xref: /llvm-project/clang/lib/CodeGen/CodeGenModule.cpp (revision 6c62ad446b2441b78ae524d9e700e351d5a76394)
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::ve:
302     return createVETargetCodeGenInfo(CGM);
303   case llvm::Triple::csky: {
304     bool IsSoftFloat = !Target.hasFeature("hard-float-abi");
305     bool hasFP64 =
306         Target.hasFeature("fpuv2_df") || Target.hasFeature("fpuv3_df");
307     return createCSKYTargetCodeGenInfo(CGM, IsSoftFloat ? 0
308                                             : hasFP64   ? 64
309                                                         : 32);
310   }
311   case llvm::Triple::bpfeb:
312   case llvm::Triple::bpfel:
313     return createBPFTargetCodeGenInfo(CGM);
314   case llvm::Triple::loongarch32:
315   case llvm::Triple::loongarch64: {
316     StringRef ABIStr = Target.getABI();
317     unsigned ABIFRLen = 0;
318     if (ABIStr.ends_with("f"))
319       ABIFRLen = 32;
320     else if (ABIStr.ends_with("d"))
321       ABIFRLen = 64;
322     return createLoongArchTargetCodeGenInfo(
323         CGM, Target.getPointerWidth(LangAS::Default), ABIFRLen);
324   }
325   }
326 }
327 
328 const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
329   if (!TheTargetCodeGenInfo)
330     TheTargetCodeGenInfo = createTargetCodeGenInfo(*this);
331   return *TheTargetCodeGenInfo;
332 }
333 
334 CodeGenModule::CodeGenModule(ASTContext &C,
335                              IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS,
336                              const HeaderSearchOptions &HSO,
337                              const PreprocessorOptions &PPO,
338                              const CodeGenOptions &CGO, llvm::Module &M,
339                              DiagnosticsEngine &diags,
340                              CoverageSourceInfo *CoverageInfo)
341     : Context(C), LangOpts(C.getLangOpts()), FS(FS), HeaderSearchOpts(HSO),
342       PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
343       Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
344       VMContext(M.getContext()), VTables(*this),
345       SanitizerMD(new SanitizerMetadata(*this)) {
346 
347   // Initialize the type cache.
348   Types.reset(new CodeGenTypes(*this));
349   llvm::LLVMContext &LLVMContext = M.getContext();
350   VoidTy = llvm::Type::getVoidTy(LLVMContext);
351   Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
352   Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
353   Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
354   Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
355   HalfTy = llvm::Type::getHalfTy(LLVMContext);
356   BFloatTy = llvm::Type::getBFloatTy(LLVMContext);
357   FloatTy = llvm::Type::getFloatTy(LLVMContext);
358   DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
359   PointerWidthInBits = C.getTargetInfo().getPointerWidth(LangAS::Default);
360   PointerAlignInBytes =
361       C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(LangAS::Default))
362           .getQuantity();
363   SizeSizeInBytes =
364     C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
365   IntAlignInBytes =
366     C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
367   CharTy =
368     llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getCharWidth());
369   IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
370   IntPtrTy = llvm::IntegerType::get(LLVMContext,
371     C.getTargetInfo().getMaxPointerWidth());
372   Int8PtrTy = llvm::PointerType::get(LLVMContext,
373                                      C.getTargetAddressSpace(LangAS::Default));
374   const llvm::DataLayout &DL = M.getDataLayout();
375   AllocaInt8PtrTy =
376       llvm::PointerType::get(LLVMContext, DL.getAllocaAddrSpace());
377   GlobalsInt8PtrTy =
378       llvm::PointerType::get(LLVMContext, DL.getDefaultGlobalsAddressSpace());
379   ConstGlobalsPtrTy = llvm::PointerType::get(
380       LLVMContext, C.getTargetAddressSpace(GetGlobalConstantAddressSpace()));
381   ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
382 
383   // Build C++20 Module initializers.
384   // TODO: Add Microsoft here once we know the mangling required for the
385   // initializers.
386   CXX20ModuleInits =
387       LangOpts.CPlusPlusModules && getCXXABI().getMangleContext().getKind() ==
388                                        ItaniumMangleContext::MK_Itanium;
389 
390   RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
391 
392   if (LangOpts.ObjC)
393     createObjCRuntime();
394   if (LangOpts.OpenCL)
395     createOpenCLRuntime();
396   if (LangOpts.OpenMP)
397     createOpenMPRuntime();
398   if (LangOpts.CUDA)
399     createCUDARuntime();
400   if (LangOpts.HLSL)
401     createHLSLRuntime();
402 
403   // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
404   if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
405       (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
406     TBAA.reset(new CodeGenTBAA(Context, getTypes(), TheModule, CodeGenOpts,
407                                getLangOpts()));
408 
409   // If debug info or coverage generation is enabled, create the CGDebugInfo
410   // object.
411   if (CodeGenOpts.getDebugInfo() != llvm::codegenoptions::NoDebugInfo ||
412       CodeGenOpts.CoverageNotesFile.size() ||
413       CodeGenOpts.CoverageDataFile.size())
414     DebugInfo.reset(new CGDebugInfo(*this));
415 
416   Block.GlobalUniqueCount = 0;
417 
418   if (C.getLangOpts().ObjC)
419     ObjCData.reset(new ObjCEntrypoints());
420 
421   if (CodeGenOpts.hasProfileClangUse()) {
422     auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
423         CodeGenOpts.ProfileInstrumentUsePath, *FS,
424         CodeGenOpts.ProfileRemappingFile);
425     // We're checking for profile read errors in CompilerInvocation, so if
426     // there was an error it should've already been caught. If it hasn't been
427     // somehow, trip an assertion.
428     assert(ReaderOrErr);
429     PGOReader = std::move(ReaderOrErr.get());
430   }
431 
432   // If coverage mapping generation is enabled, create the
433   // CoverageMappingModuleGen object.
434   if (CodeGenOpts.CoverageMapping)
435     CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
436 
437   // Generate the module name hash here if needed.
438   if (CodeGenOpts.UniqueInternalLinkageNames &&
439       !getModule().getSourceFileName().empty()) {
440     std::string Path = getModule().getSourceFileName();
441     // Check if a path substitution is needed from the MacroPrefixMap.
442     for (const auto &Entry : LangOpts.MacroPrefixMap)
443       if (Path.rfind(Entry.first, 0) != std::string::npos) {
444         Path = Entry.second + Path.substr(Entry.first.size());
445         break;
446       }
447     ModuleNameHash = llvm::getUniqueInternalLinkagePostfix(Path);
448   }
449 
450   // Record mregparm value now so it is visible through all of codegen.
451   if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
452     getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
453                               CodeGenOpts.NumRegisterParameters);
454 }
455 
456 CodeGenModule::~CodeGenModule() {}
457 
458 void CodeGenModule::createObjCRuntime() {
459   // This is just isGNUFamily(), but we want to force implementors of
460   // new ABIs to decide how best to do this.
461   switch (LangOpts.ObjCRuntime.getKind()) {
462   case ObjCRuntime::GNUstep:
463   case ObjCRuntime::GCC:
464   case ObjCRuntime::ObjFW:
465     ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
466     return;
467 
468   case ObjCRuntime::FragileMacOSX:
469   case ObjCRuntime::MacOSX:
470   case ObjCRuntime::iOS:
471   case ObjCRuntime::WatchOS:
472     ObjCRuntime.reset(CreateMacObjCRuntime(*this));
473     return;
474   }
475   llvm_unreachable("bad runtime kind");
476 }
477 
478 void CodeGenModule::createOpenCLRuntime() {
479   OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
480 }
481 
482 void CodeGenModule::createOpenMPRuntime() {
483   // Select a specialized code generation class based on the target, if any.
484   // If it does not exist use the default implementation.
485   switch (getTriple().getArch()) {
486   case llvm::Triple::nvptx:
487   case llvm::Triple::nvptx64:
488   case llvm::Triple::amdgcn:
489     assert(getLangOpts().OpenMPIsTargetDevice &&
490            "OpenMP AMDGPU/NVPTX is only prepared to deal with device code.");
491     OpenMPRuntime.reset(new CGOpenMPRuntimeGPU(*this));
492     break;
493   default:
494     if (LangOpts.OpenMPSimd)
495       OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
496     else
497       OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
498     break;
499   }
500 }
501 
502 void CodeGenModule::createCUDARuntime() {
503   CUDARuntime.reset(CreateNVCUDARuntime(*this));
504 }
505 
506 void CodeGenModule::createHLSLRuntime() {
507   HLSLRuntime.reset(new CGHLSLRuntime(*this));
508 }
509 
510 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
511   Replacements[Name] = C;
512 }
513 
514 void CodeGenModule::applyReplacements() {
515   for (auto &I : Replacements) {
516     StringRef MangledName = I.first;
517     llvm::Constant *Replacement = I.second;
518     llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
519     if (!Entry)
520       continue;
521     auto *OldF = cast<llvm::Function>(Entry);
522     auto *NewF = dyn_cast<llvm::Function>(Replacement);
523     if (!NewF) {
524       if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
525         NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
526       } else {
527         auto *CE = cast<llvm::ConstantExpr>(Replacement);
528         assert(CE->getOpcode() == llvm::Instruction::BitCast ||
529                CE->getOpcode() == llvm::Instruction::GetElementPtr);
530         NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
531       }
532     }
533 
534     // Replace old with new, but keep the old order.
535     OldF->replaceAllUsesWith(Replacement);
536     if (NewF) {
537       NewF->removeFromParent();
538       OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
539                                                        NewF);
540     }
541     OldF->eraseFromParent();
542   }
543 }
544 
545 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
546   GlobalValReplacements.push_back(std::make_pair(GV, C));
547 }
548 
549 void CodeGenModule::applyGlobalValReplacements() {
550   for (auto &I : GlobalValReplacements) {
551     llvm::GlobalValue *GV = I.first;
552     llvm::Constant *C = I.second;
553 
554     GV->replaceAllUsesWith(C);
555     GV->eraseFromParent();
556   }
557 }
558 
559 // This is only used in aliases that we created and we know they have a
560 // linear structure.
561 static const llvm::GlobalValue *getAliasedGlobal(const llvm::GlobalValue *GV) {
562   const llvm::Constant *C;
563   if (auto *GA = dyn_cast<llvm::GlobalAlias>(GV))
564     C = GA->getAliasee();
565   else if (auto *GI = dyn_cast<llvm::GlobalIFunc>(GV))
566     C = GI->getResolver();
567   else
568     return GV;
569 
570   const auto *AliaseeGV = dyn_cast<llvm::GlobalValue>(C->stripPointerCasts());
571   if (!AliaseeGV)
572     return nullptr;
573 
574   const llvm::GlobalValue *FinalGV = AliaseeGV->getAliaseeObject();
575   if (FinalGV == GV)
576     return nullptr;
577 
578   return FinalGV;
579 }
580 
581 static bool checkAliasedGlobal(
582     const ASTContext &Context, DiagnosticsEngine &Diags, SourceLocation Location,
583     bool IsIFunc, const llvm::GlobalValue *Alias, const llvm::GlobalValue *&GV,
584     const llvm::MapVector<GlobalDecl, StringRef> &MangledDeclNames,
585     SourceRange AliasRange) {
586   GV = getAliasedGlobal(Alias);
587   if (!GV) {
588     Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
589     return false;
590   }
591 
592   if (GV->hasCommonLinkage()) {
593     const llvm::Triple &Triple = Context.getTargetInfo().getTriple();
594     if (Triple.getObjectFormat() == llvm::Triple::XCOFF) {
595       Diags.Report(Location, diag::err_alias_to_common);
596       return false;
597     }
598   }
599 
600   if (GV->isDeclaration()) {
601     Diags.Report(Location, diag::err_alias_to_undefined) << IsIFunc << IsIFunc;
602     Diags.Report(Location, diag::note_alias_requires_mangled_name)
603         << IsIFunc << IsIFunc;
604     // Provide a note if the given function is not found and exists as a
605     // mangled name.
606     for (const auto &[Decl, Name] : MangledDeclNames) {
607       if (const auto *ND = dyn_cast<NamedDecl>(Decl.getDecl())) {
608         if (ND->getName() == GV->getName()) {
609           Diags.Report(Location, diag::note_alias_mangled_name_alternative)
610               << Name
611               << FixItHint::CreateReplacement(
612                      AliasRange,
613                      (Twine(IsIFunc ? "ifunc" : "alias") + "(\"" + Name + "\")")
614                          .str());
615         }
616       }
617     }
618     return false;
619   }
620 
621   if (IsIFunc) {
622     // Check resolver function type.
623     const auto *F = dyn_cast<llvm::Function>(GV);
624     if (!F) {
625       Diags.Report(Location, diag::err_alias_to_undefined)
626           << IsIFunc << IsIFunc;
627       return false;
628     }
629 
630     llvm::FunctionType *FTy = F->getFunctionType();
631     if (!FTy->getReturnType()->isPointerTy()) {
632       Diags.Report(Location, diag::err_ifunc_resolver_return);
633       return false;
634     }
635   }
636 
637   return true;
638 }
639 
640 // Emit a warning if toc-data attribute is requested for global variables that
641 // have aliases and remove the toc-data attribute.
642 static void checkAliasForTocData(llvm::GlobalVariable *GVar,
643                                  const CodeGenOptions &CodeGenOpts,
644                                  DiagnosticsEngine &Diags,
645                                  SourceLocation Location) {
646   if (GVar->hasAttribute("toc-data")) {
647     auto GVId = GVar->getName();
648     // Is this a global variable specified by the user as local?
649     if ((llvm::binary_search(CodeGenOpts.TocDataVarsUserSpecified, GVId))) {
650       Diags.Report(Location, diag::warn_toc_unsupported_type)
651           << GVId << "the variable has an alias";
652     }
653     llvm::AttributeSet CurrAttributes = GVar->getAttributes();
654     llvm::AttributeSet NewAttributes =
655         CurrAttributes.removeAttribute(GVar->getContext(), "toc-data");
656     GVar->setAttributes(NewAttributes);
657   }
658 }
659 
660 void CodeGenModule::checkAliases() {
661   // Check if the constructed aliases are well formed. It is really unfortunate
662   // that we have to do this in CodeGen, but we only construct mangled names
663   // and aliases during codegen.
664   bool Error = false;
665   DiagnosticsEngine &Diags = getDiags();
666   for (const GlobalDecl &GD : Aliases) {
667     const auto *D = cast<ValueDecl>(GD.getDecl());
668     SourceLocation Location;
669     SourceRange Range;
670     bool IsIFunc = D->hasAttr<IFuncAttr>();
671     if (const Attr *A = D->getDefiningAttr()) {
672       Location = A->getLocation();
673       Range = A->getRange();
674     } else
675       llvm_unreachable("Not an alias or ifunc?");
676 
677     StringRef MangledName = getMangledName(GD);
678     llvm::GlobalValue *Alias = GetGlobalValue(MangledName);
679     const llvm::GlobalValue *GV = nullptr;
680     if (!checkAliasedGlobal(getContext(), Diags, Location, IsIFunc, Alias, GV,
681                             MangledDeclNames, Range)) {
682       Error = true;
683       continue;
684     }
685 
686     if (getContext().getTargetInfo().getTriple().isOSAIX())
687       if (const llvm::GlobalVariable *GVar =
688               dyn_cast<const llvm::GlobalVariable>(GV))
689         checkAliasForTocData(const_cast<llvm::GlobalVariable *>(GVar),
690                              getCodeGenOpts(), Diags, Location);
691 
692     llvm::Constant *Aliasee =
693         IsIFunc ? cast<llvm::GlobalIFunc>(Alias)->getResolver()
694                 : cast<llvm::GlobalAlias>(Alias)->getAliasee();
695 
696     llvm::GlobalValue *AliaseeGV;
697     if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
698       AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
699     else
700       AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
701 
702     if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
703       StringRef AliasSection = SA->getName();
704       if (AliasSection != AliaseeGV->getSection())
705         Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
706             << AliasSection << IsIFunc << IsIFunc;
707     }
708 
709     // We have to handle alias to weak aliases in here. LLVM itself disallows
710     // this since the object semantics would not match the IL one. For
711     // compatibility with gcc we implement it by just pointing the alias
712     // to its aliasee's aliasee. We also warn, since the user is probably
713     // expecting the link to be weak.
714     if (auto *GA = dyn_cast<llvm::GlobalAlias>(AliaseeGV)) {
715       if (GA->isInterposable()) {
716         Diags.Report(Location, diag::warn_alias_to_weak_alias)
717             << GV->getName() << GA->getName() << IsIFunc;
718         Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
719             GA->getAliasee(), Alias->getType());
720 
721         if (IsIFunc)
722           cast<llvm::GlobalIFunc>(Alias)->setResolver(Aliasee);
723         else
724           cast<llvm::GlobalAlias>(Alias)->setAliasee(Aliasee);
725       }
726     }
727     // ifunc resolvers are usually implemented to run before sanitizer
728     // initialization. Disable instrumentation to prevent the ordering issue.
729     if (IsIFunc)
730       cast<llvm::Function>(Aliasee)->addFnAttr(
731           llvm::Attribute::DisableSanitizerInstrumentation);
732   }
733   if (!Error)
734     return;
735 
736   for (const GlobalDecl &GD : Aliases) {
737     StringRef MangledName = getMangledName(GD);
738     llvm::GlobalValue *Alias = GetGlobalValue(MangledName);
739     Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
740     Alias->eraseFromParent();
741   }
742 }
743 
744 void CodeGenModule::clear() {
745   DeferredDeclsToEmit.clear();
746   EmittedDeferredDecls.clear();
747   DeferredAnnotations.clear();
748   if (OpenMPRuntime)
749     OpenMPRuntime->clear();
750 }
751 
752 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
753                                        StringRef MainFile) {
754   if (!hasDiagnostics())
755     return;
756   if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
757     if (MainFile.empty())
758       MainFile = "<stdin>";
759     Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
760   } else {
761     if (Mismatched > 0)
762       Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
763 
764     if (Missing > 0)
765       Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
766   }
767 }
768 
769 static std::optional<llvm::GlobalValue::VisibilityTypes>
770 getLLVMVisibility(clang::LangOptions::VisibilityFromDLLStorageClassKinds K) {
771   // Map to LLVM visibility.
772   switch (K) {
773   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Keep:
774     return std::nullopt;
775   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Default:
776     return llvm::GlobalValue::DefaultVisibility;
777   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Hidden:
778     return llvm::GlobalValue::HiddenVisibility;
779   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Protected:
780     return llvm::GlobalValue::ProtectedVisibility;
781   }
782   llvm_unreachable("unknown option value!");
783 }
784 
785 void setLLVMVisibility(llvm::GlobalValue &GV,
786                        std::optional<llvm::GlobalValue::VisibilityTypes> V) {
787   if (!V)
788     return;
789 
790   // Reset DSO locality before setting the visibility. This removes
791   // any effects that visibility options and annotations may have
792   // had on the DSO locality. Setting the visibility will implicitly set
793   // appropriate globals to DSO Local; however, this will be pessimistic
794   // w.r.t. to the normal compiler IRGen.
795   GV.setDSOLocal(false);
796   GV.setVisibility(*V);
797 }
798 
799 static void setVisibilityFromDLLStorageClass(const clang::LangOptions &LO,
800                                              llvm::Module &M) {
801   if (!LO.VisibilityFromDLLStorageClass)
802     return;
803 
804   std::optional<llvm::GlobalValue::VisibilityTypes> DLLExportVisibility =
805       getLLVMVisibility(LO.getDLLExportVisibility());
806 
807   std::optional<llvm::GlobalValue::VisibilityTypes>
808       NoDLLStorageClassVisibility =
809           getLLVMVisibility(LO.getNoDLLStorageClassVisibility());
810 
811   std::optional<llvm::GlobalValue::VisibilityTypes>
812       ExternDeclDLLImportVisibility =
813           getLLVMVisibility(LO.getExternDeclDLLImportVisibility());
814 
815   std::optional<llvm::GlobalValue::VisibilityTypes>
816       ExternDeclNoDLLStorageClassVisibility =
817           getLLVMVisibility(LO.getExternDeclNoDLLStorageClassVisibility());
818 
819   for (llvm::GlobalValue &GV : M.global_values()) {
820     if (GV.hasAppendingLinkage() || GV.hasLocalLinkage())
821       continue;
822 
823     if (GV.isDeclarationForLinker())
824       setLLVMVisibility(GV, GV.getDLLStorageClass() ==
825                                     llvm::GlobalValue::DLLImportStorageClass
826                                 ? ExternDeclDLLImportVisibility
827                                 : ExternDeclNoDLLStorageClassVisibility);
828     else
829       setLLVMVisibility(GV, GV.getDLLStorageClass() ==
830                                     llvm::GlobalValue::DLLExportStorageClass
831                                 ? DLLExportVisibility
832                                 : NoDLLStorageClassVisibility);
833 
834     GV.setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
835   }
836 }
837 
838 static bool isStackProtectorOn(const LangOptions &LangOpts,
839                                const llvm::Triple &Triple,
840                                clang::LangOptions::StackProtectorMode Mode) {
841   if (Triple.isAMDGPU() || Triple.isNVPTX())
842     return false;
843   return LangOpts.getStackProtector() == Mode;
844 }
845 
846 void CodeGenModule::Release() {
847   Module *Primary = getContext().getCurrentNamedModule();
848   if (CXX20ModuleInits && Primary && !Primary->isHeaderLikeModule())
849     EmitModuleInitializers(Primary);
850   EmitDeferred();
851   DeferredDecls.insert(EmittedDeferredDecls.begin(),
852                        EmittedDeferredDecls.end());
853   EmittedDeferredDecls.clear();
854   EmitVTablesOpportunistically();
855   applyGlobalValReplacements();
856   applyReplacements();
857   emitMultiVersionFunctions();
858 
859   if (Context.getLangOpts().IncrementalExtensions &&
860       GlobalTopLevelStmtBlockInFlight.first) {
861     const TopLevelStmtDecl *TLSD = GlobalTopLevelStmtBlockInFlight.second;
862     GlobalTopLevelStmtBlockInFlight.first->FinishFunction(TLSD->getEndLoc());
863     GlobalTopLevelStmtBlockInFlight = {nullptr, nullptr};
864   }
865 
866   // Module implementations are initialized the same way as a regular TU that
867   // imports one or more modules.
868   if (CXX20ModuleInits && Primary && Primary->isInterfaceOrPartition())
869     EmitCXXModuleInitFunc(Primary);
870   else
871     EmitCXXGlobalInitFunc();
872   EmitCXXGlobalCleanUpFunc();
873   registerGlobalDtorsWithAtExit();
874   EmitCXXThreadLocalInitFunc();
875   if (ObjCRuntime)
876     if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
877       AddGlobalCtor(ObjCInitFunction);
878   if (Context.getLangOpts().CUDA && CUDARuntime) {
879     if (llvm::Function *CudaCtorFunction = CUDARuntime->finalizeModule())
880       AddGlobalCtor(CudaCtorFunction);
881   }
882   if (OpenMPRuntime) {
883     OpenMPRuntime->createOffloadEntriesAndInfoMetadata();
884     OpenMPRuntime->clear();
885   }
886   if (PGOReader) {
887     getModule().setProfileSummary(
888         PGOReader->getSummary(/* UseCS */ false).getMD(VMContext),
889         llvm::ProfileSummary::PSK_Instr);
890     if (PGOStats.hasDiagnostics())
891       PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
892   }
893   llvm::stable_sort(GlobalCtors, [](const Structor &L, const Structor &R) {
894     return L.LexOrder < R.LexOrder;
895   });
896   EmitCtorList(GlobalCtors, "llvm.global_ctors");
897   EmitCtorList(GlobalDtors, "llvm.global_dtors");
898   EmitGlobalAnnotations();
899   EmitStaticExternCAliases();
900   checkAliases();
901   EmitDeferredUnusedCoverageMappings();
902   CodeGenPGO(*this).setValueProfilingFlag(getModule());
903   CodeGenPGO(*this).setProfileVersion(getModule());
904   if (CoverageMapping)
905     CoverageMapping->emit();
906   if (CodeGenOpts.SanitizeCfiCrossDso) {
907     CodeGenFunction(*this).EmitCfiCheckFail();
908     CodeGenFunction(*this).EmitCfiCheckStub();
909   }
910   if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
911     finalizeKCFITypes();
912   emitAtAvailableLinkGuard();
913   if (Context.getTargetInfo().getTriple().isWasm())
914     EmitMainVoidAlias();
915 
916   if (getTriple().isAMDGPU() ||
917       (getTriple().isSPIRV() && getTriple().getVendor() == llvm::Triple::AMD)) {
918     // Emit amdhsa_code_object_version module flag, which is code object version
919     // times 100.
920     if (getTarget().getTargetOpts().CodeObjectVersion !=
921         llvm::CodeObjectVersionKind::COV_None) {
922       getModule().addModuleFlag(llvm::Module::Error,
923                                 "amdhsa_code_object_version",
924                                 getTarget().getTargetOpts().CodeObjectVersion);
925     }
926 
927     // Currently, "-mprintf-kind" option is only supported for HIP
928     if (LangOpts.HIP) {
929       auto *MDStr = llvm::MDString::get(
930           getLLVMContext(), (getTarget().getTargetOpts().AMDGPUPrintfKindVal ==
931                              TargetOptions::AMDGPUPrintfKind::Hostcall)
932                                 ? "hostcall"
933                                 : "buffered");
934       getModule().addModuleFlag(llvm::Module::Error, "amdgpu_printf_kind",
935                                 MDStr);
936     }
937   }
938 
939   // Emit a global array containing all external kernels or device variables
940   // used by host functions and mark it as used for CUDA/HIP. This is necessary
941   // to get kernels or device variables in archives linked in even if these
942   // kernels or device variables are only used in host functions.
943   if (!Context.CUDAExternalDeviceDeclODRUsedByHost.empty()) {
944     SmallVector<llvm::Constant *, 8> UsedArray;
945     for (auto D : Context.CUDAExternalDeviceDeclODRUsedByHost) {
946       GlobalDecl GD;
947       if (auto *FD = dyn_cast<FunctionDecl>(D))
948         GD = GlobalDecl(FD, KernelReferenceKind::Kernel);
949       else
950         GD = GlobalDecl(D);
951       UsedArray.push_back(llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
952           GetAddrOfGlobal(GD), Int8PtrTy));
953     }
954 
955     llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size());
956 
957     auto *GV = new llvm::GlobalVariable(
958         getModule(), ATy, false, llvm::GlobalValue::InternalLinkage,
959         llvm::ConstantArray::get(ATy, UsedArray), "__clang_gpu_used_external");
960     addCompilerUsedGlobal(GV);
961   }
962   if (LangOpts.HIP && !getLangOpts().OffloadingNewDriver) {
963     // Emit a unique ID so that host and device binaries from the same
964     // compilation unit can be associated.
965     auto *GV = new llvm::GlobalVariable(
966         getModule(), Int8Ty, false, llvm::GlobalValue::ExternalLinkage,
967         llvm::Constant::getNullValue(Int8Ty),
968         "__hip_cuid_" + getContext().getCUIDHash());
969     addCompilerUsedGlobal(GV);
970   }
971   emitLLVMUsed();
972   if (SanStats)
973     SanStats->finish();
974 
975   if (CodeGenOpts.Autolink &&
976       (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
977     EmitModuleLinkOptions();
978   }
979 
980   // On ELF we pass the dependent library specifiers directly to the linker
981   // without manipulating them. This is in contrast to other platforms where
982   // they are mapped to a specific linker option by the compiler. This
983   // difference is a result of the greater variety of ELF linkers and the fact
984   // that ELF linkers tend to handle libraries in a more complicated fashion
985   // than on other platforms. This forces us to defer handling the dependent
986   // libs to the linker.
987   //
988   // CUDA/HIP device and host libraries are different. Currently there is no
989   // way to differentiate dependent libraries for host or device. Existing
990   // usage of #pragma comment(lib, *) is intended for host libraries on
991   // Windows. Therefore emit llvm.dependent-libraries only for host.
992   if (!ELFDependentLibraries.empty() && !Context.getLangOpts().CUDAIsDevice) {
993     auto *NMD = getModule().getOrInsertNamedMetadata("llvm.dependent-libraries");
994     for (auto *MD : ELFDependentLibraries)
995       NMD->addOperand(MD);
996   }
997 
998   if (CodeGenOpts.DwarfVersion) {
999     getModule().addModuleFlag(llvm::Module::Max, "Dwarf Version",
1000                               CodeGenOpts.DwarfVersion);
1001   }
1002 
1003   if (CodeGenOpts.Dwarf64)
1004     getModule().addModuleFlag(llvm::Module::Max, "DWARF64", 1);
1005 
1006   if (Context.getLangOpts().SemanticInterposition)
1007     // Require various optimization to respect semantic interposition.
1008     getModule().setSemanticInterposition(true);
1009 
1010   if (CodeGenOpts.EmitCodeView) {
1011     // Indicate that we want CodeView in the metadata.
1012     getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
1013   }
1014   if (CodeGenOpts.CodeViewGHash) {
1015     getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
1016   }
1017   if (CodeGenOpts.ControlFlowGuard) {
1018     // Function ID tables and checks for Control Flow Guard (cfguard=2).
1019     getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 2);
1020   } else if (CodeGenOpts.ControlFlowGuardNoChecks) {
1021     // Function ID tables for Control Flow Guard (cfguard=1).
1022     getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 1);
1023   }
1024   if (CodeGenOpts.EHContGuard) {
1025     // Function ID tables for EH Continuation Guard.
1026     getModule().addModuleFlag(llvm::Module::Warning, "ehcontguard", 1);
1027   }
1028   if (Context.getLangOpts().Kernel) {
1029     // Note if we are compiling with /kernel.
1030     getModule().addModuleFlag(llvm::Module::Warning, "ms-kernel", 1);
1031   }
1032   if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
1033     // We don't support LTO with 2 with different StrictVTablePointers
1034     // FIXME: we could support it by stripping all the information introduced
1035     // by StrictVTablePointers.
1036 
1037     getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
1038 
1039     llvm::Metadata *Ops[2] = {
1040               llvm::MDString::get(VMContext, "StrictVTablePointers"),
1041               llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1042                   llvm::Type::getInt32Ty(VMContext), 1))};
1043 
1044     getModule().addModuleFlag(llvm::Module::Require,
1045                               "StrictVTablePointersRequirement",
1046                               llvm::MDNode::get(VMContext, Ops));
1047   }
1048   if (getModuleDebugInfo())
1049     // We support a single version in the linked module. The LLVM
1050     // parser will drop debug info with a different version number
1051     // (and warn about it, too).
1052     getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
1053                               llvm::DEBUG_METADATA_VERSION);
1054 
1055   // We need to record the widths of enums and wchar_t, so that we can generate
1056   // the correct build attributes in the ARM backend. wchar_size is also used by
1057   // TargetLibraryInfo.
1058   uint64_t WCharWidth =
1059       Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
1060   getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
1061 
1062   if (getTriple().isOSzOS()) {
1063     getModule().addModuleFlag(llvm::Module::Warning,
1064                               "zos_product_major_version",
1065                               uint32_t(CLANG_VERSION_MAJOR));
1066     getModule().addModuleFlag(llvm::Module::Warning,
1067                               "zos_product_minor_version",
1068                               uint32_t(CLANG_VERSION_MINOR));
1069     getModule().addModuleFlag(llvm::Module::Warning, "zos_product_patchlevel",
1070                               uint32_t(CLANG_VERSION_PATCHLEVEL));
1071     std::string ProductId = getClangVendor() + "clang";
1072     getModule().addModuleFlag(llvm::Module::Error, "zos_product_id",
1073                               llvm::MDString::get(VMContext, ProductId));
1074 
1075     // Record the language because we need it for the PPA2.
1076     StringRef lang_str = languageToString(
1077         LangStandard::getLangStandardForKind(LangOpts.LangStd).Language);
1078     getModule().addModuleFlag(llvm::Module::Error, "zos_cu_language",
1079                               llvm::MDString::get(VMContext, lang_str));
1080 
1081     time_t TT = PreprocessorOpts.SourceDateEpoch
1082                     ? *PreprocessorOpts.SourceDateEpoch
1083                     : std::time(nullptr);
1084     getModule().addModuleFlag(llvm::Module::Max, "zos_translation_time",
1085                               static_cast<uint64_t>(TT));
1086 
1087     // Multiple modes will be supported here.
1088     getModule().addModuleFlag(llvm::Module::Error, "zos_le_char_mode",
1089                               llvm::MDString::get(VMContext, "ascii"));
1090   }
1091 
1092   llvm::Triple T = Context.getTargetInfo().getTriple();
1093   if (T.isARM() || T.isThumb()) {
1094     // The minimum width of an enum in bytes
1095     uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
1096     getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
1097   }
1098 
1099   if (T.isRISCV()) {
1100     StringRef ABIStr = Target.getABI();
1101     llvm::LLVMContext &Ctx = TheModule.getContext();
1102     getModule().addModuleFlag(llvm::Module::Error, "target-abi",
1103                               llvm::MDString::get(Ctx, ABIStr));
1104 
1105     // Add the canonical ISA string as metadata so the backend can set the ELF
1106     // attributes correctly. We use AppendUnique so LTO will keep all of the
1107     // unique ISA strings that were linked together.
1108     const std::vector<std::string> &Features =
1109         getTarget().getTargetOpts().Features;
1110     auto ParseResult =
1111         llvm::RISCVISAInfo::parseFeatures(T.isRISCV64() ? 64 : 32, Features);
1112     if (!errorToBool(ParseResult.takeError()))
1113       getModule().addModuleFlag(
1114           llvm::Module::AppendUnique, "riscv-isa",
1115           llvm::MDNode::get(
1116               Ctx, llvm::MDString::get(Ctx, (*ParseResult)->toString())));
1117   }
1118 
1119   if (CodeGenOpts.SanitizeCfiCrossDso) {
1120     // Indicate that we want cross-DSO control flow integrity checks.
1121     getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
1122   }
1123 
1124   if (CodeGenOpts.WholeProgramVTables) {
1125     // Indicate whether VFE was enabled for this module, so that the
1126     // vcall_visibility metadata added under whole program vtables is handled
1127     // appropriately in the optimizer.
1128     getModule().addModuleFlag(llvm::Module::Error, "Virtual Function Elim",
1129                               CodeGenOpts.VirtualFunctionElimination);
1130   }
1131 
1132   if (LangOpts.Sanitize.has(SanitizerKind::CFIICall)) {
1133     getModule().addModuleFlag(llvm::Module::Override,
1134                               "CFI Canonical Jump Tables",
1135                               CodeGenOpts.SanitizeCfiCanonicalJumpTables);
1136   }
1137 
1138   if (CodeGenOpts.SanitizeCfiICallNormalizeIntegers) {
1139     getModule().addModuleFlag(llvm::Module::Override, "cfi-normalize-integers",
1140                               1);
1141   }
1142 
1143   if (LangOpts.Sanitize.has(SanitizerKind::KCFI)) {
1144     getModule().addModuleFlag(llvm::Module::Override, "kcfi", 1);
1145     // KCFI assumes patchable-function-prefix is the same for all indirectly
1146     // called functions. Store the expected offset for code generation.
1147     if (CodeGenOpts.PatchableFunctionEntryOffset)
1148       getModule().addModuleFlag(llvm::Module::Override, "kcfi-offset",
1149                                 CodeGenOpts.PatchableFunctionEntryOffset);
1150   }
1151 
1152   if (CodeGenOpts.CFProtectionReturn &&
1153       Target.checkCFProtectionReturnSupported(getDiags())) {
1154     // Indicate that we want to instrument return control flow protection.
1155     getModule().addModuleFlag(llvm::Module::Min, "cf-protection-return",
1156                               1);
1157   }
1158 
1159   if (CodeGenOpts.CFProtectionBranch &&
1160       Target.checkCFProtectionBranchSupported(getDiags())) {
1161     // Indicate that we want to instrument branch control flow protection.
1162     getModule().addModuleFlag(llvm::Module::Min, "cf-protection-branch",
1163                               1);
1164   }
1165 
1166   if (CodeGenOpts.FunctionReturnThunks)
1167     getModule().addModuleFlag(llvm::Module::Override, "function_return_thunk_extern", 1);
1168 
1169   if (CodeGenOpts.IndirectBranchCSPrefix)
1170     getModule().addModuleFlag(llvm::Module::Override, "indirect_branch_cs_prefix", 1);
1171 
1172   // Add module metadata for return address signing (ignoring
1173   // non-leaf/all) and stack tagging. These are actually turned on by function
1174   // attributes, but we use module metadata to emit build attributes. This is
1175   // needed for LTO, where the function attributes are inside bitcode
1176   // serialised into a global variable by the time build attributes are
1177   // emitted, so we can't access them. LTO objects could be compiled with
1178   // different flags therefore module flags are set to "Min" behavior to achieve
1179   // the same end result of the normal build where e.g BTI is off if any object
1180   // doesn't support it.
