1 //===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This coordinates the per-module state used while generating code.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "CodeGenModule.h"
14 #include "CGBlocks.h"
15 #include "CGCUDARuntime.h"
16 #include "CGCXXABI.h"
17 #include "CGCall.h"
18 #include "CGDebugInfo.h"
19 #include "CGObjCRuntime.h"
20 #include "CGOpenCLRuntime.h"
21 #include "CGOpenMPRuntime.h"
22 #include "CGOpenMPRuntimeNVPTX.h"
23 #include "CodeGenFunction.h"
24 #include "CodeGenPGO.h"
25 #include "ConstantEmitter.h"
26 #include "CoverageMappingGen.h"
27 #include "TargetInfo.h"
28 #include "clang/AST/ASTContext.h"
29 #include "clang/AST/CharUnits.h"
30 #include "clang/AST/DeclCXX.h"
31 #include "clang/AST/DeclObjC.h"
32 #include "clang/AST/DeclTemplate.h"
33 #include "clang/AST/Mangle.h"
34 #include "clang/AST/RecordLayout.h"
35 #include "clang/AST/RecursiveASTVisitor.h"
36 #include "clang/AST/StmtVisitor.h"
37 #include "clang/Basic/Builtins.h"
38 #include "clang/Basic/CharInfo.h"
39 #include "clang/Basic/CodeGenOptions.h"
40 #include "clang/Basic/Diagnostic.h"
41 #include "clang/Basic/Module.h"
42 #include "clang/Basic/SourceManager.h"
43 #include "clang/Basic/TargetInfo.h"
44 #include "clang/Basic/Version.h"
45 #include "clang/CodeGen/ConstantInitBuilder.h"
46 #include "clang/Frontend/FrontendDiagnostic.h"
47 #include "llvm/ADT/StringSwitch.h"
48 #include "llvm/ADT/Triple.h"
49 #include "llvm/Analysis/TargetLibraryInfo.h"
50 #include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
51 #include "llvm/IR/CallingConv.h"
52 #include "llvm/IR/DataLayout.h"
53 #include "llvm/IR/Intrinsics.h"
54 #include "llvm/IR/LLVMContext.h"
55 #include "llvm/IR/Module.h"
56 #include "llvm/IR/ProfileSummary.h"
57 #include "llvm/ProfileData/InstrProfReader.h"
58 #include "llvm/Support/CodeGen.h"
59 #include "llvm/Support/CommandLine.h"
60 #include "llvm/Support/ConvertUTF.h"
61 #include "llvm/Support/ErrorHandling.h"
62 #include "llvm/Support/MD5.h"
63 #include "llvm/Support/TimeProfiler.h"
64
65 using namespace clang;
66 using namespace CodeGen;
67
68 static llvm::cl::opt<bool> LimitedCoverage(
69 "limited-coverage-experimental", llvm::cl::ZeroOrMore, llvm::cl::Hidden,
70 llvm::cl::desc("Emit limited coverage mapping information (experimental)"),
71 llvm::cl::init(false));
72
73 static const char AnnotationSection[] = "llvm.metadata";
74
createCXXABI(CodeGenModule & CGM)75 static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
76 switch (CGM.getTarget().getCXXABI().getKind()) {
77 case TargetCXXABI::Fuchsia:
78 case TargetCXXABI::GenericAArch64:
79 case TargetCXXABI::GenericARM:
80 case TargetCXXABI::iOS:
81 case TargetCXXABI::iOS64:
82 case TargetCXXABI::WatchOS:
83 case TargetCXXABI::GenericMIPS:
84 case TargetCXXABI::GenericItanium:
85 case TargetCXXABI::WebAssembly:
86 return CreateItaniumCXXABI(CGM);
87 case TargetCXXABI::Microsoft:
88 return CreateMicrosoftCXXABI(CGM);
89 }
90
91 llvm_unreachable("invalid C++ ABI kind");
92 }
93
CodeGenModule(ASTContext & C,const HeaderSearchOptions & HSO,const PreprocessorOptions & PPO,const CodeGenOptions & CGO,llvm::Module & M,DiagnosticsEngine & diags,CoverageSourceInfo * CoverageInfo)94 CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
95 const PreprocessorOptions &PPO,
96 const CodeGenOptions &CGO, llvm::Module &M,
97 DiagnosticsEngine &diags,
98 CoverageSourceInfo *CoverageInfo)
99 : Context(C), LangOpts(C.getLangOpts()), HeaderSearchOpts(HSO),
100 PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
101 Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
102 VMContext(M.getContext()), Types(*this), VTables(*this),
103 SanitizerMD(new SanitizerMetadata(*this)) {
104
105 // Initialize the type cache.
106 llvm::LLVMContext &LLVMContext = M.getContext();
107 VoidTy = llvm::Type::getVoidTy(LLVMContext);
108 Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
109 Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
110 Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
111 Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
112 HalfTy = llvm::Type::getHalfTy(LLVMContext);
113 FloatTy = llvm::Type::getFloatTy(LLVMContext);
114 DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
115 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
116 PointerAlignInBytes =
117 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
118 SizeSizeInBytes =
119 C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
120 IntAlignInBytes =
121 C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
122 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
123 IntPtrTy = llvm::IntegerType::get(LLVMContext,
124 C.getTargetInfo().getMaxPointerWidth());
125 Int8PtrTy = Int8Ty->getPointerTo(0);
126 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
127 AllocaInt8PtrTy = Int8Ty->getPointerTo(
128 M.getDataLayout().getAllocaAddrSpace());
129 ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
130
131 RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
132
133 if (LangOpts.ObjC)
134 createObjCRuntime();
135 if (LangOpts.OpenCL)
136 createOpenCLRuntime();
137 if (LangOpts.OpenMP)
138 createOpenMPRuntime();
139 if (LangOpts.CUDA)
140 createCUDARuntime();
141
142 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
143 if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
144 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
145 TBAA.reset(new CodeGenTBAA(Context, TheModule, CodeGenOpts, getLangOpts(),
146 getCXXABI().getMangleContext()));
147
148 // If debug info or coverage generation is enabled, create the CGDebugInfo
149 // object.
150 if (CodeGenOpts.getDebugInfo() != codegenoptions::NoDebugInfo ||
151 CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)
152 DebugInfo.reset(new CGDebugInfo(*this));
153
154 Block.GlobalUniqueCount = 0;
155
156 if (C.getLangOpts().ObjC)
157 ObjCData.reset(new ObjCEntrypoints());
158
159 if (CodeGenOpts.hasProfileClangUse()) {
160 auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
161 CodeGenOpts.ProfileInstrumentUsePath, CodeGenOpts.ProfileRemappingFile);
162 if (auto E = ReaderOrErr.takeError()) {
163 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
164 "Could not read profile %0: %1");
165 llvm::handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EI) {
166 getDiags().Report(DiagID) << CodeGenOpts.ProfileInstrumentUsePath
167 << EI.message();
168 });
169 } else
170 PGOReader = std::move(ReaderOrErr.get());
171 }
172
173 // If coverage mapping generation is enabled, create the
174 // CoverageMappingModuleGen object.
175 if (CodeGenOpts.CoverageMapping)
176 CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
177 }
178
~CodeGenModule()179 CodeGenModule::~CodeGenModule() {}
180
createObjCRuntime()181 void CodeGenModule::createObjCRuntime() {
182 // This is just isGNUFamily(), but we want to force implementors of
183 // new ABIs to decide how best to do this.
184 switch (LangOpts.ObjCRuntime.getKind()) {
185 case ObjCRuntime::GNUstep:
186 case ObjCRuntime::GCC:
187 case ObjCRuntime::ObjFW:
188 ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
189 return;
190
191 case ObjCRuntime::FragileMacOSX:
192 case ObjCRuntime::MacOSX:
193 case ObjCRuntime::iOS:
194 case ObjCRuntime::WatchOS:
195 ObjCRuntime.reset(CreateMacObjCRuntime(*this));
196 return;
197 }
198 llvm_unreachable("bad runtime kind");
199 }
200
createOpenCLRuntime()201 void CodeGenModule::createOpenCLRuntime() {
202 OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
203 }
204
createOpenMPRuntime()205 void CodeGenModule::createOpenMPRuntime() {
206 // Select a specialized code generation class based on the target, if any.
207 // If it does not exist use the default implementation.
208 switch (getTriple().getArch()) {
209 case llvm::Triple::nvptx:
210 case llvm::Triple::nvptx64:
211 assert(getLangOpts().OpenMPIsDevice &&
212 "OpenMP NVPTX is only prepared to deal with device code.");
213 OpenMPRuntime.reset(new CGOpenMPRuntimeNVPTX(*this));
214 break;
215 default:
216 if (LangOpts.OpenMPSimd)
217 OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
218 else
219 OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
220 break;
221 }
222
223 // The OpenMP-IR-Builder should eventually replace the above runtime codegens
224 // but we are not there yet so they both reside in CGModule for now and the
225 // OpenMP-IR-Builder is opt-in only.
226 if (LangOpts.OpenMPIRBuilder) {
227 OMPBuilder.reset(new llvm::OpenMPIRBuilder(TheModule));
228 OMPBuilder->initialize();
229 }
230 }
231
createCUDARuntime()232 void CodeGenModule::createCUDARuntime() {
233 CUDARuntime.reset(CreateNVCUDARuntime(*this));
234 }
235
addReplacement(StringRef Name,llvm::Constant * C)236 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
237 Replacements[Name] = C;
238 }
239
applyReplacements()240 void CodeGenModule::applyReplacements() {
241 for (auto &I : Replacements) {
242 StringRef MangledName = I.first();
243 llvm::Constant *Replacement = I.second;
244 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
245 if (!Entry)
246 continue;
247 auto *OldF = cast<llvm::Function>(Entry);
248 auto *NewF = dyn_cast<llvm::Function>(Replacement);
249 if (!NewF) {
250 if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
251 NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
252 } else {
253 auto *CE = cast<llvm::ConstantExpr>(Replacement);
254 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
255 CE->getOpcode() == llvm::Instruction::GetElementPtr);
256 NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
257 }
258 }
259
260 // Replace old with new, but keep the old order.
261 OldF->replaceAllUsesWith(Replacement);
262 if (NewF) {
263 NewF->removeFromParent();
264 OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
265 NewF);
266 }
267 OldF->eraseFromParent();
268 }
269 }
270
addGlobalValReplacement(llvm::GlobalValue * GV,llvm::Constant * C)271 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
272 GlobalValReplacements.push_back(std::make_pair(GV, C));
273 }
274
applyGlobalValReplacements()275 void CodeGenModule::applyGlobalValReplacements() {
276 for (auto &I : GlobalValReplacements) {
277 llvm::GlobalValue *GV = I.first;
278 llvm::Constant *C = I.second;
279
280 GV->replaceAllUsesWith(C);
281 GV->eraseFromParent();
282 }
283 }
284
285 // This is only used in aliases that we created and we know they have a
286 // linear structure.
getAliasedGlobal(const llvm::GlobalIndirectSymbol & GIS)287 static const llvm::GlobalObject *getAliasedGlobal(
288 const llvm::GlobalIndirectSymbol &GIS) {
289 llvm::SmallPtrSet<const llvm::GlobalIndirectSymbol*, 4> Visited;
290 const llvm::Constant *C = &GIS;
291 for (;;) {
292 C = C->stripPointerCasts();
293 if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
294 return GO;
295 // stripPointerCasts will not walk over weak aliases.
296 auto *GIS2 = dyn_cast<llvm::GlobalIndirectSymbol>(C);
297 if (!GIS2)
298 return nullptr;
299 if (!Visited.insert(GIS2).second)
300 return nullptr;
301 C = GIS2->getIndirectSymbol();
302 }
303 }
304
checkAliases()305 void CodeGenModule::checkAliases() {
306 // Check if the constructed aliases are well formed. It is really unfortunate
307 // that we have to do this in CodeGen, but we only construct mangled names
308 // and aliases during codegen.
309 bool Error = false;
310 DiagnosticsEngine &Diags = getDiags();
311 for (const GlobalDecl &GD : Aliases) {
312 const auto *D = cast<ValueDecl>(GD.getDecl());
313 SourceLocation Location;
314 bool IsIFunc = D->hasAttr<IFuncAttr>();
315 if (const Attr *A = D->getDefiningAttr())
316 Location = A->getLocation();
317 else
318 llvm_unreachable("Not an alias or ifunc?");
319 StringRef MangledName = getMangledName(GD);
320 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
321 auto *Alias = cast<llvm::GlobalIndirectSymbol>(Entry);
322 const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
323 if (!GV) {
324 Error = true;
325 Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
326 } else if (GV->isDeclaration()) {
327 Error = true;
328 Diags.Report(Location, diag::err_alias_to_undefined)
329 << IsIFunc << IsIFunc;
330 } else if (IsIFunc) {
331 // Check resolver function type.
