xref: /freebsd/contrib/llvm-project/clang/lib/CodeGen/CodeGenModule.cpp (revision 770cf0a5f02dc8983a89c6568d741fbc25baa999)
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/CodeGenOptions.h"
42 #include "clang/Basic/Diagnostic.h"
43 #include "clang/Basic/Module.h"
44 #include "clang/Basic/SourceManager.h"
45 #include "clang/Basic/TargetInfo.h"
46 #include "clang/Basic/Version.h"
47 #include "clang/CodeGen/BackendUtil.h"
48 #include "clang/CodeGen/ConstantInitBuilder.h"
49 #include "clang/Frontend/FrontendDiagnostic.h"
50 #include "llvm/ADT/STLExtras.h"
51 #include "llvm/ADT/StringExtras.h"
52 #include "llvm/ADT/StringSwitch.h"
53 #include "llvm/Analysis/TargetLibraryInfo.h"
54 #include "llvm/BinaryFormat/ELF.h"
55 #include "llvm/IR/AttributeMask.h"
56 #include "llvm/IR/CallingConv.h"
57 #include "llvm/IR/DataLayout.h"
58 #include "llvm/IR/Intrinsics.h"
59 #include "llvm/IR/LLVMContext.h"
60 #include "llvm/IR/Module.h"
61 #include "llvm/IR/ProfileSummary.h"
62 #include "llvm/ProfileData/InstrProfReader.h"
63 #include "llvm/ProfileData/SampleProf.h"
64 #include "llvm/Support/CRC.h"
65 #include "llvm/Support/CodeGen.h"
66 #include "llvm/Support/CommandLine.h"
67 #include "llvm/Support/ConvertUTF.h"
68 #include "llvm/Support/ErrorHandling.h"
69 #include "llvm/Support/TimeProfiler.h"
70 #include "llvm/Support/xxhash.h"
71 #include "llvm/TargetParser/RISCVISAInfo.h"
72 #include "llvm/TargetParser/Triple.h"
73 #include "llvm/TargetParser/X86TargetParser.h"
74 #include "llvm/Transforms/Utils/BuildLibCalls.h"
75 #include <optional>
76 #include <set>
77 
78 using namespace clang;
79 using namespace CodeGen;
80 
81 static llvm::cl::opt<bool> LimitedCoverage(
82     "limited-coverage-experimental", llvm::cl::Hidden,
83     llvm::cl::desc("Emit limited coverage mapping information (experimental)"));
84 
85 static const char AnnotationSection[] = "llvm.metadata";
86 
87 static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
88   switch (CGM.getContext().getCXXABIKind()) {
89   case TargetCXXABI::AppleARM64:
90   case TargetCXXABI::Fuchsia:
91   case TargetCXXABI::GenericAArch64:
92   case TargetCXXABI::GenericARM:
93   case TargetCXXABI::iOS:
94   case TargetCXXABI::WatchOS:
95   case TargetCXXABI::GenericMIPS:
96   case TargetCXXABI::GenericItanium:
97   case TargetCXXABI::WebAssembly:
98   case TargetCXXABI::XL:
99     return CreateItaniumCXXABI(CGM);
100   case TargetCXXABI::Microsoft:
101     return CreateMicrosoftCXXABI(CGM);
102   }
103 
104   llvm_unreachable("invalid C++ ABI kind");
105 }
106 
107 static std::unique_ptr<TargetCodeGenInfo>
108 createTargetCodeGenInfo(CodeGenModule &CGM) {
109   const TargetInfo &Target = CGM.getTarget();
110   const llvm::Triple &Triple = Target.getTriple();
111   const CodeGenOptions &CodeGenOpts = CGM.getCodeGenOpts();
112 
113   switch (Triple.getArch()) {
114   default:
115     return createDefaultTargetCodeGenInfo(CGM);
116 
117   case llvm::Triple::m68k:
118     return createM68kTargetCodeGenInfo(CGM);
119   case llvm::Triple::mips:
120   case llvm::Triple::mipsel:
121     if (Triple.getOS() == llvm::Triple::NaCl)
122       return createPNaClTargetCodeGenInfo(CGM);
123     else if (Triple.getOS() == llvm::Triple::Win32)
124       return createWindowsMIPSTargetCodeGenInfo(CGM, /*IsOS32=*/true);
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" && Triple.isHardFloatABI()))
179       Kind = ARMABIKind::AAPCS_VFP;
180 
181     return createARMTargetCodeGenInfo(CGM, Kind);
182   }
183 
184   case llvm::Triple::ppc: {
185     if (Triple.isOSAIX())
186       return createAIXTargetCodeGenInfo(CGM, /*Is64Bit=*/false);
187 
188     bool IsSoftFloat =
189         CodeGenOpts.FloatABI == "soft" || Target.hasFeature("spe");
190     return createPPC32TargetCodeGenInfo(CGM, IsSoftFloat);
191   }
192   case llvm::Triple::ppcle: {
193     bool IsSoftFloat = CodeGenOpts.FloatABI == "soft";
194     return createPPC32TargetCodeGenInfo(CGM, IsSoftFloat);
195   }
196   case llvm::Triple::ppc64:
197     if (Triple.isOSAIX())
198       return createAIXTargetCodeGenInfo(CGM, /*Is64Bit=*/true);
199 
200     if (Triple.isOSBinFormatELF()) {
201       PPC64_SVR4_ABIKind Kind = PPC64_SVR4_ABIKind::ELFv1;
202       if (Target.getABI() == "elfv2")
203         Kind = PPC64_SVR4_ABIKind::ELFv2;
204       bool IsSoftFloat = CodeGenOpts.FloatABI == "soft";
205 
206       return createPPC64_SVR4_TargetCodeGenInfo(CGM, Kind, IsSoftFloat);
207     }
208     return createPPC64TargetCodeGenInfo(CGM);
209   case llvm::Triple::ppc64le: {
210     assert(Triple.isOSBinFormatELF() && "PPC64 LE non-ELF not supported!");
211     PPC64_SVR4_ABIKind Kind = PPC64_SVR4_ABIKind::ELFv2;
212     if (Target.getABI() == "elfv1")
213       Kind = PPC64_SVR4_ABIKind::ELFv1;
214     bool IsSoftFloat = CodeGenOpts.FloatABI == "soft";
215 
216     return createPPC64_SVR4_TargetCodeGenInfo(CGM, Kind, IsSoftFloat);
217   }
218 
219   case llvm::Triple::nvptx:
220   case llvm::Triple::nvptx64:
221     return createNVPTXTargetCodeGenInfo(CGM);
222 
223   case llvm::Triple::msp430:
224     return createMSP430TargetCodeGenInfo(CGM);
225 
226   case llvm::Triple::riscv32:
227   case llvm::Triple::riscv64: {
228     StringRef ABIStr = Target.getABI();
229     unsigned XLen = Target.getPointerWidth(LangAS::Default);
230     unsigned ABIFLen = 0;
231     if (ABIStr.ends_with("f"))
232       ABIFLen = 32;
233     else if (ABIStr.ends_with("d"))
234       ABIFLen = 64;
235     bool EABI = ABIStr.ends_with("e");
236     return createRISCVTargetCodeGenInfo(CGM, XLen, ABIFLen, EABI);
237   }
238 
239   case llvm::Triple::systemz: {
240     bool SoftFloat = CodeGenOpts.FloatABI == "soft";
241     bool HasVector = !SoftFloat && Target.getABI() == "vector";
242     return createSystemZTargetCodeGenInfo(CGM, HasVector, SoftFloat);
243   }
244 
245   case llvm::Triple::tce:
246   case llvm::Triple::tcele:
247     return createTCETargetCodeGenInfo(CGM);
248 
249   case llvm::Triple::x86: {
250     bool IsDarwinVectorABI = Triple.isOSDarwin();
251     bool IsWin32FloatStructABI = Triple.isOSWindows() && !Triple.isOSCygMing();
252 
253     if (Triple.getOS() == llvm::Triple::Win32) {
254       return createWinX86_32TargetCodeGenInfo(
255           CGM, IsDarwinVectorABI, IsWin32FloatStructABI,
256           CodeGenOpts.NumRegisterParameters);
257     }
258     return createX86_32TargetCodeGenInfo(
259         CGM, IsDarwinVectorABI, IsWin32FloatStructABI,
260         CodeGenOpts.NumRegisterParameters, CodeGenOpts.FloatABI == "soft");
261   }
262 
263   case llvm::Triple::x86_64: {
264     StringRef ABI = Target.getABI();
265     X86AVXABILevel AVXLevel = (ABI == "avx512" ? X86AVXABILevel::AVX512
266                                : ABI == "avx"  ? X86AVXABILevel::AVX
267                                                : X86AVXABILevel::None);
268 
269     switch (Triple.getOS()) {
270     case llvm::Triple::UEFI:
271     case llvm::Triple::Win32:
272       return createWinX86_64TargetCodeGenInfo(CGM, AVXLevel);
273     default:
274       return createX86_64TargetCodeGenInfo(CGM, AVXLevel);
275     }
276   }
277   case llvm::Triple::hexagon:
278     return createHexagonTargetCodeGenInfo(CGM);
279   case llvm::Triple::lanai:
280     return createLanaiTargetCodeGenInfo(CGM);
281   case llvm::Triple::r600:
282     return createAMDGPUTargetCodeGenInfo(CGM);
283   case llvm::Triple::amdgcn:
284     return createAMDGPUTargetCodeGenInfo(CGM);
285   case llvm::Triple::sparc:
286     return createSparcV8TargetCodeGenInfo(CGM);
287   case llvm::Triple::sparcv9:
288     return createSparcV9TargetCodeGenInfo(CGM);
289   case llvm::Triple::xcore:
290     return createXCoreTargetCodeGenInfo(CGM);
291   case llvm::Triple::arc:
292     return createARCTargetCodeGenInfo(CGM);
293   case llvm::Triple::spir:
294   case llvm::Triple::spir64:
295     return createCommonSPIRTargetCodeGenInfo(CGM);
296   case llvm::Triple::spirv32:
297   case llvm::Triple::spirv64:
298   case llvm::Triple::spirv:
299     return createSPIRVTargetCodeGenInfo(CGM);
300   case llvm::Triple::dxil:
301     return createDirectXTargetCodeGenInfo(CGM);
302   case llvm::Triple::ve:
303     return createVETargetCodeGenInfo(CGM);
304   case llvm::Triple::csky: {
305     bool IsSoftFloat = !Target.hasFeature("hard-float-abi");
306     bool hasFP64 =
307         Target.hasFeature("fpuv2_df") || Target.hasFeature("fpuv3_df");
308     return createCSKYTargetCodeGenInfo(CGM, IsSoftFloat ? 0
309                                             : hasFP64   ? 64
310                                                         : 32);
311   }
312   case llvm::Triple::bpfeb:
313   case llvm::Triple::bpfel:
314     return createBPFTargetCodeGenInfo(CGM);
315   case llvm::Triple::loongarch32:
316   case llvm::Triple::loongarch64: {
317     StringRef ABIStr = Target.getABI();
318     unsigned ABIFRLen = 0;
319     if (ABIStr.ends_with("f"))
320       ABIFRLen = 32;
321     else if (ABIStr.ends_with("d"))
322       ABIFRLen = 64;
323     return createLoongArchTargetCodeGenInfo(
324         CGM, Target.getPointerWidth(LangAS::Default), ABIFRLen);
325   }
326   }
327 }
328 
329 const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
330   if (!TheTargetCodeGenInfo)
331     TheTargetCodeGenInfo = createTargetCodeGenInfo(*this);
332   return *TheTargetCodeGenInfo;
333 }
334 
335 static void checkDataLayoutConsistency(const TargetInfo &Target,
336                                        llvm::LLVMContext &Context,
337                                        const LangOptions &Opts) {
338 #ifndef NDEBUG
339   // Don't verify non-standard ABI configurations.
340   if (Opts.AlignDouble || Opts.OpenCL || Opts.HLSL)
341     return;
342 
343   llvm::Triple Triple = Target.getTriple();
344   llvm::DataLayout DL(Target.getDataLayoutString());
345   auto Check = [&](const char *Name, llvm::Type *Ty, unsigned Alignment) {
346     llvm::Align DLAlign = DL.getABITypeAlign(Ty);
347     llvm::Align ClangAlign(Alignment / 8);
348     if (DLAlign != ClangAlign) {
349       llvm::errs() << "For target " << Triple.str() << " type " << Name
350                    << " mapping to " << *Ty << " has data layout alignment "
351                    << DLAlign.value() << " while clang specifies "
352                    << ClangAlign.value() << "\n";
353       abort();
354     }
355   };
356 
357   Check("bool", llvm::Type::getIntNTy(Context, Target.BoolWidth),
358         Target.BoolAlign);
359   Check("short", llvm::Type::getIntNTy(Context, Target.ShortWidth),
360         Target.ShortAlign);
361   Check("int", llvm::Type::getIntNTy(Context, Target.IntWidth),
362         Target.IntAlign);
363   Check("long", llvm::Type::getIntNTy(Context, Target.LongWidth),
364         Target.LongAlign);
365   // FIXME: M68k specifies incorrect long long alignment in both LLVM and Clang.
366   if (Triple.getArch() != llvm::Triple::m68k)
367     Check("long long", llvm::Type::getIntNTy(Context, Target.LongLongWidth),
368           Target.LongLongAlign);
369   // FIXME: There are int128 alignment mismatches on multiple targets.
370   if (Target.hasInt128Type() && !Target.getTargetOpts().ForceEnableInt128 &&
371       !Triple.isAMDGPU() && !Triple.isSPIRV() &&
372       Triple.getArch() != llvm::Triple::ve)
373     Check("__int128", llvm::Type::getIntNTy(Context, 128), Target.Int128Align);
374 
375   if (Target.hasFloat16Type())
376     Check("half", llvm::Type::getFloatingPointTy(Context, *Target.HalfFormat),
377           Target.HalfAlign);
378   if (Target.hasBFloat16Type())
379     Check("bfloat", llvm::Type::getBFloatTy(Context), Target.BFloat16Align);
380   Check("float", llvm::Type::getFloatingPointTy(Context, *Target.FloatFormat),
381         Target.FloatAlign);
382   // FIXME: AIX specifies wrong double alignment in DataLayout
383   if (!Triple.isOSAIX()) {
384     Check("double",
385           llvm::Type::getFloatingPointTy(Context, *Target.DoubleFormat),
386           Target.DoubleAlign);
387     Check("long double",
388           llvm::Type::getFloatingPointTy(Context, *Target.LongDoubleFormat),
389           Target.LongDoubleAlign);
390   }
391   if (Target.hasFloat128Type())
392     Check("__float128", llvm::Type::getFP128Ty(Context), Target.Float128Align);
393   if (Target.hasIbm128Type())
394     Check("__ibm128", llvm::Type::getPPC_FP128Ty(Context), Target.Ibm128Align);
395 
396   Check("void*", llvm::PointerType::getUnqual(Context), Target.PointerAlign);
397 #endif
398 }
399 
400 CodeGenModule::CodeGenModule(ASTContext &C,
401                              IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS,
402                              const HeaderSearchOptions &HSO,
403                              const PreprocessorOptions &PPO,
404                              const CodeGenOptions &CGO, llvm::Module &M,
405                              DiagnosticsEngine &diags,
406                              CoverageSourceInfo *CoverageInfo)
407     : Context(C), LangOpts(C.getLangOpts()), FS(FS), HeaderSearchOpts(HSO),
408       PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
409       Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
410       VMContext(M.getContext()), VTables(*this), StackHandler(diags),
411       SanitizerMD(new SanitizerMetadata(*this)),
412       AtomicOpts(Target.getAtomicOpts()) {
413 
414   // Initialize the type cache.
415   Types.reset(new CodeGenTypes(*this));
416   llvm::LLVMContext &LLVMContext = M.getContext();
417   VoidTy = llvm::Type::getVoidTy(LLVMContext);
418   Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
419   Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
420   Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
421   Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
422   HalfTy = llvm::Type::getHalfTy(LLVMContext);
423   BFloatTy = llvm::Type::getBFloatTy(LLVMContext);
424   FloatTy = llvm::Type::getFloatTy(LLVMContext);
425   DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
426   PointerWidthInBits = C.getTargetInfo().getPointerWidth(LangAS::Default);
427   PointerAlignInBytes =
428       C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(LangAS::Default))
429           .getQuantity();
430   SizeSizeInBytes =
431     C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
432   IntAlignInBytes =
433     C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
434   CharTy =
435     llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getCharWidth());
436   IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
437   IntPtrTy = llvm::IntegerType::get(LLVMContext,
438     C.getTargetInfo().getMaxPointerWidth());
439   Int8PtrTy = llvm::PointerType::get(LLVMContext,
440                                      C.getTargetAddressSpace(LangAS::Default));
441   const llvm::DataLayout &DL = M.getDataLayout();
442   AllocaInt8PtrTy =
443       llvm::PointerType::get(LLVMContext, DL.getAllocaAddrSpace());
444   GlobalsInt8PtrTy =
445       llvm::PointerType::get(LLVMContext, DL.getDefaultGlobalsAddressSpace());
446   ConstGlobalsPtrTy = llvm::PointerType::get(
447       LLVMContext, C.getTargetAddressSpace(GetGlobalConstantAddressSpace()));
448   ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
449 
450   // Build C++20 Module initializers.
451   // TODO: Add Microsoft here once we know the mangling required for the
452   // initializers.
453   CXX20ModuleInits =
454       LangOpts.CPlusPlusModules && getCXXABI().getMangleContext().getKind() ==
455                                        ItaniumMangleContext::MK_Itanium;
456 
457   RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
458 
459   if (LangOpts.ObjC)
460     createObjCRuntime();
461   if (LangOpts.OpenCL)
462     createOpenCLRuntime();
463   if (LangOpts.OpenMP)
464     createOpenMPRuntime();
465   if (LangOpts.CUDA)
466     createCUDARuntime();
467   if (LangOpts.HLSL)
468     createHLSLRuntime();
469 
470   // Enable TBAA unless it's suppressed. TSan and TySan need TBAA even at O0.
471   if (LangOpts.Sanitize.hasOneOf(SanitizerKind::Thread | SanitizerKind::Type) ||
472       (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
473     TBAA.reset(new CodeGenTBAA(Context, getTypes(), TheModule, CodeGenOpts,
474                                getLangOpts()));
475 
476   // If debug info or coverage generation is enabled, create the CGDebugInfo
477   // object.
478   if (CodeGenOpts.getDebugInfo() != llvm::codegenoptions::NoDebugInfo ||
479       CodeGenOpts.CoverageNotesFile.size() ||
480       CodeGenOpts.CoverageDataFile.size())
481     DebugInfo.reset(new CGDebugInfo(*this));
482   else if (getTriple().isOSWindows())
483     // On Windows targets, we want to emit compiler info even if debug info is
484     // otherwise disabled. Use a temporary CGDebugInfo instance to emit only
485     // basic compiler metadata.
486     CGDebugInfo(*this);
487 
488   Block.GlobalUniqueCount = 0;
489 
490   if (C.getLangOpts().ObjC)
491     ObjCData.reset(new ObjCEntrypoints());
492 
493   if (CodeGenOpts.hasProfileClangUse()) {
494     auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
495         CodeGenOpts.ProfileInstrumentUsePath, *FS,
496         CodeGenOpts.ProfileRemappingFile);
497     // We're checking for profile read errors in CompilerInvocation, so if
498     // there was an error it should've already been caught. If it hasn't been
499     // somehow, trip an assertion.
500     assert(ReaderOrErr);
501     PGOReader = std::move(ReaderOrErr.get());
502   }
503 
504   // If coverage mapping generation is enabled, create the
505   // CoverageMappingModuleGen object.
506   if (CodeGenOpts.CoverageMapping)
507     CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
508 
509   // Generate the module name hash here if needed.
510   if (CodeGenOpts.UniqueInternalLinkageNames &&
511       !getModule().getSourceFileName().empty()) {
512     std::string Path = getModule().getSourceFileName();
513     // Check if a path substitution is needed from the MacroPrefixMap.
514     for (const auto &Entry : LangOpts.MacroPrefixMap)
515       if (Path.rfind(Entry.first, 0) != std::string::npos) {
516         Path = Entry.second + Path.substr(Entry.first.size());
517         break;
518       }
519     ModuleNameHash = llvm::getUniqueInternalLinkagePostfix(Path);
520   }
521 
522   // Record mregparm value now so it is visible through all of codegen.
523   if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
524     getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
525                               CodeGenOpts.NumRegisterParameters);
526 
527   // If there are any functions that are marked for Windows secure hot-patching,
528   // then build the list of functions now.
529   if (!CGO.MSSecureHotPatchFunctionsFile.empty() ||
530       !CGO.MSSecureHotPatchFunctionsList.empty()) {
531     if (!CGO.MSSecureHotPatchFunctionsFile.empty()) {
532       auto BufOrErr =
533           llvm::MemoryBuffer::getFile(CGO.MSSecureHotPatchFunctionsFile);
534       if (BufOrErr) {
535         const llvm::MemoryBuffer &FileBuffer = **BufOrErr;
536         for (llvm::line_iterator I(FileBuffer.getMemBufferRef(), true), E;
537              I != E; ++I)
538           this->MSHotPatchFunctions.push_back(std::string{*I});
539       } else {
540         auto &DE = Context.getDiagnostics();
541         unsigned DiagID =
542             DE.getCustomDiagID(DiagnosticsEngine::Error,
543                                "failed to open hotpatch functions file "
544                                "(-fms-hotpatch-functions-file): %0 : %1");
545         DE.Report(DiagID) << CGO.MSSecureHotPatchFunctionsFile
546                           << BufOrErr.getError().message();
547       }
548     }
549 
550     for (const auto &FuncName : CGO.MSSecureHotPatchFunctionsList)
551       this->MSHotPatchFunctions.push_back(FuncName);
552 
553     llvm::sort(this->MSHotPatchFunctions);
554   }
555 
556   if (!Context.getAuxTargetInfo())
557     checkDataLayoutConsistency(Context.getTargetInfo(), LLVMContext, LangOpts);
558 }
559 
560 CodeGenModule::~CodeGenModule() {}
561 
562 void CodeGenModule::createObjCRuntime() {
563   // This is just isGNUFamily(), but we want to force implementors of
564   // new ABIs to decide how best to do this.
565   switch (LangOpts.ObjCRuntime.getKind()) {
566   case ObjCRuntime::GNUstep:
567   case ObjCRuntime::GCC:
568   case ObjCRuntime::ObjFW:
569     ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
570     return;
571 
572   case ObjCRuntime::FragileMacOSX:
573   case ObjCRuntime::MacOSX:
574   case ObjCRuntime::iOS:
575   case ObjCRuntime::WatchOS:
576     ObjCRuntime.reset(CreateMacObjCRuntime(*this));
577     return;
578   }
579   llvm_unreachable("bad runtime kind");
580 }
581 
582 void CodeGenModule::createOpenCLRuntime() {
583   OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
584 }
585 
586 void CodeGenModule::createOpenMPRuntime() {
587   // Select a specialized code generation class based on the target, if any.
588   // If it does not exist use the default implementation.
589   switch (getTriple().getArch()) {
590   case llvm::Triple::nvptx:
591   case llvm::Triple::nvptx64:
592   case llvm::Triple::amdgcn:
593   case llvm::Triple::spirv64:
594     assert(
595         getLangOpts().OpenMPIsTargetDevice &&
596         "OpenMP AMDGPU/NVPTX/SPIRV is only prepared to deal with device code.");
597     OpenMPRuntime.reset(new CGOpenMPRuntimeGPU(*this));
598     break;
599   default:
600     if (LangOpts.OpenMPSimd)
601       OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
602     else
603       OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
604     break;
605   }
606 }
607 
608 void CodeGenModule::createCUDARuntime() {
609   CUDARuntime.reset(CreateNVCUDARuntime(*this));
610 }
611 
612 void CodeGenModule::createHLSLRuntime() {
613   HLSLRuntime.reset(new CGHLSLRuntime(*this));
614 }
615 
616 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
617   Replacements[Name] = C;
618 }
619 
620 void CodeGenModule::applyReplacements() {
621   for (auto &I : Replacements) {
622     StringRef MangledName = I.first;
623     llvm::Constant *Replacement = I.second;
624     llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
625     if (!Entry)
626       continue;
627     auto *OldF = cast<llvm::Function>(Entry);
628     auto *NewF = dyn_cast<llvm::Function>(Replacement);
629     if (!NewF) {
630       if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
631         NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
632       } else {
633         auto *CE = cast<llvm::ConstantExpr>(Replacement);
634         assert(CE->getOpcode() == llvm::Instruction::BitCast ||
635                CE->getOpcode() == llvm::Instruction::GetElementPtr);
636         NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
637       }
638     }
639 
640     // Replace old with new, but keep the old order.
641     OldF->replaceAllUsesWith(Replacement);
642     if (NewF) {
643       NewF->removeFromParent();
644       OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
645                                                        NewF);
646     }
647     OldF->eraseFromParent();
648   }
649 }
650 
651 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
652   GlobalValReplacements.push_back(std::make_pair(GV, C));
653 }
654 
655 void CodeGenModule::applyGlobalValReplacements() {
656   for (auto &I : GlobalValReplacements) {
657     llvm::GlobalValue *GV = I.first;
658     llvm::Constant *C = I.second;
659 
660     GV->replaceAllUsesWith(C);
661     GV->eraseFromParent();
662   }
663 }
664 
665 // This is only used in aliases that we created and we know they have a
666 // linear structure.
667 static const llvm::GlobalValue *getAliasedGlobal(const llvm::GlobalValue *GV) {
668   const llvm::Constant *C;
669   if (auto *GA = dyn_cast<llvm::GlobalAlias>(GV))
670     C = GA->getAliasee();
671   else if (auto *GI = dyn_cast<llvm::GlobalIFunc>(GV))
672     C = GI->getResolver();
673   else
674     return GV;
675 
676   const auto *AliaseeGV = dyn_cast<llvm::GlobalValue>(C->stripPointerCasts());
677   if (!AliaseeGV)
678     return nullptr;
679 
680   const llvm::GlobalValue *FinalGV = AliaseeGV->getAliaseeObject();
681   if (FinalGV == GV)
682     return nullptr;
683 
684   return FinalGV;
685 }
686 
687 static bool checkAliasedGlobal(
688     const ASTContext &Context, DiagnosticsEngine &Diags, SourceLocation Location,
689     bool IsIFunc, const llvm::GlobalValue *Alias, const llvm::GlobalValue *&GV,
690     const llvm::MapVector<GlobalDecl, StringRef> &MangledDeclNames,
691     SourceRange AliasRange) {
692   GV = getAliasedGlobal(Alias);
693   if (!GV) {
694     Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
695     return false;
696   }
697 
698   if (GV->hasCommonLinkage()) {
699     const llvm::Triple &Triple = Context.getTargetInfo().getTriple();
700     if (Triple.getObjectFormat() == llvm::Triple::XCOFF) {
701       Diags.Report(Location, diag::err_alias_to_common);
702       return false;
703     }
704   }
705 
706   if (GV->isDeclaration()) {
707     Diags.Report(Location, diag::err_alias_to_undefined) << IsIFunc << IsIFunc;
708     Diags.Report(Location, diag::note_alias_requires_mangled_name)
709         << IsIFunc << IsIFunc;
710     // Provide a note if the given function is not found and exists as a
711     // mangled name.
712     for (const auto &[Decl, Name] : MangledDeclNames) {
713       if (const auto *ND = dyn_cast<NamedDecl>(Decl.getDecl())) {
714         IdentifierInfo *II = ND->getIdentifier();
715         if (II && II->getName() == GV->getName()) {
716           Diags.Report(Location, diag::note_alias_mangled_name_alternative)
717               << Name
718               << FixItHint::CreateReplacement(
719                      AliasRange,
720                      (Twine(IsIFunc ? "ifunc" : "alias") + "(\"" + Name + "\")")
721                          .str());
722         }
723       }
724     }
725     return false;
726   }
727 
728   if (IsIFunc) {
729     // Check resolver function type.
730     const auto *F = dyn_cast<llvm::Function>(GV);
731     if (!F) {
732       Diags.Report(Location, diag::err_alias_to_undefined)
733           << IsIFunc << IsIFunc;
734       return false;
735     }
736 
737     llvm::FunctionType *FTy = F->getFunctionType();
738     if (!FTy->getReturnType()->isPointerTy()) {
739       Diags.Report(Location, diag::err_ifunc_resolver_return);
740       return false;
741     }
742   }
743 
744   return true;
745 }
746 
747 // Emit a warning if toc-data attribute is requested for global variables that
748 // have aliases and remove the toc-data attribute.
749 static void checkAliasForTocData(llvm::GlobalVariable *GVar,
750                                  const CodeGenOptions &CodeGenOpts,
751                                  DiagnosticsEngine &Diags,
752                                  SourceLocation Location) {
753   if (GVar->hasAttribute("toc-data")) {
754     auto GVId = GVar->getName();
755     // Is this a global variable specified by the user as local?
756     if ((llvm::binary_search(CodeGenOpts.TocDataVarsUserSpecified, GVId))) {
757       Diags.Report(Location, diag::warn_toc_unsupported_type)
758           << GVId << "the variable has an alias";
759     }
760     llvm::AttributeSet CurrAttributes = GVar->getAttributes();
761     llvm::AttributeSet NewAttributes =
762         CurrAttributes.removeAttribute(GVar->getContext(), "toc-data");
763     GVar->setAttributes(NewAttributes);
764   }
765 }
766 
767 void CodeGenModule::checkAliases() {
768   // Check if the constructed aliases are well formed. It is really unfortunate
769   // that we have to do this in CodeGen, but we only construct mangled names
770   // and aliases during codegen.
771   bool Error = false;
772   DiagnosticsEngine &Diags = getDiags();
773   for (const GlobalDecl &GD : Aliases) {
774     const auto *D = cast<ValueDecl>(GD.getDecl());
775     SourceLocation Location;
776     SourceRange Range;
777     bool IsIFunc = D->hasAttr<IFuncAttr>();
778     if (const Attr *A = D->getDefiningAttr()) {
779       Location = A->getLocation();
780       Range = A->getRange();
781     } else
782       llvm_unreachable("Not an alias or ifunc?");
783 
784     StringRef MangledName = getMangledName(GD);
785     llvm::GlobalValue *Alias = GetGlobalValue(MangledName);
786     const llvm::GlobalValue *GV = nullptr;
787     if (!checkAliasedGlobal(getContext(), Diags, Location, IsIFunc, Alias, GV,
788                             MangledDeclNames, Range)) {
789       Error = true;
790       continue;
791     }
792 
793     if (getContext().getTargetInfo().getTriple().isOSAIX())
794       if (const llvm::GlobalVariable *GVar =
795               dyn_cast<const llvm::GlobalVariable>(GV))
796         checkAliasForTocData(const_cast<llvm::GlobalVariable *>(GVar),
797                              getCodeGenOpts(), Diags, Location);
798 
799     llvm::Constant *Aliasee =
800         IsIFunc ? cast<llvm::GlobalIFunc>(Alias)->getResolver()
801                 : cast<llvm::GlobalAlias>(Alias)->getAliasee();
802 
803     llvm::GlobalValue *AliaseeGV;
804     if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
805       AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
806     else
807       AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
808 
809     if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
810       StringRef AliasSection = SA->getName();
811       if (AliasSection != AliaseeGV->getSection())
812         Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
813             << AliasSection << IsIFunc << IsIFunc;
814     }
815 
816     // We have to handle alias to weak aliases in here. LLVM itself disallows
817     // this since the object semantics would not match the IL one. For
818     // compatibility with gcc we implement it by just pointing the alias
819     // to its aliasee's aliasee. We also warn, since the user is probably
820     // expecting the link to be weak.
821     if (auto *GA = dyn_cast<llvm::GlobalAlias>(AliaseeGV)) {
822       if (GA->isInterposable()) {
823         Diags.Report(Location, diag::warn_alias_to_weak_alias)
824             << GV->getName() << GA->getName() << IsIFunc;
825         Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
826             GA->getAliasee(), Alias->getType());
827 
828         if (IsIFunc)
829           cast<llvm::GlobalIFunc>(Alias)->setResolver(Aliasee);
830         else
831           cast<llvm::GlobalAlias>(Alias)->setAliasee(Aliasee);
832       }
833     }
834     // ifunc resolvers are usually implemented to run before sanitizer
835     // initialization. Disable instrumentation to prevent the ordering issue.
836     if (IsIFunc)
837       cast<llvm::Function>(Aliasee)->addFnAttr(
838           llvm::Attribute::DisableSanitizerInstrumentation);
839   }
840   if (!Error)
841     return;
842 
843   for (const GlobalDecl &GD : Aliases) {
844     StringRef MangledName = getMangledName(GD);
845     llvm::GlobalValue *Alias = GetGlobalValue(MangledName);
846     Alias->replaceAllUsesWith(llvm::PoisonValue::get(Alias->getType()));
847     Alias->eraseFromParent();
848   }
849 }
850 
851 void CodeGenModule::clear() {
852   DeferredDeclsToEmit.clear();
853   EmittedDeferredDecls.clear();
854   DeferredAnnotations.clear();
855   if (OpenMPRuntime)
856     OpenMPRuntime->clear();
857 }
858 
859 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
860                                        StringRef MainFile) {
861   if (!hasDiagnostics())
862     return;
863   if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
864     if (MainFile.empty())
865       MainFile = "<stdin>";
866     Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
867   } else {
868     if (Mismatched > 0)
869       Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
870 
871     if (Missing > 0)
872       Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
873   }
874 }
875 
876 static std::optional<llvm::GlobalValue::VisibilityTypes>
877 getLLVMVisibility(clang::LangOptions::VisibilityFromDLLStorageClassKinds K) {
878   // Map to LLVM visibility.
879   switch (K) {
880   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Keep:
881     return std::nullopt;
882   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Default:
883     return llvm::GlobalValue::DefaultVisibility;
884   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Hidden:
885     return llvm::GlobalValue::HiddenVisibility;
886   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Protected:
887     return llvm::GlobalValue::ProtectedVisibility;
888   }
889   llvm_unreachable("unknown option value!");
890 }
891 
892 static void
893 setLLVMVisibility(llvm::GlobalValue &GV,
894                   std::optional<llvm::GlobalValue::VisibilityTypes> V) {
895   if (!V)
896     return;
897 
898   // Reset DSO locality before setting the visibility. This removes
899   // any effects that visibility options and annotations may have
900   // had on the DSO locality. Setting the visibility will implicitly set
901   // appropriate globals to DSO Local; however, this will be pessimistic
902   // w.r.t. to the normal compiler IRGen.
903   GV.setDSOLocal(false);
904   GV.setVisibility(*V);
905 }
906 
907 static void setVisibilityFromDLLStorageClass(const clang::LangOptions &LO,
908                                              llvm::Module &M) {
909   if (!LO.VisibilityFromDLLStorageClass)
910     return;
911 
912   std::optional<llvm::GlobalValue::VisibilityTypes> DLLExportVisibility =
913       getLLVMVisibility(LO.getDLLExportVisibility());
914 
915   std::optional<llvm::GlobalValue::VisibilityTypes>
916       NoDLLStorageClassVisibility =
917           getLLVMVisibility(LO.getNoDLLStorageClassVisibility());
918 
919   std::optional<llvm::GlobalValue::VisibilityTypes>
920       ExternDeclDLLImportVisibility =
921           getLLVMVisibility(LO.getExternDeclDLLImportVisibility());
922 
923   std::optional<llvm::GlobalValue::VisibilityTypes>
924       ExternDeclNoDLLStorageClassVisibility =
925           getLLVMVisibility(LO.getExternDeclNoDLLStorageClassVisibility());
926 
927   for (llvm::GlobalValue &GV : M.global_values()) {
928     if (GV.hasAppendingLinkage() || GV.hasLocalLinkage())
929       continue;
930 
931     if (GV.isDeclarationForLinker())
932       setLLVMVisibility(GV, GV.getDLLStorageClass() ==
933                                     llvm::GlobalValue::DLLImportStorageClass
934                                 ? ExternDeclDLLImportVisibility
935                                 : ExternDeclNoDLLStorageClassVisibility);
936     else
937       setLLVMVisibility(GV, GV.getDLLStorageClass() ==
938                                     llvm::GlobalValue::DLLExportStorageClass
939                                 ? DLLExportVisibility
940                                 : NoDLLStorageClassVisibility);
941 
942     GV.setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
943   }
944 }
945 
946 static bool isStackProtectorOn(const LangOptions &LangOpts,
947                                const llvm::Triple &Triple,
948                                clang::LangOptions::StackProtectorMode Mode) {
949   if (Triple.isGPU())
950     return false;
951   return LangOpts.getStackProtector() == Mode;
952 }
953 
954 void CodeGenModule::Release() {
955   Module *Primary = getContext().getCurrentNamedModule();
956   if (CXX20ModuleInits && Primary && !Primary->isHeaderLikeModule())
957     EmitModuleInitializers(Primary);
958   EmitDeferred();
959   DeferredDecls.insert_range(EmittedDeferredDecls);
960   EmittedDeferredDecls.clear();
961   EmitVTablesOpportunistically();
962   applyGlobalValReplacements();
963   applyReplacements();
964   emitMultiVersionFunctions();
965 
966   if (Context.getLangOpts().IncrementalExtensions &&
967       GlobalTopLevelStmtBlockInFlight.first) {
968     const TopLevelStmtDecl *TLSD = GlobalTopLevelStmtBlockInFlight.second;
969     GlobalTopLevelStmtBlockInFlight.first->FinishFunction(TLSD->getEndLoc());
970     GlobalTopLevelStmtBlockInFlight = {nullptr, nullptr};
971   }
972 
973   // Module implementations are initialized the same way as a regular TU that
974   // imports one or more modules.
975   if (CXX20ModuleInits && Primary && Primary->isInterfaceOrPartition())
976     EmitCXXModuleInitFunc(Primary);
977   else
978     EmitCXXGlobalInitFunc();
979   EmitCXXGlobalCleanUpFunc();
980   registerGlobalDtorsWithAtExit();
981   EmitCXXThreadLocalInitFunc();
982   if (ObjCRuntime)
983     if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
984       AddGlobalCtor(ObjCInitFunction);
985   if (Context.getLangOpts().CUDA && CUDARuntime) {
986     if (llvm::Function *CudaCtorFunction = CUDARuntime->finalizeModule())
987       AddGlobalCtor(CudaCtorFunction);
988   }
989   if (OpenMPRuntime) {
990     OpenMPRuntime->createOffloadEntriesAndInfoMetadata();
991     OpenMPRuntime->clear();
992   }
993   if (PGOReader) {
994     getModule().setProfileSummary(
995         PGOReader->getSummary(/* UseCS */ false).getMD(VMContext),
996         llvm::ProfileSummary::PSK_Instr);
997     if (PGOStats.hasDiagnostics())
998       PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
999   }
1000   llvm::stable_sort(GlobalCtors, [](const Structor &L, const Structor &R) {
1001     return L.LexOrder < R.LexOrder;
1002   });
1003   EmitCtorList(GlobalCtors, "llvm.global_ctors");
1004   EmitCtorList(GlobalDtors, "llvm.global_dtors");
1005   EmitGlobalAnnotations();
1006   EmitStaticExternCAliases();
1007   checkAliases();
1008   EmitDeferredUnusedCoverageMappings();
1009   CodeGenPGO(*this).setValueProfilingFlag(getModule());
1010   CodeGenPGO(*this).setProfileVersion(getModule());
1011   if (CoverageMapping)
1012     CoverageMapping->emit();
1013   if (CodeGenOpts.SanitizeCfiCrossDso) {
1014     CodeGenFunction(*this).EmitCfiCheckFail();
1015     CodeGenFunction(*this).EmitCfiCheckStub();
1016   }
1017   if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
1018     finalizeKCFITypes();
1019   emitAtAvailableLinkGuard();
1020   if (Context.getTargetInfo().getTriple().isWasm())
1021     EmitMainVoidAlias();
1022 
1023   if (getTriple().isAMDGPU() ||
1024       (getTriple().isSPIRV() && getTriple().getVendor() == llvm::Triple::AMD)) {
1025     // Emit amdhsa_code_object_version module flag, which is code object version
1026     // times 100.
1027     if (getTarget().getTargetOpts().CodeObjectVersion !=
1028         llvm::CodeObjectVersionKind::COV_None) {
1029       getModule().addModuleFlag(llvm::Module::Error,
1030                                 "amdhsa_code_object_version",
1031                                 getTarget().getTargetOpts().CodeObjectVersion);
1032     }
1033 
1034     // Currently, "-mprintf-kind" option is only supported for HIP
1035     if (LangOpts.HIP) {
1036       auto *MDStr = llvm::MDString::get(
1037           getLLVMContext(), (getTarget().getTargetOpts().AMDGPUPrintfKindVal ==
1038                              TargetOptions::AMDGPUPrintfKind::Hostcall)
1039                                 ? "hostcall"
1040                                 : "buffered");
1041       getModule().addModuleFlag(llvm::Module::Error, "amdgpu_printf_kind",
1042                                 MDStr);
1043     }
1044   }
1045 
1046   // Emit a global array containing all external kernels or device variables
1047   // used by host functions and mark it as used for CUDA/HIP. This is necessary
1048   // to get kernels or device variables in archives linked in even if these
1049   // kernels or device variables are only used in host functions.
