xref: /llvm-project/clang/lib/CodeGen/CodeGenModule.cpp (revision becb03f3c624a9570fdb3f2d5dee1ed75922e70b)
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 "ABIInfo.h"
15 #include "CGBlocks.h"
16 #include "CGCUDARuntime.h"
17 #include "CGCXXABI.h"
18 #include "CGCall.h"
19 #include "CGDebugInfo.h"
20 #include "CGHLSLRuntime.h"
21 #include "CGObjCRuntime.h"
22 #include "CGOpenCLRuntime.h"
23 #include "CGOpenMPRuntime.h"
24 #include "CGOpenMPRuntimeGPU.h"
25 #include "CodeGenFunction.h"
26 #include "CodeGenPGO.h"
27 #include "ConstantEmitter.h"
28 #include "CoverageMappingGen.h"
29 #include "TargetInfo.h"
30 #include "clang/AST/ASTContext.h"
31 #include "clang/AST/ASTLambda.h"
32 #include "clang/AST/CharUnits.h"
33 #include "clang/AST/Decl.h"
34 #include "clang/AST/DeclCXX.h"
35 #include "clang/AST/DeclObjC.h"
36 #include "clang/AST/DeclTemplate.h"
37 #include "clang/AST/Mangle.h"
38 #include "clang/AST/RecursiveASTVisitor.h"
39 #include "clang/AST/StmtVisitor.h"
40 #include "clang/Basic/Builtins.h"
41 #include "clang/Basic/CharInfo.h"
42 #include "clang/Basic/CodeGenOptions.h"
43 #include "clang/Basic/Diagnostic.h"
44 #include "clang/Basic/FileManager.h"
45 #include "clang/Basic/Module.h"
46 #include "clang/Basic/SourceManager.h"
47 #include "clang/Basic/TargetInfo.h"
48 #include "clang/Basic/Version.h"
49 #include "clang/CodeGen/BackendUtil.h"
50 #include "clang/CodeGen/ConstantInitBuilder.h"
51 #include "clang/Frontend/FrontendDiagnostic.h"
52 #include "llvm/ADT/STLExtras.h"
53 #include "llvm/ADT/StringExtras.h"
54 #include "llvm/ADT/StringSwitch.h"
55 #include "llvm/Analysis/TargetLibraryInfo.h"
56 #include "llvm/BinaryFormat/ELF.h"
57 #include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
58 #include "llvm/IR/AttributeMask.h"
59 #include "llvm/IR/CallingConv.h"
60 #include "llvm/IR/DataLayout.h"
61 #include "llvm/IR/Intrinsics.h"
62 #include "llvm/IR/LLVMContext.h"
63 #include "llvm/IR/Module.h"
64 #include "llvm/IR/ProfileSummary.h"
65 #include "llvm/ProfileData/InstrProfReader.h"
66 #include "llvm/ProfileData/SampleProf.h"
67 #include "llvm/Support/CRC.h"
68 #include "llvm/Support/CodeGen.h"
69 #include "llvm/Support/CommandLine.h"
70 #include "llvm/Support/ConvertUTF.h"
71 #include "llvm/Support/ErrorHandling.h"
72 #include "llvm/Support/TimeProfiler.h"
73 #include "llvm/Support/xxhash.h"
74 #include "llvm/TargetParser/RISCVISAInfo.h"
75 #include "llvm/TargetParser/Triple.h"
76 #include "llvm/TargetParser/X86TargetParser.h"
77 #include "llvm/Transforms/Utils/BuildLibCalls.h"
78 #include <optional>
79 
80 using namespace clang;
81 using namespace CodeGen;
82 
83 static llvm::cl::opt<bool> LimitedCoverage(
84     "limited-coverage-experimental", llvm::cl::Hidden,
85     llvm::cl::desc("Emit limited coverage mapping information (experimental)"));
86 
87 static const char AnnotationSection[] = "llvm.metadata";
88 
89 static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
90   switch (CGM.getContext().getCXXABIKind()) {
91   case TargetCXXABI::AppleARM64:
92   case TargetCXXABI::Fuchsia:
93   case TargetCXXABI::GenericAArch64:
94   case TargetCXXABI::GenericARM:
95   case TargetCXXABI::iOS:
96   case TargetCXXABI::WatchOS:
97   case TargetCXXABI::GenericMIPS:
98   case TargetCXXABI::GenericItanium:
99   case TargetCXXABI::WebAssembly:
100   case TargetCXXABI::XL:
101     return CreateItaniumCXXABI(CGM);
102   case TargetCXXABI::Microsoft:
103     return CreateMicrosoftCXXABI(CGM);
104   }
105 
106   llvm_unreachable("invalid C++ ABI kind");
107 }
108 
109 static std::unique_ptr<TargetCodeGenInfo>
110 createTargetCodeGenInfo(CodeGenModule &CGM) {
111   const TargetInfo &Target = CGM.getTarget();
112   const llvm::Triple &Triple = Target.getTriple();
113   const CodeGenOptions &CodeGenOpts = CGM.getCodeGenOpts();
114 
115   switch (Triple.getArch()) {
116   default:
117     return createDefaultTargetCodeGenInfo(CGM);
118 
119   case llvm::Triple::m68k:
120     return createM68kTargetCodeGenInfo(CGM);
121   case llvm::Triple::mips:
122   case llvm::Triple::mipsel:
123     if (Triple.getOS() == llvm::Triple::NaCl)
124       return createPNaClTargetCodeGenInfo(CGM);
125     return createMIPSTargetCodeGenInfo(CGM, /*IsOS32=*/true);
126 
127   case llvm::Triple::mips64:
128   case llvm::Triple::mips64el:
129     return createMIPSTargetCodeGenInfo(CGM, /*IsOS32=*/false);
130 
131   case llvm::Triple::avr: {
132     // For passing parameters, R8~R25 are used on avr, and R18~R25 are used
133     // on avrtiny. For passing return value, R18~R25 are used on avr, and
134     // R22~R25 are used on avrtiny.
135     unsigned NPR = Target.getABI() == "avrtiny" ? 6 : 18;
136     unsigned NRR = Target.getABI() == "avrtiny" ? 4 : 8;
137     return createAVRTargetCodeGenInfo(CGM, NPR, NRR);
138   }
139 
140   case llvm::Triple::aarch64:
141   case llvm::Triple::aarch64_32:
142   case llvm::Triple::aarch64_be: {
143     AArch64ABIKind Kind = AArch64ABIKind::AAPCS;
144     if (Target.getABI() == "darwinpcs")
145       Kind = AArch64ABIKind::DarwinPCS;
146     else if (Triple.isOSWindows())
147       return createWindowsAArch64TargetCodeGenInfo(CGM, AArch64ABIKind::Win64);
148     else if (Target.getABI() == "aapcs-soft")
149       Kind = AArch64ABIKind::AAPCSSoft;
150     else if (Target.getABI() == "pauthtest")
151       Kind = AArch64ABIKind::PAuthTest;
152 
153     return createAArch64TargetCodeGenInfo(CGM, Kind);
154   }
155 
156   case llvm::Triple::wasm32:
157   case llvm::Triple::wasm64: {
158     WebAssemblyABIKind Kind = WebAssemblyABIKind::MVP;
159     if (Target.getABI() == "experimental-mv")
160       Kind = WebAssemblyABIKind::ExperimentalMV;
161     return createWebAssemblyTargetCodeGenInfo(CGM, Kind);
162   }
163 
164   case llvm::Triple::arm:
165   case llvm::Triple::armeb:
166   case llvm::Triple::thumb:
167   case llvm::Triple::thumbeb: {
168     if (Triple.getOS() == llvm::Triple::Win32)
169       return createWindowsARMTargetCodeGenInfo(CGM, ARMABIKind::AAPCS_VFP);
170 
171     ARMABIKind Kind = ARMABIKind::AAPCS;
172     StringRef ABIStr = Target.getABI();
173     if (ABIStr == "apcs-gnu")
174       Kind = ARMABIKind::APCS;
175     else if (ABIStr == "aapcs16")
176       Kind = ARMABIKind::AAPCS16_VFP;
177     else if (CodeGenOpts.FloatABI == "hard" ||
178              (CodeGenOpts.FloatABI != "soft" &&
179               (Triple.getEnvironment() == llvm::Triple::GNUEABIHF ||
180                Triple.getEnvironment() == llvm::Triple::MuslEABIHF ||
181                Triple.getEnvironment() == llvm::Triple::EABIHF)))
182       Kind = ARMABIKind::AAPCS_VFP;
183 
184     return createARMTargetCodeGenInfo(CGM, Kind);
185   }
186 
187   case llvm::Triple::ppc: {
188     if (Triple.isOSAIX())
189       return createAIXTargetCodeGenInfo(CGM, /*Is64Bit=*/false);
190 
191     bool IsSoftFloat =
192         CodeGenOpts.FloatABI == "soft" || Target.hasFeature("spe");
193     return createPPC32TargetCodeGenInfo(CGM, IsSoftFloat);
194   }
195   case llvm::Triple::ppcle: {
196     bool IsSoftFloat = CodeGenOpts.FloatABI == "soft";
197     return createPPC32TargetCodeGenInfo(CGM, IsSoftFloat);
198   }
199   case llvm::Triple::ppc64:
200     if (Triple.isOSAIX())
201       return createAIXTargetCodeGenInfo(CGM, /*Is64Bit=*/true);
202 
203     if (Triple.isOSBinFormatELF()) {
204       PPC64_SVR4_ABIKind Kind = PPC64_SVR4_ABIKind::ELFv1;
205       if (Target.getABI() == "elfv2")
206         Kind = PPC64_SVR4_ABIKind::ELFv2;
207       bool IsSoftFloat = CodeGenOpts.FloatABI == "soft";
208 
209       return createPPC64_SVR4_TargetCodeGenInfo(CGM, Kind, IsSoftFloat);
210     }
211     return createPPC64TargetCodeGenInfo(CGM);
212   case llvm::Triple::ppc64le: {
213     assert(Triple.isOSBinFormatELF() && "PPC64 LE non-ELF not supported!");
214     PPC64_SVR4_ABIKind Kind = PPC64_SVR4_ABIKind::ELFv2;
215     if (Target.getABI() == "elfv1")
216       Kind = PPC64_SVR4_ABIKind::ELFv1;
217     bool IsSoftFloat = CodeGenOpts.FloatABI == "soft";
218 
219     return createPPC64_SVR4_TargetCodeGenInfo(CGM, Kind, IsSoftFloat);
220   }
221 
222   case llvm::Triple::nvptx:
223   case llvm::Triple::nvptx64:
224     return createNVPTXTargetCodeGenInfo(CGM);
225 
226   case llvm::Triple::msp430:
227     return createMSP430TargetCodeGenInfo(CGM);
228 
229   case llvm::Triple::riscv32:
230   case llvm::Triple::riscv64: {
231     StringRef ABIStr = Target.getABI();
232     unsigned XLen = Target.getPointerWidth(LangAS::Default);
233     unsigned ABIFLen = 0;
234     if (ABIStr.ends_with("f"))
235       ABIFLen = 32;
236     else if (ABIStr.ends_with("d"))
237       ABIFLen = 64;
238     bool EABI = ABIStr.ends_with("e");
239     return createRISCVTargetCodeGenInfo(CGM, XLen, ABIFLen, EABI);
240   }
241 
242   case llvm::Triple::systemz: {
243     bool SoftFloat = CodeGenOpts.FloatABI == "soft";
244     bool HasVector = !SoftFloat && Target.getABI() == "vector";
245     return createSystemZTargetCodeGenInfo(CGM, HasVector, SoftFloat);
246   }
247 
248   case llvm::Triple::tce:
249   case llvm::Triple::tcele:
250     return createTCETargetCodeGenInfo(CGM);
251 
252   case llvm::Triple::x86: {
253     bool IsDarwinVectorABI = Triple.isOSDarwin();
254     bool IsWin32FloatStructABI = Triple.isOSWindows() && !Triple.isOSCygMing();
255 
256     if (Triple.getOS() == llvm::Triple::Win32) {
257       return createWinX86_32TargetCodeGenInfo(
258           CGM, IsDarwinVectorABI, IsWin32FloatStructABI,
259           CodeGenOpts.NumRegisterParameters);
260     }
261     return createX86_32TargetCodeGenInfo(
262         CGM, IsDarwinVectorABI, IsWin32FloatStructABI,
263         CodeGenOpts.NumRegisterParameters, CodeGenOpts.FloatABI == "soft");
264   }
265 
266   case llvm::Triple::x86_64: {
267     StringRef ABI = Target.getABI();
268     X86AVXABILevel AVXLevel = (ABI == "avx512" ? X86AVXABILevel::AVX512
269                                : ABI == "avx"  ? X86AVXABILevel::AVX
270                                                : X86AVXABILevel::None);
271 
272     switch (Triple.getOS()) {
273     case llvm::Triple::Win32:
274       return createWinX86_64TargetCodeGenInfo(CGM, AVXLevel);
275     default:
276       return createX86_64TargetCodeGenInfo(CGM, AVXLevel);
277     }
278   }
279   case llvm::Triple::hexagon:
280     return createHexagonTargetCodeGenInfo(CGM);
281   case llvm::Triple::lanai:
282     return createLanaiTargetCodeGenInfo(CGM);
283   case llvm::Triple::r600:
284     return createAMDGPUTargetCodeGenInfo(CGM);
285   case llvm::Triple::amdgcn:
286     return createAMDGPUTargetCodeGenInfo(CGM);
287   case llvm::Triple::sparc:
288     return createSparcV8TargetCodeGenInfo(CGM);
289   case llvm::Triple::sparcv9:
290     return createSparcV9TargetCodeGenInfo(CGM);
291   case llvm::Triple::xcore:
292     return createXCoreTargetCodeGenInfo(CGM);
293   case llvm::Triple::arc:
294     return createARCTargetCodeGenInfo(CGM);
295   case llvm::Triple::spir:
296   case llvm::Triple::spir64:
297     return createCommonSPIRTargetCodeGenInfo(CGM);
298   case llvm::Triple::spirv32:
299   case llvm::Triple::spirv64:
300     return createSPIRVTargetCodeGenInfo(CGM);
301   case llvm::Triple::dxil:
302     return createDirectXTargetCodeGenInfo(CGM);
303   case llvm::Triple::ve:
304     return createVETargetCodeGenInfo(CGM);
305   case llvm::Triple::csky: {
306     bool IsSoftFloat = !Target.hasFeature("hard-float-abi");
307     bool hasFP64 =
308         Target.hasFeature("fpuv2_df") || Target.hasFeature("fpuv3_df");
309     return createCSKYTargetCodeGenInfo(CGM, IsSoftFloat ? 0
310                                             : hasFP64   ? 64
311                                                         : 32);
312   }
313   case llvm::Triple::bpfeb:
314   case llvm::Triple::bpfel:
315     return createBPFTargetCodeGenInfo(CGM);
316   case llvm::Triple::loongarch32:
317   case llvm::Triple::loongarch64: {
318     StringRef ABIStr = Target.getABI();
319     unsigned ABIFRLen = 0;
320     if (ABIStr.ends_with("f"))
321       ABIFRLen = 32;
322     else if (ABIStr.ends_with("d"))
323       ABIFRLen = 64;
324     return createLoongArchTargetCodeGenInfo(
325         CGM, Target.getPointerWidth(LangAS::Default), ABIFRLen);
326   }
327   }
328 }
329 
330 const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
331   if (!TheTargetCodeGenInfo)
332     TheTargetCodeGenInfo = createTargetCodeGenInfo(*this);
333   return *TheTargetCodeGenInfo;
334 }
335 
336 CodeGenModule::CodeGenModule(ASTContext &C,
337                              IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS,
338                              const HeaderSearchOptions &HSO,
339                              const PreprocessorOptions &PPO,
340                              const CodeGenOptions &CGO, llvm::Module &M,
341                              DiagnosticsEngine &diags,
342                              CoverageSourceInfo *CoverageInfo)
343     : Context(C), LangOpts(C.getLangOpts()), FS(FS), HeaderSearchOpts(HSO),
344       PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
345       Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
346       VMContext(M.getContext()), VTables(*this),
347       SanitizerMD(new SanitizerMetadata(*this)) {
348 
349   // Initialize the type cache.
350   Types.reset(new CodeGenTypes(*this));
351   llvm::LLVMContext &LLVMContext = M.getContext();
352   VoidTy = llvm::Type::getVoidTy(LLVMContext);
353   Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
354   Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
355   Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
356   Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
357   HalfTy = llvm::Type::getHalfTy(LLVMContext);
358   BFloatTy = llvm::Type::getBFloatTy(LLVMContext);
359   FloatTy = llvm::Type::getFloatTy(LLVMContext);
360   DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
361   PointerWidthInBits = C.getTargetInfo().getPointerWidth(LangAS::Default);
362   PointerAlignInBytes =
363       C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(LangAS::Default))
364           .getQuantity();
365   SizeSizeInBytes =
366     C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
367   IntAlignInBytes =
368     C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
369   CharTy =
370     llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getCharWidth());
371   IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
372   IntPtrTy = llvm::IntegerType::get(LLVMContext,
373     C.getTargetInfo().getMaxPointerWidth());
374   Int8PtrTy = llvm::PointerType::get(LLVMContext,
375                                      C.getTargetAddressSpace(LangAS::Default));
376   const llvm::DataLayout &DL = M.getDataLayout();
377   AllocaInt8PtrTy =
378       llvm::PointerType::get(LLVMContext, DL.getAllocaAddrSpace());
379   GlobalsInt8PtrTy =
380       llvm::PointerType::get(LLVMContext, DL.getDefaultGlobalsAddressSpace());
381   ConstGlobalsPtrTy = llvm::PointerType::get(
382       LLVMContext, C.getTargetAddressSpace(GetGlobalConstantAddressSpace()));
383   ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
384 
385   // Build C++20 Module initializers.
386   // TODO: Add Microsoft here once we know the mangling required for the
387   // initializers.
388   CXX20ModuleInits =
389       LangOpts.CPlusPlusModules && getCXXABI().getMangleContext().getKind() ==
390                                        ItaniumMangleContext::MK_Itanium;
391 
392   RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
393 
394   if (LangOpts.ObjC)
395     createObjCRuntime();
396   if (LangOpts.OpenCL)
397     createOpenCLRuntime();
398   if (LangOpts.OpenMP)
399     createOpenMPRuntime();
400   if (LangOpts.CUDA)
401     createCUDARuntime();
402   if (LangOpts.HLSL)
403     createHLSLRuntime();
404 
405   // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
406   if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
407       (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
408     TBAA.reset(new CodeGenTBAA(Context, getTypes(), TheModule, CodeGenOpts,
409                                getLangOpts()));
410 
411   // If debug info or coverage generation is enabled, create the CGDebugInfo
412   // object.
413   if (CodeGenOpts.getDebugInfo() != llvm::codegenoptions::NoDebugInfo ||
414       CodeGenOpts.CoverageNotesFile.size() ||
415       CodeGenOpts.CoverageDataFile.size())
416     DebugInfo.reset(new CGDebugInfo(*this));
417 
418   Block.GlobalUniqueCount = 0;
419 
420   if (C.getLangOpts().ObjC)
421     ObjCData.reset(new ObjCEntrypoints());
422 
423   if (CodeGenOpts.hasProfileClangUse()) {
424     auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
425         CodeGenOpts.ProfileInstrumentUsePath, *FS,
426         CodeGenOpts.ProfileRemappingFile);
427     // We're checking for profile read errors in CompilerInvocation, so if
428     // there was an error it should've already been caught. If it hasn't been
429     // somehow, trip an assertion.
430     assert(ReaderOrErr);
431     PGOReader = std::move(ReaderOrErr.get());
432   }
433 
434   // If coverage mapping generation is enabled, create the
435   // CoverageMappingModuleGen object.
436   if (CodeGenOpts.CoverageMapping)
437     CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
438 
439   // Generate the module name hash here if needed.
440   if (CodeGenOpts.UniqueInternalLinkageNames &&
441       !getModule().getSourceFileName().empty()) {
442     std::string Path = getModule().getSourceFileName();
443     // Check if a path substitution is needed from the MacroPrefixMap.
444     for (const auto &Entry : LangOpts.MacroPrefixMap)
445       if (Path.rfind(Entry.first, 0) != std::string::npos) {
446         Path = Entry.second + Path.substr(Entry.first.size());
447         break;
448       }
449     ModuleNameHash = llvm::getUniqueInternalLinkagePostfix(Path);
450   }
451 
452   // Record mregparm value now so it is visible through all of codegen.
453   if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
454     getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
455                               CodeGenOpts.NumRegisterParameters);
456 }
457 
458 CodeGenModule::~CodeGenModule() {}
459 
460 void CodeGenModule::createObjCRuntime() {
461   // This is just isGNUFamily(), but we want to force implementors of
462   // new ABIs to decide how best to do this.
463   switch (LangOpts.ObjCRuntime.getKind()) {
464   case ObjCRuntime::GNUstep:
465   case ObjCRuntime::GCC:
466   case ObjCRuntime::ObjFW:
467     ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
468     return;
469 
470   case ObjCRuntime::FragileMacOSX:
471   case ObjCRuntime::MacOSX:
472   case ObjCRuntime::iOS:
473   case ObjCRuntime::WatchOS:
474     ObjCRuntime.reset(CreateMacObjCRuntime(*this));
475     return;
476   }
477   llvm_unreachable("bad runtime kind");
478 }
479 
480 void CodeGenModule::createOpenCLRuntime() {
481   OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
482 }
483 
484 void CodeGenModule::createOpenMPRuntime() {
485   // Select a specialized code generation class based on the target, if any.
486   // If it does not exist use the default implementation.
487   switch (getTriple().getArch()) {
488   case llvm::Triple::nvptx:
489   case llvm::Triple::nvptx64:
490   case llvm::Triple::amdgcn:
491     assert(getLangOpts().OpenMPIsTargetDevice &&
492            "OpenMP AMDGPU/NVPTX is only prepared to deal with device code.");
493     OpenMPRuntime.reset(new CGOpenMPRuntimeGPU(*this));
494     break;
495   default:
496     if (LangOpts.OpenMPSimd)
497       OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
498     else
499       OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
500     break;
501   }
502 }
503 
504 void CodeGenModule::createCUDARuntime() {
505   CUDARuntime.reset(CreateNVCUDARuntime(*this));
506 }
507 
508 void CodeGenModule::createHLSLRuntime() {
509   HLSLRuntime.reset(new CGHLSLRuntime(*this));
510 }
511 
512 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
513   Replacements[Name] = C;
514 }
515 
516 void CodeGenModule::applyReplacements() {
517   for (auto &I : Replacements) {
518     StringRef MangledName = I.first;
519     llvm::Constant *Replacement = I.second;
520     llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
521     if (!Entry)
522       continue;
523     auto *OldF = cast<llvm::Function>(Entry);
524     auto *NewF = dyn_cast<llvm::Function>(Replacement);
525     if (!NewF) {
526       if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
527         NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
528       } else {
529         auto *CE = cast<llvm::ConstantExpr>(Replacement);
530         assert(CE->getOpcode() == llvm::Instruction::BitCast ||
531                CE->getOpcode() == llvm::Instruction::GetElementPtr);
532         NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
533       }
534     }
535 
536     // Replace old with new, but keep the old order.
537     OldF->replaceAllUsesWith(Replacement);
538     if (NewF) {
539       NewF->removeFromParent();
540       OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
541                                                        NewF);
542     }
543     OldF->eraseFromParent();
544   }
545 }
546 
547 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
548   GlobalValReplacements.push_back(std::make_pair(GV, C));
549 }
550 
551 void CodeGenModule::applyGlobalValReplacements() {
552   for (auto &I : GlobalValReplacements) {
553     llvm::GlobalValue *GV = I.first;
554     llvm::Constant *C = I.second;
555 
556     GV->replaceAllUsesWith(C);
557     GV->eraseFromParent();
558   }
559 }
560 
561 // This is only used in aliases that we created and we know they have a
562 // linear structure.
563 static const llvm::GlobalValue *getAliasedGlobal(const llvm::GlobalValue *GV) {
564   const llvm::Constant *C;
565   if (auto *GA = dyn_cast<llvm::GlobalAlias>(GV))
566     C = GA->getAliasee();
567   else if (auto *GI = dyn_cast<llvm::GlobalIFunc>(GV))
568     C = GI->getResolver();
569   else
570     return GV;
571 
572   const auto *AliaseeGV = dyn_cast<llvm::GlobalValue>(C->stripPointerCasts());
573   if (!AliaseeGV)
574     return nullptr;
575 
576   const llvm::GlobalValue *FinalGV = AliaseeGV->getAliaseeObject();
577   if (FinalGV == GV)
578     return nullptr;
579 
580   return FinalGV;
581 }
582 
583 static bool checkAliasedGlobal(
584     const ASTContext &Context, DiagnosticsEngine &Diags, SourceLocation Location,
585     bool IsIFunc, const llvm::GlobalValue *Alias, const llvm::GlobalValue *&GV,
586     const llvm::MapVector<GlobalDecl, StringRef> &MangledDeclNames,
587     SourceRange AliasRange) {
588   GV = getAliasedGlobal(Alias);
589   if (!GV) {
590     Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
591     return false;
592   }
593 
594   if (GV->hasCommonLinkage()) {
595     const llvm::Triple &Triple = Context.getTargetInfo().getTriple();
596     if (Triple.getObjectFormat() == llvm::Triple::XCOFF) {
597       Diags.Report(Location, diag::err_alias_to_common);
598       return false;
599     }
600   }
601 
602   if (GV->isDeclaration()) {
603     Diags.Report(Location, diag::err_alias_to_undefined) << IsIFunc << IsIFunc;
604     Diags.Report(Location, diag::note_alias_requires_mangled_name)
605         << IsIFunc << IsIFunc;
606     // Provide a note if the given function is not found and exists as a
607     // mangled name.
608     for (const auto &[Decl, Name] : MangledDeclNames) {
609       if (const auto *ND = dyn_cast<NamedDecl>(Decl.getDecl())) {
610         if (ND->getName() == GV->getName()) {
611           Diags.Report(Location, diag::note_alias_mangled_name_alternative)
612               << Name
613               << FixItHint::CreateReplacement(
614                      AliasRange,
615                      (Twine(IsIFunc ? "ifunc" : "alias") + "(\"" + Name + "\")")
616                          .str());
617         }
618       }
619     }
620     return false;
621   }
622 
623   if (IsIFunc) {
624     // Check resolver function type.
625     const auto *F = dyn_cast<llvm::Function>(GV);
626     if (!F) {
627       Diags.Report(Location, diag::err_alias_to_undefined)
628           << IsIFunc << IsIFunc;
629       return false;
630     }
631 
632     llvm::FunctionType *FTy = F->getFunctionType();
633     if (!FTy->getReturnType()->isPointerTy()) {
634       Diags.Report(Location, diag::err_ifunc_resolver_return);
635       return false;
636     }
637   }
638 
639   return true;
640 }
641 
642 // Emit a warning if toc-data attribute is requested for global variables that
643 // have aliases and remove the toc-data attribute.
644 static void checkAliasForTocData(llvm::GlobalVariable *GVar,
645                                  const CodeGenOptions &CodeGenOpts,
646                                  DiagnosticsEngine &Diags,
647                                  SourceLocation Location) {
648   if (GVar->hasAttribute("toc-data")) {
649     auto GVId = GVar->getName();
650     // Is this a global variable specified by the user as local?
651     if ((llvm::binary_search(CodeGenOpts.TocDataVarsUserSpecified, GVId))) {
652       Diags.Report(Location, diag::warn_toc_unsupported_type)
653           << GVId << "the variable has an alias";
654     }
655     llvm::AttributeSet CurrAttributes = GVar->getAttributes();
656     llvm::AttributeSet NewAttributes =
657         CurrAttributes.removeAttribute(GVar->getContext(), "toc-data");
658     GVar->setAttributes(NewAttributes);
659   }
660 }
661 
662 void CodeGenModule::checkAliases() {
663   // Check if the constructed aliases are well formed. It is really unfortunate
664   // that we have to do this in CodeGen, but we only construct mangled names
665   // and aliases during codegen.
666   bool Error = false;
667   DiagnosticsEngine &Diags = getDiags();
668   for (const GlobalDecl &GD : Aliases) {
669     const auto *D = cast<ValueDecl>(GD.getDecl());
670     SourceLocation Location;
671     SourceRange Range;
672     bool IsIFunc = D->hasAttr<IFuncAttr>();
673     if (const Attr *A = D->getDefiningAttr()) {
674       Location = A->getLocation();
675       Range = A->getRange();
676     } else
677       llvm_unreachable("Not an alias or ifunc?");
678 
679     StringRef MangledName = getMangledName(GD);
680     llvm::GlobalValue *Alias = GetGlobalValue(MangledName);
681     const llvm::GlobalValue *GV = nullptr;
682     if (!checkAliasedGlobal(getContext(), Diags, Location, IsIFunc, Alias, GV,
683                             MangledDeclNames, Range)) {
684       Error = true;
685       continue;
686     }
687 
688     if (getContext().getTargetInfo().getTriple().isOSAIX())
689       if (const llvm::GlobalVariable *GVar =
690               dyn_cast<const llvm::GlobalVariable>(GV))
691         checkAliasForTocData(const_cast<llvm::GlobalVariable *>(GVar),
692                              getCodeGenOpts(), Diags, Location);
693 
694     llvm::Constant *Aliasee =
695         IsIFunc ? cast<llvm::GlobalIFunc>(Alias)->getResolver()
696                 : cast<llvm::GlobalAlias>(Alias)->getAliasee();
697 
698     llvm::GlobalValue *AliaseeGV;
699     if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
700       AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
701     else
702       AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
703 
704     if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
705       StringRef AliasSection = SA->getName();
706       if (AliasSection != AliaseeGV->getSection())
707         Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
708             << AliasSection << IsIFunc << IsIFunc;
709     }
710 
711     // We have to handle alias to weak aliases in here. LLVM itself disallows
712     // this since the object semantics would not match the IL one. For
713     // compatibility with gcc we implement it by just pointing the alias
714     // to its aliasee's aliasee. We also warn, since the user is probably
715     // expecting the link to be weak.
716     if (auto *GA = dyn_cast<llvm::GlobalAlias>(AliaseeGV)) {
717       if (GA->isInterposable()) {
718         Diags.Report(Location, diag::warn_alias_to_weak_alias)
719             << GV->getName() << GA->getName() << IsIFunc;
720         Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
721             GA->getAliasee(), Alias->getType());
722 
723         if (IsIFunc)
724           cast<llvm::GlobalIFunc>(Alias)->setResolver(Aliasee);
725         else
726           cast<llvm::GlobalAlias>(Alias)->setAliasee(Aliasee);
727       }
728     }
729     // ifunc resolvers are usually implemented to run before sanitizer
730     // initialization. Disable instrumentation to prevent the ordering issue.
731     if (IsIFunc)
732       cast<llvm::Function>(Aliasee)->addFnAttr(
733           llvm::Attribute::DisableSanitizerInstrumentation);
734   }
735   if (!Error)
736     return;
737 
738   for (const GlobalDecl &GD : Aliases) {
739     StringRef MangledName = getMangledName(GD);
740     llvm::GlobalValue *Alias = GetGlobalValue(MangledName);
741     Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
742     Alias->eraseFromParent();
743   }
744 }
745 
746 void CodeGenModule::clear() {
747   DeferredDeclsToEmit.clear();
748   EmittedDeferredDecls.clear();
749   DeferredAnnotations.clear();
750   if (OpenMPRuntime)
751     OpenMPRuntime->clear();
752 }
753 
754 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
755                                        StringRef MainFile) {
756   if (!hasDiagnostics())
757     return;
758   if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
759     if (MainFile.empty())
760       MainFile = "<stdin>";
761     Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
762   } else {
763     if (Mismatched > 0)
764       Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
765 
766     if (Missing > 0)
767       Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
768   }
769 }
770 
771 static std::optional<llvm::GlobalValue::VisibilityTypes>
772 getLLVMVisibility(clang::LangOptions::VisibilityFromDLLStorageClassKinds K) {
773   // Map to LLVM visibility.
774   switch (K) {
775   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Keep:
776     return std::nullopt;
777   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Default:
778     return llvm::GlobalValue::DefaultVisibility;
779   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Hidden:
780     return llvm::GlobalValue::HiddenVisibility;
781   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Protected:
782     return llvm::GlobalValue::ProtectedVisibility;
783   }
784   llvm_unreachable("unknown option value!");
785 }
786 
787 void setLLVMVisibility(llvm::GlobalValue &GV,
788                        std::optional<llvm::GlobalValue::VisibilityTypes> V) {
789   if (!V)
790     return;
791 
792   // Reset DSO locality before setting the visibility. This removes
793   // any effects that visibility options and annotations may have
794   // had on the DSO locality. Setting the visibility will implicitly set
795   // appropriate globals to DSO Local; however, this will be pessimistic
796   // w.r.t. to the normal compiler IRGen.
797   GV.setDSOLocal(false);
798   GV.setVisibility(*V);
799 }
800 
801 static void setVisibilityFromDLLStorageClass(const clang::LangOptions &LO,
802                                              llvm::Module &M) {
803   if (!LO.VisibilityFromDLLStorageClass)
804     return;
805 
806   std::optional<llvm::GlobalValue::VisibilityTypes> DLLExportVisibility =
807       getLLVMVisibility(LO.getDLLExportVisibility());
808 
809   std::optional<llvm::GlobalValue::VisibilityTypes>
810       NoDLLStorageClassVisibility =
811           getLLVMVisibility(LO.getNoDLLStorageClassVisibility());
812 
813   std::optional<llvm::GlobalValue::VisibilityTypes>
814       ExternDeclDLLImportVisibility =
815           getLLVMVisibility(LO.getExternDeclDLLImportVisibility());
816 
817   std::optional<llvm::GlobalValue::VisibilityTypes>
818       ExternDeclNoDLLStorageClassVisibility =
819           getLLVMVisibility(LO.getExternDeclNoDLLStorageClassVisibility());
820 
821   for (llvm::GlobalValue &GV : M.global_values()) {
822     if (GV.hasAppendingLinkage() || GV.hasLocalLinkage())
823       continue;
824 
825     if (GV.isDeclarationForLinker())
826       setLLVMVisibility(GV, GV.getDLLStorageClass() ==
827                                     llvm::GlobalValue::DLLImportStorageClass
828                                 ? ExternDeclDLLImportVisibility
829                                 : ExternDeclNoDLLStorageClassVisibility);
830     else
831       setLLVMVisibility(GV, GV.getDLLStorageClass() ==
832                                     llvm::GlobalValue::DLLExportStorageClass
833                                 ? DLLExportVisibility
834                                 : NoDLLStorageClassVisibility);
835 
836     GV.setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
837   }
838 }
839 
840 static bool isStackProtectorOn(const LangOptions &LangOpts,
841                                const llvm::Triple &Triple,
842                                clang::LangOptions::StackProtectorMode Mode) {
843   if (Triple.isAMDGPU() || Triple.isNVPTX())
844     return false;
845   return LangOpts.getStackProtector() == Mode;
846 }
847 
848 void CodeGenModule::Release() {
849   Module *Primary = getContext().getCurrentNamedModule();
850   if (CXX20ModuleInits && Primary && !Primary->isHeaderLikeModule())
851     EmitModuleInitializers(Primary);
852   EmitDeferred();
853   DeferredDecls.insert(EmittedDeferredDecls.begin(),
854                        EmittedDeferredDecls.end());
855   EmittedDeferredDecls.clear();
856   EmitVTablesOpportunistically();
857   applyGlobalValReplacements();
858   applyReplacements();
859   emitMultiVersionFunctions();
860 
861   if (Context.getLangOpts().IncrementalExtensions &&
862       GlobalTopLevelStmtBlockInFlight.first) {
863     const TopLevelStmtDecl *TLSD = GlobalTopLevelStmtBlockInFlight.second;
864     GlobalTopLevelStmtBlockInFlight.first->FinishFunction(TLSD->getEndLoc());
865     GlobalTopLevelStmtBlockInFlight = {nullptr, nullptr};
866   }
867 
868   // Module implementations are initialized the same way as a regular TU that
869   // imports one or more modules.
870   if (CXX20ModuleInits && Primary && Primary->isInterfaceOrPartition())
871     EmitCXXModuleInitFunc(Primary);
872   else
873     EmitCXXGlobalInitFunc();
874   EmitCXXGlobalCleanUpFunc();
875   registerGlobalDtorsWithAtExit();
876   EmitCXXThreadLocalInitFunc();
877   if (ObjCRuntime)
878     if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
879       AddGlobalCtor(ObjCInitFunction);
880   if (Context.getLangOpts().CUDA && CUDARuntime) {
881     if (llvm::Function *CudaCtorFunction = CUDARuntime->finalizeModule())
882       AddGlobalCtor(CudaCtorFunction);
883   }
884   if (OpenMPRuntime) {
885     OpenMPRuntime->createOffloadEntriesAndInfoMetadata();
886     OpenMPRuntime->clear();
887   }
888   if (PGOReader) {
889     getModule().setProfileSummary(
890         PGOReader->getSummary(/* UseCS */ false).getMD(VMContext),
891         llvm::ProfileSummary::PSK_Instr);
892     if (PGOStats.hasDiagnostics())
893       PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
894   }
895   llvm::stable_sort(GlobalCtors, [](const Structor &L, const Structor &R) {
896     return L.LexOrder < R.LexOrder;
897   });
898   EmitCtorList(GlobalCtors, "llvm.global_ctors");
899   EmitCtorList(GlobalDtors, "llvm.global_dtors");
900   EmitGlobalAnnotations();
901   EmitStaticExternCAliases();
902   checkAliases();
903   EmitDeferredUnusedCoverageMappings();
904   CodeGenPGO(*this).setValueProfilingFlag(getModule());
905   CodeGenPGO(*this).setProfileVersion(getModule());
906   if (CoverageMapping)
907     CoverageMapping->emit();
908   if (CodeGenOpts.SanitizeCfiCrossDso) {
909     CodeGenFunction(*this).EmitCfiCheckFail();
910     CodeGenFunction(*this).EmitCfiCheckStub();
911   }
912   if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
913     finalizeKCFITypes();
914   emitAtAvailableLinkGuard();
915   if (Context.getTargetInfo().getTriple().isWasm())
916     EmitMainVoidAlias();
917 
918   if (getTriple().isAMDGPU() ||
919       (getTriple().isSPIRV() && getTriple().getVendor() == llvm::Triple::AMD)) {
920     // Emit amdhsa_code_object_version module flag, which is code object version
921     // times 100.
922     if (getTarget().getTargetOpts().CodeObjectVersion !=
923         llvm::CodeObjectVersionKind::COV_None) {
924       getModule().addModuleFlag(llvm::Module::Error,
925                                 "amdhsa_code_object_version",
926                                 getTarget().getTargetOpts().CodeObjectVersion);
927     }
928 
929     // Currently, "-mprintf-kind" option is only supported for HIP
930     if (LangOpts.HIP) {
931       auto *MDStr = llvm::MDString::get(
932           getLLVMContext(), (getTarget().getTargetOpts().AMDGPUPrintfKindVal ==
933                              TargetOptions::AMDGPUPrintfKind::Hostcall)
934                                 ? "hostcall"
935                                 : "buffered");
936       getModule().addModuleFlag(llvm::Module::Error, "amdgpu_printf_kind",
937                                 MDStr);
938     }
939   }
940 
941   // Emit a global array containing all external kernels or device variables
942   // used by host functions and mark it as used for CUDA/HIP. This is necessary
943   // to get kernels or device variables in archives linked in even if these
944   // kernels or device variables are only used in host functions.
