->hasMutableFields();
3934      if (!HasMutableFields) {
3935        const VarDecl *InitDecl;
3936        const Expr *InitExpr = D->getAnyInitializer(InitDecl);
3937        if (InitExpr) {
3938          ConstantEmitter emitter(*this);
3939          llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
3940          if (Init) {
3941            auto *InitType = Init->getType();
3942            if (GV->getValueType() != InitType) {
3943              // The type of the initializer does not match the definition.
3944              // This happens when an initializer has a different type from
3945              // the type of the global (because of padding at the end of a
3946              // structure for instance).
3947              GV->setName(StringRef());
3948              // Make a new global with the correct type, this is now guaranteed
3949              // to work.
3950              auto *NewGV = cast<llvm::GlobalVariable>(
3951                  GetAddrOfGlobalVar(D, InitType, IsForDefinition)
3952                      ->stripPointerCasts());
3953
3954              // Erase the old global, since it is no longer used.
3955              GV->eraseFromParent();
3956              GV = NewGV;
3957            } else {
3958              GV->setInitializer(Init);
3959              GV->setConstant(true);
3960              GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
3961            }
3962            emitter.finalize(GV);
3963          }
3964        }
3965      }
3966    }
3967  }
3968
3969  if (GV->isDeclaration()) {
3970    getTargetCodeGenInfo().setTargetAttributes(D, GV, *this);
3971    // External HIP managed variables needed to be recorded for transformation
3972    // in both device and host compilations.
3973    if (getLangOpts().CUDA && D && D->hasAttr<HIPManagedAttr>() &&
3974        D->hasExternalStorage())
3975      getCUDARuntime().handleVarRegistration(D, *GV);
3976  }
3977
3978  LangAS ExpectedAS =
3979      D ? D->getType().getAddressSpace()
3980        : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
3981  assert(getContext().getTargetAddressSpace(ExpectedAS) == AddrSpace);
3982  if (DAddrSpace != ExpectedAS) {
3983    return getTargetCodeGenInfo().performAddrSpaceCast(
3984        *this, GV, DAddrSpace, ExpectedAS, Ty->getPointerTo(AddrSpace));
3985  }
3986
3987  return GV;
3988}
3989
3990llvm::Constant *
3991CodeGenModule::GetAddrOfGlobal(GlobalDecl GD, ForDefinition_t IsForDefinition) {
3992  const Decl *D = GD.getDecl();
3993
3994  if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
3995    return getAddrOfCXXStructor(GD, /*FnInfo=*/nullptr, /*FnType=*/nullptr,
3996                                /*DontDefer=*/false, IsForDefinition);
3997
3998  if (isa<CXXMethodDecl>(D)) {
3999    auto FInfo =
4000        &getTypes().arrangeCXXMethodDeclaration(cast<CXXMethodDecl>(D));
4001    auto Ty = getTypes().GetFunctionType(*FInfo);
4002    return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
4003                             IsForDefinition);
4004  }
4005
4006  if (isa<FunctionDecl>(D)) {
4007    const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4008    llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4009    return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
4010                             IsForDefinition);
4011  }
4012
4013  return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr, IsForDefinition);
4014}
4015
4016llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
4017    StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
4018    unsigned Alignment) {
4019  llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
4020  llvm::GlobalVariable *OldGV = nullptr;
4021
4022  if (GV) {
4023    // Check if the variable has the right type.
4024    if (GV->getValueType() == Ty)
4025      return GV;
4026
4027    // Because C++ name mangling, the only way we can end up with an already
4028    // existing global with the same name is if it has been declared extern "C".
4029    assert(GV->isDeclaration() && "Declaration has wrong type!");
4030    OldGV = GV;
4031  }
4032
4033  // Create a new variable.
4034  GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
4035                                Linkage, nullptr, Name);
4036
4037  if (OldGV) {
4038    // Replace occurrences of the old variable if needed.
4039    GV->takeName(OldGV);
4040
4041    if (!OldGV->use_empty()) {
4042      llvm::Constant *NewPtrForOldDecl =
4043      llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
4044      OldGV->replaceAllUsesWith(NewPtrForOldDecl);
4045    }
4046
4047    OldGV->eraseFromParent();
4048  }
4049
4050  if (supportsCOMDAT() && GV->isWeakForLinker() &&
4051      !GV->hasAvailableExternallyLinkage())
4052    GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
4053
4054  GV->setAlignment(llvm::MaybeAlign(Alignment));
4055
4056  return GV;
4057}
4058
4059/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
4060/// given global variable.  If Ty is non-null and if the global doesn't exist,
4061/// then it will be created with the specified type instead of whatever the
4062/// normal requested type would be. If IsForDefinition is true, it is guaranteed
4063/// that an actual global with type Ty will be returned, not conversion of a
4064/// variable with the same mangled name but some other type.
4065llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
4066                                                  llvm::Type *Ty,
4067                                           ForDefinition_t IsForDefinition) {
4068  assert(D->hasGlobalStorage() && "Not a global variable");
4069  QualType ASTTy = D->getType();
4070  if (!Ty)
4071    Ty = getTypes().ConvertTypeForMem(ASTTy);
4072
4073  StringRef MangledName = getMangledName(D);
4074  return GetOrCreateLLVMGlobal(MangledName, Ty,
4075                               getContext().getTargetAddressSpace(ASTTy), D,
4076                               IsForDefinition);
4077}
4078
4079/// CreateRuntimeVariable - Create a new runtime global variable with the
4080/// specified type and name.
4081llvm::Constant *
4082CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
4083                                     StringRef Name) {
4084  auto AddrSpace =
4085      getContext().getLangOpts().OpenCL
4086          ? getContext().getTargetAddressSpace(LangAS::opencl_global)
4087          : 0;
4088  auto *Ret = GetOrCreateLLVMGlobal(Name, Ty, AddrSpace, nullptr);
4089  setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
4090  return Ret;
4091}
4092
4093void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
4094  assert(!D->getInit() && "Cannot emit definite definitions here!");
4095
4096  StringRef MangledName = getMangledName(D);
4097  llvm::GlobalValue *GV = GetGlobalValue(MangledName);
4098
4099  // We already have a definition, not declaration, with the same mangled name.
4100  // Emitting of declaration is not required (and actually overwrites emitted
4101  // definition).
4102  if (GV && !GV->isDeclaration())
4103    return;
4104
4105  // If we have not seen a reference to this variable yet, place it into the
4106  // deferred declarations table to be emitted if needed later.
4107  if (!MustBeEmitted(D) && !GV) {
4108      DeferredDecls[MangledName] = D;
4109      return;
4110  }
4111
4112  // The tentative definition is the only definition.
4113  EmitGlobalVarDefinition(D);
4114}
4115
4116void CodeGenModule::EmitExternalDeclaration(const VarDecl *D) {
4117  EmitExternalVarDeclaration(D);
4118}
4119
4120CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
4121  return Context.toCharUnitsFromBits(
4122      getDataLayout().getTypeStoreSizeInBits(Ty));
4123}
4124
4125LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
4126  LangAS AddrSpace = LangAS::Default;
4127  if (LangOpts.OpenCL) {
4128    AddrSpace = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
4129    assert(AddrSpace == LangAS::opencl_global ||
4130           AddrSpace == LangAS::opencl_global_device ||
4131           AddrSpace == LangAS::opencl_global_host ||
4132           AddrSpace == LangAS::opencl_constant ||
4133           AddrSpace == LangAS::opencl_local ||
4134           AddrSpace >= LangAS::FirstTargetAddressSpace);
4135    return AddrSpace;
4136  }
4137
4138  if (LangOpts.SYCLIsDevice &&
4139      (!D || D->getType().getAddressSpace() == LangAS::Default))
4140    return LangAS::sycl_global;
4141
4142  if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
4143    if (D && D->hasAttr<CUDAConstantAttr>())
4144      return LangAS::cuda_constant;
4145    else if (D && D->hasAttr<CUDASharedAttr>())
4146      return LangAS::cuda_shared;
4147    else if (D && D->hasAttr<CUDADeviceAttr>())
4148      return LangAS::cuda_device;
4149    else if (D && D->getType().isConstQualified())
4150      return LangAS::cuda_constant;
4151    else
4152      return LangAS::cuda_device;
4153  }
4154
4155  if (LangOpts.OpenMP) {
4156    LangAS AS;
4157    if (OpenMPRuntime->hasAllocateAttributeForGlobalVar(D, AS))
4158      return AS;
4159  }
4160  return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
4161}
4162
4163LangAS CodeGenModule::GetGlobalConstantAddressSpace() const {
4164  // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
4165  if (LangOpts.OpenCL)
4166    return LangAS::opencl_constant;
4167  if (LangOpts.SYCLIsDevice)
4168    return LangAS::sycl_global;
4169  if (auto AS = getTarget().getConstantAddressSpace())
4170    return AS.getValue();
4171  return LangAS::Default;
4172}
4173
4174// In address space agnostic languages, string literals are in default address
4175// space in AST. However, certain targets (e.g. amdgcn) request them to be
4176// emitted in constant address space in LLVM IR. To be consistent with other
4177// parts of AST, string literal global variables in constant address space
4178// need to be casted to default address space before being put into address
4179// map and referenced by other part of CodeGen.
4180// In OpenCL, string literals are in constant address space in AST, therefore
4181// they should not be casted to default address space.
4182static llvm::Constant *
4183castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM,
4184                                       llvm::GlobalVariable *GV) {
4185  llvm::Constant *Cast = GV;
4186  if (!CGM.getLangOpts().OpenCL) {
4187    auto AS = CGM.GetGlobalConstantAddressSpace();
4188    if (AS != LangAS::Default)
4189      Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast(
4190          CGM, GV, AS, LangAS::Default,
4191          GV->getValueType()->getPointerTo(
4192              CGM.getContext().getTargetAddressSpace(LangAS::Default)));
4193  }
4194  return Cast;
4195}
4196
4197template<typename SomeDecl>
4198void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
4199                                               llvm::GlobalValue *GV) {
4200  if (!getLangOpts().CPlusPlus)
4201    return;
4202
4203  // Must have 'used' attribute, or else inline assembly can't rely on
4204  // the name existing.
4205  if (!D->template hasAttr<UsedAttr>())
4206    return;
4207
4208  // Must have internal linkage and an ordinary name.
4209  if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage)
4210    return;
4211
4212  // Must be in an extern "C" context. Entities declared directly within
4213  // a record are not extern "C" even if the record is in such a context.
4214  const SomeDecl *First = D->getFirstDecl();
4215  if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
4216    return;
4217
4218  // OK, this is an internal linkage entity inside an extern "C" linkage
4219  // specification. Make a note of that so we can give it the "expected"
4220  // mangled name if nothing else is using that name.
4221  std::pair<StaticExternCMap::iterator, bool> R =
4222      StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
4223
4224  // If we have multiple internal linkage entities with the same name
4225  // in extern "C" regions, none of them gets that name.
4226  if (!R.second)
4227    R.first->second = nullptr;
4228}
4229
4230static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
4231  if (!CGM.supportsCOMDAT())
4232    return false;
4233
4234  // Do not set COMDAT attribute for CUDA/HIP stub functions to prevent
4235  // them being "merged" by the COMDAT Folding linker optimization.