1050   if (!Context.CUDAExternalDeviceDeclODRUsedByHost.empty()) {
1051     SmallVector<llvm::Constant *, 8> UsedArray;
1052     for (auto D : Context.CUDAExternalDeviceDeclODRUsedByHost) {
1053       GlobalDecl GD;
1054       if (auto *FD = dyn_cast<FunctionDecl>(D))
1055         GD = GlobalDecl(FD, KernelReferenceKind::Kernel);
1056       else
1057         GD = GlobalDecl(D);
1058       UsedArray.push_back(llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
1059           GetAddrOfGlobal(GD), Int8PtrTy));
1060     }
1061 
1062     llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size());
1063 
1064     auto *GV = new llvm::GlobalVariable(
1065         getModule(), ATy, false, llvm::GlobalValue::InternalLinkage,
1066         llvm::ConstantArray::get(ATy, UsedArray), "__clang_gpu_used_external");
1067     addCompilerUsedGlobal(GV);
1068   }
1069   if (LangOpts.HIP) {
1070     // Emit a unique ID so that host and device binaries from the same
1071     // compilation unit can be associated.
1072     auto *GV = new llvm::GlobalVariable(
1073         getModule(), Int8Ty, false, llvm::GlobalValue::ExternalLinkage,
1074         llvm::Constant::getNullValue(Int8Ty),
1075         "__hip_cuid_" + getContext().getCUIDHash());
1076     getSanitizerMetadata()->disableSanitizerForGlobal(GV);
1077     addCompilerUsedGlobal(GV);
1078   }
1079   emitLLVMUsed();
1080   if (SanStats)
1081     SanStats->finish();
1082 
1083   if (CodeGenOpts.Autolink &&
1084       (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
1085     EmitModuleLinkOptions();
1086   }
1087 
1088   // On ELF we pass the dependent library specifiers directly to the linker
1089   // without manipulating them. This is in contrast to other platforms where
1090   // they are mapped to a specific linker option by the compiler. This
1091   // difference is a result of the greater variety of ELF linkers and the fact
1092   // that ELF linkers tend to handle libraries in a more complicated fashion
1093   // than on other platforms. This forces us to defer handling the dependent
1094   // libs to the linker.
1095   //
1096   // CUDA/HIP device and host libraries are different. Currently there is no
1097   // way to differentiate dependent libraries for host or device. Existing
1098   // usage of #pragma comment(lib, *) is intended for host libraries on
1099   // Windows. Therefore emit llvm.dependent-libraries only for host.
1100   if (!ELFDependentLibraries.empty() && !Context.getLangOpts().CUDAIsDevice) {
1101     auto *NMD = getModule().getOrInsertNamedMetadata("llvm.dependent-libraries");
1102     for (auto *MD : ELFDependentLibraries)
1103       NMD->addOperand(MD);
1104   }
1105 
1106   if (CodeGenOpts.DwarfVersion) {
1107     getModule().addModuleFlag(llvm::Module::Max, "Dwarf Version",
1108                               CodeGenOpts.DwarfVersion);
1109   }
1110 
1111   if (CodeGenOpts.Dwarf64)
1112     getModule().addModuleFlag(llvm::Module::Max, "DWARF64", 1);
1113 
1114   if (Context.getLangOpts().SemanticInterposition)
1115     // Require various optimization to respect semantic interposition.
1116     getModule().setSemanticInterposition(true);
1117 
1118   if (CodeGenOpts.EmitCodeView) {
1119     // Indicate that we want CodeView in the metadata.
1120     getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
1121   }
1122   if (CodeGenOpts.CodeViewGHash) {
1123     getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
1124   }
1125   if (CodeGenOpts.ControlFlowGuard) {
1126     // Function ID tables and checks for Control Flow Guard (cfguard=2).
1127     getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 2);
1128   } else if (CodeGenOpts.ControlFlowGuardNoChecks) {
1129     // Function ID tables for Control Flow Guard (cfguard=1).
1130     getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 1);
1131   }
1132   if (CodeGenOpts.EHContGuard) {
1133     // Function ID tables for EH Continuation Guard.
1134     getModule().addModuleFlag(llvm::Module::Warning, "ehcontguard", 1);
1135   }
1136   if (Context.getLangOpts().Kernel) {
1137     // Note if we are compiling with /kernel.
1138     getModule().addModuleFlag(llvm::Module::Warning, "ms-kernel", 1);
1139   }
1140   if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
1141     // We don't support LTO with 2 with different StrictVTablePointers
1142     // FIXME: we could support it by stripping all the information introduced
1143     // by StrictVTablePointers.
1144 
1145     getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
1146 
1147     llvm::Metadata *Ops[2] = {
1148               llvm::MDString::get(VMContext, "StrictVTablePointers"),
1149               llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1150                   llvm::Type::getInt32Ty(VMContext), 1))};
1151 
1152     getModule().addModuleFlag(llvm::Module::Require,
1153                               "StrictVTablePointersRequirement",
1154                               llvm::MDNode::get(VMContext, Ops));
1155   }
1156   if (getModuleDebugInfo() || getTriple().isOSWindows())
1157     // We support a single version in the linked module. The LLVM
1158     // parser will drop debug info with a different version number
1159     // (and warn about it, too).
1160     getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
1161                               llvm::DEBUG_METADATA_VERSION);
1162 
1163   // We need to record the widths of enums and wchar_t, so that we can generate
1164   // the correct build attributes in the ARM backend. wchar_size is also used by
1165   // TargetLibraryInfo.
1166   uint64_t WCharWidth =
1167       Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
1168   getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
1169 
1170   if (getTriple().isOSzOS()) {
1171     getModule().addModuleFlag(llvm::Module::Warning,
1172                               "zos_product_major_version",
1173                               uint32_t(CLANG_VERSION_MAJOR));
1174     getModule().addModuleFlag(llvm::Module::Warning,
1175                               "zos_product_minor_version",
1176                               uint32_t(CLANG_VERSION_MINOR));
1177     getModule().addModuleFlag(llvm::Module::Warning, "zos_product_patchlevel",
1178                               uint32_t(CLANG_VERSION_PATCHLEVEL));
1179     std::string ProductId = getClangVendor() + "clang";
1180     getModule().addModuleFlag(llvm::Module::Error, "zos_product_id",
1181                               llvm::MDString::get(VMContext, ProductId));
1182 
1183     // Record the language because we need it for the PPA2.
1184     StringRef lang_str = languageToString(
1185         LangStandard::getLangStandardForKind(LangOpts.LangStd).Language);
1186     getModule().addModuleFlag(llvm::Module::Error, "zos_cu_language",
1187                               llvm::MDString::get(VMContext, lang_str));
1188 
1189     time_t TT = PreprocessorOpts.SourceDateEpoch
1190                     ? *PreprocessorOpts.SourceDateEpoch
1191                     : std::time(nullptr);
1192     getModule().addModuleFlag(llvm::Module::Max, "zos_translation_time",
1193                               static_cast<uint64_t>(TT));
1194 
1195     // Multiple modes will be supported here.
1196     getModule().addModuleFlag(llvm::Module::Error, "zos_le_char_mode",
1197                               llvm::MDString::get(VMContext, "ascii"));
1198   }
1199 
1200   llvm::Triple T = Context.getTargetInfo().getTriple();
1201   if (T.isARM() || T.isThumb()) {
1202     // The minimum width of an enum in bytes
1203     uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
1204     getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
1205   }
1206 
1207   if (T.isRISCV()) {
1208     StringRef ABIStr = Target.getABI();
1209     llvm::LLVMContext &Ctx = TheModule.getContext();
1210     getModule().addModuleFlag(llvm::Module::Error, "target-abi",
1211                               llvm::MDString::get(Ctx, ABIStr));
1212 
1213     // Add the canonical ISA string as metadata so the backend can set the ELF
1214     // attributes correctly. We use AppendUnique so LTO will keep all of the
1215     // unique ISA strings that were linked together.
1216     const std::vector<std::string> &Features =
1217         getTarget().getTargetOpts().Features;
1218     auto ParseResult =
1219         llvm::RISCVISAInfo::parseFeatures(T.isRISCV64() ? 64 : 32, Features);
1220     if (!errorToBool(ParseResult.takeError()))
1221       getModule().addModuleFlag(
1222           llvm::Module::AppendUnique, "riscv-isa",
1223           llvm::MDNode::get(
1224               Ctx, llvm::MDString::get(Ctx, (*ParseResult)->toString())));
1225   }
1226 
1227   if (CodeGenOpts.SanitizeCfiCrossDso) {
1228     // Indicate that we want cross-DSO control flow integrity checks.
1229     getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
1230   }
1231 
1232   if (CodeGenOpts.WholeProgramVTables) {
1233     // Indicate whether VFE was enabled for this module, so that the
1234     // vcall_visibility metadata added under whole program vtables is handled
1235     // appropriately in the optimizer.
1236     getModule().addModuleFlag(llvm::Module::Error, "Virtual Function Elim",
1237                               CodeGenOpts.VirtualFunctionElimination);
1238   }
1239 
1240   if (LangOpts.Sanitize.has(SanitizerKind::CFIICall)) {
1241     getModule().addModuleFlag(llvm::Module::Override,
1242                               "CFI Canonical Jump Tables",
1243                               CodeGenOpts.SanitizeCfiCanonicalJumpTables);
1244   }
1245 
1246   if (CodeGenOpts.SanitizeCfiICallNormalizeIntegers) {
1247     getModule().addModuleFlag(llvm::Module::Override, "cfi-normalize-integers",
1248                               1);
1249   }
1250 
1251   if (!CodeGenOpts.UniqueSourceFileIdentifier.empty()) {
1252     getModule().addModuleFlag(
1253         llvm::Module::Append, "Unique Source File Identifier",
1254         llvm::MDTuple::get(
1255             TheModule.getContext(),
1256             llvm::MDString::get(TheModule.getContext(),
1257                                 CodeGenOpts.UniqueSourceFileIdentifier)));
1258   }
1259 
1260   if (LangOpts.Sanitize.has(SanitizerKind::KCFI)) {
1261     getModule().addModuleFlag(llvm::Module::Override, "kcfi", 1);
1262     // KCFI assumes patchable-function-prefix is the same for all indirectly
1263     // called functions. Store the expected offset for code generation.
1264     if (CodeGenOpts.PatchableFunctionEntryOffset)
1265       getModule().addModuleFlag(llvm::Module::Override, "kcfi-offset",
1266                                 CodeGenOpts.PatchableFunctionEntryOffset);
1267     if (CodeGenOpts.SanitizeKcfiArity)
1268       getModule().addModuleFlag(llvm::Module::Override, "kcfi-arity", 1);
1269   }
1270 
1271   if (CodeGenOpts.CFProtectionReturn &&
1272       Target.checkCFProtectionReturnSupported(getDiags())) {
1273     // Indicate that we want to instrument return control flow protection.
1274     getModule().addModuleFlag(llvm::Module::Min, "cf-protection-return",
1275                               1);
1276   }
1277 
1278   if (CodeGenOpts.CFProtectionBranch &&
1279       Target.checkCFProtectionBranchSupported(getDiags())) {
1280     // Indicate that we want to instrument branch control flow protection.
1281     getModule().addModuleFlag(llvm::Module::Min, "cf-protection-branch",
1282                               1);
1283 
1284     auto Scheme = CodeGenOpts.getCFBranchLabelScheme();
1285     if (Target.checkCFBranchLabelSchemeSupported(Scheme, getDiags())) {
1286       if (Scheme == CFBranchLabelSchemeKind::Default)
1287         Scheme = Target.getDefaultCFBranchLabelScheme();
1288       getModule().addModuleFlag(
1289           llvm::Module::Error, "cf-branch-label-scheme",
1290           llvm::MDString::get(getLLVMContext(),
1291                               getCFBranchLabelSchemeFlagVal(Scheme)));
1292     }
1293   }
1294 
1295   if (CodeGenOpts.FunctionReturnThunks)
1296     getModule().addModuleFlag(llvm::Module::Override, "function_return_thunk_extern", 1);
1297 
1298   if (CodeGenOpts.IndirectBranchCSPrefix)
1299     getModule().addModuleFlag(llvm::Module::Override, "indirect_branch_cs_prefix", 1);
1300 
1301   // Add module metadata for return address signing (ignoring
1302   // non-leaf/all) and stack tagging. These are actually turned on by function
1303   // attributes, but we use module metadata to emit build attributes. This is
1304   // needed for LTO, where the function attributes are inside bitcode
1305   // serialised into a global variable by the time build attributes are
1306   // emitted, so we can't access them. LTO objects could be compiled with
1307   // different flags therefore module flags are set to "Min" behavior to achieve
1308   // the same end result of the normal build where e.g BTI is off if any object
1309   // doesn't support it.
1310   if (Context.getTargetInfo().hasFeature("ptrauth") &&
1311       LangOpts.getSignReturnAddressScope() !=
1312           LangOptions::SignReturnAddressScopeKind::None)
1313     getModule().addModuleFlag(llvm::Module::Override,
1314                               "sign-return-address-buildattr", 1);
1315   if (LangOpts.Sanitize.has(SanitizerKind::MemtagStack))
1316     getModule().addModuleFlag(llvm::Module::Override,
1317                               "tag-stack-memory-buildattr", 1);
1318 
1319   if (T.isARM() || T.isThumb() || T.isAArch64()) {
1320     if (LangOpts.BranchTargetEnforcement)
1321       getModule().addModuleFlag(llvm::Module::Min, "branch-target-enforcement",
1322                                 1);
1323     if (LangOpts.BranchProtectionPAuthLR)
1324       getModule().addModuleFlag(llvm::Module::Min, "branch-protection-pauth-lr",
1325                                 1);
1326     if (LangOpts.GuardedControlStack)
1327       getModule().addModuleFlag(llvm::Module::Min, "guarded-control-stack", 1);
1328     if (LangOpts.hasSignReturnAddress())
1329       getModule().addModuleFlag(llvm::Module::Min, "sign-return-address", 1);
1330     if (LangOpts.isSignReturnAddressScopeAll())
1331       getModule().addModuleFlag(llvm::Module::Min, "sign-return-address-all",
1332                                 1);
1333     if (!LangOpts.isSignReturnAddressWithAKey())
1334       getModule().addModuleFlag(llvm::Module::Min,
1335                                 "sign-return-address-with-bkey", 1);
1336 
1337     if (LangOpts.PointerAuthELFGOT)
1338       getModule().addModuleFlag(llvm::Module::Min, "ptrauth-elf-got", 1);
1339 
1340     if (getTriple().isOSLinux()) {
1341       if (LangOpts.PointerAuthCalls)
1342         getModule().addModuleFlag(llvm::Module::Min, "ptrauth-sign-personality",
1343                                   1);
1344       assert(getTriple().isOSBinFormatELF());
1345       using namespace llvm::ELF;
1346       uint64_t PAuthABIVersion =
1347           (LangOpts.PointerAuthIntrinsics
1348            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_INTRINSICS) |
1349           (LangOpts.PointerAuthCalls
1350            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_CALLS) |
1351           (LangOpts.PointerAuthReturns
1352            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_RETURNS) |
1353           (LangOpts.PointerAuthAuthTraps
1354            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_AUTHTRAPS) |
1355           (LangOpts.PointerAuthVTPtrAddressDiscrimination
1356            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_VPTRADDRDISCR) |
1357           (LangOpts.PointerAuthVTPtrTypeDiscrimination
1358            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_VPTRTYPEDISCR) |
1359           (LangOpts.PointerAuthInitFini
1360            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_INITFINI) |
1361           (LangOpts.PointerAuthInitFiniAddressDiscrimination
1362            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_INITFINIADDRDISC) |
1363           (LangOpts.PointerAuthELFGOT
1364            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_GOT) |
1365           (LangOpts.PointerAuthIndirectGotos
1366            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_GOTOS) |
1367           (LangOpts.PointerAuthTypeInfoVTPtrDiscrimination
1368            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_TYPEINFOVPTRDISCR) |
1369           (LangOpts.PointerAuthFunctionTypeDiscrimination
1370            << AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_FPTRTYPEDISCR);
1371       static_assert(AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_FPTRTYPEDISCR ==
1372                         AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_LAST,
1373                     "Update when new enum items are defined");
1374       if (PAuthABIVersion != 0) {
1375         getModule().addModuleFlag(llvm::Module::Error,
1376                                   "aarch64-elf-pauthabi-platform",
1377                                   AARCH64_PAUTH_PLATFORM_LLVM_LINUX);
1378         getModule().addModuleFlag(llvm::Module::Error,
1379                                   "aarch64-elf-pauthabi-version",
1380                                   PAuthABIVersion);
1381       }
1382     }
1383   }
1384 
1385   if (CodeGenOpts.StackClashProtector)
1386     getModule().addModuleFlag(
1387         llvm::Module::Override, "probe-stack",
1388         llvm::MDString::get(TheModule.getContext(), "inline-asm"));
1389 
1390   if (CodeGenOpts.StackProbeSize && CodeGenOpts.StackProbeSize != 4096)
1391     getModule().addModuleFlag(llvm::Module::Min, "stack-probe-size",
1392                               CodeGenOpts.StackProbeSize);
1393 
1394   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
1395     llvm::LLVMContext &Ctx = TheModule.getContext();
1396     getModule().addModuleFlag(
1397         llvm::Module::Error, "MemProfProfileFilename",
1398         llvm::MDString::get(Ctx, CodeGenOpts.MemoryProfileOutput));
1399   }
1400 
1401   if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
1402     // Indicate whether __nvvm_reflect should be configured to flush denormal
1403     // floating point values to 0.  (This corresponds to its "__CUDA_FTZ"
1404     // property.)
1405     getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
1406                               CodeGenOpts.FP32DenormalMode.Output !=
1407                                   llvm::DenormalMode::IEEE);
1408   }
1409 
1410   if (LangOpts.EHAsynch)
1411     getModule().addModuleFlag(llvm::Module::Warning, "eh-asynch", 1);
1412 
1413   // Emit Import Call section.
1414   if (CodeGenOpts.ImportCallOptimization)
1415     getModule().addModuleFlag(llvm::Module::Warning, "import-call-optimization",
1416                               1);
1417 
1418   // Enable unwind v2 (epilog).
1419   if (CodeGenOpts.getWinX64EHUnwindV2() != llvm::WinX64EHUnwindV2Mode::Disabled)
1420     getModule().addModuleFlag(
1421         llvm::Module::Warning, "winx64-eh-unwindv2",
1422         static_cast<unsigned>(CodeGenOpts.getWinX64EHUnwindV2()));
1423 
1424   // Indicate whether this Module was compiled with -fopenmp
1425   if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
1426     getModule().addModuleFlag(llvm::Module::Max, "openmp", LangOpts.OpenMP);
1427   if (getLangOpts().OpenMPIsTargetDevice)
1428     getModule().addModuleFlag(llvm::Module::Max, "openmp-device",
1429                               LangOpts.OpenMP);
1430 
1431   // Emit OpenCL specific module metadata: OpenCL/SPIR version.
1432   if (LangOpts.OpenCL || (LangOpts.CUDAIsDevice && getTriple().isSPIRV())) {
1433     EmitOpenCLMetadata();
1434     // Emit SPIR version.
1435     if (getTriple().isSPIR()) {
1436       // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
1437       // opencl.spir.version named metadata.
1438       // C++ for OpenCL has a distinct mapping for version compatibility with
1439       // OpenCL.
1440       auto Version = LangOpts.getOpenCLCompatibleVersion();
1441       llvm::Metadata *SPIRVerElts[] = {
1442           llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1443               Int32Ty, Version / 100)),
1444           llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1445               Int32Ty, (Version / 100 > 1) ? 0 : 2))};
1446       llvm::NamedMDNode *SPIRVerMD =
1447           TheModule.getOrInsertNamedMetadata("opencl.spir.version");
1448       llvm::LLVMContext &Ctx = TheModule.getContext();
1449       SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
1450     }
1451   }
1452 
1453   // HLSL related end of code gen work items.
1454   if (LangOpts.HLSL)
1455     getHLSLRuntime().finishCodeGen();
1456 
1457   if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
1458     assert(PLevel < 3 && "Invalid PIC Level");
1459     getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
1460     if (Context.getLangOpts().PIE)
1461       getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
1462   }
1463 
1464   if (getCodeGenOpts().CodeModel.size() > 0) {
1465     unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
1466                   .Case("tiny", llvm::CodeModel::Tiny)
1467                   .Case("small", llvm::CodeModel::Small)
1468                   .Case("kernel", llvm::CodeModel::Kernel)
1469                   .Case("medium", llvm::CodeModel::Medium)
1470                   .Case("large", llvm::CodeModel::Large)
1471                   .Default(~0u);
1472     if (CM != ~0u) {
1473       llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
1474       getModule().setCodeModel(codeModel);
1475 
1476       if ((CM == llvm::CodeModel::Medium || CM == llvm::CodeModel::Large) &&
1477           Context.getTargetInfo().getTriple().getArch() ==
1478               llvm::Triple::x86_64) {
1479         getModule().setLargeDataThreshold(getCodeGenOpts().LargeDataThreshold);
1480       }
1481     }
1482   }
1483 
1484   if (CodeGenOpts.NoPLT)
1485     getModule().setRtLibUseGOT();
1486   if (getTriple().isOSBinFormatELF() &&
1487       CodeGenOpts.DirectAccessExternalData !=
1488           getModule().getDirectAccessExternalData()) {
1489     getModule().setDirectAccessExternalData(
1490         CodeGenOpts.DirectAccessExternalData);
1491   }
1492   if (CodeGenOpts.UnwindTables)
1493     getModule().setUwtable(llvm::UWTableKind(CodeGenOpts.UnwindTables));
1494 
1495   switch (CodeGenOpts.getFramePointer()) {
1496   case CodeGenOptions::FramePointerKind::None:
1497     // 0 ("none") is the default.
1498     break;
1499   case CodeGenOptions::FramePointerKind::Reserved:
1500     getModule().setFramePointer(llvm::FramePointerKind::Reserved);
1501     break;
1502   case CodeGenOptions::FramePointerKind::NonLeaf:
1503     getModule().setFramePointer(llvm::FramePointerKind::NonLeaf);
1504     break;
1505   case CodeGenOptions::FramePointerKind::All:
1506     getModule().setFramePointer(llvm::FramePointerKind::All);
1507     break;
1508   }
1509 
1510   SimplifyPersonality();
1511 
1512   if (getCodeGenOpts().EmitDeclMetadata)
1513     EmitDeclMetadata();
1514 
1515   if (getCodeGenOpts().CoverageNotesFile.size() ||
1516       getCodeGenOpts().CoverageDataFile.size())
1517     EmitCoverageFile();
1518 
1519   if (CGDebugInfo *DI = getModuleDebugInfo())
1520     DI->finalize();
1521 
1522   if (getCodeGenOpts().EmitVersionIdentMetadata)
1523     EmitVersionIdentMetadata();
1524 
1525   if (!getCodeGenOpts().RecordCommandLine.empty())
1526     EmitCommandLineMetadata();
1527 
1528   if (!getCodeGenOpts().StackProtectorGuard.empty())
1529     getModule().setStackProtectorGuard(getCodeGenOpts().StackProtectorGuard);
1530   if (!getCodeGenOpts().StackProtectorGuardReg.empty())
1531     getModule().setStackProtectorGuardReg(
1532         getCodeGenOpts().StackProtectorGuardReg);
1533   if (!getCodeGenOpts().StackProtectorGuardSymbol.empty())
1534     getModule().setStackProtectorGuardSymbol(
1535         getCodeGenOpts().StackProtectorGuardSymbol);
1536   if (getCodeGenOpts().StackProtectorGuardOffset != INT_MAX)
1537     getModule().setStackProtectorGuardOffset(
1538         getCodeGenOpts().StackProtectorGuardOffset);
1539   if (getCodeGenOpts().StackAlignment)
1540     getModule().setOverrideStackAlignment(getCodeGenOpts().StackAlignment);
1541   if (getCodeGenOpts().SkipRaxSetup)
1542     getModule().addModuleFlag(llvm::Module::Override, "SkipRaxSetup", 1);
1543   if (getLangOpts().RegCall4)
1544     getModule().addModuleFlag(llvm::Module::Override, "RegCallv4", 1);
1545 
1546   if (getContext().getTargetInfo().getMaxTLSAlign())
1547     getModule().addModuleFlag(llvm::Module::Error, "MaxTLSAlign",
1548                               getContext().getTargetInfo().getMaxTLSAlign());
1549 
1550   getTargetCodeGenInfo().emitTargetGlobals(*this);
1551 
1552   getTargetCodeGenInfo().emitTargetMetadata(*this, MangledDeclNames);
1553 
1554   EmitBackendOptionsMetadata(getCodeGenOpts());
1555 
1556   // If there is device offloading code embed it in the host now.
1557   EmbedObject(&getModule(), CodeGenOpts, getDiags());
1558 
1559   // Set visibility from DLL storage class
1560   // We do this at the end of LLVM IR generation; after any operation
1561   // that might affect the DLL storage class or the visibility, and
1562   // before anything that might act on these.
1563   setVisibilityFromDLLStorageClass(LangOpts, getModule());
1564 
1565   // Check the tail call symbols are truly undefined.
1566   if (getTriple().isPPC() && !MustTailCallUndefinedGlobals.empty()) {
1567     for (auto &I : MustTailCallUndefinedGlobals) {
1568       if (!I.first->isDefined())
1569         getDiags().Report(I.second, diag::err_ppc_impossible_musttail) << 2;
1570       else {
1571         StringRef MangledName = getMangledName(GlobalDecl(I.first));
1572         llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
1573         if (!Entry || Entry->isWeakForLinker() ||
1574             Entry->isDeclarationForLinker())
1575           getDiags().Report(I.second, diag::err_ppc_impossible_musttail) << 2;
1576       }
1577     }
1578   }
1579 }
1580 
1581 void CodeGenModule::EmitOpenCLMetadata() {
1582   // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
1583   // opencl.ocl.version named metadata node.
1584   // C++ for OpenCL has a distinct mapping for versions compatible with OpenCL.
1585   auto CLVersion = LangOpts.getOpenCLCompatibleVersion();
1586 
1587   auto EmitVersion = [this](StringRef MDName, int Version) {
1588     llvm::Metadata *OCLVerElts[] = {
1589         llvm::ConstantAsMetadata::get(
1590             llvm::ConstantInt::get(Int32Ty, Version / 100)),
1591         llvm::ConstantAsMetadata::get(
1592             llvm::ConstantInt::get(Int32Ty, (Version % 100) / 10))};
1593     llvm::NamedMDNode *OCLVerMD = TheModule.getOrInsertNamedMetadata(MDName);
1594     llvm::LLVMContext &Ctx = TheModule.getContext();
1595     OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
1596   };
1597 
1598   EmitVersion("opencl.ocl.version", CLVersion);
1599   if (LangOpts.OpenCLCPlusPlus) {
1600     // In addition to the OpenCL compatible version, emit the C++ version.
1601     EmitVersion("opencl.cxx.version", LangOpts.OpenCLCPlusPlusVersion);
1602   }
1603 }
1604 
1605 void CodeGenModule::EmitBackendOptionsMetadata(
1606     const CodeGenOptions &CodeGenOpts) {
1607   if (getTriple().isRISCV()) {
1608     getModule().addModuleFlag(llvm::Module::Min, "SmallDataLimit",
1609                               CodeGenOpts.SmallDataLimit);
1610   }
1611 }
1612 
1613 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
1614   // Make sure that this type is translated.
1615   getTypes().UpdateCompletedType(TD);
1616 }
1617 
1618 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
1619   // Make sure that this type is translated.
1620   getTypes().RefreshTypeCacheForClass(RD);
1621 }
1622 
1623 llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
1624   if (!TBAA)
1625     return nullptr;
1626   return TBAA->getTypeInfo(QTy);
1627 }
1628 
1629 TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
1630   if (!TBAA)
1631     return TBAAAccessInfo();
1632   if (getLangOpts().CUDAIsDevice) {
1633     // As CUDA builtin surface/texture types are replaced, skip generating TBAA
1634     // access info.
1635     if (AccessType->isCUDADeviceBuiltinSurfaceType()) {
1636       if (getTargetCodeGenInfo().getCUDADeviceBuiltinSurfaceDeviceType() !=
1637           nullptr)
1638         return TBAAAccessInfo();
1639     } else if (AccessType->isCUDADeviceBuiltinTextureType()) {
1640       if (getTargetCodeGenInfo().getCUDADeviceBuiltinTextureDeviceType() !=
1641           nullptr)
1642         return TBAAAccessInfo();
1643     }
1644   }
1645   return TBAA->getAccessInfo(AccessType);
1646 }
1647 
1648 TBAAAccessInfo
1649 CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
1650   if (!TBAA)
1651     return TBAAAccessInfo();
1652   return TBAA->getVTablePtrAccessInfo(VTablePtrType);
1653 }
1654 
1655 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
1656   if (!TBAA)
1657     return nullptr;
1658   return TBAA->getTBAAStructInfo(QTy);
1659 }
1660 
1661 llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
1662   if (!TBAA)
1663     return nullptr;
1664   return TBAA->getBaseTypeInfo(QTy);
1665 }
1666 
1667 llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
1668   if (!TBAA)
1669     return nullptr;
1670   return TBAA->getAccessTagInfo(Info);
1671 }
1672 
1673 TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
1674                                                    TBAAAccessInfo TargetInfo) {
1675   if (!TBAA)
1676     return TBAAAccessInfo();
1677   return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
1678 }
1679 
1680 TBAAAccessInfo
1681 CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
1682                                                    TBAAAccessInfo InfoB) {
1683   if (!TBAA)
1684     return TBAAAccessInfo();
1685   return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
1686 }
1687 
1688 TBAAAccessInfo
1689 CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
1690                                               TBAAAccessInfo SrcInfo) {
1691   if (!TBAA)
1692     return TBAAAccessInfo();
1693   return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
1694 }
1695 
1696 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
1697                                                 TBAAAccessInfo TBAAInfo) {
1698   if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
1699     Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
1700 }
1701 
1702 void CodeGenModule::DecorateInstructionWithInvariantGroup(
1703     llvm::Instruction *I, const CXXRecordDecl *RD) {
1704   I->setMetadata(llvm::LLVMContext::MD_invariant_group,
1705                  llvm::MDNode::get(getLLVMContext(), {}));
1706 }
1707 
1708 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
1709   unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
1710   getDiags().Report(Context.getFullLoc(loc), diagID) << message;
1711 }
1712 
1713 /// ErrorUnsupported - Print out an error that codegen doesn't support the
1714 /// specified stmt yet.
1715 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
1716   unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
1717                                                "cannot compile this %0 yet");
1718   std::string Msg = Type;
1719   getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID)
1720       << Msg << S->getSourceRange();
1721 }
1722 
1723 /// ErrorUnsupported - Print out an error that codegen doesn't support the
1724 /// specified decl yet.
1725 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
1726   unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
1727                                                "cannot compile this %0 yet");
1728   std::string Msg = Type;
1729   getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
1730 }
1731 
1732 void CodeGenModule::runWithSufficientStackSpace(SourceLocation Loc,
1733                                                 llvm::function_ref<void()> Fn) {
1734   StackHandler.runWithSufficientStackSpace(Loc, Fn);
1735 }
1736 
1737 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
1738   return llvm::ConstantInt::get(SizeTy, size.getQuantity());
1739 }
1740 
1741 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
1742                                         const NamedDecl *D) const {
1743   // Internal definitions always have default visibility.
1744   if (GV->hasLocalLinkage()) {
1745     GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1746     return;
1747   }
1748   if (!D)
1749     return;
1750 
1751   // Set visibility for definitions, and for declarations if requested globally
1752   // or set explicitly.
1753   LinkageInfo LV = D->getLinkageAndVisibility();
1754 
1755   // OpenMP declare target variables must be visible to the host so they can
1756   // be registered. We require protected visibility unless the variable has
1757   // the DT_nohost modifier and does not need to be registered.
1758   if (Context.getLangOpts().OpenMP &&
1759       Context.getLangOpts().OpenMPIsTargetDevice && isa<VarDecl>(D) &&
1760       D->hasAttr<OMPDeclareTargetDeclAttr>() &&
1761       D->getAttr<OMPDeclareTargetDeclAttr>()->getDevType() !=
1762           OMPDeclareTargetDeclAttr::DT_NoHost &&
1763       LV.getVisibility() == HiddenVisibility) {
1764     GV->setVisibility(llvm::GlobalValue::ProtectedVisibility);
1765     return;
1766   }
1767 
1768   if (Context.getLangOpts().HLSL && !D->isInExportDeclContext()) {
1769     GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
1770     return;
1771   }
1772 
1773   if (GV->hasDLLExportStorageClass() || GV->hasDLLImportStorageClass()) {
1774     // Reject incompatible dlllstorage and visibility annotations.
1775     if (!LV.isVisibilityExplicit())
1776       return;
1777     if (GV->hasDLLExportStorageClass()) {
1778       if (LV.getVisibility() == HiddenVisibility)
1779         getDiags().Report(D->getLocation(),
1780                           diag::err_hidden_visibility_dllexport);
1781     } else if (LV.getVisibility() != DefaultVisibility) {
1782       getDiags().Report(D->getLocation(),
1783                         diag::err_non_default_visibility_dllimport);
1784     }
1785     return;
1786   }
1787 
1788   if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
1789       !GV->isDeclarationForLinker())
1790     GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
1791 }
1792 
1793 static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
1794                                  llvm::GlobalValue *GV) {
1795   if (GV->hasLocalLinkage())
1796     return true;
1797 
1798   if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
1799     return true;
1800 
1801   // DLLImport explicitly marks the GV as external.
1802   if (GV->hasDLLImportStorageClass())
1803     return false;
1804 
1805   const llvm::Triple &TT = CGM.getTriple();
1806   const auto &CGOpts = CGM.getCodeGenOpts();
1807   if (TT.isOSCygMing()) {
1808     // In MinGW, variables without DLLImport can still be automatically
1809     // imported from a DLL by the linker; don't mark variables that
1810     // potentially could come from another DLL as DSO local.
1811 
1812     // With EmulatedTLS, TLS variables can be autoimported from other DLLs
1813     // (and this actually happens in the public interface of libstdc++), so
1814     // such variables can't be marked as DSO local. (Native TLS variables
1815     // can't be dllimported at all, though.)
1816     if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
1817         (!GV->isThreadLocal() || CGM.getCodeGenOpts().EmulatedTLS) &&
1818         CGOpts.AutoImport)
1819       return false;
1820   }
1821 
1822   // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
1823   // remain unresolved in the link, they can be resolved to zero, which is
1824   // outside the current DSO.
1825   if (TT.isOSBinFormatCOFF() && GV->hasExternalWeakLinkage())
1826     return false;
1827 
1828   // Every other GV is local on COFF.
1829   // Make an exception for windows OS in the triple: Some firmware builds use
1830   // *-win32-macho triples. This (accidentally?) produced windows relocations
1831   // without GOT tables in older clang versions; Keep this behaviour.
1832   // FIXME: even thread local variables?
1833   if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
1834     return true;
1835 
1836   // Only handle COFF and ELF for now.
1837   if (!TT.isOSBinFormatELF())
1838     return false;
1839 
1840   // If this is not an executable, don't assume anything is local.
1841   llvm::Reloc::Model RM = CGOpts.RelocationModel;
1842   const auto &LOpts = CGM.getLangOpts();
1843   if (RM != llvm::Reloc::Static && !LOpts.PIE) {
1844     // On ELF, if -fno-semantic-interposition is specified and the target
1845     // supports local aliases, there will be neither CC1
1846     // -fsemantic-interposition nor -fhalf-no-semantic-interposition. Set
1847     // dso_local on the function if using a local alias is preferable (can avoid
1848     // PLT indirection).
1849     if (!(isa<llvm::Function>(GV) && GV->canBenefitFromLocalAlias()))
1850       return false;
1851     return !(CGM.getLangOpts().SemanticInterposition ||
1852              CGM.getLangOpts().HalfNoSemanticInterposition);
1853   }
1854 
1855   // A definition cannot be preempted from an executable.
1856   if (!GV->isDeclarationForLinker())
1857     return true;
1858 
1859   // Most PIC code sequences that assume that a symbol is local cannot produce a
1860   // 0 if it turns out the symbol is undefined. While this is ABI and relocation
1861   // depended, it seems worth it to handle it here.
1862   if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
1863     return false;
1864 
1865   // PowerPC64 prefers TOC indirection to avoid copy relocations.
1866   if (TT.isPPC64())
1867     return false;
1868 
1869   if (CGOpts.DirectAccessExternalData) {
1870     // If -fdirect-access-external-data (default for -fno-pic), set dso_local
1871     // for non-thread-local variables. If the symbol is not defined in the
1872     // executable, a copy relocation will be needed at link time. dso_local is
1873     // excluded for thread-local variables because they generally don't support
1874     // copy relocations.
1875     if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
1876       if (!Var->isThreadLocal())
1877         return true;
1878 
1879     // -fno-pic sets dso_local on a function declaration to allow direct
1880     // accesses when taking its address (similar to a data symbol). If the
1881     // function is not defined in the executable, a canonical PLT entry will be
1882     // needed at link time. -fno-direct-access-external-data can avoid the
1883     // canonical PLT entry. We don't generalize this condition to -fpie/-fpic as
1884     // it could just cause trouble without providing perceptible benefits.
1885     if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
1886       return true;
1887   }
1888 
1889   // If we can use copy relocations we can assume it is local.
1890 
1891   // Otherwise don't assume it is local.
1892   return false;
1893 }
1894 
1895 void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
1896   GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
1897 }
1898 
1899 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1900                                           GlobalDecl GD) const {
1901   const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
1902   // C++ destructors have a few C++ ABI specific special cases.
1903   if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
1904     getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
1905     return;
1906   }
1907   setDLLImportDLLExport(GV, D);
1908 }
1909 
1910 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1911                                           const NamedDecl *D) const {
1912   if (D && D->isExternallyVisible()) {
1913     if (D->hasAttr<DLLImportAttr>())
1914       GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
1915     else if ((D->hasAttr<DLLExportAttr>() ||
1916               shouldMapVisibilityToDLLExport(D)) &&
1917              !GV->isDeclarationForLinker())
1918       GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
1919   }
1920 }
1921 
1922 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1923                                     GlobalDecl GD) const {
1924   setDLLImportDLLExport(GV, GD);
1925   setGVPropertiesAux(GV, dyn_cast<NamedDecl>(GD.getDecl()));
1926 }
1927 
1928 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1929                                     const NamedDecl *D) const {
1930   setDLLImportDLLExport(GV, D);
1931   setGVPropertiesAux(GV, D);
1932 }
1933 
1934 void CodeGenModule::setGVPropertiesAux(llvm::GlobalValue *GV,
1935                                        const NamedDecl *D) const {
1936   setGlobalVisibility(GV, D);
1937   setDSOLocal(GV);
1938   GV->setPartition(CodeGenOpts.SymbolPartition);
1939 }
1940 
1941 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
1942   return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
1943       .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
1944       .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
1945       .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
1946       .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
1947 }
1948 
1949 llvm::GlobalVariable::ThreadLocalMode
1950 CodeGenModule::GetDefaultLLVMTLSModel() const {
1951   switch (CodeGenOpts.getDefaultTLSModel()) {
1952   case CodeGenOptions::GeneralDynamicTLSModel:
1953     return llvm::GlobalVariable::GeneralDynamicTLSModel;
1954   case CodeGenOptions::LocalDynamicTLSModel:
1955     return llvm::GlobalVariable::LocalDynamicTLSModel;
1956   case CodeGenOptions::InitialExecTLSModel:
1957     return llvm::GlobalVariable::InitialExecTLSModel;
1958   case CodeGenOptions::LocalExecTLSModel:
1959     return llvm::GlobalVariable::LocalExecTLSModel;
1960   }
1961   llvm_unreachable("Invalid TLS model!");
1962 }
1963 
1964 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
1965   assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
1966 
1967   llvm::GlobalValue::ThreadLocalMode TLM;
1968   TLM = GetDefaultLLVMTLSModel();
1969 
1970   // Override the TLS model if it is explicitly specified.
1971   if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
1972     TLM = GetLLVMTLSModel(Attr->getModel());
1973   }
1974 
1975   GV->setThreadLocalMode(TLM);
1976 }
1977 
1978 static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
1979                                           StringRef Name) {
1980   const TargetInfo &Target = CGM.getTarget();
1981   return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
1982 }
1983 
1984 static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
1985                                                  const CPUSpecificAttr *Attr,
1986                                                  unsigned CPUIndex,
1987                                                  raw_ostream &Out) {
1988   // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
1989   // supported.
1990   if (Attr)
1991     Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
1992   else if (CGM.getTarget().supportsIFunc())
1993     Out << ".resolver";
1994 }
1995 
1996 // Returns true if GD is a function decl with internal linkage and
1997 // needs a unique suffix after the mangled name.