945   if (!Context.CUDAExternalDeviceDeclODRUsedByHost.empty()) {
946     SmallVector<llvm::Constant *, 8> UsedArray;
947     for (auto D : Context.CUDAExternalDeviceDeclODRUsedByHost) {
948       GlobalDecl GD;
949       if (auto *FD = dyn_cast<FunctionDecl>(D))
950         GD = GlobalDecl(FD, KernelReferenceKind::Kernel);
951       else
952         GD = GlobalDecl(D);
953       UsedArray.push_back(llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
954           GetAddrOfGlobal(GD), Int8PtrTy));
955     }
956 
957     llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size());
958 
959     auto *GV = new llvm::GlobalVariable(
960         getModule(), ATy, false, llvm::GlobalValue::InternalLinkage,
961         llvm::ConstantArray::get(ATy, UsedArray), "__clang_gpu_used_external");
962     addCompilerUsedGlobal(GV);
963   }
964   if (LangOpts.HIP && !getLangOpts().OffloadingNewDriver) {
965     // Emit a unique ID so that host and device binaries from the same
966     // compilation unit can be associated.
967     auto *GV = new llvm::GlobalVariable(
968         getModule(), Int8Ty, false, llvm::GlobalValue::ExternalLinkage,
969         llvm::Constant::getNullValue(Int8Ty),
970         "__hip_cuid_" + getContext().getCUIDHash());
971     addCompilerUsedGlobal(GV);
972   }
973   emitLLVMUsed();
974   if (SanStats)
975     SanStats->finish();
976 
977   if (CodeGenOpts.Autolink &&
978       (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
979     EmitModuleLinkOptions();
980   }
981 
982   // On ELF we pass the dependent library specifiers directly to the linker
983   // without manipulating them. This is in contrast to other platforms where
984   // they are mapped to a specific linker option by the compiler. This
985   // difference is a result of the greater variety of ELF linkers and the fact
986   // that ELF linkers tend to handle libraries in a more complicated fashion
987   // than on other platforms. This forces us to defer handling the dependent
988   // libs to the linker.
989   //
990   // CUDA/HIP device and host libraries are different. Currently there is no
991   // way to differentiate dependent libraries for host or device. Existing
992   // usage of #pragma comment(lib, *) is intended for host libraries on
993   // Windows. Therefore emit llvm.dependent-libraries only for host.
994   if (!ELFDependentLibraries.empty() && !Context.getLangOpts().CUDAIsDevice) {
995     auto *NMD = getModule().getOrInsertNamedMetadata("llvm.dependent-libraries");
996     for (auto *MD : ELFDependentLibraries)
997       NMD->addOperand(MD);
998   }
999 
1000   if (CodeGenOpts.DwarfVersion) {
1001     getModule().addModuleFlag(llvm::Module::Max, "Dwarf Version",
1002                               CodeGenOpts.DwarfVersion);
1003   }
1004 
1005   if (CodeGenOpts.Dwarf64)
1006     getModule().addModuleFlag(llvm::Module::Max, "DWARF64", 1);
1007 
1008   if (Context.getLangOpts().SemanticInterposition)
1009     // Require various optimization to respect semantic interposition.
1010     getModule().setSemanticInterposition(true);
1011 
1012   if (CodeGenOpts.EmitCodeView) {
1013     // Indicate that we want CodeView in the metadata.
1014     getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
1015   }
1016   if (CodeGenOpts.CodeViewGHash) {
1017     getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
1018   }
1019   if (CodeGenOpts.ControlFlowGuard) {
1020     // Function ID tables and checks for Control Flow Guard (cfguard=2).
1021     getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 2);
1022   } else if (CodeGenOpts.ControlFlowGuardNoChecks) {
1023     // Function ID tables for Control Flow Guard (cfguard=1).
1024     getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 1);
1025   }
1026   if (CodeGenOpts.EHContGuard) {
1027     // Function ID tables for EH Continuation Guard.
1028     getModule().addModuleFlag(llvm::Module::Warning, "ehcontguard", 1);
1029   }
1030   if (Context.getLangOpts().Kernel) {
1031     // Note if we are compiling with /kernel.
1032     getModule().addModuleFlag(llvm::Module::Warning, "ms-kernel", 1);
1033   }
1034   if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
1035     // We don't support LTO with 2 with different StrictVTablePointers
1036     // FIXME: we could support it by stripping all the information introduced
1037     // by StrictVTablePointers.
1038 
1039     getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
1040 
1041     llvm::Metadata *Ops[2] = {
1042               llvm::MDString::get(VMContext, "StrictVTablePointers"),
1043               llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1044                   llvm::Type::getInt32Ty(VMContext), 1))};
1045 
1046     getModule().addModuleFlag(llvm::Module::Require,
1047                               "StrictVTablePointersRequirement",
1048                               llvm::MDNode::get(VMContext, Ops));
1049   }
1050   if (getModuleDebugInfo())
1051     // We support a single version in the linked module. The LLVM
1052     // parser will drop debug info with a different version number
1053     // (and warn about it, too).
1054     getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
1055                               llvm::DEBUG_METADATA_VERSION);
1056 
1057   // We need to record the widths of enums and wchar_t, so that we can generate
1058   // the correct build attributes in the ARM backend. wchar_size is also used by
1059   // TargetLibraryInfo.
1060   uint64_t WCharWidth =
1061       Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
1062   getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
1063 
1064   if (getTriple().isOSzOS()) {
1065     getModule().addModuleFlag(llvm::Module::Warning,
1066                               "zos_product_major_version",
1067                               uint32_t(CLANG_VERSION_MAJOR));
1068     getModule().addModuleFlag(llvm::Module::Warning,
1069                               "zos_product_minor_version",
1070                               uint32_t(CLANG_VERSION_MINOR));
1071     getModule().addModuleFlag(llvm::Module::Warning, "zos_product_patchlevel",
1072                               uint32_t(CLANG_VERSION_PATCHLEVEL));
1073     std::string ProductId = getClangVendor() + "clang";
1074     getModule().addModuleFlag(llvm::Module::Error, "zos_product_id",
1075                               llvm::MDString::get(VMContext, ProductId));
1076 
1077     // Record the language because we need it for the PPA2.
1078     StringRef lang_str = languageToString(
1079         LangStandard::getLangStandardForKind(LangOpts.LangStd).Language);
1080     getModule().addModuleFlag(llvm::Module::Error, "zos_cu_language",
1081                               llvm::MDString::get(VMContext, lang_str));
1082 
1083     time_t TT = PreprocessorOpts.SourceDateEpoch
1084                     ? *PreprocessorOpts.SourceDateEpoch
1085                     : std::time(nullptr);
1086     getModule().addModuleFlag(llvm::Module::Max, "zos_translation_time",
1087                               static_cast<uint64_t>(TT));
1088 
1089     // Multiple modes will be supported here.
1090     getModule().addModuleFlag(llvm::Module::Error, "zos_le_char_mode",
1091                               llvm::MDString::get(VMContext, "ascii"));
1092   }
1093 
1094   llvm::Triple T = Context.getTargetInfo().getTriple();
1095   if (T.isARM() || T.isThumb()) {
1096     // The minimum width of an enum in bytes
1097     uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
1098     getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
1099   }
1100 
1101   if (T.isRISCV()) {
1102     StringRef ABIStr = Target.getABI();
1103     llvm::LLVMContext &Ctx = TheModule.getContext();
1104     getModule().addModuleFlag(llvm::Module::Error, "target-abi",
1105                               llvm::MDString::get(Ctx, ABIStr));
1106 
1107     // Add the canonical ISA string as metadata so the backend can set the ELF
1108     // attributes correctly. We use AppendUnique so LTO will keep all of the
1109     // unique ISA strings that were linked together.
1110     const std::vector<std::string> &Features =
1111         getTarget().getTargetOpts().Features;
1112     auto ParseResult =
1113         llvm::RISCVISAInfo::parseFeatures(T.isRISCV64() ? 64 : 32, Features);
1114     if (!errorToBool(ParseResult.takeError()))
1115       getModule().addModuleFlag(
1116           llvm::Module::AppendUnique, "riscv-isa",
1117           llvm::MDNode::get(
1118               Ctx, llvm::MDString::get(Ctx, (*ParseResult)->toString())));
1119   }
1120 
1121   if (CodeGenOpts.SanitizeCfiCrossDso) {
1122     // Indicate that we want cross-DSO control flow integrity checks.
1123     getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
1124   }
1125 
1126   if (CodeGenOpts.WholeProgramVTables) {
1127     // Indicate whether VFE was enabled for this module, so that the
1128     // vcall_visibility metadata added under whole program vtables is handled
1129     // appropriately in the optimizer.
1130     getModule().addModuleFlag(llvm::Module::Error, "Virtual Function Elim",
1131                               CodeGenOpts.VirtualFunctionElimination);
1132   }
1133 
1134   if (LangOpts.Sanitize.has(SanitizerKind::CFIICall)) {
1135     getModule().addModuleFlag(llvm::Module::Override,
1136                               "CFI Canonical Jump Tables",
1137                               CodeGenOpts.SanitizeCfiCanonicalJumpTables);
1138   }
1139 
1140   if (CodeGenOpts.SanitizeCfiICallNormalizeIntegers) {
1141     getModule().addModuleFlag(llvm::Module::Override, "cfi-normalize-integers",
1142                               1);
1143   }
1144 
1145   if (LangOpts.Sanitize.has(SanitizerKind::KCFI)) {
1146     getModule().addModuleFlag(llvm::Module::Override, "kcfi", 1);
1147     // KCFI assumes patchable-function-prefix is the same for all indirectly
1148     // called functions. Store the expected offset for code generation.
1149     if (CodeGenOpts.PatchableFunctionEntryOffset)
1150       getModule().addModuleFlag(llvm::Module::Override, "kcfi-offset",
1151                                 CodeGenOpts.PatchableFunctionEntryOffset);
1152   }
1153 
1154   if (CodeGenOpts.CFProtectionReturn &&
1155       Target.checkCFProtectionReturnSupported(getDiags())) {
1156     // Indicate that we want to instrument return control flow protection.
1157     getModule().addModuleFlag(llvm::Module::Min, "cf-protection-return",
1158                               1);
1159   }
1160 
1161   if (CodeGenOpts.CFProtectionBranch &&
1162       Target.checkCFProtectionBranchSupported(getDiags())) {
1163     // Indicate that we want to instrument branch control flow protection.
1164     getModule().addModuleFlag(llvm::Module::Min, "cf-protection-branch",
1165                               1);
1166   }
1167 
1168   if (CodeGenOpts.FunctionReturnThunks)
1169     getModule().addModuleFlag(llvm::Module::Override, "function_return_thunk_extern", 1);
1170 
1171   if (CodeGenOpts.IndirectBranchCSPrefix)
1172     getModule().addModuleFlag(llvm::Module::Override, "indirect_branch_cs_prefix", 1);
1173 
1174   // Add module metadata for return address signing (ignoring
1175   // non-leaf/all) and stack tagging. These are actually turned on by function
1176   // attributes, but we use module metadata to emit build attributes. This is
1177   // needed for LTO, where the function attributes are inside bitcode
1178   // serialised into a global variable by the time build attributes are
1179   // emitted, so we can't access them. LTO objects could be compiled with
1180   // different flags therefore module flags are set to "Min" behavior to achieve
1181   // the same end result of the normal build where e.g BTI is off if any object
1182   // doesn't support it.
1183   if (Context.getTargetInfo().hasFeature("ptrauth") &&
1184       LangOpts.getSignReturnAddressScope() !=
1185           LangOptions::SignReturnAddressScopeKind::None)
1186     getModule().addModuleFlag(llvm::Module::Override,
1187                               "sign-return-address-buildattr", 1);
1188   if (LangOpts.Sanitize.has(SanitizerKind::MemtagStack))
1189     getModule().addModuleFlag(llvm::Module::Override,
1190                               "tag-stack-memory-buildattr", 1);
1191 
1192   if (T.isARM() || T.isThumb() || T.isAArch64()) {
1193     if (LangOpts.BranchTargetEnforcement)
1194       getModule().addModuleFlag(llvm::Module::Min, "branch-target-enforcement",
1195                                 1);
1196     if (LangOpts.BranchProtectionPAuthLR)
1197       getModule().addModuleFlag(llvm::Module::Min, "branch-protection-pauth-lr",
1198                                 1);
1199     if (LangOpts.GuardedControlStack)
1200       getModule().addModuleFlag(llvm::Module::Min, "guarded-control-stack", 1);
1201     if (LangOpts.hasSignReturnAddress())
1202       getModule().addModuleFlag(llvm::Module::Min, "sign-return-address", 1);
1203     if (LangOpts.isSignReturnAddressScopeAll())
1204       getModule().addModuleFlag(llvm::Module::Min, "sign-return-address-all",
1205                                 1);
1206     if (!LangOpts.isSignReturnAddressWithAKey())
1207       getModule().addModuleFlag(llvm::Module::Min,
1208                                 "sign-return-address-with-bkey", 1);
1209 
1210     if (getTriple().isOSLinux()) {
1211       assert(getTriple().isOSBinFormatELF());
1212       using namespace llvm::ELF;
1213       uint64_t PAuthABIVersion =
1214           (LangOpts.PointerAuthIntrinsics
1215            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_INTRINSICS) |
1216           (LangOpts.PointerAuthCalls
1217            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_CALLS) |
1218           (LangOpts.PointerAuthReturns
1219            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_RETURNS) |
1220           (LangOpts.PointerAuthAuthTraps
1221            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_AUTHTRAPS) |
1222           (LangOpts.PointerAuthVTPtrAddressDiscrimination
1223            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_VPTRADDRDISCR) |
1224           (LangOpts.PointerAuthVTPtrTypeDiscrimination
1225            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_VPTRTYPEDISCR) |
1226           (LangOpts.PointerAuthInitFini
1227            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_INITFINI) |
1228           (LangOpts.PointerAuthInitFiniAddressDiscrimination
1229            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_INITFINIADDRDISC) |
1230           (LangOpts.PointerAuthELFGOT
1231            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_GOT) |
1232           (LangOpts.PointerAuthIndirectGotos
1233            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_GOTOS) |
1234           (LangOpts.PointerAuthTypeInfoVTPtrDiscrimination
1235            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_TYPEINFOVPTRDISCR) |
1236           (LangOpts.PointerAuthFunctionTypeDiscrimination
1237            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_FPTRTYPEDISCR);
1238       static_assert(AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_FPTRTYPEDISCR ==
1239                         AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_LAST,
1240                     "Update when new enum items are defined");
1241       if (PAuthABIVersion != 0) {
1242         getModule().addModuleFlag(llvm::Module::Error,
1243                                   "aarch64-elf-pauthabi-platform",
1244                                   AARCH64_PAUTH_PLATFORM_LLVM_LINUX);
1245         getModule().addModuleFlag(llvm::Module::Error,
1246                                   "aarch64-elf-pauthabi-version",
1247                                   PAuthABIVersion);
1248       }
1249     }
1250   }
1251 
1252   if (CodeGenOpts.StackClashProtector)
1253     getModule().addModuleFlag(
1254         llvm::Module::Override, "probe-stack",
1255         llvm::MDString::get(TheModule.getContext(), "inline-asm"));
1256 
1257   if (CodeGenOpts.StackProbeSize && CodeGenOpts.StackProbeSize != 4096)
1258     getModule().addModuleFlag(llvm::Module::Min, "stack-probe-size",
1259                               CodeGenOpts.StackProbeSize);
1260 
1261   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
1262     llvm::LLVMContext &Ctx = TheModule.getContext();
1263     getModule().addModuleFlag(
1264         llvm::Module::Error, "MemProfProfileFilename",
1265         llvm::MDString::get(Ctx, CodeGenOpts.MemoryProfileOutput));
1266   }
1267 
1268   if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
1269     // Indicate whether __nvvm_reflect should be configured to flush denormal
1270     // floating point values to 0.  (This corresponds to its "__CUDA_FTZ"
1271     // property.)
1272     getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
1273                               CodeGenOpts.FP32DenormalMode.Output !=
1274                                   llvm::DenormalMode::IEEE);
1275   }
1276 
1277   if (LangOpts.EHAsynch)
1278     getModule().addModuleFlag(llvm::Module::Warning, "eh-asynch", 1);
1279 
1280   // Indicate whether this Module was compiled with -fopenmp
1281   if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
1282     getModule().addModuleFlag(llvm::Module::Max, "openmp", LangOpts.OpenMP);
1283   if (getLangOpts().OpenMPIsTargetDevice)
1284     getModule().addModuleFlag(llvm::Module::Max, "openmp-device",
1285                               LangOpts.OpenMP);
1286 
1287   // Emit OpenCL specific module metadata: OpenCL/SPIR version.
1288   if (LangOpts.OpenCL || (LangOpts.CUDAIsDevice && getTriple().isSPIRV())) {
1289     EmitOpenCLMetadata();
1290     // Emit SPIR version.
1291     if (getTriple().isSPIR()) {
1292       // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
1293       // opencl.spir.version named metadata.
1294       // C++ for OpenCL has a distinct mapping for version compatibility with
1295       // OpenCL.
1296       auto Version = LangOpts.getOpenCLCompatibleVersion();
1297       llvm::Metadata *SPIRVerElts[] = {
1298           llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1299               Int32Ty, Version / 100)),
1300           llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1301               Int32Ty, (Version / 100 > 1) ? 0 : 2))};
1302       llvm::NamedMDNode *SPIRVerMD =
1303           TheModule.getOrInsertNamedMetadata("opencl.spir.version");
1304       llvm::LLVMContext &Ctx = TheModule.getContext();
1305       SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
1306     }
1307   }
1308 
1309   // HLSL related end of code gen work items.
1310   if (LangOpts.HLSL)
1311     getHLSLRuntime().finishCodeGen();
1312 
1313   if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
1314     assert(PLevel < 3 && "Invalid PIC Level");
1315     getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
1316     if (Context.getLangOpts().PIE)
1317       getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
1318   }
1319 
1320   if (getCodeGenOpts().CodeModel.size() > 0) {
1321     unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
1322                   .Case("tiny", llvm::CodeModel::Tiny)
1323                   .Case("small", llvm::CodeModel::Small)
1324                   .Case("kernel", llvm::CodeModel::Kernel)
1325                   .Case("medium", llvm::CodeModel::Medium)
1326                   .Case("large", llvm::CodeModel::Large)
1327                   .Default(~0u);
1328     if (CM != ~0u) {
1329       llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
1330       getModule().setCodeModel(codeModel);
1331 
1332       if ((CM == llvm::CodeModel::Medium || CM == llvm::CodeModel::Large) &&
1333           Context.getTargetInfo().getTriple().getArch() ==
1334               llvm::Triple::x86_64) {
1335         getModule().setLargeDataThreshold(getCodeGenOpts().LargeDataThreshold);
1336       }
1337     }
1338   }
1339 
1340   if (CodeGenOpts.NoPLT)
1341     getModule().setRtLibUseGOT();
1342   if (getTriple().isOSBinFormatELF() &&
1343       CodeGenOpts.DirectAccessExternalData !=
1344           getModule().getDirectAccessExternalData()) {
1345     getModule().setDirectAccessExternalData(
1346         CodeGenOpts.DirectAccessExternalData);
1347   }
1348   if (CodeGenOpts.UnwindTables)
1349     getModule().setUwtable(llvm::UWTableKind(CodeGenOpts.UnwindTables));
1350 
1351   switch (CodeGenOpts.getFramePointer()) {
1352   case CodeGenOptions::FramePointerKind::None:
1353     // 0 ("none") is the default.
1354     break;
1355   case CodeGenOptions::FramePointerKind::Reserved:
1356     getModule().setFramePointer(llvm::FramePointerKind::Reserved);
1357     break;
1358   case CodeGenOptions::FramePointerKind::NonLeaf:
1359     getModule().setFramePointer(llvm::FramePointerKind::NonLeaf);
1360     break;
1361   case CodeGenOptions::FramePointerKind::All:
1362     getModule().setFramePointer(llvm::FramePointerKind::All);
1363     break;
1364   }
1365 
1366   SimplifyPersonality();
1367 
1368   if (getCodeGenOpts().EmitDeclMetadata)
1369     EmitDeclMetadata();
1370 
1371   if (getCodeGenOpts().CoverageNotesFile.size() ||
1372       getCodeGenOpts().CoverageDataFile.size())
1373     EmitCoverageFile();
1374 
1375   if (CGDebugInfo *DI = getModuleDebugInfo())
1376     DI->finalize();
1377 
1378   if (getCodeGenOpts().EmitVersionIdentMetadata)
1379     EmitVersionIdentMetadata();
1380 
1381   if (!getCodeGenOpts().RecordCommandLine.empty())
1382     EmitCommandLineMetadata();
1383 
1384   if (!getCodeGenOpts().StackProtectorGuard.empty())
1385     getModule().setStackProtectorGuard(getCodeGenOpts().StackProtectorGuard);
1386   if (!getCodeGenOpts().StackProtectorGuardReg.empty())
1387     getModule().setStackProtectorGuardReg(
1388         getCodeGenOpts().StackProtectorGuardReg);
1389   if (!getCodeGenOpts().StackProtectorGuardSymbol.empty())
1390     getModule().setStackProtectorGuardSymbol(
1391         getCodeGenOpts().StackProtectorGuardSymbol);
1392   if (getCodeGenOpts().StackProtectorGuardOffset != INT_MAX)
1393     getModule().setStackProtectorGuardOffset(
1394         getCodeGenOpts().StackProtectorGuardOffset);
1395   if (getCodeGenOpts().StackAlignment)
1396     getModule().setOverrideStackAlignment(getCodeGenOpts().StackAlignment);
1397   if (getCodeGenOpts().SkipRaxSetup)
1398     getModule().addModuleFlag(llvm::Module::Override, "SkipRaxSetup", 1);
1399   if (getLangOpts().RegCall4)
1400     getModule().addModuleFlag(llvm::Module::Override, "RegCallv4", 1);
1401 
1402   if (getContext().getTargetInfo().getMaxTLSAlign())
1403     getModule().addModuleFlag(llvm::Module::Error, "MaxTLSAlign",
1404                               getContext().getTargetInfo().getMaxTLSAlign());
1405 
1406   getTargetCodeGenInfo().emitTargetGlobals(*this);
1407 
1408   getTargetCodeGenInfo().emitTargetMetadata(*this, MangledDeclNames);
1409 
1410   EmitBackendOptionsMetadata(getCodeGenOpts());
1411 
1412   // If there is device offloading code embed it in the host now.
1413   EmbedObject(&getModule(), CodeGenOpts, getDiags());
1414 
1415   // Set visibility from DLL storage class
1416   // We do this at the end of LLVM IR generation; after any operation
1417   // that might affect the DLL storage class or the visibility, and
1418   // before anything that might act on these.
1419   setVisibilityFromDLLStorageClass(LangOpts, getModule());
1420 
1421   // Check the tail call symbols are truly undefined.
1422   if (getTriple().isPPC() && !MustTailCallUndefinedGlobals.empty()) {
1423     for (auto &I : MustTailCallUndefinedGlobals) {
1424       if (!I.first->isDefined())
1425         getDiags().Report(I.second, diag::err_ppc_impossible_musttail) << 2;
1426       else {
1427         StringRef MangledName = getMangledName(GlobalDecl(I.first));
1428         llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
1429         if (!Entry || Entry->isWeakForLinker() ||
1430             Entry->isDeclarationForLinker())
1431           getDiags().Report(I.second, diag::err_ppc_impossible_musttail) << 2;
1432       }
1433     }
1434   }
1435 }
1436 
1437 void CodeGenModule::EmitOpenCLMetadata() {
1438   // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
1439   // opencl.ocl.version named metadata node.
1440   // C++ for OpenCL has a distinct mapping for versions compatible with OpenCL.
1441   auto CLVersion = LangOpts.getOpenCLCompatibleVersion();
1442 
1443   auto EmitVersion = [this](StringRef MDName, int Version) {
1444     llvm::Metadata *OCLVerElts[] = {
1445         llvm::ConstantAsMetadata::get(
1446             llvm::ConstantInt::get(Int32Ty, Version / 100)),
1447         llvm::ConstantAsMetadata::get(
1448             llvm::ConstantInt::get(Int32Ty, (Version % 100) / 10))};
1449     llvm::NamedMDNode *OCLVerMD = TheModule.getOrInsertNamedMetadata(MDName);
1450     llvm::LLVMContext &Ctx = TheModule.getContext();
1451     OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
1452   };
1453 
1454   EmitVersion("opencl.ocl.version", CLVersion);
1455   if (LangOpts.OpenCLCPlusPlus) {
1456     // In addition to the OpenCL compatible version, emit the C++ version.
1457     EmitVersion("opencl.cxx.version", LangOpts.OpenCLCPlusPlusVersion);
1458   }
1459 }
1460 
1461 void CodeGenModule::EmitBackendOptionsMetadata(
1462     const CodeGenOptions &CodeGenOpts) {
1463   if (getTriple().isRISCV()) {
1464     getModule().addModuleFlag(llvm::Module::Min, "SmallDataLimit",
1465                               CodeGenOpts.SmallDataLimit);
1466   }
1467 }
1468 
1469 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
1470   // Make sure that this type is translated.
1471   getTypes().UpdateCompletedType(TD);
1472 }
1473 
1474 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
1475   // Make sure that this type is translated.
1476   getTypes().RefreshTypeCacheForClass(RD);
1477 }
1478 
1479 llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
1480   if (!TBAA)
1481     return nullptr;
1482   return TBAA->getTypeInfo(QTy);
1483 }
1484 
1485 TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
1486   if (!TBAA)
1487     return TBAAAccessInfo();
1488   if (getLangOpts().CUDAIsDevice) {
1489     // As CUDA builtin surface/texture types are replaced, skip generating TBAA
1490     // access info.
1491     if (AccessType->isCUDADeviceBuiltinSurfaceType()) {
1492       if (getTargetCodeGenInfo().getCUDADeviceBuiltinSurfaceDeviceType() !=
1493           nullptr)
1494         return TBAAAccessInfo();
1495     } else if (AccessType->isCUDADeviceBuiltinTextureType()) {
1496       if (getTargetCodeGenInfo().getCUDADeviceBuiltinTextureDeviceType() !=
1497           nullptr)
1498         return TBAAAccessInfo();
1499     }
1500   }
1501   return TBAA->getAccessInfo(AccessType);
1502 }
1503 
1504 TBAAAccessInfo
1505 CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
1506   if (!TBAA)
1507     return TBAAAccessInfo();
1508   return TBAA->getVTablePtrAccessInfo(VTablePtrType);
1509 }
1510 
1511 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
1512   if (!TBAA)
1513     return nullptr;
1514   return TBAA->getTBAAStructInfo(QTy);
1515 }
1516 
1517 llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
1518   if (!TBAA)
1519     return nullptr;
1520   return TBAA->getBaseTypeInfo(QTy);
1521 }
1522 
1523 llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
1524   if (!TBAA)
1525     return nullptr;
1526   return TBAA->getAccessTagInfo(Info);
1527 }
1528 
1529 TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
1530                                                    TBAAAccessInfo TargetInfo) {
1531   if (!TBAA)
1532     return TBAAAccessInfo();
1533   return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
1534 }
1535 
1536 TBAAAccessInfo
1537 CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
1538                                                    TBAAAccessInfo InfoB) {
1539   if (!TBAA)
1540     return TBAAAccessInfo();
1541   return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
1542 }
1543 
1544 TBAAAccessInfo
1545 CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
1546                                               TBAAAccessInfo SrcInfo) {
1547   if (!TBAA)
1548     return TBAAAccessInfo();
1549   return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
1550 }
1551 
1552 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
1553                                                 TBAAAccessInfo TBAAInfo) {
1554   if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
1555     Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
1556 }
1557 
1558 void CodeGenModule::DecorateInstructionWithInvariantGroup(
1559     llvm::Instruction *I, const CXXRecordDecl *RD) {
1560   I->setMetadata(llvm::LLVMContext::MD_invariant_group,
1561                  llvm::MDNode::get(getLLVMContext(), {}));
1562 }
1563 
1564 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
1565   unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
1566   getDiags().Report(Context.getFullLoc(loc), diagID) << message;
1567 }
1568 
1569 /// ErrorUnsupported - Print out an error that codegen doesn't support the
1570 /// specified stmt yet.
1571 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
1572   unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
1573                                                "cannot compile this %0 yet");
1574   std::string Msg = Type;
1575   getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID)
1576       << Msg << S->getSourceRange();
1577 }
1578 
1579 /// ErrorUnsupported - Print out an error that codegen doesn't support the
1580 /// specified decl yet.
1581 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
1582   unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
1583                                                "cannot compile this %0 yet");
1584   std::string Msg = Type;
1585   getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
1586 }
1587 
1588 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
1589   return llvm::ConstantInt::get(SizeTy, size.getQuantity());
1590 }
1591 
1592 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
1593                                         const NamedDecl *D) const {
1594   // Internal definitions always have default visibility.
1595   if (GV->hasLocalLinkage()) {
1596     GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1597     return;
1598   }
1599   if (!D)
1600     return;
1601 
1602   // Set visibility for definitions, and for declarations if requested globally
1603   // or set explicitly.
1604   LinkageInfo LV = D->getLinkageAndVisibility();
1605 
1606   // OpenMP declare target variables must be visible to the host so they can
1607   // be registered. We require protected visibility unless the variable has
1608   // the DT_nohost modifier and does not need to be registered.
1609   if (Context.getLangOpts().OpenMP &&
1610       Context.getLangOpts().OpenMPIsTargetDevice && isa<VarDecl>(D) &&
1611       D->hasAttr<OMPDeclareTargetDeclAttr>() &&
1612       D->getAttr<OMPDeclareTargetDeclAttr>()->getDevType() !=
1613           OMPDeclareTargetDeclAttr::DT_NoHost &&
1614       LV.getVisibility() == HiddenVisibility) {
1615     GV->setVisibility(llvm::GlobalValue::ProtectedVisibility);
1616     return;
1617   }
1618 
1619   if (GV->hasDLLExportStorageClass() || GV->hasDLLImportStorageClass()) {
1620     // Reject incompatible dlllstorage and visibility annotations.
1621     if (!LV.isVisibilityExplicit())
1622       return;
1623     if (GV->hasDLLExportStorageClass()) {
1624       if (LV.getVisibility() == HiddenVisibility)
1625         getDiags().Report(D->getLocation(),
1626                           diag::err_hidden_visibility_dllexport);
1627     } else if (LV.getVisibility() != DefaultVisibility) {
1628       getDiags().Report(D->getLocation(),
1629                         diag::err_non_default_visibility_dllimport);
1630     }
1631     return;
1632   }
1633 
1634   if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
1635       !GV->isDeclarationForLinker())
1636     GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
1637 }
1638 
1639 static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
1640                                  llvm::GlobalValue *GV) {
1641   if (GV->hasLocalLinkage())
1642     return true;
1643 
1644   if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
1645     return true;
1646 
1647   // DLLImport explicitly marks the GV as external.
1648   if (GV->hasDLLImportStorageClass())
1649     return false;
1650 
1651   const llvm::Triple &TT = CGM.getTriple();
1652   const auto &CGOpts = CGM.getCodeGenOpts();
1653   if (TT.isWindowsGNUEnvironment()) {
1654     // In MinGW, variables without DLLImport can still be automatically
1655     // imported from a DLL by the linker; don't mark variables that
1656     // potentially could come from another DLL as DSO local.
1657 
1658     // With EmulatedTLS, TLS variables can be autoimported from other DLLs
1659     // (and this actually happens in the public interface of libstdc++), so
1660     // such variables can't be marked as DSO local. (Native TLS variables
1661     // can't be dllimported at all, though.)
1662     if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
1663         (!GV->isThreadLocal() || CGM.getCodeGenOpts().EmulatedTLS) &&
1664         CGOpts.AutoImport)
1665       return false;
1666   }
1667 
1668   // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
1669   // remain unresolved in the link, they can be resolved to zero, which is
1670   // outside the current DSO.
1671   if (TT.isOSBinFormatCOFF() && GV->hasExternalWeakLinkage())
1672     return false;
1673 
1674   // Every other GV is local on COFF.
1675   // Make an exception for windows OS in the triple: Some firmware builds use
1676   // *-win32-macho triples. This (accidentally?) produced windows relocations
1677   // without GOT tables in older clang versions; Keep this behaviour.
1678   // FIXME: even thread local variables?
1679   if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
1680     return true;
1681 
1682   // Only handle COFF and ELF for now.
1683   if (!TT.isOSBinFormatELF())
1684     return false;
1685 
1686   // If this is not an executable, don't assume anything is local.
1687   llvm::Reloc::Model RM = CGOpts.RelocationModel;
1688   const auto &LOpts = CGM.getLangOpts();
1689   if (RM != llvm::Reloc::Static && !LOpts.PIE) {
1690     // On ELF, if -fno-semantic-interposition is specified and the target
1691     // supports local aliases, there will be neither CC1
1692     // -fsemantic-interposition nor -fhalf-no-semantic-interposition. Set
1693     // dso_local on the function if using a local alias is preferable (can avoid
1694     // PLT indirection).
1695     if (!(isa<llvm::Function>(GV) && GV->canBenefitFromLocalAlias()))
1696       return false;
1697     return !(CGM.getLangOpts().SemanticInterposition ||
1698              CGM.getLangOpts().HalfNoSemanticInterposition);
1699   }
1700 
1701   // A definition cannot be preempted from an executable.
1702   if (!GV->isDeclarationForLinker())
1703     return true;
1704 
1705   // Most PIC code sequences that assume that a symbol is local cannot produce a
1706   // 0 if it turns out the symbol is undefined. While this is ABI and relocation
1707   // depended, it seems worth it to handle it here.
1708   if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
1709     return false;
1710 
1711   // PowerPC64 prefers TOC indirection to avoid copy relocations.
1712   if (TT.isPPC64())
1713     return false;
1714 
1715   if (CGOpts.DirectAccessExternalData) {
1716     // If -fdirect-access-external-data (default for -fno-pic), set dso_local
1717     // for non-thread-local variables. If the symbol is not defined in the
1718     // executable, a copy relocation will be needed at link time. dso_local is
1719     // excluded for thread-local variables because they generally don't support
1720     // copy relocations.
1721     if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
1722       if (!Var->isThreadLocal())
1723         return true;
1724 
1725     // -fno-pic sets dso_local on a function declaration to allow direct
1726     // accesses when taking its address (similar to a data symbol). If the
1727     // function is not defined in the executable, a canonical PLT entry will be
1728     // needed at link time. -fno-direct-access-external-data can avoid the
1729     // canonical PLT entry. We don't generalize this condition to -fpie/-fpic as
1730     // it could just cause trouble without providing perceptible benefits.
1731     if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
1732       return true;
1733   }
1734 
1735   // If we can use copy relocations we can assume it is local.
1736 
1737   // Otherwise don't assume it is local.
1738   return false;
1739 }
1740 
1741 void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
1742   GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
1743 }
1744 
1745 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1746                                           GlobalDecl GD) const {
1747   const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
1748   // C++ destructors have a few C++ ABI specific special cases.
1749   if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
1750     getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
1751     return;
1752   }
1753   setDLLImportDLLExport(GV, D);
1754 }
1755 
1756 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1757                                           const NamedDecl *D) const {
1758   if (D && D->isExternallyVisible()) {
1759     if (D->hasAttr<DLLImportAttr>())
1760       GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
1761     else if ((D->hasAttr<DLLExportAttr>() ||
1762               shouldMapVisibilityToDLLExport(D)) &&
1763              !GV->isDeclarationForLinker())
1764       GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
1765   }
1766 }
1767 
1768 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1769                                     GlobalDecl GD) const {
1770   setDLLImportDLLExport(GV, GD);
1771   setGVPropertiesAux(GV, dyn_cast<NamedDecl>(GD.getDecl()));
1772 }
1773 
1774 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1775                                     const NamedDecl *D) const {
1776   setDLLImportDLLExport(GV, D);
1777   setGVPropertiesAux(GV, D);
1778 }
1779 
1780 void CodeGenModule::setGVPropertiesAux(llvm::GlobalValue *GV,
1781                                        const NamedDecl *D) const {
1782   setGlobalVisibility(GV, D);
1783   setDSOLocal(GV);
1784   GV->setPartition(CodeGenOpts.SymbolPartition);
1785 }
1786 
1787 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
1788   return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
1789       .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
1790       .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
1791       .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
1792       .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
1793 }
1794 
1795 llvm::GlobalVariable::ThreadLocalMode
1796 CodeGenModule::GetDefaultLLVMTLSModel() const {
1797   switch (CodeGenOpts.getDefaultTLSModel()) {
1798   case CodeGenOptions::GeneralDynamicTLSModel:
1799     return llvm::GlobalVariable::GeneralDynamicTLSModel;
1800   case CodeGenOptions::LocalDynamicTLSModel:
1801     return llvm::GlobalVariable::LocalDynamicTLSModel;
1802   case CodeGenOptions::InitialExecTLSModel:
1803     return llvm::GlobalVariable::InitialExecTLSModel;
1804   case CodeGenOptions::LocalExecTLSModel:
1805     return llvm::GlobalVariable::LocalExecTLSModel;
1806   }
1807   llvm_unreachable("Invalid TLS model!");
1808 }
1809 
1810 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
1811   assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
1812 
1813   llvm::GlobalValue::ThreadLocalMode TLM;
1814   TLM = GetDefaultLLVMTLSModel();
1815 
1816   // Override the TLS model if it is explicitly specified.
1817   if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
1818     TLM = GetLLVMTLSModel(Attr->getModel());
1819   }
1820 
1821   GV->setThreadLocalMode(TLM);
1822 }
1823 
1824 static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
1825                                           StringRef Name) {
1826   const TargetInfo &Target = CGM.getTarget();
1827   return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
1828 }
1829 
1830 static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
1831                                                  const CPUSpecificAttr *Attr,
1832                                                  unsigned CPUIndex,
1833                                                  raw_ostream &Out) {
1834   // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
1835   // supported.
1836   if (Attr)
1837     Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
1838   else if (CGM.getTarget().supportsIFunc())
1839     Out << ".resolver";
1840 }
1841 
1842 // Returns true if GD is a function decl with internal linkage and
1843 // needs a unique suffix after the mangled name.