4236  if (D.hasAttr<CUDAGlobalAttr>())
4237    return false;
4238
4239  if (D.hasAttr<SelectAnyAttr>())
4240    return true;
4241
4242  GVALinkage Linkage;
4243  if (auto *VD = dyn_cast<VarDecl>(&D))
4244    Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
4245  else
4246    Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
4247
4248  switch (Linkage) {
4249  case GVA_Internal:
4250  case GVA_AvailableExternally:
4251  case GVA_StrongExternal:
4252    return false;
4253  case GVA_DiscardableODR:
4254  case GVA_StrongODR:
4255    return true;
4256  }
4257  llvm_unreachable("No such linkage");
4258}
4259
4260void CodeGenModule::maybeSetTrivialComdat(const Decl &D,
4261                                          llvm::GlobalObject &GO) {
4262  if (!shouldBeInCOMDAT(*this, D))
4263    return;
4264  GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
4265}
4266
4267/// Pass IsTentative as true if you want to create a tentative definition.
4268void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
4269                                            bool IsTentative) {
4270  // OpenCL global variables of sampler type are translated to function calls,
4271  // therefore no need to be translated.
4272  QualType ASTTy = D->getType();
4273  if (getLangOpts().OpenCL && ASTTy->isSamplerT())
4274    return;
4275
4276  // If this is OpenMP device, check if it is legal to emit this global
4277  // normally.
4278  if (LangOpts.OpenMPIsDevice && OpenMPRuntime &&
4279      OpenMPRuntime->emitTargetGlobalVariable(D))
4280    return;
4281
4282  llvm::Constant *Init = nullptr;
4283  bool NeedsGlobalCtor = false;
4284  bool NeedsGlobalDtor =
4285      D->needsDestruction(getContext()) == QualType::DK_cxx_destructor;
4286
4287  const VarDecl *InitDecl;
4288  const Expr *InitExpr = D->getAnyInitializer(InitDecl);
4289
4290  Optional<ConstantEmitter> emitter;
4291
4292  // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
4293  // as part of their declaration."  Sema has already checked for
4294  // error cases, so we just need to set Init to UndefValue.
4295  bool IsCUDASharedVar =
4296      getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
4297  // Shadows of initialized device-side global variables are also left
4298  // undefined.
4299  // Managed Variables should be initialized on both host side and device side.
4300  bool IsCUDAShadowVar =
4301      !getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
4302      (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
4303       D->hasAttr<CUDASharedAttr>());
4304  bool IsCUDADeviceShadowVar =
4305      getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
4306      (D->getType()->isCUDADeviceBuiltinSurfaceType() ||
4307       D->getType()->isCUDADeviceBuiltinTextureType());
4308  if (getLangOpts().CUDA &&
4309      (IsCUDASharedVar || IsCUDAShadowVar || IsCUDADeviceShadowVar))
4310    Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
4311  else if (D->hasAttr<LoaderUninitializedAttr>())
4312    Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
4313  else if (!InitExpr) {
4314    // This is a tentative definition; tentative definitions are
4315    // implicitly initialized with { 0 }.
4316    //
4317    // Note that tentative definitions are only emitted at the end of
4318    // a translation unit, so they should never have incomplete
4319    // type. In addition, EmitTentativeDefinition makes sure that we
4320    // never attempt to emit a tentative definition if a real one
4321    // exists. A use may still exists, however, so we still may need
4322    // to do a RAUW.
4323    assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
4324    Init = EmitNullConstant(D->getType());
4325  } else {
4326    initializedGlobalDecl = GlobalDecl(D);
4327    emitter.emplace(*this);
4328    Init = emitter->tryEmitForInitializer(*InitDecl);
4329
4330    if (!Init) {
4331      QualType T = InitExpr->getType();
4332      if (D->getType()->isReferenceType())
4333        T = D->getType();
4334
4335      if (getLangOpts().CPlusPlus) {
4336        Init = EmitNullConstant(T);
4337        NeedsGlobalCtor = true;
4338      } else {
4339        ErrorUnsupported(D, "static initializer");
4340        Init = llvm::UndefValue::get(getTypes().ConvertType(T));
4341      }
4342    } else {
4343      // We don't need an initializer, so remove the entry for the delayed
4344      // initializer position (just in case this entry was delayed) if we
4345      // also don't need to register a destructor.
4346      if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
4347        DelayedCXXInitPosition.erase(D);
4348    }
4349  }
4350
4351  llvm::Type* InitType = Init->getType();
4352  llvm::Constant *Entry =
4353      GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
4354
4355  // Strip off pointer casts if we got them.
4356  Entry = Entry->stripPointerCasts();
4357
4358  // Entry is now either a Function or GlobalVariable.
4359  auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
4360
4361  // We have a definition after a declaration with the wrong type.
4362  // We must make a new GlobalVariable* and update everything that used OldGV
4363  // (a declaration or tentative definition) with the new GlobalVariable*
4364  // (which will be a definition).
4365  //
4366  // This happens if there is a prototype for a global (e.g.
4367  // "extern int x[];") and then a definition of a different type (e.g.
4368  // "int x[10];"). This also happens when an initializer has a different type
4369  // from the type of the global (this happens with unions).
4370  if (!GV || GV->getValueType() != InitType ||
4371      GV->getType()->getAddressSpace() !=
4372          getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
4373
4374    // Move the old entry aside so that we'll create a new one.
4375    Entry->setName(StringRef());
4376
4377    // Make a new global with the correct type, this is now guaranteed to work.
4378    GV = cast<llvm::GlobalVariable>(
4379        GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative))
4380            ->stripPointerCasts());
4381
4382    // Replace all uses of the old global with the new global
4383    llvm::Constant *NewPtrForOldDecl =
4384        llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV,
4385                                                             Entry->getType());
4386    Entry->replaceAllUsesWith(NewPtrForOldDecl);
4387
4388    // Erase the old global, since it is no longer used.
4389    cast<llvm::GlobalValue>(Entry)->eraseFromParent();
4390  }
4391
4392  MaybeHandleStaticInExternC(D, GV);
4393
4394  if (D->hasAttr<AnnotateAttr>())
4395    AddGlobalAnnotations(D, GV);
4396
4397  // Set the llvm linkage type as appropriate.
4398  llvm::GlobalValue::LinkageTypes Linkage =
4399      getLLVMLinkageVarDefinition(D, GV->isConstant());
4400
4401  // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
4402  // the device. [...]"
4403  // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
4404  // __device__, declares a variable that: [...]
4405  // Is accessible from all the threads within the grid and from the host
4406  // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
4407  // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
4408  if (GV && LangOpts.CUDA) {
4409    if (LangOpts.CUDAIsDevice) {
4410      if (Linkage != llvm::GlobalValue::InternalLinkage &&
4411          (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()))
4412        GV->setExternallyInitialized(true);
4413    } else {
4414      getCUDARuntime().internalizeDeviceSideVar(D, Linkage);
4415    }
4416    getCUDARuntime().handleVarRegistration(D, *GV);
4417  }
4418
4419  GV->setInitializer(Init);
4420  if (emitter)
4421    emitter->finalize(GV);
4422
4423  // If it is safe to mark the global 'constant', do so now.
4424  GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
4425                  isTypeConstant(D->getType(), true));
4426
4427  // If it is in a read-only section, mark it 'constant'.
4428  if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
4429    const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
4430    if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
4431      GV->setConstant(true);
4432  }
4433
4434  GV->setAlignment(getContext().getDeclAlign(D).getAsAlign());
4435
4436  // On Darwin, unlike other Itanium C++ ABI platforms, the thread-wrapper
4437  // function is only defined alongside the variable, not also alongside
4438  // callers. Normally, all accesses to a thread_local go through the
4439  // thread-wrapper in order to ensure initialization has occurred, underlying
4440  // variable will never be used other than the thread-wrapper, so it can be
4441  // converted to internal linkage.
4442  //
4443  // However, if the variable has the 'constinit' attribute, it _can_ be
4444  // referenced directly, without calling the thread-wrapper, so the linkage
4445  // must not be changed.
4446  //
4447  // Additionally, if the variable isn't plain external linkage, e.g. if it's
4448  // weak or linkonce, the de-duplication semantics are important to preserve,
4449  // so we don't change the linkage.
4450  if (D->getTLSKind() == VarDecl::TLS_Dynamic &&
4451      Linkage == llvm::GlobalValue::ExternalLinkage &&
4452      Context.getTargetInfo().getTriple().isOSDarwin() &&
4453      !D->hasAttr<ConstInitAttr>())
4454    Linkage = llvm::GlobalValue::InternalLinkage;
4455
4456  GV->setLinkage(Linkage);
4457  if (D->hasAttr<DLLImportAttr>())
4458    GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
4459  else if (D->hasAttr<DLLExportAttr>())
4460    GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
4461  else
4462    GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
4463
4464  if (Linkage == llvm::GlobalVariable::CommonLinkage) {
4465    // common vars aren't constant even if declared const.
4466    GV->setConstant(false);
4467    // Tentative definition of global variables may be initialized with
4468    // non-zero null pointers. In this case they should have weak linkage
4469    // since common linkage must have zero initializer and must not have
4470    // explicit section therefore cannot have non-zero initial value.
4471    if (!GV->getInitializer()->isNullValue())
4472      GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
4473  }
4474
4475  setNonAliasAttributes(D, GV);
4476
4477  if (D->getTLSKind() && !GV->isThreadLocal()) {
4478    if (D->getTLSKind() == VarDecl::TLS_Dynamic)
4479      CXXThreadLocals.push_back(D);
4480    setTLSMode(GV, *D);
4481  }
4482
4483  maybeSetTrivialComdat(*D, *GV);
4484
4485  // Emit the initializer function if necessary.
4486  if (NeedsGlobalCtor || NeedsGlobalDtor)
4487    EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
4488
4489  SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor);
4490
4491  // Emit global variable debug information.
4492  if (CGDebugInfo *DI = getModuleDebugInfo())
4493    if (getCodeGenOpts().hasReducedDebugInfo())
4494      DI->EmitGlobalVariable(GV, D);
4495}
4496
4497void CodeGenModule::EmitExternalVarDeclaration(const VarDecl *D) {
4498  if (CGDebugInfo *DI = getModuleDebugInfo())
4499    if (getCodeGenOpts().hasReducedDebugInfo()) {
4500      QualType ASTTy = D->getType();
4501      llvm::Type *Ty = getTypes().ConvertTypeForMem(D->getType());
4502      llvm::Constant *GV = GetOrCreateLLVMGlobal(
4503          D->getName(), Ty, getContext().getTargetAddressSpace(ASTTy), D);
4504      DI->EmitExternalVariable(
4505          cast<llvm::GlobalVariable>(GV->stripPointerCasts()), D);
4506    }
4507}
4508
4509static bool isVarDeclStrongDefinition(const ASTContext &Context,
4510                                      CodeGenModule &CGM, const VarDecl *D,
4511                                      bool NoCommon) {
4512  // Don't give variables common linkage if -fno-common was specified unless it
4513  // was overridden by a NoCommon attribute.
4514  if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
4515    return true;
4516
4517  // C11 6.9.2/2:
4518  //   A declaration of an identifier for an object that has file scope without
4519  //   an initializer, and without a storage-class specifier or with the
4520  //   storage-class specifier static, constitutes a tentative definition.
4521  if (D->getInit() || D->hasExternalStorage())
4522    return true;
4523
4524  // A variable cannot be both common and exist in a section.
4525  if (D->hasAttr<SectionAttr>())
4526    return true;
4527
4528  // A variable cannot be both common and exist in a section.
4529  // We don't try to determine which is the right section in the front-end.
4530  // If no specialized section name is applicable, it will resort to default.