1998 static bool isUniqueInternalLinkageDecl(GlobalDecl GD,
1999                                         CodeGenModule &CGM) {
2000   const Decl *D = GD.getDecl();
2001   return !CGM.getModuleNameHash().empty() && isa<FunctionDecl>(D) &&
2002          (CGM.getFunctionLinkage(GD) == llvm::GlobalValue::InternalLinkage);
2003 }
2004 
2005 static std::string getMangledNameImpl(CodeGenModule &CGM, GlobalDecl GD,
2006                                       const NamedDecl *ND,
2007                                       bool OmitMultiVersionMangling = false) {
2008   SmallString<256> Buffer;
2009   llvm::raw_svector_ostream Out(Buffer);
2010   MangleContext &MC = CGM.getCXXABI().getMangleContext();
2011   if (!CGM.getModuleNameHash().empty())
2012     MC.needsUniqueInternalLinkageNames();
2013   bool ShouldMangle = MC.shouldMangleDeclName(ND);
2014   if (ShouldMangle)
2015     MC.mangleName(GD.getWithDecl(ND), Out);
2016   else {
2017     IdentifierInfo *II = ND->getIdentifier();
2018     assert(II && "Attempt to mangle unnamed decl.");
2019     const auto *FD = dyn_cast<FunctionDecl>(ND);
2020 
2021     if (FD &&
2022         FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
2023       if (CGM.getLangOpts().RegCall4)
2024         Out << "__regcall4__" << II->getName();
2025       else
2026         Out << "__regcall3__" << II->getName();
2027     } else if (FD && FD->hasAttr<CUDAGlobalAttr>() &&
2028                GD.getKernelReferenceKind() == KernelReferenceKind::Stub) {
2029       Out << "__device_stub__" << II->getName();
2030     } else if (FD &&
2031                DeviceKernelAttr::isOpenCLSpelling(
2032                    FD->getAttr<DeviceKernelAttr>()) &&
2033                GD.getKernelReferenceKind() == KernelReferenceKind::Stub) {
2034       Out << "__clang_ocl_kern_imp_" << II->getName();
2035     } else {
2036       Out << II->getName();
2037     }
2038   }
2039 
2040   // Check if the module name hash should be appended for internal linkage
2041   // symbols.   This should come before multi-version target suffixes are
2042   // appended. This is to keep the name and module hash suffix of the
2043   // internal linkage function together.  The unique suffix should only be
2044   // added when name mangling is done to make sure that the final name can
2045   // be properly demangled.  For example, for C functions without prototypes,
2046   // name mangling is not done and the unique suffix should not be appeneded
2047   // then.
2048   if (ShouldMangle && isUniqueInternalLinkageDecl(GD, CGM)) {
2049     assert(CGM.getCodeGenOpts().UniqueInternalLinkageNames &&
2050            "Hash computed when not explicitly requested");
2051     Out << CGM.getModuleNameHash();
2052   }
2053 
2054   if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2055     if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
2056       switch (FD->getMultiVersionKind()) {
2057       case MultiVersionKind::CPUDispatch:
2058       case MultiVersionKind::CPUSpecific:
2059         AppendCPUSpecificCPUDispatchMangling(CGM,
2060                                              FD->getAttr<CPUSpecificAttr>(),
2061                                              GD.getMultiVersionIndex(), Out);
2062         break;
2063       case MultiVersionKind::Target: {
2064         auto *Attr = FD->getAttr<TargetAttr>();
2065         assert(Attr && "Expected TargetAttr to be present "
2066                        "for attribute mangling");
2067         const ABIInfo &Info = CGM.getTargetCodeGenInfo().getABIInfo();
2068         Info.appendAttributeMangling(Attr, Out);
2069         break;
2070       }
2071       case MultiVersionKind::TargetVersion: {
2072         auto *Attr = FD->getAttr<TargetVersionAttr>();
2073         assert(Attr && "Expected TargetVersionAttr to be present "
2074                        "for attribute mangling");
2075         const ABIInfo &Info = CGM.getTargetCodeGenInfo().getABIInfo();
2076         Info.appendAttributeMangling(Attr, Out);
2077         break;
2078       }
2079       case MultiVersionKind::TargetClones: {
2080         auto *Attr = FD->getAttr<TargetClonesAttr>();
2081         assert(Attr && "Expected TargetClonesAttr to be present "
2082                        "for attribute mangling");
2083         unsigned Index = GD.getMultiVersionIndex();
2084         const ABIInfo &Info = CGM.getTargetCodeGenInfo().getABIInfo();
2085         Info.appendAttributeMangling(Attr, Index, Out);
2086         break;
2087       }
2088       case MultiVersionKind::None:
2089         llvm_unreachable("None multiversion type isn't valid here");
2090       }
2091     }
2092 
2093   // Make unique name for device side static file-scope variable for HIP.
2094   if (CGM.getContext().shouldExternalize(ND) &&
2095       CGM.getLangOpts().GPURelocatableDeviceCode &&
2096       CGM.getLangOpts().CUDAIsDevice)
2097     CGM.printPostfixForExternalizedDecl(Out, ND);
2098 
2099   return std::string(Out.str());
2100 }
2101 
2102 void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
2103                                             const FunctionDecl *FD,
2104                                             StringRef &CurName) {
2105   if (!FD->isMultiVersion())
2106     return;
2107 
2108   // Get the name of what this would be without the 'target' attribute.  This
2109   // allows us to lookup the version that was emitted when this wasn't a
2110   // multiversion function.
2111   std::string NonTargetName =
2112       getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
2113   GlobalDecl OtherGD;
2114   if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
2115     assert(OtherGD.getCanonicalDecl()
2116                .getDecl()
2117                ->getAsFunction()
2118                ->isMultiVersion() &&
2119            "Other GD should now be a multiversioned function");
2120     // OtherFD is the version of this function that was mangled BEFORE
2121     // becoming a MultiVersion function.  It potentially needs to be updated.
2122     const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
2123                                       .getDecl()
2124                                       ->getAsFunction()
2125                                       ->getMostRecentDecl();
2126     std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
2127     // This is so that if the initial version was already the 'default'
2128     // version, we don't try to update it.
2129     if (OtherName != NonTargetName) {
2130       // Remove instead of erase, since others may have stored the StringRef
2131       // to this.
2132       const auto ExistingRecord = Manglings.find(NonTargetName);
2133       if (ExistingRecord != std::end(Manglings))
2134         Manglings.remove(&(*ExistingRecord));
2135       auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
2136       StringRef OtherNameRef = MangledDeclNames[OtherGD.getCanonicalDecl()] =
2137           Result.first->first();
2138       // If this is the current decl is being created, make sure we update the name.
2139       if (GD.getCanonicalDecl() == OtherGD.getCanonicalDecl())
2140         CurName = OtherNameRef;
2141       if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
2142         Entry->setName(OtherName);
2143     }
2144   }
2145 }
2146 
2147 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
2148   GlobalDecl CanonicalGD = GD.getCanonicalDecl();
2149 
2150   // Some ABIs don't have constructor variants.  Make sure that base and
2151   // complete constructors get mangled the same.
2152   if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
2153     if (!getTarget().getCXXABI().hasConstructorVariants()) {
2154       CXXCtorType OrigCtorType = GD.getCtorType();
2155       assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
2156       if (OrigCtorType == Ctor_Base)
2157         CanonicalGD = GlobalDecl(CD, Ctor_Complete);
2158     }
2159   }
2160 
2161   // In CUDA/HIP device compilation with -fgpu-rdc, the mangled name of a
2162   // static device variable depends on whether the variable is referenced by
2163   // a host or device host function. Therefore the mangled name cannot be
2164   // cached.
2165   if (!LangOpts.CUDAIsDevice || !getContext().mayExternalize(GD.getDecl())) {
2166     auto FoundName = MangledDeclNames.find(CanonicalGD);
2167     if (FoundName != MangledDeclNames.end())
2168       return FoundName->second;
2169   }
2170 
2171   // Keep the first result in the case of a mangling collision.
2172   const auto *ND = cast<NamedDecl>(GD.getDecl());
2173   std::string MangledName = getMangledNameImpl(*this, GD, ND);
2174 
2175   // Ensure either we have different ABIs between host and device compilations,
2176   // says host compilation following MSVC ABI but device compilation follows
2177   // Itanium C++ ABI or, if they follow the same ABI, kernel names after
2178   // mangling should be the same after name stubbing. The later checking is
2179   // very important as the device kernel name being mangled in host-compilation
2180   // is used to resolve the device binaries to be executed. Inconsistent naming
2181   // result in undefined behavior. Even though we cannot check that naming
2182   // directly between host- and device-compilations, the host- and
2183   // device-mangling in host compilation could help catching certain ones.
2184   assert(!isa<FunctionDecl>(ND) || !ND->hasAttr<CUDAGlobalAttr>() ||
2185          getContext().shouldExternalize(ND) || getLangOpts().CUDAIsDevice ||
2186          (getContext().getAuxTargetInfo() &&
2187           (getContext().getAuxTargetInfo()->getCXXABI() !=
2188            getContext().getTargetInfo().getCXXABI())) ||
2189          getCUDARuntime().getDeviceSideName(ND) ==
2190              getMangledNameImpl(
2191                  *this,
2192                  GD.getWithKernelReferenceKind(KernelReferenceKind::Kernel),
2193                  ND));
2194 
2195   // This invariant should hold true in the future.
2196   // Prior work:
2197   // https://discourse.llvm.org/t/rfc-clang-diagnostic-for-demangling-failures/82835/8
2198   // https://github.com/llvm/llvm-project/issues/111345
2199   // assert(!((StringRef(MangledName).starts_with("_Z") ||
2200   //           StringRef(MangledName).starts_with("?")) &&
2201   //          !GD.getDecl()->hasAttr<AsmLabelAttr>() &&
2202   //          llvm::demangle(MangledName) == MangledName) &&
2203   //        "LLVM demangler must demangle clang-generated names");
2204 
2205   auto Result = Manglings.insert(std::make_pair(MangledName, GD));
2206   return MangledDeclNames[CanonicalGD] = Result.first->first();
2207 }
2208 
2209 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
2210                                              const BlockDecl *BD) {
2211   MangleContext &MangleCtx = getCXXABI().getMangleContext();
2212   const Decl *D = GD.getDecl();
2213 
2214   SmallString<256> Buffer;
2215   llvm::raw_svector_ostream Out(Buffer);
2216   if (!D)
2217     MangleCtx.mangleGlobalBlock(BD,
2218       dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
2219   else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
2220     MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
2221   else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
2222     MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
2223   else
2224     MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
2225 
2226   auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
2227   return Result.first->first();
2228 }
2229 
2230 const GlobalDecl CodeGenModule::getMangledNameDecl(StringRef Name) {
2231   auto it = MangledDeclNames.begin();
2232   while (it != MangledDeclNames.end()) {
2233     if (it->second == Name)
2234       return it->first;
2235     it++;
2236   }
2237   return GlobalDecl();
2238 }
2239 
2240 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
2241   return getModule().getNamedValue(Name);
2242 }
2243 
2244 /// AddGlobalCtor - Add a function to the list that will be called before
2245 /// main() runs.
2246 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
2247                                   unsigned LexOrder,
2248                                   llvm::Constant *AssociatedData) {
2249   // FIXME: Type coercion of void()* types.
2250   GlobalCtors.push_back(Structor(Priority, LexOrder, Ctor, AssociatedData));
2251 }
2252 
2253 /// AddGlobalDtor - Add a function to the list that will be called
2254 /// when the module is unloaded.
2255 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority,
2256                                   bool IsDtorAttrFunc) {
2257   if (CodeGenOpts.RegisterGlobalDtorsWithAtExit &&
2258       (!getContext().getTargetInfo().getTriple().isOSAIX() || IsDtorAttrFunc)) {
2259     DtorsUsingAtExit[Priority].push_back(Dtor);
2260     return;
2261   }
2262 
2263   // FIXME: Type coercion of void()* types.
2264   GlobalDtors.push_back(Structor(Priority, ~0U, Dtor, nullptr));
2265 }
2266 
2267 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
2268   if (Fns.empty()) return;
2269 
2270   const PointerAuthSchema &InitFiniAuthSchema =
2271       getCodeGenOpts().PointerAuth.InitFiniPointers;
2272 
2273   // Ctor function type is ptr.
2274   llvm::PointerType *PtrTy = llvm::PointerType::get(
2275       getLLVMContext(), TheModule.getDataLayout().getProgramAddressSpace());
2276 
2277   // Get the type of a ctor entry, { i32, ptr, ptr }.
2278   llvm::StructType *CtorStructTy = llvm::StructType::get(Int32Ty, PtrTy, PtrTy);
2279 
2280   // Construct the constructor and destructor arrays.
2281   ConstantInitBuilder Builder(*this);
2282   auto Ctors = Builder.beginArray(CtorStructTy);
2283   for (const auto &I : Fns) {
2284     auto Ctor = Ctors.beginStruct(CtorStructTy);
2285     Ctor.addInt(Int32Ty, I.Priority);
2286     if (InitFiniAuthSchema) {
2287       llvm::Constant *StorageAddress =
2288           (InitFiniAuthSchema.isAddressDiscriminated()
2289                ? llvm::ConstantExpr::getIntToPtr(
2290                      llvm::ConstantInt::get(
2291                          IntPtrTy,
2292                          llvm::ConstantPtrAuth::AddrDiscriminator_CtorsDtors),
2293                      PtrTy)
2294                : nullptr);
2295       llvm::Constant *SignedCtorPtr = getConstantSignedPointer(
2296           I.Initializer, InitFiniAuthSchema.getKey(), StorageAddress,
2297           llvm::ConstantInt::get(
2298               SizeTy, InitFiniAuthSchema.getConstantDiscrimination()));
2299       Ctor.add(SignedCtorPtr);
2300     } else {
2301       Ctor.add(I.Initializer);
2302     }
2303     if (I.AssociatedData)
2304       Ctor.add(I.AssociatedData);
2305     else
2306       Ctor.addNullPointer(PtrTy);
2307     Ctor.finishAndAddTo(Ctors);
2308   }
2309 
2310   auto List = Ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
2311                                           /*constant*/ false,
2312                                           llvm::GlobalValue::AppendingLinkage);
2313 
2314   // The LTO linker doesn't seem to like it when we set an alignment
2315   // on appending variables.  Take it off as a workaround.
2316   List->setAlignment(std::nullopt);
2317 
2318   Fns.clear();
2319 }
2320 
2321 llvm::GlobalValue::LinkageTypes
2322 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
2323   const auto *D = cast<FunctionDecl>(GD.getDecl());
2324 
2325   GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
2326 
2327   if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
2328     return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
2329 
2330   return getLLVMLinkageForDeclarator(D, Linkage);
2331 }
2332 
2333 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
2334   llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
2335   if (!MDS) return nullptr;
2336 
2337   return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
2338 }
2339 
2340 llvm::ConstantInt *CodeGenModule::CreateKCFITypeId(QualType T) {
2341   if (auto *FnType = T->getAs<FunctionProtoType>())
2342     T = getContext().getFunctionType(
2343         FnType->getReturnType(), FnType->getParamTypes(),
2344         FnType->getExtProtoInfo().withExceptionSpec(EST_None));
2345 
2346   std::string OutName;
2347   llvm::raw_string_ostream Out(OutName);
2348   getCXXABI().getMangleContext().mangleCanonicalTypeName(
2349       T, Out, getCodeGenOpts().SanitizeCfiICallNormalizeIntegers);
2350 
2351   if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
2352     Out << ".normalized";
2353 
2354   return llvm::ConstantInt::get(Int32Ty,
2355                                 static_cast<uint32_t>(llvm::xxHash64(OutName)));
2356 }
2357 
2358 void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
2359                                               const CGFunctionInfo &Info,
2360                                               llvm::Function *F, bool IsThunk) {
2361   unsigned CallingConv;
2362   llvm::AttributeList PAL;
2363   ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv,
2364                          /*AttrOnCallSite=*/false, IsThunk);
2365   if (CallingConv == llvm::CallingConv::X86_VectorCall &&
2366       getTarget().getTriple().isWindowsArm64EC()) {
2367     SourceLocation Loc;
2368     if (const Decl *D = GD.getDecl())
2369       Loc = D->getLocation();
2370 
2371     Error(Loc, "__vectorcall calling convention is not currently supported");
2372   }
2373   F->setAttributes(PAL);
2374   F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
2375 }
2376 
2377 static void removeImageAccessQualifier(std::string& TyName) {
2378   std::string ReadOnlyQual("__read_only");
2379   std::string::size_type ReadOnlyPos = TyName.find(ReadOnlyQual);
2380   if (ReadOnlyPos != std::string::npos)
2381     // "+ 1" for the space after access qualifier.
2382     TyName.erase(ReadOnlyPos, ReadOnlyQual.size() + 1);
2383   else {
2384     std::string WriteOnlyQual("__write_only");
2385     std::string::size_type WriteOnlyPos = TyName.find(WriteOnlyQual);
2386     if (WriteOnlyPos != std::string::npos)
2387       TyName.erase(WriteOnlyPos, WriteOnlyQual.size() + 1);
2388     else {
2389       std::string ReadWriteQual("__read_write");
2390       std::string::size_type ReadWritePos = TyName.find(ReadWriteQual);
2391       if (ReadWritePos != std::string::npos)
2392         TyName.erase(ReadWritePos, ReadWriteQual.size() + 1);
2393     }
2394   }
2395 }
2396 
2397 // Returns the address space id that should be produced to the
2398 // kernel_arg_addr_space metadata. This is always fixed to the ids
2399 // as specified in the SPIR 2.0 specification in order to differentiate
2400 // for example in clGetKernelArgInfo() implementation between the address
2401 // spaces with targets without unique mapping to the OpenCL address spaces
2402 // (basically all single AS CPUs).
2403 static unsigned ArgInfoAddressSpace(LangAS AS) {
2404   switch (AS) {
2405   case LangAS::opencl_global:
2406     return 1;
2407   case LangAS::opencl_constant:
2408     return 2;
2409   case LangAS::opencl_local:
2410     return 3;
2411   case LangAS::opencl_generic:
2412     return 4; // Not in SPIR 2.0 specs.
2413   case LangAS::opencl_global_device:
2414     return 5;
2415   case LangAS::opencl_global_host:
2416     return 6;
2417   default:
2418     return 0; // Assume private.
2419   }
2420 }
2421 
2422 void CodeGenModule::GenKernelArgMetadata(llvm::Function *Fn,
2423                                          const FunctionDecl *FD,
2424                                          CodeGenFunction *CGF) {
2425   assert(((FD && CGF) || (!FD && !CGF)) &&
2426          "Incorrect use - FD and CGF should either be both null or not!");
2427   // Create MDNodes that represent the kernel arg metadata.
2428   // Each MDNode is a list in the form of "key", N number of values which is
2429   // the same number of values as their are kernel arguments.
2430 
2431   const PrintingPolicy &Policy = Context.getPrintingPolicy();
2432 
2433   // MDNode for the kernel argument address space qualifiers.
2434   SmallVector<llvm::Metadata *, 8> addressQuals;
2435 
2436   // MDNode for the kernel argument access qualifiers (images only).
2437   SmallVector<llvm::Metadata *, 8> accessQuals;
2438 
2439   // MDNode for the kernel argument type names.
2440   SmallVector<llvm::Metadata *, 8> argTypeNames;
2441 
2442   // MDNode for the kernel argument base type names.
2443   SmallVector<llvm::Metadata *, 8> argBaseTypeNames;
2444 
2445   // MDNode for the kernel argument type qualifiers.
2446   SmallVector<llvm::Metadata *, 8> argTypeQuals;
2447 
2448   // MDNode for the kernel argument names.
2449   SmallVector<llvm::Metadata *, 8> argNames;
2450 
2451   if (FD && CGF)
2452     for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
2453       const ParmVarDecl *parm = FD->getParamDecl(i);
2454       // Get argument name.
2455       argNames.push_back(llvm::MDString::get(VMContext, parm->getName()));
2456 
2457       if (!getLangOpts().OpenCL)
2458         continue;
2459       QualType ty = parm->getType();
2460       std::string typeQuals;
2461 
2462       // Get image and pipe access qualifier:
2463       if (ty->isImageType() || ty->isPipeType()) {
2464         const Decl *PDecl = parm;
2465         if (const auto *TD = ty->getAs<TypedefType>())
2466           PDecl = TD->getDecl();
2467         const OpenCLAccessAttr *A = PDecl->getAttr<OpenCLAccessAttr>();
2468         if (A && A->isWriteOnly())
2469           accessQuals.push_back(llvm::MDString::get(VMContext, "write_only"));
2470         else if (A && A->isReadWrite())
2471           accessQuals.push_back(llvm::MDString::get(VMContext, "read_write"));
2472         else
2473           accessQuals.push_back(llvm::MDString::get(VMContext, "read_only"));
2474       } else
2475         accessQuals.push_back(llvm::MDString::get(VMContext, "none"));
2476 
2477       auto getTypeSpelling = [&](QualType Ty) {
2478         auto typeName = Ty.getUnqualifiedType().getAsString(Policy);
2479 
2480         if (Ty.isCanonical()) {
2481           StringRef typeNameRef = typeName;
2482           // Turn "unsigned type" to "utype"
2483           if (typeNameRef.consume_front("unsigned "))
2484             return std::string("u") + typeNameRef.str();
2485           if (typeNameRef.consume_front("signed "))
2486             return typeNameRef.str();
2487         }
2488 
2489         return typeName;
2490       };
2491 
2492       if (ty->isPointerType()) {
2493         QualType pointeeTy = ty->getPointeeType();
2494 
2495         // Get address qualifier.
2496         addressQuals.push_back(
2497             llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(
2498                 ArgInfoAddressSpace(pointeeTy.getAddressSpace()))));
2499 
2500         // Get argument type name.
2501         std::string typeName = getTypeSpelling(pointeeTy) + "*";
2502         std::string baseTypeName =
2503             getTypeSpelling(pointeeTy.getCanonicalType()) + "*";
2504         argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
2505         argBaseTypeNames.push_back(
2506             llvm::MDString::get(VMContext, baseTypeName));
2507 
2508         // Get argument type qualifiers:
2509         if (ty.isRestrictQualified())
2510           typeQuals = "restrict";
2511         if (pointeeTy.isConstQualified() ||
2512             (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
2513           typeQuals += typeQuals.empty() ? "const" : " const";
2514         if (pointeeTy.isVolatileQualified())
2515           typeQuals += typeQuals.empty() ? "volatile" : " volatile";
2516       } else {
2517         uint32_t AddrSpc = 0;
2518         bool isPipe = ty->isPipeType();
2519         if (ty->isImageType() || isPipe)
2520           AddrSpc = ArgInfoAddressSpace(LangAS::opencl_global);
2521 
2522         addressQuals.push_back(
2523             llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(AddrSpc)));
2524 
2525         // Get argument type name.
2526         ty = isPipe ? ty->castAs<PipeType>()->getElementType() : ty;
2527         std::string typeName = getTypeSpelling(ty);
2528         std::string baseTypeName = getTypeSpelling(ty.getCanonicalType());
2529 
2530         // Remove access qualifiers on images
2531         // (as they are inseparable from type in clang implementation,
2532         // but OpenCL spec provides a special query to get access qualifier
2533         // via clGetKernelArgInfo with CL_KERNEL_ARG_ACCESS_QUALIFIER):
2534         if (ty->isImageType()) {
2535           removeImageAccessQualifier(typeName);
2536           removeImageAccessQualifier(baseTypeName);
2537         }
2538 
2539         argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
2540         argBaseTypeNames.push_back(
2541             llvm::MDString::get(VMContext, baseTypeName));
2542 
2543         if (isPipe)
2544           typeQuals = "pipe";
2545       }
2546       argTypeQuals.push_back(llvm::MDString::get(VMContext, typeQuals));
2547     }
2548 
2549   if (getLangOpts().OpenCL) {
2550     Fn->setMetadata("kernel_arg_addr_space",
2551                     llvm::MDNode::get(VMContext, addressQuals));
2552     Fn->setMetadata("kernel_arg_access_qual",
2553                     llvm::MDNode::get(VMContext, accessQuals));
2554     Fn->setMetadata("kernel_arg_type",
2555                     llvm::MDNode::get(VMContext, argTypeNames));
2556     Fn->setMetadata("kernel_arg_base_type",
2557                     llvm::MDNode::get(VMContext, argBaseTypeNames));
2558     Fn->setMetadata("kernel_arg_type_qual",
2559                     llvm::MDNode::get(VMContext, argTypeQuals));
2560   }
2561   if (getCodeGenOpts().EmitOpenCLArgMetadata ||
2562       getCodeGenOpts().HIPSaveKernelArgName)
2563     Fn->setMetadata("kernel_arg_name",
2564                     llvm::MDNode::get(VMContext, argNames));
2565 }
2566 
2567 /// Determines whether the language options require us to model
2568 /// unwind exceptions.  We treat -fexceptions as mandating this
2569 /// except under the fragile ObjC ABI with only ObjC exceptions
2570 /// enabled.  This means, for example, that C with -fexceptions
2571 /// enables this.
2572 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
2573   // If exceptions are completely disabled, obviously this is false.
2574   if (!LangOpts.Exceptions) return false;
2575 
2576   // If C++ exceptions are enabled, this is true.
2577   if (LangOpts.CXXExceptions) return true;
2578 
2579   // If ObjC exceptions are enabled, this depends on the ABI.
2580   if (LangOpts.ObjCExceptions) {
2581     return LangOpts.ObjCRuntime.hasUnwindExceptions();
2582   }
2583 
2584   return true;
2585 }
2586 
2587 static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM,
2588                                                       const CXXMethodDecl *MD) {
2589   // Check that the type metadata can ever actually be used by a call.
2590   if (!CGM.getCodeGenOpts().LTOUnit ||
2591       !CGM.HasHiddenLTOVisibility(MD->getParent()))
2592     return false;
2593 
2594   // Only functions whose address can be taken with a member function pointer
2595   // need this sort of type metadata.
2596   return MD->isImplicitObjectMemberFunction() && !MD->isVirtual() &&
2597          !isa<CXXConstructorDecl, CXXDestructorDecl>(MD);
2598 }
2599 
2600 SmallVector<const CXXRecordDecl *, 0>
2601 CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
2602   llvm::SetVector<const CXXRecordDecl *> MostBases;
2603 
2604   std::function<void (const CXXRecordDecl *)> CollectMostBases;
2605   CollectMostBases = [&](const CXXRecordDecl *RD) {
2606     if (RD->getNumBases() == 0)
2607       MostBases.insert(RD);
2608     for (const CXXBaseSpecifier &B : RD->bases())
2609       CollectMostBases(B.getType()->getAsCXXRecordDecl());
2610   };
2611   CollectMostBases(RD);
2612   return MostBases.takeVector();
2613 }
2614 
2615 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
2616                                                            llvm::Function *F) {
2617   llvm::AttrBuilder B(F->getContext());
2618 
2619   if ((!D || !D->hasAttr<NoUwtableAttr>()) && CodeGenOpts.UnwindTables)
2620     B.addUWTableAttr(llvm::UWTableKind(CodeGenOpts.UnwindTables));
2621 
2622   if (CodeGenOpts.StackClashProtector)
2623     B.addAttribute("probe-stack", "inline-asm");
2624 
2625   if (CodeGenOpts.StackProbeSize && CodeGenOpts.StackProbeSize != 4096)
2626     B.addAttribute("stack-probe-size",
2627                    std::to_string(CodeGenOpts.StackProbeSize));
2628 
2629   if (!hasUnwindExceptions(LangOpts))
2630     B.addAttribute(llvm::Attribute::NoUnwind);
2631 
2632   if (D && D->hasAttr<NoStackProtectorAttr>())
2633     ; // Do nothing.
2634   else if (D && D->hasAttr<StrictGuardStackCheckAttr>() &&
2635            isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPOn))
2636     B.addAttribute(llvm::Attribute::StackProtectStrong);
2637   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPOn))
2638     B.addAttribute(llvm::Attribute::StackProtect);
2639   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPStrong))
2640     B.addAttribute(llvm::Attribute::StackProtectStrong);
2641   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPReq))
2642     B.addAttribute(llvm::Attribute::StackProtectReq);
2643 
2644   if (!D) {
2645     // Non-entry HLSL functions must always be inlined.
2646     if (getLangOpts().HLSL && !F->hasFnAttribute(llvm::Attribute::NoInline))
2647       B.addAttribute(llvm::Attribute::AlwaysInline);
2648     // If we don't have a declaration to control inlining, the function isn't
2649     // explicitly marked as alwaysinline for semantic reasons, and inlining is
2650     // disabled, mark the function as noinline.
2651     else if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
2652              CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
2653       B.addAttribute(llvm::Attribute::NoInline);
2654 
2655     F->addFnAttrs(B);
2656     return;
2657   }
2658 
2659   // Handle SME attributes that apply to function definitions,
2660   // rather than to function prototypes.
2661   if (D->hasAttr<ArmLocallyStreamingAttr>())
2662     B.addAttribute("aarch64_pstate_sm_body");
2663 
2664   if (auto *Attr = D->getAttr<ArmNewAttr>()) {
2665     if (Attr->isNewZA())
2666       B.addAttribute("aarch64_new_za");
2667     if (Attr->isNewZT0())
2668       B.addAttribute("aarch64_new_zt0");
2669   }
2670 
2671   // Track whether we need to add the optnone LLVM attribute,
2672   // starting with the default for this optimization level.
2673   bool ShouldAddOptNone =
2674       !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
2675   // We can't add optnone in the following cases, it won't pass the verifier.
2676   ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
2677   ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
2678 
2679   // Non-entry HLSL functions must always be inlined.
2680   if (getLangOpts().HLSL && !F->hasFnAttribute(llvm::Attribute::NoInline) &&
2681       !D->hasAttr<NoInlineAttr>()) {
2682     B.addAttribute(llvm::Attribute::AlwaysInline);
2683   } else if ((ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) &&
2684              !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2685     // Add optnone, but do so only if the function isn't always_inline.
2686     B.addAttribute(llvm::Attribute::OptimizeNone);
2687 
2688     // OptimizeNone implies noinline; we should not be inlining such functions.
2689     B.addAttribute(llvm::Attribute::NoInline);
2690 
2691     // We still need to handle naked functions even though optnone subsumes
2692     // much of their semantics.
2693     if (D->hasAttr<NakedAttr>())
2694       B.addAttribute(llvm::Attribute::Naked);
2695 
2696     // OptimizeNone wins over OptimizeForSize and MinSize.
2697     F->removeFnAttr(llvm::Attribute::OptimizeForSize);
2698     F->removeFnAttr(llvm::Attribute::MinSize);
2699   } else if (D->hasAttr<NakedAttr>()) {
2700     // Naked implies noinline: we should not be inlining such functions.
2701     B.addAttribute(llvm::Attribute::Naked);
2702     B.addAttribute(llvm::Attribute::NoInline);
2703   } else if (D->hasAttr<NoDuplicateAttr>()) {
2704     B.addAttribute(llvm::Attribute::NoDuplicate);
2705   } else if (D->hasAttr<NoInlineAttr>() &&
2706              !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2707     // Add noinline if the function isn't always_inline.
2708     B.addAttribute(llvm::Attribute::NoInline);
2709   } else if (D->hasAttr<AlwaysInlineAttr>() &&
2710              !F->hasFnAttribute(llvm::Attribute::NoInline)) {
2711     // (noinline wins over always_inline, and we can't specify both in IR)
2712     B.addAttribute(llvm::Attribute::AlwaysInline);
2713   } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
2714     // If we're not inlining, then force everything that isn't always_inline to
2715     // carry an explicit noinline attribute.
2716     if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
2717       B.addAttribute(llvm::Attribute::NoInline);
2718   } else {
2719     // Otherwise, propagate the inline hint attribute and potentially use its
2720     // absence to mark things as noinline.
2721     if (auto *FD = dyn_cast<FunctionDecl>(D)) {
2722       // Search function and template pattern redeclarations for inline.
2723       auto CheckForInline = [](const FunctionDecl *FD) {
2724         auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
2725           return Redecl->isInlineSpecified();
2726         };
2727         if (any_of(FD->redecls(), CheckRedeclForInline))
2728           return true;
2729         const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
2730         if (!Pattern)
2731           return false;
2732         return any_of(Pattern->redecls(), CheckRedeclForInline);
2733       };
2734       if (CheckForInline(FD)) {
2735         B.addAttribute(llvm::Attribute::InlineHint);
2736       } else if (CodeGenOpts.getInlining() ==
2737                      CodeGenOptions::OnlyHintInlining &&
2738                  !FD->isInlined() &&
2739                  !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2740         B.addAttribute(llvm::Attribute::NoInline);
2741       }
2742     }
2743   }
2744 
2745   // Add other optimization related attributes if we are optimizing this
2746   // function.
2747   if (!D->hasAttr<OptimizeNoneAttr>()) {
2748     if (D->hasAttr<ColdAttr>()) {
2749       if (!ShouldAddOptNone)
2750         B.addAttribute(llvm::Attribute::OptimizeForSize);
2751       B.addAttribute(llvm::Attribute::Cold);
2752     }
2753     if (D->hasAttr<HotAttr>())
2754       B.addAttribute(llvm::Attribute::Hot);
2755     if (D->hasAttr<MinSizeAttr>())
2756       B.addAttribute(llvm::Attribute::MinSize);
2757   }
2758 
2759   F->addFnAttrs(B);
2760 
2761   unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
2762   if (alignment)
2763     F->setAlignment(llvm::Align(alignment));
2764 
2765   if (!D->hasAttr<AlignedAttr>())
2766     if (LangOpts.FunctionAlignment)
2767       F->setAlignment(llvm::Align(1ull << LangOpts.FunctionAlignment));
2768 
2769   // Some C++ ABIs require 2-byte alignment for member functions, in order to
2770   // reserve a bit for differentiating between virtual and non-virtual member
2771   // functions. If the current target's C++ ABI requires this and this is a
2772   // member function, set its alignment accordingly.
2773   if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
2774     if (isa<CXXMethodDecl>(D) && F->getPointerAlignment(getDataLayout()) < 2)
2775       F->setAlignment(std::max(llvm::Align(2), F->getAlign().valueOrOne()));
2776   }
2777 
2778   // In the cross-dso CFI mode with canonical jump tables, we want !type
2779   // attributes on definitions only.
2780   if (CodeGenOpts.SanitizeCfiCrossDso &&
2781       CodeGenOpts.SanitizeCfiCanonicalJumpTables) {
2782     if (auto *FD = dyn_cast<FunctionDecl>(D)) {
2783       // Skip available_externally functions. They won't be codegen'ed in the
2784       // current module anyway.
2785       if (getContext().GetGVALinkageForFunction(FD) != GVA_AvailableExternally)
2786         createFunctionTypeMetadataForIcall(FD, F);
2787     }
2788   }
2789 
2790   // Emit type metadata on member functions for member function pointer checks.
2791   // These are only ever necessary on definitions; we're guaranteed that the
2792   // definition will be present in the LTO unit as a result of LTO visibility.
2793   auto *MD = dyn_cast<CXXMethodDecl>(D);
2794   if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
2795     for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
2796       llvm::Metadata *Id =
2797           CreateMetadataIdentifierForType(Context.getMemberPointerType(
2798               MD->getType(), /*Qualifier=*/nullptr, Base));
2799       F->addTypeMetadata(0, Id);
2800     }
2801   }
2802 }
2803 
2804 void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
2805   const Decl *D = GD.getDecl();
2806   if (isa_and_nonnull<NamedDecl>(D))
2807     setGVProperties(GV, GD);
2808   else
2809     GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
2810 
2811   if (D && D->hasAttr<UsedAttr>())
2812     addUsedOrCompilerUsedGlobal(GV);
2813 
2814   if (const auto *VD = dyn_cast_if_present<VarDecl>(D);
2815       VD &&
2816       ((CodeGenOpts.KeepPersistentStorageVariables &&
2817         (VD->getStorageDuration() == SD_Static ||
2818          VD->getStorageDuration() == SD_Thread)) ||
2819        (CodeGenOpts.KeepStaticConsts && VD->getStorageDuration() == SD_Static &&
2820         VD->getType().isConstQualified())))
2821     addUsedOrCompilerUsedGlobal(GV);
2822 }
2823 
2824 bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
2825                                                 llvm::AttrBuilder &Attrs,
2826                                                 bool SetTargetFeatures) {
2827   // Add target-cpu and target-features attributes to functions. If
2828   // we have a decl for the function and it has a target attribute then
2829   // parse that and add it to the feature set.
2830   StringRef TargetCPU = getTarget().getTargetOpts().CPU;
2831   StringRef TuneCPU = getTarget().getTargetOpts().TuneCPU;
2832   std::vector<std::string> Features;
2833   const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
2834   FD = FD ? FD->getMostRecentDecl() : FD;
2835   const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
2836   const auto *TV = FD ? FD->getAttr<TargetVersionAttr>() : nullptr;
2837   assert((!TD || !TV) && "both target_version and target specified");
2838   const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
2839   const auto *TC = FD ? FD->getAttr<TargetClonesAttr>() : nullptr;
2840   bool AddedAttr = false;
2841   if (TD || TV || SD || TC) {
2842     llvm::StringMap<bool> FeatureMap;
2843     getContext().getFunctionFeatureMap(FeatureMap, GD);
2844 
2845     // Produce the canonical string for this set of features.
2846     for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
2847       Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
2848 
2849     // Now add the target-cpu and target-features to the function.
2850     // While we populated the feature map above, we still need to
2851     // get and parse the target attribute so we can get the cpu for
2852     // the function.
2853     if (TD) {
2854       ParsedTargetAttr ParsedAttr =
2855           Target.parseTargetAttr(TD->getFeaturesStr());
2856       if (!ParsedAttr.CPU.empty() &&
2857           getTarget().isValidCPUName(ParsedAttr.CPU)) {
2858         TargetCPU = ParsedAttr.CPU;
2859         TuneCPU = ""; // Clear the tune CPU.
2860       }
2861       if (!ParsedAttr.Tune.empty() &&
2862           getTarget().isValidCPUName(ParsedAttr.Tune))
2863         TuneCPU = ParsedAttr.Tune;
2864     }
2865 
2866     if (SD) {
2867       // Apply the given CPU name as the 'tune-cpu' so that the optimizer can
2868       // favor this processor.
2869       TuneCPU = SD->getCPUName(GD.getMultiVersionIndex())->getName();
2870     }
2871   } else {
2872     // Otherwise just add the existing target cpu and target features to the
2873     // function.
2874     Features = getTarget().getTargetOpts().Features;
2875   }
2876 
2877   if (!TargetCPU.empty()) {
2878     Attrs.addAttribute("target-cpu", TargetCPU);
2879     AddedAttr = true;
2880   }
2881   if (!TuneCPU.empty()) {
2882     Attrs.addAttribute("tune-cpu", TuneCPU);
2883     AddedAttr = true;
2884   }
2885   if (!Features.empty() && SetTargetFeatures) {
2886     llvm::erase_if(Features, [&](const std::string& F) {
2887        return getTarget().isReadOnlyFeature(F.substr(1));
2888     });
2889     llvm::sort(Features);
2890     Attrs.addAttribute("target-features", llvm::join(Features, ","));
2891     AddedAttr = true;
2892   }
2893   // Add metadata for AArch64 Function Multi Versioning.
2894   if (getTarget().getTriple().isAArch64()) {
2895     llvm::SmallVector<StringRef, 8> Feats;
2896     bool IsDefault = false;
2897     if (TV) {
2898       IsDefault = TV->isDefaultVersion();
2899       TV->getFeatures(Feats);
2900     } else if (TC) {
2901       IsDefault = TC->isDefaultVersion(GD.getMultiVersionIndex());
2902       TC->getFeatures(Feats, GD.getMultiVersionIndex());
2903     }
2904     if (IsDefault) {
2905       Attrs.addAttribute("fmv-features");
2906       AddedAttr = true;
2907     } else if (!Feats.empty()) {
2908       // Sort features and remove duplicates.
2909       std::set<StringRef> OrderedFeats(Feats.begin(), Feats.end());
2910       std::string FMVFeatures;
2911       for (StringRef F : OrderedFeats)
2912         FMVFeatures.append("," + F.str());
2913       Attrs.addAttribute("fmv-features", FMVFeatures.substr(1));
2914       AddedAttr = true;
2915     }
2916   }
2917   return AddedAttr;
2918 }
2919 
2920 void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
2921                                           llvm::GlobalObject *GO) {
2922   const Decl *D = GD.getDecl();
2923   SetCommonAttributes(GD, GO);
2924 
2925   if (D) {
2926     if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
2927       if (D->hasAttr<RetainAttr>())
2928         addUsedGlobal(GV);
2929       if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
2930         GV->addAttribute("bss-section", SA->getName());
2931       if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
2932         GV->addAttribute("data-section", SA->getName());
2933       if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
2934         GV->addAttribute("rodata-section", SA->getName());
2935       if (auto *SA = D->getAttr<PragmaClangRelroSectionAttr>())
2936         GV->addAttribute("relro-section", SA->getName());
2937     }
2938 
2939     if (auto *F = dyn_cast<llvm::Function>(GO)) {
2940       if (D->hasAttr<RetainAttr>())
2941         addUsedGlobal(F);
2942       if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
2943         if (!D->getAttr<SectionAttr>())
2944           F->setSection(SA->getName());
2945 
2946       llvm::AttrBuilder Attrs(F->getContext());
2947       if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
2948         // We know that GetCPUAndFeaturesAttributes will always have the
2949         // newest set, since it has the newest possible FunctionDecl, so the
2950         // new ones should replace the old.
