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/DeclCXX.h"
34 #include "clang/AST/DeclObjC.h"
35 #include "clang/AST/DeclTemplate.h"
36 #include "clang/AST/Mangle.h"
37 #include "clang/AST/RecursiveASTVisitor.h"
38 #include "clang/AST/StmtVisitor.h"
39 #include "clang/Basic/Builtins.h"
40 #include "clang/Basic/CharInfo.h"
41 #include "clang/Basic/CodeGenOptions.h"
42 #include "clang/Basic/Diagnostic.h"
43 #include "clang/Basic/FileManager.h"
44 #include "clang/Basic/Module.h"
45 #include "clang/Basic/SourceManager.h"
46 #include "clang/Basic/TargetInfo.h"
47 #include "clang/Basic/Version.h"
48 #include "clang/CodeGen/BackendUtil.h"
49 #include "clang/CodeGen/ConstantInitBuilder.h"
50 #include "clang/Frontend/FrontendDiagnostic.h"
51 #include "llvm/ADT/STLExtras.h"
52 #include "llvm/ADT/StringExtras.h"
53 #include "llvm/ADT/StringSwitch.h"
54 #include "llvm/Analysis/TargetLibraryInfo.h"
55 #include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
56 #include "llvm/IR/AttributeMask.h"
57 #include "llvm/IR/CallingConv.h"
58 #include "llvm/IR/DataLayout.h"
59 #include "llvm/IR/Intrinsics.h"
60 #include "llvm/IR/LLVMContext.h"
61 #include "llvm/IR/Module.h"
62 #include "llvm/IR/ProfileSummary.h"
63 #include "llvm/ProfileData/InstrProfReader.h"
64 #include "llvm/ProfileData/SampleProf.h"
65 #include "llvm/Support/CRC.h"
66 #include "llvm/Support/CodeGen.h"
67 #include "llvm/Support/CommandLine.h"
68 #include "llvm/Support/ConvertUTF.h"
69 #include "llvm/Support/ErrorHandling.h"
70 #include "llvm/Support/TimeProfiler.h"
71 #include "llvm/Support/xxhash.h"
72 #include "llvm/TargetParser/Triple.h"
73 #include "llvm/TargetParser/X86TargetParser.h"
74 #include <optional>
75 
76 using namespace clang;
77 using namespace CodeGen;
78 
79 static llvm::cl::opt<bool> LimitedCoverage(
80     "limited-coverage-experimental", llvm::cl::Hidden,
81     llvm::cl::desc("Emit limited coverage mapping information (experimental)"));
82 
83 static const char AnnotationSection[] = "llvm.metadata";
84 
createCXXABI(CodeGenModule & CGM)85 static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
86   switch (CGM.getContext().getCXXABIKind()) {
87   case TargetCXXABI::AppleARM64:
88   case TargetCXXABI::Fuchsia:
89   case TargetCXXABI::GenericAArch64:
90   case TargetCXXABI::GenericARM:
91   case TargetCXXABI::iOS:
92   case TargetCXXABI::WatchOS:
93   case TargetCXXABI::GenericMIPS:
94   case TargetCXXABI::GenericItanium:
95   case TargetCXXABI::WebAssembly:
96   case TargetCXXABI::XL:
97     return CreateItaniumCXXABI(CGM);
98   case TargetCXXABI::Microsoft:
99     return CreateMicrosoftCXXABI(CGM);
100   }
101 
102   llvm_unreachable("invalid C++ ABI kind");
103 }
104 
105 static std::unique_ptr<TargetCodeGenInfo>
createTargetCodeGenInfo(CodeGenModule & CGM)106 createTargetCodeGenInfo(CodeGenModule &CGM) {
107   const TargetInfo &Target = CGM.getTarget();
108   const llvm::Triple &Triple = Target.getTriple();
109   const CodeGenOptions &CodeGenOpts = CGM.getCodeGenOpts();
110 
111   switch (Triple.getArch()) {
112   default:
113     return createDefaultTargetCodeGenInfo(CGM);
114 
115   case llvm::Triple::le32:
116     return createPNaClTargetCodeGenInfo(CGM);
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     return createMIPSTargetCodeGenInfo(CGM, /*IsOS32=*/true);
124 
125   case llvm::Triple::mips64:
126   case llvm::Triple::mips64el:
127     return createMIPSTargetCodeGenInfo(CGM, /*IsOS32=*/false);
128 
129   case llvm::Triple::avr: {
130     // For passing parameters, R8~R25 are used on avr, and R18~R25 are used
131     // on avrtiny. For passing return value, R18~R25 are used on avr, and
132     // R22~R25 are used on avrtiny.
133     unsigned NPR = Target.getABI() == "avrtiny" ? 6 : 18;
134     unsigned NRR = Target.getABI() == "avrtiny" ? 4 : 8;
135     return createAVRTargetCodeGenInfo(CGM, NPR, NRR);
136   }
137 
138   case llvm::Triple::aarch64:
139   case llvm::Triple::aarch64_32:
140   case llvm::Triple::aarch64_be: {
141     AArch64ABIKind Kind = AArch64ABIKind::AAPCS;
142     if (Target.getABI() == "darwinpcs")
143       Kind = AArch64ABIKind::DarwinPCS;
144     else if (Triple.isOSWindows())
145       return createWindowsAArch64TargetCodeGenInfo(CGM, AArch64ABIKind::Win64);
146 
147     return createAArch64TargetCodeGenInfo(CGM, Kind);
148   }
149 
150   case llvm::Triple::wasm32:
151   case llvm::Triple::wasm64: {
152     WebAssemblyABIKind Kind = WebAssemblyABIKind::MVP;
153     if (Target.getABI() == "experimental-mv")
154       Kind = WebAssemblyABIKind::ExperimentalMV;
155     return createWebAssemblyTargetCodeGenInfo(CGM, Kind);
156   }
157 
158   case llvm::Triple::arm:
159   case llvm::Triple::armeb:
160   case llvm::Triple::thumb:
161   case llvm::Triple::thumbeb: {
162     if (Triple.getOS() == llvm::Triple::Win32)
163       return createWindowsARMTargetCodeGenInfo(CGM, ARMABIKind::AAPCS_VFP);
164 
165     ARMABIKind Kind = ARMABIKind::AAPCS;
166     StringRef ABIStr = Target.getABI();
167     if (ABIStr == "apcs-gnu")
168       Kind = ARMABIKind::APCS;
169     else if (ABIStr == "aapcs16")
170       Kind = ARMABIKind::AAPCS16_VFP;
171     else if (CodeGenOpts.FloatABI == "hard" ||
172              (CodeGenOpts.FloatABI != "soft" &&
173               (Triple.getEnvironment() == llvm::Triple::GNUEABIHF ||
174                Triple.getEnvironment() == llvm::Triple::MuslEABIHF ||
175                Triple.getEnvironment() == llvm::Triple::EABIHF)))
176       Kind = ARMABIKind::AAPCS_VFP;
177 
178     return createARMTargetCodeGenInfo(CGM, Kind);
179   }
180 
181   case llvm::Triple::ppc: {
182     if (Triple.isOSAIX())
183       return createAIXTargetCodeGenInfo(CGM, /*Is64Bit=*/false);
184 
185     bool IsSoftFloat =
186         CodeGenOpts.FloatABI == "soft" || Target.hasFeature("spe");
187     return createPPC32TargetCodeGenInfo(CGM, IsSoftFloat);
188   }
189   case llvm::Triple::ppcle: {
190     bool IsSoftFloat = CodeGenOpts.FloatABI == "soft";
191     return createPPC32TargetCodeGenInfo(CGM, IsSoftFloat);
192   }
193   case llvm::Triple::ppc64:
194     if (Triple.isOSAIX())
195       return createAIXTargetCodeGenInfo(CGM, /*Is64Bit=*/true);
196 
197     if (Triple.isOSBinFormatELF()) {
198       PPC64_SVR4_ABIKind Kind = PPC64_SVR4_ABIKind::ELFv1;
199       if (Target.getABI() == "elfv2")
200         Kind = PPC64_SVR4_ABIKind::ELFv2;
201       bool IsSoftFloat = CodeGenOpts.FloatABI == "soft";
202 
203       return createPPC64_SVR4_TargetCodeGenInfo(CGM, Kind, IsSoftFloat);
204     }
205     return createPPC64TargetCodeGenInfo(CGM);
206   case llvm::Triple::ppc64le: {
207     assert(Triple.isOSBinFormatELF() && "PPC64 LE non-ELF not supported!");
208     PPC64_SVR4_ABIKind Kind = PPC64_SVR4_ABIKind::ELFv2;
209     if (Target.getABI() == "elfv1")
210       Kind = PPC64_SVR4_ABIKind::ELFv1;
211     bool IsSoftFloat = CodeGenOpts.FloatABI == "soft";
212 
213     return createPPC64_SVR4_TargetCodeGenInfo(CGM, Kind, IsSoftFloat);
214   }
215 
216   case llvm::Triple::nvptx:
217   case llvm::Triple::nvptx64:
218     return createNVPTXTargetCodeGenInfo(CGM);
219 
220   case llvm::Triple::msp430:
221     return createMSP430TargetCodeGenInfo(CGM);
222 
223   case llvm::Triple::riscv32:
224   case llvm::Triple::riscv64: {
225     StringRef ABIStr = Target.getABI();
226     unsigned XLen = Target.getPointerWidth(LangAS::Default);
227     unsigned ABIFLen = 0;
228     if (ABIStr.ends_with("f"))
229       ABIFLen = 32;
230     else if (ABIStr.ends_with("d"))
231       ABIFLen = 64;
232     bool EABI = ABIStr.ends_with("e");
233     return createRISCVTargetCodeGenInfo(CGM, XLen, ABIFLen, EABI);
234   }
235 
236   case llvm::Triple::systemz: {
237     bool SoftFloat = CodeGenOpts.FloatABI == "soft";
238     bool HasVector = !SoftFloat && Target.getABI() == "vector";
239     return createSystemZTargetCodeGenInfo(CGM, HasVector, SoftFloat);
240   }
241 
242   case llvm::Triple::tce:
243   case llvm::Triple::tcele:
244     return createTCETargetCodeGenInfo(CGM);
245 
246   case llvm::Triple::x86: {
247     bool IsDarwinVectorABI = Triple.isOSDarwin();
248     bool IsWin32FloatStructABI = Triple.isOSWindows() && !Triple.isOSCygMing();
249 
250     if (Triple.getOS() == llvm::Triple::Win32) {
251       return createWinX86_32TargetCodeGenInfo(
252           CGM, IsDarwinVectorABI, IsWin32FloatStructABI,
253           CodeGenOpts.NumRegisterParameters);
254     }
255     return createX86_32TargetCodeGenInfo(
256         CGM, IsDarwinVectorABI, IsWin32FloatStructABI,
257         CodeGenOpts.NumRegisterParameters, CodeGenOpts.FloatABI == "soft");
258   }
259 
260   case llvm::Triple::x86_64: {
261     StringRef ABI = Target.getABI();
262     X86AVXABILevel AVXLevel = (ABI == "avx512" ? X86AVXABILevel::AVX512
263                                : ABI == "avx"  ? X86AVXABILevel::AVX
264                                                : X86AVXABILevel::None);
265 
266     switch (Triple.getOS()) {
267     case llvm::Triple::Win32:
268       return createWinX86_64TargetCodeGenInfo(CGM, AVXLevel);
269     default:
270       return createX86_64TargetCodeGenInfo(CGM, AVXLevel);
271     }
272   }
273   case llvm::Triple::hexagon:
274     return createHexagonTargetCodeGenInfo(CGM);
275   case llvm::Triple::lanai:
276     return createLanaiTargetCodeGenInfo(CGM);
277   case llvm::Triple::r600:
278     return createAMDGPUTargetCodeGenInfo(CGM);
279   case llvm::Triple::amdgcn:
280     return createAMDGPUTargetCodeGenInfo(CGM);
281   case llvm::Triple::sparc:
282     return createSparcV8TargetCodeGenInfo(CGM);
283   case llvm::Triple::sparcv9:
284     return createSparcV9TargetCodeGenInfo(CGM);
285   case llvm::Triple::xcore:
286     return createXCoreTargetCodeGenInfo(CGM);
287   case llvm::Triple::arc:
288     return createARCTargetCodeGenInfo(CGM);
289   case llvm::Triple::spir:
290   case llvm::Triple::spir64:
291     return createCommonSPIRTargetCodeGenInfo(CGM);
292   case llvm::Triple::spirv32:
293   case llvm::Triple::spirv64:
294     return createSPIRVTargetCodeGenInfo(CGM);
295   case llvm::Triple::ve:
296     return createVETargetCodeGenInfo(CGM);
297   case llvm::Triple::csky: {
298     bool IsSoftFloat = !Target.hasFeature("hard-float-abi");
299     bool hasFP64 =
300         Target.hasFeature("fpuv2_df") || Target.hasFeature("fpuv3_df");
301     return createCSKYTargetCodeGenInfo(CGM, IsSoftFloat ? 0
302                                             : hasFP64   ? 64
303                                                         : 32);
304   }
305   case llvm::Triple::bpfeb:
306   case llvm::Triple::bpfel:
307     return createBPFTargetCodeGenInfo(CGM);
308   case llvm::Triple::loongarch32:
309   case llvm::Triple::loongarch64: {
310     StringRef ABIStr = Target.getABI();
311     unsigned ABIFRLen = 0;
312     if (ABIStr.ends_with("f"))
313       ABIFRLen = 32;
314     else if (ABIStr.ends_with("d"))
315       ABIFRLen = 64;
316     return createLoongArchTargetCodeGenInfo(
317         CGM, Target.getPointerWidth(LangAS::Default), ABIFRLen);
318   }
319   }
320 }
321 
getTargetCodeGenInfo()322 const TargetCodeGenInfo &CodeGenModule::getTargetCodeGenInfo() {
323   if (!TheTargetCodeGenInfo)
324     TheTargetCodeGenInfo = createTargetCodeGenInfo(*this);
325   return *TheTargetCodeGenInfo;
326 }
327 
CodeGenModule(ASTContext & C,IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS,const HeaderSearchOptions & HSO,const PreprocessorOptions & PPO,const CodeGenOptions & CGO,llvm::Module & M,DiagnosticsEngine & diags,CoverageSourceInfo * CoverageInfo)328 CodeGenModule::CodeGenModule(ASTContext &C,
329                              IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS,
330                              const HeaderSearchOptions &HSO,
331                              const PreprocessorOptions &PPO,
332                              const CodeGenOptions &CGO, llvm::Module &M,
333                              DiagnosticsEngine &diags,
334                              CoverageSourceInfo *CoverageInfo)
335     : Context(C), LangOpts(C.getLangOpts()), FS(FS), HeaderSearchOpts(HSO),
336       PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
337       Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
338       VMContext(M.getContext()), Types(*this), VTables(*this),
339       SanitizerMD(new SanitizerMetadata(*this)) {
340 
341   // Initialize the type cache.
342   llvm::LLVMContext &LLVMContext = M.getContext();
343   VoidTy = llvm::Type::getVoidTy(LLVMContext);
344   Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
345   Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
346   Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
347   Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
348   HalfTy = llvm::Type::getHalfTy(LLVMContext);
349   BFloatTy = llvm::Type::getBFloatTy(LLVMContext);
350   FloatTy = llvm::Type::getFloatTy(LLVMContext);
351   DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
352   PointerWidthInBits = C.getTargetInfo().getPointerWidth(LangAS::Default);
353   PointerAlignInBytes =
354       C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(LangAS::Default))
355           .getQuantity();
356   SizeSizeInBytes =
357     C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
358   IntAlignInBytes =
359     C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
360   CharTy =
361     llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getCharWidth());
362   IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
363   IntPtrTy = llvm::IntegerType::get(LLVMContext,
364     C.getTargetInfo().getMaxPointerWidth());
365   Int8PtrTy = llvm::PointerType::get(LLVMContext, 0);
366   const llvm::DataLayout &DL = M.getDataLayout();
367   AllocaInt8PtrTy =
368       llvm::PointerType::get(LLVMContext, DL.getAllocaAddrSpace());
369   GlobalsInt8PtrTy =
370       llvm::PointerType::get(LLVMContext, DL.getDefaultGlobalsAddressSpace());
371   ConstGlobalsPtrTy = llvm::PointerType::get(
372       LLVMContext, C.getTargetAddressSpace(GetGlobalConstantAddressSpace()));
373   ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
374 
375   // Build C++20 Module initializers.
376   // TODO: Add Microsoft here once we know the mangling required for the
377   // initializers.
378   CXX20ModuleInits =
379       LangOpts.CPlusPlusModules && getCXXABI().getMangleContext().getKind() ==
380                                        ItaniumMangleContext::MK_Itanium;
381 
382   RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
383 
384   if (LangOpts.ObjC)
385     createObjCRuntime();
386   if (LangOpts.OpenCL)
387     createOpenCLRuntime();
388   if (LangOpts.OpenMP)
389     createOpenMPRuntime();
390   if (LangOpts.CUDA)
391     createCUDARuntime();
392   if (LangOpts.HLSL)
393     createHLSLRuntime();
394 
395   // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
396   if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
397       (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
398     TBAA.reset(new CodeGenTBAA(Context, TheModule, CodeGenOpts, getLangOpts(),
399                                getCXXABI().getMangleContext()));
400 
401   // If debug info or coverage generation is enabled, create the CGDebugInfo
402   // object.
403   if (CodeGenOpts.getDebugInfo() != llvm::codegenoptions::NoDebugInfo ||
404       CodeGenOpts.CoverageNotesFile.size() ||
405       CodeGenOpts.CoverageDataFile.size())
406     DebugInfo.reset(new CGDebugInfo(*this));
407 
408   Block.GlobalUniqueCount = 0;
409 
410   if (C.getLangOpts().ObjC)
411     ObjCData.reset(new ObjCEntrypoints());
412 
413   if (CodeGenOpts.hasProfileClangUse()) {
414     auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
415         CodeGenOpts.ProfileInstrumentUsePath, *FS,
416         CodeGenOpts.ProfileRemappingFile);
417     // We're checking for profile read errors in CompilerInvocation, so if
418     // there was an error it should've already been caught. If it hasn't been
419     // somehow, trip an assertion.
420     assert(ReaderOrErr);
421     PGOReader = std::move(ReaderOrErr.get());
422   }
423 
424   // If coverage mapping generation is enabled, create the
425   // CoverageMappingModuleGen object.
426   if (CodeGenOpts.CoverageMapping)
427     CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
428 
429   // Generate the module name hash here if needed.
430   if (CodeGenOpts.UniqueInternalLinkageNames &&
431       !getModule().getSourceFileName().empty()) {
432     std::string Path = getModule().getSourceFileName();
433     // Check if a path substitution is needed from the MacroPrefixMap.
434     for (const auto &Entry : LangOpts.MacroPrefixMap)
435       if (Path.rfind(Entry.first, 0) != std::string::npos) {
436         Path = Entry.second + Path.substr(Entry.first.size());
437         break;
438       }
439     ModuleNameHash = llvm::getUniqueInternalLinkagePostfix(Path);
440   }
441 }
442 
~CodeGenModule()443 CodeGenModule::~CodeGenModule() {}
444 
createObjCRuntime()445 void CodeGenModule::createObjCRuntime() {
446   // This is just isGNUFamily(), but we want to force implementors of
447   // new ABIs to decide how best to do this.
448   switch (LangOpts.ObjCRuntime.getKind()) {
449   case ObjCRuntime::GNUstep:
450   case ObjCRuntime::GCC:
451   case ObjCRuntime::ObjFW:
452     ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
453     return;
454 
455   case ObjCRuntime::FragileMacOSX:
456   case ObjCRuntime::MacOSX:
457   case ObjCRuntime::iOS:
458   case ObjCRuntime::WatchOS:
459     ObjCRuntime.reset(CreateMacObjCRuntime(*this));
460     return;
461   }
462   llvm_unreachable("bad runtime kind");
463 }
464 
createOpenCLRuntime()465 void CodeGenModule::createOpenCLRuntime() {
466   OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
467 }
468 
createOpenMPRuntime()469 void CodeGenModule::createOpenMPRuntime() {
470   // Select a specialized code generation class based on the target, if any.
471   // If it does not exist use the default implementation.
472   switch (getTriple().getArch()) {
473   case llvm::Triple::nvptx:
474   case llvm::Triple::nvptx64:
475   case llvm::Triple::amdgcn:
476     assert(getLangOpts().OpenMPIsTargetDevice &&
477            "OpenMP AMDGPU/NVPTX is only prepared to deal with device code.");
478     OpenMPRuntime.reset(new CGOpenMPRuntimeGPU(*this));
479     break;
480   default:
481     if (LangOpts.OpenMPSimd)
482       OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
483     else
484       OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
485     break;
486   }
487 }
488 
createCUDARuntime()489 void CodeGenModule::createCUDARuntime() {
490   CUDARuntime.reset(CreateNVCUDARuntime(*this));
491 }
492 
createHLSLRuntime()493 void CodeGenModule::createHLSLRuntime() {
494   HLSLRuntime.reset(new CGHLSLRuntime(*this));
495 }
496 
addReplacement(StringRef Name,llvm::Constant * C)497 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
498   Replacements[Name] = C;
499 }
500 
applyReplacements()501 void CodeGenModule::applyReplacements() {
502   for (auto &I : Replacements) {
503     StringRef MangledName = I.first;
504     llvm::Constant *Replacement = I.second;
505     llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
506     if (!Entry)
507       continue;
508     auto *OldF = cast<llvm::Function>(Entry);
509     auto *NewF = dyn_cast<llvm::Function>(Replacement);
510     if (!NewF) {
511       if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
512         NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
513       } else {
514         auto *CE = cast<llvm::ConstantExpr>(Replacement);
515         assert(CE->getOpcode() == llvm::Instruction::BitCast ||
516                CE->getOpcode() == llvm::Instruction::GetElementPtr);
517         NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
518       }
519     }
520 
521     // Replace old with new, but keep the old order.
522     OldF->replaceAllUsesWith(Replacement);
523     if (NewF) {
524       NewF->removeFromParent();
525       OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
526                                                        NewF);
527     }
528     OldF->eraseFromParent();
529   }
530 }
531 
addGlobalValReplacement(llvm::GlobalValue * GV,llvm::Constant * C)532 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
533   GlobalValReplacements.push_back(std::make_pair(GV, C));
534 }
535 
applyGlobalValReplacements()536 void CodeGenModule::applyGlobalValReplacements() {
537   for (auto &I : GlobalValReplacements) {
538     llvm::GlobalValue *GV = I.first;
539     llvm::Constant *C = I.second;
540 
541     GV->replaceAllUsesWith(C);
542     GV->eraseFromParent();
543   }
544 }
545 
546 // This is only used in aliases that we created and we know they have a
547 // linear structure.
getAliasedGlobal(const llvm::GlobalValue * GV)548 static const llvm::GlobalValue *getAliasedGlobal(const llvm::GlobalValue *GV) {
549   const llvm::Constant *C;
550   if (auto *GA = dyn_cast<llvm::GlobalAlias>(GV))
551     C = GA->getAliasee();
552   else if (auto *GI = dyn_cast<llvm::GlobalIFunc>(GV))
553     C = GI->getResolver();
554   else
555     return GV;
556 
557   const auto *AliaseeGV = dyn_cast<llvm::GlobalValue>(C->stripPointerCasts());
558   if (!AliaseeGV)
559     return nullptr;
560 
561   const llvm::GlobalValue *FinalGV = AliaseeGV->getAliaseeObject();
562   if (FinalGV == GV)
563     return nullptr;
564 
565   return FinalGV;
566 }
567 
checkAliasedGlobal(const ASTContext & Context,DiagnosticsEngine & Diags,SourceLocation Location,bool IsIFunc,const llvm::GlobalValue * Alias,const llvm::GlobalValue * & GV,const llvm::MapVector<GlobalDecl,StringRef> & MangledDeclNames,SourceRange AliasRange)568 static bool checkAliasedGlobal(
569     const ASTContext &Context, DiagnosticsEngine &Diags, SourceLocation Location,
570     bool IsIFunc, const llvm::GlobalValue *Alias, const llvm::GlobalValue *&GV,
571     const llvm::MapVector<GlobalDecl, StringRef> &MangledDeclNames,
572     SourceRange AliasRange) {
573   GV = getAliasedGlobal(Alias);
574   if (!GV) {
575     Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
576     return false;
577   }
578 
579   if (GV->hasCommonLinkage()) {
580     const llvm::Triple &Triple = Context.getTargetInfo().getTriple();
581     if (Triple.getObjectFormat() == llvm::Triple::XCOFF) {
582       Diags.Report(Location, diag::err_alias_to_common);
583       return false;
584     }
585   }
586 
587   if (GV->isDeclaration()) {
588     Diags.Report(Location, diag::err_alias_to_undefined) << IsIFunc << IsIFunc;
589     Diags.Report(Location, diag::note_alias_requires_mangled_name)
590         << IsIFunc << IsIFunc;
591     // Provide a note if the given function is not found and exists as a
592     // mangled name.
593     for (const auto &[Decl, Name] : MangledDeclNames) {
594       if (const auto *ND = dyn_cast<NamedDecl>(Decl.getDecl())) {
595         if (ND->getName() == GV->getName()) {
596           Diags.Report(Location, diag::note_alias_mangled_name_alternative)
597               << Name
598               << FixItHint::CreateReplacement(
599                      AliasRange,
600                      (Twine(IsIFunc ? "ifunc" : "alias") + "(\"" + Name + "\")")
601                          .str());
602         }
603       }
604     }
605     return false;
606   }
607 
608   if (IsIFunc) {
609     // Check resolver function type.
610     const auto *F = dyn_cast<llvm::Function>(GV);
611     if (!F) {
612       Diags.Report(Location, diag::err_alias_to_undefined)
613           << IsIFunc << IsIFunc;
614       return false;
615     }
616 
617     llvm::FunctionType *FTy = F->getFunctionType();
618     if (!FTy->getReturnType()->isPointerTy()) {
619       Diags.Report(Location, diag::err_ifunc_resolver_return);
620       return false;
621     }
622   }
623 
624   return true;
625 }
626 
checkAliases()627 void CodeGenModule::checkAliases() {
628   // Check if the constructed aliases are well formed. It is really unfortunate
629   // that we have to do this in CodeGen, but we only construct mangled names
630   // and aliases during codegen.
631   bool Error = false;
632   DiagnosticsEngine &Diags = getDiags();
633   for (const GlobalDecl &GD : Aliases) {
634     const auto *D = cast<ValueDecl>(GD.getDecl());
635     SourceLocation Location;
636     SourceRange Range;
637     bool IsIFunc = D->hasAttr<IFuncAttr>();
638     if (const Attr *A = D->getDefiningAttr()) {
639       Location = A->getLocation();
640       Range = A->getRange();
641     } else
642       llvm_unreachable("Not an alias or ifunc?");
643 
644     StringRef MangledName = getMangledName(GD);
645     llvm::GlobalValue *Alias = GetGlobalValue(MangledName);
646     const llvm::GlobalValue *GV = nullptr;
647     if (!checkAliasedGlobal(getContext(), Diags, Location, IsIFunc, Alias, GV,
648                             MangledDeclNames, Range)) {
649       Error = true;
650       continue;
651     }
652 
653     llvm::Constant *Aliasee =
654         IsIFunc ? cast<llvm::GlobalIFunc>(Alias)->getResolver()
655                 : cast<llvm::GlobalAlias>(Alias)->getAliasee();
656 
657     llvm::GlobalValue *AliaseeGV;
658     if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
659       AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
660     else
661       AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
662 
663     if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
664       StringRef AliasSection = SA->getName();
665       if (AliasSection != AliaseeGV->getSection())
666         Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
667             << AliasSection << IsIFunc << IsIFunc;
668     }
669 
670     // We have to handle alias to weak aliases in here. LLVM itself disallows
671     // this since the object semantics would not match the IL one. For
672     // compatibility with gcc we implement it by just pointing the alias
673     // to its aliasee's aliasee. We also warn, since the user is probably
674     // expecting the link to be weak.
675     if (auto *GA = dyn_cast<llvm::GlobalAlias>(AliaseeGV)) {
676       if (GA->isInterposable()) {
677         Diags.Report(Location, diag::warn_alias_to_weak_alias)
678             << GV->getName() << GA->getName() << IsIFunc;
679         Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
680             GA->getAliasee(), Alias->getType());
681 
682         if (IsIFunc)
683           cast<llvm::GlobalIFunc>(Alias)->setResolver(Aliasee);
684         else
685           cast<llvm::GlobalAlias>(Alias)->setAliasee(Aliasee);
686       }
687     }
688   }
689   if (!Error)
690     return;
691 
692   for (const GlobalDecl &GD : Aliases) {
693     StringRef MangledName = getMangledName(GD);
694     llvm::GlobalValue *Alias = GetGlobalValue(MangledName);
695     Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
696     Alias->eraseFromParent();
697   }
698 }
699 
clear()700 void CodeGenModule::clear() {
701   DeferredDeclsToEmit.clear();
702   EmittedDeferredDecls.clear();
703   DeferredAnnotations.clear();
704   if (OpenMPRuntime)
705     OpenMPRuntime->clear();
706 }
707 
reportDiagnostics(DiagnosticsEngine & Diags,StringRef MainFile)708 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
709                                        StringRef MainFile) {
710   if (!hasDiagnostics())
711     return;
712   if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
713     if (MainFile.empty())
714       MainFile = "<stdin>";
715     Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
716   } else {
717     if (Mismatched > 0)
718       Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
719 
720     if (Missing > 0)
721       Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
722   }
723 }
724 
725 static std::optional<llvm::GlobalValue::VisibilityTypes>
getLLVMVisibility(clang::LangOptions::VisibilityFromDLLStorageClassKinds K)726 getLLVMVisibility(clang::LangOptions::VisibilityFromDLLStorageClassKinds K) {
727   // Map to LLVM visibility.
728   switch (K) {
729   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Keep:
730     return std::nullopt;
731   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Default:
732     return llvm::GlobalValue::DefaultVisibility;
733   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Hidden:
734     return llvm::GlobalValue::HiddenVisibility;
735   case clang::LangOptions::VisibilityFromDLLStorageClassKinds::Protected:
736     return llvm::GlobalValue::ProtectedVisibility;
737   }
738   llvm_unreachable("unknown option value!");
739 }
740 
setLLVMVisibility(llvm::GlobalValue & GV,std::optional<llvm::GlobalValue::VisibilityTypes> V)741 void setLLVMVisibility(llvm::GlobalValue &GV,
742                        std::optional<llvm::GlobalValue::VisibilityTypes> V) {
743   if (!V)
744     return;
745 
746   // Reset DSO locality before setting the visibility. This removes
747   // any effects that visibility options and annotations may have
748   // had on the DSO locality. Setting the visibility will implicitly set
749   // appropriate globals to DSO Local; however, this will be pessimistic
750   // w.r.t. to the normal compiler IRGen.
751   GV.setDSOLocal(false);
752   GV.setVisibility(*V);
753 }
754 
setVisibilityFromDLLStorageClass(const clang::LangOptions & LO,llvm::Module & M)755 static void setVisibilityFromDLLStorageClass(const clang::LangOptions &LO,
756                                              llvm::Module &M) {
757   if (!LO.VisibilityFromDLLStorageClass)
758     return;
759 
760   std::optional<llvm::GlobalValue::VisibilityTypes> DLLExportVisibility =
761       getLLVMVisibility(LO.getDLLExportVisibility());
762 
763   std::optional<llvm::GlobalValue::VisibilityTypes>
764       NoDLLStorageClassVisibility =
765           getLLVMVisibility(LO.getNoDLLStorageClassVisibility());
766 
767   std::optional<llvm::GlobalValue::VisibilityTypes>
768       ExternDeclDLLImportVisibility =
769           getLLVMVisibility(LO.getExternDeclDLLImportVisibility());
770 
771   std::optional<llvm::GlobalValue::VisibilityTypes>
772       ExternDeclNoDLLStorageClassVisibility =
773           getLLVMVisibility(LO.getExternDeclNoDLLStorageClassVisibility());
774 
775   for (llvm::GlobalValue &GV : M.global_values()) {
776     if (GV.hasAppendingLinkage() || GV.hasLocalLinkage())
777       continue;
778 
779     if (GV.isDeclarationForLinker())
780       setLLVMVisibility(GV, GV.getDLLStorageClass() ==
781                                     llvm::GlobalValue::DLLImportStorageClass
782                                 ? ExternDeclDLLImportVisibility
783                                 : ExternDeclNoDLLStorageClassVisibility);
784     else
785       setLLVMVisibility(GV, GV.getDLLStorageClass() ==
786                                     llvm::GlobalValue::DLLExportStorageClass
787                                 ? DLLExportVisibility
788                                 : NoDLLStorageClassVisibility);
789 
790     GV.setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
791   }
792 }
793 
isStackProtectorOn(const LangOptions & LangOpts,const llvm::Triple & Triple,clang::LangOptions::StackProtectorMode Mode)794 static bool isStackProtectorOn(const LangOptions &LangOpts,
795                                const llvm::Triple &Triple,
796                                clang::LangOptions::StackProtectorMode Mode) {
797   if (Triple.isAMDGPU() || Triple.isNVPTX())
798     return false;
799   return LangOpts.getStackProtector() == Mode;
800 }
801 
Release()802 void CodeGenModule::Release() {
803   Module *Primary = getContext().getCurrentNamedModule();
804   if (CXX20ModuleInits && Primary && !Primary->isHeaderLikeModule())
805     EmitModuleInitializers(Primary);
806   EmitDeferred();
807   DeferredDecls.insert(EmittedDeferredDecls.begin(),
808                        EmittedDeferredDecls.end());
809   EmittedDeferredDecls.clear();
810   EmitVTablesOpportunistically();
811   applyGlobalValReplacements();
812   applyReplacements();
813   emitMultiVersionFunctions();
814 
815   if (Context.getLangOpts().IncrementalExtensions &&
816       GlobalTopLevelStmtBlockInFlight.first) {
817     const TopLevelStmtDecl *TLSD = GlobalTopLevelStmtBlockInFlight.second;
818     GlobalTopLevelStmtBlockInFlight.first->FinishFunction(TLSD->getEndLoc());
819     GlobalTopLevelStmtBlockInFlight = {nullptr, nullptr};
820   }
821 
822   // Module implementations are initialized the same way as a regular TU that
823   // imports one or more modules.
824   if (CXX20ModuleInits && Primary && Primary->isInterfaceOrPartition())
825     EmitCXXModuleInitFunc(Primary);
826   else
827     EmitCXXGlobalInitFunc();
828   EmitCXXGlobalCleanUpFunc();
829   registerGlobalDtorsWithAtExit();
830   EmitCXXThreadLocalInitFunc();
831   if (ObjCRuntime)
832     if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
833       AddGlobalCtor(ObjCInitFunction);
834   if (Context.getLangOpts().CUDA && CUDARuntime) {
835     if (llvm::Function *CudaCtorFunction = CUDARuntime->finalizeModule())
836       AddGlobalCtor(CudaCtorFunction);
837   }
838   if (OpenMPRuntime) {
839     if (llvm::Function *OpenMPRequiresDirectiveRegFun =
840             OpenMPRuntime->emitRequiresDirectiveRegFun()) {
841       AddGlobalCtor(OpenMPRequiresDirectiveRegFun, 0);
842     }
843     OpenMPRuntime->createOffloadEntriesAndInfoMetadata();
844     OpenMPRuntime->clear();
845   }
846   if (PGOReader) {
847     getModule().setProfileSummary(
848         PGOReader->getSummary(/* UseCS */ false).getMD(VMContext),
849         llvm::ProfileSummary::PSK_Instr);
850     if (PGOStats.hasDiagnostics())
851       PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
852   }
853   llvm::stable_sort(GlobalCtors, [](const Structor &L, const Structor &R) {
854     return L.LexOrder < R.LexOrder;
855   });
856   EmitCtorList(GlobalCtors, "llvm.global_ctors");
857   EmitCtorList(GlobalDtors, "llvm.global_dtors");
858   EmitGlobalAnnotations();
859   EmitStaticExternCAliases();
860   checkAliases();
861   EmitDeferredUnusedCoverageMappings();
862   CodeGenPGO(*this).setValueProfilingFlag(getModule());
863   if (CoverageMapping)
864     CoverageMapping->emit();
865   if (CodeGenOpts.SanitizeCfiCrossDso) {
866     CodeGenFunction(*this).EmitCfiCheckFail();
867     CodeGenFunction(*this).EmitCfiCheckStub();
868   }
869   if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
870     finalizeKCFITypes();
871   emitAtAvailableLinkGuard();
872   if (Context.getTargetInfo().getTriple().isWasm())
873     EmitMainVoidAlias();
874 
875   if (getTriple().isAMDGPU()) {
876     // Emit amdgpu_code_object_version module flag, which is code object version
877     // times 100.
878     if (getTarget().getTargetOpts().CodeObjectVersion !=
879         llvm::CodeObjectVersionKind::COV_None) {
880       getModule().addModuleFlag(llvm::Module::Error,
881                                 "amdgpu_code_object_version",
882                                 getTarget().getTargetOpts().CodeObjectVersion);
883     }
884 
885     // Currently, "-mprintf-kind" option is only supported for HIP
886     if (LangOpts.HIP) {
887       auto *MDStr = llvm::MDString::get(
888           getLLVMContext(), (getTarget().getTargetOpts().AMDGPUPrintfKindVal ==
889                              TargetOptions::AMDGPUPrintfKind::Hostcall)
890                                 ? "hostcall"
891                                 : "buffered");
892       getModule().addModuleFlag(llvm::Module::Error, "amdgpu_printf_kind",
893                                 MDStr);
894     }
895   }
896 
897   // Emit a global array containing all external kernels or device variables
898   // used by host functions and mark it as used for CUDA/HIP. This is necessary
899   // to get kernels or device variables in archives linked in even if these
900   // kernels or device variables are only used in host functions.
901   if (!Context.CUDAExternalDeviceDeclODRUsedByHost.empty()) {
902     SmallVector<llvm::Constant *, 8> UsedArray;
903     for (auto D : Context.CUDAExternalDeviceDeclODRUsedByHost) {
904       GlobalDecl GD;
905       if (auto *FD = dyn_cast<FunctionDecl>(D))
906         GD = GlobalDecl(FD, KernelReferenceKind::Kernel);
907       else
908         GD = GlobalDecl(D);
909       UsedArray.push_back(llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
910           GetAddrOfGlobal(GD), Int8PtrTy));
911     }
912 
913     llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size());
914 
915     auto *GV = new llvm::GlobalVariable(
916         getModule(), ATy, false, llvm::GlobalValue::InternalLinkage,
917         llvm::ConstantArray::get(ATy, UsedArray), "__clang_gpu_used_external");
918     addCompilerUsedGlobal(GV);
919   }
920 
921   emitLLVMUsed();
922   if (SanStats)
923     SanStats->finish();
924 
925   if (CodeGenOpts.Autolink &&
926       (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
927     EmitModuleLinkOptions();
928   }
929 
930   // On ELF we pass the dependent library specifiers directly to the linker
931   // without manipulating them. This is in contrast to other platforms where
932   // they are mapped to a specific linker option by the compiler. This
933   // difference is a result of the greater variety of ELF linkers and the fact
934   // that ELF linkers tend to handle libraries in a more complicated fashion
935   // than on other platforms. This forces us to defer handling the dependent
936   // libs to the linker.
937   //
938   // CUDA/HIP device and host libraries are different. Currently there is no
939   // way to differentiate dependent libraries for host or device. Existing
940   // usage of #pragma comment(lib, *) is intended for host libraries on
941   // Windows. Therefore emit llvm.dependent-libraries only for host.
942   if (!ELFDependentLibraries.empty() && !Context.getLangOpts().CUDAIsDevice) {
943     auto *NMD = getModule().getOrInsertNamedMetadata("llvm.dependent-libraries");
944     for (auto *MD : ELFDependentLibraries)
945       NMD->addOperand(MD);
946   }
947 
948   // Record mregparm value now so it is visible through rest of codegen.