1181   if (Context.getTargetInfo().hasFeature("ptrauth") &&
1182       LangOpts.getSignReturnAddressScope() !=
1183           LangOptions::SignReturnAddressScopeKind::None)
1184     getModule().addModuleFlag(llvm::Module::Override,
1185                               "sign-return-address-buildattr", 1);
1186   if (LangOpts.Sanitize.has(SanitizerKind::MemtagStack))
1187     getModule().addModuleFlag(llvm::Module::Override,
1188                               "tag-stack-memory-buildattr", 1);
1189 
1190   if (T.isARM() || T.isThumb() || T.isAArch64()) {
1191     if (LangOpts.BranchTargetEnforcement)
1192       getModule().addModuleFlag(llvm::Module::Min, "branch-target-enforcement",
1193                                 1);
1194     if (LangOpts.BranchProtectionPAuthLR)
1195       getModule().addModuleFlag(llvm::Module::Min, "branch-protection-pauth-lr",
1196                                 1);
1197     if (LangOpts.GuardedControlStack)
1198       getModule().addModuleFlag(llvm::Module::Min, "guarded-control-stack", 1);
1199     if (LangOpts.hasSignReturnAddress())
1200       getModule().addModuleFlag(llvm::Module::Min, "sign-return-address", 1);
1201     if (LangOpts.isSignReturnAddressScopeAll())
1202       getModule().addModuleFlag(llvm::Module::Min, "sign-return-address-all",
1203                                 1);
1204     if (!LangOpts.isSignReturnAddressWithAKey())
1205       getModule().addModuleFlag(llvm::Module::Min,
1206                                 "sign-return-address-with-bkey", 1);
1207 
1208     if (getTriple().isOSLinux()) {
1209       assert(getTriple().isOSBinFormatELF());
1210       using namespace llvm::ELF;
1211       uint64_t PAuthABIVersion =
1212           (LangOpts.PointerAuthIntrinsics
1213            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_INTRINSICS) |
1214           (LangOpts.PointerAuthCalls
1215            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_CALLS) |
1216           (LangOpts.PointerAuthReturns
1217            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_RETURNS) |
1218           (LangOpts.PointerAuthAuthTraps
1219            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_AUTHTRAPS) |
1220           (LangOpts.PointerAuthVTPtrAddressDiscrimination
1221            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_VPTRADDRDISCR) |
1222           (LangOpts.PointerAuthVTPtrTypeDiscrimination
1223            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_VPTRTYPEDISCR) |
1224           (LangOpts.PointerAuthInitFini
1225            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_INITFINI) |
1226           (LangOpts.PointerAuthInitFiniAddressDiscrimination
1227            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_INITFINIADDRDISC) |
1228           (LangOpts.PointerAuthELFGOT
1229            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_GOT) |
1230           (LangOpts.PointerAuthIndirectGotos
1231            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_GOTOS) |
1232           (LangOpts.PointerAuthTypeInfoVTPtrDiscrimination
1233            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_TYPEINFOVPTRDISCR) |
1234           (LangOpts.PointerAuthFunctionTypeDiscrimination
1235            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_FPTRTYPEDISCR);
1236       static_assert(AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_FPTRTYPEDISCR ==
1237                         AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_LAST,
1238                     "Update when new enum items are defined");
1239       if (PAuthABIVersion != 0) {
1240         getModule().addModuleFlag(llvm::Module::Error,
1241                                   "aarch64-elf-pauthabi-platform",
1242                                   AARCH64_PAUTH_PLATFORM_LLVM_LINUX);
1243         getModule().addModuleFlag(llvm::Module::Error,
1244                                   "aarch64-elf-pauthabi-version",
1245                                   PAuthABIVersion);
1246       }
1247     }
1248   }
1249 
1250   if (CodeGenOpts.StackClashProtector)
1251     getModule().addModuleFlag(
1252         llvm::Module::Override, "probe-stack",
1253         llvm::MDString::get(TheModule.getContext(), "inline-asm"));
1254 
1255   if (CodeGenOpts.StackProbeSize && CodeGenOpts.StackProbeSize != 4096)
1256     getModule().addModuleFlag(llvm::Module::Min, "stack-probe-size",
1257                               CodeGenOpts.StackProbeSize);
1258 
1259   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
1260     llvm::LLVMContext &Ctx = TheModule.getContext();
1261     getModule().addModuleFlag(
1262         llvm::Module::Error, "MemProfProfileFilename",
1263         llvm::MDString::get(Ctx, CodeGenOpts.MemoryProfileOutput));
1264   }
1265 
1266   if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
1267     // Indicate whether __nvvm_reflect should be configured to flush denormal
1268     // floating point values to 0.  (This corresponds to its "__CUDA_FTZ"
1269     // property.)
1270     getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
1271                               CodeGenOpts.FP32DenormalMode.Output !=
1272                                   llvm::DenormalMode::IEEE);
1273   }
1274 
1275   if (LangOpts.EHAsynch)
1276     getModule().addModuleFlag(llvm::Module::Warning, "eh-asynch", 1);
1277 
1278   // Indicate whether this Module was compiled with -fopenmp
1279   if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
1280     getModule().addModuleFlag(llvm::Module::Max, "openmp", LangOpts.OpenMP);
1281   if (getLangOpts().OpenMPIsTargetDevice)
1282     getModule().addModuleFlag(llvm::Module::Max, "openmp-device",
1283                               LangOpts.OpenMP);
1284 
1285   // Emit OpenCL specific module metadata: OpenCL/SPIR version.
1286   if (LangOpts.OpenCL || (LangOpts.CUDAIsDevice && getTriple().isSPIRV())) {
1287     EmitOpenCLMetadata();
1288     // Emit SPIR version.
1289     if (getTriple().isSPIR()) {
1290       // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
1291       // opencl.spir.version named metadata.
1292       // C++ for OpenCL has a distinct mapping for version compatibility with
1293       // OpenCL.
1294       auto Version = LangOpts.getOpenCLCompatibleVersion();
1295       llvm::Metadata *SPIRVerElts[] = {
1296           llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1297               Int32Ty, Version / 100)),
1298           llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1299               Int32Ty, (Version / 100 > 1) ? 0 : 2))};
1300       llvm::NamedMDNode *SPIRVerMD =
1301           TheModule.getOrInsertNamedMetadata("opencl.spir.version");
1302       llvm::LLVMContext &Ctx = TheModule.getContext();
1303       SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
1304     }
1305   }
1306 
1307   // HLSL related end of code gen work items.
1308   if (LangOpts.HLSL)
1309     getHLSLRuntime().finishCodeGen();
1310 
1311   if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
1312     assert(PLevel < 3 && "Invalid PIC Level");
1313     getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
1314     if (Context.getLangOpts().PIE)
1315       getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
1316   }
1317 
1318   if (getCodeGenOpts().CodeModel.size() > 0) {
1319     unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
1320                   .Case("tiny", llvm::CodeModel::Tiny)
1321                   .Case("small", llvm::CodeModel::Small)
1322                   .Case("kernel", llvm::CodeModel::Kernel)
1323                   .Case("medium", llvm::CodeModel::Medium)
1324                   .Case("large", llvm::CodeModel::Large)
1325                   .Default(~0u);
1326     if (CM != ~0u) {
1327       llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
1328       getModule().setCodeModel(codeModel);
1329 
1330       if ((CM == llvm::CodeModel::Medium || CM == llvm::CodeModel::Large) &&
1331           Context.getTargetInfo().getTriple().getArch() ==
1332               llvm::Triple::x86_64) {
1333         getModule().setLargeDataThreshold(getCodeGenOpts().LargeDataThreshold);
1334       }
1335     }
1336   }
1337 
1338   if (CodeGenOpts.NoPLT)
1339     getModule().setRtLibUseGOT();
1340   if (getTriple().isOSBinFormatELF() &&
1341       CodeGenOpts.DirectAccessExternalData !=
1342           getModule().getDirectAccessExternalData()) {
1343     getModule().setDirectAccessExternalData(
1344         CodeGenOpts.DirectAccessExternalData);
1345   }
1346   if (CodeGenOpts.UnwindTables)
1347     getModule().setUwtable(llvm::UWTableKind(CodeGenOpts.UnwindTables));
1348 
1349   switch (CodeGenOpts.getFramePointer()) {
1350   case CodeGenOptions::FramePointerKind::None:
1351     // 0 ("none") is the default.
1352     break;
1353   case CodeGenOptions::FramePointerKind::Reserved:
1354     getModule().setFramePointer(llvm::FramePointerKind::Reserved);
1355     break;
1356   case CodeGenOptions::FramePointerKind::NonLeaf:
1357     getModule().setFramePointer(llvm::FramePointerKind::NonLeaf);
1358     break;
1359   case CodeGenOptions::FramePointerKind::All:
1360     getModule().setFramePointer(llvm::FramePointerKind::All);
1361     break;
1362   }
1363 
1364   SimplifyPersonality();
1365 
1366   if (getCodeGenOpts().EmitDeclMetadata)
1367     EmitDeclMetadata();
1368 
1369   if (getCodeGenOpts().CoverageNotesFile.size() ||
1370       getCodeGenOpts().CoverageDataFile.size())
1371     EmitCoverageFile();
1372 
1373   if (CGDebugInfo *DI = getModuleDebugInfo())
1374     DI->finalize();
1375 
1376   if (getCodeGenOpts().EmitVersionIdentMetadata)
1377     EmitVersionIdentMetadata();
1378 
1379   if (!getCodeGenOpts().RecordCommandLine.empty())
1380     EmitCommandLineMetadata();
1381 
1382   if (!getCodeGenOpts().StackProtectorGuard.empty())
1383     getModule().setStackProtectorGuard(getCodeGenOpts().StackProtectorGuard);
1384   if (!getCodeGenOpts().StackProtectorGuardReg.empty())
1385     getModule().setStackProtectorGuardReg(
1386         getCodeGenOpts().StackProtectorGuardReg);
1387   if (!getCodeGenOpts().StackProtectorGuardSymbol.empty())
1388     getModule().setStackProtectorGuardSymbol(
1389         getCodeGenOpts().StackProtectorGuardSymbol);
1390   if (getCodeGenOpts().StackProtectorGuardOffset != INT_MAX)
1391     getModule().setStackProtectorGuardOffset(
1392         getCodeGenOpts().StackProtectorGuardOffset);
1393   if (getCodeGenOpts().StackAlignment)
1394     getModule().setOverrideStackAlignment(getCodeGenOpts().StackAlignment);
1395   if (getCodeGenOpts().SkipRaxSetup)
1396     getModule().addModuleFlag(llvm::Module::Override, "SkipRaxSetup", 1);
1397   if (getLangOpts().RegCall4)
1398     getModule().addModuleFlag(llvm::Module::Override, "RegCallv4", 1);
1399 
1400   if (getContext().getTargetInfo().getMaxTLSAlign())
1401     getModule().addModuleFlag(llvm::Module::Error, "MaxTLSAlign",
1402                               getContext().getTargetInfo().getMaxTLSAlign());
1403 
1404   getTargetCodeGenInfo().emitTargetGlobals(*this);
1405 
1406   getTargetCodeGenInfo().emitTargetMetadata(*this, MangledDeclNames);
1407 
1408   EmitBackendOptionsMetadata(getCodeGenOpts());
1409 
1410   // If there is device offloading code embed it in the host now.
1411   EmbedObject(&getModule(), CodeGenOpts, getDiags());
1412 
1413   // Set visibility from DLL storage class
1414   // We do this at the end of LLVM IR generation; after any operation
1415   // that might affect the DLL storage class or the visibility, and
1416   // before anything that might act on these.
1417   setVisibilityFromDLLStorageClass(LangOpts, getModule());
1418 
1419   // Check the tail call symbols are truly undefined.
1420   if (getTriple().isPPC() && !MustTailCallUndefinedGlobals.empty()) {
1421     for (auto &I : MustTailCallUndefinedGlobals) {
1422       if (!I.first->isDefined())
1423         getDiags().Report(I.second, diag::err_ppc_impossible_musttail) << 2;
1424       else {
1425         StringRef MangledName = getMangledName(GlobalDecl(I.first));
1426         llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
1427         if (!Entry || Entry->isWeakForLinker() ||
1428             Entry->isDeclarationForLinker())
1429           getDiags().Report(I.second, diag::err_ppc_impossible_musttail) << 2;
1430       }
1431     }
1432   }
1433 }
1434 
1435 void CodeGenModule::EmitOpenCLMetadata() {
1436   // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
1437   // opencl.ocl.version named metadata node.
1438   // C++ for OpenCL has a distinct mapping for versions compatible with OpenCL.
1439   auto CLVersion = LangOpts.getOpenCLCompatibleVersion();
1440 
1441   auto EmitVersion = [this](StringRef MDName, int Version) {
1442     llvm::Metadata *OCLVerElts[] = {
1443         llvm::ConstantAsMetadata::get(
1444             llvm::ConstantInt::get(Int32Ty, Version / 100)),
1445         llvm::ConstantAsMetadata::get(
1446             llvm::ConstantInt::get(Int32Ty, (Version % 100) / 10))};
1447     llvm::NamedMDNode *OCLVerMD = TheModule.getOrInsertNamedMetadata(MDName);
1448     llvm::LLVMContext &Ctx = TheModule.getContext();
1449     OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
1450   };
1451 
1452   EmitVersion("opencl.ocl.version", CLVersion);
1453   if (LangOpts.OpenCLCPlusPlus) {
1454     // In addition to the OpenCL compatible version, emit the C++ version.
1455     EmitVersion("opencl.cxx.version", LangOpts.OpenCLCPlusPlusVersion);
1456   }
1457 }
1458 
1459 void CodeGenModule::EmitBackendOptionsMetadata(
1460     const CodeGenOptions &CodeGenOpts) {
1461   if (getTriple().isRISCV()) {
1462     getModule().addModuleFlag(llvm::Module::Min, "SmallDataLimit",
1463                               CodeGenOpts.SmallDataLimit);
1464   }
1465 }
1466 
1467 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
1468   // Make sure that this type is translated.
1469   getTypes().UpdateCompletedType(TD);
1470 }
1471 
1472 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
1473   // Make sure that this type is translated.
1474   getTypes().RefreshTypeCacheForClass(RD);
1475 }
1476 
1477 llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
1478   if (!TBAA)
1479     return nullptr;
1480   return TBAA->getTypeInfo(QTy);
1481 }
1482 
1483 TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
1484   if (!TBAA)
1485     return TBAAAccessInfo();
1486   if (getLangOpts().CUDAIsDevice) {
1487     // As CUDA builtin surface/texture types are replaced, skip generating TBAA
1488     // access info.
1489     if (AccessType->isCUDADeviceBuiltinSurfaceType()) {
1490       if (getTargetCodeGenInfo().getCUDADeviceBuiltinSurfaceDeviceType() !=
1491           nullptr)
1492         return TBAAAccessInfo();
1493     } else if (AccessType->isCUDADeviceBuiltinTextureType()) {
1494       if (getTargetCodeGenInfo().getCUDADeviceBuiltinTextureDeviceType() !=
1495           nullptr)
1496         return TBAAAccessInfo();
1497     }
1498   }
1499   return TBAA->getAccessInfo(AccessType);
1500 }
1501 
1502 TBAAAccessInfo
1503 CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
1504   if (!TBAA)
1505     return TBAAAccessInfo();
1506   return TBAA->getVTablePtrAccessInfo(VTablePtrType);
1507 }
1508 
1509 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
1510   if (!TBAA)
1511     return nullptr;
1512   return TBAA->getTBAAStructInfo(QTy);
1513 }
1514 
1515 llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
1516   if (!TBAA)
1517     return nullptr;
1518   return TBAA->getBaseTypeInfo(QTy);
1519 }
1520 
1521 llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
1522   if (!TBAA)
1523     return nullptr;
1524   return TBAA->getAccessTagInfo(Info);
1525 }
1526 
1527 TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
1528                                                    TBAAAccessInfo TargetInfo) {
1529   if (!TBAA)
1530     return TBAAAccessInfo();
1531   return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
1532 }
1533 
1534 TBAAAccessInfo
1535 CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
1536                                                    TBAAAccessInfo InfoB) {
1537   if (!TBAA)
1538     return TBAAAccessInfo();
1539   return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
1540 }
1541 
1542 TBAAAccessInfo
1543 CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
1544                                               TBAAAccessInfo SrcInfo) {
1545   if (!TBAA)
1546     return TBAAAccessInfo();
1547   return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
1548 }
1549 
1550 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
1551                                                 TBAAAccessInfo TBAAInfo) {
1552   if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
1553     Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
1554 }
1555 
1556 void CodeGenModule::DecorateInstructionWithInvariantGroup(
1557     llvm::Instruction *I, const CXXRecordDecl *RD) {
1558   I->setMetadata(llvm::LLVMContext::MD_invariant_group,
1559                  llvm::MDNode::get(getLLVMContext(), {}));
1560 }
1561 
1562 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
1563   unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
1564   getDiags().Report(Context.getFullLoc(loc), diagID) << message;
1565 }
1566 
1567 /// ErrorUnsupported - Print out an error that codegen doesn't support the
1568 /// specified stmt yet.
1569 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
1570   unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
1571                                                "cannot compile this %0 yet");
1572   std::string Msg = Type;
1573   getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID)
1574       << Msg << S->getSourceRange();
1575 }
1576 
1577 /// ErrorUnsupported - Print out an error that codegen doesn't support the
1578 /// specified decl yet.
1579 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
1580   unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
1581                                                "cannot compile this %0 yet");
1582   std::string Msg = Type;
1583   getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
1584 }
1585 
1586 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
1587   return llvm::ConstantInt::get(SizeTy, size.getQuantity());
1588 }
1589 
1590 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
1591                                         const NamedDecl *D) const {
1592   // Internal definitions always have default visibility.
1593   if (GV->hasLocalLinkage()) {
1594     GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1595     return;
1596   }
1597   if (!D)
1598     return;
1599 
1600   // Set visibility for definitions, and for declarations if requested globally
1601   // or set explicitly.
1602   LinkageInfo LV = D->getLinkageAndVisibility();
1603 
1604   // OpenMP declare target variables must be visible to the host so they can
1605   // be registered. We require protected visibility unless the variable has
1606   // the DT_nohost modifier and does not need to be registered.
1607   if (Context.getLangOpts().OpenMP &&
1608       Context.getLangOpts().OpenMPIsTargetDevice && isa<VarDecl>(D) &&
1609       D->hasAttr<OMPDeclareTargetDeclAttr>() &&
1610       D->getAttr<OMPDeclareTargetDeclAttr>()->getDevType() !=
1611           OMPDeclareTargetDeclAttr::DT_NoHost &&
1612       LV.getVisibility() == HiddenVisibility) {
1613     GV->setVisibility(llvm::GlobalValue::ProtectedVisibility);
1614     return;
1615   }
1616 
1617   if (GV->hasDLLExportStorageClass() || GV->hasDLLImportStorageClass()) {
1618     // Reject incompatible dlllstorage and visibility annotations.
1619     if (!LV.isVisibilityExplicit())
1620       return;
1621     if (GV->hasDLLExportStorageClass()) {
1622       if (LV.getVisibility() == HiddenVisibility)
1623         getDiags().Report(D->getLocation(),
1624                           diag::err_hidden_visibility_dllexport);
1625     } else if (LV.getVisibility() != DefaultVisibility) {
1626       getDiags().Report(D->getLocation(),
1627                         diag::err_non_default_visibility_dllimport);
1628     }
1629     return;
1630   }
1631 
1632   if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
1633       !GV->isDeclarationForLinker())
1634     GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
1635 }
1636 
1637 static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
1638                                  llvm::GlobalValue *GV) {
1639   if (GV->hasLocalLinkage())
1640     return true;
1641 
1642   if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
1643     return true;
1644 
1645   // DLLImport explicitly marks the GV as external.
1646   if (GV->hasDLLImportStorageClass())
1647     return false;
1648 
1649   const llvm::Triple &TT = CGM.getTriple();
1650   const auto &CGOpts = CGM.getCodeGenOpts();
1651   if (TT.isWindowsGNUEnvironment()) {
1652     // In MinGW, variables without DLLImport can still be automatically
1653     // imported from a DLL by the linker; don't mark variables that
1654     // potentially could come from another DLL as DSO local.
1655 
1656     // With EmulatedTLS, TLS variables can be autoimported from other DLLs
1657     // (and this actually happens in the public interface of libstdc++), so
1658     // such variables can't be marked as DSO local. (Native TLS variables
1659     // can't be dllimported at all, though.)
1660     if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
1661         (!GV->isThreadLocal() || CGM.getCodeGenOpts().EmulatedTLS) &&
1662         CGOpts.AutoImport)
1663       return false;
1664   }
1665 
1666   // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
1667   // remain unresolved in the link, they can be resolved to zero, which is
1668   // outside the current DSO.
1669   if (TT.isOSBinFormatCOFF() && GV->hasExternalWeakLinkage())
1670     return false;
1671 
1672   // Every other GV is local on COFF.
1673   // Make an exception for windows OS in the triple: Some firmware builds use
1674   // *-win32-macho triples. This (accidentally?) produced windows relocations
1675   // without GOT tables in older clang versions; Keep this behaviour.
1676   // FIXME: even thread local variables?
1677   if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
1678     return true;
1679 
1680   // Only handle COFF and ELF for now.
1681   if (!TT.isOSBinFormatELF())
1682     return false;
1683 
1684   // If this is not an executable, don't assume anything is local.
1685   llvm::Reloc::Model RM = CGOpts.RelocationModel;
1686   const auto &LOpts = CGM.getLangOpts();
1687   if (RM != llvm::Reloc::Static && !LOpts.PIE) {
1688     // On ELF, if -fno-semantic-interposition is specified and the target
1689     // supports local aliases, there will be neither CC1
1690     // -fsemantic-interposition nor -fhalf-no-semantic-interposition. Set
1691     // dso_local on the function if using a local alias is preferable (can avoid
1692     // PLT indirection).
1693     if (!(isa<llvm::Function>(GV) && GV->canBenefitFromLocalAlias()))
1694       return false;
1695     return !(CGM.getLangOpts().SemanticInterposition ||
1696              CGM.getLangOpts().HalfNoSemanticInterposition);
1697   }
1698 
1699   // A definition cannot be preempted from an executable.
1700   if (!GV->isDeclarationForLinker())
1701     return true;
1702 
1703   // Most PIC code sequences that assume that a symbol is local cannot produce a
1704   // 0 if it turns out the symbol is undefined. While this is ABI and relocation
1705   // depended, it seems worth it to handle it here.
1706   if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
1707     return false;
1708 
1709   // PowerPC64 prefers TOC indirection to avoid copy relocations.
1710   if (TT.isPPC64())
1711     return false;
1712 
1713   if (CGOpts.DirectAccessExternalData) {
1714     // If -fdirect-access-external-data (default for -fno-pic), set dso_local
1715     // for non-thread-local variables. If the symbol is not defined in the
1716     // executable, a copy relocation will be needed at link time. dso_local is
1717     // excluded for thread-local variables because they generally don't support
1718     // copy relocations.
1719     if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
1720       if (!Var->isThreadLocal())
1721         return true;
1722 
1723     // -fno-pic sets dso_local on a function declaration to allow direct
1724     // accesses when taking its address (similar to a data symbol). If the
1725     // function is not defined in the executable, a canonical PLT entry will be
1726     // needed at link time. -fno-direct-access-external-data can avoid the
1727     // canonical PLT entry. We don't generalize this condition to -fpie/-fpic as
1728     // it could just cause trouble without providing perceptible benefits.
1729     if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
1730       return true;
1731   }
1732 
1733   // If we can use copy relocations we can assume it is local.
1734 
1735   // Otherwise don't assume it is local.
1736   return false;
1737 }
1738 
1739 void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
1740   GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
1741 }
1742 
1743 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1744                                           GlobalDecl GD) const {
1745   const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
1746   // C++ destructors have a few C++ ABI specific special cases.
1747   if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
1748     getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
1749     return;
1750   }
1751   setDLLImportDLLExport(GV, D);
1752 }
1753 
1754 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1755                                           const NamedDecl *D) const {
1756   if (D && D->isExternallyVisible()) {
1757     if (D->hasAttr<DLLImportAttr>())
1758       GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
1759     else if ((D->hasAttr<DLLExportAttr>() ||
1760               shouldMapVisibilityToDLLExport(D)) &&
1761              !GV->isDeclarationForLinker())
1762       GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
1763   }
1764 }
1765 
1766 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1767                                     GlobalDecl GD) const {
1768   setDLLImportDLLExport(GV, GD);
1769   setGVPropertiesAux(GV, dyn_cast<NamedDecl>(GD.getDecl()));
1770 }
1771 
1772 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1773                                     const NamedDecl *D) const {
1774   setDLLImportDLLExport(GV, D);
1775   setGVPropertiesAux(GV, D);
1776 }
1777 
1778 void CodeGenModule::setGVPropertiesAux(llvm::GlobalValue *GV,
1779                                        const NamedDecl *D) const {
1780   setGlobalVisibility(GV, D);
1781   setDSOLocal(GV);
1782   GV->setPartition(CodeGenOpts.SymbolPartition);
1783 }
1784 
1785 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
1786   return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
1787       .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
1788       .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
1789       .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
1790       .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
1791 }
1792 
1793 llvm::GlobalVariable::ThreadLocalMode
1794 CodeGenModule::GetDefaultLLVMTLSModel() const {
1795   switch (CodeGenOpts.getDefaultTLSModel()) {
1796   case CodeGenOptions::GeneralDynamicTLSModel:
1797     return llvm::GlobalVariable::GeneralDynamicTLSModel;
1798   case CodeGenOptions::LocalDynamicTLSModel:
1799     return llvm::GlobalVariable::LocalDynamicTLSModel;
1800   case CodeGenOptions::InitialExecTLSModel:
1801     return llvm::GlobalVariable::InitialExecTLSModel;
1802   case CodeGenOptions::LocalExecTLSModel:
1803     return llvm::GlobalVariable::LocalExecTLSModel;
1804   }
1805   llvm_unreachable("Invalid TLS model!");
1806 }
1807 
1808 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
1809   assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
1810 
1811   llvm::GlobalValue::ThreadLocalMode TLM;
1812   TLM = GetDefaultLLVMTLSModel();
1813 
1814   // Override the TLS model if it is explicitly specified.
1815   if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
1816     TLM = GetLLVMTLSModel(Attr->getModel());
1817   }
1818 
1819   GV->setThreadLocalMode(TLM);
1820 }
1821 
1822 static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
1823                                           StringRef Name) {
1824   const TargetInfo &Target = CGM.getTarget();
1825   return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
1826 }
1827 
1828 static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
1829                                                  const CPUSpecificAttr *Attr,
1830                                                  unsigned CPUIndex,
1831                                                  raw_ostream &Out) {
1832   // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
1833   // supported.
1834   if (Attr)
1835     Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
1836   else if (CGM.getTarget().supportsIFunc())
1837     Out << ".resolver";
1838 }
1839 
1840 // Returns true if GD is a function decl with internal linkage and
1841 // needs a unique suffix after the mangled name.
1842 static bool isUniqueInternalLinkageDecl(GlobalDecl GD,
1843                                         CodeGenModule &CGM) {
1844   const Decl *D = GD.getDecl();
1845   return !CGM.getModuleNameHash().empty() && isa<FunctionDecl>(D) &&
1846          (CGM.getFunctionLinkage(GD) == llvm::GlobalValue::InternalLinkage);
1847 }
1848 
1849 static std::string getMangledNameImpl(CodeGenModule &CGM, GlobalDecl GD,
1850                                       const NamedDecl *ND,
1851                                       bool OmitMultiVersionMangling = false) {
1852   SmallString<256> Buffer;
1853   llvm::raw_svector_ostream Out(Buffer);
1854   MangleContext &MC = CGM.getCXXABI().getMangleContext();
1855   if (!CGM.getModuleNameHash().empty())
1856     MC.needsUniqueInternalLinkageNames();
1857   bool ShouldMangle = MC.shouldMangleDeclName(ND);
1858   if (ShouldMangle)
1859     MC.mangleName(GD.getWithDecl(ND), Out);
1860   else {
1861     IdentifierInfo *II = ND->getIdentifier();
1862     assert(II && "Attempt to mangle unnamed decl.");
1863     const auto *FD = dyn_cast<FunctionDecl>(ND);
1864 
1865     if (FD &&
1866         FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
1867       if (CGM.getLangOpts().RegCall4)
1868         Out << "__regcall4__" << II->getName();
1869       else
1870         Out << "__regcall3__" << II->getName();
1871     } else if (FD && FD->hasAttr<CUDAGlobalAttr>() &&
1872                GD.getKernelReferenceKind() == KernelReferenceKind::Stub) {
1873       Out << "__device_stub__" << II->getName();
1874     } else {
1875       Out << II->getName();
1876     }
1877   }
1878 
1879   // Check if the module name hash should be appended for internal linkage
1880   // symbols.   This should come before multi-version target suffixes are
1881   // appended. This is to keep the name and module hash suffix of the
1882   // internal linkage function together.  The unique suffix should only be
1883   // added when name mangling is done to make sure that the final name can
1884   // be properly demangled.  For example, for C functions without prototypes,
1885   // name mangling is not done and the unique suffix should not be appeneded
1886   // then.
1887   if (ShouldMangle && isUniqueInternalLinkageDecl(GD, CGM)) {
1888     assert(CGM.getCodeGenOpts().UniqueInternalLinkageNames &&
1889            "Hash computed when not explicitly requested");
1890     Out << CGM.getModuleNameHash();
1891   }
1892 
1893   if (const auto *FD = dyn_cast<FunctionDecl>(ND))
1894     if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
1895       switch (FD->getMultiVersionKind()) {
1896       case MultiVersionKind::CPUDispatch:
1897       case MultiVersionKind::CPUSpecific:
1898         AppendCPUSpecificCPUDispatchMangling(CGM,
1899                                              FD->getAttr<CPUSpecificAttr>(),
1900                                              GD.getMultiVersionIndex(), Out);
1901         break;
1902       case MultiVersionKind::Target: {
1903         auto *Attr = FD->getAttr<TargetAttr>();
1904         assert(Attr && "Expected TargetAttr to be present "
1905                        "for attribute mangling");
1906         const ABIInfo &Info = CGM.getTargetCodeGenInfo().getABIInfo();
1907         Info.appendAttributeMangling(Attr, Out);
1908         break;
1909       }
1910       case MultiVersionKind::TargetVersion: {
1911         auto *Attr = FD->getAttr<TargetVersionAttr>();
1912         assert(Attr && "Expected TargetVersionAttr to be present "
1913                        "for attribute mangling");
1914         const ABIInfo &Info = CGM.getTargetCodeGenInfo().getABIInfo();
1915         Info.appendAttributeMangling(Attr, Out);
1916         break;
1917       }
1918       case MultiVersionKind::TargetClones: {
1919         auto *Attr = FD->getAttr<TargetClonesAttr>();
1920         assert(Attr && "Expected TargetClonesAttr to be present "
1921                        "for attribute mangling");
1922         unsigned Index = GD.getMultiVersionIndex();
1923         const ABIInfo &Info = CGM.getTargetCodeGenInfo().getABIInfo();
1924         Info.appendAttributeMangling(Attr, Index, Out);
1925         break;
1926       }
1927       case MultiVersionKind::None:
1928         llvm_unreachable("None multiversion type isn't valid here");
1929       }
1930     }
1931 
1932   // Make unique name for device side static file-scope variable for HIP.
1933   if (CGM.getContext().shouldExternalize(ND) &&
1934       CGM.getLangOpts().GPURelocatableDeviceCode &&
1935       CGM.getLangOpts().CUDAIsDevice)
1936     CGM.printPostfixForExternalizedDecl(Out, ND);
1937 
1938   return std::string(Out.str());
1939 }
1940 
1941 void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
1942                                             const FunctionDecl *FD,
1943                                             StringRef &CurName) {
1944   if (!FD->isMultiVersion())
1945     return;
1946 
1947   // Get the name of what this would be without the 'target' attribute.  This
1948   // allows us to lookup the version that was emitted when this wasn't a
1949   // multiversion function.
1950   std::string NonTargetName =
1951       getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
1952   GlobalDecl OtherGD;
1953   if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
1954     assert(OtherGD.getCanonicalDecl()
1955                .getDecl()
1956                ->getAsFunction()
1957                ->isMultiVersion() &&
1958            "Other GD should now be a multiversioned function");
1959     // OtherFD is the version of this function that was mangled BEFORE
1960     // becoming a MultiVersion function.  It potentially needs to be updated.
1961     const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
1962                                       .getDecl()
1963                                       ->getAsFunction()
1964                                       ->getMostRecentDecl();
1965     std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
1966     // This is so that if the initial version was already the 'default'
1967     // version, we don't try to update it.
1968     if (OtherName != NonTargetName) {
1969       // Remove instead of erase, since others may have stored the StringRef
1970       // to this.
1971       const auto ExistingRecord = Manglings.find(NonTargetName);
1972       if (ExistingRecord != std::end(Manglings))
1973         Manglings.remove(&(*ExistingRecord));
1974       auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
1975       StringRef OtherNameRef = MangledDeclNames[OtherGD.getCanonicalDecl()] =
1976           Result.first->first();
1977       // If this is the current decl is being created, make sure we update the name.
1978       if (GD.getCanonicalDecl() == OtherGD.getCanonicalDecl())
1979         CurName = OtherNameRef;
1980       if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
1981         Entry->setName(OtherName);
1982     }
1983   }
1984 }
1985 
1986 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
1987   GlobalDecl CanonicalGD = GD.getCanonicalDecl();
1988 
1989   // Some ABIs don't have constructor variants.  Make sure that base and
1990   // complete constructors get mangled the same.
1991   if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
1992     if (!getTarget().getCXXABI().hasConstructorVariants()) {
1993       CXXCtorType OrigCtorType = GD.getCtorType();
1994       assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
1995       if (OrigCtorType == Ctor_Base)
1996         CanonicalGD = GlobalDecl(CD, Ctor_Complete);
1997     }
1998   }
1999 
2000   // In CUDA/HIP device compilation with -fgpu-rdc, the mangled name of a
2001   // static device variable depends on whether the variable is referenced by
2002   // a host or device host function. Therefore the mangled name cannot be
2003   // cached.
2004   if (!LangOpts.CUDAIsDevice || !getContext().mayExternalize(GD.getDecl())) {
2005     auto FoundName = MangledDeclNames.find(CanonicalGD);
2006     if (FoundName != MangledDeclNames.end())
2007       return FoundName->second;
2008   }
2009 
2010   // Keep the first result in the case of a mangling collision.
2011   const auto *ND = cast<NamedDecl>(GD.getDecl());
2012   std::string MangledName = getMangledNameImpl(*this, GD, ND);
2013 
2014   // Ensure either we have different ABIs between host and device compilations,
2015   // says host compilation following MSVC ABI but device compilation follows
2016   // Itanium C++ ABI or, if they follow the same ABI, kernel names after
2017   // mangling should be the same after name stubbing. The later checking is
2018   // very important as the device kernel name being mangled in host-compilation
2019   // is used to resolve the device binaries to be executed. Inconsistent naming
2020   // result in undefined behavior. Even though we cannot check that naming
2021   // directly between host- and device-compilations, the host- and
2022   // device-mangling in host compilation could help catching certain ones.
2023   assert(!isa<FunctionDecl>(ND) || !ND->hasAttr<CUDAGlobalAttr>() ||
2024          getContext().shouldExternalize(ND) || getLangOpts().CUDAIsDevice ||
2025          (getContext().getAuxTargetInfo() &&
2026           (getContext().getAuxTargetInfo()->getCXXABI() !=
2027            getContext().getTargetInfo().getCXXABI())) ||
2028          getCUDARuntime().getDeviceSideName(ND) ==
2029              getMangledNameImpl(
2030                  *this,
2031                  GD.getWithKernelReferenceKind(KernelReferenceKind::Kernel),
2032                  ND));
2033 
2034   auto Result = Manglings.insert(std::make_pair(MangledName, GD));
2035   return MangledDeclNames[CanonicalGD] = Result.first->first();
2036 }
2037 
2038 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
2039                                              const BlockDecl *BD) {
2040   MangleContext &MangleCtx = getCXXABI().getMangleContext();
2041   const Decl *D = GD.getDecl();
2042 
2043   SmallString<256> Buffer;
2044   llvm::raw_svector_ostream Out(Buffer);
2045   if (!D)
2046     MangleCtx.mangleGlobalBlock(BD,
2047       dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
2048   else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
2049     MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
2050   else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
2051     MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
2052   else
2053     MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
2054 
2055   auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
2056   return Result.first->first();
2057 }
2058 
2059 const GlobalDecl CodeGenModule::getMangledNameDecl(StringRef Name) {
2060   auto it = MangledDeclNames.begin();
2061   while (it != MangledDeclNames.end()) {
2062     if (it->second == Name)
2063       return it->first;
2064     it++;
2065   }
2066   return GlobalDecl();
2067 }
2068 
2069 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
2070   return getModule().getNamedValue(Name);
2071 }
2072 
2073 /// AddGlobalCtor - Add a function to the list that will be called before
2074 /// main() runs.
2075 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
2076                                   unsigned LexOrder,
2077                                   llvm::Constant *AssociatedData) {
2078   // FIXME: Type coercion of void()* types.
2079   GlobalCtors.push_back(Structor(Priority, LexOrder, Ctor, AssociatedData));
2080 }
2081 
2082 /// AddGlobalDtor - Add a function to the list that will be called
2083 /// when the module is unloaded.
2084 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority,
2085                                   bool IsDtorAttrFunc) {
2086   if (CodeGenOpts.RegisterGlobalDtorsWithAtExit &&
2087       (!getContext().getTargetInfo().getTriple().isOSAIX() || IsDtorAttrFunc)) {
2088     DtorsUsingAtExit[Priority].push_back(Dtor);
2089     return;
2090   }
2091 
2092   // FIXME: Type coercion of void()* types.
2093   GlobalDtors.push_back(Structor(Priority, ~0U, Dtor, nullptr));
2094 }
2095 
2096 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
2097   if (Fns.empty()) return;
2098 
2099   const PointerAuthSchema &InitFiniAuthSchema =
2100       getCodeGenOpts().PointerAuth.InitFiniPointers;
2101 
2102   // Ctor function type is ptr.
2103   llvm::PointerType *PtrTy = llvm::PointerType::get(
2104       getLLVMContext(), TheModule.getDataLayout().getProgramAddressSpace());
2105 
2106   // Get the type of a ctor entry, { i32, ptr, ptr }.