2951         llvm::AttributeMask RemoveAttrs;
2952         RemoveAttrs.addAttribute("target-cpu");
2953         RemoveAttrs.addAttribute("target-features");
2954         RemoveAttrs.addAttribute("fmv-features");
2955         RemoveAttrs.addAttribute("tune-cpu");
2956         F->removeFnAttrs(RemoveAttrs);
2957         F->addFnAttrs(Attrs);
2958       }
2959     }
2960 
2961     if (const auto *CSA = D->getAttr<CodeSegAttr>())
2962       GO->setSection(CSA->getName());
2963     else if (const auto *SA = D->getAttr<SectionAttr>())
2964       GO->setSection(SA->getName());
2965   }
2966 
2967   getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
2968 }
2969 
2970 void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
2971                                                   llvm::Function *F,
2972                                                   const CGFunctionInfo &FI) {
2973   const Decl *D = GD.getDecl();
2974   SetLLVMFunctionAttributes(GD, FI, F, /*IsThunk=*/false);
2975   SetLLVMFunctionAttributesForDefinition(D, F);
2976 
2977   F->setLinkage(llvm::Function::InternalLinkage);
2978 
2979   setNonAliasAttributes(GD, F);
2980 }
2981 
2982 static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
2983   // Set linkage and visibility in case we never see a definition.
2984   LinkageInfo LV = ND->getLinkageAndVisibility();
2985   // Don't set internal linkage on declarations.
2986   // "extern_weak" is overloaded in LLVM; we probably should have
2987   // separate linkage types for this.
2988   if (isExternallyVisible(LV.getLinkage()) &&
2989       (ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
2990     GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2991 }
2992 
2993 void CodeGenModule::createFunctionTypeMetadataForIcall(const FunctionDecl *FD,
2994                                                        llvm::Function *F) {
2995   // Only if we are checking indirect calls.
2996   if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
2997     return;
2998 
2999   // Non-static class methods are handled via vtable or member function pointer
3000   // checks elsewhere.
3001   if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
3002     return;
3003 
3004   llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
3005   F->addTypeMetadata(0, MD);
3006   F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
3007 
3008   // Emit a hash-based bit set entry for cross-DSO calls.
3009   if (CodeGenOpts.SanitizeCfiCrossDso)
3010     if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
3011       F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
3012 }
3013 
3014 void CodeGenModule::setKCFIType(const FunctionDecl *FD, llvm::Function *F) {
3015   llvm::LLVMContext &Ctx = F->getContext();
3016   llvm::MDBuilder MDB(Ctx);
3017   F->setMetadata(llvm::LLVMContext::MD_kcfi_type,
3018                  llvm::MDNode::get(
3019                      Ctx, MDB.createConstant(CreateKCFITypeId(FD->getType()))));
3020 }
3021 
3022 static bool allowKCFIIdentifier(StringRef Name) {
3023   // KCFI type identifier constants are only necessary for external assembly
3024   // functions, which means it's safe to skip unusual names. Subset of
3025   // MCAsmInfo::isAcceptableChar() and MCAsmInfoXCOFF::isAcceptableChar().
3026   return llvm::all_of(Name, [](const char &C) {
3027     return llvm::isAlnum(C) || C == '_' || C == '.';
3028   });
3029 }
3030 
3031 void CodeGenModule::finalizeKCFITypes() {
3032   llvm::Module &M = getModule();
3033   for (auto &F : M.functions()) {
3034     // Remove KCFI type metadata from non-address-taken local functions.
3035     bool AddressTaken = F.hasAddressTaken();
3036     if (!AddressTaken && F.hasLocalLinkage())
3037       F.eraseMetadata(llvm::LLVMContext::MD_kcfi_type);
3038 
3039     // Generate a constant with the expected KCFI type identifier for all
3040     // address-taken function declarations to support annotating indirectly
3041     // called assembly functions.
3042     if (!AddressTaken || !F.isDeclaration())
3043       continue;
3044 
3045     const llvm::ConstantInt *Type;
3046     if (const llvm::MDNode *MD = F.getMetadata(llvm::LLVMContext::MD_kcfi_type))
3047       Type = llvm::mdconst::extract<llvm::ConstantInt>(MD->getOperand(0));
3048     else
3049       continue;
3050 
3051     StringRef Name = F.getName();
3052     if (!allowKCFIIdentifier(Name))
3053       continue;
3054 
3055     std::string Asm = (".weak __kcfi_typeid_" + Name + "\n.set __kcfi_typeid_" +
3056                        Name + ", " + Twine(Type->getZExtValue()) + "\n")
3057                           .str();
3058     M.appendModuleInlineAsm(Asm);
3059   }
3060 }
3061 
3062 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
3063                                           bool IsIncompleteFunction,
3064                                           bool IsThunk) {
3065 
3066   if (F->getIntrinsicID() != llvm::Intrinsic::not_intrinsic) {
3067     // If this is an intrinsic function, the attributes will have been set
3068     // when the function was created.
3069     return;
3070   }
3071 
3072   const auto *FD = cast<FunctionDecl>(GD.getDecl());
3073 
3074   if (!IsIncompleteFunction)
3075     SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F,
3076                               IsThunk);
3077 
3078   // Add the Returned attribute for "this", except for iOS 5 and earlier
3079   // where substantial code, including the libstdc++ dylib, was compiled with
3080   // GCC and does not actually return "this".
3081   if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
3082       !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
3083     assert(!F->arg_empty() &&
3084            F->arg_begin()->getType()
3085              ->canLosslesslyBitCastTo(F->getReturnType()) &&
3086            "unexpected this return");
3087     F->addParamAttr(0, llvm::Attribute::Returned);
3088   }
3089 
3090   // Only a few attributes are set on declarations; these may later be
3091   // overridden by a definition.
3092 
3093   setLinkageForGV(F, FD);
3094   setGVProperties(F, FD);
3095 
3096   // Setup target-specific attributes.
3097   if (!IsIncompleteFunction && F->isDeclaration())
3098     getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
3099 
3100   if (const auto *CSA = FD->getAttr<CodeSegAttr>())
3101     F->setSection(CSA->getName());
3102   else if (const auto *SA = FD->getAttr<SectionAttr>())
3103      F->setSection(SA->getName());
3104 
3105   if (const auto *EA = FD->getAttr<ErrorAttr>()) {
3106     if (EA->isError())
3107       F->addFnAttr("dontcall-error", EA->getUserDiagnostic());
3108     else if (EA->isWarning())
3109       F->addFnAttr("dontcall-warn", EA->getUserDiagnostic());
3110   }
3111 
3112   // If we plan on emitting this inline builtin, we can't treat it as a builtin.
3113   if (FD->isInlineBuiltinDeclaration()) {
3114     const FunctionDecl *FDBody;
3115     bool HasBody = FD->hasBody(FDBody);
3116     (void)HasBody;
3117     assert(HasBody && "Inline builtin declarations should always have an "
3118                       "available body!");
3119     if (shouldEmitFunction(FDBody))
3120       F->addFnAttr(llvm::Attribute::NoBuiltin);
3121   }
3122 
3123   if (FD->isReplaceableGlobalAllocationFunction()) {
3124     // A replaceable global allocation function does not act like a builtin by
3125     // default, only if it is invoked by a new-expression or delete-expression.
3126     F->addFnAttr(llvm::Attribute::NoBuiltin);
3127   }
3128 
3129   if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
3130     F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3131   else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
3132     if (MD->isVirtual())
3133       F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3134 
3135   // Don't emit entries for function declarations in the cross-DSO mode. This
3136   // is handled with better precision by the receiving DSO. But if jump tables
3137   // are non-canonical then we need type metadata in order to produce the local
3138   // jump table.
3139   if (!CodeGenOpts.SanitizeCfiCrossDso ||
3140       !CodeGenOpts.SanitizeCfiCanonicalJumpTables)
3141     createFunctionTypeMetadataForIcall(FD, F);
3142 
3143   if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
3144     setKCFIType(FD, F);
3145 
3146   if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
3147     getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
3148 
3149   if (CodeGenOpts.InlineMaxStackSize != UINT_MAX)
3150     F->addFnAttr("inline-max-stacksize", llvm::utostr(CodeGenOpts.InlineMaxStackSize));
3151 
3152   if (const auto *CB = FD->getAttr<CallbackAttr>()) {
3153     // Annotate the callback behavior as metadata:
3154     //  - The callback callee (as argument number).
3155     //  - The callback payloads (as argument numbers).
3156     llvm::LLVMContext &Ctx = F->getContext();
3157     llvm::MDBuilder MDB(Ctx);
3158 
3159     // The payload indices are all but the first one in the encoding. The first
3160     // identifies the callback callee.
3161     int CalleeIdx = *CB->encoding_begin();
3162     ArrayRef<int> PayloadIndices(CB->encoding_begin() + 1, CB->encoding_end());
3163     F->addMetadata(llvm::LLVMContext::MD_callback,
3164                    *llvm::MDNode::get(Ctx, {MDB.createCallbackEncoding(
3165                                                CalleeIdx, PayloadIndices,
3166                                                /* VarArgsArePassed */ false)}));
3167   }
3168 }
3169 
3170 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
3171   assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
3172          "Only globals with definition can force usage.");
3173   LLVMUsed.emplace_back(GV);
3174 }
3175 
3176 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
3177   assert(!GV->isDeclaration() &&
3178          "Only globals with definition can force usage.");
3179   LLVMCompilerUsed.emplace_back(GV);
3180 }
3181 
3182 void CodeGenModule::addUsedOrCompilerUsedGlobal(llvm::GlobalValue *GV) {
3183   assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
3184          "Only globals with definition can force usage.");
3185   if (getTriple().isOSBinFormatELF())
3186     LLVMCompilerUsed.emplace_back(GV);
3187   else
3188     LLVMUsed.emplace_back(GV);
3189 }
3190 
3191 static void emitUsed(CodeGenModule &CGM, StringRef Name,
3192                      std::vector<llvm::WeakTrackingVH> &List) {
3193   // Don't create llvm.used if there is no need.
3194   if (List.empty())
3195     return;
3196 
3197   // Convert List to what ConstantArray needs.
3198   SmallVector<llvm::Constant*, 8> UsedArray;
3199   UsedArray.resize(List.size());
3200   for (unsigned i = 0, e = List.size(); i != e; ++i) {
3201     UsedArray[i] =
3202         llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
3203             cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
3204   }
3205 
3206   if (UsedArray.empty())
3207     return;
3208   llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
3209 
3210   auto *GV = new llvm::GlobalVariable(
3211       CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
3212       llvm::ConstantArray::get(ATy, UsedArray), Name);
3213 
3214   GV->setSection("llvm.metadata");
3215 }
3216 
3217 void CodeGenModule::emitLLVMUsed() {
3218   emitUsed(*this, "llvm.used", LLVMUsed);
3219   emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
3220 }
3221 
3222 void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
3223   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
3224   LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
3225 }
3226 
3227 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
3228   llvm::SmallString<32> Opt;
3229   getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
3230   if (Opt.empty())
3231     return;
3232   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
3233   LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
3234 }
3235 
3236 void CodeGenModule::AddDependentLib(StringRef Lib) {
3237   auto &C = getLLVMContext();
3238   if (getTarget().getTriple().isOSBinFormatELF()) {
3239       ELFDependentLibraries.push_back(
3240         llvm::MDNode::get(C, llvm::MDString::get(C, Lib)));
3241     return;
3242   }
3243 
3244   llvm::SmallString<24> Opt;
3245   getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
3246   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
3247   LinkerOptionsMetadata.push_back(llvm::MDNode::get(C, MDOpts));
3248 }
3249 
3250 /// Add link options implied by the given module, including modules
3251 /// it depends on, using a postorder walk.
3252 static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
3253                                     SmallVectorImpl<llvm::MDNode *> &Metadata,
3254                                     llvm::SmallPtrSet<Module *, 16> &Visited) {
3255   // Import this module's parent.
3256   if (Mod->Parent && Visited.insert(Mod->Parent).second) {
3257     addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
3258   }
3259 
3260   // Import this module's dependencies.
3261   for (Module *Import : llvm::reverse(Mod->Imports)) {
3262     if (Visited.insert(Import).second)
3263       addLinkOptionsPostorder(CGM, Import, Metadata, Visited);
3264   }
3265 
3266   // Add linker options to link against the libraries/frameworks
3267   // described by this module.
3268   llvm::LLVMContext &Context = CGM.getLLVMContext();
3269   bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
3270 
3271   // For modules that use export_as for linking, use that module
3272   // name instead.
3273   if (Mod->UseExportAsModuleLinkName)
3274     return;
3275 
3276   for (const Module::LinkLibrary &LL : llvm::reverse(Mod->LinkLibraries)) {
3277     // Link against a framework.  Frameworks are currently Darwin only, so we
3278     // don't to ask TargetCodeGenInfo for the spelling of the linker option.
3279     if (LL.IsFramework) {
3280       llvm::Metadata *Args[2] = {llvm::MDString::get(Context, "-framework"),
3281                                  llvm::MDString::get(Context, LL.Library)};
3282 
3283       Metadata.push_back(llvm::MDNode::get(Context, Args));
3284       continue;
3285     }
3286 
3287     // Link against a library.
3288     if (IsELF) {
3289       llvm::Metadata *Args[2] = {
3290           llvm::MDString::get(Context, "lib"),
3291           llvm::MDString::get(Context, LL.Library),
3292       };
3293       Metadata.push_back(llvm::MDNode::get(Context, Args));
3294     } else {
3295       llvm::SmallString<24> Opt;
3296       CGM.getTargetCodeGenInfo().getDependentLibraryOption(LL.Library, Opt);
3297       auto *OptString = llvm::MDString::get(Context, Opt);
3298       Metadata.push_back(llvm::MDNode::get(Context, OptString));
3299     }
3300   }
3301 }
3302 
3303 void CodeGenModule::EmitModuleInitializers(clang::Module *Primary) {
3304   assert(Primary->isNamedModuleUnit() &&
3305          "We should only emit module initializers for named modules.");
3306 
3307   // Emit the initializers in the order that sub-modules appear in the
3308   // source, first Global Module Fragments, if present.
3309   if (auto GMF = Primary->getGlobalModuleFragment()) {
3310     for (Decl *D : getContext().getModuleInitializers(GMF)) {
3311       if (isa<ImportDecl>(D))
3312         continue;
3313       assert(isa<VarDecl>(D) && "GMF initializer decl is not a var?");
3314       EmitTopLevelDecl(D);
3315     }
3316   }
3317   // Second any associated with the module, itself.
3318   for (Decl *D : getContext().getModuleInitializers(Primary)) {
3319     // Skip import decls, the inits for those are called explicitly.
3320     if (isa<ImportDecl>(D))
3321       continue;
3322     EmitTopLevelDecl(D);
3323   }
3324   // Third any associated with the Privat eMOdule Fragment, if present.
3325   if (auto PMF = Primary->getPrivateModuleFragment()) {
3326     for (Decl *D : getContext().getModuleInitializers(PMF)) {
3327       // Skip import decls, the inits for those are called explicitly.
3328       if (isa<ImportDecl>(D))
3329         continue;
3330       assert(isa<VarDecl>(D) && "PMF initializer decl is not a var?");
3331       EmitTopLevelDecl(D);
3332     }
3333   }
3334 }
3335 
3336 void CodeGenModule::EmitModuleLinkOptions() {
3337   // Collect the set of all of the modules we want to visit to emit link
3338   // options, which is essentially the imported modules and all of their
3339   // non-explicit child modules.
3340   llvm::SetVector<clang::Module *> LinkModules;
3341   llvm::SmallPtrSet<clang::Module *, 16> Visited;
3342   SmallVector<clang::Module *, 16> Stack;
3343 
3344   // Seed the stack with imported modules.
3345   for (Module *M : ImportedModules) {
3346     // Do not add any link flags when an implementation TU of a module imports
3347     // a header of that same module.
3348     if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
3349         !getLangOpts().isCompilingModule())
3350       continue;
3351     if (Visited.insert(M).second)
3352       Stack.push_back(M);
3353   }
3354 
3355   // Find all of the modules to import, making a little effort to prune
3356   // non-leaf modules.
3357   while (!Stack.empty()) {
3358     clang::Module *Mod = Stack.pop_back_val();
3359 
3360     bool AnyChildren = false;
3361 
3362     // Visit the submodules of this module.
3363     for (const auto &SM : Mod->submodules()) {
3364       // Skip explicit children; they need to be explicitly imported to be
3365       // linked against.
3366       if (SM->IsExplicit)
3367         continue;
3368 
3369       if (Visited.insert(SM).second) {
3370         Stack.push_back(SM);
3371         AnyChildren = true;
3372       }
3373     }
3374 
3375     // We didn't find any children, so add this module to the list of
3376     // modules to link against.
3377     if (!AnyChildren) {
3378       LinkModules.insert(Mod);
3379     }
3380   }
3381 
3382   // Add link options for all of the imported modules in reverse topological
3383   // order.  We don't do anything to try to order import link flags with respect
3384   // to linker options inserted by things like #pragma comment().
3385   SmallVector<llvm::MDNode *, 16> MetadataArgs;
3386   Visited.clear();
3387   for (Module *M : LinkModules)
3388     if (Visited.insert(M).second)
3389       addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
3390   std::reverse(MetadataArgs.begin(), MetadataArgs.end());
3391   LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
3392 
3393   // Add the linker options metadata flag.
3394   if (!LinkerOptionsMetadata.empty()) {
3395     auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
3396     for (auto *MD : LinkerOptionsMetadata)
3397       NMD->addOperand(MD);
3398   }
3399 }
3400 
3401 void CodeGenModule::EmitDeferred() {
3402   // Emit deferred declare target declarations.
3403   if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
3404     getOpenMPRuntime().emitDeferredTargetDecls();
3405 
3406   // Emit code for any potentially referenced deferred decls.  Since a
3407   // previously unused static decl may become used during the generation of code
3408   // for a static function, iterate until no changes are made.
3409 
3410   if (!DeferredVTables.empty()) {
3411     EmitDeferredVTables();
3412 
3413     // Emitting a vtable doesn't directly cause more vtables to
3414     // become deferred, although it can cause functions to be
3415     // emitted that then need those vtables.
3416     assert(DeferredVTables.empty());
3417   }
3418 
3419   // Emit CUDA/HIP static device variables referenced by host code only.
3420   // Note we should not clear CUDADeviceVarODRUsedByHost since it is still
3421   // needed for further handling.
3422   if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
3423     llvm::append_range(DeferredDeclsToEmit,
3424                        getContext().CUDADeviceVarODRUsedByHost);
3425 
3426   // Stop if we're out of both deferred vtables and deferred declarations.
3427   if (DeferredDeclsToEmit.empty())
3428     return;
3429 
3430   // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
3431   // work, it will not interfere with this.
3432   std::vector<GlobalDecl> CurDeclsToEmit;
3433   CurDeclsToEmit.swap(DeferredDeclsToEmit);
3434 
3435   for (GlobalDecl &D : CurDeclsToEmit) {
3436     // Functions declared with the sycl_kernel_entry_point attribute are
3437     // emitted normally during host compilation. During device compilation,
3438     // a SYCL kernel caller offload entry point function is generated and
3439     // emitted in place of each of these functions.
3440     if (const auto *FD = D.getDecl()->getAsFunction()) {
3441       if (LangOpts.SYCLIsDevice && FD->hasAttr<SYCLKernelEntryPointAttr>() &&
3442           FD->isDefined()) {
3443         // Functions with an invalid sycl_kernel_entry_point attribute are
3444         // ignored during device compilation.
3445         if (!FD->getAttr<SYCLKernelEntryPointAttr>()->isInvalidAttr()) {
3446           // Generate and emit the SYCL kernel caller function.
3447           EmitSYCLKernelCaller(FD, getContext());
3448           // Recurse to emit any symbols directly or indirectly referenced
3449           // by the SYCL kernel caller function.
3450           EmitDeferred();
3451         }
3452         // Do not emit the sycl_kernel_entry_point attributed function.
3453         continue;
3454       }
3455     }
3456 
3457     // We should call GetAddrOfGlobal with IsForDefinition set to true in order
3458     // to get GlobalValue with exactly the type we need, not something that
3459     // might had been created for another decl with the same mangled name but
3460     // different type.
3461     llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
3462         GetAddrOfGlobal(D, ForDefinition));
3463 
3464     // In case of different address spaces, we may still get a cast, even with
3465     // IsForDefinition equal to true. Query mangled names table to get
3466     // GlobalValue.
3467     if (!GV)
3468       GV = GetGlobalValue(getMangledName(D));
3469 
3470     // Make sure GetGlobalValue returned non-null.
3471     assert(GV);
3472 
3473     // Check to see if we've already emitted this.  This is necessary
3474     // for a couple of reasons: first, decls can end up in the
3475     // deferred-decls queue multiple times, and second, decls can end
3476     // up with definitions in unusual ways (e.g. by an extern inline
3477     // function acquiring a strong function redefinition).  Just
3478     // ignore these cases.
3479     if (!GV->isDeclaration())
3480       continue;
3481 
3482     // If this is OpenMP, check if it is legal to emit this global normally.
3483     if (LangOpts.OpenMP && OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(D))
3484       continue;
3485 
3486     // Otherwise, emit the definition and move on to the next one.
3487     EmitGlobalDefinition(D, GV);
3488 
3489     // If we found out that we need to emit more decls, do that recursively.
3490     // This has the advantage that the decls are emitted in a DFS and related
3491     // ones are close together, which is convenient for testing.
3492     if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
3493       EmitDeferred();
3494       assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
3495     }
3496   }
3497 }
3498 
3499 void CodeGenModule::EmitVTablesOpportunistically() {
3500   // Try to emit external vtables as available_externally if they have emitted
3501   // all inlined virtual functions.  It runs after EmitDeferred() and therefore
3502   // is not allowed to create new references to things that need to be emitted
3503   // lazily. Note that it also uses fact that we eagerly emitting RTTI.
3504 
3505   assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
3506          && "Only emit opportunistic vtables with optimizations");
3507 
3508   for (const CXXRecordDecl *RD : OpportunisticVTables) {
3509     assert(getVTables().isVTableExternal(RD) &&
3510            "This queue should only contain external vtables");
3511     if (getCXXABI().canSpeculativelyEmitVTable(RD))
3512       VTables.GenerateClassData(RD);
3513   }
3514   OpportunisticVTables.clear();
3515 }
3516 
3517 void CodeGenModule::EmitGlobalAnnotations() {
3518   for (const auto& [MangledName, VD] : DeferredAnnotations) {
3519     llvm::GlobalValue *GV = GetGlobalValue(MangledName);
3520     if (GV)
3521       AddGlobalAnnotations(VD, GV);
3522   }
3523   DeferredAnnotations.clear();
3524 
3525   if (Annotations.empty())
3526     return;
3527 
3528   // Create a new global variable for the ConstantStruct in the Module.
3529   llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
3530     Annotations[0]->getType(), Annotations.size()), Annotations);
3531   auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
3532                                       llvm::GlobalValue::AppendingLinkage,
3533                                       Array, "llvm.global.annotations");
3534   gv->setSection(AnnotationSection);
3535 }
3536 
3537 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
3538   llvm::Constant *&AStr = AnnotationStrings[Str];
3539   if (AStr)
3540     return AStr;
3541 
3542   // Not found yet, create a new global.
3543   llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
3544   auto *gv = new llvm::GlobalVariable(
3545       getModule(), s->getType(), true, llvm::GlobalValue::PrivateLinkage, s,
3546       ".str", nullptr, llvm::GlobalValue::NotThreadLocal,
3547       ConstGlobalsPtrTy->getAddressSpace());
3548   gv->setSection(AnnotationSection);
3549   gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3550   AStr = gv;
3551   return gv;
3552 }
3553 
3554 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
3555   SourceManager &SM = getContext().getSourceManager();
3556   PresumedLoc PLoc = SM.getPresumedLoc(Loc);
3557   if (PLoc.isValid())
3558     return EmitAnnotationString(PLoc.getFilename());
3559   return EmitAnnotationString(SM.getBufferName(Loc));
3560 }
3561 
3562 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
3563   SourceManager &SM = getContext().getSourceManager();
3564   PresumedLoc PLoc = SM.getPresumedLoc(L);
3565   unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
3566     SM.getExpansionLineNumber(L);
3567   return llvm::ConstantInt::get(Int32Ty, LineNo);
3568 }
3569 
3570 llvm::Constant *CodeGenModule::EmitAnnotationArgs(const AnnotateAttr *Attr) {
3571   ArrayRef<Expr *> Exprs = {Attr->args_begin(), Attr->args_size()};
3572   if (Exprs.empty())
3573     return llvm::ConstantPointerNull::get(ConstGlobalsPtrTy);
3574 
3575   llvm::FoldingSetNodeID ID;
3576   for (Expr *E : Exprs) {
3577     ID.Add(cast<clang::ConstantExpr>(E)->getAPValueResult());
3578   }
3579   llvm::Constant *&Lookup = AnnotationArgs[ID.ComputeHash()];
3580   if (Lookup)
3581     return Lookup;
3582 
3583   llvm::SmallVector<llvm::Constant *, 4> LLVMArgs;
3584   LLVMArgs.reserve(Exprs.size());
3585   ConstantEmitter ConstEmiter(*this);
3586   llvm::transform(Exprs, std::back_inserter(LLVMArgs), [&](const Expr *E) {
3587     const auto *CE = cast<clang::ConstantExpr>(E);
3588     return ConstEmiter.emitAbstract(CE->getBeginLoc(), CE->getAPValueResult(),
3589                                     CE->getType());
3590   });
3591   auto *Struct = llvm::ConstantStruct::getAnon(LLVMArgs);
3592   auto *GV = new llvm::GlobalVariable(getModule(), Struct->getType(), true,
3593                                       llvm::GlobalValue::PrivateLinkage, Struct,
3594                                       ".args");
3595   GV->setSection(AnnotationSection);
3596   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3597 
3598   Lookup = GV;
3599   return GV;
3600 }
3601 
3602 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
3603                                                 const AnnotateAttr *AA,
3604                                                 SourceLocation L) {
3605   // Get the globals for file name, annotation, and the line number.
3606   llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
3607                  *UnitGV = EmitAnnotationUnit(L),
3608                  *LineNoCst = EmitAnnotationLineNo(L),
3609                  *Args = EmitAnnotationArgs(AA);
3610 
3611   llvm::Constant *GVInGlobalsAS = GV;
3612   if (GV->getAddressSpace() !=
3613       getDataLayout().getDefaultGlobalsAddressSpace()) {
3614     GVInGlobalsAS = llvm::ConstantExpr::getAddrSpaceCast(
3615         GV,
3616         llvm::PointerType::get(
3617             GV->getContext(), getDataLayout().getDefaultGlobalsAddressSpace()));
3618   }
3619 
3620   // Create the ConstantStruct for the global annotation.
3621   llvm::Constant *Fields[] = {
3622       GVInGlobalsAS, AnnoGV, UnitGV, LineNoCst, Args,
3623   };
3624   return llvm::ConstantStruct::getAnon(Fields);
3625 }
3626 
3627 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
3628                                          llvm::GlobalValue *GV) {
3629   assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
3630   // Get the struct elements for these annotations.
3631   for (const auto *I : D->specific_attrs<AnnotateAttr>())
3632     Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
3633 }
3634 
3635 bool CodeGenModule::isInNoSanitizeList(SanitizerMask Kind, llvm::Function *Fn,
3636                                        SourceLocation Loc) const {
3637   const auto &NoSanitizeL = getContext().getNoSanitizeList();
3638   // NoSanitize by function name.
3639   if (NoSanitizeL.containsFunction(Kind, Fn->getName()))
3640     return true;
3641   // NoSanitize by location. Check "mainfile" prefix.
3642   auto &SM = Context.getSourceManager();
3643   FileEntryRef MainFile = *SM.getFileEntryRefForID(SM.getMainFileID());
3644   if (NoSanitizeL.containsMainFile(Kind, MainFile.getName()))
3645     return true;
3646 
3647   // Check "src" prefix.
3648   if (Loc.isValid())
3649     return NoSanitizeL.containsLocation(Kind, Loc);
3650   // If location is unknown, this may be a compiler-generated function. Assume
3651   // it's located in the main file.
3652   return NoSanitizeL.containsFile(Kind, MainFile.getName());
3653 }
3654 
3655 bool CodeGenModule::isInNoSanitizeList(SanitizerMask Kind,
3656                                        llvm::GlobalVariable *GV,
3657                                        SourceLocation Loc, QualType Ty,
3658                                        StringRef Category) const {
3659   const auto &NoSanitizeL = getContext().getNoSanitizeList();
3660   if (NoSanitizeL.containsGlobal(Kind, GV->getName(), Category))
3661     return true;
3662   auto &SM = Context.getSourceManager();
3663   if (NoSanitizeL.containsMainFile(
3664           Kind, SM.getFileEntryRefForID(SM.getMainFileID())->getName(),
3665           Category))
3666     return true;
3667   if (NoSanitizeL.containsLocation(Kind, Loc, Category))
3668     return true;
3669 
3670   // Check global type.
3671   if (!Ty.isNull()) {
3672     // Drill down the array types: if global variable of a fixed type is
3673     // not sanitized, we also don't instrument arrays of them.
3674     while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
3675       Ty = AT->getElementType();
3676     Ty = Ty.getCanonicalType().getUnqualifiedType();
3677     // Only record types (classes, structs etc.) are ignored.
3678     if (Ty->isRecordType()) {
3679       std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
3680       if (NoSanitizeL.containsType(Kind, TypeStr, Category))
3681         return true;
3682     }
3683   }
3684   return false;
3685 }
3686 
3687 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
3688                                    StringRef Category) const {
3689   const auto &XRayFilter = getContext().getXRayFilter();
3690   using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
3691   auto Attr = ImbueAttr::NONE;
3692   if (Loc.isValid())
3693     Attr = XRayFilter.shouldImbueLocation(Loc, Category);
3694   if (Attr == ImbueAttr::NONE)
3695     Attr = XRayFilter.shouldImbueFunction(Fn->getName());
3696   switch (Attr) {
3697   case ImbueAttr::NONE:
3698     return false;
3699   case ImbueAttr::ALWAYS:
3700     Fn->addFnAttr("function-instrument", "xray-always");
3701     break;
3702   case ImbueAttr::ALWAYS_ARG1:
3703     Fn->addFnAttr("function-instrument", "xray-always");
3704     Fn->addFnAttr("xray-log-args", "1");
3705     break;
3706   case ImbueAttr::NEVER:
3707     Fn->addFnAttr("function-instrument", "xray-never");
3708     break;
3709   }
3710   return true;
3711 }
3712 
3713 ProfileList::ExclusionType
3714 CodeGenModule::isFunctionBlockedByProfileList(llvm::Function *Fn,
3715                                               SourceLocation Loc) const {
3716   const auto &ProfileList = getContext().getProfileList();
3717   // If the profile list is empty, then instrument everything.
3718   if (ProfileList.isEmpty())
3719     return ProfileList::Allow;
3720   llvm::driver::ProfileInstrKind Kind = getCodeGenOpts().getProfileInstr();
3721   // First, check the function name.
3722   if (auto V = ProfileList.isFunctionExcluded(Fn->getName(), Kind))
3723     return *V;
3724   // Next, check the source location.
3725   if (Loc.isValid())
3726     if (auto V = ProfileList.isLocationExcluded(Loc, Kind))
3727       return *V;
3728   // If location is unknown, this may be a compiler-generated function. Assume
3729   // it's located in the main file.
3730   auto &SM = Context.getSourceManager();
3731   if (auto MainFile = SM.getFileEntryRefForID(SM.getMainFileID()))
3732     if (auto V = ProfileList.isFileExcluded(MainFile->getName(), Kind))
3733       return *V;
3734   return ProfileList.getDefault(Kind);
3735 }
3736 
3737 ProfileList::ExclusionType
3738 CodeGenModule::isFunctionBlockedFromProfileInstr(llvm::Function *Fn,
3739                                                  SourceLocation Loc) const {
3740   auto V = isFunctionBlockedByProfileList(Fn, Loc);
3741   if (V != ProfileList::Allow)
3742     return V;
3743 
3744   auto NumGroups = getCodeGenOpts().ProfileTotalFunctionGroups;
3745   if (NumGroups > 1) {
3746     auto Group = llvm::crc32(arrayRefFromStringRef(Fn->getName())) % NumGroups;
3747     if (Group != getCodeGenOpts().ProfileSelectedFunctionGroup)
3748       return ProfileList::Skip;
3749   }
3750   return ProfileList::Allow;
3751 }
3752 
3753 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
3754   // Never defer when EmitAllDecls is specified.
3755   if (LangOpts.EmitAllDecls)
3756     return true;
3757 
3758   const auto *VD = dyn_cast<VarDecl>(Global);
3759   if (VD &&
3760       ((CodeGenOpts.KeepPersistentStorageVariables &&
3761         (VD->getStorageDuration() == SD_Static ||
3762          VD->getStorageDuration() == SD_Thread)) ||
3763        (CodeGenOpts.KeepStaticConsts && VD->getStorageDuration() == SD_Static &&
3764         VD->getType().isConstQualified())))
3765     return true;
3766 
3767   return getContext().DeclMustBeEmitted(Global);
3768 }
3769 
3770 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
3771   // In OpenMP 5.0 variables and function may be marked as
3772   // device_type(host/nohost) and we should not emit them eagerly unless we sure
3773   // that they must be emitted on the host/device. To be sure we need to have
3774   // seen a declare target with an explicit mentioning of the function, we know
3775   // we have if the level of the declare target attribute is -1. Note that we
3776   // check somewhere else if we should emit this at all.
3777   if (LangOpts.OpenMP >= 50 && !LangOpts.OpenMPSimd) {
3778     std::optional<OMPDeclareTargetDeclAttr *> ActiveAttr =
3779         OMPDeclareTargetDeclAttr::getActiveAttr(Global);
3780     if (!ActiveAttr || (*ActiveAttr)->getLevel() != (unsigned)-1)
3781       return false;
3782   }
3783 
3784   if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
3785     if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
3786       // Implicit template instantiations may change linkage if they are later
3787       // explicitly instantiated, so they should not be emitted eagerly.
3788       return false;
3789     // Defer until all versions have been semantically checked.
3790     if (FD->hasAttr<TargetVersionAttr>() && !FD->isMultiVersion())
3791       return false;
3792     // Defer emission of SYCL kernel entry point functions during device
3793     // compilation.
3794     if (LangOpts.SYCLIsDevice && FD->hasAttr<SYCLKernelEntryPointAttr>())
3795       return false;
3796   }
3797   if (const auto *VD = dyn_cast<VarDecl>(Global)) {
3798     if (Context.getInlineVariableDefinitionKind(VD) ==
3799         ASTContext::InlineVariableDefinitionKind::WeakUnknown)
3800       // A definition of an inline constexpr static data member may change
3801       // linkage later if it's redeclared outside the class.
3802       return false;
3803     if (CXX20ModuleInits && VD->getOwningModule() &&
3804         !VD->getOwningModule()->isModuleMapModule()) {
3805       // For CXX20, module-owned initializers need to be deferred, since it is
3806       // not known at this point if they will be run for the current module or
3807       // as part of the initializer for an imported one.
3808       return false;
3809     }
3810   }
3811   // If OpenMP is enabled and threadprivates must be generated like TLS, delay
3812   // codegen for global variables, because they may be marked as threadprivate.
3813   if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
3814       getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
3815       !Global->getType().isConstantStorage(getContext(), false, false) &&
3816       !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
3817     return false;
3818 
3819   return true;
3820 }
3821 
3822 ConstantAddress CodeGenModule::GetAddrOfMSGuidDecl(const MSGuidDecl *GD) {
3823   StringRef Name = getMangledName(GD);
3824 
3825   // The UUID descriptor should be pointer aligned.
3826   CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
3827 
3828   // Look for an existing global.
3829   if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
3830     return ConstantAddress(GV, GV->getValueType(), Alignment);
3831 
3832   ConstantEmitter Emitter(*this);
3833   llvm::Constant *Init;
3834 
3835   APValue &V = GD->getAsAPValue();
3836   if (!V.isAbsent()) {
3837     // If possible, emit the APValue version of the initializer. In particular,
3838     // this gets the type of the constant right.
3839     Init = Emitter.emitForInitializer(
3840         GD->getAsAPValue(), GD->getType().getAddressSpace(), GD->getType());
3841   } else {
3842     // As a fallback, directly construct the constant.
3843     // FIXME: This may get padding wrong under esoteric struct layout rules.
3844     // MSVC appears to create a complete type 'struct __s_GUID' that it
3845     // presumably uses to represent these constants.
3846     MSGuidDecl::Parts Parts = GD->getParts();
3847     llvm::Constant *Fields[4] = {
3848         llvm::ConstantInt::get(Int32Ty, Parts.Part1),
3849         llvm::ConstantInt::get(Int16Ty, Parts.Part2),
3850         llvm::ConstantInt::get(Int16Ty, Parts.Part3),
3851         llvm::ConstantDataArray::getRaw(
3852             StringRef(reinterpret_cast<char *>(Parts.Part4And5), 8), 8,
3853             Int8Ty)};
3854     Init = llvm::ConstantStruct::getAnon(Fields);
3855   }
3856 
3857   auto *GV = new llvm::GlobalVariable(
3858       getModule(), Init->getType(),
3859       /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
3860   if (supportsCOMDAT())
3861     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3862   setDSOLocal(GV);
3863 
3864   if (!V.isAbsent()) {
3865     Emitter.finalize(GV);
3866     return ConstantAddress(GV, GV->getValueType(), Alignment);
3867   }
3868 
3869   llvm::Type *Ty = getTypes().ConvertTypeForMem(GD->getType());
3870   return ConstantAddress(GV, Ty, Alignment);
3871 }
3872 
3873 ConstantAddress CodeGenModule::GetAddrOfUnnamedGlobalConstantDecl(
3874     const UnnamedGlobalConstantDecl *GCD) {
3875   CharUnits Alignment = getContext().getTypeAlignInChars(GCD->getType());
3876 
3877   llvm::GlobalVariable **Entry = nullptr;
3878   Entry = &UnnamedGlobalConstantDeclMap[GCD];
3879   if (*Entry)
3880     return ConstantAddress(*Entry, (*Entry)->getValueType(), Alignment);
3881 
3882   ConstantEmitter Emitter(*this);
3883   llvm::Constant *Init;
3884 
3885   const APValue &V = GCD->getValue();
3886 
3887   assert(!V.isAbsent());
3888   Init = Emitter.emitForInitializer(V, GCD->getType().getAddressSpace(),
3889                                     GCD->getType());
3890 
3891   auto *GV = new llvm::GlobalVariable(getModule(), Init->getType(),
3892                                       /*isConstant=*/true,
3893                                       llvm::GlobalValue::PrivateLinkage, Init,
3894                                       ".constant");
3895   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3896   GV->setAlignment(Alignment.getAsAlign());
3897 
3898   Emitter.finalize(GV);
3899 
3900   *Entry = GV;
3901   return ConstantAddress(GV, GV->getValueType(), Alignment);
3902 }
3903 
3904 ConstantAddress CodeGenModule::GetAddrOfTemplateParamObject(
3905     const TemplateParamObjectDecl *TPO) {
3906   StringRef Name = getMangledName(TPO);
3907   CharUnits Alignment = getNaturalTypeAlignment(TPO->getType());
3908 
3909   if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
3910     return ConstantAddress(GV, GV->getValueType(), Alignment);
3911 
3912   ConstantEmitter Emitter(*this);
3913   llvm::Constant *Init = Emitter.emitForInitializer(
3914         TPO->getValue(), TPO->getType().getAddressSpace(), TPO->getType());
3915 
3916   if (!Init) {
3917     ErrorUnsupported(TPO, "template parameter object");
3918     return ConstantAddress::invalid();
3919   }
3920 
3921   llvm::GlobalValue::LinkageTypes Linkage =
3922       isExternallyVisible(TPO->getLinkageAndVisibility().getLinkage())
3923           ? llvm::GlobalValue::LinkOnceODRLinkage
3924           : llvm::GlobalValue::InternalLinkage;
3925   auto *GV = new llvm::GlobalVariable(getModule(), Init->getType(),
3926                                       /*isConstant=*/true, Linkage, Init, Name);
3927   setGVProperties(GV, TPO);
3928   if (supportsCOMDAT() && Linkage == llvm::GlobalValue::LinkOnceODRLinkage)
3929     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3930   Emitter.finalize(GV);
3931 
3932     return ConstantAddress(GV, GV->getValueType(), Alignment);
3933 }
3934 
3935 ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
3936   const AliasAttr *AA = VD->getAttr<AliasAttr>();
3937   assert(AA && "No alias?");
3938 
3939   CharUnits Alignment = getContext().getDeclAlign(VD);
3940   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
3941 
3942   // See if there is already something with the target's name in the module.