332 llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(
333 GV->getType()->getPointerElementType());
334 assert(FTy);
335 if (!FTy->getReturnType()->isPointerTy())
336 Diags.Report(Location, diag::err_ifunc_resolver_return);
337 }
338
339 llvm::Constant *Aliasee = Alias->getIndirectSymbol();
340 llvm::GlobalValue *AliaseeGV;
341 if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
342 AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
343 else
344 AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
345
346 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
347 StringRef AliasSection = SA->getName();
348 if (AliasSection != AliaseeGV->getSection())
349 Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
350 << AliasSection << IsIFunc << IsIFunc;
351 }
352
353 // We have to handle alias to weak aliases in here. LLVM itself disallows
354 // this since the object semantics would not match the IL one. For
355 // compatibility with gcc we implement it by just pointing the alias
356 // to its aliasee's aliasee. We also warn, since the user is probably
357 // expecting the link to be weak.
358 if (auto GA = dyn_cast<llvm::GlobalIndirectSymbol>(AliaseeGV)) {
359 if (GA->isInterposable()) {
360 Diags.Report(Location, diag::warn_alias_to_weak_alias)
361 << GV->getName() << GA->getName() << IsIFunc;
362 Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
363 GA->getIndirectSymbol(), Alias->getType());
364 Alias->setIndirectSymbol(Aliasee);
365 }
366 }
367 }
368 if (!Error)
369 return;
370
371 for (const GlobalDecl &GD : Aliases) {
372 StringRef MangledName = getMangledName(GD);
373 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
374 auto *Alias = dyn_cast<llvm::GlobalIndirectSymbol>(Entry);
375 Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
376 Alias->eraseFromParent();
377 }
378 }
379
clear()380 void CodeGenModule::clear() {
381 DeferredDeclsToEmit.clear();
382 if (OpenMPRuntime)
383 OpenMPRuntime->clear();
384 }
385
reportDiagnostics(DiagnosticsEngine & Diags,StringRef MainFile)386 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
387 StringRef MainFile) {
388 if (!hasDiagnostics())
389 return;
390 if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
391 if (MainFile.empty())
392 MainFile = "<stdin>";
393 Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
394 } else {
395 if (Mismatched > 0)
396 Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
397
398 if (Missing > 0)
399 Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
400 }
401 }
402
Release()403 void CodeGenModule::Release() {
404 EmitDeferred();
405 EmitVTablesOpportunistically();
406 applyGlobalValReplacements();
407 applyReplacements();
408 checkAliases();
409 emitMultiVersionFunctions();
410 EmitCXXGlobalInitFunc();
411 EmitCXXGlobalDtorFunc();
412 registerGlobalDtorsWithAtExit();
413 EmitCXXThreadLocalInitFunc();
414 if (ObjCRuntime)
415 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
416 AddGlobalCtor(ObjCInitFunction);
417 if (Context.getLangOpts().CUDA && !Context.getLangOpts().CUDAIsDevice &&
418 CUDARuntime) {
419 if (llvm::Function *CudaCtorFunction =
420 CUDARuntime->makeModuleCtorFunction())
421 AddGlobalCtor(CudaCtorFunction);
422 }
423 if (OpenMPRuntime) {
424 if (llvm::Function *OpenMPRequiresDirectiveRegFun =
425 OpenMPRuntime->emitRequiresDirectiveRegFun()) {
426 AddGlobalCtor(OpenMPRequiresDirectiveRegFun, 0);
427 }
428 OpenMPRuntime->createOffloadEntriesAndInfoMetadata();
429 OpenMPRuntime->clear();
430 }
431 if (PGOReader) {
432 getModule().setProfileSummary(
433 PGOReader->getSummary(/* UseCS */ false).getMD(VMContext),
434 llvm::ProfileSummary::PSK_Instr);
435 if (PGOStats.hasDiagnostics())
436 PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
437 }
438 EmitCtorList(GlobalCtors, "llvm.global_ctors");
439 EmitCtorList(GlobalDtors, "llvm.global_dtors");
440 EmitGlobalAnnotations();
441 EmitStaticExternCAliases();
442 EmitDeferredUnusedCoverageMappings();
443 if (CoverageMapping)
444 CoverageMapping->emit();
445 if (CodeGenOpts.SanitizeCfiCrossDso) {
446 CodeGenFunction(*this).EmitCfiCheckFail();
447 CodeGenFunction(*this).EmitCfiCheckStub();
448 }
449 emitAtAvailableLinkGuard();
450 emitLLVMUsed();
451 if (SanStats)
452 SanStats->finish();
453
454 if (CodeGenOpts.Autolink &&
455 (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
456 EmitModuleLinkOptions();
457 }
458
459 // On ELF we pass the dependent library specifiers directly to the linker
460 // without manipulating them. This is in contrast to other platforms where
461 // they are mapped to a specific linker option by the compiler. This
462 // difference is a result of the greater variety of ELF linkers and the fact
463 // that ELF linkers tend to handle libraries in a more complicated fashion
464 // than on other platforms. This forces us to defer handling the dependent
465 // libs to the linker.
466 //
467 // CUDA/HIP device and host libraries are different. Currently there is no
468 // way to differentiate dependent libraries for host or device. Existing
469 // usage of #pragma comment(lib, *) is intended for host libraries on
470 // Windows. Therefore emit llvm.dependent-libraries only for host.
471 if (!ELFDependentLibraries.empty() && !Context.getLangOpts().CUDAIsDevice) {
472 auto *NMD = getModule().getOrInsertNamedMetadata("llvm.dependent-libraries");
473 for (auto *MD : ELFDependentLibraries)
474 NMD->addOperand(MD);
475 }
476
477 // Record mregparm value now so it is visible through rest of codegen.
478 if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
479 getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
480 CodeGenOpts.NumRegisterParameters);
481
482 if (CodeGenOpts.DwarfVersion) {
483 getModule().addModuleFlag(llvm::Module::Max, "Dwarf Version",
484 CodeGenOpts.DwarfVersion);
485 }
486 if (CodeGenOpts.EmitCodeView) {
487 // Indicate that we want CodeView in the metadata.
488 getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
489 }
490 if (CodeGenOpts.CodeViewGHash) {
491 getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
492 }
493 if (CodeGenOpts.ControlFlowGuard) {
494 // Function ID tables and checks for Control Flow Guard (cfguard=2).
495 getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 2);
496 } else if (CodeGenOpts.ControlFlowGuardNoChecks) {
497 // Function ID tables for Control Flow Guard (cfguard=1).
498 getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 1);
499 }
500 if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
501 // We don't support LTO with 2 with different StrictVTablePointers
502 // FIXME: we could support it by stripping all the information introduced
503 // by StrictVTablePointers.
504
505 getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
506
507 llvm::Metadata *Ops[2] = {
508 llvm::MDString::get(VMContext, "StrictVTablePointers"),
509 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
510 llvm::Type::getInt32Ty(VMContext), 1))};
511
512 getModule().addModuleFlag(llvm::Module::Require,
513 "StrictVTablePointersRequirement",
514 llvm::MDNode::get(VMContext, Ops));
515 }
516 if (DebugInfo)
517 // We support a single version in the linked module. The LLVM
518 // parser will drop debug info with a different version number
519 // (and warn about it, too).
520 getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
521 llvm::DEBUG_METADATA_VERSION);
522
523 // We need to record the widths of enums and wchar_t, so that we can generate
524 // the correct build attributes in the ARM backend. wchar_size is also used by
525 // TargetLibraryInfo.
526 uint64_t WCharWidth =
527 Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
528 getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
529
530 llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
531 if ( Arch == llvm::Triple::arm
532 || Arch == llvm::Triple::armeb
533 || Arch == llvm::Triple::thumb
534 || Arch == llvm::Triple::thumbeb) {
535 // The minimum width of an enum in bytes
536 uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
537 getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
538 }
539
540 if (Arch == llvm::Triple::riscv32 || Arch == llvm::Triple::riscv64) {
541 StringRef ABIStr = Target.getABI();
542 llvm::LLVMContext &Ctx = TheModule.getContext();
543 getModule().addModuleFlag(llvm::Module::Error, "target-abi",
544 llvm::MDString::get(Ctx, ABIStr));
545 }
546
547 if (CodeGenOpts.SanitizeCfiCrossDso) {
548 // Indicate that we want cross-DSO control flow integrity checks.
549 getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
550 }
551
552 if (LangOpts.Sanitize.has(SanitizerKind::CFIICall)) {
553 getModule().addModuleFlag(llvm::Module::Override,
554 "CFI Canonical Jump Tables",
555 CodeGenOpts.SanitizeCfiCanonicalJumpTables);
556 }
557
558 if (CodeGenOpts.CFProtectionReturn &&
559 Target.checkCFProtectionReturnSupported(getDiags())) {
560 // Indicate that we want to instrument return control flow protection.
561 getModule().addModuleFlag(llvm::Module::Override, "cf-protection-return",
562 1);
563 }
564
565 if (CodeGenOpts.CFProtectionBranch &&
566 Target.checkCFProtectionBranchSupported(getDiags())) {
567 // Indicate that we want to instrument branch control flow protection.
568 getModule().addModuleFlag(llvm::Module::Override, "cf-protection-branch",
569 1);
570 }
571
572 if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
573 // Indicate whether __nvvm_reflect should be configured to flush denormal
574 // floating point values to 0. (This corresponds to its "__CUDA_FTZ"
575 // property.)
576 getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
577 CodeGenOpts.FlushDenorm ? 1 : 0);
578 }
579
580 // Emit OpenCL specific module metadata: OpenCL/SPIR version.
581 if (LangOpts.OpenCL) {
582 EmitOpenCLMetadata();
583 // Emit SPIR version.
584 if (getTriple().isSPIR()) {
585 // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
586 // opencl.spir.version named metadata.
587 // C++ is backwards compatible with OpenCL v2.0.
588 auto Version = LangOpts.OpenCLCPlusPlus ? 200 : LangOpts.OpenCLVersion;
589 llvm::Metadata *SPIRVerElts[] = {
590 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
591 Int32Ty, Version / 100)),
592 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
593 Int32Ty, (Version / 100 > 1) ? 0 : 2))};
594 llvm::NamedMDNode *SPIRVerMD =
595 TheModule.getOrInsertNamedMetadata("opencl.spir.version");
596 llvm::LLVMContext &Ctx = TheModule.getContext();
597 SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
598 }
599 }
600
601 if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
602 assert(PLevel < 3 && "Invalid PIC Level");
603 getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
604 if (Context.getLangOpts().PIE)
605 getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
606 }
607
608 if (getCodeGenOpts().CodeModel.size() > 0) {
609 unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
610 .Case("tiny", llvm::CodeModel::Tiny)
611 .Case("small", llvm::CodeModel::Small)
612 .Case("kernel", llvm::CodeModel::Kernel)
613 .Case("medium", llvm::CodeModel::Medium)
614 .Case("large", llvm::CodeModel::Large)
615 .Default(~0u);
616 if (CM != ~0u) {
617 llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
618 getModule().setCodeModel(codeModel);
619 }
620 }
621
622 if (CodeGenOpts.NoPLT)
623 getModule().setRtLibUseGOT();
624
625 SimplifyPersonality();
626
627 if (getCodeGenOpts().EmitDeclMetadata)
628 EmitDeclMetadata();
629
630 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
631 EmitCoverageFile();
632
633 if (DebugInfo)
634 DebugInfo->finalize();
635
636 if (getCodeGenOpts().EmitVersionIdentMetadata)
637 EmitVersionIdentMetadata();
638
639 if (!getCodeGenOpts().RecordCommandLine.empty())
640 EmitCommandLineMetadata();
641
642 EmitTargetMetadata();
643 }
644
EmitOpenCLMetadata()645 void CodeGenModule::EmitOpenCLMetadata() {
646 // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
647 // opencl.ocl.version named metadata node.
648 // C++ is backwards compatible with OpenCL v2.0.
649 // FIXME: We might need to add CXX version at some point too?
650 auto Version = LangOpts.OpenCLCPlusPlus ? 200 : LangOpts.OpenCLVersion;
651 llvm::Metadata *OCLVerElts[] = {
652 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
653 Int32Ty, Version / 100)),
654 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
655 Int32Ty, (Version % 100) / 10))};
656 llvm::NamedMDNode *OCLVerMD =
657 TheModule.getOrInsertNamedMetadata("opencl.ocl.version");
658 llvm::LLVMContext &Ctx = TheModule.getContext();
659 OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
660 }
661
UpdateCompletedType(const TagDecl * TD)662 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
663 // Make sure that this type is translated.