1844 static bool isUniqueInternalLinkageDecl(GlobalDecl GD,
1845                                         CodeGenModule &CGM) {
1846   const Decl *D = GD.getDecl();
1847   return !CGM.getModuleNameHash().empty() && isa<FunctionDecl>(D) &&
1848          (CGM.getFunctionLinkage(GD) == llvm::GlobalValue::InternalLinkage);
1849 }
1850 
1851 static std::string getMangledNameImpl(CodeGenModule &CGM, GlobalDecl GD,
1852                                       const NamedDecl *ND,
1853                                       bool OmitMultiVersionMangling = false) {
1854   SmallString<256> Buffer;
1855   llvm::raw_svector_ostream Out(Buffer);
1856   MangleContext &MC = CGM.getCXXABI().getMangleContext();
1857   if (!CGM.getModuleNameHash().empty())
1858     MC.needsUniqueInternalLinkageNames();
1859   bool ShouldMangle = MC.shouldMangleDeclName(ND);
1860   if (ShouldMangle)
1861     MC.mangleName(GD.getWithDecl(ND), Out);
1862   else {
1863     IdentifierInfo *II = ND->getIdentifier();
1864     assert(II && "Attempt to mangle unnamed decl.");
1865     const auto *FD = dyn_cast<FunctionDecl>(ND);
1866 
1867     if (FD &&
1868         FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
1869       if (CGM.getLangOpts().RegCall4)
1870         Out << "__regcall4__" << II->getName();
1871       else
1872         Out << "__regcall3__" << II->getName();
1873     } else if (FD && FD->hasAttr<CUDAGlobalAttr>() &&
1874                GD.getKernelReferenceKind() == KernelReferenceKind::Stub) {
1875       Out << "__device_stub__" << II->getName();
1876     } else {
1877       Out << II->getName();
1878     }
1879   }
1880 
1881   // Check if the module name hash should be appended for internal linkage
1882   // symbols.   This should come before multi-version target suffixes are
1883   // appended. This is to keep the name and module hash suffix of the
1884   // internal linkage function together.  The unique suffix should only be
1885   // added when name mangling is done to make sure that the final name can
1886   // be properly demangled.  For example, for C functions without prototypes,
1887   // name mangling is not done and the unique suffix should not be appeneded
1888   // then.
1889   if (ShouldMangle && isUniqueInternalLinkageDecl(GD, CGM)) {
1890     assert(CGM.getCodeGenOpts().UniqueInternalLinkageNames &&
1891            "Hash computed when not explicitly requested");
1892     Out << CGM.getModuleNameHash();
1893   }
1894 
1895   if (const auto *FD = dyn_cast<FunctionDecl>(ND))
1896     if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
1897       switch (FD->getMultiVersionKind()) {
1898       case MultiVersionKind::CPUDispatch:
1899       case MultiVersionKind::CPUSpecific:
1900         AppendCPUSpecificCPUDispatchMangling(CGM,
1901                                              FD->getAttr<CPUSpecificAttr>(),
1902                                              GD.getMultiVersionIndex(), Out);
1903         break;
1904       case MultiVersionKind::Target: {
1905         auto *Attr = FD->getAttr<TargetAttr>();
1906         assert(Attr && "Expected TargetAttr to be present "
1907                        "for attribute mangling");
1908         const ABIInfo &Info = CGM.getTargetCodeGenInfo().getABIInfo();
1909         Info.appendAttributeMangling(Attr, Out);
1910         break;
1911       }
1912       case MultiVersionKind::TargetVersion: {
1913         auto *Attr = FD->getAttr<TargetVersionAttr>();
1914         assert(Attr && "Expected TargetVersionAttr to be present "
1915                        "for attribute mangling");
1916         const ABIInfo &Info = CGM.getTargetCodeGenInfo().getABIInfo();
1917         Info.appendAttributeMangling(Attr, Out);
1918         break;
1919       }
1920       case MultiVersionKind::TargetClones: {
1921         auto *Attr = FD->getAttr<TargetClonesAttr>();
1922         assert(Attr && "Expected TargetClonesAttr to be present "
1923                        "for attribute mangling");
1924         unsigned Index = GD.getMultiVersionIndex();
1925         const ABIInfo &Info = CGM.getTargetCodeGenInfo().getABIInfo();
1926         Info.appendAttributeMangling(Attr, Index, Out);
1927         break;
1928       }
1929       case MultiVersionKind::None:
1930         llvm_unreachable("None multiversion type isn't valid here");
1931       }
1932     }
1933 
1934   // Make unique name for device side static file-scope variable for HIP.
1935   if (CGM.getContext().shouldExternalize(ND) &&
1936       CGM.getLangOpts().GPURelocatableDeviceCode &&
1937       CGM.getLangOpts().CUDAIsDevice)
1938     CGM.printPostfixForExternalizedDecl(Out, ND);
1939 
1940   return std::string(Out.str());
1941 }
1942 
1943 void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
1944                                             const FunctionDecl *FD,
1945                                             StringRef &CurName) {
1946   if (!FD->isMultiVersion())
1947     return;
1948 
1949   // Get the name of what this would be without the 'target' attribute.  This
1950   // allows us to lookup the version that was emitted when this wasn't a
1951   // multiversion function.
1952   std::string NonTargetName =
1953       getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
1954   GlobalDecl OtherGD;
1955   if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
1956     assert(OtherGD.getCanonicalDecl()
1957                .getDecl()
1958                ->getAsFunction()
1959                ->isMultiVersion() &&
1960            "Other GD should now be a multiversioned function");
1961     // OtherFD is the version of this function that was mangled BEFORE
1962     // becoming a MultiVersion function.  It potentially needs to be updated.
1963     const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
1964                                       .getDecl()
1965                                       ->getAsFunction()
1966                                       ->getMostRecentDecl();
1967     std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
1968     // This is so that if the initial version was already the 'default'
1969     // version, we don't try to update it.
1970     if (OtherName != NonTargetName) {
1971       // Remove instead of erase, since others may have stored the StringRef
1972       // to this.
1973       const auto ExistingRecord = Manglings.find(NonTargetName);
1974       if (ExistingRecord != std::end(Manglings))
1975         Manglings.remove(&(*ExistingRecord));
1976       auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
1977       StringRef OtherNameRef = MangledDeclNames[OtherGD.getCanonicalDecl()] =
1978           Result.first->first();
1979       // If this is the current decl is being created, make sure we update the name.
1980       if (GD.getCanonicalDecl() == OtherGD.getCanonicalDecl())
1981         CurName = OtherNameRef;
1982       if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
1983         Entry->setName(OtherName);
1984     }
1985   }
1986 }
1987 
1988 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
1989   GlobalDecl CanonicalGD = GD.getCanonicalDecl();
1990 
1991   // Some ABIs don't have constructor variants.  Make sure that base and
1992   // complete constructors get mangled the same.
1993   if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
1994     if (!getTarget().getCXXABI().hasConstructorVariants()) {
1995       CXXCtorType OrigCtorType = GD.getCtorType();
1996       assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
1997       if (OrigCtorType == Ctor_Base)
1998         CanonicalGD = GlobalDecl(CD, Ctor_Complete);
1999     }
2000   }
2001 
2002   // In CUDA/HIP device compilation with -fgpu-rdc, the mangled name of a
2003   // static device variable depends on whether the variable is referenced by
2004   // a host or device host function. Therefore the mangled name cannot be
2005   // cached.
2006   if (!LangOpts.CUDAIsDevice || !getContext().mayExternalize(GD.getDecl())) {
2007     auto FoundName = MangledDeclNames.find(CanonicalGD);
2008     if (FoundName != MangledDeclNames.end())
2009       return FoundName->second;
2010   }
2011 
2012   // Keep the first result in the case of a mangling collision.
2013   const auto *ND = cast<NamedDecl>(GD.getDecl());
2014   std::string MangledName = getMangledNameImpl(*this, GD, ND);
2015 
2016   // Ensure either we have different ABIs between host and device compilations,
2017   // says host compilation following MSVC ABI but device compilation follows
2018   // Itanium C++ ABI or, if they follow the same ABI, kernel names after
2019   // mangling should be the same after name stubbing. The later checking is
2020   // very important as the device kernel name being mangled in host-compilation
2021   // is used to resolve the device binaries to be executed. Inconsistent naming
2022   // result in undefined behavior. Even though we cannot check that naming
2023   // directly between host- and device-compilations, the host- and
2024   // device-mangling in host compilation could help catching certain ones.
2025   assert(!isa<FunctionDecl>(ND) || !ND->hasAttr<CUDAGlobalAttr>() ||
2026          getContext().shouldExternalize(ND) || getLangOpts().CUDAIsDevice ||
2027          (getContext().getAuxTargetInfo() &&
2028           (getContext().getAuxTargetInfo()->getCXXABI() !=
2029            getContext().getTargetInfo().getCXXABI())) ||
2030          getCUDARuntime().getDeviceSideName(ND) ==
2031              getMangledNameImpl(
2032                  *this,
2033                  GD.getWithKernelReferenceKind(KernelReferenceKind::Kernel),
2034                  ND));
2035 
2036   auto Result = Manglings.insert(std::make_pair(MangledName, GD));
2037   return MangledDeclNames[CanonicalGD] = Result.first->first();
2038 }
2039 
2040 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
2041                                              const BlockDecl *BD) {
2042   MangleContext &MangleCtx = getCXXABI().getMangleContext();
2043   const Decl *D = GD.getDecl();
2044 
2045   SmallString<256> Buffer;
2046   llvm::raw_svector_ostream Out(Buffer);
2047   if (!D)
2048     MangleCtx.mangleGlobalBlock(BD,
2049       dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
2050   else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
2051     MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
2052   else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
2053     MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
2054   else
2055     MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
2056 
2057   auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
2058   return Result.first->first();
2059 }
2060 
2061 const GlobalDecl CodeGenModule::getMangledNameDecl(StringRef Name) {
2062   auto it = MangledDeclNames.begin();
2063   while (it != MangledDeclNames.end()) {
2064     if (it->second == Name)
2065       return it->first;
2066     it++;
2067   }
2068   return GlobalDecl();
2069 }
2070 
2071 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
2072   return getModule().getNamedValue(Name);
2073 }
2074 
2075 /// AddGlobalCtor - Add a function to the list that will be called before
2076 /// main() runs.
2077 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
2078                                   unsigned LexOrder,
2079                                   llvm::Constant *AssociatedData) {
2080   // FIXME: Type coercion of void()* types.
2081   GlobalCtors.push_back(Structor(Priority, LexOrder, Ctor, AssociatedData));
2082 }
2083 
2084 /// AddGlobalDtor - Add a function to the list that will be called
2085 /// when the module is unloaded.
2086 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority,
2087                                   bool IsDtorAttrFunc) {
2088   if (CodeGenOpts.RegisterGlobalDtorsWithAtExit &&
2089       (!getContext().getTargetInfo().getTriple().isOSAIX() || IsDtorAttrFunc)) {
2090     DtorsUsingAtExit[Priority].push_back(Dtor);
2091     return;
2092   }
2093 
2094   // FIXME: Type coercion of void()* types.
2095   GlobalDtors.push_back(Structor(Priority, ~0U, Dtor, nullptr));
2096 }
2097 
2098 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
2099   if (Fns.empty()) return;
2100 
2101   const PointerAuthSchema &InitFiniAuthSchema =
2102       getCodeGenOpts().PointerAuth.InitFiniPointers;
2103 
2104   // Ctor function type is ptr.
2105   llvm::PointerType *PtrTy = llvm::PointerType::get(
2106       getLLVMContext(), TheModule.getDataLayout().getProgramAddressSpace());
2107 
2108   // Get the type of a ctor entry, { i32, ptr, ptr }.
2109   llvm::StructType *CtorStructTy = llvm::StructType::get(Int32Ty, PtrTy, PtrTy);
2110 
2111   // Construct the constructor and destructor arrays.
2112   ConstantInitBuilder Builder(*this);
2113   auto Ctors = Builder.beginArray(CtorStructTy);
2114   for (const auto &I : Fns) {
2115     auto Ctor = Ctors.beginStruct(CtorStructTy);
2116     Ctor.addInt(Int32Ty, I.Priority);
2117     if (InitFiniAuthSchema) {
2118       llvm::Constant *StorageAddress =
2119           (InitFiniAuthSchema.isAddressDiscriminated()
2120                ? llvm::ConstantExpr::getIntToPtr(
2121                      llvm::ConstantInt::get(
2122                          IntPtrTy,
2123                          llvm::ConstantPtrAuth::AddrDiscriminator_CtorsDtors),
2124                      PtrTy)
2125                : nullptr);
2126       llvm::Constant *SignedCtorPtr = getConstantSignedPointer(
2127           I.Initializer, InitFiniAuthSchema.getKey(), StorageAddress,
2128           llvm::ConstantInt::get(
2129               SizeTy, InitFiniAuthSchema.getConstantDiscrimination()));
2130       Ctor.add(SignedCtorPtr);
2131     } else {
2132       Ctor.add(I.Initializer);
2133     }
2134     if (I.AssociatedData)
2135       Ctor.add(I.AssociatedData);
2136     else
2137       Ctor.addNullPointer(PtrTy);
2138     Ctor.finishAndAddTo(Ctors);
2139   }
2140 
2141   auto List = Ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
2142                                           /*constant*/ false,
2143                                           llvm::GlobalValue::AppendingLinkage);
2144 
2145   // The LTO linker doesn't seem to like it when we set an alignment
2146   // on appending variables.  Take it off as a workaround.
2147   List->setAlignment(std::nullopt);
2148 
2149   Fns.clear();
2150 }
2151 
2152 llvm::GlobalValue::LinkageTypes
2153 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
2154   const auto *D = cast<FunctionDecl>(GD.getDecl());
2155 
2156   GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
2157 
2158   if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
2159     return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
2160 
2161   return getLLVMLinkageForDeclarator(D, Linkage);
2162 }
2163 
2164 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
2165   llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
2166   if (!MDS) return nullptr;
2167 
2168   return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
2169 }
2170 
2171 llvm::ConstantInt *CodeGenModule::CreateKCFITypeId(QualType T) {
2172   if (auto *FnType = T->getAs<FunctionProtoType>())
2173     T = getContext().getFunctionType(
2174         FnType->getReturnType(), FnType->getParamTypes(),
2175         FnType->getExtProtoInfo().withExceptionSpec(EST_None));
2176 
2177   std::string OutName;
2178   llvm::raw_string_ostream Out(OutName);
2179   getCXXABI().getMangleContext().mangleCanonicalTypeName(
2180       T, Out, getCodeGenOpts().SanitizeCfiICallNormalizeIntegers);
2181 
2182   if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
2183     Out << ".normalized";
2184 
2185   return llvm::ConstantInt::get(Int32Ty,
2186                                 static_cast<uint32_t>(llvm::xxHash64(OutName)));
2187 }
2188 
2189 void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
2190                                               const CGFunctionInfo &Info,
2191                                               llvm::Function *F, bool IsThunk) {
2192   unsigned CallingConv;
2193   llvm::AttributeList PAL;
2194   ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv,
2195                          /*AttrOnCallSite=*/false, IsThunk);
2196   if (CallingConv == llvm::CallingConv::X86_VectorCall &&
2197       getTarget().getTriple().isWindowsArm64EC()) {
2198     SourceLocation Loc;
2199     if (const Decl *D = GD.getDecl())
2200       Loc = D->getLocation();
2201 
2202     Error(Loc, "__vectorcall calling convention is not currently supported");
2203   }
2204   F->setAttributes(PAL);
2205   F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
2206 }
2207 
2208 static void removeImageAccessQualifier(std::string& TyName) {
2209   std::string ReadOnlyQual("__read_only");
2210   std::string::size_type ReadOnlyPos = TyName.find(ReadOnlyQual);
2211   if (ReadOnlyPos != std::string::npos)
2212     // "+ 1" for the space after access qualifier.
2213     TyName.erase(ReadOnlyPos, ReadOnlyQual.size() + 1);
2214   else {
2215     std::string WriteOnlyQual("__write_only");
2216     std::string::size_type WriteOnlyPos = TyName.find(WriteOnlyQual);
2217     if (WriteOnlyPos != std::string::npos)
2218       TyName.erase(WriteOnlyPos, WriteOnlyQual.size() + 1);
2219     else {
2220       std::string ReadWriteQual("__read_write");
2221       std::string::size_type ReadWritePos = TyName.find(ReadWriteQual);
2222       if (ReadWritePos != std::string::npos)
2223         TyName.erase(ReadWritePos, ReadWriteQual.size() + 1);
2224     }
2225   }
2226 }
2227 
2228 // Returns the address space id that should be produced to the
2229 // kernel_arg_addr_space metadata. This is always fixed to the ids
2230 // as specified in the SPIR 2.0 specification in order to differentiate
2231 // for example in clGetKernelArgInfo() implementation between the address
2232 // spaces with targets without unique mapping to the OpenCL address spaces
2233 // (basically all single AS CPUs).
2234 static unsigned ArgInfoAddressSpace(LangAS AS) {
2235   switch (AS) {
2236   case LangAS::opencl_global:
2237     return 1;
2238   case LangAS::opencl_constant:
2239     return 2;
2240   case LangAS::opencl_local:
2241     return 3;
2242   case LangAS::opencl_generic:
2243     return 4; // Not in SPIR 2.0 specs.
2244   case LangAS::opencl_global_device:
2245     return 5;
2246   case LangAS::opencl_global_host:
2247     return 6;
2248   default:
2249     return 0; // Assume private.
2250   }
2251 }
2252 
2253 void CodeGenModule::GenKernelArgMetadata(llvm::Function *Fn,
2254                                          const FunctionDecl *FD,
2255                                          CodeGenFunction *CGF) {
2256   assert(((FD && CGF) || (!FD && !CGF)) &&
2257          "Incorrect use - FD and CGF should either be both null or not!");
2258   // Create MDNodes that represent the kernel arg metadata.
2259   // Each MDNode is a list in the form of "key", N number of values which is
2260   // the same number of values as their are kernel arguments.
2261 
2262   const PrintingPolicy &Policy = Context.getPrintingPolicy();
2263 
2264   // MDNode for the kernel argument address space qualifiers.
2265   SmallVector<llvm::Metadata *, 8> addressQuals;
2266 
2267   // MDNode for the kernel argument access qualifiers (images only).
2268   SmallVector<llvm::Metadata *, 8> accessQuals;
2269 
2270   // MDNode for the kernel argument type names.
2271   SmallVector<llvm::Metadata *, 8> argTypeNames;
2272 
2273   // MDNode for the kernel argument base type names.
2274   SmallVector<llvm::Metadata *, 8> argBaseTypeNames;
2275 
2276   // MDNode for the kernel argument type qualifiers.
2277   SmallVector<llvm::Metadata *, 8> argTypeQuals;
2278 
2279   // MDNode for the kernel argument names.
2280   SmallVector<llvm::Metadata *, 8> argNames;
2281 
2282   if (FD && CGF)
2283     for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
2284       const ParmVarDecl *parm = FD->getParamDecl(i);
2285       // Get argument name.
2286       argNames.push_back(llvm::MDString::get(VMContext, parm->getName()));
2287 
2288       if (!getLangOpts().OpenCL)
2289         continue;
2290       QualType ty = parm->getType();
2291       std::string typeQuals;
2292 
2293       // Get image and pipe access qualifier:
2294       if (ty->isImageType() || ty->isPipeType()) {
2295         const Decl *PDecl = parm;
2296         if (const auto *TD = ty->getAs<TypedefType>())
2297           PDecl = TD->getDecl();
2298         const OpenCLAccessAttr *A = PDecl->getAttr<OpenCLAccessAttr>();
2299         if (A && A->isWriteOnly())
2300           accessQuals.push_back(llvm::MDString::get(VMContext, "write_only"));
2301         else if (A && A->isReadWrite())
2302           accessQuals.push_back(llvm::MDString::get(VMContext, "read_write"));
2303         else
2304           accessQuals.push_back(llvm::MDString::get(VMContext, "read_only"));
2305       } else
2306         accessQuals.push_back(llvm::MDString::get(VMContext, "none"));
2307 
2308       auto getTypeSpelling = [&](QualType Ty) {
2309         auto typeName = Ty.getUnqualifiedType().getAsString(Policy);
2310 
2311         if (Ty.isCanonical()) {
2312           StringRef typeNameRef = typeName;
2313           // Turn "unsigned type" to "utype"
2314           if (typeNameRef.consume_front("unsigned "))
2315             return std::string("u") + typeNameRef.str();
2316           if (typeNameRef.consume_front("signed "))
2317             return typeNameRef.str();
2318         }
2319 
2320         return typeName;
2321       };
2322 
2323       if (ty->isPointerType()) {
2324         QualType pointeeTy = ty->getPointeeType();
2325 
2326         // Get address qualifier.
2327         addressQuals.push_back(
2328             llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(
2329                 ArgInfoAddressSpace(pointeeTy.getAddressSpace()))));
2330 
2331         // Get argument type name.
2332         std::string typeName = getTypeSpelling(pointeeTy) + "*";
2333         std::string baseTypeName =
2334             getTypeSpelling(pointeeTy.getCanonicalType()) + "*";
2335         argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
2336         argBaseTypeNames.push_back(
2337             llvm::MDString::get(VMContext, baseTypeName));
2338 
2339         // Get argument type qualifiers:
2340         if (ty.isRestrictQualified())
2341           typeQuals = "restrict";
2342         if (pointeeTy.isConstQualified() ||
2343             (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
2344           typeQuals += typeQuals.empty() ? "const" : " const";
2345         if (pointeeTy.isVolatileQualified())
2346           typeQuals += typeQuals.empty() ? "volatile" : " volatile";
2347       } else {
2348         uint32_t AddrSpc = 0;
2349         bool isPipe = ty->isPipeType();
2350         if (ty->isImageType() || isPipe)
2351           AddrSpc = ArgInfoAddressSpace(LangAS::opencl_global);
2352 
2353         addressQuals.push_back(
2354             llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(AddrSpc)));
2355 
2356         // Get argument type name.
2357         ty = isPipe ? ty->castAs<PipeType>()->getElementType() : ty;
2358         std::string typeName = getTypeSpelling(ty);
2359         std::string baseTypeName = getTypeSpelling(ty.getCanonicalType());
2360 
2361         // Remove access qualifiers on images
2362         // (as they are inseparable from type in clang implementation,
2363         // but OpenCL spec provides a special query to get access qualifier
2364         // via clGetKernelArgInfo with CL_KERNEL_ARG_ACCESS_QUALIFIER):
2365         if (ty->isImageType()) {
2366           removeImageAccessQualifier(typeName);
2367           removeImageAccessQualifier(baseTypeName);
2368         }
2369 
2370         argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
2371         argBaseTypeNames.push_back(
2372             llvm::MDString::get(VMContext, baseTypeName));
2373 
2374         if (isPipe)
2375           typeQuals = "pipe";
2376       }
2377       argTypeQuals.push_back(llvm::MDString::get(VMContext, typeQuals));
2378     }
2379 
2380   if (getLangOpts().OpenCL) {
2381     Fn->setMetadata("kernel_arg_addr_space",
2382                     llvm::MDNode::get(VMContext, addressQuals));
2383     Fn->setMetadata("kernel_arg_access_qual",
2384                     llvm::MDNode::get(VMContext, accessQuals));
2385     Fn->setMetadata("kernel_arg_type",
2386                     llvm::MDNode::get(VMContext, argTypeNames));
2387     Fn->setMetadata("kernel_arg_base_type",
2388                     llvm::MDNode::get(VMContext, argBaseTypeNames));
2389     Fn->setMetadata("kernel_arg_type_qual",
2390                     llvm::MDNode::get(VMContext, argTypeQuals));
2391   }
2392   if (getCodeGenOpts().EmitOpenCLArgMetadata ||
2393       getCodeGenOpts().HIPSaveKernelArgName)
2394     Fn->setMetadata("kernel_arg_name",
2395                     llvm::MDNode::get(VMContext, argNames));
2396 }
2397 
2398 /// Determines whether the language options require us to model
2399 /// unwind exceptions.  We treat -fexceptions as mandating this
2400 /// except under the fragile ObjC ABI with only ObjC exceptions
2401 /// enabled.  This means, for example, that C with -fexceptions
2402 /// enables this.
2403 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
2404   // If exceptions are completely disabled, obviously this is false.
2405   if (!LangOpts.Exceptions) return false;
2406 
2407   // If C++ exceptions are enabled, this is true.
2408   if (LangOpts.CXXExceptions) return true;
2409 
2410   // If ObjC exceptions are enabled, this depends on the ABI.
2411   if (LangOpts.ObjCExceptions) {
2412     return LangOpts.ObjCRuntime.hasUnwindExceptions();
2413   }
2414 
2415   return true;
2416 }
2417 
2418 static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM,
2419                                                       const CXXMethodDecl *MD) {
2420   // Check that the type metadata can ever actually be used by a call.
2421   if (!CGM.getCodeGenOpts().LTOUnit ||
2422       !CGM.HasHiddenLTOVisibility(MD->getParent()))
2423     return false;
2424 
2425   // Only functions whose address can be taken with a member function pointer
2426   // need this sort of type metadata.
2427   return MD->isImplicitObjectMemberFunction() && !MD->isVirtual() &&
2428          !isa<CXXConstructorDecl, CXXDestructorDecl>(MD);
2429 }
2430 
2431 SmallVector<const CXXRecordDecl *, 0>
2432 CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
2433   llvm::SetVector<const CXXRecordDecl *> MostBases;
2434 
2435   std::function<void (const CXXRecordDecl *)> CollectMostBases;
2436   CollectMostBases = [&](const CXXRecordDecl *RD) {
2437     if (RD->getNumBases() == 0)
2438       MostBases.insert(RD);
2439     for (const CXXBaseSpecifier &B : RD->bases())
2440       CollectMostBases(B.getType()->getAsCXXRecordDecl());
2441   };
2442   CollectMostBases(RD);
2443   return MostBases.takeVector();
2444 }
2445 
2446 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
2447                                                            llvm::Function *F) {
2448   llvm::AttrBuilder B(F->getContext());
2449 
2450   if ((!D || !D->hasAttr<NoUwtableAttr>()) && CodeGenOpts.UnwindTables)
2451     B.addUWTableAttr(llvm::UWTableKind(CodeGenOpts.UnwindTables));
2452 
2453   if (CodeGenOpts.StackClashProtector)
2454     B.addAttribute("probe-stack", "inline-asm");
2455 
2456   if (CodeGenOpts.StackProbeSize && CodeGenOpts.StackProbeSize != 4096)
2457     B.addAttribute("stack-probe-size",
2458                    std::to_string(CodeGenOpts.StackProbeSize));
2459 
2460   if (!hasUnwindExceptions(LangOpts))
2461     B.addAttribute(llvm::Attribute::NoUnwind);
2462 
2463   if (D && D->hasAttr<NoStackProtectorAttr>())
2464     ; // Do nothing.
2465   else if (D && D->hasAttr<StrictGuardStackCheckAttr>() &&
2466            isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPOn))
2467     B.addAttribute(llvm::Attribute::StackProtectStrong);
2468   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPOn))
2469     B.addAttribute(llvm::Attribute::StackProtect);
2470   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPStrong))
2471     B.addAttribute(llvm::Attribute::StackProtectStrong);
2472   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPReq))
2473     B.addAttribute(llvm::Attribute::StackProtectReq);
2474 
2475   if (!D) {
2476     // If we don't have a declaration to control inlining, the function isn't
2477     // explicitly marked as alwaysinline for semantic reasons, and inlining is
2478     // disabled, mark the function as noinline.
2479     if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
2480         CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
2481       B.addAttribute(llvm::Attribute::NoInline);
2482 
2483     F->addFnAttrs(B);
2484     return;
2485   }
2486 
2487   // Handle SME attributes that apply to function definitions,
2488   // rather than to function prototypes.
2489   if (D->hasAttr<ArmLocallyStreamingAttr>())
2490     B.addAttribute("aarch64_pstate_sm_body");
2491 
2492   if (auto *Attr = D->getAttr<ArmNewAttr>()) {
2493     if (Attr->isNewZA())
2494       B.addAttribute("aarch64_new_za");
2495     if (Attr->isNewZT0())
2496       B.addAttribute("aarch64_new_zt0");
2497   }
2498 
2499   // Track whether we need to add the optnone LLVM attribute,
2500   // starting with the default for this optimization level.
2501   bool ShouldAddOptNone =
2502       !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
2503   // We can't add optnone in the following cases, it won't pass the verifier.
2504   ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
2505   ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
2506 
2507   // Add optnone, but do so only if the function isn't always_inline.
2508   if ((ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) &&
2509       !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2510     B.addAttribute(llvm::Attribute::OptimizeNone);
2511 
2512     // OptimizeNone implies noinline; we should not be inlining such functions.
2513     B.addAttribute(llvm::Attribute::NoInline);
2514 
2515     // We still need to handle naked functions even though optnone subsumes
2516     // much of their semantics.
2517     if (D->hasAttr<NakedAttr>())
2518       B.addAttribute(llvm::Attribute::Naked);
2519 
2520     // OptimizeNone wins over OptimizeForSize and MinSize.
2521     F->removeFnAttr(llvm::Attribute::OptimizeForSize);
2522     F->removeFnAttr(llvm::Attribute::MinSize);
2523   } else if (D->hasAttr<NakedAttr>()) {
2524     // Naked implies noinline: we should not be inlining such functions.
2525     B.addAttribute(llvm::Attribute::Naked);
2526     B.addAttribute(llvm::Attribute::NoInline);
2527   } else if (D->hasAttr<NoDuplicateAttr>()) {
2528     B.addAttribute(llvm::Attribute::NoDuplicate);
2529   } else if (D->hasAttr<NoInlineAttr>() && !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2530     // Add noinline if the function isn't always_inline.
2531     B.addAttribute(llvm::Attribute::NoInline);
2532   } else if (D->hasAttr<AlwaysInlineAttr>() &&
2533              !F->hasFnAttribute(llvm::Attribute::NoInline)) {
2534     // (noinline wins over always_inline, and we can't specify both in IR)
2535     B.addAttribute(llvm::Attribute::AlwaysInline);
2536   } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
2537     // If we're not inlining, then force everything that isn't always_inline to
2538     // carry an explicit noinline attribute.
2539     if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
2540       B.addAttribute(llvm::Attribute::NoInline);
2541   } else {
2542     // Otherwise, propagate the inline hint attribute and potentially use its
2543     // absence to mark things as noinline.
2544     if (auto *FD = dyn_cast<FunctionDecl>(D)) {
2545       // Search function and template pattern redeclarations for inline.
2546       auto CheckForInline = [](const FunctionDecl *FD) {
2547         auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
2548           return Redecl->isInlineSpecified();
2549         };
2550         if (any_of(FD->redecls(), CheckRedeclForInline))
2551           return true;
2552         const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
2553         if (!Pattern)
2554           return false;
2555         return any_of(Pattern->redecls(), CheckRedeclForInline);
2556       };
2557       if (CheckForInline(FD)) {
2558         B.addAttribute(llvm::Attribute::InlineHint);
2559       } else if (CodeGenOpts.getInlining() ==
2560                      CodeGenOptions::OnlyHintInlining &&
2561                  !FD->isInlined() &&
2562                  !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2563         B.addAttribute(llvm::Attribute::NoInline);
2564       }
2565     }
2566   }
2567 
2568   // Add other optimization related attributes if we are optimizing this
2569   // function.
2570   if (!D->hasAttr<OptimizeNoneAttr>()) {
2571     if (D->hasAttr<ColdAttr>()) {
2572       if (!ShouldAddOptNone)
2573         B.addAttribute(llvm::Attribute::OptimizeForSize);
2574       B.addAttribute(llvm::Attribute::Cold);
2575     }
2576     if (D->hasAttr<HotAttr>())
2577       B.addAttribute(llvm::Attribute::Hot);
2578     if (D->hasAttr<MinSizeAttr>())
2579       B.addAttribute(llvm::Attribute::MinSize);
2580   }
2581 
2582   F->addFnAttrs(B);
2583 
2584   unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
2585   if (alignment)
2586     F->setAlignment(llvm::Align(alignment));
2587 
2588   if (!D->hasAttr<AlignedAttr>())
2589     if (LangOpts.FunctionAlignment)
2590       F->setAlignment(llvm::Align(1ull << LangOpts.FunctionAlignment));
2591 
2592   // Some C++ ABIs require 2-byte alignment for member functions, in order to
2593   // reserve a bit for differentiating between virtual and non-virtual member
2594   // functions. If the current target's C++ ABI requires this and this is a
2595   // member function, set its alignment accordingly.
2596   if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
2597     if (isa<CXXMethodDecl>(D) && F->getPointerAlignment(getDataLayout()) < 2)
2598       F->setAlignment(std::max(llvm::Align(2), F->getAlign().valueOrOne()));
2599   }
2600 
2601   // In the cross-dso CFI mode with canonical jump tables, we want !type
2602   // attributes on definitions only.
2603   if (CodeGenOpts.SanitizeCfiCrossDso &&
2604       CodeGenOpts.SanitizeCfiCanonicalJumpTables) {
2605     if (auto *FD = dyn_cast<FunctionDecl>(D)) {
2606       // Skip available_externally functions. They won't be codegen'ed in the
2607       // current module anyway.
2608       if (getContext().GetGVALinkageForFunction(FD) != GVA_AvailableExternally)
2609         CreateFunctionTypeMetadataForIcall(FD, F);
2610     }
2611   }
2612 
2613   // Emit type metadata on member functions for member function pointer checks.
2614   // These are only ever necessary on definitions; we're guaranteed that the
2615   // definition will be present in the LTO unit as a result of LTO visibility.
2616   auto *MD = dyn_cast<CXXMethodDecl>(D);
2617   if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
2618     for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
2619       llvm::Metadata *Id =
2620           CreateMetadataIdentifierForType(Context.getMemberPointerType(
2621               MD->getType(), Context.getRecordType(Base).getTypePtr()));
2622       F->addTypeMetadata(0, Id);
2623     }
2624   }
2625 }
2626 
2627 void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
2628   const Decl *D = GD.getDecl();
2629   if (isa_and_nonnull<NamedDecl>(D))
2630     setGVProperties(GV, GD);
2631   else
2632     GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
2633 
2634   if (D && D->hasAttr<UsedAttr>())
2635     addUsedOrCompilerUsedGlobal(GV);
2636 
2637   if (const auto *VD = dyn_cast_if_present<VarDecl>(D);
2638       VD &&
2639       ((CodeGenOpts.KeepPersistentStorageVariables &&
2640         (VD->getStorageDuration() == SD_Static ||
2641          VD->getStorageDuration() == SD_Thread)) ||
2642        (CodeGenOpts.KeepStaticConsts && VD->getStorageDuration() == SD_Static &&
2643         VD->getType().isConstQualified())))
2644     addUsedOrCompilerUsedGlobal(GV);
2645 }
2646 
2647 bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
2648                                                 llvm::AttrBuilder &Attrs,
2649                                                 bool SetTargetFeatures) {
2650   // Add target-cpu and target-features attributes to functions. If
2651   // we have a decl for the function and it has a target attribute then
2652   // parse that and add it to the feature set.
2653   StringRef TargetCPU = getTarget().getTargetOpts().CPU;
2654   StringRef TuneCPU = getTarget().getTargetOpts().TuneCPU;
2655   std::vector<std::string> Features;
2656   const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
2657   FD = FD ? FD->getMostRecentDecl() : FD;
2658   const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
2659   const auto *TV = FD ? FD->getAttr<TargetVersionAttr>() : nullptr;
2660   assert((!TD || !TV) && "both target_version and target specified");
2661   const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
2662   const auto *TC = FD ? FD->getAttr<TargetClonesAttr>() : nullptr;
2663   bool AddedAttr = false;
2664   if (TD || TV || SD || TC) {
2665     llvm::StringMap<bool> FeatureMap;
2666     getContext().getFunctionFeatureMap(FeatureMap, GD);
2667 
2668     // Produce the canonical string for this set of features.
2669     for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
2670       Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
2671 
2672     // Now add the target-cpu and target-features to the function.
2673     // While we populated the feature map above, we still need to
2674     // get and parse the target attribute so we can get the cpu for
2675     // the function.
2676     if (TD) {
2677       ParsedTargetAttr ParsedAttr =
2678           Target.parseTargetAttr(TD->getFeaturesStr());
2679       if (!ParsedAttr.CPU.empty() &&
2680           getTarget().isValidCPUName(ParsedAttr.CPU)) {
2681         TargetCPU = ParsedAttr.CPU;
2682         TuneCPU = ""; // Clear the tune CPU.
2683       }
2684       if (!ParsedAttr.Tune.empty() &&
2685           getTarget().isValidCPUName(ParsedAttr.Tune))
2686         TuneCPU = ParsedAttr.Tune;
2687     }
2688 
2689     if (SD) {
2690       // Apply the given CPU name as the 'tune-cpu' so that the optimizer can
2691       // favor this processor.
2692       TuneCPU = SD->getCPUName(GD.getMultiVersionIndex())->getName();
2693     }
2694   } else {
2695     // Otherwise just add the existing target cpu and target features to the
2696     // function.
2697     Features = getTarget().getTargetOpts().Features;
2698   }
2699 
2700   if (!TargetCPU.empty()) {
2701     Attrs.addAttribute("target-cpu", TargetCPU);
2702     AddedAttr = true;
2703   }
2704   if (!TuneCPU.empty()) {
2705     Attrs.addAttribute("tune-cpu", TuneCPU);
2706     AddedAttr = true;
2707   }
2708   if (!Features.empty() && SetTargetFeatures) {
2709     llvm::erase_if(Features, [&](const std::string& F) {
2710        return getTarget().isReadOnlyFeature(F.substr(1));
2711     });
2712     llvm::sort(Features);
2713     Attrs.addAttribute("target-features", llvm::join(Features, ","));
2714     AddedAttr = true;
2715   }
2716 
2717   return AddedAttr;
2718 }
2719 
2720 void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
2721                                           llvm::GlobalObject *GO) {
2722   const Decl *D = GD.getDecl();
2723   SetCommonAttributes(GD, GO);
2724 
2725   if (D) {
2726     if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
2727       if (D->hasAttr<RetainAttr>())
2728         addUsedGlobal(GV);
2729       if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
2730         GV->addAttribute("bss-section", SA->getName());
2731       if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
2732         GV->addAttribute("data-section", SA->getName());
2733       if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
2734         GV->addAttribute("rodata-section", SA->getName());
2735       if (auto *SA = D->getAttr<PragmaClangRelroSectionAttr>())
2736         GV->addAttribute("relro-section", SA->getName());
2737     }
2738 
2739     if (auto *F = dyn_cast<llvm::Function>(GO)) {
2740       if (D->hasAttr<RetainAttr>())
2741         addUsedGlobal(F);
2742       if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
2743         if (!D->getAttr<SectionAttr>())
2744           F->setSection(SA->getName());
2745 
2746       llvm::AttrBuilder Attrs(F->getContext());
2747       if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
2748         // We know that GetCPUAndFeaturesAttributes will always have the
2749         // newest set, since it has the newest possible FunctionDecl, so the
2750         // new ones should replace the old.
2751         llvm::AttributeMask RemoveAttrs;
2752         RemoveAttrs.addAttribute("target-cpu");
2753         RemoveAttrs.addAttribute("target-features");
2754         RemoveAttrs.addAttribute("tune-cpu");
2755         F->removeFnAttrs(RemoveAttrs);
2756         F->addFnAttrs(Attrs);
2757       }
2758     }
2759 
2760     if (const auto *CSA = D->getAttr<CodeSegAttr>())
2761       GO->setSection(CSA->getName());
2762     else if (const auto *SA = D->getAttr<SectionAttr>())
2763       GO->setSection(SA->getName());
2764   }
2765 
2766   getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
2767 }
2768 
2769 void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
2770                                                   llvm::Function *F,
2771                                                   const CGFunctionInfo &FI) {
2772   const Decl *D = GD.getDecl();
2773   SetLLVMFunctionAttributes(GD, FI, F, /*IsThunk=*/false);
2774   SetLLVMFunctionAttributesForDefinition(D, F);
2775 
2776   F->setLinkage(llvm::Function::InternalLinkage);
2777 
2778   setNonAliasAttributes(GD, F);
2779 }
2780 
2781 static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
2782   // Set linkage and visibility in case we never see a definition.
2783   LinkageInfo LV = ND->getLinkageAndVisibility();
2784   // Don't set internal linkage on declarations.
2785   // "extern_weak" is overloaded in LLVM; we probably should have
2786   // separate linkage types for this.