3943   llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
3944   if (Entry)
3945     return ConstantAddress(Entry, DeclTy, Alignment);
3946 
3947   llvm::Constant *Aliasee;
3948   if (isa<llvm::FunctionType>(DeclTy))
3949     Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
3950                                       GlobalDecl(cast<FunctionDecl>(VD)),
3951                                       /*ForVTable=*/false);
3952   else
3953     Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, LangAS::Default,
3954                                     nullptr);
3955 
3956   auto *F = cast<llvm::GlobalValue>(Aliasee);
3957   F->setLinkage(llvm::Function::ExternalWeakLinkage);
3958   WeakRefReferences.insert(F);
3959 
3960   return ConstantAddress(Aliasee, DeclTy, Alignment);
3961 }
3962 
3963 template <typename AttrT> static bool hasImplicitAttr(const ValueDecl *D) {
3964   if (!D)
3965     return false;
3966   if (auto *A = D->getAttr<AttrT>())
3967     return A->isImplicit();
3968   return D->isImplicit();
3969 }
3970 
3971 bool CodeGenModule::shouldEmitCUDAGlobalVar(const VarDecl *Global) const {
3972   assert(LangOpts.CUDA && "Should not be called by non-CUDA languages");
3973   // We need to emit host-side 'shadows' for all global
3974   // device-side variables because the CUDA runtime needs their
3975   // size and host-side address in order to provide access to
3976   // their device-side incarnations.
3977   return !LangOpts.CUDAIsDevice || Global->hasAttr<CUDADeviceAttr>() ||
3978          Global->hasAttr<CUDAConstantAttr>() ||
3979          Global->hasAttr<CUDASharedAttr>() ||
3980          Global->getType()->isCUDADeviceBuiltinSurfaceType() ||
3981          Global->getType()->isCUDADeviceBuiltinTextureType();
3982 }
3983 
3984 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
3985   const auto *Global = cast<ValueDecl>(GD.getDecl());
3986 
3987   // Weak references don't produce any output by themselves.
3988   if (Global->hasAttr<WeakRefAttr>())
3989     return;
3990 
3991   // If this is an alias definition (which otherwise looks like a declaration)
3992   // emit it now.
3993   if (Global->hasAttr<AliasAttr>())
3994     return EmitAliasDefinition(GD);
3995 
3996   // IFunc like an alias whose value is resolved at runtime by calling resolver.
3997   if (Global->hasAttr<IFuncAttr>())
3998     return emitIFuncDefinition(GD);
3999 
4000   // If this is a cpu_dispatch multiversion function, emit the resolver.
4001   if (Global->hasAttr<CPUDispatchAttr>())
4002     return emitCPUDispatchDefinition(GD);
4003 
4004   // If this is CUDA, be selective about which declarations we emit.
4005   // Non-constexpr non-lambda implicit host device functions are not emitted
4006   // unless they are used on device side.
4007   if (LangOpts.CUDA) {
4008     assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
4009            "Expected Variable or Function");
4010     if (const auto *VD = dyn_cast<VarDecl>(Global)) {
4011       if (!shouldEmitCUDAGlobalVar(VD))
4012         return;
4013     } else if (LangOpts.CUDAIsDevice) {
4014       const auto *FD = dyn_cast<FunctionDecl>(Global);
4015       if ((!Global->hasAttr<CUDADeviceAttr>() ||
4016            (LangOpts.OffloadImplicitHostDeviceTemplates &&
4017             hasImplicitAttr<CUDAHostAttr>(FD) &&
4018             hasImplicitAttr<CUDADeviceAttr>(FD) && !FD->isConstexpr() &&
4019             !isLambdaCallOperator(FD) &&
4020             !getContext().CUDAImplicitHostDeviceFunUsedByDevice.count(FD))) &&
4021           !Global->hasAttr<CUDAGlobalAttr>() &&
4022           !(LangOpts.HIPStdPar && isa<FunctionDecl>(Global) &&
4023             !Global->hasAttr<CUDAHostAttr>()))
4024         return;
4025       // Device-only functions are the only things we skip.
4026     } else if (!Global->hasAttr<CUDAHostAttr>() &&
4027                Global->hasAttr<CUDADeviceAttr>())
4028       return;
4029   }
4030 
4031   if (LangOpts.OpenMP) {
4032     // If this is OpenMP, check if it is legal to emit this global normally.
4033     if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
4034       return;
4035     if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
4036       if (MustBeEmitted(Global))
4037         EmitOMPDeclareReduction(DRD);
4038       return;
4039     }
4040     if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) {
4041       if (MustBeEmitted(Global))
4042         EmitOMPDeclareMapper(DMD);
4043       return;
4044     }
4045   }
4046 
4047   // Ignore declarations, they will be emitted on their first use.
4048   if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
4049     if (DeviceKernelAttr::isOpenCLSpelling(FD->getAttr<DeviceKernelAttr>()) &&
4050         FD->doesThisDeclarationHaveABody())
4051       addDeferredDeclToEmit(GlobalDecl(FD, KernelReferenceKind::Stub));
4052 
4053     // Update deferred annotations with the latest declaration if the function
4054     // function was already used or defined.
4055     if (FD->hasAttr<AnnotateAttr>()) {
4056       StringRef MangledName = getMangledName(GD);
4057       if (GetGlobalValue(MangledName))
4058         DeferredAnnotations[MangledName] = FD;
4059     }
4060 
4061     // Forward declarations are emitted lazily on first use.
4062     if (!FD->doesThisDeclarationHaveABody()) {
4063       if (!FD->doesDeclarationForceExternallyVisibleDefinition() &&
4064           (!FD->isMultiVersion() || !getTarget().getTriple().isAArch64()))
4065         return;
4066 
4067       StringRef MangledName = getMangledName(GD);
4068 
4069       // Compute the function info and LLVM type.
4070       const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4071       llvm::Type *Ty = getTypes().GetFunctionType(FI);
4072 
4073       GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
4074                               /*DontDefer=*/false);
4075       return;
4076     }
4077   } else {
4078     const auto *VD = cast<VarDecl>(Global);
4079     assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
4080     if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
4081         !Context.isMSStaticDataMemberInlineDefinition(VD)) {
4082       if (LangOpts.OpenMP) {
4083         // Emit declaration of the must-be-emitted declare target variable.
4084         if (std::optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
4085                 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
4086 
4087           // If this variable has external storage and doesn't require special
4088           // link handling we defer to its canonical definition.
4089           if (VD->hasExternalStorage() &&
4090               Res != OMPDeclareTargetDeclAttr::MT_Link)
4091             return;
4092 
4093           bool UnifiedMemoryEnabled =
4094               getOpenMPRuntime().hasRequiresUnifiedSharedMemory();
4095           if ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
4096                *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
4097               !UnifiedMemoryEnabled) {
4098             (void)GetAddrOfGlobalVar(VD);
4099           } else {
4100             assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
4101                     ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
4102                       *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
4103                      UnifiedMemoryEnabled)) &&
4104                    "Link clause or to clause with unified memory expected.");
4105             (void)getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
4106           }
4107 
4108           return;
4109         }
4110       }
4111       // If this declaration may have caused an inline variable definition to
4112       // change linkage, make sure that it's emitted.
4113       if (Context.getInlineVariableDefinitionKind(VD) ==
4114           ASTContext::InlineVariableDefinitionKind::Strong)
4115         GetAddrOfGlobalVar(VD);
4116       return;
4117     }
4118   }
4119 
4120   // Defer code generation to first use when possible, e.g. if this is an inline
4121   // function. If the global must always be emitted, do it eagerly if possible
4122   // to benefit from cache locality.
4123   if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
4124     // Emit the definition if it can't be deferred.
4125     EmitGlobalDefinition(GD);
4126     addEmittedDeferredDecl(GD);
4127     return;
4128   }
4129 
4130   // If we're deferring emission of a C++ variable with an
4131   // initializer, remember the order in which it appeared in the file.
4132   if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
4133       cast<VarDecl>(Global)->hasInit()) {
4134     DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
4135     CXXGlobalInits.push_back(nullptr);
4136   }
4137 
4138   StringRef MangledName = getMangledName(GD);
4139   if (GetGlobalValue(MangledName) != nullptr) {
4140     // The value has already been used and should therefore be emitted.
4141     addDeferredDeclToEmit(GD);
4142   } else if (MustBeEmitted(Global)) {
4143     // The value must be emitted, but cannot be emitted eagerly.
4144     assert(!MayBeEmittedEagerly(Global));
4145     addDeferredDeclToEmit(GD);
4146   } else {
4147     // Otherwise, remember that we saw a deferred decl with this name.  The
4148     // first use of the mangled name will cause it to move into
4149     // DeferredDeclsToEmit.
4150     DeferredDecls[MangledName] = GD;
4151   }
4152 }
4153 
4154 // Check if T is a class type with a destructor that's not dllimport.
4155 static bool HasNonDllImportDtor(QualType T) {
4156   if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
4157     if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
4158       if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
4159         return true;
4160 
4161   return false;
4162 }
4163 
4164 namespace {
4165   struct FunctionIsDirectlyRecursive
4166       : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> {
4167     const StringRef Name;
4168     const Builtin::Context &BI;
4169     FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C)
4170         : Name(N), BI(C) {}
4171 
4172     bool VisitCallExpr(const CallExpr *E) {
4173       const FunctionDecl *FD = E->getDirectCallee();
4174       if (!FD)
4175         return false;
4176       AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
4177       if (Attr && Name == Attr->getLabel())
4178         return true;
4179       unsigned BuiltinID = FD->getBuiltinID();
4180       if (!BuiltinID || !BI.isLibFunction(BuiltinID))
4181         return false;
4182       std::string BuiltinNameStr = BI.getName(BuiltinID);
4183       StringRef BuiltinName = BuiltinNameStr;
4184       return BuiltinName.consume_front("__builtin_") && Name == BuiltinName;
4185     }
4186 
4187     bool VisitStmt(const Stmt *S) {
4188       for (const Stmt *Child : S->children())
4189         if (Child && this->Visit(Child))
4190           return true;
4191       return false;
4192     }
4193   };
4194 
4195   // Make sure we're not referencing non-imported vars or functions.
4196   struct DLLImportFunctionVisitor
4197       : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
4198     bool SafeToInline = true;
4199 
4200     bool shouldVisitImplicitCode() const { return true; }
4201 
4202     bool VisitVarDecl(VarDecl *VD) {
4203       if (VD->getTLSKind()) {
4204         // A thread-local variable cannot be imported.
4205         SafeToInline = false;
4206         return SafeToInline;
4207       }
4208 
4209       // A variable definition might imply a destructor call.
4210       if (VD->isThisDeclarationADefinition())
4211         SafeToInline = !HasNonDllImportDtor(VD->getType());
4212 
4213       return SafeToInline;
4214     }
4215 
4216     bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
4217       if (const auto *D = E->getTemporary()->getDestructor())
4218         SafeToInline = D->hasAttr<DLLImportAttr>();
4219       return SafeToInline;
4220     }
4221 
4222     bool VisitDeclRefExpr(DeclRefExpr *E) {
4223       ValueDecl *VD = E->getDecl();
4224       if (isa<FunctionDecl>(VD))
4225         SafeToInline = VD->hasAttr<DLLImportAttr>();
4226       else if (VarDecl *V = dyn_cast<VarDecl>(VD))
4227         SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
4228       return SafeToInline;
4229     }
4230 
4231     bool VisitCXXConstructExpr(CXXConstructExpr *E) {
4232       SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
4233       return SafeToInline;
4234     }
4235 
4236     bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
4237       CXXMethodDecl *M = E->getMethodDecl();
4238       if (!M) {
4239         // Call through a pointer to member function. This is safe to inline.
4240         SafeToInline = true;
4241       } else {
4242         SafeToInline = M->hasAttr<DLLImportAttr>();
4243       }
4244       return SafeToInline;
4245     }
4246 
4247     bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
4248       SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
4249       return SafeToInline;
4250     }
4251 
4252     bool VisitCXXNewExpr(CXXNewExpr *E) {
4253       SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
4254       return SafeToInline;
4255     }
4256   };
4257 }
4258 
4259 // isTriviallyRecursive - Check if this function calls another
4260 // decl that, because of the asm attribute or the other decl being a builtin,
4261 // ends up pointing to itself.
4262 bool
4263 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
4264   StringRef Name;
4265   if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
4266     // asm labels are a special kind of mangling we have to support.
4267     AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
4268     if (!Attr)
4269       return false;
4270     Name = Attr->getLabel();
4271   } else {
4272     Name = FD->getName();
4273   }
4274 
4275   FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
4276   const Stmt *Body = FD->getBody();
4277   return Body ? Walker.Visit(Body) : false;
4278 }
4279 
4280 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
4281   if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
4282     return true;
4283 
4284   const auto *F = cast<FunctionDecl>(GD.getDecl());
4285   // Inline builtins declaration must be emitted. They often are fortified
4286   // functions.
4287   if (F->isInlineBuiltinDeclaration())
4288     return true;
4289 
4290   if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
4291     return false;
4292 
4293   // We don't import function bodies from other named module units since that
4294   // behavior may break ABI compatibility of the current unit.
4295   if (const Module *M = F->getOwningModule();
4296       M && M->getTopLevelModule()->isNamedModule() &&
4297       getContext().getCurrentNamedModule() != M->getTopLevelModule()) {
4298     // There are practices to mark template member function as always-inline
4299     // and mark the template as extern explicit instantiation but not give
4300     // the definition for member function. So we have to emit the function
4301     // from explicitly instantiation with always-inline.
4302     //
4303     // See https://github.com/llvm/llvm-project/issues/86893 for details.
4304     //
4305     // TODO: Maybe it is better to give it a warning if we call a non-inline
4306     // function from other module units which is marked as always-inline.
4307     if (!F->isTemplateInstantiation() || !F->hasAttr<AlwaysInlineAttr>()) {
4308       return false;
4309     }
4310   }
4311 
4312   if (F->hasAttr<NoInlineAttr>())
4313     return false;
4314 
4315   if (F->hasAttr<DLLImportAttr>() && !F->hasAttr<AlwaysInlineAttr>()) {
4316     // Check whether it would be safe to inline this dllimport function.
4317     DLLImportFunctionVisitor Visitor;
4318     Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
4319     if (!Visitor.SafeToInline)
4320       return false;
4321 
4322     if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
4323       // Implicit destructor invocations aren't captured in the AST, so the
4324       // check above can't see them. Check for them manually here.
4325       for (const Decl *Member : Dtor->getParent()->decls())
4326         if (isa<FieldDecl>(Member))
4327           if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
4328             return false;
4329       for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
4330         if (HasNonDllImportDtor(B.getType()))
4331           return false;
4332     }
4333   }
4334 
4335   // PR9614. Avoid cases where the source code is lying to us. An available
4336   // externally function should have an equivalent function somewhere else,
4337   // but a function that calls itself through asm label/`__builtin_` trickery is
4338   // clearly not equivalent to the real implementation.
4339   // This happens in glibc's btowc and in some configure checks.
4340   return !isTriviallyRecursive(F);
4341 }
4342 
4343 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
4344   return CodeGenOpts.OptimizationLevel > 0;
4345 }
4346 
4347 void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
4348                                                        llvm::GlobalValue *GV) {
4349   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4350 
4351   if (FD->isCPUSpecificMultiVersion()) {
4352     auto *Spec = FD->getAttr<CPUSpecificAttr>();
4353     for (unsigned I = 0; I < Spec->cpus_size(); ++I)
4354       EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
4355   } else if (auto *TC = FD->getAttr<TargetClonesAttr>()) {
4356     for (unsigned I = 0; I < TC->featuresStrs_size(); ++I)
4357       if (TC->isFirstOfVersion(I))
4358         EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
4359   } else
4360     EmitGlobalFunctionDefinition(GD, GV);
4361 
4362   // Ensure that the resolver function is also emitted.
4363   if (FD->isTargetVersionMultiVersion() || FD->isTargetClonesMultiVersion()) {
4364     // On AArch64 defer the resolver emission until the entire TU is processed.
4365     if (getTarget().getTriple().isAArch64())
4366       AddDeferredMultiVersionResolverToEmit(GD);
4367     else
4368       GetOrCreateMultiVersionResolver(GD);
4369   }
4370 }
4371 
4372 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
4373   const auto *D = cast<ValueDecl>(GD.getDecl());
4374 
4375   PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
4376                                  Context.getSourceManager(),
4377                                  "Generating code for declaration");
4378 
4379   if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
4380     // At -O0, don't generate IR for functions with available_externally
4381     // linkage.
4382     if (!shouldEmitFunction(GD))
4383       return;
4384 
4385     llvm::TimeTraceScope TimeScope("CodeGen Function", [&]() {
4386       std::string Name;
4387       llvm::raw_string_ostream OS(Name);
4388       FD->getNameForDiagnostic(OS, getContext().getPrintingPolicy(),
4389                                /*Qualified=*/true);
4390       return Name;
4391     });
4392 
4393     if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
4394       // Make sure to emit the definition(s) before we emit the thunks.
4395       // This is necessary for the generation of certain thunks.
4396       if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
4397         ABI->emitCXXStructor(GD);
4398       else if (FD->isMultiVersion())
4399         EmitMultiVersionFunctionDefinition(GD, GV);
4400       else
4401         EmitGlobalFunctionDefinition(GD, GV);
4402 
4403       if (Method->isVirtual())
4404         getVTables().EmitThunks(GD);
4405 
4406       return;
4407     }
4408 
4409     if (FD->isMultiVersion())
4410       return EmitMultiVersionFunctionDefinition(GD, GV);
4411     return EmitGlobalFunctionDefinition(GD, GV);
4412   }
4413 
4414   if (const auto *VD = dyn_cast<VarDecl>(D))
4415     return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
4416 
4417   llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
4418 }
4419 
4420 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
4421                                                       llvm::Function *NewFn);
4422 
4423 static uint64_t getFMVPriority(const TargetInfo &TI,
4424                                const CodeGenFunction::FMVResolverOption &RO) {
4425   llvm::SmallVector<StringRef, 8> Features{RO.Features};
4426   if (RO.Architecture)
4427     Features.push_back(*RO.Architecture);
4428   return TI.getFMVPriority(Features);
4429 }
4430 
4431 // Multiversion functions should be at most 'WeakODRLinkage' so that a different
4432 // TU can forward declare the function without causing problems.  Particularly
4433 // in the cases of CPUDispatch, this causes issues. This also makes sure we
4434 // work with internal linkage functions, so that the same function name can be
4435 // used with internal linkage in multiple TUs.
4436 static llvm::GlobalValue::LinkageTypes
4437 getMultiversionLinkage(CodeGenModule &CGM, GlobalDecl GD) {
4438   const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
4439   if (FD->getFormalLinkage() == Linkage::Internal)
4440     return llvm::GlobalValue::InternalLinkage;
4441   return llvm::GlobalValue::WeakODRLinkage;
4442 }
4443 
4444 void CodeGenModule::emitMultiVersionFunctions() {
4445   std::vector<GlobalDecl> MVFuncsToEmit;
4446   MultiVersionFuncs.swap(MVFuncsToEmit);
4447   for (GlobalDecl GD : MVFuncsToEmit) {
4448     const auto *FD = cast<FunctionDecl>(GD.getDecl());
4449     assert(FD && "Expected a FunctionDecl");
4450 
4451     auto createFunction = [&](const FunctionDecl *Decl, unsigned MVIdx = 0) {
4452       GlobalDecl CurGD{Decl->isDefined() ? Decl->getDefinition() : Decl, MVIdx};
4453       StringRef MangledName = getMangledName(CurGD);
4454       llvm::Constant *Func = GetGlobalValue(MangledName);
4455       if (!Func) {
4456         if (Decl->isDefined()) {
4457           EmitGlobalFunctionDefinition(CurGD, nullptr);
4458           Func = GetGlobalValue(MangledName);
4459         } else {
4460           const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(CurGD);
4461           llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4462           Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
4463                                    /*DontDefer=*/false, ForDefinition);
4464         }
4465         assert(Func && "This should have just been created");
4466       }
4467       return cast<llvm::Function>(Func);
4468     };
4469 
4470     // For AArch64, a resolver is only emitted if a function marked with
4471     // target_version("default")) or target_clones("default") is defined
4472     // in this TU. For other architectures it is always emitted.
4473     bool ShouldEmitResolver = !getTarget().getTriple().isAArch64();
4474     SmallVector<CodeGenFunction::FMVResolverOption, 10> Options;
4475 
4476     getContext().forEachMultiversionedFunctionVersion(
4477         FD, [&](const FunctionDecl *CurFD) {
4478           llvm::SmallVector<StringRef, 8> Feats;
4479           bool IsDefined = CurFD->getDefinition() != nullptr;
4480 
4481           if (const auto *TA = CurFD->getAttr<TargetAttr>()) {
4482             assert(getTarget().getTriple().isX86() && "Unsupported target");
4483             TA->getX86AddedFeatures(Feats);
4484             llvm::Function *Func = createFunction(CurFD);
4485             Options.emplace_back(Func, Feats, TA->getX86Architecture());
4486           } else if (const auto *TVA = CurFD->getAttr<TargetVersionAttr>()) {
4487             if (TVA->isDefaultVersion() && IsDefined)
4488               ShouldEmitResolver = true;
4489             llvm::Function *Func = createFunction(CurFD);
4490             char Delim = getTarget().getTriple().isAArch64() ? '+' : ',';
4491             TVA->getFeatures(Feats, Delim);
4492             Options.emplace_back(Func, Feats);
4493           } else if (const auto *TC = CurFD->getAttr<TargetClonesAttr>()) {
4494             for (unsigned I = 0; I < TC->featuresStrs_size(); ++I) {
4495               if (!TC->isFirstOfVersion(I))
4496                 continue;
4497               if (TC->isDefaultVersion(I) && IsDefined)
4498                 ShouldEmitResolver = true;
4499               llvm::Function *Func = createFunction(CurFD, I);
4500               Feats.clear();
4501               if (getTarget().getTriple().isX86()) {
4502                 TC->getX86Feature(Feats, I);
4503                 Options.emplace_back(Func, Feats, TC->getX86Architecture(I));
4504               } else {
4505                 char Delim = getTarget().getTriple().isAArch64() ? '+' : ',';
4506                 TC->getFeatures(Feats, I, Delim);
4507                 Options.emplace_back(Func, Feats);
4508               }
4509             }
4510           } else
4511             llvm_unreachable("unexpected MultiVersionKind");
4512         });
4513 
4514     if (!ShouldEmitResolver)
4515       continue;
4516 
4517     llvm::Constant *ResolverConstant = GetOrCreateMultiVersionResolver(GD);
4518     if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(ResolverConstant)) {
4519       ResolverConstant = IFunc->getResolver();
4520       if (FD->isTargetClonesMultiVersion() &&
4521           !getTarget().getTriple().isAArch64()) {
4522         std::string MangledName = getMangledNameImpl(
4523             *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4524         if (!GetGlobalValue(MangledName + ".ifunc")) {
4525           const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4526           llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4527           // In prior versions of Clang, the mangling for ifuncs incorrectly
4528           // included an .ifunc suffix. This alias is generated for backward
4529           // compatibility. It is deprecated, and may be removed in the future.
4530           auto *Alias = llvm::GlobalAlias::create(
4531               DeclTy, 0, getMultiversionLinkage(*this, GD),
4532               MangledName + ".ifunc", IFunc, &getModule());
4533           SetCommonAttributes(FD, Alias);
4534         }
4535       }
4536     }
4537     llvm::Function *ResolverFunc = cast<llvm::Function>(ResolverConstant);
4538 
4539     ResolverFunc->setLinkage(getMultiversionLinkage(*this, GD));
4540 
4541     if (!ResolverFunc->hasLocalLinkage() && supportsCOMDAT())
4542       ResolverFunc->setComdat(
4543           getModule().getOrInsertComdat(ResolverFunc->getName()));
4544 
4545     const TargetInfo &TI = getTarget();
4546     llvm::stable_sort(
4547         Options, [&TI](const CodeGenFunction::FMVResolverOption &LHS,
4548                        const CodeGenFunction::FMVResolverOption &RHS) {
4549           return getFMVPriority(TI, LHS) > getFMVPriority(TI, RHS);
4550         });
4551     CodeGenFunction CGF(*this);
4552     CGF.EmitMultiVersionResolver(ResolverFunc, Options);
4553   }
4554 
4555   // Ensure that any additions to the deferred decls list caused by emitting a
4556   // variant are emitted.  This can happen when the variant itself is inline and
4557   // calls a function without linkage.
4558   if (!MVFuncsToEmit.empty())
4559     EmitDeferred();
4560 
4561   // Ensure that any additions to the multiversion funcs list from either the
4562   // deferred decls or the multiversion functions themselves are emitted.
4563   if (!MultiVersionFuncs.empty())
4564     emitMultiVersionFunctions();
4565 }
4566 
4567 static void replaceDeclarationWith(llvm::GlobalValue *Old,
4568                                    llvm::Constant *New) {
4569   assert(cast<llvm::Function>(Old)->isDeclaration() && "Not a declaration");
4570   New->takeName(Old);
4571   Old->replaceAllUsesWith(New);
4572   Old->eraseFromParent();
4573 }
4574 
4575 void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
4576   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4577   assert(FD && "Not a FunctionDecl?");
4578   assert(FD->isCPUDispatchMultiVersion() && "Not a multiversion function?");
4579   const auto *DD = FD->getAttr<CPUDispatchAttr>();
4580   assert(DD && "Not a cpu_dispatch Function?");
4581 
4582   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4583   llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4584 
4585   StringRef ResolverName = getMangledName(GD);
4586   UpdateMultiVersionNames(GD, FD, ResolverName);
4587 
4588   llvm::Type *ResolverType;
4589   GlobalDecl ResolverGD;
4590   if (getTarget().supportsIFunc()) {
4591     ResolverType = llvm::FunctionType::get(
4592         llvm::PointerType::get(getLLVMContext(),
4593                                getTypes().getTargetAddressSpace(FD->getType())),
4594         false);
4595   }
4596   else {
4597     ResolverType = DeclTy;
4598     ResolverGD = GD;
4599   }
4600 
4601   auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
4602       ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
4603   ResolverFunc->setLinkage(getMultiversionLinkage(*this, GD));
4604   if (supportsCOMDAT())
4605     ResolverFunc->setComdat(
4606         getModule().getOrInsertComdat(ResolverFunc->getName()));
4607 
4608   SmallVector<CodeGenFunction::FMVResolverOption, 10> Options;
4609   const TargetInfo &Target = getTarget();
4610   unsigned Index = 0;
4611   for (const IdentifierInfo *II : DD->cpus()) {
4612     // Get the name of the target function so we can look it up/create it.
4613     std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
4614                               getCPUSpecificMangling(*this, II->getName());
4615 
4616     llvm::Constant *Func = GetGlobalValue(MangledName);
4617 
4618     if (!Func) {
4619       GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
4620       if (ExistingDecl.getDecl() &&
4621           ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
4622         EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
4623         Func = GetGlobalValue(MangledName);
4624       } else {
4625         if (!ExistingDecl.getDecl())
4626           ExistingDecl = GD.getWithMultiVersionIndex(Index);
4627 
4628       Func = GetOrCreateLLVMFunction(
4629           MangledName, DeclTy, ExistingDecl,
4630           /*ForVTable=*/false, /*DontDefer=*/true,
4631           /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
4632       }
4633     }
4634 
4635     llvm::SmallVector<StringRef, 32> Features;
4636     Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
4637     llvm::transform(Features, Features.begin(),
4638                     [](StringRef Str) { return Str.substr(1); });
4639     llvm::erase_if(Features, [&Target](StringRef Feat) {
4640       return !Target.validateCpuSupports(Feat);
4641     });
4642     Options.emplace_back(cast<llvm::Function>(Func), Features);
4643     ++Index;
4644   }
4645 
4646   llvm::stable_sort(Options, [](const CodeGenFunction::FMVResolverOption &LHS,
4647                                 const CodeGenFunction::FMVResolverOption &RHS) {
4648     return llvm::X86::getCpuSupportsMask(LHS.Features) >
4649            llvm::X86::getCpuSupportsMask(RHS.Features);
4650   });
4651 
4652   // If the list contains multiple 'default' versions, such as when it contains
4653   // 'pentium' and 'generic', don't emit the call to the generic one (since we
4654   // always run on at least a 'pentium'). We do this by deleting the 'least
4655   // advanced' (read, lowest mangling letter).
4656   while (Options.size() > 1 && llvm::all_of(llvm::X86::getCpuSupportsMask(
4657                                                 (Options.end() - 2)->Features),
4658                                             [](auto X) { return X == 0; })) {
4659     StringRef LHSName = (Options.end() - 2)->Function->getName();
4660     StringRef RHSName = (Options.end() - 1)->Function->getName();
4661     if (LHSName.compare(RHSName) < 0)
4662       Options.erase(Options.end() - 2);
4663     else
4664       Options.erase(Options.end() - 1);
4665   }
4666 
4667   CodeGenFunction CGF(*this);
4668   CGF.EmitMultiVersionResolver(ResolverFunc, Options);
4669 
4670   if (getTarget().supportsIFunc()) {
4671     llvm::GlobalValue::LinkageTypes Linkage = getMultiversionLinkage(*this, GD);
4672     auto *IFunc = cast<llvm::GlobalValue>(GetOrCreateMultiVersionResolver(GD));
4673     unsigned AS = IFunc->getType()->getPointerAddressSpace();
4674 
4675     // Fix up function declarations that were created for cpu_specific before
4676     // cpu_dispatch was known
4677     if (!isa<llvm::GlobalIFunc>(IFunc)) {
4678       auto *GI = llvm::GlobalIFunc::create(DeclTy, AS, Linkage, "",
4679                                            ResolverFunc, &getModule());
4680       replaceDeclarationWith(IFunc, GI);
4681       IFunc = GI;
4682     }
4683 
4684     std::string AliasName = getMangledNameImpl(
4685         *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4686     llvm::Constant *AliasFunc = GetGlobalValue(AliasName);
4687     if (!AliasFunc) {
4688       auto *GA = llvm::GlobalAlias::create(DeclTy, AS, Linkage, AliasName,
4689                                            IFunc, &getModule());
4690       SetCommonAttributes(GD, GA);
4691     }
4692   }
4693 }
4694 
4695 /// Adds a declaration to the list of multi version functions if not present.
4696 void CodeGenModule::AddDeferredMultiVersionResolverToEmit(GlobalDecl GD) {
4697   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4698   assert(FD && "Not a FunctionDecl?");
4699 
4700   if (FD->isTargetVersionMultiVersion() || FD->isTargetClonesMultiVersion()) {
4701     std::string MangledName =
4702         getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
4703     if (!DeferredResolversToEmit.insert(MangledName).second)
4704       return;
4705   }
4706   MultiVersionFuncs.push_back(GD);
4707 }
4708 
4709 /// If a dispatcher for the specified mangled name is not in the module, create
4710 /// and return it. The dispatcher is either an llvm Function with the specified
4711 /// type, or a global ifunc.
4712 llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(GlobalDecl GD) {
4713   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4714   assert(FD && "Not a FunctionDecl?");
4715 
4716   std::string MangledName =
4717       getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
4718 
4719   // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
4720   // a separate resolver).
4721   std::string ResolverName = MangledName;
4722   if (getTarget().supportsIFunc()) {
4723     switch (FD->getMultiVersionKind()) {
4724     case MultiVersionKind::None:
4725       llvm_unreachable("unexpected MultiVersionKind::None for resolver");
4726     case MultiVersionKind::Target:
4727     case MultiVersionKind::CPUSpecific:
4728     case MultiVersionKind::CPUDispatch:
4729       ResolverName += ".ifunc";
4730       break;
4731     case MultiVersionKind::TargetClones:
4732     case MultiVersionKind::TargetVersion:
4733       break;
4734     }
4735   } else if (FD->isTargetMultiVersion()) {
4736     ResolverName += ".resolver";
4737   }
4738 
4739   bool ShouldReturnIFunc =
4740       getTarget().supportsIFunc() && !FD->isCPUSpecificMultiVersion();
4741 
4742   // If the resolver has already been created, just return it. This lookup may
4743   // yield a function declaration instead of a resolver on AArch64. That is
4744   // because we didn't know whether a resolver will be generated when we first
4745   // encountered a use of the symbol named after this resolver. Therefore,
4746   // targets which support ifuncs should not return here unless we actually
4747   // found an ifunc.
4748   llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName);
4749   if (ResolverGV && (isa<llvm::GlobalIFunc>(ResolverGV) || !ShouldReturnIFunc))
4750     return ResolverGV;
4751 
4752   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4753   llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4754 
4755   // The resolver needs to be created. For target and target_clones, defer
4756   // creation until the end of the TU.
4757   if (FD->isTargetMultiVersion() || FD->isTargetClonesMultiVersion())
4758     AddDeferredMultiVersionResolverToEmit(GD);
4759 
4760   // For cpu_specific, don't create an ifunc yet because we don't know if the
4761   // cpu_dispatch will be emitted in this translation unit.
4762   if (ShouldReturnIFunc) {
4763     unsigned AS = getTypes().getTargetAddressSpace(FD->getType());
4764     llvm::Type *ResolverType = llvm::FunctionType::get(
4765         llvm::PointerType::get(getLLVMContext(), AS), false);
4766     llvm::Constant *Resolver = GetOrCreateLLVMFunction(
4767         MangledName + ".resolver", ResolverType, GlobalDecl{},
4768         /*ForVTable=*/false);
4769     llvm::GlobalIFunc *GIF =
4770         llvm::GlobalIFunc::create(DeclTy, AS, getMultiversionLinkage(*this, GD),
4771                                   "", Resolver, &getModule());
4772     GIF->setName(ResolverName);
4773     SetCommonAttributes(FD, GIF);
4774     if (ResolverGV)
4775       replaceDeclarationWith(ResolverGV, GIF);
4776     return GIF;
4777   }
4778 
4779   llvm::Constant *Resolver = GetOrCreateLLVMFunction(
4780       ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
4781   assert(isa<llvm::GlobalValue>(Resolver) && !ResolverGV &&
4782          "Resolver should be created for the first time");
4783   SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
4784   return Resolver;
4785 }
4786 
4787 bool CodeGenModule::shouldDropDLLAttribute(const Decl *D,
4788                                            const llvm::GlobalValue *GV) const {
4789   auto SC = GV->getDLLStorageClass();
4790   if (SC == llvm::GlobalValue::DefaultStorageClass)
4791     return false;
4792   const Decl *MRD = D->getMostRecentDecl();
4793   return (((SC == llvm::GlobalValue::DLLImportStorageClass &&
4794             !MRD->hasAttr<DLLImportAttr>()) ||
4795            (SC == llvm::GlobalValue::DLLExportStorageClass &&
4796             !MRD->hasAttr<DLLExportAttr>())) &&
4797           !shouldMapVisibilityToDLLExport(cast<NamedDecl>(MRD)));
4798 }
4799 
4800 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
4801 /// module, create and return an llvm Function with the specified type. If there
4802 /// is something in the module with the specified name, return it potentially
4803 /// bitcasted to the right type.
4804 ///
4805 /// If D is non-null, it specifies a decl that correspond to this.  This is used
4806 /// to set the attributes on the function when it is first created.
4807 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
4808     StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
4809     bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
4810     ForDefinition_t IsForDefinition) {
4811   const Decl *D = GD.getDecl();
4812 
4813   std::string NameWithoutMultiVersionMangling;
4814   if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
4815     // For the device mark the function as one that should be emitted.
4816     if (getLangOpts().OpenMPIsTargetDevice && OpenMPRuntime &&
4817         !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
4818         !DontDefer && !IsForDefinition) {
4819       if (const FunctionDecl *FDDef = FD->getDefinition()) {
4820         GlobalDecl GDDef;
4821         if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
4822           GDDef = GlobalDecl(CD, GD.getCtorType());
4823         else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
4824           GDDef = GlobalDecl(DD, GD.getDtorType());
4825         else
4826           GDDef = GlobalDecl(FDDef);
4827         EmitGlobal(GDDef);
4828       }
4829     }
4830 
4831     // Any attempts to use a MultiVersion function should result in retrieving
4832     // the iFunc instead. Name Mangling will handle the rest of the changes.
4833     if (FD->isMultiVersion()) {
4834       UpdateMultiVersionNames(GD, FD, MangledName);
4835       if (!IsForDefinition) {
4836         // On AArch64 we do not immediatelly emit an ifunc resolver when a
4837         // function is used. Instead we defer the emission until we see a
4838         // default definition. In the meantime we just reference the symbol
4839         // without FMV mangling (it may or may not be replaced later).
4840         if (getTarget().getTriple().isAArch64()) {
4841           AddDeferredMultiVersionResolverToEmit(GD);
4842           NameWithoutMultiVersionMangling = getMangledNameImpl(
4843               *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4844         } else
4845           return GetOrCreateMultiVersionResolver(GD);
4846       }
4847     }
4848   }
4849 
4850   if (!NameWithoutMultiVersionMangling.empty())
4851     MangledName = NameWithoutMultiVersionMangling;
4852 
4853   // Lookup the entry, lazily creating it if necessary.
4854   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4855   if (Entry) {
4856     if (WeakRefReferences.erase(Entry)) {
4857       const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
4858       if (FD && !FD->hasAttr<WeakAttr>())
4859         Entry->setLinkage(llvm::Function::ExternalLinkage);
4860     }
4861 
4862     // Handle dropped DLL attributes.
4863     if (D && shouldDropDLLAttribute(D, Entry)) {
4864       Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
4865       setDSOLocal(Entry);
4866     }
4867 
4868     // If there are two attempts to define the same mangled name, issue an
4869     // error.
4870     if (IsForDefinition && !Entry->isDeclaration()) {
4871       GlobalDecl OtherGD;
4872       // Check that GD is not yet in DiagnosedConflictingDefinitions is required
4873       // to make sure that we issue an error only once.
4874       if (lookupRepresentativeDecl(MangledName, OtherGD) &&
4875           (GD.getCanonicalDecl().getDecl() !=
4876            OtherGD.getCanonicalDecl().getDecl()) &&
4877           DiagnosedConflictingDefinitions.insert(GD).second) {
4878         getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
4879             << MangledName;
4880         getDiags().Report(OtherGD.getDecl()->getLocation(),
4881                           diag::note_previous_definition);
4882       }
4883     }
4884 
4885     if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
4886         (Entry->getValueType() == Ty)) {
4887       return Entry;
4888     }
4889 
4890     // Make sure the result is of the correct type.
4891     // (If function is requested for a definition, we always need to create a new
4892     // function, not just return a bitcast.)
4893     if (!IsForDefinition)
4894       return Entry;
4895   }
4896 
4897   // This function doesn't have a complete type (for example, the return
4898   // type is an incomplete struct). Use a fake type instead, and make
4899   // sure not to try to set attributes.
4900   bool IsIncompleteFunction = false;
4901 
4902   llvm::FunctionType *FTy;
4903   if (isa<llvm::FunctionType>(Ty)) {
4904     FTy = cast<llvm::FunctionType>(Ty);
4905   } else {
4906     FTy = llvm::FunctionType::get(VoidTy, false);
4907     IsIncompleteFunction = true;
4908   }
4909 
4910   llvm::Function *F =
4911       llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
4912                              Entry ? StringRef() : MangledName, &getModule());
4913 
4914   // Store the declaration associated with this function so it is potentially
4915   // updated by further declarations or definitions and emitted at the end.
4916   if (D && D->hasAttr<AnnotateAttr>())
4917     DeferredAnnotations[MangledName] = cast<ValueDecl>(D);
4918 
4919   // If we already created a function with the same mangled name (but different
4920   // type) before, take its name and add it to the list of functions to be
4921   // replaced with F at the end of CodeGen.
4922   //
4923   // This happens if there is a prototype for a function (e.g. "int f()") and
4924   // then a definition of a different type (e.g. "int f(int x)").
4925   if (Entry) {
4926     F->takeName(Entry);
4927 
4928     // This might be an implementation of a function without a prototype, in
4929     // which case, try to do special replacement of calls which match the new
4930     // prototype.  The really key thing here is that we also potentially drop
4931     // arguments from the call site so as to make a direct call, which makes the
4932     // inliner happier and suppresses a number of optimizer warnings (!) about
4933     // dropping arguments.
4934     if (!Entry->use_empty()) {
4935       ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
4936       Entry->removeDeadConstantUsers();
4937     }
4938 
4939     addGlobalValReplacement(Entry, F);
4940   }
4941 
4942   assert(F->getName() == MangledName && "name was uniqued!");
4943   if (D)
4944     SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
4945   if (ExtraAttrs.hasFnAttrs()) {
4946     llvm::AttrBuilder B(F->getContext(), ExtraAttrs.getFnAttrs());
4947     F->addFnAttrs(B);
4948   }
4949 
4950   if (!DontDefer) {
4951     // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
4952     // each other bottoming out with the base dtor.  Therefore we emit non-base
4953     // dtors on usage, even if there is no dtor definition in the TU.
4954     if (isa_and_nonnull<CXXDestructorDecl>(D) &&
4955         getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
4956                                            GD.getDtorType()))
4957       addDeferredDeclToEmit(GD);
4958 
4959     // This is the first use or definition of a mangled name.  If there is a
4960     // deferred decl with this name, remember that we need to emit it at the end
4961     // of the file.
4962     auto DDI = DeferredDecls.find(MangledName);
4963     if (DDI != DeferredDecls.end()) {
4964       // Move the potentially referenced deferred decl to the
4965       // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
4966       // don't need it anymore).