664 Types.UpdateCompletedType(TD);
665 }
666
RefreshTypeCacheForClass(const CXXRecordDecl * RD)667 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
668 // Make sure that this type is translated.
669 Types.RefreshTypeCacheForClass(RD);
670 }
671
getTBAATypeInfo(QualType QTy)672 llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
673 if (!TBAA)
674 return nullptr;
675 return TBAA->getTypeInfo(QTy);
676 }
677
getTBAAAccessInfo(QualType AccessType)678 TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
679 if (!TBAA)
680 return TBAAAccessInfo();
681 return TBAA->getAccessInfo(AccessType);
682 }
683
684 TBAAAccessInfo
getTBAAVTablePtrAccessInfo(llvm::Type * VTablePtrType)685 CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
686 if (!TBAA)
687 return TBAAAccessInfo();
688 return TBAA->getVTablePtrAccessInfo(VTablePtrType);
689 }
690
getTBAAStructInfo(QualType QTy)691 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
692 if (!TBAA)
693 return nullptr;
694 return TBAA->getTBAAStructInfo(QTy);
695 }
696
getTBAABaseTypeInfo(QualType QTy)697 llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
698 if (!TBAA)
699 return nullptr;
700 return TBAA->getBaseTypeInfo(QTy);
701 }
702
getTBAAAccessTagInfo(TBAAAccessInfo Info)703 llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
704 if (!TBAA)
705 return nullptr;
706 return TBAA->getAccessTagInfo(Info);
707 }
708
mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,TBAAAccessInfo TargetInfo)709 TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
710 TBAAAccessInfo TargetInfo) {
711 if (!TBAA)
712 return TBAAAccessInfo();
713 return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
714 }
715
716 TBAAAccessInfo
mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,TBAAAccessInfo InfoB)717 CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
718 TBAAAccessInfo InfoB) {
719 if (!TBAA)
720 return TBAAAccessInfo();
721 return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
722 }
723
724 TBAAAccessInfo
mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,TBAAAccessInfo SrcInfo)725 CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
726 TBAAAccessInfo SrcInfo) {
727 if (!TBAA)
728 return TBAAAccessInfo();
729 return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
730 }
731
DecorateInstructionWithTBAA(llvm::Instruction * Inst,TBAAAccessInfo TBAAInfo)732 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
733 TBAAAccessInfo TBAAInfo) {
734 if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
735 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
736 }
737
DecorateInstructionWithInvariantGroup(llvm::Instruction * I,const CXXRecordDecl * RD)738 void CodeGenModule::DecorateInstructionWithInvariantGroup(
739 llvm::Instruction *I, const CXXRecordDecl *RD) {
740 I->setMetadata(llvm::LLVMContext::MD_invariant_group,
741 llvm::MDNode::get(getLLVMContext(), {}));
742 }
743
Error(SourceLocation loc,StringRef message)744 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
745 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
746 getDiags().Report(Context.getFullLoc(loc), diagID) << message;
747 }
748
749 /// ErrorUnsupported - Print out an error that codegen doesn't support the
750 /// specified stmt yet.
ErrorUnsupported(const Stmt * S,const char * Type)751 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
752 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
753 "cannot compile this %0 yet");
754 std::string Msg = Type;
755 getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID)
756 << Msg << S->getSourceRange();
757 }
758
759 /// ErrorUnsupported - Print out an error that codegen doesn't support the
760 /// specified decl yet.
ErrorUnsupported(const Decl * D,const char * Type)761 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
762 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
763 "cannot compile this %0 yet");
764 std::string Msg = Type;
765 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
766 }
767
getSize(CharUnits size)768 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
769 return llvm::ConstantInt::get(SizeTy, size.getQuantity());
770 }
771
setGlobalVisibility(llvm::GlobalValue * GV,const NamedDecl * D) const772 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
773 const NamedDecl *D) const {
774 if (GV->hasDLLImportStorageClass())
775 return;
776 // Internal definitions always have default visibility.
777 if (GV->hasLocalLinkage()) {
778 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
779 return;
780 }
781 if (!D)
782 return;
783 // Set visibility for definitions, and for declarations if requested globally
784 // or set explicitly.
785 LinkageInfo LV = D->getLinkageAndVisibility();
786 if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
787 !GV->isDeclarationForLinker())
788 GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
789 }
790
shouldAssumeDSOLocal(const CodeGenModule & CGM,llvm::GlobalValue * GV)791 static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
792 llvm::GlobalValue *GV) {
793 if (GV->hasLocalLinkage())
794 return true;
795
796 if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
797 return true;
798
799 // DLLImport explicitly marks the GV as external.
800 if (GV->hasDLLImportStorageClass())
801 return false;
802
803 const llvm::Triple &TT = CGM.getTriple();
804 if (TT.isWindowsGNUEnvironment()) {
805 // In MinGW, variables without DLLImport can still be automatically
806 // imported from a DLL by the linker; don't mark variables that
807 // potentially could come from another DLL as DSO local.
808 if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
809 !GV->isThreadLocal())
810 return false;
811 }
812
813 // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
814 // remain unresolved in the link, they can be resolved to zero, which is
815 // outside the current DSO.
816 if (TT.isOSBinFormatCOFF() && GV->hasExternalWeakLinkage())
817 return false;
818
819 // Every other GV is local on COFF.
820 // Make an exception for windows OS in the triple: Some firmware builds use
821 // *-win32-macho triples. This (accidentally?) produced windows relocations
822 // without GOT tables in older clang versions; Keep this behaviour.
823 // FIXME: even thread local variables?
824 if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
825 return true;
826
827 // Only handle COFF and ELF for now.
828 if (!TT.isOSBinFormatELF())
829 return false;
830
831 // If this is not an executable, don't assume anything is local.
832 const auto &CGOpts = CGM.getCodeGenOpts();
833 llvm::Reloc::Model RM = CGOpts.RelocationModel;
834 const auto &LOpts = CGM.getLangOpts();
835 if (RM != llvm::Reloc::Static && !LOpts.PIE)
836 return false;
837
838 // A definition cannot be preempted from an executable.
839 if (!GV->isDeclarationForLinker())
840 return true;
841
842 // Most PIC code sequences that assume that a symbol is local cannot produce a
843 // 0 if it turns out the symbol is undefined. While this is ABI and relocation
844 // depended, it seems worth it to handle it here.
845 if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
846 return false;
847
848 // PPC has no copy relocations and cannot use a plt entry as a symbol address.
849 llvm::Triple::ArchType Arch = TT.getArch();
850 if (Arch == llvm::Triple::ppc || Arch == llvm::Triple::ppc64 ||
851 Arch == llvm::Triple::ppc64le)
852 return false;
853
854 // If we can use copy relocations we can assume it is local.
855 if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
856 if (!Var->isThreadLocal() &&
857 (RM == llvm::Reloc::Static || CGOpts.PIECopyRelocations))
858 return true;
859
860 // If we can use a plt entry as the symbol address we can assume it
861 // is local.
862 // FIXME: This should work for PIE, but the gold linker doesn't support it.
863 if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
864 return true;
865
866 // Otherwise don't assue it is local.
867 return false;
868 }
869
setDSOLocal(llvm::GlobalValue * GV) const870 void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
871 GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
872 }
873
setDLLImportDLLExport(llvm::GlobalValue * GV,GlobalDecl GD) const874 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
875 GlobalDecl GD) const {
876 const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
877 // C++ destructors have a few C++ ABI specific special cases.
878 if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
879 getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
880 return;
881 }
882 setDLLImportDLLExport(GV, D);
883 }
884
setDLLImportDLLExport(llvm::GlobalValue * GV,const NamedDecl * D) const885 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
886 const NamedDecl *D) const {
887 if (D && D->isExternallyVisible()) {
888 if (D->hasAttr<DLLImportAttr>())
889 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
890 else if (D->hasAttr<DLLExportAttr>() && !GV->isDeclarationForLinker())
891 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
892 }
893 }
894
setGVProperties(llvm::GlobalValue * GV,GlobalDecl GD) const895 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
896 GlobalDecl GD) const {
897 setDLLImportDLLExport(GV, GD);
898 setGVPropertiesAux(GV, dyn_cast<NamedDecl>(GD.getDecl()));
899 }
900
setGVProperties(llvm::GlobalValue * GV,const NamedDecl * D) const901 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
902 const NamedDecl *D) const {
903 setDLLImportDLLExport(GV, D);
904 setGVPropertiesAux(GV, D);
905 }
906
setGVPropertiesAux(llvm::GlobalValue * GV,const NamedDecl * D) const907 void CodeGenModule::setGVPropertiesAux(llvm::GlobalValue *GV,
908 const NamedDecl *D) const {
909 setGlobalVisibility(GV, D);
910 setDSOLocal(GV);
911 GV->setPartition(CodeGenOpts.SymbolPartition);
912 }
913
GetLLVMTLSModel(StringRef S)914 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
915 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
916 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
917 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
918 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
919 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
920 }
921
GetLLVMTLSModel(CodeGenOptions::TLSModel M)922 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(
923 CodeGenOptions::TLSModel M) {
924 switch (M) {
925 case CodeGenOptions::GeneralDynamicTLSModel:
926 return llvm::GlobalVariable::GeneralDynamicTLSModel;
927 case CodeGenOptions::LocalDynamicTLSModel:
928 return llvm::GlobalVariable::LocalDynamicTLSModel;
929 case CodeGenOptions::InitialExecTLSModel:
930 return llvm::GlobalVariable::InitialExecTLSModel;
931 case CodeGenOptions::LocalExecTLSModel:
932 return llvm::GlobalVariable::LocalExecTLSModel;
933 }
934 llvm_unreachable("Invalid TLS model!");
935 }
936
setTLSMode(llvm::GlobalValue * GV,const VarDecl & D) const937 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
938 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
939
940 llvm::GlobalValue::ThreadLocalMode TLM;
941 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel());
942
943 // Override the TLS model if it is explicitly specified.
944 if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
945 TLM = GetLLVMTLSModel(Attr->getModel());
946 }
947
948 GV->setThreadLocalMode(TLM);
949 }
950
getCPUSpecificMangling(const CodeGenModule & CGM,StringRef Name)951 static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
952 StringRef Name) {
953 const TargetInfo &Target = CGM.getTarget();
954 return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
955 }
956
AppendCPUSpecificCPUDispatchMangling(const CodeGenModule & CGM,const CPUSpecificAttr * Attr,unsigned CPUIndex,raw_ostream & Out)957 static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
958 const CPUSpecificAttr *Attr,
959 unsigned CPUIndex,
960 raw_ostream &Out) {
961 // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
962 // supported.
963 if (Attr)
964 Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
965 else if (CGM.getTarget().supportsIFunc())
966 Out << ".resolver";
967 }
968
AppendTargetMangling(const CodeGenModule & CGM,const TargetAttr * Attr,raw_ostream & Out)969 static void AppendTargetMangling(const CodeGenModule &CGM,
970 const TargetAttr *Attr, raw_ostream &Out) {
971 if (Attr->isDefaultVersion())
972 return;
973
974 Out << '.';
975 const TargetInfo &Target = CGM.getTarget();
976 ParsedTargetAttr Info =
977 Attr->parse([&Target](StringRef LHS, StringRef RHS) {
978 // Multiversioning doesn't allow "no-${feature}", so we can
979 // only have "+" prefixes here.