4531  if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
4532      D->hasAttr<PragmaClangDataSectionAttr>() ||
4533      D->hasAttr<PragmaClangRelroSectionAttr>() ||
4534      D->hasAttr<PragmaClangRodataSectionAttr>())
4535    return true;
4536
4537  // Thread local vars aren't considered common linkage.
4538  if (D->getTLSKind())
4539    return true;
4540
4541  // Tentative definitions marked with WeakImportAttr are true definitions.
4542  if (D->hasAttr<WeakImportAttr>())
4543    return true;
4544
4545  // A variable cannot be both common and exist in a comdat.
4546  if (shouldBeInCOMDAT(CGM, *D))
4547    return true;
4548
4549  // Declarations with a required alignment do not have common linkage in MSVC
4550  // mode.
4551  if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
4552    if (D->hasAttr<AlignedAttr>())
4553      return true;
4554    QualType VarType = D->getType();
4555    if (Context.isAlignmentRequired(VarType))
4556      return true;
4557
4558    if (const auto *RT = VarType->getAs<RecordType>()) {
4559      const RecordDecl *RD = RT->getDecl();
4560      for (const FieldDecl *FD : RD->fields()) {
4561        if (FD->isBitField())
4562          continue;
4563        if (FD->hasAttr<AlignedAttr>())
4564          return true;
4565        if (Context.isAlignmentRequired(FD->getType()))
4566          return true;
4567      }
4568    }
4569  }
4570
4571  // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
4572  // common symbols, so symbols with greater alignment requirements cannot be
4573  // common.
4574  // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
4575  // alignments for common symbols via the aligncomm directive, so this
4576  // restriction only applies to MSVC environments.
4577  if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
4578      Context.getTypeAlignIfKnown(D->getType()) >
4579          Context.toBits(CharUnits::fromQuantity(32)))
4580    return true;
4581
4582  return false;
4583}
4584
4585llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
4586    const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) {
4587  if (Linkage == GVA_Internal)
4588    return llvm::Function::InternalLinkage;
4589
4590  if (D->hasAttr<WeakAttr>()) {
4591    if (IsConstantVariable)
4592      return llvm::GlobalVariable::WeakODRLinkage;
4593    else
4594      return llvm::GlobalVariable::WeakAnyLinkage;
4595  }
4596
4597  if (const auto *FD = D->getAsFunction())
4598    if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
4599      return llvm::GlobalVariable::LinkOnceAnyLinkage;
4600
4601  // We are guaranteed to have a strong definition somewhere else,
4602  // so we can use available_externally linkage.
4603  if (Linkage == GVA_AvailableExternally)
4604    return llvm::GlobalValue::AvailableExternallyLinkage;
4605
4606  // Note that Apple's kernel linker doesn't support symbol
4607  // coalescing, so we need to avoid linkonce and weak linkages there.
4608  // Normally, this means we just map to internal, but for explicit
4609  // instantiations we'll map to external.
4610
4611  // In C++, the compiler has to emit a definition in every translation unit
4612  // that references the function.  We should use linkonce_odr because
4613  // a) if all references in this translation unit are optimized away, we
4614  // don't need to codegen it.  b) if the function persists, it needs to be
4615  // merged with other definitions. c) C++ has the ODR, so we know the
4616  // definition is dependable.
4617  if (Linkage == GVA_DiscardableODR)
4618    return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
4619                                            : llvm::Function::InternalLinkage;
4620
4621  // An explicit instantiation of a template has weak linkage, since
4622  // explicit instantiations can occur in multiple translation units
4623  // and must all be equivalent. However, we are not allowed to
4624  // throw away these explicit instantiations.
4625  //
4626  // CUDA/HIP: For -fno-gpu-rdc case, device code is limited to one TU,
4627  // so say that CUDA templates are either external (for kernels) or internal.
4628  // This lets llvm perform aggressive inter-procedural optimizations. For
4629  // -fgpu-rdc case, device function calls across multiple TU's are allowed,
4630  // therefore we need to follow the normal linkage paradigm.
4631  if (Linkage == GVA_StrongODR) {
4632    if (getLangOpts().AppleKext)
4633      return llvm::Function::ExternalLinkage;
4634    if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
4635        !getLangOpts().GPURelocatableDeviceCode)
4636      return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
4637                                          : llvm::Function::InternalLinkage;
4638    return llvm::Function::WeakODRLinkage;
4639  }
4640
4641  // C++ doesn't have tentative definitions and thus cannot have common
4642  // linkage.
4643  if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
4644      !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
4645                                 CodeGenOpts.NoCommon))
4646    return llvm::GlobalVariable::CommonLinkage;
4647
4648  // selectany symbols are externally visible, so use weak instead of
4649  // linkonce.  MSVC optimizes away references to const selectany globals, so
4650  // all definitions should be the same and ODR linkage should be used.
4651  // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
4652  if (D->hasAttr<SelectAnyAttr>())
4653    return llvm::GlobalVariable::WeakODRLinkage;
4654
4655  // Otherwise, we have strong external linkage.
4656  assert(Linkage == GVA_StrongExternal);
4657  return llvm::GlobalVariable::ExternalLinkage;
4658}
4659
4660llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition(
4661    const VarDecl *VD, bool IsConstant) {
4662  GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
4663  return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant);
4664}
4665
4666/// Replace the uses of a function that was declared with a non-proto type.
4667/// We want to silently drop extra arguments from call sites
4668static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
4669                                          llvm::Function *newFn) {
4670  // Fast path.
4671  if (old->use_empty()) return;
4672
4673  llvm::Type *newRetTy = newFn->getReturnType();
4674  SmallVector<llvm::Value*, 4> newArgs;
4675
4676  for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
4677         ui != ue; ) {
4678    llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
4679    llvm::User *user = use->getUser();
4680
4681    // Recognize and replace uses of bitcasts.  Most calls to
4682    // unprototyped functions will use bitcasts.
4683    if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
4684      if (bitcast->getOpcode() == llvm::Instruction::BitCast)
4685        replaceUsesOfNonProtoConstant(bitcast, newFn);
4686      continue;
4687    }
4688
4689    // Recognize calls to the function.
4690    llvm::CallBase *callSite = dyn_cast<llvm::CallBase>(user);
4691    if (!callSite) continue;
4692    if (!callSite->isCallee(&*use))
4693      continue;
4694
4695    // If the return types don't match exactly, then we can't
4696    // transform this call unless it's dead.
4697    if (callSite->getType() != newRetTy && !callSite->use_empty())
4698      continue;
4699
4700    // Get the call site's attribute list.
4701    SmallVector<llvm::AttributeSet, 8> newArgAttrs;
4702    llvm::AttributeList oldAttrs = callSite->getAttributes();
4703
4704    // If the function was passed too few arguments, don't transform.
4705    unsigned newNumArgs = newFn->arg_size();
4706    if (callSite->arg_size() < newNumArgs)
4707      continue;
4708
4709    // If extra arguments were passed, we silently drop them.
4710    // If any of the types mismatch, we don't transform.
4711    unsigned argNo = 0;
4712    bool dontTransform = false;
4713    for (llvm::Argument &A : newFn->args()) {
4714      if (callSite->getArgOperand(argNo)->getType() != A.getType()) {
4715        dontTransform = true;
4716        break;
4717      }
4718
4719      // Add any parameter attributes.
4720      newArgAttrs.push_back(oldAttrs.getParamAttributes(argNo));
4721      argNo++;
4722    }
4723    if (dontTransform)
4724      continue;
4725
4726    // Okay, we can transform this.  Create the new call instruction and copy
4727    // over the required information.
4728    newArgs.append(callSite->arg_begin(), callSite->arg_begin() + argNo);
4729
4730    // Copy over any operand bundles.
4731    SmallVector<llvm::OperandBundleDef, 1> newBundles;
4732    callSite->getOperandBundlesAsDefs(newBundles);
4733
4734    llvm::CallBase *newCall;
4735    if (dyn_cast<llvm::CallInst>(callSite)) {
4736      newCall =
4737          llvm::CallInst::Create(newFn, newArgs, newBundles, "", callSite);
4738    } else {
4739      auto *oldInvoke = cast<llvm::InvokeInst>(callSite);
4740      newCall = llvm::InvokeInst::Create(newFn, oldInvoke->getNormalDest(),
4741                                         oldInvoke->getUnwindDest(), newArgs,
4742                                         newBundles, "", callSite);
4743    }
4744    newArgs.clear(); // for the next iteration
4745
4746    if (!newCall->getType()->isVoidTy())
4747      newCall->takeName(callSite);
4748    newCall->setAttributes(llvm::AttributeList::get(
4749        newFn->getContext(), oldAttrs.getFnAttributes(),
4750        oldAttrs.getRetAttributes(), newArgAttrs));
4751    newCall->setCallingConv(callSite->getCallingConv());
4752
4753    // Finally, remove the old call, replacing any uses with the new one.
4754    if (!callSite->use_empty())
4755      callSite->replaceAllUsesWith(newCall);
4756
4757    // Copy debug location attached to CI.
4758    if (callSite->getDebugLoc())
4759      newCall->setDebugLoc(callSite->getDebugLoc());
4760
4761    callSite->eraseFromParent();
4762  }
4763}
4764
4765/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
4766/// implement a function with no prototype, e.g. "int foo() {}".  If there are
4767/// existing call uses of the old function in the module, this adjusts them to
4768/// call the new function directly.
4769///
4770/// This is not just a cleanup: the always_inline pass requires direct calls to
4771/// functions to be able to inline them.  If there is a bitcast in the way, it
4772/// won't inline them.  Instcombine normally deletes these calls, but it isn't
4773/// run at -O0.
4774static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
4775                                                      llvm::Function *NewFn) {
4776  // If we're redefining a global as a function, don't transform it.
4777  if (!isa<llvm::Function>(Old)) return;
4778
4779  replaceUsesOfNonProtoConstant(Old, NewFn);
4780}
4781
4782void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
4783  auto DK = VD->isThisDeclarationADefinition();
4784  if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
4785    return;
4786
4787  TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
4788  // If we have a definition, this might be a deferred decl. If the
4789  // instantiation is explicit, make sure we emit it at the end.
4790  if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
4791    GetAddrOfGlobalVar(VD);
4792
4793  EmitTopLevelDecl(VD);
4794}
4795
4796void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
4797                                                 llvm::GlobalValue *GV) {
4798  const auto *D = cast<FunctionDecl>(GD.getDecl());
4799
4800  // Compute the function info and LLVM type.
4801  const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4802  llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4803
4804  // Get or create the prototype for the function.
4805  if (!GV || (GV->getValueType() != Ty))
4806    GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
4807                                                   /*DontDefer=*/true,
4808                                                   ForDefinition));
4809
4810  // Already emitted.
4811  if (!GV->isDeclaration())
4812    return;
4813
4814  // We need to set linkage and visibility on the function before
4815  // generating code for it because various parts of IR generation
4816  // want to propagate this information down (e.g. to local static
4817  // declarations).
4818  auto *Fn = cast<llvm::Function>(GV);
4819  setFunctionLinkage(GD, Fn);
4820
4821  // FIXME: this is redundant with part of setFunctionDefinitionAttributes
4822  setGVProperties(Fn, GD);
4823
4824  MaybeHandleStaticInExternC(D, Fn);
4825
4826  maybeSetTrivialComdat(*D, *Fn);
4827
4828  // Set CodeGen attributes that represent floating point environment.