4967       addDeferredDeclToEmit(DDI->second);
4968       DeferredDecls.erase(DDI);
4969 
4970       // Otherwise, there are cases we have to worry about where we're
4971       // using a declaration for which we must emit a definition but where
4972       // we might not find a top-level definition:
4973       //   - member functions defined inline in their classes
4974       //   - friend functions defined inline in some class
4975       //   - special member functions with implicit definitions
4976       // If we ever change our AST traversal to walk into class methods,
4977       // this will be unnecessary.
4978       //
4979       // We also don't emit a definition for a function if it's going to be an
4980       // entry in a vtable, unless it's already marked as used.
4981     } else if (getLangOpts().CPlusPlus && D) {
4982       // Look for a declaration that's lexically in a record.
4983       for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
4984            FD = FD->getPreviousDecl()) {
4985         if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
4986           if (FD->doesThisDeclarationHaveABody()) {
4987             addDeferredDeclToEmit(GD.getWithDecl(FD));
4988             break;
4989           }
4990         }
4991       }
4992     }
4993   }
4994 
4995   // Make sure the result is of the requested type.
4996   if (!IsIncompleteFunction) {
4997     assert(F->getFunctionType() == Ty);
4998     return F;
4999   }
5000 
5001   return F;
5002 }
5003 
5004 /// GetAddrOfFunction - Return the address of the given function.  If Ty is
5005 /// non-null, then this function will use the specified type if it has to
5006 /// create it (this occurs when we see a definition of the function).
5007 llvm::Constant *
5008 CodeGenModule::GetAddrOfFunction(GlobalDecl GD, llvm::Type *Ty, bool ForVTable,
5009                                  bool DontDefer,
5010                                  ForDefinition_t IsForDefinition) {
5011   // If there was no specific requested type, just convert it now.
5012   if (!Ty) {
5013     const auto *FD = cast<FunctionDecl>(GD.getDecl());
5014     Ty = getTypes().ConvertType(FD->getType());
5015     if (DeviceKernelAttr::isOpenCLSpelling(FD->getAttr<DeviceKernelAttr>()) &&
5016         GD.getKernelReferenceKind() == KernelReferenceKind::Stub) {
5017       const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
5018       Ty = getTypes().GetFunctionType(FI);
5019     }
5020   }
5021 
5022   // Devirtualized destructor calls may come through here instead of via
5023   // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
5024   // of the complete destructor when necessary.
5025   if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
5026     if (getTarget().getCXXABI().isMicrosoft() &&
5027         GD.getDtorType() == Dtor_Complete &&
5028         DD->getParent()->getNumVBases() == 0)
5029       GD = GlobalDecl(DD, Dtor_Base);
5030   }
5031 
5032   StringRef MangledName = getMangledName(GD);
5033   auto *F = GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
5034                                     /*IsThunk=*/false, llvm::AttributeList(),
5035                                     IsForDefinition);
5036   // Returns kernel handle for HIP kernel stub function.
5037   if (LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
5038       cast<FunctionDecl>(GD.getDecl())->hasAttr<CUDAGlobalAttr>()) {
5039     auto *Handle = getCUDARuntime().getKernelHandle(
5040         cast<llvm::Function>(F->stripPointerCasts()), GD);
5041     if (IsForDefinition)
5042       return F;
5043     return Handle;
5044   }
5045   return F;
5046 }
5047 
5048 llvm::Constant *CodeGenModule::GetFunctionStart(const ValueDecl *Decl) {
5049   llvm::GlobalValue *F =
5050       cast<llvm::GlobalValue>(GetAddrOfFunction(Decl)->stripPointerCasts());
5051 
5052   return llvm::NoCFIValue::get(F);
5053 }
5054 
5055 static const FunctionDecl *
5056 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
5057   TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
5058   DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
5059 
5060   IdentifierInfo &CII = C.Idents.get(Name);
5061   for (const auto *Result : DC->lookup(&CII))
5062     if (const auto *FD = dyn_cast<FunctionDecl>(Result))
5063       return FD;
5064 
5065   if (!C.getLangOpts().CPlusPlus)
5066     return nullptr;
5067 
5068   // Demangle the premangled name from getTerminateFn()
5069   IdentifierInfo &CXXII =
5070       (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
5071           ? C.Idents.get("terminate")
5072           : C.Idents.get(Name);
5073 
5074   for (const auto &N : {"__cxxabiv1", "std"}) {
5075     IdentifierInfo &NS = C.Idents.get(N);
5076     for (const auto *Result : DC->lookup(&NS)) {
5077       const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
5078       if (auto *LSD = dyn_cast<LinkageSpecDecl>(Result))
5079         for (const auto *Result : LSD->lookup(&NS))
5080           if ((ND = dyn_cast<NamespaceDecl>(Result)))
5081             break;
5082 
5083       if (ND)
5084         for (const auto *Result : ND->lookup(&CXXII))
5085           if (const auto *FD = dyn_cast<FunctionDecl>(Result))
5086             return FD;
5087     }
5088   }
5089 
5090   return nullptr;
5091 }
5092 
5093 static void setWindowsItaniumDLLImport(CodeGenModule &CGM, bool Local,
5094                                        llvm::Function *F, StringRef Name) {
5095   // In Windows Itanium environments, try to mark runtime functions
5096   // dllimport. For Mingw and MSVC, don't. We don't really know if the user
5097   // will link their standard library statically or dynamically. Marking
5098   // functions imported when they are not imported can cause linker errors
5099   // and warnings.
5100   if (!Local && CGM.getTriple().isWindowsItaniumEnvironment() &&
5101       !CGM.getCodeGenOpts().LTOVisibilityPublicStd) {
5102     const FunctionDecl *FD = GetRuntimeFunctionDecl(CGM.getContext(), Name);
5103     if (!FD || FD->hasAttr<DLLImportAttr>()) {
5104       F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
5105       F->setLinkage(llvm::GlobalValue::ExternalLinkage);
5106     }
5107   }
5108 }
5109 
5110 llvm::FunctionCallee CodeGenModule::CreateRuntimeFunction(
5111     QualType ReturnTy, ArrayRef<QualType> ArgTys, StringRef Name,
5112     llvm::AttributeList ExtraAttrs, bool Local, bool AssumeConvergent) {
5113   if (AssumeConvergent) {
5114     ExtraAttrs =
5115         ExtraAttrs.addFnAttribute(VMContext, llvm::Attribute::Convergent);
5116   }
5117 
5118   QualType FTy = Context.getFunctionType(ReturnTy, ArgTys,
5119                                          FunctionProtoType::ExtProtoInfo());
5120   const CGFunctionInfo &Info = getTypes().arrangeFreeFunctionType(
5121       Context.getCanonicalType(FTy).castAs<FunctionProtoType>());
5122   auto *ConvTy = getTypes().GetFunctionType(Info);
5123   llvm::Constant *C = GetOrCreateLLVMFunction(
5124       Name, ConvTy, GlobalDecl(), /*ForVTable=*/false,
5125       /*DontDefer=*/false, /*IsThunk=*/false, ExtraAttrs);
5126 
5127   if (auto *F = dyn_cast<llvm::Function>(C)) {
5128     if (F->empty()) {
5129       SetLLVMFunctionAttributes(GlobalDecl(), Info, F, /*IsThunk*/ false);
5130       // FIXME: Set calling-conv properly in ExtProtoInfo
5131       F->setCallingConv(getRuntimeCC());
5132       setWindowsItaniumDLLImport(*this, Local, F, Name);
5133       setDSOLocal(F);
5134     }
5135   }
5136   return {ConvTy, C};
5137 }
5138 
5139 /// CreateRuntimeFunction - Create a new runtime function with the specified
5140 /// type and name.
5141 llvm::FunctionCallee
5142 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
5143                                      llvm::AttributeList ExtraAttrs, bool Local,
5144                                      bool AssumeConvergent) {
5145   if (AssumeConvergent) {
5146     ExtraAttrs =
5147         ExtraAttrs.addFnAttribute(VMContext, llvm::Attribute::Convergent);
5148   }
5149 
5150   llvm::Constant *C =
5151       GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
5152                               /*DontDefer=*/false, /*IsThunk=*/false,
5153                               ExtraAttrs);
5154 
5155   if (auto *F = dyn_cast<llvm::Function>(C)) {
5156     if (F->empty()) {
5157       F->setCallingConv(getRuntimeCC());
5158       setWindowsItaniumDLLImport(*this, Local, F, Name);
5159       setDSOLocal(F);
5160       // FIXME: We should use CodeGenModule::SetLLVMFunctionAttributes() instead
5161       // of trying to approximate the attributes using the LLVM function
5162       // signature.  The other overload of CreateRuntimeFunction does this; it
5163       // should be used for new code.
5164       markRegisterParameterAttributes(F);
5165     }
5166   }
5167 
5168   return {FTy, C};
5169 }
5170 
5171 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
5172 /// create and return an llvm GlobalVariable with the specified type and address
5173 /// space. If there is something in the module with the specified name, return
5174 /// it potentially bitcasted to the right type.
5175 ///
5176 /// If D is non-null, it specifies a decl that correspond to this.  This is used
5177 /// to set the attributes on the global when it is first created.
5178 ///
5179 /// If IsForDefinition is true, it is guaranteed that an actual global with
5180 /// type Ty will be returned, not conversion of a variable with the same
5181 /// mangled name but some other type.
5182 llvm::Constant *
5183 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, llvm::Type *Ty,
5184                                      LangAS AddrSpace, const VarDecl *D,
5185                                      ForDefinition_t IsForDefinition) {
5186   // Lookup the entry, lazily creating it if necessary.
5187   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
5188   unsigned TargetAS = getContext().getTargetAddressSpace(AddrSpace);
5189   if (Entry) {
5190     if (WeakRefReferences.erase(Entry)) {
5191       if (D && !D->hasAttr<WeakAttr>())
5192         Entry->setLinkage(llvm::Function::ExternalLinkage);
5193     }
5194 
5195     // Handle dropped DLL attributes.
5196     if (D && shouldDropDLLAttribute(D, Entry))
5197       Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
5198 
5199     if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
5200       getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
5201 
5202     if (Entry->getValueType() == Ty && Entry->getAddressSpace() == TargetAS)
5203       return Entry;
5204 
5205     // If there are two attempts to define the same mangled name, issue an
5206     // error.
5207     if (IsForDefinition && !Entry->isDeclaration()) {
5208       GlobalDecl OtherGD;
5209       const VarDecl *OtherD;
5210 
5211       // Check that D is not yet in DiagnosedConflictingDefinitions is required
5212       // to make sure that we issue an error only once.
5213       if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
5214           (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
5215           (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
5216           OtherD->hasInit() &&
5217           DiagnosedConflictingDefinitions.insert(D).second) {
5218         getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
5219             << MangledName;
5220         getDiags().Report(OtherGD.getDecl()->getLocation(),
5221                           diag::note_previous_definition);
5222       }
5223     }
5224 
5225     // Make sure the result is of the correct type.
5226     if (Entry->getType()->getAddressSpace() != TargetAS)
5227       return llvm::ConstantExpr::getAddrSpaceCast(
5228           Entry, llvm::PointerType::get(Ty->getContext(), TargetAS));
5229 
5230     // (If global is requested for a definition, we always need to create a new
5231     // global, not just return a bitcast.)
5232     if (!IsForDefinition)
5233       return Entry;
5234   }
5235 
5236   auto DAddrSpace = GetGlobalVarAddressSpace(D);
5237 
5238   auto *GV = new llvm::GlobalVariable(
5239       getModule(), Ty, false, llvm::GlobalValue::ExternalLinkage, nullptr,
5240       MangledName, nullptr, llvm::GlobalVariable::NotThreadLocal,
5241       getContext().getTargetAddressSpace(DAddrSpace));
5242 
5243   // If we already created a global with the same mangled name (but different
5244   // type) before, take its name and remove it from its parent.
5245   if (Entry) {
5246     GV->takeName(Entry);
5247 
5248     if (!Entry->use_empty()) {
5249       Entry->replaceAllUsesWith(GV);
5250     }
5251 
5252     Entry->eraseFromParent();
5253   }
5254 
5255   // This is the first use or definition of a mangled name.  If there is a
5256   // deferred decl with this name, remember that we need to emit it at the end
5257   // of the file.
5258   auto DDI = DeferredDecls.find(MangledName);
5259   if (DDI != DeferredDecls.end()) {
5260     // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
5261     // list, and remove it from DeferredDecls (since we don't need it anymore).
5262     addDeferredDeclToEmit(DDI->second);
5263     DeferredDecls.erase(DDI);
5264   }
5265 
5266   // Handle things which are present even on external declarations.
5267   if (D) {
5268     if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
5269       getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
5270 
5271     // FIXME: This code is overly simple and should be merged with other global
5272     // handling.
5273     GV->setConstant(D->getType().isConstantStorage(getContext(), false, false));
5274 
5275     GV->setAlignment(getContext().getDeclAlign(D).getAsAlign());
5276 
5277     setLinkageForGV(GV, D);
5278 
5279     if (D->getTLSKind()) {
5280       if (D->getTLSKind() == VarDecl::TLS_Dynamic)
5281         CXXThreadLocals.push_back(D);
5282       setTLSMode(GV, *D);
5283     }
5284 
5285     setGVProperties(GV, D);
5286 
5287     // If required by the ABI, treat declarations of static data members with
5288     // inline initializers as definitions.
5289     if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
5290       EmitGlobalVarDefinition(D);
5291     }
5292 
5293     // Emit section information for extern variables.
5294     if (D->hasExternalStorage()) {
5295       if (const SectionAttr *SA = D->getAttr<SectionAttr>())
5296         GV->setSection(SA->getName());
5297     }
5298 
5299     // Handle XCore specific ABI requirements.
5300     if (getTriple().getArch() == llvm::Triple::xcore &&
5301         D->getLanguageLinkage() == CLanguageLinkage &&
5302         D->getType().isConstant(Context) &&
5303         isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
5304       GV->setSection(".cp.rodata");
5305 
5306     // Handle code model attribute
5307     if (const auto *CMA = D->getAttr<CodeModelAttr>())
5308       GV->setCodeModel(CMA->getModel());
5309 
5310     // Check if we a have a const declaration with an initializer, we may be
5311     // able to emit it as available_externally to expose it's value to the
5312     // optimizer.
5313     if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
5314         D->getType().isConstQualified() && !GV->hasInitializer() &&
5315         !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
5316       const auto *Record =
5317           Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
5318       bool HasMutableFields = Record && Record->hasMutableFields();
5319       if (!HasMutableFields) {
5320         const VarDecl *InitDecl;
5321         const Expr *InitExpr = D->getAnyInitializer(InitDecl);
5322         if (InitExpr) {
5323           ConstantEmitter emitter(*this);
5324           llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
5325           if (Init) {
5326             auto *InitType = Init->getType();
5327             if (GV->getValueType() != InitType) {
5328               // The type of the initializer does not match the definition.
5329               // This happens when an initializer has a different type from
5330               // the type of the global (because of padding at the end of a
5331               // structure for instance).
5332               GV->setName(StringRef());
5333               // Make a new global with the correct type, this is now guaranteed
5334               // to work.
5335               auto *NewGV = cast<llvm::GlobalVariable>(
5336                   GetAddrOfGlobalVar(D, InitType, IsForDefinition)
5337                       ->stripPointerCasts());
5338 
5339               // Erase the old global, since it is no longer used.
5340               GV->eraseFromParent();
5341               GV = NewGV;
5342             } else {
5343               GV->setInitializer(Init);
5344               GV->setConstant(true);
5345               GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
5346             }
5347             emitter.finalize(GV);
5348           }
5349         }
5350       }
5351     }
5352   }
5353 
5354   if (D &&
5355       D->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly) {
5356     getTargetCodeGenInfo().setTargetAttributes(D, GV, *this);
5357     // External HIP managed variables needed to be recorded for transformation
5358     // in both device and host compilations.
5359     if (getLangOpts().CUDA && D && D->hasAttr<HIPManagedAttr>() &&
5360         D->hasExternalStorage())
5361       getCUDARuntime().handleVarRegistration(D, *GV);
5362   }
5363 
5364   if (D)
5365     SanitizerMD->reportGlobal(GV, *D);
5366 
5367   LangAS ExpectedAS =
5368       D ? D->getType().getAddressSpace()
5369         : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
5370   assert(getContext().getTargetAddressSpace(ExpectedAS) == TargetAS);
5371   if (DAddrSpace != ExpectedAS) {
5372     return getTargetCodeGenInfo().performAddrSpaceCast(
5373         *this, GV, DAddrSpace,
5374         llvm::PointerType::get(getLLVMContext(), TargetAS));
5375   }
5376 
5377   return GV;
5378 }
5379 
5380 llvm::Constant *
5381 CodeGenModule::GetAddrOfGlobal(GlobalDecl GD, ForDefinition_t IsForDefinition) {
5382   const Decl *D = GD.getDecl();
5383 
5384   if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
5385     return getAddrOfCXXStructor(GD, /*FnInfo=*/nullptr, /*FnType=*/nullptr,
5386                                 /*DontDefer=*/false, IsForDefinition);
5387 
5388   if (isa<CXXMethodDecl>(D)) {
5389     auto FInfo =
5390         &getTypes().arrangeCXXMethodDeclaration(cast<CXXMethodDecl>(D));
5391     auto Ty = getTypes().GetFunctionType(*FInfo);
5392     return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
5393                              IsForDefinition);
5394   }
5395 
5396   if (isa<FunctionDecl>(D)) {
5397     const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
5398     llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
5399     return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
5400                              IsForDefinition);
5401   }
5402 
5403   return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr, IsForDefinition);
5404 }
5405 
5406 llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
5407     StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
5408     llvm::Align Alignment) {
5409   llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
5410   llvm::GlobalVariable *OldGV = nullptr;
5411 
5412   if (GV) {
5413     // Check if the variable has the right type.
5414     if (GV->getValueType() == Ty)
5415       return GV;
5416 
5417     // Because C++ name mangling, the only way we can end up with an already
5418     // existing global with the same name is if it has been declared extern "C".
5419     assert(GV->isDeclaration() && "Declaration has wrong type!");
5420     OldGV = GV;
5421   }
5422 
5423   // Create a new variable.
5424   GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
5425                                 Linkage, nullptr, Name);
5426 
5427   if (OldGV) {
5428     // Replace occurrences of the old variable if needed.
5429     GV->takeName(OldGV);
5430 
5431     if (!OldGV->use_empty()) {
5432       OldGV->replaceAllUsesWith(GV);
5433     }
5434 
5435     OldGV->eraseFromParent();
5436   }
5437 
5438   if (supportsCOMDAT() && GV->isWeakForLinker() &&
5439       !GV->hasAvailableExternallyLinkage())
5440     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
5441 
5442   GV->setAlignment(Alignment);
5443 
5444   return GV;
5445 }
5446 
5447 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
5448 /// given global variable.  If Ty is non-null and if the global doesn't exist,
5449 /// then it will be created with the specified type instead of whatever the
5450 /// normal requested type would be. If IsForDefinition is true, it is guaranteed
5451 /// that an actual global with type Ty will be returned, not conversion of a
5452 /// variable with the same mangled name but some other type.
5453 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
5454                                                   llvm::Type *Ty,
5455                                            ForDefinition_t IsForDefinition) {
5456   assert(D->hasGlobalStorage() && "Not a global variable");
5457   QualType ASTTy = D->getType();
5458   if (!Ty)
5459     Ty = getTypes().ConvertTypeForMem(ASTTy);
5460 
5461   StringRef MangledName = getMangledName(D);
5462   return GetOrCreateLLVMGlobal(MangledName, Ty, ASTTy.getAddressSpace(), D,
5463                                IsForDefinition);
5464 }
5465 
5466 /// CreateRuntimeVariable - Create a new runtime global variable with the
5467 /// specified type and name.
5468 llvm::Constant *
5469 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
5470                                      StringRef Name) {
5471   LangAS AddrSpace = getContext().getLangOpts().OpenCL ? LangAS::opencl_global
5472                                                        : LangAS::Default;
5473   auto *Ret = GetOrCreateLLVMGlobal(Name, Ty, AddrSpace, nullptr);
5474   setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
5475   return Ret;
5476 }
5477 
5478 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
5479   assert(!D->getInit() && "Cannot emit definite definitions here!");
5480 
5481   StringRef MangledName = getMangledName(D);
5482   llvm::GlobalValue *GV = GetGlobalValue(MangledName);
5483 
5484   // We already have a definition, not declaration, with the same mangled name.
5485   // Emitting of declaration is not required (and actually overwrites emitted
5486   // definition).
5487   if (GV && !GV->isDeclaration())
5488     return;
5489 
5490   // If we have not seen a reference to this variable yet, place it into the
5491   // deferred declarations table to be emitted if needed later.
5492   if (!MustBeEmitted(D) && !GV) {
5493       DeferredDecls[MangledName] = D;
5494       return;
5495   }
5496 
5497   // The tentative definition is the only definition.
5498   EmitGlobalVarDefinition(D);
5499 }
5500 
5501 // Return a GlobalDecl. Use the base variants for destructors and constructors.
5502 static GlobalDecl getBaseVariantGlobalDecl(const NamedDecl *D) {
5503   if (auto const *CD = dyn_cast<const CXXConstructorDecl>(D))
5504     return GlobalDecl(CD, CXXCtorType::Ctor_Base);
5505   else if (auto const *DD = dyn_cast<const CXXDestructorDecl>(D))
5506     return GlobalDecl(DD, CXXDtorType::Dtor_Base);
5507   return GlobalDecl(D);
5508 }
5509 
5510 void CodeGenModule::EmitExternalDeclaration(const DeclaratorDecl *D) {
5511   CGDebugInfo *DI = getModuleDebugInfo();
5512   if (!DI || !getCodeGenOpts().hasReducedDebugInfo())
5513     return;
5514 
5515   GlobalDecl GD = getBaseVariantGlobalDecl(D);
5516   if (!GD)
5517     return;
5518 
5519   llvm::Constant *Addr = GetAddrOfGlobal(GD)->stripPointerCasts();
5520   if (const auto *VD = dyn_cast<VarDecl>(D)) {
5521     DI->EmitExternalVariable(
5522         cast<llvm::GlobalVariable>(Addr->stripPointerCasts()), VD);
5523   } else if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
5524     llvm::Function *Fn = cast<llvm::Function>(Addr);
5525     if (!Fn->getSubprogram())
5526       DI->EmitFunctionDecl(GD, FD->getLocation(), FD->getType(), Fn);
5527   }
5528 }
5529 
5530 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
5531   return Context.toCharUnitsFromBits(
5532       getDataLayout().getTypeStoreSizeInBits(Ty));
5533 }
5534 
5535 LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
5536   if (LangOpts.OpenCL) {
5537     LangAS AS = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
5538     assert(AS == LangAS::opencl_global ||
5539            AS == LangAS::opencl_global_device ||
5540            AS == LangAS::opencl_global_host ||
5541            AS == LangAS::opencl_constant ||
5542            AS == LangAS::opencl_local ||
5543            AS >= LangAS::FirstTargetAddressSpace);
5544     return AS;
5545   }
5546 
5547   if (LangOpts.SYCLIsDevice &&
5548       (!D || D->getType().getAddressSpace() == LangAS::Default))
5549     return LangAS::sycl_global;
5550 
5551   if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
5552     if (D) {
5553       if (D->hasAttr<CUDAConstantAttr>())
5554         return LangAS::cuda_constant;
5555       if (D->hasAttr<CUDASharedAttr>())
5556         return LangAS::cuda_shared;
5557       if (D->hasAttr<CUDADeviceAttr>())
5558         return LangAS::cuda_device;
5559       if (D->getType().isConstQualified())
5560         return LangAS::cuda_constant;
5561     }
5562     return LangAS::cuda_device;
5563   }
5564 
5565   if (LangOpts.OpenMP) {
5566     LangAS AS;
5567     if (OpenMPRuntime->hasAllocateAttributeForGlobalVar(D, AS))
5568       return AS;
5569   }
5570   return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
5571 }
5572 
5573 LangAS CodeGenModule::GetGlobalConstantAddressSpace() const {
5574   // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
5575   if (LangOpts.OpenCL)
5576     return LangAS::opencl_constant;
5577   if (LangOpts.SYCLIsDevice)
5578     return LangAS::sycl_global;
5579   if (LangOpts.HIP && LangOpts.CUDAIsDevice && getTriple().isSPIRV())
5580     // For HIPSPV map literals to cuda_device (maps to CrossWorkGroup in SPIR-V)
5581     // instead of default AS (maps to Generic in SPIR-V). Otherwise, we end up
5582     // with OpVariable instructions with Generic storage class which is not
5583     // allowed (SPIR-V V1.6 s3.42.8). Also, mapping literals to SPIR-V
5584     // UniformConstant storage class is not viable as pointers to it may not be
5585     // casted to Generic pointers which are used to model HIP's "flat" pointers.
5586     return LangAS::cuda_device;
5587   if (auto AS = getTarget().getConstantAddressSpace())
5588     return *AS;
5589   return LangAS::Default;
5590 }
5591 
5592 // In address space agnostic languages, string literals are in default address
5593 // space in AST. However, certain targets (e.g. amdgcn) request them to be
5594 // emitted in constant address space in LLVM IR. To be consistent with other
5595 // parts of AST, string literal global variables in constant address space
5596 // need to be casted to default address space before being put into address
5597 // map and referenced by other part of CodeGen.
5598 // In OpenCL, string literals are in constant address space in AST, therefore
5599 // they should not be casted to default address space.
5600 static llvm::Constant *
5601 castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM,
5602                                        llvm::GlobalVariable *GV) {
5603   llvm::Constant *Cast = GV;
5604   if (!CGM.getLangOpts().OpenCL) {
5605     auto AS = CGM.GetGlobalConstantAddressSpace();
5606     if (AS != LangAS::Default)
5607       Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast(
5608           CGM, GV, AS,
5609           llvm::PointerType::get(
5610               CGM.getLLVMContext(),
5611               CGM.getContext().getTargetAddressSpace(LangAS::Default)));
5612   }
5613   return Cast;
5614 }
5615 
5616 template<typename SomeDecl>
5617 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
5618                                                llvm::GlobalValue *GV) {
5619   if (!getLangOpts().CPlusPlus)
5620     return;
5621 
5622   // Must have 'used' attribute, or else inline assembly can't rely on
5623   // the name existing.
5624   if (!D->template hasAttr<UsedAttr>())
5625     return;
5626 
5627   // Must have internal linkage and an ordinary name.
5628   if (!D->getIdentifier() || D->getFormalLinkage() != Linkage::Internal)
5629     return;
5630 
5631   // Must be in an extern "C" context. Entities declared directly within
5632   // a record are not extern "C" even if the record is in such a context.
5633   const SomeDecl *First = D->getFirstDecl();
5634   if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
5635     return;
5636 
5637   // OK, this is an internal linkage entity inside an extern "C" linkage
5638   // specification. Make a note of that so we can give it the "expected"
5639   // mangled name if nothing else is using that name.
5640   std::pair<StaticExternCMap::iterator, bool> R =
5641       StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
5642 
5643   // If we have multiple internal linkage entities with the same name
5644   // in extern "C" regions, none of them gets that name.
5645   if (!R.second)
5646     R.first->second = nullptr;
5647 }
5648 
5649 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
5650   if (!CGM.supportsCOMDAT())
5651     return false;
5652 
5653   if (D.hasAttr<SelectAnyAttr>())
5654     return true;
5655 
5656   GVALinkage Linkage;
5657   if (auto *VD = dyn_cast<VarDecl>(&D))
5658     Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
5659   else
5660     Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
5661 
5662   switch (Linkage) {
5663   case GVA_Internal:
5664   case GVA_AvailableExternally:
5665   case GVA_StrongExternal:
5666     return false;
5667   case GVA_DiscardableODR:
5668   case GVA_StrongODR:
5669     return true;
5670   }
5671   llvm_unreachable("No such linkage");
5672 }
5673 
5674 bool CodeGenModule::supportsCOMDAT() const {
5675   return getTriple().supportsCOMDAT();
5676 }
5677 
5678 void CodeGenModule::maybeSetTrivialComdat(const Decl &D,
5679                                           llvm::GlobalObject &GO) {
5680   if (!shouldBeInCOMDAT(*this, D))
5681     return;
5682   GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
5683 }
5684 
5685 const ABIInfo &CodeGenModule::getABIInfo() {
5686   return getTargetCodeGenInfo().getABIInfo();
5687 }
5688 
5689 /// Pass IsTentative as true if you want to create a tentative definition.
5690 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
5691                                             bool IsTentative) {
5692   // OpenCL global variables of sampler type are translated to function calls,
5693   // therefore no need to be translated.
5694   QualType ASTTy = D->getType();
5695   if (getLangOpts().OpenCL && ASTTy->isSamplerT())
5696     return;
5697 
5698   // HLSL default buffer constants will be emitted during HLSLBufferDecl codegen
5699   if (getLangOpts().HLSL &&
5700       D->getType().getAddressSpace() == LangAS::hlsl_constant)
5701     return;
5702 
5703   // If this is OpenMP device, check if it is legal to emit this global
5704   // normally.
5705   if (LangOpts.OpenMPIsTargetDevice && OpenMPRuntime &&
5706       OpenMPRuntime->emitTargetGlobalVariable(D))
5707     return;
5708 
5709   llvm::TrackingVH<llvm::Constant> Init;
5710   bool NeedsGlobalCtor = false;
5711   // Whether the definition of the variable is available externally.
5712   // If yes, we shouldn't emit the GloablCtor and GlobalDtor for the variable
5713   // since this is the job for its original source.
5714   bool IsDefinitionAvailableExternally =
5715       getContext().GetGVALinkageForVariable(D) == GVA_AvailableExternally;
5716   bool NeedsGlobalDtor =
5717       !IsDefinitionAvailableExternally &&
5718       D->needsDestruction(getContext()) == QualType::DK_cxx_destructor;
5719 
5720   // It is helpless to emit the definition for an available_externally variable
5721   // which can't be marked as const.
5722   // We don't need to check if it needs global ctor or dtor. See the above
5723   // comment for ideas.
5724   if (IsDefinitionAvailableExternally &&
5725       (!D->hasConstantInitialization() ||
5726        // TODO: Update this when we have interface to check constexpr
5727        // destructor.
5728        D->needsDestruction(getContext()) ||
5729        !D->getType().isConstantStorage(getContext(), true, true)))
5730     return;
5731 
5732   const VarDecl *InitDecl;
5733   const Expr *InitExpr = D->getAnyInitializer(InitDecl);
5734 
5735   std::optional<ConstantEmitter> emitter;
5736 
5737   // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
5738   // as part of their declaration."  Sema has already checked for
5739   // error cases, so we just need to set Init to UndefValue.
5740   bool IsCUDASharedVar =
5741       getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
5742   // Shadows of initialized device-side global variables are also left
5743   // undefined.
5744   // Managed Variables should be initialized on both host side and device side.
5745   bool IsCUDAShadowVar =
5746       !getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
5747       (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
5748        D->hasAttr<CUDASharedAttr>());
5749   bool IsCUDADeviceShadowVar =
5750       getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
5751       (D->getType()->isCUDADeviceBuiltinSurfaceType() ||
5752        D->getType()->isCUDADeviceBuiltinTextureType());
5753   if (getLangOpts().CUDA &&
5754       (IsCUDASharedVar || IsCUDAShadowVar || IsCUDADeviceShadowVar))
5755     Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
5756   else if (D->hasAttr<LoaderUninitializedAttr>())
5757     Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
5758   else if (!InitExpr) {
5759     // This is a tentative definition; tentative definitions are
5760     // implicitly initialized with { 0 }.
5761     //
5762     // Note that tentative definitions are only emitted at the end of
5763     // a translation unit, so they should never have incomplete
5764     // type. In addition, EmitTentativeDefinition makes sure that we
5765     // never attempt to emit a tentative definition if a real one
5766     // exists. A use may still exists, however, so we still may need
5767     // to do a RAUW.
5768     assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
5769     Init = EmitNullConstant(D->getType());
5770   } else {
5771     initializedGlobalDecl = GlobalDecl(D);
5772     emitter.emplace(*this);
5773     llvm::Constant *Initializer = emitter->tryEmitForInitializer(*InitDecl);
5774     if (!Initializer) {
5775       QualType T = InitExpr->getType();
5776       if (D->getType()->isReferenceType())
5777         T = D->getType();
5778 
5779       if (getLangOpts().HLSL &&
5780           D->getType().getTypePtr()->isHLSLResourceRecord()) {
5781         Init = llvm::PoisonValue::get(getTypes().ConvertType(ASTTy));
5782         NeedsGlobalCtor = true;
5783       } else if (getLangOpts().CPlusPlus) {
5784         Init = EmitNullConstant(T);
5785         if (!IsDefinitionAvailableExternally)
5786           NeedsGlobalCtor = true;
5787         if (InitDecl->hasFlexibleArrayInit(getContext())) {
5788           ErrorUnsupported(D, "flexible array initializer");
5789           // We cannot create ctor for flexible array initializer
5790           NeedsGlobalCtor = false;
5791         }
5792       } else {
5793         ErrorUnsupported(D, "static initializer");
5794         Init = llvm::PoisonValue::get(getTypes().ConvertType(T));
5795       }
5796     } else {
5797       Init = Initializer;
5798       // We don't need an initializer, so remove the entry for the delayed
5799       // initializer position (just in case this entry was delayed) if we
5800       // also don't need to register a destructor.
5801       if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
5802         DelayedCXXInitPosition.erase(D);
5803 
5804 #ifndef NDEBUG
5805       CharUnits VarSize = getContext().getTypeSizeInChars(ASTTy) +
5806                           InitDecl->getFlexibleArrayInitChars(getContext());
5807       CharUnits CstSize = CharUnits::fromQuantity(
5808           getDataLayout().getTypeAllocSize(Init->getType()));
5809       assert(VarSize == CstSize && "Emitted constant has unexpected size");
5810 #endif
5811     }
5812   }
5813 
5814   llvm::Type* InitType = Init->getType();
5815   llvm::Constant *Entry =
5816       GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
5817 
5818   // Strip off pointer casts if we got them.
5819   Entry = Entry->stripPointerCasts();
5820 
5821   // Entry is now either a Function or GlobalVariable.
5822   auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
5823 
5824   // We have a definition after a declaration with the wrong type.
5825   // We must make a new GlobalVariable* and update everything that used OldGV
5826   // (a declaration or tentative definition) with the new GlobalVariable*
5827   // (which will be a definition).
5828   //
5829   // This happens if there is a prototype for a global (e.g.
5830   // "extern int x[];") and then a definition of a different type (e.g.
5831   // "int x[10];"). This also happens when an initializer has a different type
5832   // from the type of the global (this happens with unions).
5833   if (!GV || GV->getValueType() != InitType ||
5834       GV->getType()->getAddressSpace() !=
5835           getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
5836 
5837     // Move the old entry aside so that we'll create a new one.
5838     Entry->setName(StringRef());
5839 
5840     // Make a new global with the correct type, this is now guaranteed to work.
5841     GV = cast<llvm::GlobalVariable>(
5842         GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative))
5843             ->stripPointerCasts());
5844 
5845     // Replace all uses of the old global with the new global
5846     llvm::Constant *NewPtrForOldDecl =
5847         llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV,
5848                                                              Entry->getType());
5849     Entry->replaceAllUsesWith(NewPtrForOldDecl);
5850 
5851     // Erase the old global, since it is no longer used.
5852     cast<llvm::GlobalValue>(Entry)->eraseFromParent();
5853   }
5854 
5855   MaybeHandleStaticInExternC(D, GV);
5856 
5857   if (D->hasAttr<AnnotateAttr>())
5858     AddGlobalAnnotations(D, GV);
5859 
5860   // Set the llvm linkage type as appropriate.
5861   llvm::GlobalValue::LinkageTypes Linkage = getLLVMLinkageVarDefinition(D);
5862 
5863   // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
5864   // the device. [...]"
5865   // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
5866   // __device__, declares a variable that: [...]
5867   // Is accessible from all the threads within the grid and from the host
5868   // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
5869   // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
5870   if (LangOpts.CUDA) {
5871     if (LangOpts.CUDAIsDevice) {
5872       if (Linkage != llvm::GlobalValue::InternalLinkage &&
5873           (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
5874            D->getType()->isCUDADeviceBuiltinSurfaceType() ||
5875            D->getType()->isCUDADeviceBuiltinTextureType()))
5876         GV->setExternallyInitialized(true);
5877     } else {
5878       getCUDARuntime().internalizeDeviceSideVar(D, Linkage);
5879     }
5880     getCUDARuntime().handleVarRegistration(D, *GV);
5881   }
5882 
5883   if (LangOpts.HLSL && GetGlobalVarAddressSpace(D) == LangAS::hlsl_input) {
5884     // HLSL Input variables are considered to be set by the driver/pipeline, but
5885     // only visible to a single thread/wave.
5886     GV->setExternallyInitialized(true);
5887   } else {
5888     GV->setInitializer(Init);
5889   }
5890 
5891   if (LangOpts.HLSL)
5892     getHLSLRuntime().handleGlobalVarDefinition(D, GV);
5893 
5894   if (emitter)
5895     emitter->finalize(GV);
5896 
5897   // If it is safe to mark the global 'constant', do so now.
5898   GV->setConstant((D->hasAttr<CUDAConstantAttr>() && LangOpts.CUDAIsDevice) ||
5899                   (!NeedsGlobalCtor && !NeedsGlobalDtor &&
5900                    D->getType().isConstantStorage(getContext(), true, true)));
5901 
5902   // If it is in a read-only section, mark it 'constant'.
5903   if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
5904     const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
5905     if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
5906       GV->setConstant(true);
5907   }
5908 
5909   CharUnits AlignVal = getContext().getDeclAlign(D);
5910   // Check for alignment specifed in an 'omp allocate' directive.
5911   if (std::optional<CharUnits> AlignValFromAllocate =
5912           getOMPAllocateAlignment(D))
5913     AlignVal = *AlignValFromAllocate;
5914   GV->setAlignment(AlignVal.getAsAlign());
5915 
5916   // On Darwin, unlike other Itanium C++ ABI platforms, the thread-wrapper
5917   // function is only defined alongside the variable, not also alongside
5918   // callers. Normally, all accesses to a thread_local go through the
5919   // thread-wrapper in order to ensure initialization has occurred, underlying
5920   // variable will never be used other than the thread-wrapper, so it can be
5921   // converted to internal linkage.
5922   //
5923   // However, if the variable has the 'constinit' attribute, it _can_ be
5924   // referenced directly, without calling the thread-wrapper, so the linkage
5925   // must not be changed.
5926   //
5927   // Additionally, if the variable isn't plain external linkage, e.g. if it's
5928   // weak or linkonce, the de-duplication semantics are important to preserve,
5929   // so we don't change the linkage.
5930   if (D->getTLSKind() == VarDecl::TLS_Dynamic &&
5931       Linkage == llvm::GlobalValue::ExternalLinkage &&
5932       Context.getTargetInfo().getTriple().isOSDarwin() &&
5933       !D->hasAttr<ConstInitAttr>())
5934     Linkage = llvm::GlobalValue::InternalLinkage;
5935 
5936   // HLSL variables in the input address space maps like memory-mapped
5937   // variables. Even if they are 'static', they are externally initialized and
5938   // read/write by the hardware/driver/pipeline.
5939   if (LangOpts.HLSL && GetGlobalVarAddressSpace(D) == LangAS::hlsl_input)
5940     Linkage = llvm::GlobalValue::ExternalLinkage;
5941 
5942   GV->setLinkage(Linkage);
5943   if (D->hasAttr<DLLImportAttr>())
5944     GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
5945   else if (D->hasAttr<DLLExportAttr>())
5946     GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
5947   else
5948     GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
5949 
5950   if (Linkage == llvm::GlobalVariable::CommonLinkage) {
5951     // common vars aren't constant even if declared const.
5952     GV->setConstant(false);
5953     // Tentative definition of global variables may be initialized with
5954     // non-zero null pointers. In this case they should have weak linkage
5955     // since common linkage must have zero initializer and must not have
5956     // explicit section therefore cannot have non-zero initial value.
5957     if (!GV->getInitializer()->isNullValue())
5958       GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
5959   }
5960 
5961   setNonAliasAttributes(D, GV);
5962 
5963   if (D->getTLSKind() && !GV->isThreadLocal()) {
5964     if (D->getTLSKind() == VarDecl::TLS_Dynamic)
5965       CXXThreadLocals.push_back(D);
5966     setTLSMode(GV, *D);
5967   }
5968 
5969   maybeSetTrivialComdat(*D, *GV);
5970 
5971   // Emit the initializer function if necessary.
5972   if (NeedsGlobalCtor || NeedsGlobalDtor)
5973     EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
5974 
5975   SanitizerMD->reportGlobal(GV, *D, NeedsGlobalCtor);
5976 
5977   // Emit global variable debug information.