2107   llvm::StructType *CtorStructTy = llvm::StructType::get(Int32Ty, PtrTy, PtrTy);
2108 
2109   // Construct the constructor and destructor arrays.
2110   ConstantInitBuilder Builder(*this);
2111   auto Ctors = Builder.beginArray(CtorStructTy);
2112   for (const auto &I : Fns) {
2113     auto Ctor = Ctors.beginStruct(CtorStructTy);
2114     Ctor.addInt(Int32Ty, I.Priority);
2115     if (InitFiniAuthSchema) {
2116       llvm::Constant *StorageAddress =
2117           (InitFiniAuthSchema.isAddressDiscriminated()
2118                ? llvm::ConstantExpr::getIntToPtr(
2119                      llvm::ConstantInt::get(
2120                          IntPtrTy,
2121                          llvm::ConstantPtrAuth::AddrDiscriminator_CtorsDtors),
2122                      PtrTy)
2123                : nullptr);
2124       llvm::Constant *SignedCtorPtr = getConstantSignedPointer(
2125           I.Initializer, InitFiniAuthSchema.getKey(), StorageAddress,
2126           llvm::ConstantInt::get(
2127               SizeTy, InitFiniAuthSchema.getConstantDiscrimination()));
2128       Ctor.add(SignedCtorPtr);
2129     } else {
2130       Ctor.add(I.Initializer);
2131     }
2132     if (I.AssociatedData)
2133       Ctor.add(I.AssociatedData);
2134     else
2135       Ctor.addNullPointer(PtrTy);
2136     Ctor.finishAndAddTo(Ctors);
2137   }
2138 
2139   auto List = Ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
2140                                           /*constant*/ false,
2141                                           llvm::GlobalValue::AppendingLinkage);
2142 
2143   // The LTO linker doesn't seem to like it when we set an alignment
2144   // on appending variables.  Take it off as a workaround.
2145   List->setAlignment(std::nullopt);
2146 
2147   Fns.clear();
2148 }
2149 
2150 llvm::GlobalValue::LinkageTypes
2151 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
2152   const auto *D = cast<FunctionDecl>(GD.getDecl());
2153 
2154   GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
2155 
2156   if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
2157     return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
2158 
2159   return getLLVMLinkageForDeclarator(D, Linkage);
2160 }
2161 
2162 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
2163   llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
2164   if (!MDS) return nullptr;
2165 
2166   return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
2167 }
2168 
2169 llvm::ConstantInt *CodeGenModule::CreateKCFITypeId(QualType T) {
2170   if (auto *FnType = T->getAs<FunctionProtoType>())
2171     T = getContext().getFunctionType(
2172         FnType->getReturnType(), FnType->getParamTypes(),
2173         FnType->getExtProtoInfo().withExceptionSpec(EST_None));
2174 
2175   std::string OutName;
2176   llvm::raw_string_ostream Out(OutName);
2177   getCXXABI().getMangleContext().mangleCanonicalTypeName(
2178       T, Out, getCodeGenOpts().SanitizeCfiICallNormalizeIntegers);
2179 
2180   if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
2181     Out << ".normalized";
2182 
2183   return llvm::ConstantInt::get(Int32Ty,
2184                                 static_cast<uint32_t>(llvm::xxHash64(OutName)));
2185 }
2186 
2187 void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
2188                                               const CGFunctionInfo &Info,
2189                                               llvm::Function *F, bool IsThunk) {
2190   unsigned CallingConv;
2191   llvm::AttributeList PAL;
2192   ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv,
2193                          /*AttrOnCallSite=*/false, IsThunk);
2194   if (CallingConv == llvm::CallingConv::X86_VectorCall &&
2195       getTarget().getTriple().isWindowsArm64EC()) {
2196     SourceLocation Loc;
2197     if (const Decl *D = GD.getDecl())
2198       Loc = D->getLocation();
2199 
2200     Error(Loc, "__vectorcall calling convention is not currently supported");
2201   }
2202   F->setAttributes(PAL);
2203   F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
2204 }
2205 
2206 static void removeImageAccessQualifier(std::string& TyName) {
2207   std::string ReadOnlyQual("__read_only");
2208   std::string::size_type ReadOnlyPos = TyName.find(ReadOnlyQual);
2209   if (ReadOnlyPos != std::string::npos)
2210     // "+ 1" for the space after access qualifier.
2211     TyName.erase(ReadOnlyPos, ReadOnlyQual.size() + 1);
2212   else {
2213     std::string WriteOnlyQual("__write_only");
2214     std::string::size_type WriteOnlyPos = TyName.find(WriteOnlyQual);
2215     if (WriteOnlyPos != std::string::npos)
2216       TyName.erase(WriteOnlyPos, WriteOnlyQual.size() + 1);
2217     else {
2218       std::string ReadWriteQual("__read_write");
2219       std::string::size_type ReadWritePos = TyName.find(ReadWriteQual);
2220       if (ReadWritePos != std::string::npos)
2221         TyName.erase(ReadWritePos, ReadWriteQual.size() + 1);
2222     }
2223   }
2224 }
2225 
2226 // Returns the address space id that should be produced to the
2227 // kernel_arg_addr_space metadata. This is always fixed to the ids
2228 // as specified in the SPIR 2.0 specification in order to differentiate
2229 // for example in clGetKernelArgInfo() implementation between the address
2230 // spaces with targets without unique mapping to the OpenCL address spaces
2231 // (basically all single AS CPUs).
2232 static unsigned ArgInfoAddressSpace(LangAS AS) {
2233   switch (AS) {
2234   case LangAS::opencl_global:
2235     return 1;
2236   case LangAS::opencl_constant:
2237     return 2;
2238   case LangAS::opencl_local:
2239     return 3;
2240   case LangAS::opencl_generic:
2241     return 4; // Not in SPIR 2.0 specs.
2242   case LangAS::opencl_global_device:
2243     return 5;
2244   case LangAS::opencl_global_host:
2245     return 6;
2246   default:
2247     return 0; // Assume private.
2248   }
2249 }
2250 
2251 void CodeGenModule::GenKernelArgMetadata(llvm::Function *Fn,
2252                                          const FunctionDecl *FD,
2253                                          CodeGenFunction *CGF) {
2254   assert(((FD && CGF) || (!FD && !CGF)) &&
2255          "Incorrect use - FD and CGF should either be both null or not!");
2256   // Create MDNodes that represent the kernel arg metadata.
2257   // Each MDNode is a list in the form of "key", N number of values which is
2258   // the same number of values as their are kernel arguments.
2259 
2260   const PrintingPolicy &Policy = Context.getPrintingPolicy();
2261 
2262   // MDNode for the kernel argument address space qualifiers.
2263   SmallVector<llvm::Metadata *, 8> addressQuals;
2264 
2265   // MDNode for the kernel argument access qualifiers (images only).
2266   SmallVector<llvm::Metadata *, 8> accessQuals;
2267 
2268   // MDNode for the kernel argument type names.
2269   SmallVector<llvm::Metadata *, 8> argTypeNames;
2270 
2271   // MDNode for the kernel argument base type names.
2272   SmallVector<llvm::Metadata *, 8> argBaseTypeNames;
2273 
2274   // MDNode for the kernel argument type qualifiers.
2275   SmallVector<llvm::Metadata *, 8> argTypeQuals;
2276 
2277   // MDNode for the kernel argument names.
2278   SmallVector<llvm::Metadata *, 8> argNames;
2279 
2280   if (FD && CGF)
2281     for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
2282       const ParmVarDecl *parm = FD->getParamDecl(i);
2283       // Get argument name.
2284       argNames.push_back(llvm::MDString::get(VMContext, parm->getName()));
2285 
2286       if (!getLangOpts().OpenCL)
2287         continue;
2288       QualType ty = parm->getType();
2289       std::string typeQuals;
2290 
2291       // Get image and pipe access qualifier:
2292       if (ty->isImageType() || ty->isPipeType()) {
2293         const Decl *PDecl = parm;
2294         if (const auto *TD = ty->getAs<TypedefType>())
2295           PDecl = TD->getDecl();
2296         const OpenCLAccessAttr *A = PDecl->getAttr<OpenCLAccessAttr>();
2297         if (A && A->isWriteOnly())
2298           accessQuals.push_back(llvm::MDString::get(VMContext, "write_only"));
2299         else if (A && A->isReadWrite())
2300           accessQuals.push_back(llvm::MDString::get(VMContext, "read_write"));
2301         else
2302           accessQuals.push_back(llvm::MDString::get(VMContext, "read_only"));
2303       } else
2304         accessQuals.push_back(llvm::MDString::get(VMContext, "none"));
2305 
2306       auto getTypeSpelling = [&](QualType Ty) {
2307         auto typeName = Ty.getUnqualifiedType().getAsString(Policy);
2308 
2309         if (Ty.isCanonical()) {
2310           StringRef typeNameRef = typeName;
2311           // Turn "unsigned type" to "utype"
2312           if (typeNameRef.consume_front("unsigned "))
2313             return std::string("u") + typeNameRef.str();
2314           if (typeNameRef.consume_front("signed "))
2315             return typeNameRef.str();
2316         }
2317 
2318         return typeName;
2319       };
2320 
2321       if (ty->isPointerType()) {
2322         QualType pointeeTy = ty->getPointeeType();
2323 
2324         // Get address qualifier.
2325         addressQuals.push_back(
2326             llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(
2327                 ArgInfoAddressSpace(pointeeTy.getAddressSpace()))));
2328 
2329         // Get argument type name.
2330         std::string typeName = getTypeSpelling(pointeeTy) + "*";
2331         std::string baseTypeName =
2332             getTypeSpelling(pointeeTy.getCanonicalType()) + "*";
2333         argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
2334         argBaseTypeNames.push_back(
2335             llvm::MDString::get(VMContext, baseTypeName));
2336 
2337         // Get argument type qualifiers:
2338         if (ty.isRestrictQualified())
2339           typeQuals = "restrict";
2340         if (pointeeTy.isConstQualified() ||
2341             (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
2342           typeQuals += typeQuals.empty() ? "const" : " const";
2343         if (pointeeTy.isVolatileQualified())
2344           typeQuals += typeQuals.empty() ? "volatile" : " volatile";
2345       } else {
2346         uint32_t AddrSpc = 0;
2347         bool isPipe = ty->isPipeType();
2348         if (ty->isImageType() || isPipe)
2349           AddrSpc = ArgInfoAddressSpace(LangAS::opencl_global);
2350 
2351         addressQuals.push_back(
2352             llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(AddrSpc)));
2353 
2354         // Get argument type name.
2355         ty = isPipe ? ty->castAs<PipeType>()->getElementType() : ty;
2356         std::string typeName = getTypeSpelling(ty);
2357         std::string baseTypeName = getTypeSpelling(ty.getCanonicalType());
2358 
2359         // Remove access qualifiers on images
2360         // (as they are inseparable from type in clang implementation,
2361         // but OpenCL spec provides a special query to get access qualifier
2362         // via clGetKernelArgInfo with CL_KERNEL_ARG_ACCESS_QUALIFIER):
2363         if (ty->isImageType()) {
2364           removeImageAccessQualifier(typeName);
2365           removeImageAccessQualifier(baseTypeName);
2366         }
2367 
2368         argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
2369         argBaseTypeNames.push_back(
2370             llvm::MDString::get(VMContext, baseTypeName));
2371 
2372         if (isPipe)
2373           typeQuals = "pipe";
2374       }
2375       argTypeQuals.push_back(llvm::MDString::get(VMContext, typeQuals));
2376     }
2377 
2378   if (getLangOpts().OpenCL) {
2379     Fn->setMetadata("kernel_arg_addr_space",
2380                     llvm::MDNode::get(VMContext, addressQuals));
2381     Fn->setMetadata("kernel_arg_access_qual",
2382                     llvm::MDNode::get(VMContext, accessQuals));
2383     Fn->setMetadata("kernel_arg_type",
2384                     llvm::MDNode::get(VMContext, argTypeNames));
2385     Fn->setMetadata("kernel_arg_base_type",
2386                     llvm::MDNode::get(VMContext, argBaseTypeNames));
2387     Fn->setMetadata("kernel_arg_type_qual",
2388                     llvm::MDNode::get(VMContext, argTypeQuals));
2389   }
2390   if (getCodeGenOpts().EmitOpenCLArgMetadata ||
2391       getCodeGenOpts().HIPSaveKernelArgName)
2392     Fn->setMetadata("kernel_arg_name",
2393                     llvm::MDNode::get(VMContext, argNames));
2394 }
2395 
2396 /// Determines whether the language options require us to model
2397 /// unwind exceptions.  We treat -fexceptions as mandating this
2398 /// except under the fragile ObjC ABI with only ObjC exceptions
2399 /// enabled.  This means, for example, that C with -fexceptions
2400 /// enables this.
2401 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
2402   // If exceptions are completely disabled, obviously this is false.
2403   if (!LangOpts.Exceptions) return false;
2404 
2405   // If C++ exceptions are enabled, this is true.
2406   if (LangOpts.CXXExceptions) return true;
2407 
2408   // If ObjC exceptions are enabled, this depends on the ABI.
2409   if (LangOpts.ObjCExceptions) {
2410     return LangOpts.ObjCRuntime.hasUnwindExceptions();
2411   }
2412 
2413   return true;
2414 }
2415 
2416 static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM,
2417                                                       const CXXMethodDecl *MD) {
2418   // Check that the type metadata can ever actually be used by a call.
2419   if (!CGM.getCodeGenOpts().LTOUnit ||
2420       !CGM.HasHiddenLTOVisibility(MD->getParent()))
2421     return false;
2422 
2423   // Only functions whose address can be taken with a member function pointer
2424   // need this sort of type metadata.
2425   return MD->isImplicitObjectMemberFunction() && !MD->isVirtual() &&
2426          !isa<CXXConstructorDecl, CXXDestructorDecl>(MD);
2427 }
2428 
2429 SmallVector<const CXXRecordDecl *, 0>
2430 CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
2431   llvm::SetVector<const CXXRecordDecl *> MostBases;
2432 
2433   std::function<void (const CXXRecordDecl *)> CollectMostBases;
2434   CollectMostBases = [&](const CXXRecordDecl *RD) {
2435     if (RD->getNumBases() == 0)
2436       MostBases.insert(RD);
2437     for (const CXXBaseSpecifier &B : RD->bases())
2438       CollectMostBases(B.getType()->getAsCXXRecordDecl());
2439   };
2440   CollectMostBases(RD);
2441   return MostBases.takeVector();
2442 }
2443 
2444 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
2445                                                            llvm::Function *F) {
2446   llvm::AttrBuilder B(F->getContext());
2447 
2448   if ((!D || !D->hasAttr<NoUwtableAttr>()) && CodeGenOpts.UnwindTables)
2449     B.addUWTableAttr(llvm::UWTableKind(CodeGenOpts.UnwindTables));
2450 
2451   if (CodeGenOpts.StackClashProtector)
2452     B.addAttribute("probe-stack", "inline-asm");
2453 
2454   if (CodeGenOpts.StackProbeSize && CodeGenOpts.StackProbeSize != 4096)
2455     B.addAttribute("stack-probe-size",
2456                    std::to_string(CodeGenOpts.StackProbeSize));
2457 
2458   if (!hasUnwindExceptions(LangOpts))
2459     B.addAttribute(llvm::Attribute::NoUnwind);
2460 
2461   if (D && D->hasAttr<NoStackProtectorAttr>())
2462     ; // Do nothing.
2463   else if (D && D->hasAttr<StrictGuardStackCheckAttr>() &&
2464            isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPOn))
2465     B.addAttribute(llvm::Attribute::StackProtectStrong);
2466   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPOn))
2467     B.addAttribute(llvm::Attribute::StackProtect);
2468   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPStrong))
2469     B.addAttribute(llvm::Attribute::StackProtectStrong);
2470   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPReq))
2471     B.addAttribute(llvm::Attribute::StackProtectReq);
2472 
2473   if (!D) {
2474     // If we don't have a declaration to control inlining, the function isn't
2475     // explicitly marked as alwaysinline for semantic reasons, and inlining is
2476     // disabled, mark the function as noinline.
2477     if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
2478         CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
2479       B.addAttribute(llvm::Attribute::NoInline);
2480 
2481     F->addFnAttrs(B);
2482     return;
2483   }
2484 
2485   // Handle SME attributes that apply to function definitions,
2486   // rather than to function prototypes.
2487   if (D->hasAttr<ArmLocallyStreamingAttr>())
2488     B.addAttribute("aarch64_pstate_sm_body");
2489 
2490   if (auto *Attr = D->getAttr<ArmNewAttr>()) {
2491     if (Attr->isNewZA())
2492       B.addAttribute("aarch64_new_za");
2493     if (Attr->isNewZT0())
2494       B.addAttribute("aarch64_new_zt0");
2495   }
2496 
2497   // Track whether we need to add the optnone LLVM attribute,
2498   // starting with the default for this optimization level.
2499   bool ShouldAddOptNone =
2500       !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
2501   // We can't add optnone in the following cases, it won't pass the verifier.
2502   ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
2503   ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
2504 
2505   // Add optnone, but do so only if the function isn't always_inline.
2506   if ((ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) &&
2507       !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2508     B.addAttribute(llvm::Attribute::OptimizeNone);
2509 
2510     // OptimizeNone implies noinline; we should not be inlining such functions.
2511     B.addAttribute(llvm::Attribute::NoInline);
2512 
2513     // We still need to handle naked functions even though optnone subsumes
2514     // much of their semantics.
2515     if (D->hasAttr<NakedAttr>())
2516       B.addAttribute(llvm::Attribute::Naked);
2517 
2518     // OptimizeNone wins over OptimizeForSize and MinSize.
2519     F->removeFnAttr(llvm::Attribute::OptimizeForSize);
2520     F->removeFnAttr(llvm::Attribute::MinSize);
2521   } else if (D->hasAttr<NakedAttr>()) {
2522     // Naked implies noinline: we should not be inlining such functions.
2523     B.addAttribute(llvm::Attribute::Naked);
2524     B.addAttribute(llvm::Attribute::NoInline);
2525   } else if (D->hasAttr<NoDuplicateAttr>()) {
2526     B.addAttribute(llvm::Attribute::NoDuplicate);
2527   } else if (D->hasAttr<NoInlineAttr>() && !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2528     // Add noinline if the function isn't always_inline.
2529     B.addAttribute(llvm::Attribute::NoInline);
2530   } else if (D->hasAttr<AlwaysInlineAttr>() &&
2531              !F->hasFnAttribute(llvm::Attribute::NoInline)) {
2532     // (noinline wins over always_inline, and we can't specify both in IR)
2533     B.addAttribute(llvm::Attribute::AlwaysInline);
2534   } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
2535     // If we're not inlining, then force everything that isn't always_inline to
2536     // carry an explicit noinline attribute.
2537     if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
2538       B.addAttribute(llvm::Attribute::NoInline);
2539   } else {
2540     // Otherwise, propagate the inline hint attribute and potentially use its
2541     // absence to mark things as noinline.
2542     if (auto *FD = dyn_cast<FunctionDecl>(D)) {
2543       // Search function and template pattern redeclarations for inline.
2544       auto CheckForInline = [](const FunctionDecl *FD) {
2545         auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
2546           return Redecl->isInlineSpecified();
2547         };
2548         if (any_of(FD->redecls(), CheckRedeclForInline))
2549           return true;
2550         const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
2551         if (!Pattern)
2552           return false;
2553         return any_of(Pattern->redecls(), CheckRedeclForInline);
2554       };
2555       if (CheckForInline(FD)) {
2556         B.addAttribute(llvm::Attribute::InlineHint);
2557       } else if (CodeGenOpts.getInlining() ==
2558                      CodeGenOptions::OnlyHintInlining &&
2559                  !FD->isInlined() &&
2560                  !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2561         B.addAttribute(llvm::Attribute::NoInline);
2562       }
2563     }
2564   }
2565 
2566   // Add other optimization related attributes if we are optimizing this
2567   // function.
2568   if (!D->hasAttr<OptimizeNoneAttr>()) {
2569     if (D->hasAttr<ColdAttr>()) {
2570       if (!ShouldAddOptNone)
2571         B.addAttribute(llvm::Attribute::OptimizeForSize);
2572       B.addAttribute(llvm::Attribute::Cold);
2573     }
2574     if (D->hasAttr<HotAttr>())
2575       B.addAttribute(llvm::Attribute::Hot);
2576     if (D->hasAttr<MinSizeAttr>())
2577       B.addAttribute(llvm::Attribute::MinSize);
2578   }
2579 
2580   F->addFnAttrs(B);
2581 
2582   unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
2583   if (alignment)
2584     F->setAlignment(llvm::Align(alignment));
2585 
2586   if (!D->hasAttr<AlignedAttr>())
2587     if (LangOpts.FunctionAlignment)
2588       F->setAlignment(llvm::Align(1ull << LangOpts.FunctionAlignment));
2589 
2590   // Some C++ ABIs require 2-byte alignment for member functions, in order to
2591   // reserve a bit for differentiating between virtual and non-virtual member
2592   // functions. If the current target's C++ ABI requires this and this is a
2593   // member function, set its alignment accordingly.
2594   if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
2595     if (isa<CXXMethodDecl>(D) && F->getPointerAlignment(getDataLayout()) < 2)
2596       F->setAlignment(std::max(llvm::Align(2), F->getAlign().valueOrOne()));
2597   }
2598 
2599   // In the cross-dso CFI mode with canonical jump tables, we want !type
2600   // attributes on definitions only.
2601   if (CodeGenOpts.SanitizeCfiCrossDso &&
2602       CodeGenOpts.SanitizeCfiCanonicalJumpTables) {
2603     if (auto *FD = dyn_cast<FunctionDecl>(D)) {
2604       // Skip available_externally functions. They won't be codegen'ed in the
2605       // current module anyway.
2606       if (getContext().GetGVALinkageForFunction(FD) != GVA_AvailableExternally)
2607         CreateFunctionTypeMetadataForIcall(FD, F);
2608     }
2609   }
2610 
2611   // Emit type metadata on member functions for member function pointer checks.
2612   // These are only ever necessary on definitions; we're guaranteed that the
2613   // definition will be present in the LTO unit as a result of LTO visibility.
2614   auto *MD = dyn_cast<CXXMethodDecl>(D);
2615   if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
2616     for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
2617       llvm::Metadata *Id =
2618           CreateMetadataIdentifierForType(Context.getMemberPointerType(
2619               MD->getType(), Context.getRecordType(Base).getTypePtr()));
2620       F->addTypeMetadata(0, Id);
2621     }
2622   }
2623 }
2624 
2625 void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
2626   const Decl *D = GD.getDecl();
2627   if (isa_and_nonnull<NamedDecl>(D))
2628     setGVProperties(GV, GD);
2629   else
2630     GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
2631 
2632   if (D && D->hasAttr<UsedAttr>())
2633     addUsedOrCompilerUsedGlobal(GV);
2634 
2635   if (const auto *VD = dyn_cast_if_present<VarDecl>(D);
2636       VD &&
2637       ((CodeGenOpts.KeepPersistentStorageVariables &&
2638         (VD->getStorageDuration() == SD_Static ||
2639          VD->getStorageDuration() == SD_Thread)) ||
2640        (CodeGenOpts.KeepStaticConsts && VD->getStorageDuration() == SD_Static &&
2641         VD->getType().isConstQualified())))
2642     addUsedOrCompilerUsedGlobal(GV);
2643 }
2644 
2645 bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
2646                                                 llvm::AttrBuilder &Attrs,
2647                                                 bool SetTargetFeatures) {
2648   // Add target-cpu and target-features attributes to functions. If
2649   // we have a decl for the function and it has a target attribute then
2650   // parse that and add it to the feature set.
2651   StringRef TargetCPU = getTarget().getTargetOpts().CPU;
2652   StringRef TuneCPU = getTarget().getTargetOpts().TuneCPU;
2653   std::vector<std::string> Features;
2654   const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
2655   FD = FD ? FD->getMostRecentDecl() : FD;
2656   const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
2657   const auto *TV = FD ? FD->getAttr<TargetVersionAttr>() : nullptr;
2658   assert((!TD || !TV) && "both target_version and target specified");
2659   const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
2660   const auto *TC = FD ? FD->getAttr<TargetClonesAttr>() : nullptr;
2661   bool AddedAttr = false;
2662   if (TD || TV || SD || TC) {
2663     llvm::StringMap<bool> FeatureMap;
2664     getContext().getFunctionFeatureMap(FeatureMap, GD);
2665 
2666     // Produce the canonical string for this set of features.
2667     for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
2668       Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
2669 
2670     // Now add the target-cpu and target-features to the function.
2671     // While we populated the feature map above, we still need to
2672     // get and parse the target attribute so we can get the cpu for
2673     // the function.
2674     if (TD) {
2675       ParsedTargetAttr ParsedAttr =
2676           Target.parseTargetAttr(TD->getFeaturesStr());
2677       if (!ParsedAttr.CPU.empty() &&
2678           getTarget().isValidCPUName(ParsedAttr.CPU)) {
2679         TargetCPU = ParsedAttr.CPU;
2680         TuneCPU = ""; // Clear the tune CPU.
2681       }
2682       if (!ParsedAttr.Tune.empty() &&
2683           getTarget().isValidCPUName(ParsedAttr.Tune))
2684         TuneCPU = ParsedAttr.Tune;
2685     }
2686 
2687     if (SD) {
2688       // Apply the given CPU name as the 'tune-cpu' so that the optimizer can
2689       // favor this processor.
2690       TuneCPU = SD->getCPUName(GD.getMultiVersionIndex())->getName();
2691     }
2692   } else {
2693     // Otherwise just add the existing target cpu and target features to the
2694     // function.
2695     Features = getTarget().getTargetOpts().Features;
2696   }
2697 
2698   if (!TargetCPU.empty()) {
2699     Attrs.addAttribute("target-cpu", TargetCPU);
2700     AddedAttr = true;
2701   }
2702   if (!TuneCPU.empty()) {
2703     Attrs.addAttribute("tune-cpu", TuneCPU);
2704     AddedAttr = true;
2705   }
2706   if (!Features.empty() && SetTargetFeatures) {
2707     llvm::erase_if(Features, [&](const std::string& F) {
2708        return getTarget().isReadOnlyFeature(F.substr(1));
2709     });
2710     llvm::sort(Features);
2711     Attrs.addAttribute("target-features", llvm::join(Features, ","));
2712     AddedAttr = true;
2713   }
2714 
2715   return AddedAttr;
2716 }
2717 
2718 void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
2719                                           llvm::GlobalObject *GO) {
2720   const Decl *D = GD.getDecl();
2721   SetCommonAttributes(GD, GO);
2722 
2723   if (D) {
2724     if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
2725       if (D->hasAttr<RetainAttr>())
2726         addUsedGlobal(GV);
2727       if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
2728         GV->addAttribute("bss-section", SA->getName());
2729       if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
2730         GV->addAttribute("data-section", SA->getName());
2731       if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
2732         GV->addAttribute("rodata-section", SA->getName());
2733       if (auto *SA = D->getAttr<PragmaClangRelroSectionAttr>())
2734         GV->addAttribute("relro-section", SA->getName());
2735     }
2736 
2737     if (auto *F = dyn_cast<llvm::Function>(GO)) {
2738       if (D->hasAttr<RetainAttr>())
2739         addUsedGlobal(F);
2740       if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
2741         if (!D->getAttr<SectionAttr>())
2742           F->setSection(SA->getName());
2743 
2744       llvm::AttrBuilder Attrs(F->getContext());
2745       if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
2746         // We know that GetCPUAndFeaturesAttributes will always have the
2747         // newest set, since it has the newest possible FunctionDecl, so the
2748         // new ones should replace the old.
2749         llvm::AttributeMask RemoveAttrs;
2750         RemoveAttrs.addAttribute("target-cpu");
2751         RemoveAttrs.addAttribute("target-features");
2752         RemoveAttrs.addAttribute("tune-cpu");
2753         F->removeFnAttrs(RemoveAttrs);
2754         F->addFnAttrs(Attrs);
2755       }
2756     }
2757 
2758     if (const auto *CSA = D->getAttr<CodeSegAttr>())
2759       GO->setSection(CSA->getName());
2760     else if (const auto *SA = D->getAttr<SectionAttr>())
2761       GO->setSection(SA->getName());
2762   }
2763 
2764   getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
2765 }
2766 
2767 void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
2768                                                   llvm::Function *F,
2769                                                   const CGFunctionInfo &FI) {
2770   const Decl *D = GD.getDecl();
2771   SetLLVMFunctionAttributes(GD, FI, F, /*IsThunk=*/false);
2772   SetLLVMFunctionAttributesForDefinition(D, F);
2773 
2774   F->setLinkage(llvm::Function::InternalLinkage);
2775 
2776   setNonAliasAttributes(GD, F);
2777 }
2778 
2779 static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
2780   // Set linkage and visibility in case we never see a definition.
2781   LinkageInfo LV = ND->getLinkageAndVisibility();
2782   // Don't set internal linkage on declarations.
2783   // "extern_weak" is overloaded in LLVM; we probably should have
2784   // separate linkage types for this.
2785   if (isExternallyVisible(LV.getLinkage()) &&
2786       (ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
2787     GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2788 }
2789 
2790 void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
2791                                                        llvm::Function *F) {
2792   // Only if we are checking indirect calls.
2793   if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
2794     return;
2795 
2796   // Non-static class methods are handled via vtable or member function pointer
2797   // checks elsewhere.
2798   if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
2799     return;
2800 
2801   llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
2802   F->addTypeMetadata(0, MD);
2803   F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
2804 
2805   // Emit a hash-based bit set entry for cross-DSO calls.
2806   if (CodeGenOpts.SanitizeCfiCrossDso)
2807     if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
2808       F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
2809 }
2810 
2811 void CodeGenModule::setKCFIType(const FunctionDecl *FD, llvm::Function *F) {
2812   llvm::LLVMContext &Ctx = F->getContext();
2813   llvm::MDBuilder MDB(Ctx);
2814   F->setMetadata(llvm::LLVMContext::MD_kcfi_type,
2815                  llvm::MDNode::get(
2816                      Ctx, MDB.createConstant(CreateKCFITypeId(FD->getType()))));
2817 }
2818 
2819 static bool allowKCFIIdentifier(StringRef Name) {
2820   // KCFI type identifier constants are only necessary for external assembly
2821   // functions, which means it's safe to skip unusual names. Subset of
2822   // MCAsmInfo::isAcceptableChar() and MCAsmInfoXCOFF::isAcceptableChar().
2823   return llvm::all_of(Name, [](const char &C) {
2824     return llvm::isAlnum(C) || C == '_' || C == '.';
2825   });
2826 }
2827 
2828 void CodeGenModule::finalizeKCFITypes() {
2829   llvm::Module &M = getModule();
2830   for (auto &F : M.functions()) {
2831     // Remove KCFI type metadata from non-address-taken local functions.
2832     bool AddressTaken = F.hasAddressTaken();
2833     if (!AddressTaken && F.hasLocalLinkage())
2834       F.eraseMetadata(llvm::LLVMContext::MD_kcfi_type);
2835 
2836     // Generate a constant with the expected KCFI type identifier for all
2837     // address-taken function declarations to support annotating indirectly
2838     // called assembly functions.
2839     if (!AddressTaken || !F.isDeclaration())
2840       continue;
2841 
2842     const llvm::ConstantInt *Type;
2843     if (const llvm::MDNode *MD = F.getMetadata(llvm::LLVMContext::MD_kcfi_type))
2844       Type = llvm::mdconst::extract<llvm::ConstantInt>(MD->getOperand(0));
2845     else
2846       continue;
2847 
2848     StringRef Name = F.getName();
2849     if (!allowKCFIIdentifier(Name))
2850       continue;
2851 
2852     std::string Asm = (".weak __kcfi_typeid_" + Name + "\n.set __kcfi_typeid_" +
2853                        Name + ", " + Twine(Type->getZExtValue()) + "\n")
2854                           .str();
2855     M.appendModuleInlineAsm(Asm);
2856   }
2857 }
2858 
2859 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
2860                                           bool IsIncompleteFunction,
2861                                           bool IsThunk) {
2862 
2863   if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) {
2864     // If this is an intrinsic function, set the function's attributes
2865     // to the intrinsic's attributes.
2866     F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID));
2867     return;
2868   }
2869 
2870   const auto *FD = cast<FunctionDecl>(GD.getDecl());
2871 
2872   if (!IsIncompleteFunction)
2873     SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F,
2874                               IsThunk);
2875 
2876   // Add the Returned attribute for "this", except for iOS 5 and earlier
2877   // where substantial code, including the libstdc++ dylib, was compiled with
2878   // GCC and does not actually return "this".
2879   if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
2880       !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
2881     assert(!F->arg_empty() &&
2882            F->arg_begin()->getType()
2883              ->canLosslesslyBitCastTo(F->getReturnType()) &&
2884            "unexpected this return");
2885     F->addParamAttr(0, llvm::Attribute::Returned);
2886   }
2887 
2888   // Only a few attributes are set on declarations; these may later be
2889   // overridden by a definition.
2890 
2891   setLinkageForGV(F, FD);
2892   setGVProperties(F, FD);
2893 
2894   // Setup target-specific attributes.
2895   if (!IsIncompleteFunction && F->isDeclaration())
2896     getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
2897 
2898   if (const auto *CSA = FD->getAttr<CodeSegAttr>())
2899     F->setSection(CSA->getName());
2900   else if (const auto *SA = FD->getAttr<SectionAttr>())
2901      F->setSection(SA->getName());
2902 
2903   if (const auto *EA = FD->getAttr<ErrorAttr>()) {
2904     if (EA->isError())
2905       F->addFnAttr("dontcall-error", EA->getUserDiagnostic());
2906     else if (EA->isWarning())
2907       F->addFnAttr("dontcall-warn", EA->getUserDiagnostic());
2908   }
2909 
2910   // If we plan on emitting this inline builtin, we can't treat it as a builtin.
2911   if (FD->isInlineBuiltinDeclaration()) {
2912     const FunctionDecl *FDBody;
2913     bool HasBody = FD->hasBody(FDBody);
2914     (void)HasBody;
2915     assert(HasBody && "Inline builtin declarations should always have an "
2916                       "available body!");
2917     if (shouldEmitFunction(FDBody))
2918       F->addFnAttr(llvm::Attribute::NoBuiltin);
2919   }
2920 
2921   if (FD->isReplaceableGlobalAllocationFunction()) {
2922     // A replaceable global allocation function does not act like a builtin by
2923     // default, only if it is invoked by a new-expression or delete-expression.
2924     F->addFnAttr(llvm::Attribute::NoBuiltin);
2925   }
2926 
2927   if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
2928     F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2929   else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
2930     if (MD->isVirtual())
2931       F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2932 
2933   // Don't emit entries for function declarations in the cross-DSO mode. This
2934   // is handled with better precision by the receiving DSO. But if jump tables
2935   // are non-canonical then we need type metadata in order to produce the local
2936   // jump table.
2937   if (!CodeGenOpts.SanitizeCfiCrossDso ||
2938       !CodeGenOpts.SanitizeCfiCanonicalJumpTables)
2939     CreateFunctionTypeMetadataForIcall(FD, F);
2940 
2941   if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
2942     setKCFIType(FD, F);
2943 
2944   if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
2945     getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
2946 
2947   if (CodeGenOpts.InlineMaxStackSize != UINT_MAX)
2948     F->addFnAttr("inline-max-stacksize", llvm::utostr(CodeGenOpts.InlineMaxStackSize));
2949 
2950   if (const auto *CB = FD->getAttr<CallbackAttr>()) {
2951     // Annotate the callback behavior as metadata:
2952     //  - The callback callee (as argument number).
2953     //  - The callback payloads (as argument numbers).
2954     llvm::LLVMContext &Ctx = F->getContext();
2955     llvm::MDBuilder MDB(Ctx);
2956 
2957     // The payload indices are all but the first one in the encoding. The first
2958     // identifies the callback callee.
2959     int CalleeIdx = *CB->encoding_begin();
2960     ArrayRef<int> PayloadIndices(CB->encoding_begin() + 1, CB->encoding_end());
2961     F->addMetadata(llvm::LLVMContext::MD_callback,
2962                    *llvm::MDNode::get(Ctx, {MDB.createCallbackEncoding(
2963                                                CalleeIdx, PayloadIndices,
2964                                                /* VarArgsArePassed */ false)}));
2965   }
2966 }
2967 
2968 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
2969   assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
2970          "Only globals with definition can force usage.");
2971   LLVMUsed.emplace_back(GV);
2972 }
2973 
2974 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
2975   assert(!GV->isDeclaration() &&
2976          "Only globals with definition can force usage.");
2977   LLVMCompilerUsed.emplace_back(GV);
2978 }
2979 
2980 void CodeGenModule::addUsedOrCompilerUsedGlobal(llvm::GlobalValue *GV) {
2981   assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
2982          "Only globals with definition can force usage.");
2983   if (getTriple().isOSBinFormatELF())
2984     LLVMCompilerUsed.emplace_back(GV);
2985   else
2986     LLVMUsed.emplace_back(GV);
2987 }
2988 
2989 static void emitUsed(CodeGenModule &CGM, StringRef Name,
2990                      std::vector<llvm::WeakTrackingVH> &List) {
2991   // Don't create llvm.used if there is no need.
2992   if (List.empty())
2993     return;
2994 
2995   // Convert List to what ConstantArray needs.