980 assert(LHS.startswith("+") && RHS.startswith("+") &&
981 "Features should always have a prefix.");
982 return Target.multiVersionSortPriority(LHS.substr(1)) >
983 Target.multiVersionSortPriority(RHS.substr(1));
984 });
985
986 bool IsFirst = true;
987
988 if (!Info.Architecture.empty()) {
989 IsFirst = false;
990 Out << "arch_" << Info.Architecture;
991 }
992
993 for (StringRef Feat : Info.Features) {
994 if (!IsFirst)
995 Out << '_';
996 IsFirst = false;
997 Out << Feat.substr(1);
998 }
999 }
1000
getMangledNameImpl(const CodeGenModule & CGM,GlobalDecl GD,const NamedDecl * ND,bool OmitMultiVersionMangling=false)1001 static std::string getMangledNameImpl(const CodeGenModule &CGM, GlobalDecl GD,
1002 const NamedDecl *ND,
1003 bool OmitMultiVersionMangling = false) {
1004 SmallString<256> Buffer;
1005 llvm::raw_svector_ostream Out(Buffer);
1006 MangleContext &MC = CGM.getCXXABI().getMangleContext();
1007 if (MC.shouldMangleDeclName(ND)) {
1008 llvm::raw_svector_ostream Out(Buffer);
1009 if (const auto *D = dyn_cast<CXXConstructorDecl>(ND))
1010 MC.mangleCXXCtor(D, GD.getCtorType(), Out);
1011 else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND))
1012 MC.mangleCXXDtor(D, GD.getDtorType(), Out);
1013 else
1014 MC.mangleName(ND, Out);
1015 } else {
1016 IdentifierInfo *II = ND->getIdentifier();
1017 assert(II && "Attempt to mangle unnamed decl.");
1018 const auto *FD = dyn_cast<FunctionDecl>(ND);
1019
1020 if (FD &&
1021 FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
1022 llvm::raw_svector_ostream Out(Buffer);
1023 Out << "__regcall3__" << II->getName();
1024 } else {
1025 Out << II->getName();
1026 }
1027 }
1028
1029 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
1030 if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
1031 switch (FD->getMultiVersionKind()) {
1032 case MultiVersionKind::CPUDispatch:
1033 case MultiVersionKind::CPUSpecific:
1034 AppendCPUSpecificCPUDispatchMangling(CGM,
1035 FD->getAttr<CPUSpecificAttr>(),
1036 GD.getMultiVersionIndex(), Out);
1037 break;
1038 case MultiVersionKind::Target:
1039 AppendTargetMangling(CGM, FD->getAttr<TargetAttr>(), Out);
1040 break;
1041 case MultiVersionKind::None:
1042 llvm_unreachable("None multiversion type isn't valid here");
1043 }
1044 }
1045
1046 return Out.str();
1047 }
1048
UpdateMultiVersionNames(GlobalDecl GD,const FunctionDecl * FD)1049 void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
1050 const FunctionDecl *FD) {
1051 if (!FD->isMultiVersion())
1052 return;
1053
1054 // Get the name of what this would be without the 'target' attribute. This
1055 // allows us to lookup the version that was emitted when this wasn't a
1056 // multiversion function.
1057 std::string NonTargetName =
1058 getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
1059 GlobalDecl OtherGD;
1060 if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
1061 assert(OtherGD.getCanonicalDecl()
1062 .getDecl()
1063 ->getAsFunction()
1064 ->isMultiVersion() &&
1065 "Other GD should now be a multiversioned function");
1066 // OtherFD is the version of this function that was mangled BEFORE
1067 // becoming a MultiVersion function. It potentially needs to be updated.
1068 const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
1069 .getDecl()
1070 ->getAsFunction()
1071 ->getMostRecentDecl();
1072 std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
1073 // This is so that if the initial version was already the 'default'
1074 // version, we don't try to update it.
1075 if (OtherName != NonTargetName) {
1076 // Remove instead of erase, since others may have stored the StringRef
1077 // to this.
1078 const auto ExistingRecord = Manglings.find(NonTargetName);
1079 if (ExistingRecord != std::end(Manglings))
1080 Manglings.remove(&(*ExistingRecord));
1081 auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
1082 MangledDeclNames[OtherGD.getCanonicalDecl()] = Result.first->first();
1083 if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
1084 Entry->setName(OtherName);
1085 }
1086 }
1087 }
1088
getMangledName(GlobalDecl GD)1089 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
1090 GlobalDecl CanonicalGD = GD.getCanonicalDecl();
1091
1092 // Some ABIs don't have constructor variants. Make sure that base and
1093 // complete constructors get mangled the same.
1094 if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
1095 if (!getTarget().getCXXABI().hasConstructorVariants()) {
1096 CXXCtorType OrigCtorType = GD.getCtorType();
1097 assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
1098 if (OrigCtorType == Ctor_Base)
1099 CanonicalGD = GlobalDecl(CD, Ctor_Complete);
1100 }
1101 }
1102
1103 auto FoundName = MangledDeclNames.find(CanonicalGD);
1104 if (FoundName != MangledDeclNames.end())
1105 return FoundName->second;
1106
1107 // Keep the first result in the case of a mangling collision.
1108 const auto *ND = cast<NamedDecl>(GD.getDecl());
1109 std::string MangledName = getMangledNameImpl(*this, GD, ND);
1110
1111 // Adjust kernel stub mangling as we may need to be able to differentiate
1112 // them from the kernel itself (e.g., for HIP).
1113 if (auto *FD = dyn_cast<FunctionDecl>(GD.getDecl()))
1114 if (!getLangOpts().CUDAIsDevice && FD->hasAttr<CUDAGlobalAttr>())
1115 MangledName = getCUDARuntime().getDeviceStubName(MangledName);
1116
1117 auto Result = Manglings.insert(std::make_pair(MangledName, GD));
1118 return MangledDeclNames[CanonicalGD] = Result.first->first();
1119 }
1120
getBlockMangledName(GlobalDecl GD,const BlockDecl * BD)1121 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
1122 const BlockDecl *BD) {
1123 MangleContext &MangleCtx = getCXXABI().getMangleContext();
1124 const Decl *D = GD.getDecl();
1125
1126 SmallString<256> Buffer;
1127 llvm::raw_svector_ostream Out(Buffer);
1128 if (!D)
1129 MangleCtx.mangleGlobalBlock(BD,
1130 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
1131 else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
1132 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
1133 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
1134 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
1135 else
1136 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
1137
1138 auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
1139 return Result.first->first();
1140 }
1141
GetGlobalValue(StringRef Name)1142 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
1143 return getModule().getNamedValue(Name);
1144 }
1145
1146 /// AddGlobalCtor - Add a function to the list that will be called before
1147 /// main() runs.
AddGlobalCtor(llvm::Function * Ctor,int Priority,llvm::Constant * AssociatedData)1148 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
1149 llvm::Constant *AssociatedData) {
1150 // FIXME: Type coercion of void()* types.
1151 GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData));
1152 }
1153
1154 /// AddGlobalDtor - Add a function to the list that will be called
1155 /// when the module is unloaded.
AddGlobalDtor(llvm::Function * Dtor,int Priority)1156 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority) {
1157 if (CodeGenOpts.RegisterGlobalDtorsWithAtExit) {
1158 DtorsUsingAtExit[Priority].push_back(Dtor);
1159 return;
1160 }
1161
1162 // FIXME: Type coercion of void()* types.
1163 GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
1164 }
1165
EmitCtorList(CtorList & Fns,const char * GlobalName)1166 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
1167 if (Fns.empty()) return;
1168
1169 // Ctor function type is void()*.
1170 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
1171 llvm::Type *CtorPFTy = llvm::PointerType::get(CtorFTy,
1172 TheModule.getDataLayout().getProgramAddressSpace());
1173
1174 // Get the type of a ctor entry, { i32, void ()*, i8* }.
1175 llvm::StructType *CtorStructTy = llvm::StructType::get(
1176 Int32Ty, CtorPFTy, VoidPtrTy);
1177
1178 // Construct the constructor and destructor arrays.
1179 ConstantInitBuilder builder(*this);
1180 auto ctors = builder.beginArray(CtorStructTy);
1181 for (const auto &I : Fns) {
1182 auto ctor = ctors.beginStruct(CtorStructTy);
1183 ctor.addInt(Int32Ty, I.Priority);
1184 ctor.add(llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy));
1185 if (I.AssociatedData)
1186 ctor.add(llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy));
1187 else
1188 ctor.addNullPointer(VoidPtrTy);
1189 ctor.finishAndAddTo(ctors);
1190 }
1191
1192 auto list =
1193 ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
1194 /*constant*/ false,
1195 llvm::GlobalValue::AppendingLinkage);
1196
1197 // The LTO linker doesn't seem to like it when we set an alignment
1198 // on appending variables. Take it off as a workaround.
1199 list->setAlignment(llvm::None);
1200
1201 Fns.clear();
1202 }
1203
1204 llvm::GlobalValue::LinkageTypes
getFunctionLinkage(GlobalDecl GD)1205 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
1206 const auto *D = cast<FunctionDecl>(GD.getDecl());
1207
1208 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
1209
1210 if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
1211 return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
1212
1213 if (isa<CXXConstructorDecl>(D) &&
1214 cast<CXXConstructorDecl>(D)->isInheritingConstructor() &&
1215 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
1216 // Our approach to inheriting constructors is fundamentally different from
1217 // that used by the MS ABI, so keep our inheriting constructor thunks
1218 // internal rather than trying to pick an unambiguous mangling for them.
1219 return llvm::GlobalValue::InternalLinkage;
1220 }
1221
1222 return getLLVMLinkageForDeclarator(D, Linkage, /*IsConstantVariable=*/false);
1223 }
1224
CreateCrossDsoCfiTypeId(llvm::Metadata * MD)1225 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
1226 llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
1227 if (!MDS) return nullptr;
1228
1229 return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
1230 }
1231
SetLLVMFunctionAttributes(GlobalDecl GD,const CGFunctionInfo & Info,llvm::Function * F)1232 void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
1233 const CGFunctionInfo &Info,
1234 llvm::Function *F) {
1235 unsigned CallingConv;
1236 llvm::AttributeList PAL;
1237 ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv, false);
1238 F->setAttributes(PAL);
1239 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
1240 }
1241
removeImageAccessQualifier(std::string & TyName)1242 static void removeImageAccessQualifier(std::string& TyName) {
1243 std::string ReadOnlyQual("__read_only");
1244 std::string::size_type ReadOnlyPos = TyName.find(ReadOnlyQual);
1245 if (ReadOnlyPos != std::string::npos)
1246 // "+ 1" for the space after access qualifier.
1247 TyName.erase(ReadOnlyPos, ReadOnlyQual.size() + 1);
1248 else {
1249 std::string WriteOnlyQual("__write_only");
1250 std::string::size_type WriteOnlyPos = TyName.find(WriteOnlyQual);
1251 if (WriteOnlyPos != std::string::npos)
1252 TyName.erase(WriteOnlyPos, WriteOnlyQual.size() + 1);
1253 else {
1254 std::string ReadWriteQual("__read_write");
1255 std::string::size_type ReadWritePos = TyName.find(ReadWriteQual);
1256 if (ReadWritePos != std::string::npos)
1257 TyName.erase(ReadWritePos, ReadWriteQual.size() + 1);
1258 }
1259 }
1260 }
1261
1262 // Returns the address space id that should be produced to the
1263 // kernel_arg_addr_space metadata. This is always fixed to the ids
1264 // as specified in the SPIR 2.0 specification in order to differentiate
1265 // for example in clGetKernelArgInfo() implementation between the address
1266 // spaces with targets without unique mapping to the OpenCL address spaces
1267 // (basically all single AS CPUs).
ArgInfoAddressSpace(LangAS AS)1268 static unsigned ArgInfoAddressSpace(LangAS AS) {
1269 switch (AS) {
1270 case LangAS::opencl_global: return 1;
1271 case LangAS::opencl_constant: return 2;
1272 case LangAS::opencl_local: return 3;
1273 case LangAS::opencl_generic: return 4; // Not in SPIR 2.0 specs.
1274 default:
1275 return 0; // Assume private.
1276 }
1277 }
1278
GenOpenCLArgMetadata(llvm::Function * Fn,const FunctionDecl * FD,CodeGenFunction * CGF)1279 void CodeGenModule::GenOpenCLArgMetadata(llvm::Function *Fn,
1280 const FunctionDecl *FD,
1281 CodeGenFunction *CGF) {
1282 assert(((FD && CGF) || (!FD && !CGF)) &&
1283 "Incorrect use - FD and CGF should either be both null or not!");
1284 // Create MDNodes that represent the kernel arg metadata.
1285 // Each MDNode is a list in the form of "key", N number of values which is
1286 // the same number of values as their are kernel arguments.
1287
1288 const PrintingPolicy &Policy = Context.getPrintingPolicy();
1289
1290 // MDNode for the kernel argument address space qualifiers.
1291 SmallVector<llvm::Metadata *, 8> addressQuals;
1292
1293 // MDNode for the kernel argument access qualifiers (images only).
1294 SmallVector<llvm::Metadata *, 8> accessQuals;
1295
1296 // MDNode for the kernel argument type names.
1297 SmallVector<llvm::Metadata *, 8> argTypeNames;
1298
1299 // MDNode for the kernel argument base type names.
1300 SmallVector<llvm::Metadata *, 8> argBaseTypeNames;
1301
1302 // MDNode for the kernel argument type qualifiers.
1303 SmallVector<llvm::Metadata *, 8> argTypeQuals;
1304
1305 // MDNode for the kernel argument names.