2787   if (isExternallyVisible(LV.getLinkage()) &&
2788       (ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
2789     GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2790 }
2791 
2792 void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
2793                                                        llvm::Function *F) {
2794   // Only if we are checking indirect calls.
2795   if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
2796     return;
2797 
2798   // Non-static class methods are handled via vtable or member function pointer
2799   // checks elsewhere.
2800   if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
2801     return;
2802 
2803   llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
2804   F->addTypeMetadata(0, MD);
2805   F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
2806 
2807   // Emit a hash-based bit set entry for cross-DSO calls.
2808   if (CodeGenOpts.SanitizeCfiCrossDso)
2809     if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
2810       F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
2811 }
2812 
2813 void CodeGenModule::setKCFIType(const FunctionDecl *FD, llvm::Function *F) {
2814   llvm::LLVMContext &Ctx = F->getContext();
2815   llvm::MDBuilder MDB(Ctx);
2816   F->setMetadata(llvm::LLVMContext::MD_kcfi_type,
2817                  llvm::MDNode::get(
2818                      Ctx, MDB.createConstant(CreateKCFITypeId(FD->getType()))));
2819 }
2820 
2821 static bool allowKCFIIdentifier(StringRef Name) {
2822   // KCFI type identifier constants are only necessary for external assembly
2823   // functions, which means it's safe to skip unusual names. Subset of
2824   // MCAsmInfo::isAcceptableChar() and MCAsmInfoXCOFF::isAcceptableChar().
2825   return llvm::all_of(Name, [](const char &C) {
2826     return llvm::isAlnum(C) || C == '_' || C == '.';
2827   });
2828 }
2829 
2830 void CodeGenModule::finalizeKCFITypes() {
2831   llvm::Module &M = getModule();
2832   for (auto &F : M.functions()) {
2833     // Remove KCFI type metadata from non-address-taken local functions.
2834     bool AddressTaken = F.hasAddressTaken();
2835     if (!AddressTaken && F.hasLocalLinkage())
2836       F.eraseMetadata(llvm::LLVMContext::MD_kcfi_type);
2837 
2838     // Generate a constant with the expected KCFI type identifier for all
2839     // address-taken function declarations to support annotating indirectly
2840     // called assembly functions.
2841     if (!AddressTaken || !F.isDeclaration())
2842       continue;
2843 
2844     const llvm::ConstantInt *Type;
2845     if (const llvm::MDNode *MD = F.getMetadata(llvm::LLVMContext::MD_kcfi_type))
2846       Type = llvm::mdconst::extract<llvm::ConstantInt>(MD->getOperand(0));
2847     else
2848       continue;
2849 
2850     StringRef Name = F.getName();
2851     if (!allowKCFIIdentifier(Name))
2852       continue;
2853 
2854     std::string Asm = (".weak __kcfi_typeid_" + Name + "\n.set __kcfi_typeid_" +
2855                        Name + ", " + Twine(Type->getZExtValue()) + "\n")
2856                           .str();
2857     M.appendModuleInlineAsm(Asm);
2858   }
2859 }
2860 
2861 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
2862                                           bool IsIncompleteFunction,
2863                                           bool IsThunk) {
2864 
2865   if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) {
2866     // If this is an intrinsic function, set the function's attributes
2867     // to the intrinsic's attributes.
2868     F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID));
2869     return;
2870   }
2871 
2872   const auto *FD = cast<FunctionDecl>(GD.getDecl());
2873 
2874   if (!IsIncompleteFunction)
2875     SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F,
2876                               IsThunk);
2877 
2878   // Add the Returned attribute for "this", except for iOS 5 and earlier
2879   // where substantial code, including the libstdc++ dylib, was compiled with
2880   // GCC and does not actually return "this".
2881   if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
2882       !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
2883     assert(!F->arg_empty() &&
2884            F->arg_begin()->getType()
2885              ->canLosslesslyBitCastTo(F->getReturnType()) &&
2886            "unexpected this return");
2887     F->addParamAttr(0, llvm::Attribute::Returned);
2888   }
2889 
2890   // Only a few attributes are set on declarations; these may later be
2891   // overridden by a definition.
2892 
2893   setLinkageForGV(F, FD);
2894   setGVProperties(F, FD);
2895 
2896   // Setup target-specific attributes.
2897   if (!IsIncompleteFunction && F->isDeclaration())
2898     getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
2899 
2900   if (const auto *CSA = FD->getAttr<CodeSegAttr>())
2901     F->setSection(CSA->getName());
2902   else if (const auto *SA = FD->getAttr<SectionAttr>())
2903      F->setSection(SA->getName());
2904 
2905   if (const auto *EA = FD->getAttr<ErrorAttr>()) {
2906     if (EA->isError())
2907       F->addFnAttr("dontcall-error", EA->getUserDiagnostic());
2908     else if (EA->isWarning())
2909       F->addFnAttr("dontcall-warn", EA->getUserDiagnostic());
2910   }
2911 
2912   // If we plan on emitting this inline builtin, we can't treat it as a builtin.
2913   if (FD->isInlineBuiltinDeclaration()) {
2914     const FunctionDecl *FDBody;
2915     bool HasBody = FD->hasBody(FDBody);
2916     (void)HasBody;
2917     assert(HasBody && "Inline builtin declarations should always have an "
2918                       "available body!");
2919     if (shouldEmitFunction(FDBody))
2920       F->addFnAttr(llvm::Attribute::NoBuiltin);
2921   }
2922 
2923   if (FD->isReplaceableGlobalAllocationFunction()) {
2924     // A replaceable global allocation function does not act like a builtin by
2925     // default, only if it is invoked by a new-expression or delete-expression.
2926     F->addFnAttr(llvm::Attribute::NoBuiltin);
2927   }
2928 
2929   if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
2930     F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2931   else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
2932     if (MD->isVirtual())
2933       F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2934 
2935   // Don't emit entries for function declarations in the cross-DSO mode. This
2936   // is handled with better precision by the receiving DSO. But if jump tables
2937   // are non-canonical then we need type metadata in order to produce the local
2938   // jump table.
2939   if (!CodeGenOpts.SanitizeCfiCrossDso ||
2940       !CodeGenOpts.SanitizeCfiCanonicalJumpTables)
2941     CreateFunctionTypeMetadataForIcall(FD, F);
2942 
2943   if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
2944     setKCFIType(FD, F);
2945 
2946   if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
2947     getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
2948 
2949   if (CodeGenOpts.InlineMaxStackSize != UINT_MAX)
2950     F->addFnAttr("inline-max-stacksize", llvm::utostr(CodeGenOpts.InlineMaxStackSize));
2951 
2952   if (const auto *CB = FD->getAttr<CallbackAttr>()) {
2953     // Annotate the callback behavior as metadata:
2954     //  - The callback callee (as argument number).
2955     //  - The callback payloads (as argument numbers).
2956     llvm::LLVMContext &Ctx = F->getContext();
2957     llvm::MDBuilder MDB(Ctx);
2958 
2959     // The payload indices are all but the first one in the encoding. The first
2960     // identifies the callback callee.
2961     int CalleeIdx = *CB->encoding_begin();
2962     ArrayRef<int> PayloadIndices(CB->encoding_begin() + 1, CB->encoding_end());
2963     F->addMetadata(llvm::LLVMContext::MD_callback,
2964                    *llvm::MDNode::get(Ctx, {MDB.createCallbackEncoding(
2965                                                CalleeIdx, PayloadIndices,
2966                                                /* VarArgsArePassed */ false)}));
2967   }
2968 }
2969 
2970 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
2971   assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
2972          "Only globals with definition can force usage.");
2973   LLVMUsed.emplace_back(GV);
2974 }
2975 
2976 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
2977   assert(!GV->isDeclaration() &&
2978          "Only globals with definition can force usage.");
2979   LLVMCompilerUsed.emplace_back(GV);
2980 }
2981 
2982 void CodeGenModule::addUsedOrCompilerUsedGlobal(llvm::GlobalValue *GV) {
2983   assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
2984          "Only globals with definition can force usage.");
2985   if (getTriple().isOSBinFormatELF())
2986     LLVMCompilerUsed.emplace_back(GV);
2987   else
2988     LLVMUsed.emplace_back(GV);
2989 }
2990 
2991 static void emitUsed(CodeGenModule &CGM, StringRef Name,
2992                      std::vector<llvm::WeakTrackingVH> &List) {
2993   // Don't create llvm.used if there is no need.
2994   if (List.empty())
2995     return;
2996 
2997   // Convert List to what ConstantArray needs.
2998   SmallVector<llvm::Constant*, 8> UsedArray;
2999   UsedArray.resize(List.size());
3000   for (unsigned i = 0, e = List.size(); i != e; ++i) {
3001     UsedArray[i] =
3002         llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
3003             cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
3004   }
3005 
3006   if (UsedArray.empty())
3007     return;
3008   llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
3009 
3010   auto *GV = new llvm::GlobalVariable(
3011       CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
3012       llvm::ConstantArray::get(ATy, UsedArray), Name);
3013 
3014   GV->setSection("llvm.metadata");
3015 }
3016 
3017 void CodeGenModule::emitLLVMUsed() {
3018   emitUsed(*this, "llvm.used", LLVMUsed);
3019   emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
3020 }
3021 
3022 void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
3023   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
3024   LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
3025 }
3026 
3027 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
3028   llvm::SmallString<32> Opt;
3029   getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
3030   if (Opt.empty())
3031     return;
3032   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
3033   LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
3034 }
3035 
3036 void CodeGenModule::AddDependentLib(StringRef Lib) {
3037   auto &C = getLLVMContext();
3038   if (getTarget().getTriple().isOSBinFormatELF()) {
3039       ELFDependentLibraries.push_back(
3040         llvm::MDNode::get(C, llvm::MDString::get(C, Lib)));
3041     return;
3042   }
3043 
3044   llvm::SmallString<24> Opt;
3045   getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
3046   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
3047   LinkerOptionsMetadata.push_back(llvm::MDNode::get(C, MDOpts));
3048 }
3049 
3050 /// Add link options implied by the given module, including modules
3051 /// it depends on, using a postorder walk.
3052 static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
3053                                     SmallVectorImpl<llvm::MDNode *> &Metadata,
3054                                     llvm::SmallPtrSet<Module *, 16> &Visited) {
3055   // Import this module's parent.
3056   if (Mod->Parent && Visited.insert(Mod->Parent).second) {
3057     addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
3058   }
3059 
3060   // Import this module's dependencies.
3061   for (Module *Import : llvm::reverse(Mod->Imports)) {
3062     if (Visited.insert(Import).second)
3063       addLinkOptionsPostorder(CGM, Import, Metadata, Visited);
3064   }
3065 
3066   // Add linker options to link against the libraries/frameworks
3067   // described by this module.
3068   llvm::LLVMContext &Context = CGM.getLLVMContext();
3069   bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
3070 
3071   // For modules that use export_as for linking, use that module
3072   // name instead.
3073   if (Mod->UseExportAsModuleLinkName)
3074     return;
3075 
3076   for (const Module::LinkLibrary &LL : llvm::reverse(Mod->LinkLibraries)) {
3077     // Link against a framework.  Frameworks are currently Darwin only, so we
3078     // don't to ask TargetCodeGenInfo for the spelling of the linker option.
3079     if (LL.IsFramework) {
3080       llvm::Metadata *Args[2] = {llvm::MDString::get(Context, "-framework"),
3081                                  llvm::MDString::get(Context, LL.Library)};
3082 
3083       Metadata.push_back(llvm::MDNode::get(Context, Args));
3084       continue;
3085     }
3086 
3087     // Link against a library.
3088     if (IsELF) {
3089       llvm::Metadata *Args[2] = {
3090           llvm::MDString::get(Context, "lib"),
3091           llvm::MDString::get(Context, LL.Library),
3092       };
3093       Metadata.push_back(llvm::MDNode::get(Context, Args));
3094     } else {
3095       llvm::SmallString<24> Opt;
3096       CGM.getTargetCodeGenInfo().getDependentLibraryOption(LL.Library, Opt);
3097       auto *OptString = llvm::MDString::get(Context, Opt);
3098       Metadata.push_back(llvm::MDNode::get(Context, OptString));
3099     }
3100   }
3101 }
3102 
3103 void CodeGenModule::EmitModuleInitializers(clang::Module *Primary) {
3104   assert(Primary->isNamedModuleUnit() &&
3105          "We should only emit module initializers for named modules.");
3106 
3107   // Emit the initializers in the order that sub-modules appear in the
3108   // source, first Global Module Fragments, if present.
3109   if (auto GMF = Primary->getGlobalModuleFragment()) {
3110     for (Decl *D : getContext().getModuleInitializers(GMF)) {
3111       if (isa<ImportDecl>(D))
3112         continue;
3113       assert(isa<VarDecl>(D) && "GMF initializer decl is not a var?");
3114       EmitTopLevelDecl(D);
3115     }
3116   }
3117   // Second any associated with the module, itself.
3118   for (Decl *D : getContext().getModuleInitializers(Primary)) {
3119     // Skip import decls, the inits for those are called explicitly.
3120     if (isa<ImportDecl>(D))
3121       continue;
3122     EmitTopLevelDecl(D);
3123   }
3124   // Third any associated with the Privat eMOdule Fragment, if present.
3125   if (auto PMF = Primary->getPrivateModuleFragment()) {
3126     for (Decl *D : getContext().getModuleInitializers(PMF)) {
3127       // Skip import decls, the inits for those are called explicitly.
3128       if (isa<ImportDecl>(D))
3129         continue;
3130       assert(isa<VarDecl>(D) && "PMF initializer decl is not a var?");
3131       EmitTopLevelDecl(D);
3132     }
3133   }
3134 }
3135 
3136 void CodeGenModule::EmitModuleLinkOptions() {
3137   // Collect the set of all of the modules we want to visit to emit link
3138   // options, which is essentially the imported modules and all of their
3139   // non-explicit child modules.
3140   llvm::SetVector<clang::Module *> LinkModules;
3141   llvm::SmallPtrSet<clang::Module *, 16> Visited;
3142   SmallVector<clang::Module *, 16> Stack;
3143 
3144   // Seed the stack with imported modules.
3145   for (Module *M : ImportedModules) {
3146     // Do not add any link flags when an implementation TU of a module imports
3147     // a header of that same module.
3148     if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
3149         !getLangOpts().isCompilingModule())
3150       continue;
3151     if (Visited.insert(M).second)
3152       Stack.push_back(M);
3153   }
3154 
3155   // Find all of the modules to import, making a little effort to prune
3156   // non-leaf modules.
3157   while (!Stack.empty()) {
3158     clang::Module *Mod = Stack.pop_back_val();
3159 
3160     bool AnyChildren = false;
3161 
3162     // Visit the submodules of this module.
3163     for (const auto &SM : Mod->submodules()) {
3164       // Skip explicit children; they need to be explicitly imported to be
3165       // linked against.
3166       if (SM->IsExplicit)
3167         continue;
3168 
3169       if (Visited.insert(SM).second) {
3170         Stack.push_back(SM);
3171         AnyChildren = true;
3172       }
3173     }
3174 
3175     // We didn't find any children, so add this module to the list of
3176     // modules to link against.
3177     if (!AnyChildren) {
3178       LinkModules.insert(Mod);
3179     }
3180   }
3181 
3182   // Add link options for all of the imported modules in reverse topological
3183   // order.  We don't do anything to try to order import link flags with respect
3184   // to linker options inserted by things like #pragma comment().
3185   SmallVector<llvm::MDNode *, 16> MetadataArgs;
3186   Visited.clear();
3187   for (Module *M : LinkModules)
3188     if (Visited.insert(M).second)
3189       addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
3190   std::reverse(MetadataArgs.begin(), MetadataArgs.end());
3191   LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
3192 
3193   // Add the linker options metadata flag.
3194   auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
3195   for (auto *MD : LinkerOptionsMetadata)
3196     NMD->addOperand(MD);
3197 }
3198 
3199 void CodeGenModule::EmitDeferred() {
3200   // Emit deferred declare target declarations.
3201   if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
3202     getOpenMPRuntime().emitDeferredTargetDecls();
3203 
3204   // Emit code for any potentially referenced deferred decls.  Since a
3205   // previously unused static decl may become used during the generation of code
3206   // for a static function, iterate until no changes are made.
3207 
3208   if (!DeferredVTables.empty()) {
3209     EmitDeferredVTables();
3210 
3211     // Emitting a vtable doesn't directly cause more vtables to
3212     // become deferred, although it can cause functions to be
3213     // emitted that then need those vtables.
3214     assert(DeferredVTables.empty());
3215   }
3216 
3217   // Emit CUDA/HIP static device variables referenced by host code only.
3218   // Note we should not clear CUDADeviceVarODRUsedByHost since it is still
3219   // needed for further handling.
3220   if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
3221     llvm::append_range(DeferredDeclsToEmit,
3222                        getContext().CUDADeviceVarODRUsedByHost);
3223 
3224   // Stop if we're out of both deferred vtables and deferred declarations.
3225   if (DeferredDeclsToEmit.empty())
3226     return;
3227 
3228   // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
3229   // work, it will not interfere with this.
3230   std::vector<GlobalDecl> CurDeclsToEmit;
3231   CurDeclsToEmit.swap(DeferredDeclsToEmit);
3232 
3233   for (GlobalDecl &D : CurDeclsToEmit) {
3234     // We should call GetAddrOfGlobal with IsForDefinition set to true in order
3235     // to get GlobalValue with exactly the type we need, not something that
3236     // might had been created for another decl with the same mangled name but
3237     // different type.
3238     llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
3239         GetAddrOfGlobal(D, ForDefinition));
3240 
3241     // In case of different address spaces, we may still get a cast, even with
3242     // IsForDefinition equal to true. Query mangled names table to get
3243     // GlobalValue.
3244     if (!GV)
3245       GV = GetGlobalValue(getMangledName(D));
3246 
3247     // Make sure GetGlobalValue returned non-null.
3248     assert(GV);
3249 
3250     // Check to see if we've already emitted this.  This is necessary
3251     // for a couple of reasons: first, decls can end up in the
3252     // deferred-decls queue multiple times, and second, decls can end
3253     // up with definitions in unusual ways (e.g. by an extern inline
3254     // function acquiring a strong function redefinition).  Just
3255     // ignore these cases.
3256     if (!GV->isDeclaration())
3257       continue;
3258 
3259     // If this is OpenMP, check if it is legal to emit this global normally.
3260     if (LangOpts.OpenMP && OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(D))
3261       continue;
3262 
3263     // Otherwise, emit the definition and move on to the next one.
3264     EmitGlobalDefinition(D, GV);
3265 
3266     // If we found out that we need to emit more decls, do that recursively.
3267     // This has the advantage that the decls are emitted in a DFS and related
3268     // ones are close together, which is convenient for testing.
3269     if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
3270       EmitDeferred();
3271       assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
3272     }
3273   }
3274 }
3275 
3276 void CodeGenModule::EmitVTablesOpportunistically() {
3277   // Try to emit external vtables as available_externally if they have emitted
3278   // all inlined virtual functions.  It runs after EmitDeferred() and therefore
3279   // is not allowed to create new references to things that need to be emitted
3280   // lazily. Note that it also uses fact that we eagerly emitting RTTI.
3281 
3282   assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
3283          && "Only emit opportunistic vtables with optimizations");
3284 
3285   for (const CXXRecordDecl *RD : OpportunisticVTables) {
3286     assert(getVTables().isVTableExternal(RD) &&
3287            "This queue should only contain external vtables");
3288     if (getCXXABI().canSpeculativelyEmitVTable(RD))
3289       VTables.GenerateClassData(RD);
3290   }
3291   OpportunisticVTables.clear();
3292 }
3293 
3294 void CodeGenModule::EmitGlobalAnnotations() {
3295   for (const auto& [MangledName, VD] : DeferredAnnotations) {
3296     llvm::GlobalValue *GV = GetGlobalValue(MangledName);
3297     if (GV)
3298       AddGlobalAnnotations(VD, GV);
3299   }
3300   DeferredAnnotations.clear();
3301 
3302   if (Annotations.empty())
3303     return;
3304 
3305   // Create a new global variable for the ConstantStruct in the Module.
3306   llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
3307     Annotations[0]->getType(), Annotations.size()), Annotations);
3308   auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
3309                                       llvm::GlobalValue::AppendingLinkage,
3310                                       Array, "llvm.global.annotations");
3311   gv->setSection(AnnotationSection);
3312 }
3313 
3314 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
3315   llvm::Constant *&AStr = AnnotationStrings[Str];
3316   if (AStr)
3317     return AStr;
3318 
3319   // Not found yet, create a new global.
3320   llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
3321   auto *gv = new llvm::GlobalVariable(
3322       getModule(), s->getType(), true, llvm::GlobalValue::PrivateLinkage, s,
3323       ".str", nullptr, llvm::GlobalValue::NotThreadLocal,
3324       ConstGlobalsPtrTy->getAddressSpace());
3325   gv->setSection(AnnotationSection);
3326   gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3327   AStr = gv;
3328   return gv;
3329 }
3330 
3331 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
3332   SourceManager &SM = getContext().getSourceManager();
3333   PresumedLoc PLoc = SM.getPresumedLoc(Loc);
3334   if (PLoc.isValid())
3335     return EmitAnnotationString(PLoc.getFilename());
3336   return EmitAnnotationString(SM.getBufferName(Loc));
3337 }
3338 
3339 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
3340   SourceManager &SM = getContext().getSourceManager();
3341   PresumedLoc PLoc = SM.getPresumedLoc(L);
3342   unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
3343     SM.getExpansionLineNumber(L);
3344   return llvm::ConstantInt::get(Int32Ty, LineNo);
3345 }
3346 
3347 llvm::Constant *CodeGenModule::EmitAnnotationArgs(const AnnotateAttr *Attr) {
3348   ArrayRef<Expr *> Exprs = {Attr->args_begin(), Attr->args_size()};
3349   if (Exprs.empty())
3350     return llvm::ConstantPointerNull::get(ConstGlobalsPtrTy);
3351 
3352   llvm::FoldingSetNodeID ID;
3353   for (Expr *E : Exprs) {
3354     ID.Add(cast<clang::ConstantExpr>(E)->getAPValueResult());
3355   }
3356   llvm::Constant *&Lookup = AnnotationArgs[ID.ComputeHash()];
3357   if (Lookup)
3358     return Lookup;
3359 
3360   llvm::SmallVector<llvm::Constant *, 4> LLVMArgs;
3361   LLVMArgs.reserve(Exprs.size());
3362   ConstantEmitter ConstEmiter(*this);
3363   llvm::transform(Exprs, std::back_inserter(LLVMArgs), [&](const Expr *E) {
3364     const auto *CE = cast<clang::ConstantExpr>(E);
3365     return ConstEmiter.emitAbstract(CE->getBeginLoc(), CE->getAPValueResult(),
3366                                     CE->getType());
3367   });
3368   auto *Struct = llvm::ConstantStruct::getAnon(LLVMArgs);
3369   auto *GV = new llvm::GlobalVariable(getModule(), Struct->getType(), true,
3370                                       llvm::GlobalValue::PrivateLinkage, Struct,
3371                                       ".args");
3372   GV->setSection(AnnotationSection);
3373   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3374 
3375   Lookup = GV;
3376   return GV;
3377 }
3378 
3379 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
3380                                                 const AnnotateAttr *AA,
3381                                                 SourceLocation L) {
3382   // Get the globals for file name, annotation, and the line number.
3383   llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
3384                  *UnitGV = EmitAnnotationUnit(L),
3385                  *LineNoCst = EmitAnnotationLineNo(L),
3386                  *Args = EmitAnnotationArgs(AA);
3387 
3388   llvm::Constant *GVInGlobalsAS = GV;
3389   if (GV->getAddressSpace() !=
3390       getDataLayout().getDefaultGlobalsAddressSpace()) {
3391     GVInGlobalsAS = llvm::ConstantExpr::getAddrSpaceCast(
3392         GV,
3393         llvm::PointerType::get(
3394             GV->getContext(), getDataLayout().getDefaultGlobalsAddressSpace()));
3395   }
3396 
3397   // Create the ConstantStruct for the global annotation.
3398   llvm::Constant *Fields[] = {
3399       GVInGlobalsAS, AnnoGV, UnitGV, LineNoCst, Args,
3400   };
3401   return llvm::ConstantStruct::getAnon(Fields);
3402 }
3403 
3404 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
3405                                          llvm::GlobalValue *GV) {
3406   assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
3407   // Get the struct elements for these annotations.
3408   for (const auto *I : D->specific_attrs<AnnotateAttr>())
3409     Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
3410 }
3411 
3412 bool CodeGenModule::isInNoSanitizeList(SanitizerMask Kind, llvm::Function *Fn,
3413                                        SourceLocation Loc) const {
3414   const auto &NoSanitizeL = getContext().getNoSanitizeList();
3415   // NoSanitize by function name.
3416   if (NoSanitizeL.containsFunction(Kind, Fn->getName()))
3417     return true;
3418   // NoSanitize by location. Check "mainfile" prefix.
3419   auto &SM = Context.getSourceManager();
3420   FileEntryRef MainFile = *SM.getFileEntryRefForID(SM.getMainFileID());
3421   if (NoSanitizeL.containsMainFile(Kind, MainFile.getName()))
3422     return true;
3423 
3424   // Check "src" prefix.
3425   if (Loc.isValid())
3426     return NoSanitizeL.containsLocation(Kind, Loc);
3427   // If location is unknown, this may be a compiler-generated function. Assume
3428   // it's located in the main file.
3429   return NoSanitizeL.containsFile(Kind, MainFile.getName());
3430 }
3431 
3432 bool CodeGenModule::isInNoSanitizeList(SanitizerMask Kind,
3433                                        llvm::GlobalVariable *GV,
3434                                        SourceLocation Loc, QualType Ty,
3435                                        StringRef Category) const {
3436   const auto &NoSanitizeL = getContext().getNoSanitizeList();
3437   if (NoSanitizeL.containsGlobal(Kind, GV->getName(), Category))
3438     return true;
3439   auto &SM = Context.getSourceManager();
3440   if (NoSanitizeL.containsMainFile(
3441           Kind, SM.getFileEntryRefForID(SM.getMainFileID())->getName(),
3442           Category))
3443     return true;
3444   if (NoSanitizeL.containsLocation(Kind, Loc, Category))
3445     return true;
3446 
3447   // Check global type.
3448   if (!Ty.isNull()) {
3449     // Drill down the array types: if global variable of a fixed type is
3450     // not sanitized, we also don't instrument arrays of them.
3451     while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
3452       Ty = AT->getElementType();
3453     Ty = Ty.getCanonicalType().getUnqualifiedType();
3454     // Only record types (classes, structs etc.) are ignored.
3455     if (Ty->isRecordType()) {
3456       std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
3457       if (NoSanitizeL.containsType(Kind, TypeStr, Category))
3458         return true;
3459     }
3460   }
3461   return false;
3462 }
3463 
3464 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
3465                                    StringRef Category) const {
3466   const auto &XRayFilter = getContext().getXRayFilter();
3467   using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
3468   auto Attr = ImbueAttr::NONE;
3469   if (Loc.isValid())
3470     Attr = XRayFilter.shouldImbueLocation(Loc, Category);
3471   if (Attr == ImbueAttr::NONE)
3472     Attr = XRayFilter.shouldImbueFunction(Fn->getName());
3473   switch (Attr) {
3474   case ImbueAttr::NONE:
3475     return false;
3476   case ImbueAttr::ALWAYS:
3477     Fn->addFnAttr("function-instrument", "xray-always");
3478     break;
3479   case ImbueAttr::ALWAYS_ARG1:
3480     Fn->addFnAttr("function-instrument", "xray-always");
3481     Fn->addFnAttr("xray-log-args", "1");
3482     break;
3483   case ImbueAttr::NEVER:
3484     Fn->addFnAttr("function-instrument", "xray-never");
3485     break;
3486   }
3487   return true;
3488 }
3489 
3490 ProfileList::ExclusionType
3491 CodeGenModule::isFunctionBlockedByProfileList(llvm::Function *Fn,
3492                                               SourceLocation Loc) const {
3493   const auto &ProfileList = getContext().getProfileList();
3494   // If the profile list is empty, then instrument everything.
3495   if (ProfileList.isEmpty())
3496     return ProfileList::Allow;
3497   CodeGenOptions::ProfileInstrKind Kind = getCodeGenOpts().getProfileInstr();
3498   // First, check the function name.
3499   if (auto V = ProfileList.isFunctionExcluded(Fn->getName(), Kind))
3500     return *V;
3501   // Next, check the source location.
3502   if (Loc.isValid())
3503     if (auto V = ProfileList.isLocationExcluded(Loc, Kind))
3504       return *V;
3505   // If location is unknown, this may be a compiler-generated function. Assume
3506   // it's located in the main file.
3507   auto &SM = Context.getSourceManager();
3508   if (auto MainFile = SM.getFileEntryRefForID(SM.getMainFileID()))
3509     if (auto V = ProfileList.isFileExcluded(MainFile->getName(), Kind))
3510       return *V;
3511   return ProfileList.getDefault(Kind);
3512 }
3513 
3514 ProfileList::ExclusionType
3515 CodeGenModule::isFunctionBlockedFromProfileInstr(llvm::Function *Fn,
3516                                                  SourceLocation Loc) const {
3517   auto V = isFunctionBlockedByProfileList(Fn, Loc);
3518   if (V != ProfileList::Allow)
3519     return V;
3520 
3521   auto NumGroups = getCodeGenOpts().ProfileTotalFunctionGroups;
3522   if (NumGroups > 1) {
3523     auto Group = llvm::crc32(arrayRefFromStringRef(Fn->getName())) % NumGroups;
3524     if (Group != getCodeGenOpts().ProfileSelectedFunctionGroup)
3525       return ProfileList::Skip;
3526   }
3527   return ProfileList::Allow;
3528 }
3529 
3530 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
3531   // Never defer when EmitAllDecls is specified.
3532   if (LangOpts.EmitAllDecls)
3533     return true;
3534 
3535   const auto *VD = dyn_cast<VarDecl>(Global);
3536   if (VD &&
3537       ((CodeGenOpts.KeepPersistentStorageVariables &&
3538         (VD->getStorageDuration() == SD_Static ||
3539          VD->getStorageDuration() == SD_Thread)) ||
3540        (CodeGenOpts.KeepStaticConsts && VD->getStorageDuration() == SD_Static &&
3541         VD->getType().isConstQualified())))
3542     return true;
3543 
3544   return getContext().DeclMustBeEmitted(Global);
3545 }
3546 
3547 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
3548   // In OpenMP 5.0 variables and function may be marked as
3549   // device_type(host/nohost) and we should not emit them eagerly unless we sure
3550   // that they must be emitted on the host/device. To be sure we need to have
3551   // seen a declare target with an explicit mentioning of the function, we know
3552   // we have if the level of the declare target attribute is -1. Note that we
3553   // check somewhere else if we should emit this at all.
3554   if (LangOpts.OpenMP >= 50 && !LangOpts.OpenMPSimd) {
3555     std::optional<OMPDeclareTargetDeclAttr *> ActiveAttr =
3556         OMPDeclareTargetDeclAttr::getActiveAttr(Global);
3557     if (!ActiveAttr || (*ActiveAttr)->getLevel() != (unsigned)-1)
3558       return false;
3559   }
3560 
3561   if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
3562     if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
3563       // Implicit template instantiations may change linkage if they are later
3564       // explicitly instantiated, so they should not be emitted eagerly.
3565       return false;
3566     // Defer until all versions have been semantically checked.
3567     if (FD->hasAttr<TargetVersionAttr>() && !FD->isMultiVersion())
3568       return false;
3569   }
3570   if (const auto *VD = dyn_cast<VarDecl>(Global)) {
3571     if (Context.getInlineVariableDefinitionKind(VD) ==
3572         ASTContext::InlineVariableDefinitionKind::WeakUnknown)
3573       // A definition of an inline constexpr static data member may change
3574       // linkage later if it's redeclared outside the class.
3575       return false;
3576     if (CXX20ModuleInits && VD->getOwningModule() &&
3577         !VD->getOwningModule()->isModuleMapModule()) {
3578       // For CXX20, module-owned initializers need to be deferred, since it is
3579       // not known at this point if they will be run for the current module or
3580       // as part of the initializer for an imported one.
3581       return false;
3582     }
3583   }
3584   // If OpenMP is enabled and threadprivates must be generated like TLS, delay
3585   // codegen for global variables, because they may be marked as threadprivate.
3586   if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
3587       getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
3588       !Global->getType().isConstantStorage(getContext(), false, false) &&
3589       !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
3590     return false;
3591 
3592   return true;
3593 }
3594 
3595 ConstantAddress CodeGenModule::GetAddrOfMSGuidDecl(const MSGuidDecl *GD) {
3596   StringRef Name = getMangledName(GD);
3597 
3598   // The UUID descriptor should be pointer aligned.
3599   CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
3600 
3601   // Look for an existing global.
3602   if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
3603     return ConstantAddress(GV, GV->getValueType(), Alignment);
3604 
3605   ConstantEmitter Emitter(*this);
3606   llvm::Constant *Init;
3607 
3608   APValue &V = GD->getAsAPValue();
3609   if (!V.isAbsent()) {
3610     // If possible, emit the APValue version of the initializer. In particular,
3611     // this gets the type of the constant right.
3612     Init = Emitter.emitForInitializer(
3613         GD->getAsAPValue(), GD->getType().getAddressSpace(), GD->getType());
3614   } else {
3615     // As a fallback, directly construct the constant.
3616     // FIXME: This may get padding wrong under esoteric struct layout rules.
3617     // MSVC appears to create a complete type 'struct __s_GUID' that it
3618     // presumably uses to represent these constants.
3619     MSGuidDecl::Parts Parts = GD->getParts();
3620     llvm::Constant *Fields[4] = {
3621         llvm::ConstantInt::get(Int32Ty, Parts.Part1),
3622         llvm::ConstantInt::get(Int16Ty, Parts.Part2),
3623         llvm::ConstantInt::get(Int16Ty, Parts.Part3),
3624         llvm::ConstantDataArray::getRaw(
3625             StringRef(reinterpret_cast<char *>(Parts.Part4And5), 8), 8,
3626             Int8Ty)};
3627     Init = llvm::ConstantStruct::getAnon(Fields);
3628   }
3629 
3630   auto *GV = new llvm::GlobalVariable(
3631       getModule(), Init->getType(),
3632       /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
3633   if (supportsCOMDAT())
3634     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3635   setDSOLocal(GV);
3636 
3637   if (!V.isAbsent()) {
3638     Emitter.finalize(GV);
3639     return ConstantAddress(GV, GV->getValueType(), Alignment);
3640   }
3641 
3642   llvm::Type *Ty = getTypes().ConvertTypeForMem(GD->getType());
3643   return ConstantAddress(GV, Ty, Alignment);
3644 }
3645 
3646 ConstantAddress CodeGenModule::GetAddrOfUnnamedGlobalConstantDecl(
3647     const UnnamedGlobalConstantDecl *GCD) {
3648   CharUnits Alignment = getContext().getTypeAlignInChars(GCD->getType());
3649 
3650   llvm::GlobalVariable **Entry = nullptr;
3651   Entry = &UnnamedGlobalConstantDeclMap[GCD];
3652   if (*Entry)
3653     return ConstantAddress(*Entry, (*Entry)->getValueType(), Alignment);
3654 
3655   ConstantEmitter Emitter(*this);
3656   llvm::Constant *Init;
3657 
3658   const APValue &V = GCD->getValue();
3659 
3660   assert(!V.isAbsent());
3661   Init = Emitter.emitForInitializer(V, GCD->getType().getAddressSpace(),
3662                                     GCD->getType());
3663 
3664   auto *GV = new llvm::GlobalVariable(getModule(), Init->getType(),
3665                                       /*isConstant=*/true,
3666                                       llvm::GlobalValue::PrivateLinkage, Init,
3667                                       ".constant");
3668   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3669   GV->setAlignment(Alignment.getAsAlign());
3670 
3671   Emitter.finalize(GV);
3672 
3673   *Entry = GV;
3674   return ConstantAddress(GV, GV->getValueType(), Alignment);
3675 }
3676 
3677 ConstantAddress CodeGenModule::GetAddrOfTemplateParamObject(
3678     const TemplateParamObjectDecl *TPO) {
3679   StringRef Name = getMangledName(TPO);
3680   CharUnits Alignment = getNaturalTypeAlignment(TPO->getType());
3681 
3682   if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
3683     return ConstantAddress(GV, GV->getValueType(), Alignment);
3684 
3685   ConstantEmitter Emitter(*this);
3686   llvm::Constant *Init = Emitter.emitForInitializer(
3687         TPO->getValue(), TPO->getType().getAddressSpace(), TPO->getType());
3688 
3689   if (!Init) {
3690     ErrorUnsupported(TPO, "template parameter object");
3691     return ConstantAddress::invalid();
3692   }
3693 
3694   llvm::GlobalValue::LinkageTypes Linkage =
3695       isExternallyVisible(TPO->getLinkageAndVisibility().getLinkage())
3696           ? llvm::GlobalValue::LinkOnceODRLinkage
3697           : llvm::GlobalValue::InternalLinkage;
3698   auto *GV = new llvm::GlobalVariable(getModule(), Init->getType(),
3699                                       /*isConstant=*/true, Linkage, Init, Name);
3700   setGVProperties(GV, TPO);
3701   if (supportsCOMDAT())
3702     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3703   Emitter.finalize(GV);
3704 
3705     return ConstantAddress(GV, GV->getValueType(), Alignment);
3706 }
3707 
3708 ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
3709   const AliasAttr *AA = VD->getAttr<AliasAttr>();
3710   assert(AA && "No alias?");
3711 
3712   CharUnits Alignment = getContext().getDeclAlign(VD);
3713   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
3714 
3715   // See if there is already something with the target's name in the module.
3716   llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
3717   if (Entry)
3718     return ConstantAddress(Entry, DeclTy, Alignment);
3719 
3720   llvm::Constant *Aliasee;
3721   if (isa<llvm::FunctionType>(DeclTy))
3722     Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
3723                                       GlobalDecl(cast<FunctionDecl>(VD)),
3724                                       /*ForVTable=*/false);
3725   else
3726     Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, LangAS::Default,
3727                                     nullptr);
3728 
3729   auto *F = cast<llvm::GlobalValue>(Aliasee);
3730   F->setLinkage(llvm::Function::ExternalWeakLinkage);
3731   WeakRefReferences.insert(F);
3732 
3733   return ConstantAddress(Aliasee, DeclTy, Alignment);
3734 }
3735 
3736 template <typename AttrT> static bool hasImplicitAttr(const ValueDecl *D) {
3737   if (!D)
3738     return false;
3739   if (auto *A = D->getAttr<AttrT>())
3740     return A->isImplicit();
3741   return D->isImplicit();
3742 }
3743 
3744 bool CodeGenModule::shouldEmitCUDAGlobalVar(const VarDecl *Global) const {
3745   assert(LangOpts.CUDA && "Should not be called by non-CUDA languages");
3746   // We need to emit host-side 'shadows' for all global
3747   // device-side variables because the CUDA runtime needs their
3748   // size and host-side address in order to provide access to
3749   // their device-side incarnations.