2996   SmallVector<llvm::Constant*, 8> UsedArray;
2997   UsedArray.resize(List.size());
2998   for (unsigned i = 0, e = List.size(); i != e; ++i) {
2999     UsedArray[i] =
3000         llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
3001             cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
3002   }
3003 
3004   if (UsedArray.empty())
3005     return;
3006   llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
3007 
3008   auto *GV = new llvm::GlobalVariable(
3009       CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
3010       llvm::ConstantArray::get(ATy, UsedArray), Name);
3011 
3012   GV->setSection("llvm.metadata");
3013 }
3014 
3015 void CodeGenModule::emitLLVMUsed() {
3016   emitUsed(*this, "llvm.used", LLVMUsed);
3017   emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
3018 }
3019 
3020 void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
3021   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
3022   LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
3023 }
3024 
3025 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
3026   llvm::SmallString<32> Opt;
3027   getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
3028   if (Opt.empty())
3029     return;
3030   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
3031   LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
3032 }
3033 
3034 void CodeGenModule::AddDependentLib(StringRef Lib) {
3035   auto &C = getLLVMContext();
3036   if (getTarget().getTriple().isOSBinFormatELF()) {
3037       ELFDependentLibraries.push_back(
3038         llvm::MDNode::get(C, llvm::MDString::get(C, Lib)));
3039     return;
3040   }
3041 
3042   llvm::SmallString<24> Opt;
3043   getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
3044   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
3045   LinkerOptionsMetadata.push_back(llvm::MDNode::get(C, MDOpts));
3046 }
3047 
3048 /// Add link options implied by the given module, including modules
3049 /// it depends on, using a postorder walk.
3050 static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
3051                                     SmallVectorImpl<llvm::MDNode *> &Metadata,
3052                                     llvm::SmallPtrSet<Module *, 16> &Visited) {
3053   // Import this module's parent.
3054   if (Mod->Parent && Visited.insert(Mod->Parent).second) {
3055     addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
3056   }
3057 
3058   // Import this module's dependencies.
3059   for (Module *Import : llvm::reverse(Mod->Imports)) {
3060     if (Visited.insert(Import).second)
3061       addLinkOptionsPostorder(CGM, Import, Metadata, Visited);
3062   }
3063 
3064   // Add linker options to link against the libraries/frameworks
3065   // described by this module.
3066   llvm::LLVMContext &Context = CGM.getLLVMContext();
3067   bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
3068 
3069   // For modules that use export_as for linking, use that module
3070   // name instead.
3071   if (Mod->UseExportAsModuleLinkName)
3072     return;
3073 
3074   for (const Module::LinkLibrary &LL : llvm::reverse(Mod->LinkLibraries)) {
3075     // Link against a framework.  Frameworks are currently Darwin only, so we
3076     // don't to ask TargetCodeGenInfo for the spelling of the linker option.
3077     if (LL.IsFramework) {
3078       llvm::Metadata *Args[2] = {llvm::MDString::get(Context, "-framework"),
3079                                  llvm::MDString::get(Context, LL.Library)};
3080 
3081       Metadata.push_back(llvm::MDNode::get(Context, Args));
3082       continue;
3083     }
3084 
3085     // Link against a library.
3086     if (IsELF) {
3087       llvm::Metadata *Args[2] = {
3088           llvm::MDString::get(Context, "lib"),
3089           llvm::MDString::get(Context, LL.Library),
3090       };
3091       Metadata.push_back(llvm::MDNode::get(Context, Args));
3092     } else {
3093       llvm::SmallString<24> Opt;
3094       CGM.getTargetCodeGenInfo().getDependentLibraryOption(LL.Library, Opt);
3095       auto *OptString = llvm::MDString::get(Context, Opt);
3096       Metadata.push_back(llvm::MDNode::get(Context, OptString));
3097     }
3098   }
3099 }
3100 
3101 void CodeGenModule::EmitModuleInitializers(clang::Module *Primary) {
3102   assert(Primary->isNamedModuleUnit() &&
3103          "We should only emit module initializers for named modules.");
3104 
3105   // Emit the initializers in the order that sub-modules appear in the
3106   // source, first Global Module Fragments, if present.
3107   if (auto GMF = Primary->getGlobalModuleFragment()) {
3108     for (Decl *D : getContext().getModuleInitializers(GMF)) {
3109       if (isa<ImportDecl>(D))
3110         continue;
3111       assert(isa<VarDecl>(D) && "GMF initializer decl is not a var?");
3112       EmitTopLevelDecl(D);
3113     }
3114   }
3115   // Second any associated with the module, itself.
3116   for (Decl *D : getContext().getModuleInitializers(Primary)) {
3117     // Skip import decls, the inits for those are called explicitly.
3118     if (isa<ImportDecl>(D))
3119       continue;
3120     EmitTopLevelDecl(D);
3121   }
3122   // Third any associated with the Privat eMOdule Fragment, if present.
3123   if (auto PMF = Primary->getPrivateModuleFragment()) {
3124     for (Decl *D : getContext().getModuleInitializers(PMF)) {
3125       // Skip import decls, the inits for those are called explicitly.
3126       if (isa<ImportDecl>(D))
3127         continue;
3128       assert(isa<VarDecl>(D) && "PMF initializer decl is not a var?");
3129       EmitTopLevelDecl(D);
3130     }
3131   }
3132 }
3133 
3134 void CodeGenModule::EmitModuleLinkOptions() {
3135   // Collect the set of all of the modules we want to visit to emit link
3136   // options, which is essentially the imported modules and all of their
3137   // non-explicit child modules.
3138   llvm::SetVector<clang::Module *> LinkModules;
3139   llvm::SmallPtrSet<clang::Module *, 16> Visited;
3140   SmallVector<clang::Module *, 16> Stack;
3141 
3142   // Seed the stack with imported modules.
3143   for (Module *M : ImportedModules) {
3144     // Do not add any link flags when an implementation TU of a module imports
3145     // a header of that same module.
3146     if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
3147         !getLangOpts().isCompilingModule())
3148       continue;
3149     if (Visited.insert(M).second)
3150       Stack.push_back(M);
3151   }
3152 
3153   // Find all of the modules to import, making a little effort to prune
3154   // non-leaf modules.
3155   while (!Stack.empty()) {
3156     clang::Module *Mod = Stack.pop_back_val();
3157 
3158     bool AnyChildren = false;
3159 
3160     // Visit the submodules of this module.
3161     for (const auto &SM : Mod->submodules()) {
3162       // Skip explicit children; they need to be explicitly imported to be
3163       // linked against.
3164       if (SM->IsExplicit)
3165         continue;
3166 
3167       if (Visited.insert(SM).second) {
3168         Stack.push_back(SM);
3169         AnyChildren = true;
3170       }
3171     }
3172 
3173     // We didn't find any children, so add this module to the list of
3174     // modules to link against.
3175     if (!AnyChildren) {
3176       LinkModules.insert(Mod);
3177     }
3178   }
3179 
3180   // Add link options for all of the imported modules in reverse topological
3181   // order.  We don't do anything to try to order import link flags with respect
3182   // to linker options inserted by things like #pragma comment().
3183   SmallVector<llvm::MDNode *, 16> MetadataArgs;
3184   Visited.clear();
3185   for (Module *M : LinkModules)
3186     if (Visited.insert(M).second)
3187       addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
3188   std::reverse(MetadataArgs.begin(), MetadataArgs.end());
3189   LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
3190 
3191   // Add the linker options metadata flag.
3192   auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
3193   for (auto *MD : LinkerOptionsMetadata)
3194     NMD->addOperand(MD);
3195 }
3196 
3197 void CodeGenModule::EmitDeferred() {
3198   // Emit deferred declare target declarations.
3199   if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
3200     getOpenMPRuntime().emitDeferredTargetDecls();
3201 
3202   // Emit code for any potentially referenced deferred decls.  Since a
3203   // previously unused static decl may become used during the generation of code
3204   // for a static function, iterate until no changes are made.
3205 
3206   if (!DeferredVTables.empty()) {
3207     EmitDeferredVTables();
3208 
3209     // Emitting a vtable doesn't directly cause more vtables to
3210     // become deferred, although it can cause functions to be
3211     // emitted that then need those vtables.
3212     assert(DeferredVTables.empty());
3213   }
3214 
3215   // Emit CUDA/HIP static device variables referenced by host code only.
3216   // Note we should not clear CUDADeviceVarODRUsedByHost since it is still
3217   // needed for further handling.
3218   if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
3219     llvm::append_range(DeferredDeclsToEmit,
3220                        getContext().CUDADeviceVarODRUsedByHost);
3221 
3222   // Stop if we're out of both deferred vtables and deferred declarations.
3223   if (DeferredDeclsToEmit.empty())
3224     return;
3225 
3226   // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
3227   // work, it will not interfere with this.
3228   std::vector<GlobalDecl> CurDeclsToEmit;
3229   CurDeclsToEmit.swap(DeferredDeclsToEmit);
3230 
3231   for (GlobalDecl &D : CurDeclsToEmit) {
3232     // We should call GetAddrOfGlobal with IsForDefinition set to true in order
3233     // to get GlobalValue with exactly the type we need, not something that
3234     // might had been created for another decl with the same mangled name but
3235     // different type.
3236     llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
3237         GetAddrOfGlobal(D, ForDefinition));
3238 
3239     // In case of different address spaces, we may still get a cast, even with
3240     // IsForDefinition equal to true. Query mangled names table to get
3241     // GlobalValue.
3242     if (!GV)
3243       GV = GetGlobalValue(getMangledName(D));
3244 
3245     // Make sure GetGlobalValue returned non-null.
3246     assert(GV);
3247 
3248     // Check to see if we've already emitted this.  This is necessary
3249     // for a couple of reasons: first, decls can end up in the
3250     // deferred-decls queue multiple times, and second, decls can end
3251     // up with definitions in unusual ways (e.g. by an extern inline
3252     // function acquiring a strong function redefinition).  Just
3253     // ignore these cases.
3254     if (!GV->isDeclaration())
3255       continue;
3256 
3257     // If this is OpenMP, check if it is legal to emit this global normally.
3258     if (LangOpts.OpenMP && OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(D))
3259       continue;
3260 
3261     // Otherwise, emit the definition and move on to the next one.
3262     EmitGlobalDefinition(D, GV);
3263 
3264     // If we found out that we need to emit more decls, do that recursively.
3265     // This has the advantage that the decls are emitted in a DFS and related
3266     // ones are close together, which is convenient for testing.
3267     if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
3268       EmitDeferred();
3269       assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
3270     }
3271   }
3272 }
3273 
3274 void CodeGenModule::EmitVTablesOpportunistically() {
3275   // Try to emit external vtables as available_externally if they have emitted
3276   // all inlined virtual functions.  It runs after EmitDeferred() and therefore
3277   // is not allowed to create new references to things that need to be emitted
3278   // lazily. Note that it also uses fact that we eagerly emitting RTTI.
3279 
3280   assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
3281          && "Only emit opportunistic vtables with optimizations");
3282 
3283   for (const CXXRecordDecl *RD : OpportunisticVTables) {
3284     assert(getVTables().isVTableExternal(RD) &&
3285            "This queue should only contain external vtables");
3286     if (getCXXABI().canSpeculativelyEmitVTable(RD))
3287       VTables.GenerateClassData(RD);
3288   }
3289   OpportunisticVTables.clear();
3290 }
3291 
3292 void CodeGenModule::EmitGlobalAnnotations() {
3293   for (const auto& [MangledName, VD] : DeferredAnnotations) {
3294     llvm::GlobalValue *GV = GetGlobalValue(MangledName);
3295     if (GV)
3296       AddGlobalAnnotations(VD, GV);
3297   }
3298   DeferredAnnotations.clear();
3299 
3300   if (Annotations.empty())
3301     return;
3302 
3303   // Create a new global variable for the ConstantStruct in the Module.
3304   llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
3305     Annotations[0]->getType(), Annotations.size()), Annotations);
3306   auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
3307                                       llvm::GlobalValue::AppendingLinkage,
3308                                       Array, "llvm.global.annotations");
3309   gv->setSection(AnnotationSection);
3310 }
3311 
3312 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
3313   llvm::Constant *&AStr = AnnotationStrings[Str];
3314   if (AStr)
3315     return AStr;
3316 
3317   // Not found yet, create a new global.
3318   llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
3319   auto *gv = new llvm::GlobalVariable(
3320       getModule(), s->getType(), true, llvm::GlobalValue::PrivateLinkage, s,
3321       ".str", nullptr, llvm::GlobalValue::NotThreadLocal,
3322       ConstGlobalsPtrTy->getAddressSpace());
3323   gv->setSection(AnnotationSection);
3324   gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3325   AStr = gv;
3326   return gv;
3327 }
3328 
3329 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
3330   SourceManager &SM = getContext().getSourceManager();
3331   PresumedLoc PLoc = SM.getPresumedLoc(Loc);
3332   if (PLoc.isValid())
3333     return EmitAnnotationString(PLoc.getFilename());
3334   return EmitAnnotationString(SM.getBufferName(Loc));
3335 }
3336 
3337 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
3338   SourceManager &SM = getContext().getSourceManager();
3339   PresumedLoc PLoc = SM.getPresumedLoc(L);
3340   unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
3341     SM.getExpansionLineNumber(L);
3342   return llvm::ConstantInt::get(Int32Ty, LineNo);
3343 }
3344 
3345 llvm::Constant *CodeGenModule::EmitAnnotationArgs(const AnnotateAttr *Attr) {
3346   ArrayRef<Expr *> Exprs = {Attr->args_begin(), Attr->args_size()};
3347   if (Exprs.empty())
3348     return llvm::ConstantPointerNull::get(ConstGlobalsPtrTy);
3349 
3350   llvm::FoldingSetNodeID ID;
3351   for (Expr *E : Exprs) {
3352     ID.Add(cast<clang::ConstantExpr>(E)->getAPValueResult());
3353   }
3354   llvm::Constant *&Lookup = AnnotationArgs[ID.ComputeHash()];
3355   if (Lookup)
3356     return Lookup;
3357 
3358   llvm::SmallVector<llvm::Constant *, 4> LLVMArgs;
3359   LLVMArgs.reserve(Exprs.size());
3360   ConstantEmitter ConstEmiter(*this);
3361   llvm::transform(Exprs, std::back_inserter(LLVMArgs), [&](const Expr *E) {
3362     const auto *CE = cast<clang::ConstantExpr>(E);
3363     return ConstEmiter.emitAbstract(CE->getBeginLoc(), CE->getAPValueResult(),
3364                                     CE->getType());
3365   });
3366   auto *Struct = llvm::ConstantStruct::getAnon(LLVMArgs);
3367   auto *GV = new llvm::GlobalVariable(getModule(), Struct->getType(), true,
3368                                       llvm::GlobalValue::PrivateLinkage, Struct,
3369                                       ".args");
3370   GV->setSection(AnnotationSection);
3371   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3372 
3373   Lookup = GV;
3374   return GV;
3375 }
3376 
3377 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
3378                                                 const AnnotateAttr *AA,
3379                                                 SourceLocation L) {
3380   // Get the globals for file name, annotation, and the line number.
3381   llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
3382                  *UnitGV = EmitAnnotationUnit(L),
3383                  *LineNoCst = EmitAnnotationLineNo(L),
3384                  *Args = EmitAnnotationArgs(AA);
3385 
3386   llvm::Constant *GVInGlobalsAS = GV;
3387   if (GV->getAddressSpace() !=
3388       getDataLayout().getDefaultGlobalsAddressSpace()) {
3389     GVInGlobalsAS = llvm::ConstantExpr::getAddrSpaceCast(
3390         GV,
3391         llvm::PointerType::get(
3392             GV->getContext(), getDataLayout().getDefaultGlobalsAddressSpace()));
3393   }
3394 
3395   // Create the ConstantStruct for the global annotation.
3396   llvm::Constant *Fields[] = {
3397       GVInGlobalsAS, AnnoGV, UnitGV, LineNoCst, Args,
3398   };
3399   return llvm::ConstantStruct::getAnon(Fields);
3400 }
3401 
3402 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
3403                                          llvm::GlobalValue *GV) {
3404   assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
3405   // Get the struct elements for these annotations.
3406   for (const auto *I : D->specific_attrs<AnnotateAttr>())
3407     Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
3408 }
3409 
3410 bool CodeGenModule::isInNoSanitizeList(SanitizerMask Kind, llvm::Function *Fn,
3411                                        SourceLocation Loc) const {
3412   const auto &NoSanitizeL = getContext().getNoSanitizeList();
3413   // NoSanitize by function name.
3414   if (NoSanitizeL.containsFunction(Kind, Fn->getName()))
3415     return true;
3416   // NoSanitize by location. Check "mainfile" prefix.
3417   auto &SM = Context.getSourceManager();
3418   FileEntryRef MainFile = *SM.getFileEntryRefForID(SM.getMainFileID());
3419   if (NoSanitizeL.containsMainFile(Kind, MainFile.getName()))
3420     return true;
3421 
3422   // Check "src" prefix.
3423   if (Loc.isValid())
3424     return NoSanitizeL.containsLocation(Kind, Loc);
3425   // If location is unknown, this may be a compiler-generated function. Assume
3426   // it's located in the main file.
3427   return NoSanitizeL.containsFile(Kind, MainFile.getName());
3428 }
3429 
3430 bool CodeGenModule::isInNoSanitizeList(SanitizerMask Kind,
3431                                        llvm::GlobalVariable *GV,
3432                                        SourceLocation Loc, QualType Ty,
3433                                        StringRef Category) const {
3434   const auto &NoSanitizeL = getContext().getNoSanitizeList();
3435   if (NoSanitizeL.containsGlobal(Kind, GV->getName(), Category))
3436     return true;
3437   auto &SM = Context.getSourceManager();
3438   if (NoSanitizeL.containsMainFile(
3439           Kind, SM.getFileEntryRefForID(SM.getMainFileID())->getName(),
3440           Category))
3441     return true;
3442   if (NoSanitizeL.containsLocation(Kind, Loc, Category))
3443     return true;
3444 
3445   // Check global type.
3446   if (!Ty.isNull()) {
3447     // Drill down the array types: if global variable of a fixed type is
3448     // not sanitized, we also don't instrument arrays of them.
3449     while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
3450       Ty = AT->getElementType();
3451     Ty = Ty.getCanonicalType().getUnqualifiedType();
3452     // Only record types (classes, structs etc.) are ignored.
3453     if (Ty->isRecordType()) {
3454       std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
3455       if (NoSanitizeL.containsType(Kind, TypeStr, Category))
3456         return true;
3457     }
3458   }
3459   return false;
3460 }
3461 
3462 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
3463                                    StringRef Category) const {
3464   const auto &XRayFilter = getContext().getXRayFilter();
3465   using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
3466   auto Attr = ImbueAttr::NONE;
3467   if (Loc.isValid())
3468     Attr = XRayFilter.shouldImbueLocation(Loc, Category);
3469   if (Attr == ImbueAttr::NONE)
3470     Attr = XRayFilter.shouldImbueFunction(Fn->getName());
3471   switch (Attr) {
3472   case ImbueAttr::NONE:
3473     return false;
3474   case ImbueAttr::ALWAYS:
3475     Fn->addFnAttr("function-instrument", "xray-always");
3476     break;
3477   case ImbueAttr::ALWAYS_ARG1:
3478     Fn->addFnAttr("function-instrument", "xray-always");
3479     Fn->addFnAttr("xray-log-args", "1");
3480     break;
3481   case ImbueAttr::NEVER:
3482     Fn->addFnAttr("function-instrument", "xray-never");
3483     break;
3484   }
3485   return true;
3486 }
3487 
3488 ProfileList::ExclusionType
3489 CodeGenModule::isFunctionBlockedByProfileList(llvm::Function *Fn,
3490                                               SourceLocation Loc) const {
3491   const auto &ProfileList = getContext().getProfileList();
3492   // If the profile list is empty, then instrument everything.
3493   if (ProfileList.isEmpty())
3494     return ProfileList::Allow;
3495   CodeGenOptions::ProfileInstrKind Kind = getCodeGenOpts().getProfileInstr();
3496   // First, check the function name.
3497   if (auto V = ProfileList.isFunctionExcluded(Fn->getName(), Kind))
3498     return *V;
3499   // Next, check the source location.
3500   if (Loc.isValid())
3501     if (auto V = ProfileList.isLocationExcluded(Loc, Kind))
3502       return *V;
3503   // If location is unknown, this may be a compiler-generated function. Assume
3504   // it's located in the main file.
3505   auto &SM = Context.getSourceManager();
3506   if (auto MainFile = SM.getFileEntryRefForID(SM.getMainFileID()))
3507     if (auto V = ProfileList.isFileExcluded(MainFile->getName(), Kind))
3508       return *V;
3509   return ProfileList.getDefault(Kind);
3510 }
3511 
3512 ProfileList::ExclusionType
3513 CodeGenModule::isFunctionBlockedFromProfileInstr(llvm::Function *Fn,
3514                                                  SourceLocation Loc) const {
3515   auto V = isFunctionBlockedByProfileList(Fn, Loc);
3516   if (V != ProfileList::Allow)
3517     return V;
3518 
3519   auto NumGroups = getCodeGenOpts().ProfileTotalFunctionGroups;
3520   if (NumGroups > 1) {
3521     auto Group = llvm::crc32(arrayRefFromStringRef(Fn->getName())) % NumGroups;
3522     if (Group != getCodeGenOpts().ProfileSelectedFunctionGroup)
3523       return ProfileList::Skip;
3524   }
3525   return ProfileList::Allow;
3526 }
3527 
3528 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
3529   // Never defer when EmitAllDecls is specified.
3530   if (LangOpts.EmitAllDecls)
3531     return true;
3532 
3533   const auto *VD = dyn_cast<VarDecl>(Global);
3534   if (VD &&
3535       ((CodeGenOpts.KeepPersistentStorageVariables &&
3536         (VD->getStorageDuration() == SD_Static ||
3537          VD->getStorageDuration() == SD_Thread)) ||
3538        (CodeGenOpts.KeepStaticConsts && VD->getStorageDuration() == SD_Static &&
3539         VD->getType().isConstQualified())))
3540     return true;
3541 
3542   return getContext().DeclMustBeEmitted(Global);
3543 }
3544 
3545 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
3546   // In OpenMP 5.0 variables and function may be marked as
3547   // device_type(host/nohost) and we should not emit them eagerly unless we sure
3548   // that they must be emitted on the host/device. To be sure we need to have
3549   // seen a declare target with an explicit mentioning of the function, we know
3550   // we have if the level of the declare target attribute is -1. Note that we
3551   // check somewhere else if we should emit this at all.
3552   if (LangOpts.OpenMP >= 50 && !LangOpts.OpenMPSimd) {
3553     std::optional<OMPDeclareTargetDeclAttr *> ActiveAttr =
3554         OMPDeclareTargetDeclAttr::getActiveAttr(Global);
3555     if (!ActiveAttr || (*ActiveAttr)->getLevel() != (unsigned)-1)
3556       return false;
3557   }
3558 
3559   if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
3560     if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
3561       // Implicit template instantiations may change linkage if they are later
3562       // explicitly instantiated, so they should not be emitted eagerly.
3563       return false;
3564     // Defer until all versions have been semantically checked.
3565     if (FD->hasAttr<TargetVersionAttr>() && !FD->isMultiVersion())
3566       return false;
3567   }
3568   if (const auto *VD = dyn_cast<VarDecl>(Global)) {
3569     if (Context.getInlineVariableDefinitionKind(VD) ==
3570         ASTContext::InlineVariableDefinitionKind::WeakUnknown)
3571       // A definition of an inline constexpr static data member may change
3572       // linkage later if it's redeclared outside the class.
3573       return false;
3574     if (CXX20ModuleInits && VD->getOwningModule() &&
3575         !VD->getOwningModule()->isModuleMapModule()) {
3576       // For CXX20, module-owned initializers need to be deferred, since it is
3577       // not known at this point if they will be run for the current module or
3578       // as part of the initializer for an imported one.
3579       return false;
3580     }
3581   }
3582   // If OpenMP is enabled and threadprivates must be generated like TLS, delay
3583   // codegen for global variables, because they may be marked as threadprivate.
3584   if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
3585       getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
3586       !Global->getType().isConstantStorage(getContext(), false, false) &&
3587       !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
3588     return false;
3589 
3590   return true;
3591 }
3592 
3593 ConstantAddress CodeGenModule::GetAddrOfMSGuidDecl(const MSGuidDecl *GD) {
3594   StringRef Name = getMangledName(GD);
3595 
3596   // The UUID descriptor should be pointer aligned.
3597   CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
3598 
3599   // Look for an existing global.
3600   if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
3601     return ConstantAddress(GV, GV->getValueType(), Alignment);
3602 
3603   ConstantEmitter Emitter(*this);
3604   llvm::Constant *Init;
3605 
3606   APValue &V = GD->getAsAPValue();
3607   if (!V.isAbsent()) {
3608     // If possible, emit the APValue version of the initializer. In particular,
3609     // this gets the type of the constant right.
3610     Init = Emitter.emitForInitializer(
3611         GD->getAsAPValue(), GD->getType().getAddressSpace(), GD->getType());
3612   } else {
3613     // As a fallback, directly construct the constant.
3614     // FIXME: This may get padding wrong under esoteric struct layout rules.
3615     // MSVC appears to create a complete type 'struct __s_GUID' that it
3616     // presumably uses to represent these constants.
3617     MSGuidDecl::Parts Parts = GD->getParts();
3618     llvm::Constant *Fields[4] = {
3619         llvm::ConstantInt::get(Int32Ty, Parts.Part1),
3620         llvm::ConstantInt::get(Int16Ty, Parts.Part2),
3621         llvm::ConstantInt::get(Int16Ty, Parts.Part3),
3622         llvm::ConstantDataArray::getRaw(
3623             StringRef(reinterpret_cast<char *>(Parts.Part4And5), 8), 8,
3624             Int8Ty)};
3625     Init = llvm::ConstantStruct::getAnon(Fields);
3626   }
3627 
3628   auto *GV = new llvm::GlobalVariable(
3629       getModule(), Init->getType(),
3630       /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
3631   if (supportsCOMDAT())
3632     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3633   setDSOLocal(GV);
3634 
3635   if (!V.isAbsent()) {
3636     Emitter.finalize(GV);
3637     return ConstantAddress(GV, GV->getValueType(), Alignment);
3638   }
3639 
3640   llvm::Type *Ty = getTypes().ConvertTypeForMem(GD->getType());
3641   return ConstantAddress(GV, Ty, Alignment);
3642 }
3643 
3644 ConstantAddress CodeGenModule::GetAddrOfUnnamedGlobalConstantDecl(
3645     const UnnamedGlobalConstantDecl *GCD) {
3646   CharUnits Alignment = getContext().getTypeAlignInChars(GCD->getType());
3647 
3648   llvm::GlobalVariable **Entry = nullptr;
3649   Entry = &UnnamedGlobalConstantDeclMap[GCD];
3650   if (*Entry)
3651     return ConstantAddress(*Entry, (*Entry)->getValueType(), Alignment);
3652 
3653   ConstantEmitter Emitter(*this);
3654   llvm::Constant *Init;
3655 
3656   const APValue &V = GCD->getValue();
3657 
3658   assert(!V.isAbsent());
3659   Init = Emitter.emitForInitializer(V, GCD->getType().getAddressSpace(),
3660                                     GCD->getType());
3661 
3662   auto *GV = new llvm::GlobalVariable(getModule(), Init->getType(),
3663                                       /*isConstant=*/true,
3664                                       llvm::GlobalValue::PrivateLinkage, Init,
3665                                       ".constant");
3666   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3667   GV->setAlignment(Alignment.getAsAlign());
3668 
3669   Emitter.finalize(GV);
3670 
3671   *Entry = GV;
3672   return ConstantAddress(GV, GV->getValueType(), Alignment);
3673 }
3674 
3675 ConstantAddress CodeGenModule::GetAddrOfTemplateParamObject(
3676     const TemplateParamObjectDecl *TPO) {
3677   StringRef Name = getMangledName(TPO);
3678   CharUnits Alignment = getNaturalTypeAlignment(TPO->getType());
3679 
3680   if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
3681     return ConstantAddress(GV, GV->getValueType(), Alignment);
3682 
3683   ConstantEmitter Emitter(*this);
3684   llvm::Constant *Init = Emitter.emitForInitializer(
3685         TPO->getValue(), TPO->getType().getAddressSpace(), TPO->getType());
3686 
3687   if (!Init) {
3688     ErrorUnsupported(TPO, "template parameter object");
3689     return ConstantAddress::invalid();
3690   }
3691 
3692   llvm::GlobalValue::LinkageTypes Linkage =
3693       isExternallyVisible(TPO->getLinkageAndVisibility().getLinkage())
3694           ? llvm::GlobalValue::LinkOnceODRLinkage
3695           : llvm::GlobalValue::InternalLinkage;
3696   auto *GV = new llvm::GlobalVariable(getModule(), Init->getType(),
3697                                       /*isConstant=*/true, Linkage, Init, Name);
3698   setGVProperties(GV, TPO);
3699   if (supportsCOMDAT())
3700     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3701   Emitter.finalize(GV);
3702 
3703     return ConstantAddress(GV, GV->getValueType(), Alignment);
3704 }
3705 
3706 ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
3707   const AliasAttr *AA = VD->getAttr<AliasAttr>();
3708   assert(AA && "No alias?");
3709 
3710   CharUnits Alignment = getContext().getDeclAlign(VD);
3711   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
3712 
3713   // See if there is already something with the target's name in the module.
3714   llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
3715   if (Entry)
3716     return ConstantAddress(Entry, DeclTy, Alignment);
3717 
3718   llvm::Constant *Aliasee;
3719   if (isa<llvm::FunctionType>(DeclTy))
3720     Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
3721                                       GlobalDecl(cast<FunctionDecl>(VD)),
3722                                       /*ForVTable=*/false);
3723   else
3724     Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, LangAS::Default,
3725                                     nullptr);
3726 
3727   auto *F = cast<llvm::GlobalValue>(Aliasee);
3728   F->setLinkage(llvm::Function::ExternalWeakLinkage);
3729   WeakRefReferences.insert(F);
3730 
3731   return ConstantAddress(Aliasee, DeclTy, Alignment);
3732 }
3733 
3734 template <typename AttrT> static bool hasImplicitAttr(const ValueDecl *D) {
3735   if (!D)
3736     return false;
3737   if (auto *A = D->getAttr<AttrT>())
3738     return A->isImplicit();
3739   return D->isImplicit();
3740 }
3741 
3742 bool CodeGenModule::shouldEmitCUDAGlobalVar(const VarDecl *Global) const {
3743   assert(LangOpts.CUDA && "Should not be called by non-CUDA languages");
3744   // We need to emit host-side 'shadows' for all global
3745   // device-side variables because the CUDA runtime needs their
3746   // size and host-side address in order to provide access to
3747   // their device-side incarnations.
3748   return !LangOpts.CUDAIsDevice || Global->hasAttr<CUDADeviceAttr>() ||
3749          Global->hasAttr<CUDAConstantAttr>() ||
3750          Global->hasAttr<CUDASharedAttr>() ||
3751          Global->getType()->isCUDADeviceBuiltinSurfaceType() ||
3752          Global->getType()->isCUDADeviceBuiltinTextureType();
3753 }
3754 
3755 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
3756   const auto *Global = cast<ValueDecl>(GD.getDecl());
3757 
3758   // Weak references don't produce any output by themselves.
3759   if (Global->hasAttr<WeakRefAttr>())
3760     return;
3761 
3762   // If this is an alias definition (which otherwise looks like a declaration)
3763   // emit it now.
3764   if (Global->hasAttr<AliasAttr>())
3765     return EmitAliasDefinition(GD);
3766 
3767   // IFunc like an alias whose value is resolved at runtime by calling resolver.
3768   if (Global->hasAttr<IFuncAttr>())
3769     return emitIFuncDefinition(GD);
3770 
3771   // If this is a cpu_dispatch multiversion function, emit the resolver.
3772   if (Global->hasAttr<CPUDispatchAttr>())
3773     return emitCPUDispatchDefinition(GD);
3774 
3775   // If this is CUDA, be selective about which declarations we emit.
3776   // Non-constexpr non-lambda implicit host device functions are not emitted
3777   // unless they are used on device side.
3778   if (LangOpts.CUDA) {
3779     assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
3780            "Expected Variable or Function");
3781     if (const auto *VD = dyn_cast<VarDecl>(Global)) {
3782       if (!shouldEmitCUDAGlobalVar(VD))
3783         return;
3784     } else if (LangOpts.CUDAIsDevice) {
3785       const auto *FD = dyn_cast<FunctionDecl>(Global);
3786       if ((!Global->hasAttr<CUDADeviceAttr>() ||
3787            (LangOpts.OffloadImplicitHostDeviceTemplates &&
3788             hasImplicitAttr<CUDAHostAttr>(FD) &&
3789             hasImplicitAttr<CUDADeviceAttr>(FD) && !FD->isConstexpr() &&
3790             !isLambdaCallOperator(FD) &&
3791             !getContext().CUDAImplicitHostDeviceFunUsedByDevice.count(FD))) &&
3792           !Global->hasAttr<CUDAGlobalAttr>() &&
3793           !(LangOpts.HIPStdPar && isa<FunctionDecl>(Global) &&
3794             !Global->hasAttr<CUDAHostAttr>()))
3795         return;
3796       // Device-only functions are the only things we skip.
3797     } else if (!Global->hasAttr<CUDAHostAttr>() &&
3798                Global->hasAttr<CUDADeviceAttr>())
3799       return;
3800   }
3801 
3802   if (LangOpts.OpenMP) {
3803     // If this is OpenMP, check if it is legal to emit this global normally.
3804     if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
3805       return;
3806     if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
3807       if (MustBeEmitted(Global))
3808         EmitOMPDeclareReduction(DRD);
3809       return;
3810     }
3811     if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) {
3812       if (MustBeEmitted(Global))
3813         EmitOMPDeclareMapper(DMD);
3814       return;
3815     }
3816   }
3817 
3818   // Ignore declarations, they will be emitted on their first use.
3819   if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
3820     // Update deferred annotations with the latest declaration if the function
3821     // function was already used or defined.
3822     if (FD->hasAttr<AnnotateAttr>()) {
3823       StringRef MangledName = getMangledName(GD);
3824       if (GetGlobalValue(MangledName))
3825         DeferredAnnotations[MangledName] = FD;
3826     }
3827 
3828     // Forward declarations are emitted lazily on first use.
3829     if (!FD->doesThisDeclarationHaveABody()) {
3830       if (!FD->doesDeclarationForceExternallyVisibleDefinition() &&
3831           (!FD->isMultiVersion() || !getTarget().getTriple().isAArch64()))
3832         return;
3833 
3834       StringRef MangledName = getMangledName(GD);
3835 
3836       // Compute the function info and LLVM type.
3837       const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
3838       llvm::Type *Ty = getTypes().GetFunctionType(FI);
3839 
3840       GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
3841                               /*DontDefer=*/false);
3842       return;
3843     }
3844   } else {
3845     const auto *VD = cast<VarDecl>(Global);
3846     assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
3847     if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
3848         !Context.isMSStaticDataMemberInlineDefinition(VD)) {
3849       if (LangOpts.OpenMP) {
3850         // Emit declaration of the must-be-emitted declare target variable.
3851         if (std::optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
3852                 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
3853 
3854           // If this variable has external storage and doesn't require special
3855           // link handling we defer to its canonical definition.
3856           if (VD->hasExternalStorage() &&
3857               Res != OMPDeclareTargetDeclAttr::MT_Link)
3858             return;
3859 
3860           bool UnifiedMemoryEnabled =
3861               getOpenMPRuntime().hasRequiresUnifiedSharedMemory();
3862           if ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
3863                *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
3864               !UnifiedMemoryEnabled) {
3865             (void)GetAddrOfGlobalVar(VD);
3866           } else {
3867             assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
3868                     ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
3869                       *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
3870                      UnifiedMemoryEnabled)) &&
3871                    "Link clause or to clause with unified memory expected.");
3872             (void)getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
3873           }
3874 
3875           return;
3876         }
3877       }
3878       // If this declaration may have caused an inline variable definition to
3879       // change linkage, make sure that it's emitted.
3880       if (Context.getInlineVariableDefinitionKind(VD) ==
3881           ASTContext::InlineVariableDefinitionKind::Strong)
3882         GetAddrOfGlobalVar(VD);
3883       return;
3884     }
3885   }
3886 
3887   // Defer code generation to first use when possible, e.g. if this is an inline
3888   // function. If the global must always be emitted, do it eagerly if possible
3889   // to benefit from cache locality.
3890   if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
3891     // Emit the definition if it can't be deferred.
3892     EmitGlobalDefinition(GD);
3893     addEmittedDeferredDecl(GD);
3894     return;
3895   }
3896 
3897   // If we're deferring emission of a C++ variable with an
3898   // initializer, remember the order in which it appeared in the file.
3899   if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
3900       cast<VarDecl>(Global)->hasInit()) {
3901     DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
3902     CXXGlobalInits.push_back(nullptr);
3903   }
3904 
3905   StringRef MangledName = getMangledName(GD);
3906   if (GetGlobalValue(MangledName) != nullptr) {
3907     // The value has already been used and should therefore be emitted.
3908     addDeferredDeclToEmit(GD);
3909   } else if (MustBeEmitted(Global)) {
3910     // The value must be emitted, but cannot be emitted eagerly.
3911     assert(!MayBeEmittedEagerly(Global));
3912     addDeferredDeclToEmit(GD);
3913   } else {
3914     // Otherwise, remember that we saw a deferred decl with this name.  The
3915     // first use of the mangled name will cause it to move into
3916     // DeferredDeclsToEmit.
3917     DeferredDecls[MangledName] = GD;
3918   }
3919 }
3920 
3921 // Check if T is a class type with a destructor that's not dllimport.