4829  setLLVMFunctionFEnvAttributes(D, Fn);
4830
4831  CodeGenFunction(*this).GenerateCode(GD, Fn, FI);
4832
4833  setNonAliasAttributes(GD, Fn);
4834  SetLLVMFunctionAttributesForDefinition(D, Fn);
4835
4836  if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
4837    AddGlobalCtor(Fn, CA->getPriority());
4838  if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
4839    AddGlobalDtor(Fn, DA->getPriority(), true);
4840  if (D->hasAttr<AnnotateAttr>())
4841    AddGlobalAnnotations(D, Fn);
4842}
4843
4844void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
4845  const auto *D = cast<ValueDecl>(GD.getDecl());
4846  const AliasAttr *AA = D->getAttr<AliasAttr>();
4847  assert(AA && "Not an alias?");
4848
4849  StringRef MangledName = getMangledName(GD);
4850
4851  if (AA->getAliasee() == MangledName) {
4852    Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4853    return;
4854  }
4855
4856  // If there is a definition in the module, then it wins over the alias.
4857  // This is dubious, but allow it to be safe.  Just ignore the alias.
4858  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4859  if (Entry && !Entry->isDeclaration())
4860    return;
4861
4862  Aliases.push_back(GD);
4863
4864  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4865
4866  // Create a reference to the named value.  This ensures that it is emitted
4867  // if a deferred decl.
4868  llvm::Constant *Aliasee;
4869  llvm::GlobalValue::LinkageTypes LT;
4870  if (isa<llvm::FunctionType>(DeclTy)) {
4871    Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
4872                                      /*ForVTable=*/false);
4873    LT = getFunctionLinkage(GD);
4874  } else {
4875    Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, 0,
4876                                    /*D=*/nullptr);
4877    if (const auto *VD = dyn_cast<VarDecl>(GD.getDecl()))
4878      LT = getLLVMLinkageVarDefinition(VD, D->getType().isConstQualified());
4879    else
4880      LT = getFunctionLinkage(GD);
4881  }
4882
4883  // Create the new alias itself, but don't set a name yet.
4884  unsigned AS = Aliasee->getType()->getPointerAddressSpace();
4885  auto *GA =
4886      llvm::GlobalAlias::create(DeclTy, AS, LT, "", Aliasee, &getModule());
4887
4888  if (Entry) {
4889    if (GA->getAliasee() == Entry) {
4890      Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4891      return;
4892    }
4893
4894    assert(Entry->isDeclaration());
4895
4896    // If there is a declaration in the module, then we had an extern followed
4897    // by the alias, as in:
4898    //   extern int test6();
4899    //   ...
4900    //   int test6() __attribute__((alias("test7")));
4901    //
4902    // Remove it and replace uses of it with the alias.
4903    GA->takeName(Entry);
4904
4905    Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
4906                                                          Entry->getType()));
4907    Entry->eraseFromParent();
4908  } else {
4909    GA->setName(MangledName);
4910  }
4911
4912  // Set attributes which are particular to an alias; this is a
4913  // specialization of the attributes which may be set on a global
4914  // variable/function.
4915  if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
4916      D->isWeakImported()) {
4917    GA->setLinkage(llvm::Function::WeakAnyLinkage);
4918  }
4919
4920  if (const auto *VD = dyn_cast<VarDecl>(D))
4921    if (VD->getTLSKind())
4922      setTLSMode(GA, *VD);
4923
4924  SetCommonAttributes(GD, GA);
4925}
4926
4927void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
4928  const auto *D = cast<ValueDecl>(GD.getDecl());
4929  const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
4930  assert(IFA && "Not an ifunc?");
4931
4932  StringRef MangledName = getMangledName(GD);
4933
4934  if (IFA->getResolver() == MangledName) {
4935    Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4936    return;
4937  }
4938
4939  // Report an error if some definition overrides ifunc.
4940  llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4941  if (Entry && !Entry->isDeclaration()) {
4942    GlobalDecl OtherGD;
4943    if (lookupRepresentativeDecl(MangledName, OtherGD) &&
4944        DiagnosedConflictingDefinitions.insert(GD).second) {
4945      Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
4946          << MangledName;
4947      Diags.Report(OtherGD.getDecl()->getLocation(),
4948                   diag::note_previous_definition);
4949    }
4950    return;
4951  }
4952
4953  Aliases.push_back(GD);
4954
4955  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4956  llvm::Constant *Resolver =
4957      GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD,
4958                              /*ForVTable=*/false);
4959  llvm::GlobalIFunc *GIF =
4960      llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage,
4961                                "", Resolver, &getModule());
4962  if (Entry) {
4963    if (GIF->getResolver() == Entry) {
4964      Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4965      return;
4966    }
4967    assert(Entry->isDeclaration());
4968
4969    // If there is a declaration in the module, then we had an extern followed
4970    // by the ifunc, as in:
4971    //   extern int test();
4972    //   ...
4973    //   int test() __attribute__((ifunc("resolver")));
4974    //
4975    // Remove it and replace uses of it with the ifunc.
4976    GIF->takeName(Entry);
4977
4978    Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
4979                                                          Entry->getType()));
4980    Entry->eraseFromParent();
4981  } else
4982    GIF->setName(MangledName);
4983
4984  SetCommonAttributes(GD, GIF);
4985}
4986
4987llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
4988                                            ArrayRef<llvm::Type*> Tys) {
4989  return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
4990                                         Tys);
4991}
4992
4993static llvm::StringMapEntry<llvm::GlobalVariable *> &
4994GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
4995                         const StringLiteral *Literal, bool TargetIsLSB,
4996                         bool &IsUTF16, unsigned &StringLength) {
4997  StringRef String = Literal->getString();
4998  unsigned NumBytes = String.size();
4999
5000  // Check for simple case.
5001  if (!Literal->containsNonAsciiOrNull()) {
5002    StringLength = NumBytes;
5003    return *Map.insert(std::make_pair(String, nullptr)).first;
5004  }
5005
5006  // Otherwise, convert the UTF8 literals into a string of shorts.
5007  IsUTF16 = true;
5008
5009  SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
5010  const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
5011  llvm::UTF16 *ToPtr = &ToBuf[0];
5012
5013  (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
5014                                 ToPtr + NumBytes, llvm::strictConversion);
5015
5016  // ConvertUTF8toUTF16 returns the length in ToPtr.
5017  StringLength = ToPtr - &ToBuf[0];
5018
5019  // Add an explicit null.
5020  *ToPtr = 0;
5021  return *Map.insert(std::make_pair(
5022                         StringRef(reinterpret_cast<const char *>(ToBuf.data()),
5023                                   (StringLength + 1) * 2),
5024                         nullptr)).first;
5025}
5026
5027ConstantAddress
5028CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
5029  unsigned StringLength = 0;
5030  bool isUTF16 = false;
5031  llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
5032      GetConstantCFStringEntry(CFConstantStringMap, Literal,
5033                               getDataLayout().isLittleEndian(), isUTF16,
5034                               StringLength);
5035
5036  if (auto *C = Entry.second)
5037    return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment()));
5038
5039  llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
5040  llvm::Constant *Zeros[] = { Zero, Zero };
5041
5042  const ASTContext &Context = getContext();
5043  const llvm::Triple &Triple = getTriple();
5044
5045  const auto CFRuntime = getLangOpts().CFRuntime;
5046  const bool IsSwiftABI =
5047      static_cast<unsigned>(CFRuntime) >=
5048      static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
5049  const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
5050
5051  // If we don't already have it, get __CFConstantStringClassReference.
5052  if (!CFConstantStringClassRef) {
5053    const char *CFConstantStringClassName = "__CFConstantStringClassReference";
5054    llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
5055    Ty = llvm::ArrayType::get(Ty, 0);
5056
5057    switch (CFRuntime) {
5058    default: break;
5059    case LangOptions::CoreFoundationABI::Swift: LLVM_FALLTHROUGH;
5060    case LangOptions::CoreFoundationABI::Swift5_0:
5061      CFConstantStringClassName =
5062          Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
5063                              : "$s10Foundation19_NSCFConstantStringCN";
5064      Ty = IntPtrTy;
5065      break;
5066    case LangOptions::CoreFoundationABI::Swift4_2:
5067      CFConstantStringClassName =
5068          Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
5069                              : "$S10Foundation19_NSCFConstantStringCN";
5070      Ty = IntPtrTy;
5071      break;
5072    case LangOptions::CoreFoundationABI::Swift4_1:
5073      CFConstantStringClassName =
5074          Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
5075                              : "__T010Foundation19_NSCFConstantStringCN";
5076      Ty = IntPtrTy;
5077      break;
5078    }
5079
5080    llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
5081
5082    if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
5083      llvm::GlobalValue *GV = nullptr;
5084
5085      if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
5086        IdentifierInfo &II = Context.Idents.get(GV->getName());
5087        TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
5088        DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
5089
5090        const VarDecl *VD = nullptr;
5091        for (const auto *Result : DC->lookup(&II))
5092          if ((VD = dyn_cast<VarDecl>(Result)))
5093            break;
5094
5095        if (Triple.isOSBinFormatELF()) {
5096          if (!VD)
5097            GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
5098        } else {
5099          GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
5100          if (!VD || !VD->hasAttr<DLLExportAttr>())
5101            GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
5102          else
5103            GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
5104        }
5105
5106        setDSOLocal(GV);
5107      }
5108    }
5109
5110    // Decay array -> ptr
5111    CFConstantStringClassRef =
5112        IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty)
5113                   : llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros);
5114  }
5115
5116  QualType CFTy = Context.getCFConstantStringType();
5117
5118  auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
5119
5120  ConstantInitBuilder Builder(*this);
5121  auto Fields = Builder.beginStruct(STy);
5122
5123  // Class pointer.
5124  Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
5125
5126  // Flags.
5127  if (IsSwiftABI) {
5128    Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
5129    Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
5130  } else {
5131    Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
5132  }
5133
5134  // String pointer.
5135  llvm::Constant *C = nullptr;
5136  if (isUTF16) {
5137    auto Arr = llvm::makeArrayRef(
5138        reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
5139        Entry.first().size() / 2);
5140    C = llvm::ConstantDataArray::get(VMContext, Arr);
5141  } else {
5142    C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
5143  }
5144
5145  // Note: -fwritable-strings doesn't make the backing store strings of
5146  // CFStrings writable. (See <rdar://problem/10657500>)
5147  auto *GV =
5148      new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
5149                               llvm::GlobalValue::PrivateLinkage, C, ".str");
5150  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
5151  // Don't enforce the target's minimum global alignment, since the only use
5152  // of the string is via this class initializer.
5153  CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
5154                            : Context.getTypeAlignInChars(Context.CharTy);
5155  GV->setAlignment(Align.getAsAlign());
5156
5157  // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
5158  // Without it LLVM can merge the string with a non unnamed_addr one during
5159  // LTO.  Doing that changes the section it ends in, which surprises ld64.
5160  if (Triple.isOSBinFormatMachO())
5161    GV->setSection(isUTF16 ? "__TEXT,__ustring"
5162                           : "__TEXT,__cstring,cstring_literals");
5163  // Make sure the literal ends up in .rodata to allow for safe ICF and for
5164  // the static linker to adjust permissions to read-only later on.
5165  else if (Triple.isOSBinFormatELF())
5166    GV->setSection(".rodata");
5167
5168  // String.
5169  llvm::Constant *Str =
5170      llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
5171
5172  if (isUTF16)
5173    // Cast the UTF16 string to the correct type.
5174    Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
5175  Fields.add(Str);
5176
5177  // String length.