5978   if (CGDebugInfo *DI = getModuleDebugInfo())
5979     if (getCodeGenOpts().hasReducedDebugInfo())
5980       DI->EmitGlobalVariable(GV, D);
5981 }
5982 
5983 static bool isVarDeclStrongDefinition(const ASTContext &Context,
5984                                       CodeGenModule &CGM, const VarDecl *D,
5985                                       bool NoCommon) {
5986   // Don't give variables common linkage if -fno-common was specified unless it
5987   // was overridden by a NoCommon attribute.
5988   if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
5989     return true;
5990 
5991   // C11 6.9.2/2:
5992   //   A declaration of an identifier for an object that has file scope without
5993   //   an initializer, and without a storage-class specifier or with the
5994   //   storage-class specifier static, constitutes a tentative definition.
5995   if (D->getInit() || D->hasExternalStorage())
5996     return true;
5997 
5998   // A variable cannot be both common and exist in a section.
5999   if (D->hasAttr<SectionAttr>())
6000     return true;
6001 
6002   // A variable cannot be both common and exist in a section.
6003   // We don't try to determine which is the right section in the front-end.
6004   // If no specialized section name is applicable, it will resort to default.
6005   if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
6006       D->hasAttr<PragmaClangDataSectionAttr>() ||
6007       D->hasAttr<PragmaClangRelroSectionAttr>() ||
6008       D->hasAttr<PragmaClangRodataSectionAttr>())
6009     return true;
6010 
6011   // Thread local vars aren't considered common linkage.
6012   if (D->getTLSKind())
6013     return true;
6014 
6015   // Tentative definitions marked with WeakImportAttr are true definitions.
6016   if (D->hasAttr<WeakImportAttr>())
6017     return true;
6018 
6019   // A variable cannot be both common and exist in a comdat.
6020   if (shouldBeInCOMDAT(CGM, *D))
6021     return true;
6022 
6023   // Declarations with a required alignment do not have common linkage in MSVC
6024   // mode.
6025   if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
6026     if (D->hasAttr<AlignedAttr>())
6027       return true;
6028     QualType VarType = D->getType();
6029     if (Context.isAlignmentRequired(VarType))
6030       return true;
6031 
6032     if (const auto *RT = VarType->getAs<RecordType>()) {
6033       const RecordDecl *RD = RT->getDecl();
6034       for (const FieldDecl *FD : RD->fields()) {
6035         if (FD->isBitField())
6036           continue;
6037         if (FD->hasAttr<AlignedAttr>())
6038           return true;
6039         if (Context.isAlignmentRequired(FD->getType()))
6040           return true;
6041       }
6042     }
6043   }
6044 
6045   // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
6046   // common symbols, so symbols with greater alignment requirements cannot be
6047   // common.
6048   // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
6049   // alignments for common symbols via the aligncomm directive, so this
6050   // restriction only applies to MSVC environments.
6051   if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
6052       Context.getTypeAlignIfKnown(D->getType()) >
6053           Context.toBits(CharUnits::fromQuantity(32)))
6054     return true;
6055 
6056   return false;
6057 }
6058 
6059 llvm::GlobalValue::LinkageTypes
6060 CodeGenModule::getLLVMLinkageForDeclarator(const DeclaratorDecl *D,
6061                                            GVALinkage Linkage) {
6062   if (Linkage == GVA_Internal)
6063     return llvm::Function::InternalLinkage;
6064 
6065   if (D->hasAttr<WeakAttr>())
6066     return llvm::GlobalVariable::WeakAnyLinkage;
6067 
6068   if (const auto *FD = D->getAsFunction())
6069     if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
6070       return llvm::GlobalVariable::LinkOnceAnyLinkage;
6071 
6072   // We are guaranteed to have a strong definition somewhere else,
6073   // so we can use available_externally linkage.
6074   if (Linkage == GVA_AvailableExternally)
6075     return llvm::GlobalValue::AvailableExternallyLinkage;
6076 
6077   // Note that Apple's kernel linker doesn't support symbol
6078   // coalescing, so we need to avoid linkonce and weak linkages there.
6079   // Normally, this means we just map to internal, but for explicit
6080   // instantiations we'll map to external.
6081 
6082   // In C++, the compiler has to emit a definition in every translation unit
6083   // that references the function.  We should use linkonce_odr because
6084   // a) if all references in this translation unit are optimized away, we
6085   // don't need to codegen it.  b) if the function persists, it needs to be
6086   // merged with other definitions. c) C++ has the ODR, so we know the
6087   // definition is dependable.
6088   if (Linkage == GVA_DiscardableODR)
6089     return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
6090                                             : llvm::Function::InternalLinkage;
6091 
6092   // An explicit instantiation of a template has weak linkage, since
6093   // explicit instantiations can occur in multiple translation units
6094   // and must all be equivalent. However, we are not allowed to
6095   // throw away these explicit instantiations.
6096   //
6097   // CUDA/HIP: For -fno-gpu-rdc case, device code is limited to one TU,
6098   // so say that CUDA templates are either external (for kernels) or internal.
6099   // This lets llvm perform aggressive inter-procedural optimizations. For
6100   // -fgpu-rdc case, device function calls across multiple TU's are allowed,
6101   // therefore we need to follow the normal linkage paradigm.
6102   if (Linkage == GVA_StrongODR) {
6103     if (getLangOpts().AppleKext)
6104       return llvm::Function::ExternalLinkage;
6105     if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
6106         !getLangOpts().GPURelocatableDeviceCode)
6107       return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
6108                                           : llvm::Function::InternalLinkage;
6109     return llvm::Function::WeakODRLinkage;
6110   }
6111 
6112   // C++ doesn't have tentative definitions and thus cannot have common
6113   // linkage.
6114   if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
6115       !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
6116                                  CodeGenOpts.NoCommon))
6117     return llvm::GlobalVariable::CommonLinkage;
6118 
6119   // selectany symbols are externally visible, so use weak instead of
6120   // linkonce.  MSVC optimizes away references to const selectany globals, so
6121   // all definitions should be the same and ODR linkage should be used.
6122   // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
6123   if (D->hasAttr<SelectAnyAttr>())
6124     return llvm::GlobalVariable::WeakODRLinkage;
6125 
6126   // Otherwise, we have strong external linkage.
6127   assert(Linkage == GVA_StrongExternal);
6128   return llvm::GlobalVariable::ExternalLinkage;
6129 }
6130 
6131 llvm::GlobalValue::LinkageTypes
6132 CodeGenModule::getLLVMLinkageVarDefinition(const VarDecl *VD) {
6133   GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
6134   return getLLVMLinkageForDeclarator(VD, Linkage);
6135 }
6136 
6137 /// Replace the uses of a function that was declared with a non-proto type.
6138 /// We want to silently drop extra arguments from call sites
6139 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
6140                                           llvm::Function *newFn) {
6141   // Fast path.
6142   if (old->use_empty())
6143     return;
6144 
6145   llvm::Type *newRetTy = newFn->getReturnType();
6146   SmallVector<llvm::Value *, 4> newArgs;
6147 
6148   SmallVector<llvm::CallBase *> callSitesToBeRemovedFromParent;
6149 
6150   for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
6151        ui != ue; ui++) {
6152     llvm::User *user = ui->getUser();
6153 
6154     // Recognize and replace uses of bitcasts.  Most calls to
6155     // unprototyped functions will use bitcasts.
6156     if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
6157       if (bitcast->getOpcode() == llvm::Instruction::BitCast)
6158         replaceUsesOfNonProtoConstant(bitcast, newFn);
6159       continue;
6160     }
6161 
6162     // Recognize calls to the function.
6163     llvm::CallBase *callSite = dyn_cast<llvm::CallBase>(user);
6164     if (!callSite)
6165       continue;
6166     if (!callSite->isCallee(&*ui))
6167       continue;
6168 
6169     // If the return types don't match exactly, then we can't
6170     // transform this call unless it's dead.
6171     if (callSite->getType() != newRetTy && !callSite->use_empty())
6172       continue;
6173 
6174     // Get the call site's attribute list.
6175     SmallVector<llvm::AttributeSet, 8> newArgAttrs;
6176     llvm::AttributeList oldAttrs = callSite->getAttributes();
6177 
6178     // If the function was passed too few arguments, don't transform.
6179     unsigned newNumArgs = newFn->arg_size();
6180     if (callSite->arg_size() < newNumArgs)
6181       continue;
6182 
6183     // If extra arguments were passed, we silently drop them.
6184     // If any of the types mismatch, we don't transform.
6185     unsigned argNo = 0;
6186     bool dontTransform = false;
6187     for (llvm::Argument &A : newFn->args()) {
6188       if (callSite->getArgOperand(argNo)->getType() != A.getType()) {
6189         dontTransform = true;
6190         break;
6191       }
6192 
6193       // Add any parameter attributes.
6194       newArgAttrs.push_back(oldAttrs.getParamAttrs(argNo));
6195       argNo++;
6196     }
6197     if (dontTransform)
6198       continue;
6199 
6200     // Okay, we can transform this.  Create the new call instruction and copy
6201     // over the required information.
6202     newArgs.append(callSite->arg_begin(), callSite->arg_begin() + argNo);
6203 
6204     // Copy over any operand bundles.
6205     SmallVector<llvm::OperandBundleDef, 1> newBundles;
6206     callSite->getOperandBundlesAsDefs(newBundles);
6207 
6208     llvm::CallBase *newCall;
6209     if (isa<llvm::CallInst>(callSite)) {
6210       newCall = llvm::CallInst::Create(newFn, newArgs, newBundles, "",
6211                                        callSite->getIterator());
6212     } else {
6213       auto *oldInvoke = cast<llvm::InvokeInst>(callSite);
6214       newCall = llvm::InvokeInst::Create(
6215           newFn, oldInvoke->getNormalDest(), oldInvoke->getUnwindDest(),
6216           newArgs, newBundles, "", callSite->getIterator());
6217     }
6218     newArgs.clear(); // for the next iteration
6219 
6220     if (!newCall->getType()->isVoidTy())
6221       newCall->takeName(callSite);
6222     newCall->setAttributes(
6223         llvm::AttributeList::get(newFn->getContext(), oldAttrs.getFnAttrs(),
6224                                  oldAttrs.getRetAttrs(), newArgAttrs));
6225     newCall->setCallingConv(callSite->getCallingConv());
6226 
6227     // Finally, remove the old call, replacing any uses with the new one.
6228     if (!callSite->use_empty())
6229       callSite->replaceAllUsesWith(newCall);
6230 
6231     // Copy debug location attached to CI.
6232     if (callSite->getDebugLoc())
6233       newCall->setDebugLoc(callSite->getDebugLoc());
6234 
6235     callSitesToBeRemovedFromParent.push_back(callSite);
6236   }
6237 
6238   for (auto *callSite : callSitesToBeRemovedFromParent) {
6239     callSite->eraseFromParent();
6240   }
6241 }
6242 
6243 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
6244 /// implement a function with no prototype, e.g. "int foo() {}".  If there are
6245 /// existing call uses of the old function in the module, this adjusts them to
6246 /// call the new function directly.
6247 ///
6248 /// This is not just a cleanup: the always_inline pass requires direct calls to
6249 /// functions to be able to inline them.  If there is a bitcast in the way, it
6250 /// won't inline them.  Instcombine normally deletes these calls, but it isn't
6251 /// run at -O0.
6252 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
6253                                                       llvm::Function *NewFn) {
6254   // If we're redefining a global as a function, don't transform it.
6255   if (!isa<llvm::Function>(Old)) return;
6256 
6257   replaceUsesOfNonProtoConstant(Old, NewFn);
6258 }
6259 
6260 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
6261   auto DK = VD->isThisDeclarationADefinition();
6262   if ((DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>()) ||
6263       (LangOpts.CUDA && !shouldEmitCUDAGlobalVar(VD)))
6264     return;
6265 
6266   TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
6267   // If we have a definition, this might be a deferred decl. If the
6268   // instantiation is explicit, make sure we emit it at the end.
6269   if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
6270     GetAddrOfGlobalVar(VD);
6271 
6272   EmitTopLevelDecl(VD);
6273 }
6274 
6275 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
6276                                                  llvm::GlobalValue *GV) {
6277   const auto *D = cast<FunctionDecl>(GD.getDecl());
6278 
6279   // Compute the function info and LLVM type.
6280   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
6281   llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
6282 
6283   // Get or create the prototype for the function.
6284   if (!GV || (GV->getValueType() != Ty))
6285     GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
6286                                                    /*DontDefer=*/true,
6287                                                    ForDefinition));
6288 
6289   // Already emitted.
6290   if (!GV->isDeclaration())
6291     return;
6292 
6293   // We need to set linkage and visibility on the function before
6294   // generating code for it because various parts of IR generation
6295   // want to propagate this information down (e.g. to local static
6296   // declarations).
6297   auto *Fn = cast<llvm::Function>(GV);
6298   setFunctionLinkage(GD, Fn);
6299 
6300   // FIXME: this is redundant with part of setFunctionDefinitionAttributes
6301   setGVProperties(Fn, GD);
6302 
6303   MaybeHandleStaticInExternC(D, Fn);
6304 
6305   maybeSetTrivialComdat(*D, *Fn);
6306 
6307   CodeGenFunction(*this).GenerateCode(GD, Fn, FI);
6308 
6309   setNonAliasAttributes(GD, Fn);
6310 
6311   bool ShouldAddOptNone = !CodeGenOpts.DisableO0ImplyOptNone &&
6312                           (CodeGenOpts.OptimizationLevel == 0) &&
6313                           !D->hasAttr<MinSizeAttr>();
6314 
6315   if (DeviceKernelAttr::isOpenCLSpelling(D->getAttr<DeviceKernelAttr>())) {
6316     if (GD.getKernelReferenceKind() == KernelReferenceKind::Stub &&
6317         !D->hasAttr<NoInlineAttr>() &&
6318         !Fn->hasFnAttribute(llvm::Attribute::NoInline) &&
6319         !D->hasAttr<OptimizeNoneAttr>() &&
6320         !Fn->hasFnAttribute(llvm::Attribute::OptimizeNone) &&
6321         !ShouldAddOptNone) {
6322       Fn->addFnAttr(llvm::Attribute::AlwaysInline);
6323     }
6324   }
6325 
6326   SetLLVMFunctionAttributesForDefinition(D, Fn);
6327 
6328   if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
6329     AddGlobalCtor(Fn, CA->getPriority());
6330   if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
6331     AddGlobalDtor(Fn, DA->getPriority(), true);
6332   if (getLangOpts().OpenMP && D->hasAttr<OMPDeclareTargetDeclAttr>())
6333     getOpenMPRuntime().emitDeclareTargetFunction(D, GV);
6334 }
6335 
6336 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
6337   const auto *D = cast<ValueDecl>(GD.getDecl());
6338   const AliasAttr *AA = D->getAttr<AliasAttr>();
6339   assert(AA && "Not an alias?");
6340 
6341   StringRef MangledName = getMangledName(GD);
6342 
6343   if (AA->getAliasee() == MangledName) {
6344     Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
6345     return;
6346   }
6347 
6348   // If there is a definition in the module, then it wins over the alias.
6349   // This is dubious, but allow it to be safe.  Just ignore the alias.
6350   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
6351   if (Entry && !Entry->isDeclaration())
6352     return;
6353 
6354   Aliases.push_back(GD);
6355 
6356   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
6357 
6358   // Create a reference to the named value.  This ensures that it is emitted
6359   // if a deferred decl.
6360   llvm::Constant *Aliasee;
6361   llvm::GlobalValue::LinkageTypes LT;
6362   if (isa<llvm::FunctionType>(DeclTy)) {
6363     Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
6364                                       /*ForVTable=*/false);
6365     LT = getFunctionLinkage(GD);
6366   } else {
6367     Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, LangAS::Default,
6368                                     /*D=*/nullptr);
6369     if (const auto *VD = dyn_cast<VarDecl>(GD.getDecl()))
6370       LT = getLLVMLinkageVarDefinition(VD);
6371     else
6372       LT = getFunctionLinkage(GD);
6373   }
6374 
6375   // Create the new alias itself, but don't set a name yet.
6376   unsigned AS = Aliasee->getType()->getPointerAddressSpace();
6377   auto *GA =
6378       llvm::GlobalAlias::create(DeclTy, AS, LT, "", Aliasee, &getModule());
6379 
6380   if (Entry) {
6381     if (GA->getAliasee() == Entry) {
6382       Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
6383       return;
6384     }
6385 
6386     assert(Entry->isDeclaration());
6387 
6388     // If there is a declaration in the module, then we had an extern followed
6389     // by the alias, as in:
6390     //   extern int test6();
6391     //   ...
6392     //   int test6() __attribute__((alias("test7")));
6393     //
6394     // Remove it and replace uses of it with the alias.
6395     GA->takeName(Entry);
6396 
6397     Entry->replaceAllUsesWith(GA);
6398     Entry->eraseFromParent();
6399   } else {
6400     GA->setName(MangledName);
6401   }
6402 
6403   // Set attributes which are particular to an alias; this is a
6404   // specialization of the attributes which may be set on a global
6405   // variable/function.
6406   if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
6407       D->isWeakImported()) {
6408     GA->setLinkage(llvm::Function::WeakAnyLinkage);
6409   }
6410 
6411   if (const auto *VD = dyn_cast<VarDecl>(D))
6412     if (VD->getTLSKind())
6413       setTLSMode(GA, *VD);
6414 
6415   SetCommonAttributes(GD, GA);
6416 
6417   // Emit global alias debug information.
6418   if (isa<VarDecl>(D))
6419     if (CGDebugInfo *DI = getModuleDebugInfo())
6420       DI->EmitGlobalAlias(cast<llvm::GlobalValue>(GA->getAliasee()->stripPointerCasts()), GD);
6421 }
6422 
6423 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
6424   const auto *D = cast<ValueDecl>(GD.getDecl());
6425   const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
6426   assert(IFA && "Not an ifunc?");
6427 
6428   StringRef MangledName = getMangledName(GD);
6429 
6430   if (IFA->getResolver() == MangledName) {
6431     Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
6432     return;
6433   }
6434 
6435   // Report an error if some definition overrides ifunc.
6436   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
6437   if (Entry && !Entry->isDeclaration()) {
6438     GlobalDecl OtherGD;
6439     if (lookupRepresentativeDecl(MangledName, OtherGD) &&
6440         DiagnosedConflictingDefinitions.insert(GD).second) {
6441       Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
6442           << MangledName;
6443       Diags.Report(OtherGD.getDecl()->getLocation(),
6444                    diag::note_previous_definition);
6445     }
6446     return;
6447   }
6448 
6449   Aliases.push_back(GD);
6450 
6451   // The resolver might not be visited yet. Specify a dummy non-function type to
6452   // indicate IsIncompleteFunction. Either the type is ignored (if the resolver
6453   // was emitted) or the whole function will be replaced (if the resolver has
6454   // not been emitted).
6455   llvm::Constant *Resolver =
6456       GetOrCreateLLVMFunction(IFA->getResolver(), VoidTy, {},
6457                               /*ForVTable=*/false);
6458   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
6459   unsigned AS = getTypes().getTargetAddressSpace(D->getType());
6460   llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
6461       DeclTy, AS, llvm::Function::ExternalLinkage, "", Resolver, &getModule());
6462   if (Entry) {
6463     if (GIF->getResolver() == Entry) {
6464       Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
6465       return;
6466     }
6467     assert(Entry->isDeclaration());
6468 
6469     // If there is a declaration in the module, then we had an extern followed
6470     // by the ifunc, as in:
6471     //   extern int test();
6472     //   ...
6473     //   int test() __attribute__((ifunc("resolver")));
6474     //
6475     // Remove it and replace uses of it with the ifunc.
6476     GIF->takeName(Entry);
6477 
6478     Entry->replaceAllUsesWith(GIF);
6479     Entry->eraseFromParent();
6480   } else
6481     GIF->setName(MangledName);
6482   SetCommonAttributes(GD, GIF);
6483 }
6484 
6485 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
6486                                             ArrayRef<llvm::Type*> Tys) {
6487   return llvm::Intrinsic::getOrInsertDeclaration(&getModule(),
6488                                                  (llvm::Intrinsic::ID)IID, Tys);
6489 }
6490 
6491 static llvm::StringMapEntry<llvm::GlobalVariable *> &
6492 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
6493                          const StringLiteral *Literal, bool TargetIsLSB,
6494                          bool &IsUTF16, unsigned &StringLength) {
6495   StringRef String = Literal->getString();
6496   unsigned NumBytes = String.size();
6497 
6498   // Check for simple case.
6499   if (!Literal->containsNonAsciiOrNull()) {
6500     StringLength = NumBytes;
6501     return *Map.insert(std::make_pair(String, nullptr)).first;
6502   }
6503 
6504   // Otherwise, convert the UTF8 literals into a string of shorts.
6505   IsUTF16 = true;
6506 
6507   SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
6508   const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
6509   llvm::UTF16 *ToPtr = &ToBuf[0];
6510 
6511   (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
6512                                  ToPtr + NumBytes, llvm::strictConversion);
6513 
6514   // ConvertUTF8toUTF16 returns the length in ToPtr.
6515   StringLength = ToPtr - &ToBuf[0];
6516 
6517   // Add an explicit null.
6518   *ToPtr = 0;
6519   return *Map.insert(std::make_pair(
6520                          StringRef(reinterpret_cast<const char *>(ToBuf.data()),
6521                                    (StringLength + 1) * 2),
6522                          nullptr)).first;
6523 }
6524 
6525 ConstantAddress
6526 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
6527   unsigned StringLength = 0;
6528   bool isUTF16 = false;
6529   llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
6530       GetConstantCFStringEntry(CFConstantStringMap, Literal,
6531                                getDataLayout().isLittleEndian(), isUTF16,
6532                                StringLength);
6533 
6534   if (auto *C = Entry.second)
6535     return ConstantAddress(
6536         C, C->getValueType(), CharUnits::fromQuantity(C->getAlignment()));
6537 
6538   const ASTContext &Context = getContext();
6539   const llvm::Triple &Triple = getTriple();
6540 
6541   const auto CFRuntime = getLangOpts().CFRuntime;
6542   const bool IsSwiftABI =
6543       static_cast<unsigned>(CFRuntime) >=
6544       static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
6545   const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
6546 
6547   // If we don't already have it, get __CFConstantStringClassReference.
6548   if (!CFConstantStringClassRef) {
6549     const char *CFConstantStringClassName = "__CFConstantStringClassReference";
6550     llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
6551     Ty = llvm::ArrayType::get(Ty, 0);
6552 
6553     switch (CFRuntime) {
6554     default: break;
6555     case LangOptions::CoreFoundationABI::Swift: [[fallthrough]];
6556     case LangOptions::CoreFoundationABI::Swift5_0:
6557       CFConstantStringClassName =
6558           Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
6559                               : "$s10Foundation19_NSCFConstantStringCN";
6560       Ty = IntPtrTy;
6561       break;
6562     case LangOptions::CoreFoundationABI::Swift4_2:
6563       CFConstantStringClassName =
6564           Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
6565                               : "$S10Foundation19_NSCFConstantStringCN";
6566       Ty = IntPtrTy;
6567       break;
6568     case LangOptions::CoreFoundationABI::Swift4_1:
6569       CFConstantStringClassName =
6570           Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
6571                               : "__T010Foundation19_NSCFConstantStringCN";
6572       Ty = IntPtrTy;
6573       break;
6574     }
6575 
6576     llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
6577 
6578     if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
6579       llvm::GlobalValue *GV = nullptr;
6580 
6581       if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
6582         IdentifierInfo &II = Context.Idents.get(GV->getName());
6583         TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
6584         DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
6585 
6586         const VarDecl *VD = nullptr;
6587         for (const auto *Result : DC->lookup(&II))
6588           if ((VD = dyn_cast<VarDecl>(Result)))
6589             break;
6590 
6591         if (Triple.isOSBinFormatELF()) {
6592           if (!VD)
6593             GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
6594         } else {
6595           GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
6596           if (!VD || !VD->hasAttr<DLLExportAttr>())
6597             GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
6598           else
6599             GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
6600         }
6601 
6602         setDSOLocal(GV);
6603       }
6604     }
6605 
6606     // Decay array -> ptr
6607     CFConstantStringClassRef =
6608         IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty) : C;
6609   }
6610 
6611   QualType CFTy = Context.getCFConstantStringType();
6612 
6613   auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
6614 
6615   ConstantInitBuilder Builder(*this);
6616   auto Fields = Builder.beginStruct(STy);
6617 
6618   // Class pointer.
6619   Fields.addSignedPointer(cast<llvm::Constant>(CFConstantStringClassRef),
6620                           getCodeGenOpts().PointerAuth.ObjCIsaPointers,
6621                           GlobalDecl(), QualType());
6622 
6623   // Flags.
6624   if (IsSwiftABI) {
6625     Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
6626     Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
6627   } else {
6628     Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
6629   }
6630 
6631   // String pointer.
6632   llvm::Constant *C = nullptr;
6633   if (isUTF16) {
6634     auto Arr = llvm::ArrayRef(
6635         reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
6636         Entry.first().size() / 2);
6637     C = llvm::ConstantDataArray::get(VMContext, Arr);
6638   } else {
6639     C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
6640   }
6641 
6642   // Note: -fwritable-strings doesn't make the backing store strings of
6643   // CFStrings writable.
6644   auto *GV =
6645       new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
6646                                llvm::GlobalValue::PrivateLinkage, C, ".str");
6647   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
6648   // Don't enforce the target's minimum global alignment, since the only use
6649   // of the string is via this class initializer.
6650   CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
6651                             : Context.getTypeAlignInChars(Context.CharTy);
6652   GV->setAlignment(Align.getAsAlign());
6653 
6654   // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
6655   // Without it LLVM can merge the string with a non unnamed_addr one during
6656   // LTO.  Doing that changes the section it ends in, which surprises ld64.
6657   if (Triple.isOSBinFormatMachO())
6658     GV->setSection(isUTF16 ? "__TEXT,__ustring"
6659                            : "__TEXT,__cstring,cstring_literals");
6660   // Make sure the literal ends up in .rodata to allow for safe ICF and for
6661   // the static linker to adjust permissions to read-only later on.
6662   else if (Triple.isOSBinFormatELF())
6663     GV->setSection(".rodata");
6664 
6665   // String.
6666   Fields.add(GV);
6667 
6668   // String length.
6669   llvm::IntegerType *LengthTy =
6670       llvm::IntegerType::get(getModule().getContext(),
6671                              Context.getTargetInfo().getLongWidth());
6672   if (IsSwiftABI) {
6673     if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
6674         CFRuntime == LangOptions::CoreFoundationABI::Swift4_2)
6675       LengthTy = Int32Ty;
6676     else
6677       LengthTy = IntPtrTy;
6678   }
6679   Fields.addInt(LengthTy, StringLength);
6680 
6681   // Swift ABI requires 8-byte alignment to ensure that the _Atomic(uint64_t) is
6682   // properly aligned on 32-bit platforms.
6683   CharUnits Alignment =
6684       IsSwiftABI ? Context.toCharUnitsFromBits(64) : getPointerAlign();
6685 
6686   // The struct.
6687   GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
6688                                     /*isConstant=*/false,
6689                                     llvm::GlobalVariable::PrivateLinkage);
6690   GV->addAttribute("objc_arc_inert");
6691   switch (Triple.getObjectFormat()) {
6692   case llvm::Triple::UnknownObjectFormat:
6693     llvm_unreachable("unknown file format");
6694   case llvm::Triple::DXContainer:
6695   case llvm::Triple::GOFF:
6696   case llvm::Triple::SPIRV:
6697   case llvm::Triple::XCOFF:
6698     llvm_unreachable("unimplemented");
6699   case llvm::Triple::COFF:
6700   case llvm::Triple::ELF:
6701   case llvm::Triple::Wasm:
6702     GV->setSection("cfstring");
6703     break;
6704   case llvm::Triple::MachO:
6705     GV->setSection("__DATA,__cfstring");
6706     break;
6707   }
6708   Entry.second = GV;
6709 
6710   return ConstantAddress(GV, GV->getValueType(), Alignment);
6711 }
6712 
6713 bool CodeGenModule::getExpressionLocationsEnabled() const {
6714   return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
6715 }
6716 
6717 QualType CodeGenModule::getObjCFastEnumerationStateType() {
6718   if (ObjCFastEnumerationStateType.isNull()) {
6719     RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
6720     D->startDefinition();
6721 
6722     QualType FieldTypes[] = {
6723         Context.UnsignedLongTy, Context.getPointerType(Context.getObjCIdType()),
6724         Context.getPointerType(Context.UnsignedLongTy),
6725         Context.getConstantArrayType(Context.UnsignedLongTy, llvm::APInt(32, 5),
6726                                      nullptr, ArraySizeModifier::Normal, 0)};
6727 
6728     for (size_t i = 0; i < 4; ++i) {
6729       FieldDecl *Field = FieldDecl::Create(Context,
6730                                            D,
6731                                            SourceLocation(),
6732                                            SourceLocation(), nullptr,
6733                                            FieldTypes[i], /*TInfo=*/nullptr,
6734                                            /*BitWidth=*/nullptr,
6735                                            /*Mutable=*/false,
6736                                            ICIS_NoInit);
6737       Field->setAccess(AS_public);
6738       D->addDecl(Field);
6739     }
6740 
6741     D->completeDefinition();
6742     ObjCFastEnumerationStateType = Context.getTagDeclType(D);
6743   }
6744 
6745   return ObjCFastEnumerationStateType;
6746 }
6747 
6748 llvm::Constant *
6749 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
6750   assert(!E->getType()->isPointerType() && "Strings are always arrays");
6751 
6752   // Don't emit it as the address of the string, emit the string data itself
6753   // as an inline array.
6754   if (E->getCharByteWidth() == 1) {
6755     SmallString<64> Str(E->getString());
6756 
6757     // Resize the string to the right size, which is indicated by its type.
6758     const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
6759     assert(CAT && "String literal not of constant array type!");
6760     Str.resize(CAT->getZExtSize());
6761     return llvm::ConstantDataArray::getString(VMContext, Str, false);
6762   }
6763 
6764   auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
6765   llvm::Type *ElemTy = AType->getElementType();
6766   unsigned NumElements = AType->getNumElements();
6767 
6768   // Wide strings have either 2-byte or 4-byte elements.
6769   if (ElemTy->getPrimitiveSizeInBits() == 16) {
6770     SmallVector<uint16_t, 32> Elements;
6771     Elements.reserve(NumElements);
6772 
6773     for(unsigned i = 0, e = E->getLength(); i != e; ++i)
6774       Elements.push_back(E->getCodeUnit(i));
6775     Elements.resize(NumElements);
6776     return llvm::ConstantDataArray::get(VMContext, Elements);
6777   }
6778 
6779   assert(ElemTy->getPrimitiveSizeInBits() == 32);
6780   SmallVector<uint32_t, 32> Elements;
6781   Elements.reserve(NumElements);
6782 
6783   for(unsigned i = 0, e = E->getLength(); i != e; ++i)
6784     Elements.push_back(E->getCodeUnit(i));
6785   Elements.resize(NumElements);
6786   return llvm::ConstantDataArray::get(VMContext, Elements);
6787 }
6788 
6789 static llvm::GlobalVariable *
6790 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
6791                       CodeGenModule &CGM, StringRef GlobalName,
6792                       CharUnits Alignment) {
6793   unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
6794       CGM.GetGlobalConstantAddressSpace());
6795 
6796   llvm::Module &M = CGM.getModule();
6797   // Create a global variable for this string
6798   auto *GV = new llvm::GlobalVariable(
6799       M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
6800       nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
6801   GV->setAlignment(Alignment.getAsAlign());
6802   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
6803   if (GV->isWeakForLinker()) {
6804     assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
6805     GV->setComdat(M.getOrInsertComdat(GV->getName()));
6806   }
6807   CGM.setDSOLocal(GV);
6808 
6809   return GV;
6810 }
6811 
6812 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
6813 /// constant array for the given string literal.
6814 ConstantAddress
6815 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
6816                                                   StringRef Name) {
6817   CharUnits Alignment =
6818       getContext().getAlignOfGlobalVarInChars(S->getType(), /*VD=*/nullptr);
6819 
6820   llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
6821   llvm::GlobalVariable **Entry = nullptr;
6822   if (!LangOpts.WritableStrings) {
6823     Entry = &ConstantStringMap[C];
6824     if (auto GV = *Entry) {
6825       if (uint64_t(Alignment.getQuantity()) > GV->getAlignment())
6826         GV->setAlignment(Alignment.getAsAlign());
6827       return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6828                              GV->getValueType(), Alignment);
6829     }
6830   }
6831 
6832   SmallString<256> MangledNameBuffer;
6833   StringRef GlobalVariableName;
6834   llvm::GlobalValue::LinkageTypes LT;
6835 
6836   // Mangle the string literal if that's how the ABI merges duplicate strings.
6837   // Don't do it if they are writable, since we don't want writes in one TU to
6838   // affect strings in another.
6839   if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
6840       !LangOpts.WritableStrings) {
6841     llvm::raw_svector_ostream Out(MangledNameBuffer);
6842     getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
6843     LT = llvm::GlobalValue::LinkOnceODRLinkage;
6844     GlobalVariableName = MangledNameBuffer;
6845   } else {
6846     LT = llvm::GlobalValue::PrivateLinkage;
6847     GlobalVariableName = Name;
6848   }
6849 
6850   auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
6851 
6852   CGDebugInfo *DI = getModuleDebugInfo();
6853   if (DI && getCodeGenOpts().hasReducedDebugInfo())
6854     DI->AddStringLiteralDebugInfo(GV, S);
6855 
6856   if (Entry)
6857     *Entry = GV;
6858 
6859   SanitizerMD->reportGlobal(GV, S->getStrTokenLoc(0), "<string literal>");
6860 
6861   return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6862                          GV->getValueType(), Alignment);
6863 }
6864 
6865 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
6866 /// array for the given ObjCEncodeExpr node.
6867 ConstantAddress
6868 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
6869   std::string Str;
6870   getContext().getObjCEncodingForType(E->getEncodedType(), Str);
6871 
6872   return GetAddrOfConstantCString(Str);
6873 }
6874 
6875 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
6876 /// the literal and a terminating '\0' character.
6877 /// The result has pointer to array type.
6878 ConstantAddress CodeGenModule::GetAddrOfConstantCString(
6879     const std::string &Str, const char *GlobalName) {
6880   StringRef StrWithNull(Str.c_str(), Str.size() + 1);
6881   CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(
6882       getContext().CharTy, /*VD=*/nullptr);
6883 
6884   llvm::Constant *C =
6885       llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
6886 
6887   // Don't share any string literals if strings aren't constant.
6888   llvm::GlobalVariable **Entry = nullptr;
6889   if (!LangOpts.WritableStrings) {
6890     Entry = &ConstantStringMap[C];
6891     if (auto GV = *Entry) {
6892       if (uint64_t(Alignment.getQuantity()) > GV->getAlignment())
6893         GV->setAlignment(Alignment.getAsAlign());
6894       return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6895                              GV->getValueType(), Alignment);
6896     }
6897   }
6898 
6899   // Get the default prefix if a name wasn't specified.
6900   if (!GlobalName)
6901     GlobalName = ".str";
6902   // Create a global variable for this.
6903   auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
6904                                   GlobalName, Alignment);
6905   if (Entry)
6906     *Entry = GV;
6907 
6908   return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6909                          GV->getValueType(), Alignment);
6910 }
6911 
6912 ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
6913     const MaterializeTemporaryExpr *E, const Expr *Init) {
6914   assert((E->getStorageDuration() == SD_Static ||
6915           E->getStorageDuration() == SD_Thread) && "not a global temporary");
6916   const auto *VD = cast<VarDecl>(E->getExtendingDecl());
6917 
6918   // If we're not materializing a subobject of the temporary, keep the
6919   // cv-qualifiers from the type of the MaterializeTemporaryExpr.
6920   QualType MaterializedType = Init->getType();
6921   if (Init == E->getSubExpr())
6922     MaterializedType = E->getType();
6923 
6924   CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
6925 
6926   auto InsertResult = MaterializedGlobalTemporaryMap.insert({E, nullptr});
6927   if (!InsertResult.second) {
6928     // We've seen this before: either we already created it or we're in the
6929     // process of doing so.
6930     if (!InsertResult.first->second) {
6931       // We recursively re-entered this function, probably during emission of
6932       // the initializer. Create a placeholder. We'll clean this up in the
6933       // outer call, at the end of this function.
6934       llvm::Type *Type = getTypes().ConvertTypeForMem(MaterializedType);
6935       InsertResult.first->second = new llvm::GlobalVariable(
6936           getModule(), Type, false, llvm::GlobalVariable::InternalLinkage,
6937           nullptr);
6938     }
6939     return ConstantAddress(InsertResult.first->second,
6940                            llvm::cast<llvm::GlobalVariable>(
6941                                InsertResult.first->second->stripPointerCasts())
6942                                ->getValueType(),
6943                            Align);
6944   }
6945 
6946   // FIXME: If an externally-visible declaration extends multiple temporaries,
6947   // we need to give each temporary the same name in every translation unit (and
6948   // we also need to make the temporaries externally-visible).
6949   SmallString<256> Name;
6950   llvm::raw_svector_ostream Out(Name);
6951   getCXXABI().getMangleContext().mangleReferenceTemporary(
6952       VD, E->getManglingNumber(), Out);
6953 
6954   APValue *Value = nullptr;
6955   if (E->getStorageDuration() == SD_Static && VD->evaluateValue()) {
6956     // If the initializer of the extending declaration is a constant
6957     // initializer, we should have a cached constant initializer for this
6958     // temporary. Note that this might have a different value from the value
6959     // computed by evaluating the initializer if the surrounding constant
6960     // expression modifies the temporary.
6961     Value = E->getOrCreateValue(false);
6962   }
6963 
6964   // Try evaluating it now, it might have a constant initializer.
6965   Expr::EvalResult EvalResult;
6966   if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
6967       !EvalResult.hasSideEffects())
6968     Value = &EvalResult.Val;
6969 
6970   LangAS AddrSpace = GetGlobalVarAddressSpace(VD);
6971 
6972   std::optional<ConstantEmitter> emitter;
6973   llvm::Constant *InitialValue = nullptr;
6974   bool Constant = false;
6975   llvm::Type *Type;
6976   if (Value) {
6977     // The temporary has a constant initializer, use it.
6978     emitter.emplace(*this);
6979     InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
6980                                                MaterializedType);
6981     Constant =
6982         MaterializedType.isConstantStorage(getContext(), /*ExcludeCtor*/ Value,
6983                                            /*ExcludeDtor*/ false);
6984     Type = InitialValue->getType();
6985   } else {
6986     // No initializer, the initialization will be provided when we
6987     // initialize the declaration which performed lifetime extension.
6988     Type = getTypes().ConvertTypeForMem(MaterializedType);
6989   }
6990 
6991   // Create a global variable for this lifetime-extended temporary.
6992   llvm::GlobalValue::LinkageTypes Linkage = getLLVMLinkageVarDefinition(VD);
6993   if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
6994     const VarDecl *InitVD;
6995     if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
6996         isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
6997       // Temporaries defined inside a class get linkonce_odr linkage because the
6998       // class can be defined in multiple translation units.
6999       Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
7000     } else {
7001       // There is no need for this temporary to have external linkage if the
7002       // VarDecl has external linkage.
7003       Linkage = llvm::GlobalVariable::InternalLinkage;
7004     }
7005   }
7006   auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
7007   auto *GV = new llvm::GlobalVariable(
7008       getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
7009       /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
7010   if (emitter) emitter->finalize(GV);
7011   // Don't assign dllimport or dllexport to local linkage globals.
7012   if (!llvm::GlobalValue::isLocalLinkage(Linkage)) {
7013     setGVProperties(GV, VD);
7014     if (GV->getDLLStorageClass() == llvm::GlobalVariable::DLLExportStorageClass)
7015       // The reference temporary should never be dllexport.
7016       GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
7017   }
7018   GV->setAlignment(Align.getAsAlign());
7019   if (supportsCOMDAT() && GV->isWeakForLinker())
7020     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
7021   if (VD->getTLSKind())
7022     setTLSMode(GV, *VD);
7023   llvm::Constant *CV = GV;
7024   if (AddrSpace != LangAS::Default)
7025     CV = getTargetCodeGenInfo().performAddrSpaceCast(
7026         *this, GV, AddrSpace,
7027         llvm::PointerType::get(
7028             getLLVMContext(),
7029             getContext().getTargetAddressSpace(LangAS::Default)));
7030 
7031   // Update the map with the new temporary. If we created a placeholder above,
7032   // replace it with the new global now.
7033   llvm::Constant *&Entry = MaterializedGlobalTemporaryMap[E];
7034   if (Entry) {
7035     Entry->replaceAllUsesWith(CV);
7036     llvm::cast<llvm::GlobalVariable>(Entry)->eraseFromParent();
7037   }
7038   Entry = CV;
7039 
7040   return ConstantAddress(CV, Type, Align);
7041 }
7042 
7043 /// EmitObjCPropertyImplementations - Emit information for synthesized
7044 /// properties for an implementation.
7045 void CodeGenModule::EmitObjCPropertyImplementations(const
7046                                                     ObjCImplementationDecl *D) {
7047   for (const auto *PID : D->property_impls()) {
7048     // Dynamic is just for type-checking.