1306 SmallVector<llvm::Metadata *, 8> argNames;
1307
1308 if (FD && CGF)
1309 for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
1310 const ParmVarDecl *parm = FD->getParamDecl(i);
1311 QualType ty = parm->getType();
1312 std::string typeQuals;
1313
1314 if (ty->isPointerType()) {
1315 QualType pointeeTy = ty->getPointeeType();
1316
1317 // Get address qualifier.
1318 addressQuals.push_back(
1319 llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(
1320 ArgInfoAddressSpace(pointeeTy.getAddressSpace()))));
1321
1322 // Get argument type name.
1323 std::string typeName =
1324 pointeeTy.getUnqualifiedType().getAsString(Policy) + "*";
1325
1326 // Turn "unsigned type" to "utype"
1327 std::string::size_type pos = typeName.find("unsigned");
1328 if (pointeeTy.isCanonical() && pos != std::string::npos)
1329 typeName.erase(pos + 1, 8);
1330
1331 argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
1332
1333 std::string baseTypeName =
1334 pointeeTy.getUnqualifiedType().getCanonicalType().getAsString(
1335 Policy) +
1336 "*";
1337
1338 // Turn "unsigned type" to "utype"
1339 pos = baseTypeName.find("unsigned");
1340 if (pos != std::string::npos)
1341 baseTypeName.erase(pos + 1, 8);
1342
1343 argBaseTypeNames.push_back(
1344 llvm::MDString::get(VMContext, baseTypeName));
1345
1346 // Get argument type qualifiers:
1347 if (ty.isRestrictQualified())
1348 typeQuals = "restrict";
1349 if (pointeeTy.isConstQualified() ||
1350 (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
1351 typeQuals += typeQuals.empty() ? "const" : " const";
1352 if (pointeeTy.isVolatileQualified())
1353 typeQuals += typeQuals.empty() ? "volatile" : " volatile";
1354 } else {
1355 uint32_t AddrSpc = 0;
1356 bool isPipe = ty->isPipeType();
1357 if (ty->isImageType() || isPipe)
1358 AddrSpc = ArgInfoAddressSpace(LangAS::opencl_global);
1359
1360 addressQuals.push_back(
1361 llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(AddrSpc)));
1362
1363 // Get argument type name.
1364 std::string typeName;
1365 if (isPipe)
1366 typeName = ty.getCanonicalType()
1367 ->getAs<PipeType>()
1368 ->getElementType()
1369 .getAsString(Policy);
1370 else
1371 typeName = ty.getUnqualifiedType().getAsString(Policy);
1372
1373 // Turn "unsigned type" to "utype"
1374 std::string::size_type pos = typeName.find("unsigned");
1375 if (ty.isCanonical() && pos != std::string::npos)
1376 typeName.erase(pos + 1, 8);
1377
1378 std::string baseTypeName;
1379 if (isPipe)
1380 baseTypeName = ty.getCanonicalType()
1381 ->getAs<PipeType>()
1382 ->getElementType()
1383 .getCanonicalType()
1384 .getAsString(Policy);
1385 else
1386 baseTypeName =
1387 ty.getUnqualifiedType().getCanonicalType().getAsString(Policy);
1388
1389 // Remove access qualifiers on images
1390 // (as they are inseparable from type in clang implementation,
1391 // but OpenCL spec provides a special query to get access qualifier
1392 // via clGetKernelArgInfo with CL_KERNEL_ARG_ACCESS_QUALIFIER):
1393 if (ty->isImageType()) {
1394 removeImageAccessQualifier(typeName);
1395 removeImageAccessQualifier(baseTypeName);
1396 }
1397
1398 argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
1399
1400 // Turn "unsigned type" to "utype"
1401 pos = baseTypeName.find("unsigned");
1402 if (pos != std::string::npos)
1403 baseTypeName.erase(pos + 1, 8);
1404
1405 argBaseTypeNames.push_back(
1406 llvm::MDString::get(VMContext, baseTypeName));
1407
1408 if (isPipe)
1409 typeQuals = "pipe";
1410 }
1411
1412 argTypeQuals.push_back(llvm::MDString::get(VMContext, typeQuals));
1413
1414 // Get image and pipe access qualifier:
1415 if (ty->isImageType() || ty->isPipeType()) {
1416 const Decl *PDecl = parm;
1417 if (auto *TD = dyn_cast<TypedefType>(ty))
1418 PDecl = TD->getDecl();
1419 const OpenCLAccessAttr *A = PDecl->getAttr<OpenCLAccessAttr>();
1420 if (A && A->isWriteOnly())
1421 accessQuals.push_back(llvm::MDString::get(VMContext, "write_only"));
1422 else if (A && A->isReadWrite())
1423 accessQuals.push_back(llvm::MDString::get(VMContext, "read_write"));
1424 else
1425 accessQuals.push_back(llvm::MDString::get(VMContext, "read_only"));
1426 } else
1427 accessQuals.push_back(llvm::MDString::get(VMContext, "none"));
1428
1429 // Get argument name.
1430 argNames.push_back(llvm::MDString::get(VMContext, parm->getName()));
1431 }
1432
1433 Fn->setMetadata("kernel_arg_addr_space",
1434 llvm::MDNode::get(VMContext, addressQuals));
1435 Fn->setMetadata("kernel_arg_access_qual",
1436 llvm::MDNode::get(VMContext, accessQuals));
1437 Fn->setMetadata("kernel_arg_type",
1438 llvm::MDNode::get(VMContext, argTypeNames));
1439 Fn->setMetadata("kernel_arg_base_type",
1440 llvm::MDNode::get(VMContext, argBaseTypeNames));
1441 Fn->setMetadata("kernel_arg_type_qual",
1442 llvm::MDNode::get(VMContext, argTypeQuals));
1443 if (getCodeGenOpts().EmitOpenCLArgMetadata)
1444 Fn->setMetadata("kernel_arg_name",
1445 llvm::MDNode::get(VMContext, argNames));
1446 }
1447
1448 /// Determines whether the language options require us to model
1449 /// unwind exceptions. We treat -fexceptions as mandating this
1450 /// except under the fragile ObjC ABI with only ObjC exceptions
1451 /// enabled. This means, for example, that C with -fexceptions
1452 /// enables this.
hasUnwindExceptions(const LangOptions & LangOpts)1453 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
1454 // If exceptions are completely disabled, obviously this is false.
1455 if (!LangOpts.Exceptions) return false;
1456
1457 // If C++ exceptions are enabled, this is true.
1458 if (LangOpts.CXXExceptions) return true;
1459
1460 // If ObjC exceptions are enabled, this depends on the ABI.
1461 if (LangOpts.ObjCExceptions) {
1462 return LangOpts.ObjCRuntime.hasUnwindExceptions();
1463 }
1464
1465 return true;
1466 }
1467
requiresMemberFunctionPointerTypeMetadata(CodeGenModule & CGM,const CXXMethodDecl * MD)1468 static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM,
1469 const CXXMethodDecl *MD) {
1470 // Check that the type metadata can ever actually be used by a call.
1471 if (!CGM.getCodeGenOpts().LTOUnit ||
1472 !CGM.HasHiddenLTOVisibility(MD->getParent()))
1473 return false;
1474
1475 // Only functions whose address can be taken with a member function pointer
1476 // need this sort of type metadata.
1477 return !MD->isStatic() && !MD->isVirtual() && !isa<CXXConstructorDecl>(MD) &&
1478 !isa<CXXDestructorDecl>(MD);
1479 }
1480
1481 std::vector<const CXXRecordDecl *>
getMostBaseClasses(const CXXRecordDecl * RD)1482 CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
1483 llvm::SetVector<const CXXRecordDecl *> MostBases;
1484
1485 std::function<void (const CXXRecordDecl *)> CollectMostBases;
1486 CollectMostBases = [&](const CXXRecordDecl *RD) {
1487 if (RD->getNumBases() == 0)
1488 MostBases.insert(RD);
1489 for (const CXXBaseSpecifier &B : RD->bases())
1490 CollectMostBases(B.getType()->getAsCXXRecordDecl());
1491 };
1492 CollectMostBases(RD);
1493 return MostBases.takeVector();
1494 }
1495
SetLLVMFunctionAttributesForDefinition(const Decl * D,llvm::Function * F)1496 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
1497 llvm::Function *F) {
1498 llvm::AttrBuilder B;
1499
1500 if (CodeGenOpts.UnwindTables)
1501 B.addAttribute(llvm::Attribute::UWTable);
1502
1503 if (!hasUnwindExceptions(LangOpts))
1504 B.addAttribute(llvm::Attribute::NoUnwind);
1505
1506 if (!D || !D->hasAttr<NoStackProtectorAttr>()) {
1507 if (LangOpts.getStackProtector() == LangOptions::SSPOn)
1508 B.addAttribute(llvm::Attribute::StackProtect);
1509 else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
1510 B.addAttribute(llvm::Attribute::StackProtectStrong);
1511 else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
1512 B.addAttribute(llvm::Attribute::StackProtectReq);
1513 }
1514
1515 if (!D) {
1516 // If we don't have a declaration to control inlining, the function isn't
1517 // explicitly marked as alwaysinline for semantic reasons, and inlining is
1518 // disabled, mark the function as noinline.
1519 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
1520 CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
1521 B.addAttribute(llvm::Attribute::NoInline);
1522
1523 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1524 return;
1525 }
1526
1527 // Track whether we need to add the optnone LLVM attribute,
1528 // starting with the default for this optimization level.
1529 bool ShouldAddOptNone =
1530 !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
1531 // We can't add optnone in the following cases, it won't pass the verifier.
1532 ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
1533 ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
1534
1535 // Add optnone, but do so only if the function isn't always_inline.
1536 if ((ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) &&
1537 !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1538 B.addAttribute(llvm::Attribute::OptimizeNone);
1539
1540 // OptimizeNone implies noinline; we should not be inlining such functions.
1541 B.addAttribute(llvm::Attribute::NoInline);
1542
1543 // We still need to handle naked functions even though optnone subsumes
1544 // much of their semantics.
1545 if (D->hasAttr<NakedAttr>())
1546 B.addAttribute(llvm::Attribute::Naked);
1547
1548 // OptimizeNone wins over OptimizeForSize and MinSize.
1549 F->removeFnAttr(llvm::Attribute::OptimizeForSize);
1550 F->removeFnAttr(llvm::Attribute::MinSize);
1551 } else if (D->hasAttr<NakedAttr>()) {
1552 // Naked implies noinline: we should not be inlining such functions.
1553 B.addAttribute(llvm::Attribute::Naked);
1554 B.addAttribute(llvm::Attribute::NoInline);
1555 } else if (D->hasAttr<NoDuplicateAttr>()) {
1556 B.addAttribute(llvm::Attribute::NoDuplicate);
1557 } else if (D->hasAttr<NoInlineAttr>() && !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1558 // Add noinline if the function isn't always_inline.
1559 B.addAttribute(llvm::Attribute::NoInline);
1560 } else if (D->hasAttr<AlwaysInlineAttr>() &&
1561 !F->hasFnAttribute(llvm::Attribute::NoInline)) {
1562 // (noinline wins over always_inline, and we can't specify both in IR)
1563 B.addAttribute(llvm::Attribute::AlwaysInline);
1564 } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
1565 // If we're not inlining, then force everything that isn't always_inline to
1566 // carry an explicit noinline attribute.
1567 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
1568 B.addAttribute(llvm::Attribute::NoInline);
1569 } else {
1570 // Otherwise, propagate the inline hint attribute and potentially use its
1571 // absence to mark things as noinline.
1572 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
1573 // Search function and template pattern redeclarations for inline.
1574 auto CheckForInline = [](const FunctionDecl *FD) {
1575 auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
1576 return Redecl->isInlineSpecified();
1577 };
1578 if (any_of(FD->redecls(), CheckRedeclForInline))
1579 return true;
1580 const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
1581 if (!Pattern)
1582 return false;
1583 return any_of(Pattern->redecls(), CheckRedeclForInline);
1584 };
1585 if (CheckForInline(FD)) {
1586 B.addAttribute(llvm::Attribute::InlineHint);
1587 } else if (CodeGenOpts.getInlining() ==
1588 CodeGenOptions::OnlyHintInlining &&
1589 !FD->isInlined() &&
1590 !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1591 B.addAttribute(llvm::Attribute::NoInline);
1592 }
1593 }
1594 }
1595
1596 // Add other optimization related attributes if we are optimizing this
1597 // function.