5178  llvm::IntegerType *LengthTy =
5179      llvm::IntegerType::get(getModule().getContext(),
5180                             Context.getTargetInfo().getLongWidth());
5181  if (IsSwiftABI) {
5182    if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
5183        CFRuntime == LangOptions::CoreFoundationABI::Swift4_2)
5184      LengthTy = Int32Ty;
5185    else
5186      LengthTy = IntPtrTy;
5187  }
5188  Fields.addInt(LengthTy, StringLength);
5189
5190  // Swift ABI requires 8-byte alignment to ensure that the _Atomic(uint64_t) is
5191  // properly aligned on 32-bit platforms.
5192  CharUnits Alignment =
5193      IsSwiftABI ? Context.toCharUnitsFromBits(64) : getPointerAlign();
5194
5195  // The struct.
5196  GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
5197                                    /*isConstant=*/false,
5198                                    llvm::GlobalVariable::PrivateLinkage);
5199  GV->addAttribute("objc_arc_inert");
5200  switch (Triple.getObjectFormat()) {
5201  case llvm::Triple::UnknownObjectFormat:
5202    llvm_unreachable("unknown file format");
5203  case llvm::Triple::GOFF:
5204    llvm_unreachable("GOFF is not yet implemented");
5205  case llvm::Triple::XCOFF:
5206    llvm_unreachable("XCOFF is not yet implemented");
5207  case llvm::Triple::COFF:
5208  case llvm::Triple::ELF:
5209  case llvm::Triple::Wasm:
5210    GV->setSection("cfstring");
5211    break;
5212  case llvm::Triple::MachO:
5213    GV->setSection("__DATA,__cfstring");
5214    break;
5215  }
5216  Entry.second = GV;
5217
5218  return ConstantAddress(GV, Alignment);
5219}
5220
5221bool CodeGenModule::getExpressionLocationsEnabled() const {
5222  return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
5223}
5224
5225QualType CodeGenModule::getObjCFastEnumerationStateType() {
5226  if (ObjCFastEnumerationStateType.isNull()) {
5227    RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
5228    D->startDefinition();
5229
5230    QualType FieldTypes[] = {
5231      Context.UnsignedLongTy,
5232      Context.getPointerType(Context.getObjCIdType()),
5233      Context.getPointerType(Context.UnsignedLongTy),
5234      Context.getConstantArrayType(Context.UnsignedLongTy,
5235                           llvm::APInt(32, 5), nullptr, ArrayType::Normal, 0)
5236    };
5237
5238    for (size_t i = 0; i < 4; ++i) {
5239      FieldDecl *Field = FieldDecl::Create(Context,
5240                                           D,
5241                                           SourceLocation(),
5242                                           SourceLocation(), nullptr,
5243                                           FieldTypes[i], /*TInfo=*/nullptr,
5244                                           /*BitWidth=*/nullptr,
5245                                           /*Mutable=*/false,
5246                                           ICIS_NoInit);
5247      Field->setAccess(AS_public);
5248      D->addDecl(Field);
5249    }
5250
5251    D->completeDefinition();
5252    ObjCFastEnumerationStateType = Context.getTagDeclType(D);
5253  }
5254
5255  return ObjCFastEnumerationStateType;
5256}
5257
5258llvm::Constant *
5259CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
5260  assert(!E->getType()->isPointerType() && "Strings are always arrays");
5261
5262  // Don't emit it as the address of the string, emit the string data itself
5263  // as an inline array.
5264  if (E->getCharByteWidth() == 1) {
5265    SmallString<64> Str(E->getString());
5266
5267    // Resize the string to the right size, which is indicated by its type.
5268    const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
5269    Str.resize(CAT->getSize().getZExtValue());
5270    return llvm::ConstantDataArray::getString(VMContext, Str, false);
5271  }
5272
5273  auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
5274  llvm::Type *ElemTy = AType->getElementType();
5275  unsigned NumElements = AType->getNumElements();
5276
5277  // Wide strings have either 2-byte or 4-byte elements.
5278  if (ElemTy->getPrimitiveSizeInBits() == 16) {
5279    SmallVector<uint16_t, 32> Elements;
5280    Elements.reserve(NumElements);
5281
5282    for(unsigned i = 0, e = E->getLength(); i != e; ++i)
5283      Elements.push_back(E->getCodeUnit(i));
5284    Elements.resize(NumElements);
5285    return llvm::ConstantDataArray::get(VMContext, Elements);
5286  }
5287
5288  assert(ElemTy->getPrimitiveSizeInBits() == 32);
5289  SmallVector<uint32_t, 32> Elements;
5290  Elements.reserve(NumElements);
5291
5292  for(unsigned i = 0, e = E->getLength(); i != e; ++i)
5293    Elements.push_back(E->getCodeUnit(i));
5294  Elements.resize(NumElements);
5295  return llvm::ConstantDataArray::get(VMContext, Elements);
5296}
5297
5298static llvm::GlobalVariable *
5299GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
5300                      CodeGenModule &CGM, StringRef GlobalName,
5301                      CharUnits Alignment) {
5302  unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
5303      CGM.GetGlobalConstantAddressSpace());
5304
5305  llvm::Module &M = CGM.getModule();
5306  // Create a global variable for this string
5307  auto *GV = new llvm::GlobalVariable(
5308      M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
5309      nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
5310  GV->setAlignment(Alignment.getAsAlign());
5311  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
5312  if (GV->isWeakForLinker()) {
5313    assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
5314    GV->setComdat(M.getOrInsertComdat(GV->getName()));
5315  }
5316  CGM.setDSOLocal(GV);
5317
5318  return GV;
5319}
5320
5321/// GetAddrOfConstantStringFromLiteral - Return a pointer to a
5322/// constant array for the given string literal.
5323ConstantAddress
5324CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
5325                                                  StringRef Name) {
5326  CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType());
5327
5328  llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
5329  llvm::GlobalVariable **Entry = nullptr;
5330  if (!LangOpts.WritableStrings) {
5331    Entry = &ConstantStringMap[C];
5332    if (auto GV = *Entry) {
5333      if (Alignment.getQuantity() > GV->getAlignment())
5334        GV->setAlignment(Alignment.getAsAlign());
5335      return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5336                             Alignment);
5337    }
5338  }
5339
5340  SmallString<256> MangledNameBuffer;
5341  StringRef GlobalVariableName;
5342  llvm::GlobalValue::LinkageTypes LT;
5343
5344  // Mangle the string literal if that's how the ABI merges duplicate strings.
5345  // Don't do it if they are writable, since we don't want writes in one TU to
5346  // affect strings in another.
5347  if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
5348      !LangOpts.WritableStrings) {
5349    llvm::raw_svector_ostream Out(MangledNameBuffer);
5350    getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
5351    LT = llvm::GlobalValue::LinkOnceODRLinkage;
5352    GlobalVariableName = MangledNameBuffer;
5353  } else {
5354    LT = llvm::GlobalValue::PrivateLinkage;
5355    GlobalVariableName = Name;
5356  }
5357
5358  auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
5359  if (Entry)
5360    *Entry = GV;
5361
5362  SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>",
5363                                  QualType());
5364
5365  return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5366                         Alignment);
5367}
5368
5369/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
5370/// array for the given ObjCEncodeExpr node.
5371ConstantAddress
5372CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
5373  std::string Str;
5374  getContext().getObjCEncodingForType(E->getEncodedType(), Str);
5375
5376  return GetAddrOfConstantCString(Str);
5377}
5378
5379/// GetAddrOfConstantCString - Returns a pointer to a character array containing
5380/// the literal and a terminating '\0' character.
5381/// The result has pointer to array type.
5382ConstantAddress CodeGenModule::GetAddrOfConstantCString(
5383    const std::string &Str, const char *GlobalName) {
5384  StringRef StrWithNull(Str.c_str(), Str.size() + 1);
5385  CharUnits Alignment =
5386    getContext().getAlignOfGlobalVarInChars(getContext().CharTy);
5387
5388  llvm::Constant *C =
5389      llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
5390
5391  // Don't share any string literals if strings aren't constant.
5392  llvm::GlobalVariable **Entry = nullptr;
5393  if (!LangOpts.WritableStrings) {
5394    Entry = &ConstantStringMap[C];
5395    if (auto GV = *Entry) {
5396      if (Alignment.getQuantity() > GV->getAlignment())
5397        GV->setAlignment(Alignment.getAsAlign());
5398      return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5399                             Alignment);
5400    }
5401  }
5402
5403  // Get the default prefix if a name wasn't specified.
5404  if (!GlobalName)
5405    GlobalName = ".str";
5406  // Create a global variable for this.
5407  auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
5408                                  GlobalName, Alignment);
5409  if (Entry)
5410    *Entry = GV;
5411
5412  return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5413                         Alignment);
5414}
5415
5416ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
5417    const MaterializeTemporaryExpr *E, const Expr *Init) {
5418  assert((E->getStorageDuration() == SD_Static ||
5419          E->getStorageDuration() == SD_Thread) && "not a global temporary");
5420  const auto *VD = cast<VarDecl>(E->getExtendingDecl());
5421
5422  // If we're not materializing a subobject of the temporary, keep the
5423  // cv-qualifiers from the type of the MaterializeTemporaryExpr.
5424  QualType MaterializedType = Init->getType();
5425  if (Init == E->getSubExpr())
5426    MaterializedType = E->getType();
5427
5428  CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
5429
5430  auto InsertResult = MaterializedGlobalTemporaryMap.insert({E, nullptr});
5431  if (!InsertResult.second) {
5432    // We've seen this before: either we already created it or we're in the
5433    // process of doing so.
5434    if (!InsertResult.first->second) {
5435      // We recursively re-entered this function, probably during emission of
5436      // the initializer. Create a placeholder. We'll clean this up in the
5437      // outer call, at the end of this function.
5438      llvm::Type *Type = getTypes().ConvertTypeForMem(MaterializedType);
5439      InsertResult.first->second = new llvm::GlobalVariable(
5440          getModule(), Type, false, llvm::GlobalVariable::InternalLinkage,
5441          nullptr);
5442    }
5443    return ConstantAddress(InsertResult.first->second, Align);
5444  }
5445
5446  // FIXME: If an externally-visible declaration extends multiple temporaries,
5447  // we need to give each temporary the same name in every translation unit (and
5448  // we also need to make the temporaries externally-visible).
5449  SmallString<256> Name;
5450  llvm::raw_svector_ostream Out(Name);
5451  getCXXABI().getMangleContext().mangleReferenceTemporary(
5452      VD, E->getManglingNumber(), Out);
5453
5454  APValue *Value = nullptr;
5455  if (E->getStorageDuration() == SD_Static && VD && VD->evaluateValue()) {
5456    // If the initializer of the extending declaration is a constant
5457    // initializer, we should have a cached constant initializer for this
5458    // temporary. Note that this might have a different value from the value
5459    // computed by evaluating the initializer if the surrounding constant
5460    // expression modifies the temporary.
5461    Value = E->getOrCreateValue(false);
5462  }
5463
5464  // Try evaluating it now, it might have a constant initializer.
5465  Expr::EvalResult EvalResult;
5466  if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
5467      !EvalResult.hasSideEffects())
5468    Value = &EvalResult.Val;
5469
5470  LangAS AddrSpace =
5471      VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace();
5472
5473  Optional<ConstantEmitter> emitter;
5474  llvm::Constant *InitialValue = nullptr;
5475  bool Constant = false;
5476  llvm::Type *Type;
5477  if (Value) {
5478    // The temporary has a constant initializer, use it.