949   if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
950     getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
951                               CodeGenOpts.NumRegisterParameters);
952 
953   if (CodeGenOpts.DwarfVersion) {
954     getModule().addModuleFlag(llvm::Module::Max, "Dwarf Version",
955                               CodeGenOpts.DwarfVersion);
956   }
957 
958   if (CodeGenOpts.Dwarf64)
959     getModule().addModuleFlag(llvm::Module::Max, "DWARF64", 1);
960 
961   if (Context.getLangOpts().SemanticInterposition)
962     // Require various optimization to respect semantic interposition.
963     getModule().setSemanticInterposition(true);
964 
965   if (CodeGenOpts.EmitCodeView) {
966     // Indicate that we want CodeView in the metadata.
967     getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
968   }
969   if (CodeGenOpts.CodeViewGHash) {
970     getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
971   }
972   if (CodeGenOpts.ControlFlowGuard) {
973     // Function ID tables and checks for Control Flow Guard (cfguard=2).
974     getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 2);
975   } else if (CodeGenOpts.ControlFlowGuardNoChecks) {
976     // Function ID tables for Control Flow Guard (cfguard=1).
977     getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 1);
978   }
979   if (CodeGenOpts.EHContGuard) {
980     // Function ID tables for EH Continuation Guard.
981     getModule().addModuleFlag(llvm::Module::Warning, "ehcontguard", 1);
982   }
983   if (Context.getLangOpts().Kernel) {
984     // Note if we are compiling with /kernel.
985     getModule().addModuleFlag(llvm::Module::Warning, "ms-kernel", 1);
986   }
987   if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
988     // We don't support LTO with 2 with different StrictVTablePointers
989     // FIXME: we could support it by stripping all the information introduced
990     // by StrictVTablePointers.
991 
992     getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
993 
994     llvm::Metadata *Ops[2] = {
995               llvm::MDString::get(VMContext, "StrictVTablePointers"),
996               llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
997                   llvm::Type::getInt32Ty(VMContext), 1))};
998 
999     getModule().addModuleFlag(llvm::Module::Require,
1000                               "StrictVTablePointersRequirement",
1001                               llvm::MDNode::get(VMContext, Ops));
1002   }
1003   if (getModuleDebugInfo())
1004     // We support a single version in the linked module. The LLVM
1005     // parser will drop debug info with a different version number
1006     // (and warn about it, too).
1007     getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
1008                               llvm::DEBUG_METADATA_VERSION);
1009 
1010   // We need to record the widths of enums and wchar_t, so that we can generate
1011   // the correct build attributes in the ARM backend. wchar_size is also used by
1012   // TargetLibraryInfo.
1013   uint64_t WCharWidth =
1014       Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
1015   getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
1016 
1017   if (getTriple().isOSzOS()) {
1018     getModule().addModuleFlag(llvm::Module::Warning,
1019                               "zos_product_major_version",
1020                               uint32_t(CLANG_VERSION_MAJOR));
1021     getModule().addModuleFlag(llvm::Module::Warning,
1022                               "zos_product_minor_version",
1023                               uint32_t(CLANG_VERSION_MINOR));
1024     getModule().addModuleFlag(llvm::Module::Warning, "zos_product_patchlevel",
1025                               uint32_t(CLANG_VERSION_PATCHLEVEL));
1026     std::string ProductId = getClangVendor() + "clang";
1027     getModule().addModuleFlag(llvm::Module::Error, "zos_product_id",
1028                               llvm::MDString::get(VMContext, ProductId));
1029 
1030     // Record the language because we need it for the PPA2.
1031     StringRef lang_str = languageToString(
1032         LangStandard::getLangStandardForKind(LangOpts.LangStd).Language);
1033     getModule().addModuleFlag(llvm::Module::Error, "zos_cu_language",
1034                               llvm::MDString::get(VMContext, lang_str));
1035 
1036     time_t TT = PreprocessorOpts.SourceDateEpoch
1037                     ? *PreprocessorOpts.SourceDateEpoch
1038                     : std::time(nullptr);
1039     getModule().addModuleFlag(llvm::Module::Max, "zos_translation_time",
1040                               static_cast<uint64_t>(TT));
1041 
1042     // Multiple modes will be supported here.
1043     getModule().addModuleFlag(llvm::Module::Error, "zos_le_char_mode",
1044                               llvm::MDString::get(VMContext, "ascii"));
1045   }
1046 
1047   llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
1048   if (   Arch == llvm::Triple::arm
1049       || Arch == llvm::Triple::armeb
1050       || Arch == llvm::Triple::thumb
1051       || Arch == llvm::Triple::thumbeb) {
1052     // The minimum width of an enum in bytes
1053     uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
1054     getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
1055   }
1056 
1057   if (Arch == llvm::Triple::riscv32 || Arch == llvm::Triple::riscv64) {
1058     StringRef ABIStr = Target.getABI();
1059     llvm::LLVMContext &Ctx = TheModule.getContext();
1060     getModule().addModuleFlag(llvm::Module::Error, "target-abi",
1061                               llvm::MDString::get(Ctx, ABIStr));
1062   }
1063 
1064   if (CodeGenOpts.SanitizeCfiCrossDso) {
1065     // Indicate that we want cross-DSO control flow integrity checks.
1066     getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
1067   }
1068 
1069   if (CodeGenOpts.WholeProgramVTables) {
1070     // Indicate whether VFE was enabled for this module, so that the
1071     // vcall_visibility metadata added under whole program vtables is handled
1072     // appropriately in the optimizer.
1073     getModule().addModuleFlag(llvm::Module::Error, "Virtual Function Elim",
1074                               CodeGenOpts.VirtualFunctionElimination);
1075   }
1076 
1077   if (LangOpts.Sanitize.has(SanitizerKind::CFIICall)) {
1078     getModule().addModuleFlag(llvm::Module::Override,
1079                               "CFI Canonical Jump Tables",
1080                               CodeGenOpts.SanitizeCfiCanonicalJumpTables);
1081   }
1082 
1083   if (LangOpts.Sanitize.has(SanitizerKind::KCFI)) {
1084     getModule().addModuleFlag(llvm::Module::Override, "kcfi", 1);
1085     // KCFI assumes patchable-function-prefix is the same for all indirectly
1086     // called functions. Store the expected offset for code generation.
1087     if (CodeGenOpts.PatchableFunctionEntryOffset)
1088       getModule().addModuleFlag(llvm::Module::Override, "kcfi-offset",
1089                                 CodeGenOpts.PatchableFunctionEntryOffset);
1090   }
1091 
1092   if (CodeGenOpts.CFProtectionReturn &&
1093       Target.checkCFProtectionReturnSupported(getDiags())) {
1094     // Indicate that we want to instrument return control flow protection.
1095     getModule().addModuleFlag(llvm::Module::Min, "cf-protection-return",
1096                               1);
1097   }
1098 
1099   if (CodeGenOpts.CFProtectionBranch &&
1100       Target.checkCFProtectionBranchSupported(getDiags())) {
1101     // Indicate that we want to instrument branch control flow protection.
1102     getModule().addModuleFlag(llvm::Module::Min, "cf-protection-branch",
1103                               1);
1104   }
1105 
1106   if (CodeGenOpts.FunctionReturnThunks)
1107     getModule().addModuleFlag(llvm::Module::Override, "function_return_thunk_extern", 1);
1108 
1109   if (CodeGenOpts.IndirectBranchCSPrefix)
1110     getModule().addModuleFlag(llvm::Module::Override, "indirect_branch_cs_prefix", 1);
1111 
1112   // Add module metadata for return address signing (ignoring
1113   // non-leaf/all) and stack tagging. These are actually turned on by function
1114   // attributes, but we use module metadata to emit build attributes. This is
1115   // needed for LTO, where the function attributes are inside bitcode
1116   // serialised into a global variable by the time build attributes are
1117   // emitted, so we can't access them. LTO objects could be compiled with
1118   // different flags therefore module flags are set to "Min" behavior to achieve
1119   // the same end result of the normal build where e.g BTI is off if any object
1120   // doesn't support it.
1121   if (Context.getTargetInfo().hasFeature("ptrauth") &&
1122       LangOpts.getSignReturnAddressScope() !=
1123           LangOptions::SignReturnAddressScopeKind::None)
1124     getModule().addModuleFlag(llvm::Module::Override,
1125                               "sign-return-address-buildattr", 1);
1126   if (LangOpts.Sanitize.has(SanitizerKind::MemtagStack))
1127     getModule().addModuleFlag(llvm::Module::Override,
1128                               "tag-stack-memory-buildattr", 1);
1129 
1130   if (Arch == llvm::Triple::thumb || Arch == llvm::Triple::thumbeb ||
1131       Arch == llvm::Triple::arm || Arch == llvm::Triple::armeb ||
1132       Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_32 ||
1133       Arch == llvm::Triple::aarch64_be) {
1134     if (LangOpts.BranchTargetEnforcement)
1135       getModule().addModuleFlag(llvm::Module::Min, "branch-target-enforcement",
1136                                 1);
1137     if (LangOpts.BranchProtectionPAuthLR)
1138       getModule().addModuleFlag(llvm::Module::Min, "branch-protection-pauth-lr",
1139                                 1);
1140     if (LangOpts.GuardedControlStack)
1141       getModule().addModuleFlag(llvm::Module::Min, "guarded-control-stack", 1);
1142     if (LangOpts.hasSignReturnAddress())
1143       getModule().addModuleFlag(llvm::Module::Min, "sign-return-address", 1);
1144     if (LangOpts.isSignReturnAddressScopeAll())
1145       getModule().addModuleFlag(llvm::Module::Min, "sign-return-address-all",
1146                                 1);
1147     if (!LangOpts.isSignReturnAddressWithAKey())
1148       getModule().addModuleFlag(llvm::Module::Min,
1149                                 "sign-return-address-with-bkey", 1);
1150   }
1151 
1152   if (CodeGenOpts.StackClashProtector)
1153     getModule().addModuleFlag(
1154         llvm::Module::Override, "probe-stack",
1155         llvm::MDString::get(TheModule.getContext(), "inline-asm"));
1156 
1157   if (CodeGenOpts.StackProbeSize && CodeGenOpts.StackProbeSize != 4096)
1158     getModule().addModuleFlag(llvm::Module::Min, "stack-probe-size",
1159                               CodeGenOpts.StackProbeSize);
1160 
1161   if (!CodeGenOpts.MemoryProfileOutput.empty()) {
1162     llvm::LLVMContext &Ctx = TheModule.getContext();
1163     getModule().addModuleFlag(
1164         llvm::Module::Error, "MemProfProfileFilename",
1165         llvm::MDString::get(Ctx, CodeGenOpts.MemoryProfileOutput));
1166   }
1167 
1168   if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
1169     // Indicate whether __nvvm_reflect should be configured to flush denormal
1170     // floating point values to 0.  (This corresponds to its "__CUDA_FTZ"
1171     // property.)
1172     getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
1173                               CodeGenOpts.FP32DenormalMode.Output !=
1174                                   llvm::DenormalMode::IEEE);
1175   }
1176 
1177   if (LangOpts.EHAsynch)
1178     getModule().addModuleFlag(llvm::Module::Warning, "eh-asynch", 1);
1179 
1180   // Indicate whether this Module was compiled with -fopenmp
1181   if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
1182     getModule().addModuleFlag(llvm::Module::Max, "openmp", LangOpts.OpenMP);
1183   if (getLangOpts().OpenMPIsTargetDevice)
1184     getModule().addModuleFlag(llvm::Module::Max, "openmp-device",
1185                               LangOpts.OpenMP);
1186 
1187   // Emit OpenCL specific module metadata: OpenCL/SPIR version.
1188   if (LangOpts.OpenCL || (LangOpts.CUDAIsDevice && getTriple().isSPIRV())) {
1189     EmitOpenCLMetadata();
1190     // Emit SPIR version.
1191     if (getTriple().isSPIR()) {
1192       // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
1193       // opencl.spir.version named metadata.
1194       // C++ for OpenCL has a distinct mapping for version compatibility with
1195       // OpenCL.
1196       auto Version = LangOpts.getOpenCLCompatibleVersion();
1197       llvm::Metadata *SPIRVerElts[] = {
1198           llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1199               Int32Ty, Version / 100)),
1200           llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1201               Int32Ty, (Version / 100 > 1) ? 0 : 2))};
1202       llvm::NamedMDNode *SPIRVerMD =
1203           TheModule.getOrInsertNamedMetadata("opencl.spir.version");
1204       llvm::LLVMContext &Ctx = TheModule.getContext();
1205       SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
1206     }
1207   }
1208 
1209   // HLSL related end of code gen work items.
1210   if (LangOpts.HLSL)
1211     getHLSLRuntime().finishCodeGen();
1212 
1213   if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
1214     assert(PLevel < 3 && "Invalid PIC Level");
1215     getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
1216     if (Context.getLangOpts().PIE)
1217       getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
1218   }
1219 
1220   if (getCodeGenOpts().CodeModel.size() > 0) {
1221     unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
1222                   .Case("tiny", llvm::CodeModel::Tiny)
1223                   .Case("small", llvm::CodeModel::Small)
1224                   .Case("kernel", llvm::CodeModel::Kernel)
1225                   .Case("medium", llvm::CodeModel::Medium)
1226                   .Case("large", llvm::CodeModel::Large)
1227                   .Default(~0u);
1228     if (CM != ~0u) {
1229       llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
1230       getModule().setCodeModel(codeModel);
1231 
1232       if ((CM == llvm::CodeModel::Medium || CM == llvm::CodeModel::Large) &&
1233           Context.getTargetInfo().getTriple().getArch() ==
1234               llvm::Triple::x86_64) {
1235         getModule().setLargeDataThreshold(getCodeGenOpts().LargeDataThreshold);
1236       }
1237     }
1238   }
1239 
1240   if (CodeGenOpts.NoPLT)
1241     getModule().setRtLibUseGOT();
1242   if (getTriple().isOSBinFormatELF() &&
1243       CodeGenOpts.DirectAccessExternalData !=
1244           getModule().getDirectAccessExternalData()) {
1245     getModule().setDirectAccessExternalData(
1246         CodeGenOpts.DirectAccessExternalData);
1247   }
1248   if (CodeGenOpts.UnwindTables)
1249     getModule().setUwtable(llvm::UWTableKind(CodeGenOpts.UnwindTables));
1250 
1251   switch (CodeGenOpts.getFramePointer()) {
1252   case CodeGenOptions::FramePointerKind::None:
1253     // 0 ("none") is the default.
1254     break;
1255   case CodeGenOptions::FramePointerKind::NonLeaf:
1256     getModule().setFramePointer(llvm::FramePointerKind::NonLeaf);
1257     break;
1258   case CodeGenOptions::FramePointerKind::All:
1259     getModule().setFramePointer(llvm::FramePointerKind::All);
1260     break;
1261   }
1262 
1263   SimplifyPersonality();
1264 
1265   if (getCodeGenOpts().EmitDeclMetadata)
1266     EmitDeclMetadata();
1267 
1268   if (getCodeGenOpts().CoverageNotesFile.size() ||
1269       getCodeGenOpts().CoverageDataFile.size())
1270     EmitCoverageFile();
1271 
1272   if (CGDebugInfo *DI = getModuleDebugInfo())
1273     DI->finalize();
1274 
1275   if (getCodeGenOpts().EmitVersionIdentMetadata)
1276     EmitVersionIdentMetadata();
1277 
1278   if (!getCodeGenOpts().RecordCommandLine.empty())
1279     EmitCommandLineMetadata();
1280 
1281   if (!getCodeGenOpts().StackProtectorGuard.empty())
1282     getModule().setStackProtectorGuard(getCodeGenOpts().StackProtectorGuard);
1283   if (!getCodeGenOpts().StackProtectorGuardReg.empty())
1284     getModule().setStackProtectorGuardReg(
1285         getCodeGenOpts().StackProtectorGuardReg);
1286   if (!getCodeGenOpts().StackProtectorGuardSymbol.empty())
1287     getModule().setStackProtectorGuardSymbol(
1288         getCodeGenOpts().StackProtectorGuardSymbol);
1289   if (getCodeGenOpts().StackProtectorGuardOffset != INT_MAX)
1290     getModule().setStackProtectorGuardOffset(
1291         getCodeGenOpts().StackProtectorGuardOffset);
1292   if (getCodeGenOpts().StackAlignment)
1293     getModule().setOverrideStackAlignment(getCodeGenOpts().StackAlignment);
1294   if (getCodeGenOpts().SkipRaxSetup)
1295     getModule().addModuleFlag(llvm::Module::Override, "SkipRaxSetup", 1);
1296   if (getLangOpts().RegCall4)
1297     getModule().addModuleFlag(llvm::Module::Override, "RegCallv4", 1);
1298 
1299   if (getContext().getTargetInfo().getMaxTLSAlign())
1300     getModule().addModuleFlag(llvm::Module::Error, "MaxTLSAlign",
1301                               getContext().getTargetInfo().getMaxTLSAlign());
1302 
1303   getTargetCodeGenInfo().emitTargetGlobals(*this);
1304 
1305   getTargetCodeGenInfo().emitTargetMetadata(*this, MangledDeclNames);
1306 
1307   EmitBackendOptionsMetadata(getCodeGenOpts());
1308 
1309   // If there is device offloading code embed it in the host now.
1310   EmbedObject(&getModule(), CodeGenOpts, getDiags());
1311 
1312   // Set visibility from DLL storage class
1313   // We do this at the end of LLVM IR generation; after any operation
1314   // that might affect the DLL storage class or the visibility, and
1315   // before anything that might act on these.
1316   setVisibilityFromDLLStorageClass(LangOpts, getModule());
1317 }
1318 
EmitOpenCLMetadata()1319 void CodeGenModule::EmitOpenCLMetadata() {
1320   // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
1321   // opencl.ocl.version named metadata node.
1322   // C++ for OpenCL has a distinct mapping for versions compatibile with OpenCL.
1323   auto Version = LangOpts.getOpenCLCompatibleVersion();
1324   llvm::Metadata *OCLVerElts[] = {
1325       llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1326           Int32Ty, Version / 100)),
1327       llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
1328           Int32Ty, (Version % 100) / 10))};
1329   llvm::NamedMDNode *OCLVerMD =
1330       TheModule.getOrInsertNamedMetadata("opencl.ocl.version");
1331   llvm::LLVMContext &Ctx = TheModule.getContext();
1332   OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
1333 }
1334 
EmitBackendOptionsMetadata(const CodeGenOptions & CodeGenOpts)1335 void CodeGenModule::EmitBackendOptionsMetadata(
1336     const CodeGenOptions &CodeGenOpts) {
1337   if (getTriple().isRISCV()) {
1338     getModule().addModuleFlag(llvm::Module::Min, "SmallDataLimit",
1339                               CodeGenOpts.SmallDataLimit);
1340   }
1341 }
1342 
UpdateCompletedType(const TagDecl * TD)1343 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
1344   // Make sure that this type is translated.
1345   Types.UpdateCompletedType(TD);
1346 }
1347 
RefreshTypeCacheForClass(const CXXRecordDecl * RD)1348 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
1349   // Make sure that this type is translated.
1350   Types.RefreshTypeCacheForClass(RD);
1351 }
1352 
getTBAATypeInfo(QualType QTy)1353 llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
1354   if (!TBAA)
1355     return nullptr;
1356   return TBAA->getTypeInfo(QTy);
1357 }
1358 
getTBAAAccessInfo(QualType AccessType)1359 TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
1360   if (!TBAA)
1361     return TBAAAccessInfo();
1362   if (getLangOpts().CUDAIsDevice) {
1363     // As CUDA builtin surface/texture types are replaced, skip generating TBAA
1364     // access info.
1365     if (AccessType->isCUDADeviceBuiltinSurfaceType()) {
1366       if (getTargetCodeGenInfo().getCUDADeviceBuiltinSurfaceDeviceType() !=
1367           nullptr)
1368         return TBAAAccessInfo();
1369     } else if (AccessType->isCUDADeviceBuiltinTextureType()) {
1370       if (getTargetCodeGenInfo().getCUDADeviceBuiltinTextureDeviceType() !=
1371           nullptr)
1372         return TBAAAccessInfo();
1373     }
1374   }
1375   return TBAA->getAccessInfo(AccessType);
1376 }
1377 
1378 TBAAAccessInfo
getTBAAVTablePtrAccessInfo(llvm::Type * VTablePtrType)1379 CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
1380   if (!TBAA)
1381     return TBAAAccessInfo();
1382   return TBAA->getVTablePtrAccessInfo(VTablePtrType);
1383 }
1384 
getTBAAStructInfo(QualType QTy)1385 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
1386   if (!TBAA)
1387     return nullptr;
1388   return TBAA->getTBAAStructInfo(QTy);
1389 }
1390 
getTBAABaseTypeInfo(QualType QTy)1391 llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
1392   if (!TBAA)
1393     return nullptr;
1394   return TBAA->getBaseTypeInfo(QTy);
1395 }
1396 
getTBAAAccessTagInfo(TBAAAccessInfo Info)1397 llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
1398   if (!TBAA)
1399     return nullptr;
1400   return TBAA->getAccessTagInfo(Info);
1401 }
1402 
mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,TBAAAccessInfo TargetInfo)1403 TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
1404                                                    TBAAAccessInfo TargetInfo) {
1405   if (!TBAA)
1406     return TBAAAccessInfo();
1407   return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
1408 }
1409 
1410 TBAAAccessInfo
mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,TBAAAccessInfo InfoB)1411 CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
1412                                                    TBAAAccessInfo InfoB) {
1413   if (!TBAA)
1414     return TBAAAccessInfo();
1415   return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
1416 }
1417 
1418 TBAAAccessInfo
mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,TBAAAccessInfo SrcInfo)1419 CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
1420                                               TBAAAccessInfo SrcInfo) {
1421   if (!TBAA)
1422     return TBAAAccessInfo();
1423   return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
1424 }
1425 
DecorateInstructionWithTBAA(llvm::Instruction * Inst,TBAAAccessInfo TBAAInfo)1426 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
1427                                                 TBAAAccessInfo TBAAInfo) {
1428   if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
1429     Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
1430 }
1431 
DecorateInstructionWithInvariantGroup(llvm::Instruction * I,const CXXRecordDecl * RD)1432 void CodeGenModule::DecorateInstructionWithInvariantGroup(
1433     llvm::Instruction *I, const CXXRecordDecl *RD) {
1434   I->setMetadata(llvm::LLVMContext::MD_invariant_group,
1435                  llvm::MDNode::get(getLLVMContext(), {}));
1436 }
1437 
Error(SourceLocation loc,StringRef message)1438 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
1439   unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
1440   getDiags().Report(Context.getFullLoc(loc), diagID) << message;
1441 }
1442 
1443 /// ErrorUnsupported - Print out an error that codegen doesn't support the
1444 /// specified stmt yet.
ErrorUnsupported(const Stmt * S,const char * Type)1445 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
1446   unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
1447                                                "cannot compile this %0 yet");
1448   std::string Msg = Type;
1449   getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID)
1450       << Msg << S->getSourceRange();
1451 }
1452 
1453 /// ErrorUnsupported - Print out an error that codegen doesn't support the
1454 /// specified decl yet.
ErrorUnsupported(const Decl * D,const char * Type)1455 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
1456   unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
1457                                                "cannot compile this %0 yet");
1458   std::string Msg = Type;
1459   getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
1460 }
1461 
getSize(CharUnits size)1462 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
1463   return llvm::ConstantInt::get(SizeTy, size.getQuantity());
1464 }
1465 
setGlobalVisibility(llvm::GlobalValue * GV,const NamedDecl * D) const1466 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
1467                                         const NamedDecl *D) const {
1468   // Internal definitions always have default visibility.
1469   if (GV->hasLocalLinkage()) {
1470     GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1471     return;
1472   }
1473   if (!D)
1474     return;
1475 
1476   // Set visibility for definitions, and for declarations if requested globally
1477   // or set explicitly.
1478   LinkageInfo LV = D->getLinkageAndVisibility();
1479 
1480   // OpenMP declare target variables must be visible to the host so they can
1481   // be registered. We require protected visibility unless the variable has
1482   // the DT_nohost modifier and does not need to be registered.
1483   if (Context.getLangOpts().OpenMP &&
1484       Context.getLangOpts().OpenMPIsTargetDevice && isa<VarDecl>(D) &&
1485       D->hasAttr<OMPDeclareTargetDeclAttr>() &&
1486       D->getAttr<OMPDeclareTargetDeclAttr>()->getDevType() !=
1487           OMPDeclareTargetDeclAttr::DT_NoHost &&
1488       LV.getVisibility() == HiddenVisibility) {
1489     GV->setVisibility(llvm::GlobalValue::ProtectedVisibility);
1490     return;
1491   }
1492 
1493   if (GV->hasDLLExportStorageClass() || GV->hasDLLImportStorageClass()) {
1494     // Reject incompatible dlllstorage and visibility annotations.
1495     if (!LV.isVisibilityExplicit())
1496       return;
1497     if (GV->hasDLLExportStorageClass()) {
1498       if (LV.getVisibility() == HiddenVisibility)
1499         getDiags().Report(D->getLocation(),
1500                           diag::err_hidden_visibility_dllexport);
1501     } else if (LV.getVisibility() != DefaultVisibility) {
1502       getDiags().Report(D->getLocation(),
1503                         diag::err_non_default_visibility_dllimport);
1504     }
1505     return;
1506   }
1507 
1508   if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
1509       !GV->isDeclarationForLinker())
1510     GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
1511 }
1512 
shouldAssumeDSOLocal(const CodeGenModule & CGM,llvm::GlobalValue * GV)1513 static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
1514                                  llvm::GlobalValue *GV) {
1515   if (GV->hasLocalLinkage())
1516     return true;
1517 
1518   if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
1519     return true;
1520 
1521   // DLLImport explicitly marks the GV as external.
1522   if (GV->hasDLLImportStorageClass())
1523     return false;
1524 
1525   const llvm::Triple &TT = CGM.getTriple();
1526   const auto &CGOpts = CGM.getCodeGenOpts();
1527   if (TT.isWindowsGNUEnvironment()) {
1528     // In MinGW, variables without DLLImport can still be automatically
1529     // imported from a DLL by the linker; don't mark variables that
1530     // potentially could come from another DLL as DSO local.
1531 
1532     // With EmulatedTLS, TLS variables can be autoimported from other DLLs
1533     // (and this actually happens in the public interface of libstdc++), so
1534     // such variables can't be marked as DSO local. (Native TLS variables
1535     // can't be dllimported at all, though.)
1536     if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
1537         (!GV->isThreadLocal() || CGM.getCodeGenOpts().EmulatedTLS) &&
1538         CGOpts.AutoImport)
1539       return false;
1540   }
1541 
1542   // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
1543   // remain unresolved in the link, they can be resolved to zero, which is
1544   // outside the current DSO.
1545   if (TT.isOSBinFormatCOFF() && GV->hasExternalWeakLinkage())
1546     return false;
1547 
1548   // Every other GV is local on COFF.
1549   // Make an exception for windows OS in the triple: Some firmware builds use
1550   // *-win32-macho triples. This (accidentally?) produced windows relocations
1551   // without GOT tables in older clang versions; Keep this behaviour.
1552   // FIXME: even thread local variables?
1553   if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
1554     return true;
1555 
1556   // Only handle COFF and ELF for now.
1557   if (!TT.isOSBinFormatELF())
1558     return false;
1559 
1560   // If this is not an executable, don't assume anything is local.
1561   llvm::Reloc::Model RM = CGOpts.RelocationModel;
1562   const auto &LOpts = CGM.getLangOpts();
1563   if (RM != llvm::Reloc::Static && !LOpts.PIE) {
1564     // On ELF, if -fno-semantic-interposition is specified and the target
1565     // supports local aliases, there will be neither CC1
1566     // -fsemantic-interposition nor -fhalf-no-semantic-interposition. Set
1567     // dso_local on the function if using a local alias is preferable (can avoid
1568     // PLT indirection).
1569     if (!(isa<llvm::Function>(GV) && GV->canBenefitFromLocalAlias()))
1570       return false;
1571     return !(CGM.getLangOpts().SemanticInterposition ||
1572              CGM.getLangOpts().HalfNoSemanticInterposition);
1573   }
1574 
1575   // A definition cannot be preempted from an executable.
1576   if (!GV->isDeclarationForLinker())
1577     return true;
1578 
1579   // Most PIC code sequences that assume that a symbol is local cannot produce a
1580   // 0 if it turns out the symbol is undefined. While this is ABI and relocation
1581   // depended, it seems worth it to handle it here.
1582   if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
1583     return false;
1584 
1585   // PowerPC64 prefers TOC indirection to avoid copy relocations.
1586   if (TT.isPPC64())
1587     return false;
1588 
1589   if (CGOpts.DirectAccessExternalData) {
1590     // If -fdirect-access-external-data (default for -fno-pic), set dso_local
1591     // for non-thread-local variables. If the symbol is not defined in the
1592     // executable, a copy relocation will be needed at link time. dso_local is
1593     // excluded for thread-local variables because they generally don't support
1594     // copy relocations.
1595     if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
1596       if (!Var->isThreadLocal())
1597         return true;
1598 
1599     // -fno-pic sets dso_local on a function declaration to allow direct
1600     // accesses when taking its address (similar to a data symbol). If the
1601     // function is not defined in the executable, a canonical PLT entry will be
1602     // needed at link time. -fno-direct-access-external-data can avoid the
1603     // canonical PLT entry. We don't generalize this condition to -fpie/-fpic as
1604     // it could just cause trouble without providing perceptible benefits.
1605     if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
1606       return true;
1607   }
1608 
1609   // If we can use copy relocations we can assume it is local.
1610 
1611   // Otherwise don't assume it is local.
1612   return false;
1613 }
1614 
setDSOLocal(llvm::GlobalValue * GV) const1615 void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
1616   GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
1617 }
1618 
setDLLImportDLLExport(llvm::GlobalValue * GV,GlobalDecl GD) const1619 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1620                                           GlobalDecl GD) const {
1621   const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
1622   // C++ destructors have a few C++ ABI specific special cases.
1623   if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
1624     getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
1625     return;
1626   }
1627   setDLLImportDLLExport(GV, D);
1628 }
1629 
setDLLImportDLLExport(llvm::GlobalValue * GV,const NamedDecl * D) const1630 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1631                                           const NamedDecl *D) const {
1632   if (D && D->isExternallyVisible()) {
1633     if (D->hasAttr<DLLImportAttr>())
1634       GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
1635     else if ((D->hasAttr<DLLExportAttr>() ||
1636               shouldMapVisibilityToDLLExport(D)) &&
1637              !GV->isDeclarationForLinker())
1638       GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
1639   }
1640 }
1641 
setGVProperties(llvm::GlobalValue * GV,GlobalDecl GD) const1642 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1643                                     GlobalDecl GD) const {
1644   setDLLImportDLLExport(GV, GD);
1645   setGVPropertiesAux(GV, dyn_cast<NamedDecl>(GD.getDecl()));
1646 }
1647 
setGVProperties(llvm::GlobalValue * GV,const NamedDecl * D) const1648 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1649                                     const NamedDecl *D) const {
1650   setDLLImportDLLExport(GV, D);
1651   setGVPropertiesAux(GV, D);
1652 }
1653 
setGVPropertiesAux(llvm::GlobalValue * GV,const NamedDecl * D) const1654 void CodeGenModule::setGVPropertiesAux(llvm::GlobalValue *GV,
1655                                        const NamedDecl *D) const {
1656   setGlobalVisibility(GV, D);
1657   setDSOLocal(GV);
1658   GV->setPartition(CodeGenOpts.SymbolPartition);
1659 }
1660 
GetLLVMTLSModel(StringRef S)1661 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
1662   return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
1663       .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
1664       .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
1665       .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
1666       .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
1667 }
1668 
1669 llvm::GlobalVariable::ThreadLocalMode
GetDefaultLLVMTLSModel() const1670 CodeGenModule::GetDefaultLLVMTLSModel() const {
1671   switch (CodeGenOpts.getDefaultTLSModel()) {
1672   case CodeGenOptions::GeneralDynamicTLSModel:
1673     return llvm::GlobalVariable::GeneralDynamicTLSModel;
1674   case CodeGenOptions::LocalDynamicTLSModel:
1675     return llvm::GlobalVariable::LocalDynamicTLSModel;
1676   case CodeGenOptions::InitialExecTLSModel:
1677     return llvm::GlobalVariable::InitialExecTLSModel;
1678   case CodeGenOptions::LocalExecTLSModel:
1679     return llvm::GlobalVariable::LocalExecTLSModel;
1680   }
1681   llvm_unreachable("Invalid TLS model!");
1682 }
1683 
setTLSMode(llvm::GlobalValue * GV,const VarDecl & D) const1684 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
1685   assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
1686 
1687   llvm::GlobalValue::ThreadLocalMode TLM;
1688   TLM = GetDefaultLLVMTLSModel();
1689 
1690   // Override the TLS model if it is explicitly specified.
1691   if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
1692     TLM = GetLLVMTLSModel(Attr->getModel());
1693   }
1694 
1695   GV->setThreadLocalMode(TLM);
1696 }
1697 
getCPUSpecificMangling(const CodeGenModule & CGM,StringRef Name)1698 static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
1699                                           StringRef Name) {
1700   const TargetInfo &Target = CGM.getTarget();
1701   return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
1702 }
1703 
AppendCPUSpecificCPUDispatchMangling(const CodeGenModule & CGM,const CPUSpecificAttr * Attr,unsigned CPUIndex,raw_ostream & Out)1704 static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
1705                                                  const CPUSpecificAttr *Attr,
1706                                                  unsigned CPUIndex,
1707                                                  raw_ostream &Out) {
1708   // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
1709   // supported.
1710   if (Attr)
1711     Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
1712   else if (CGM.getTarget().supportsIFunc())
1713     Out << ".resolver";
1714 }
1715 
AppendTargetVersionMangling(const CodeGenModule & CGM,const TargetVersionAttr * Attr,raw_ostream & Out)1716 static void AppendTargetVersionMangling(const CodeGenModule &CGM,
1717                                         const TargetVersionAttr *Attr,
1718                                         raw_ostream &Out) {
1719   if (Attr->isDefaultVersion()) {
1720     Out << ".default";
1721     return;
1722   }
1723   Out << "._";
1724   const TargetInfo &TI = CGM.getTarget();
1725   llvm::SmallVector<StringRef, 8> Feats;
1726   Attr->getFeatures(Feats);
1727   llvm::stable_sort(Feats, [&TI](const StringRef FeatL, const StringRef FeatR) {
1728     return TI.multiVersionSortPriority(FeatL) <
1729            TI.multiVersionSortPriority(FeatR);
1730   });
1731   for (const auto &Feat : Feats) {
1732     Out << 'M';
1733     Out << Feat;
1734   }
1735 }
1736 
AppendTargetMangling(const CodeGenModule & CGM,const TargetAttr * Attr,raw_ostream & Out)1737 static void AppendTargetMangling(const CodeGenModule &CGM,
1738                                  const TargetAttr *Attr, raw_ostream &Out) {
1739   if (Attr->isDefaultVersion())
1740     return;
1741 
1742   Out << '.';
1743   const TargetInfo &Target = CGM.getTarget();
1744   ParsedTargetAttr Info = Target.parseTargetAttr(Attr->getFeaturesStr());
1745   llvm::sort(Info.Features, [&Target](StringRef LHS, StringRef RHS) {
1746     // Multiversioning doesn't allow "no-${feature}", so we can
1747     // only have "+" prefixes here.
1748     assert(LHS.starts_with("+") && RHS.starts_with("+") &&
1749            "Features should always have a prefix.");
1750     return Target.multiVersionSortPriority(LHS.substr(1)) >
1751            Target.multiVersionSortPriority(RHS.substr(1));
1752   });
1753 
1754   bool IsFirst = true;
1755 
1756   if (!Info.CPU.empty()) {
1757     IsFirst = false;
1758     Out << "arch_" << Info.CPU;
1759   }
1760 
1761   for (StringRef Feat : Info.Features) {
1762     if (!IsFirst)
1763       Out << '_';
1764     IsFirst = false;
1765     Out << Feat.substr(1);
1766   }
1767 }
1768 
1769 // Returns true if GD is a function decl with internal linkage and
1770 // needs a unique suffix after the mangled name.
isUniqueInternalLinkageDecl(GlobalDecl GD,CodeGenModule & CGM)1771 static bool isUniqueInternalLinkageDecl(GlobalDecl GD,
1772                                         CodeGenModule &CGM) {
1773   const Decl *D = GD.getDecl();
1774   return !CGM.getModuleNameHash().empty() && isa<FunctionDecl>(D) &&
1775          (CGM.getFunctionLinkage(GD) == llvm::GlobalValue::InternalLinkage);
1776 }
1777 
AppendTargetClonesMangling(const CodeGenModule & CGM,const TargetClonesAttr * Attr,unsigned VersionIndex,raw_ostream & Out)1778 static void AppendTargetClonesMangling(const CodeGenModule &CGM,
1779                                        const TargetClonesAttr *Attr,
1780                                        unsigned VersionIndex,
1781                                        raw_ostream &Out) {
1782   const TargetInfo &TI = CGM.getTarget();
1783   if (TI.getTriple().isAArch64()) {
1784     StringRef FeatureStr = Attr->getFeatureStr(VersionIndex);
1785     if (FeatureStr == "default") {
1786       Out << ".default";
1787       return;
1788     }
1789     Out << "._";
1790     SmallVector<StringRef, 8> Features;
1791     FeatureStr.split(Features, "+");
1792     llvm::stable_sort(Features,
1793                       [&TI](const StringRef FeatL, const StringRef FeatR) {
1794                         return TI.multiVersionSortPriority(FeatL) <
1795                                TI.multiVersionSortPriority(FeatR);
1796                       });
1797     for (auto &Feat : Features) {
1798       Out << 'M';
1799       Out << Feat;
1800     }
1801   } else {
1802     Out << '.';
1803     StringRef FeatureStr = Attr->getFeatureStr(VersionIndex);
1804     if (FeatureStr.starts_with("arch="))
1805       Out << "arch_" << FeatureStr.substr(sizeof("arch=") - 1);
1806     else
1807       Out << FeatureStr;
1808 
1809     Out << '.' << Attr->getMangledIndex(VersionIndex);
1810   }
1811 }
1812 
getMangledNameImpl(CodeGenModule & CGM,GlobalDecl GD,const NamedDecl * ND,bool OmitMultiVersionMangling=false)1813 static std::string getMangledNameImpl(CodeGenModule &CGM, GlobalDecl GD,
1814                                       const NamedDecl *ND,
1815                                       bool OmitMultiVersionMangling = false) {
1816   SmallString<256> Buffer;
1817   llvm::raw_svector_ostream Out(Buffer);
1818   MangleContext &MC = CGM.getCXXABI().getMangleContext();
1819   if (!CGM.getModuleNameHash().empty())
1820     MC.needsUniqueInternalLinkageNames();
1821   bool ShouldMangle = MC.shouldMangleDeclName(ND);
1822   if (ShouldMangle)
1823     MC.mangleName(GD.getWithDecl(ND), Out);
1824   else {
1825     IdentifierInfo *II = ND->getIdentifier();
1826     assert(II && "Attempt to mangle unnamed decl.");
1827     const auto *FD = dyn_cast<FunctionDecl>(ND);
1828 
1829     if (FD &&
1830         FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
1831       if (CGM.getLangOpts().RegCall4)
1832         Out << "__regcall4__" << II->getName();
1833       else
1834         Out << "__regcall3__" << II->getName();
1835     } else if (FD && FD->hasAttr<CUDAGlobalAttr>() &&
1836                GD.getKernelReferenceKind() == KernelReferenceKind::Stub) {
1837       Out << "__device_stub__" << II->getName();
1838     } else {
1839       Out << II->getName();
1840     }
1841   }
1842 
1843   // Check if the module name hash should be appended for internal linkage
1844   // symbols.   This should come before multi-version target suffixes are
1845   // appended. This is to keep the name and module hash suffix of the
1846   // internal linkage function together.  The unique suffix should only be
1847   // added when name mangling is done to make sure that the final name can
1848   // be properly demangled.  For example, for C functions without prototypes,
1849   // name mangling is not done and the unique suffix should not be appeneded
1850   // then.