3750   return !LangOpts.CUDAIsDevice || Global->hasAttr<CUDADeviceAttr>() ||
3751          Global->hasAttr<CUDAConstantAttr>() ||
3752          Global->hasAttr<CUDASharedAttr>() ||
3753          Global->getType()->isCUDADeviceBuiltinSurfaceType() ||
3754          Global->getType()->isCUDADeviceBuiltinTextureType();
3755 }
3756 
3757 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
3758   const auto *Global = cast<ValueDecl>(GD.getDecl());
3759 
3760   // Weak references don't produce any output by themselves.
3761   if (Global->hasAttr<WeakRefAttr>())
3762     return;
3763 
3764   // If this is an alias definition (which otherwise looks like a declaration)
3765   // emit it now.
3766   if (Global->hasAttr<AliasAttr>())
3767     return EmitAliasDefinition(GD);
3768 
3769   // IFunc like an alias whose value is resolved at runtime by calling resolver.
3770   if (Global->hasAttr<IFuncAttr>())
3771     return emitIFuncDefinition(GD);
3772 
3773   // If this is a cpu_dispatch multiversion function, emit the resolver.
3774   if (Global->hasAttr<CPUDispatchAttr>())
3775     return emitCPUDispatchDefinition(GD);
3776 
3777   // If this is CUDA, be selective about which declarations we emit.
3778   // Non-constexpr non-lambda implicit host device functions are not emitted
3779   // unless they are used on device side.
3780   if (LangOpts.CUDA) {
3781     assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
3782            "Expected Variable or Function");
3783     if (const auto *VD = dyn_cast<VarDecl>(Global)) {
3784       if (!shouldEmitCUDAGlobalVar(VD))
3785         return;
3786     } else if (LangOpts.CUDAIsDevice) {
3787       const auto *FD = dyn_cast<FunctionDecl>(Global);
3788       if ((!Global->hasAttr<CUDADeviceAttr>() ||
3789            (LangOpts.OffloadImplicitHostDeviceTemplates &&
3790             hasImplicitAttr<CUDAHostAttr>(FD) &&
3791             hasImplicitAttr<CUDADeviceAttr>(FD) && !FD->isConstexpr() &&
3792             !isLambdaCallOperator(FD) &&
3793             !getContext().CUDAImplicitHostDeviceFunUsedByDevice.count(FD))) &&
3794           !Global->hasAttr<CUDAGlobalAttr>() &&
3795           !(LangOpts.HIPStdPar && isa<FunctionDecl>(Global) &&
3796             !Global->hasAttr<CUDAHostAttr>()))
3797         return;
3798       // Device-only functions are the only things we skip.
3799     } else if (!Global->hasAttr<CUDAHostAttr>() &&
3800                Global->hasAttr<CUDADeviceAttr>())
3801       return;
3802   }
3803 
3804   if (LangOpts.OpenMP) {
3805     // If this is OpenMP, check if it is legal to emit this global normally.
3806     if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
3807       return;
3808     if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
3809       if (MustBeEmitted(Global))
3810         EmitOMPDeclareReduction(DRD);
3811       return;
3812     }
3813     if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) {
3814       if (MustBeEmitted(Global))
3815         EmitOMPDeclareMapper(DMD);
3816       return;
3817     }
3818   }
3819 
3820   // Ignore declarations, they will be emitted on their first use.
3821   if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
3822     // Update deferred annotations with the latest declaration if the function
3823     // function was already used or defined.
3824     if (FD->hasAttr<AnnotateAttr>()) {
3825       StringRef MangledName = getMangledName(GD);
3826       if (GetGlobalValue(MangledName))
3827         DeferredAnnotations[MangledName] = FD;
3828     }
3829 
3830     // Forward declarations are emitted lazily on first use.
3831     if (!FD->doesThisDeclarationHaveABody()) {
3832       if (!FD->doesDeclarationForceExternallyVisibleDefinition() &&
3833           (!FD->isMultiVersion() || !getTarget().getTriple().isAArch64()))
3834         return;
3835 
3836       StringRef MangledName = getMangledName(GD);
3837 
3838       // Compute the function info and LLVM type.
3839       const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
3840       llvm::Type *Ty = getTypes().GetFunctionType(FI);
3841 
3842       GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
3843                               /*DontDefer=*/false);
3844       return;
3845     }
3846   } else {
3847     const auto *VD = cast<VarDecl>(Global);
3848     assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
3849     if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
3850         !Context.isMSStaticDataMemberInlineDefinition(VD)) {
3851       if (LangOpts.OpenMP) {
3852         // Emit declaration of the must-be-emitted declare target variable.
3853         if (std::optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
3854                 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
3855 
3856           // If this variable has external storage and doesn't require special
3857           // link handling we defer to its canonical definition.
3858           if (VD->hasExternalStorage() &&
3859               Res != OMPDeclareTargetDeclAttr::MT_Link)
3860             return;
3861 
3862           bool UnifiedMemoryEnabled =
3863               getOpenMPRuntime().hasRequiresUnifiedSharedMemory();
3864           if ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
3865                *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
3866               !UnifiedMemoryEnabled) {
3867             (void)GetAddrOfGlobalVar(VD);
3868           } else {
3869             assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
3870                     ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
3871                       *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
3872                      UnifiedMemoryEnabled)) &&
3873                    "Link clause or to clause with unified memory expected.");
3874             (void)getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
3875           }
3876 
3877           return;
3878         }
3879       }
3880       // If this declaration may have caused an inline variable definition to
3881       // change linkage, make sure that it's emitted.
3882       if (Context.getInlineVariableDefinitionKind(VD) ==
3883           ASTContext::InlineVariableDefinitionKind::Strong)
3884         GetAddrOfGlobalVar(VD);
3885       return;
3886     }
3887   }
3888 
3889   // Defer code generation to first use when possible, e.g. if this is an inline
3890   // function. If the global must always be emitted, do it eagerly if possible
3891   // to benefit from cache locality.
3892   if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
3893     // Emit the definition if it can't be deferred.
3894     EmitGlobalDefinition(GD);
3895     addEmittedDeferredDecl(GD);
3896     return;
3897   }
3898 
3899   // If we're deferring emission of a C++ variable with an
3900   // initializer, remember the order in which it appeared in the file.
3901   if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
3902       cast<VarDecl>(Global)->hasInit()) {
3903     DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
3904     CXXGlobalInits.push_back(nullptr);
3905   }
3906 
3907   StringRef MangledName = getMangledName(GD);
3908   if (GetGlobalValue(MangledName) != nullptr) {
3909     // The value has already been used and should therefore be emitted.
3910     addDeferredDeclToEmit(GD);
3911   } else if (MustBeEmitted(Global)) {
3912     // The value must be emitted, but cannot be emitted eagerly.
3913     assert(!MayBeEmittedEagerly(Global));
3914     addDeferredDeclToEmit(GD);
3915   } else {
3916     // Otherwise, remember that we saw a deferred decl with this name.  The
3917     // first use of the mangled name will cause it to move into
3918     // DeferredDeclsToEmit.
3919     DeferredDecls[MangledName] = GD;
3920   }
3921 }
3922 
3923 // Check if T is a class type with a destructor that's not dllimport.
3924 static bool HasNonDllImportDtor(QualType T) {
3925   if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
3926     if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
3927       if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
3928         return true;
3929 
3930   return false;
3931 }
3932 
3933 namespace {
3934   struct FunctionIsDirectlyRecursive
3935       : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> {
3936     const StringRef Name;
3937     const Builtin::Context &BI;
3938     FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C)
3939         : Name(N), BI(C) {}
3940 
3941     bool VisitCallExpr(const CallExpr *E) {
3942       const FunctionDecl *FD = E->getDirectCallee();
3943       if (!FD)
3944         return false;
3945       AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
3946       if (Attr && Name == Attr->getLabel())
3947         return true;
3948       unsigned BuiltinID = FD->getBuiltinID();
3949       if (!BuiltinID || !BI.isLibFunction(BuiltinID))
3950         return false;
3951       StringRef BuiltinName = BI.getName(BuiltinID);
3952       if (BuiltinName.starts_with("__builtin_") &&
3953           Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
3954         return true;
3955       }
3956       return false;
3957     }
3958 
3959     bool VisitStmt(const Stmt *S) {
3960       for (const Stmt *Child : S->children())
3961         if (Child && this->Visit(Child))
3962           return true;
3963       return false;
3964     }
3965   };
3966 
3967   // Make sure we're not referencing non-imported vars or functions.
3968   struct DLLImportFunctionVisitor
3969       : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
3970     bool SafeToInline = true;
3971 
3972     bool shouldVisitImplicitCode() const { return true; }
3973 
3974     bool VisitVarDecl(VarDecl *VD) {
3975       if (VD->getTLSKind()) {
3976         // A thread-local variable cannot be imported.
3977         SafeToInline = false;
3978         return SafeToInline;
3979       }
3980 
3981       // A variable definition might imply a destructor call.
3982       if (VD->isThisDeclarationADefinition())
3983         SafeToInline = !HasNonDllImportDtor(VD->getType());
3984 
3985       return SafeToInline;
3986     }
3987 
3988     bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
3989       if (const auto *D = E->getTemporary()->getDestructor())
3990         SafeToInline = D->hasAttr<DLLImportAttr>();
3991       return SafeToInline;
3992     }
3993 
3994     bool VisitDeclRefExpr(DeclRefExpr *E) {
3995       ValueDecl *VD = E->getDecl();
3996       if (isa<FunctionDecl>(VD))
3997         SafeToInline = VD->hasAttr<DLLImportAttr>();
3998       else if (VarDecl *V = dyn_cast<VarDecl>(VD))
3999         SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
4000       return SafeToInline;
4001     }
4002 
4003     bool VisitCXXConstructExpr(CXXConstructExpr *E) {
4004       SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
4005       return SafeToInline;
4006     }
4007 
4008     bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
4009       CXXMethodDecl *M = E->getMethodDecl();
4010       if (!M) {
4011         // Call through a pointer to member function. This is safe to inline.
4012         SafeToInline = true;
4013       } else {
4014         SafeToInline = M->hasAttr<DLLImportAttr>();
4015       }
4016       return SafeToInline;
4017     }
4018 
4019     bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
4020       SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
4021       return SafeToInline;
4022     }
4023 
4024     bool VisitCXXNewExpr(CXXNewExpr *E) {
4025       SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
4026       return SafeToInline;
4027     }
4028   };
4029 }
4030 
4031 // isTriviallyRecursive - Check if this function calls another
4032 // decl that, because of the asm attribute or the other decl being a builtin,
4033 // ends up pointing to itself.
4034 bool
4035 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
4036   StringRef Name;
4037   if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
4038     // asm labels are a special kind of mangling we have to support.
4039     AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
4040     if (!Attr)
4041       return false;
4042     Name = Attr->getLabel();
4043   } else {
4044     Name = FD->getName();
4045   }
4046 
4047   FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
4048   const Stmt *Body = FD->getBody();
4049   return Body ? Walker.Visit(Body) : false;
4050 }
4051 
4052 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
4053   if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
4054     return true;
4055 
4056   const auto *F = cast<FunctionDecl>(GD.getDecl());
4057   // Inline builtins declaration must be emitted. They often are fortified
4058   // functions.
4059   if (F->isInlineBuiltinDeclaration())
4060     return true;
4061 
4062   if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
4063     return false;
4064 
4065   // We don't import function bodies from other named module units since that
4066   // behavior may break ABI compatibility of the current unit.
4067   if (const Module *M = F->getOwningModule();
4068       M && M->getTopLevelModule()->isNamedModule() &&
4069       getContext().getCurrentNamedModule() != M->getTopLevelModule()) {
4070     // There are practices to mark template member function as always-inline
4071     // and mark the template as extern explicit instantiation but not give
4072     // the definition for member function. So we have to emit the function
4073     // from explicitly instantiation with always-inline.
4074     //
4075     // See https://github.com/llvm/llvm-project/issues/86893 for details.
4076     //
4077     // TODO: Maybe it is better to give it a warning if we call a non-inline
4078     // function from other module units which is marked as always-inline.
4079     if (!F->isTemplateInstantiation() || !F->hasAttr<AlwaysInlineAttr>()) {
4080       return false;
4081     }
4082   }
4083 
4084   if (F->hasAttr<NoInlineAttr>())
4085     return false;
4086 
4087   if (F->hasAttr<DLLImportAttr>() && !F->hasAttr<AlwaysInlineAttr>()) {
4088     // Check whether it would be safe to inline this dllimport function.
4089     DLLImportFunctionVisitor Visitor;
4090     Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
4091     if (!Visitor.SafeToInline)
4092       return false;
4093 
4094     if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
4095       // Implicit destructor invocations aren't captured in the AST, so the
4096       // check above can't see them. Check for them manually here.
4097       for (const Decl *Member : Dtor->getParent()->decls())
4098         if (isa<FieldDecl>(Member))
4099           if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
4100             return false;
4101       for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
4102         if (HasNonDllImportDtor(B.getType()))
4103           return false;
4104     }
4105   }
4106 
4107   // PR9614. Avoid cases where the source code is lying to us. An available
4108   // externally function should have an equivalent function somewhere else,
4109   // but a function that calls itself through asm label/`__builtin_` trickery is
4110   // clearly not equivalent to the real implementation.
4111   // This happens in glibc's btowc and in some configure checks.
4112   return !isTriviallyRecursive(F);
4113 }
4114 
4115 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
4116   return CodeGenOpts.OptimizationLevel > 0;
4117 }
4118 
4119 void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
4120                                                        llvm::GlobalValue *GV) {
4121   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4122 
4123   if (FD->isCPUSpecificMultiVersion()) {
4124     auto *Spec = FD->getAttr<CPUSpecificAttr>();
4125     for (unsigned I = 0; I < Spec->cpus_size(); ++I)
4126       EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
4127   } else if (auto *TC = FD->getAttr<TargetClonesAttr>()) {
4128     for (unsigned I = 0; I < TC->featuresStrs_size(); ++I)
4129       // AArch64 favors the default target version over the clone if any.
4130       if ((!TC->isDefaultVersion(I) || !getTarget().getTriple().isAArch64()) &&
4131           TC->isFirstOfVersion(I))
4132         EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
4133     // Ensure that the resolver function is also emitted.
4134     GetOrCreateMultiVersionResolver(GD);
4135   } else
4136     EmitGlobalFunctionDefinition(GD, GV);
4137 
4138   // Defer the resolver emission until we can reason whether the TU
4139   // contains a default target version implementation.
4140   if (FD->isTargetVersionMultiVersion())
4141     AddDeferredMultiVersionResolverToEmit(GD);
4142 }
4143 
4144 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
4145   const auto *D = cast<ValueDecl>(GD.getDecl());
4146 
4147   PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
4148                                  Context.getSourceManager(),
4149                                  "Generating code for declaration");
4150 
4151   if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
4152     // At -O0, don't generate IR for functions with available_externally
4153     // linkage.
4154     if (!shouldEmitFunction(GD))
4155       return;
4156 
4157     llvm::TimeTraceScope TimeScope("CodeGen Function", [&]() {
4158       std::string Name;
4159       llvm::raw_string_ostream OS(Name);
4160       FD->getNameForDiagnostic(OS, getContext().getPrintingPolicy(),
4161                                /*Qualified=*/true);
4162       return Name;
4163     });
4164 
4165     if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
4166       // Make sure to emit the definition(s) before we emit the thunks.
4167       // This is necessary for the generation of certain thunks.
4168       if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
4169         ABI->emitCXXStructor(GD);
4170       else if (FD->isMultiVersion())
4171         EmitMultiVersionFunctionDefinition(GD, GV);
4172       else
4173         EmitGlobalFunctionDefinition(GD, GV);
4174 
4175       if (Method->isVirtual())
4176         getVTables().EmitThunks(GD);
4177 
4178       return;
4179     }
4180 
4181     if (FD->isMultiVersion())
4182       return EmitMultiVersionFunctionDefinition(GD, GV);
4183     return EmitGlobalFunctionDefinition(GD, GV);
4184   }
4185 
4186   if (const auto *VD = dyn_cast<VarDecl>(D))
4187     return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
4188 
4189   llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
4190 }
4191 
4192 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
4193                                                       llvm::Function *NewFn);
4194 
4195 static unsigned
4196 TargetMVPriority(const TargetInfo &TI,
4197                  const CodeGenFunction::MultiVersionResolverOption &RO) {
4198   unsigned Priority = 0;
4199   unsigned NumFeatures = 0;
4200   for (StringRef Feat : RO.Conditions.Features) {
4201     Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
4202     NumFeatures++;
4203   }
4204 
4205   if (!RO.Conditions.Architecture.empty())
4206     Priority = std::max(
4207         Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
4208 
4209   Priority += TI.multiVersionFeatureCost() * NumFeatures;
4210 
4211   return Priority;
4212 }
4213 
4214 // Multiversion functions should be at most 'WeakODRLinkage' so that a different
4215 // TU can forward declare the function without causing problems.  Particularly
4216 // in the cases of CPUDispatch, this causes issues. This also makes sure we
4217 // work with internal linkage functions, so that the same function name can be
4218 // used with internal linkage in multiple TUs.
4219 llvm::GlobalValue::LinkageTypes getMultiversionLinkage(CodeGenModule &CGM,
4220                                                        GlobalDecl GD) {
4221   const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
4222   if (FD->getFormalLinkage() == Linkage::Internal)
4223     return llvm::GlobalValue::InternalLinkage;
4224   return llvm::GlobalValue::WeakODRLinkage;
4225 }
4226 
4227 void CodeGenModule::emitMultiVersionFunctions() {
4228   std::vector<GlobalDecl> MVFuncsToEmit;
4229   MultiVersionFuncs.swap(MVFuncsToEmit);
4230   for (GlobalDecl GD : MVFuncsToEmit) {
4231     const auto *FD = cast<FunctionDecl>(GD.getDecl());
4232     assert(FD && "Expected a FunctionDecl");
4233 
4234     auto createFunction = [&](const FunctionDecl *Decl, unsigned MVIdx = 0) {
4235       GlobalDecl CurGD{Decl->isDefined() ? Decl->getDefinition() : Decl, MVIdx};
4236       StringRef MangledName = getMangledName(CurGD);
4237       llvm::Constant *Func = GetGlobalValue(MangledName);
4238       if (!Func) {
4239         if (Decl->isDefined()) {
4240           EmitGlobalFunctionDefinition(CurGD, nullptr);
4241           Func = GetGlobalValue(MangledName);
4242         } else {
4243           const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(CurGD);
4244           llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4245           Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
4246                                    /*DontDefer=*/false, ForDefinition);
4247         }
4248         assert(Func && "This should have just been created");
4249       }
4250       return cast<llvm::Function>(Func);
4251     };
4252 
4253     // For AArch64, a resolver is only emitted if a function marked with
4254     // target_version("default")) or target_clones() is present and defined
4255     // in this TU. For other architectures it is always emitted.
4256     bool ShouldEmitResolver = !getTarget().getTriple().isAArch64();
4257     SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
4258 
4259     getContext().forEachMultiversionedFunctionVersion(
4260         FD, [&](const FunctionDecl *CurFD) {
4261           llvm::SmallVector<StringRef, 8> Feats;
4262           bool IsDefined = CurFD->doesThisDeclarationHaveABody();
4263 
4264           if (const auto *TA = CurFD->getAttr<TargetAttr>()) {
4265             TA->getAddedFeatures(Feats);
4266             llvm::Function *Func = createFunction(CurFD);
4267             Options.emplace_back(Func, TA->getArchitecture(), Feats);
4268           } else if (const auto *TVA = CurFD->getAttr<TargetVersionAttr>()) {
4269             if (TVA->isDefaultVersion() && IsDefined)
4270               ShouldEmitResolver = true;
4271             TVA->getFeatures(Feats);
4272             llvm::Function *Func = createFunction(CurFD);
4273             Options.emplace_back(Func, /*Architecture*/ "", Feats);
4274           } else if (const auto *TC = CurFD->getAttr<TargetClonesAttr>()) {
4275             if (IsDefined)
4276               ShouldEmitResolver = true;
4277             for (unsigned I = 0; I < TC->featuresStrs_size(); ++I) {
4278               if (!TC->isFirstOfVersion(I))
4279                 continue;
4280 
4281               llvm::Function *Func = createFunction(CurFD, I);
4282               StringRef Architecture;
4283               Feats.clear();
4284               if (getTarget().getTriple().isAArch64())
4285                 TC->getFeatures(Feats, I);
4286               else {
4287                 StringRef Version = TC->getFeatureStr(I);
4288                 if (Version.starts_with("arch="))
4289                   Architecture = Version.drop_front(sizeof("arch=") - 1);
4290                 else if (Version != "default")
4291                   Feats.push_back(Version);
4292               }
4293               Options.emplace_back(Func, Architecture, Feats);
4294             }
4295           } else
4296             llvm_unreachable("unexpected MultiVersionKind");
4297         });
4298 
4299     if (!ShouldEmitResolver)
4300       continue;
4301 
4302     llvm::Constant *ResolverConstant = GetOrCreateMultiVersionResolver(GD);
4303     if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(ResolverConstant)) {
4304       ResolverConstant = IFunc->getResolver();
4305       if (FD->isTargetClonesMultiVersion() &&
4306           !getTarget().getTriple().isAArch64()) {
4307         std::string MangledName = getMangledNameImpl(
4308             *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4309         if (!GetGlobalValue(MangledName + ".ifunc")) {
4310           const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4311           llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4312           // In prior versions of Clang, the mangling for ifuncs incorrectly
4313           // included an .ifunc suffix. This alias is generated for backward
4314           // compatibility. It is deprecated, and may be removed in the future.
4315           auto *Alias = llvm::GlobalAlias::create(
4316               DeclTy, 0, getMultiversionLinkage(*this, GD),
4317               MangledName + ".ifunc", IFunc, &getModule());
4318           SetCommonAttributes(FD, Alias);
4319         }
4320       }
4321     }
4322     llvm::Function *ResolverFunc = cast<llvm::Function>(ResolverConstant);
4323 
4324     ResolverFunc->setLinkage(getMultiversionLinkage(*this, GD));
4325 
4326     if (!ResolverFunc->hasLocalLinkage() && supportsCOMDAT())
4327       ResolverFunc->setComdat(
4328           getModule().getOrInsertComdat(ResolverFunc->getName()));
4329 
4330     const TargetInfo &TI = getTarget();
4331     llvm::stable_sort(
4332         Options, [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
4333                        const CodeGenFunction::MultiVersionResolverOption &RHS) {
4334           return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
4335         });
4336     CodeGenFunction CGF(*this);
4337     CGF.EmitMultiVersionResolver(ResolverFunc, Options);
4338   }
4339 
4340   // Ensure that any additions to the deferred decls list caused by emitting a
4341   // variant are emitted.  This can happen when the variant itself is inline and
4342   // calls a function without linkage.
4343   if (!MVFuncsToEmit.empty())
4344     EmitDeferred();
4345 
4346   // Ensure that any additions to the multiversion funcs list from either the
4347   // deferred decls or the multiversion functions themselves are emitted.
4348   if (!MultiVersionFuncs.empty())
4349     emitMultiVersionFunctions();
4350 }
4351 
4352 static void replaceDeclarationWith(llvm::GlobalValue *Old,
4353                                    llvm::Constant *New) {
4354   assert(cast<llvm::Function>(Old)->isDeclaration() && "Not a declaration");
4355   New->takeName(Old);
4356   Old->replaceAllUsesWith(New);
4357   Old->eraseFromParent();
4358 }
4359 
4360 void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
4361   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4362   assert(FD && "Not a FunctionDecl?");
4363   assert(FD->isCPUDispatchMultiVersion() && "Not a multiversion function?");
4364   const auto *DD = FD->getAttr<CPUDispatchAttr>();
4365   assert(DD && "Not a cpu_dispatch Function?");
4366 
4367   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4368   llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4369 
4370   StringRef ResolverName = getMangledName(GD);
4371   UpdateMultiVersionNames(GD, FD, ResolverName);
4372 
4373   llvm::Type *ResolverType;
4374   GlobalDecl ResolverGD;
4375   if (getTarget().supportsIFunc()) {
4376     ResolverType = llvm::FunctionType::get(
4377         llvm::PointerType::get(DeclTy,
4378                                getTypes().getTargetAddressSpace(FD->getType())),
4379         false);
4380   }
4381   else {
4382     ResolverType = DeclTy;
4383     ResolverGD = GD;
4384   }
4385 
4386   auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
4387       ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
4388   ResolverFunc->setLinkage(getMultiversionLinkage(*this, GD));
4389   if (supportsCOMDAT())
4390     ResolverFunc->setComdat(
4391         getModule().getOrInsertComdat(ResolverFunc->getName()));
4392 
4393   SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
4394   const TargetInfo &Target = getTarget();
4395   unsigned Index = 0;
4396   for (const IdentifierInfo *II : DD->cpus()) {
4397     // Get the name of the target function so we can look it up/create it.
4398     std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
4399                               getCPUSpecificMangling(*this, II->getName());
4400 
4401     llvm::Constant *Func = GetGlobalValue(MangledName);
4402 
4403     if (!Func) {
4404       GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
4405       if (ExistingDecl.getDecl() &&
4406           ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
4407         EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
4408         Func = GetGlobalValue(MangledName);
4409       } else {
4410         if (!ExistingDecl.getDecl())
4411           ExistingDecl = GD.getWithMultiVersionIndex(Index);
4412 
4413       Func = GetOrCreateLLVMFunction(
4414           MangledName, DeclTy, ExistingDecl,
4415           /*ForVTable=*/false, /*DontDefer=*/true,
4416           /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
4417       }
4418     }
4419 
4420     llvm::SmallVector<StringRef, 32> Features;
4421     Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
4422     llvm::transform(Features, Features.begin(),
4423                     [](StringRef Str) { return Str.substr(1); });
4424     llvm::erase_if(Features, [&Target](StringRef Feat) {
4425       return !Target.validateCpuSupports(Feat);
4426     });
4427     Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
4428     ++Index;
4429   }
4430 
4431   llvm::stable_sort(
4432       Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
4433                   const CodeGenFunction::MultiVersionResolverOption &RHS) {
4434         return llvm::X86::getCpuSupportsMask(LHS.Conditions.Features) >
4435                llvm::X86::getCpuSupportsMask(RHS.Conditions.Features);
4436       });
4437 
4438   // If the list contains multiple 'default' versions, such as when it contains
4439   // 'pentium' and 'generic', don't emit the call to the generic one (since we
4440   // always run on at least a 'pentium'). We do this by deleting the 'least
4441   // advanced' (read, lowest mangling letter).
4442   while (Options.size() > 1 &&
4443          llvm::all_of(llvm::X86::getCpuSupportsMask(
4444                           (Options.end() - 2)->Conditions.Features),
4445                       [](auto X) { return X == 0; })) {
4446     StringRef LHSName = (Options.end() - 2)->Function->getName();
4447     StringRef RHSName = (Options.end() - 1)->Function->getName();
4448     if (LHSName.compare(RHSName) < 0)
4449       Options.erase(Options.end() - 2);
4450     else
4451       Options.erase(Options.end() - 1);
4452   }
4453 
4454   CodeGenFunction CGF(*this);
4455   CGF.EmitMultiVersionResolver(ResolverFunc, Options);
4456 
4457   if (getTarget().supportsIFunc()) {
4458     llvm::GlobalValue::LinkageTypes Linkage = getMultiversionLinkage(*this, GD);
4459     auto *IFunc = cast<llvm::GlobalValue>(GetOrCreateMultiVersionResolver(GD));
4460     unsigned AS = IFunc->getType()->getPointerAddressSpace();
4461 
4462     // Fix up function declarations that were created for cpu_specific before
4463     // cpu_dispatch was known
4464     if (!isa<llvm::GlobalIFunc>(IFunc)) {
4465       auto *GI = llvm::GlobalIFunc::create(DeclTy, AS, Linkage, "",
4466                                            ResolverFunc, &getModule());
4467       replaceDeclarationWith(IFunc, GI);
4468       IFunc = GI;
4469     }
4470 
4471     std::string AliasName = getMangledNameImpl(
4472         *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4473     llvm::Constant *AliasFunc = GetGlobalValue(AliasName);
4474     if (!AliasFunc) {
4475       auto *GA = llvm::GlobalAlias::create(DeclTy, AS, Linkage, AliasName,
4476                                            IFunc, &getModule());
4477       SetCommonAttributes(GD, GA);
4478     }
4479   }
4480 }
4481 
4482 /// Adds a declaration to the list of multi version functions if not present.
4483 void CodeGenModule::AddDeferredMultiVersionResolverToEmit(GlobalDecl GD) {
4484   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4485   assert(FD && "Not a FunctionDecl?");
4486 
4487   if (FD->isTargetVersionMultiVersion() || FD->isTargetClonesMultiVersion()) {
4488     std::string MangledName =
4489         getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
4490     if (!DeferredResolversToEmit.insert(MangledName).second)
4491       return;
4492   }
4493   MultiVersionFuncs.push_back(GD);
4494 }
4495 
4496 /// If a dispatcher for the specified mangled name is not in the module, create
4497 /// and return it. The dispatcher is either an llvm Function with the specified
4498 /// type, or a global ifunc.
4499 llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(GlobalDecl GD) {
4500   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4501   assert(FD && "Not a FunctionDecl?");
4502 
4503   std::string MangledName =
4504       getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
4505 
4506   // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
4507   // a separate resolver).
4508   std::string ResolverName = MangledName;
4509   if (getTarget().supportsIFunc()) {
4510     switch (FD->getMultiVersionKind()) {
4511     case MultiVersionKind::None:
4512       llvm_unreachable("unexpected MultiVersionKind::None for resolver");
4513     case MultiVersionKind::Target:
4514     case MultiVersionKind::CPUSpecific:
4515     case MultiVersionKind::CPUDispatch:
4516       ResolverName += ".ifunc";
4517       break;
4518     case MultiVersionKind::TargetClones:
4519     case MultiVersionKind::TargetVersion:
4520       break;
4521     }
4522   } else if (FD->isTargetMultiVersion()) {
4523     ResolverName += ".resolver";
4524   }
4525 
4526   // If the resolver has already been created, just return it. This lookup may
4527   // yield a function declaration instead of a resolver on AArch64. That is
4528   // because we didn't know whether a resolver will be generated when we first
4529   // encountered a use of the symbol named after this resolver. Therefore,
4530   // targets which support ifuncs should not return here unless we actually
4531   // found an ifunc.
4532   llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName);
4533   if (ResolverGV &&
4534       (isa<llvm::GlobalIFunc>(ResolverGV) || !getTarget().supportsIFunc()))
4535     return ResolverGV;
4536 
4537   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4538   llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4539 
4540   // The resolver needs to be created. For target and target_clones, defer
4541   // creation until the end of the TU.
4542   if (FD->isTargetMultiVersion() || FD->isTargetClonesMultiVersion())
4543     AddDeferredMultiVersionResolverToEmit(GD);
4544 
4545   // For cpu_specific, don't create an ifunc yet because we don't know if the
4546   // cpu_dispatch will be emitted in this translation unit.
4547   if (getTarget().supportsIFunc() && !FD->isCPUSpecificMultiVersion()) {
4548     unsigned AS = getTypes().getTargetAddressSpace(FD->getType());
4549     llvm::Type *ResolverType =
4550         llvm::FunctionType::get(llvm::PointerType::get(DeclTy, AS), false);
4551     llvm::Constant *Resolver = GetOrCreateLLVMFunction(
4552         MangledName + ".resolver", ResolverType, GlobalDecl{},
4553         /*ForVTable=*/false);
4554     llvm::GlobalIFunc *GIF =
4555         llvm::GlobalIFunc::create(DeclTy, AS, getMultiversionLinkage(*this, GD),
4556                                   "", Resolver, &getModule());
4557     GIF->setName(ResolverName);
4558     SetCommonAttributes(FD, GIF);
4559     if (ResolverGV)
4560       replaceDeclarationWith(ResolverGV, GIF);
4561     return GIF;
4562   }
4563 
4564   llvm::Constant *Resolver = GetOrCreateLLVMFunction(
4565       ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
4566   assert(isa<llvm::GlobalValue>(Resolver) &&
4567          "Resolver should be created for the first time");
4568   SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
4569   if (ResolverGV)
4570     replaceDeclarationWith(ResolverGV, Resolver);
4571   return Resolver;
4572 }
4573 
4574 bool CodeGenModule::shouldDropDLLAttribute(const Decl *D,
4575                                            const llvm::GlobalValue *GV) const {
4576   auto SC = GV->getDLLStorageClass();
4577   if (SC == llvm::GlobalValue::DefaultStorageClass)
4578     return false;
4579   const Decl *MRD = D->getMostRecentDecl();
4580   return (((SC == llvm::GlobalValue::DLLImportStorageClass &&
4581             !MRD->hasAttr<DLLImportAttr>()) ||
4582            (SC == llvm::GlobalValue::DLLExportStorageClass &&
4583             !MRD->hasAttr<DLLExportAttr>())) &&
4584           !shouldMapVisibilityToDLLExport(cast<NamedDecl>(MRD)));
4585 }
4586 
4587 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
4588 /// module, create and return an llvm Function with the specified type. If there
4589 /// is something in the module with the specified name, return it potentially
4590 /// bitcasted to the right type.
4591 ///
4592 /// If D is non-null, it specifies a decl that correspond to this.  This is used
4593 /// to set the attributes on the function when it is first created.
4594 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
4595     StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
4596     bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
4597     ForDefinition_t IsForDefinition) {
4598   const Decl *D = GD.getDecl();
4599 
4600   std::string NameWithoutMultiVersionMangling;
4601   // Any attempts to use a MultiVersion function should result in retrieving
4602   // the iFunc instead. Name Mangling will handle the rest of the changes.
4603   if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
4604     // For the device mark the function as one that should be emitted.
4605     if (getLangOpts().OpenMPIsTargetDevice && OpenMPRuntime &&
4606         !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
4607         !DontDefer && !IsForDefinition) {
4608       if (const FunctionDecl *FDDef = FD->getDefinition()) {
4609         GlobalDecl GDDef;
4610         if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
4611           GDDef = GlobalDecl(CD, GD.getCtorType());
4612         else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
4613           GDDef = GlobalDecl(DD, GD.getDtorType());
4614         else
4615           GDDef = GlobalDecl(FDDef);
4616         EmitGlobal(GDDef);
4617       }
4618     }
4619 
4620     if (FD->isMultiVersion()) {
4621       UpdateMultiVersionNames(GD, FD, MangledName);
4622       if (!IsForDefinition) {
4623         // On AArch64 we do not immediatelly emit an ifunc resolver when a
4624         // function is used. Instead we defer the emission until we see a
4625         // default definition. In the meantime we just reference the symbol
4626         // without FMV mangling (it may or may not be replaced later).
4627         if (getTarget().getTriple().isAArch64()) {
4628           AddDeferredMultiVersionResolverToEmit(GD);
4629           NameWithoutMultiVersionMangling = getMangledNameImpl(
4630               *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4631         } else
4632           return GetOrCreateMultiVersionResolver(GD);
4633       }
4634     }
4635   }
4636 
4637   if (!NameWithoutMultiVersionMangling.empty())
4638     MangledName = NameWithoutMultiVersionMangling;
4639 
4640   // Lookup the entry, lazily creating it if necessary.
4641   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4642   if (Entry) {
4643     if (WeakRefReferences.erase(Entry)) {
4644       const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
4645       if (FD && !FD->hasAttr<WeakAttr>())
4646         Entry->setLinkage(llvm::Function::ExternalLinkage);
4647     }
4648 
4649     // Handle dropped DLL attributes.
4650     if (D && shouldDropDLLAttribute(D, Entry)) {
4651       Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
4652       setDSOLocal(Entry);
4653     }
4654 
4655     // If there are two attempts to define the same mangled name, issue an
4656     // error.
4657     if (IsForDefinition && !Entry->isDeclaration()) {
4658       GlobalDecl OtherGD;
4659       // Check that GD is not yet in DiagnosedConflictingDefinitions is required
4660       // to make sure that we issue an error only once.
4661       if (lookupRepresentativeDecl(MangledName, OtherGD) &&
4662           (GD.getCanonicalDecl().getDecl() !=
4663            OtherGD.getCanonicalDecl().getDecl()) &&
4664           DiagnosedConflictingDefinitions.insert(GD).second) {
4665         getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
4666             << MangledName;
4667         getDiags().Report(OtherGD.getDecl()->getLocation(),
4668                           diag::note_previous_definition);
4669       }
4670     }
4671 
4672     if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
4673         (Entry->getValueType() == Ty)) {
4674       return Entry;
4675     }
4676 
4677     // Make sure the result is of the correct type.
4678     // (If function is requested for a definition, we always need to create a new
4679     // function, not just return a bitcast.)
4680     if (!IsForDefinition)
4681       return Entry;
4682   }
4683 
4684   // This function doesn't have a complete type (for example, the return
4685   // type is an incomplete struct). Use a fake type instead, and make
4686   // sure not to try to set attributes.
4687   bool IsIncompleteFunction = false;
4688 
4689   llvm::FunctionType *FTy;
4690   if (isa<llvm::FunctionType>(Ty)) {
4691     FTy = cast<llvm::FunctionType>(Ty);
4692   } else {
4693     FTy = llvm::FunctionType::get(VoidTy, false);
4694     IsIncompleteFunction = true;
4695   }
4696 
4697   llvm::Function *F =
4698       llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
4699                              Entry ? StringRef() : MangledName, &getModule());
4700 
4701   // Store the declaration associated with this function so it is potentially
4702   // updated by further declarations or definitions and emitted at the end.
4703   if (D && D->hasAttr<AnnotateAttr>())
4704     DeferredAnnotations[MangledName] = cast<ValueDecl>(D);
4705 
4706   // If we already created a function with the same mangled name (but different
4707   // type) before, take its name and add it to the list of functions to be
4708   // replaced with F at the end of CodeGen.
4709   //
4710   // This happens if there is a prototype for a function (e.g. "int f()") and
4711   // then a definition of a different type (e.g. "int f(int x)").
4712   if (Entry) {
4713     F->takeName(Entry);
4714 
4715     // This might be an implementation of a function without a prototype, in
4716     // which case, try to do special replacement of calls which match the new
4717     // prototype.  The really key thing here is that we also potentially drop
4718     // arguments from the call site so as to make a direct call, which makes the
4719     // inliner happier and suppresses a number of optimizer warnings (!) about
4720     // dropping arguments.
4721     if (!Entry->use_empty()) {
4722       ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
4723       Entry->removeDeadConstantUsers();
4724     }
4725 
4726     addGlobalValReplacement(Entry, F);
4727   }
4728 
4729   assert(F->getName() == MangledName && "name was uniqued!");
4730   if (D)
4731     SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
4732   if (ExtraAttrs.hasFnAttrs()) {
4733     llvm::AttrBuilder B(F->getContext(), ExtraAttrs.getFnAttrs());
4734     F->addFnAttrs(B);
4735   }
4736 
4737   if (!DontDefer) {
4738     // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
4739     // each other bottoming out with the base dtor.  Therefore we emit non-base
4740     // dtors on usage, even if there is no dtor definition in the TU.
4741     if (isa_and_nonnull<CXXDestructorDecl>(D) &&
4742         getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
4743                                            GD.getDtorType()))
4744       addDeferredDeclToEmit(GD);
4745 
4746     // This is the first use or definition of a mangled name.  If there is a
4747     // deferred decl with this name, remember that we need to emit it at the end
4748     // of the file.
4749     auto DDI = DeferredDecls.find(MangledName);
4750     if (DDI != DeferredDecls.end()) {
4751       // Move the potentially referenced deferred decl to the
4752       // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
4753       // don't need it anymore).