5479    emitter.emplace(*this);
5480    InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
5481                                               MaterializedType);
5482    Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value);
5483    Type = InitialValue->getType();
5484  } else {
5485    // No initializer, the initialization will be provided when we
5486    // initialize the declaration which performed lifetime extension.
5487    Type = getTypes().ConvertTypeForMem(MaterializedType);
5488  }
5489
5490  // Create a global variable for this lifetime-extended temporary.
5491  llvm::GlobalValue::LinkageTypes Linkage =
5492      getLLVMLinkageVarDefinition(VD, Constant);
5493  if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
5494    const VarDecl *InitVD;
5495    if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
5496        isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
5497      // Temporaries defined inside a class get linkonce_odr linkage because the
5498      // class can be defined in multiple translation units.
5499      Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
5500    } else {
5501      // There is no need for this temporary to have external linkage if the
5502      // VarDecl has external linkage.
5503      Linkage = llvm::GlobalVariable::InternalLinkage;
5504    }
5505  }
5506  auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
5507  auto *GV = new llvm::GlobalVariable(
5508      getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
5509      /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
5510  if (emitter) emitter->finalize(GV);
5511  setGVProperties(GV, VD);
5512  GV->setAlignment(Align.getAsAlign());
5513  if (supportsCOMDAT() && GV->isWeakForLinker())
5514    GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
5515  if (VD->getTLSKind())
5516    setTLSMode(GV, *VD);
5517  llvm::Constant *CV = GV;
5518  if (AddrSpace != LangAS::Default)
5519    CV = getTargetCodeGenInfo().performAddrSpaceCast(
5520        *this, GV, AddrSpace, LangAS::Default,
5521        Type->getPointerTo(
5522            getContext().getTargetAddressSpace(LangAS::Default)));
5523
5524  // Update the map with the new temporary. If we created a placeholder above,
5525  // replace it with the new global now.
5526  llvm::Constant *&Entry = MaterializedGlobalTemporaryMap[E];
5527  if (Entry) {
5528    Entry->replaceAllUsesWith(
5529        llvm::ConstantExpr::getBitCast(CV, Entry->getType()));
5530    llvm::cast<llvm::GlobalVariable>(Entry)->eraseFromParent();
5531  }
5532  Entry = CV;
5533
5534  return ConstantAddress(CV, Align);
5535}
5536
5537/// EmitObjCPropertyImplementations - Emit information for synthesized
5538/// properties for an implementation.
5539void CodeGenModule::EmitObjCPropertyImplementations(const
5540                                                    ObjCImplementationDecl *D) {
5541  for (const auto *PID : D->property_impls()) {
5542    // Dynamic is just for type-checking.
5543    if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
5544      ObjCPropertyDecl *PD = PID->getPropertyDecl();
5545
5546      // Determine which methods need to be implemented, some may have
5547      // been overridden. Note that ::isPropertyAccessor is not the method
5548      // we want, that just indicates if the decl came from a
5549      // property. What we want to know is if the method is defined in
5550      // this implementation.
5551      auto *Getter = PID->getGetterMethodDecl();
5552      if (!Getter || Getter->isSynthesizedAccessorStub())
5553        CodeGenFunction(*this).GenerateObjCGetter(
5554            const_cast<ObjCImplementationDecl *>(D), PID);
5555      auto *Setter = PID->getSetterMethodDecl();
5556      if (!PD->isReadOnly() && (!Setter || Setter->isSynthesizedAccessorStub()))
5557        CodeGenFunction(*this).GenerateObjCSetter(
5558                                 const_cast<ObjCImplementationDecl *>(D), PID);
5559    }
5560  }
5561}
5562
5563static bool needsDestructMethod(ObjCImplementationDecl *impl) {
5564  const ObjCInterfaceDecl *iface = impl->getClassInterface();
5565  for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
5566       ivar; ivar = ivar->getNextIvar())
5567    if (ivar->getType().isDestructedType())
5568      return true;
5569
5570  return false;
5571}
5572
5573static bool AllTrivialInitializers(CodeGenModule &CGM,
5574                                   ObjCImplementationDecl *D) {
5575  CodeGenFunction CGF(CGM);
5576  for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
5577       E = D->init_end(); B != E; ++B) {
5578    CXXCtorInitializer *CtorInitExp = *B;
5579    Expr *Init = CtorInitExp->getInit();
5580    if (!CGF.isTrivialInitializer(Init))
5581      return false;
5582  }
5583  return true;
5584}
5585
5586/// EmitObjCIvarInitializations - Emit information for ivar initialization
5587/// for an implementation.
5588void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
5589  // We might need a .cxx_destruct even if we don't have any ivar initializers.
5590  if (needsDestructMethod(D)) {
5591    IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
5592    Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
5593    ObjCMethodDecl *DTORMethod = ObjCMethodDecl::Create(
5594        getContext(), D->getLocation(), D->getLocation(), cxxSelector,
5595        getContext().VoidTy, nullptr, D,
5596        /*isInstance=*/true, /*isVariadic=*/false,
5597        /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
5598        /*isImplicitlyDeclared=*/true,
5599        /*isDefined=*/false, ObjCMethodDecl::Required);
5600    D->addInstanceMethod(DTORMethod);
5601    CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
5602    D->setHasDestructors(true);
5603  }
5604
5605  // If the implementation doesn't have any ivar initializers, we don't need
5606  // a .cxx_construct.
5607  if (D->getNumIvarInitializers() == 0 ||
5608      AllTrivialInitializers(*this, D))
5609    return;
5610
5611  IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
5612  Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
5613  // The constructor returns 'self'.
5614  ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(
5615      getContext(), D->getLocation(), D->getLocation(), cxxSelector,
5616      getContext().getObjCIdType(), nullptr, D, /*isInstance=*/true,
5617      /*isVariadic=*/false,
5618      /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
5619      /*isImplicitlyDeclared=*/true,
5620      /*isDefined=*/false, ObjCMethodDecl::Required);
5621  D->addInstanceMethod(CTORMethod);
5622  CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
5623  D->setHasNonZeroConstructors(true);
5624}
5625
5626// EmitLinkageSpec - Emit all declarations in a linkage spec.
5627void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
5628  if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
5629      LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
5630    ErrorUnsupported(LSD, "linkage spec");
5631    return;
5632  }
5633
5634  EmitDeclContext(LSD);
5635}
5636
5637void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
5638  for (auto *I : DC->decls()) {
5639    // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
5640    // are themselves considered "top-level", so EmitTopLevelDecl on an
5641    // ObjCImplDecl does not recursively visit them. We need to do that in
5642    // case they're nested inside another construct (LinkageSpecDecl /
5643    // ExportDecl) that does stop them from being considered "top-level".
5644    if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
5645      for (auto *M : OID->methods())
5646        EmitTopLevelDecl(M);
5647    }
5648
5649    EmitTopLevelDecl(I);
5650  }
5651}
5652
5653/// EmitTopLevelDecl - Emit code for a single top level declaration.
5654void CodeGenModule::EmitTopLevelDecl(Decl *D) {
5655  // Ignore dependent declarations.
5656  if (D->isTemplated())
5657    return;
5658
5659  // Consteval function shouldn't be emitted.
5660  if (auto *FD = dyn_cast<FunctionDecl>(D))
5661    if (FD->isConsteval())
5662      return;
5663
5664  switch (D->getKind()) {
5665  case Decl::CXXConversion:
5666  case Decl::CXXMethod:
5667  case Decl::Function:
5668    EmitGlobal(cast<FunctionDecl>(D));
5669    // Always provide some coverage mapping
5670    // even for the functions that aren't emitted.
5671    AddDeferredUnusedCoverageMapping(D);
5672    break;
5673
5674  case Decl::CXXDeductionGuide:
5675    // Function-like, but does not result in code emission.
5676    break;
5677
5678  case Decl::Var:
5679  case Decl::Decomposition:
5680  case Decl::VarTemplateSpecialization:
5681    EmitGlobal(cast<VarDecl>(D));
5682    if (auto *DD = dyn_cast<DecompositionDecl>(D))
5683      for (auto *B : DD->bindings())
5684        if (auto *HD = B->getHoldingVar())
5685          EmitGlobal(HD);
5686    break;
5687
5688  // Indirect fields from global anonymous structs and unions can be
5689  // ignored; only the actual variable requires IR gen support.
5690  case Decl::IndirectField:
5691    break;
5692
5693  // C++ Decls
5694  case Decl::Namespace:
5695    EmitDeclContext(cast<NamespaceDecl>(D));
5696    break;
5697  case Decl::ClassTemplateSpecialization: {
5698    const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
5699    if (CGDebugInfo *DI = getModuleDebugInfo())
5700      if (Spec->getSpecializationKind() ==
5701              TSK_ExplicitInstantiationDefinition &&
5702          Spec->hasDefinition())
5703        DI->completeTemplateDefinition(*Spec);
5704  } LLVM_FALLTHROUGH;
5705  case Decl::CXXRecord: {
5706    CXXRecordDecl *CRD = cast<CXXRecordDecl>(D);
5707    if (CGDebugInfo *DI = getModuleDebugInfo()) {
5708      if (CRD->hasDefinition())
5709        DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
5710      if (auto *ES = D->getASTContext().getExternalSource())
5711        if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
5712          DI->completeUnusedClass(*CRD);
5713    }
5714    // Emit any static data members, they may be definitions.
5715    for (auto *I : CRD->decls())
5716      if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
5717        EmitTopLevelDecl(I);
5718    break;
5719  }
5720    // No code generation needed.
5721  case Decl::UsingShadow:
5722  case Decl::ClassTemplate:
5723  case Decl::VarTemplate:
5724  case Decl::Concept:
5725  case Decl::VarTemplatePartialSpecialization:
5726  case Decl::FunctionTemplate:
5727  case Decl::TypeAliasTemplate:
5728  case Decl::Block:
5729  case Decl::Empty:
5730  case Decl::Binding:
5731    break;
5732  case Decl::Using:          // using X; [C++]
5733    if (CGDebugInfo *DI = getModuleDebugInfo())
5734        DI->EmitUsingDecl(cast<UsingDecl>(*D));
5735    break;
5736  case Decl::NamespaceAlias:
5737    if (CGDebugInfo *DI = getModuleDebugInfo())
5738        DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
5739    break;
5740  case Decl::UsingDirective: // using namespace X; [C++]
5741    if (CGDebugInfo *DI = getModuleDebugInfo())
5742      DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
5743    break;
5744  case Decl::CXXConstructor:
5745    getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
5746    break;
5747  case Decl::CXXDestructor:
5748    getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
5749    break;
5750
5751  case Decl::StaticAssert:
5752    // Nothing to do.
5753    break;
5754
5755  // Objective-C Decls
5756
5757  // Forward declarations, no (immediate) code generation.
5758  case Decl::ObjCInterface:
5759  case Decl::ObjCCategory:
5760    break;
5761
5762  case Decl::ObjCProtocol: {
5763    auto *Proto = cast<ObjCProtocolDecl>(D);
5764    if (Proto->isThisDeclarationADefinition())
5765      ObjCRuntime->GenerateProtocol(Proto);
5766    break;
5767  }
5768
5769  case Decl::ObjCCategoryImpl:
5770    // Categories have properties but don't support synthesize so we
5771    // can ignore them here.
5772    ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
5773    break;
5774
5775  case Decl::ObjCImplementation: {
5776    auto *OMD = cast<ObjCImplementationDecl>(D);
5777    EmitObjCPropertyImplementations(OMD);
5778    EmitObjCIvarInitializations(OMD);
5779    ObjCRuntime->GenerateClass(OMD);
5780    // Emit global variable debug information.