1851   if (ShouldMangle && isUniqueInternalLinkageDecl(GD, CGM)) {
1852     assert(CGM.getCodeGenOpts().UniqueInternalLinkageNames &&
1853            "Hash computed when not explicitly requested");
1854     Out << CGM.getModuleNameHash();
1855   }
1856 
1857   if (const auto *FD = dyn_cast<FunctionDecl>(ND))
1858     if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
1859       switch (FD->getMultiVersionKind()) {
1860       case MultiVersionKind::CPUDispatch:
1861       case MultiVersionKind::CPUSpecific:
1862         AppendCPUSpecificCPUDispatchMangling(CGM,
1863                                              FD->getAttr<CPUSpecificAttr>(),
1864                                              GD.getMultiVersionIndex(), Out);
1865         break;
1866       case MultiVersionKind::Target:
1867         AppendTargetMangling(CGM, FD->getAttr<TargetAttr>(), Out);
1868         break;
1869       case MultiVersionKind::TargetVersion:
1870         AppendTargetVersionMangling(CGM, FD->getAttr<TargetVersionAttr>(), Out);
1871         break;
1872       case MultiVersionKind::TargetClones:
1873         AppendTargetClonesMangling(CGM, FD->getAttr<TargetClonesAttr>(),
1874                                    GD.getMultiVersionIndex(), Out);
1875         break;
1876       case MultiVersionKind::None:
1877         llvm_unreachable("None multiversion type isn't valid here");
1878       }
1879     }
1880 
1881   // Make unique name for device side static file-scope variable for HIP.
1882   if (CGM.getContext().shouldExternalize(ND) &&
1883       CGM.getLangOpts().GPURelocatableDeviceCode &&
1884       CGM.getLangOpts().CUDAIsDevice)
1885     CGM.printPostfixForExternalizedDecl(Out, ND);
1886 
1887   return std::string(Out.str());
1888 }
1889 
UpdateMultiVersionNames(GlobalDecl GD,const FunctionDecl * FD,StringRef & CurName)1890 void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
1891                                             const FunctionDecl *FD,
1892                                             StringRef &CurName) {
1893   if (!FD->isMultiVersion())
1894     return;
1895 
1896   // Get the name of what this would be without the 'target' attribute.  This
1897   // allows us to lookup the version that was emitted when this wasn't a
1898   // multiversion function.
1899   std::string NonTargetName =
1900       getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
1901   GlobalDecl OtherGD;
1902   if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
1903     assert(OtherGD.getCanonicalDecl()
1904                .getDecl()
1905                ->getAsFunction()
1906                ->isMultiVersion() &&
1907            "Other GD should now be a multiversioned function");
1908     // OtherFD is the version of this function that was mangled BEFORE
1909     // becoming a MultiVersion function.  It potentially needs to be updated.
1910     const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
1911                                       .getDecl()
1912                                       ->getAsFunction()
1913                                       ->getMostRecentDecl();
1914     std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
1915     // This is so that if the initial version was already the 'default'
1916     // version, we don't try to update it.
1917     if (OtherName != NonTargetName) {
1918       // Remove instead of erase, since others may have stored the StringRef
1919       // to this.
1920       const auto ExistingRecord = Manglings.find(NonTargetName);
1921       if (ExistingRecord != std::end(Manglings))
1922         Manglings.remove(&(*ExistingRecord));
1923       auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
1924       StringRef OtherNameRef = MangledDeclNames[OtherGD.getCanonicalDecl()] =
1925           Result.first->first();
1926       // If this is the current decl is being created, make sure we update the name.
1927       if (GD.getCanonicalDecl() == OtherGD.getCanonicalDecl())
1928         CurName = OtherNameRef;
1929       if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
1930         Entry->setName(OtherName);
1931     }
1932   }
1933 }
1934 
getMangledName(GlobalDecl GD)1935 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
1936   GlobalDecl CanonicalGD = GD.getCanonicalDecl();
1937 
1938   // Some ABIs don't have constructor variants.  Make sure that base and
1939   // complete constructors get mangled the same.
1940   if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
1941     if (!getTarget().getCXXABI().hasConstructorVariants()) {
1942       CXXCtorType OrigCtorType = GD.getCtorType();
1943       assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
1944       if (OrigCtorType == Ctor_Base)
1945         CanonicalGD = GlobalDecl(CD, Ctor_Complete);
1946     }
1947   }
1948 
1949   // In CUDA/HIP device compilation with -fgpu-rdc, the mangled name of a
1950   // static device variable depends on whether the variable is referenced by
1951   // a host or device host function. Therefore the mangled name cannot be
1952   // cached.
1953   if (!LangOpts.CUDAIsDevice || !getContext().mayExternalize(GD.getDecl())) {
1954     auto FoundName = MangledDeclNames.find(CanonicalGD);
1955     if (FoundName != MangledDeclNames.end())
1956       return FoundName->second;
1957   }
1958 
1959   // Keep the first result in the case of a mangling collision.
1960   const auto *ND = cast<NamedDecl>(GD.getDecl());
1961   std::string MangledName = getMangledNameImpl(*this, GD, ND);
1962 
1963   // Ensure either we have different ABIs between host and device compilations,
1964   // says host compilation following MSVC ABI but device compilation follows
1965   // Itanium C++ ABI or, if they follow the same ABI, kernel names after
1966   // mangling should be the same after name stubbing. The later checking is
1967   // very important as the device kernel name being mangled in host-compilation
1968   // is used to resolve the device binaries to be executed. Inconsistent naming
1969   // result in undefined behavior. Even though we cannot check that naming
1970   // directly between host- and device-compilations, the host- and
1971   // device-mangling in host compilation could help catching certain ones.
1972   assert(!isa<FunctionDecl>(ND) || !ND->hasAttr<CUDAGlobalAttr>() ||
1973          getContext().shouldExternalize(ND) || getLangOpts().CUDAIsDevice ||
1974          (getContext().getAuxTargetInfo() &&
1975           (getContext().getAuxTargetInfo()->getCXXABI() !=
1976            getContext().getTargetInfo().getCXXABI())) ||
1977          getCUDARuntime().getDeviceSideName(ND) ==
1978              getMangledNameImpl(
1979                  *this,
1980                  GD.getWithKernelReferenceKind(KernelReferenceKind::Kernel),
1981                  ND));
1982 
1983   auto Result = Manglings.insert(std::make_pair(MangledName, GD));
1984   return MangledDeclNames[CanonicalGD] = Result.first->first();
1985 }
1986 
getBlockMangledName(GlobalDecl GD,const BlockDecl * BD)1987 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
1988                                              const BlockDecl *BD) {
1989   MangleContext &MangleCtx = getCXXABI().getMangleContext();
1990   const Decl *D = GD.getDecl();
1991 
1992   SmallString<256> Buffer;
1993   llvm::raw_svector_ostream Out(Buffer);
1994   if (!D)
1995     MangleCtx.mangleGlobalBlock(BD,
1996       dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
1997   else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
1998     MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
1999   else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
2000     MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
2001   else
2002     MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
2003 
2004   auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
2005   return Result.first->first();
2006 }
2007 
getMangledNameDecl(StringRef Name)2008 const GlobalDecl CodeGenModule::getMangledNameDecl(StringRef Name) {
2009   auto it = MangledDeclNames.begin();
2010   while (it != MangledDeclNames.end()) {
2011     if (it->second == Name)
2012       return it->first;
2013     it++;
2014   }
2015   return GlobalDecl();
2016 }
2017 
GetGlobalValue(StringRef Name)2018 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
2019   return getModule().getNamedValue(Name);
2020 }
2021 
2022 /// AddGlobalCtor - Add a function to the list that will be called before
2023 /// main() runs.
AddGlobalCtor(llvm::Function * Ctor,int Priority,unsigned LexOrder,llvm::Constant * AssociatedData)2024 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
2025                                   unsigned LexOrder,
2026                                   llvm::Constant *AssociatedData) {
2027   // FIXME: Type coercion of void()* types.
2028   GlobalCtors.push_back(Structor(Priority, LexOrder, Ctor, AssociatedData));
2029 }
2030 
2031 /// AddGlobalDtor - Add a function to the list that will be called
2032 /// when the module is unloaded.
AddGlobalDtor(llvm::Function * Dtor,int Priority,bool IsDtorAttrFunc)2033 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority,
2034                                   bool IsDtorAttrFunc) {
2035   if (CodeGenOpts.RegisterGlobalDtorsWithAtExit &&
2036       (!getContext().getTargetInfo().getTriple().isOSAIX() || IsDtorAttrFunc)) {
2037     DtorsUsingAtExit[Priority].push_back(Dtor);
2038     return;
2039   }
2040 
2041   // FIXME: Type coercion of void()* types.
2042   GlobalDtors.push_back(Structor(Priority, ~0U, Dtor, nullptr));
2043 }
2044 
EmitCtorList(CtorList & Fns,const char * GlobalName)2045 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
2046   if (Fns.empty()) return;
2047 
2048   // Ctor function type is void()*.
2049   llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
2050   llvm::Type *CtorPFTy = llvm::PointerType::get(CtorFTy,
2051       TheModule.getDataLayout().getProgramAddressSpace());
2052 
2053   // Get the type of a ctor entry, { i32, void ()*, i8* }.
2054   llvm::StructType *CtorStructTy = llvm::StructType::get(
2055       Int32Ty, CtorPFTy, VoidPtrTy);
2056 
2057   // Construct the constructor and destructor arrays.
2058   ConstantInitBuilder builder(*this);
2059   auto ctors = builder.beginArray(CtorStructTy);
2060   for (const auto &I : Fns) {
2061     auto ctor = ctors.beginStruct(CtorStructTy);
2062     ctor.addInt(Int32Ty, I.Priority);
2063     ctor.add(I.Initializer);
2064     if (I.AssociatedData)
2065       ctor.add(I.AssociatedData);
2066     else
2067       ctor.addNullPointer(VoidPtrTy);
2068     ctor.finishAndAddTo(ctors);
2069   }
2070 
2071   auto list =
2072     ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
2073                                 /*constant*/ false,
2074                                 llvm::GlobalValue::AppendingLinkage);
2075 
2076   // The LTO linker doesn't seem to like it when we set an alignment
2077   // on appending variables.  Take it off as a workaround.
2078   list->setAlignment(std::nullopt);
2079 
2080   Fns.clear();
2081 }
2082 
2083 llvm::GlobalValue::LinkageTypes
getFunctionLinkage(GlobalDecl GD)2084 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
2085   const auto *D = cast<FunctionDecl>(GD.getDecl());
2086 
2087   GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
2088 
2089   if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
2090     return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
2091 
2092   return getLLVMLinkageForDeclarator(D, Linkage);
2093 }
2094 
CreateCrossDsoCfiTypeId(llvm::Metadata * MD)2095 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
2096   llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
2097   if (!MDS) return nullptr;
2098 
2099   return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
2100 }
2101 
CreateKCFITypeId(QualType T)2102 llvm::ConstantInt *CodeGenModule::CreateKCFITypeId(QualType T) {
2103   if (auto *FnType = T->getAs<FunctionProtoType>())
2104     T = getContext().getFunctionType(
2105         FnType->getReturnType(), FnType->getParamTypes(),
2106         FnType->getExtProtoInfo().withExceptionSpec(EST_None));
2107 
2108   std::string OutName;
2109   llvm::raw_string_ostream Out(OutName);
2110   getCXXABI().getMangleContext().mangleCanonicalTypeName(
2111       T, Out, getCodeGenOpts().SanitizeCfiICallNormalizeIntegers);
2112 
2113   if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
2114     Out << ".normalized";
2115 
2116   return llvm::ConstantInt::get(Int32Ty,
2117                                 static_cast<uint32_t>(llvm::xxHash64(OutName)));
2118 }
2119 
SetLLVMFunctionAttributes(GlobalDecl GD,const CGFunctionInfo & Info,llvm::Function * F,bool IsThunk)2120 void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
2121                                               const CGFunctionInfo &Info,
2122                                               llvm::Function *F, bool IsThunk) {
2123   unsigned CallingConv;
2124   llvm::AttributeList PAL;
2125   ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv,
2126                          /*AttrOnCallSite=*/false, IsThunk);
2127   F->setAttributes(PAL);
2128   F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
2129 }
2130 
removeImageAccessQualifier(std::string & TyName)2131 static void removeImageAccessQualifier(std::string& TyName) {
2132   std::string ReadOnlyQual("__read_only");
2133   std::string::size_type ReadOnlyPos = TyName.find(ReadOnlyQual);
2134   if (ReadOnlyPos != std::string::npos)
2135     // "+ 1" for the space after access qualifier.
2136     TyName.erase(ReadOnlyPos, ReadOnlyQual.size() + 1);
2137   else {
2138     std::string WriteOnlyQual("__write_only");
2139     std::string::size_type WriteOnlyPos = TyName.find(WriteOnlyQual);
2140     if (WriteOnlyPos != std::string::npos)
2141       TyName.erase(WriteOnlyPos, WriteOnlyQual.size() + 1);
2142     else {
2143       std::string ReadWriteQual("__read_write");
2144       std::string::size_type ReadWritePos = TyName.find(ReadWriteQual);
2145       if (ReadWritePos != std::string::npos)
2146         TyName.erase(ReadWritePos, ReadWriteQual.size() + 1);
2147     }
2148   }
2149 }
2150 
2151 // Returns the address space id that should be produced to the
2152 // kernel_arg_addr_space metadata. This is always fixed to the ids
2153 // as specified in the SPIR 2.0 specification in order to differentiate
2154 // for example in clGetKernelArgInfo() implementation between the address
2155 // spaces with targets without unique mapping to the OpenCL address spaces
2156 // (basically all single AS CPUs).
ArgInfoAddressSpace(LangAS AS)2157 static unsigned ArgInfoAddressSpace(LangAS AS) {
2158   switch (AS) {
2159   case LangAS::opencl_global:
2160     return 1;
2161   case LangAS::opencl_constant:
2162     return 2;
2163   case LangAS::opencl_local:
2164     return 3;
2165   case LangAS::opencl_generic:
2166     return 4; // Not in SPIR 2.0 specs.
2167   case LangAS::opencl_global_device:
2168     return 5;
2169   case LangAS::opencl_global_host:
2170     return 6;
2171   default:
2172     return 0; // Assume private.
2173   }
2174 }
2175 
GenKernelArgMetadata(llvm::Function * Fn,const FunctionDecl * FD,CodeGenFunction * CGF)2176 void CodeGenModule::GenKernelArgMetadata(llvm::Function *Fn,
2177                                          const FunctionDecl *FD,
2178                                          CodeGenFunction *CGF) {
2179   assert(((FD && CGF) || (!FD && !CGF)) &&
2180          "Incorrect use - FD and CGF should either be both null or not!");
2181   // Create MDNodes that represent the kernel arg metadata.
2182   // Each MDNode is a list in the form of "key", N number of values which is
2183   // the same number of values as their are kernel arguments.
2184 
2185   const PrintingPolicy &Policy = Context.getPrintingPolicy();
2186 
2187   // MDNode for the kernel argument address space qualifiers.
2188   SmallVector<llvm::Metadata *, 8> addressQuals;
2189 
2190   // MDNode for the kernel argument access qualifiers (images only).
2191   SmallVector<llvm::Metadata *, 8> accessQuals;
2192 
2193   // MDNode for the kernel argument type names.
2194   SmallVector<llvm::Metadata *, 8> argTypeNames;
2195 
2196   // MDNode for the kernel argument base type names.
2197   SmallVector<llvm::Metadata *, 8> argBaseTypeNames;
2198 
2199   // MDNode for the kernel argument type qualifiers.
2200   SmallVector<llvm::Metadata *, 8> argTypeQuals;
2201 
2202   // MDNode for the kernel argument names.
2203   SmallVector<llvm::Metadata *, 8> argNames;
2204 
2205   if (FD && CGF)
2206     for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
2207       const ParmVarDecl *parm = FD->getParamDecl(i);
2208       // Get argument name.
2209       argNames.push_back(llvm::MDString::get(VMContext, parm->getName()));
2210 
2211       if (!getLangOpts().OpenCL)
2212         continue;
2213       QualType ty = parm->getType();
2214       std::string typeQuals;
2215 
2216       // Get image and pipe access qualifier:
2217       if (ty->isImageType() || ty->isPipeType()) {
2218         const Decl *PDecl = parm;
2219         if (const auto *TD = ty->getAs<TypedefType>())
2220           PDecl = TD->getDecl();
2221         const OpenCLAccessAttr *A = PDecl->getAttr<OpenCLAccessAttr>();
2222         if (A && A->isWriteOnly())
2223           accessQuals.push_back(llvm::MDString::get(VMContext, "write_only"));
2224         else if (A && A->isReadWrite())
2225           accessQuals.push_back(llvm::MDString::get(VMContext, "read_write"));
2226         else
2227           accessQuals.push_back(llvm::MDString::get(VMContext, "read_only"));
2228       } else
2229         accessQuals.push_back(llvm::MDString::get(VMContext, "none"));
2230 
2231       auto getTypeSpelling = [&](QualType Ty) {
2232         auto typeName = Ty.getUnqualifiedType().getAsString(Policy);
2233 
2234         if (Ty.isCanonical()) {
2235           StringRef typeNameRef = typeName;
2236           // Turn "unsigned type" to "utype"
2237           if (typeNameRef.consume_front("unsigned "))
2238             return std::string("u") + typeNameRef.str();
2239           if (typeNameRef.consume_front("signed "))
2240             return typeNameRef.str();
2241         }
2242 
2243         return typeName;
2244       };
2245 
2246       if (ty->isPointerType()) {
2247         QualType pointeeTy = ty->getPointeeType();
2248 
2249         // Get address qualifier.
2250         addressQuals.push_back(
2251             llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(
2252                 ArgInfoAddressSpace(pointeeTy.getAddressSpace()))));
2253 
2254         // Get argument type name.
2255         std::string typeName = getTypeSpelling(pointeeTy) + "*";
2256         std::string baseTypeName =
2257             getTypeSpelling(pointeeTy.getCanonicalType()) + "*";
2258         argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
2259         argBaseTypeNames.push_back(
2260             llvm::MDString::get(VMContext, baseTypeName));
2261 
2262         // Get argument type qualifiers:
2263         if (ty.isRestrictQualified())
2264           typeQuals = "restrict";
2265         if (pointeeTy.isConstQualified() ||
2266             (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
2267           typeQuals += typeQuals.empty() ? "const" : " const";
2268         if (pointeeTy.isVolatileQualified())
2269           typeQuals += typeQuals.empty() ? "volatile" : " volatile";
2270       } else {
2271         uint32_t AddrSpc = 0;
2272         bool isPipe = ty->isPipeType();
2273         if (ty->isImageType() || isPipe)
2274           AddrSpc = ArgInfoAddressSpace(LangAS::opencl_global);
2275 
2276         addressQuals.push_back(
2277             llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(AddrSpc)));
2278 
2279         // Get argument type name.
2280         ty = isPipe ? ty->castAs<PipeType>()->getElementType() : ty;
2281         std::string typeName = getTypeSpelling(ty);
2282         std::string baseTypeName = getTypeSpelling(ty.getCanonicalType());
2283 
2284         // Remove access qualifiers on images
2285         // (as they are inseparable from type in clang implementation,
2286         // but OpenCL spec provides a special query to get access qualifier
2287         // via clGetKernelArgInfo with CL_KERNEL_ARG_ACCESS_QUALIFIER):
2288         if (ty->isImageType()) {
2289           removeImageAccessQualifier(typeName);
2290           removeImageAccessQualifier(baseTypeName);
2291         }
2292 
2293         argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
2294         argBaseTypeNames.push_back(
2295             llvm::MDString::get(VMContext, baseTypeName));
2296 
2297         if (isPipe)
2298           typeQuals = "pipe";
2299       }
2300       argTypeQuals.push_back(llvm::MDString::get(VMContext, typeQuals));
2301     }
2302 
2303   if (getLangOpts().OpenCL) {
2304     Fn->setMetadata("kernel_arg_addr_space",
2305                     llvm::MDNode::get(VMContext, addressQuals));
2306     Fn->setMetadata("kernel_arg_access_qual",
2307                     llvm::MDNode::get(VMContext, accessQuals));
2308     Fn->setMetadata("kernel_arg_type",
2309                     llvm::MDNode::get(VMContext, argTypeNames));
2310     Fn->setMetadata("kernel_arg_base_type",
2311                     llvm::MDNode::get(VMContext, argBaseTypeNames));
2312     Fn->setMetadata("kernel_arg_type_qual",
2313                     llvm::MDNode::get(VMContext, argTypeQuals));
2314   }
2315   if (getCodeGenOpts().EmitOpenCLArgMetadata ||
2316       getCodeGenOpts().HIPSaveKernelArgName)
2317     Fn->setMetadata("kernel_arg_name",
2318                     llvm::MDNode::get(VMContext, argNames));
2319 }
2320 
2321 /// Determines whether the language options require us to model
2322 /// unwind exceptions.  We treat -fexceptions as mandating this
2323 /// except under the fragile ObjC ABI with only ObjC exceptions
2324 /// enabled.  This means, for example, that C with -fexceptions
2325 /// enables this.
hasUnwindExceptions(const LangOptions & LangOpts)2326 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
2327   // If exceptions are completely disabled, obviously this is false.
2328   if (!LangOpts.Exceptions) return false;
2329 
2330   // If C++ exceptions are enabled, this is true.
2331   if (LangOpts.CXXExceptions) return true;
2332 
2333   // If ObjC exceptions are enabled, this depends on the ABI.
2334   if (LangOpts.ObjCExceptions) {
2335     return LangOpts.ObjCRuntime.hasUnwindExceptions();
2336   }
2337 
2338   return true;
2339 }
2340 
requiresMemberFunctionPointerTypeMetadata(CodeGenModule & CGM,const CXXMethodDecl * MD)2341 static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM,
2342                                                       const CXXMethodDecl *MD) {
2343   // Check that the type metadata can ever actually be used by a call.
2344   if (!CGM.getCodeGenOpts().LTOUnit ||
2345       !CGM.HasHiddenLTOVisibility(MD->getParent()))
2346     return false;
2347 
2348   // Only functions whose address can be taken with a member function pointer
2349   // need this sort of type metadata.
2350   return MD->isImplicitObjectMemberFunction() && !MD->isVirtual() &&
2351          !isa<CXXConstructorDecl, CXXDestructorDecl>(MD);
2352 }
2353 
2354 SmallVector<const CXXRecordDecl *, 0>
getMostBaseClasses(const CXXRecordDecl * RD)2355 CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
2356   llvm::SetVector<const CXXRecordDecl *> MostBases;
2357 
2358   std::function<void (const CXXRecordDecl *)> CollectMostBases;
2359   CollectMostBases = [&](const CXXRecordDecl *RD) {
2360     if (RD->getNumBases() == 0)
2361       MostBases.insert(RD);
2362     for (const CXXBaseSpecifier &B : RD->bases())
2363       CollectMostBases(B.getType()->getAsCXXRecordDecl());
2364   };
2365   CollectMostBases(RD);
2366   return MostBases.takeVector();
2367 }
2368 
SetLLVMFunctionAttributesForDefinition(const Decl * D,llvm::Function * F)2369 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
2370                                                            llvm::Function *F) {
2371   llvm::AttrBuilder B(F->getContext());
2372 
2373   if ((!D || !D->hasAttr<NoUwtableAttr>()) && CodeGenOpts.UnwindTables)
2374     B.addUWTableAttr(llvm::UWTableKind(CodeGenOpts.UnwindTables));
2375 
2376   if (CodeGenOpts.StackClashProtector)
2377     B.addAttribute("probe-stack", "inline-asm");
2378 
2379   if (CodeGenOpts.StackProbeSize && CodeGenOpts.StackProbeSize != 4096)
2380     B.addAttribute("stack-probe-size",
2381                    std::to_string(CodeGenOpts.StackProbeSize));
2382 
2383   if (!hasUnwindExceptions(LangOpts))
2384     B.addAttribute(llvm::Attribute::NoUnwind);
2385 
2386   if (D && D->hasAttr<NoStackProtectorAttr>())
2387     ; // Do nothing.
2388   else if (D && D->hasAttr<StrictGuardStackCheckAttr>() &&
2389            isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPOn))
2390     B.addAttribute(llvm::Attribute::StackProtectStrong);
2391   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPOn))
2392     B.addAttribute(llvm::Attribute::StackProtect);
2393   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPStrong))
2394     B.addAttribute(llvm::Attribute::StackProtectStrong);
2395   else if (isStackProtectorOn(LangOpts, getTriple(), LangOptions::SSPReq))
2396     B.addAttribute(llvm::Attribute::StackProtectReq);
2397 
2398   if (!D) {
2399     // If we don't have a declaration to control inlining, the function isn't
2400     // explicitly marked as alwaysinline for semantic reasons, and inlining is
2401     // disabled, mark the function as noinline.
2402     if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
2403         CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
2404       B.addAttribute(llvm::Attribute::NoInline);
2405 
2406     F->addFnAttrs(B);
2407     return;
2408   }
2409 
2410   // Handle SME attributes that apply to function definitions,
2411   // rather than to function prototypes.
2412   if (D->hasAttr<ArmLocallyStreamingAttr>())
2413     B.addAttribute("aarch64_pstate_sm_body");
2414 
2415   if (auto *Attr = D->getAttr<ArmNewAttr>()) {
2416     if (Attr->isNewZA())
2417       B.addAttribute("aarch64_pstate_za_new");
2418     if (Attr->isNewZT0())
2419       B.addAttribute("aarch64_new_zt0");
2420   }
2421 
2422   // Track whether we need to add the optnone LLVM attribute,
2423   // starting with the default for this optimization level.
2424   bool ShouldAddOptNone =
2425       !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
2426   // We can't add optnone in the following cases, it won't pass the verifier.
2427   ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
2428   ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
2429 
2430   // Add optnone, but do so only if the function isn't always_inline.
2431   if ((ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) &&
2432       !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2433     B.addAttribute(llvm::Attribute::OptimizeNone);
2434 
2435     // OptimizeNone implies noinline; we should not be inlining such functions.
2436     B.addAttribute(llvm::Attribute::NoInline);
2437 
2438     // We still need to handle naked functions even though optnone subsumes
2439     // much of their semantics.
2440     if (D->hasAttr<NakedAttr>())
2441       B.addAttribute(llvm::Attribute::Naked);
2442 
2443     // OptimizeNone wins over OptimizeForSize and MinSize.
2444     F->removeFnAttr(llvm::Attribute::OptimizeForSize);
2445     F->removeFnAttr(llvm::Attribute::MinSize);
2446   } else if (D->hasAttr<NakedAttr>()) {
2447     // Naked implies noinline: we should not be inlining such functions.
2448     B.addAttribute(llvm::Attribute::Naked);
2449     B.addAttribute(llvm::Attribute::NoInline);
2450   } else if (D->hasAttr<NoDuplicateAttr>()) {
2451     B.addAttribute(llvm::Attribute::NoDuplicate);
2452   } else if (D->hasAttr<NoInlineAttr>() && !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2453     // Add noinline if the function isn't always_inline.
2454     B.addAttribute(llvm::Attribute::NoInline);
2455   } else if (D->hasAttr<AlwaysInlineAttr>() &&
2456              !F->hasFnAttribute(llvm::Attribute::NoInline)) {
2457     // (noinline wins over always_inline, and we can't specify both in IR)
2458     B.addAttribute(llvm::Attribute::AlwaysInline);
2459   } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
2460     // If we're not inlining, then force everything that isn't always_inline to
2461     // carry an explicit noinline attribute.
2462     if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
2463       B.addAttribute(llvm::Attribute::NoInline);
2464   } else {
2465     // Otherwise, propagate the inline hint attribute and potentially use its
2466     // absence to mark things as noinline.
2467     if (auto *FD = dyn_cast<FunctionDecl>(D)) {
2468       // Search function and template pattern redeclarations for inline.
2469       auto CheckForInline = [](const FunctionDecl *FD) {
2470         auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
2471           return Redecl->isInlineSpecified();
2472         };
2473         if (any_of(FD->redecls(), CheckRedeclForInline))
2474           return true;
2475         const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
2476         if (!Pattern)
2477           return false;
2478         return any_of(Pattern->redecls(), CheckRedeclForInline);
2479       };
2480       if (CheckForInline(FD)) {
2481         B.addAttribute(llvm::Attribute::InlineHint);
2482       } else if (CodeGenOpts.getInlining() ==
2483                      CodeGenOptions::OnlyHintInlining &&
2484                  !FD->isInlined() &&
2485                  !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
2486         B.addAttribute(llvm::Attribute::NoInline);
2487       }
2488     }
2489   }
2490 
2491   // Add other optimization related attributes if we are optimizing this
2492   // function.
2493   if (!D->hasAttr<OptimizeNoneAttr>()) {
2494     if (D->hasAttr<ColdAttr>()) {
2495       if (!ShouldAddOptNone)
2496         B.addAttribute(llvm::Attribute::OptimizeForSize);
2497       B.addAttribute(llvm::Attribute::Cold);
2498     }
2499     if (D->hasAttr<HotAttr>())
2500       B.addAttribute(llvm::Attribute::Hot);
2501     if (D->hasAttr<MinSizeAttr>())
2502       B.addAttribute(llvm::Attribute::MinSize);
2503   }
2504 
2505   F->addFnAttrs(B);
2506 
2507   unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
2508   if (alignment)
2509     F->setAlignment(llvm::Align(alignment));
2510 
2511   if (!D->hasAttr<AlignedAttr>())
2512     if (LangOpts.FunctionAlignment)
2513       F->setAlignment(llvm::Align(1ull << LangOpts.FunctionAlignment));
2514 
2515   // Some C++ ABIs require 2-byte alignment for member functions, in order to
2516   // reserve a bit for differentiating between virtual and non-virtual member
2517   // functions. If the current target's C++ ABI requires this and this is a
2518   // member function, set its alignment accordingly.
2519   if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
2520     if (isa<CXXMethodDecl>(D) && F->getPointerAlignment(getDataLayout()) < 2)
2521       F->setAlignment(std::max(llvm::Align(2), F->getAlign().valueOrOne()));
2522   }
2523 
2524   // In the cross-dso CFI mode with canonical jump tables, we want !type
2525   // attributes on definitions only.
2526   if (CodeGenOpts.SanitizeCfiCrossDso &&
2527       CodeGenOpts.SanitizeCfiCanonicalJumpTables) {
2528     if (auto *FD = dyn_cast<FunctionDecl>(D)) {
2529       // Skip available_externally functions. They won't be codegen'ed in the
2530       // current module anyway.
2531       if (getContext().GetGVALinkageForFunction(FD) != GVA_AvailableExternally)
2532         CreateFunctionTypeMetadataForIcall(FD, F);
2533     }
2534   }
2535 
2536   // Emit type metadata on member functions for member function pointer checks.
2537   // These are only ever necessary on definitions; we're guaranteed that the
2538   // definition will be present in the LTO unit as a result of LTO visibility.
2539   auto *MD = dyn_cast<CXXMethodDecl>(D);
2540   if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
2541     for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
2542       llvm::Metadata *Id =
2543           CreateMetadataIdentifierForType(Context.getMemberPointerType(
2544               MD->getType(), Context.getRecordType(Base).getTypePtr()));
2545       F->addTypeMetadata(0, Id);
2546     }
2547   }
2548 }
2549 
SetCommonAttributes(GlobalDecl GD,llvm::GlobalValue * GV)2550 void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
2551   const Decl *D = GD.getDecl();
2552   if (isa_and_nonnull<NamedDecl>(D))
2553     setGVProperties(GV, GD);
2554   else
2555     GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
2556 
2557   if (D && D->hasAttr<UsedAttr>())
2558     addUsedOrCompilerUsedGlobal(GV);
2559 
2560   if (const auto *VD = dyn_cast_if_present<VarDecl>(D);
2561       VD &&
2562       ((CodeGenOpts.KeepPersistentStorageVariables &&
2563         (VD->getStorageDuration() == SD_Static ||
2564          VD->getStorageDuration() == SD_Thread)) ||
2565        (CodeGenOpts.KeepStaticConsts && VD->getStorageDuration() == SD_Static &&
2566         VD->getType().isConstQualified())))
2567     addUsedOrCompilerUsedGlobal(GV);
2568 }
2569 
GetCPUAndFeaturesAttributes(GlobalDecl GD,llvm::AttrBuilder & Attrs,bool SetTargetFeatures)2570 bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
2571                                                 llvm::AttrBuilder &Attrs,
2572                                                 bool SetTargetFeatures) {
2573   // Add target-cpu and target-features attributes to functions. If
2574   // we have a decl for the function and it has a target attribute then
2575   // parse that and add it to the feature set.
2576   StringRef TargetCPU = getTarget().getTargetOpts().CPU;
2577   StringRef TuneCPU = getTarget().getTargetOpts().TuneCPU;
2578   std::vector<std::string> Features;
2579   const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
2580   FD = FD ? FD->getMostRecentDecl() : FD;
2581   const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
2582   const auto *TV = FD ? FD->getAttr<TargetVersionAttr>() : nullptr;
2583   assert((!TD || !TV) && "both target_version and target specified");
2584   const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
2585   const auto *TC = FD ? FD->getAttr<TargetClonesAttr>() : nullptr;
2586   bool AddedAttr = false;
2587   if (TD || TV || SD || TC) {
2588     llvm::StringMap<bool> FeatureMap;
2589     getContext().getFunctionFeatureMap(FeatureMap, GD);
2590 
2591     // Produce the canonical string for this set of features.
2592     for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
2593       Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
2594 
2595     // Now add the target-cpu and target-features to the function.
2596     // While we populated the feature map above, we still need to
2597     // get and parse the target attribute so we can get the cpu for
2598     // the function.
2599     if (TD) {
2600       ParsedTargetAttr ParsedAttr =
2601           Target.parseTargetAttr(TD->getFeaturesStr());
2602       if (!ParsedAttr.CPU.empty() &&
2603           getTarget().isValidCPUName(ParsedAttr.CPU)) {
2604         TargetCPU = ParsedAttr.CPU;
2605         TuneCPU = ""; // Clear the tune CPU.
2606       }
2607       if (!ParsedAttr.Tune.empty() &&
2608           getTarget().isValidCPUName(ParsedAttr.Tune))
2609         TuneCPU = ParsedAttr.Tune;
2610     }
2611 
2612     if (SD) {
2613       // Apply the given CPU name as the 'tune-cpu' so that the optimizer can
2614       // favor this processor.
2615       TuneCPU = SD->getCPUName(GD.getMultiVersionIndex())->getName();
2616     }
2617   } else {
2618     // Otherwise just add the existing target cpu and target features to the
2619     // function.
2620     Features = getTarget().getTargetOpts().Features;
2621   }
2622 
2623   if (!TargetCPU.empty()) {
2624     Attrs.addAttribute("target-cpu", TargetCPU);
2625     AddedAttr = true;
2626   }
2627   if (!TuneCPU.empty()) {
2628     Attrs.addAttribute("tune-cpu", TuneCPU);
2629     AddedAttr = true;
2630   }
2631   if (!Features.empty() && SetTargetFeatures) {
2632     llvm::erase_if(Features, [&](const std::string& F) {
2633        return getTarget().isReadOnlyFeature(F.substr(1));
2634     });
2635     llvm::sort(Features);
2636     Attrs.addAttribute("target-features", llvm::join(Features, ","));
2637     AddedAttr = true;
2638   }
2639 
2640   return AddedAttr;
2641 }
2642 
setNonAliasAttributes(GlobalDecl GD,llvm::GlobalObject * GO)2643 void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
2644                                           llvm::GlobalObject *GO) {
2645   const Decl *D = GD.getDecl();
2646   SetCommonAttributes(GD, GO);
2647 
2648   if (D) {
2649     if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
2650       if (D->hasAttr<RetainAttr>())
2651         addUsedGlobal(GV);
2652       if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
2653         GV->addAttribute("bss-section", SA->getName());
2654       if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
2655         GV->addAttribute("data-section", SA->getName());
2656       if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
2657         GV->addAttribute("rodata-section", SA->getName());
2658       if (auto *SA = D->getAttr<PragmaClangRelroSectionAttr>())
2659         GV->addAttribute("relro-section", SA->getName());
2660     }
2661 
2662     if (auto *F = dyn_cast<llvm::Function>(GO)) {
2663       if (D->hasAttr<RetainAttr>())
2664         addUsedGlobal(F);
2665       if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
2666         if (!D->getAttr<SectionAttr>())
2667           F->addFnAttr("implicit-section-name", SA->getName());
2668 
2669       llvm::AttrBuilder Attrs(F->getContext());
2670       if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
2671         // We know that GetCPUAndFeaturesAttributes will always have the
2672         // newest set, since it has the newest possible FunctionDecl, so the
2673         // new ones should replace the old.
2674         llvm::AttributeMask RemoveAttrs;
2675         RemoveAttrs.addAttribute("target-cpu");
2676         RemoveAttrs.addAttribute("target-features");
2677         RemoveAttrs.addAttribute("tune-cpu");
2678         F->removeFnAttrs(RemoveAttrs);
2679         F->addFnAttrs(Attrs);
2680       }
2681     }
2682 
2683     if (const auto *CSA = D->getAttr<CodeSegAttr>())
2684       GO->setSection(CSA->getName());
2685     else if (const auto *SA = D->getAttr<SectionAttr>())
2686       GO->setSection(SA->getName());
2687   }
2688 
2689   getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
2690 }
2691 
SetInternalFunctionAttributes(GlobalDecl GD,llvm::Function * F,const CGFunctionInfo & FI)2692 void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
2693                                                   llvm::Function *F,
2694                                                   const CGFunctionInfo &FI) {
2695   const Decl *D = GD.getDecl();
2696   SetLLVMFunctionAttributes(GD, FI, F, /*IsThunk=*/false);
2697   SetLLVMFunctionAttributesForDefinition(D, F);
2698 
2699   F->setLinkage(llvm::Function::InternalLinkage);
2700 
2701   setNonAliasAttributes(GD, F);
2702 }
2703 
setLinkageForGV(llvm::GlobalValue * GV,const NamedDecl * ND)2704 static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
2705   // Set linkage and visibility in case we never see a definition.
2706   LinkageInfo LV = ND->getLinkageAndVisibility();
2707   // Don't set internal linkage on declarations.
2708   // "extern_weak" is overloaded in LLVM; we probably should have
2709   // separate linkage types for this.
2710   if (isExternallyVisible(LV.getLinkage()) &&
2711       (ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
2712     GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
2713 }
2714 
CreateFunctionTypeMetadataForIcall(const FunctionDecl * FD,llvm::Function * F)2715 void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
2716                                                        llvm::Function *F) {
2717   // Only if we are checking indirect calls.
2718   if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
2719     return;
2720 
2721   // Non-static class methods are handled via vtable or member function pointer
2722   // checks elsewhere.
2723   if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
2724     return;
2725 
2726   llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
2727   F->addTypeMetadata(0, MD);
2728   F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
2729 
2730   // Emit a hash-based bit set entry for cross-DSO calls.
2731   if (CodeGenOpts.SanitizeCfiCrossDso)
2732     if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
2733       F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
2734 }
2735 
setKCFIType(const FunctionDecl * FD,llvm::Function * F)2736 void CodeGenModule::setKCFIType(const FunctionDecl *FD, llvm::Function *F) {
2737   llvm::LLVMContext &Ctx = F->getContext();
2738   llvm::MDBuilder MDB(Ctx);
2739   F->setMetadata(llvm::LLVMContext::MD_kcfi_type,
2740                  llvm::MDNode::get(
2741                      Ctx, MDB.createConstant(CreateKCFITypeId(FD->getType()))));
2742 }
2743 
allowKCFIIdentifier(StringRef Name)2744 static bool allowKCFIIdentifier(StringRef Name) {
2745   // KCFI type identifier constants are only necessary for external assembly
2746   // functions, which means it's safe to skip unusual names. Subset of
2747   // MCAsmInfo::isAcceptableChar() and MCAsmInfoXCOFF::isAcceptableChar().