3922 static bool HasNonDllImportDtor(QualType T) {
3923   if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
3924     if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
3925       if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
3926         return true;
3927 
3928   return false;
3929 }
3930 
3931 namespace {
3932   struct FunctionIsDirectlyRecursive
3933       : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> {
3934     const StringRef Name;
3935     const Builtin::Context &BI;
3936     FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C)
3937         : Name(N), BI(C) {}
3938 
3939     bool VisitCallExpr(const CallExpr *E) {
3940       const FunctionDecl *FD = E->getDirectCallee();
3941       if (!FD)
3942         return false;
3943       AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
3944       if (Attr && Name == Attr->getLabel())
3945         return true;
3946       unsigned BuiltinID = FD->getBuiltinID();
3947       if (!BuiltinID || !BI.isLibFunction(BuiltinID))
3948         return false;
3949       StringRef BuiltinName = BI.getName(BuiltinID);
3950       if (BuiltinName.starts_with("__builtin_") &&
3951           Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
3952         return true;
3953       }
3954       return false;
3955     }
3956 
3957     bool VisitStmt(const Stmt *S) {
3958       for (const Stmt *Child : S->children())
3959         if (Child && this->Visit(Child))
3960           return true;
3961       return false;
3962     }
3963   };
3964 
3965   // Make sure we're not referencing non-imported vars or functions.
3966   struct DLLImportFunctionVisitor
3967       : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
3968     bool SafeToInline = true;
3969 
3970     bool shouldVisitImplicitCode() const { return true; }
3971 
3972     bool VisitVarDecl(VarDecl *VD) {
3973       if (VD->getTLSKind()) {
3974         // A thread-local variable cannot be imported.
3975         SafeToInline = false;
3976         return SafeToInline;
3977       }
3978 
3979       // A variable definition might imply a destructor call.
3980       if (VD->isThisDeclarationADefinition())
3981         SafeToInline = !HasNonDllImportDtor(VD->getType());
3982 
3983       return SafeToInline;
3984     }
3985 
3986     bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
3987       if (const auto *D = E->getTemporary()->getDestructor())
3988         SafeToInline = D->hasAttr<DLLImportAttr>();
3989       return SafeToInline;
3990     }
3991 
3992     bool VisitDeclRefExpr(DeclRefExpr *E) {
3993       ValueDecl *VD = E->getDecl();
3994       if (isa<FunctionDecl>(VD))
3995         SafeToInline = VD->hasAttr<DLLImportAttr>();
3996       else if (VarDecl *V = dyn_cast<VarDecl>(VD))
3997         SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
3998       return SafeToInline;
3999     }
4000 
4001     bool VisitCXXConstructExpr(CXXConstructExpr *E) {
4002       SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
4003       return SafeToInline;
4004     }
4005 
4006     bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
4007       CXXMethodDecl *M = E->getMethodDecl();
4008       if (!M) {
4009         // Call through a pointer to member function. This is safe to inline.
4010         SafeToInline = true;
4011       } else {
4012         SafeToInline = M->hasAttr<DLLImportAttr>();
4013       }
4014       return SafeToInline;
4015     }
4016 
4017     bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
4018       SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
4019       return SafeToInline;
4020     }
4021 
4022     bool VisitCXXNewExpr(CXXNewExpr *E) {
4023       SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
4024       return SafeToInline;
4025     }
4026   };
4027 }
4028 
4029 // isTriviallyRecursive - Check if this function calls another
4030 // decl that, because of the asm attribute or the other decl being a builtin,
4031 // ends up pointing to itself.
4032 bool
4033 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
4034   StringRef Name;
4035   if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
4036     // asm labels are a special kind of mangling we have to support.
4037     AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
4038     if (!Attr)
4039       return false;
4040     Name = Attr->getLabel();
4041   } else {
4042     Name = FD->getName();
4043   }
4044 
4045   FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
4046   const Stmt *Body = FD->getBody();
4047   return Body ? Walker.Visit(Body) : false;
4048 }
4049 
4050 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
4051   if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
4052     return true;
4053 
4054   const auto *F = cast<FunctionDecl>(GD.getDecl());
4055   // Inline builtins declaration must be emitted. They often are fortified
4056   // functions.
4057   if (F->isInlineBuiltinDeclaration())
4058     return true;
4059 
4060   if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
4061     return false;
4062 
4063   // We don't import function bodies from other named module units since that
4064   // behavior may break ABI compatibility of the current unit.
4065   if (const Module *M = F->getOwningModule();
4066       M && M->getTopLevelModule()->isNamedModule() &&
4067       getContext().getCurrentNamedModule() != M->getTopLevelModule()) {
4068     // There are practices to mark template member function as always-inline
4069     // and mark the template as extern explicit instantiation but not give
4070     // the definition for member function. So we have to emit the function
4071     // from explicitly instantiation with always-inline.
4072     //
4073     // See https://github.com/llvm/llvm-project/issues/86893 for details.
4074     //
4075     // TODO: Maybe it is better to give it a warning if we call a non-inline
4076     // function from other module units which is marked as always-inline.
4077     if (!F->isTemplateInstantiation() || !F->hasAttr<AlwaysInlineAttr>()) {
4078       return false;
4079     }
4080   }
4081 
4082   if (F->hasAttr<NoInlineAttr>())
4083     return false;
4084 
4085   if (F->hasAttr<DLLImportAttr>() && !F->hasAttr<AlwaysInlineAttr>()) {
4086     // Check whether it would be safe to inline this dllimport function.
4087     DLLImportFunctionVisitor Visitor;
4088     Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
4089     if (!Visitor.SafeToInline)
4090       return false;
4091 
4092     if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
4093       // Implicit destructor invocations aren't captured in the AST, so the
4094       // check above can't see them. Check for them manually here.
4095       for (const Decl *Member : Dtor->getParent()->decls())
4096         if (isa<FieldDecl>(Member))
4097           if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
4098             return false;
4099       for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
4100         if (HasNonDllImportDtor(B.getType()))
4101           return false;
4102     }
4103   }
4104 
4105   // PR9614. Avoid cases where the source code is lying to us. An available
4106   // externally function should have an equivalent function somewhere else,
4107   // but a function that calls itself through asm label/`__builtin_` trickery is
4108   // clearly not equivalent to the real implementation.
4109   // This happens in glibc's btowc and in some configure checks.
4110   return !isTriviallyRecursive(F);
4111 }
4112 
4113 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
4114   return CodeGenOpts.OptimizationLevel > 0;
4115 }
4116 
4117 void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
4118                                                        llvm::GlobalValue *GV) {
4119   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4120 
4121   if (FD->isCPUSpecificMultiVersion()) {
4122     auto *Spec = FD->getAttr<CPUSpecificAttr>();
4123     for (unsigned I = 0; I < Spec->cpus_size(); ++I)
4124       EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
4125   } else if (auto *TC = FD->getAttr<TargetClonesAttr>()) {
4126     for (unsigned I = 0; I < TC->featuresStrs_size(); ++I)
4127       // AArch64 favors the default target version over the clone if any.
4128       if ((!TC->isDefaultVersion(I) || !getTarget().getTriple().isAArch64()) &&
4129           TC->isFirstOfVersion(I))
4130         EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
4131     // Ensure that the resolver function is also emitted.
4132     GetOrCreateMultiVersionResolver(GD);
4133   } else
4134     EmitGlobalFunctionDefinition(GD, GV);
4135 
4136   // Defer the resolver emission until we can reason whether the TU
4137   // contains a default target version implementation.
4138   if (FD->isTargetVersionMultiVersion())
4139     AddDeferredMultiVersionResolverToEmit(GD);
4140 }
4141 
4142 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
4143   const auto *D = cast<ValueDecl>(GD.getDecl());
4144 
4145   PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
4146                                  Context.getSourceManager(),
4147                                  "Generating code for declaration");
4148 
4149   if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
4150     // At -O0, don't generate IR for functions with available_externally
4151     // linkage.
4152     if (!shouldEmitFunction(GD))
4153       return;
4154 
4155     llvm::TimeTraceScope TimeScope("CodeGen Function", [&]() {
4156       std::string Name;
4157       llvm::raw_string_ostream OS(Name);
4158       FD->getNameForDiagnostic(OS, getContext().getPrintingPolicy(),
4159                                /*Qualified=*/true);
4160       return Name;
4161     });
4162 
4163     if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
4164       // Make sure to emit the definition(s) before we emit the thunks.
4165       // This is necessary for the generation of certain thunks.
4166       if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
4167         ABI->emitCXXStructor(GD);
4168       else if (FD->isMultiVersion())
4169         EmitMultiVersionFunctionDefinition(GD, GV);
4170       else
4171         EmitGlobalFunctionDefinition(GD, GV);
4172 
4173       if (Method->isVirtual())
4174         getVTables().EmitThunks(GD);
4175 
4176       return;
4177     }
4178 
4179     if (FD->isMultiVersion())
4180       return EmitMultiVersionFunctionDefinition(GD, GV);
4181     return EmitGlobalFunctionDefinition(GD, GV);
4182   }
4183 
4184   if (const auto *VD = dyn_cast<VarDecl>(D))
4185     return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
4186 
4187   llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
4188 }
4189 
4190 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
4191                                                       llvm::Function *NewFn);
4192 
4193 static unsigned
4194 TargetMVPriority(const TargetInfo &TI,
4195                  const CodeGenFunction::MultiVersionResolverOption &RO) {
4196   unsigned Priority = 0;
4197   unsigned NumFeatures = 0;
4198   for (StringRef Feat : RO.Conditions.Features) {
4199     Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
4200     NumFeatures++;
4201   }
4202 
4203   if (!RO.Conditions.Architecture.empty())
4204     Priority = std::max(
4205         Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
4206 
4207   Priority += TI.multiVersionFeatureCost() * NumFeatures;
4208 
4209   return Priority;
4210 }
4211 
4212 // Multiversion functions should be at most 'WeakODRLinkage' so that a different
4213 // TU can forward declare the function without causing problems.  Particularly
4214 // in the cases of CPUDispatch, this causes issues. This also makes sure we
4215 // work with internal linkage functions, so that the same function name can be
4216 // used with internal linkage in multiple TUs.
4217 llvm::GlobalValue::LinkageTypes getMultiversionLinkage(CodeGenModule &CGM,
4218                                                        GlobalDecl GD) {
4219   const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
4220   if (FD->getFormalLinkage() == Linkage::Internal)
4221     return llvm::GlobalValue::InternalLinkage;
4222   return llvm::GlobalValue::WeakODRLinkage;
4223 }
4224 
4225 void CodeGenModule::emitMultiVersionFunctions() {
4226   std::vector<GlobalDecl> MVFuncsToEmit;
4227   MultiVersionFuncs.swap(MVFuncsToEmit);
4228   for (GlobalDecl GD : MVFuncsToEmit) {
4229     const auto *FD = cast<FunctionDecl>(GD.getDecl());
4230     assert(FD && "Expected a FunctionDecl");
4231 
4232     auto createFunction = [&](const FunctionDecl *Decl, unsigned MVIdx = 0) {
4233       GlobalDecl CurGD{Decl->isDefined() ? Decl->getDefinition() : Decl, MVIdx};
4234       StringRef MangledName = getMangledName(CurGD);
4235       llvm::Constant *Func = GetGlobalValue(MangledName);
4236       if (!Func) {
4237         if (Decl->isDefined()) {
4238           EmitGlobalFunctionDefinition(CurGD, nullptr);
4239           Func = GetGlobalValue(MangledName);
4240         } else {
4241           const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(CurGD);
4242           llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4243           Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
4244                                    /*DontDefer=*/false, ForDefinition);
4245         }
4246         assert(Func && "This should have just been created");
4247       }
4248       return cast<llvm::Function>(Func);
4249     };
4250 
4251     // For AArch64, a resolver is only emitted if a function marked with
4252     // target_version("default")) or target_clones() is present and defined
4253     // in this TU. For other architectures it is always emitted.
4254     bool ShouldEmitResolver = !getTarget().getTriple().isAArch64();
4255     SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
4256 
4257     getContext().forEachMultiversionedFunctionVersion(
4258         FD, [&](const FunctionDecl *CurFD) {
4259           llvm::SmallVector<StringRef, 8> Feats;
4260           bool IsDefined = CurFD->doesThisDeclarationHaveABody();
4261 
4262           if (const auto *TA = CurFD->getAttr<TargetAttr>()) {
4263             TA->getAddedFeatures(Feats);
4264             llvm::Function *Func = createFunction(CurFD);
4265             Options.emplace_back(Func, TA->getArchitecture(), Feats);
4266           } else if (const auto *TVA = CurFD->getAttr<TargetVersionAttr>()) {
4267             if (TVA->isDefaultVersion() && IsDefined)
4268               ShouldEmitResolver = true;
4269             TVA->getFeatures(Feats);
4270             llvm::Function *Func = createFunction(CurFD);
4271             Options.emplace_back(Func, /*Architecture*/ "", Feats);
4272           } else if (const auto *TC = CurFD->getAttr<TargetClonesAttr>()) {
4273             if (IsDefined)
4274               ShouldEmitResolver = true;
4275             for (unsigned I = 0; I < TC->featuresStrs_size(); ++I) {
4276               if (!TC->isFirstOfVersion(I))
4277                 continue;
4278 
4279               llvm::Function *Func = createFunction(CurFD, I);
4280               StringRef Architecture;
4281               Feats.clear();
4282               if (getTarget().getTriple().isAArch64())
4283                 TC->getFeatures(Feats, I);
4284               else {
4285                 StringRef Version = TC->getFeatureStr(I);
4286                 if (Version.starts_with("arch="))
4287                   Architecture = Version.drop_front(sizeof("arch=") - 1);
4288                 else if (Version != "default")
4289                   Feats.push_back(Version);
4290               }
4291               Options.emplace_back(Func, Architecture, Feats);
4292             }
4293           } else
4294             llvm_unreachable("unexpected MultiVersionKind");
4295         });
4296 
4297     if (!ShouldEmitResolver)
4298       continue;
4299 
4300     llvm::Constant *ResolverConstant = GetOrCreateMultiVersionResolver(GD);
4301     if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(ResolverConstant)) {
4302       ResolverConstant = IFunc->getResolver();
4303       if (FD->isTargetClonesMultiVersion() &&
4304           !getTarget().getTriple().isAArch64()) {
4305         std::string MangledName = getMangledNameImpl(
4306             *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4307         if (!GetGlobalValue(MangledName + ".ifunc")) {
4308           const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4309           llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4310           // In prior versions of Clang, the mangling for ifuncs incorrectly
4311           // included an .ifunc suffix. This alias is generated for backward
4312           // compatibility. It is deprecated, and may be removed in the future.
4313           auto *Alias = llvm::GlobalAlias::create(
4314               DeclTy, 0, getMultiversionLinkage(*this, GD),
4315               MangledName + ".ifunc", IFunc, &getModule());
4316           SetCommonAttributes(FD, Alias);
4317         }
4318       }
4319     }
4320     llvm::Function *ResolverFunc = cast<llvm::Function>(ResolverConstant);
4321 
4322     ResolverFunc->setLinkage(getMultiversionLinkage(*this, GD));
4323 
4324     if (!ResolverFunc->hasLocalLinkage() && supportsCOMDAT())
4325       ResolverFunc->setComdat(
4326           getModule().getOrInsertComdat(ResolverFunc->getName()));
4327 
4328     const TargetInfo &TI = getTarget();
4329     llvm::stable_sort(
4330         Options, [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
4331                        const CodeGenFunction::MultiVersionResolverOption &RHS) {
4332           return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
4333         });
4334     CodeGenFunction CGF(*this);
4335     CGF.EmitMultiVersionResolver(ResolverFunc, Options);
4336   }
4337 
4338   // Ensure that any additions to the deferred decls list caused by emitting a
4339   // variant are emitted.  This can happen when the variant itself is inline and
4340   // calls a function without linkage.
4341   if (!MVFuncsToEmit.empty())
4342     EmitDeferred();
4343 
4344   // Ensure that any additions to the multiversion funcs list from either the
4345   // deferred decls or the multiversion functions themselves are emitted.
4346   if (!MultiVersionFuncs.empty())
4347     emitMultiVersionFunctions();
4348 }
4349 
4350 static void replaceDeclarationWith(llvm::GlobalValue *Old,
4351                                    llvm::Constant *New) {
4352   assert(cast<llvm::Function>(Old)->isDeclaration() && "Not a declaration");
4353   New->takeName(Old);
4354   Old->replaceAllUsesWith(New);
4355   Old->eraseFromParent();
4356 }
4357 
4358 void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
4359   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4360   assert(FD && "Not a FunctionDecl?");
4361   assert(FD->isCPUDispatchMultiVersion() && "Not a multiversion function?");
4362   const auto *DD = FD->getAttr<CPUDispatchAttr>();
4363   assert(DD && "Not a cpu_dispatch Function?");
4364 
4365   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4366   llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4367 
4368   StringRef ResolverName = getMangledName(GD);
4369   UpdateMultiVersionNames(GD, FD, ResolverName);
4370 
4371   llvm::Type *ResolverType;
4372   GlobalDecl ResolverGD;
4373   if (getTarget().supportsIFunc()) {
4374     ResolverType = llvm::FunctionType::get(
4375         llvm::PointerType::get(DeclTy,
4376                                getTypes().getTargetAddressSpace(FD->getType())),
4377         false);
4378   }
4379   else {
4380     ResolverType = DeclTy;
4381     ResolverGD = GD;
4382   }
4383 
4384   auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
4385       ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
4386   ResolverFunc->setLinkage(getMultiversionLinkage(*this, GD));
4387   if (supportsCOMDAT())
4388     ResolverFunc->setComdat(
4389         getModule().getOrInsertComdat(ResolverFunc->getName()));
4390 
4391   SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
4392   const TargetInfo &Target = getTarget();
4393   unsigned Index = 0;
4394   for (const IdentifierInfo *II : DD->cpus()) {
4395     // Get the name of the target function so we can look it up/create it.
4396     std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
4397                               getCPUSpecificMangling(*this, II->getName());
4398 
4399     llvm::Constant *Func = GetGlobalValue(MangledName);
4400 
4401     if (!Func) {
4402       GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
4403       if (ExistingDecl.getDecl() &&
4404           ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
4405         EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
4406         Func = GetGlobalValue(MangledName);
4407       } else {
4408         if (!ExistingDecl.getDecl())
4409           ExistingDecl = GD.getWithMultiVersionIndex(Index);
4410 
4411       Func = GetOrCreateLLVMFunction(
4412           MangledName, DeclTy, ExistingDecl,
4413           /*ForVTable=*/false, /*DontDefer=*/true,
4414           /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
4415       }
4416     }
4417 
4418     llvm::SmallVector<StringRef, 32> Features;
4419     Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
4420     llvm::transform(Features, Features.begin(),
4421                     [](StringRef Str) { return Str.substr(1); });
4422     llvm::erase_if(Features, [&Target](StringRef Feat) {
4423       return !Target.validateCpuSupports(Feat);
4424     });
4425     Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
4426     ++Index;
4427   }
4428 
4429   llvm::stable_sort(
4430       Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
4431                   const CodeGenFunction::MultiVersionResolverOption &RHS) {
4432         return llvm::X86::getCpuSupportsMask(LHS.Conditions.Features) >
4433                llvm::X86::getCpuSupportsMask(RHS.Conditions.Features);
4434       });
4435 
4436   // If the list contains multiple 'default' versions, such as when it contains
4437   // 'pentium' and 'generic', don't emit the call to the generic one (since we
4438   // always run on at least a 'pentium'). We do this by deleting the 'least
4439   // advanced' (read, lowest mangling letter).
4440   while (Options.size() > 1 &&
4441          llvm::all_of(llvm::X86::getCpuSupportsMask(
4442                           (Options.end() - 2)->Conditions.Features),
4443                       [](auto X) { return X == 0; })) {
4444     StringRef LHSName = (Options.end() - 2)->Function->getName();
4445     StringRef RHSName = (Options.end() - 1)->Function->getName();
4446     if (LHSName.compare(RHSName) < 0)
4447       Options.erase(Options.end() - 2);
4448     else
4449       Options.erase(Options.end() - 1);
4450   }
4451 
4452   CodeGenFunction CGF(*this);
4453   CGF.EmitMultiVersionResolver(ResolverFunc, Options);
4454 
4455   if (getTarget().supportsIFunc()) {
4456     llvm::GlobalValue::LinkageTypes Linkage = getMultiversionLinkage(*this, GD);
4457     auto *IFunc = cast<llvm::GlobalValue>(GetOrCreateMultiVersionResolver(GD));
4458 
4459     // Fix up function declarations that were created for cpu_specific before
4460     // cpu_dispatch was known
4461     if (!isa<llvm::GlobalIFunc>(IFunc)) {
4462       auto *GI = llvm::GlobalIFunc::create(DeclTy, 0, Linkage, "", ResolverFunc,
4463                                            &getModule());
4464       replaceDeclarationWith(IFunc, GI);
4465       IFunc = GI;
4466     }
4467 
4468     std::string AliasName = getMangledNameImpl(
4469         *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4470     llvm::Constant *AliasFunc = GetGlobalValue(AliasName);
4471     if (!AliasFunc) {
4472       auto *GA = llvm::GlobalAlias::create(DeclTy, 0, Linkage, AliasName, IFunc,
4473                                            &getModule());
4474       SetCommonAttributes(GD, GA);
4475     }
4476   }
4477 }
4478 
4479 /// Adds a declaration to the list of multi version functions if not present.
4480 void CodeGenModule::AddDeferredMultiVersionResolverToEmit(GlobalDecl GD) {
4481   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4482   assert(FD && "Not a FunctionDecl?");
4483 
4484   if (FD->isTargetVersionMultiVersion() || FD->isTargetClonesMultiVersion()) {
4485     std::string MangledName =
4486         getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
4487     if (!DeferredResolversToEmit.insert(MangledName).second)
4488       return;
4489   }
4490   MultiVersionFuncs.push_back(GD);
4491 }
4492 
4493 /// If a dispatcher for the specified mangled name is not in the module, create
4494 /// and return it. The dispatcher is either an llvm Function with the specified
4495 /// type, or a global ifunc.
4496 llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(GlobalDecl GD) {
4497   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4498   assert(FD && "Not a FunctionDecl?");
4499 
4500   std::string MangledName =
4501       getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
4502 
4503   // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
4504   // a separate resolver).
4505   std::string ResolverName = MangledName;
4506   if (getTarget().supportsIFunc()) {
4507     switch (FD->getMultiVersionKind()) {
4508     case MultiVersionKind::None:
4509       llvm_unreachable("unexpected MultiVersionKind::None for resolver");
4510     case MultiVersionKind::Target:
4511     case MultiVersionKind::CPUSpecific:
4512     case MultiVersionKind::CPUDispatch:
4513       ResolverName += ".ifunc";
4514       break;
4515     case MultiVersionKind::TargetClones:
4516     case MultiVersionKind::TargetVersion:
4517       break;
4518     }
4519   } else if (FD->isTargetMultiVersion()) {
4520     ResolverName += ".resolver";
4521   }
4522 
4523   // If the resolver has already been created, just return it. This lookup may
4524   // yield a function declaration instead of a resolver on AArch64. That is
4525   // because we didn't know whether a resolver will be generated when we first
4526   // encountered a use of the symbol named after this resolver. Therefore,
4527   // targets which support ifuncs should not return here unless we actually
4528   // found an ifunc.
4529   llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName);
4530   if (ResolverGV &&
4531       (isa<llvm::GlobalIFunc>(ResolverGV) || !getTarget().supportsIFunc()))
4532     return ResolverGV;
4533 
4534   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4535   llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4536 
4537   // The resolver needs to be created. For target and target_clones, defer
4538   // creation until the end of the TU.
4539   if (FD->isTargetMultiVersion() || FD->isTargetClonesMultiVersion())
4540     AddDeferredMultiVersionResolverToEmit(GD);
4541 
4542   // For cpu_specific, don't create an ifunc yet because we don't know if the
4543   // cpu_dispatch will be emitted in this translation unit.
4544   if (getTarget().supportsIFunc() && !FD->isCPUSpecificMultiVersion()) {
4545     llvm::Type *ResolverType = llvm::FunctionType::get(
4546         llvm::PointerType::get(DeclTy,
4547                                getTypes().getTargetAddressSpace(FD->getType())),
4548         false);
4549     llvm::Constant *Resolver = GetOrCreateLLVMFunction(
4550         MangledName + ".resolver", ResolverType, GlobalDecl{},
4551         /*ForVTable=*/false);
4552     llvm::GlobalIFunc *GIF =
4553         llvm::GlobalIFunc::create(DeclTy, 0, getMultiversionLinkage(*this, GD),
4554                                   "", Resolver, &getModule());
4555     GIF->setName(ResolverName);
4556     SetCommonAttributes(FD, GIF);
4557     if (ResolverGV)
4558       replaceDeclarationWith(ResolverGV, GIF);
4559     return GIF;
4560   }
4561 
4562   llvm::Constant *Resolver = GetOrCreateLLVMFunction(
4563       ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
4564   assert(isa<llvm::GlobalValue>(Resolver) &&
4565          "Resolver should be created for the first time");
4566   SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
4567   if (ResolverGV)
4568     replaceDeclarationWith(ResolverGV, Resolver);
4569   return Resolver;
4570 }
4571 
4572 bool CodeGenModule::shouldDropDLLAttribute(const Decl *D,
4573                                            const llvm::GlobalValue *GV) const {
4574   auto SC = GV->getDLLStorageClass();
4575   if (SC == llvm::GlobalValue::DefaultStorageClass)
4576     return false;
4577   const Decl *MRD = D->getMostRecentDecl();
4578   return (((SC == llvm::GlobalValue::DLLImportStorageClass &&
4579             !MRD->hasAttr<DLLImportAttr>()) ||
4580            (SC == llvm::GlobalValue::DLLExportStorageClass &&
4581             !MRD->hasAttr<DLLExportAttr>())) &&
4582           !shouldMapVisibilityToDLLExport(cast<NamedDecl>(MRD)));
4583 }
4584 
4585 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
4586 /// module, create and return an llvm Function with the specified type. If there
4587 /// is something in the module with the specified name, return it potentially
4588 /// bitcasted to the right type.
4589 ///
4590 /// If D is non-null, it specifies a decl that correspond to this.  This is used
4591 /// to set the attributes on the function when it is first created.
4592 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
4593     StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
4594     bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
4595     ForDefinition_t IsForDefinition) {
4596   const Decl *D = GD.getDecl();
4597 
4598   std::string NameWithoutMultiVersionMangling;
4599   // Any attempts to use a MultiVersion function should result in retrieving
4600   // the iFunc instead. Name Mangling will handle the rest of the changes.
4601   if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
4602     // For the device mark the function as one that should be emitted.
4603     if (getLangOpts().OpenMPIsTargetDevice && OpenMPRuntime &&
4604         !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
4605         !DontDefer && !IsForDefinition) {
4606       if (const FunctionDecl *FDDef = FD->getDefinition()) {
4607         GlobalDecl GDDef;
4608         if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
4609           GDDef = GlobalDecl(CD, GD.getCtorType());
4610         else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
4611           GDDef = GlobalDecl(DD, GD.getDtorType());
4612         else
4613           GDDef = GlobalDecl(FDDef);
4614         EmitGlobal(GDDef);
4615       }
4616     }
4617 
4618     if (FD->isMultiVersion()) {
4619       UpdateMultiVersionNames(GD, FD, MangledName);
4620       if (!IsForDefinition) {
4621         // On AArch64 we do not immediatelly emit an ifunc resolver when a
4622         // function is used. Instead we defer the emission until we see a
4623         // default definition. In the meantime we just reference the symbol
4624         // without FMV mangling (it may or may not be replaced later).
4625         if (getTarget().getTriple().isAArch64()) {
4626           AddDeferredMultiVersionResolverToEmit(GD);
4627           NameWithoutMultiVersionMangling = getMangledNameImpl(
4628               *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4629         } else
4630           return GetOrCreateMultiVersionResolver(GD);
4631       }
4632     }
4633   }
4634 
4635   if (!NameWithoutMultiVersionMangling.empty())
4636     MangledName = NameWithoutMultiVersionMangling;
4637 
4638   // Lookup the entry, lazily creating it if necessary.
4639   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4640   if (Entry) {
4641     if (WeakRefReferences.erase(Entry)) {
4642       const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
4643       if (FD && !FD->hasAttr<WeakAttr>())
4644         Entry->setLinkage(llvm::Function::ExternalLinkage);
4645     }
4646 
4647     // Handle dropped DLL attributes.
4648     if (D && shouldDropDLLAttribute(D, Entry)) {
4649       Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
4650       setDSOLocal(Entry);
4651     }
4652 
4653     // If there are two attempts to define the same mangled name, issue an
4654     // error.
4655     if (IsForDefinition && !Entry->isDeclaration()) {
4656       GlobalDecl OtherGD;
4657       // Check that GD is not yet in DiagnosedConflictingDefinitions is required
4658       // to make sure that we issue an error only once.
4659       if (lookupRepresentativeDecl(MangledName, OtherGD) &&
4660           (GD.getCanonicalDecl().getDecl() !=
4661            OtherGD.getCanonicalDecl().getDecl()) &&
4662           DiagnosedConflictingDefinitions.insert(GD).second) {
4663         getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
4664             << MangledName;
4665         getDiags().Report(OtherGD.getDecl()->getLocation(),
4666                           diag::note_previous_definition);
4667       }
4668     }
4669 
4670     if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
4671         (Entry->getValueType() == Ty)) {
4672       return Entry;
4673     }
4674 
4675     // Make sure the result is of the correct type.
4676     // (If function is requested for a definition, we always need to create a new
4677     // function, not just return a bitcast.)
4678     if (!IsForDefinition)
4679       return Entry;
4680   }
4681 
4682   // This function doesn't have a complete type (for example, the return
4683   // type is an incomplete struct). Use a fake type instead, and make
4684   // sure not to try to set attributes.
4685   bool IsIncompleteFunction = false;
4686 
4687   llvm::FunctionType *FTy;
4688   if (isa<llvm::FunctionType>(Ty)) {
4689     FTy = cast<llvm::FunctionType>(Ty);
4690   } else {
4691     FTy = llvm::FunctionType::get(VoidTy, false);
4692     IsIncompleteFunction = true;
4693   }
4694 
4695   llvm::Function *F =
4696       llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
4697                              Entry ? StringRef() : MangledName, &getModule());
4698 
4699   // Store the declaration associated with this function so it is potentially
4700   // updated by further declarations or definitions and emitted at the end.
4701   if (D && D->hasAttr<AnnotateAttr>())
4702     DeferredAnnotations[MangledName] = cast<ValueDecl>(D);
4703 
4704   // If we already created a function with the same mangled name (but different
4705   // type) before, take its name and add it to the list of functions to be
4706   // replaced with F at the end of CodeGen.
4707   //
4708   // This happens if there is a prototype for a function (e.g. "int f()") and
4709   // then a definition of a different type (e.g. "int f(int x)").
4710   if (Entry) {
4711     F->takeName(Entry);
4712 
4713     // This might be an implementation of a function without a prototype, in
4714     // which case, try to do special replacement of calls which match the new
4715     // prototype.  The really key thing here is that we also potentially drop
4716     // arguments from the call site so as to make a direct call, which makes the
4717     // inliner happier and suppresses a number of optimizer warnings (!) about
4718     // dropping arguments.
4719     if (!Entry->use_empty()) {
4720       ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
4721       Entry->removeDeadConstantUsers();
4722     }
4723 
4724     addGlobalValReplacement(Entry, F);
4725   }
4726 
4727   assert(F->getName() == MangledName && "name was uniqued!");
4728   if (D)
4729     SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
4730   if (ExtraAttrs.hasFnAttrs()) {
4731     llvm::AttrBuilder B(F->getContext(), ExtraAttrs.getFnAttrs());
4732     F->addFnAttrs(B);
4733   }
4734 
4735   if (!DontDefer) {
4736     // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
4737     // each other bottoming out with the base dtor.  Therefore we emit non-base
4738     // dtors on usage, even if there is no dtor definition in the TU.
4739     if (isa_and_nonnull<CXXDestructorDecl>(D) &&
4740         getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
4741                                            GD.getDtorType()))
4742       addDeferredDeclToEmit(GD);
4743 
4744     // This is the first use or definition of a mangled name.  If there is a
4745     // deferred decl with this name, remember that we need to emit it at the end
4746     // of the file.
4747     auto DDI = DeferredDecls.find(MangledName);
4748     if (DDI != DeferredDecls.end()) {
4749       // Move the potentially referenced deferred decl to the
4750       // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
4751       // don't need it anymore).
4752       addDeferredDeclToEmit(DDI->second);
4753       DeferredDecls.erase(DDI);
4754 
4755       // Otherwise, there are cases we have to worry about where we're
4756       // using a declaration for which we must emit a definition but where
4757       // we might not find a top-level definition:
4758       //   - member functions defined inline in their classes
4759       //   - friend functions defined inline in some class
4760       //   - special member functions with implicit definitions
4761       // If we ever change our AST traversal to walk into class methods,
4762       // this will be unnecessary.
4763       //
4764       // We also don't emit a definition for a function if it's going to be an
4765       // entry in a vtable, unless it's already marked as used.
4766     } else if (getLangOpts().CPlusPlus && D) {
4767       // Look for a declaration that's lexically in a record.
4768       for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
4769            FD = FD->getPreviousDecl()) {
4770         if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
4771           if (FD->doesThisDeclarationHaveABody()) {
4772             addDeferredDeclToEmit(GD.getWithDecl(FD));
4773             break;
4774           }
4775         }
4776       }
4777     }
4778   }
4779 
4780   // Make sure the result is of the requested type.
4781   if (!IsIncompleteFunction) {
4782     assert(F->getFunctionType() == Ty);
4783     return F;
4784   }
4785 
4786   return F;
4787 }
4788 
4789 /// GetAddrOfFunction - Return the address of the given function.  If Ty is
4790 /// non-null, then this function will use the specified type if it has to
4791 /// create it (this occurs when we see a definition of the function).
4792 llvm::Constant *
4793 CodeGenModule::GetAddrOfFunction(GlobalDecl GD, llvm::Type *Ty, bool ForVTable,
4794                                  bool DontDefer,
4795                                  ForDefinition_t IsForDefinition) {
4796   // If there was no specific requested type, just convert it now.
4797   if (!Ty) {
4798     const auto *FD = cast<FunctionDecl>(GD.getDecl());
4799     Ty = getTypes().ConvertType(FD->getType());
4800   }
4801 
4802   // Devirtualized destructor calls may come through here instead of via
4803   // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
4804   // of the complete destructor when necessary.
4805   if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
4806     if (getTarget().getCXXABI().isMicrosoft() &&
4807         GD.getDtorType() == Dtor_Complete &&
4808         DD->getParent()->getNumVBases() == 0)
4809       GD = GlobalDecl(DD, Dtor_Base);
4810   }
4811 
4812   StringRef MangledName = getMangledName(GD);
4813   auto *F = GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
4814                                     /*IsThunk=*/false, llvm::AttributeList(),
4815                                     IsForDefinition);
4816   // Returns kernel handle for HIP kernel stub function.
4817   if (LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
4818       cast<FunctionDecl>(GD.getDecl())->hasAttr<CUDAGlobalAttr>()) {
4819     auto *Handle = getCUDARuntime().getKernelHandle(
4820         cast<llvm::Function>(F->stripPointerCasts()), GD);
4821     if (IsForDefinition)
4822       return F;
4823     return Handle;
4824   }
4825   return F;
4826 }
4827 
4828 llvm::Constant *CodeGenModule::GetFunctionStart(const ValueDecl *Decl) {
4829   llvm::GlobalValue *F =
4830       cast<llvm::GlobalValue>(GetAddrOfFunction(Decl)->stripPointerCasts());
4831 
4832   return llvm::NoCFIValue::get(F);
4833 }
4834 
4835 static const FunctionDecl *
4836 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
4837   TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
4838   DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
4839 
4840   IdentifierInfo &CII = C.Idents.get(Name);
4841   for (const auto *Result : DC->lookup(&CII))
4842     if (const auto *FD = dyn_cast<FunctionDecl>(Result))
4843       return FD;
4844 
4845   if (!C.getLangOpts().CPlusPlus)
4846     return nullptr;
4847 
4848   // Demangle the premangled name from getTerminateFn()
4849   IdentifierInfo &CXXII =
4850       (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
4851           ? C.Idents.get("terminate")
4852           : C.Idents.get(Name);
4853 
4854   for (const auto &N : {"__cxxabiv1", "std"}) {
4855     IdentifierInfo &NS = C.Idents.get(N);
4856     for (const auto *Result : DC->lookup(&NS)) {
4857       const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
4858       if (auto *LSD = dyn_cast<LinkageSpecDecl>(Result))
4859         for (const auto *Result : LSD->lookup(&NS))
4860           if ((ND = dyn_cast<NamespaceDecl>(Result)))
4861             break;
4862 
4863       if (ND)
4864         for (const auto *Result : ND->lookup(&CXXII))
4865           if (const auto *FD = dyn_cast<FunctionDecl>(Result))
4866             return FD;
4867     }
4868   }
4869 
4870   return nullptr;
4871 }
4872 
4873 /// CreateRuntimeFunction - Create a new runtime function with the specified
4874 /// type and name.
4875 llvm::FunctionCallee
4876 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
4877                                      llvm::AttributeList ExtraAttrs, bool Local,
4878                                      bool AssumeConvergent) {
4879   if (AssumeConvergent) {
4880     ExtraAttrs =
4881         ExtraAttrs.addFnAttribute(VMContext, llvm::Attribute::Convergent);
4882   }
4883 
4884   llvm::Constant *C =
4885       GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
4886                               /*DontDefer=*/false, /*IsThunk=*/false,
4887                               ExtraAttrs);
4888 
4889   if (auto *F = dyn_cast<llvm::Function>(C)) {
4890     if (F->empty()) {
4891       F->setCallingConv(getRuntimeCC());
4892 
4893       // In Windows Itanium environments, try to mark runtime functions
4894       // dllimport. For Mingw and MSVC, don't. We don't really know if the user
4895       // will link their standard library statically or dynamically. Marking
4896       // functions imported when they are not imported can cause linker errors
4897       // and warnings.