1598 if (!D->hasAttr<OptimizeNoneAttr>()) {
1599 if (D->hasAttr<ColdAttr>()) {
1600 if (!ShouldAddOptNone)
1601 B.addAttribute(llvm::Attribute::OptimizeForSize);
1602 B.addAttribute(llvm::Attribute::Cold);
1603 }
1604
1605 if (D->hasAttr<MinSizeAttr>())
1606 B.addAttribute(llvm::Attribute::MinSize);
1607 }
1608
1609 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1610
1611 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
1612 if (alignment)
1613 F->setAlignment(llvm::Align(alignment));
1614
1615 if (!D->hasAttr<AlignedAttr>())
1616 if (LangOpts.FunctionAlignment)
1617 F->setAlignment(llvm::Align(1ull << LangOpts.FunctionAlignment));
1618
1619 // Some C++ ABIs require 2-byte alignment for member functions, in order to
1620 // reserve a bit for differentiating between virtual and non-virtual member
1621 // functions. If the current target's C++ ABI requires this and this is a
1622 // member function, set its alignment accordingly.
1623 if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
1624 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
1625 F->setAlignment(llvm::Align(2));
1626 }
1627
1628 // In the cross-dso CFI mode with canonical jump tables, we want !type
1629 // attributes on definitions only.
1630 if (CodeGenOpts.SanitizeCfiCrossDso &&
1631 CodeGenOpts.SanitizeCfiCanonicalJumpTables) {
1632 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
1633 // Skip available_externally functions. They won't be codegen'ed in the
1634 // current module anyway.
1635 if (getContext().GetGVALinkageForFunction(FD) != GVA_AvailableExternally)
1636 CreateFunctionTypeMetadataForIcall(FD, F);
1637 }
1638 }
1639
1640 // Emit type metadata on member functions for member function pointer checks.
1641 // These are only ever necessary on definitions; we're guaranteed that the
1642 // definition will be present in the LTO unit as a result of LTO visibility.
1643 auto *MD = dyn_cast<CXXMethodDecl>(D);
1644 if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
1645 for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
1646 llvm::Metadata *Id =
1647 CreateMetadataIdentifierForType(Context.getMemberPointerType(
1648 MD->getType(), Context.getRecordType(Base).getTypePtr()));
1649 F->addTypeMetadata(0, Id);
1650 }
1651 }
1652 }
1653
SetCommonAttributes(GlobalDecl GD,llvm::GlobalValue * GV)1654 void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
1655 const Decl *D = GD.getDecl();
1656 if (dyn_cast_or_null<NamedDecl>(D))
1657 setGVProperties(GV, GD);
1658 else
1659 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1660
1661 if (D && D->hasAttr<UsedAttr>())
1662 addUsedGlobal(GV);
1663
1664 if (CodeGenOpts.KeepStaticConsts && D && isa<VarDecl>(D)) {
1665 const auto *VD = cast<VarDecl>(D);
1666 if (VD->getType().isConstQualified() &&
1667 VD->getStorageDuration() == SD_Static)
1668 addUsedGlobal(GV);
1669 }
1670 }
1671
GetCPUAndFeaturesAttributes(GlobalDecl GD,llvm::AttrBuilder & Attrs)1672 bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
1673 llvm::AttrBuilder &Attrs) {
1674 // Add target-cpu and target-features attributes to functions. If
1675 // we have a decl for the function and it has a target attribute then
1676 // parse that and add it to the feature set.
1677 StringRef TargetCPU = getTarget().getTargetOpts().CPU;
1678 std::vector<std::string> Features;
1679 const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
1680 FD = FD ? FD->getMostRecentDecl() : FD;
1681 const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
1682 const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
1683 bool AddedAttr = false;
1684 if (TD || SD) {
1685 llvm::StringMap<bool> FeatureMap;
1686 getContext().getFunctionFeatureMap(FeatureMap, GD);
1687
1688 // Produce the canonical string for this set of features.
1689 for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
1690 Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
1691
1692 // Now add the target-cpu and target-features to the function.
1693 // While we populated the feature map above, we still need to
1694 // get and parse the target attribute so we can get the cpu for
1695 // the function.
1696 if (TD) {
1697 ParsedTargetAttr ParsedAttr = TD->parse();
1698 if (ParsedAttr.Architecture != "" &&
1699 getTarget().isValidCPUName(ParsedAttr.Architecture))
1700 TargetCPU = ParsedAttr.Architecture;
1701 }
1702 } else {
1703 // Otherwise just add the existing target cpu and target features to the
1704 // function.
1705 Features = getTarget().getTargetOpts().Features;
1706 }
1707
1708 if (TargetCPU != "") {
1709 Attrs.addAttribute("target-cpu", TargetCPU);
1710 AddedAttr = true;
1711 }
1712 if (!Features.empty()) {
1713 llvm::sort(Features);
1714 Attrs.addAttribute("target-features", llvm::join(Features, ","));
1715 AddedAttr = true;
1716 }
1717
1718 return AddedAttr;
1719 }
1720
setNonAliasAttributes(GlobalDecl GD,llvm::GlobalObject * GO)1721 void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
1722 llvm::GlobalObject *GO) {
1723 const Decl *D = GD.getDecl();
1724 SetCommonAttributes(GD, GO);
1725
1726 if (D) {
1727 if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
1728 if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
1729 GV->addAttribute("bss-section", SA->getName());
1730 if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
1731 GV->addAttribute("data-section", SA->getName());
1732 if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
1733 GV->addAttribute("rodata-section", SA->getName());
1734 if (auto *SA = D->getAttr<PragmaClangRelroSectionAttr>())
1735 GV->addAttribute("relro-section", SA->getName());
1736 }
1737
1738 if (auto *F = dyn_cast<llvm::Function>(GO)) {
1739 if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
1740 if (!D->getAttr<SectionAttr>())
1741 F->addFnAttr("implicit-section-name", SA->getName());
1742
1743 llvm::AttrBuilder Attrs;
1744 if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
1745 // We know that GetCPUAndFeaturesAttributes will always have the
1746 // newest set, since it has the newest possible FunctionDecl, so the
1747 // new ones should replace the old.
1748 F->removeFnAttr("target-cpu");
1749 F->removeFnAttr("target-features");
1750 F->addAttributes(llvm::AttributeList::FunctionIndex, Attrs);
1751 }
1752 }
1753
1754 if (const auto *CSA = D->getAttr<CodeSegAttr>())
1755 GO->setSection(CSA->getName());
1756 else if (const auto *SA = D->getAttr<SectionAttr>())
1757 GO->setSection(SA->getName());
1758 }
1759
1760 getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
1761 }
1762
SetInternalFunctionAttributes(GlobalDecl GD,llvm::Function * F,const CGFunctionInfo & FI)1763 void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
1764 llvm::Function *F,
1765 const CGFunctionInfo &FI) {
1766 const Decl *D = GD.getDecl();
1767 SetLLVMFunctionAttributes(GD, FI, F);
1768 SetLLVMFunctionAttributesForDefinition(D, F);
1769
1770 F->setLinkage(llvm::Function::InternalLinkage);
1771
1772 setNonAliasAttributes(GD, F);
1773 }
1774
setLinkageForGV(llvm::GlobalValue * GV,const NamedDecl * ND)1775 static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
1776 // Set linkage and visibility in case we never see a definition.
1777 LinkageInfo LV = ND->getLinkageAndVisibility();
1778 // Don't set internal linkage on declarations.
1779 // "extern_weak" is overloaded in LLVM; we probably should have
1780 // separate linkage types for this.
1781 if (isExternallyVisible(LV.getLinkage()) &&
1782 (ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
1783 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
1784 }
1785
CreateFunctionTypeMetadataForIcall(const FunctionDecl * FD,llvm::Function * F)1786 void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
1787 llvm::Function *F) {
1788 // Only if we are checking indirect calls.
1789 if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
1790 return;
1791
1792 // Non-static class methods are handled via vtable or member function pointer
1793 // checks elsewhere.
1794 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
1795 return;
1796
1797 llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
1798 F->addTypeMetadata(0, MD);
1799 F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
1800
1801 // Emit a hash-based bit set entry for cross-DSO calls.
1802 if (CodeGenOpts.SanitizeCfiCrossDso)
1803 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
1804 F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
1805 }
1806
SetFunctionAttributes(GlobalDecl GD,llvm::Function * F,bool IsIncompleteFunction,bool IsThunk)1807 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
1808 bool IsIncompleteFunction,
1809 bool IsThunk) {
1810
1811 if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) {
1812 // If this is an intrinsic function, set the function's attributes
1813 // to the intrinsic's attributes.
1814 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID));
1815 return;
1816 }
1817
1818 const auto *FD = cast<FunctionDecl>(GD.getDecl());
1819
1820 if (!IsIncompleteFunction)
1821 SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F);
1822
1823 // Add the Returned attribute for "this", except for iOS 5 and earlier
1824 // where substantial code, including the libstdc++ dylib, was compiled with
1825 // GCC and does not actually return "this".
1826 if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
1827 !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
1828 assert(!F->arg_empty() &&
1829 F->arg_begin()->getType()
1830 ->canLosslesslyBitCastTo(F->getReturnType()) &&
1831 "unexpected this return");
1832 F->addAttribute(1, llvm::Attribute::Returned);
1833 }
1834
1835 // Only a few attributes are set on declarations; these may later be
1836 // overridden by a definition.
1837
1838 setLinkageForGV(F, FD);
1839 setGVProperties(F, FD);
1840
1841 // Setup target-specific attributes.
1842 if (!IsIncompleteFunction && F->isDeclaration())
1843 getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
1844
1845 if (const auto *CSA = FD->getAttr<CodeSegAttr>())
1846 F->setSection(CSA->getName());
1847 else if (const auto *SA = FD->getAttr<SectionAttr>())
1848 F->setSection(SA->getName());
1849
1850 // If we plan on emitting this inline builtin, we can't treat it as a builtin.
1851 if (FD->isInlineBuiltinDeclaration()) {
1852 const FunctionDecl *FDBody;
1853 bool HasBody = FD->hasBody(FDBody);
1854 (void)HasBody;
1855 assert(HasBody && "Inline builtin declarations should always have an "
1856 "available body!");
1857 if (shouldEmitFunction(FDBody))
1858 F->addAttribute(llvm::AttributeList::FunctionIndex,
1859 llvm::Attribute::NoBuiltin);
1860 }
1861
1862 if (FD->isReplaceableGlobalAllocationFunction()) {
1863 // A replaceable global allocation function does not act like a builtin by
1864 // default, only if it is invoked by a new-expression or delete-expression.
1865 F->addAttribute(llvm::AttributeList::FunctionIndex,
1866 llvm::Attribute::NoBuiltin);
1867
1868 // A sane operator new returns a non-aliasing pointer.
1869 // FIXME: Also add NonNull attribute to the return value
1870 // for the non-nothrow forms?
1871 auto Kind = FD->getDeclName().getCXXOverloadedOperator();
1872 if (getCodeGenOpts().AssumeSaneOperatorNew &&
1873 (Kind == OO_New || Kind == OO_Array_New))
1874 F->addAttribute(llvm::AttributeList::ReturnIndex,
1875 llvm::Attribute::NoAlias);
1876 }
1877
1878 if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
1879 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1880 else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
1881 if (MD->isVirtual())
1882 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1883
1884 // Don't emit entries for function declarations in the cross-DSO mode. This
1885 // is handled with better precision by the receiving DSO. But if jump tables
1886 // are non-canonical then we need type metadata in order to produce the local
1887 // jump table.
1888 if (!CodeGenOpts.SanitizeCfiCrossDso ||
1889 !CodeGenOpts.SanitizeCfiCanonicalJumpTables)
1890 CreateFunctionTypeMetadataForIcall(FD, F);
1891
1892 if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
1893 getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
1894
1895 if (const auto *CB = FD->getAttr<CallbackAttr>()) {
1896 // Annotate the callback behavior as metadata:
1897 // - The callback callee (as argument number).
1898 // - The callback payloads (as argument numbers).
1899 llvm::LLVMContext &Ctx = F->getContext();
1900 llvm::MDBuilder MDB(Ctx);
1901
1902 // The payload indices are all but the first one in the encoding. The first
1903 // identifies the callback callee.
1904 int CalleeIdx = *CB->encoding_begin();
1905 ArrayRef<int> PayloadIndices(CB->encoding_begin() + 1, CB->encoding_end());
1906 F->addMetadata(llvm::LLVMContext::MD_callback,
1907 *llvm::MDNode::get(Ctx, {MDB.createCallbackEncoding(
1908 CalleeIdx, PayloadIndices,
1909 /* VarArgsArePassed */ false)}));
1910 }
1911 }
1912
addUsedGlobal(llvm::GlobalValue * GV)1913 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
1914 assert(!GV->isDeclaration() &&
1915 "Only globals with definition can force usage.");
1916 LLVMUsed.emplace_back(GV);
1917 }
1918
addCompilerUsedGlobal(llvm::GlobalValue * GV)1919 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
1920 assert(!GV->isDeclaration() &&
1921 "Only globals with definition can force usage.");
1922 LLVMCompilerUsed.emplace_back(GV);
1923 }
1924
emitUsed(CodeGenModule & CGM,StringRef Name,std::vector<llvm::WeakTrackingVH> & List)1925 static void emitUsed(CodeGenModule &CGM, StringRef Name,
1926 std::vector<llvm::WeakTrackingVH> &List) {
1927 // Don't create llvm.used if there is no need.