2748   return llvm::all_of(Name, [](const char &C) {
2749     return llvm::isAlnum(C) || C == '_' || C == '.';
2750   });
2751 }
2752 
finalizeKCFITypes()2753 void CodeGenModule::finalizeKCFITypes() {
2754   llvm::Module &M = getModule();
2755   for (auto &F : M.functions()) {
2756     // Remove KCFI type metadata from non-address-taken local functions.
2757     bool AddressTaken = F.hasAddressTaken();
2758     if (!AddressTaken && F.hasLocalLinkage())
2759       F.eraseMetadata(llvm::LLVMContext::MD_kcfi_type);
2760 
2761     // Generate a constant with the expected KCFI type identifier for all
2762     // address-taken function declarations to support annotating indirectly
2763     // called assembly functions.
2764     if (!AddressTaken || !F.isDeclaration())
2765       continue;
2766 
2767     const llvm::ConstantInt *Type;
2768     if (const llvm::MDNode *MD = F.getMetadata(llvm::LLVMContext::MD_kcfi_type))
2769       Type = llvm::mdconst::extract<llvm::ConstantInt>(MD->getOperand(0));
2770     else
2771       continue;
2772 
2773     StringRef Name = F.getName();
2774     if (!allowKCFIIdentifier(Name))
2775       continue;
2776 
2777     std::string Asm = (".weak __kcfi_typeid_" + Name + "\n.set __kcfi_typeid_" +
2778                        Name + ", " + Twine(Type->getZExtValue()) + "\n")
2779                           .str();
2780     M.appendModuleInlineAsm(Asm);
2781   }
2782 }
2783 
SetFunctionAttributes(GlobalDecl GD,llvm::Function * F,bool IsIncompleteFunction,bool IsThunk)2784 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
2785                                           bool IsIncompleteFunction,
2786                                           bool IsThunk) {
2787 
2788   if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) {
2789     // If this is an intrinsic function, set the function's attributes
2790     // to the intrinsic's attributes.
2791     F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID));
2792     return;
2793   }
2794 
2795   const auto *FD = cast<FunctionDecl>(GD.getDecl());
2796 
2797   if (!IsIncompleteFunction)
2798     SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F,
2799                               IsThunk);
2800 
2801   // Add the Returned attribute for "this", except for iOS 5 and earlier
2802   // where substantial code, including the libstdc++ dylib, was compiled with
2803   // GCC and does not actually return "this".
2804   if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
2805       !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
2806     assert(!F->arg_empty() &&
2807            F->arg_begin()->getType()
2808              ->canLosslesslyBitCastTo(F->getReturnType()) &&
2809            "unexpected this return");
2810     F->addParamAttr(0, llvm::Attribute::Returned);
2811   }
2812 
2813   // Only a few attributes are set on declarations; these may later be
2814   // overridden by a definition.
2815 
2816   setLinkageForGV(F, FD);
2817   setGVProperties(F, FD);
2818 
2819   // Setup target-specific attributes.
2820   if (!IsIncompleteFunction && F->isDeclaration())
2821     getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
2822 
2823   if (const auto *CSA = FD->getAttr<CodeSegAttr>())
2824     F->setSection(CSA->getName());
2825   else if (const auto *SA = FD->getAttr<SectionAttr>())
2826      F->setSection(SA->getName());
2827 
2828   if (const auto *EA = FD->getAttr<ErrorAttr>()) {
2829     if (EA->isError())
2830       F->addFnAttr("dontcall-error", EA->getUserDiagnostic());
2831     else if (EA->isWarning())
2832       F->addFnAttr("dontcall-warn", EA->getUserDiagnostic());
2833   }
2834 
2835   // If we plan on emitting this inline builtin, we can't treat it as a builtin.
2836   if (FD->isInlineBuiltinDeclaration()) {
2837     const FunctionDecl *FDBody;
2838     bool HasBody = FD->hasBody(FDBody);
2839     (void)HasBody;
2840     assert(HasBody && "Inline builtin declarations should always have an "
2841                       "available body!");
2842     if (shouldEmitFunction(FDBody))
2843       F->addFnAttr(llvm::Attribute::NoBuiltin);
2844   }
2845 
2846   if (FD->isReplaceableGlobalAllocationFunction()) {
2847     // A replaceable global allocation function does not act like a builtin by
2848     // default, only if it is invoked by a new-expression or delete-expression.
2849     F->addFnAttr(llvm::Attribute::NoBuiltin);
2850   }
2851 
2852   if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
2853     F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2854   else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
2855     if (MD->isVirtual())
2856       F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2857 
2858   // Don't emit entries for function declarations in the cross-DSO mode. This
2859   // is handled with better precision by the receiving DSO. But if jump tables
2860   // are non-canonical then we need type metadata in order to produce the local
2861   // jump table.
2862   if (!CodeGenOpts.SanitizeCfiCrossDso ||
2863       !CodeGenOpts.SanitizeCfiCanonicalJumpTables)
2864     CreateFunctionTypeMetadataForIcall(FD, F);
2865 
2866   if (LangOpts.Sanitize.has(SanitizerKind::KCFI))
2867     setKCFIType(FD, F);
2868 
2869   if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
2870     getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
2871 
2872   if (CodeGenOpts.InlineMaxStackSize != UINT_MAX)
2873     F->addFnAttr("inline-max-stacksize", llvm::utostr(CodeGenOpts.InlineMaxStackSize));
2874 
2875   if (const auto *CB = FD->getAttr<CallbackAttr>()) {
2876     // Annotate the callback behavior as metadata:
2877     //  - The callback callee (as argument number).
2878     //  - The callback payloads (as argument numbers).
2879     llvm::LLVMContext &Ctx = F->getContext();
2880     llvm::MDBuilder MDB(Ctx);
2881 
2882     // The payload indices are all but the first one in the encoding. The first
2883     // identifies the callback callee.
2884     int CalleeIdx = *CB->encoding_begin();
2885     ArrayRef<int> PayloadIndices(CB->encoding_begin() + 1, CB->encoding_end());
2886     F->addMetadata(llvm::LLVMContext::MD_callback,
2887                    *llvm::MDNode::get(Ctx, {MDB.createCallbackEncoding(
2888                                                CalleeIdx, PayloadIndices,
2889                                                /* VarArgsArePassed */ false)}));
2890   }
2891 }
2892 
addUsedGlobal(llvm::GlobalValue * GV)2893 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
2894   assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
2895          "Only globals with definition can force usage.");
2896   LLVMUsed.emplace_back(GV);
2897 }
2898 
addCompilerUsedGlobal(llvm::GlobalValue * GV)2899 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
2900   assert(!GV->isDeclaration() &&
2901          "Only globals with definition can force usage.");
2902   LLVMCompilerUsed.emplace_back(GV);
2903 }
2904 
addUsedOrCompilerUsedGlobal(llvm::GlobalValue * GV)2905 void CodeGenModule::addUsedOrCompilerUsedGlobal(llvm::GlobalValue *GV) {
2906   assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
2907          "Only globals with definition can force usage.");
2908   if (getTriple().isOSBinFormatELF())
2909     LLVMCompilerUsed.emplace_back(GV);
2910   else
2911     LLVMUsed.emplace_back(GV);
2912 }
2913 
emitUsed(CodeGenModule & CGM,StringRef Name,std::vector<llvm::WeakTrackingVH> & List)2914 static void emitUsed(CodeGenModule &CGM, StringRef Name,
2915                      std::vector<llvm::WeakTrackingVH> &List) {
2916   // Don't create llvm.used if there is no need.
2917   if (List.empty())
2918     return;
2919 
2920   // Convert List to what ConstantArray needs.
2921   SmallVector<llvm::Constant*, 8> UsedArray;
2922   UsedArray.resize(List.size());
2923   for (unsigned i = 0, e = List.size(); i != e; ++i) {
2924     UsedArray[i] =
2925         llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
2926             cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
2927   }
2928 
2929   if (UsedArray.empty())
2930     return;
2931   llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
2932 
2933   auto *GV = new llvm::GlobalVariable(
2934       CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
2935       llvm::ConstantArray::get(ATy, UsedArray), Name);
2936 
2937   GV->setSection("llvm.metadata");
2938 }
2939 
emitLLVMUsed()2940 void CodeGenModule::emitLLVMUsed() {
2941   emitUsed(*this, "llvm.used", LLVMUsed);
2942   emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
2943 }
2944 
AppendLinkerOptions(StringRef Opts)2945 void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
2946   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
2947   LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
2948 }
2949 
AddDetectMismatch(StringRef Name,StringRef Value)2950 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
2951   llvm::SmallString<32> Opt;
2952   getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
2953   if (Opt.empty())
2954     return;
2955   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
2956   LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
2957 }
2958 
AddDependentLib(StringRef Lib)2959 void CodeGenModule::AddDependentLib(StringRef Lib) {
2960   auto &C = getLLVMContext();
2961   if (getTarget().getTriple().isOSBinFormatELF()) {
2962       ELFDependentLibraries.push_back(
2963         llvm::MDNode::get(C, llvm::MDString::get(C, Lib)));
2964     return;
2965   }
2966 
2967   llvm::SmallString<24> Opt;
2968   getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
2969   auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
2970   LinkerOptionsMetadata.push_back(llvm::MDNode::get(C, MDOpts));
2971 }
2972 
2973 /// Add link options implied by the given module, including modules
2974 /// it depends on, using a postorder walk.
addLinkOptionsPostorder(CodeGenModule & CGM,Module * Mod,SmallVectorImpl<llvm::MDNode * > & Metadata,llvm::SmallPtrSet<Module *,16> & Visited)2975 static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
2976                                     SmallVectorImpl<llvm::MDNode *> &Metadata,
2977                                     llvm::SmallPtrSet<Module *, 16> &Visited) {
2978   // Import this module's parent.
2979   if (Mod->Parent && Visited.insert(Mod->Parent).second) {
2980     addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
2981   }
2982 
2983   // Import this module's dependencies.
2984   for (Module *Import : llvm::reverse(Mod->Imports)) {
2985     if (Visited.insert(Import).second)
2986       addLinkOptionsPostorder(CGM, Import, Metadata, Visited);
2987   }
2988 
2989   // Add linker options to link against the libraries/frameworks
2990   // described by this module.
2991   llvm::LLVMContext &Context = CGM.getLLVMContext();
2992   bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
2993 
2994   // For modules that use export_as for linking, use that module
2995   // name instead.
2996   if (Mod->UseExportAsModuleLinkName)
2997     return;
2998 
2999   for (const Module::LinkLibrary &LL : llvm::reverse(Mod->LinkLibraries)) {
3000     // Link against a framework.  Frameworks are currently Darwin only, so we
3001     // don't to ask TargetCodeGenInfo for the spelling of the linker option.
3002     if (LL.IsFramework) {
3003       llvm::Metadata *Args[2] = {llvm::MDString::get(Context, "-framework"),
3004                                  llvm::MDString::get(Context, LL.Library)};
3005 
3006       Metadata.push_back(llvm::MDNode::get(Context, Args));
3007       continue;
3008     }
3009 
3010     // Link against a library.
3011     if (IsELF) {
3012       llvm::Metadata *Args[2] = {
3013           llvm::MDString::get(Context, "lib"),
3014           llvm::MDString::get(Context, LL.Library),
3015       };
3016       Metadata.push_back(llvm::MDNode::get(Context, Args));
3017     } else {
3018       llvm::SmallString<24> Opt;
3019       CGM.getTargetCodeGenInfo().getDependentLibraryOption(LL.Library, Opt);
3020       auto *OptString = llvm::MDString::get(Context, Opt);
3021       Metadata.push_back(llvm::MDNode::get(Context, OptString));
3022     }
3023   }
3024 }
3025 
EmitModuleInitializers(clang::Module * Primary)3026 void CodeGenModule::EmitModuleInitializers(clang::Module *Primary) {
3027   assert(Primary->isNamedModuleUnit() &&
3028          "We should only emit module initializers for named modules.");
3029 
3030   // Emit the initializers in the order that sub-modules appear in the
3031   // source, first Global Module Fragments, if present.
3032   if (auto GMF = Primary->getGlobalModuleFragment()) {
3033     for (Decl *D : getContext().getModuleInitializers(GMF)) {
3034       if (isa<ImportDecl>(D))
3035         continue;
3036       assert(isa<VarDecl>(D) && "GMF initializer decl is not a var?");
3037       EmitTopLevelDecl(D);
3038     }
3039   }
3040   // Second any associated with the module, itself.
3041   for (Decl *D : getContext().getModuleInitializers(Primary)) {
3042     // Skip import decls, the inits for those are called explicitly.
3043     if (isa<ImportDecl>(D))
3044       continue;
3045     EmitTopLevelDecl(D);
3046   }
3047   // Third any associated with the Privat eMOdule Fragment, if present.
3048   if (auto PMF = Primary->getPrivateModuleFragment()) {
3049     for (Decl *D : getContext().getModuleInitializers(PMF)) {
3050       // Skip import decls, the inits for those are called explicitly.
3051       if (isa<ImportDecl>(D))
3052         continue;
3053       assert(isa<VarDecl>(D) && "PMF initializer decl is not a var?");
3054       EmitTopLevelDecl(D);
3055     }
3056   }
3057 }
3058 
EmitModuleLinkOptions()3059 void CodeGenModule::EmitModuleLinkOptions() {
3060   // Collect the set of all of the modules we want to visit to emit link
3061   // options, which is essentially the imported modules and all of their
3062   // non-explicit child modules.
3063   llvm::SetVector<clang::Module *> LinkModules;
3064   llvm::SmallPtrSet<clang::Module *, 16> Visited;
3065   SmallVector<clang::Module *, 16> Stack;
3066 
3067   // Seed the stack with imported modules.
3068   for (Module *M : ImportedModules) {
3069     // Do not add any link flags when an implementation TU of a module imports
3070     // a header of that same module.
3071     if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
3072         !getLangOpts().isCompilingModule())
3073       continue;
3074     if (Visited.insert(M).second)
3075       Stack.push_back(M);
3076   }
3077 
3078   // Find all of the modules to import, making a little effort to prune
3079   // non-leaf modules.
3080   while (!Stack.empty()) {
3081     clang::Module *Mod = Stack.pop_back_val();
3082 
3083     bool AnyChildren = false;
3084 
3085     // Visit the submodules of this module.
3086     for (const auto &SM : Mod->submodules()) {
3087       // Skip explicit children; they need to be explicitly imported to be
3088       // linked against.
3089       if (SM->IsExplicit)
3090         continue;
3091 
3092       if (Visited.insert(SM).second) {
3093         Stack.push_back(SM);
3094         AnyChildren = true;
3095       }
3096     }
3097 
3098     // We didn't find any children, so add this module to the list of
3099     // modules to link against.
3100     if (!AnyChildren) {
3101       LinkModules.insert(Mod);
3102     }
3103   }
3104 
3105   // Add link options for all of the imported modules in reverse topological
3106   // order.  We don't do anything to try to order import link flags with respect
3107   // to linker options inserted by things like #pragma comment().
3108   SmallVector<llvm::MDNode *, 16> MetadataArgs;
3109   Visited.clear();
3110   for (Module *M : LinkModules)
3111     if (Visited.insert(M).second)
3112       addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
3113   std::reverse(MetadataArgs.begin(), MetadataArgs.end());
3114   LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
3115 
3116   // Add the linker options metadata flag.
3117   auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
3118   for (auto *MD : LinkerOptionsMetadata)
3119     NMD->addOperand(MD);
3120 }
3121 
EmitDeferred()3122 void CodeGenModule::EmitDeferred() {
3123   // Emit deferred declare target declarations.
3124   if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
3125     getOpenMPRuntime().emitDeferredTargetDecls();
3126 
3127   // Emit code for any potentially referenced deferred decls.  Since a
3128   // previously unused static decl may become used during the generation of code
3129   // for a static function, iterate until no changes are made.
3130 
3131   if (!DeferredVTables.empty()) {
3132     EmitDeferredVTables();
3133 
3134     // Emitting a vtable doesn't directly cause more vtables to
3135     // become deferred, although it can cause functions to be
3136     // emitted that then need those vtables.
3137     assert(DeferredVTables.empty());
3138   }
3139 
3140   // Emit CUDA/HIP static device variables referenced by host code only.
3141   // Note we should not clear CUDADeviceVarODRUsedByHost since it is still
3142   // needed for further handling.
3143   if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
3144     llvm::append_range(DeferredDeclsToEmit,
3145                        getContext().CUDADeviceVarODRUsedByHost);
3146 
3147   // Stop if we're out of both deferred vtables and deferred declarations.
3148   if (DeferredDeclsToEmit.empty())
3149     return;
3150 
3151   // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
3152   // work, it will not interfere with this.
3153   std::vector<GlobalDecl> CurDeclsToEmit;
3154   CurDeclsToEmit.swap(DeferredDeclsToEmit);
3155 
3156   for (GlobalDecl &D : CurDeclsToEmit) {
3157     // We should call GetAddrOfGlobal with IsForDefinition set to true in order
3158     // to get GlobalValue with exactly the type we need, not something that
3159     // might had been created for another decl with the same mangled name but
3160     // different type.
3161     llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
3162         GetAddrOfGlobal(D, ForDefinition));
3163 
3164     // In case of different address spaces, we may still get a cast, even with
3165     // IsForDefinition equal to true. Query mangled names table to get
3166     // GlobalValue.
3167     if (!GV)
3168       GV = GetGlobalValue(getMangledName(D));
3169 
3170     // Make sure GetGlobalValue returned non-null.
3171     assert(GV);
3172 
3173     // Check to see if we've already emitted this.  This is necessary
3174     // for a couple of reasons: first, decls can end up in the
3175     // deferred-decls queue multiple times, and second, decls can end
3176     // up with definitions in unusual ways (e.g. by an extern inline
3177     // function acquiring a strong function redefinition).  Just
3178     // ignore these cases.
3179     if (!GV->isDeclaration())
3180       continue;
3181 
3182     // If this is OpenMP, check if it is legal to emit this global normally.
3183     if (LangOpts.OpenMP && OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(D))
3184       continue;
3185 
3186     // Otherwise, emit the definition and move on to the next one.
3187     EmitGlobalDefinition(D, GV);
3188 
3189     // If we found out that we need to emit more decls, do that recursively.
3190     // This has the advantage that the decls are emitted in a DFS and related
3191     // ones are close together, which is convenient for testing.
3192     if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
3193       EmitDeferred();
3194       assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
3195     }
3196   }
3197 }
3198 
EmitVTablesOpportunistically()3199 void CodeGenModule::EmitVTablesOpportunistically() {
3200   // Try to emit external vtables as available_externally if they have emitted
3201   // all inlined virtual functions.  It runs after EmitDeferred() and therefore
3202   // is not allowed to create new references to things that need to be emitted
3203   // lazily. Note that it also uses fact that we eagerly emitting RTTI.
3204 
3205   assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
3206          && "Only emit opportunistic vtables with optimizations");
3207 
3208   for (const CXXRecordDecl *RD : OpportunisticVTables) {
3209     assert(getVTables().isVTableExternal(RD) &&
3210            "This queue should only contain external vtables");
3211     if (getCXXABI().canSpeculativelyEmitVTable(RD))
3212       VTables.GenerateClassData(RD);
3213   }
3214   OpportunisticVTables.clear();
3215 }
3216 
EmitGlobalAnnotations()3217 void CodeGenModule::EmitGlobalAnnotations() {
3218   for (const auto& [MangledName, VD] : DeferredAnnotations) {
3219     llvm::GlobalValue *GV = GetGlobalValue(MangledName);
3220     if (GV)
3221       AddGlobalAnnotations(VD, GV);
3222   }
3223   DeferredAnnotations.clear();
3224 
3225   if (Annotations.empty())
3226     return;
3227 
3228   // Create a new global variable for the ConstantStruct in the Module.
3229   llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
3230     Annotations[0]->getType(), Annotations.size()), Annotations);
3231   auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
3232                                       llvm::GlobalValue::AppendingLinkage,
3233                                       Array, "llvm.global.annotations");
3234   gv->setSection(AnnotationSection);
3235 }
3236 
EmitAnnotationString(StringRef Str)3237 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
3238   llvm::Constant *&AStr = AnnotationStrings[Str];
3239   if (AStr)
3240     return AStr;
3241 
3242   // Not found yet, create a new global.
3243   llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
3244   auto *gv = new llvm::GlobalVariable(
3245       getModule(), s->getType(), true, llvm::GlobalValue::PrivateLinkage, s,
3246       ".str", nullptr, llvm::GlobalValue::NotThreadLocal,
3247       ConstGlobalsPtrTy->getAddressSpace());
3248   gv->setSection(AnnotationSection);
3249   gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3250   AStr = gv;
3251   return gv;
3252 }
3253 
EmitAnnotationUnit(SourceLocation Loc)3254 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
3255   SourceManager &SM = getContext().getSourceManager();
3256   PresumedLoc PLoc = SM.getPresumedLoc(Loc);
3257   if (PLoc.isValid())
3258     return EmitAnnotationString(PLoc.getFilename());
3259   return EmitAnnotationString(SM.getBufferName(Loc));
3260 }
3261 
EmitAnnotationLineNo(SourceLocation L)3262 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
3263   SourceManager &SM = getContext().getSourceManager();
3264   PresumedLoc PLoc = SM.getPresumedLoc(L);
3265   unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
3266     SM.getExpansionLineNumber(L);
3267   return llvm::ConstantInt::get(Int32Ty, LineNo);
3268 }
3269 
EmitAnnotationArgs(const AnnotateAttr * Attr)3270 llvm::Constant *CodeGenModule::EmitAnnotationArgs(const AnnotateAttr *Attr) {
3271   ArrayRef<Expr *> Exprs = {Attr->args_begin(), Attr->args_size()};
3272   if (Exprs.empty())
3273     return llvm::ConstantPointerNull::get(ConstGlobalsPtrTy);
3274 
3275   llvm::FoldingSetNodeID ID;
3276   for (Expr *E : Exprs) {
3277     ID.Add(cast<clang::ConstantExpr>(E)->getAPValueResult());
3278   }
3279   llvm::Constant *&Lookup = AnnotationArgs[ID.ComputeHash()];
3280   if (Lookup)
3281     return Lookup;
3282 
3283   llvm::SmallVector<llvm::Constant *, 4> LLVMArgs;
3284   LLVMArgs.reserve(Exprs.size());
3285   ConstantEmitter ConstEmiter(*this);
3286   llvm::transform(Exprs, std::back_inserter(LLVMArgs), [&](const Expr *E) {
3287     const auto *CE = cast<clang::ConstantExpr>(E);
3288     return ConstEmiter.emitAbstract(CE->getBeginLoc(), CE->getAPValueResult(),
3289                                     CE->getType());
3290   });
3291   auto *Struct = llvm::ConstantStruct::getAnon(LLVMArgs);
3292   auto *GV = new llvm::GlobalVariable(getModule(), Struct->getType(), true,
3293                                       llvm::GlobalValue::PrivateLinkage, Struct,
3294                                       ".args");
3295   GV->setSection(AnnotationSection);
3296   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3297 
3298   Lookup = GV;
3299   return GV;
3300 }
3301 
EmitAnnotateAttr(llvm::GlobalValue * GV,const AnnotateAttr * AA,SourceLocation L)3302 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
3303                                                 const AnnotateAttr *AA,
3304                                                 SourceLocation L) {
3305   // Get the globals for file name, annotation, and the line number.
3306   llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
3307                  *UnitGV = EmitAnnotationUnit(L),
3308                  *LineNoCst = EmitAnnotationLineNo(L),
3309                  *Args = EmitAnnotationArgs(AA);
3310 
3311   llvm::Constant *GVInGlobalsAS = GV;
3312   if (GV->getAddressSpace() !=
3313       getDataLayout().getDefaultGlobalsAddressSpace()) {
3314     GVInGlobalsAS = llvm::ConstantExpr::getAddrSpaceCast(
3315         GV,
3316         llvm::PointerType::get(
3317             GV->getContext(), getDataLayout().getDefaultGlobalsAddressSpace()));
3318   }
3319 
3320   // Create the ConstantStruct for the global annotation.
3321   llvm::Constant *Fields[] = {
3322       GVInGlobalsAS, AnnoGV, UnitGV, LineNoCst, Args,
3323   };
3324   return llvm::ConstantStruct::getAnon(Fields);
3325 }
3326 
AddGlobalAnnotations(const ValueDecl * D,llvm::GlobalValue * GV)3327 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
3328                                          llvm::GlobalValue *GV) {
3329   assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
3330   // Get the struct elements for these annotations.
3331   for (const auto *I : D->specific_attrs<AnnotateAttr>())
3332     Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
3333 }
3334 
isInNoSanitizeList(SanitizerMask Kind,llvm::Function * Fn,SourceLocation Loc) const3335 bool CodeGenModule::isInNoSanitizeList(SanitizerMask Kind, llvm::Function *Fn,
3336                                        SourceLocation Loc) const {
3337   const auto &NoSanitizeL = getContext().getNoSanitizeList();
3338   // NoSanitize by function name.
3339   if (NoSanitizeL.containsFunction(Kind, Fn->getName()))
3340     return true;
3341   // NoSanitize by location. Check "mainfile" prefix.
3342   auto &SM = Context.getSourceManager();
3343   FileEntryRef MainFile = *SM.getFileEntryRefForID(SM.getMainFileID());
3344   if (NoSanitizeL.containsMainFile(Kind, MainFile.getName()))
3345     return true;
3346 
3347   // Check "src" prefix.
3348   if (Loc.isValid())
3349     return NoSanitizeL.containsLocation(Kind, Loc);
3350   // If location is unknown, this may be a compiler-generated function. Assume
3351   // it's located in the main file.
3352   return NoSanitizeL.containsFile(Kind, MainFile.getName());
3353 }
3354 
isInNoSanitizeList(SanitizerMask Kind,llvm::GlobalVariable * GV,SourceLocation Loc,QualType Ty,StringRef Category) const3355 bool CodeGenModule::isInNoSanitizeList(SanitizerMask Kind,
3356                                        llvm::GlobalVariable *GV,
3357                                        SourceLocation Loc, QualType Ty,
3358                                        StringRef Category) const {
3359   const auto &NoSanitizeL = getContext().getNoSanitizeList();
3360   if (NoSanitizeL.containsGlobal(Kind, GV->getName(), Category))
3361     return true;
3362   auto &SM = Context.getSourceManager();
3363   if (NoSanitizeL.containsMainFile(
3364           Kind, SM.getFileEntryRefForID(SM.getMainFileID())->getName(),
3365           Category))
3366     return true;
3367   if (NoSanitizeL.containsLocation(Kind, Loc, Category))
3368     return true;
3369 
3370   // Check global type.
3371   if (!Ty.isNull()) {
3372     // Drill down the array types: if global variable of a fixed type is
3373     // not sanitized, we also don't instrument arrays of them.
3374     while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
3375       Ty = AT->getElementType();
3376     Ty = Ty.getCanonicalType().getUnqualifiedType();
3377     // Only record types (classes, structs etc.) are ignored.
3378     if (Ty->isRecordType()) {
3379       std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
3380       if (NoSanitizeL.containsType(Kind, TypeStr, Category))
3381         return true;
3382     }
3383   }
3384   return false;
3385 }
3386 
imbueXRayAttrs(llvm::Function * Fn,SourceLocation Loc,StringRef Category) const3387 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
3388                                    StringRef Category) const {
3389   const auto &XRayFilter = getContext().getXRayFilter();
3390   using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
3391   auto Attr = ImbueAttr::NONE;
3392   if (Loc.isValid())
3393     Attr = XRayFilter.shouldImbueLocation(Loc, Category);
3394   if (Attr == ImbueAttr::NONE)
3395     Attr = XRayFilter.shouldImbueFunction(Fn->getName());
3396   switch (Attr) {
3397   case ImbueAttr::NONE:
3398     return false;
3399   case ImbueAttr::ALWAYS:
3400     Fn->addFnAttr("function-instrument", "xray-always");
3401     break;
3402   case ImbueAttr::ALWAYS_ARG1:
3403     Fn->addFnAttr("function-instrument", "xray-always");
3404     Fn->addFnAttr("xray-log-args", "1");
3405     break;
3406   case ImbueAttr::NEVER:
3407     Fn->addFnAttr("function-instrument", "xray-never");
3408     break;
3409   }
3410   return true;
3411 }
3412 
3413 ProfileList::ExclusionType
isFunctionBlockedByProfileList(llvm::Function * Fn,SourceLocation Loc) const3414 CodeGenModule::isFunctionBlockedByProfileList(llvm::Function *Fn,
3415                                               SourceLocation Loc) const {
3416   const auto &ProfileList = getContext().getProfileList();
3417   // If the profile list is empty, then instrument everything.
3418   if (ProfileList.isEmpty())
3419     return ProfileList::Allow;
3420   CodeGenOptions::ProfileInstrKind Kind = getCodeGenOpts().getProfileInstr();
3421   // First, check the function name.
3422   if (auto V = ProfileList.isFunctionExcluded(Fn->getName(), Kind))
3423     return *V;
3424   // Next, check the source location.
3425   if (Loc.isValid())
3426     if (auto V = ProfileList.isLocationExcluded(Loc, Kind))
3427       return *V;
3428   // If location is unknown, this may be a compiler-generated function. Assume
3429   // it's located in the main file.
3430   auto &SM = Context.getSourceManager();
3431   if (auto MainFile = SM.getFileEntryRefForID(SM.getMainFileID()))
3432     if (auto V = ProfileList.isFileExcluded(MainFile->getName(), Kind))
3433       return *V;
3434   return ProfileList.getDefault(Kind);
3435 }
3436 
3437 ProfileList::ExclusionType
isFunctionBlockedFromProfileInstr(llvm::Function * Fn,SourceLocation Loc) const3438 CodeGenModule::isFunctionBlockedFromProfileInstr(llvm::Function *Fn,
3439                                                  SourceLocation Loc) const {
3440   auto V = isFunctionBlockedByProfileList(Fn, Loc);
3441   if (V != ProfileList::Allow)
3442     return V;
3443 
3444   auto NumGroups = getCodeGenOpts().ProfileTotalFunctionGroups;
3445   if (NumGroups > 1) {
3446     auto Group = llvm::crc32(arrayRefFromStringRef(Fn->getName())) % NumGroups;
3447     if (Group != getCodeGenOpts().ProfileSelectedFunctionGroup)
3448       return ProfileList::Skip;
3449   }
3450   return ProfileList::Allow;
3451 }
3452 
MustBeEmitted(const ValueDecl * Global)3453 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
3454   // Never defer when EmitAllDecls is specified.
3455   if (LangOpts.EmitAllDecls)
3456     return true;
3457 
3458   const auto *VD = dyn_cast<VarDecl>(Global);
3459   if (VD &&
3460       ((CodeGenOpts.KeepPersistentStorageVariables &&
3461         (VD->getStorageDuration() == SD_Static ||
3462          VD->getStorageDuration() == SD_Thread)) ||
3463        (CodeGenOpts.KeepStaticConsts && VD->getStorageDuration() == SD_Static &&
3464         VD->getType().isConstQualified())))
3465     return true;
3466 
3467   return getContext().DeclMustBeEmitted(Global);
3468 }
3469 
MayBeEmittedEagerly(const ValueDecl * Global)3470 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
3471   // In OpenMP 5.0 variables and function may be marked as
3472   // device_type(host/nohost) and we should not emit them eagerly unless we sure
3473   // that they must be emitted on the host/device. To be sure we need to have
3474   // seen a declare target with an explicit mentioning of the function, we know
3475   // we have if the level of the declare target attribute is -1. Note that we
3476   // check somewhere else if we should emit this at all.
3477   if (LangOpts.OpenMP >= 50 && !LangOpts.OpenMPSimd) {
3478     std::optional<OMPDeclareTargetDeclAttr *> ActiveAttr =
3479         OMPDeclareTargetDeclAttr::getActiveAttr(Global);
3480     if (!ActiveAttr || (*ActiveAttr)->getLevel() != (unsigned)-1)
3481       return false;
3482   }
3483 
3484   if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
3485     if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
3486       // Implicit template instantiations may change linkage if they are later
3487       // explicitly instantiated, so they should not be emitted eagerly.
3488       return false;
3489   }
3490   if (const auto *VD = dyn_cast<VarDecl>(Global)) {
3491     if (Context.getInlineVariableDefinitionKind(VD) ==
3492         ASTContext::InlineVariableDefinitionKind::WeakUnknown)
3493       // A definition of an inline constexpr static data member may change
3494       // linkage later if it's redeclared outside the class.
3495       return false;
3496     if (CXX20ModuleInits && VD->getOwningModule() &&
3497         !VD->getOwningModule()->isModuleMapModule()) {
3498       // For CXX20, module-owned initializers need to be deferred, since it is
3499       // not known at this point if they will be run for the current module or
3500       // as part of the initializer for an imported one.
3501       return false;
3502     }
3503   }
3504   // If OpenMP is enabled and threadprivates must be generated like TLS, delay
3505   // codegen for global variables, because they may be marked as threadprivate.
3506   if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
3507       getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
3508       !Global->getType().isConstantStorage(getContext(), false, false) &&
3509       !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
3510     return false;
3511 
3512   return true;
3513 }
3514 
GetAddrOfMSGuidDecl(const MSGuidDecl * GD)3515 ConstantAddress CodeGenModule::GetAddrOfMSGuidDecl(const MSGuidDecl *GD) {
3516   StringRef Name = getMangledName(GD);
3517 
3518   // The UUID descriptor should be pointer aligned.
3519   CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
3520 
3521   // Look for an existing global.
3522   if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
3523     return ConstantAddress(GV, GV->getValueType(), Alignment);
3524 
3525   ConstantEmitter Emitter(*this);
3526   llvm::Constant *Init;
3527 
3528   APValue &V = GD->getAsAPValue();
3529   if (!V.isAbsent()) {
3530     // If possible, emit the APValue version of the initializer. In particular,
3531     // this gets the type of the constant right.
3532     Init = Emitter.emitForInitializer(
3533         GD->getAsAPValue(), GD->getType().getAddressSpace(), GD->getType());
3534   } else {
3535     // As a fallback, directly construct the constant.
3536     // FIXME: This may get padding wrong under esoteric struct layout rules.
3537     // MSVC appears to create a complete type 'struct __s_GUID' that it
3538     // presumably uses to represent these constants.
3539     MSGuidDecl::Parts Parts = GD->getParts();
3540     llvm::Constant *Fields[4] = {
3541         llvm::ConstantInt::get(Int32Ty, Parts.Part1),
3542         llvm::ConstantInt::get(Int16Ty, Parts.Part2),
3543         llvm::ConstantInt::get(Int16Ty, Parts.Part3),
3544         llvm::ConstantDataArray::getRaw(
3545             StringRef(reinterpret_cast<char *>(Parts.Part4And5), 8), 8,
3546             Int8Ty)};
3547     Init = llvm::ConstantStruct::getAnon(Fields);
3548   }
3549 
3550   auto *GV = new llvm::GlobalVariable(
3551       getModule(), Init->getType(),
3552       /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
3553   if (supportsCOMDAT())
3554     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3555   setDSOLocal(GV);
3556 
3557   if (!V.isAbsent()) {
3558     Emitter.finalize(GV);
3559     return ConstantAddress(GV, GV->getValueType(), Alignment);
3560   }
3561 
3562   llvm::Type *Ty = getTypes().ConvertTypeForMem(GD->getType());
3563   return ConstantAddress(GV, Ty, Alignment);
3564 }
3565 
GetAddrOfUnnamedGlobalConstantDecl(const UnnamedGlobalConstantDecl * GCD)3566 ConstantAddress CodeGenModule::GetAddrOfUnnamedGlobalConstantDecl(
3567     const UnnamedGlobalConstantDecl *GCD) {
3568   CharUnits Alignment = getContext().getTypeAlignInChars(GCD->getType());
3569 
3570   llvm::GlobalVariable **Entry = nullptr;
3571   Entry = &UnnamedGlobalConstantDeclMap[GCD];
3572   if (*Entry)
3573     return ConstantAddress(*Entry, (*Entry)->getValueType(), Alignment);
3574 
3575   ConstantEmitter Emitter(*this);
3576   llvm::Constant *Init;
3577 
3578   const APValue &V = GCD->getValue();
3579 
3580   assert(!V.isAbsent());
3581   Init = Emitter.emitForInitializer(V, GCD->getType().getAddressSpace(),
3582                                     GCD->getType());
3583 
3584   auto *GV = new llvm::GlobalVariable(getModule(), Init->getType(),
3585                                       /*isConstant=*/true,
3586                                       llvm::GlobalValue::PrivateLinkage, Init,
3587                                       ".constant");
3588   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3589   GV->setAlignment(Alignment.getAsAlign());
3590 
3591   Emitter.finalize(GV);
3592 
3593   *Entry = GV;
3594   return ConstantAddress(GV, GV->getValueType(), Alignment);
3595 }
3596 
GetAddrOfTemplateParamObject(const TemplateParamObjectDecl * TPO)3597 ConstantAddress CodeGenModule::GetAddrOfTemplateParamObject(
3598     const TemplateParamObjectDecl *TPO) {
3599   StringRef Name = getMangledName(TPO);
3600   CharUnits Alignment = getNaturalTypeAlignment(TPO->getType());
3601 
3602   if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
3603     return ConstantAddress(GV, GV->getValueType(), Alignment);
3604 
3605   ConstantEmitter Emitter(*this);
3606   llvm::Constant *Init = Emitter.emitForInitializer(
3607         TPO->getValue(), TPO->getType().getAddressSpace(), TPO->getType());
3608 
3609   if (!Init) {
3610     ErrorUnsupported(TPO, "template parameter object");
3611     return ConstantAddress::invalid();
3612   }
3613 
3614   llvm::GlobalValue::LinkageTypes Linkage =
3615       isExternallyVisible(TPO->getLinkageAndVisibility().getLinkage())
3616           ? llvm::GlobalValue::LinkOnceODRLinkage
3617           : llvm::GlobalValue::InternalLinkage;
3618   auto *GV = new llvm::GlobalVariable(getModule(), Init->getType(),
3619                                       /*isConstant=*/true, Linkage, Init, Name);
3620   setGVProperties(GV, TPO);
3621   if (supportsCOMDAT())
3622     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3623   Emitter.finalize(GV);
3624 
3625     return ConstantAddress(GV, GV->getValueType(), Alignment);
3626 }
3627 
GetWeakRefReference(const ValueDecl * VD)3628 ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
3629   const AliasAttr *AA = VD->getAttr<AliasAttr>();
3630   assert(AA && "No alias?");
3631 
3632   CharUnits Alignment = getContext().getDeclAlign(VD);
3633   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
3634 
3635   // See if there is already something with the target's name in the module.
3636   llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
3637   if (Entry)
3638     return ConstantAddress(Entry, DeclTy, Alignment);
3639 
3640   llvm::Constant *Aliasee;
3641   if (isa<llvm::FunctionType>(DeclTy))
3642     Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
3643                                       GlobalDecl(cast<FunctionDecl>(VD)),
3644                                       /*ForVTable=*/false);
3645   else
3646     Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, LangAS::Default,
3647                                     nullptr);
3648 
3649   auto *F = cast<llvm::GlobalValue>(Aliasee);
3650   F->setLinkage(llvm::Function::ExternalWeakLinkage);
3651   WeakRefReferences.insert(F);
3652 
3653   return ConstantAddress(Aliasee, DeclTy, Alignment);
3654 }
3655 
hasImplicitAttr(const ValueDecl * D)3656 template <typename AttrT> static bool hasImplicitAttr(const ValueDecl *D) {
3657   if (!D)
3658     return false;
3659   if (auto *A = D->getAttr<AttrT>())
3660     return A->isImplicit();
3661   return D->isImplicit();
3662 }
3663 
EmitGlobal(GlobalDecl GD)3664 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
3665   const auto *Global = cast<ValueDecl>(GD.getDecl());
3666 
3667   // Weak references don't produce any output by themselves.