4898       if (!Local && getTriple().isWindowsItaniumEnvironment() &&
4899           !getCodeGenOpts().LTOVisibilityPublicStd) {
4900         const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
4901         if (!FD || FD->hasAttr<DLLImportAttr>()) {
4902           F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
4903           F->setLinkage(llvm::GlobalValue::ExternalLinkage);
4904         }
4905       }
4906       setDSOLocal(F);
4907       // FIXME: We should use CodeGenModule::SetLLVMFunctionAttributes() instead
4908       // of trying to approximate the attributes using the LLVM function
4909       // signature. This requires revising the API of CreateRuntimeFunction().
4910       markRegisterParameterAttributes(F);
4911     }
4912   }
4913 
4914   return {FTy, C};
4915 }
4916 
4917 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
4918 /// create and return an llvm GlobalVariable with the specified type and address
4919 /// space. If there is something in the module with the specified name, return
4920 /// it potentially bitcasted to the right type.
4921 ///
4922 /// If D is non-null, it specifies a decl that correspond to this.  This is used
4923 /// to set the attributes on the global when it is first created.
4924 ///
4925 /// If IsForDefinition is true, it is guaranteed that an actual global with
4926 /// type Ty will be returned, not conversion of a variable with the same
4927 /// mangled name but some other type.
4928 llvm::Constant *
4929 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, llvm::Type *Ty,
4930                                      LangAS AddrSpace, const VarDecl *D,
4931                                      ForDefinition_t IsForDefinition) {
4932   // Lookup the entry, lazily creating it if necessary.
4933   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4934   unsigned TargetAS = getContext().getTargetAddressSpace(AddrSpace);
4935   if (Entry) {
4936     if (WeakRefReferences.erase(Entry)) {
4937       if (D && !D->hasAttr<WeakAttr>())
4938         Entry->setLinkage(llvm::Function::ExternalLinkage);
4939     }
4940 
4941     // Handle dropped DLL attributes.
4942     if (D && shouldDropDLLAttribute(D, Entry))
4943       Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
4944 
4945     if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
4946       getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
4947 
4948     if (Entry->getValueType() == Ty && Entry->getAddressSpace() == TargetAS)
4949       return Entry;
4950 
4951     // If there are two attempts to define the same mangled name, issue an
4952     // error.
4953     if (IsForDefinition && !Entry->isDeclaration()) {
4954       GlobalDecl OtherGD;
4955       const VarDecl *OtherD;
4956 
4957       // Check that D is not yet in DiagnosedConflictingDefinitions is required
4958       // to make sure that we issue an error only once.
4959       if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
4960           (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
4961           (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
4962           OtherD->hasInit() &&
4963           DiagnosedConflictingDefinitions.insert(D).second) {
4964         getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
4965             << MangledName;
4966         getDiags().Report(OtherGD.getDecl()->getLocation(),
4967                           diag::note_previous_definition);
4968       }
4969     }
4970 
4971     // Make sure the result is of the correct type.
4972     if (Entry->getType()->getAddressSpace() != TargetAS)
4973       return llvm::ConstantExpr::getAddrSpaceCast(
4974           Entry, llvm::PointerType::get(Ty->getContext(), TargetAS));
4975 
4976     // (If global is requested for a definition, we always need to create a new
4977     // global, not just return a bitcast.)
4978     if (!IsForDefinition)
4979       return Entry;
4980   }
4981 
4982   auto DAddrSpace = GetGlobalVarAddressSpace(D);
4983 
4984   auto *GV = new llvm::GlobalVariable(
4985       getModule(), Ty, false, llvm::GlobalValue::ExternalLinkage, nullptr,
4986       MangledName, nullptr, llvm::GlobalVariable::NotThreadLocal,
4987       getContext().getTargetAddressSpace(DAddrSpace));
4988 
4989   // If we already created a global with the same mangled name (but different
4990   // type) before, take its name and remove it from its parent.
4991   if (Entry) {
4992     GV->takeName(Entry);
4993 
4994     if (!Entry->use_empty()) {
4995       Entry->replaceAllUsesWith(GV);
4996     }
4997 
4998     Entry->eraseFromParent();
4999   }
5000 
5001   // This is the first use or definition of a mangled name.  If there is a
5002   // deferred decl with this name, remember that we need to emit it at the end
5003   // of the file.
5004   auto DDI = DeferredDecls.find(MangledName);
5005   if (DDI != DeferredDecls.end()) {
5006     // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
5007     // list, and remove it from DeferredDecls (since we don't need it anymore).
5008     addDeferredDeclToEmit(DDI->second);
5009     DeferredDecls.erase(DDI);
5010   }
5011 
5012   // Handle things which are present even on external declarations.
5013   if (D) {
5014     if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
5015       getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
5016 
5017     // FIXME: This code is overly simple and should be merged with other global
5018     // handling.
5019     GV->setConstant(D->getType().isConstantStorage(getContext(), false, false));
5020 
5021     GV->setAlignment(getContext().getDeclAlign(D).getAsAlign());
5022 
5023     setLinkageForGV(GV, D);
5024 
5025     if (D->getTLSKind()) {
5026       if (D->getTLSKind() == VarDecl::TLS_Dynamic)
5027         CXXThreadLocals.push_back(D);
5028       setTLSMode(GV, *D);
5029     }
5030 
5031     setGVProperties(GV, D);
5032 
5033     // If required by the ABI, treat declarations of static data members with
5034     // inline initializers as definitions.
5035     if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
5036       EmitGlobalVarDefinition(D);
5037     }
5038 
5039     // Emit section information for extern variables.
5040     if (D->hasExternalStorage()) {
5041       if (const SectionAttr *SA = D->getAttr<SectionAttr>())
5042         GV->setSection(SA->getName());
5043     }
5044 
5045     // Handle XCore specific ABI requirements.
5046     if (getTriple().getArch() == llvm::Triple::xcore &&
5047         D->getLanguageLinkage() == CLanguageLinkage &&
5048         D->getType().isConstant(Context) &&
5049         isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
5050       GV->setSection(".cp.rodata");
5051 
5052     // Handle code model attribute
5053     if (const auto *CMA = D->getAttr<CodeModelAttr>())
5054       GV->setCodeModel(CMA->getModel());
5055 
5056     // Check if we a have a const declaration with an initializer, we may be
5057     // able to emit it as available_externally to expose it's value to the
5058     // optimizer.
5059     if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
5060         D->getType().isConstQualified() && !GV->hasInitializer() &&
5061         !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
5062       const auto *Record =
5063           Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
5064       bool HasMutableFields = Record && Record->hasMutableFields();
5065       if (!HasMutableFields) {
5066         const VarDecl *InitDecl;
5067         const Expr *InitExpr = D->getAnyInitializer(InitDecl);
5068         if (InitExpr) {
5069           ConstantEmitter emitter(*this);
5070           llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
5071           if (Init) {
5072             auto *InitType = Init->getType();
5073             if (GV->getValueType() != InitType) {
5074               // The type of the initializer does not match the definition.
5075               // This happens when an initializer has a different type from
5076               // the type of the global (because of padding at the end of a
5077               // structure for instance).
5078               GV->setName(StringRef());
5079               // Make a new global with the correct type, this is now guaranteed
5080               // to work.
5081               auto *NewGV = cast<llvm::GlobalVariable>(
5082                   GetAddrOfGlobalVar(D, InitType, IsForDefinition)
5083                       ->stripPointerCasts());
5084 
5085               // Erase the old global, since it is no longer used.
5086               GV->eraseFromParent();
5087               GV = NewGV;
5088             } else {
5089               GV->setInitializer(Init);
5090               GV->setConstant(true);
5091               GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
5092             }
5093             emitter.finalize(GV);
5094           }
5095         }
5096       }
5097     }
5098   }
5099 
5100   if (D &&
5101       D->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly) {
5102     getTargetCodeGenInfo().setTargetAttributes(D, GV, *this);
5103     // External HIP managed variables needed to be recorded for transformation
5104     // in both device and host compilations.
5105     if (getLangOpts().CUDA && D && D->hasAttr<HIPManagedAttr>() &&
5106         D->hasExternalStorage())
5107       getCUDARuntime().handleVarRegistration(D, *GV);
5108   }
5109 
5110   if (D)
5111     SanitizerMD->reportGlobal(GV, *D);
5112 
5113   LangAS ExpectedAS =
5114       D ? D->getType().getAddressSpace()
5115         : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
5116   assert(getContext().getTargetAddressSpace(ExpectedAS) == TargetAS);
5117   if (DAddrSpace != ExpectedAS) {
5118     return getTargetCodeGenInfo().performAddrSpaceCast(
5119         *this, GV, DAddrSpace, ExpectedAS,
5120         llvm::PointerType::get(getLLVMContext(), TargetAS));
5121   }
5122 
5123   return GV;
5124 }
5125 
5126 llvm::Constant *
5127 CodeGenModule::GetAddrOfGlobal(GlobalDecl GD, ForDefinition_t IsForDefinition) {
5128   const Decl *D = GD.getDecl();
5129 
5130   if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
5131     return getAddrOfCXXStructor(GD, /*FnInfo=*/nullptr, /*FnType=*/nullptr,
5132                                 /*DontDefer=*/false, IsForDefinition);
5133 
5134   if (isa<CXXMethodDecl>(D)) {
5135     auto FInfo =
5136         &getTypes().arrangeCXXMethodDeclaration(cast<CXXMethodDecl>(D));
5137     auto Ty = getTypes().GetFunctionType(*FInfo);
5138     return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
5139                              IsForDefinition);
5140   }
5141 
5142   if (isa<FunctionDecl>(D)) {
5143     const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
5144     llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
5145     return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
5146                              IsForDefinition);
5147   }
5148 
5149   return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr, IsForDefinition);
5150 }
5151 
5152 llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
5153     StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
5154     llvm::Align Alignment) {
5155   llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
5156   llvm::GlobalVariable *OldGV = nullptr;
5157 
5158   if (GV) {
5159     // Check if the variable has the right type.
5160     if (GV->getValueType() == Ty)
5161       return GV;
5162 
5163     // Because C++ name mangling, the only way we can end up with an already
5164     // existing global with the same name is if it has been declared extern "C".
5165     assert(GV->isDeclaration() && "Declaration has wrong type!");
5166     OldGV = GV;
5167   }
5168 
5169   // Create a new variable.
5170   GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
5171                                 Linkage, nullptr, Name);
5172 
5173   if (OldGV) {
5174     // Replace occurrences of the old variable if needed.
5175     GV->takeName(OldGV);
5176 
5177     if (!OldGV->use_empty()) {
5178       OldGV->replaceAllUsesWith(GV);
5179     }
5180 
5181     OldGV->eraseFromParent();
5182   }
5183 
5184   if (supportsCOMDAT() && GV->isWeakForLinker() &&
5185       !GV->hasAvailableExternallyLinkage())
5186     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
5187 
5188   GV->setAlignment(Alignment);
5189 
5190   return GV;
5191 }
5192 
5193 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
5194 /// given global variable.  If Ty is non-null and if the global doesn't exist,
5195 /// then it will be created with the specified type instead of whatever the
5196 /// normal requested type would be. If IsForDefinition is true, it is guaranteed
5197 /// that an actual global with type Ty will be returned, not conversion of a
5198 /// variable with the same mangled name but some other type.
5199 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
5200                                                   llvm::Type *Ty,
5201                                            ForDefinition_t IsForDefinition) {
5202   assert(D->hasGlobalStorage() && "Not a global variable");
5203   QualType ASTTy = D->getType();
5204   if (!Ty)
5205     Ty = getTypes().ConvertTypeForMem(ASTTy);
5206 
5207   StringRef MangledName = getMangledName(D);
5208   return GetOrCreateLLVMGlobal(MangledName, Ty, ASTTy.getAddressSpace(), D,
5209                                IsForDefinition);
5210 }
5211 
5212 /// CreateRuntimeVariable - Create a new runtime global variable with the
5213 /// specified type and name.
5214 llvm::Constant *
5215 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
5216                                      StringRef Name) {
5217   LangAS AddrSpace = getContext().getLangOpts().OpenCL ? LangAS::opencl_global
5218                                                        : LangAS::Default;
5219   auto *Ret = GetOrCreateLLVMGlobal(Name, Ty, AddrSpace, nullptr);
5220   setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
5221   return Ret;
5222 }
5223 
5224 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
5225   assert(!D->getInit() && "Cannot emit definite definitions here!");
5226 
5227   StringRef MangledName = getMangledName(D);
5228   llvm::GlobalValue *GV = GetGlobalValue(MangledName);
5229 
5230   // We already have a definition, not declaration, with the same mangled name.
5231   // Emitting of declaration is not required (and actually overwrites emitted
5232   // definition).
5233   if (GV && !GV->isDeclaration())
5234     return;
5235 
5236   // If we have not seen a reference to this variable yet, place it into the
5237   // deferred declarations table to be emitted if needed later.
5238   if (!MustBeEmitted(D) && !GV) {
5239       DeferredDecls[MangledName] = D;
5240       return;
5241   }
5242 
5243   // The tentative definition is the only definition.
5244   EmitGlobalVarDefinition(D);
5245 }
5246 
5247 void CodeGenModule::EmitExternalDeclaration(const DeclaratorDecl *D) {
5248   if (auto const *V = dyn_cast<const VarDecl>(D))
5249     EmitExternalVarDeclaration(V);
5250   if (auto const *FD = dyn_cast<const FunctionDecl>(D))
5251     EmitExternalFunctionDeclaration(FD);
5252 }
5253 
5254 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
5255   return Context.toCharUnitsFromBits(
5256       getDataLayout().getTypeStoreSizeInBits(Ty));
5257 }
5258 
5259 LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
5260   if (LangOpts.OpenCL) {
5261     LangAS AS = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
5262     assert(AS == LangAS::opencl_global ||
5263            AS == LangAS::opencl_global_device ||
5264            AS == LangAS::opencl_global_host ||
5265            AS == LangAS::opencl_constant ||
5266            AS == LangAS::opencl_local ||
5267            AS >= LangAS::FirstTargetAddressSpace);
5268     return AS;
5269   }
5270 
5271   if (LangOpts.SYCLIsDevice &&
5272       (!D || D->getType().getAddressSpace() == LangAS::Default))
5273     return LangAS::sycl_global;
5274 
5275   if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
5276     if (D) {
5277       if (D->hasAttr<CUDAConstantAttr>())
5278         return LangAS::cuda_constant;
5279       if (D->hasAttr<CUDASharedAttr>())
5280         return LangAS::cuda_shared;
5281       if (D->hasAttr<CUDADeviceAttr>())
5282         return LangAS::cuda_device;
5283       if (D->getType().isConstQualified())
5284         return LangAS::cuda_constant;
5285     }
5286     return LangAS::cuda_device;
5287   }
5288 
5289   if (LangOpts.OpenMP) {
5290     LangAS AS;
5291     if (OpenMPRuntime->hasAllocateAttributeForGlobalVar(D, AS))
5292       return AS;
5293   }
5294   return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
5295 }
5296 
5297 LangAS CodeGenModule::GetGlobalConstantAddressSpace() const {
5298   // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
5299   if (LangOpts.OpenCL)
5300     return LangAS::opencl_constant;
5301   if (LangOpts.SYCLIsDevice)
5302     return LangAS::sycl_global;
5303   if (LangOpts.HIP && LangOpts.CUDAIsDevice && getTriple().isSPIRV())
5304     // For HIPSPV map literals to cuda_device (maps to CrossWorkGroup in SPIR-V)
5305     // instead of default AS (maps to Generic in SPIR-V). Otherwise, we end up
5306     // with OpVariable instructions with Generic storage class which is not
5307     // allowed (SPIR-V V1.6 s3.42.8). Also, mapping literals to SPIR-V
5308     // UniformConstant storage class is not viable as pointers to it may not be
5309     // casted to Generic pointers which are used to model HIP's "flat" pointers.
5310     return LangAS::cuda_device;
5311   if (auto AS = getTarget().getConstantAddressSpace())
5312     return *AS;
5313   return LangAS::Default;
5314 }
5315 
5316 // In address space agnostic languages, string literals are in default address
5317 // space in AST. However, certain targets (e.g. amdgcn) request them to be
5318 // emitted in constant address space in LLVM IR. To be consistent with other
5319 // parts of AST, string literal global variables in constant address space
5320 // need to be casted to default address space before being put into address
5321 // map and referenced by other part of CodeGen.
5322 // In OpenCL, string literals are in constant address space in AST, therefore
5323 // they should not be casted to default address space.
5324 static llvm::Constant *
5325 castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM,
5326                                        llvm::GlobalVariable *GV) {
5327   llvm::Constant *Cast = GV;
5328   if (!CGM.getLangOpts().OpenCL) {
5329     auto AS = CGM.GetGlobalConstantAddressSpace();
5330     if (AS != LangAS::Default)
5331       Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast(
5332           CGM, GV, AS, LangAS::Default,
5333           llvm::PointerType::get(
5334               CGM.getLLVMContext(),
5335               CGM.getContext().getTargetAddressSpace(LangAS::Default)));
5336   }
5337   return Cast;
5338 }
5339 
5340 template<typename SomeDecl>
5341 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
5342                                                llvm::GlobalValue *GV) {
5343   if (!getLangOpts().CPlusPlus)
5344     return;
5345 
5346   // Must have 'used' attribute, or else inline assembly can't rely on
5347   // the name existing.
5348   if (!D->template hasAttr<UsedAttr>())
5349     return;
5350 
5351   // Must have internal linkage and an ordinary name.
5352   if (!D->getIdentifier() || D->getFormalLinkage() != Linkage::Internal)
5353     return;
5354 
5355   // Must be in an extern "C" context. Entities declared directly within
5356   // a record are not extern "C" even if the record is in such a context.
5357   const SomeDecl *First = D->getFirstDecl();
5358   if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
5359     return;
5360 
5361   // OK, this is an internal linkage entity inside an extern "C" linkage
5362   // specification. Make a note of that so we can give it the "expected"
5363   // mangled name if nothing else is using that name.
5364   std::pair<StaticExternCMap::iterator, bool> R =
5365       StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
5366 
5367   // If we have multiple internal linkage entities with the same name
5368   // in extern "C" regions, none of them gets that name.
5369   if (!R.second)
5370     R.first->second = nullptr;
5371 }
5372 
5373 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
5374   if (!CGM.supportsCOMDAT())
5375     return false;
5376 
5377   if (D.hasAttr<SelectAnyAttr>())
5378     return true;
5379 
5380   GVALinkage Linkage;
5381   if (auto *VD = dyn_cast<VarDecl>(&D))
5382     Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
5383   else
5384     Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
5385 
5386   switch (Linkage) {
5387   case GVA_Internal:
5388   case GVA_AvailableExternally:
5389   case GVA_StrongExternal:
5390     return false;
5391   case GVA_DiscardableODR:
5392   case GVA_StrongODR:
5393     return true;
5394   }
5395   llvm_unreachable("No such linkage");
5396 }
5397 
5398 bool CodeGenModule::supportsCOMDAT() const {
5399   return getTriple().supportsCOMDAT();
5400 }
5401 
5402 void CodeGenModule::maybeSetTrivialComdat(const Decl &D,
5403                                           llvm::GlobalObject &GO) {
5404   if (!shouldBeInCOMDAT(*this, D))
5405     return;
5406   GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
5407 }
5408 
5409 const ABIInfo &CodeGenModule::getABIInfo() {
5410   return getTargetCodeGenInfo().getABIInfo();
5411 }
5412 
5413 /// Pass IsTentative as true if you want to create a tentative definition.
5414 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
5415                                             bool IsTentative) {
5416   // OpenCL global variables of sampler type are translated to function calls,
5417   // therefore no need to be translated.
5418   QualType ASTTy = D->getType();
5419   if (getLangOpts().OpenCL && ASTTy->isSamplerT())
5420     return;
5421 
5422   // If this is OpenMP device, check if it is legal to emit this global
5423   // normally.
5424   if (LangOpts.OpenMPIsTargetDevice && OpenMPRuntime &&
5425       OpenMPRuntime->emitTargetGlobalVariable(D))
5426     return;
5427 
5428   llvm::TrackingVH<llvm::Constant> Init;
5429   bool NeedsGlobalCtor = false;
5430   // Whether the definition of the variable is available externally.
5431   // If yes, we shouldn't emit the GloablCtor and GlobalDtor for the variable
5432   // since this is the job for its original source.
5433   bool IsDefinitionAvailableExternally =
5434       getContext().GetGVALinkageForVariable(D) == GVA_AvailableExternally;
5435   bool NeedsGlobalDtor =
5436       !IsDefinitionAvailableExternally &&
5437       D->needsDestruction(getContext()) == QualType::DK_cxx_destructor;
5438 
5439   // It is helpless to emit the definition for an available_externally variable
5440   // which can't be marked as const.
5441   // We don't need to check if it needs global ctor or dtor. See the above
5442   // comment for ideas.
5443   if (IsDefinitionAvailableExternally &&
5444       (!D->hasConstantInitialization() ||
5445        // TODO: Update this when we have interface to check constexpr
5446        // destructor.
5447        D->needsDestruction(getContext()) ||
5448        !D->getType().isConstantStorage(getContext(), true, true)))
5449     return;
5450 
5451   const VarDecl *InitDecl;
5452   const Expr *InitExpr = D->getAnyInitializer(InitDecl);
5453 
5454   std::optional<ConstantEmitter> emitter;
5455 
5456   // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
5457   // as part of their declaration."  Sema has already checked for
5458   // error cases, so we just need to set Init to UndefValue.
5459   bool IsCUDASharedVar =
5460       getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
5461   // Shadows of initialized device-side global variables are also left
5462   // undefined.
5463   // Managed Variables should be initialized on both host side and device side.
5464   bool IsCUDAShadowVar =
5465       !getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
5466       (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
5467        D->hasAttr<CUDASharedAttr>());
5468   bool IsCUDADeviceShadowVar =
5469       getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
5470       (D->getType()->isCUDADeviceBuiltinSurfaceType() ||
5471        D->getType()->isCUDADeviceBuiltinTextureType());
5472   if (getLangOpts().CUDA &&
5473       (IsCUDASharedVar || IsCUDAShadowVar || IsCUDADeviceShadowVar))
5474     Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
5475   else if (D->hasAttr<LoaderUninitializedAttr>())
5476     Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
5477   else if (!InitExpr) {
5478     // This is a tentative definition; tentative definitions are
5479     // implicitly initialized with { 0 }.
5480     //
5481     // Note that tentative definitions are only emitted at the end of
5482     // a translation unit, so they should never have incomplete
5483     // type. In addition, EmitTentativeDefinition makes sure that we
5484     // never attempt to emit a tentative definition if a real one
5485     // exists. A use may still exists, however, so we still may need
5486     // to do a RAUW.
5487     assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
5488     Init = EmitNullConstant(D->getType());
5489   } else {
5490     initializedGlobalDecl = GlobalDecl(D);
5491     emitter.emplace(*this);
5492     llvm::Constant *Initializer = emitter->tryEmitForInitializer(*InitDecl);
5493     if (!Initializer) {
5494       QualType T = InitExpr->getType();
5495       if (D->getType()->isReferenceType())
5496         T = D->getType();
5497 
5498       if (getLangOpts().CPlusPlus) {
5499         if (InitDecl->hasFlexibleArrayInit(getContext()))
5500           ErrorUnsupported(D, "flexible array initializer");
5501         Init = EmitNullConstant(T);
5502 
5503         if (!IsDefinitionAvailableExternally)
5504           NeedsGlobalCtor = true;
5505       } else {
5506         ErrorUnsupported(D, "static initializer");
5507         Init = llvm::UndefValue::get(getTypes().ConvertType(T));
5508       }
5509     } else {
5510       Init = Initializer;
5511       // We don't need an initializer, so remove the entry for the delayed
5512       // initializer position (just in case this entry was delayed) if we
5513       // also don't need to register a destructor.
5514       if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
5515         DelayedCXXInitPosition.erase(D);
5516 
5517 #ifndef NDEBUG
5518       CharUnits VarSize = getContext().getTypeSizeInChars(ASTTy) +
5519                           InitDecl->getFlexibleArrayInitChars(getContext());
5520       CharUnits CstSize = CharUnits::fromQuantity(
5521           getDataLayout().getTypeAllocSize(Init->getType()));
5522       assert(VarSize == CstSize && "Emitted constant has unexpected size");
5523 #endif
5524     }
5525   }
5526 
5527   llvm::Type* InitType = Init->getType();
5528   llvm::Constant *Entry =
5529       GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
5530 
5531   // Strip off pointer casts if we got them.
5532   Entry = Entry->stripPointerCasts();
5533 
5534   // Entry is now either a Function or GlobalVariable.
5535   auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
5536 
5537   // We have a definition after a declaration with the wrong type.
5538   // We must make a new GlobalVariable* and update everything that used OldGV
5539   // (a declaration or tentative definition) with the new GlobalVariable*
5540   // (which will be a definition).
5541   //
5542   // This happens if there is a prototype for a global (e.g.
5543   // "extern int x[];") and then a definition of a different type (e.g.
5544   // "int x[10];"). This also happens when an initializer has a different type
5545   // from the type of the global (this happens with unions).
5546   if (!GV || GV->getValueType() != InitType ||
5547       GV->getType()->getAddressSpace() !=
5548           getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
5549 
5550     // Move the old entry aside so that we'll create a new one.
5551     Entry->setName(StringRef());
5552 
5553     // Make a new global with the correct type, this is now guaranteed to work.
5554     GV = cast<llvm::GlobalVariable>(
5555         GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative))
5556             ->stripPointerCasts());
5557 
5558     // Replace all uses of the old global with the new global
5559     llvm::Constant *NewPtrForOldDecl =
5560         llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV,
5561                                                              Entry->getType());
5562     Entry->replaceAllUsesWith(NewPtrForOldDecl);
5563 
5564     // Erase the old global, since it is no longer used.
5565     cast<llvm::GlobalValue>(Entry)->eraseFromParent();
5566   }
5567 
5568   MaybeHandleStaticInExternC(D, GV);
5569 
5570   if (D->hasAttr<AnnotateAttr>())
5571     AddGlobalAnnotations(D, GV);
5572 
5573   // Set the llvm linkage type as appropriate.
5574   llvm::GlobalValue::LinkageTypes Linkage = getLLVMLinkageVarDefinition(D);
5575 
5576   // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
5577   // the device. [...]"
5578   // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
5579   // __device__, declares a variable that: [...]
5580   // Is accessible from all the threads within the grid and from the host
5581   // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
5582   // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
5583   if (LangOpts.CUDA) {
5584     if (LangOpts.CUDAIsDevice) {
5585       if (Linkage != llvm::GlobalValue::InternalLinkage &&
5586           (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
5587            D->getType()->isCUDADeviceBuiltinSurfaceType() ||
5588            D->getType()->isCUDADeviceBuiltinTextureType()))
5589         GV->setExternallyInitialized(true);
5590     } else {
5591       getCUDARuntime().internalizeDeviceSideVar(D, Linkage);
5592     }
5593     getCUDARuntime().handleVarRegistration(D, *GV);
5594   }
5595 
5596   GV->setInitializer(Init);
5597   if (emitter)
5598     emitter->finalize(GV);
5599 
5600   // If it is safe to mark the global 'constant', do so now.
5601   GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
5602                   D->getType().isConstantStorage(getContext(), true, true));
5603 
5604   // If it is in a read-only section, mark it 'constant'.
5605   if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
5606     const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
5607     if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
5608       GV->setConstant(true);
5609   }
5610 
5611   CharUnits AlignVal = getContext().getDeclAlign(D);
5612   // Check for alignment specifed in an 'omp allocate' directive.
5613   if (std::optional<CharUnits> AlignValFromAllocate =
5614           getOMPAllocateAlignment(D))
5615     AlignVal = *AlignValFromAllocate;
5616   GV->setAlignment(AlignVal.getAsAlign());
5617 
5618   // On Darwin, unlike other Itanium C++ ABI platforms, the thread-wrapper
5619   // function is only defined alongside the variable, not also alongside
5620   // callers. Normally, all accesses to a thread_local go through the
5621   // thread-wrapper in order to ensure initialization has occurred, underlying
5622   // variable will never be used other than the thread-wrapper, so it can be
5623   // converted to internal linkage.
5624   //
5625   // However, if the variable has the 'constinit' attribute, it _can_ be
5626   // referenced directly, without calling the thread-wrapper, so the linkage
5627   // must not be changed.
5628   //
5629   // Additionally, if the variable isn't plain external linkage, e.g. if it's
5630   // weak or linkonce, the de-duplication semantics are important to preserve,
5631   // so we don't change the linkage.
5632   if (D->getTLSKind() == VarDecl::TLS_Dynamic &&
5633       Linkage == llvm::GlobalValue::ExternalLinkage &&
5634       Context.getTargetInfo().getTriple().isOSDarwin() &&
5635       !D->hasAttr<ConstInitAttr>())
5636     Linkage = llvm::GlobalValue::InternalLinkage;
5637 
5638   GV->setLinkage(Linkage);
5639   if (D->hasAttr<DLLImportAttr>())
5640     GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
5641   else if (D->hasAttr<DLLExportAttr>())
5642     GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
5643   else
5644     GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
5645 
5646   if (Linkage == llvm::GlobalVariable::CommonLinkage) {
5647     // common vars aren't constant even if declared const.
5648     GV->setConstant(false);
5649     // Tentative definition of global variables may be initialized with
5650     // non-zero null pointers. In this case they should have weak linkage
5651     // since common linkage must have zero initializer and must not have
5652     // explicit section therefore cannot have non-zero initial value.
5653     if (!GV->getInitializer()->isNullValue())
5654       GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
5655   }
5656 
5657   setNonAliasAttributes(D, GV);
5658 
5659   if (D->getTLSKind() && !GV->isThreadLocal()) {
5660     if (D->getTLSKind() == VarDecl::TLS_Dynamic)
5661       CXXThreadLocals.push_back(D);
5662     setTLSMode(GV, *D);
5663   }
5664 
5665   maybeSetTrivialComdat(*D, *GV);
5666 
5667   // Emit the initializer function if necessary.
5668   if (NeedsGlobalCtor || NeedsGlobalDtor)
5669     EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
5670 
5671   SanitizerMD->reportGlobal(GV, *D, NeedsGlobalCtor);
5672 
5673   // Emit global variable debug information.
5674   if (CGDebugInfo *DI = getModuleDebugInfo())
5675     if (getCodeGenOpts().hasReducedDebugInfo())
5676       DI->EmitGlobalVariable(GV, D);
5677 }
5678 
5679 void CodeGenModule::EmitExternalVarDeclaration(const VarDecl *D) {
5680   if (CGDebugInfo *DI = getModuleDebugInfo())
5681     if (getCodeGenOpts().hasReducedDebugInfo()) {
5682       QualType ASTTy = D->getType();
5683       llvm::Type *Ty = getTypes().ConvertTypeForMem(D->getType());
5684       llvm::Constant *GV =
5685           GetOrCreateLLVMGlobal(D->getName(), Ty, ASTTy.getAddressSpace(), D);
5686       DI->EmitExternalVariable(
5687           cast<llvm::GlobalVariable>(GV->stripPointerCasts()), D);
5688     }
5689 }
5690 
5691 void CodeGenModule::EmitExternalFunctionDeclaration(const FunctionDecl *FD) {
5692   if (CGDebugInfo *DI = getModuleDebugInfo())
5693     if (getCodeGenOpts().hasReducedDebugInfo()) {
5694       auto *Ty = getTypes().ConvertType(FD->getType());
5695       StringRef MangledName = getMangledName(FD);
5696       auto *Fn = cast<llvm::Function>(
5697           GetOrCreateLLVMFunction(MangledName, Ty, FD, /* ForVTable */ false));
5698       if (!Fn->getSubprogram())
5699         DI->EmitFunctionDecl(FD, FD->getLocation(), FD->getType(), Fn);
5700     }
5701 }
5702 
5703 static bool isVarDeclStrongDefinition(const ASTContext &Context,
5704                                       CodeGenModule &CGM, const VarDecl *D,
5705                                       bool NoCommon) {
5706   // Don't give variables common linkage if -fno-common was specified unless it
5707   // was overridden by a NoCommon attribute.
5708   if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
5709     return true;
5710 
5711   // C11 6.9.2/2:
5712   //   A declaration of an identifier for an object that has file scope without
5713   //   an initializer, and without a storage-class specifier or with the
5714   //   storage-class specifier static, constitutes a tentative definition.
5715   if (D->getInit() || D->hasExternalStorage())
5716     return true;
5717 
5718   // A variable cannot be both common and exist in a section.
5719   if (D->hasAttr<SectionAttr>())
5720     return true;
5721 
5722   // A variable cannot be both common and exist in a section.
5723   // We don't try to determine which is the right section in the front-end.
5724   // If no specialized section name is applicable, it will resort to default.
5725   if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
5726       D->hasAttr<PragmaClangDataSectionAttr>() ||
5727       D->hasAttr<PragmaClangRelroSectionAttr>() ||
5728       D->hasAttr<PragmaClangRodataSectionAttr>())
5729     return true;
5730 
5731   // Thread local vars aren't considered common linkage.
5732   if (D->getTLSKind())
5733     return true;
5734 
5735   // Tentative definitions marked with WeakImportAttr are true definitions.
5736   if (D->hasAttr<WeakImportAttr>())
5737     return true;
5738 
5739   // A variable cannot be both common and exist in a comdat.
5740   if (shouldBeInCOMDAT(CGM, *D))
5741     return true;
5742 
5743   // Declarations with a required alignment do not have common linkage in MSVC
5744   // mode.
5745   if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
5746     if (D->hasAttr<AlignedAttr>())
5747       return true;
5748     QualType VarType = D->getType();
5749     if (Context.isAlignmentRequired(VarType))
5750       return true;
5751 
5752     if (const auto *RT = VarType->getAs<RecordType>()) {
5753       const RecordDecl *RD = RT->getDecl();
5754       for (const FieldDecl *FD : RD->fields()) {
5755         if (FD->isBitField())
5756           continue;
5757         if (FD->hasAttr<AlignedAttr>())
5758           return true;
5759         if (Context.isAlignmentRequired(FD->getType()))
5760           return true;
5761       }
5762     }
5763   }
5764 
5765   // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
5766   // common symbols, so symbols with greater alignment requirements cannot be
5767   // common.
5768   // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
5769   // alignments for common symbols via the aligncomm directive, so this
5770   // restriction only applies to MSVC environments.
5771   if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
5772       Context.getTypeAlignIfKnown(D->getType()) >
5773           Context.toBits(CharUnits::fromQuantity(32)))
5774     return true;
5775 
5776   return false;
5777 }
5778 
5779 llvm::GlobalValue::LinkageTypes
5780 CodeGenModule::getLLVMLinkageForDeclarator(const DeclaratorDecl *D,
5781                                            GVALinkage Linkage) {
5782   if (Linkage == GVA_Internal)
5783     return llvm::Function::InternalLinkage;
5784 
5785   if (D->hasAttr<WeakAttr>())
5786     return llvm::GlobalVariable::WeakAnyLinkage;
5787 
5788   if (const auto *FD = D->getAsFunction())
5789     if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
5790       return llvm::GlobalVariable::LinkOnceAnyLinkage;
5791 
5792   // We are guaranteed to have a strong definition somewhere else,
5793   // so we can use available_externally linkage.
5794   if (Linkage == GVA_AvailableExternally)
5795     return llvm::GlobalValue::AvailableExternallyLinkage;
5796 
5797   // Note that Apple's kernel linker doesn't support symbol
5798   // coalescing, so we need to avoid linkonce and weak linkages there.
5799   // Normally, this means we just map to internal, but for explicit
5800   // instantiations we'll map to external.
5801 
5802   // In C++, the compiler has to emit a definition in every translation unit
5803   // that references the function.  We should use linkonce_odr because
5804   // a) if all references in this translation unit are optimized away, we
5805   // don't need to codegen it.  b) if the function persists, it needs to be
5806   // merged with other definitions. c) C++ has the ODR, so we know the
5807   // definition is dependable.
5808   if (Linkage == GVA_DiscardableODR)
5809     return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
5810                                             : llvm::Function::InternalLinkage;
5811 
5812   // An explicit instantiation of a template has weak linkage, since
5813   // explicit instantiations can occur in multiple translation units
5814   // and must all be equivalent. However, we are not allowed to
5815   // throw away these explicit instantiations.
5816   //
5817   // CUDA/HIP: For -fno-gpu-rdc case, device code is limited to one TU,
5818   // so say that CUDA templates are either external (for kernels) or internal.
5819   // This lets llvm perform aggressive inter-procedural optimizations. For
5820   // -fgpu-rdc case, device function calls across multiple TU's are allowed,
5821   // therefore we need to follow the normal linkage paradigm.
5822   if (Linkage == GVA_StrongODR) {
5823     if (getLangOpts().AppleKext)
5824       return llvm::Function::ExternalLinkage;
5825     if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
5826         !getLangOpts().GPURelocatableDeviceCode)
5827       return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
5828                                           : llvm::Function::InternalLinkage;
5829     return llvm::Function::WeakODRLinkage;
5830   }
5831 
5832   // C++ doesn't have tentative definitions and thus cannot have common
5833   // linkage.