7049     if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
7050       ObjCPropertyDecl *PD = PID->getPropertyDecl();
7051 
7052       // Determine which methods need to be implemented, some may have
7053       // been overridden. Note that ::isPropertyAccessor is not the method
7054       // we want, that just indicates if the decl came from a
7055       // property. What we want to know is if the method is defined in
7056       // this implementation.
7057       auto *Getter = PID->getGetterMethodDecl();
7058       if (!Getter || Getter->isSynthesizedAccessorStub())
7059         CodeGenFunction(*this).GenerateObjCGetter(
7060             const_cast<ObjCImplementationDecl *>(D), PID);
7061       auto *Setter = PID->getSetterMethodDecl();
7062       if (!PD->isReadOnly() && (!Setter || Setter->isSynthesizedAccessorStub()))
7063         CodeGenFunction(*this).GenerateObjCSetter(
7064                                  const_cast<ObjCImplementationDecl *>(D), PID);
7065     }
7066   }
7067 }
7068 
7069 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
7070   const ObjCInterfaceDecl *iface = impl->getClassInterface();
7071   for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
7072        ivar; ivar = ivar->getNextIvar())
7073     if (ivar->getType().isDestructedType())
7074       return true;
7075 
7076   return false;
7077 }
7078 
7079 static bool AllTrivialInitializers(CodeGenModule &CGM,
7080                                    ObjCImplementationDecl *D) {
7081   CodeGenFunction CGF(CGM);
7082   for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
7083        E = D->init_end(); B != E; ++B) {
7084     CXXCtorInitializer *CtorInitExp = *B;
7085     Expr *Init = CtorInitExp->getInit();
7086     if (!CGF.isTrivialInitializer(Init))
7087       return false;
7088   }
7089   return true;
7090 }
7091 
7092 /// EmitObjCIvarInitializations - Emit information for ivar initialization
7093 /// for an implementation.
7094 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
7095   // We might need a .cxx_destruct even if we don't have any ivar initializers.
7096   if (needsDestructMethod(D)) {
7097     const IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
7098     Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
7099     ObjCMethodDecl *DTORMethod = ObjCMethodDecl::Create(
7100         getContext(), D->getLocation(), D->getLocation(), cxxSelector,
7101         getContext().VoidTy, nullptr, D,
7102         /*isInstance=*/true, /*isVariadic=*/false,
7103         /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
7104         /*isImplicitlyDeclared=*/true,
7105         /*isDefined=*/false, ObjCImplementationControl::Required);
7106     D->addInstanceMethod(DTORMethod);
7107     CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
7108     D->setHasDestructors(true);
7109   }
7110 
7111   // If the implementation doesn't have any ivar initializers, we don't need
7112   // a .cxx_construct.
7113   if (D->getNumIvarInitializers() == 0 ||
7114       AllTrivialInitializers(*this, D))
7115     return;
7116 
7117   const IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
7118   Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
7119   // The constructor returns 'self'.
7120   ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(
7121       getContext(), D->getLocation(), D->getLocation(), cxxSelector,
7122       getContext().getObjCIdType(), nullptr, D, /*isInstance=*/true,
7123       /*isVariadic=*/false,
7124       /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
7125       /*isImplicitlyDeclared=*/true,
7126       /*isDefined=*/false, ObjCImplementationControl::Required);
7127   D->addInstanceMethod(CTORMethod);
7128   CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
7129   D->setHasNonZeroConstructors(true);
7130 }
7131 
7132 // EmitLinkageSpec - Emit all declarations in a linkage spec.
7133 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
7134   if (LSD->getLanguage() != LinkageSpecLanguageIDs::C &&
7135       LSD->getLanguage() != LinkageSpecLanguageIDs::CXX) {
7136     ErrorUnsupported(LSD, "linkage spec");
7137     return;
7138   }
7139 
7140   EmitDeclContext(LSD);
7141 }
7142 
7143 void CodeGenModule::EmitTopLevelStmt(const TopLevelStmtDecl *D) {
7144   // Device code should not be at top level.
7145   if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
7146     return;
7147 
7148   std::unique_ptr<CodeGenFunction> &CurCGF =
7149       GlobalTopLevelStmtBlockInFlight.first;
7150 
7151   // We emitted a top-level stmt but after it there is initialization.
7152   // Stop squashing the top-level stmts into a single function.
7153   if (CurCGF && CXXGlobalInits.back() != CurCGF->CurFn) {
7154     CurCGF->FinishFunction(D->getEndLoc());
7155     CurCGF = nullptr;
7156   }
7157 
7158   if (!CurCGF) {
7159     // void __stmts__N(void)
7160     // FIXME: Ask the ABI name mangler to pick a name.
7161     std::string Name = "__stmts__" + llvm::utostr(CXXGlobalInits.size());
7162     FunctionArgList Args;
7163     QualType RetTy = getContext().VoidTy;
7164     const CGFunctionInfo &FnInfo =
7165         getTypes().arrangeBuiltinFunctionDeclaration(RetTy, Args);
7166     llvm::FunctionType *FnTy = getTypes().GetFunctionType(FnInfo);
7167     llvm::Function *Fn = llvm::Function::Create(
7168         FnTy, llvm::GlobalValue::InternalLinkage, Name, &getModule());
7169 
7170     CurCGF.reset(new CodeGenFunction(*this));
7171     GlobalTopLevelStmtBlockInFlight.second = D;
7172     CurCGF->StartFunction(GlobalDecl(), RetTy, Fn, FnInfo, Args,
7173                           D->getBeginLoc(), D->getBeginLoc());
7174     CXXGlobalInits.push_back(Fn);
7175   }
7176 
7177   CurCGF->EmitStmt(D->getStmt());
7178 }
7179 
7180 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
7181   for (auto *I : DC->decls()) {
7182     // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
7183     // are themselves considered "top-level", so EmitTopLevelDecl on an
7184     // ObjCImplDecl does not recursively visit them. We need to do that in
7185     // case they're nested inside another construct (LinkageSpecDecl /
7186     // ExportDecl) that does stop them from being considered "top-level".
7187     if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
7188       for (auto *M : OID->methods())
7189         EmitTopLevelDecl(M);
7190     }
7191 
7192     EmitTopLevelDecl(I);
7193   }
7194 }
7195 
7196 /// EmitTopLevelDecl - Emit code for a single top level declaration.
7197 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
7198   // Ignore dependent declarations.
7199   if (D->isTemplated())
7200     return;
7201 
7202   // Consteval function shouldn't be emitted.
7203   if (auto *FD = dyn_cast<FunctionDecl>(D); FD && FD->isImmediateFunction())
7204     return;
7205 
7206   switch (D->getKind()) {
7207   case Decl::CXXConversion:
7208   case Decl::CXXMethod:
7209   case Decl::Function:
7210     EmitGlobal(cast<FunctionDecl>(D));
7211     // Always provide some coverage mapping
7212     // even for the functions that aren't emitted.
7213     AddDeferredUnusedCoverageMapping(D);
7214     break;
7215 
7216   case Decl::CXXDeductionGuide:
7217     // Function-like, but does not result in code emission.
7218     break;
7219 
7220   case Decl::Var:
7221   case Decl::Decomposition:
7222   case Decl::VarTemplateSpecialization:
7223     EmitGlobal(cast<VarDecl>(D));
7224     if (auto *DD = dyn_cast<DecompositionDecl>(D))
7225       for (auto *B : DD->flat_bindings())
7226         if (auto *HD = B->getHoldingVar())
7227           EmitGlobal(HD);
7228 
7229     break;
7230 
7231   // Indirect fields from global anonymous structs and unions can be
7232   // ignored; only the actual variable requires IR gen support.
7233   case Decl::IndirectField:
7234     break;
7235 
7236   // C++ Decls
7237   case Decl::Namespace:
7238     EmitDeclContext(cast<NamespaceDecl>(D));
7239     break;
7240   case Decl::ClassTemplateSpecialization: {
7241     const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
7242     if (CGDebugInfo *DI = getModuleDebugInfo())
7243       if (Spec->getSpecializationKind() ==
7244               TSK_ExplicitInstantiationDefinition &&
7245           Spec->hasDefinition())
7246         DI->completeTemplateDefinition(*Spec);
7247   } [[fallthrough]];
7248   case Decl::CXXRecord: {
7249     CXXRecordDecl *CRD = cast<CXXRecordDecl>(D);
7250     if (CGDebugInfo *DI = getModuleDebugInfo()) {
7251       if (CRD->hasDefinition())
7252         DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
7253       if (auto *ES = D->getASTContext().getExternalSource())
7254         if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
7255           DI->completeUnusedClass(*CRD);
7256     }
7257     // Emit any static data members, they may be definitions.
7258     for (auto *I : CRD->decls())
7259       if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I) || isa<EnumDecl>(I))
7260         EmitTopLevelDecl(I);
7261     break;
7262   }
7263     // No code generation needed.
7264   case Decl::UsingShadow:
7265   case Decl::ClassTemplate:
7266   case Decl::VarTemplate:
7267   case Decl::Concept:
7268   case Decl::VarTemplatePartialSpecialization:
7269   case Decl::FunctionTemplate:
7270   case Decl::TypeAliasTemplate:
7271   case Decl::Block:
7272   case Decl::Empty:
7273   case Decl::Binding:
7274     break;
7275   case Decl::Using:          // using X; [C++]
7276     if (CGDebugInfo *DI = getModuleDebugInfo())
7277         DI->EmitUsingDecl(cast<UsingDecl>(*D));
7278     break;
7279   case Decl::UsingEnum: // using enum X; [C++]
7280     if (CGDebugInfo *DI = getModuleDebugInfo())
7281       DI->EmitUsingEnumDecl(cast<UsingEnumDecl>(*D));
7282     break;
7283   case Decl::NamespaceAlias:
7284     if (CGDebugInfo *DI = getModuleDebugInfo())
7285         DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
7286     break;
7287   case Decl::UsingDirective: // using namespace X; [C++]
7288     if (CGDebugInfo *DI = getModuleDebugInfo())
7289       DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
7290     break;
7291   case Decl::CXXConstructor:
7292     getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
7293     break;
7294   case Decl::CXXDestructor:
7295     getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
7296     break;
7297 
7298   case Decl::StaticAssert:
7299     // Nothing to do.
7300     break;
7301 
7302   // Objective-C Decls
7303 
7304   // Forward declarations, no (immediate) code generation.
7305   case Decl::ObjCInterface:
7306   case Decl::ObjCCategory:
7307     break;
7308 
7309   case Decl::ObjCProtocol: {
7310     auto *Proto = cast<ObjCProtocolDecl>(D);
7311     if (Proto->isThisDeclarationADefinition())
7312       ObjCRuntime->GenerateProtocol(Proto);
7313     break;
7314   }
7315 
7316   case Decl::ObjCCategoryImpl:
7317     // Categories have properties but don't support synthesize so we
7318     // can ignore them here.
7319     ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
7320     break;
7321 
7322   case Decl::ObjCImplementation: {
7323     auto *OMD = cast<ObjCImplementationDecl>(D);
7324     EmitObjCPropertyImplementations(OMD);
7325     EmitObjCIvarInitializations(OMD);
7326     ObjCRuntime->GenerateClass(OMD);
7327     // Emit global variable debug information.
7328     if (CGDebugInfo *DI = getModuleDebugInfo())
7329       if (getCodeGenOpts().hasReducedDebugInfo())
7330         DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
7331             OMD->getClassInterface()), OMD->getLocation());
7332     break;
7333   }
7334   case Decl::ObjCMethod: {
7335     auto *OMD = cast<ObjCMethodDecl>(D);
7336     // If this is not a prototype, emit the body.
7337     if (OMD->getBody())
7338       CodeGenFunction(*this).GenerateObjCMethod(OMD);
7339     break;
7340   }
7341   case Decl::ObjCCompatibleAlias:
7342     ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
7343     break;
7344 
7345   case Decl::PragmaComment: {
7346     const auto *PCD = cast<PragmaCommentDecl>(D);
7347     switch (PCD->getCommentKind()) {
7348     case PCK_Unknown:
7349       llvm_unreachable("unexpected pragma comment kind");
7350     case PCK_Linker:
7351       AppendLinkerOptions(PCD->getArg());
7352       break;
7353     case PCK_Lib:
7354         AddDependentLib(PCD->getArg());
7355       break;
7356     case PCK_Compiler:
7357     case PCK_ExeStr:
7358     case PCK_User:
7359       break; // We ignore all of these.
7360     }
7361     break;
7362   }
7363 
7364   case Decl::PragmaDetectMismatch: {
7365     const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
7366     AddDetectMismatch(PDMD->getName(), PDMD->getValue());
7367     break;
7368   }
7369 
7370   case Decl::LinkageSpec:
7371     EmitLinkageSpec(cast<LinkageSpecDecl>(D));
7372     break;
7373 
7374   case Decl::FileScopeAsm: {
7375     // File-scope asm is ignored during device-side CUDA compilation.
7376     if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
7377       break;
7378     // File-scope asm is ignored during device-side OpenMP compilation.
7379     if (LangOpts.OpenMPIsTargetDevice)
7380       break;
7381     // File-scope asm is ignored during device-side SYCL compilation.
7382     if (LangOpts.SYCLIsDevice)
7383       break;
7384     auto *AD = cast<FileScopeAsmDecl>(D);
7385     getModule().appendModuleInlineAsm(AD->getAsmString());
7386     break;
7387   }
7388 
7389   case Decl::TopLevelStmt:
7390     EmitTopLevelStmt(cast<TopLevelStmtDecl>(D));
7391     break;
7392 
7393   case Decl::Import: {
7394     auto *Import = cast<ImportDecl>(D);
7395 
7396     // If we've already imported this module, we're done.
7397     if (!ImportedModules.insert(Import->getImportedModule()))
7398       break;
7399 
7400     // Emit debug information for direct imports.
7401     if (!Import->getImportedOwningModule()) {
7402       if (CGDebugInfo *DI = getModuleDebugInfo())
7403         DI->EmitImportDecl(*Import);
7404     }
7405 
7406     // For C++ standard modules we are done - we will call the module
7407     // initializer for imported modules, and that will likewise call those for
7408     // any imports it has.
7409     if (CXX20ModuleInits && Import->getImportedModule() &&
7410         Import->getImportedModule()->isNamedModule())
7411       break;
7412 
7413     // For clang C++ module map modules the initializers for sub-modules are
7414     // emitted here.
7415 
7416     // Find all of the submodules and emit the module initializers.
7417     llvm::SmallPtrSet<clang::Module *, 16> Visited;
7418     SmallVector<clang::Module *, 16> Stack;
7419     Visited.insert(Import->getImportedModule());
7420     Stack.push_back(Import->getImportedModule());
7421 
7422     while (!Stack.empty()) {
7423       clang::Module *Mod = Stack.pop_back_val();
7424       if (!EmittedModuleInitializers.insert(Mod).second)
7425         continue;
7426 
7427       for (auto *D : Context.getModuleInitializers(Mod))
7428         EmitTopLevelDecl(D);
7429 
7430       // Visit the submodules of this module.
7431       for (auto *Submodule : Mod->submodules()) {
7432         // Skip explicit children; they need to be explicitly imported to emit
7433         // the initializers.
7434         if (Submodule->IsExplicit)
7435           continue;
7436 
7437         if (Visited.insert(Submodule).second)
7438           Stack.push_back(Submodule);
7439       }
7440     }
7441     break;
7442   }
7443 
7444   case Decl::Export:
7445     EmitDeclContext(cast<ExportDecl>(D));
7446     break;
7447 
7448   case Decl::OMPThreadPrivate:
7449     EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
7450     break;
7451 
7452   case Decl::OMPAllocate:
7453     EmitOMPAllocateDecl(cast<OMPAllocateDecl>(D));
7454     break;
7455 
7456   case Decl::OMPDeclareReduction:
7457     EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
7458     break;
7459 
7460   case Decl::OMPDeclareMapper:
7461     EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D));
7462     break;
7463 
7464   case Decl::OMPRequires:
7465     EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
7466     break;
7467 
7468   case Decl::Typedef:
7469   case Decl::TypeAlias: // using foo = bar; [C++11]
7470     if (CGDebugInfo *DI = getModuleDebugInfo())
7471       DI->EmitAndRetainType(
7472           getContext().getTypedefType(cast<TypedefNameDecl>(D)));
7473     break;
7474 
7475   case Decl::Record:
7476     if (CGDebugInfo *DI = getModuleDebugInfo())
7477       if (cast<RecordDecl>(D)->getDefinition())
7478         DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
7479     break;
7480 
7481   case Decl::Enum:
7482     if (CGDebugInfo *DI = getModuleDebugInfo())
7483       if (cast<EnumDecl>(D)->getDefinition())
7484         DI->EmitAndRetainType(getContext().getEnumType(cast<EnumDecl>(D)));
7485     break;
7486 
7487   case Decl::HLSLBuffer:
7488     getHLSLRuntime().addBuffer(cast<HLSLBufferDecl>(D));
7489     break;
7490 
7491   case Decl::OpenACCDeclare:
7492     EmitOpenACCDeclare(cast<OpenACCDeclareDecl>(D));
7493     break;
7494   case Decl::OpenACCRoutine:
7495     EmitOpenACCRoutine(cast<OpenACCRoutineDecl>(D));
7496     break;
7497 
7498   default:
7499     // Make sure we handled everything we should, every other kind is a
7500     // non-top-level decl.  FIXME: Would be nice to have an isTopLevelDeclKind
7501     // function. Need to recode Decl::Kind to do that easily.
7502     assert(isa<TypeDecl>(D) && "Unsupported decl kind");
7503     break;
7504   }
7505 }
7506 
7507 void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
7508   // Do we need to generate coverage mapping?
7509   if (!CodeGenOpts.CoverageMapping)
7510     return;
7511   switch (D->getKind()) {
7512   case Decl::CXXConversion:
7513   case Decl::CXXMethod:
7514   case Decl::Function:
7515   case Decl::ObjCMethod:
7516   case Decl::CXXConstructor:
7517   case Decl::CXXDestructor: {
7518     if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
7519       break;
7520     SourceManager &SM = getContext().getSourceManager();
7521     if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
7522       break;
7523     if (!llvm::coverage::SystemHeadersCoverage &&
7524         SM.isInSystemHeader(D->getBeginLoc()))
7525       break;
7526     DeferredEmptyCoverageMappingDecls.try_emplace(D, true);
7527     break;
7528   }
7529   default:
7530     break;
7531   };
7532 }
7533 
7534 void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
7535   // Do we need to generate coverage mapping?
7536   if (!CodeGenOpts.CoverageMapping)
7537     return;
7538   if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
7539     if (Fn->isTemplateInstantiation())
7540       ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
7541   }
7542   DeferredEmptyCoverageMappingDecls.insert_or_assign(D, false);
7543 }
7544 
7545 void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
7546   // We call takeVector() here to avoid use-after-free.
7547   // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
7548   // we deserialize function bodies to emit coverage info for them, and that
7549   // deserializes more declarations. How should we handle that case?
7550   for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
7551     if (!Entry.second)
7552       continue;
7553     const Decl *D = Entry.first;
7554     switch (D->getKind()) {
7555     case Decl::CXXConversion:
7556     case Decl::CXXMethod:
7557     case Decl::Function:
7558     case Decl::ObjCMethod: {
7559       CodeGenPGO PGO(*this);
7560       GlobalDecl GD(cast<FunctionDecl>(D));
7561       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7562                                   getFunctionLinkage(GD));
7563       break;
7564     }
7565     case Decl::CXXConstructor: {
7566       CodeGenPGO PGO(*this);
7567       GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
7568       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7569                                   getFunctionLinkage(GD));
7570       break;
7571     }
7572     case Decl::CXXDestructor: {
7573       CodeGenPGO PGO(*this);
7574       GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
7575       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7576                                   getFunctionLinkage(GD));
7577       break;
7578     }
7579     default:
7580       break;
7581     };
7582   }
7583 }
7584 
7585 void CodeGenModule::EmitMainVoidAlias() {
7586   // In order to transition away from "__original_main" gracefully, emit an
7587   // alias for "main" in the no-argument case so that libc can detect when
7588   // new-style no-argument main is in used.
7589   if (llvm::Function *F = getModule().getFunction("main")) {
7590     if (!F->isDeclaration() && F->arg_size() == 0 && !F->isVarArg() &&
7591         F->getReturnType()->isIntegerTy(Context.getTargetInfo().getIntWidth())) {
7592       auto *GA = llvm::GlobalAlias::create("__main_void", F);
7593       GA->setVisibility(llvm::GlobalValue::HiddenVisibility);
7594     }
7595   }
7596 }
7597 
7598 /// Turns the given pointer into a constant.
7599 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
7600                                           const void *Ptr) {
7601   uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
7602   llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
7603   return llvm::ConstantInt::get(i64, PtrInt);
7604 }
7605 
7606 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
7607                                    llvm::NamedMDNode *&GlobalMetadata,
7608                                    GlobalDecl D,
7609                                    llvm::GlobalValue *Addr) {
7610   if (!GlobalMetadata)
7611     GlobalMetadata =
7612       CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
7613 
7614   // TODO: should we report variant information for ctors/dtors?
7615   llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
7616                            llvm::ConstantAsMetadata::get(GetPointerConstant(
7617                                CGM.getLLVMContext(), D.getDecl()))};
7618   GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
7619 }
7620 
7621 bool CodeGenModule::CheckAndReplaceExternCIFuncs(llvm::GlobalValue *Elem,
7622                                                  llvm::GlobalValue *CppFunc) {
7623   // Store the list of ifuncs we need to replace uses in.
7624   llvm::SmallVector<llvm::GlobalIFunc *> IFuncs;
7625   // List of ConstantExprs that we should be able to delete when we're done
7626   // here.
7627   llvm::SmallVector<llvm::ConstantExpr *> CEs;
7628 
7629   // It isn't valid to replace the extern-C ifuncs if all we find is itself!
7630   if (Elem == CppFunc)
7631     return false;
7632 
7633   // First make sure that all users of this are ifuncs (or ifuncs via a
7634   // bitcast), and collect the list of ifuncs and CEs so we can work on them
7635   // later.
7636   for (llvm::User *User : Elem->users()) {
7637     // Users can either be a bitcast ConstExpr that is used by the ifuncs, OR an
7638     // ifunc directly. In any other case, just give up, as we don't know what we
7639     // could break by changing those.
7640     if (auto *ConstExpr = dyn_cast<llvm::ConstantExpr>(User)) {
7641       if (ConstExpr->getOpcode() != llvm::Instruction::BitCast)
7642         return false;
7643 
7644       for (llvm::User *CEUser : ConstExpr->users()) {
7645         if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(CEUser)) {
7646           IFuncs.push_back(IFunc);
7647         } else {
7648           return false;
7649         }
7650       }
7651       CEs.push_back(ConstExpr);
7652     } else if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(User)) {
7653       IFuncs.push_back(IFunc);
7654     } else {
7655       // This user is one we don't know how to handle, so fail redirection. This
7656       // will result in an ifunc retaining a resolver name that will ultimately
7657       // fail to be resolved to a defined function.
7658       return false;
7659     }
7660   }
7661 
7662   // Now we know this is a valid case where we can do this alias replacement, we
7663   // need to remove all of the references to Elem (and the bitcasts!) so we can
7664   // delete it.
7665   for (llvm::GlobalIFunc *IFunc : IFuncs)
7666     IFunc->setResolver(nullptr);
7667   for (llvm::ConstantExpr *ConstExpr : CEs)
7668     ConstExpr->destroyConstant();
7669 
7670   // We should now be out of uses for the 'old' version of this function, so we
7671   // can erase it as well.
7672   Elem->eraseFromParent();
7673 
7674   for (llvm::GlobalIFunc *IFunc : IFuncs) {
7675     // The type of the resolver is always just a function-type that returns the
7676     // type of the IFunc, so create that here. If the type of the actual
7677     // resolver doesn't match, it just gets bitcast to the right thing.
7678     auto *ResolverTy =
7679         llvm::FunctionType::get(IFunc->getType(), /*isVarArg*/ false);
7680     llvm::Constant *Resolver = GetOrCreateLLVMFunction(
7681         CppFunc->getName(), ResolverTy, {}, /*ForVTable*/ false);
7682     IFunc->setResolver(Resolver);
7683   }
7684   return true;
7685 }
7686 
7687 /// For each function which is declared within an extern "C" region and marked
7688 /// as 'used', but has internal linkage, create an alias from the unmangled
7689 /// name to the mangled name if possible. People expect to be able to refer
7690 /// to such functions with an unmangled name from inline assembly within the
7691 /// same translation unit.
7692 void CodeGenModule::EmitStaticExternCAliases() {
7693   if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
7694     return;
7695   for (auto &I : StaticExternCValues) {
7696     const IdentifierInfo *Name = I.first;
7697     llvm::GlobalValue *Val = I.second;
7698 
7699     // If Val is null, that implies there were multiple declarations that each
7700     // had a claim to the unmangled name. In this case, generation of the alias
7701     // is suppressed. See CodeGenModule::MaybeHandleStaticInExternC.
7702     if (!Val)
7703       break;
7704 
7705     llvm::GlobalValue *ExistingElem =
7706         getModule().getNamedValue(Name->getName());
7707 
7708     // If there is either not something already by this name, or we were able to
7709     // replace all uses from IFuncs, create the alias.
7710     if (!ExistingElem || CheckAndReplaceExternCIFuncs(ExistingElem, Val))
7711       addCompilerUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
7712   }
7713 }
7714 
7715 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
7716                                              GlobalDecl &Result) const {
7717   auto Res = Manglings.find(MangledName);
7718   if (Res == Manglings.end())
7719     return false;
7720   Result = Res->getValue();
7721   return true;
7722 }
7723 
7724 /// Emits metadata nodes associating all the global values in the
7725 /// current module with the Decls they came from.  This is useful for
7726 /// projects using IR gen as a subroutine.
7727 ///
7728 /// Since there's currently no way to associate an MDNode directly
7729 /// with an llvm::GlobalValue, we create a global named metadata
7730 /// with the name 'clang.global.decl.ptrs'.
7731 void CodeGenModule::EmitDeclMetadata() {
7732   llvm::NamedMDNode *GlobalMetadata = nullptr;
7733 
7734   for (auto &I : MangledDeclNames) {
7735     llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
7736     // Some mangled names don't necessarily have an associated GlobalValue
7737     // in this module, e.g. if we mangled it for DebugInfo.
7738     if (Addr)
7739       EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
7740   }
7741 }
7742 
7743 /// Emits metadata nodes for all the local variables in the current
7744 /// function.
7745 void CodeGenFunction::EmitDeclMetadata() {
7746   if (LocalDeclMap.empty()) return;
7747 
7748   llvm::LLVMContext &Context = getLLVMContext();
7749 
7750   // Find the unique metadata ID for this name.
7751   unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
7752 
7753   llvm::NamedMDNode *GlobalMetadata = nullptr;
7754 
7755   for (auto &I : LocalDeclMap) {
7756     const Decl *D = I.first;
7757     llvm::Value *Addr = I.second.emitRawPointer(*this);
7758     if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
7759       llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
7760       Alloca->setMetadata(
7761           DeclPtrKind, llvm::MDNode::get(
7762                            Context, llvm::ValueAsMetadata::getConstant(DAddr)));
7763     } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
7764       GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
7765       EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
7766     }
7767   }
7768 }
7769 
7770 void CodeGenModule::EmitVersionIdentMetadata() {
7771   llvm::NamedMDNode *IdentMetadata =
7772     TheModule.getOrInsertNamedMetadata("llvm.ident");
7773   std::string Version = getClangFullVersion();
7774   llvm::LLVMContext &Ctx = TheModule.getContext();
7775 
7776   llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
7777   IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
7778 }
7779 
7780 void CodeGenModule::EmitCommandLineMetadata() {
7781   llvm::NamedMDNode *CommandLineMetadata =
7782     TheModule.getOrInsertNamedMetadata("llvm.commandline");
7783   std::string CommandLine = getCodeGenOpts().RecordCommandLine;
7784   llvm::LLVMContext &Ctx = TheModule.getContext();
7785 
7786   llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
7787   CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
7788 }
7789 
7790 void CodeGenModule::EmitCoverageFile() {
7791   llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
7792   if (!CUNode)
7793     return;
7794 
7795   llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
7796   llvm::LLVMContext &Ctx = TheModule.getContext();
7797   auto *CoverageDataFile =
7798       llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
7799   auto *CoverageNotesFile =
7800       llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
7801   for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
7802     llvm::MDNode *CU = CUNode->getOperand(i);
7803     llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
7804     GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
7805   }
7806 }
7807 
7808 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
7809                                                        bool ForEH) {
7810   // Return a bogus pointer if RTTI is disabled, unless it's for EH.
7811   // FIXME: should we even be calling this method if RTTI is disabled
7812   // and it's not for EH?
7813   if (!shouldEmitRTTI(ForEH))
7814     return llvm::Constant::getNullValue(GlobalsInt8PtrTy);
7815 
7816   if (ForEH && Ty->isObjCObjectPointerType() &&
7817       LangOpts.ObjCRuntime.isGNUFamily())
7818     return ObjCRuntime->GetEHType(Ty);
7819 
7820   return getCXXABI().getAddrOfRTTIDescriptor(Ty);
7821 }
7822 
7823 void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
7824   // Do not emit threadprivates in simd-only mode.
7825   if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
7826     return;
7827   for (auto RefExpr : D->varlist()) {
7828     auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
7829     bool PerformInit =
7830         VD->getAnyInitializer() &&
7831         !VD->getAnyInitializer()->isConstantInitializer(getContext(),
7832                                                         /*ForRef=*/false);
7833 
7834     Address Addr(GetAddrOfGlobalVar(VD),
7835                  getTypes().ConvertTypeForMem(VD->getType()),
7836                  getContext().getDeclAlign(VD));
7837     if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
7838             VD, Addr, RefExpr->getBeginLoc(), PerformInit))
7839       CXXGlobalInits.push_back(InitFunction);
7840   }
7841 }
7842 
7843 llvm::Metadata *
7844 CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
7845                                             StringRef Suffix) {
7846   if (auto *FnType = T->getAs<FunctionProtoType>())
7847     T = getContext().getFunctionType(
7848         FnType->getReturnType(), FnType->getParamTypes(),
7849         FnType->getExtProtoInfo().withExceptionSpec(EST_None));
7850 
7851   llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
7852   if (InternalId)
7853     return InternalId;
7854 
7855   if (isExternallyVisible(T->getLinkage())) {
7856     std::string OutName;
7857     llvm::raw_string_ostream Out(OutName);
7858     getCXXABI().getMangleContext().mangleCanonicalTypeName(
7859         T, Out, getCodeGenOpts().SanitizeCfiICallNormalizeIntegers);
7860 
7861     if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
7862       Out << ".normalized";
7863 
7864     Out << Suffix;
7865 
7866     InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
7867   } else {
7868     InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
7869                                            llvm::ArrayRef<llvm::Metadata *>());
7870   }
7871 
7872   return InternalId;
7873 }
7874 
7875 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
7876   return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
7877 }
7878 
7879 llvm::Metadata *
7880 CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
7881   return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
7882 }
7883 
7884 // Generalize pointer types to a void pointer with the qualifiers of the
7885 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
7886 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
7887 // 'void *'.
7888 static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
7889   if (!Ty->isPointerType())
7890     return Ty;
7891 
7892   return Ctx.getPointerType(
7893       QualType(Ctx.VoidTy).withCVRQualifiers(
7894           Ty->getPointeeType().getCVRQualifiers()));
7895 }
7896 
7897 // Apply type generalization to a FunctionType's return and argument types
7898 static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
7899   if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
7900     SmallVector<QualType, 8> GeneralizedParams;
7901     for (auto &Param : FnType->param_types())
7902       GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
7903 
7904     return Ctx.getFunctionType(
7905         GeneralizeType(Ctx, FnType->getReturnType()),
7906         GeneralizedParams, FnType->getExtProtoInfo());
7907   }
7908 
7909   if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
7910     return Ctx.getFunctionNoProtoType(
7911         GeneralizeType(Ctx, FnType->getReturnType()));
7912 
7913   llvm_unreachable("Encountered unknown FunctionType");
7914 }
7915 
7916 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
7917   return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
7918                                       GeneralizedMetadataIdMap, ".generalized");
7919 }
7920 
7921 /// Returns whether this module needs the "all-vtables" type identifier.
7922 bool CodeGenModule::NeedAllVtablesTypeId() const {
7923   // Returns true if at least one of vtable-based CFI checkers is enabled and
7924   // is not in the trapping mode.
7925   return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
7926            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
7927           (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
7928            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
7929           (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
7930            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
7931           (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
7932            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
7933 }
7934 
7935 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
7936                                           CharUnits Offset,
7937                                           const CXXRecordDecl *RD) {
7938   llvm::Metadata *MD =
7939       CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
7940   VTable->addTypeMetadata(Offset.getQuantity(), MD);
7941 
7942   if (CodeGenOpts.SanitizeCfiCrossDso)
7943     if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
7944       VTable->addTypeMetadata(Offset.getQuantity(),
7945                               llvm::ConstantAsMetadata::get(CrossDsoTypeId));
7946 
7947   if (NeedAllVtablesTypeId()) {
7948     llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
7949     VTable->addTypeMetadata(Offset.getQuantity(), MD);
7950   }
7951 }
7952 
7953 llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
7954   if (!SanStats)
7955     SanStats = std::make_unique<llvm::SanitizerStatReport>(&getModule());
7956 
7957   return *SanStats;
7958 }
7959 
7960 llvm::Value *
7961 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
7962                                                   CodeGenFunction &CGF) {
7963   llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
7964   auto *SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
7965   auto *FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
7966   auto *Call = CGF.EmitRuntimeCall(
7967       CreateRuntimeFunction(FTy, "__translate_sampler_initializer"), {C});
7968   return Call;
7969 }
7970 
7971 CharUnits CodeGenModule::getNaturalPointeeTypeAlignment(
7972     QualType T, LValueBaseInfo *BaseInfo, TBAAAccessInfo *TBAAInfo) {
7973   return getNaturalTypeAlignment(T->getPointeeType(), BaseInfo, TBAAInfo,
7974                                  /* forPointeeType= */ true);
7975 }
7976 
7977 CharUnits CodeGenModule::getNaturalTypeAlignment(QualType T,
7978                                                  LValueBaseInfo *BaseInfo,
7979                                                  TBAAAccessInfo *TBAAInfo,
7980                                                  bool forPointeeType) {
7981   if (TBAAInfo)
7982     *TBAAInfo = getTBAAAccessInfo(T);
7983 
7984   // FIXME: This duplicates logic in ASTContext::getTypeAlignIfKnown. But
7985   // that doesn't return the information we need to compute BaseInfo.
7986 
7987   // Honor alignment typedef attributes even on incomplete types.
7988   // We also honor them straight for C++ class types, even as pointees;
7989   // there's an expressivity gap here.
7990   if (auto TT = T->getAs<TypedefType>()) {
7991     if (auto Align = TT->getDecl()->getMaxAlignment()) {
7992       if (BaseInfo)
7993         *BaseInfo = LValueBaseInfo(AlignmentSource::AttributedType);
7994       return getContext().toCharUnitsFromBits(Align);
7995     }
7996   }
7997 
7998   bool AlignForArray = T->isArrayType();
7999 
8000   // Analyze the base element type, so we don't get confused by incomplete
8001   // array types.
8002   T = getContext().getBaseElementType(T);
8003 
8004   if (T->isIncompleteType()) {
8005     // We could try to replicate the logic from
8006     // ASTContext::getTypeAlignIfKnown, but nothing uses the alignment if the
8007     // type is incomplete, so it's impossible to test. We could try to reuse
8008     // getTypeAlignIfKnown, but that doesn't return the information we need
8009     // to set BaseInfo.  So just ignore the possibility that the alignment is
8010     // greater than one.
8011     if (BaseInfo)
8012       *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
8013     return CharUnits::One();
8014   }
8015 
8016   if (BaseInfo)
8017     *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
8018 
8019   CharUnits Alignment;
8020   const CXXRecordDecl *RD;
8021   if (T.getQualifiers().hasUnaligned()) {
8022     Alignment = CharUnits::One();
8023   } else if (forPointeeType && !AlignForArray &&
8024              (RD = T->getAsCXXRecordDecl())) {
8025     // For C++ class pointees, we don't know whether we're pointing at a
8026     // base or a complete object, so we generally need to use the
8027     // non-virtual alignment.
8028     Alignment = getClassPointerAlignment(RD);
8029   } else {
8030     Alignment = getContext().getTypeAlignInChars(T);
8031   }
8032 
8033   // Cap to the global maximum type alignment unless the alignment
8034   // was somehow explicit on the type.
8035   if (unsigned MaxAlign = getLangOpts().MaxTypeAlign) {
8036     if (Alignment.getQuantity() > MaxAlign &&
8037         !getContext().isAlignmentRequired(T))
8038       Alignment = CharUnits::fromQuantity(MaxAlign);
8039   }
8040   return Alignment;
8041 }
8042 
8043 bool CodeGenModule::stopAutoInit() {
8044   unsigned StopAfter = getContext().getLangOpts().TrivialAutoVarInitStopAfter;
8045   if (StopAfter) {
8046     // This number is positive only when -ftrivial-auto-var-init-stop-after=* is
8047     // used
8048     if (NumAutoVarInit >= StopAfter) {
8049       return true;
8050     }
8051     if (!NumAutoVarInit) {
8052       unsigned DiagID = getDiags().getCustomDiagID(
8053           DiagnosticsEngine::Warning,
8054           "-ftrivial-auto-var-init-stop-after=%0 has been enabled to limit the "
8055           "number of times ftrivial-auto-var-init=%1 gets applied.");
8056       getDiags().Report(DiagID)
8057           << StopAfter
8058           << (getContext().getLangOpts().getTrivialAutoVarInit() ==
8059                       LangOptions::TrivialAutoVarInitKind::Zero
8060                   ? "zero"
8061                   : "pattern");
8062     }
8063     ++NumAutoVarInit;
8064   }
8065   return false;
8066 }
8067 
8068 void CodeGenModule::printPostfixForExternalizedDecl(llvm::raw_ostream &OS,
8069                                                     const Decl *D) const {
8070   // ptxas does not allow '.' in symbol names. On the other hand, HIP prefers
8071   // postfix beginning with '.' since the symbol name can be demangled.
8072   if (LangOpts.HIP)
8073     OS << (isa<VarDecl>(D) ? ".static." : ".intern.");
8074   else
8075     OS << (isa<VarDecl>(D) ? "__static__" : "__intern__");
8076 
8077   // If the CUID is not specified we try to generate a unique postfix.
8078   if (getLangOpts().CUID.empty()) {
8079     SourceManager &SM = getContext().getSourceManager();
8080     PresumedLoc PLoc = SM.getPresumedLoc(D->getLocation());
8081     assert(PLoc.isValid() && "Source location is expected to be valid.");
8082 
8083     // Get the hash of the user defined macros.
8084     llvm::MD5 Hash;
8085     llvm::MD5::MD5Result Result;
8086     for (const auto &Arg : PreprocessorOpts.Macros)
8087       Hash.update(Arg.first);
8088     Hash.final(Result);
8089 
8090     // Get the UniqueID for the file containing the decl.
8091     llvm::sys::fs::UniqueID ID;
8092     if (llvm::sys::fs::getUniqueID(PLoc.getFilename(), ID)) {
8093       PLoc = SM.getPresumedLoc(D->getLocation(), /*UseLineDirectives=*/false);
8094       assert(PLoc.isValid() && "Source location is expected to be valid.");
8095       if (auto EC = llvm::sys::fs::getUniqueID(PLoc.getFilename(), ID))
8096         SM.getDiagnostics().Report(diag::err_cannot_open_file)
8097             << PLoc.getFilename() << EC.message();
8098     }
8099     OS << llvm::format("%x", ID.getFile()) << llvm::format("%x", ID.getDevice())
8100        << "_" << llvm::utohexstr(Result.low(), /*LowerCase=*/true, /*Width=*/8);
8101   } else {
8102     OS << getContext().getCUIDHash();
8103   }
8104 }
8105 
8106 void CodeGenModule::moveLazyEmissionStates(CodeGenModule *NewBuilder) {
8107   assert(DeferredDeclsToEmit.empty() &&
8108          "Should have emitted all decls deferred to emit.");
8109   assert(NewBuilder->DeferredDecls.empty() &&
8110          "Newly created module should not have deferred decls");
8111   NewBuilder->DeferredDecls = std::move(DeferredDecls);
8112   assert(EmittedDeferredDecls.empty() &&
8113          "Still have (unmerged) EmittedDeferredDecls deferred decls");
8114 
8115   assert(NewBuilder->DeferredVTables.empty() &&
8116          "Newly created module should not have deferred vtables");
8117   NewBuilder->DeferredVTables = std::move(DeferredVTables);
8118 
8119   assert(NewBuilder->MangledDeclNames.empty() &&
8120          "Newly created module should not have mangled decl names");
8121   assert(NewBuilder->Manglings.empty() &&
8122          "Newly created module should not have manglings");
8123   NewBuilder->Manglings = std::move(Manglings);
8124 
8125   NewBuilder->WeakRefReferences = std::move(WeakRefReferences);
8126 
8127   NewBuilder->ABI->MangleCtx = std::move(ABI->MangleCtx);
8128 }
8129