3668   if (Global->hasAttr<WeakRefAttr>())
3669     return;
3670 
3671   // If this is an alias definition (which otherwise looks like a declaration)
3672   // emit it now.
3673   if (Global->hasAttr<AliasAttr>())
3674     return EmitAliasDefinition(GD);
3675 
3676   // IFunc like an alias whose value is resolved at runtime by calling resolver.
3677   if (Global->hasAttr<IFuncAttr>())
3678     return emitIFuncDefinition(GD);
3679 
3680   // If this is a cpu_dispatch multiversion function, emit the resolver.
3681   if (Global->hasAttr<CPUDispatchAttr>())
3682     return emitCPUDispatchDefinition(GD);
3683 
3684   // If this is CUDA, be selective about which declarations we emit.
3685   // Non-constexpr non-lambda implicit host device functions are not emitted
3686   // unless they are used on device side.
3687   if (LangOpts.CUDA) {
3688     if (LangOpts.CUDAIsDevice) {
3689       const auto *FD = dyn_cast<FunctionDecl>(Global);
3690       if ((!Global->hasAttr<CUDADeviceAttr>() ||
3691            (LangOpts.OffloadImplicitHostDeviceTemplates && FD &&
3692             hasImplicitAttr<CUDAHostAttr>(FD) &&
3693             hasImplicitAttr<CUDADeviceAttr>(FD) && !FD->isConstexpr() &&
3694             !isLambdaCallOperator(FD) &&
3695             !getContext().CUDAImplicitHostDeviceFunUsedByDevice.count(FD))) &&
3696           !Global->hasAttr<CUDAGlobalAttr>() &&
3697           !Global->hasAttr<CUDAConstantAttr>() &&
3698           !Global->hasAttr<CUDASharedAttr>() &&
3699           !Global->getType()->isCUDADeviceBuiltinSurfaceType() &&
3700           !Global->getType()->isCUDADeviceBuiltinTextureType() &&
3701           !(LangOpts.HIPStdPar && isa<FunctionDecl>(Global) &&
3702             !Global->hasAttr<CUDAHostAttr>()))
3703         return;
3704     } else {
3705       // We need to emit host-side 'shadows' for all global
3706       // device-side variables because the CUDA runtime needs their
3707       // size and host-side address in order to provide access to
3708       // their device-side incarnations.
3709 
3710       // So device-only functions are the only things we skip.
3711       if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
3712           Global->hasAttr<CUDADeviceAttr>())
3713         return;
3714 
3715       assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
3716              "Expected Variable or Function");
3717     }
3718   }
3719 
3720   if (LangOpts.OpenMP) {
3721     // If this is OpenMP, check if it is legal to emit this global normally.
3722     if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
3723       return;
3724     if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
3725       if (MustBeEmitted(Global))
3726         EmitOMPDeclareReduction(DRD);
3727       return;
3728     }
3729     if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) {
3730       if (MustBeEmitted(Global))
3731         EmitOMPDeclareMapper(DMD);
3732       return;
3733     }
3734   }
3735 
3736   // Ignore declarations, they will be emitted on their first use.
3737   if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
3738     // Update deferred annotations with the latest declaration if the function
3739     // function was already used or defined.
3740     if (FD->hasAttr<AnnotateAttr>()) {
3741       StringRef MangledName = getMangledName(GD);
3742       if (GetGlobalValue(MangledName))
3743         DeferredAnnotations[MangledName] = FD;
3744     }
3745 
3746     // Forward declarations are emitted lazily on first use.
3747     if (!FD->doesThisDeclarationHaveABody()) {
3748       if (!FD->doesDeclarationForceExternallyVisibleDefinition())
3749         return;
3750 
3751       StringRef MangledName = getMangledName(GD);
3752 
3753       // Compute the function info and LLVM type.
3754       const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
3755       llvm::Type *Ty = getTypes().GetFunctionType(FI);
3756 
3757       GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
3758                               /*DontDefer=*/false);
3759       return;
3760     }
3761   } else {
3762     const auto *VD = cast<VarDecl>(Global);
3763     assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
3764     if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
3765         !Context.isMSStaticDataMemberInlineDefinition(VD)) {
3766       if (LangOpts.OpenMP) {
3767         // Emit declaration of the must-be-emitted declare target variable.
3768         if (std::optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
3769                 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
3770 
3771           // If this variable has external storage and doesn't require special
3772           // link handling we defer to its canonical definition.
3773           if (VD->hasExternalStorage() &&
3774               Res != OMPDeclareTargetDeclAttr::MT_Link)
3775             return;
3776 
3777           bool UnifiedMemoryEnabled =
3778               getOpenMPRuntime().hasRequiresUnifiedSharedMemory();
3779           if ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
3780                *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
3781               !UnifiedMemoryEnabled) {
3782             (void)GetAddrOfGlobalVar(VD);
3783           } else {
3784             assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
3785                     ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
3786                       *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
3787                      UnifiedMemoryEnabled)) &&
3788                    "Link clause or to clause with unified memory expected.");
3789             (void)getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
3790           }
3791 
3792           return;
3793         }
3794       }
3795       // If this declaration may have caused an inline variable definition to
3796       // change linkage, make sure that it's emitted.
3797       if (Context.getInlineVariableDefinitionKind(VD) ==
3798           ASTContext::InlineVariableDefinitionKind::Strong)
3799         GetAddrOfGlobalVar(VD);
3800       return;
3801     }
3802   }
3803 
3804   // Defer code generation to first use when possible, e.g. if this is an inline
3805   // function. If the global must always be emitted, do it eagerly if possible
3806   // to benefit from cache locality.
3807   if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
3808     // Emit the definition if it can't be deferred.
3809     EmitGlobalDefinition(GD);
3810     addEmittedDeferredDecl(GD);
3811     return;
3812   }
3813 
3814   // If we're deferring emission of a C++ variable with an
3815   // initializer, remember the order in which it appeared in the file.
3816   if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
3817       cast<VarDecl>(Global)->hasInit()) {
3818     DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
3819     CXXGlobalInits.push_back(nullptr);
3820   }
3821 
3822   StringRef MangledName = getMangledName(GD);
3823   if (GetGlobalValue(MangledName) != nullptr) {
3824     // The value has already been used and should therefore be emitted.
3825     addDeferredDeclToEmit(GD);
3826   } else if (MustBeEmitted(Global)) {
3827     // The value must be emitted, but cannot be emitted eagerly.
3828     assert(!MayBeEmittedEagerly(Global));
3829     addDeferredDeclToEmit(GD);
3830   } else {
3831     // Otherwise, remember that we saw a deferred decl with this name.  The
3832     // first use of the mangled name will cause it to move into
3833     // DeferredDeclsToEmit.
3834     DeferredDecls[MangledName] = GD;
3835   }
3836 }
3837 
3838 // Check if T is a class type with a destructor that's not dllimport.
HasNonDllImportDtor(QualType T)3839 static bool HasNonDllImportDtor(QualType T) {
3840   if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
3841     if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
3842       if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
3843         return true;
3844 
3845   return false;
3846 }
3847 
3848 namespace {
3849   struct FunctionIsDirectlyRecursive
3850       : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> {
3851     const StringRef Name;
3852     const Builtin::Context &BI;
FunctionIsDirectlyRecursive__anonec72a1410c11::FunctionIsDirectlyRecursive3853     FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C)
3854         : Name(N), BI(C) {}
3855 
VisitCallExpr__anonec72a1410c11::FunctionIsDirectlyRecursive3856     bool VisitCallExpr(const CallExpr *E) {
3857       const FunctionDecl *FD = E->getDirectCallee();
3858       if (!FD)
3859         return false;
3860       AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
3861       if (Attr && Name == Attr->getLabel())
3862         return true;
3863       unsigned BuiltinID = FD->getBuiltinID();
3864       if (!BuiltinID || !BI.isLibFunction(BuiltinID))
3865         return false;
3866       StringRef BuiltinName = BI.getName(BuiltinID);
3867       if (BuiltinName.starts_with("__builtin_") &&
3868           Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
3869         return true;
3870       }
3871       return false;
3872     }
3873 
VisitStmt__anonec72a1410c11::FunctionIsDirectlyRecursive3874     bool VisitStmt(const Stmt *S) {
3875       for (const Stmt *Child : S->children())
3876         if (Child && this->Visit(Child))
3877           return true;
3878       return false;
3879     }
3880   };
3881 
3882   // Make sure we're not referencing non-imported vars or functions.
3883   struct DLLImportFunctionVisitor
3884       : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
3885     bool SafeToInline = true;
3886 
shouldVisitImplicitCode__anonec72a1410c11::DLLImportFunctionVisitor3887     bool shouldVisitImplicitCode() const { return true; }
3888 
VisitVarDecl__anonec72a1410c11::DLLImportFunctionVisitor3889     bool VisitVarDecl(VarDecl *VD) {
3890       if (VD->getTLSKind()) {
3891         // A thread-local variable cannot be imported.
3892         SafeToInline = false;
3893         return SafeToInline;
3894       }
3895 
3896       // A variable definition might imply a destructor call.
3897       if (VD->isThisDeclarationADefinition())
3898         SafeToInline = !HasNonDllImportDtor(VD->getType());
3899 
3900       return SafeToInline;
3901     }
3902 
VisitCXXBindTemporaryExpr__anonec72a1410c11::DLLImportFunctionVisitor3903     bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
3904       if (const auto *D = E->getTemporary()->getDestructor())
3905         SafeToInline = D->hasAttr<DLLImportAttr>();
3906       return SafeToInline;
3907     }
3908 
VisitDeclRefExpr__anonec72a1410c11::DLLImportFunctionVisitor3909     bool VisitDeclRefExpr(DeclRefExpr *E) {
3910       ValueDecl *VD = E->getDecl();
3911       if (isa<FunctionDecl>(VD))
3912         SafeToInline = VD->hasAttr<DLLImportAttr>();
3913       else if (VarDecl *V = dyn_cast<VarDecl>(VD))
3914         SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
3915       return SafeToInline;
3916     }
3917 
VisitCXXConstructExpr__anonec72a1410c11::DLLImportFunctionVisitor3918     bool VisitCXXConstructExpr(CXXConstructExpr *E) {
3919       SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
3920       return SafeToInline;
3921     }
3922 
VisitCXXMemberCallExpr__anonec72a1410c11::DLLImportFunctionVisitor3923     bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3924       CXXMethodDecl *M = E->getMethodDecl();
3925       if (!M) {
3926         // Call through a pointer to member function. This is safe to inline.
3927         SafeToInline = true;
3928       } else {
3929         SafeToInline = M->hasAttr<DLLImportAttr>();
3930       }
3931       return SafeToInline;
3932     }
3933 
VisitCXXDeleteExpr__anonec72a1410c11::DLLImportFunctionVisitor3934     bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
3935       SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
3936       return SafeToInline;
3937     }
3938 
VisitCXXNewExpr__anonec72a1410c11::DLLImportFunctionVisitor3939     bool VisitCXXNewExpr(CXXNewExpr *E) {
3940       SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
3941       return SafeToInline;
3942     }
3943   };
3944 }
3945 
3946 // isTriviallyRecursive - Check if this function calls another
3947 // decl that, because of the asm attribute or the other decl being a builtin,
3948 // ends up pointing to itself.
3949 bool
isTriviallyRecursive(const FunctionDecl * FD)3950 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
3951   StringRef Name;
3952   if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
3953     // asm labels are a special kind of mangling we have to support.
3954     AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
3955     if (!Attr)
3956       return false;
3957     Name = Attr->getLabel();
3958   } else {
3959     Name = FD->getName();
3960   }
3961 
3962   FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
3963   const Stmt *Body = FD->getBody();
3964   return Body ? Walker.Visit(Body) : false;
3965 }
3966 
shouldEmitFunction(GlobalDecl GD)3967 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
3968   if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
3969     return true;
3970 
3971   const auto *F = cast<FunctionDecl>(GD.getDecl());
3972   if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
3973     return false;
3974 
3975   // We don't import function bodies from other named module units since that
3976   // behavior may break ABI compatibility of the current unit.
3977   if (const Module *M = F->getOwningModule();
3978       M && M->getTopLevelModule()->isNamedModule() &&
3979       getContext().getCurrentNamedModule() != M->getTopLevelModule() &&
3980       !F->hasAttr<AlwaysInlineAttr>())
3981     return false;
3982 
3983   if (F->hasAttr<NoInlineAttr>())
3984     return false;
3985 
3986   if (F->hasAttr<DLLImportAttr>() && !F->hasAttr<AlwaysInlineAttr>()) {
3987     // Check whether it would be safe to inline this dllimport function.
3988     DLLImportFunctionVisitor Visitor;
3989     Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
3990     if (!Visitor.SafeToInline)
3991       return false;
3992 
3993     if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
3994       // Implicit destructor invocations aren't captured in the AST, so the
3995       // check above can't see them. Check for them manually here.
3996       for (const Decl *Member : Dtor->getParent()->decls())
3997         if (isa<FieldDecl>(Member))
3998           if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
3999             return false;
4000       for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
4001         if (HasNonDllImportDtor(B.getType()))
4002           return false;
4003     }
4004   }
4005 
4006   // Inline builtins declaration must be emitted. They often are fortified
4007   // functions.
4008   if (F->isInlineBuiltinDeclaration())
4009     return true;
4010 
4011   // PR9614. Avoid cases where the source code is lying to us. An available
4012   // externally function should have an equivalent function somewhere else,
4013   // but a function that calls itself through asm label/`__builtin_` trickery is
4014   // clearly not equivalent to the real implementation.
4015   // This happens in glibc's btowc and in some configure checks.
4016   return !isTriviallyRecursive(F);
4017 }
4018 
shouldOpportunisticallyEmitVTables()4019 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
4020   return CodeGenOpts.OptimizationLevel > 0;
4021 }
4022 
EmitMultiVersionFunctionDefinition(GlobalDecl GD,llvm::GlobalValue * GV)4023 void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
4024                                                        llvm::GlobalValue *GV) {
4025   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4026 
4027   if (FD->isCPUSpecificMultiVersion()) {
4028     auto *Spec = FD->getAttr<CPUSpecificAttr>();
4029     for (unsigned I = 0; I < Spec->cpus_size(); ++I)
4030       EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
4031   } else if (FD->isTargetClonesMultiVersion()) {
4032     auto *Clone = FD->getAttr<TargetClonesAttr>();
4033     for (unsigned I = 0; I < Clone->featuresStrs_size(); ++I)
4034       if (Clone->isFirstOfVersion(I))
4035         EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
4036     // Ensure that the resolver function is also emitted.
4037     GetOrCreateMultiVersionResolver(GD);
4038   } else if (FD->hasAttr<TargetVersionAttr>()) {
4039     GetOrCreateMultiVersionResolver(GD);
4040   } else
4041     EmitGlobalFunctionDefinition(GD, GV);
4042 }
4043 
EmitGlobalDefinition(GlobalDecl GD,llvm::GlobalValue * GV)4044 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
4045   const auto *D = cast<ValueDecl>(GD.getDecl());
4046 
4047   PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
4048                                  Context.getSourceManager(),
4049                                  "Generating code for declaration");
4050 
4051   if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
4052     // At -O0, don't generate IR for functions with available_externally
4053     // linkage.
4054     if (!shouldEmitFunction(GD))
4055       return;
4056 
4057     llvm::TimeTraceScope TimeScope("CodeGen Function", [&]() {
4058       std::string Name;
4059       llvm::raw_string_ostream OS(Name);
4060       FD->getNameForDiagnostic(OS, getContext().getPrintingPolicy(),
4061                                /*Qualified=*/true);
4062       return Name;
4063     });
4064 
4065     if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
4066       // Make sure to emit the definition(s) before we emit the thunks.
4067       // This is necessary for the generation of certain thunks.
4068       if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
4069         ABI->emitCXXStructor(GD);
4070       else if (FD->isMultiVersion())
4071         EmitMultiVersionFunctionDefinition(GD, GV);
4072       else
4073         EmitGlobalFunctionDefinition(GD, GV);
4074 
4075       if (Method->isVirtual())
4076         getVTables().EmitThunks(GD);
4077 
4078       return;
4079     }
4080 
4081     if (FD->isMultiVersion())
4082       return EmitMultiVersionFunctionDefinition(GD, GV);
4083     return EmitGlobalFunctionDefinition(GD, GV);
4084   }
4085 
4086   if (const auto *VD = dyn_cast<VarDecl>(D))
4087     return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
4088 
4089   llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
4090 }
4091 
4092 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
4093                                                       llvm::Function *NewFn);
4094 
4095 static unsigned
TargetMVPriority(const TargetInfo & TI,const CodeGenFunction::MultiVersionResolverOption & RO)4096 TargetMVPriority(const TargetInfo &TI,
4097                  const CodeGenFunction::MultiVersionResolverOption &RO) {
4098   unsigned Priority = 0;
4099   unsigned NumFeatures = 0;
4100   for (StringRef Feat : RO.Conditions.Features) {
4101     Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
4102     NumFeatures++;
4103   }
4104 
4105   if (!RO.Conditions.Architecture.empty())
4106     Priority = std::max(
4107         Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
4108 
4109   Priority += TI.multiVersionFeatureCost() * NumFeatures;
4110 
4111   return Priority;
4112 }
4113 
4114 // Multiversion functions should be at most 'WeakODRLinkage' so that a different
4115 // TU can forward declare the function without causing problems.  Particularly
4116 // in the cases of CPUDispatch, this causes issues. This also makes sure we
4117 // work with internal linkage functions, so that the same function name can be
4118 // used with internal linkage in multiple TUs.
getMultiversionLinkage(CodeGenModule & CGM,GlobalDecl GD)4119 llvm::GlobalValue::LinkageTypes getMultiversionLinkage(CodeGenModule &CGM,
4120                                                        GlobalDecl GD) {
4121   const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
4122   if (FD->getFormalLinkage() == Linkage::Internal)
4123     return llvm::GlobalValue::InternalLinkage;
4124   return llvm::GlobalValue::WeakODRLinkage;
4125 }
4126 
emitMultiVersionFunctions()4127 void CodeGenModule::emitMultiVersionFunctions() {
4128   std::vector<GlobalDecl> MVFuncsToEmit;
4129   MultiVersionFuncs.swap(MVFuncsToEmit);
4130   for (GlobalDecl GD : MVFuncsToEmit) {
4131     const auto *FD = cast<FunctionDecl>(GD.getDecl());
4132     assert(FD && "Expected a FunctionDecl");
4133 
4134     SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
4135     if (FD->isTargetMultiVersion()) {
4136       getContext().forEachMultiversionedFunctionVersion(
4137           FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
4138             GlobalDecl CurGD{
4139                 (CurFD->isDefined() ? CurFD->getDefinition() : CurFD)};
4140             StringRef MangledName = getMangledName(CurGD);
4141             llvm::Constant *Func = GetGlobalValue(MangledName);
4142             if (!Func) {
4143               if (CurFD->isDefined()) {
4144                 EmitGlobalFunctionDefinition(CurGD, nullptr);
4145                 Func = GetGlobalValue(MangledName);
4146               } else {
4147                 const CGFunctionInfo &FI =
4148                     getTypes().arrangeGlobalDeclaration(GD);
4149                 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4150                 Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
4151                                          /*DontDefer=*/false, ForDefinition);
4152               }
4153               assert(Func && "This should have just been created");
4154             }
4155             if (CurFD->getMultiVersionKind() == MultiVersionKind::Target) {
4156               const auto *TA = CurFD->getAttr<TargetAttr>();
4157               llvm::SmallVector<StringRef, 8> Feats;
4158               TA->getAddedFeatures(Feats);
4159               Options.emplace_back(cast<llvm::Function>(Func),
4160                                    TA->getArchitecture(), Feats);
4161             } else {
4162               const auto *TVA = CurFD->getAttr<TargetVersionAttr>();
4163               llvm::SmallVector<StringRef, 8> Feats;
4164               TVA->getFeatures(Feats);
4165               Options.emplace_back(cast<llvm::Function>(Func),
4166                                    /*Architecture*/ "", Feats);
4167             }
4168           });
4169     } else if (FD->isTargetClonesMultiVersion()) {
4170       const auto *TC = FD->getAttr<TargetClonesAttr>();
4171       for (unsigned VersionIndex = 0; VersionIndex < TC->featuresStrs_size();
4172            ++VersionIndex) {
4173         if (!TC->isFirstOfVersion(VersionIndex))
4174           continue;
4175         GlobalDecl CurGD{(FD->isDefined() ? FD->getDefinition() : FD),
4176                          VersionIndex};
4177         StringRef Version = TC->getFeatureStr(VersionIndex);
4178         StringRef MangledName = getMangledName(CurGD);
4179         llvm::Constant *Func = GetGlobalValue(MangledName);
4180         if (!Func) {
4181           if (FD->isDefined()) {
4182             EmitGlobalFunctionDefinition(CurGD, nullptr);
4183             Func = GetGlobalValue(MangledName);
4184           } else {
4185             const CGFunctionInfo &FI =
4186                 getTypes().arrangeGlobalDeclaration(CurGD);
4187             llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4188             Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
4189                                      /*DontDefer=*/false, ForDefinition);
4190           }
4191           assert(Func && "This should have just been created");
4192         }
4193 
4194         StringRef Architecture;
4195         llvm::SmallVector<StringRef, 1> Feature;
4196 
4197         if (getTarget().getTriple().isAArch64()) {
4198           if (Version != "default") {
4199             llvm::SmallVector<StringRef, 8> VerFeats;
4200             Version.split(VerFeats, "+");
4201             for (auto &CurFeat : VerFeats)
4202               Feature.push_back(CurFeat.trim());
4203           }
4204         } else {
4205           if (Version.starts_with("arch="))
4206             Architecture = Version.drop_front(sizeof("arch=") - 1);
4207           else if (Version != "default")
4208             Feature.push_back(Version);
4209         }
4210 
4211         Options.emplace_back(cast<llvm::Function>(Func), Architecture, Feature);
4212       }
4213     } else {
4214       assert(0 && "Expected a target or target_clones multiversion function");
4215       continue;
4216     }
4217 
4218     llvm::Constant *ResolverConstant = GetOrCreateMultiVersionResolver(GD);
4219     if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(ResolverConstant)) {
4220       ResolverConstant = IFunc->getResolver();
4221       if (FD->isTargetClonesMultiVersion()) {
4222         const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4223         llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4224         std::string MangledName = getMangledNameImpl(
4225             *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4226         // In prior versions of Clang, the mangling for ifuncs incorrectly
4227         // included an .ifunc suffix. This alias is generated for backward
4228         // compatibility. It is deprecated, and may be removed in the future.
4229         auto *Alias = llvm::GlobalAlias::create(
4230             DeclTy, 0, getMultiversionLinkage(*this, GD),
4231             MangledName + ".ifunc", IFunc, &getModule());
4232         SetCommonAttributes(FD, Alias);
4233       }
4234     }
4235     llvm::Function *ResolverFunc = cast<llvm::Function>(ResolverConstant);
4236 
4237     ResolverFunc->setLinkage(getMultiversionLinkage(*this, GD));
4238 
4239     if (!ResolverFunc->hasLocalLinkage() && supportsCOMDAT())
4240       ResolverFunc->setComdat(
4241           getModule().getOrInsertComdat(ResolverFunc->getName()));
4242 
4243     const TargetInfo &TI = getTarget();
4244     llvm::stable_sort(
4245         Options, [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
4246                        const CodeGenFunction::MultiVersionResolverOption &RHS) {
4247           return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
4248         });
4249     CodeGenFunction CGF(*this);
4250     CGF.EmitMultiVersionResolver(ResolverFunc, Options);
4251   }
4252 
4253   // Ensure that any additions to the deferred decls list caused by emitting a
4254   // variant are emitted.  This can happen when the variant itself is inline and
4255   // calls a function without linkage.
4256   if (!MVFuncsToEmit.empty())
4257     EmitDeferred();
4258 
4259   // Ensure that any additions to the multiversion funcs list from either the
4260   // deferred decls or the multiversion functions themselves are emitted.
4261   if (!MultiVersionFuncs.empty())
4262     emitMultiVersionFunctions();
4263 }
4264 
emitCPUDispatchDefinition(GlobalDecl GD)4265 void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
4266   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4267   assert(FD && "Not a FunctionDecl?");
4268   assert(FD->isCPUDispatchMultiVersion() && "Not a multiversion function?");
4269   const auto *DD = FD->getAttr<CPUDispatchAttr>();
4270   assert(DD && "Not a cpu_dispatch Function?");
4271 
4272   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4273   llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4274 
4275   StringRef ResolverName = getMangledName(GD);
4276   UpdateMultiVersionNames(GD, FD, ResolverName);
4277 
4278   llvm::Type *ResolverType;
4279   GlobalDecl ResolverGD;
4280   if (getTarget().supportsIFunc()) {
4281     ResolverType = llvm::FunctionType::get(
4282         llvm::PointerType::get(DeclTy,
4283                                getTypes().getTargetAddressSpace(FD->getType())),
4284         false);
4285   }
4286   else {
4287     ResolverType = DeclTy;
4288     ResolverGD = GD;
4289   }
4290 
4291   auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
4292       ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
4293   ResolverFunc->setLinkage(getMultiversionLinkage(*this, GD));
4294   if (supportsCOMDAT())
4295     ResolverFunc->setComdat(
4296         getModule().getOrInsertComdat(ResolverFunc->getName()));
4297 
4298   SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
4299   const TargetInfo &Target = getTarget();
4300   unsigned Index = 0;
4301   for (const IdentifierInfo *II : DD->cpus()) {
4302     // Get the name of the target function so we can look it up/create it.
4303     std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
4304                               getCPUSpecificMangling(*this, II->getName());
4305 
4306     llvm::Constant *Func = GetGlobalValue(MangledName);
4307 
4308     if (!Func) {
4309       GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
4310       if (ExistingDecl.getDecl() &&
4311           ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
4312         EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
4313         Func = GetGlobalValue(MangledName);
4314       } else {
4315         if (!ExistingDecl.getDecl())
4316           ExistingDecl = GD.getWithMultiVersionIndex(Index);
4317 
4318       Func = GetOrCreateLLVMFunction(
4319           MangledName, DeclTy, ExistingDecl,
4320           /*ForVTable=*/false, /*DontDefer=*/true,
4321           /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
4322       }
4323     }
4324 
4325     llvm::SmallVector<StringRef, 32> Features;
4326     Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
4327     llvm::transform(Features, Features.begin(),
4328                     [](StringRef Str) { return Str.substr(1); });
4329     llvm::erase_if(Features, [&Target](StringRef Feat) {
4330       return !Target.validateCpuSupports(Feat);
4331     });
4332     Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
4333     ++Index;
4334   }
4335 
4336   llvm::stable_sort(
4337       Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
4338                   const CodeGenFunction::MultiVersionResolverOption &RHS) {
4339         return llvm::X86::getCpuSupportsMask(LHS.Conditions.Features) >
4340                llvm::X86::getCpuSupportsMask(RHS.Conditions.Features);
4341       });
4342 
4343   // If the list contains multiple 'default' versions, such as when it contains
4344   // 'pentium' and 'generic', don't emit the call to the generic one (since we
4345   // always run on at least a 'pentium'). We do this by deleting the 'least
4346   // advanced' (read, lowest mangling letter).
4347   while (Options.size() > 1 &&
4348          llvm::all_of(llvm::X86::getCpuSupportsMask(
4349                           (Options.end() - 2)->Conditions.Features),
4350                       [](auto X) { return X == 0; })) {
4351     StringRef LHSName = (Options.end() - 2)->Function->getName();
4352     StringRef RHSName = (Options.end() - 1)->Function->getName();
4353     if (LHSName.compare(RHSName) < 0)
4354       Options.erase(Options.end() - 2);
4355     else
4356       Options.erase(Options.end() - 1);
4357   }
4358 
4359   CodeGenFunction CGF(*this);
4360   CGF.EmitMultiVersionResolver(ResolverFunc, Options);
4361 
4362   if (getTarget().supportsIFunc()) {
4363     llvm::GlobalValue::LinkageTypes Linkage = getMultiversionLinkage(*this, GD);
4364     auto *IFunc = cast<llvm::GlobalValue>(GetOrCreateMultiVersionResolver(GD));
4365 
4366     // Fix up function declarations that were created for cpu_specific before
4367     // cpu_dispatch was known
4368     if (!isa<llvm::GlobalIFunc>(IFunc)) {
4369       assert(cast<llvm::Function>(IFunc)->isDeclaration());
4370       auto *GI = llvm::GlobalIFunc::create(DeclTy, 0, Linkage, "", ResolverFunc,
4371                                            &getModule());
4372       GI->takeName(IFunc);
4373       IFunc->replaceAllUsesWith(GI);
4374       IFunc->eraseFromParent();
4375       IFunc = GI;
4376     }
4377 
4378     std::string AliasName = getMangledNameImpl(
4379         *this, GD, FD, /*OmitMultiVersionMangling=*/true);
4380     llvm::Constant *AliasFunc = GetGlobalValue(AliasName);
4381     if (!AliasFunc) {
4382       auto *GA = llvm::GlobalAlias::create(DeclTy, 0, Linkage, AliasName, IFunc,
4383                                            &getModule());
4384       SetCommonAttributes(GD, GA);
4385     }
4386   }
4387 }
4388 
4389 /// If a dispatcher for the specified mangled name is not in the module, create
4390 /// and return an llvm Function with the specified type.
GetOrCreateMultiVersionResolver(GlobalDecl GD)4391 llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(GlobalDecl GD) {
4392   const auto *FD = cast<FunctionDecl>(GD.getDecl());
4393   assert(FD && "Not a FunctionDecl?");
4394 
4395   std::string MangledName =
4396       getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
4397 
4398   // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
4399   // a separate resolver).
4400   std::string ResolverName = MangledName;
4401   if (getTarget().supportsIFunc()) {
4402     if (!FD->isTargetClonesMultiVersion())
4403       ResolverName += ".ifunc";
4404   } else if (FD->isTargetMultiVersion()) {
4405     ResolverName += ".resolver";
4406   }
4407 
4408   // If the resolver has already been created, just return it.
4409   if (llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName))
4410     return ResolverGV;
4411 
4412   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4413   llvm::FunctionType *DeclTy = getTypes().GetFunctionType(FI);
4414 
4415   // The resolver needs to be created. For target and target_clones, defer
4416   // creation until the end of the TU.
4417   if (FD->isTargetMultiVersion() || FD->isTargetClonesMultiVersion())
4418     MultiVersionFuncs.push_back(GD);
4419 
4420   // For cpu_specific, don't create an ifunc yet because we don't know if the
4421   // cpu_dispatch will be emitted in this translation unit.
4422   if (getTarget().supportsIFunc() && !FD->isCPUSpecificMultiVersion()) {
4423     llvm::Type *ResolverType = llvm::FunctionType::get(
4424         llvm::PointerType::get(DeclTy,
4425                                getTypes().getTargetAddressSpace(FD->getType())),
4426         false);
4427     llvm::Constant *Resolver = GetOrCreateLLVMFunction(
4428         MangledName + ".resolver", ResolverType, GlobalDecl{},
4429         /*ForVTable=*/false);
4430     llvm::GlobalIFunc *GIF =
4431         llvm::GlobalIFunc::create(DeclTy, 0, getMultiversionLinkage(*this, GD),
4432                                   "", Resolver, &getModule());
4433     GIF->setName(ResolverName);
4434     SetCommonAttributes(FD, GIF);
4435 
4436     return GIF;
4437   }
4438 
4439   llvm::Constant *Resolver = GetOrCreateLLVMFunction(
4440       ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
4441   assert(isa<llvm::GlobalValue>(Resolver) &&
4442          "Resolver should be created for the first time");
4443   SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
4444   return Resolver;
4445 }
4446 
4447 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
4448 /// module, create and return an llvm Function with the specified type. If there
4449 /// is something in the module with the specified name, return it potentially
4450 /// bitcasted to the right type.
4451 ///
4452 /// If D is non-null, it specifies a decl that correspond to this.  This is used
4453 /// to set the attributes on the function when it is first created.
GetOrCreateLLVMFunction(StringRef MangledName,llvm::Type * Ty,GlobalDecl GD,bool ForVTable,bool DontDefer,bool IsThunk,llvm::AttributeList ExtraAttrs,ForDefinition_t IsForDefinition)4454 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
4455     StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
4456     bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
4457     ForDefinition_t IsForDefinition) {
4458   const Decl *D = GD.getDecl();
4459 
4460   // Any attempts to use a MultiVersion function should result in retrieving
4461   // the iFunc instead. Name Mangling will handle the rest of the changes.
4462   if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
4463     // For the device mark the function as one that should be emitted.
4464     if (getLangOpts().OpenMPIsTargetDevice && OpenMPRuntime &&
4465         !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
4466         !DontDefer && !IsForDefinition) {
4467       if (const FunctionDecl *FDDef = FD->getDefinition()) {
4468         GlobalDecl GDDef;
4469         if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
4470           GDDef = GlobalDecl(CD, GD.getCtorType());
4471         else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
4472           GDDef = GlobalDecl(DD, GD.getDtorType());
4473         else
4474           GDDef = GlobalDecl(FDDef);
4475         EmitGlobal(GDDef);
4476       }
4477     }
4478 
4479     if (FD->isMultiVersion()) {
4480       UpdateMultiVersionNames(GD, FD, MangledName);
4481       if (!IsForDefinition)
4482         return GetOrCreateMultiVersionResolver(GD);
4483     }
4484   }
4485 
4486   // Lookup the entry, lazily creating it if necessary.
4487   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4488   if (Entry) {
4489     if (WeakRefReferences.erase(Entry)) {
4490       const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
4491       if (FD && !FD->hasAttr<WeakAttr>())
4492         Entry->setLinkage(llvm::Function::ExternalLinkage);
4493     }
4494 
4495     // Handle dropped DLL attributes.
4496     if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>() &&
4497         !shouldMapVisibilityToDLLExport(cast_or_null<NamedDecl>(D))) {
4498       Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
4499       setDSOLocal(Entry);
4500     }
4501 
4502     // If there are two attempts to define the same mangled name, issue an
4503     // error.
4504     if (IsForDefinition && !Entry->isDeclaration()) {
4505       GlobalDecl OtherGD;
4506       // Check that GD is not yet in DiagnosedConflictingDefinitions is required
4507       // to make sure that we issue an error only once.
4508       if (lookupRepresentativeDecl(MangledName, OtherGD) &&
4509           (GD.getCanonicalDecl().getDecl() !=
4510            OtherGD.getCanonicalDecl().getDecl()) &&
4511           DiagnosedConflictingDefinitions.insert(GD).second) {
4512         getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
4513             << MangledName;
4514         getDiags().Report(OtherGD.getDecl()->getLocation(),
4515                           diag::note_previous_definition);
4516       }
4517     }
4518 
4519     if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
4520         (Entry->getValueType() == Ty)) {
4521       return Entry;
4522     }
4523 
4524     // Make sure the result is of the correct type.
4525     // (If function is requested for a definition, we always need to create a new
4526     // function, not just return a bitcast.)
4527     if (!IsForDefinition)
4528       return Entry;
4529   }
4530 
4531   // This function doesn't have a complete type (for example, the return
4532   // type is an incomplete struct). Use a fake type instead, and make
4533   // sure not to try to set attributes.
4534   bool IsIncompleteFunction = false;
4535 
4536   llvm::FunctionType *FTy;
4537   if (isa<llvm::FunctionType>(Ty)) {
4538     FTy = cast<llvm::FunctionType>(Ty);
4539   } else {
4540     FTy = llvm::FunctionType::get(VoidTy, false);
4541     IsIncompleteFunction = true;
4542   }
4543 
4544   llvm::Function *F =
4545       llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
4546                              Entry ? StringRef() : MangledName, &getModule());
4547 
4548   // Store the declaration associated with this function so it is potentially
4549   // updated by further declarations or definitions and emitted at the end.
4550   if (D && D->hasAttr<AnnotateAttr>())
4551     DeferredAnnotations[MangledName] = cast<ValueDecl>(D);
4552 
4553   // If we already created a function with the same mangled name (but different
4554   // type) before, take its name and add it to the list of functions to be
4555   // replaced with F at the end of CodeGen.
4556   //
4557   // This happens if there is a prototype for a function (e.g. "int f()") and
4558   // then a definition of a different type (e.g. "int f(int x)").
4559   if (Entry) {
4560     F->takeName(Entry);
4561 
4562     // This might be an implementation of a function without a prototype, in
4563     // which case, try to do special replacement of calls which match the new
4564     // prototype.  The really key thing here is that we also potentially drop
4565     // arguments from the call site so as to make a direct call, which makes the
4566     // inliner happier and suppresses a number of optimizer warnings (!) about
4567     // dropping arguments.
4568     if (!Entry->use_empty()) {
4569       ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
4570       Entry->removeDeadConstantUsers();
4571     }
4572 
4573     addGlobalValReplacement(Entry, F);
4574   }
4575 
4576   assert(F->getName() == MangledName && "name was uniqued!");
4577   if (D)
4578     SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
4579   if (ExtraAttrs.hasFnAttrs()) {
4580     llvm::AttrBuilder B(F->getContext(), ExtraAttrs.getFnAttrs());
4581     F->addFnAttrs(B);
4582   }
4583 
4584   if (!DontDefer) {
4585     // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
4586     // each other bottoming out with the base dtor.  Therefore we emit non-base
4587     // dtors on usage, even if there is no dtor definition in the TU.
4588     if (isa_and_nonnull<CXXDestructorDecl>(D) &&
4589         getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
4590                                            GD.getDtorType()))
4591       addDeferredDeclToEmit(GD);
4592 
4593     // This is the first use or definition of a mangled name.  If there is a
4594     // deferred decl with this name, remember that we need to emit it at the end
4595     // of the file.
4596     auto DDI = DeferredDecls.find(MangledName);
4597     if (DDI != DeferredDecls.end()) {
4598       // Move the potentially referenced deferred decl to the
4599       // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
4600       // don't need it anymore).
4601       addDeferredDeclToEmit(DDI->second);
4602       DeferredDecls.erase(DDI);
4603 
4604       // Otherwise, there are cases we have to worry about where we're
4605       // using a declaration for which we must emit a definition but where
4606       // we might not find a top-level definition:
4607       //   - member functions defined inline in their classes
4608       //   - friend functions defined inline in some class
4609       //   - special member functions with implicit definitions
4610       // If we ever change our AST traversal to walk into class methods,
4611       // this will be unnecessary.
4612       //
4613       // We also don't emit a definition for a function if it's going to be an
4614       // entry in a vtable, unless it's already marked as used.
4615     } else if (getLangOpts().CPlusPlus && D) {
4616       // Look for a declaration that's lexically in a record.
4617       for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
4618            FD = FD->getPreviousDecl()) {
4619         if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
4620           if (FD->doesThisDeclarationHaveABody()) {
4621             addDeferredDeclToEmit(GD.getWithDecl(FD));
4622             break;
4623           }
4624         }
4625       }
4626     }
4627   }
4628 
4629   // Make sure the result is of the requested type.
4630   if (!IsIncompleteFunction) {
4631     assert(F->getFunctionType() == Ty);
4632     return F;
4633   }
4634 
4635   return F;
4636 }
4637 
4638 /// GetAddrOfFunction - Return the address of the given function.  If Ty is
4639 /// non-null, then this function will use the specified type if it has to
4640 /// create it (this occurs when we see a definition of the function).
4641 llvm::Constant *
GetAddrOfFunction(GlobalDecl GD,llvm::Type * Ty,bool ForVTable,bool DontDefer,ForDefinition_t IsForDefinition)4642 CodeGenModule::GetAddrOfFunction(GlobalDecl GD, llvm::Type *Ty, bool ForVTable,
4643                                  bool DontDefer,
4644                                  ForDefinition_t IsForDefinition) {
4645   // If there was no specific requested type, just convert it now.
4646   if (!Ty) {
4647     const auto *FD = cast<FunctionDecl>(GD.getDecl());
4648     Ty = getTypes().ConvertType(FD->getType());
4649   }
4650 
4651   // Devirtualized destructor calls may come through here instead of via
4652   // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
4653   // of the complete destructor when necessary.