5781    if (CGDebugInfo *DI = getModuleDebugInfo())
5782      if (getCodeGenOpts().hasReducedDebugInfo())
5783        DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
5784            OMD->getClassInterface()), OMD->getLocation());
5785    break;
5786  }
5787  case Decl::ObjCMethod: {
5788    auto *OMD = cast<ObjCMethodDecl>(D);
5789    // If this is not a prototype, emit the body.
5790    if (OMD->getBody())
5791      CodeGenFunction(*this).GenerateObjCMethod(OMD);
5792    break;
5793  }
5794  case Decl::ObjCCompatibleAlias:
5795    ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
5796    break;
5797
5798  case Decl::PragmaComment: {
5799    const auto *PCD = cast<PragmaCommentDecl>(D);
5800    switch (PCD->getCommentKind()) {
5801    case PCK_Unknown:
5802      llvm_unreachable("unexpected pragma comment kind");
5803    case PCK_Linker:
5804      AppendLinkerOptions(PCD->getArg());
5805      break;
5806    case PCK_Lib:
5807        AddDependentLib(PCD->getArg());
5808      break;
5809    case PCK_Compiler:
5810    case PCK_ExeStr:
5811    case PCK_User:
5812      break; // We ignore all of these.
5813    }
5814    break;
5815  }
5816
5817  case Decl::PragmaDetectMismatch: {
5818    const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
5819    AddDetectMismatch(PDMD->getName(), PDMD->getValue());
5820    break;
5821  }
5822
5823  case Decl::LinkageSpec:
5824    EmitLinkageSpec(cast<LinkageSpecDecl>(D));
5825    break;
5826
5827  case Decl::FileScopeAsm: {
5828    // File-scope asm is ignored during device-side CUDA compilation.
5829    if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
5830      break;
5831    // File-scope asm is ignored during device-side OpenMP compilation.
5832    if (LangOpts.OpenMPIsDevice)
5833      break;
5834    // File-scope asm is ignored during device-side SYCL compilation.
5835    if (LangOpts.SYCLIsDevice)
5836      break;
5837    auto *AD = cast<FileScopeAsmDecl>(D);
5838    getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
5839    break;
5840  }
5841
5842  case Decl::Import: {
5843    auto *Import = cast<ImportDecl>(D);
5844
5845    // If we've already imported this module, we're done.
5846    if (!ImportedModules.insert(Import->getImportedModule()))
5847      break;
5848
5849    // Emit debug information for direct imports.
5850    if (!Import->getImportedOwningModule()) {
5851      if (CGDebugInfo *DI = getModuleDebugInfo())
5852        DI->EmitImportDecl(*Import);
5853    }
5854
5855    // Find all of the submodules and emit the module initializers.
5856    llvm::SmallPtrSet<clang::Module *, 16> Visited;
5857    SmallVector<clang::Module *, 16> Stack;
5858    Visited.insert(Import->getImportedModule());
5859    Stack.push_back(Import->getImportedModule());
5860
5861    while (!Stack.empty()) {
5862      clang::Module *Mod = Stack.pop_back_val();
5863      if (!EmittedModuleInitializers.insert(Mod).second)
5864        continue;
5865
5866      for (auto *D : Context.getModuleInitializers(Mod))
5867        EmitTopLevelDecl(D);
5868
5869      // Visit the submodules of this module.
5870      for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
5871                                             SubEnd = Mod->submodule_end();
5872           Sub != SubEnd; ++Sub) {
5873        // Skip explicit children; they need to be explicitly imported to emit
5874        // the initializers.
5875        if ((*Sub)->IsExplicit)
5876          continue;
5877
5878        if (Visited.insert(*Sub).second)
5879          Stack.push_back(*Sub);
5880      }
5881    }
5882    break;
5883  }
5884
5885  case Decl::Export:
5886    EmitDeclContext(cast<ExportDecl>(D));
5887    break;
5888
5889  case Decl::OMPThreadPrivate:
5890    EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
5891    break;
5892
5893  case Decl::OMPAllocate:
5894    EmitOMPAllocateDecl(cast<OMPAllocateDecl>(D));
5895    break;
5896
5897  case Decl::OMPDeclareReduction:
5898    EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
5899    break;
5900
5901  case Decl::OMPDeclareMapper:
5902    EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D));
5903    break;
5904
5905  case Decl::OMPRequires:
5906    EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
5907    break;
5908
5909  case Decl::Typedef:
5910  case Decl::TypeAlias: // using foo = bar; [C++11]
5911    if (CGDebugInfo *DI = getModuleDebugInfo())
5912      DI->EmitAndRetainType(
5913          getContext().getTypedefType(cast<TypedefNameDecl>(D)));
5914    break;
5915
5916  case Decl::Record:
5917    if (CGDebugInfo *DI = getModuleDebugInfo())
5918      if (cast<RecordDecl>(D)->getDefinition())
5919        DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
5920    break;
5921
5922  case Decl::Enum:
5923    if (CGDebugInfo *DI = getModuleDebugInfo())
5924      if (cast<EnumDecl>(D)->getDefinition())
5925        DI->EmitAndRetainType(getContext().getEnumType(cast<EnumDecl>(D)));
5926    break;
5927
5928  default:
5929    // Make sure we handled everything we should, every other kind is a
5930    // non-top-level decl.  FIXME: Would be nice to have an isTopLevelDeclKind
5931    // function. Need to recode Decl::Kind to do that easily.
5932    assert(isa<TypeDecl>(D) && "Unsupported decl kind");
5933    break;
5934  }
5935}
5936
5937void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
5938  // Do we need to generate coverage mapping?
5939  if (!CodeGenOpts.CoverageMapping)
5940    return;
5941  switch (D->getKind()) {
5942  case Decl::CXXConversion:
5943  case Decl::CXXMethod:
5944  case Decl::Function:
5945  case Decl::ObjCMethod:
5946  case Decl::CXXConstructor:
5947  case Decl::CXXDestructor: {
5948    if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
5949      break;
5950    SourceManager &SM = getContext().getSourceManager();
5951    if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
5952      break;
5953    auto I = DeferredEmptyCoverageMappingDecls.find(D);
5954    if (I == DeferredEmptyCoverageMappingDecls.end())
5955      DeferredEmptyCoverageMappingDecls[D] = true;
5956    break;
5957  }
5958  default:
5959    break;
5960  };
5961}
5962
5963void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
5964  // Do we need to generate coverage mapping?
5965  if (!CodeGenOpts.CoverageMapping)
5966    return;
5967  if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
5968    if (Fn->isTemplateInstantiation())
5969      ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
5970  }
5971  auto I = DeferredEmptyCoverageMappingDecls.find(D);
5972  if (I == DeferredEmptyCoverageMappingDecls.end())
5973    DeferredEmptyCoverageMappingDecls[D] = false;
5974  else
5975    I->second = false;
5976}
5977
5978void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
5979  // We call takeVector() here to avoid use-after-free.
5980  // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
5981  // we deserialize function bodies to emit coverage info for them, and that
5982  // deserializes more declarations. How should we handle that case?
5983  for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
5984    if (!Entry.second)
5985      continue;
5986    const Decl *D = Entry.first;
5987    switch (D->getKind()) {
5988    case Decl::CXXConversion:
5989    case Decl::CXXMethod:
5990    case Decl::Function:
5991    case Decl::ObjCMethod: {
5992      CodeGenPGO PGO(*this);
5993      GlobalDecl GD(cast<FunctionDecl>(D));
5994      PGO.emitEmptyCounterMapping(D, getMangledName(GD),
5995                                  getFunctionLinkage(GD));
5996      break;
5997    }
5998    case Decl::CXXConstructor: {
5999      CodeGenPGO PGO(*this);
6000      GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
6001      PGO.emitEmptyCounterMapping(D, getMangledName(GD),
6002                                  getFunctionLinkage(GD));
6003      break;
6004    }
6005    case Decl::CXXDestructor: {
6006      CodeGenPGO PGO(*this);
6007      GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
6008      PGO.emitEmptyCounterMapping(D, getMangledName(GD),
6009                                  getFunctionLinkage(GD));
6010      break;
6011    }
6012    default:
6013      break;
6014    };
6015  }
6016}
6017
6018void CodeGenModule::EmitMainVoidAlias() {
6019  // In order to transition away from "__original_main" gracefully, emit an
6020  // alias for "main" in the no-argument case so that libc can detect when
6021  // new-style no-argument main is in used.
6022  if (llvm::Function *F = getModule().getFunction("main")) {
6023    if (!F->isDeclaration() && F->arg_size() == 0 && !F->isVarArg() &&
6024        F->getReturnType()->isIntegerTy(Context.getTargetInfo().getIntWidth()))
6025      addUsedGlobal(llvm::GlobalAlias::create("__main_void", F));
6026  }
6027}
6028
6029/// Turns the given pointer into a constant.
6030static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
6031                                          const void *Ptr) {
6032  uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
6033  llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
6034  return llvm::ConstantInt::get(i64, PtrInt);
6035}
6036
6037static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
6038                                   llvm::NamedMDNode *&GlobalMetadata,
6039                                   GlobalDecl D,
6040                                   llvm::GlobalValue *Addr) {
6041  if (!GlobalMetadata)
6042    GlobalMetadata =
6043      CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
6044
6045  // TODO: should we report variant information for ctors/dtors?
6046  llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
6047                           llvm::ConstantAsMetadata::get(GetPointerConstant(
6048                               CGM.getLLVMContext(), D.getDecl()))};
6049  GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
6050}
6051
6052/// For each function which is declared within an extern "C" region and marked
6053/// as 'used', but has internal linkage, create an alias from the unmangled
6054/// name to the mangled name if possible. People expect to be able to refer
6055/// to such functions with an unmangled name from inline assembly within the
6056/// same translation unit.
6057void CodeGenModule::EmitStaticExternCAliases() {
6058  if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
6059    return;
6060  for (auto &I : StaticExternCValues) {
6061    IdentifierInfo *Name = I.first;
6062    llvm::GlobalValue *Val = I.second;
6063    if (Val && !getModule().getNamedValue(Name->getName()))
6064      addCompilerUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
6065  }
6066}
6067
6068bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
6069                                             GlobalDecl &Result) const {
6070  auto Res = Manglings.find(MangledName);
6071  if (Res == Manglings.end())
6072    return false;
6073  Result = Res->getValue();
6074  return true;
6075}
6076
6077/// Emits metadata nodes associating all the global values in the
6078/// current module with the Decls they came from.  This is useful for
6079/// projects using IR gen as a subroutine.
6080///
6081/// Since there's currently no way to associate an MDNode directly
6082/// with an llvm::GlobalValue, we create a global named metadata
6083/// with the name 'clang.global.decl.ptrs'.
6084void CodeGenModule::EmitDeclMetadata() {
6085  llvm::NamedMDNode *GlobalMetadata = nullptr;
6086
6087  for (auto &I : MangledDeclNames) {
6088    llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
6089    // Some mangled names don't necessarily have an associated GlobalValue
6090    // in this module, e.g. if we mangled it for DebugInfo.
6091    if (Addr)
6092      EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
6093  }
6094}
6095
6096/// Emits metadata nodes for all the local variables in the current
6097/// function.
6098void CodeGenFunction::EmitDeclMetadata() {
6099  if (LocalDeclMap.empty()) return;
6100
6101  llvm::LLVMContext &Context = getLLVMContext();
6102
6103  // Find the unique metadata ID for this name.