1928 if (List.empty())
1929 return;
1930
1931 // Convert List to what ConstantArray needs.
1932 SmallVector<llvm::Constant*, 8> UsedArray;
1933 UsedArray.resize(List.size());
1934 for (unsigned i = 0, e = List.size(); i != e; ++i) {
1935 UsedArray[i] =
1936 llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
1937 cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
1938 }
1939
1940 if (UsedArray.empty())
1941 return;
1942 llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
1943
1944 auto *GV = new llvm::GlobalVariable(
1945 CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
1946 llvm::ConstantArray::get(ATy, UsedArray), Name);
1947
1948 GV->setSection("llvm.metadata");
1949 }
1950
emitLLVMUsed()1951 void CodeGenModule::emitLLVMUsed() {
1952 emitUsed(*this, "llvm.used", LLVMUsed);
1953 emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
1954 }
1955
AppendLinkerOptions(StringRef Opts)1956 void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
1957 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
1958 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1959 }
1960
AddDetectMismatch(StringRef Name,StringRef Value)1961 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
1962 llvm::SmallString<32> Opt;
1963 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
1964 if (Opt.empty())
1965 return;
1966 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
1967 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1968 }
1969
AddDependentLib(StringRef Lib)1970 void CodeGenModule::AddDependentLib(StringRef Lib) {
1971 auto &C = getLLVMContext();
1972 if (getTarget().getTriple().isOSBinFormatELF()) {
1973 ELFDependentLibraries.push_back(
1974 llvm::MDNode::get(C, llvm::MDString::get(C, Lib)));
1975 return;
1976 }
1977
1978 llvm::SmallString<24> Opt;
1979 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
1980 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
1981 LinkerOptionsMetadata.push_back(llvm::MDNode::get(C, MDOpts));
1982 }
1983
1984 /// Add link options implied by the given module, including modules
1985 /// it depends on, using a postorder walk.
addLinkOptionsPostorder(CodeGenModule & CGM,Module * Mod,SmallVectorImpl<llvm::MDNode * > & Metadata,llvm::SmallPtrSet<Module *,16> & Visited)1986 static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
1987 SmallVectorImpl<llvm::MDNode *> &Metadata,
1988 llvm::SmallPtrSet<Module *, 16> &Visited) {
1989 // Import this module's parent.
1990 if (Mod->Parent && Visited.insert(Mod->Parent).second) {
1991 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
1992 }
1993
1994 // Import this module's dependencies.
1995 for (unsigned I = Mod->Imports.size(); I > 0; --I) {
1996 if (Visited.insert(Mod->Imports[I - 1]).second)
1997 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited);
1998 }
1999
2000 // Add linker options to link against the libraries/frameworks
2001 // described by this module.
2002 llvm::LLVMContext &Context = CGM.getLLVMContext();
2003 bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
2004
2005 // For modules that use export_as for linking, use that module
2006 // name instead.
2007 if (Mod->UseExportAsModuleLinkName)
2008 return;
2009
2010 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) {
2011 // Link against a framework. Frameworks are currently Darwin only, so we
2012 // don't to ask TargetCodeGenInfo for the spelling of the linker option.
2013 if (Mod->LinkLibraries[I-1].IsFramework) {
2014 llvm::Metadata *Args[2] = {
2015 llvm::MDString::get(Context, "-framework"),
2016 llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library)};
2017
2018 Metadata.push_back(llvm::MDNode::get(Context, Args));
2019 continue;
2020 }
2021
2022 // Link against a library.
2023 if (IsELF) {
2024 llvm::Metadata *Args[2] = {
2025 llvm::MDString::get(Context, "lib"),
2026 llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library),
2027 };
2028 Metadata.push_back(llvm::MDNode::get(Context, Args));
2029 } else {
2030 llvm::SmallString<24> Opt;
2031 CGM.getTargetCodeGenInfo().getDependentLibraryOption(
2032 Mod->LinkLibraries[I - 1].Library, Opt);
2033 auto *OptString = llvm::MDString::get(Context, Opt);
2034 Metadata.push_back(llvm::MDNode::get(Context, OptString));
2035 }
2036 }
2037 }
2038
EmitModuleLinkOptions()2039 void CodeGenModule::EmitModuleLinkOptions() {
2040 // Collect the set of all of the modules we want to visit to emit link
2041 // options, which is essentially the imported modules and all of their
2042 // non-explicit child modules.
2043 llvm::SetVector<clang::Module *> LinkModules;
2044 llvm::SmallPtrSet<clang::Module *, 16> Visited;
2045 SmallVector<clang::Module *, 16> Stack;
2046
2047 // Seed the stack with imported modules.
2048 for (Module *M : ImportedModules) {
2049 // Do not add any link flags when an implementation TU of a module imports
2050 // a header of that same module.
2051 if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
2052 !getLangOpts().isCompilingModule())
2053 continue;
2054 if (Visited.insert(M).second)
2055 Stack.push_back(M);
2056 }
2057
2058 // Find all of the modules to import, making a little effort to prune
2059 // non-leaf modules.
2060 while (!Stack.empty()) {
2061 clang::Module *Mod = Stack.pop_back_val();
2062
2063 bool AnyChildren = false;
2064
2065 // Visit the submodules of this module.
2066 for (const auto &SM : Mod->submodules()) {
2067 // Skip explicit children; they need to be explicitly imported to be
2068 // linked against.
2069 if (SM->IsExplicit)
2070 continue;
2071
2072 if (Visited.insert(SM).second) {
2073 Stack.push_back(SM);
2074 AnyChildren = true;
2075 }
2076 }
2077
2078 // We didn't find any children, so add this module to the list of
2079 // modules to link against.
2080 if (!AnyChildren) {
2081 LinkModules.insert(Mod);
2082 }
2083 }
2084
2085 // Add link options for all of the imported modules in reverse topological
2086 // order. We don't do anything to try to order import link flags with respect
2087 // to linker options inserted by things like #pragma comment().
2088 SmallVector<llvm::MDNode *, 16> MetadataArgs;
2089 Visited.clear();
2090 for (Module *M : LinkModules)
2091 if (Visited.insert(M).second)
2092 addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
2093 std::reverse(MetadataArgs.begin(), MetadataArgs.end());
2094 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
2095
2096 // Add the linker options metadata flag.
2097 auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
2098 for (auto *MD : LinkerOptionsMetadata)
2099 NMD->addOperand(MD);
2100 }
2101
EmitDeferred()2102 void CodeGenModule::EmitDeferred() {
2103 // Emit deferred declare target declarations.
2104 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
2105 getOpenMPRuntime().emitDeferredTargetDecls();
2106
2107 // Emit code for any potentially referenced deferred decls. Since a
2108 // previously unused static decl may become used during the generation of code
2109 // for a static function, iterate until no changes are made.
2110
2111 if (!DeferredVTables.empty()) {
2112 EmitDeferredVTables();
2113
2114 // Emitting a vtable doesn't directly cause more vtables to
2115 // become deferred, although it can cause functions to be
2116 // emitted that then need those vtables.
2117 assert(DeferredVTables.empty());
2118 }
2119
2120 // Stop if we're out of both deferred vtables and deferred declarations.
2121 if (DeferredDeclsToEmit.empty())
2122 return;
2123
2124 // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
2125 // work, it will not interfere with this.
2126 std::vector<GlobalDecl> CurDeclsToEmit;
2127 CurDeclsToEmit.swap(DeferredDeclsToEmit);
2128
2129 for (GlobalDecl &D : CurDeclsToEmit) {
2130 // We should call GetAddrOfGlobal with IsForDefinition set to true in order
2131 // to get GlobalValue with exactly the type we need, not something that
2132 // might had been created for another decl with the same mangled name but
2133 // different type.
2134 llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
2135 GetAddrOfGlobal(D, ForDefinition));
2136
2137 // In case of different address spaces, we may still get a cast, even with
2138 // IsForDefinition equal to true. Query mangled names table to get
2139 // GlobalValue.
2140 if (!GV)
2141 GV = GetGlobalValue(getMangledName(D));
2142
2143 // Make sure GetGlobalValue returned non-null.
2144 assert(GV);
2145
2146 // Check to see if we've already emitted this. This is necessary
2147 // for a couple of reasons: first, decls can end up in the
2148 // deferred-decls queue multiple times, and second, decls can end
2149 // up with definitions in unusual ways (e.g. by an extern inline
2150 // function acquiring a strong function redefinition). Just
2151 // ignore these cases.
2152 if (!GV->isDeclaration())
2153 continue;
2154
2155 // If this is OpenMP, check if it is legal to emit this global normally.
2156 if (LangOpts.OpenMP && OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(D))
2157 continue;
2158
2159 // Otherwise, emit the definition and move on to the next one.
2160 EmitGlobalDefinition(D, GV);
2161
2162 // If we found out that we need to emit more decls, do that recursively.
2163 // This has the advantage that the decls are emitted in a DFS and related
2164 // ones are close together, which is convenient for testing.
2165 if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
2166 EmitDeferred();
2167 assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
2168 }
2169 }
2170 }
2171
EmitVTablesOpportunistically()2172 void CodeGenModule::EmitVTablesOpportunistically() {
2173 // Try to emit external vtables as available_externally if they have emitted
2174 // all inlined virtual functions. It runs after EmitDeferred() and therefore
2175 // is not allowed to create new references to things that need to be emitted
2176 // lazily. Note that it also uses fact that we eagerly emitting RTTI.
2177
2178 assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
2179 && "Only emit opportunistic vtables with optimizations");
2180
2181 for (const CXXRecordDecl *RD : OpportunisticVTables) {
2182 assert(getVTables().isVTableExternal(RD) &&
2183 "This queue should only contain external vtables");
2184 if (getCXXABI().canSpeculativelyEmitVTable(RD))
2185 VTables.GenerateClassData(RD);
2186 }
2187 OpportunisticVTables.clear();
2188 }
2189
EmitGlobalAnnotations()2190 void CodeGenModule::EmitGlobalAnnotations() {
2191 if (Annotations.empty())
2192 return;
2193
2194 // Create a new global variable for the ConstantStruct in the Module.
2195 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
2196 Annotations[0]->getType(), Annotations.size()), Annotations);
2197 auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
2198 llvm::GlobalValue::AppendingLinkage,
2199 Array, "llvm.global.annotations");
2200 gv->setSection(AnnotationSection);
2201 }
2202
EmitAnnotationString(StringRef Str)2203 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
2204 llvm::Constant *&AStr = AnnotationStrings[Str];
2205 if (AStr)
2206 return AStr;
2207
2208 // Not found yet, create a new global.
2209 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
2210 auto *gv =
2211 new llvm::GlobalVariable(getModule(), s->getType(), true,
2212 llvm::GlobalValue::PrivateLinkage, s, ".str");
2213 gv->setSection(AnnotationSection);
2214 gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2215 AStr = gv;
2216 return gv;
2217 }
2218
EmitAnnotationUnit(SourceLocation Loc)2219 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
2220 SourceManager &SM = getContext().getSourceManager();
2221 PresumedLoc PLoc = SM.getPresumedLoc(Loc);
2222 if (PLoc.isValid())
2223 return EmitAnnotationString(PLoc.getFilename());
2224 return EmitAnnotationString(SM.getBufferName(Loc));
2225 }
2226
EmitAnnotationLineNo(SourceLocation L)2227 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
2228 SourceManager &SM = getContext().getSourceManager();
2229 PresumedLoc PLoc = SM.getPresumedLoc(L);
2230 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
2231 SM.getExpansionLineNumber(L);
2232 return llvm::ConstantInt::get(Int32Ty, LineNo);
2233 }
2234
EmitAnnotateAttr(llvm::GlobalValue * GV,const AnnotateAttr * AA,SourceLocation L)2235 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
2236 const AnnotateAttr *AA,
2237 SourceLocation L) {
2238 // Get the globals for file name, annotation, and the line number.
2239 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
2240 *UnitGV = EmitAnnotationUnit(L),
2241 *LineNoCst = EmitAnnotationLineNo(L);
2242
2243 llvm::Constant *ASZeroGV = GV;
2244 if (GV->getAddressSpace() != 0) {
2245 ASZeroGV = llvm::ConstantExpr::getAddrSpaceCast(
2246 GV, GV->getValueType()->getPointerTo(0));
2247 }
2248
2249 // Create the ConstantStruct for the global annotation.