4754       addDeferredDeclToEmit(DDI->second);
4755       DeferredDecls.erase(DDI);
4756 
4757       // Otherwise, there are cases we have to worry about where we're
4758       // using a declaration for which we must emit a definition but where
4759       // we might not find a top-level definition:
4760       //   - member functions defined inline in their classes
4761       //   - friend functions defined inline in some class
4762       //   - special member functions with implicit definitions
4763       // If we ever change our AST traversal to walk into class methods,
4764       // this will be unnecessary.
4765       //
4766       // We also don't emit a definition for a function if it's going to be an
4767       // entry in a vtable, unless it's already marked as used.
4768     } else if (getLangOpts().CPlusPlus && D) {
4769       // Look for a declaration that's lexically in a record.
4770       for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
4771            FD = FD->getPreviousDecl()) {
4772         if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
4773           if (FD->doesThisDeclarationHaveABody()) {
4774             addDeferredDeclToEmit(GD.getWithDecl(FD));
4775             break;
4776           }
4777         }
4778       }
4779     }
4780   }
4781 
4782   // Make sure the result is of the requested type.
4783   if (!IsIncompleteFunction) {
4784     assert(F->getFunctionType() == Ty);
4785     return F;
4786   }
4787 
4788   return F;
4789 }
4790 
4791 /// GetAddrOfFunction - Return the address of the given function.  If Ty is
4792 /// non-null, then this function will use the specified type if it has to
4793 /// create it (this occurs when we see a definition of the function).
4794 llvm::Constant *
4795 CodeGenModule::GetAddrOfFunction(GlobalDecl GD, llvm::Type *Ty, bool ForVTable,
4796                                  bool DontDefer,
4797                                  ForDefinition_t IsForDefinition) {
4798   // If there was no specific requested type, just convert it now.
4799   if (!Ty) {
4800     const auto *FD = cast<FunctionDecl>(GD.getDecl());
4801     Ty = getTypes().ConvertType(FD->getType());
4802   }
4803 
4804   // Devirtualized destructor calls may come through here instead of via
4805   // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
4806   // of the complete destructor when necessary.
4807   if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
4808     if (getTarget().getCXXABI().isMicrosoft() &&
4809         GD.getDtorType() == Dtor_Complete &&
4810         DD->getParent()->getNumVBases() == 0)
4811       GD = GlobalDecl(DD, Dtor_Base);
4812   }
4813 
4814   StringRef MangledName = getMangledName(GD);
4815   auto *F = GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
4816                                     /*IsThunk=*/false, llvm::AttributeList(),
4817                                     IsForDefinition);
4818   // Returns kernel handle for HIP kernel stub function.
4819   if (LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
4820       cast<FunctionDecl>(GD.getDecl())->hasAttr<CUDAGlobalAttr>()) {
4821     auto *Handle = getCUDARuntime().getKernelHandle(
4822         cast<llvm::Function>(F->stripPointerCasts()), GD);
4823     if (IsForDefinition)
4824       return F;
4825     return Handle;
4826   }
4827   return F;
4828 }
4829 
4830 llvm::Constant *CodeGenModule::GetFunctionStart(const ValueDecl *Decl) {
4831   llvm::GlobalValue *F =
4832       cast<llvm::GlobalValue>(GetAddrOfFunction(Decl)->stripPointerCasts());
4833 
4834   return llvm::NoCFIValue::get(F);
4835 }
4836 
4837 static const FunctionDecl *
4838 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
4839   TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
4840   DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
4841 
4842   IdentifierInfo &CII = C.Idents.get(Name);
4843   for (const auto *Result : DC->lookup(&CII))
4844     if (const auto *FD = dyn_cast<FunctionDecl>(Result))
4845       return FD;
4846 
4847   if (!C.getLangOpts().CPlusPlus)
4848     return nullptr;
4849 
4850   // Demangle the premangled name from getTerminateFn()
4851   IdentifierInfo &CXXII =
4852       (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
4853           ? C.Idents.get("terminate")
4854           : C.Idents.get(Name);
4855 
4856   for (const auto &N : {"__cxxabiv1", "std"}) {
4857     IdentifierInfo &NS = C.Idents.get(N);
4858     for (const auto *Result : DC->lookup(&NS)) {
4859       const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
4860       if (auto *LSD = dyn_cast<LinkageSpecDecl>(Result))
4861         for (const auto *Result : LSD->lookup(&NS))
4862           if ((ND = dyn_cast<NamespaceDecl>(Result)))
4863             break;
4864 
4865       if (ND)
4866         for (const auto *Result : ND->lookup(&CXXII))
4867           if (const auto *FD = dyn_cast<FunctionDecl>(Result))
4868             return FD;
4869     }
4870   }
4871 
4872   return nullptr;
4873 }
4874 
4875 /// CreateRuntimeFunction - Create a new runtime function with the specified
4876 /// type and name.
4877 llvm::FunctionCallee
4878 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
4879                                      llvm::AttributeList ExtraAttrs, bool Local,
4880                                      bool AssumeConvergent) {
4881   if (AssumeConvergent) {
4882     ExtraAttrs =
4883         ExtraAttrs.addFnAttribute(VMContext, llvm::Attribute::Convergent);
4884   }
4885 
4886   llvm::Constant *C =
4887       GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
4888                               /*DontDefer=*/false, /*IsThunk=*/false,
4889                               ExtraAttrs);
4890 
4891   if (auto *F = dyn_cast<llvm::Function>(C)) {
4892     if (F->empty()) {
4893       F->setCallingConv(getRuntimeCC());
4894 
4895       // In Windows Itanium environments, try to mark runtime functions
4896       // dllimport. For Mingw and MSVC, don't. We don't really know if the user
4897       // will link their standard library statically or dynamically. Marking
4898       // functions imported when they are not imported can cause linker errors
4899       // and warnings.
4900       if (!Local && getTriple().isWindowsItaniumEnvironment() &&
4901           !getCodeGenOpts().LTOVisibilityPublicStd) {
4902         const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
4903         if (!FD || FD->hasAttr<DLLImportAttr>()) {
4904           F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
4905           F->setLinkage(llvm::GlobalValue::ExternalLinkage);
4906         }
4907       }
4908       setDSOLocal(F);
4909       // FIXME: We should use CodeGenModule::SetLLVMFunctionAttributes() instead
4910       // of trying to approximate the attributes using the LLVM function
4911       // signature. This requires revising the API of CreateRuntimeFunction().
4912       markRegisterParameterAttributes(F);
4913     }
4914   }
4915 
4916   return {FTy, C};
4917 }
4918 
4919 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
4920 /// create and return an llvm GlobalVariable with the specified type and address
4921 /// space. If there is something in the module with the specified name, return
4922 /// it potentially bitcasted to the right type.
4923 ///
4924 /// If D is non-null, it specifies a decl that correspond to this.  This is used
4925 /// to set the attributes on the global when it is first created.
4926 ///
4927 /// If IsForDefinition is true, it is guaranteed that an actual global with
4928 /// type Ty will be returned, not conversion of a variable with the same
4929 /// mangled name but some other type.
4930 llvm::Constant *
4931 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, llvm::Type *Ty,
4932                                      LangAS AddrSpace, const VarDecl *D,
4933                                      ForDefinition_t IsForDefinition) {
4934   // Lookup the entry, lazily creating it if necessary.
4935   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4936   unsigned TargetAS = getContext().getTargetAddressSpace(AddrSpace);
4937   if (Entry) {
4938     if (WeakRefReferences.erase(Entry)) {
4939       if (D && !D->hasAttr<WeakAttr>())
4940         Entry->setLinkage(llvm::Function::ExternalLinkage);
4941     }
4942 
4943     // Handle dropped DLL attributes.
4944     if (D && shouldDropDLLAttribute(D, Entry))
4945       Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
4946 
4947     if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
4948       getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
4949 
4950     if (Entry->getValueType() == Ty && Entry->getAddressSpace() == TargetAS)
4951       return Entry;
4952 
4953     // If there are two attempts to define the same mangled name, issue an
4954     // error.
4955     if (IsForDefinition && !Entry->isDeclaration()) {
4956       GlobalDecl OtherGD;
4957       const VarDecl *OtherD;
4958 
4959       // Check that D is not yet in DiagnosedConflictingDefinitions is required
4960       // to make sure that we issue an error only once.
4961       if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
4962           (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
4963           (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
4964           OtherD->hasInit() &&
4965           DiagnosedConflictingDefinitions.insert(D).second) {
4966         getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
4967             << MangledName;
4968         getDiags().Report(OtherGD.getDecl()->getLocation(),
4969                           diag::note_previous_definition);
4970       }
4971     }
4972 
4973     // Make sure the result is of the correct type.
4974     if (Entry->getType()->getAddressSpace() != TargetAS)
4975       return llvm::ConstantExpr::getAddrSpaceCast(
4976           Entry, llvm::PointerType::get(Ty->getContext(), TargetAS));
4977 
4978     // (If global is requested for a definition, we always need to create a new
4979     // global, not just return a bitcast.)
4980     if (!IsForDefinition)
4981       return Entry;
4982   }
4983 
4984   auto DAddrSpace = GetGlobalVarAddressSpace(D);
4985 
4986   auto *GV = new llvm::GlobalVariable(
4987       getModule(), Ty, false, llvm::GlobalValue::ExternalLinkage, nullptr,
4988       MangledName, nullptr, llvm::GlobalVariable::NotThreadLocal,
4989       getContext().getTargetAddressSpace(DAddrSpace));
4990 
4991   // If we already created a global with the same mangled name (but different
4992   // type) before, take its name and remove it from its parent.
4993   if (Entry) {
4994     GV->takeName(Entry);
4995 
4996     if (!Entry->use_empty()) {
4997       Entry->replaceAllUsesWith(GV);
4998     }
4999 
5000     Entry->eraseFromParent();
5001   }
5002 
5003   // This is the first use or definition of a mangled name.  If there is a
5004   // deferred decl with this name, remember that we need to emit it at the end
5005   // of the file.
5006   auto DDI = DeferredDecls.find(MangledName);
5007   if (DDI != DeferredDecls.end()) {
5008     // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
5009     // list, and remove it from DeferredDecls (since we don't need it anymore).
5010     addDeferredDeclToEmit(DDI->second);
5011     DeferredDecls.erase(DDI);
5012   }
5013 
5014   // Handle things which are present even on external declarations.
5015   if (D) {
5016     if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
5017       getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
5018 
5019     // FIXME: This code is overly simple and should be merged with other global
5020     // handling.
5021     GV->setConstant(D->getType().isConstantStorage(getContext(), false, false));
5022 
5023     GV->setAlignment(getContext().getDeclAlign(D).getAsAlign());
5024 
5025     setLinkageForGV(GV, D);
5026 
5027     if (D->getTLSKind()) {
5028       if (D->getTLSKind() == VarDecl::TLS_Dynamic)
5029         CXXThreadLocals.push_back(D);
5030       setTLSMode(GV, *D);
5031     }
5032 
5033     setGVProperties(GV, D);
5034 
5035     // If required by the ABI, treat declarations of static data members with
5036     // inline initializers as definitions.
5037     if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
5038       EmitGlobalVarDefinition(D);
5039     }
5040 
5041     // Emit section information for extern variables.
5042     if (D->hasExternalStorage()) {
5043       if (const SectionAttr *SA = D->getAttr<SectionAttr>())
5044         GV->setSection(SA->getName());
5045     }
5046 
5047     // Handle XCore specific ABI requirements.
5048     if (getTriple().getArch() == llvm::Triple::xcore &&
5049         D->getLanguageLinkage() == CLanguageLinkage &&
5050         D->getType().isConstant(Context) &&
5051         isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
5052       GV->setSection(".cp.rodata");
5053 
5054     // Handle code model attribute
5055     if (const auto *CMA = D->getAttr<CodeModelAttr>())
5056       GV->setCodeModel(CMA->getModel());
5057 
5058     // Check if we a have a const declaration with an initializer, we may be
5059     // able to emit it as available_externally to expose it's value to the
5060     // optimizer.
5061     if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
5062         D->getType().isConstQualified() && !GV->hasInitializer() &&
5063         !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
5064       const auto *Record =
5065           Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
5066       bool HasMutableFields = Record && Record->hasMutableFields();
5067       if (!HasMutableFields) {
5068         const VarDecl *InitDecl;
5069         const Expr *InitExpr = D->getAnyInitializer(InitDecl);
5070         if (InitExpr) {
5071           ConstantEmitter emitter(*this);
5072           llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
5073           if (Init) {
5074             auto *InitType = Init->getType();
5075             if (GV->getValueType() != InitType) {
5076               // The type of the initializer does not match the definition.
5077               // This happens when an initializer has a different type from
5078               // the type of the global (because of padding at the end of a
5079               // structure for instance).
5080               GV->setName(StringRef());
5081               // Make a new global with the correct type, this is now guaranteed
5082               // to work.
5083               auto *NewGV = cast<llvm::GlobalVariable>(
5084                   GetAddrOfGlobalVar(D, InitType, IsForDefinition)
5085                       ->stripPointerCasts());
5086 
5087               // Erase the old global, since it is no longer used.
5088               GV->eraseFromParent();
5089               GV = NewGV;
5090             } else {
5091               GV->setInitializer(Init);
5092               GV->setConstant(true);
5093               GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
5094             }
5095             emitter.finalize(GV);
5096           }
5097         }
5098       }
5099     }
5100   }
5101 
5102   if (D &&
5103       D->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly) {
5104     getTargetCodeGenInfo().setTargetAttributes(D, GV, *this);
5105     // External HIP managed variables needed to be recorded for transformation
5106     // in both device and host compilations.
5107     if (getLangOpts().CUDA && D && D->hasAttr<HIPManagedAttr>() &&
5108         D->hasExternalStorage())
5109       getCUDARuntime().handleVarRegistration(D, *GV);
5110   }
5111 
5112   if (D)
5113     SanitizerMD->reportGlobal(GV, *D);
5114 
5115   LangAS ExpectedAS =
5116       D ? D->getType().getAddressSpace()
5117         : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
5118   assert(getContext().getTargetAddressSpace(ExpectedAS) == TargetAS);
5119   if (DAddrSpace != ExpectedAS) {
5120     return getTargetCodeGenInfo().performAddrSpaceCast(
5121         *this, GV, DAddrSpace, ExpectedAS,
5122         llvm::PointerType::get(getLLVMContext(), TargetAS));
5123   }
5124 
5125   return GV;
5126 }
5127 
5128 llvm::Constant *
5129 CodeGenModule::GetAddrOfGlobal(GlobalDecl GD, ForDefinition_t IsForDefinition) {
5130   const Decl *D = GD.getDecl();
5131 
5132   if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
5133     return getAddrOfCXXStructor(GD, /*FnInfo=*/nullptr, /*FnType=*/nullptr,
5134                                 /*DontDefer=*/false, IsForDefinition);
5135 
5136   if (isa<CXXMethodDecl>(D)) {
5137     auto FInfo =
5138         &getTypes().arrangeCXXMethodDeclaration(cast<CXXMethodDecl>(D));
5139     auto Ty = getTypes().GetFunctionType(*FInfo);
5140     return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
5141                              IsForDefinition);
5142   }
5143 
5144   if (isa<FunctionDecl>(D)) {
5145     const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
5146     llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
5147     return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
5148                              IsForDefinition);
5149   }
5150 
5151   return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr, IsForDefinition);
5152 }
5153 
5154 llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
5155     StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
5156     llvm::Align Alignment) {
5157   llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
5158   llvm::GlobalVariable *OldGV = nullptr;
5159 
5160   if (GV) {
5161     // Check if the variable has the right type.
5162     if (GV->getValueType() == Ty)
5163       return GV;
5164 
5165     // Because C++ name mangling, the only way we can end up with an already
5166     // existing global with the same name is if it has been declared extern "C".
5167     assert(GV->isDeclaration() && "Declaration has wrong type!");
5168     OldGV = GV;
5169   }
5170 
5171   // Create a new variable.
5172   GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
5173                                 Linkage, nullptr, Name);
5174 
5175   if (OldGV) {
5176     // Replace occurrences of the old variable if needed.
5177     GV->takeName(OldGV);
5178 
5179     if (!OldGV->use_empty()) {
5180       OldGV->replaceAllUsesWith(GV);
5181     }
5182 
5183     OldGV->eraseFromParent();
5184   }
5185 
5186   if (supportsCOMDAT() && GV->isWeakForLinker() &&
5187       !GV->hasAvailableExternallyLinkage())
5188     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
5189 
5190   GV->setAlignment(Alignment);
5191 
5192   return GV;
5193 }
5194 
5195 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
5196 /// given global variable.  If Ty is non-null and if the global doesn't exist,
5197 /// then it will be created with the specified type instead of whatever the
5198 /// normal requested type would be. If IsForDefinition is true, it is guaranteed
5199 /// that an actual global with type Ty will be returned, not conversion of a
5200 /// variable with the same mangled name but some other type.
5201 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
5202                                                   llvm::Type *Ty,
5203                                            ForDefinition_t IsForDefinition) {
5204   assert(D->hasGlobalStorage() && "Not a global variable");
5205   QualType ASTTy = D->getType();
5206   if (!Ty)
5207     Ty = getTypes().ConvertTypeForMem(ASTTy);
5208 
5209   StringRef MangledName = getMangledName(D);
5210   return GetOrCreateLLVMGlobal(MangledName, Ty, ASTTy.getAddressSpace(), D,
5211                                IsForDefinition);
5212 }
5213 
5214 /// CreateRuntimeVariable - Create a new runtime global variable with the
5215 /// specified type and name.
5216 llvm::Constant *
5217 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
5218                                      StringRef Name) {
5219   LangAS AddrSpace = getContext().getLangOpts().OpenCL ? LangAS::opencl_global
5220                                                        : LangAS::Default;
5221   auto *Ret = GetOrCreateLLVMGlobal(Name, Ty, AddrSpace, nullptr);
5222   setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
5223   return Ret;
5224 }
5225 
5226 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
5227   assert(!D->getInit() && "Cannot emit definite definitions here!");
5228 
5229   StringRef MangledName = getMangledName(D);
5230   llvm::GlobalValue *GV = GetGlobalValue(MangledName);
5231 
5232   // We already have a definition, not declaration, with the same mangled name.
5233   // Emitting of declaration is not required (and actually overwrites emitted
5234   // definition).
5235   if (GV && !GV->isDeclaration())
5236     return;
5237 
5238   // If we have not seen a reference to this variable yet, place it into the
5239   // deferred declarations table to be emitted if needed later.
5240   if (!MustBeEmitted(D) && !GV) {
5241       DeferredDecls[MangledName] = D;
5242       return;
5243   }
5244 
5245   // The tentative definition is the only definition.
5246   EmitGlobalVarDefinition(D);
5247 }
5248 
5249 void CodeGenModule::EmitExternalDeclaration(const DeclaratorDecl *D) {
5250   if (auto const *V = dyn_cast<const VarDecl>(D))
5251     EmitExternalVarDeclaration(V);
5252   if (auto const *FD = dyn_cast<const FunctionDecl>(D))
5253     EmitExternalFunctionDeclaration(FD);
5254 }
5255 
5256 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
5257   return Context.toCharUnitsFromBits(
5258       getDataLayout().getTypeStoreSizeInBits(Ty));
5259 }
5260 
5261 LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
5262   if (LangOpts.OpenCL) {
5263     LangAS AS = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
5264     assert(AS == LangAS::opencl_global ||
5265            AS == LangAS::opencl_global_device ||
5266            AS == LangAS::opencl_global_host ||
5267            AS == LangAS::opencl_constant ||
5268            AS == LangAS::opencl_local ||
5269            AS >= LangAS::FirstTargetAddressSpace);
5270     return AS;
5271   }
5272 
5273   if (LangOpts.SYCLIsDevice &&
5274       (!D || D->getType().getAddressSpace() == LangAS::Default))
5275     return LangAS::sycl_global;
5276 
5277   if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
5278     if (D) {
5279       if (D->hasAttr<CUDAConstantAttr>())
5280         return LangAS::cuda_constant;
5281       if (D->hasAttr<CUDASharedAttr>())
5282         return LangAS::cuda_shared;
5283       if (D->hasAttr<CUDADeviceAttr>())
5284         return LangAS::cuda_device;
5285       if (D->getType().isConstQualified())
5286         return LangAS::cuda_constant;
5287     }
5288     return LangAS::cuda_device;
5289   }
5290 
5291   if (LangOpts.OpenMP) {
5292     LangAS AS;
5293     if (OpenMPRuntime->hasAllocateAttributeForGlobalVar(D, AS))
5294       return AS;
5295   }
5296   return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
5297 }
5298 
5299 LangAS CodeGenModule::GetGlobalConstantAddressSpace() const {
5300   // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
5301   if (LangOpts.OpenCL)
5302     return LangAS::opencl_constant;
5303   if (LangOpts.SYCLIsDevice)
5304     return LangAS::sycl_global;
5305   if (LangOpts.HIP && LangOpts.CUDAIsDevice && getTriple().isSPIRV())
5306     // For HIPSPV map literals to cuda_device (maps to CrossWorkGroup in SPIR-V)
5307     // instead of default AS (maps to Generic in SPIR-V). Otherwise, we end up
5308     // with OpVariable instructions with Generic storage class which is not
5309     // allowed (SPIR-V V1.6 s3.42.8). Also, mapping literals to SPIR-V
5310     // UniformConstant storage class is not viable as pointers to it may not be
5311     // casted to Generic pointers which are used to model HIP's "flat" pointers.
5312     return LangAS::cuda_device;
5313   if (auto AS = getTarget().getConstantAddressSpace())
5314     return *AS;
5315   return LangAS::Default;
5316 }
5317 
5318 // In address space agnostic languages, string literals are in default address
5319 // space in AST. However, certain targets (e.g. amdgcn) request them to be
5320 // emitted in constant address space in LLVM IR. To be consistent with other
5321 // parts of AST, string literal global variables in constant address space
5322 // need to be casted to default address space before being put into address
5323 // map and referenced by other part of CodeGen.
5324 // In OpenCL, string literals are in constant address space in AST, therefore
5325 // they should not be casted to default address space.
5326 static llvm::Constant *
5327 castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM,
5328                                        llvm::GlobalVariable *GV) {
5329   llvm::Constant *Cast = GV;
5330   if (!CGM.getLangOpts().OpenCL) {
5331     auto AS = CGM.GetGlobalConstantAddressSpace();
5332     if (AS != LangAS::Default)
5333       Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast(
5334           CGM, GV, AS, LangAS::Default,
5335           llvm::PointerType::get(
5336               CGM.getLLVMContext(),
5337               CGM.getContext().getTargetAddressSpace(LangAS::Default)));
5338   }
5339   return Cast;
5340 }
5341 
5342 template<typename SomeDecl>
5343 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
5344                                                llvm::GlobalValue *GV) {
5345   if (!getLangOpts().CPlusPlus)
5346     return;
5347 
5348   // Must have 'used' attribute, or else inline assembly can't rely on
5349   // the name existing.
5350   if (!D->template hasAttr<UsedAttr>())
5351     return;
5352 
5353   // Must have internal linkage and an ordinary name.
5354   if (!D->getIdentifier() || D->getFormalLinkage() != Linkage::Internal)
5355     return;
5356 
5357   // Must be in an extern "C" context. Entities declared directly within
5358   // a record are not extern "C" even if the record is in such a context.
5359   const SomeDecl *First = D->getFirstDecl();
5360   if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
5361     return;
5362 
5363   // OK, this is an internal linkage entity inside an extern "C" linkage
5364   // specification. Make a note of that so we can give it the "expected"
5365   // mangled name if nothing else is using that name.
5366   std::pair<StaticExternCMap::iterator, bool> R =
5367       StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
5368 
5369   // If we have multiple internal linkage entities with the same name
5370   // in extern "C" regions, none of them gets that name.
5371   if (!R.second)
5372     R.first->second = nullptr;
5373 }
5374 
5375 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
5376   if (!CGM.supportsCOMDAT())
5377     return false;
5378 
5379   if (D.hasAttr<SelectAnyAttr>())
5380     return true;
5381 
5382   GVALinkage Linkage;
5383   if (auto *VD = dyn_cast<VarDecl>(&D))
5384     Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
5385   else
5386     Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
5387 
5388   switch (Linkage) {
5389   case GVA_Internal:
5390   case GVA_AvailableExternally:
5391   case GVA_StrongExternal:
5392     return false;
5393   case GVA_DiscardableODR:
5394   case GVA_StrongODR:
5395     return true;
5396   }
5397   llvm_unreachable("No such linkage");
5398 }
5399 
5400 bool CodeGenModule::supportsCOMDAT() const {
5401   return getTriple().supportsCOMDAT();
5402 }
5403 
5404 void CodeGenModule::maybeSetTrivialComdat(const Decl &D,
5405                                           llvm::GlobalObject &GO) {
5406   if (!shouldBeInCOMDAT(*this, D))
5407     return;
5408   GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
5409 }
5410 
5411 const ABIInfo &CodeGenModule::getABIInfo() {
5412   return getTargetCodeGenInfo().getABIInfo();
5413 }
5414 
5415 /// Pass IsTentative as true if you want to create a tentative definition.
5416 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
5417                                             bool IsTentative) {
5418   // OpenCL global variables of sampler type are translated to function calls,
5419   // therefore no need to be translated.
5420   QualType ASTTy = D->getType();
5421   if (getLangOpts().OpenCL && ASTTy->isSamplerT())
5422     return;
5423 
5424   // If this is OpenMP device, check if it is legal to emit this global
5425   // normally.
5426   if (LangOpts.OpenMPIsTargetDevice && OpenMPRuntime &&
5427       OpenMPRuntime->emitTargetGlobalVariable(D))
5428     return;
5429 
5430   llvm::TrackingVH<llvm::Constant> Init;
5431   bool NeedsGlobalCtor = false;
5432   // Whether the definition of the variable is available externally.
5433   // If yes, we shouldn't emit the GloablCtor and GlobalDtor for the variable
5434   // since this is the job for its original source.
5435   bool IsDefinitionAvailableExternally =
5436       getContext().GetGVALinkageForVariable(D) == GVA_AvailableExternally;
5437   bool NeedsGlobalDtor =
5438       !IsDefinitionAvailableExternally &&
5439       D->needsDestruction(getContext()) == QualType::DK_cxx_destructor;
5440 
5441   // It is helpless to emit the definition for an available_externally variable
5442   // which can't be marked as const.
5443   // We don't need to check if it needs global ctor or dtor. See the above
5444   // comment for ideas.
5445   if (IsDefinitionAvailableExternally &&
5446       (!D->hasConstantInitialization() ||
5447        // TODO: Update this when we have interface to check constexpr
5448        // destructor.
5449        D->needsDestruction(getContext()) ||
5450        !D->getType().isConstantStorage(getContext(), true, true)))
5451     return;
5452 
5453   const VarDecl *InitDecl;
5454   const Expr *InitExpr = D->getAnyInitializer(InitDecl);
5455 
5456   std::optional<ConstantEmitter> emitter;
5457 
5458   // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
5459   // as part of their declaration."  Sema has already checked for
5460   // error cases, so we just need to set Init to UndefValue.
5461   bool IsCUDASharedVar =
5462       getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
5463   // Shadows of initialized device-side global variables are also left
5464   // undefined.
5465   // Managed Variables should be initialized on both host side and device side.
5466   bool IsCUDAShadowVar =
5467       !getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
5468       (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
5469        D->hasAttr<CUDASharedAttr>());
5470   bool IsCUDADeviceShadowVar =
5471       getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
5472       (D->getType()->isCUDADeviceBuiltinSurfaceType() ||
5473        D->getType()->isCUDADeviceBuiltinTextureType());
5474   if (getLangOpts().CUDA &&
5475       (IsCUDASharedVar || IsCUDAShadowVar || IsCUDADeviceShadowVar))
5476     Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
5477   else if (D->hasAttr<LoaderUninitializedAttr>())
5478     Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
5479   else if (!InitExpr) {
5480     // This is a tentative definition; tentative definitions are
5481     // implicitly initialized with { 0 }.
5482     //
5483     // Note that tentative definitions are only emitted at the end of
5484     // a translation unit, so they should never have incomplete
5485     // type. In addition, EmitTentativeDefinition makes sure that we
5486     // never attempt to emit a tentative definition if a real one
5487     // exists. A use may still exists, however, so we still may need
5488     // to do a RAUW.
5489     assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
5490     Init = EmitNullConstant(D->getType());
5491   } else {
5492     initializedGlobalDecl = GlobalDecl(D);
5493     emitter.emplace(*this);
5494     llvm::Constant *Initializer = emitter->tryEmitForInitializer(*InitDecl);
5495     if (!Initializer) {
5496       QualType T = InitExpr->getType();
5497       if (D->getType()->isReferenceType())
5498         T = D->getType();
5499 
5500       if (getLangOpts().CPlusPlus) {
5501         if (InitDecl->hasFlexibleArrayInit(getContext()))
5502           ErrorUnsupported(D, "flexible array initializer");
5503         Init = EmitNullConstant(T);
5504 
5505         if (!IsDefinitionAvailableExternally)
5506           NeedsGlobalCtor = true;
5507       } else {
5508         ErrorUnsupported(D, "static initializer");
5509         Init = llvm::UndefValue::get(getTypes().ConvertType(T));
5510       }
5511     } else {
5512       Init = Initializer;
5513       // We don't need an initializer, so remove the entry for the delayed
5514       // initializer position (just in case this entry was delayed) if we
5515       // also don't need to register a destructor.
5516       if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
5517         DelayedCXXInitPosition.erase(D);
5518 
5519 #ifndef NDEBUG
5520       CharUnits VarSize = getContext().getTypeSizeInChars(ASTTy) +
5521                           InitDecl->getFlexibleArrayInitChars(getContext());
5522       CharUnits CstSize = CharUnits::fromQuantity(
5523           getDataLayout().getTypeAllocSize(Init->getType()));
5524       assert(VarSize == CstSize && "Emitted constant has unexpected size");
5525 #endif
5526     }
5527   }
5528 
5529   llvm::Type* InitType = Init->getType();
5530   llvm::Constant *Entry =
5531       GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
5532 
5533   // Strip off pointer casts if we got them.
5534   Entry = Entry->stripPointerCasts();
5535 
5536   // Entry is now either a Function or GlobalVariable.
5537   auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
5538 
5539   // We have a definition after a declaration with the wrong type.
5540   // We must make a new GlobalVariable* and update everything that used OldGV
5541   // (a declaration or tentative definition) with the new GlobalVariable*
5542   // (which will be a definition).
5543   //
5544   // This happens if there is a prototype for a global (e.g.
5545   // "extern int x[];") and then a definition of a different type (e.g.
5546   // "int x[10];"). This also happens when an initializer has a different type
5547   // from the type of the global (this happens with unions).
5548   if (!GV || GV->getValueType() != InitType ||
5549       GV->getType()->getAddressSpace() !=
5550           getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
5551 
5552     // Move the old entry aside so that we'll create a new one.
5553     Entry->setName(StringRef());
5554 
5555     // Make a new global with the correct type, this is now guaranteed to work.
5556     GV = cast<llvm::GlobalVariable>(
5557         GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative))
5558             ->stripPointerCasts());
5559 
5560     // Replace all uses of the old global with the new global
5561     llvm::Constant *NewPtrForOldDecl =
5562         llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV,
5563                                                              Entry->getType());
5564     Entry->replaceAllUsesWith(NewPtrForOldDecl);
5565 
5566     // Erase the old global, since it is no longer used.
5567     cast<llvm::GlobalValue>(Entry)->eraseFromParent();
5568   }
5569 
5570   MaybeHandleStaticInExternC(D, GV);
5571 
5572   if (D->hasAttr<AnnotateAttr>())
5573     AddGlobalAnnotations(D, GV);
5574 
5575   // Set the llvm linkage type as appropriate.
5576   llvm::GlobalValue::LinkageTypes Linkage = getLLVMLinkageVarDefinition(D);
5577 
5578   // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
5579   // the device. [...]"
5580   // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
5581   // __device__, declares a variable that: [...]
5582   // Is accessible from all the threads within the grid and from the host
5583   // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
5584   // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
5585   if (LangOpts.CUDA) {
5586     if (LangOpts.CUDAIsDevice) {
5587       if (Linkage != llvm::GlobalValue::InternalLinkage &&
5588           (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
5589            D->getType()->isCUDADeviceBuiltinSurfaceType() ||
5590            D->getType()->isCUDADeviceBuiltinTextureType()))
5591         GV->setExternallyInitialized(true);
5592     } else {
5593       getCUDARuntime().internalizeDeviceSideVar(D, Linkage);
5594     }
5595     getCUDARuntime().handleVarRegistration(D, *GV);
5596   }
5597 
5598   GV->setInitializer(Init);
5599   if (emitter)
5600     emitter->finalize(GV);
5601 
5602   // If it is safe to mark the global 'constant', do so now.
5603   GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
5604                   D->getType().isConstantStorage(getContext(), true, true));
5605 
5606   // If it is in a read-only section, mark it 'constant'.
5607   if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
5608     const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
5609     if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
5610       GV->setConstant(true);
5611   }
5612 
5613   CharUnits AlignVal = getContext().getDeclAlign(D);
5614   // Check for alignment specifed in an 'omp allocate' directive.
5615   if (std::optional<CharUnits> AlignValFromAllocate =
5616           getOMPAllocateAlignment(D))
5617     AlignVal = *AlignValFromAllocate;
5618   GV->setAlignment(AlignVal.getAsAlign());
5619 
5620   // On Darwin, unlike other Itanium C++ ABI platforms, the thread-wrapper
5621   // function is only defined alongside the variable, not also alongside
5622   // callers. Normally, all accesses to a thread_local go through the
5623   // thread-wrapper in order to ensure initialization has occurred, underlying
5624   // variable will never be used other than the thread-wrapper, so it can be
5625   // converted to internal linkage.
5626   //
5627   // However, if the variable has the 'constinit' attribute, it _can_ be
5628   // referenced directly, without calling the thread-wrapper, so the linkage
5629   // must not be changed.
5630   //
5631   // Additionally, if the variable isn't plain external linkage, e.g. if it's
5632   // weak or linkonce, the de-duplication semantics are important to preserve,
5633   // so we don't change the linkage.
5634   if (D->getTLSKind() == VarDecl::TLS_Dynamic &&
5635       Linkage == llvm::GlobalValue::ExternalLinkage &&
5636       Context.getTargetInfo().getTriple().isOSDarwin() &&
5637       !D->hasAttr<ConstInitAttr>())
5638     Linkage = llvm::GlobalValue::InternalLinkage;
5639 
5640   GV->setLinkage(Linkage);
5641   if (D->hasAttr<DLLImportAttr>())
5642     GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
5643   else if (D->hasAttr<DLLExportAttr>())
5644     GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
5645   else
5646     GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
5647 
5648   if (Linkage == llvm::GlobalVariable::CommonLinkage) {
5649     // common vars aren't constant even if declared const.
5650     GV->setConstant(false);
5651     // Tentative definition of global variables may be initialized with
5652     // non-zero null pointers. In this case they should have weak linkage
5653     // since common linkage must have zero initializer and must not have
5654     // explicit section therefore cannot have non-zero initial value.
5655     if (!GV->getInitializer()->isNullValue())
5656       GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
5657   }
5658 
5659   setNonAliasAttributes(D, GV);
5660 
5661   if (D->getTLSKind() && !GV->isThreadLocal()) {
5662     if (D->getTLSKind() == VarDecl::TLS_Dynamic)
5663       CXXThreadLocals.push_back(D);
5664     setTLSMode(GV, *D);
5665   }
5666 
5667   maybeSetTrivialComdat(*D, *GV);
5668 
5669   // Emit the initializer function if necessary.
5670   if (NeedsGlobalCtor || NeedsGlobalDtor)
5671     EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
5672 
5673   SanitizerMD->reportGlobal(GV, *D, NeedsGlobalCtor);
5674 
5675   // Emit global variable debug information.
5676   if (CGDebugInfo *DI = getModuleDebugInfo())
5677     if (getCodeGenOpts().hasReducedDebugInfo())
5678       DI->EmitGlobalVariable(GV, D);
5679 }
5680 
5681 void CodeGenModule::EmitExternalVarDeclaration(const VarDecl *D) {
5682   if (CGDebugInfo *DI = getModuleDebugInfo())
5683     if (getCodeGenOpts().hasReducedDebugInfo()) {
5684       QualType ASTTy = D->getType();
5685       llvm::Type *Ty = getTypes().ConvertTypeForMem(D->getType());
5686       llvm::Constant *GV =
5687           GetOrCreateLLVMGlobal(D->getName(), Ty, ASTTy.getAddressSpace(), D);
5688       DI->EmitExternalVariable(
5689           cast<llvm::GlobalVariable>(GV->stripPointerCasts()), D);
5690     }
5691 }
5692 
5693 void CodeGenModule::EmitExternalFunctionDeclaration(const FunctionDecl *FD) {
5694   if (CGDebugInfo *DI = getModuleDebugInfo())
5695     if (getCodeGenOpts().hasReducedDebugInfo()) {
5696       auto *Ty = getTypes().ConvertType(FD->getType());
5697       StringRef MangledName = getMangledName(FD);
5698       auto *Fn = cast<llvm::Function>(
5699           GetOrCreateLLVMFunction(MangledName, Ty, FD, /* ForVTable */ false));
5700       if (!Fn->getSubprogram())
5701         DI->EmitFunctionDecl(FD, FD->getLocation(), FD->getType(), Fn);
5702     }
5703 }
5704 
5705 static bool isVarDeclStrongDefinition(const ASTContext &Context,
5706                                       CodeGenModule &CGM, const VarDecl *D,
5707                                       bool NoCommon) {
5708   // Don't give variables common linkage if -fno-common was specified unless it
5709   // was overridden by a NoCommon attribute.
5710   if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
5711     return true;
5712 
5713   // C11 6.9.2/2:
5714   //   A declaration of an identifier for an object that has file scope without
5715   //   an initializer, and without a storage-class specifier or with the
5716   //   storage-class specifier static, constitutes a tentative definition.
5717   if (D->getInit() || D->hasExternalStorage())
5718     return true;
5719 
5720   // A variable cannot be both common and exist in a section.
5721   if (D->hasAttr<SectionAttr>())
5722     return true;
5723 
5724   // A variable cannot be both common and exist in a section.
5725   // We don't try to determine which is the right section in the front-end.
5726   // If no specialized section name is applicable, it will resort to default.
5727   if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
5728       D->hasAttr<PragmaClangDataSectionAttr>() ||
5729       D->hasAttr<PragmaClangRelroSectionAttr>() ||
5730       D->hasAttr<PragmaClangRodataSectionAttr>())
5731     return true;
5732 
5733   // Thread local vars aren't considered common linkage.
5734   if (D->getTLSKind())
5735     return true;
5736 
5737   // Tentative definitions marked with WeakImportAttr are true definitions.
5738   if (D->hasAttr<WeakImportAttr>())
5739     return true;
5740 
5741   // A variable cannot be both common and exist in a comdat.
5742   if (shouldBeInCOMDAT(CGM, *D))
5743     return true;
5744 
5745   // Declarations with a required alignment do not have common linkage in MSVC
5746   // mode.