4654   if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
4655     if (getTarget().getCXXABI().isMicrosoft() &&
4656         GD.getDtorType() == Dtor_Complete &&
4657         DD->getParent()->getNumVBases() == 0)
4658       GD = GlobalDecl(DD, Dtor_Base);
4659   }
4660 
4661   StringRef MangledName = getMangledName(GD);
4662   auto *F = GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
4663                                     /*IsThunk=*/false, llvm::AttributeList(),
4664                                     IsForDefinition);
4665   // Returns kernel handle for HIP kernel stub function.
4666   if (LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
4667       cast<FunctionDecl>(GD.getDecl())->hasAttr<CUDAGlobalAttr>()) {
4668     auto *Handle = getCUDARuntime().getKernelHandle(
4669         cast<llvm::Function>(F->stripPointerCasts()), GD);
4670     if (IsForDefinition)
4671       return F;
4672     return Handle;
4673   }
4674   return F;
4675 }
4676 
GetFunctionStart(const ValueDecl * Decl)4677 llvm::Constant *CodeGenModule::GetFunctionStart(const ValueDecl *Decl) {
4678   llvm::GlobalValue *F =
4679       cast<llvm::GlobalValue>(GetAddrOfFunction(Decl)->stripPointerCasts());
4680 
4681   return llvm::NoCFIValue::get(F);
4682 }
4683 
4684 static const FunctionDecl *
GetRuntimeFunctionDecl(ASTContext & C,StringRef Name)4685 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
4686   TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
4687   DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
4688 
4689   IdentifierInfo &CII = C.Idents.get(Name);
4690   for (const auto *Result : DC->lookup(&CII))
4691     if (const auto *FD = dyn_cast<FunctionDecl>(Result))
4692       return FD;
4693 
4694   if (!C.getLangOpts().CPlusPlus)
4695     return nullptr;
4696 
4697   // Demangle the premangled name from getTerminateFn()
4698   IdentifierInfo &CXXII =
4699       (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
4700           ? C.Idents.get("terminate")
4701           : C.Idents.get(Name);
4702 
4703   for (const auto &N : {"__cxxabiv1", "std"}) {
4704     IdentifierInfo &NS = C.Idents.get(N);
4705     for (const auto *Result : DC->lookup(&NS)) {
4706       const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
4707       if (auto *LSD = dyn_cast<LinkageSpecDecl>(Result))
4708         for (const auto *Result : LSD->lookup(&NS))
4709           if ((ND = dyn_cast<NamespaceDecl>(Result)))
4710             break;
4711 
4712       if (ND)
4713         for (const auto *Result : ND->lookup(&CXXII))
4714           if (const auto *FD = dyn_cast<FunctionDecl>(Result))
4715             return FD;
4716     }
4717   }
4718 
4719   return nullptr;
4720 }
4721 
4722 /// CreateRuntimeFunction - Create a new runtime function with the specified
4723 /// type and name.
4724 llvm::FunctionCallee
CreateRuntimeFunction(llvm::FunctionType * FTy,StringRef Name,llvm::AttributeList ExtraAttrs,bool Local,bool AssumeConvergent)4725 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
4726                                      llvm::AttributeList ExtraAttrs, bool Local,
4727                                      bool AssumeConvergent) {
4728   if (AssumeConvergent) {
4729     ExtraAttrs =
4730         ExtraAttrs.addFnAttribute(VMContext, llvm::Attribute::Convergent);
4731   }
4732 
4733   llvm::Constant *C =
4734       GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
4735                               /*DontDefer=*/false, /*IsThunk=*/false,
4736                               ExtraAttrs);
4737 
4738   if (auto *F = dyn_cast<llvm::Function>(C)) {
4739     if (F->empty()) {
4740       F->setCallingConv(getRuntimeCC());
4741 
4742       // In Windows Itanium environments, try to mark runtime functions
4743       // dllimport. For Mingw and MSVC, don't. We don't really know if the user
4744       // will link their standard library statically or dynamically. Marking
4745       // functions imported when they are not imported can cause linker errors
4746       // and warnings.
4747       if (!Local && getTriple().isWindowsItaniumEnvironment() &&
4748           !getCodeGenOpts().LTOVisibilityPublicStd) {
4749         const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
4750         if (!FD || FD->hasAttr<DLLImportAttr>()) {
4751           F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
4752           F->setLinkage(llvm::GlobalValue::ExternalLinkage);
4753         }
4754       }
4755       setDSOLocal(F);
4756     }
4757   }
4758 
4759   return {FTy, C};
4760 }
4761 
4762 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
4763 /// create and return an llvm GlobalVariable with the specified type and address
4764 /// space. If there is something in the module with the specified name, return
4765 /// it potentially bitcasted to the right type.
4766 ///
4767 /// If D is non-null, it specifies a decl that correspond to this.  This is used
4768 /// to set the attributes on the global when it is first created.
4769 ///
4770 /// If IsForDefinition is true, it is guaranteed that an actual global with
4771 /// type Ty will be returned, not conversion of a variable with the same
4772 /// mangled name but some other type.
4773 llvm::Constant *
GetOrCreateLLVMGlobal(StringRef MangledName,llvm::Type * Ty,LangAS AddrSpace,const VarDecl * D,ForDefinition_t IsForDefinition)4774 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, llvm::Type *Ty,
4775                                      LangAS AddrSpace, const VarDecl *D,
4776                                      ForDefinition_t IsForDefinition) {
4777   // Lookup the entry, lazily creating it if necessary.
4778   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4779   unsigned TargetAS = getContext().getTargetAddressSpace(AddrSpace);
4780   if (Entry) {
4781     if (WeakRefReferences.erase(Entry)) {
4782       if (D && !D->hasAttr<WeakAttr>())
4783         Entry->setLinkage(llvm::Function::ExternalLinkage);
4784     }
4785 
4786     // Handle dropped DLL attributes.
4787     if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>() &&
4788         !shouldMapVisibilityToDLLExport(D))
4789       Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
4790 
4791     if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
4792       getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
4793 
4794     if (Entry->getValueType() == Ty && Entry->getAddressSpace() == TargetAS)
4795       return Entry;
4796 
4797     // If there are two attempts to define the same mangled name, issue an
4798     // error.
4799     if (IsForDefinition && !Entry->isDeclaration()) {
4800       GlobalDecl OtherGD;
4801       const VarDecl *OtherD;
4802 
4803       // Check that D is not yet in DiagnosedConflictingDefinitions is required
4804       // to make sure that we issue an error only once.
4805       if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
4806           (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
4807           (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
4808           OtherD->hasInit() &&
4809           DiagnosedConflictingDefinitions.insert(D).second) {
4810         getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
4811             << MangledName;
4812         getDiags().Report(OtherGD.getDecl()->getLocation(),
4813                           diag::note_previous_definition);
4814       }
4815     }
4816 
4817     // Make sure the result is of the correct type.
4818     if (Entry->getType()->getAddressSpace() != TargetAS)
4819       return llvm::ConstantExpr::getAddrSpaceCast(
4820           Entry, llvm::PointerType::get(Ty->getContext(), TargetAS));
4821 
4822     // (If global is requested for a definition, we always need to create a new
4823     // global, not just return a bitcast.)
4824     if (!IsForDefinition)
4825       return Entry;
4826   }
4827 
4828   auto DAddrSpace = GetGlobalVarAddressSpace(D);
4829 
4830   auto *GV = new llvm::GlobalVariable(
4831       getModule(), Ty, false, llvm::GlobalValue::ExternalLinkage, nullptr,
4832       MangledName, nullptr, llvm::GlobalVariable::NotThreadLocal,
4833       getContext().getTargetAddressSpace(DAddrSpace));
4834 
4835   // If we already created a global with the same mangled name (but different
4836   // type) before, take its name and remove it from its parent.
4837   if (Entry) {
4838     GV->takeName(Entry);
4839 
4840     if (!Entry->use_empty()) {
4841       Entry->replaceAllUsesWith(GV);
4842     }
4843 
4844     Entry->eraseFromParent();
4845   }
4846 
4847   // This is the first use or definition of a mangled name.  If there is a
4848   // deferred decl with this name, remember that we need to emit it at the end
4849   // of the file.
4850   auto DDI = DeferredDecls.find(MangledName);
4851   if (DDI != DeferredDecls.end()) {
4852     // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
4853     // list, and remove it from DeferredDecls (since we don't need it anymore).
4854     addDeferredDeclToEmit(DDI->second);
4855     DeferredDecls.erase(DDI);
4856   }
4857 
4858   // Handle things which are present even on external declarations.
4859   if (D) {
4860     if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
4861       getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
4862 
4863     // FIXME: This code is overly simple and should be merged with other global
4864     // handling.
4865     GV->setConstant(D->getType().isConstantStorage(getContext(), false, false));
4866 
4867     GV->setAlignment(getContext().getDeclAlign(D).getAsAlign());
4868 
4869     setLinkageForGV(GV, D);
4870 
4871     if (D->getTLSKind()) {
4872       if (D->getTLSKind() == VarDecl::TLS_Dynamic)
4873         CXXThreadLocals.push_back(D);
4874       setTLSMode(GV, *D);
4875     }
4876 
4877     setGVProperties(GV, D);
4878 
4879     // If required by the ABI, treat declarations of static data members with
4880     // inline initializers as definitions.
4881     if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
4882       EmitGlobalVarDefinition(D);
4883     }
4884 
4885     // Emit section information for extern variables.
4886     if (D->hasExternalStorage()) {
4887       if (const SectionAttr *SA = D->getAttr<SectionAttr>())
4888         GV->setSection(SA->getName());
4889     }
4890 
4891     // Handle XCore specific ABI requirements.
4892     if (getTriple().getArch() == llvm::Triple::xcore &&
4893         D->getLanguageLinkage() == CLanguageLinkage &&
4894         D->getType().isConstant(Context) &&
4895         isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
4896       GV->setSection(".cp.rodata");
4897 
4898     // Handle code model attribute
4899     if (const auto *CMA = D->getAttr<CodeModelAttr>())
4900       GV->setCodeModel(CMA->getModel());
4901 
4902     // Check if we a have a const declaration with an initializer, we may be
4903     // able to emit it as available_externally to expose it's value to the
4904     // optimizer.
4905     if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
4906         D->getType().isConstQualified() && !GV->hasInitializer() &&
4907         !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
4908       const auto *Record =
4909           Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
4910       bool HasMutableFields = Record && Record->hasMutableFields();
4911       if (!HasMutableFields) {
4912         const VarDecl *InitDecl;
4913         const Expr *InitExpr = D->getAnyInitializer(InitDecl);
4914         if (InitExpr) {
4915           ConstantEmitter emitter(*this);
4916           llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
4917           if (Init) {
4918             auto *InitType = Init->getType();
4919             if (GV->getValueType() != InitType) {
4920               // The type of the initializer does not match the definition.
4921               // This happens when an initializer has a different type from
4922               // the type of the global (because of padding at the end of a
4923               // structure for instance).
4924               GV->setName(StringRef());
4925               // Make a new global with the correct type, this is now guaranteed
4926               // to work.
4927               auto *NewGV = cast<llvm::GlobalVariable>(
4928                   GetAddrOfGlobalVar(D, InitType, IsForDefinition)
4929                       ->stripPointerCasts());
4930 
4931               // Erase the old global, since it is no longer used.
4932               GV->eraseFromParent();
4933               GV = NewGV;
4934             } else {
4935               GV->setInitializer(Init);
4936               GV->setConstant(true);
4937               GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
4938             }
4939             emitter.finalize(GV);
4940           }
4941         }
4942       }
4943     }
4944   }
4945 
4946   if (D &&
4947       D->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly) {
4948     getTargetCodeGenInfo().setTargetAttributes(D, GV, *this);
4949     // External HIP managed variables needed to be recorded for transformation
4950     // in both device and host compilations.
4951     if (getLangOpts().CUDA && D && D->hasAttr<HIPManagedAttr>() &&
4952         D->hasExternalStorage())
4953       getCUDARuntime().handleVarRegistration(D, *GV);
4954   }
4955 
4956   if (D)
4957     SanitizerMD->reportGlobal(GV, *D);
4958 
4959   LangAS ExpectedAS =
4960       D ? D->getType().getAddressSpace()
4961         : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
4962   assert(getContext().getTargetAddressSpace(ExpectedAS) == TargetAS);
4963   if (DAddrSpace != ExpectedAS) {
4964     return getTargetCodeGenInfo().performAddrSpaceCast(
4965         *this, GV, DAddrSpace, ExpectedAS,
4966         llvm::PointerType::get(getLLVMContext(), TargetAS));
4967   }
4968 
4969   return GV;
4970 }
4971 
4972 llvm::Constant *
GetAddrOfGlobal(GlobalDecl GD,ForDefinition_t IsForDefinition)4973 CodeGenModule::GetAddrOfGlobal(GlobalDecl GD, ForDefinition_t IsForDefinition) {
4974   const Decl *D = GD.getDecl();
4975 
4976   if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
4977     return getAddrOfCXXStructor(GD, /*FnInfo=*/nullptr, /*FnType=*/nullptr,
4978                                 /*DontDefer=*/false, IsForDefinition);
4979 
4980   if (isa<CXXMethodDecl>(D)) {
4981     auto FInfo =
4982         &getTypes().arrangeCXXMethodDeclaration(cast<CXXMethodDecl>(D));
4983     auto Ty = getTypes().GetFunctionType(*FInfo);
4984     return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
4985                              IsForDefinition);
4986   }
4987 
4988   if (isa<FunctionDecl>(D)) {
4989     const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4990     llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4991     return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
4992                              IsForDefinition);
4993   }
4994 
4995   return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr, IsForDefinition);
4996 }
4997 
CreateOrReplaceCXXRuntimeVariable(StringRef Name,llvm::Type * Ty,llvm::GlobalValue::LinkageTypes Linkage,llvm::Align Alignment)4998 llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
4999     StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
5000     llvm::Align Alignment) {
5001   llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
5002   llvm::GlobalVariable *OldGV = nullptr;
5003 
5004   if (GV) {
5005     // Check if the variable has the right type.
5006     if (GV->getValueType() == Ty)
5007       return GV;
5008 
5009     // Because C++ name mangling, the only way we can end up with an already
5010     // existing global with the same name is if it has been declared extern "C".
5011     assert(GV->isDeclaration() && "Declaration has wrong type!");
5012     OldGV = GV;
5013   }
5014 
5015   // Create a new variable.
5016   GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
5017                                 Linkage, nullptr, Name);
5018 
5019   if (OldGV) {
5020     // Replace occurrences of the old variable if needed.
5021     GV->takeName(OldGV);
5022 
5023     if (!OldGV->use_empty()) {
5024       OldGV->replaceAllUsesWith(GV);
5025     }
5026 
5027     OldGV->eraseFromParent();
5028   }
5029 
5030   if (supportsCOMDAT() && GV->isWeakForLinker() &&
5031       !GV->hasAvailableExternallyLinkage())
5032     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
5033 
5034   GV->setAlignment(Alignment);
5035 
5036   return GV;
5037 }
5038 
5039 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
5040 /// given global variable.  If Ty is non-null and if the global doesn't exist,
5041 /// then it will be created with the specified type instead of whatever the
5042 /// normal requested type would be. If IsForDefinition is true, it is guaranteed
5043 /// that an actual global with type Ty will be returned, not conversion of a
5044 /// variable with the same mangled name but some other type.
GetAddrOfGlobalVar(const VarDecl * D,llvm::Type * Ty,ForDefinition_t IsForDefinition)5045 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
5046                                                   llvm::Type *Ty,
5047                                            ForDefinition_t IsForDefinition) {
5048   assert(D->hasGlobalStorage() && "Not a global variable");
5049   QualType ASTTy = D->getType();
5050   if (!Ty)
5051     Ty = getTypes().ConvertTypeForMem(ASTTy);
5052 
5053   StringRef MangledName = getMangledName(D);
5054   return GetOrCreateLLVMGlobal(MangledName, Ty, ASTTy.getAddressSpace(), D,
5055                                IsForDefinition);
5056 }
5057 
5058 /// CreateRuntimeVariable - Create a new runtime global variable with the
5059 /// specified type and name.
5060 llvm::Constant *
CreateRuntimeVariable(llvm::Type * Ty,StringRef Name)5061 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
5062                                      StringRef Name) {
5063   LangAS AddrSpace = getContext().getLangOpts().OpenCL ? LangAS::opencl_global
5064                                                        : LangAS::Default;
5065   auto *Ret = GetOrCreateLLVMGlobal(Name, Ty, AddrSpace, nullptr);
5066   setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
5067   return Ret;
5068 }
5069 
EmitTentativeDefinition(const VarDecl * D)5070 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
5071   assert(!D->getInit() && "Cannot emit definite definitions here!");
5072 
5073   StringRef MangledName = getMangledName(D);
5074   llvm::GlobalValue *GV = GetGlobalValue(MangledName);
5075 
5076   // We already have a definition, not declaration, with the same mangled name.
5077   // Emitting of declaration is not required (and actually overwrites emitted
5078   // definition).
5079   if (GV && !GV->isDeclaration())
5080     return;
5081 
5082   // If we have not seen a reference to this variable yet, place it into the
5083   // deferred declarations table to be emitted if needed later.
5084   if (!MustBeEmitted(D) && !GV) {
5085       DeferredDecls[MangledName] = D;
5086       return;
5087   }
5088 
5089   // The tentative definition is the only definition.
5090   EmitGlobalVarDefinition(D);
5091 }
5092 
EmitExternalDeclaration(const VarDecl * D)5093 void CodeGenModule::EmitExternalDeclaration(const VarDecl *D) {
5094   EmitExternalVarDeclaration(D);
5095 }
5096 
GetTargetTypeStoreSize(llvm::Type * Ty) const5097 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
5098   return Context.toCharUnitsFromBits(
5099       getDataLayout().getTypeStoreSizeInBits(Ty));
5100 }
5101 
GetGlobalVarAddressSpace(const VarDecl * D)5102 LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
5103   if (LangOpts.OpenCL) {
5104     LangAS AS = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
5105     assert(AS == LangAS::opencl_global ||
5106            AS == LangAS::opencl_global_device ||
5107            AS == LangAS::opencl_global_host ||
5108            AS == LangAS::opencl_constant ||
5109            AS == LangAS::opencl_local ||
5110            AS >= LangAS::FirstTargetAddressSpace);
5111     return AS;
5112   }
5113 
5114   if (LangOpts.SYCLIsDevice &&
5115       (!D || D->getType().getAddressSpace() == LangAS::Default))
5116     return LangAS::sycl_global;
5117 
5118   if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
5119     if (D) {
5120       if (D->hasAttr<CUDAConstantAttr>())
5121         return LangAS::cuda_constant;
5122       if (D->hasAttr<CUDASharedAttr>())
5123         return LangAS::cuda_shared;
5124       if (D->hasAttr<CUDADeviceAttr>())
5125         return LangAS::cuda_device;
5126       if (D->getType().isConstQualified())
5127         return LangAS::cuda_constant;
5128     }
5129     return LangAS::cuda_device;
5130   }
5131 
5132   if (LangOpts.OpenMP) {
5133     LangAS AS;
5134     if (OpenMPRuntime->hasAllocateAttributeForGlobalVar(D, AS))
5135       return AS;
5136   }
5137   return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
5138 }
5139 
GetGlobalConstantAddressSpace() const5140 LangAS CodeGenModule::GetGlobalConstantAddressSpace() const {
5141   // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
5142   if (LangOpts.OpenCL)
5143     return LangAS::opencl_constant;
5144   if (LangOpts.SYCLIsDevice)
5145     return LangAS::sycl_global;
5146   if (LangOpts.HIP && LangOpts.CUDAIsDevice && getTriple().isSPIRV())
5147     // For HIPSPV map literals to cuda_device (maps to CrossWorkGroup in SPIR-V)
5148     // instead of default AS (maps to Generic in SPIR-V). Otherwise, we end up
5149     // with OpVariable instructions with Generic storage class which is not
5150     // allowed (SPIR-V V1.6 s3.42.8). Also, mapping literals to SPIR-V
5151     // UniformConstant storage class is not viable as pointers to it may not be
5152     // casted to Generic pointers which are used to model HIP's "flat" pointers.
5153     return LangAS::cuda_device;
5154   if (auto AS = getTarget().getConstantAddressSpace())
5155     return *AS;
5156   return LangAS::Default;
5157 }
5158 
5159 // In address space agnostic languages, string literals are in default address
5160 // space in AST. However, certain targets (e.g. amdgcn) request them to be
5161 // emitted in constant address space in LLVM IR. To be consistent with other
5162 // parts of AST, string literal global variables in constant address space
5163 // need to be casted to default address space before being put into address
5164 // map and referenced by other part of CodeGen.
5165 // In OpenCL, string literals are in constant address space in AST, therefore
5166 // they should not be casted to default address space.
5167 static llvm::Constant *
castStringLiteralToDefaultAddressSpace(CodeGenModule & CGM,llvm::GlobalVariable * GV)5168 castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM,
5169                                        llvm::GlobalVariable *GV) {
5170   llvm::Constant *Cast = GV;
5171   if (!CGM.getLangOpts().OpenCL) {
5172     auto AS = CGM.GetGlobalConstantAddressSpace();
5173     if (AS != LangAS::Default)
5174       Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast(
5175           CGM, GV, AS, LangAS::Default,
5176           llvm::PointerType::get(
5177               CGM.getLLVMContext(),
5178               CGM.getContext().getTargetAddressSpace(LangAS::Default)));
5179   }
5180   return Cast;
5181 }
5182 
5183 template<typename SomeDecl>
MaybeHandleStaticInExternC(const SomeDecl * D,llvm::GlobalValue * GV)5184 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
5185                                                llvm::GlobalValue *GV) {
5186   if (!getLangOpts().CPlusPlus)
5187     return;
5188 
5189   // Must have 'used' attribute, or else inline assembly can't rely on
5190   // the name existing.
5191   if (!D->template hasAttr<UsedAttr>())
5192     return;
5193 
5194   // Must have internal linkage and an ordinary name.
5195   if (!D->getIdentifier() || D->getFormalLinkage() != Linkage::Internal)
5196     return;
5197 
5198   // Must be in an extern "C" context. Entities declared directly within
5199   // a record are not extern "C" even if the record is in such a context.
5200   const SomeDecl *First = D->getFirstDecl();
5201   if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
5202     return;
5203 
5204   // OK, this is an internal linkage entity inside an extern "C" linkage
5205   // specification. Make a note of that so we can give it the "expected"
5206   // mangled name if nothing else is using that name.
5207   std::pair<StaticExternCMap::iterator, bool> R =
5208       StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
5209 
5210   // If we have multiple internal linkage entities with the same name
5211   // in extern "C" regions, none of them gets that name.
5212   if (!R.second)
5213     R.first->second = nullptr;
5214 }
5215 
shouldBeInCOMDAT(CodeGenModule & CGM,const Decl & D)5216 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
5217   if (!CGM.supportsCOMDAT())
5218     return false;
5219 
5220   if (D.hasAttr<SelectAnyAttr>())
5221     return true;
5222 
5223   GVALinkage Linkage;
5224   if (auto *VD = dyn_cast<VarDecl>(&D))
5225     Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
5226   else
5227     Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
5228 
5229   switch (Linkage) {
5230   case GVA_Internal:
5231   case GVA_AvailableExternally:
5232   case GVA_StrongExternal:
5233     return false;
5234   case GVA_DiscardableODR:
5235   case GVA_StrongODR:
5236     return true;
5237   }
5238   llvm_unreachable("No such linkage");
5239 }
5240 
supportsCOMDAT() const5241 bool CodeGenModule::supportsCOMDAT() const {
5242   return getTriple().supportsCOMDAT();
5243 }
5244 
maybeSetTrivialComdat(const Decl & D,llvm::GlobalObject & GO)5245 void CodeGenModule::maybeSetTrivialComdat(const Decl &D,
5246                                           llvm::GlobalObject &GO) {
5247   if (!shouldBeInCOMDAT(*this, D))
5248     return;
5249   GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
5250 }
5251 
5252 /// Pass IsTentative as true if you want to create a tentative definition.
EmitGlobalVarDefinition(const VarDecl * D,bool IsTentative)5253 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
5254                                             bool IsTentative) {
5255   // OpenCL global variables of sampler type are translated to function calls,
5256   // therefore no need to be translated.
5257   QualType ASTTy = D->getType();
5258   if (getLangOpts().OpenCL && ASTTy->isSamplerT())
5259     return;
5260 
5261   // If this is OpenMP device, check if it is legal to emit this global
5262   // normally.
5263   if (LangOpts.OpenMPIsTargetDevice && OpenMPRuntime &&
5264       OpenMPRuntime->emitTargetGlobalVariable(D))
5265     return;
5266 
5267   llvm::TrackingVH<llvm::Constant> Init;
5268   bool NeedsGlobalCtor = false;
5269   // Whether the definition of the variable is available externally.
5270   // If yes, we shouldn't emit the GloablCtor and GlobalDtor for the variable
5271   // since this is the job for its original source.
5272   bool IsDefinitionAvailableExternally =
5273       getContext().GetGVALinkageForVariable(D) == GVA_AvailableExternally;
5274   bool NeedsGlobalDtor =
5275       !IsDefinitionAvailableExternally &&
5276       D->needsDestruction(getContext()) == QualType::DK_cxx_destructor;
5277 
5278   const VarDecl *InitDecl;
5279   const Expr *InitExpr = D->getAnyInitializer(InitDecl);
5280 
5281   std::optional<ConstantEmitter> emitter;
5282 
5283   // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
5284   // as part of their declaration."  Sema has already checked for
5285   // error cases, so we just need to set Init to UndefValue.
5286   bool IsCUDASharedVar =
5287       getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
5288   // Shadows of initialized device-side global variables are also left
5289   // undefined.
5290   // Managed Variables should be initialized on both host side and device side.
5291   bool IsCUDAShadowVar =
5292       !getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
5293       (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
5294        D->hasAttr<CUDASharedAttr>());
5295   bool IsCUDADeviceShadowVar =
5296       getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
5297       (D->getType()->isCUDADeviceBuiltinSurfaceType() ||
5298        D->getType()->isCUDADeviceBuiltinTextureType());
5299   if (getLangOpts().CUDA &&
5300       (IsCUDASharedVar || IsCUDAShadowVar || IsCUDADeviceShadowVar))
5301     Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
5302   else if (D->hasAttr<LoaderUninitializedAttr>())
5303     Init = llvm::UndefValue::get(getTypes().ConvertTypeForMem(ASTTy));
5304   else if (!InitExpr) {
5305     // This is a tentative definition; tentative definitions are
5306     // implicitly initialized with { 0 }.
5307     //
5308     // Note that tentative definitions are only emitted at the end of
5309     // a translation unit, so they should never have incomplete
5310     // type. In addition, EmitTentativeDefinition makes sure that we
5311     // never attempt to emit a tentative definition if a real one
5312     // exists. A use may still exists, however, so we still may need
5313     // to do a RAUW.
5314     assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
5315     Init = EmitNullConstant(D->getType());
5316   } else {
5317     initializedGlobalDecl = GlobalDecl(D);
5318     emitter.emplace(*this);
5319     llvm::Constant *Initializer = emitter->tryEmitForInitializer(*InitDecl);
5320     if (!Initializer) {
5321       QualType T = InitExpr->getType();
5322       if (D->getType()->isReferenceType())
5323         T = D->getType();
5324 
5325       if (getLangOpts().CPlusPlus) {
5326         if (InitDecl->hasFlexibleArrayInit(getContext()))
5327           ErrorUnsupported(D, "flexible array initializer");
5328         Init = EmitNullConstant(T);
5329 
5330         if (!IsDefinitionAvailableExternally)
5331           NeedsGlobalCtor = true;
5332       } else {
5333         ErrorUnsupported(D, "static initializer");
5334         Init = llvm::UndefValue::get(getTypes().ConvertType(T));
5335       }
5336     } else {
5337       Init = Initializer;
5338       // We don't need an initializer, so remove the entry for the delayed
5339       // initializer position (just in case this entry was delayed) if we
5340       // also don't need to register a destructor.
5341       if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
5342         DelayedCXXInitPosition.erase(D);
5343 
5344 #ifndef NDEBUG
5345       CharUnits VarSize = getContext().getTypeSizeInChars(ASTTy) +
5346                           InitDecl->getFlexibleArrayInitChars(getContext());
5347       CharUnits CstSize = CharUnits::fromQuantity(
5348           getDataLayout().getTypeAllocSize(Init->getType()));
5349       assert(VarSize == CstSize && "Emitted constant has unexpected size");
5350 #endif
5351     }
5352   }
5353 
5354   llvm::Type* InitType = Init->getType();
5355   llvm::Constant *Entry =
5356       GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
5357 
5358   // Strip off pointer casts if we got them.
5359   Entry = Entry->stripPointerCasts();
5360 
5361   // Entry is now either a Function or GlobalVariable.
5362   auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
5363 
5364   // We have a definition after a declaration with the wrong type.
5365   // We must make a new GlobalVariable* and update everything that used OldGV
5366   // (a declaration or tentative definition) with the new GlobalVariable*
5367   // (which will be a definition).
5368   //
5369   // This happens if there is a prototype for a global (e.g.
5370   // "extern int x[];") and then a definition of a different type (e.g.
5371   // "int x[10];"). This also happens when an initializer has a different type
5372   // from the type of the global (this happens with unions).
5373   if (!GV || GV->getValueType() != InitType ||
5374       GV->getType()->getAddressSpace() !=
5375           getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
5376 
5377     // Move the old entry aside so that we'll create a new one.
5378     Entry->setName(StringRef());
5379 
5380     // Make a new global with the correct type, this is now guaranteed to work.
5381     GV = cast<llvm::GlobalVariable>(
5382         GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative))
5383             ->stripPointerCasts());
5384 
5385     // Replace all uses of the old global with the new global
5386     llvm::Constant *NewPtrForOldDecl =
5387         llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV,
5388                                                              Entry->getType());
5389     Entry->replaceAllUsesWith(NewPtrForOldDecl);
5390 
5391     // Erase the old global, since it is no longer used.
5392     cast<llvm::GlobalValue>(Entry)->eraseFromParent();
5393   }
5394 
5395   MaybeHandleStaticInExternC(D, GV);
5396 
5397   if (D->hasAttr<AnnotateAttr>())
5398     AddGlobalAnnotations(D, GV);
5399 
5400   // Set the llvm linkage type as appropriate.
5401   llvm::GlobalValue::LinkageTypes Linkage = getLLVMLinkageVarDefinition(D);
5402 
5403   // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
5404   // the device. [...]"
5405   // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
5406   // __device__, declares a variable that: [...]
5407   // Is accessible from all the threads within the grid and from the host
5408   // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
5409   // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
5410   if (LangOpts.CUDA) {
5411     if (LangOpts.CUDAIsDevice) {
5412       if (Linkage != llvm::GlobalValue::InternalLinkage &&
5413           (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
5414            D->getType()->isCUDADeviceBuiltinSurfaceType() ||
5415            D->getType()->isCUDADeviceBuiltinTextureType()))
5416         GV->setExternallyInitialized(true);
5417     } else {
5418       getCUDARuntime().internalizeDeviceSideVar(D, Linkage);
5419     }
5420     getCUDARuntime().handleVarRegistration(D, *GV);
5421   }
5422 
5423   GV->setInitializer(Init);
5424   if (emitter)
5425     emitter->finalize(GV);
5426 
5427   // If it is safe to mark the global 'constant', do so now.
5428   GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
5429                   D->getType().isConstantStorage(getContext(), true, true));
5430 
5431   // If it is in a read-only section, mark it 'constant'.
5432   if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
5433     const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
5434     if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
5435       GV->setConstant(true);
5436   }
5437 
5438   CharUnits AlignVal = getContext().getDeclAlign(D);
5439   // Check for alignment specifed in an 'omp allocate' directive.
5440   if (std::optional<CharUnits> AlignValFromAllocate =
5441           getOMPAllocateAlignment(D))
5442     AlignVal = *AlignValFromAllocate;
5443   GV->setAlignment(AlignVal.getAsAlign());
5444 
5445   // On Darwin, unlike other Itanium C++ ABI platforms, the thread-wrapper
5446   // function is only defined alongside the variable, not also alongside
5447   // callers. Normally, all accesses to a thread_local go through the
5448   // thread-wrapper in order to ensure initialization has occurred, underlying
5449   // variable will never be used other than the thread-wrapper, so it can be
5450   // converted to internal linkage.
5451   //
5452   // However, if the variable has the 'constinit' attribute, it _can_ be
5453   // referenced directly, without calling the thread-wrapper, so the linkage
5454   // must not be changed.
5455   //
5456   // Additionally, if the variable isn't plain external linkage, e.g. if it's
5457   // weak or linkonce, the de-duplication semantics are important to preserve,
5458   // so we don't change the linkage.
5459   if (D->getTLSKind() == VarDecl::TLS_Dynamic &&
5460       Linkage == llvm::GlobalValue::ExternalLinkage &&
5461       Context.getTargetInfo().getTriple().isOSDarwin() &&
5462       !D->hasAttr<ConstInitAttr>())
5463     Linkage = llvm::GlobalValue::InternalLinkage;
5464 
5465   GV->setLinkage(Linkage);
5466   if (D->hasAttr<DLLImportAttr>())
5467     GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
5468   else if (D->hasAttr<DLLExportAttr>())
5469     GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
5470   else
5471     GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
5472 
5473   if (Linkage == llvm::GlobalVariable::CommonLinkage) {
5474     // common vars aren't constant even if declared const.
5475     GV->setConstant(false);
5476     // Tentative definition of global variables may be initialized with
5477     // non-zero null pointers. In this case they should have weak linkage
5478     // since common linkage must have zero initializer and must not have
5479     // explicit section therefore cannot have non-zero initial value.
5480     if (!GV->getInitializer()->isNullValue())
5481       GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
5482   }
5483 
5484   setNonAliasAttributes(D, GV);
5485 
5486   if (D->getTLSKind() && !GV->isThreadLocal()) {
5487     if (D->getTLSKind() == VarDecl::TLS_Dynamic)
5488       CXXThreadLocals.push_back(D);
5489     setTLSMode(GV, *D);
5490   }
5491 
5492   maybeSetTrivialComdat(*D, *GV);
5493 
5494   // Emit the initializer function if necessary.
5495   if (NeedsGlobalCtor || NeedsGlobalDtor)
5496     EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
5497 
5498   SanitizerMD->reportGlobal(GV, *D, NeedsGlobalCtor);
5499 
5500   // Emit global variable debug information.
5501   if (CGDebugInfo *DI = getModuleDebugInfo())
5502     if (getCodeGenOpts().hasReducedDebugInfo())
5503       DI->EmitGlobalVariable(GV, D);
5504 }
5505 
EmitExternalVarDeclaration(const VarDecl * D)5506 void CodeGenModule::EmitExternalVarDeclaration(const VarDecl *D) {
5507   if (CGDebugInfo *DI = getModuleDebugInfo())
5508     if (getCodeGenOpts().hasReducedDebugInfo()) {
5509       QualType ASTTy = D->getType();
5510       llvm::Type *Ty = getTypes().ConvertTypeForMem(D->getType());
5511       llvm::Constant *GV =
5512           GetOrCreateLLVMGlobal(D->getName(), Ty, ASTTy.getAddressSpace(), D);
5513       DI->EmitExternalVariable(
5514           cast<llvm::GlobalVariable>(GV->stripPointerCasts()), D);
5515     }
5516 }
5517 
isVarDeclStrongDefinition(const ASTContext & Context,CodeGenModule & CGM,const VarDecl * D,bool NoCommon)5518 static bool isVarDeclStrongDefinition(const ASTContext &Context,
5519                                       CodeGenModule &CGM, const VarDecl *D,
5520                                       bool NoCommon) {
5521   // Don't give variables common linkage if -fno-common was specified unless it
5522   // was overridden by a NoCommon attribute.
5523   if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
5524     return true;
5525 
5526   // C11 6.9.2/2:
5527   //   A declaration of an identifier for an object that has file scope without
5528   //   an initializer, and without a storage-class specifier or with the
5529   //   storage-class specifier static, constitutes a tentative definition.
5530   if (D->getInit() || D->hasExternalStorage())
5531     return true;
5532 
5533   // A variable cannot be both common and exist in a section.
5534   if (D->hasAttr<SectionAttr>())
5535     return true;
5536 
5537   // A variable cannot be both common and exist in a section.
5538   // We don't try to determine which is the right section in the front-end.
5539   // If no specialized section name is applicable, it will resort to default.
5540   if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
5541       D->hasAttr<PragmaClangDataSectionAttr>() ||
5542       D->hasAttr<PragmaClangRelroSectionAttr>() ||
5543       D->hasAttr<PragmaClangRodataSectionAttr>())
5544     return true;
5545 
5546   // Thread local vars aren't considered common linkage.
5547   if (D->getTLSKind())
5548     return true;
5549 
5550   // Tentative definitions marked with WeakImportAttr are true definitions.
5551   if (D->hasAttr<WeakImportAttr>())
5552     return true;
5553 
5554   // A variable cannot be both common and exist in a comdat.
5555   if (shouldBeInCOMDAT(CGM, *D))
5556     return true;
5557 
5558   // Declarations with a required alignment do not have common linkage in MSVC
5559   // mode.
5560   if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
5561     if (D->hasAttr<AlignedAttr>())
5562       return true;
5563     QualType VarType = D->getType();
5564     if (Context.isAlignmentRequired(VarType))
5565       return true;
5566 
5567     if (const auto *RT = VarType->getAs<RecordType>()) {
5568       const RecordDecl *RD = RT->getDecl();
5569       for (const FieldDecl *FD : RD->fields()) {
5570         if (FD->isBitField())
5571           continue;
5572         if (FD->hasAttr<AlignedAttr>())
5573           return true;
5574         if (Context.isAlignmentRequired(FD->getType()))
5575           return true;
5576       }
5577     }
5578   }
5579 
5580   // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
5581   // common symbols, so symbols with greater alignment requirements cannot be
5582   // common.
5583   // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
5584   // alignments for common symbols via the aligncomm directive, so this
5585   // restriction only applies to MSVC environments.
5586   if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
5587       Context.getTypeAlignIfKnown(D->getType()) >
5588           Context.toBits(CharUnits::fromQuantity(32)))
5589     return true;
5590 
5591   return false;
5592 }
5593 
5594 llvm::GlobalValue::LinkageTypes
getLLVMLinkageForDeclarator(const DeclaratorDecl * D,GVALinkage Linkage)5595 CodeGenModule::getLLVMLinkageForDeclarator(const DeclaratorDecl *D,
5596                                            GVALinkage Linkage) {
5597   if (Linkage == GVA_Internal)
5598     return llvm::Function::InternalLinkage;
5599 
5600   if (D->hasAttr<WeakAttr>())
5601     return llvm::GlobalVariable::WeakAnyLinkage;
5602 
5603   if (const auto *FD = D->getAsFunction())
5604     if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
5605       return llvm::GlobalVariable::LinkOnceAnyLinkage;
5606 
5607   // We are guaranteed to have a strong definition somewhere else,
5608   // so we can use available_externally linkage.
5609   if (Linkage == GVA_AvailableExternally)
5610     return llvm::GlobalValue::AvailableExternallyLinkage;
5611 
5612   // Note that Apple's kernel linker doesn't support symbol
5613   // coalescing, so we need to avoid linkonce and weak linkages there.
5614   // Normally, this means we just map to internal, but for explicit
5615   // instantiations we'll map to external.
5616 
5617   // In C++, the compiler has to emit a definition in every translation unit
5618   // that references the function.  We should use linkonce_odr because
5619   // a) if all references in this translation unit are optimized away, we
5620   // don't need to codegen it.  b) if the function persists, it needs to be
5621   // merged with other definitions. c) C++ has the ODR, so we know the
5622   // definition is dependable.
5623   if (Linkage == GVA_DiscardableODR)
5624     return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
5625                                             : llvm::Function::InternalLinkage;
5626 
5627   // An explicit instantiation of a template has weak linkage, since
5628   // explicit instantiations can occur in multiple translation units
5629   // and must all be equivalent. However, we are not allowed to
5630   // throw away these explicit instantiations.