5834   if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
5835       !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
5836                                  CodeGenOpts.NoCommon))
5837     return llvm::GlobalVariable::CommonLinkage;
5838 
5839   // selectany symbols are externally visible, so use weak instead of
5840   // linkonce.  MSVC optimizes away references to const selectany globals, so
5841   // all definitions should be the same and ODR linkage should be used.
5842   // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
5843   if (D->hasAttr<SelectAnyAttr>())
5844     return llvm::GlobalVariable::WeakODRLinkage;
5845 
5846   // Otherwise, we have strong external linkage.
5847   assert(Linkage == GVA_StrongExternal);
5848   return llvm::GlobalVariable::ExternalLinkage;
5849 }
5850 
5851 llvm::GlobalValue::LinkageTypes
5852 CodeGenModule::getLLVMLinkageVarDefinition(const VarDecl *VD) {
5853   GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
5854   return getLLVMLinkageForDeclarator(VD, Linkage);
5855 }
5856 
5857 /// Replace the uses of a function that was declared with a non-proto type.
5858 /// We want to silently drop extra arguments from call sites
5859 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
5860                                           llvm::Function *newFn) {
5861   // Fast path.
5862   if (old->use_empty())
5863     return;
5864 
5865   llvm::Type *newRetTy = newFn->getReturnType();
5866   SmallVector<llvm::Value *, 4> newArgs;
5867 
5868   SmallVector<llvm::CallBase *> callSitesToBeRemovedFromParent;
5869 
5870   for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
5871        ui != ue; ui++) {
5872     llvm::User *user = ui->getUser();
5873 
5874     // Recognize and replace uses of bitcasts.  Most calls to
5875     // unprototyped functions will use bitcasts.
5876     if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
5877       if (bitcast->getOpcode() == llvm::Instruction::BitCast)
5878         replaceUsesOfNonProtoConstant(bitcast, newFn);
5879       continue;
5880     }
5881 
5882     // Recognize calls to the function.
5883     llvm::CallBase *callSite = dyn_cast<llvm::CallBase>(user);
5884     if (!callSite)
5885       continue;
5886     if (!callSite->isCallee(&*ui))
5887       continue;
5888 
5889     // If the return types don't match exactly, then we can't
5890     // transform this call unless it's dead.
5891     if (callSite->getType() != newRetTy && !callSite->use_empty())
5892       continue;
5893 
5894     // Get the call site's attribute list.
5895     SmallVector<llvm::AttributeSet, 8> newArgAttrs;
5896     llvm::AttributeList oldAttrs = callSite->getAttributes();
5897 
5898     // If the function was passed too few arguments, don't transform.
5899     unsigned newNumArgs = newFn->arg_size();
5900     if (callSite->arg_size() < newNumArgs)
5901       continue;
5902 
5903     // If extra arguments were passed, we silently drop them.
5904     // If any of the types mismatch, we don't transform.
5905     unsigned argNo = 0;
5906     bool dontTransform = false;
5907     for (llvm::Argument &A : newFn->args()) {
5908       if (callSite->getArgOperand(argNo)->getType() != A.getType()) {
5909         dontTransform = true;
5910         break;
5911       }
5912 
5913       // Add any parameter attributes.
5914       newArgAttrs.push_back(oldAttrs.getParamAttrs(argNo));
5915       argNo++;
5916     }
5917     if (dontTransform)
5918       continue;
5919 
5920     // Okay, we can transform this.  Create the new call instruction and copy
5921     // over the required information.
5922     newArgs.append(callSite->arg_begin(), callSite->arg_begin() + argNo);
5923 
5924     // Copy over any operand bundles.
5925     SmallVector<llvm::OperandBundleDef, 1> newBundles;
5926     callSite->getOperandBundlesAsDefs(newBundles);
5927 
5928     llvm::CallBase *newCall;
5929     if (isa<llvm::CallInst>(callSite)) {
5930       newCall = llvm::CallInst::Create(newFn, newArgs, newBundles, "",
5931                                        callSite->getIterator());
5932     } else {
5933       auto *oldInvoke = cast<llvm::InvokeInst>(callSite);
5934       newCall = llvm::InvokeInst::Create(
5935           newFn, oldInvoke->getNormalDest(), oldInvoke->getUnwindDest(),
5936           newArgs, newBundles, "", callSite->getIterator());
5937     }
5938     newArgs.clear(); // for the next iteration
5939 
5940     if (!newCall->getType()->isVoidTy())
5941       newCall->takeName(callSite);
5942     newCall->setAttributes(
5943         llvm::AttributeList::get(newFn->getContext(), oldAttrs.getFnAttrs(),
5944                                  oldAttrs.getRetAttrs(), newArgAttrs));
5945     newCall->setCallingConv(callSite->getCallingConv());
5946 
5947     // Finally, remove the old call, replacing any uses with the new one.
5948     if (!callSite->use_empty())
5949       callSite->replaceAllUsesWith(newCall);
5950 
5951     // Copy debug location attached to CI.
5952     if (callSite->getDebugLoc())
5953       newCall->setDebugLoc(callSite->getDebugLoc());
5954 
5955     callSitesToBeRemovedFromParent.push_back(callSite);
5956   }
5957 
5958   for (auto *callSite : callSitesToBeRemovedFromParent) {
5959     callSite->eraseFromParent();
5960   }
5961 }
5962 
5963 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
5964 /// implement a function with no prototype, e.g. "int foo() {}".  If there are
5965 /// existing call uses of the old function in the module, this adjusts them to
5966 /// call the new function directly.
5967 ///
5968 /// This is not just a cleanup: the always_inline pass requires direct calls to
5969 /// functions to be able to inline them.  If there is a bitcast in the way, it
5970 /// won't inline them.  Instcombine normally deletes these calls, but it isn't
5971 /// run at -O0.
5972 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
5973                                                       llvm::Function *NewFn) {
5974   // If we're redefining a global as a function, don't transform it.
5975   if (!isa<llvm::Function>(Old)) return;
5976 
5977   replaceUsesOfNonProtoConstant(Old, NewFn);
5978 }
5979 
5980 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
5981   auto DK = VD->isThisDeclarationADefinition();
5982   if ((DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>()) ||
5983       (LangOpts.CUDA && !shouldEmitCUDAGlobalVar(VD)))
5984     return;
5985 
5986   TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
5987   // If we have a definition, this might be a deferred decl. If the
5988   // instantiation is explicit, make sure we emit it at the end.
5989   if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
5990     GetAddrOfGlobalVar(VD);
5991 
5992   EmitTopLevelDecl(VD);
5993 }
5994 
5995 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
5996                                                  llvm::GlobalValue *GV) {
5997   const auto *D = cast<FunctionDecl>(GD.getDecl());
5998 
5999   // Compute the function info and LLVM type.
6000   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
6001   llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
6002 
6003   // Get or create the prototype for the function.
6004   if (!GV || (GV->getValueType() != Ty))
6005     GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
6006                                                    /*DontDefer=*/true,
6007                                                    ForDefinition));
6008 
6009   // Already emitted.
6010   if (!GV->isDeclaration())
6011     return;
6012 
6013   // We need to set linkage and visibility on the function before
6014   // generating code for it because various parts of IR generation
6015   // want to propagate this information down (e.g. to local static
6016   // declarations).
6017   auto *Fn = cast<llvm::Function>(GV);
6018   setFunctionLinkage(GD, Fn);
6019 
6020   // FIXME: this is redundant with part of setFunctionDefinitionAttributes
6021   setGVProperties(Fn, GD);
6022 
6023   MaybeHandleStaticInExternC(D, Fn);
6024 
6025   maybeSetTrivialComdat(*D, *Fn);
6026 
6027   CodeGenFunction(*this).GenerateCode(GD, Fn, FI);
6028 
6029   setNonAliasAttributes(GD, Fn);
6030   SetLLVMFunctionAttributesForDefinition(D, Fn);
6031 
6032   if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
6033     AddGlobalCtor(Fn, CA->getPriority());
6034   if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
6035     AddGlobalDtor(Fn, DA->getPriority(), true);
6036   if (getLangOpts().OpenMP && D->hasAttr<OMPDeclareTargetDeclAttr>())
6037     getOpenMPRuntime().emitDeclareTargetFunction(D, GV);
6038 }
6039 
6040 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
6041   const auto *D = cast<ValueDecl>(GD.getDecl());
6042   const AliasAttr *AA = D->getAttr<AliasAttr>();
6043   assert(AA && "Not an alias?");
6044 
6045   StringRef MangledName = getMangledName(GD);
6046 
6047   if (AA->getAliasee() == MangledName) {
6048     Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
6049     return;
6050   }
6051 
6052   // If there is a definition in the module, then it wins over the alias.
6053   // This is dubious, but allow it to be safe.  Just ignore the alias.
6054   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
6055   if (Entry && !Entry->isDeclaration())
6056     return;
6057 
6058   Aliases.push_back(GD);
6059 
6060   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
6061 
6062   // Create a reference to the named value.  This ensures that it is emitted
6063   // if a deferred decl.
6064   llvm::Constant *Aliasee;
6065   llvm::GlobalValue::LinkageTypes LT;
6066   if (isa<llvm::FunctionType>(DeclTy)) {
6067     Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
6068                                       /*ForVTable=*/false);
6069     LT = getFunctionLinkage(GD);
6070   } else {
6071     Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, LangAS::Default,
6072                                     /*D=*/nullptr);
6073     if (const auto *VD = dyn_cast<VarDecl>(GD.getDecl()))
6074       LT = getLLVMLinkageVarDefinition(VD);
6075     else
6076       LT = getFunctionLinkage(GD);
6077   }
6078 
6079   // Create the new alias itself, but don't set a name yet.
6080   unsigned AS = Aliasee->getType()->getPointerAddressSpace();
6081   auto *GA =
6082       llvm::GlobalAlias::create(DeclTy, AS, LT, "", Aliasee, &getModule());
6083 
6084   if (Entry) {
6085     if (GA->getAliasee() == Entry) {
6086       Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
6087       return;
6088     }
6089 
6090     assert(Entry->isDeclaration());
6091 
6092     // If there is a declaration in the module, then we had an extern followed
6093     // by the alias, as in:
6094     //   extern int test6();
6095     //   ...
6096     //   int test6() __attribute__((alias("test7")));
6097     //
6098     // Remove it and replace uses of it with the alias.
6099     GA->takeName(Entry);
6100 
6101     Entry->replaceAllUsesWith(GA);
6102     Entry->eraseFromParent();
6103   } else {
6104     GA->setName(MangledName);
6105   }
6106 
6107   // Set attributes which are particular to an alias; this is a
6108   // specialization of the attributes which may be set on a global
6109   // variable/function.
6110   if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
6111       D->isWeakImported()) {
6112     GA->setLinkage(llvm::Function::WeakAnyLinkage);
6113   }
6114 
6115   if (const auto *VD = dyn_cast<VarDecl>(D))
6116     if (VD->getTLSKind())
6117       setTLSMode(GA, *VD);
6118 
6119   SetCommonAttributes(GD, GA);
6120 
6121   // Emit global alias debug information.
6122   if (isa<VarDecl>(D))
6123     if (CGDebugInfo *DI = getModuleDebugInfo())
6124       DI->EmitGlobalAlias(cast<llvm::GlobalValue>(GA->getAliasee()->stripPointerCasts()), GD);
6125 }
6126 
6127 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
6128   const auto *D = cast<ValueDecl>(GD.getDecl());
6129   const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
6130   assert(IFA && "Not an ifunc?");
6131 
6132   StringRef MangledName = getMangledName(GD);
6133 
6134   if (IFA->getResolver() == MangledName) {
6135     Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
6136     return;
6137   }
6138 
6139   // Report an error if some definition overrides ifunc.
6140   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
6141   if (Entry && !Entry->isDeclaration()) {
6142     GlobalDecl OtherGD;
6143     if (lookupRepresentativeDecl(MangledName, OtherGD) &&
6144         DiagnosedConflictingDefinitions.insert(GD).second) {
6145       Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
6146           << MangledName;
6147       Diags.Report(OtherGD.getDecl()->getLocation(),
6148                    diag::note_previous_definition);
6149     }
6150     return;
6151   }
6152 
6153   Aliases.push_back(GD);
6154 
6155   // The resolver might not be visited yet. Specify a dummy non-function type to
6156   // indicate IsIncompleteFunction. Either the type is ignored (if the resolver
6157   // was emitted) or the whole function will be replaced (if the resolver has
6158   // not been emitted).
6159   llvm::Constant *Resolver =
6160       GetOrCreateLLVMFunction(IFA->getResolver(), VoidTy, {},
6161                               /*ForVTable=*/false);
6162   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
6163   llvm::GlobalIFunc *GIF =
6164       llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage,
6165                                 "", Resolver, &getModule());
6166   if (Entry) {
6167     if (GIF->getResolver() == Entry) {
6168       Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
6169       return;
6170     }
6171     assert(Entry->isDeclaration());
6172 
6173     // If there is a declaration in the module, then we had an extern followed
6174     // by the ifunc, as in:
6175     //   extern int test();
6176     //   ...
6177     //   int test() __attribute__((ifunc("resolver")));
6178     //
6179     // Remove it and replace uses of it with the ifunc.
6180     GIF->takeName(Entry);
6181 
6182     Entry->replaceAllUsesWith(GIF);
6183     Entry->eraseFromParent();
6184   } else
6185     GIF->setName(MangledName);
6186   SetCommonAttributes(GD, GIF);
6187 }
6188 
6189 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
6190                                             ArrayRef<llvm::Type*> Tys) {
6191   return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
6192                                          Tys);
6193 }
6194 
6195 static llvm::StringMapEntry<llvm::GlobalVariable *> &
6196 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
6197                          const StringLiteral *Literal, bool TargetIsLSB,
6198                          bool &IsUTF16, unsigned &StringLength) {
6199   StringRef String = Literal->getString();
6200   unsigned NumBytes = String.size();
6201 
6202   // Check for simple case.
6203   if (!Literal->containsNonAsciiOrNull()) {
6204     StringLength = NumBytes;
6205     return *Map.insert(std::make_pair(String, nullptr)).first;
6206   }
6207 
6208   // Otherwise, convert the UTF8 literals into a string of shorts.
6209   IsUTF16 = true;
6210 
6211   SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
6212   const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
6213   llvm::UTF16 *ToPtr = &ToBuf[0];
6214 
6215   (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
6216                                  ToPtr + NumBytes, llvm::strictConversion);
6217 
6218   // ConvertUTF8toUTF16 returns the length in ToPtr.
6219   StringLength = ToPtr - &ToBuf[0];
6220 
6221   // Add an explicit null.
6222   *ToPtr = 0;
6223   return *Map.insert(std::make_pair(
6224                          StringRef(reinterpret_cast<const char *>(ToBuf.data()),
6225                                    (StringLength + 1) * 2),
6226                          nullptr)).first;
6227 }
6228 
6229 ConstantAddress
6230 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
6231   unsigned StringLength = 0;
6232   bool isUTF16 = false;
6233   llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
6234       GetConstantCFStringEntry(CFConstantStringMap, Literal,
6235                                getDataLayout().isLittleEndian(), isUTF16,
6236                                StringLength);
6237 
6238   if (auto *C = Entry.second)
6239     return ConstantAddress(
6240         C, C->getValueType(), CharUnits::fromQuantity(C->getAlignment()));
6241 
6242   const ASTContext &Context = getContext();
6243   const llvm::Triple &Triple = getTriple();
6244 
6245   const auto CFRuntime = getLangOpts().CFRuntime;
6246   const bool IsSwiftABI =
6247       static_cast<unsigned>(CFRuntime) >=
6248       static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
6249   const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
6250 
6251   // If we don't already have it, get __CFConstantStringClassReference.
6252   if (!CFConstantStringClassRef) {
6253     const char *CFConstantStringClassName = "__CFConstantStringClassReference";
6254     llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
6255     Ty = llvm::ArrayType::get(Ty, 0);
6256 
6257     switch (CFRuntime) {
6258     default: break;
6259     case LangOptions::CoreFoundationABI::Swift: [[fallthrough]];
6260     case LangOptions::CoreFoundationABI::Swift5_0:
6261       CFConstantStringClassName =
6262           Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
6263                               : "$s10Foundation19_NSCFConstantStringCN";
6264       Ty = IntPtrTy;
6265       break;
6266     case LangOptions::CoreFoundationABI::Swift4_2:
6267       CFConstantStringClassName =
6268           Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
6269                               : "$S10Foundation19_NSCFConstantStringCN";
6270       Ty = IntPtrTy;
6271       break;
6272     case LangOptions::CoreFoundationABI::Swift4_1:
6273       CFConstantStringClassName =
6274           Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
6275                               : "__T010Foundation19_NSCFConstantStringCN";
6276       Ty = IntPtrTy;
6277       break;
6278     }
6279 
6280     llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
6281 
6282     if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
6283       llvm::GlobalValue *GV = nullptr;
6284 
6285       if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
6286         IdentifierInfo &II = Context.Idents.get(GV->getName());
6287         TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
6288         DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
6289 
6290         const VarDecl *VD = nullptr;
6291         for (const auto *Result : DC->lookup(&II))
6292           if ((VD = dyn_cast<VarDecl>(Result)))
6293             break;
6294 
6295         if (Triple.isOSBinFormatELF()) {
6296           if (!VD)
6297             GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
6298         } else {
6299           GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
6300           if (!VD || !VD->hasAttr<DLLExportAttr>())
6301             GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
6302           else
6303             GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
6304         }
6305 
6306         setDSOLocal(GV);
6307       }
6308     }
6309 
6310     // Decay array -> ptr
6311     CFConstantStringClassRef =
6312         IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty) : C;
6313   }
6314 
6315   QualType CFTy = Context.getCFConstantStringType();
6316 
6317   auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
6318 
6319   ConstantInitBuilder Builder(*this);
6320   auto Fields = Builder.beginStruct(STy);
6321 
6322   // Class pointer.
6323   Fields.add(cast<llvm::Constant>(CFConstantStringClassRef));
6324 
6325   // Flags.
6326   if (IsSwiftABI) {
6327     Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
6328     Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
6329   } else {
6330     Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
6331   }
6332 
6333   // String pointer.
6334   llvm::Constant *C = nullptr;
6335   if (isUTF16) {
6336     auto Arr = llvm::ArrayRef(
6337         reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
6338         Entry.first().size() / 2);
6339     C = llvm::ConstantDataArray::get(VMContext, Arr);
6340   } else {
6341     C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
6342   }
6343 
6344   // Note: -fwritable-strings doesn't make the backing store strings of
6345   // CFStrings writable.
6346   auto *GV =
6347       new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
6348                                llvm::GlobalValue::PrivateLinkage, C, ".str");
6349   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
6350   // Don't enforce the target's minimum global alignment, since the only use
6351   // of the string is via this class initializer.
6352   CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
6353                             : Context.getTypeAlignInChars(Context.CharTy);
6354   GV->setAlignment(Align.getAsAlign());
6355 
6356   // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
6357   // Without it LLVM can merge the string with a non unnamed_addr one during
6358   // LTO.  Doing that changes the section it ends in, which surprises ld64.
6359   if (Triple.isOSBinFormatMachO())
6360     GV->setSection(isUTF16 ? "__TEXT,__ustring"
6361                            : "__TEXT,__cstring,cstring_literals");
6362   // Make sure the literal ends up in .rodata to allow for safe ICF and for
6363   // the static linker to adjust permissions to read-only later on.
6364   else if (Triple.isOSBinFormatELF())
6365     GV->setSection(".rodata");
6366 
6367   // String.
6368   Fields.add(GV);
6369 
6370   // String length.
6371   llvm::IntegerType *LengthTy =
6372       llvm::IntegerType::get(getModule().getContext(),
6373                              Context.getTargetInfo().getLongWidth());
6374   if (IsSwiftABI) {
6375     if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
6376         CFRuntime == LangOptions::CoreFoundationABI::Swift4_2)
6377       LengthTy = Int32Ty;
6378     else
6379       LengthTy = IntPtrTy;
6380   }
6381   Fields.addInt(LengthTy, StringLength);
6382 
6383   // Swift ABI requires 8-byte alignment to ensure that the _Atomic(uint64_t) is
6384   // properly aligned on 32-bit platforms.
6385   CharUnits Alignment =
6386       IsSwiftABI ? Context.toCharUnitsFromBits(64) : getPointerAlign();
6387 
6388   // The struct.
6389   GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
6390                                     /*isConstant=*/false,
6391                                     llvm::GlobalVariable::PrivateLinkage);
6392   GV->addAttribute("objc_arc_inert");
6393   switch (Triple.getObjectFormat()) {
6394   case llvm::Triple::UnknownObjectFormat:
6395     llvm_unreachable("unknown file format");
6396   case llvm::Triple::DXContainer:
6397   case llvm::Triple::GOFF:
6398   case llvm::Triple::SPIRV:
6399   case llvm::Triple::XCOFF:
6400     llvm_unreachable("unimplemented");
6401   case llvm::Triple::COFF:
6402   case llvm::Triple::ELF:
6403   case llvm::Triple::Wasm:
6404     GV->setSection("cfstring");
6405     break;
6406   case llvm::Triple::MachO:
6407     GV->setSection("__DATA,__cfstring");
6408     break;
6409   }
6410   Entry.second = GV;
6411 
6412   return ConstantAddress(GV, GV->getValueType(), Alignment);
6413 }
6414 
6415 bool CodeGenModule::getExpressionLocationsEnabled() const {
6416   return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
6417 }
6418 
6419 QualType CodeGenModule::getObjCFastEnumerationStateType() {
6420   if (ObjCFastEnumerationStateType.isNull()) {
6421     RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
6422     D->startDefinition();
6423 
6424     QualType FieldTypes[] = {
6425         Context.UnsignedLongTy, Context.getPointerType(Context.getObjCIdType()),
6426         Context.getPointerType(Context.UnsignedLongTy),
6427         Context.getConstantArrayType(Context.UnsignedLongTy, llvm::APInt(32, 5),
6428                                      nullptr, ArraySizeModifier::Normal, 0)};
6429 
6430     for (size_t i = 0; i < 4; ++i) {
6431       FieldDecl *Field = FieldDecl::Create(Context,
6432                                            D,
6433                                            SourceLocation(),
6434                                            SourceLocation(), nullptr,
6435                                            FieldTypes[i], /*TInfo=*/nullptr,
6436                                            /*BitWidth=*/nullptr,
6437                                            /*Mutable=*/false,
6438                                            ICIS_NoInit);
6439       Field->setAccess(AS_public);
6440       D->addDecl(Field);
6441     }
6442 
6443     D->completeDefinition();
6444     ObjCFastEnumerationStateType = Context.getTagDeclType(D);
6445   }
6446 
6447   return ObjCFastEnumerationStateType;
6448 }
6449 
6450 llvm::Constant *
6451 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
6452   assert(!E->getType()->isPointerType() && "Strings are always arrays");
6453 
6454   // Don't emit it as the address of the string, emit the string data itself
6455   // as an inline array.
6456   if (E->getCharByteWidth() == 1) {
6457     SmallString<64> Str(E->getString());
6458 
6459     // Resize the string to the right size, which is indicated by its type.
6460     const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
6461     assert(CAT && "String literal not of constant array type!");
6462     Str.resize(CAT->getZExtSize());
6463     return llvm::ConstantDataArray::getString(VMContext, Str, false);
6464   }
6465 
6466   auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
6467   llvm::Type *ElemTy = AType->getElementType();
6468   unsigned NumElements = AType->getNumElements();
6469 
6470   // Wide strings have either 2-byte or 4-byte elements.
6471   if (ElemTy->getPrimitiveSizeInBits() == 16) {
6472     SmallVector<uint16_t, 32> Elements;
6473     Elements.reserve(NumElements);
6474 
6475     for(unsigned i = 0, e = E->getLength(); i != e; ++i)
6476       Elements.push_back(E->getCodeUnit(i));
6477     Elements.resize(NumElements);
6478     return llvm::ConstantDataArray::get(VMContext, Elements);
6479   }
6480 
6481   assert(ElemTy->getPrimitiveSizeInBits() == 32);
6482   SmallVector<uint32_t, 32> Elements;
6483   Elements.reserve(NumElements);
6484 
6485   for(unsigned i = 0, e = E->getLength(); i != e; ++i)
6486     Elements.push_back(E->getCodeUnit(i));
6487   Elements.resize(NumElements);
6488   return llvm::ConstantDataArray::get(VMContext, Elements);
6489 }
6490 
6491 static llvm::GlobalVariable *
6492 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
6493                       CodeGenModule &CGM, StringRef GlobalName,
6494                       CharUnits Alignment) {
6495   unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
6496       CGM.GetGlobalConstantAddressSpace());
6497 
6498   llvm::Module &M = CGM.getModule();
6499   // Create a global variable for this string
6500   auto *GV = new llvm::GlobalVariable(
6501       M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
6502       nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
6503   GV->setAlignment(Alignment.getAsAlign());
6504   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
6505   if (GV->isWeakForLinker()) {
6506     assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
6507     GV->setComdat(M.getOrInsertComdat(GV->getName()));
6508   }
6509   CGM.setDSOLocal(GV);
6510 
6511   return GV;
6512 }
6513 
6514 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
6515 /// constant array for the given string literal.
6516 ConstantAddress
6517 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
6518                                                   StringRef Name) {
6519   CharUnits Alignment =
6520       getContext().getAlignOfGlobalVarInChars(S->getType(), /*VD=*/nullptr);
6521 
6522   llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
6523   llvm::GlobalVariable **Entry = nullptr;
6524   if (!LangOpts.WritableStrings) {
6525     Entry = &ConstantStringMap[C];
6526     if (auto GV = *Entry) {
6527       if (uint64_t(Alignment.getQuantity()) > GV->getAlignment())
6528         GV->setAlignment(Alignment.getAsAlign());
6529       return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6530                              GV->getValueType(), Alignment);
6531     }
6532   }
6533 
6534   SmallString<256> MangledNameBuffer;
6535   StringRef GlobalVariableName;
6536   llvm::GlobalValue::LinkageTypes LT;
6537 
6538   // Mangle the string literal if that's how the ABI merges duplicate strings.
6539   // Don't do it if they are writable, since we don't want writes in one TU to
6540   // affect strings in another.
6541   if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
6542       !LangOpts.WritableStrings) {
6543     llvm::raw_svector_ostream Out(MangledNameBuffer);
6544     getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
6545     LT = llvm::GlobalValue::LinkOnceODRLinkage;
6546     GlobalVariableName = MangledNameBuffer;
6547   } else {
6548     LT = llvm::GlobalValue::PrivateLinkage;
6549     GlobalVariableName = Name;
6550   }
6551 
6552   auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
6553 
6554   CGDebugInfo *DI = getModuleDebugInfo();
6555   if (DI && getCodeGenOpts().hasReducedDebugInfo())
6556     DI->AddStringLiteralDebugInfo(GV, S);
6557 
6558   if (Entry)
6559     *Entry = GV;
6560 
6561   SanitizerMD->reportGlobal(GV, S->getStrTokenLoc(0), "<string literal>");
6562 
6563   return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6564                          GV->getValueType(), Alignment);
6565 }
6566 
6567 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
6568 /// array for the given ObjCEncodeExpr node.
6569 ConstantAddress
6570 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
6571   std::string Str;
6572   getContext().getObjCEncodingForType(E->getEncodedType(), Str);
6573 
6574   return GetAddrOfConstantCString(Str);
6575 }
6576 
6577 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
6578 /// the literal and a terminating '\0' character.
6579 /// The result has pointer to array type.
6580 ConstantAddress CodeGenModule::GetAddrOfConstantCString(
6581     const std::string &Str, const char *GlobalName) {
6582   StringRef StrWithNull(Str.c_str(), Str.size() + 1);
6583   CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(
6584       getContext().CharTy, /*VD=*/nullptr);
6585 
6586   llvm::Constant *C =
6587       llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
6588 
6589   // Don't share any string literals if strings aren't constant.
6590   llvm::GlobalVariable **Entry = nullptr;
6591   if (!LangOpts.WritableStrings) {
6592     Entry = &ConstantStringMap[C];
6593     if (auto GV = *Entry) {
6594       if (uint64_t(Alignment.getQuantity()) > GV->getAlignment())
6595         GV->setAlignment(Alignment.getAsAlign());
6596       return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6597                              GV->getValueType(), Alignment);
6598     }
6599   }
6600 
6601   // Get the default prefix if a name wasn't specified.
6602   if (!GlobalName)
6603     GlobalName = ".str";
6604   // Create a global variable for this.
6605   auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
6606                                   GlobalName, Alignment);
6607   if (Entry)
6608     *Entry = GV;
6609 
6610   return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6611                          GV->getValueType(), Alignment);
6612 }
6613 
6614 ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
6615     const MaterializeTemporaryExpr *E, const Expr *Init) {
6616   assert((E->getStorageDuration() == SD_Static ||
6617           E->getStorageDuration() == SD_Thread) && "not a global temporary");
6618   const auto *VD = cast<VarDecl>(E->getExtendingDecl());
6619 
6620   // If we're not materializing a subobject of the temporary, keep the
6621   // cv-qualifiers from the type of the MaterializeTemporaryExpr.
6622   QualType MaterializedType = Init->getType();
6623   if (Init == E->getSubExpr())
6624     MaterializedType = E->getType();
6625 
6626   CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
6627 
6628   auto InsertResult = MaterializedGlobalTemporaryMap.insert({E, nullptr});
6629   if (!InsertResult.second) {
6630     // We've seen this before: either we already created it or we're in the
6631     // process of doing so.
6632     if (!InsertResult.first->second) {
6633       // We recursively re-entered this function, probably during emission of
6634       // the initializer. Create a placeholder. We'll clean this up in the
6635       // outer call, at the end of this function.
6636       llvm::Type *Type = getTypes().ConvertTypeForMem(MaterializedType);
6637       InsertResult.first->second = new llvm::GlobalVariable(
6638           getModule(), Type, false, llvm::GlobalVariable::InternalLinkage,
6639           nullptr);
6640     }
6641     return ConstantAddress(InsertResult.first->second,
6642                            llvm::cast<llvm::GlobalVariable>(
6643                                InsertResult.first->second->stripPointerCasts())
6644                                ->getValueType(),
6645                            Align);
6646   }
6647 
6648   // FIXME: If an externally-visible declaration extends multiple temporaries,
6649   // we need to give each temporary the same name in every translation unit (and
6650   // we also need to make the temporaries externally-visible).
6651   SmallString<256> Name;
6652   llvm::raw_svector_ostream Out(Name);
6653   getCXXABI().getMangleContext().mangleReferenceTemporary(
6654       VD, E->getManglingNumber(), Out);
6655 
6656   APValue *Value = nullptr;
6657   if (E->getStorageDuration() == SD_Static && VD->evaluateValue()) {
6658     // If the initializer of the extending declaration is a constant
6659     // initializer, we should have a cached constant initializer for this
6660     // temporary. Note that this might have a different value from the value
6661     // computed by evaluating the initializer if the surrounding constant
6662     // expression modifies the temporary.
6663     Value = E->getOrCreateValue(false);
6664   }
6665 
6666   // Try evaluating it now, it might have a constant initializer.
6667   Expr::EvalResult EvalResult;
6668   if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
6669       !EvalResult.hasSideEffects())
6670     Value = &EvalResult.Val;
6671 
6672   LangAS AddrSpace = GetGlobalVarAddressSpace(VD);
6673 
6674   std::optional<ConstantEmitter> emitter;
6675   llvm::Constant *InitialValue = nullptr;
6676   bool Constant = false;
6677   llvm::Type *Type;
6678   if (Value) {
6679     // The temporary has a constant initializer, use it.
6680     emitter.emplace(*this);
6681     InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
6682                                                MaterializedType);
6683     Constant =
6684         MaterializedType.isConstantStorage(getContext(), /*ExcludeCtor*/ Value,
6685                                            /*ExcludeDtor*/ false);
6686     Type = InitialValue->getType();
6687   } else {
6688     // No initializer, the initialization will be provided when we
6689     // initialize the declaration which performed lifetime extension.
6690     Type = getTypes().ConvertTypeForMem(MaterializedType);
6691   }
6692 
6693   // Create a global variable for this lifetime-extended temporary.
6694   llvm::GlobalValue::LinkageTypes Linkage = getLLVMLinkageVarDefinition(VD);
6695   if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
6696     const VarDecl *InitVD;
6697     if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
6698         isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
6699       // Temporaries defined inside a class get linkonce_odr linkage because the
6700       // class can be defined in multiple translation units.
6701       Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
6702     } else {
6703       // There is no need for this temporary to have external linkage if the
6704       // VarDecl has external linkage.
6705       Linkage = llvm::GlobalVariable::InternalLinkage;
6706     }
6707   }
6708   auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
6709   auto *GV = new llvm::GlobalVariable(
6710       getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
6711       /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
6712   if (emitter) emitter->finalize(GV);
6713   // Don't assign dllimport or dllexport to local linkage globals.
6714   if (!llvm::GlobalValue::isLocalLinkage(Linkage)) {
6715     setGVProperties(GV, VD);
6716     if (GV->getDLLStorageClass() == llvm::GlobalVariable::DLLExportStorageClass)
6717       // The reference temporary should never be dllexport.
6718       GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
6719   }
6720   GV->setAlignment(Align.getAsAlign());
6721   if (supportsCOMDAT() && GV->isWeakForLinker())
6722     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
6723   if (VD->getTLSKind())
6724     setTLSMode(GV, *VD);
6725   llvm::Constant *CV = GV;
6726   if (AddrSpace != LangAS::Default)
6727     CV = getTargetCodeGenInfo().performAddrSpaceCast(
6728         *this, GV, AddrSpace, LangAS::Default,
6729         llvm::PointerType::get(
6730             getLLVMContext(),
6731             getContext().getTargetAddressSpace(LangAS::Default)));
6732 
6733   // Update the map with the new temporary. If we created a placeholder above,
6734   // replace it with the new global now.
6735   llvm::Constant *&Entry = MaterializedGlobalTemporaryMap[E];
6736   if (Entry) {
6737     Entry->replaceAllUsesWith(CV);
6738     llvm::cast<llvm::GlobalVariable>(Entry)->eraseFromParent();
6739   }
6740   Entry = CV;
6741 
6742   return ConstantAddress(CV, Type, Align);
6743 }
6744 
6745 /// EmitObjCPropertyImplementations - Emit information for synthesized
6746 /// properties for an implementation.
6747 void CodeGenModule::EmitObjCPropertyImplementations(const
6748                                                     ObjCImplementationDecl *D) {
6749   for (const auto *PID : D->property_impls()) {
6750     // Dynamic is just for type-checking.
6751     if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
6752       ObjCPropertyDecl *PD = PID->getPropertyDecl();
6753 
6754       // Determine which methods need to be implemented, some may have
6755       // been overridden. Note that ::isPropertyAccessor is not the method
6756       // we want, that just indicates if the decl came from a
6757       // property. What we want to know is if the method is defined in
6758       // this implementation.
6759       auto *Getter = PID->getGetterMethodDecl();
6760       if (!Getter || Getter->isSynthesizedAccessorStub())
6761         CodeGenFunction(*this).GenerateObjCGetter(
6762             const_cast<ObjCImplementationDecl *>(D), PID);
6763       auto *Setter = PID->getSetterMethodDecl();
6764       if (!PD->isReadOnly() && (!Setter || Setter->isSynthesizedAccessorStub()))
6765         CodeGenFunction(*this).GenerateObjCSetter(
6766                                  const_cast<ObjCImplementationDecl *>(D), PID);
6767     }
6768   }
6769 }
6770 
6771 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
6772   const ObjCInterfaceDecl *iface = impl->getClassInterface();
6773   for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
6774        ivar; ivar = ivar->getNextIvar())
6775     if (ivar->getType().isDestructedType())
6776       return true;
6777 
6778   return false;
6779 }
6780 
6781 static bool AllTrivialInitializers(CodeGenModule &CGM,
6782                                    ObjCImplementationDecl *D) {
6783   CodeGenFunction CGF(CGM);
6784   for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
6785        E = D->init_end(); B != E; ++B) {
6786     CXXCtorInitializer *CtorInitExp = *B;
6787     Expr *Init = CtorInitExp->getInit();
6788     if (!CGF.isTrivialInitializer(Init))
6789       return false;
6790   }
6791   return true;
6792 }
6793 
6794 /// EmitObjCIvarInitializations - Emit information for ivar initialization
6795 /// for an implementation.
6796 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
6797   // We might need a .cxx_destruct even if we don't have any ivar initializers.
6798   if (needsDestructMethod(D)) {
6799     const IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
6800     Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
6801     ObjCMethodDecl *DTORMethod = ObjCMethodDecl::Create(
6802         getContext(), D->getLocation(), D->getLocation(), cxxSelector,
6803         getContext().VoidTy, nullptr, D,
6804         /*isInstance=*/true, /*isVariadic=*/false,
6805         /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
6806         /*isImplicitlyDeclared=*/true,
6807         /*isDefined=*/false, ObjCImplementationControl::Required);
6808     D->addInstanceMethod(DTORMethod);
6809     CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
6810     D->setHasDestructors(true);
6811   }
6812 
6813   // If the implementation doesn't have any ivar initializers, we don't need
6814   // a .cxx_construct.
6815   if (D->getNumIvarInitializers() == 0 ||
6816       AllTrivialInitializers(*this, D))
6817     return;
6818 
6819   const IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
6820   Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
6821   // The constructor returns 'self'.
6822   ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(
6823       getContext(), D->getLocation(), D->getLocation(), cxxSelector,
6824       getContext().getObjCIdType(), nullptr, D, /*isInstance=*/true,
6825       /*isVariadic=*/false,
6826       /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
6827       /*isImplicitlyDeclared=*/true,
6828       /*isDefined=*/false, ObjCImplementationControl::Required);
6829   D->addInstanceMethod(CTORMethod);
6830   CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
6831   D->setHasNonZeroConstructors(true);
6832 }
6833 
6834 // EmitLinkageSpec - Emit all declarations in a linkage spec.