5747   if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
5748     if (D->hasAttr<AlignedAttr>())
5749       return true;
5750     QualType VarType = D->getType();
5751     if (Context.isAlignmentRequired(VarType))
5752       return true;
5753 
5754     if (const auto *RT = VarType->getAs<RecordType>()) {
5755       const RecordDecl *RD = RT->getDecl();
5756       for (const FieldDecl *FD : RD->fields()) {
5757         if (FD->isBitField())
5758           continue;
5759         if (FD->hasAttr<AlignedAttr>())
5760           return true;
5761         if (Context.isAlignmentRequired(FD->getType()))
5762           return true;
5763       }
5764     }
5765   }
5766 
5767   // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
5768   // common symbols, so symbols with greater alignment requirements cannot be
5769   // common.
5770   // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
5771   // alignments for common symbols via the aligncomm directive, so this
5772   // restriction only applies to MSVC environments.
5773   if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
5774       Context.getTypeAlignIfKnown(D->getType()) >
5775           Context.toBits(CharUnits::fromQuantity(32)))
5776     return true;
5777 
5778   return false;
5779 }
5780 
5781 llvm::GlobalValue::LinkageTypes
5782 CodeGenModule::getLLVMLinkageForDeclarator(const DeclaratorDecl *D,
5783                                            GVALinkage Linkage) {
5784   if (Linkage == GVA_Internal)
5785     return llvm::Function::InternalLinkage;
5786 
5787   if (D->hasAttr<WeakAttr>())
5788     return llvm::GlobalVariable::WeakAnyLinkage;
5789 
5790   if (const auto *FD = D->getAsFunction())
5791     if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
5792       return llvm::GlobalVariable::LinkOnceAnyLinkage;
5793 
5794   // We are guaranteed to have a strong definition somewhere else,
5795   // so we can use available_externally linkage.
5796   if (Linkage == GVA_AvailableExternally)
5797     return llvm::GlobalValue::AvailableExternallyLinkage;
5798 
5799   // Note that Apple's kernel linker doesn't support symbol
5800   // coalescing, so we need to avoid linkonce and weak linkages there.
5801   // Normally, this means we just map to internal, but for explicit
5802   // instantiations we'll map to external.
5803 
5804   // In C++, the compiler has to emit a definition in every translation unit
5805   // that references the function.  We should use linkonce_odr because
5806   // a) if all references in this translation unit are optimized away, we
5807   // don't need to codegen it.  b) if the function persists, it needs to be
5808   // merged with other definitions. c) C++ has the ODR, so we know the
5809   // definition is dependable.
5810   if (Linkage == GVA_DiscardableODR)
5811     return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
5812                                             : llvm::Function::InternalLinkage;
5813 
5814   // An explicit instantiation of a template has weak linkage, since
5815   // explicit instantiations can occur in multiple translation units
5816   // and must all be equivalent. However, we are not allowed to
5817   // throw away these explicit instantiations.
5818   //
5819   // CUDA/HIP: For -fno-gpu-rdc case, device code is limited to one TU,
5820   // so say that CUDA templates are either external (for kernels) or internal.
5821   // This lets llvm perform aggressive inter-procedural optimizations. For
5822   // -fgpu-rdc case, device function calls across multiple TU's are allowed,
5823   // therefore we need to follow the normal linkage paradigm.
5824   if (Linkage == GVA_StrongODR) {
5825     if (getLangOpts().AppleKext)
5826       return llvm::Function::ExternalLinkage;
5827     if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
5828         !getLangOpts().GPURelocatableDeviceCode)
5829       return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
5830                                           : llvm::Function::InternalLinkage;
5831     return llvm::Function::WeakODRLinkage;
5832   }
5833 
5834   // C++ doesn't have tentative definitions and thus cannot have common
5835   // linkage.
5836   if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
5837       !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
5838                                  CodeGenOpts.NoCommon))
5839     return llvm::GlobalVariable::CommonLinkage;
5840 
5841   // selectany symbols are externally visible, so use weak instead of
5842   // linkonce.  MSVC optimizes away references to const selectany globals, so
5843   // all definitions should be the same and ODR linkage should be used.
5844   // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
5845   if (D->hasAttr<SelectAnyAttr>())
5846     return llvm::GlobalVariable::WeakODRLinkage;
5847 
5848   // Otherwise, we have strong external linkage.
5849   assert(Linkage == GVA_StrongExternal);
5850   return llvm::GlobalVariable::ExternalLinkage;
5851 }
5852 
5853 llvm::GlobalValue::LinkageTypes
5854 CodeGenModule::getLLVMLinkageVarDefinition(const VarDecl *VD) {
5855   GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
5856   return getLLVMLinkageForDeclarator(VD, Linkage);
5857 }
5858 
5859 /// Replace the uses of a function that was declared with a non-proto type.
5860 /// We want to silently drop extra arguments from call sites
5861 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
5862                                           llvm::Function *newFn) {
5863   // Fast path.
5864   if (old->use_empty())
5865     return;
5866 
5867   llvm::Type *newRetTy = newFn->getReturnType();
5868   SmallVector<llvm::Value *, 4> newArgs;
5869 
5870   SmallVector<llvm::CallBase *> callSitesToBeRemovedFromParent;
5871 
5872   for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
5873        ui != ue; ui++) {
5874     llvm::User *user = ui->getUser();
5875 
5876     // Recognize and replace uses of bitcasts.  Most calls to
5877     // unprototyped functions will use bitcasts.
5878     if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
5879       if (bitcast->getOpcode() == llvm::Instruction::BitCast)
5880         replaceUsesOfNonProtoConstant(bitcast, newFn);
5881       continue;
5882     }
5883 
5884     // Recognize calls to the function.
5885     llvm::CallBase *callSite = dyn_cast<llvm::CallBase>(user);
5886     if (!callSite)
5887       continue;
5888     if (!callSite->isCallee(&*ui))
5889       continue;
5890 
5891     // If the return types don't match exactly, then we can't
5892     // transform this call unless it's dead.
5893     if (callSite->getType() != newRetTy && !callSite->use_empty())
5894       continue;
5895 
5896     // Get the call site's attribute list.
5897     SmallVector<llvm::AttributeSet, 8> newArgAttrs;
5898     llvm::AttributeList oldAttrs = callSite->getAttributes();
5899 
5900     // If the function was passed too few arguments, don't transform.
5901     unsigned newNumArgs = newFn->arg_size();
5902     if (callSite->arg_size() < newNumArgs)
5903       continue;
5904 
5905     // If extra arguments were passed, we silently drop them.
5906     // If any of the types mismatch, we don't transform.
5907     unsigned argNo = 0;
5908     bool dontTransform = false;
5909     for (llvm::Argument &A : newFn->args()) {
5910       if (callSite->getArgOperand(argNo)->getType() != A.getType()) {
5911         dontTransform = true;
5912         break;
5913       }
5914 
5915       // Add any parameter attributes.
5916       newArgAttrs.push_back(oldAttrs.getParamAttrs(argNo));
5917       argNo++;
5918     }
5919     if (dontTransform)
5920       continue;
5921 
5922     // Okay, we can transform this.  Create the new call instruction and copy
5923     // over the required information.
5924     newArgs.append(callSite->arg_begin(), callSite->arg_begin() + argNo);
5925 
5926     // Copy over any operand bundles.
5927     SmallVector<llvm::OperandBundleDef, 1> newBundles;
5928     callSite->getOperandBundlesAsDefs(newBundles);
5929 
5930     llvm::CallBase *newCall;
5931     if (isa<llvm::CallInst>(callSite)) {
5932       newCall = llvm::CallInst::Create(newFn, newArgs, newBundles, "",
5933                                        callSite->getIterator());
5934     } else {
5935       auto *oldInvoke = cast<llvm::InvokeInst>(callSite);
5936       newCall = llvm::InvokeInst::Create(
5937           newFn, oldInvoke->getNormalDest(), oldInvoke->getUnwindDest(),
5938           newArgs, newBundles, "", callSite->getIterator());
5939     }
5940     newArgs.clear(); // for the next iteration
5941 
5942     if (!newCall->getType()->isVoidTy())
5943       newCall->takeName(callSite);
5944     newCall->setAttributes(
5945         llvm::AttributeList::get(newFn->getContext(), oldAttrs.getFnAttrs(),
5946                                  oldAttrs.getRetAttrs(), newArgAttrs));
5947     newCall->setCallingConv(callSite->getCallingConv());
5948 
5949     // Finally, remove the old call, replacing any uses with the new one.
5950     if (!callSite->use_empty())
5951       callSite->replaceAllUsesWith(newCall);
5952 
5953     // Copy debug location attached to CI.
5954     if (callSite->getDebugLoc())
5955       newCall->setDebugLoc(callSite->getDebugLoc());
5956 
5957     callSitesToBeRemovedFromParent.push_back(callSite);
5958   }
5959 
5960   for (auto *callSite : callSitesToBeRemovedFromParent) {
5961     callSite->eraseFromParent();
5962   }
5963 }
5964 
5965 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
5966 /// implement a function with no prototype, e.g. "int foo() {}".  If there are
5967 /// existing call uses of the old function in the module, this adjusts them to
5968 /// call the new function directly.
5969 ///
5970 /// This is not just a cleanup: the always_inline pass requires direct calls to
5971 /// functions to be able to inline them.  If there is a bitcast in the way, it
5972 /// won't inline them.  Instcombine normally deletes these calls, but it isn't
5973 /// run at -O0.
5974 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
5975                                                       llvm::Function *NewFn) {
5976   // If we're redefining a global as a function, don't transform it.
5977   if (!isa<llvm::Function>(Old)) return;
5978 
5979   replaceUsesOfNonProtoConstant(Old, NewFn);
5980 }
5981 
5982 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
5983   auto DK = VD->isThisDeclarationADefinition();
5984   if ((DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>()) ||
5985       (LangOpts.CUDA && !shouldEmitCUDAGlobalVar(VD)))
5986     return;
5987 
5988   TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
5989   // If we have a definition, this might be a deferred decl. If the
5990   // instantiation is explicit, make sure we emit it at the end.
5991   if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
5992     GetAddrOfGlobalVar(VD);
5993 
5994   EmitTopLevelDecl(VD);
5995 }
5996 
5997 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
5998                                                  llvm::GlobalValue *GV) {
5999   const auto *D = cast<FunctionDecl>(GD.getDecl());
6000 
6001   // Compute the function info and LLVM type.
6002   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
6003   llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
6004 
6005   // Get or create the prototype for the function.
6006   if (!GV || (GV->getValueType() != Ty))
6007     GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
6008                                                    /*DontDefer=*/true,
6009                                                    ForDefinition));
6010 
6011   // Already emitted.
6012   if (!GV->isDeclaration())
6013     return;
6014 
6015   // We need to set linkage and visibility on the function before
6016   // generating code for it because various parts of IR generation
6017   // want to propagate this information down (e.g. to local static
6018   // declarations).
6019   auto *Fn = cast<llvm::Function>(GV);
6020   setFunctionLinkage(GD, Fn);
6021 
6022   // FIXME: this is redundant with part of setFunctionDefinitionAttributes
6023   setGVProperties(Fn, GD);
6024 
6025   MaybeHandleStaticInExternC(D, Fn);
6026 
6027   maybeSetTrivialComdat(*D, *Fn);
6028 
6029   CodeGenFunction(*this).GenerateCode(GD, Fn, FI);
6030 
6031   setNonAliasAttributes(GD, Fn);
6032   SetLLVMFunctionAttributesForDefinition(D, Fn);
6033 
6034   if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
6035     AddGlobalCtor(Fn, CA->getPriority());
6036   if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
6037     AddGlobalDtor(Fn, DA->getPriority(), true);
6038   if (getLangOpts().OpenMP && D->hasAttr<OMPDeclareTargetDeclAttr>())
6039     getOpenMPRuntime().emitDeclareTargetFunction(D, GV);
6040 }
6041 
6042 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
6043   const auto *D = cast<ValueDecl>(GD.getDecl());
6044   const AliasAttr *AA = D->getAttr<AliasAttr>();
6045   assert(AA && "Not an alias?");
6046 
6047   StringRef MangledName = getMangledName(GD);
6048 
6049   if (AA->getAliasee() == MangledName) {
6050     Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
6051     return;
6052   }
6053 
6054   // If there is a definition in the module, then it wins over the alias.
6055   // This is dubious, but allow it to be safe.  Just ignore the alias.
6056   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
6057   if (Entry && !Entry->isDeclaration())
6058     return;
6059 
6060   Aliases.push_back(GD);
6061 
6062   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
6063 
6064   // Create a reference to the named value.  This ensures that it is emitted
6065   // if a deferred decl.
6066   llvm::Constant *Aliasee;
6067   llvm::GlobalValue::LinkageTypes LT;
6068   if (isa<llvm::FunctionType>(DeclTy)) {
6069     Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
6070                                       /*ForVTable=*/false);
6071     LT = getFunctionLinkage(GD);
6072   } else {
6073     Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, LangAS::Default,
6074                                     /*D=*/nullptr);
6075     if (const auto *VD = dyn_cast<VarDecl>(GD.getDecl()))
6076       LT = getLLVMLinkageVarDefinition(VD);
6077     else
6078       LT = getFunctionLinkage(GD);
6079   }
6080 
6081   // Create the new alias itself, but don't set a name yet.
6082   unsigned AS = Aliasee->getType()->getPointerAddressSpace();
6083   auto *GA =
6084       llvm::GlobalAlias::create(DeclTy, AS, LT, "", Aliasee, &getModule());
6085 
6086   if (Entry) {
6087     if (GA->getAliasee() == Entry) {
6088       Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
6089       return;
6090     }
6091 
6092     assert(Entry->isDeclaration());
6093 
6094     // If there is a declaration in the module, then we had an extern followed
6095     // by the alias, as in:
6096     //   extern int test6();
6097     //   ...
6098     //   int test6() __attribute__((alias("test7")));
6099     //
6100     // Remove it and replace uses of it with the alias.
6101     GA->takeName(Entry);
6102 
6103     Entry->replaceAllUsesWith(GA);
6104     Entry->eraseFromParent();
6105   } else {
6106     GA->setName(MangledName);
6107   }
6108 
6109   // Set attributes which are particular to an alias; this is a
6110   // specialization of the attributes which may be set on a global
6111   // variable/function.
6112   if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
6113       D->isWeakImported()) {
6114     GA->setLinkage(llvm::Function::WeakAnyLinkage);
6115   }
6116 
6117   if (const auto *VD = dyn_cast<VarDecl>(D))
6118     if (VD->getTLSKind())
6119       setTLSMode(GA, *VD);
6120 
6121   SetCommonAttributes(GD, GA);
6122 
6123   // Emit global alias debug information.
6124   if (isa<VarDecl>(D))
6125     if (CGDebugInfo *DI = getModuleDebugInfo())
6126       DI->EmitGlobalAlias(cast<llvm::GlobalValue>(GA->getAliasee()->stripPointerCasts()), GD);
6127 }
6128 
6129 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
6130   const auto *D = cast<ValueDecl>(GD.getDecl());
6131   const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
6132   assert(IFA && "Not an ifunc?");
6133 
6134   StringRef MangledName = getMangledName(GD);
6135 
6136   if (IFA->getResolver() == MangledName) {
6137     Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
6138     return;
6139   }
6140 
6141   // Report an error if some definition overrides ifunc.
6142   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
6143   if (Entry && !Entry->isDeclaration()) {
6144     GlobalDecl OtherGD;
6145     if (lookupRepresentativeDecl(MangledName, OtherGD) &&
6146         DiagnosedConflictingDefinitions.insert(GD).second) {
6147       Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
6148           << MangledName;
6149       Diags.Report(OtherGD.getDecl()->getLocation(),
6150                    diag::note_previous_definition);
6151     }
6152     return;
6153   }
6154 
6155   Aliases.push_back(GD);
6156 
6157   // The resolver might not be visited yet. Specify a dummy non-function type to
6158   // indicate IsIncompleteFunction. Either the type is ignored (if the resolver
6159   // was emitted) or the whole function will be replaced (if the resolver has
6160   // not been emitted).
6161   llvm::Constant *Resolver =
6162       GetOrCreateLLVMFunction(IFA->getResolver(), VoidTy, {},
6163                               /*ForVTable=*/false);
6164   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
6165   unsigned AS = getTypes().getTargetAddressSpace(D->getType());
6166   llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
6167       DeclTy, AS, llvm::Function::ExternalLinkage, "", Resolver, &getModule());
6168   if (Entry) {
6169     if (GIF->getResolver() == Entry) {
6170       Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
6171       return;
6172     }
6173     assert(Entry->isDeclaration());
6174 
6175     // If there is a declaration in the module, then we had an extern followed
6176     // by the ifunc, as in:
6177     //   extern int test();
6178     //   ...
6179     //   int test() __attribute__((ifunc("resolver")));
6180     //
6181     // Remove it and replace uses of it with the ifunc.
6182     GIF->takeName(Entry);
6183 
6184     Entry->replaceAllUsesWith(GIF);
6185     Entry->eraseFromParent();
6186   } else
6187     GIF->setName(MangledName);
6188   SetCommonAttributes(GD, GIF);
6189 }
6190 
6191 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
6192                                             ArrayRef<llvm::Type*> Tys) {
6193   return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
6194                                          Tys);
6195 }
6196 
6197 static llvm::StringMapEntry<llvm::GlobalVariable *> &
6198 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
6199                          const StringLiteral *Literal, bool TargetIsLSB,
6200                          bool &IsUTF16, unsigned &StringLength) {
6201   StringRef String = Literal->getString();
6202   unsigned NumBytes = String.size();
6203 
6204   // Check for simple case.
6205   if (!Literal->containsNonAsciiOrNull()) {
6206     StringLength = NumBytes;
6207     return *Map.insert(std::make_pair(String, nullptr)).first;
6208   }
6209 
6210   // Otherwise, convert the UTF8 literals into a string of shorts.
6211   IsUTF16 = true;
6212 
6213   SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
6214   const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
6215   llvm::UTF16 *ToPtr = &ToBuf[0];
6216 
6217   (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
6218                                  ToPtr + NumBytes, llvm::strictConversion);
6219 
6220   // ConvertUTF8toUTF16 returns the length in ToPtr.
6221   StringLength = ToPtr - &ToBuf[0];
6222 
6223   // Add an explicit null.
6224   *ToPtr = 0;
6225   return *Map.insert(std::make_pair(
6226                          StringRef(reinterpret_cast<const char *>(ToBuf.data()),
6227                                    (StringLength + 1) * 2),
6228                          nullptr)).first;
6229 }
6230 
6231 ConstantAddress
6232 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
6233   unsigned StringLength = 0;
6234   bool isUTF16 = false;
6235   llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
6236       GetConstantCFStringEntry(CFConstantStringMap, Literal,
6237                                getDataLayout().isLittleEndian(), isUTF16,
6238                                StringLength);
6239 
6240   if (auto *C = Entry.second)
6241     return ConstantAddress(
6242         C, C->getValueType(), CharUnits::fromQuantity(C->getAlignment()));
6243 
6244   const ASTContext &Context = getContext();
6245   const llvm::Triple &Triple = getTriple();
6246 
6247   const auto CFRuntime = getLangOpts().CFRuntime;
6248   const bool IsSwiftABI =
6249       static_cast<unsigned>(CFRuntime) >=
6250       static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
6251   const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
6252 
6253   // If we don't already have it, get __CFConstantStringClassReference.
6254   if (!CFConstantStringClassRef) {
6255     const char *CFConstantStringClassName = "__CFConstantStringClassReference";
6256     llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
6257     Ty = llvm::ArrayType::get(Ty, 0);
6258 
6259     switch (CFRuntime) {
6260     default: break;
6261     case LangOptions::CoreFoundationABI::Swift: [[fallthrough]];
6262     case LangOptions::CoreFoundationABI::Swift5_0:
6263       CFConstantStringClassName =
6264           Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
6265                               : "$s10Foundation19_NSCFConstantStringCN";
6266       Ty = IntPtrTy;
6267       break;
6268     case LangOptions::CoreFoundationABI::Swift4_2:
6269       CFConstantStringClassName =
6270           Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
6271                               : "$S10Foundation19_NSCFConstantStringCN";
6272       Ty = IntPtrTy;
6273       break;
6274     case LangOptions::CoreFoundationABI::Swift4_1:
6275       CFConstantStringClassName =
6276           Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
6277                               : "__T010Foundation19_NSCFConstantStringCN";
6278       Ty = IntPtrTy;
6279       break;
6280     }
6281 
6282     llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
6283 
6284     if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
6285       llvm::GlobalValue *GV = nullptr;
6286 
6287       if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
6288         IdentifierInfo &II = Context.Idents.get(GV->getName());
6289         TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
6290         DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
6291 
6292         const VarDecl *VD = nullptr;
6293         for (const auto *Result : DC->lookup(&II))
6294           if ((VD = dyn_cast<VarDecl>(Result)))
6295             break;
6296 
6297         if (Triple.isOSBinFormatELF()) {
6298           if (!VD)
6299             GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
6300         } else {
6301           GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
6302           if (!VD || !VD->hasAttr<DLLExportAttr>())
6303             GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
6304           else
6305             GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
6306         }
6307 
6308         setDSOLocal(GV);
6309       }
6310     }
6311 
6312     // Decay array -> ptr
6313     CFConstantStringClassRef =
6314         IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty) : C;
6315   }
6316 
6317   QualType CFTy = Context.getCFConstantStringType();
6318 
6319   auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
6320 
6321   ConstantInitBuilder Builder(*this);
6322   auto Fields = Builder.beginStruct(STy);
6323 
6324   // Class pointer.
6325   Fields.add(cast<llvm::Constant>(CFConstantStringClassRef));
6326 
6327   // Flags.
6328   if (IsSwiftABI) {
6329     Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
6330     Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
6331   } else {
6332     Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
6333   }
6334 
6335   // String pointer.
6336   llvm::Constant *C = nullptr;
6337   if (isUTF16) {
6338     auto Arr = llvm::ArrayRef(
6339         reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
6340         Entry.first().size() / 2);
6341     C = llvm::ConstantDataArray::get(VMContext, Arr);
6342   } else {
6343     C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
6344   }
6345 
6346   // Note: -fwritable-strings doesn't make the backing store strings of
6347   // CFStrings writable.
6348   auto *GV =
6349       new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
6350                                llvm::GlobalValue::PrivateLinkage, C, ".str");
6351   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
6352   // Don't enforce the target's minimum global alignment, since the only use
6353   // of the string is via this class initializer.
6354   CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
6355                             : Context.getTypeAlignInChars(Context.CharTy);
6356   GV->setAlignment(Align.getAsAlign());
6357 
6358   // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
6359   // Without it LLVM can merge the string with a non unnamed_addr one during
6360   // LTO.  Doing that changes the section it ends in, which surprises ld64.
6361   if (Triple.isOSBinFormatMachO())
6362     GV->setSection(isUTF16 ? "__TEXT,__ustring"
6363                            : "__TEXT,__cstring,cstring_literals");
6364   // Make sure the literal ends up in .rodata to allow for safe ICF and for
6365   // the static linker to adjust permissions to read-only later on.
6366   else if (Triple.isOSBinFormatELF())
6367     GV->setSection(".rodata");
6368 
6369   // String.
6370   Fields.add(GV);
6371 
6372   // String length.
6373   llvm::IntegerType *LengthTy =
6374       llvm::IntegerType::get(getModule().getContext(),
6375                              Context.getTargetInfo().getLongWidth());
6376   if (IsSwiftABI) {
6377     if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
6378         CFRuntime == LangOptions::CoreFoundationABI::Swift4_2)
6379       LengthTy = Int32Ty;
6380     else
6381       LengthTy = IntPtrTy;
6382   }
6383   Fields.addInt(LengthTy, StringLength);
6384 
6385   // Swift ABI requires 8-byte alignment to ensure that the _Atomic(uint64_t) is
6386   // properly aligned on 32-bit platforms.
6387   CharUnits Alignment =
6388       IsSwiftABI ? Context.toCharUnitsFromBits(64) : getPointerAlign();
6389 
6390   // The struct.
6391   GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
6392                                     /*isConstant=*/false,
6393                                     llvm::GlobalVariable::PrivateLinkage);
6394   GV->addAttribute("objc_arc_inert");
6395   switch (Triple.getObjectFormat()) {
6396   case llvm::Triple::UnknownObjectFormat:
6397     llvm_unreachable("unknown file format");
6398   case llvm::Triple::DXContainer:
6399   case llvm::Triple::GOFF:
6400   case llvm::Triple::SPIRV:
6401   case llvm::Triple::XCOFF:
6402     llvm_unreachable("unimplemented");
6403   case llvm::Triple::COFF:
6404   case llvm::Triple::ELF:
6405   case llvm::Triple::Wasm:
6406     GV->setSection("cfstring");
6407     break;
6408   case llvm::Triple::MachO:
6409     GV->setSection("__DATA,__cfstring");
6410     break;
6411   }
6412   Entry.second = GV;
6413 
6414   return ConstantAddress(GV, GV->getValueType(), Alignment);
6415 }
6416 
6417 bool CodeGenModule::getExpressionLocationsEnabled() const {
6418   return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
6419 }
6420 
6421 QualType CodeGenModule::getObjCFastEnumerationStateType() {
6422   if (ObjCFastEnumerationStateType.isNull()) {
6423     RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
6424     D->startDefinition();
6425 
6426     QualType FieldTypes[] = {
6427         Context.UnsignedLongTy, Context.getPointerType(Context.getObjCIdType()),
6428         Context.getPointerType(Context.UnsignedLongTy),
6429         Context.getConstantArrayType(Context.UnsignedLongTy, llvm::APInt(32, 5),
6430                                      nullptr, ArraySizeModifier::Normal, 0)};
6431 
6432     for (size_t i = 0; i < 4; ++i) {
6433       FieldDecl *Field = FieldDecl::Create(Context,
6434                                            D,
6435                                            SourceLocation(),
6436                                            SourceLocation(), nullptr,
6437                                            FieldTypes[i], /*TInfo=*/nullptr,
6438                                            /*BitWidth=*/nullptr,
6439                                            /*Mutable=*/false,
6440                                            ICIS_NoInit);
6441       Field->setAccess(AS_public);
6442       D->addDecl(Field);
6443     }
6444 
6445     D->completeDefinition();
6446     ObjCFastEnumerationStateType = Context.getTagDeclType(D);
6447   }
6448 
6449   return ObjCFastEnumerationStateType;
6450 }
6451 
6452 llvm::Constant *
6453 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
6454   assert(!E->getType()->isPointerType() && "Strings are always arrays");
6455 
6456   // Don't emit it as the address of the string, emit the string data itself
6457   // as an inline array.
6458   if (E->getCharByteWidth() == 1) {
6459     SmallString<64> Str(E->getString());
6460 
6461     // Resize the string to the right size, which is indicated by its type.
6462     const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
6463     assert(CAT && "String literal not of constant array type!");
6464     Str.resize(CAT->getZExtSize());
6465     return llvm::ConstantDataArray::getString(VMContext, Str, false);
6466   }
6467 
6468   auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
6469   llvm::Type *ElemTy = AType->getElementType();
6470   unsigned NumElements = AType->getNumElements();
6471 
6472   // Wide strings have either 2-byte or 4-byte elements.
6473   if (ElemTy->getPrimitiveSizeInBits() == 16) {
6474     SmallVector<uint16_t, 32> Elements;
6475     Elements.reserve(NumElements);
6476 
6477     for(unsigned i = 0, e = E->getLength(); i != e; ++i)
6478       Elements.push_back(E->getCodeUnit(i));
6479     Elements.resize(NumElements);
6480     return llvm::ConstantDataArray::get(VMContext, Elements);
6481   }
6482 
6483   assert(ElemTy->getPrimitiveSizeInBits() == 32);
6484   SmallVector<uint32_t, 32> Elements;
6485   Elements.reserve(NumElements);
6486 
6487   for(unsigned i = 0, e = E->getLength(); i != e; ++i)
6488     Elements.push_back(E->getCodeUnit(i));
6489   Elements.resize(NumElements);
6490   return llvm::ConstantDataArray::get(VMContext, Elements);
6491 }
6492 
6493 static llvm::GlobalVariable *
6494 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
6495                       CodeGenModule &CGM, StringRef GlobalName,
6496                       CharUnits Alignment) {
6497   unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
6498       CGM.GetGlobalConstantAddressSpace());
6499 
6500   llvm::Module &M = CGM.getModule();
6501   // Create a global variable for this string
6502   auto *GV = new llvm::GlobalVariable(
6503       M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
6504       nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
6505   GV->setAlignment(Alignment.getAsAlign());
6506   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
6507   if (GV->isWeakForLinker()) {
6508     assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
6509     GV->setComdat(M.getOrInsertComdat(GV->getName()));
6510   }
6511   CGM.setDSOLocal(GV);
6512 
6513   return GV;
6514 }
6515 
6516 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
6517 /// constant array for the given string literal.
6518 ConstantAddress
6519 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
6520                                                   StringRef Name) {
6521   CharUnits Alignment =
6522       getContext().getAlignOfGlobalVarInChars(S->getType(), /*VD=*/nullptr);
6523 
6524   llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
6525   llvm::GlobalVariable **Entry = nullptr;
6526   if (!LangOpts.WritableStrings) {
6527     Entry = &ConstantStringMap[C];
6528     if (auto GV = *Entry) {
6529       if (uint64_t(Alignment.getQuantity()) > GV->getAlignment())
6530         GV->setAlignment(Alignment.getAsAlign());
6531       return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6532                              GV->getValueType(), Alignment);
6533     }
6534   }
6535 
6536   SmallString<256> MangledNameBuffer;
6537   StringRef GlobalVariableName;
6538   llvm::GlobalValue::LinkageTypes LT;
6539 
6540   // Mangle the string literal if that's how the ABI merges duplicate strings.
6541   // Don't do it if they are writable, since we don't want writes in one TU to
6542   // affect strings in another.
6543   if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
6544       !LangOpts.WritableStrings) {
6545     llvm::raw_svector_ostream Out(MangledNameBuffer);
6546     getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
6547     LT = llvm::GlobalValue::LinkOnceODRLinkage;
6548     GlobalVariableName = MangledNameBuffer;
6549   } else {
6550     LT = llvm::GlobalValue::PrivateLinkage;
6551     GlobalVariableName = Name;
6552   }
6553 
6554   auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
6555 
6556   CGDebugInfo *DI = getModuleDebugInfo();
6557   if (DI && getCodeGenOpts().hasReducedDebugInfo())
6558     DI->AddStringLiteralDebugInfo(GV, S);
6559 
6560   if (Entry)
6561     *Entry = GV;
6562 
6563   SanitizerMD->reportGlobal(GV, S->getStrTokenLoc(0), "<string literal>");
6564 
6565   return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6566                          GV->getValueType(), Alignment);
6567 }
6568 
6569 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
6570 /// array for the given ObjCEncodeExpr node.
6571 ConstantAddress
6572 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
6573   std::string Str;
6574   getContext().getObjCEncodingForType(E->getEncodedType(), Str);
6575 
6576   return GetAddrOfConstantCString(Str);
6577 }
6578 
6579 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
6580 /// the literal and a terminating '\0' character.
6581 /// The result has pointer to array type.
6582 ConstantAddress CodeGenModule::GetAddrOfConstantCString(
6583     const std::string &Str, const char *GlobalName) {
6584   StringRef StrWithNull(Str.c_str(), Str.size() + 1);
6585   CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(
6586       getContext().CharTy, /*VD=*/nullptr);
6587 
6588   llvm::Constant *C =
6589       llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
6590 
6591   // Don't share any string literals if strings aren't constant.
6592   llvm::GlobalVariable **Entry = nullptr;
6593   if (!LangOpts.WritableStrings) {
6594     Entry = &ConstantStringMap[C];
6595     if (auto GV = *Entry) {
6596       if (uint64_t(Alignment.getQuantity()) > GV->getAlignment())
6597         GV->setAlignment(Alignment.getAsAlign());
6598       return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6599                              GV->getValueType(), Alignment);
6600     }
6601   }
6602 
6603   // Get the default prefix if a name wasn't specified.
6604   if (!GlobalName)
6605     GlobalName = ".str";
6606   // Create a global variable for this.
6607   auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
6608                                   GlobalName, Alignment);
6609   if (Entry)
6610     *Entry = GV;
6611 
6612   return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6613                          GV->getValueType(), Alignment);
6614 }
6615 
6616 ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
6617     const MaterializeTemporaryExpr *E, const Expr *Init) {
6618   assert((E->getStorageDuration() == SD_Static ||
6619           E->getStorageDuration() == SD_Thread) && "not a global temporary");
6620   const auto *VD = cast<VarDecl>(E->getExtendingDecl());
6621 
6622   // If we're not materializing a subobject of the temporary, keep the
6623   // cv-qualifiers from the type of the MaterializeTemporaryExpr.
6624   QualType MaterializedType = Init->getType();
6625   if (Init == E->getSubExpr())
6626     MaterializedType = E->getType();
6627 
6628   CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
6629 
6630   auto InsertResult = MaterializedGlobalTemporaryMap.insert({E, nullptr});
6631   if (!InsertResult.second) {
6632     // We've seen this before: either we already created it or we're in the
6633     // process of doing so.
6634     if (!InsertResult.first->second) {
6635       // We recursively re-entered this function, probably during emission of
6636       // the initializer. Create a placeholder. We'll clean this up in the
6637       // outer call, at the end of this function.
6638       llvm::Type *Type = getTypes().ConvertTypeForMem(MaterializedType);
6639       InsertResult.first->second = new llvm::GlobalVariable(
6640           getModule(), Type, false, llvm::GlobalVariable::InternalLinkage,
6641           nullptr);
6642     }
6643     return ConstantAddress(InsertResult.first->second,
6644                            llvm::cast<llvm::GlobalVariable>(
6645                                InsertResult.first->second->stripPointerCasts())
6646                                ->getValueType(),
6647                            Align);
6648   }
6649 
6650   // FIXME: If an externally-visible declaration extends multiple temporaries,
6651   // we need to give each temporary the same name in every translation unit (and
6652   // we also need to make the temporaries externally-visible).
6653   SmallString<256> Name;
6654   llvm::raw_svector_ostream Out(Name);
6655   getCXXABI().getMangleContext().mangleReferenceTemporary(
6656       VD, E->getManglingNumber(), Out);
6657 
6658   APValue *Value = nullptr;
6659   if (E->getStorageDuration() == SD_Static && VD->evaluateValue()) {
6660     // If the initializer of the extending declaration is a constant
6661     // initializer, we should have a cached constant initializer for this
6662     // temporary. Note that this might have a different value from the value
6663     // computed by evaluating the initializer if the surrounding constant
6664     // expression modifies the temporary.
6665     Value = E->getOrCreateValue(false);
6666   }
6667 
6668   // Try evaluating it now, it might have a constant initializer.
6669   Expr::EvalResult EvalResult;
6670   if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
6671       !EvalResult.hasSideEffects())
6672     Value = &EvalResult.Val;
6673 
6674   LangAS AddrSpace = GetGlobalVarAddressSpace(VD);
6675 
6676   std::optional<ConstantEmitter> emitter;
6677   llvm::Constant *InitialValue = nullptr;
6678   bool Constant = false;
6679   llvm::Type *Type;
6680   if (Value) {
6681     // The temporary has a constant initializer, use it.
6682     emitter.emplace(*this);
6683     InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
6684                                                MaterializedType);
6685     Constant =
6686         MaterializedType.isConstantStorage(getContext(), /*ExcludeCtor*/ Value,
6687                                            /*ExcludeDtor*/ false);
6688     Type = InitialValue->getType();
6689   } else {
6690     // No initializer, the initialization will be provided when we
6691     // initialize the declaration which performed lifetime extension.
6692     Type = getTypes().ConvertTypeForMem(MaterializedType);
6693   }
6694 
6695   // Create a global variable for this lifetime-extended temporary.
6696   llvm::GlobalValue::LinkageTypes Linkage = getLLVMLinkageVarDefinition(VD);
6697   if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
6698     const VarDecl *InitVD;
6699     if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
6700         isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
6701       // Temporaries defined inside a class get linkonce_odr linkage because the
6702       // class can be defined in multiple translation units.
6703       Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
6704     } else {
6705       // There is no need for this temporary to have external linkage if the
6706       // VarDecl has external linkage.
6707       Linkage = llvm::GlobalVariable::InternalLinkage;
6708     }
6709   }
6710   auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
6711   auto *GV = new llvm::GlobalVariable(
6712       getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
6713       /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
6714   if (emitter) emitter->finalize(GV);
6715   // Don't assign dllimport or dllexport to local linkage globals.
6716   if (!llvm::GlobalValue::isLocalLinkage(Linkage)) {
6717     setGVProperties(GV, VD);
6718     if (GV->getDLLStorageClass() == llvm::GlobalVariable::DLLExportStorageClass)
6719       // The reference temporary should never be dllexport.
6720       GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
6721   }
6722   GV->setAlignment(Align.getAsAlign());
6723   if (supportsCOMDAT() && GV->isWeakForLinker())
6724     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
6725   if (VD->getTLSKind())
6726     setTLSMode(GV, *VD);
6727   llvm::Constant *CV = GV;
6728   if (AddrSpace != LangAS::Default)
6729     CV = getTargetCodeGenInfo().performAddrSpaceCast(
6730         *this, GV, AddrSpace, LangAS::Default,
6731         llvm::PointerType::get(
6732             getLLVMContext(),
6733             getContext().getTargetAddressSpace(LangAS::Default)));
6734 
6735   // Update the map with the new temporary. If we created a placeholder above,
6736   // replace it with the new global now.
6737   llvm::Constant *&Entry = MaterializedGlobalTemporaryMap[E];
6738   if (Entry) {
6739     Entry->replaceAllUsesWith(CV);
6740     llvm::cast<llvm::GlobalVariable>(Entry)->eraseFromParent();
6741   }
6742   Entry = CV;
6743 
6744   return ConstantAddress(CV, Type, Align);
6745 }
6746 
6747 /// EmitObjCPropertyImplementations - Emit information for synthesized
6748 /// properties for an implementation.
6749 void CodeGenModule::EmitObjCPropertyImplementations(const
6750                                                     ObjCImplementationDecl *D) {
6751   for (const auto *PID : D->property_impls()) {
6752     // Dynamic is just for type-checking.
6753     if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
6754       ObjCPropertyDecl *PD = PID->getPropertyDecl();
6755 
6756       // Determine which methods need to be implemented, some may have
6757       // been overridden. Note that ::isPropertyAccessor is not the method
6758       // we want, that just indicates if the decl came from a
6759       // property. What we want to know is if the method is defined in
6760       // this implementation.
6761       auto *Getter = PID->getGetterMethodDecl();
6762       if (!Getter || Getter->isSynthesizedAccessorStub())
6763         CodeGenFunction(*this).GenerateObjCGetter(
6764             const_cast<ObjCImplementationDecl *>(D), PID);
6765       auto *Setter = PID->getSetterMethodDecl();
6766       if (!PD->isReadOnly() && (!Setter || Setter->isSynthesizedAccessorStub()))
6767         CodeGenFunction(*this).GenerateObjCSetter(
6768                                  const_cast<ObjCImplementationDecl *>(D), PID);
6769     }
6770   }
6771 }
6772 
6773 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
6774   const ObjCInterfaceDecl *iface = impl->getClassInterface();
6775   for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
6776        ivar; ivar = ivar->getNextIvar())
6777     if (ivar->getType().isDestructedType())
6778       return true;
6779 
6780   return false;
6781 }
6782 
6783 static bool AllTrivialInitializers(CodeGenModule &CGM,
6784                                    ObjCImplementationDecl *D) {
6785   CodeGenFunction CGF(CGM);
6786   for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
6787        E = D->init_end(); B != E; ++B) {
6788     CXXCtorInitializer *CtorInitExp = *B;
6789     Expr *Init = CtorInitExp->getInit();
6790     if (!CGF.isTrivialInitializer(Init))
6791       return false;
6792   }
6793   return true;
6794 }
6795 
6796 /// EmitObjCIvarInitializations - Emit information for ivar initialization
6797 /// for an implementation.