5631   //
5632   // CUDA/HIP: For -fno-gpu-rdc case, device code is limited to one TU,
5633   // so say that CUDA templates are either external (for kernels) or internal.
5634   // This lets llvm perform aggressive inter-procedural optimizations. For
5635   // -fgpu-rdc case, device function calls across multiple TU's are allowed,
5636   // therefore we need to follow the normal linkage paradigm.
5637   if (Linkage == GVA_StrongODR) {
5638     if (getLangOpts().AppleKext)
5639       return llvm::Function::ExternalLinkage;
5640     if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
5641         !getLangOpts().GPURelocatableDeviceCode)
5642       return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
5643                                           : llvm::Function::InternalLinkage;
5644     return llvm::Function::WeakODRLinkage;
5645   }
5646 
5647   // C++ doesn't have tentative definitions and thus cannot have common
5648   // linkage.
5649   if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
5650       !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
5651                                  CodeGenOpts.NoCommon))
5652     return llvm::GlobalVariable::CommonLinkage;
5653 
5654   // selectany symbols are externally visible, so use weak instead of
5655   // linkonce.  MSVC optimizes away references to const selectany globals, so
5656   // all definitions should be the same and ODR linkage should be used.
5657   // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
5658   if (D->hasAttr<SelectAnyAttr>())
5659     return llvm::GlobalVariable::WeakODRLinkage;
5660 
5661   // Otherwise, we have strong external linkage.
5662   assert(Linkage == GVA_StrongExternal);
5663   return llvm::GlobalVariable::ExternalLinkage;
5664 }
5665 
5666 llvm::GlobalValue::LinkageTypes
getLLVMLinkageVarDefinition(const VarDecl * VD)5667 CodeGenModule::getLLVMLinkageVarDefinition(const VarDecl *VD) {
5668   GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
5669   return getLLVMLinkageForDeclarator(VD, Linkage);
5670 }
5671 
5672 /// Replace the uses of a function that was declared with a non-proto type.
5673 /// We want to silently drop extra arguments from call sites
replaceUsesOfNonProtoConstant(llvm::Constant * old,llvm::Function * newFn)5674 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
5675                                           llvm::Function *newFn) {
5676   // Fast path.
5677   if (old->use_empty()) return;
5678 
5679   llvm::Type *newRetTy = newFn->getReturnType();
5680   SmallVector<llvm::Value*, 4> newArgs;
5681 
5682   for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
5683          ui != ue; ) {
5684     llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
5685     llvm::User *user = use->getUser();
5686 
5687     // Recognize and replace uses of bitcasts.  Most calls to
5688     // unprototyped functions will use bitcasts.
5689     if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
5690       if (bitcast->getOpcode() == llvm::Instruction::BitCast)
5691         replaceUsesOfNonProtoConstant(bitcast, newFn);
5692       continue;
5693     }
5694 
5695     // Recognize calls to the function.
5696     llvm::CallBase *callSite = dyn_cast<llvm::CallBase>(user);
5697     if (!callSite) continue;
5698     if (!callSite->isCallee(&*use))
5699       continue;
5700 
5701     // If the return types don't match exactly, then we can't
5702     // transform this call unless it's dead.
5703     if (callSite->getType() != newRetTy && !callSite->use_empty())
5704       continue;
5705 
5706     // Get the call site's attribute list.
5707     SmallVector<llvm::AttributeSet, 8> newArgAttrs;
5708     llvm::AttributeList oldAttrs = callSite->getAttributes();
5709 
5710     // If the function was passed too few arguments, don't transform.
5711     unsigned newNumArgs = newFn->arg_size();
5712     if (callSite->arg_size() < newNumArgs)
5713       continue;
5714 
5715     // If extra arguments were passed, we silently drop them.
5716     // If any of the types mismatch, we don't transform.
5717     unsigned argNo = 0;
5718     bool dontTransform = false;
5719     for (llvm::Argument &A : newFn->args()) {
5720       if (callSite->getArgOperand(argNo)->getType() != A.getType()) {
5721         dontTransform = true;
5722         break;
5723       }
5724 
5725       // Add any parameter attributes.
5726       newArgAttrs.push_back(oldAttrs.getParamAttrs(argNo));
5727       argNo++;
5728     }
5729     if (dontTransform)
5730       continue;
5731 
5732     // Okay, we can transform this.  Create the new call instruction and copy
5733     // over the required information.
5734     newArgs.append(callSite->arg_begin(), callSite->arg_begin() + argNo);
5735 
5736     // Copy over any operand bundles.
5737     SmallVector<llvm::OperandBundleDef, 1> newBundles;
5738     callSite->getOperandBundlesAsDefs(newBundles);
5739 
5740     llvm::CallBase *newCall;
5741     if (isa<llvm::CallInst>(callSite)) {
5742       newCall =
5743           llvm::CallInst::Create(newFn, newArgs, newBundles, "", callSite);
5744     } else {
5745       auto *oldInvoke = cast<llvm::InvokeInst>(callSite);
5746       newCall = llvm::InvokeInst::Create(newFn, oldInvoke->getNormalDest(),
5747                                          oldInvoke->getUnwindDest(), newArgs,
5748                                          newBundles, "", callSite);
5749     }
5750     newArgs.clear(); // for the next iteration
5751 
5752     if (!newCall->getType()->isVoidTy())
5753       newCall->takeName(callSite);
5754     newCall->setAttributes(
5755         llvm::AttributeList::get(newFn->getContext(), oldAttrs.getFnAttrs(),
5756                                  oldAttrs.getRetAttrs(), newArgAttrs));
5757     newCall->setCallingConv(callSite->getCallingConv());
5758 
5759     // Finally, remove the old call, replacing any uses with the new one.
5760     if (!callSite->use_empty())
5761       callSite->replaceAllUsesWith(newCall);
5762 
5763     // Copy debug location attached to CI.
5764     if (callSite->getDebugLoc())
5765       newCall->setDebugLoc(callSite->getDebugLoc());
5766 
5767     callSite->eraseFromParent();
5768   }
5769 }
5770 
5771 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
5772 /// implement a function with no prototype, e.g. "int foo() {}".  If there are
5773 /// existing call uses of the old function in the module, this adjusts them to
5774 /// call the new function directly.
5775 ///
5776 /// This is not just a cleanup: the always_inline pass requires direct calls to
5777 /// functions to be able to inline them.  If there is a bitcast in the way, it
5778 /// won't inline them.  Instcombine normally deletes these calls, but it isn't
5779 /// run at -O0.
ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue * Old,llvm::Function * NewFn)5780 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
5781                                                       llvm::Function *NewFn) {
5782   // If we're redefining a global as a function, don't transform it.
5783   if (!isa<llvm::Function>(Old)) return;
5784 
5785   replaceUsesOfNonProtoConstant(Old, NewFn);
5786 }
5787 
HandleCXXStaticMemberVarInstantiation(VarDecl * VD)5788 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
5789   auto DK = VD->isThisDeclarationADefinition();
5790   if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
5791     return;
5792 
5793   TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
5794   // If we have a definition, this might be a deferred decl. If the
5795   // instantiation is explicit, make sure we emit it at the end.
5796   if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
5797     GetAddrOfGlobalVar(VD);
5798 
5799   EmitTopLevelDecl(VD);
5800 }
5801 
EmitGlobalFunctionDefinition(GlobalDecl GD,llvm::GlobalValue * GV)5802 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
5803                                                  llvm::GlobalValue *GV) {
5804   const auto *D = cast<FunctionDecl>(GD.getDecl());
5805 
5806   // Compute the function info and LLVM type.
5807   const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
5808   llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
5809 
5810   // Get or create the prototype for the function.
5811   if (!GV || (GV->getValueType() != Ty))
5812     GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
5813                                                    /*DontDefer=*/true,
5814                                                    ForDefinition));
5815 
5816   // Already emitted.
5817   if (!GV->isDeclaration())
5818     return;
5819 
5820   // We need to set linkage and visibility on the function before
5821   // generating code for it because various parts of IR generation
5822   // want to propagate this information down (e.g. to local static
5823   // declarations).
5824   auto *Fn = cast<llvm::Function>(GV);
5825   setFunctionLinkage(GD, Fn);
5826 
5827   // FIXME: this is redundant with part of setFunctionDefinitionAttributes
5828   setGVProperties(Fn, GD);
5829 
5830   MaybeHandleStaticInExternC(D, Fn);
5831 
5832   maybeSetTrivialComdat(*D, *Fn);
5833 
5834   CodeGenFunction(*this).GenerateCode(GD, Fn, FI);
5835 
5836   setNonAliasAttributes(GD, Fn);
5837   SetLLVMFunctionAttributesForDefinition(D, Fn);
5838 
5839   if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
5840     AddGlobalCtor(Fn, CA->getPriority());
5841   if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
5842     AddGlobalDtor(Fn, DA->getPriority(), true);
5843   if (getLangOpts().OpenMP && D->hasAttr<OMPDeclareTargetDeclAttr>())
5844     getOpenMPRuntime().emitDeclareTargetFunction(D, GV);
5845 }
5846 
EmitAliasDefinition(GlobalDecl GD)5847 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
5848   const auto *D = cast<ValueDecl>(GD.getDecl());
5849   const AliasAttr *AA = D->getAttr<AliasAttr>();
5850   assert(AA && "Not an alias?");
5851 
5852   StringRef MangledName = getMangledName(GD);
5853 
5854   if (AA->getAliasee() == MangledName) {
5855     Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
5856     return;
5857   }
5858 
5859   // If there is a definition in the module, then it wins over the alias.
5860   // This is dubious, but allow it to be safe.  Just ignore the alias.
5861   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
5862   if (Entry && !Entry->isDeclaration())
5863     return;
5864 
5865   Aliases.push_back(GD);
5866 
5867   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
5868 
5869   // Create a reference to the named value.  This ensures that it is emitted
5870   // if a deferred decl.
5871   llvm::Constant *Aliasee;
5872   llvm::GlobalValue::LinkageTypes LT;
5873   if (isa<llvm::FunctionType>(DeclTy)) {
5874     Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
5875                                       /*ForVTable=*/false);
5876     LT = getFunctionLinkage(GD);
5877   } else {
5878     Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), DeclTy, LangAS::Default,
5879                                     /*D=*/nullptr);
5880     if (const auto *VD = dyn_cast<VarDecl>(GD.getDecl()))
5881       LT = getLLVMLinkageVarDefinition(VD);
5882     else
5883       LT = getFunctionLinkage(GD);
5884   }
5885 
5886   // Create the new alias itself, but don't set a name yet.
5887   unsigned AS = Aliasee->getType()->getPointerAddressSpace();
5888   auto *GA =
5889       llvm::GlobalAlias::create(DeclTy, AS, LT, "", Aliasee, &getModule());
5890 
5891   if (Entry) {
5892     if (GA->getAliasee() == Entry) {
5893       Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
5894       return;
5895     }
5896 
5897     assert(Entry->isDeclaration());
5898 
5899     // If there is a declaration in the module, then we had an extern followed
5900     // by the alias, as in:
5901     //   extern int test6();
5902     //   ...
5903     //   int test6() __attribute__((alias("test7")));
5904     //
5905     // Remove it and replace uses of it with the alias.
5906     GA->takeName(Entry);
5907 
5908     Entry->replaceAllUsesWith(GA);
5909     Entry->eraseFromParent();
5910   } else {
5911     GA->setName(MangledName);
5912   }
5913 
5914   // Set attributes which are particular to an alias; this is a
5915   // specialization of the attributes which may be set on a global
5916   // variable/function.
5917   if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
5918       D->isWeakImported()) {
5919     GA->setLinkage(llvm::Function::WeakAnyLinkage);
5920   }
5921 
5922   if (const auto *VD = dyn_cast<VarDecl>(D))
5923     if (VD->getTLSKind())
5924       setTLSMode(GA, *VD);
5925 
5926   SetCommonAttributes(GD, GA);
5927 
5928   // Emit global alias debug information.
5929   if (isa<VarDecl>(D))
5930     if (CGDebugInfo *DI = getModuleDebugInfo())
5931       DI->EmitGlobalAlias(cast<llvm::GlobalValue>(GA->getAliasee()->stripPointerCasts()), GD);
5932 }
5933 
emitIFuncDefinition(GlobalDecl GD)5934 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
5935   const auto *D = cast<ValueDecl>(GD.getDecl());
5936   const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
5937   assert(IFA && "Not an ifunc?");
5938 
5939   StringRef MangledName = getMangledName(GD);
5940 
5941   if (IFA->getResolver() == MangledName) {
5942     Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
5943     return;
5944   }
5945 
5946   // Report an error if some definition overrides ifunc.
5947   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
5948   if (Entry && !Entry->isDeclaration()) {
5949     GlobalDecl OtherGD;
5950     if (lookupRepresentativeDecl(MangledName, OtherGD) &&
5951         DiagnosedConflictingDefinitions.insert(GD).second) {
5952       Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
5953           << MangledName;
5954       Diags.Report(OtherGD.getDecl()->getLocation(),
5955                    diag::note_previous_definition);
5956     }
5957     return;
5958   }
5959 
5960   Aliases.push_back(GD);
5961 
5962   llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
5963   llvm::Type *ResolverTy = llvm::GlobalIFunc::getResolverFunctionType(DeclTy);
5964   llvm::Constant *Resolver =
5965       GetOrCreateLLVMFunction(IFA->getResolver(), ResolverTy, {},
5966                               /*ForVTable=*/false);
5967   llvm::GlobalIFunc *GIF =
5968       llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage,
5969                                 "", Resolver, &getModule());
5970   if (Entry) {
5971     if (GIF->getResolver() == Entry) {
5972       Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
5973       return;
5974     }
5975     assert(Entry->isDeclaration());
5976 
5977     // If there is a declaration in the module, then we had an extern followed
5978     // by the ifunc, as in:
5979     //   extern int test();
5980     //   ...
5981     //   int test() __attribute__((ifunc("resolver")));
5982     //
5983     // Remove it and replace uses of it with the ifunc.
5984     GIF->takeName(Entry);
5985 
5986     Entry->replaceAllUsesWith(GIF);
5987     Entry->eraseFromParent();
5988   } else
5989     GIF->setName(MangledName);
5990   if (auto *F = dyn_cast<llvm::Function>(Resolver)) {
5991     F->addFnAttr(llvm::Attribute::DisableSanitizerInstrumentation);
5992   }
5993   SetCommonAttributes(GD, GIF);
5994 }
5995 
getIntrinsic(unsigned IID,ArrayRef<llvm::Type * > Tys)5996 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
5997                                             ArrayRef<llvm::Type*> Tys) {
5998   return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
5999                                          Tys);
6000 }
6001 
6002 static llvm::StringMapEntry<llvm::GlobalVariable *> &
GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable * > & Map,const StringLiteral * Literal,bool TargetIsLSB,bool & IsUTF16,unsigned & StringLength)6003 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
6004                          const StringLiteral *Literal, bool TargetIsLSB,
6005                          bool &IsUTF16, unsigned &StringLength) {
6006   StringRef String = Literal->getString();
6007   unsigned NumBytes = String.size();
6008 
6009   // Check for simple case.
6010   if (!Literal->containsNonAsciiOrNull()) {
6011     StringLength = NumBytes;
6012     return *Map.insert(std::make_pair(String, nullptr)).first;
6013   }
6014 
6015   // Otherwise, convert the UTF8 literals into a string of shorts.
6016   IsUTF16 = true;
6017 
6018   SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
6019   const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
6020   llvm::UTF16 *ToPtr = &ToBuf[0];
6021 
6022   (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
6023                                  ToPtr + NumBytes, llvm::strictConversion);
6024 
6025   // ConvertUTF8toUTF16 returns the length in ToPtr.
6026   StringLength = ToPtr - &ToBuf[0];
6027 
6028   // Add an explicit null.
6029   *ToPtr = 0;
6030   return *Map.insert(std::make_pair(
6031                          StringRef(reinterpret_cast<const char *>(ToBuf.data()),
6032                                    (StringLength + 1) * 2),
6033                          nullptr)).first;
6034 }
6035 
6036 ConstantAddress
GetAddrOfConstantCFString(const StringLiteral * Literal)6037 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
6038   unsigned StringLength = 0;
6039   bool isUTF16 = false;
6040   llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
6041       GetConstantCFStringEntry(CFConstantStringMap, Literal,
6042                                getDataLayout().isLittleEndian(), isUTF16,
6043                                StringLength);
6044 
6045   if (auto *C = Entry.second)
6046     return ConstantAddress(
6047         C, C->getValueType(), CharUnits::fromQuantity(C->getAlignment()));
6048 
6049   llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
6050   llvm::Constant *Zeros[] = { Zero, Zero };
6051 
6052   const ASTContext &Context = getContext();
6053   const llvm::Triple &Triple = getTriple();
6054 
6055   const auto CFRuntime = getLangOpts().CFRuntime;
6056   const bool IsSwiftABI =
6057       static_cast<unsigned>(CFRuntime) >=
6058       static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
6059   const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
6060 
6061   // If we don't already have it, get __CFConstantStringClassReference.
6062   if (!CFConstantStringClassRef) {
6063     const char *CFConstantStringClassName = "__CFConstantStringClassReference";
6064     llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
6065     Ty = llvm::ArrayType::get(Ty, 0);
6066 
6067     switch (CFRuntime) {
6068     default: break;
6069     case LangOptions::CoreFoundationABI::Swift: [[fallthrough]];
6070     case LangOptions::CoreFoundationABI::Swift5_0:
6071       CFConstantStringClassName =
6072           Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
6073                               : "$s10Foundation19_NSCFConstantStringCN";
6074       Ty = IntPtrTy;
6075       break;
6076     case LangOptions::CoreFoundationABI::Swift4_2:
6077       CFConstantStringClassName =
6078           Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
6079                               : "$S10Foundation19_NSCFConstantStringCN";
6080       Ty = IntPtrTy;
6081       break;
6082     case LangOptions::CoreFoundationABI::Swift4_1:
6083       CFConstantStringClassName =
6084           Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
6085                               : "__T010Foundation19_NSCFConstantStringCN";
6086       Ty = IntPtrTy;
6087       break;
6088     }
6089 
6090     llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
6091 
6092     if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
6093       llvm::GlobalValue *GV = nullptr;
6094 
6095       if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
6096         IdentifierInfo &II = Context.Idents.get(GV->getName());
6097         TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
6098         DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
6099 
6100         const VarDecl *VD = nullptr;
6101         for (const auto *Result : DC->lookup(&II))
6102           if ((VD = dyn_cast<VarDecl>(Result)))
6103             break;
6104 
6105         if (Triple.isOSBinFormatELF()) {
6106           if (!VD)
6107             GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
6108         } else {
6109           GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
6110           if (!VD || !VD->hasAttr<DLLExportAttr>())
6111             GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
6112           else
6113             GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
6114         }
6115 
6116         setDSOLocal(GV);
6117       }
6118     }
6119 
6120     // Decay array -> ptr
6121     CFConstantStringClassRef =
6122         IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty)
6123                    : llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros);
6124   }
6125 
6126   QualType CFTy = Context.getCFConstantStringType();
6127 
6128   auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
6129 
6130   ConstantInitBuilder Builder(*this);
6131   auto Fields = Builder.beginStruct(STy);
6132 
6133   // Class pointer.
6134   Fields.add(cast<llvm::Constant>(CFConstantStringClassRef));
6135 
6136   // Flags.
6137   if (IsSwiftABI) {
6138     Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
6139     Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
6140   } else {
6141     Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
6142   }
6143 
6144   // String pointer.
6145   llvm::Constant *C = nullptr;
6146   if (isUTF16) {
6147     auto Arr = llvm::ArrayRef(
6148         reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
6149         Entry.first().size() / 2);
6150     C = llvm::ConstantDataArray::get(VMContext, Arr);
6151   } else {
6152     C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
6153   }
6154 
6155   // Note: -fwritable-strings doesn't make the backing store strings of
6156   // CFStrings writable.
6157   auto *GV =
6158       new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
6159                                llvm::GlobalValue::PrivateLinkage, C, ".str");
6160   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
6161   // Don't enforce the target's minimum global alignment, since the only use
6162   // of the string is via this class initializer.
6163   CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
6164                             : Context.getTypeAlignInChars(Context.CharTy);
6165   GV->setAlignment(Align.getAsAlign());
6166 
6167   // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
6168   // Without it LLVM can merge the string with a non unnamed_addr one during
6169   // LTO.  Doing that changes the section it ends in, which surprises ld64.
6170   if (Triple.isOSBinFormatMachO())
6171     GV->setSection(isUTF16 ? "__TEXT,__ustring"
6172                            : "__TEXT,__cstring,cstring_literals");
6173   // Make sure the literal ends up in .rodata to allow for safe ICF and for
6174   // the static linker to adjust permissions to read-only later on.
6175   else if (Triple.isOSBinFormatELF())
6176     GV->setSection(".rodata");
6177 
6178   // String.
6179   llvm::Constant *Str =
6180       llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
6181 
6182   Fields.add(Str);
6183 
6184   // String length.
6185   llvm::IntegerType *LengthTy =
6186       llvm::IntegerType::get(getModule().getContext(),
6187                              Context.getTargetInfo().getLongWidth());
6188   if (IsSwiftABI) {
6189     if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
6190         CFRuntime == LangOptions::CoreFoundationABI::Swift4_2)
6191       LengthTy = Int32Ty;
6192     else
6193       LengthTy = IntPtrTy;
6194   }
6195   Fields.addInt(LengthTy, StringLength);
6196 
6197   // Swift ABI requires 8-byte alignment to ensure that the _Atomic(uint64_t) is
6198   // properly aligned on 32-bit platforms.
6199   CharUnits Alignment =
6200       IsSwiftABI ? Context.toCharUnitsFromBits(64) : getPointerAlign();
6201 
6202   // The struct.
6203   GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
6204                                     /*isConstant=*/false,
6205                                     llvm::GlobalVariable::PrivateLinkage);
6206   GV->addAttribute("objc_arc_inert");
6207   switch (Triple.getObjectFormat()) {
6208   case llvm::Triple::UnknownObjectFormat:
6209     llvm_unreachable("unknown file format");
6210   case llvm::Triple::DXContainer:
6211   case llvm::Triple::GOFF:
6212   case llvm::Triple::SPIRV:
6213   case llvm::Triple::XCOFF:
6214     llvm_unreachable("unimplemented");
6215   case llvm::Triple::COFF:
6216   case llvm::Triple::ELF:
6217   case llvm::Triple::Wasm:
6218     GV->setSection("cfstring");
6219     break;
6220   case llvm::Triple::MachO:
6221     GV->setSection("__DATA,__cfstring");
6222     break;
6223   }
6224   Entry.second = GV;
6225 
6226   return ConstantAddress(GV, GV->getValueType(), Alignment);
6227 }
6228 
getExpressionLocationsEnabled() const6229 bool CodeGenModule::getExpressionLocationsEnabled() const {
6230   return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
6231 }
6232 
getObjCFastEnumerationStateType()6233 QualType CodeGenModule::getObjCFastEnumerationStateType() {
6234   if (ObjCFastEnumerationStateType.isNull()) {
6235     RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
6236     D->startDefinition();
6237 
6238     QualType FieldTypes[] = {
6239         Context.UnsignedLongTy, Context.getPointerType(Context.getObjCIdType()),
6240         Context.getPointerType(Context.UnsignedLongTy),
6241         Context.getConstantArrayType(Context.UnsignedLongTy, llvm::APInt(32, 5),
6242                                      nullptr, ArraySizeModifier::Normal, 0)};
6243 
6244     for (size_t i = 0; i < 4; ++i) {
6245       FieldDecl *Field = FieldDecl::Create(Context,
6246                                            D,
6247                                            SourceLocation(),
6248                                            SourceLocation(), nullptr,
6249                                            FieldTypes[i], /*TInfo=*/nullptr,
6250                                            /*BitWidth=*/nullptr,
6251                                            /*Mutable=*/false,
6252                                            ICIS_NoInit);
6253       Field->setAccess(AS_public);
6254       D->addDecl(Field);
6255     }
6256 
6257     D->completeDefinition();
6258     ObjCFastEnumerationStateType = Context.getTagDeclType(D);
6259   }
6260 
6261   return ObjCFastEnumerationStateType;
6262 }
6263 
6264 llvm::Constant *
GetConstantArrayFromStringLiteral(const StringLiteral * E)6265 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
6266   assert(!E->getType()->isPointerType() && "Strings are always arrays");
6267 
6268   // Don't emit it as the address of the string, emit the string data itself
6269   // as an inline array.
6270   if (E->getCharByteWidth() == 1) {
6271     SmallString<64> Str(E->getString());
6272 
6273     // Resize the string to the right size, which is indicated by its type.
6274     const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
6275     assert(CAT && "String literal not of constant array type!");
6276     Str.resize(CAT->getSize().getZExtValue());
6277     return llvm::ConstantDataArray::getString(VMContext, Str, false);
6278   }
6279 
6280   auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
6281   llvm::Type *ElemTy = AType->getElementType();
6282   unsigned NumElements = AType->getNumElements();
6283 
6284   // Wide strings have either 2-byte or 4-byte elements.
6285   if (ElemTy->getPrimitiveSizeInBits() == 16) {
6286     SmallVector<uint16_t, 32> Elements;
6287     Elements.reserve(NumElements);
6288 
6289     for(unsigned i = 0, e = E->getLength(); i != e; ++i)
6290       Elements.push_back(E->getCodeUnit(i));
6291     Elements.resize(NumElements);
6292     return llvm::ConstantDataArray::get(VMContext, Elements);
6293   }
6294 
6295   assert(ElemTy->getPrimitiveSizeInBits() == 32);
6296   SmallVector<uint32_t, 32> Elements;
6297   Elements.reserve(NumElements);
6298 
6299   for(unsigned i = 0, e = E->getLength(); i != e; ++i)
6300     Elements.push_back(E->getCodeUnit(i));
6301   Elements.resize(NumElements);
6302   return llvm::ConstantDataArray::get(VMContext, Elements);
6303 }
6304 
6305 static llvm::GlobalVariable *
GenerateStringLiteral(llvm::Constant * C,llvm::GlobalValue::LinkageTypes LT,CodeGenModule & CGM,StringRef GlobalName,CharUnits Alignment)6306 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
6307                       CodeGenModule &CGM, StringRef GlobalName,
6308                       CharUnits Alignment) {
6309   unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
6310       CGM.GetGlobalConstantAddressSpace());
6311 
6312   llvm::Module &M = CGM.getModule();
6313   // Create a global variable for this string
6314   auto *GV = new llvm::GlobalVariable(
6315       M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
6316       nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
6317   GV->setAlignment(Alignment.getAsAlign());
6318   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
6319   if (GV->isWeakForLinker()) {
6320     assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
6321     GV->setComdat(M.getOrInsertComdat(GV->getName()));
6322   }
6323   CGM.setDSOLocal(GV);
6324 
6325   return GV;
6326 }
6327 
6328 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
6329 /// constant array for the given string literal.
6330 ConstantAddress
GetAddrOfConstantStringFromLiteral(const StringLiteral * S,StringRef Name)6331 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
6332                                                   StringRef Name) {
6333   CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType());
6334 
6335   llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
6336   llvm::GlobalVariable **Entry = nullptr;
6337   if (!LangOpts.WritableStrings) {
6338     Entry = &ConstantStringMap[C];
6339     if (auto GV = *Entry) {
6340       if (uint64_t(Alignment.getQuantity()) > GV->getAlignment())
6341         GV->setAlignment(Alignment.getAsAlign());
6342       return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6343                              GV->getValueType(), Alignment);
6344     }
6345   }
6346 
6347   SmallString<256> MangledNameBuffer;
6348   StringRef GlobalVariableName;
6349   llvm::GlobalValue::LinkageTypes LT;
6350 
6351   // Mangle the string literal if that's how the ABI merges duplicate strings.
6352   // Don't do it if they are writable, since we don't want writes in one TU to
6353   // affect strings in another.
6354   if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
6355       !LangOpts.WritableStrings) {
6356     llvm::raw_svector_ostream Out(MangledNameBuffer);
6357     getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
6358     LT = llvm::GlobalValue::LinkOnceODRLinkage;
6359     GlobalVariableName = MangledNameBuffer;
6360   } else {
6361     LT = llvm::GlobalValue::PrivateLinkage;
6362     GlobalVariableName = Name;
6363   }
6364 
6365   auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
6366 
6367   CGDebugInfo *DI = getModuleDebugInfo();
6368   if (DI && getCodeGenOpts().hasReducedDebugInfo())
6369     DI->AddStringLiteralDebugInfo(GV, S);
6370 
6371   if (Entry)
6372     *Entry = GV;
6373 
6374   SanitizerMD->reportGlobal(GV, S->getStrTokenLoc(0), "<string literal>");
6375 
6376   return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6377                          GV->getValueType(), Alignment);
6378 }
6379 
6380 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
6381 /// array for the given ObjCEncodeExpr node.
6382 ConstantAddress
GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr * E)6383 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
6384   std::string Str;
6385   getContext().getObjCEncodingForType(E->getEncodedType(), Str);
6386 
6387   return GetAddrOfConstantCString(Str);
6388 }
6389 
6390 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
6391 /// the literal and a terminating '\0' character.
6392 /// The result has pointer to array type.
GetAddrOfConstantCString(const std::string & Str,const char * GlobalName)6393 ConstantAddress CodeGenModule::GetAddrOfConstantCString(
6394     const std::string &Str, const char *GlobalName) {
6395   StringRef StrWithNull(Str.c_str(), Str.size() + 1);
6396   CharUnits Alignment =
6397     getContext().getAlignOfGlobalVarInChars(getContext().CharTy);
6398 
6399   llvm::Constant *C =
6400       llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
6401 
6402   // Don't share any string literals if strings aren't constant.
6403   llvm::GlobalVariable **Entry = nullptr;
6404   if (!LangOpts.WritableStrings) {
6405     Entry = &ConstantStringMap[C];
6406     if (auto GV = *Entry) {
6407       if (uint64_t(Alignment.getQuantity()) > GV->getAlignment())
6408         GV->setAlignment(Alignment.getAsAlign());
6409       return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6410                              GV->getValueType(), Alignment);
6411     }
6412   }
6413 
6414   // Get the default prefix if a name wasn't specified.
6415   if (!GlobalName)
6416     GlobalName = ".str";
6417   // Create a global variable for this.
6418   auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
6419                                   GlobalName, Alignment);
6420   if (Entry)
6421     *Entry = GV;
6422 
6423   return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
6424                          GV->getValueType(), Alignment);
6425 }
6426 
GetAddrOfGlobalTemporary(const MaterializeTemporaryExpr * E,const Expr * Init)6427 ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
6428     const MaterializeTemporaryExpr *E, const Expr *Init) {
6429   assert((E->getStorageDuration() == SD_Static ||
6430           E->getStorageDuration() == SD_Thread) && "not a global temporary");
6431   const auto *VD = cast<VarDecl>(E->getExtendingDecl());
6432 
6433   // If we're not materializing a subobject of the temporary, keep the
6434   // cv-qualifiers from the type of the MaterializeTemporaryExpr.
6435   QualType MaterializedType = Init->getType();
6436   if (Init == E->getSubExpr())
6437     MaterializedType = E->getType();
6438 
6439   CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
6440 
6441   auto InsertResult = MaterializedGlobalTemporaryMap.insert({E, nullptr});
6442   if (!InsertResult.second) {
6443     // We've seen this before: either we already created it or we're in the
6444     // process of doing so.
6445     if (!InsertResult.first->second) {
6446       // We recursively re-entered this function, probably during emission of
6447       // the initializer. Create a placeholder. We'll clean this up in the
6448       // outer call, at the end of this function.
6449       llvm::Type *Type = getTypes().ConvertTypeForMem(MaterializedType);
6450       InsertResult.first->second = new llvm::GlobalVariable(
6451           getModule(), Type, false, llvm::GlobalVariable::InternalLinkage,
6452           nullptr);
6453     }
6454     return ConstantAddress(InsertResult.first->second,
6455                            llvm::cast<llvm::GlobalVariable>(
6456                                InsertResult.first->second->stripPointerCasts())
6457                                ->getValueType(),
6458                            Align);
6459   }
6460 
6461   // FIXME: If an externally-visible declaration extends multiple temporaries,
6462   // we need to give each temporary the same name in every translation unit (and
6463   // we also need to make the temporaries externally-visible).
6464   SmallString<256> Name;
6465   llvm::raw_svector_ostream Out(Name);
6466   getCXXABI().getMangleContext().mangleReferenceTemporary(
6467       VD, E->getManglingNumber(), Out);
6468 
6469   APValue *Value = nullptr;
6470   if (E->getStorageDuration() == SD_Static && VD->evaluateValue()) {
6471     // If the initializer of the extending declaration is a constant
6472     // initializer, we should have a cached constant initializer for this
6473     // temporary. Note that this might have a different value from the value
6474     // computed by evaluating the initializer if the surrounding constant
6475     // expression modifies the temporary.
6476     Value = E->getOrCreateValue(false);
6477   }
6478 
6479   // Try evaluating it now, it might have a constant initializer.
6480   Expr::EvalResult EvalResult;
6481   if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
6482       !EvalResult.hasSideEffects())
6483     Value = &EvalResult.Val;
6484 
6485   LangAS AddrSpace = GetGlobalVarAddressSpace(VD);
6486 
6487   std::optional<ConstantEmitter> emitter;
6488   llvm::Constant *InitialValue = nullptr;
6489   bool Constant = false;
6490   llvm::Type *Type;
6491   if (Value) {
6492     // The temporary has a constant initializer, use it.
6493     emitter.emplace(*this);
6494     InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
6495                                                MaterializedType);
6496     Constant =
6497         MaterializedType.isConstantStorage(getContext(), /*ExcludeCtor*/ Value,
6498                                            /*ExcludeDtor*/ false);
6499     Type = InitialValue->getType();
6500   } else {
6501     // No initializer, the initialization will be provided when we
6502     // initialize the declaration which performed lifetime extension.
6503     Type = getTypes().ConvertTypeForMem(MaterializedType);
6504   }
6505 
6506   // Create a global variable for this lifetime-extended temporary.
6507   llvm::GlobalValue::LinkageTypes Linkage = getLLVMLinkageVarDefinition(VD);
6508   if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
6509     const VarDecl *InitVD;
6510     if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
6511         isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
6512       // Temporaries defined inside a class get linkonce_odr linkage because the
6513       // class can be defined in multiple translation units.
6514       Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
6515     } else {
6516       // There is no need for this temporary to have external linkage if the
6517       // VarDecl has external linkage.
6518       Linkage = llvm::GlobalVariable::InternalLinkage;
6519     }
6520   }
6521   auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
6522   auto *GV = new llvm::GlobalVariable(
6523       getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
6524       /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
6525   if (emitter) emitter->finalize(GV);
6526   // Don't assign dllimport or dllexport to local linkage globals.
6527   if (!llvm::GlobalValue::isLocalLinkage(Linkage)) {
6528     setGVProperties(GV, VD);
6529     if (GV->getDLLStorageClass() == llvm::GlobalVariable::DLLExportStorageClass)
6530       // The reference temporary should never be dllexport.
6531       GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
6532   }
6533   GV->setAlignment(Align.getAsAlign());
6534   if (supportsCOMDAT() && GV->isWeakForLinker())
6535     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
6536   if (VD->getTLSKind())
6537     setTLSMode(GV, *VD);
6538   llvm::Constant *CV = GV;
6539   if (AddrSpace != LangAS::Default)
6540     CV = getTargetCodeGenInfo().performAddrSpaceCast(
6541         *this, GV, AddrSpace, LangAS::Default,
6542         llvm::PointerType::get(
6543             getLLVMContext(),
6544             getContext().getTargetAddressSpace(LangAS::Default)));
6545 
6546   // Update the map with the new temporary. If we created a placeholder above,
6547   // replace it with the new global now.
6548   llvm::Constant *&Entry = MaterializedGlobalTemporaryMap[E];
6549   if (Entry) {
6550     Entry->replaceAllUsesWith(CV);
6551     llvm::cast<llvm::GlobalVariable>(Entry)->eraseFromParent();
6552   }
6553   Entry = CV;
6554 
6555   return ConstantAddress(CV, Type, Align);
6556 }
6557 
6558 /// EmitObjCPropertyImplementations - Emit information for synthesized
6559 /// properties for an implementation.
EmitObjCPropertyImplementations(const ObjCImplementationDecl * D)6560 void CodeGenModule::EmitObjCPropertyImplementations(const
6561                                                     ObjCImplementationDecl *D) {
6562   for (const auto *PID : D->property_impls()) {
6563     // Dynamic is just for type-checking.
6564     if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
6565       ObjCPropertyDecl *PD = PID->getPropertyDecl();
6566 
6567       // Determine which methods need to be implemented, some may have
6568       // been overridden. Note that ::isPropertyAccessor is not the method
6569       // we want, that just indicates if the decl came from a
6570       // property. What we want to know is if the method is defined in
6571       // this implementation.
6572       auto *Getter = PID->getGetterMethodDecl();
6573       if (!Getter || Getter->isSynthesizedAccessorStub())
6574         CodeGenFunction(*this).GenerateObjCGetter(
6575             const_cast<ObjCImplementationDecl *>(D), PID);
6576       auto *Setter = PID->getSetterMethodDecl();
6577       if (!PD->isReadOnly() && (!Setter || Setter->isSynthesizedAccessorStub()))
6578         CodeGenFunction(*this).GenerateObjCSetter(
6579                                  const_cast<ObjCImplementationDecl *>(D), PID);
6580     }
6581   }
6582 }
6583 
needsDestructMethod(ObjCImplementationDecl * impl)6584 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
6585   const ObjCInterfaceDecl *iface = impl->getClassInterface();
6586   for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
6587        ivar; ivar = ivar->getNextIvar())
6588     if (ivar->getType().isDestructedType())
6589       return true;
6590 
6591   return false;
6592 }
6593 
AllTrivialInitializers(CodeGenModule & CGM,ObjCImplementationDecl * D)6594 static bool AllTrivialInitializers(CodeGenModule &CGM,
6595                                    ObjCImplementationDecl *D) {
6596   CodeGenFunction CGF(CGM);
6597   for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
6598        E = D->init_end(); B != E; ++B) {
6599     CXXCtorInitializer *CtorInitExp = *B;
6600     Expr *Init = CtorInitExp->getInit();
6601     if (!CGF.isTrivialInitializer(Init))
6602       return false;
6603   }
6604   return true;
6605 }
6606 
6607 /// EmitObjCIvarInitializations - Emit information for ivar initialization
6608 /// for an implementation.
EmitObjCIvarInitializations(ObjCImplementationDecl * D)6609 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
6610   // We might need a .cxx_destruct even if we don't have any ivar initializers.
6611   if (needsDestructMethod(D)) {
6612     IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
6613     Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
6614     ObjCMethodDecl *DTORMethod = ObjCMethodDecl::Create(
6615         getContext(), D->getLocation(), D->getLocation(), cxxSelector,
6616         getContext().VoidTy, nullptr, D,
6617         /*isInstance=*/true, /*isVariadic=*/false,
6618         /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
6619         /*isImplicitlyDeclared=*/true,
6620         /*isDefined=*/false, ObjCImplementationControl::Required);
6621     D->addInstanceMethod(DTORMethod);
6622     CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
6623     D->setHasDestructors(true);
6624   }
6625 
6626   // If the implementation doesn't have any ivar initializers, we don't need
6627   // a .cxx_construct.
6628   if (D->getNumIvarInitializers() == 0 ||
6629       AllTrivialInitializers(*this, D))
6630     return;
6631 
6632   IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
6633   Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
6634   // The constructor returns 'self'.
6635   ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(
6636       getContext(), D->getLocation(), D->getLocation(), cxxSelector,
6637       getContext().getObjCIdType(), nullptr, D, /*isInstance=*/true,
6638       /*isVariadic=*/false,
6639       /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
6640       /*isImplicitlyDeclared=*/true,
6641       /*isDefined=*/false, ObjCImplementationControl::Required);
6642   D->addInstanceMethod(CTORMethod);
6643   CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
6644   D->setHasNonZeroConstructors(true);
6645 }
6646 
6647 // EmitLinkageSpec - Emit all declarations in a linkage spec.