6835 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
6836   if (LSD->getLanguage() != LinkageSpecLanguageIDs::C &&
6837       LSD->getLanguage() != LinkageSpecLanguageIDs::CXX) {
6838     ErrorUnsupported(LSD, "linkage spec");
6839     return;
6840   }
6841 
6842   EmitDeclContext(LSD);
6843 }
6844 
6845 void CodeGenModule::EmitTopLevelStmt(const TopLevelStmtDecl *D) {
6846   // Device code should not be at top level.
6847   if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
6848     return;
6849 
6850   std::unique_ptr<CodeGenFunction> &CurCGF =
6851       GlobalTopLevelStmtBlockInFlight.first;
6852 
6853   // We emitted a top-level stmt but after it there is initialization.
6854   // Stop squashing the top-level stmts into a single function.
6855   if (CurCGF && CXXGlobalInits.back() != CurCGF->CurFn) {
6856     CurCGF->FinishFunction(D->getEndLoc());
6857     CurCGF = nullptr;
6858   }
6859 
6860   if (!CurCGF) {
6861     // void __stmts__N(void)
6862     // FIXME: Ask the ABI name mangler to pick a name.
6863     std::string Name = "__stmts__" + llvm::utostr(CXXGlobalInits.size());
6864     FunctionArgList Args;
6865     QualType RetTy = getContext().VoidTy;
6866     const CGFunctionInfo &FnInfo =
6867         getTypes().arrangeBuiltinFunctionDeclaration(RetTy, Args);
6868     llvm::FunctionType *FnTy = getTypes().GetFunctionType(FnInfo);
6869     llvm::Function *Fn = llvm::Function::Create(
6870         FnTy, llvm::GlobalValue::InternalLinkage, Name, &getModule());
6871 
6872     CurCGF.reset(new CodeGenFunction(*this));
6873     GlobalTopLevelStmtBlockInFlight.second = D;
6874     CurCGF->StartFunction(GlobalDecl(), RetTy, Fn, FnInfo, Args,
6875                           D->getBeginLoc(), D->getBeginLoc());
6876     CXXGlobalInits.push_back(Fn);
6877   }
6878 
6879   CurCGF->EmitStmt(D->getStmt());
6880 }
6881 
6882 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
6883   for (auto *I : DC->decls()) {
6884     // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
6885     // are themselves considered "top-level", so EmitTopLevelDecl on an
6886     // ObjCImplDecl does not recursively visit them. We need to do that in
6887     // case they're nested inside another construct (LinkageSpecDecl /
6888     // ExportDecl) that does stop them from being considered "top-level".
6889     if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
6890       for (auto *M : OID->methods())
6891         EmitTopLevelDecl(M);
6892     }
6893 
6894     EmitTopLevelDecl(I);
6895   }
6896 }
6897 
6898 /// EmitTopLevelDecl - Emit code for a single top level declaration.
6899 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
6900   // Ignore dependent declarations.
6901   if (D->isTemplated())
6902     return;
6903 
6904   // Consteval function shouldn't be emitted.
6905   if (auto *FD = dyn_cast<FunctionDecl>(D); FD && FD->isImmediateFunction())
6906     return;
6907 
6908   switch (D->getKind()) {
6909   case Decl::CXXConversion:
6910   case Decl::CXXMethod:
6911   case Decl::Function:
6912     EmitGlobal(cast<FunctionDecl>(D));
6913     // Always provide some coverage mapping
6914     // even for the functions that aren't emitted.
6915     AddDeferredUnusedCoverageMapping(D);
6916     break;
6917 
6918   case Decl::CXXDeductionGuide:
6919     // Function-like, but does not result in code emission.
6920     break;
6921 
6922   case Decl::Var:
6923   case Decl::Decomposition:
6924   case Decl::VarTemplateSpecialization:
6925     EmitGlobal(cast<VarDecl>(D));
6926     if (auto *DD = dyn_cast<DecompositionDecl>(D))
6927       for (auto *B : DD->bindings())
6928         if (auto *HD = B->getHoldingVar())
6929           EmitGlobal(HD);
6930     break;
6931 
6932   // Indirect fields from global anonymous structs and unions can be
6933   // ignored; only the actual variable requires IR gen support.
6934   case Decl::IndirectField:
6935     break;
6936 
6937   // C++ Decls
6938   case Decl::Namespace:
6939     EmitDeclContext(cast<NamespaceDecl>(D));
6940     break;
6941   case Decl::ClassTemplateSpecialization: {
6942     const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
6943     if (CGDebugInfo *DI = getModuleDebugInfo())
6944       if (Spec->getSpecializationKind() ==
6945               TSK_ExplicitInstantiationDefinition &&
6946           Spec->hasDefinition())
6947         DI->completeTemplateDefinition(*Spec);
6948   } [[fallthrough]];
6949   case Decl::CXXRecord: {
6950     CXXRecordDecl *CRD = cast<CXXRecordDecl>(D);
6951     if (CGDebugInfo *DI = getModuleDebugInfo()) {
6952       if (CRD->hasDefinition())
6953         DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
6954       if (auto *ES = D->getASTContext().getExternalSource())
6955         if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
6956           DI->completeUnusedClass(*CRD);
6957     }
6958     // Emit any static data members, they may be definitions.
6959     for (auto *I : CRD->decls())
6960       if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
6961         EmitTopLevelDecl(I);
6962     break;
6963   }
6964     // No code generation needed.
6965   case Decl::UsingShadow:
6966   case Decl::ClassTemplate:
6967   case Decl::VarTemplate:
6968   case Decl::Concept:
6969   case Decl::VarTemplatePartialSpecialization:
6970   case Decl::FunctionTemplate:
6971   case Decl::TypeAliasTemplate:
6972   case Decl::Block:
6973   case Decl::Empty:
6974   case Decl::Binding:
6975     break;
6976   case Decl::Using:          // using X; [C++]
6977     if (CGDebugInfo *DI = getModuleDebugInfo())
6978         DI->EmitUsingDecl(cast<UsingDecl>(*D));
6979     break;
6980   case Decl::UsingEnum: // using enum X; [C++]
6981     if (CGDebugInfo *DI = getModuleDebugInfo())
6982       DI->EmitUsingEnumDecl(cast<UsingEnumDecl>(*D));
6983     break;
6984   case Decl::NamespaceAlias:
6985     if (CGDebugInfo *DI = getModuleDebugInfo())
6986         DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
6987     break;
6988   case Decl::UsingDirective: // using namespace X; [C++]
6989     if (CGDebugInfo *DI = getModuleDebugInfo())
6990       DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
6991     break;
6992   case Decl::CXXConstructor:
6993     getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
6994     break;
6995   case Decl::CXXDestructor:
6996     getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
6997     break;
6998 
6999   case Decl::StaticAssert:
7000     // Nothing to do.
7001     break;
7002 
7003   // Objective-C Decls
7004 
7005   // Forward declarations, no (immediate) code generation.
7006   case Decl::ObjCInterface:
7007   case Decl::ObjCCategory:
7008     break;
7009 
7010   case Decl::ObjCProtocol: {
7011     auto *Proto = cast<ObjCProtocolDecl>(D);
7012     if (Proto->isThisDeclarationADefinition())
7013       ObjCRuntime->GenerateProtocol(Proto);
7014     break;
7015   }
7016 
7017   case Decl::ObjCCategoryImpl:
7018     // Categories have properties but don't support synthesize so we
7019     // can ignore them here.
7020     ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
7021     break;
7022 
7023   case Decl::ObjCImplementation: {
7024     auto *OMD = cast<ObjCImplementationDecl>(D);
7025     EmitObjCPropertyImplementations(OMD);
7026     EmitObjCIvarInitializations(OMD);
7027     ObjCRuntime->GenerateClass(OMD);
7028     // Emit global variable debug information.
7029     if (CGDebugInfo *DI = getModuleDebugInfo())
7030       if (getCodeGenOpts().hasReducedDebugInfo())
7031         DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
7032             OMD->getClassInterface()), OMD->getLocation());
7033     break;
7034   }
7035   case Decl::ObjCMethod: {
7036     auto *OMD = cast<ObjCMethodDecl>(D);
7037     // If this is not a prototype, emit the body.
7038     if (OMD->getBody())
7039       CodeGenFunction(*this).GenerateObjCMethod(OMD);
7040     break;
7041   }
7042   case Decl::ObjCCompatibleAlias:
7043     ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
7044     break;
7045 
7046   case Decl::PragmaComment: {
7047     const auto *PCD = cast<PragmaCommentDecl>(D);
7048     switch (PCD->getCommentKind()) {
7049     case PCK_Unknown:
7050       llvm_unreachable("unexpected pragma comment kind");
7051     case PCK_Linker:
7052       AppendLinkerOptions(PCD->getArg());
7053       break;
7054     case PCK_Lib:
7055         AddDependentLib(PCD->getArg());
7056       break;
7057     case PCK_Compiler:
7058     case PCK_ExeStr:
7059     case PCK_User:
7060       break; // We ignore all of these.
7061     }
7062     break;
7063   }
7064 
7065   case Decl::PragmaDetectMismatch: {
7066     const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
7067     AddDetectMismatch(PDMD->getName(), PDMD->getValue());
7068     break;
7069   }
7070 
7071   case Decl::LinkageSpec:
7072     EmitLinkageSpec(cast<LinkageSpecDecl>(D));
7073     break;
7074 
7075   case Decl::FileScopeAsm: {
7076     // File-scope asm is ignored during device-side CUDA compilation.
7077     if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
7078       break;
7079     // File-scope asm is ignored during device-side OpenMP compilation.
7080     if (LangOpts.OpenMPIsTargetDevice)
7081       break;
7082     // File-scope asm is ignored during device-side SYCL compilation.
7083     if (LangOpts.SYCLIsDevice)
7084       break;
7085     auto *AD = cast<FileScopeAsmDecl>(D);
7086     getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
7087     break;
7088   }
7089 
7090   case Decl::TopLevelStmt:
7091     EmitTopLevelStmt(cast<TopLevelStmtDecl>(D));
7092     break;
7093 
7094   case Decl::Import: {
7095     auto *Import = cast<ImportDecl>(D);
7096 
7097     // If we've already imported this module, we're done.
7098     if (!ImportedModules.insert(Import->getImportedModule()))
7099       break;
7100 
7101     // Emit debug information for direct imports.
7102     if (!Import->getImportedOwningModule()) {
7103       if (CGDebugInfo *DI = getModuleDebugInfo())
7104         DI->EmitImportDecl(*Import);
7105     }
7106 
7107     // For C++ standard modules we are done - we will call the module
7108     // initializer for imported modules, and that will likewise call those for
7109     // any imports it has.
7110     if (CXX20ModuleInits && Import->getImportedOwningModule() &&
7111         !Import->getImportedOwningModule()->isModuleMapModule())
7112       break;
7113 
7114     // For clang C++ module map modules the initializers for sub-modules are
7115     // emitted here.
7116 
7117     // Find all of the submodules and emit the module initializers.
7118     llvm::SmallPtrSet<clang::Module *, 16> Visited;
7119     SmallVector<clang::Module *, 16> Stack;
7120     Visited.insert(Import->getImportedModule());
7121     Stack.push_back(Import->getImportedModule());
7122 
7123     while (!Stack.empty()) {
7124       clang::Module *Mod = Stack.pop_back_val();
7125       if (!EmittedModuleInitializers.insert(Mod).second)
7126         continue;
7127 
7128       for (auto *D : Context.getModuleInitializers(Mod))
7129         EmitTopLevelDecl(D);
7130 
7131       // Visit the submodules of this module.
7132       for (auto *Submodule : Mod->submodules()) {
7133         // Skip explicit children; they need to be explicitly imported to emit
7134         // the initializers.
7135         if (Submodule->IsExplicit)
7136           continue;
7137 
7138         if (Visited.insert(Submodule).second)
7139           Stack.push_back(Submodule);
7140       }
7141     }
7142     break;
7143   }
7144 
7145   case Decl::Export:
7146     EmitDeclContext(cast<ExportDecl>(D));
7147     break;
7148 
7149   case Decl::OMPThreadPrivate:
7150     EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
7151     break;
7152 
7153   case Decl::OMPAllocate:
7154     EmitOMPAllocateDecl(cast<OMPAllocateDecl>(D));
7155     break;
7156 
7157   case Decl::OMPDeclareReduction:
7158     EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
7159     break;
7160 
7161   case Decl::OMPDeclareMapper:
7162     EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D));
7163     break;
7164 
7165   case Decl::OMPRequires:
7166     EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
7167     break;
7168 
7169   case Decl::Typedef:
7170   case Decl::TypeAlias: // using foo = bar; [C++11]
7171     if (CGDebugInfo *DI = getModuleDebugInfo())
7172       DI->EmitAndRetainType(
7173           getContext().getTypedefType(cast<TypedefNameDecl>(D)));
7174     break;
7175 
7176   case Decl::Record:
7177     if (CGDebugInfo *DI = getModuleDebugInfo())
7178       if (cast<RecordDecl>(D)->getDefinition())
7179         DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
7180     break;
7181 
7182   case Decl::Enum:
7183     if (CGDebugInfo *DI = getModuleDebugInfo())
7184       if (cast<EnumDecl>(D)->getDefinition())
7185         DI->EmitAndRetainType(getContext().getEnumType(cast<EnumDecl>(D)));
7186     break;
7187 
7188   case Decl::HLSLBuffer:
7189     getHLSLRuntime().addBuffer(cast<HLSLBufferDecl>(D));
7190     break;
7191 
7192   default:
7193     // Make sure we handled everything we should, every other kind is a
7194     // non-top-level decl.  FIXME: Would be nice to have an isTopLevelDeclKind
7195     // function. Need to recode Decl::Kind to do that easily.
7196     assert(isa<TypeDecl>(D) && "Unsupported decl kind");
7197     break;
7198   }
7199 }
7200 
7201 void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
7202   // Do we need to generate coverage mapping?
7203   if (!CodeGenOpts.CoverageMapping)
7204     return;
7205   switch (D->getKind()) {
7206   case Decl::CXXConversion:
7207   case Decl::CXXMethod:
7208   case Decl::Function:
7209   case Decl::ObjCMethod:
7210   case Decl::CXXConstructor:
7211   case Decl::CXXDestructor: {
7212     if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
7213       break;
7214     SourceManager &SM = getContext().getSourceManager();
7215     if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
7216       break;
7217     if (!llvm::coverage::SystemHeadersCoverage &&
7218         SM.isInSystemHeader(D->getBeginLoc()))
7219       break;
7220     DeferredEmptyCoverageMappingDecls.try_emplace(D, true);
7221     break;
7222   }
7223   default:
7224     break;
7225   };
7226 }
7227 
7228 void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
7229   // Do we need to generate coverage mapping?
7230   if (!CodeGenOpts.CoverageMapping)
7231     return;
7232   if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
7233     if (Fn->isTemplateInstantiation())
7234       ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
7235   }
7236   DeferredEmptyCoverageMappingDecls.insert_or_assign(D, false);
7237 }
7238 
7239 void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
7240   // We call takeVector() here to avoid use-after-free.
7241   // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
7242   // we deserialize function bodies to emit coverage info for them, and that
7243   // deserializes more declarations. How should we handle that case?
7244   for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
7245     if (!Entry.second)
7246       continue;
7247     const Decl *D = Entry.first;
7248     switch (D->getKind()) {
7249     case Decl::CXXConversion:
7250     case Decl::CXXMethod:
7251     case Decl::Function:
7252     case Decl::ObjCMethod: {
7253       CodeGenPGO PGO(*this);
7254       GlobalDecl GD(cast<FunctionDecl>(D));
7255       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7256                                   getFunctionLinkage(GD));
7257       break;
7258     }
7259     case Decl::CXXConstructor: {
7260       CodeGenPGO PGO(*this);
7261       GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
7262       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7263                                   getFunctionLinkage(GD));
7264       break;
7265     }
7266     case Decl::CXXDestructor: {
7267       CodeGenPGO PGO(*this);
7268       GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
7269       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7270                                   getFunctionLinkage(GD));
7271       break;
7272     }
7273     default:
7274       break;
7275     };
7276   }
7277 }
7278 
7279 void CodeGenModule::EmitMainVoidAlias() {
7280   // In order to transition away from "__original_main" gracefully, emit an
7281   // alias for "main" in the no-argument case so that libc can detect when
7282   // new-style no-argument main is in used.
7283   if (llvm::Function *F = getModule().getFunction("main")) {
7284     if (!F->isDeclaration() && F->arg_size() == 0 && !F->isVarArg() &&
7285         F->getReturnType()->isIntegerTy(Context.getTargetInfo().getIntWidth())) {
7286       auto *GA = llvm::GlobalAlias::create("__main_void", F);
7287       GA->setVisibility(llvm::GlobalValue::HiddenVisibility);
7288     }
7289   }
7290 }
7291 
7292 /// Turns the given pointer into a constant.
7293 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
7294                                           const void *Ptr) {
7295   uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
7296   llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
7297   return llvm::ConstantInt::get(i64, PtrInt);
7298 }
7299 
7300 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
7301                                    llvm::NamedMDNode *&GlobalMetadata,
7302                                    GlobalDecl D,
7303                                    llvm::GlobalValue *Addr) {
7304   if (!GlobalMetadata)
7305     GlobalMetadata =
7306       CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
7307 
7308   // TODO: should we report variant information for ctors/dtors?
7309   llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
7310                            llvm::ConstantAsMetadata::get(GetPointerConstant(
7311                                CGM.getLLVMContext(), D.getDecl()))};
7312   GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
7313 }
7314 
7315 bool CodeGenModule::CheckAndReplaceExternCIFuncs(llvm::GlobalValue *Elem,
7316                                                  llvm::GlobalValue *CppFunc) {
7317   // Store the list of ifuncs we need to replace uses in.
7318   llvm::SmallVector<llvm::GlobalIFunc *> IFuncs;
7319   // List of ConstantExprs that we should be able to delete when we're done
7320   // here.
7321   llvm::SmallVector<llvm::ConstantExpr *> CEs;
7322 
7323   // It isn't valid to replace the extern-C ifuncs if all we find is itself!
7324   if (Elem == CppFunc)
7325     return false;
7326 
7327   // First make sure that all users of this are ifuncs (or ifuncs via a
7328   // bitcast), and collect the list of ifuncs and CEs so we can work on them
7329   // later.
7330   for (llvm::User *User : Elem->users()) {
7331     // Users can either be a bitcast ConstExpr that is used by the ifuncs, OR an
7332     // ifunc directly. In any other case, just give up, as we don't know what we
7333     // could break by changing those.
7334     if (auto *ConstExpr = dyn_cast<llvm::ConstantExpr>(User)) {
7335       if (ConstExpr->getOpcode() != llvm::Instruction::BitCast)
7336         return false;
7337 
7338       for (llvm::User *CEUser : ConstExpr->users()) {
7339         if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(CEUser)) {
7340           IFuncs.push_back(IFunc);
7341         } else {
7342           return false;
7343         }
7344       }
7345       CEs.push_back(ConstExpr);
7346     } else if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(User)) {
7347       IFuncs.push_back(IFunc);
7348     } else {
7349       // This user is one we don't know how to handle, so fail redirection. This
7350       // will result in an ifunc retaining a resolver name that will ultimately
7351       // fail to be resolved to a defined function.
7352       return false;
7353     }
7354   }
7355 
7356   // Now we know this is a valid case where we can do this alias replacement, we
7357   // need to remove all of the references to Elem (and the bitcasts!) so we can
7358   // delete it.
7359   for (llvm::GlobalIFunc *IFunc : IFuncs)
7360     IFunc->setResolver(nullptr);
7361   for (llvm::ConstantExpr *ConstExpr : CEs)
7362     ConstExpr->destroyConstant();
7363 
7364   // We should now be out of uses for the 'old' version of this function, so we
7365   // can erase it as well.
7366   Elem->eraseFromParent();
7367 
7368   for (llvm::GlobalIFunc *IFunc : IFuncs) {
7369     // The type of the resolver is always just a function-type that returns the
7370     // type of the IFunc, so create that here. If the type of the actual
7371     // resolver doesn't match, it just gets bitcast to the right thing.
7372     auto *ResolverTy =
7373         llvm::FunctionType::get(IFunc->getType(), /*isVarArg*/ false);
7374     llvm::Constant *Resolver = GetOrCreateLLVMFunction(
7375         CppFunc->getName(), ResolverTy, {}, /*ForVTable*/ false);
7376     IFunc->setResolver(Resolver);
7377   }
7378   return true;
7379 }
7380 
7381 /// For each function which is declared within an extern "C" region and marked
7382 /// as 'used', but has internal linkage, create an alias from the unmangled
7383 /// name to the mangled name if possible. People expect to be able to refer
7384 /// to such functions with an unmangled name from inline assembly within the
7385 /// same translation unit.
7386 void CodeGenModule::EmitStaticExternCAliases() {
7387   if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
7388     return;
7389   for (auto &I : StaticExternCValues) {
7390     const IdentifierInfo *Name = I.first;
7391     llvm::GlobalValue *Val = I.second;
7392 
7393     // If Val is null, that implies there were multiple declarations that each
7394     // had a claim to the unmangled name. In this case, generation of the alias
7395     // is suppressed. See CodeGenModule::MaybeHandleStaticInExternC.
7396     if (!Val)
7397       break;
7398 
7399     llvm::GlobalValue *ExistingElem =
7400         getModule().getNamedValue(Name->getName());
7401 
7402     // If there is either not something already by this name, or we were able to
7403     // replace all uses from IFuncs, create the alias.
7404     if (!ExistingElem || CheckAndReplaceExternCIFuncs(ExistingElem, Val))
7405       addCompilerUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
7406   }
7407 }
7408 
7409 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
7410                                              GlobalDecl &Result) const {
7411   auto Res = Manglings.find(MangledName);
7412   if (Res == Manglings.end())
7413     return false;
7414   Result = Res->getValue();
7415   return true;
7416 }
7417 
7418 /// Emits metadata nodes associating all the global values in the
7419 /// current module with the Decls they came from.  This is useful for
7420 /// projects using IR gen as a subroutine.
7421 ///
7422 /// Since there's currently no way to associate an MDNode directly
7423 /// with an llvm::GlobalValue, we create a global named metadata
7424 /// with the name 'clang.global.decl.ptrs'.
7425 void CodeGenModule::EmitDeclMetadata() {
7426   llvm::NamedMDNode *GlobalMetadata = nullptr;
7427 
7428   for (auto &I : MangledDeclNames) {
7429     llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
7430     // Some mangled names don't necessarily have an associated GlobalValue
7431     // in this module, e.g. if we mangled it for DebugInfo.
7432     if (Addr)
7433       EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
7434   }
7435 }
7436 
7437 /// Emits metadata nodes for all the local variables in the current
7438 /// function.
7439 void CodeGenFunction::EmitDeclMetadata() {
7440   if (LocalDeclMap.empty()) return;
7441 
7442   llvm::LLVMContext &Context = getLLVMContext();
7443 
7444   // Find the unique metadata ID for this name.
7445   unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
7446 
7447   llvm::NamedMDNode *GlobalMetadata = nullptr;
7448 
7449   for (auto &I : LocalDeclMap) {
7450     const Decl *D = I.first;
7451     llvm::Value *Addr = I.second.emitRawPointer(*this);
7452     if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
7453       llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
7454       Alloca->setMetadata(
7455           DeclPtrKind, llvm::MDNode::get(
7456                            Context, llvm::ValueAsMetadata::getConstant(DAddr)));
7457     } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
7458       GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
7459       EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
7460     }
7461   }
7462 }
7463 
7464 void CodeGenModule::EmitVersionIdentMetadata() {
7465   llvm::NamedMDNode *IdentMetadata =
7466     TheModule.getOrInsertNamedMetadata("llvm.ident");
7467   std::string Version = getClangFullVersion();
7468   llvm::LLVMContext &Ctx = TheModule.getContext();
7469 
7470   llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
7471   IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
7472 }
7473 
7474 void CodeGenModule::EmitCommandLineMetadata() {
7475   llvm::NamedMDNode *CommandLineMetadata =
7476     TheModule.getOrInsertNamedMetadata("llvm.commandline");
7477   std::string CommandLine = getCodeGenOpts().RecordCommandLine;
7478   llvm::LLVMContext &Ctx = TheModule.getContext();
7479 
7480   llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
7481   CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
7482 }
7483 
7484 void CodeGenModule::EmitCoverageFile() {
7485   llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
7486   if (!CUNode)
7487     return;
7488 
7489   llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
7490   llvm::LLVMContext &Ctx = TheModule.getContext();
7491   auto *CoverageDataFile =
7492       llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
7493   auto *CoverageNotesFile =
7494       llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
7495   for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
7496     llvm::MDNode *CU = CUNode->getOperand(i);
7497     llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
7498     GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
7499   }
7500 }
7501 
7502 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
7503                                                        bool ForEH) {
7504   // Return a bogus pointer if RTTI is disabled, unless it's for EH.
7505   // FIXME: should we even be calling this method if RTTI is disabled
7506   // and it's not for EH?
7507   if (!shouldEmitRTTI(ForEH))
7508     return llvm::Constant::getNullValue(GlobalsInt8PtrTy);
7509 
7510   if (ForEH && Ty->isObjCObjectPointerType() &&
7511       LangOpts.ObjCRuntime.isGNUFamily())
7512     return ObjCRuntime->GetEHType(Ty);
7513 
7514   return getCXXABI().getAddrOfRTTIDescriptor(Ty);
7515 }
7516 
7517 void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
7518   // Do not emit threadprivates in simd-only mode.
7519   if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
7520     return;
7521   for (auto RefExpr : D->varlist()) {
7522     auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
7523     bool PerformInit =
7524         VD->getAnyInitializer() &&
7525         !VD->getAnyInitializer()->isConstantInitializer(getContext(),
7526                                                         /*ForRef=*/false);
7527 
7528     Address Addr(GetAddrOfGlobalVar(VD),
7529                  getTypes().ConvertTypeForMem(VD->getType()),
7530                  getContext().getDeclAlign(VD));
7531     if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
7532             VD, Addr, RefExpr->getBeginLoc(), PerformInit))
7533       CXXGlobalInits.push_back(InitFunction);
7534   }
7535 }
7536 
7537 llvm::Metadata *
7538 CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
7539                                             StringRef Suffix) {
7540   if (auto *FnType = T->getAs<FunctionProtoType>())
7541     T = getContext().getFunctionType(
7542         FnType->getReturnType(), FnType->getParamTypes(),
7543         FnType->getExtProtoInfo().withExceptionSpec(EST_None));
7544 
7545   llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
7546   if (InternalId)
7547     return InternalId;
7548 
7549   if (isExternallyVisible(T->getLinkage())) {
7550     std::string OutName;
7551     llvm::raw_string_ostream Out(OutName);
7552     getCXXABI().getMangleContext().mangleCanonicalTypeName(
7553         T, Out, getCodeGenOpts().SanitizeCfiICallNormalizeIntegers);
7554 
7555     if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
7556       Out << ".normalized";
7557 
7558     Out << Suffix;
7559 
7560     InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
7561   } else {
7562     InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
7563                                            llvm::ArrayRef<llvm::Metadata *>());
7564   }
7565 
7566   return InternalId;
7567 }
7568 
7569 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
7570   return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
7571 }
7572 
7573 llvm::Metadata *
7574 CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
7575   return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
7576 }
7577 
7578 // Generalize pointer types to a void pointer with the qualifiers of the
7579 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
7580 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
7581 // 'void *'.
7582 static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
7583   if (!Ty->isPointerType())
7584     return Ty;
7585 
7586   return Ctx.getPointerType(
7587       QualType(Ctx.VoidTy).withCVRQualifiers(
7588           Ty->getPointeeType().getCVRQualifiers()));
7589 }
7590 
7591 // Apply type generalization to a FunctionType's return and argument types
7592 static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
7593   if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
7594     SmallVector<QualType, 8> GeneralizedParams;
7595     for (auto &Param : FnType->param_types())
7596       GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
7597 
7598     return Ctx.getFunctionType(
7599         GeneralizeType(Ctx, FnType->getReturnType()),
7600         GeneralizedParams, FnType->getExtProtoInfo());
7601   }
7602 
7603   if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
7604     return Ctx.getFunctionNoProtoType(
7605         GeneralizeType(Ctx, FnType->getReturnType()));
7606 
7607   llvm_unreachable("Encountered unknown FunctionType");
7608 }
7609 
7610 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
7611   return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
7612                                       GeneralizedMetadataIdMap, ".generalized");
7613 }
7614 
7615 /// Returns whether this module needs the "all-vtables" type identifier.
7616 bool CodeGenModule::NeedAllVtablesTypeId() const {
7617   // Returns true if at least one of vtable-based CFI checkers is enabled and
7618   // is not in the trapping mode.
7619   return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
7620            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
7621           (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
7622            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
7623           (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
7624            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
7625           (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
7626            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
7627 }
7628 
7629 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
7630                                           CharUnits Offset,
7631                                           const CXXRecordDecl *RD) {
7632   llvm::Metadata *MD =
7633       CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
7634   VTable->addTypeMetadata(Offset.getQuantity(), MD);
7635 
7636   if (CodeGenOpts.SanitizeCfiCrossDso)
7637     if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
7638       VTable->addTypeMetadata(Offset.getQuantity(),
7639                               llvm::ConstantAsMetadata::get(CrossDsoTypeId));
7640 
7641   if (NeedAllVtablesTypeId()) {
7642     llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
7643     VTable->addTypeMetadata(Offset.getQuantity(), MD);
7644   }
7645 }
7646 
7647 llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
7648   if (!SanStats)
7649     SanStats = std::make_unique<llvm::SanitizerStatReport>(&getModule());
7650 
7651   return *SanStats;
7652 }
7653 
7654 llvm::Value *
7655 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
7656                                                   CodeGenFunction &CGF) {
7657   llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
7658   auto *SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
7659   auto *FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
7660   auto *Call = CGF.EmitRuntimeCall(
7661       CreateRuntimeFunction(FTy, "__translate_sampler_initializer"), {C});
7662   return Call;
7663 }
7664 
7665 CharUnits CodeGenModule::getNaturalPointeeTypeAlignment(
7666     QualType T, LValueBaseInfo *BaseInfo, TBAAAccessInfo *TBAAInfo) {
7667   return getNaturalTypeAlignment(T->getPointeeType(), BaseInfo, TBAAInfo,
7668                                  /* forPointeeType= */ true);
7669 }
7670 
7671 CharUnits CodeGenModule::getNaturalTypeAlignment(QualType T,
7672                                                  LValueBaseInfo *BaseInfo,
7673                                                  TBAAAccessInfo *TBAAInfo,
7674                                                  bool forPointeeType) {
7675   if (TBAAInfo)
7676     *TBAAInfo = getTBAAAccessInfo(T);
7677 
7678   // FIXME: This duplicates logic in ASTContext::getTypeAlignIfKnown. But
7679   // that doesn't return the information we need to compute BaseInfo.
7680 
7681   // Honor alignment typedef attributes even on incomplete types.
7682   // We also honor them straight for C++ class types, even as pointees;
7683   // there's an expressivity gap here.
7684   if (auto TT = T->getAs<TypedefType>()) {
7685     if (auto Align = TT->getDecl()->getMaxAlignment()) {
7686       if (BaseInfo)
7687         *BaseInfo = LValueBaseInfo(AlignmentSource::AttributedType);
7688       return getContext().toCharUnitsFromBits(Align);
7689     }
7690   }
7691 
7692   bool AlignForArray = T->isArrayType();
7693 
7694   // Analyze the base element type, so we don't get confused by incomplete
7695   // array types.
7696   T = getContext().getBaseElementType(T);
7697 
7698   if (T->isIncompleteType()) {
7699     // We could try to replicate the logic from
7700     // ASTContext::getTypeAlignIfKnown, but nothing uses the alignment if the
7701     // type is incomplete, so it's impossible to test. We could try to reuse
7702     // getTypeAlignIfKnown, but that doesn't return the information we need
7703     // to set BaseInfo.  So just ignore the possibility that the alignment is
7704     // greater than one.
7705     if (BaseInfo)
7706       *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
7707     return CharUnits::One();
7708   }
7709 
7710   if (BaseInfo)
7711     *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
7712 
7713   CharUnits Alignment;
7714   const CXXRecordDecl *RD;
7715   if (T.getQualifiers().hasUnaligned()) {
7716     Alignment = CharUnits::One();
7717   } else if (forPointeeType && !AlignForArray &&
7718              (RD = T->getAsCXXRecordDecl())) {
7719     // For C++ class pointees, we don't know whether we're pointing at a
7720     // base or a complete object, so we generally need to use the
7721     // non-virtual alignment.
7722     Alignment = getClassPointerAlignment(RD);
7723   } else {
7724     Alignment = getContext().getTypeAlignInChars(T);
7725   }
7726 
7727   // Cap to the global maximum type alignment unless the alignment
7728   // was somehow explicit on the type.
7729   if (unsigned MaxAlign = getLangOpts().MaxTypeAlign) {
7730     if (Alignment.getQuantity() > MaxAlign &&
7731         !getContext().isAlignmentRequired(T))
7732       Alignment = CharUnits::fromQuantity(MaxAlign);
7733   }
7734   return Alignment;
7735 }
7736 
7737 bool CodeGenModule::stopAutoInit() {
7738   unsigned StopAfter = getContext().getLangOpts().TrivialAutoVarInitStopAfter;
7739   if (StopAfter) {
7740     // This number is positive only when -ftrivial-auto-var-init-stop-after=* is
7741     // used
7742     if (NumAutoVarInit >= StopAfter) {
7743       return true;
7744     }
7745     if (!NumAutoVarInit) {
7746       unsigned DiagID = getDiags().getCustomDiagID(
7747           DiagnosticsEngine::Warning,
7748           "-ftrivial-auto-var-init-stop-after=%0 has been enabled to limit the "
7749           "number of times ftrivial-auto-var-init=%1 gets applied.");
7750       getDiags().Report(DiagID)
7751           << StopAfter
7752           << (getContext().getLangOpts().getTrivialAutoVarInit() ==
7753                       LangOptions::TrivialAutoVarInitKind::Zero
7754                   ? "zero"
7755                   : "pattern");
7756     }
7757     ++NumAutoVarInit;
7758   }
7759   return false;
7760 }
7761 
7762 void CodeGenModule::printPostfixForExternalizedDecl(llvm::raw_ostream &OS,
7763                                                     const Decl *D) const {
7764   // ptxas does not allow '.' in symbol names. On the other hand, HIP prefers
7765   // postfix beginning with '.' since the symbol name can be demangled.
7766   if (LangOpts.HIP)
7767     OS << (isa<VarDecl>(D) ? ".static." : ".intern.");
7768   else
7769     OS << (isa<VarDecl>(D) ? "__static__" : "__intern__");
7770 
7771   // If the CUID is not specified we try to generate a unique postfix.
7772   if (getLangOpts().CUID.empty()) {
7773     SourceManager &SM = getContext().getSourceManager();
7774     PresumedLoc PLoc = SM.getPresumedLoc(D->getLocation());
7775     assert(PLoc.isValid() && "Source location is expected to be valid.");
7776 
7777     // Get the hash of the user defined macros.
7778     llvm::MD5 Hash;
7779     llvm::MD5::MD5Result Result;
7780     for (const auto &Arg : PreprocessorOpts.Macros)
7781       Hash.update(Arg.first);
7782     Hash.final(Result);
7783 
7784     // Get the UniqueID for the file containing the decl.
7785     llvm::sys::fs::UniqueID ID;
7786     if (llvm::sys::fs::getUniqueID(PLoc.getFilename(), ID)) {
7787       PLoc = SM.getPresumedLoc(D->getLocation(), /*UseLineDirectives=*/false);
7788       assert(PLoc.isValid() && "Source location is expected to be valid.");
7789       if (auto EC = llvm::sys::fs::getUniqueID(PLoc.getFilename(), ID))
7790         SM.getDiagnostics().Report(diag::err_cannot_open_file)
7791             << PLoc.getFilename() << EC.message();
7792     }
7793     OS << llvm::format("%x", ID.getFile()) << llvm::format("%x", ID.getDevice())
7794        << "_" << llvm::utohexstr(Result.low(), /*LowerCase=*/true, /*Width=*/8);
7795   } else {
7796     OS << getContext().getCUIDHash();
7797   }
7798 }
7799 
7800 void CodeGenModule::moveLazyEmissionStates(CodeGenModule *NewBuilder) {
7801   assert(DeferredDeclsToEmit.empty() &&
7802          "Should have emitted all decls deferred to emit.");
7803   assert(NewBuilder->DeferredDecls.empty() &&
7804          "Newly created module should not have deferred decls");
7805   NewBuilder->DeferredDecls = std::move(DeferredDecls);
7806   assert(EmittedDeferredDecls.empty() &&
7807          "Still have (unmerged) EmittedDeferredDecls deferred decls");
7808 
7809   assert(NewBuilder->DeferredVTables.empty() &&
7810          "Newly created module should not have deferred vtables");
7811   NewBuilder->DeferredVTables = std::move(DeferredVTables);
7812 
7813   assert(NewBuilder->MangledDeclNames.empty() &&
7814          "Newly created module should not have mangled decl names");
7815   assert(NewBuilder->Manglings.empty() &&
7816          "Newly created module should not have manglings");
7817   NewBuilder->Manglings = std::move(Manglings);
7818 
7819   NewBuilder->WeakRefReferences = std::move(WeakRefReferences);
7820 
7821   NewBuilder->ABI->MangleCtx = std::move(ABI->MangleCtx);
7822 }
7823