6104  unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
6105
6106  llvm::NamedMDNode *GlobalMetadata = nullptr;
6107
6108  for (auto &I : LocalDeclMap) {
6109    const Decl *D = I.first;
6110    llvm::Value *Addr = I.second.getPointer();
6111    if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
6112      llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
6113      Alloca->setMetadata(
6114          DeclPtrKind, llvm::MDNode::get(
6115                           Context, llvm::ValueAsMetadata::getConstant(DAddr)));
6116    } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
6117      GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
6118      EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
6119    }
6120  }
6121}
6122
6123void CodeGenModule::EmitVersionIdentMetadata() {
6124  llvm::NamedMDNode *IdentMetadata =
6125    TheModule.getOrInsertNamedMetadata("llvm.ident");
6126  std::string Version = getClangFullVersion();
6127  llvm::LLVMContext &Ctx = TheModule.getContext();
6128
6129  llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
6130  IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
6131}
6132
6133void CodeGenModule::EmitCommandLineMetadata() {
6134  llvm::NamedMDNode *CommandLineMetadata =
6135    TheModule.getOrInsertNamedMetadata("llvm.commandline");
6136  std::string CommandLine = getCodeGenOpts().RecordCommandLine;
6137  llvm::LLVMContext &Ctx = TheModule.getContext();
6138
6139  llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
6140  CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
6141}
6142
6143void CodeGenModule::EmitCoverageFile() {
6144  if (getCodeGenOpts().CoverageDataFile.empty() &&
6145      getCodeGenOpts().CoverageNotesFile.empty())
6146    return;
6147
6148  llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
6149  if (!CUNode)
6150    return;
6151
6152  llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
6153  llvm::LLVMContext &Ctx = TheModule.getContext();
6154  auto *CoverageDataFile =
6155      llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
6156  auto *CoverageNotesFile =
6157      llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
6158  for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
6159    llvm::MDNode *CU = CUNode->getOperand(i);
6160    llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
6161    GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
6162  }
6163}
6164
6165llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
6166                                                       bool ForEH) {
6167  // Return a bogus pointer if RTTI is disabled, unless it's for EH.
6168  // FIXME: should we even be calling this method if RTTI is disabled
6169  // and it's not for EH?
6170  if ((!ForEH && !getLangOpts().RTTI) || getLangOpts().CUDAIsDevice ||
6171      (getLangOpts().OpenMP && getLangOpts().OpenMPIsDevice &&
6172       getTriple().isNVPTX()))
6173    return llvm::Constant::getNullValue(Int8PtrTy);
6174
6175  if (ForEH && Ty->isObjCObjectPointerType() &&
6176      LangOpts.ObjCRuntime.isGNUFamily())
6177    return ObjCRuntime->GetEHType(Ty);
6178
6179  return getCXXABI().getAddrOfRTTIDescriptor(Ty);
6180}
6181
6182void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
6183  // Do not emit threadprivates in simd-only mode.
6184  if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
6185    return;
6186  for (auto RefExpr : D->varlists()) {
6187    auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
6188    bool PerformInit =
6189        VD->getAnyInitializer() &&
6190        !VD->getAnyInitializer()->isConstantInitializer(getContext(),
6191                                                        /*ForRef=*/false);
6192
6193    Address Addr(GetAddrOfGlobalVar(VD), getContext().getDeclAlign(VD));
6194    if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
6195            VD, Addr, RefExpr->getBeginLoc(), PerformInit))
6196      CXXGlobalInits.push_back(InitFunction);
6197  }
6198}
6199
6200llvm::Metadata *
6201CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
6202                                            StringRef Suffix) {
6203  llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
6204  if (InternalId)
6205    return InternalId;
6206
6207  if (isExternallyVisible(T->getLinkage())) {
6208    std::string OutName;
6209    llvm::raw_string_ostream Out(OutName);
6210    getCXXABI().getMangleContext().mangleTypeName(T, Out);
6211    Out << Suffix;
6212
6213    InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
6214  } else {
6215    InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
6216                                           llvm::ArrayRef<llvm::Metadata *>());
6217  }
6218
6219  return InternalId;
6220}
6221
6222llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
6223  return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
6224}
6225
6226llvm::Metadata *
6227CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
6228  return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
6229}
6230
6231// Generalize pointer types to a void pointer with the qualifiers of the
6232// originally pointed-to type, e.g. 'const char *' and 'char * const *'
6233// generalize to 'const void *' while 'char *' and 'const char **' generalize to
6234// 'void *'.
6235static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
6236  if (!Ty->isPointerType())
6237    return Ty;
6238
6239  return Ctx.getPointerType(
6240      QualType(Ctx.VoidTy).withCVRQualifiers(
6241          Ty->getPointeeType().getCVRQualifiers()));
6242}
6243
6244// Apply type generalization to a FunctionType's return and argument types
6245static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
6246  if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
6247    SmallVector<QualType, 8> GeneralizedParams;
6248    for (auto &Param : FnType->param_types())
6249      GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
6250
6251    return Ctx.getFunctionType(
6252        GeneralizeType(Ctx, FnType->getReturnType()),
6253        GeneralizedParams, FnType->getExtProtoInfo());
6254  }
6255
6256  if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
6257    return Ctx.getFunctionNoProtoType(
6258        GeneralizeType(Ctx, FnType->getReturnType()));
6259
6260  llvm_unreachable("Encountered unknown FunctionType");
6261}
6262
6263llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
6264  return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
6265                                      GeneralizedMetadataIdMap, ".generalized");
6266}
6267
6268/// Returns whether this module needs the "all-vtables" type identifier.
6269bool CodeGenModule::NeedAllVtablesTypeId() const {
6270  // Returns true if at least one of vtable-based CFI checkers is enabled and
6271  // is not in the trapping mode.
6272  return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
6273           !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
6274          (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
6275           !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
6276          (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
6277           !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
6278          (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
6279           !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
6280}
6281
6282void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
6283                                          CharUnits Offset,
6284                                          const CXXRecordDecl *RD) {
6285  llvm::Metadata *MD =
6286      CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
6287  VTable->addTypeMetadata(Offset.getQuantity(), MD);
6288
6289  if (CodeGenOpts.SanitizeCfiCrossDso)
6290    if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
6291      VTable->addTypeMetadata(Offset.getQuantity(),
6292                              llvm::ConstantAsMetadata::get(CrossDsoTypeId));
6293
6294  if (NeedAllVtablesTypeId()) {
6295    llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
6296    VTable->addTypeMetadata(Offset.getQuantity(), MD);
6297  }
6298}
6299
6300llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
6301  if (!SanStats)
6302    SanStats = std::make_unique<llvm::SanitizerStatReport>(&getModule());
6303
6304  return *SanStats;
6305}
6306
6307llvm::Value *
6308CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
6309                                                  CodeGenFunction &CGF) {
6310  llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
6311  auto *SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
6312  auto *FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
6313  auto *Call = CGF.EmitRuntimeCall(
6314      CreateRuntimeFunction(FTy, "__translate_sampler_initializer"), {C});
6315  return Call;
6316}
6317
6318CharUnits CodeGenModule::getNaturalPointeeTypeAlignment(
6319    QualType T, LValueBaseInfo *BaseInfo, TBAAAccessInfo *TBAAInfo) {
6320  return getNaturalTypeAlignment(T->getPointeeType(), BaseInfo, TBAAInfo,
6321                                 /* forPointeeType= */ true);
6322}
6323
6324CharUnits CodeGenModule::getNaturalTypeAlignment(QualType T,
6325                                                 LValueBaseInfo *BaseInfo,
6326                                                 TBAAAccessInfo *TBAAInfo,
6327                                                 bool forPointeeType) {
6328  if (TBAAInfo)
6329    *TBAAInfo = getTBAAAccessInfo(T);
6330
6331  // FIXME: This duplicates logic in ASTContext::getTypeAlignIfKnown. But
6332  // that doesn't return the information we need to compute BaseInfo.
6333
6334  // Honor alignment typedef attributes even on incomplete types.
6335  // We also honor them straight for C++ class types, even as pointees;
6336  // there's an expressivity gap here.
6337  if (auto TT = T->getAs<TypedefType>()) {
6338    if (auto Align = TT->getDecl()->getMaxAlignment()) {
6339      if (BaseInfo)
6340        *BaseInfo = LValueBaseInfo(AlignmentSource::AttributedType);
6341      return getContext().toCharUnitsFromBits(Align);
6342    }
6343  }
6344
6345  bool AlignForArray = T->isArrayType();
6346
6347  // Analyze the base element type, so we don't get confused by incomplete
6348  // array types.
6349  T = getContext().getBaseElementType(T);
6350
6351  if (T->isIncompleteType()) {
6352    // We could try to replicate the logic from
6353    // ASTContext::getTypeAlignIfKnown, but nothing uses the alignment if the
6354    // type is incomplete, so it's impossible to test. We could try to reuse
6355    // getTypeAlignIfKnown, but that doesn't return the information we need
6356    // to set BaseInfo.  So just ignore the possibility that the alignment is
6357    // greater than one.
6358    if (BaseInfo)
6359      *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
6360    return CharUnits::One();
6361  }
6362
6363  if (BaseInfo)
6364    *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
6365
6366  CharUnits Alignment;
6367  const CXXRecordDecl *RD;
6368  if (T.getQualifiers().hasUnaligned()) {
6369    Alignment = CharUnits::One();
6370  } else if (forPointeeType && !AlignForArray &&
6371             (RD = T->getAsCXXRecordDecl())) {
6372    // For C++ class pointees, we don't know whether we're pointing at a
6373    // base or a complete object, so we generally need to use the
6374    // non-virtual alignment.
6375    Alignment = getClassPointerAlignment(RD);
6376  } else {
6377    Alignment = getContext().getTypeAlignInChars(T);
6378  }
6379
6380  // Cap to the global maximum type alignment unless the alignment
6381  // was somehow explicit on the type.
6382  if (unsigned MaxAlign = getLangOpts().MaxTypeAlign) {
6383    if (Alignment.getQuantity() > MaxAlign &&
6384        !getContext().isAlignmentRequired(T))
6385      Alignment = CharUnits::fromQuantity(MaxAlign);
6386  }
6387  return Alignment;
6388}
6389
6390bool CodeGenModule::stopAutoInit() {
6391  unsigned StopAfter = getContext().getLangOpts().TrivialAutoVarInitStopAfter;
6392  if (StopAfter) {
6393    // This number is positive only when -ftrivial-auto-var-init-stop-after=* is
6394    // used
6395    if (NumAutoVarInit >= StopAfter) {
6396      return true;
6397    }
6398    if (!NumAutoVarInit) {
6399      unsigned DiagID = getDiags().getCustomDiagID(
6400          DiagnosticsEngine::Warning,
6401          "-ftrivial-auto-var-init-stop-after=%0 has been enabled to limit the "
6402          "number of times ftrivial-auto-var-init=%1 gets applied.");
6403      getDiags().Report(DiagID)
6404          << StopAfter
6405          << (getContext().getLangOpts().getTrivialAutoVarInit() ==
6406                      LangOptions::TrivialAutoVarInitKind::Zero
6407                  ? "zero"
6408                  : "pattern");
6409    }
6410    ++NumAutoVarInit;
6411  }
6412  return false;
6413}
6414
6415void CodeGenModule::printPostfixForExternalizedStaticVar(
6416    llvm::raw_ostream &OS) const {
6417  OS << ".static." << getContext().getCUIDHash();
6418}
6419