6798 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
6799   // We might need a .cxx_destruct even if we don't have any ivar initializers.
6800   if (needsDestructMethod(D)) {
6801     const IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
6802     Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
6803     ObjCMethodDecl *DTORMethod = ObjCMethodDecl::Create(
6804         getContext(), D->getLocation(), D->getLocation(), cxxSelector,
6805         getContext().VoidTy, nullptr, D,
6806         /*isInstance=*/true, /*isVariadic=*/false,
6807         /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
6808         /*isImplicitlyDeclared=*/true,
6809         /*isDefined=*/false, ObjCImplementationControl::Required);
6810     D->addInstanceMethod(DTORMethod);
6811     CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
6812     D->setHasDestructors(true);
6813   }
6814 
6815   // If the implementation doesn't have any ivar initializers, we don't need
6816   // a .cxx_construct.
6817   if (D->getNumIvarInitializers() == 0 ||
6818       AllTrivialInitializers(*this, D))
6819     return;
6820 
6821   const IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
6822   Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
6823   // The constructor returns 'self'.
6824   ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(
6825       getContext(), D->getLocation(), D->getLocation(), cxxSelector,
6826       getContext().getObjCIdType(), nullptr, D, /*isInstance=*/true,
6827       /*isVariadic=*/false,
6828       /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
6829       /*isImplicitlyDeclared=*/true,
6830       /*isDefined=*/false, ObjCImplementationControl::Required);
6831   D->addInstanceMethod(CTORMethod);
6832   CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
6833   D->setHasNonZeroConstructors(true);
6834 }
6835 
6836 // EmitLinkageSpec - Emit all declarations in a linkage spec.
6837 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
6838   if (LSD->getLanguage() != LinkageSpecLanguageIDs::C &&
6839       LSD->getLanguage() != LinkageSpecLanguageIDs::CXX) {
6840     ErrorUnsupported(LSD, "linkage spec");
6841     return;
6842   }
6843 
6844   EmitDeclContext(LSD);
6845 }
6846 
6847 void CodeGenModule::EmitTopLevelStmt(const TopLevelStmtDecl *D) {
6848   // Device code should not be at top level.
6849   if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
6850     return;
6851 
6852   std::unique_ptr<CodeGenFunction> &CurCGF =
6853       GlobalTopLevelStmtBlockInFlight.first;
6854 
6855   // We emitted a top-level stmt but after it there is initialization.
6856   // Stop squashing the top-level stmts into a single function.
6857   if (CurCGF && CXXGlobalInits.back() != CurCGF->CurFn) {
6858     CurCGF->FinishFunction(D->getEndLoc());
6859     CurCGF = nullptr;
6860   }
6861 
6862   if (!CurCGF) {
6863     // void __stmts__N(void)
6864     // FIXME: Ask the ABI name mangler to pick a name.
6865     std::string Name = "__stmts__" + llvm::utostr(CXXGlobalInits.size());
6866     FunctionArgList Args;
6867     QualType RetTy = getContext().VoidTy;
6868     const CGFunctionInfo &FnInfo =
6869         getTypes().arrangeBuiltinFunctionDeclaration(RetTy, Args);
6870     llvm::FunctionType *FnTy = getTypes().GetFunctionType(FnInfo);
6871     llvm::Function *Fn = llvm::Function::Create(
6872         FnTy, llvm::GlobalValue::InternalLinkage, Name, &getModule());
6873 
6874     CurCGF.reset(new CodeGenFunction(*this));
6875     GlobalTopLevelStmtBlockInFlight.second = D;
6876     CurCGF->StartFunction(GlobalDecl(), RetTy, Fn, FnInfo, Args,
6877                           D->getBeginLoc(), D->getBeginLoc());
6878     CXXGlobalInits.push_back(Fn);
6879   }
6880 
6881   CurCGF->EmitStmt(D->getStmt());
6882 }
6883 
6884 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
6885   for (auto *I : DC->decls()) {
6886     // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
6887     // are themselves considered "top-level", so EmitTopLevelDecl on an
6888     // ObjCImplDecl does not recursively visit them. We need to do that in
6889     // case they're nested inside another construct (LinkageSpecDecl /
6890     // ExportDecl) that does stop them from being considered "top-level".
6891     if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
6892       for (auto *M : OID->methods())
6893         EmitTopLevelDecl(M);
6894     }
6895 
6896     EmitTopLevelDecl(I);
6897   }
6898 }
6899 
6900 /// EmitTopLevelDecl - Emit code for a single top level declaration.
6901 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
6902   // Ignore dependent declarations.
6903   if (D->isTemplated())
6904     return;
6905 
6906   // Consteval function shouldn't be emitted.
6907   if (auto *FD = dyn_cast<FunctionDecl>(D); FD && FD->isImmediateFunction())
6908     return;
6909 
6910   switch (D->getKind()) {
6911   case Decl::CXXConversion:
6912   case Decl::CXXMethod:
6913   case Decl::Function:
6914     EmitGlobal(cast<FunctionDecl>(D));
6915     // Always provide some coverage mapping
6916     // even for the functions that aren't emitted.
6917     AddDeferredUnusedCoverageMapping(D);
6918     break;
6919 
6920   case Decl::CXXDeductionGuide:
6921     // Function-like, but does not result in code emission.
6922     break;
6923 
6924   case Decl::Var:
6925   case Decl::Decomposition:
6926   case Decl::VarTemplateSpecialization:
6927     EmitGlobal(cast<VarDecl>(D));
6928     if (auto *DD = dyn_cast<DecompositionDecl>(D))
6929       for (auto *B : DD->bindings())
6930         if (auto *HD = B->getHoldingVar())
6931           EmitGlobal(HD);
6932     break;
6933 
6934   // Indirect fields from global anonymous structs and unions can be
6935   // ignored; only the actual variable requires IR gen support.
6936   case Decl::IndirectField:
6937     break;
6938 
6939   // C++ Decls
6940   case Decl::Namespace:
6941     EmitDeclContext(cast<NamespaceDecl>(D));
6942     break;
6943   case Decl::ClassTemplateSpecialization: {
6944     const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
6945     if (CGDebugInfo *DI = getModuleDebugInfo())
6946       if (Spec->getSpecializationKind() ==
6947               TSK_ExplicitInstantiationDefinition &&
6948           Spec->hasDefinition())
6949         DI->completeTemplateDefinition(*Spec);
6950   } [[fallthrough]];
6951   case Decl::CXXRecord: {
6952     CXXRecordDecl *CRD = cast<CXXRecordDecl>(D);
6953     if (CGDebugInfo *DI = getModuleDebugInfo()) {
6954       if (CRD->hasDefinition())
6955         DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
6956       if (auto *ES = D->getASTContext().getExternalSource())
6957         if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
6958           DI->completeUnusedClass(*CRD);
6959     }
6960     // Emit any static data members, they may be definitions.
6961     for (auto *I : CRD->decls())
6962       if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
6963         EmitTopLevelDecl(I);
6964     break;
6965   }
6966     // No code generation needed.
6967   case Decl::UsingShadow:
6968   case Decl::ClassTemplate:
6969   case Decl::VarTemplate:
6970   case Decl::Concept:
6971   case Decl::VarTemplatePartialSpecialization:
6972   case Decl::FunctionTemplate:
6973   case Decl::TypeAliasTemplate:
6974   case Decl::Block:
6975   case Decl::Empty:
6976   case Decl::Binding:
6977     break;
6978   case Decl::Using:          // using X; [C++]
6979     if (CGDebugInfo *DI = getModuleDebugInfo())
6980         DI->EmitUsingDecl(cast<UsingDecl>(*D));
6981     break;
6982   case Decl::UsingEnum: // using enum X; [C++]
6983     if (CGDebugInfo *DI = getModuleDebugInfo())
6984       DI->EmitUsingEnumDecl(cast<UsingEnumDecl>(*D));
6985     break;
6986   case Decl::NamespaceAlias:
6987     if (CGDebugInfo *DI = getModuleDebugInfo())
6988         DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
6989     break;
6990   case Decl::UsingDirective: // using namespace X; [C++]
6991     if (CGDebugInfo *DI = getModuleDebugInfo())
6992       DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
6993     break;
6994   case Decl::CXXConstructor:
6995     getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
6996     break;
6997   case Decl::CXXDestructor:
6998     getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
6999     break;
7000 
7001   case Decl::StaticAssert:
7002     // Nothing to do.
7003     break;
7004 
7005   // Objective-C Decls
7006 
7007   // Forward declarations, no (immediate) code generation.
7008   case Decl::ObjCInterface:
7009   case Decl::ObjCCategory:
7010     break;
7011 
7012   case Decl::ObjCProtocol: {
7013     auto *Proto = cast<ObjCProtocolDecl>(D);
7014     if (Proto->isThisDeclarationADefinition())
7015       ObjCRuntime->GenerateProtocol(Proto);
7016     break;
7017   }
7018 
7019   case Decl::ObjCCategoryImpl:
7020     // Categories have properties but don't support synthesize so we
7021     // can ignore them here.
7022     ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
7023     break;
7024 
7025   case Decl::ObjCImplementation: {
7026     auto *OMD = cast<ObjCImplementationDecl>(D);
7027     EmitObjCPropertyImplementations(OMD);
7028     EmitObjCIvarInitializations(OMD);
7029     ObjCRuntime->GenerateClass(OMD);
7030     // Emit global variable debug information.
7031     if (CGDebugInfo *DI = getModuleDebugInfo())
7032       if (getCodeGenOpts().hasReducedDebugInfo())
7033         DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
7034             OMD->getClassInterface()), OMD->getLocation());
7035     break;
7036   }
7037   case Decl::ObjCMethod: {
7038     auto *OMD = cast<ObjCMethodDecl>(D);
7039     // If this is not a prototype, emit the body.
7040     if (OMD->getBody())
7041       CodeGenFunction(*this).GenerateObjCMethod(OMD);
7042     break;
7043   }
7044   case Decl::ObjCCompatibleAlias:
7045     ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
7046     break;
7047 
7048   case Decl::PragmaComment: {
7049     const auto *PCD = cast<PragmaCommentDecl>(D);
7050     switch (PCD->getCommentKind()) {
7051     case PCK_Unknown:
7052       llvm_unreachable("unexpected pragma comment kind");
7053     case PCK_Linker:
7054       AppendLinkerOptions(PCD->getArg());
7055       break;
7056     case PCK_Lib:
7057         AddDependentLib(PCD->getArg());
7058       break;
7059     case PCK_Compiler:
7060     case PCK_ExeStr:
7061     case PCK_User:
7062       break; // We ignore all of these.
7063     }
7064     break;
7065   }
7066 
7067   case Decl::PragmaDetectMismatch: {
7068     const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
7069     AddDetectMismatch(PDMD->getName(), PDMD->getValue());
7070     break;
7071   }
7072 
7073   case Decl::LinkageSpec:
7074     EmitLinkageSpec(cast<LinkageSpecDecl>(D));
7075     break;
7076 
7077   case Decl::FileScopeAsm: {
7078     // File-scope asm is ignored during device-side CUDA compilation.
7079     if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
7080       break;
7081     // File-scope asm is ignored during device-side OpenMP compilation.
7082     if (LangOpts.OpenMPIsTargetDevice)
7083       break;
7084     // File-scope asm is ignored during device-side SYCL compilation.
7085     if (LangOpts.SYCLIsDevice)
7086       break;
7087     auto *AD = cast<FileScopeAsmDecl>(D);
7088     getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
7089     break;
7090   }
7091 
7092   case Decl::TopLevelStmt:
7093     EmitTopLevelStmt(cast<TopLevelStmtDecl>(D));
7094     break;
7095 
7096   case Decl::Import: {
7097     auto *Import = cast<ImportDecl>(D);
7098 
7099     // If we've already imported this module, we're done.
7100     if (!ImportedModules.insert(Import->getImportedModule()))
7101       break;
7102 
7103     // Emit debug information for direct imports.
7104     if (!Import->getImportedOwningModule()) {
7105       if (CGDebugInfo *DI = getModuleDebugInfo())
7106         DI->EmitImportDecl(*Import);
7107     }
7108 
7109     // For C++ standard modules we are done - we will call the module
7110     // initializer for imported modules, and that will likewise call those for
7111     // any imports it has.
7112     if (CXX20ModuleInits && Import->getImportedOwningModule() &&
7113         !Import->getImportedOwningModule()->isModuleMapModule())
7114       break;
7115 
7116     // For clang C++ module map modules the initializers for sub-modules are
7117     // emitted here.
7118 
7119     // Find all of the submodules and emit the module initializers.
7120     llvm::SmallPtrSet<clang::Module *, 16> Visited;
7121     SmallVector<clang::Module *, 16> Stack;
7122     Visited.insert(Import->getImportedModule());
7123     Stack.push_back(Import->getImportedModule());
7124 
7125     while (!Stack.empty()) {
7126       clang::Module *Mod = Stack.pop_back_val();
7127       if (!EmittedModuleInitializers.insert(Mod).second)
7128         continue;
7129 
7130       for (auto *D : Context.getModuleInitializers(Mod))
7131         EmitTopLevelDecl(D);
7132 
7133       // Visit the submodules of this module.
7134       for (auto *Submodule : Mod->submodules()) {
7135         // Skip explicit children; they need to be explicitly imported to emit
7136         // the initializers.
7137         if (Submodule->IsExplicit)
7138           continue;
7139 
7140         if (Visited.insert(Submodule).second)
7141           Stack.push_back(Submodule);
7142       }
7143     }
7144     break;
7145   }
7146 
7147   case Decl::Export:
7148     EmitDeclContext(cast<ExportDecl>(D));
7149     break;
7150 
7151   case Decl::OMPThreadPrivate:
7152     EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
7153     break;
7154 
7155   case Decl::OMPAllocate:
7156     EmitOMPAllocateDecl(cast<OMPAllocateDecl>(D));
7157     break;
7158 
7159   case Decl::OMPDeclareReduction:
7160     EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
7161     break;
7162 
7163   case Decl::OMPDeclareMapper:
7164     EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D));
7165     break;
7166 
7167   case Decl::OMPRequires:
7168     EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
7169     break;
7170 
7171   case Decl::Typedef:
7172   case Decl::TypeAlias: // using foo = bar; [C++11]
7173     if (CGDebugInfo *DI = getModuleDebugInfo())
7174       DI->EmitAndRetainType(
7175           getContext().getTypedefType(cast<TypedefNameDecl>(D)));
7176     break;
7177 
7178   case Decl::Record:
7179     if (CGDebugInfo *DI = getModuleDebugInfo())
7180       if (cast<RecordDecl>(D)->getDefinition())
7181         DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
7182     break;
7183 
7184   case Decl::Enum:
7185     if (CGDebugInfo *DI = getModuleDebugInfo())
7186       if (cast<EnumDecl>(D)->getDefinition())
7187         DI->EmitAndRetainType(getContext().getEnumType(cast<EnumDecl>(D)));
7188     break;
7189 
7190   case Decl::HLSLBuffer:
7191     getHLSLRuntime().addBuffer(cast<HLSLBufferDecl>(D));
7192     break;
7193 
7194   default:
7195     // Make sure we handled everything we should, every other kind is a
7196     // non-top-level decl.  FIXME: Would be nice to have an isTopLevelDeclKind
7197     // function. Need to recode Decl::Kind to do that easily.
7198     assert(isa<TypeDecl>(D) && "Unsupported decl kind");
7199     break;
7200   }
7201 }
7202 
7203 void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
7204   // Do we need to generate coverage mapping?
7205   if (!CodeGenOpts.CoverageMapping)
7206     return;
7207   switch (D->getKind()) {
7208   case Decl::CXXConversion:
7209   case Decl::CXXMethod:
7210   case Decl::Function:
7211   case Decl::ObjCMethod:
7212   case Decl::CXXConstructor:
7213   case Decl::CXXDestructor: {
7214     if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
7215       break;
7216     SourceManager &SM = getContext().getSourceManager();
7217     if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
7218       break;
7219     if (!llvm::coverage::SystemHeadersCoverage &&
7220         SM.isInSystemHeader(D->getBeginLoc()))
7221       break;
7222     DeferredEmptyCoverageMappingDecls.try_emplace(D, true);
7223     break;
7224   }
7225   default:
7226     break;
7227   };
7228 }
7229 
7230 void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
7231   // Do we need to generate coverage mapping?
7232   if (!CodeGenOpts.CoverageMapping)
7233     return;
7234   if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
7235     if (Fn->isTemplateInstantiation())
7236       ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
7237   }
7238   DeferredEmptyCoverageMappingDecls.insert_or_assign(D, false);
7239 }
7240 
7241 void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
7242   // We call takeVector() here to avoid use-after-free.
7243   // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
7244   // we deserialize function bodies to emit coverage info for them, and that
7245   // deserializes more declarations. How should we handle that case?
7246   for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
7247     if (!Entry.second)
7248       continue;
7249     const Decl *D = Entry.first;
7250     switch (D->getKind()) {
7251     case Decl::CXXConversion:
7252     case Decl::CXXMethod:
7253     case Decl::Function:
7254     case Decl::ObjCMethod: {
7255       CodeGenPGO PGO(*this);
7256       GlobalDecl GD(cast<FunctionDecl>(D));
7257       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7258                                   getFunctionLinkage(GD));
7259       break;
7260     }
7261     case Decl::CXXConstructor: {
7262       CodeGenPGO PGO(*this);
7263       GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
7264       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7265                                   getFunctionLinkage(GD));
7266       break;
7267     }
7268     case Decl::CXXDestructor: {
7269       CodeGenPGO PGO(*this);
7270       GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
7271       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7272                                   getFunctionLinkage(GD));
7273       break;
7274     }
7275     default:
7276       break;
7277     };
7278   }
7279 }
7280 
7281 void CodeGenModule::EmitMainVoidAlias() {
7282   // In order to transition away from "__original_main" gracefully, emit an
7283   // alias for "main" in the no-argument case so that libc can detect when
7284   // new-style no-argument main is in used.
7285   if (llvm::Function *F = getModule().getFunction("main")) {
7286     if (!F->isDeclaration() && F->arg_size() == 0 && !F->isVarArg() &&
7287         F->getReturnType()->isIntegerTy(Context.getTargetInfo().getIntWidth())) {
7288       auto *GA = llvm::GlobalAlias::create("__main_void", F);
7289       GA->setVisibility(llvm::GlobalValue::HiddenVisibility);
7290     }
7291   }
7292 }
7293 
7294 /// Turns the given pointer into a constant.
7295 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
7296                                           const void *Ptr) {
7297   uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
7298   llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
7299   return llvm::ConstantInt::get(i64, PtrInt);
7300 }
7301 
7302 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
7303                                    llvm::NamedMDNode *&GlobalMetadata,
7304                                    GlobalDecl D,
7305                                    llvm::GlobalValue *Addr) {
7306   if (!GlobalMetadata)
7307     GlobalMetadata =
7308       CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
7309 
7310   // TODO: should we report variant information for ctors/dtors?
7311   llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
7312                            llvm::ConstantAsMetadata::get(GetPointerConstant(
7313                                CGM.getLLVMContext(), D.getDecl()))};
7314   GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
7315 }
7316 
7317 bool CodeGenModule::CheckAndReplaceExternCIFuncs(llvm::GlobalValue *Elem,
7318                                                  llvm::GlobalValue *CppFunc) {
7319   // Store the list of ifuncs we need to replace uses in.
7320   llvm::SmallVector<llvm::GlobalIFunc *> IFuncs;
7321   // List of ConstantExprs that we should be able to delete when we're done
7322   // here.
7323   llvm::SmallVector<llvm::ConstantExpr *> CEs;
7324 
7325   // It isn't valid to replace the extern-C ifuncs if all we find is itself!
7326   if (Elem == CppFunc)
7327     return false;
7328 
7329   // First make sure that all users of this are ifuncs (or ifuncs via a
7330   // bitcast), and collect the list of ifuncs and CEs so we can work on them
7331   // later.
7332   for (llvm::User *User : Elem->users()) {
7333     // Users can either be a bitcast ConstExpr that is used by the ifuncs, OR an
7334     // ifunc directly. In any other case, just give up, as we don't know what we
7335     // could break by changing those.
7336     if (auto *ConstExpr = dyn_cast<llvm::ConstantExpr>(User)) {
7337       if (ConstExpr->getOpcode() != llvm::Instruction::BitCast)
7338         return false;
7339 
7340       for (llvm::User *CEUser : ConstExpr->users()) {
7341         if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(CEUser)) {
7342           IFuncs.push_back(IFunc);
7343         } else {
7344           return false;
7345         }
7346       }
7347       CEs.push_back(ConstExpr);
7348     } else if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(User)) {
7349       IFuncs.push_back(IFunc);
7350     } else {
7351       // This user is one we don't know how to handle, so fail redirection. This
7352       // will result in an ifunc retaining a resolver name that will ultimately
7353       // fail to be resolved to a defined function.
7354       return false;
7355     }
7356   }
7357 
7358   // Now we know this is a valid case where we can do this alias replacement, we
7359   // need to remove all of the references to Elem (and the bitcasts!) so we can
7360   // delete it.
7361   for (llvm::GlobalIFunc *IFunc : IFuncs)
7362     IFunc->setResolver(nullptr);
7363   for (llvm::ConstantExpr *ConstExpr : CEs)
7364     ConstExpr->destroyConstant();
7365 
7366   // We should now be out of uses for the 'old' version of this function, so we
7367   // can erase it as well.
7368   Elem->eraseFromParent();
7369 
7370   for (llvm::GlobalIFunc *IFunc : IFuncs) {
7371     // The type of the resolver is always just a function-type that returns the
7372     // type of the IFunc, so create that here. If the type of the actual
7373     // resolver doesn't match, it just gets bitcast to the right thing.
7374     auto *ResolverTy =
7375         llvm::FunctionType::get(IFunc->getType(), /*isVarArg*/ false);
7376     llvm::Constant *Resolver = GetOrCreateLLVMFunction(
7377         CppFunc->getName(), ResolverTy, {}, /*ForVTable*/ false);
7378     IFunc->setResolver(Resolver);
7379   }
7380   return true;
7381 }
7382 
7383 /// For each function which is declared within an extern "C" region and marked
7384 /// as 'used', but has internal linkage, create an alias from the unmangled
7385 /// name to the mangled name if possible. People expect to be able to refer
7386 /// to such functions with an unmangled name from inline assembly within the
7387 /// same translation unit.
7388 void CodeGenModule::EmitStaticExternCAliases() {
7389   if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
7390     return;
7391   for (auto &I : StaticExternCValues) {
7392     const IdentifierInfo *Name = I.first;
7393     llvm::GlobalValue *Val = I.second;
7394 
7395     // If Val is null, that implies there were multiple declarations that each
7396     // had a claim to the unmangled name. In this case, generation of the alias
7397     // is suppressed. See CodeGenModule::MaybeHandleStaticInExternC.
7398     if (!Val)
7399       break;
7400 
7401     llvm::GlobalValue *ExistingElem =
7402         getModule().getNamedValue(Name->getName());
7403 
7404     // If there is either not something already by this name, or we were able to
7405     // replace all uses from IFuncs, create the alias.
7406     if (!ExistingElem || CheckAndReplaceExternCIFuncs(ExistingElem, Val))
7407       addCompilerUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
7408   }
7409 }
7410 
7411 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
7412                                              GlobalDecl &Result) const {
7413   auto Res = Manglings.find(MangledName);
7414   if (Res == Manglings.end())
7415     return false;
7416   Result = Res->getValue();
7417   return true;
7418 }
7419 
7420 /// Emits metadata nodes associating all the global values in the
7421 /// current module with the Decls they came from.  This is useful for
7422 /// projects using IR gen as a subroutine.
7423 ///
7424 /// Since there's currently no way to associate an MDNode directly
7425 /// with an llvm::GlobalValue, we create a global named metadata
7426 /// with the name 'clang.global.decl.ptrs'.
7427 void CodeGenModule::EmitDeclMetadata() {
7428   llvm::NamedMDNode *GlobalMetadata = nullptr;
7429 
7430   for (auto &I : MangledDeclNames) {
7431     llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
7432     // Some mangled names don't necessarily have an associated GlobalValue
7433     // in this module, e.g. if we mangled it for DebugInfo.
7434     if (Addr)
7435       EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
7436   }
7437 }
7438 
7439 /// Emits metadata nodes for all the local variables in the current
7440 /// function.
7441 void CodeGenFunction::EmitDeclMetadata() {
7442   if (LocalDeclMap.empty()) return;
7443 
7444   llvm::LLVMContext &Context = getLLVMContext();
7445 
7446   // Find the unique metadata ID for this name.
7447   unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
7448 
7449   llvm::NamedMDNode *GlobalMetadata = nullptr;
7450 
7451   for (auto &I : LocalDeclMap) {
7452     const Decl *D = I.first;
7453     llvm::Value *Addr = I.second.emitRawPointer(*this);
7454     if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
7455       llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
7456       Alloca->setMetadata(
7457           DeclPtrKind, llvm::MDNode::get(
7458                            Context, llvm::ValueAsMetadata::getConstant(DAddr)));
7459     } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
7460       GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
7461       EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
7462     }
7463   }
7464 }
7465 
7466 void CodeGenModule::EmitVersionIdentMetadata() {
7467   llvm::NamedMDNode *IdentMetadata =
7468     TheModule.getOrInsertNamedMetadata("llvm.ident");
7469   std::string Version = getClangFullVersion();
7470   llvm::LLVMContext &Ctx = TheModule.getContext();
7471 
7472   llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
7473   IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
7474 }
7475 
7476 void CodeGenModule::EmitCommandLineMetadata() {
7477   llvm::NamedMDNode *CommandLineMetadata =
7478     TheModule.getOrInsertNamedMetadata("llvm.commandline");
7479   std::string CommandLine = getCodeGenOpts().RecordCommandLine;
7480   llvm::LLVMContext &Ctx = TheModule.getContext();
7481 
7482   llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
7483   CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
7484 }
7485 
7486 void CodeGenModule::EmitCoverageFile() {
7487   llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
7488   if (!CUNode)
7489     return;
7490 
7491   llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
7492   llvm::LLVMContext &Ctx = TheModule.getContext();
7493   auto *CoverageDataFile =
7494       llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
7495   auto *CoverageNotesFile =
7496       llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
7497   for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
7498     llvm::MDNode *CU = CUNode->getOperand(i);
7499     llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
7500     GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
7501   }
7502 }
7503 
7504 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
7505                                                        bool ForEH) {
7506   // Return a bogus pointer if RTTI is disabled, unless it's for EH.
7507   // FIXME: should we even be calling this method if RTTI is disabled
7508   // and it's not for EH?
7509   if (!shouldEmitRTTI(ForEH))
7510     return llvm::Constant::getNullValue(GlobalsInt8PtrTy);
7511 
7512   if (ForEH && Ty->isObjCObjectPointerType() &&
7513       LangOpts.ObjCRuntime.isGNUFamily())
7514     return ObjCRuntime->GetEHType(Ty);
7515 
7516   return getCXXABI().getAddrOfRTTIDescriptor(Ty);
7517 }
7518 
7519 void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
7520   // Do not emit threadprivates in simd-only mode.
7521   if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
7522     return;
7523   for (auto RefExpr : D->varlist()) {
7524     auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
7525     bool PerformInit =
7526         VD->getAnyInitializer() &&
7527         !VD->getAnyInitializer()->isConstantInitializer(getContext(),
7528                                                         /*ForRef=*/false);
7529 
7530     Address Addr(GetAddrOfGlobalVar(VD),
7531                  getTypes().ConvertTypeForMem(VD->getType()),
7532                  getContext().getDeclAlign(VD));
7533     if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
7534             VD, Addr, RefExpr->getBeginLoc(), PerformInit))
7535       CXXGlobalInits.push_back(InitFunction);
7536   }
7537 }
7538 
7539 llvm::Metadata *
7540 CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
7541                                             StringRef Suffix) {
7542   if (auto *FnType = T->getAs<FunctionProtoType>())
7543     T = getContext().getFunctionType(
7544         FnType->getReturnType(), FnType->getParamTypes(),
7545         FnType->getExtProtoInfo().withExceptionSpec(EST_None));
7546 
7547   llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
7548   if (InternalId)
7549     return InternalId;
7550 
7551   if (isExternallyVisible(T->getLinkage())) {
7552     std::string OutName;
7553     llvm::raw_string_ostream Out(OutName);
7554     getCXXABI().getMangleContext().mangleCanonicalTypeName(
7555         T, Out, getCodeGenOpts().SanitizeCfiICallNormalizeIntegers);
7556 
7557     if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
7558       Out << ".normalized";
7559 
7560     Out << Suffix;
7561 
7562     InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
7563   } else {
7564     InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
7565                                            llvm::ArrayRef<llvm::Metadata *>());
7566   }
7567 
7568   return InternalId;
7569 }
7570 
7571 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
7572   return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
7573 }
7574 
7575 llvm::Metadata *
7576 CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
7577   return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
7578 }
7579 
7580 // Generalize pointer types to a void pointer with the qualifiers of the
7581 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
7582 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
7583 // 'void *'.
7584 static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
7585   if (!Ty->isPointerType())
7586     return Ty;
7587 
7588   return Ctx.getPointerType(
7589       QualType(Ctx.VoidTy).withCVRQualifiers(
7590           Ty->getPointeeType().getCVRQualifiers()));
7591 }
7592 
7593 // Apply type generalization to a FunctionType's return and argument types
7594 static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
7595   if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
7596     SmallVector<QualType, 8> GeneralizedParams;
7597     for (auto &Param : FnType->param_types())
7598       GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
7599 
7600     return Ctx.getFunctionType(
7601         GeneralizeType(Ctx, FnType->getReturnType()),
7602         GeneralizedParams, FnType->getExtProtoInfo());
7603   }
7604 
7605   if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
7606     return Ctx.getFunctionNoProtoType(
7607         GeneralizeType(Ctx, FnType->getReturnType()));
7608 
7609   llvm_unreachable("Encountered unknown FunctionType");
7610 }
7611 
7612 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
7613   return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
7614                                       GeneralizedMetadataIdMap, ".generalized");
7615 }
7616 
7617 /// Returns whether this module needs the "all-vtables" type identifier.
7618 bool CodeGenModule::NeedAllVtablesTypeId() const {
7619   // Returns true if at least one of vtable-based CFI checkers is enabled and
7620   // is not in the trapping mode.
7621   return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
7622            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
7623           (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
7624            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
7625           (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
7626            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
7627           (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
7628            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
7629 }
7630 
7631 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
7632                                           CharUnits Offset,
7633                                           const CXXRecordDecl *RD) {
7634   llvm::Metadata *MD =
7635       CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
7636   VTable->addTypeMetadata(Offset.getQuantity(), MD);
7637 
7638   if (CodeGenOpts.SanitizeCfiCrossDso)
7639     if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
7640       VTable->addTypeMetadata(Offset.getQuantity(),
7641                               llvm::ConstantAsMetadata::get(CrossDsoTypeId));
7642 
7643   if (NeedAllVtablesTypeId()) {
7644     llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
7645     VTable->addTypeMetadata(Offset.getQuantity(), MD);
7646   }
7647 }
7648 
7649 llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
7650   if (!SanStats)
7651     SanStats = std::make_unique<llvm::SanitizerStatReport>(&getModule());
7652 
7653   return *SanStats;
7654 }
7655 
7656 llvm::Value *
7657 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
7658                                                   CodeGenFunction &CGF) {
7659   llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
7660   auto *SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
7661   auto *FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
7662   auto *Call = CGF.EmitRuntimeCall(
7663       CreateRuntimeFunction(FTy, "__translate_sampler_initializer"), {C});
7664   return Call;
7665 }
7666 
7667 CharUnits CodeGenModule::getNaturalPointeeTypeAlignment(
7668     QualType T, LValueBaseInfo *BaseInfo, TBAAAccessInfo *TBAAInfo) {
7669   return getNaturalTypeAlignment(T->getPointeeType(), BaseInfo, TBAAInfo,
7670                                  /* forPointeeType= */ true);
7671 }
7672 
7673 CharUnits CodeGenModule::getNaturalTypeAlignment(QualType T,
7674                                                  LValueBaseInfo *BaseInfo,
7675                                                  TBAAAccessInfo *TBAAInfo,
7676                                                  bool forPointeeType) {
7677   if (TBAAInfo)
7678     *TBAAInfo = getTBAAAccessInfo(T);
7679 
7680   // FIXME: This duplicates logic in ASTContext::getTypeAlignIfKnown. But
7681   // that doesn't return the information we need to compute BaseInfo.
7682 
7683   // Honor alignment typedef attributes even on incomplete types.
7684   // We also honor them straight for C++ class types, even as pointees;
7685   // there's an expressivity gap here.
7686   if (auto TT = T->getAs<TypedefType>()) {
7687     if (auto Align = TT->getDecl()->getMaxAlignment()) {
7688       if (BaseInfo)
7689         *BaseInfo = LValueBaseInfo(AlignmentSource::AttributedType);
7690       return getContext().toCharUnitsFromBits(Align);
7691     }
7692   }
7693 
7694   bool AlignForArray = T->isArrayType();
7695 
7696   // Analyze the base element type, so we don't get confused by incomplete
7697   // array types.
7698   T = getContext().getBaseElementType(T);
7699 
7700   if (T->isIncompleteType()) {
7701     // We could try to replicate the logic from
7702     // ASTContext::getTypeAlignIfKnown, but nothing uses the alignment if the
7703     // type is incomplete, so it's impossible to test. We could try to reuse
7704     // getTypeAlignIfKnown, but that doesn't return the information we need
7705     // to set BaseInfo.  So just ignore the possibility that the alignment is
7706     // greater than one.
7707     if (BaseInfo)
7708       *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
7709     return CharUnits::One();
7710   }
7711 
7712   if (BaseInfo)
7713     *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
7714 
7715   CharUnits Alignment;
7716   const CXXRecordDecl *RD;
7717   if (T.getQualifiers().hasUnaligned()) {
7718     Alignment = CharUnits::One();
7719   } else if (forPointeeType && !AlignForArray &&
7720              (RD = T->getAsCXXRecordDecl())) {
7721     // For C++ class pointees, we don't know whether we're pointing at a
7722     // base or a complete object, so we generally need to use the
7723     // non-virtual alignment.
7724     Alignment = getClassPointerAlignment(RD);
7725   } else {
7726     Alignment = getContext().getTypeAlignInChars(T);
7727   }
7728 
7729   // Cap to the global maximum type alignment unless the alignment
7730   // was somehow explicit on the type.
7731   if (unsigned MaxAlign = getLangOpts().MaxTypeAlign) {
7732     if (Alignment.getQuantity() > MaxAlign &&
7733         !getContext().isAlignmentRequired(T))
7734       Alignment = CharUnits::fromQuantity(MaxAlign);
7735   }
7736   return Alignment;
7737 }
7738 
7739 bool CodeGenModule::stopAutoInit() {
7740   unsigned StopAfter = getContext().getLangOpts().TrivialAutoVarInitStopAfter;
7741   if (StopAfter) {
7742     // This number is positive only when -ftrivial-auto-var-init-stop-after=* is
7743     // used
7744     if (NumAutoVarInit >= StopAfter) {
7745       return true;
7746     }
7747     if (!NumAutoVarInit) {
7748       unsigned DiagID = getDiags().getCustomDiagID(
7749           DiagnosticsEngine::Warning,
7750           "-ftrivial-auto-var-init-stop-after=%0 has been enabled to limit the "
7751           "number of times ftrivial-auto-var-init=%1 gets applied.");
7752       getDiags().Report(DiagID)
7753           << StopAfter
7754           << (getContext().getLangOpts().getTrivialAutoVarInit() ==
7755                       LangOptions::TrivialAutoVarInitKind::Zero
7756                   ? "zero"
7757                   : "pattern");
7758     }
7759     ++NumAutoVarInit;
7760   }
7761   return false;
7762 }
7763 
7764 void CodeGenModule::printPostfixForExternalizedDecl(llvm::raw_ostream &OS,
7765                                                     const Decl *D) const {
7766   // ptxas does not allow '.' in symbol names. On the other hand, HIP prefers
7767   // postfix beginning with '.' since the symbol name can be demangled.
7768   if (LangOpts.HIP)
7769     OS << (isa<VarDecl>(D) ? ".static." : ".intern.");
7770   else
7771     OS << (isa<VarDecl>(D) ? "__static__" : "__intern__");
7772 
7773   // If the CUID is not specified we try to generate a unique postfix.
7774   if (getLangOpts().CUID.empty()) {
7775     SourceManager &SM = getContext().getSourceManager();
7776     PresumedLoc PLoc = SM.getPresumedLoc(D->getLocation());
7777     assert(PLoc.isValid() && "Source location is expected to be valid.");
7778 
7779     // Get the hash of the user defined macros.
7780     llvm::MD5 Hash;
7781     llvm::MD5::MD5Result Result;
7782     for (const auto &Arg : PreprocessorOpts.Macros)
7783       Hash.update(Arg.first);
7784     Hash.final(Result);
7785 
7786     // Get the UniqueID for the file containing the decl.
7787     llvm::sys::fs::UniqueID ID;
7788     if (llvm::sys::fs::getUniqueID(PLoc.getFilename(), ID)) {
7789       PLoc = SM.getPresumedLoc(D->getLocation(), /*UseLineDirectives=*/false);
7790       assert(PLoc.isValid() && "Source location is expected to be valid.");
7791       if (auto EC = llvm::sys::fs::getUniqueID(PLoc.getFilename(), ID))
7792         SM.getDiagnostics().Report(diag::err_cannot_open_file)
7793             << PLoc.getFilename() << EC.message();
7794     }
7795     OS << llvm::format("%x", ID.getFile()) << llvm::format("%x", ID.getDevice())
7796        << "_" << llvm::utohexstr(Result.low(), /*LowerCase=*/true, /*Width=*/8);
7797   } else {
7798     OS << getContext().getCUIDHash();
7799   }
7800 }
7801 
7802 void CodeGenModule::moveLazyEmissionStates(CodeGenModule *NewBuilder) {
7803   assert(DeferredDeclsToEmit.empty() &&
7804          "Should have emitted all decls deferred to emit.");
7805   assert(NewBuilder->DeferredDecls.empty() &&
7806          "Newly created module should not have deferred decls");
7807   NewBuilder->DeferredDecls = std::move(DeferredDecls);
7808   assert(EmittedDeferredDecls.empty() &&
7809          "Still have (unmerged) EmittedDeferredDecls deferred decls");
7810 
7811   assert(NewBuilder->DeferredVTables.empty() &&
7812          "Newly created module should not have deferred vtables");
7813   NewBuilder->DeferredVTables = std::move(DeferredVTables);
7814 
7815   assert(NewBuilder->MangledDeclNames.empty() &&
7816          "Newly created module should not have mangled decl names");
7817   assert(NewBuilder->Manglings.empty() &&
7818          "Newly created module should not have manglings");
7819   NewBuilder->Manglings = std::move(Manglings);
7820 
7821   NewBuilder->WeakRefReferences = std::move(WeakRefReferences);
7822 
7823   NewBuilder->ABI->MangleCtx = std::move(ABI->MangleCtx);
7824 }
7825