EmitLinkageSpec(const LinkageSpecDecl * LSD)6648 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
6649   if (LSD->getLanguage() != LinkageSpecLanguageIDs::C &&
6650       LSD->getLanguage() != LinkageSpecLanguageIDs::CXX) {
6651     ErrorUnsupported(LSD, "linkage spec");
6652     return;
6653   }
6654 
6655   EmitDeclContext(LSD);
6656 }
6657 
EmitTopLevelStmt(const TopLevelStmtDecl * D)6658 void CodeGenModule::EmitTopLevelStmt(const TopLevelStmtDecl *D) {
6659   // Device code should not be at top level.
6660   if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
6661     return;
6662 
6663   std::unique_ptr<CodeGenFunction> &CurCGF =
6664       GlobalTopLevelStmtBlockInFlight.first;
6665 
6666   // We emitted a top-level stmt but after it there is initialization.
6667   // Stop squashing the top-level stmts into a single function.
6668   if (CurCGF && CXXGlobalInits.back() != CurCGF->CurFn) {
6669     CurCGF->FinishFunction(D->getEndLoc());
6670     CurCGF = nullptr;
6671   }
6672 
6673   if (!CurCGF) {
6674     // void __stmts__N(void)
6675     // FIXME: Ask the ABI name mangler to pick a name.
6676     std::string Name = "__stmts__" + llvm::utostr(CXXGlobalInits.size());
6677     FunctionArgList Args;
6678     QualType RetTy = getContext().VoidTy;
6679     const CGFunctionInfo &FnInfo =
6680         getTypes().arrangeBuiltinFunctionDeclaration(RetTy, Args);
6681     llvm::FunctionType *FnTy = getTypes().GetFunctionType(FnInfo);
6682     llvm::Function *Fn = llvm::Function::Create(
6683         FnTy, llvm::GlobalValue::InternalLinkage, Name, &getModule());
6684 
6685     CurCGF.reset(new CodeGenFunction(*this));
6686     GlobalTopLevelStmtBlockInFlight.second = D;
6687     CurCGF->StartFunction(GlobalDecl(), RetTy, Fn, FnInfo, Args,
6688                           D->getBeginLoc(), D->getBeginLoc());
6689     CXXGlobalInits.push_back(Fn);
6690   }
6691 
6692   CurCGF->EmitStmt(D->getStmt());
6693 }
6694 
EmitDeclContext(const DeclContext * DC)6695 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
6696   for (auto *I : DC->decls()) {
6697     // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
6698     // are themselves considered "top-level", so EmitTopLevelDecl on an
6699     // ObjCImplDecl does not recursively visit them. We need to do that in
6700     // case they're nested inside another construct (LinkageSpecDecl /
6701     // ExportDecl) that does stop them from being considered "top-level".
6702     if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
6703       for (auto *M : OID->methods())
6704         EmitTopLevelDecl(M);
6705     }
6706 
6707     EmitTopLevelDecl(I);
6708   }
6709 }
6710 
6711 /// EmitTopLevelDecl - Emit code for a single top level declaration.
EmitTopLevelDecl(Decl * D)6712 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
6713   // Ignore dependent declarations.
6714   if (D->isTemplated())
6715     return;
6716 
6717   // Consteval function shouldn't be emitted.
6718   if (auto *FD = dyn_cast<FunctionDecl>(D); FD && FD->isImmediateFunction())
6719     return;
6720 
6721   switch (D->getKind()) {
6722   case Decl::CXXConversion:
6723   case Decl::CXXMethod:
6724   case Decl::Function:
6725     EmitGlobal(cast<FunctionDecl>(D));
6726     // Always provide some coverage mapping
6727     // even for the functions that aren't emitted.
6728     AddDeferredUnusedCoverageMapping(D);
6729     break;
6730 
6731   case Decl::CXXDeductionGuide:
6732     // Function-like, but does not result in code emission.
6733     break;
6734 
6735   case Decl::Var:
6736   case Decl::Decomposition:
6737   case Decl::VarTemplateSpecialization:
6738     EmitGlobal(cast<VarDecl>(D));
6739     if (auto *DD = dyn_cast<DecompositionDecl>(D))
6740       for (auto *B : DD->bindings())
6741         if (auto *HD = B->getHoldingVar())
6742           EmitGlobal(HD);
6743     break;
6744 
6745   // Indirect fields from global anonymous structs and unions can be
6746   // ignored; only the actual variable requires IR gen support.
6747   case Decl::IndirectField:
6748     break;
6749 
6750   // C++ Decls
6751   case Decl::Namespace:
6752     EmitDeclContext(cast<NamespaceDecl>(D));
6753     break;
6754   case Decl::ClassTemplateSpecialization: {
6755     const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
6756     if (CGDebugInfo *DI = getModuleDebugInfo())
6757       if (Spec->getSpecializationKind() ==
6758               TSK_ExplicitInstantiationDefinition &&
6759           Spec->hasDefinition())
6760         DI->completeTemplateDefinition(*Spec);
6761   } [[fallthrough]];
6762   case Decl::CXXRecord: {
6763     CXXRecordDecl *CRD = cast<CXXRecordDecl>(D);
6764     if (CGDebugInfo *DI = getModuleDebugInfo()) {
6765       if (CRD->hasDefinition())
6766         DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
6767       if (auto *ES = D->getASTContext().getExternalSource())
6768         if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
6769           DI->completeUnusedClass(*CRD);
6770     }
6771     // Emit any static data members, they may be definitions.
6772     for (auto *I : CRD->decls())
6773       if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
6774         EmitTopLevelDecl(I);
6775     break;
6776   }
6777     // No code generation needed.
6778   case Decl::UsingShadow:
6779   case Decl::ClassTemplate:
6780   case Decl::VarTemplate:
6781   case Decl::Concept:
6782   case Decl::VarTemplatePartialSpecialization:
6783   case Decl::FunctionTemplate:
6784   case Decl::TypeAliasTemplate:
6785   case Decl::Block:
6786   case Decl::Empty:
6787   case Decl::Binding:
6788     break;
6789   case Decl::Using:          // using X; [C++]
6790     if (CGDebugInfo *DI = getModuleDebugInfo())
6791         DI->EmitUsingDecl(cast<UsingDecl>(*D));
6792     break;
6793   case Decl::UsingEnum: // using enum X; [C++]
6794     if (CGDebugInfo *DI = getModuleDebugInfo())
6795       DI->EmitUsingEnumDecl(cast<UsingEnumDecl>(*D));
6796     break;
6797   case Decl::NamespaceAlias:
6798     if (CGDebugInfo *DI = getModuleDebugInfo())
6799         DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
6800     break;
6801   case Decl::UsingDirective: // using namespace X; [C++]
6802     if (CGDebugInfo *DI = getModuleDebugInfo())
6803       DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
6804     break;
6805   case Decl::CXXConstructor:
6806     getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
6807     break;
6808   case Decl::CXXDestructor:
6809     getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
6810     break;
6811 
6812   case Decl::StaticAssert:
6813     // Nothing to do.
6814     break;
6815 
6816   // Objective-C Decls
6817 
6818   // Forward declarations, no (immediate) code generation.
6819   case Decl::ObjCInterface:
6820   case Decl::ObjCCategory:
6821     break;
6822 
6823   case Decl::ObjCProtocol: {
6824     auto *Proto = cast<ObjCProtocolDecl>(D);
6825     if (Proto->isThisDeclarationADefinition())
6826       ObjCRuntime->GenerateProtocol(Proto);
6827     break;
6828   }
6829 
6830   case Decl::ObjCCategoryImpl:
6831     // Categories have properties but don't support synthesize so we
6832     // can ignore them here.
6833     ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
6834     break;
6835 
6836   case Decl::ObjCImplementation: {
6837     auto *OMD = cast<ObjCImplementationDecl>(D);
6838     EmitObjCPropertyImplementations(OMD);
6839     EmitObjCIvarInitializations(OMD);
6840     ObjCRuntime->GenerateClass(OMD);
6841     // Emit global variable debug information.
6842     if (CGDebugInfo *DI = getModuleDebugInfo())
6843       if (getCodeGenOpts().hasReducedDebugInfo())
6844         DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
6845             OMD->getClassInterface()), OMD->getLocation());
6846     break;
6847   }
6848   case Decl::ObjCMethod: {
6849     auto *OMD = cast<ObjCMethodDecl>(D);
6850     // If this is not a prototype, emit the body.
6851     if (OMD->getBody())
6852       CodeGenFunction(*this).GenerateObjCMethod(OMD);
6853     break;
6854   }
6855   case Decl::ObjCCompatibleAlias:
6856     ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
6857     break;
6858 
6859   case Decl::PragmaComment: {
6860     const auto *PCD = cast<PragmaCommentDecl>(D);
6861     switch (PCD->getCommentKind()) {
6862     case PCK_Unknown:
6863       llvm_unreachable("unexpected pragma comment kind");
6864     case PCK_Linker:
6865       AppendLinkerOptions(PCD->getArg());
6866       break;
6867     case PCK_Lib:
6868         AddDependentLib(PCD->getArg());
6869       break;
6870     case PCK_Compiler:
6871     case PCK_ExeStr:
6872     case PCK_User:
6873       break; // We ignore all of these.
6874     }
6875     break;
6876   }
6877 
6878   case Decl::PragmaDetectMismatch: {
6879     const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
6880     AddDetectMismatch(PDMD->getName(), PDMD->getValue());
6881     break;
6882   }
6883 
6884   case Decl::LinkageSpec:
6885     EmitLinkageSpec(cast<LinkageSpecDecl>(D));
6886     break;
6887 
6888   case Decl::FileScopeAsm: {
6889     // File-scope asm is ignored during device-side CUDA compilation.
6890     if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
6891       break;
6892     // File-scope asm is ignored during device-side OpenMP compilation.
6893     if (LangOpts.OpenMPIsTargetDevice)
6894       break;
6895     // File-scope asm is ignored during device-side SYCL compilation.
6896     if (LangOpts.SYCLIsDevice)
6897       break;
6898     auto *AD = cast<FileScopeAsmDecl>(D);
6899     getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
6900     break;
6901   }
6902 
6903   case Decl::TopLevelStmt:
6904     EmitTopLevelStmt(cast<TopLevelStmtDecl>(D));
6905     break;
6906 
6907   case Decl::Import: {
6908     auto *Import = cast<ImportDecl>(D);
6909 
6910     // If we've already imported this module, we're done.
6911     if (!ImportedModules.insert(Import->getImportedModule()))
6912       break;
6913 
6914     // Emit debug information for direct imports.
6915     if (!Import->getImportedOwningModule()) {
6916       if (CGDebugInfo *DI = getModuleDebugInfo())
6917         DI->EmitImportDecl(*Import);
6918     }
6919 
6920     // For C++ standard modules we are done - we will call the module
6921     // initializer for imported modules, and that will likewise call those for
6922     // any imports it has.
6923     if (CXX20ModuleInits && Import->getImportedOwningModule() &&
6924         !Import->getImportedOwningModule()->isModuleMapModule())
6925       break;
6926 
6927     // For clang C++ module map modules the initializers for sub-modules are
6928     // emitted here.
6929 
6930     // Find all of the submodules and emit the module initializers.
6931     llvm::SmallPtrSet<clang::Module *, 16> Visited;
6932     SmallVector<clang::Module *, 16> Stack;
6933     Visited.insert(Import->getImportedModule());
6934     Stack.push_back(Import->getImportedModule());
6935 
6936     while (!Stack.empty()) {
6937       clang::Module *Mod = Stack.pop_back_val();
6938       if (!EmittedModuleInitializers.insert(Mod).second)
6939         continue;
6940 
6941       for (auto *D : Context.getModuleInitializers(Mod))
6942         EmitTopLevelDecl(D);
6943 
6944       // Visit the submodules of this module.
6945       for (auto *Submodule : Mod->submodules()) {
6946         // Skip explicit children; they need to be explicitly imported to emit
6947         // the initializers.
6948         if (Submodule->IsExplicit)
6949           continue;
6950 
6951         if (Visited.insert(Submodule).second)
6952           Stack.push_back(Submodule);
6953       }
6954     }
6955     break;
6956   }
6957 
6958   case Decl::Export:
6959     EmitDeclContext(cast<ExportDecl>(D));
6960     break;
6961 
6962   case Decl::OMPThreadPrivate:
6963     EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
6964     break;
6965 
6966   case Decl::OMPAllocate:
6967     EmitOMPAllocateDecl(cast<OMPAllocateDecl>(D));
6968     break;
6969 
6970   case Decl::OMPDeclareReduction:
6971     EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
6972     break;
6973 
6974   case Decl::OMPDeclareMapper:
6975     EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D));
6976     break;
6977 
6978   case Decl::OMPRequires:
6979     EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
6980     break;
6981 
6982   case Decl::Typedef:
6983   case Decl::TypeAlias: // using foo = bar; [C++11]
6984     if (CGDebugInfo *DI = getModuleDebugInfo())
6985       DI->EmitAndRetainType(
6986           getContext().getTypedefType(cast<TypedefNameDecl>(D)));
6987     break;
6988 
6989   case Decl::Record:
6990     if (CGDebugInfo *DI = getModuleDebugInfo())
6991       if (cast<RecordDecl>(D)->getDefinition())
6992         DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
6993     break;
6994 
6995   case Decl::Enum:
6996     if (CGDebugInfo *DI = getModuleDebugInfo())
6997       if (cast<EnumDecl>(D)->getDefinition())
6998         DI->EmitAndRetainType(getContext().getEnumType(cast<EnumDecl>(D)));
6999     break;
7000 
7001   case Decl::HLSLBuffer:
7002     getHLSLRuntime().addBuffer(cast<HLSLBufferDecl>(D));
7003     break;
7004 
7005   default:
7006     // Make sure we handled everything we should, every other kind is a
7007     // non-top-level decl.  FIXME: Would be nice to have an isTopLevelDeclKind
7008     // function. Need to recode Decl::Kind to do that easily.
7009     assert(isa<TypeDecl>(D) && "Unsupported decl kind");
7010     break;
7011   }
7012 }
7013 
AddDeferredUnusedCoverageMapping(Decl * D)7014 void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
7015   // Do we need to generate coverage mapping?
7016   if (!CodeGenOpts.CoverageMapping)
7017     return;
7018   switch (D->getKind()) {
7019   case Decl::CXXConversion:
7020   case Decl::CXXMethod:
7021   case Decl::Function:
7022   case Decl::ObjCMethod:
7023   case Decl::CXXConstructor:
7024   case Decl::CXXDestructor: {
7025     if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
7026       break;
7027     SourceManager &SM = getContext().getSourceManager();
7028     if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
7029       break;
7030     DeferredEmptyCoverageMappingDecls.try_emplace(D, true);
7031     break;
7032   }
7033   default:
7034     break;
7035   };
7036 }
7037 
ClearUnusedCoverageMapping(const Decl * D)7038 void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
7039   // Do we need to generate coverage mapping?
7040   if (!CodeGenOpts.CoverageMapping)
7041     return;
7042   if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
7043     if (Fn->isTemplateInstantiation())
7044       ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
7045   }
7046   DeferredEmptyCoverageMappingDecls.insert_or_assign(D, false);
7047 }
7048 
EmitDeferredUnusedCoverageMappings()7049 void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
7050   // We call takeVector() here to avoid use-after-free.
7051   // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
7052   // we deserialize function bodies to emit coverage info for them, and that
7053   // deserializes more declarations. How should we handle that case?
7054   for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
7055     if (!Entry.second)
7056       continue;
7057     const Decl *D = Entry.first;
7058     switch (D->getKind()) {
7059     case Decl::CXXConversion:
7060     case Decl::CXXMethod:
7061     case Decl::Function:
7062     case Decl::ObjCMethod: {
7063       CodeGenPGO PGO(*this);
7064       GlobalDecl GD(cast<FunctionDecl>(D));
7065       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7066                                   getFunctionLinkage(GD));
7067       break;
7068     }
7069     case Decl::CXXConstructor: {
7070       CodeGenPGO PGO(*this);
7071       GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
7072       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7073                                   getFunctionLinkage(GD));
7074       break;
7075     }
7076     case Decl::CXXDestructor: {
7077       CodeGenPGO PGO(*this);
7078       GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
7079       PGO.emitEmptyCounterMapping(D, getMangledName(GD),
7080                                   getFunctionLinkage(GD));
7081       break;
7082     }
7083     default:
7084       break;
7085     };
7086   }
7087 }
7088 
EmitMainVoidAlias()7089 void CodeGenModule::EmitMainVoidAlias() {
7090   // In order to transition away from "__original_main" gracefully, emit an
7091   // alias for "main" in the no-argument case so that libc can detect when
7092   // new-style no-argument main is in used.
7093   if (llvm::Function *F = getModule().getFunction("main")) {
7094     if (!F->isDeclaration() && F->arg_size() == 0 && !F->isVarArg() &&
7095         F->getReturnType()->isIntegerTy(Context.getTargetInfo().getIntWidth())) {
7096       auto *GA = llvm::GlobalAlias::create("__main_void", F);
7097       GA->setVisibility(llvm::GlobalValue::HiddenVisibility);
7098     }
7099   }
7100 }
7101 
7102 /// Turns the given pointer into a constant.
GetPointerConstant(llvm::LLVMContext & Context,const void * Ptr)7103 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
7104                                           const void *Ptr) {
7105   uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
7106   llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
7107   return llvm::ConstantInt::get(i64, PtrInt);
7108 }
7109 
EmitGlobalDeclMetadata(CodeGenModule & CGM,llvm::NamedMDNode * & GlobalMetadata,GlobalDecl D,llvm::GlobalValue * Addr)7110 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
7111                                    llvm::NamedMDNode *&GlobalMetadata,
7112                                    GlobalDecl D,
7113                                    llvm::GlobalValue *Addr) {
7114   if (!GlobalMetadata)
7115     GlobalMetadata =
7116       CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
7117 
7118   // TODO: should we report variant information for ctors/dtors?
7119   llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
7120                            llvm::ConstantAsMetadata::get(GetPointerConstant(
7121                                CGM.getLLVMContext(), D.getDecl()))};
7122   GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
7123 }
7124 
CheckAndReplaceExternCIFuncs(llvm::GlobalValue * Elem,llvm::GlobalValue * CppFunc)7125 bool CodeGenModule::CheckAndReplaceExternCIFuncs(llvm::GlobalValue *Elem,
7126                                                  llvm::GlobalValue *CppFunc) {
7127   // Store the list of ifuncs we need to replace uses in.
7128   llvm::SmallVector<llvm::GlobalIFunc *> IFuncs;
7129   // List of ConstantExprs that we should be able to delete when we're done
7130   // here.
7131   llvm::SmallVector<llvm::ConstantExpr *> CEs;
7132 
7133   // It isn't valid to replace the extern-C ifuncs if all we find is itself!
7134   if (Elem == CppFunc)
7135     return false;
7136 
7137   // First make sure that all users of this are ifuncs (or ifuncs via a
7138   // bitcast), and collect the list of ifuncs and CEs so we can work on them
7139   // later.
7140   for (llvm::User *User : Elem->users()) {
7141     // Users can either be a bitcast ConstExpr that is used by the ifuncs, OR an
7142     // ifunc directly. In any other case, just give up, as we don't know what we
7143     // could break by changing those.
7144     if (auto *ConstExpr = dyn_cast<llvm::ConstantExpr>(User)) {
7145       if (ConstExpr->getOpcode() != llvm::Instruction::BitCast)
7146         return false;
7147 
7148       for (llvm::User *CEUser : ConstExpr->users()) {
7149         if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(CEUser)) {
7150           IFuncs.push_back(IFunc);
7151         } else {
7152           return false;
7153         }
7154       }
7155       CEs.push_back(ConstExpr);
7156     } else if (auto *IFunc = dyn_cast<llvm::GlobalIFunc>(User)) {
7157       IFuncs.push_back(IFunc);
7158     } else {
7159       // This user is one we don't know how to handle, so fail redirection. This
7160       // will result in an ifunc retaining a resolver name that will ultimately
7161       // fail to be resolved to a defined function.
7162       return false;
7163     }
7164   }
7165 
7166   // Now we know this is a valid case where we can do this alias replacement, we
7167   // need to remove all of the references to Elem (and the bitcasts!) so we can
7168   // delete it.
7169   for (llvm::GlobalIFunc *IFunc : IFuncs)
7170     IFunc->setResolver(nullptr);
7171   for (llvm::ConstantExpr *ConstExpr : CEs)
7172     ConstExpr->destroyConstant();
7173 
7174   // We should now be out of uses for the 'old' version of this function, so we
7175   // can erase it as well.
7176   Elem->eraseFromParent();
7177 
7178   for (llvm::GlobalIFunc *IFunc : IFuncs) {
7179     // The type of the resolver is always just a function-type that returns the
7180     // type of the IFunc, so create that here. If the type of the actual
7181     // resolver doesn't match, it just gets bitcast to the right thing.
7182     auto *ResolverTy =
7183         llvm::FunctionType::get(IFunc->getType(), /*isVarArg*/ false);
7184     llvm::Constant *Resolver = GetOrCreateLLVMFunction(
7185         CppFunc->getName(), ResolverTy, {}, /*ForVTable*/ false);
7186     IFunc->setResolver(Resolver);
7187   }
7188   return true;
7189 }
7190 
7191 /// For each function which is declared within an extern "C" region and marked
7192 /// as 'used', but has internal linkage, create an alias from the unmangled
7193 /// name to the mangled name if possible. People expect to be able to refer
7194 /// to such functions with an unmangled name from inline assembly within the
7195 /// same translation unit.
EmitStaticExternCAliases()7196 void CodeGenModule::EmitStaticExternCAliases() {
7197   if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
7198     return;
7199   for (auto &I : StaticExternCValues) {
7200     IdentifierInfo *Name = I.first;
7201     llvm::GlobalValue *Val = I.second;
7202 
7203     // If Val is null, that implies there were multiple declarations that each
7204     // had a claim to the unmangled name. In this case, generation of the alias
7205     // is suppressed. See CodeGenModule::MaybeHandleStaticInExternC.
7206     if (!Val)
7207       break;
7208 
7209     llvm::GlobalValue *ExistingElem =
7210         getModule().getNamedValue(Name->getName());
7211 
7212     // If there is either not something already by this name, or we were able to
7213     // replace all uses from IFuncs, create the alias.
7214     if (!ExistingElem || CheckAndReplaceExternCIFuncs(ExistingElem, Val))
7215       addCompilerUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
7216   }
7217 }
7218 
lookupRepresentativeDecl(StringRef MangledName,GlobalDecl & Result) const7219 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
7220                                              GlobalDecl &Result) const {
7221   auto Res = Manglings.find(MangledName);
7222   if (Res == Manglings.end())
7223     return false;
7224   Result = Res->getValue();
7225   return true;
7226 }
7227 
7228 /// Emits metadata nodes associating all the global values in the
7229 /// current module with the Decls they came from.  This is useful for
7230 /// projects using IR gen as a subroutine.
7231 ///
7232 /// Since there's currently no way to associate an MDNode directly
7233 /// with an llvm::GlobalValue, we create a global named metadata
7234 /// with the name 'clang.global.decl.ptrs'.
EmitDeclMetadata()7235 void CodeGenModule::EmitDeclMetadata() {
7236   llvm::NamedMDNode *GlobalMetadata = nullptr;
7237 
7238   for (auto &I : MangledDeclNames) {
7239     llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
7240     // Some mangled names don't necessarily have an associated GlobalValue
7241     // in this module, e.g. if we mangled it for DebugInfo.
7242     if (Addr)
7243       EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
7244   }
7245 }
7246 
7247 /// Emits metadata nodes for all the local variables in the current
7248 /// function.
EmitDeclMetadata()7249 void CodeGenFunction::EmitDeclMetadata() {
7250   if (LocalDeclMap.empty()) return;
7251 
7252   llvm::LLVMContext &Context = getLLVMContext();
7253 
7254   // Find the unique metadata ID for this name.
7255   unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
7256 
7257   llvm::NamedMDNode *GlobalMetadata = nullptr;
7258 
7259   for (auto &I : LocalDeclMap) {
7260     const Decl *D = I.first;
7261     llvm::Value *Addr = I.second.getPointer();
7262     if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
7263       llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
7264       Alloca->setMetadata(
7265           DeclPtrKind, llvm::MDNode::get(
7266                            Context, llvm::ValueAsMetadata::getConstant(DAddr)));
7267     } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
7268       GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
7269       EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
7270     }
7271   }
7272 }
7273 
EmitVersionIdentMetadata()7274 void CodeGenModule::EmitVersionIdentMetadata() {
7275   llvm::NamedMDNode *IdentMetadata =
7276     TheModule.getOrInsertNamedMetadata("llvm.ident");
7277   std::string Version = getClangFullVersion();
7278   llvm::LLVMContext &Ctx = TheModule.getContext();
7279 
7280   llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
7281   IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
7282 }
7283 
EmitCommandLineMetadata()7284 void CodeGenModule::EmitCommandLineMetadata() {
7285   llvm::NamedMDNode *CommandLineMetadata =
7286     TheModule.getOrInsertNamedMetadata("llvm.commandline");
7287   std::string CommandLine = getCodeGenOpts().RecordCommandLine;
7288   llvm::LLVMContext &Ctx = TheModule.getContext();
7289 
7290   llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
7291   CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
7292 }
7293 
EmitCoverageFile()7294 void CodeGenModule::EmitCoverageFile() {
7295   llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
7296   if (!CUNode)
7297     return;
7298 
7299   llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
7300   llvm::LLVMContext &Ctx = TheModule.getContext();
7301   auto *CoverageDataFile =
7302       llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
7303   auto *CoverageNotesFile =
7304       llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
7305   for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
7306     llvm::MDNode *CU = CUNode->getOperand(i);
7307     llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
7308     GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
7309   }
7310 }
7311 
GetAddrOfRTTIDescriptor(QualType Ty,bool ForEH)7312 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
7313                                                        bool ForEH) {
7314   // Return a bogus pointer if RTTI is disabled, unless it's for EH.
7315   // FIXME: should we even be calling this method if RTTI is disabled
7316   // and it's not for EH?
7317   if (!shouldEmitRTTI(ForEH))
7318     return llvm::Constant::getNullValue(GlobalsInt8PtrTy);
7319 
7320   if (ForEH && Ty->isObjCObjectPointerType() &&
7321       LangOpts.ObjCRuntime.isGNUFamily())
7322     return ObjCRuntime->GetEHType(Ty);
7323 
7324   return getCXXABI().getAddrOfRTTIDescriptor(Ty);
7325 }
7326 
EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl * D)7327 void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
7328   // Do not emit threadprivates in simd-only mode.
7329   if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
7330     return;
7331   for (auto RefExpr : D->varlists()) {
7332     auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
7333     bool PerformInit =
7334         VD->getAnyInitializer() &&
7335         !VD->getAnyInitializer()->isConstantInitializer(getContext(),
7336                                                         /*ForRef=*/false);
7337 
7338     Address Addr(GetAddrOfGlobalVar(VD),
7339                  getTypes().ConvertTypeForMem(VD->getType()),
7340                  getContext().getDeclAlign(VD));
7341     if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
7342             VD, Addr, RefExpr->getBeginLoc(), PerformInit))
7343       CXXGlobalInits.push_back(InitFunction);
7344   }
7345 }
7346 
7347 llvm::Metadata *
CreateMetadataIdentifierImpl(QualType T,MetadataTypeMap & Map,StringRef Suffix)7348 CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
7349                                             StringRef Suffix) {
7350   if (auto *FnType = T->getAs<FunctionProtoType>())
7351     T = getContext().getFunctionType(
7352         FnType->getReturnType(), FnType->getParamTypes(),
7353         FnType->getExtProtoInfo().withExceptionSpec(EST_None));
7354 
7355   llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
7356   if (InternalId)
7357     return InternalId;
7358 
7359   if (isExternallyVisible(T->getLinkage())) {
7360     std::string OutName;
7361     llvm::raw_string_ostream Out(OutName);
7362     getCXXABI().getMangleContext().mangleCanonicalTypeName(
7363         T, Out, getCodeGenOpts().SanitizeCfiICallNormalizeIntegers);
7364 
7365     if (getCodeGenOpts().SanitizeCfiICallNormalizeIntegers)
7366       Out << ".normalized";
7367 
7368     Out << Suffix;
7369 
7370     InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
7371   } else {
7372     InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
7373                                            llvm::ArrayRef<llvm::Metadata *>());
7374   }
7375 
7376   return InternalId;
7377 }
7378 
CreateMetadataIdentifierForType(QualType T)7379 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
7380   return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
7381 }
7382 
7383 llvm::Metadata *
CreateMetadataIdentifierForVirtualMemPtrType(QualType T)7384 CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
7385   return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
7386 }
7387 
7388 // Generalize pointer types to a void pointer with the qualifiers of the
7389 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
7390 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
7391 // 'void *'.
GeneralizeType(ASTContext & Ctx,QualType Ty)7392 static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
7393   if (!Ty->isPointerType())
7394     return Ty;
7395 
7396   return Ctx.getPointerType(
7397       QualType(Ctx.VoidTy).withCVRQualifiers(
7398           Ty->getPointeeType().getCVRQualifiers()));
7399 }
7400 
7401 // Apply type generalization to a FunctionType's return and argument types
GeneralizeFunctionType(ASTContext & Ctx,QualType Ty)7402 static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
7403   if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
7404     SmallVector<QualType, 8> GeneralizedParams;
7405     for (auto &Param : FnType->param_types())
7406       GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
7407 
7408     return Ctx.getFunctionType(
7409         GeneralizeType(Ctx, FnType->getReturnType()),
7410         GeneralizedParams, FnType->getExtProtoInfo());
7411   }
7412 
7413   if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
7414     return Ctx.getFunctionNoProtoType(
7415         GeneralizeType(Ctx, FnType->getReturnType()));
7416 
7417   llvm_unreachable("Encountered unknown FunctionType");
7418 }
7419 
CreateMetadataIdentifierGeneralized(QualType T)7420 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
7421   return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
7422                                       GeneralizedMetadataIdMap, ".generalized");
7423 }
7424 
7425 /// Returns whether this module needs the "all-vtables" type identifier.
NeedAllVtablesTypeId() const7426 bool CodeGenModule::NeedAllVtablesTypeId() const {
7427   // Returns true if at least one of vtable-based CFI checkers is enabled and
7428   // is not in the trapping mode.
7429   return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
7430            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
7431           (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
7432            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
7433           (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
7434            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
7435           (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
7436            !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
7437 }
7438 
AddVTableTypeMetadata(llvm::GlobalVariable * VTable,CharUnits Offset,const CXXRecordDecl * RD)7439 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
7440                                           CharUnits Offset,
7441                                           const CXXRecordDecl *RD) {
7442   llvm::Metadata *MD =
7443       CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
7444   VTable->addTypeMetadata(Offset.getQuantity(), MD);
7445 
7446   if (CodeGenOpts.SanitizeCfiCrossDso)
7447     if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
7448       VTable->addTypeMetadata(Offset.getQuantity(),
7449                               llvm::ConstantAsMetadata::get(CrossDsoTypeId));
7450 
7451   if (NeedAllVtablesTypeId()) {
7452     llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
7453     VTable->addTypeMetadata(Offset.getQuantity(), MD);
7454   }
7455 }
7456 
getSanStats()7457 llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
7458   if (!SanStats)
7459     SanStats = std::make_unique<llvm::SanitizerStatReport>(&getModule());
7460 
7461   return *SanStats;
7462 }
7463 
7464 llvm::Value *
createOpenCLIntToSamplerConversion(const Expr * E,CodeGenFunction & CGF)7465 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
7466                                                   CodeGenFunction &CGF) {
7467   llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
7468   auto *SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
7469   auto *FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
7470   auto *Call = CGF.EmitRuntimeCall(
7471       CreateRuntimeFunction(FTy, "__translate_sampler_initializer"), {C});
7472   return Call;
7473 }
7474 
getNaturalPointeeTypeAlignment(QualType T,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo)7475 CharUnits CodeGenModule::getNaturalPointeeTypeAlignment(
7476     QualType T, LValueBaseInfo *BaseInfo, TBAAAccessInfo *TBAAInfo) {
7477   return getNaturalTypeAlignment(T->getPointeeType(), BaseInfo, TBAAInfo,
7478                                  /* forPointeeType= */ true);
7479 }
7480 
getNaturalTypeAlignment(QualType T,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo,bool forPointeeType)7481 CharUnits CodeGenModule::getNaturalTypeAlignment(QualType T,
7482                                                  LValueBaseInfo *BaseInfo,
7483                                                  TBAAAccessInfo *TBAAInfo,
7484                                                  bool forPointeeType) {
7485   if (TBAAInfo)
7486     *TBAAInfo = getTBAAAccessInfo(T);
7487 
7488   // FIXME: This duplicates logic in ASTContext::getTypeAlignIfKnown. But
7489   // that doesn't return the information we need to compute BaseInfo.
7490 
7491   // Honor alignment typedef attributes even on incomplete types.
7492   // We also honor them straight for C++ class types, even as pointees;
7493   // there's an expressivity gap here.
7494   if (auto TT = T->getAs<TypedefType>()) {
7495     if (auto Align = TT->getDecl()->getMaxAlignment()) {
7496       if (BaseInfo)
7497         *BaseInfo = LValueBaseInfo(AlignmentSource::AttributedType);
7498       return getContext().toCharUnitsFromBits(Align);
7499     }
7500   }
7501 
7502   bool AlignForArray = T->isArrayType();
7503 
7504   // Analyze the base element type, so we don't get confused by incomplete
7505   // array types.
7506   T = getContext().getBaseElementType(T);
7507 
7508   if (T->isIncompleteType()) {
7509     // We could try to replicate the logic from
7510     // ASTContext::getTypeAlignIfKnown, but nothing uses the alignment if the
7511     // type is incomplete, so it's impossible to test. We could try to reuse
7512     // getTypeAlignIfKnown, but that doesn't return the information we need
7513     // to set BaseInfo.  So just ignore the possibility that the alignment is
7514     // greater than one.
7515     if (BaseInfo)
7516       *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
7517     return CharUnits::One();
7518   }
7519 
7520   if (BaseInfo)
7521     *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
7522 
7523   CharUnits Alignment;
7524   const CXXRecordDecl *RD;
7525   if (T.getQualifiers().hasUnaligned()) {
7526     Alignment = CharUnits::One();
7527   } else if (forPointeeType && !AlignForArray &&
7528              (RD = T->getAsCXXRecordDecl())) {
7529     // For C++ class pointees, we don't know whether we're pointing at a
7530     // base or a complete object, so we generally need to use the
7531     // non-virtual alignment.
7532     Alignment = getClassPointerAlignment(RD);
7533   } else {
7534     Alignment = getContext().getTypeAlignInChars(T);
7535   }
7536 
7537   // Cap to the global maximum type alignment unless the alignment
7538   // was somehow explicit on the type.
7539   if (unsigned MaxAlign = getLangOpts().MaxTypeAlign) {
7540     if (Alignment.getQuantity() > MaxAlign &&
7541         !getContext().isAlignmentRequired(T))
7542       Alignment = CharUnits::fromQuantity(MaxAlign);
7543   }
7544   return Alignment;
7545 }
7546 
stopAutoInit()7547 bool CodeGenModule::stopAutoInit() {
7548   unsigned StopAfter = getContext().getLangOpts().TrivialAutoVarInitStopAfter;
7549   if (StopAfter) {
7550     // This number is positive only when -ftrivial-auto-var-init-stop-after=* is
7551     // used
7552     if (NumAutoVarInit >= StopAfter) {
7553       return true;
7554     }
7555     if (!NumAutoVarInit) {
7556       unsigned DiagID = getDiags().getCustomDiagID(
7557           DiagnosticsEngine::Warning,
7558           "-ftrivial-auto-var-init-stop-after=%0 has been enabled to limit the "
7559           "number of times ftrivial-auto-var-init=%1 gets applied.");
7560       getDiags().Report(DiagID)
7561           << StopAfter
7562           << (getContext().getLangOpts().getTrivialAutoVarInit() ==
7563                       LangOptions::TrivialAutoVarInitKind::Zero
7564                   ? "zero"
7565                   : "pattern");
7566     }
7567     ++NumAutoVarInit;
7568   }
7569   return false;
7570 }
7571 
printPostfixForExternalizedDecl(llvm::raw_ostream & OS,const Decl * D) const7572 void CodeGenModule::printPostfixForExternalizedDecl(llvm::raw_ostream &OS,
7573                                                     const Decl *D) const {
7574   // ptxas does not allow '.' in symbol names. On the other hand, HIP prefers
7575   // postfix beginning with '.' since the symbol name can be demangled.
7576   if (LangOpts.HIP)
7577     OS << (isa<VarDecl>(D) ? ".static." : ".intern.");
7578   else
7579     OS << (isa<VarDecl>(D) ? "__static__" : "__intern__");
7580 
7581   // If the CUID is not specified we try to generate a unique postfix.
7582   if (getLangOpts().CUID.empty()) {
7583     SourceManager &SM = getContext().getSourceManager();
7584     PresumedLoc PLoc = SM.getPresumedLoc(D->getLocation());
7585     assert(PLoc.isValid() && "Source location is expected to be valid.");
7586 
7587     // Get the hash of the user defined macros.
7588     llvm::MD5 Hash;
7589     llvm::MD5::MD5Result Result;
7590     for (const auto &Arg : PreprocessorOpts.Macros)
7591       Hash.update(Arg.first);
7592     Hash.final(Result);
7593 
7594     // Get the UniqueID for the file containing the decl.
7595     llvm::sys::fs::UniqueID ID;
7596     if (llvm::sys::fs::getUniqueID(PLoc.getFilename(), ID)) {
7597       PLoc = SM.getPresumedLoc(D->getLocation(), /*UseLineDirectives=*/false);
7598       assert(PLoc.isValid() && "Source location is expected to be valid.");
7599       if (auto EC = llvm::sys::fs::getUniqueID(PLoc.getFilename(), ID))
7600         SM.getDiagnostics().Report(diag::err_cannot_open_file)
7601             << PLoc.getFilename() << EC.message();
7602     }
7603     OS << llvm::format("%x", ID.getFile()) << llvm::format("%x", ID.getDevice())
7604        << "_" << llvm::utohexstr(Result.low(), /*LowerCase=*/true, /*Width=*/8);
7605   } else {
7606     OS << getContext().getCUIDHash();
7607   }
7608 }
7609 
moveLazyEmissionStates(CodeGenModule * NewBuilder)7610 void CodeGenModule::moveLazyEmissionStates(CodeGenModule *NewBuilder) {
7611   assert(DeferredDeclsToEmit.empty() &&
7612          "Should have emitted all decls deferred to emit.");
7613   assert(NewBuilder->DeferredDecls.empty() &&
7614          "Newly created module should not have deferred decls");
7615   NewBuilder->DeferredDecls = std::move(DeferredDecls);
7616   assert(EmittedDeferredDecls.empty() &&
7617          "Still have (unmerged) EmittedDeferredDecls deferred decls");
7618 
7619   assert(NewBuilder->DeferredVTables.empty() &&
7620          "Newly created module should not have deferred vtables");
7621   NewBuilder->DeferredVTables = std::move(DeferredVTables);
7622 
7623   assert(NewBuilder->MangledDeclNames.empty() &&
7624          "Newly created module should not have mangled decl names");
7625   assert(NewBuilder->Manglings.empty() &&
7626          "Newly created module should not have manglings");
7627   NewBuilder->Manglings = std::move(Manglings);
7628 
7629   NewBuilder->WeakRefReferences = std::move(WeakRefReferences);
7630 
7631   NewBuilder->TBAA = std::move(TBAA);
7632 
7633   NewBuilder->ABI->MangleCtx = std::move(ABI->MangleCtx);
7634 }
7635