2250 llvm::Constant *Fields[4] = {
2251 llvm::ConstantExpr::getBitCast(ASZeroGV, Int8PtrTy),
2252 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
2253 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
2254 LineNoCst
2255 };
2256 return llvm::ConstantStruct::getAnon(Fields);
2257 }
2258
AddGlobalAnnotations(const ValueDecl * D,llvm::GlobalValue * GV)2259 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
2260 llvm::GlobalValue *GV) {
2261 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
2262 // Get the struct elements for these annotations.
2263 for (const auto *I : D->specific_attrs<AnnotateAttr>())
2264 Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
2265 }
2266
isInSanitizerBlacklist(SanitizerMask Kind,llvm::Function * Fn,SourceLocation Loc) const2267 bool CodeGenModule::isInSanitizerBlacklist(SanitizerMask Kind,
2268 llvm::Function *Fn,
2269 SourceLocation Loc) const {
2270 const auto &SanitizerBL = getContext().getSanitizerBlacklist();
2271 // Blacklist by function name.
2272 if (SanitizerBL.isBlacklistedFunction(Kind, Fn->getName()))
2273 return true;
2274 // Blacklist by location.
2275 if (Loc.isValid())
2276 return SanitizerBL.isBlacklistedLocation(Kind, Loc);
2277 // If location is unknown, this may be a compiler-generated function. Assume
2278 // it's located in the main file.
2279 auto &SM = Context.getSourceManager();
2280 if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
2281 return SanitizerBL.isBlacklistedFile(Kind, MainFile->getName());
2282 }
2283 return false;
2284 }
2285
isInSanitizerBlacklist(llvm::GlobalVariable * GV,SourceLocation Loc,QualType Ty,StringRef Category) const2286 bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
2287 SourceLocation Loc, QualType Ty,
2288 StringRef Category) const {
2289 // For now globals can be blacklisted only in ASan and KASan.
2290 const SanitizerMask EnabledAsanMask =
2291 LangOpts.Sanitize.Mask &
2292 (SanitizerKind::Address | SanitizerKind::KernelAddress |
2293 SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress |
2294 SanitizerKind::MemTag);
2295 if (!EnabledAsanMask)
2296 return false;
2297 const auto &SanitizerBL = getContext().getSanitizerBlacklist();
2298 if (SanitizerBL.isBlacklistedGlobal(EnabledAsanMask, GV->getName(), Category))
2299 return true;
2300 if (SanitizerBL.isBlacklistedLocation(EnabledAsanMask, Loc, Category))
2301 return true;
2302 // Check global type.
2303 if (!Ty.isNull()) {
2304 // Drill down the array types: if global variable of a fixed type is
2305 // blacklisted, we also don't instrument arrays of them.
2306 while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
2307 Ty = AT->getElementType();
2308 Ty = Ty.getCanonicalType().getUnqualifiedType();
2309 // We allow to blacklist only record types (classes, structs etc.)
2310 if (Ty->isRecordType()) {
2311 std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
2312 if (SanitizerBL.isBlacklistedType(EnabledAsanMask, TypeStr, Category))
2313 return true;
2314 }
2315 }
2316 return false;
2317 }
2318
imbueXRayAttrs(llvm::Function * Fn,SourceLocation Loc,StringRef Category) const2319 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
2320 StringRef Category) const {
2321 const auto &XRayFilter = getContext().getXRayFilter();
2322 using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
2323 auto Attr = ImbueAttr::NONE;
2324 if (Loc.isValid())
2325 Attr = XRayFilter.shouldImbueLocation(Loc, Category);
2326 if (Attr == ImbueAttr::NONE)
2327 Attr = XRayFilter.shouldImbueFunction(Fn->getName());
2328 switch (Attr) {
2329 case ImbueAttr::NONE:
2330 return false;
2331 case ImbueAttr::ALWAYS:
2332 Fn->addFnAttr("function-instrument", "xray-always");
2333 break;
2334 case ImbueAttr::ALWAYS_ARG1:
2335 Fn->addFnAttr("function-instrument", "xray-always");
2336 Fn->addFnAttr("xray-log-args", "1");
2337 break;
2338 case ImbueAttr::NEVER:
2339 Fn->addFnAttr("function-instrument", "xray-never");
2340 break;
2341 }
2342 return true;
2343 }
2344
MustBeEmitted(const ValueDecl * Global)2345 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
2346 // Never defer when EmitAllDecls is specified.
2347 if (LangOpts.EmitAllDecls)
2348 return true;
2349
2350 if (CodeGenOpts.KeepStaticConsts) {
2351 const auto *VD = dyn_cast<VarDecl>(Global);
2352 if (VD && VD->getType().isConstQualified() &&
2353 VD->getStorageDuration() == SD_Static)
2354 return true;
2355 }
2356
2357 return getContext().DeclMustBeEmitted(Global);
2358 }
2359
MayBeEmittedEagerly(const ValueDecl * Global)2360 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
2361 if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
2362 if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
2363 // Implicit template instantiations may change linkage if they are later
2364 // explicitly instantiated, so they should not be emitted eagerly.
2365 return false;
2366 // In OpenMP 5.0 function may be marked as device_type(nohost) and we should
2367 // not emit them eagerly unless we sure that the function must be emitted on
2368 // the host.
2369 if (LangOpts.OpenMP >= 50 && !LangOpts.OpenMPSimd &&
2370 !LangOpts.OpenMPIsDevice &&
2371 !OMPDeclareTargetDeclAttr::getDeviceType(FD) &&
2372 !FD->isUsed(/*CheckUsedAttr=*/false) && !FD->isReferenced())
2373 return false;
2374 }
2375 if (const auto *VD = dyn_cast<VarDecl>(Global))
2376 if (Context.getInlineVariableDefinitionKind(VD) ==
2377 ASTContext::InlineVariableDefinitionKind::WeakUnknown)
2378 // A definition of an inline constexpr static data member may change
2379 // linkage later if it's redeclared outside the class.
2380 return false;
2381 // If OpenMP is enabled and threadprivates must be generated like TLS, delay
2382 // codegen for global variables, because they may be marked as threadprivate.
2383 if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
2384 getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
2385 !isTypeConstant(Global->getType(), false) &&
2386 !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
2387 return false;
2388
2389 return true;
2390 }
2391
GetAddrOfUuidDescriptor(const CXXUuidofExpr * E)2392 ConstantAddress CodeGenModule::GetAddrOfUuidDescriptor(
2393 const CXXUuidofExpr* E) {
2394 // Sema has verified that IIDSource has a __declspec(uuid()), and that its
2395 // well-formed.
2396 StringRef Uuid = E->getUuidStr();
2397 std::string Name = "_GUID_" + Uuid.lower();
2398 std::replace(Name.begin(), Name.end(), '-', '_');
2399
2400 // The UUID descriptor should be pointer aligned.
2401 CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
2402
2403 // Look for an existing global.
2404 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
2405 return ConstantAddress(GV, Alignment);
2406
2407 llvm::Constant *Init = EmitUuidofInitializer(Uuid);
2408 assert(Init && "failed to initialize as constant");
2409
2410 auto *GV = new llvm::GlobalVariable(
2411 getModule(), Init->getType(),
2412 /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
2413 if (supportsCOMDAT())
2414 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
2415 setDSOLocal(GV);
2416 return ConstantAddress(GV, Alignment);
2417 }
2418
GetWeakRefReference(const ValueDecl * VD)2419 ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
2420 const AliasAttr *AA = VD->getAttr<AliasAttr>();
2421 assert(AA && "No alias?");
2422
2423 CharUnits Alignment = getContext().getDeclAlign(VD);
2424 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
2425
2426 // See if there is already something with the target's name in the module.
2427 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
2428 if (Entry) {
2429 unsigned AS = getContext().getTargetAddressSpace(VD->getType());
2430 auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
2431 return ConstantAddress(Ptr, Alignment);
2432 }
2433
2434 llvm::Constant *Aliasee;
2435 if (isa<llvm::FunctionType>(DeclTy))
2436 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
2437 GlobalDecl(cast<FunctionDecl>(VD)),
2438 /*ForVTable=*/false);
2439 else
2440 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
2441 llvm::PointerType::getUnqual(DeclTy),
2442 nullptr);
2443
2444 auto *F = cast<llvm::GlobalValue>(Aliasee);
2445 F->setLinkage(llvm::Function::ExternalWeakLinkage);
2446 WeakRefReferences.insert(F);
2447
2448 return ConstantAddress(Aliasee, Alignment);
2449 }
2450
EmitGlobal(GlobalDecl GD)2451 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
2452 const auto *Global = cast<ValueDecl>(GD.getDecl());
2453
2454 // Weak references don't produce any output by themselves.
2455 if (Global->hasAttr<WeakRefAttr>())
2456 return;
2457
2458 // If this is an alias definition (which otherwise looks like a declaration)
2459 // emit it now.
2460 if (Global->hasAttr<AliasAttr>())
2461 return EmitAliasDefinition(GD);
2462
2463 // IFunc like an alias whose value is resolved at runtime by calling resolver.
2464 if (Global->hasAttr<IFuncAttr>())
2465 return emitIFuncDefinition(GD);
2466
2467 // If this is a cpu_dispatch multiversion function, emit the resolver.
2468 if (Global->hasAttr<CPUDispatchAttr>())
2469 return emitCPUDispatchDefinition(GD);
2470
2471 // If this is CUDA, be selective about which declarations we emit.
2472 if (LangOpts.CUDA) {
2473 if (LangOpts.CUDAIsDevice) {
2474 if (!Global->hasAttr<CUDADeviceAttr>() &&
2475 !Global->hasAttr<CUDAGlobalAttr>() &&
2476 !Global->hasAttr<CUDAConstantAttr>() &&
2477 !Global->hasAttr<CUDASharedAttr>() &&
2478 !(LangOpts.HIP && Global->hasAttr<HIPPinnedShadowAttr>()))
2479 return;
2480 } else {
2481 // We need to emit host-side 'shadows' for all global
2482 // device-side variables because the CUDA runtime needs their
2483 // size and host-side address in order to provide access to
2484 // their device-side incarnations.
2485
2486 // So device-only functions are the only things we skip.
2487 if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
2488 Global->hasAttr<CUDADeviceAttr>())
2489 return;
2490
2491 assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
2492 "Expected Variable or Function");
2493 }
2494 }
2495
2496 if (LangOpts.OpenMP) {
2497 // If this is OpenMP, check if it is legal to emit this global normally.
2498 if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
2499 return;
2500 if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
2501 if (MustBeEmitted(Global))
2502 EmitOMPDeclareReduction(DRD);
2503 return;
2504 } else if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) {
2505 if (MustBeEmitted(Global))
2506 EmitOMPDeclareMapper(DMD);
2507 return;
2508 }
2509 }
2510
2511 // Ignore declarations, they will be emitted on their first use.
2512 if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
2513 // Forward declarations are emitted lazily on first use.
2514 if (!FD->doesThisDeclarationHaveABody()) {
2515 if (!FD->doesDeclarationForceExternallyVisibleDefinition())
2516 return;
2517
2518 StringRef MangledName = getMangledName(GD);
2519
2520 // Compute the function info and LLVM type.
2521 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
2522 llvm::Type *Ty = getTypes().GetFunctionType(FI);
2523
2524 GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
2525 /*DontDefer=*/false);
2526 return;
2527 }
2528 } else {
2529 const auto *VD = cast<VarDecl>(Global);
2530 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
2531 if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
2532 !Context.isMSStaticDataMemberInlineDefinition(VD)) {
2533 if (LangOpts.OpenMP) {
2534 // Emit declaration of the must-be-emitted declare target variable.
2535 if (llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
2536 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
2537 bool UnifiedMemoryEnabled =
2538 getOpenMPRuntime().hasRequiresUnifiedSharedMemory();
2539 if (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2540 !UnifiedMemoryEnabled) {
2541 (void)GetAddrOfGlobalVar(VD);
2542 } else {
2543 assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2544 (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2545 UnifiedMemoryEnabled)) &&
2546 "Link clause or to clause with unified memory expected.");
2547 (void)getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2548 }
2549
2550 return;
2551 }
2552 }
2553 // If this declaration may have caused an inline variable definition to
2554 // change linkage, make sure that it's emitted.
2555 if (Context.getInlineVariableDefinitionKind(VD) ==
2556 ASTContext::InlineVariableDefinitionKind::Strong)
2557 GetAddrOfGlobalVar(VD);
2558 return;
2559 }
2560 }
2561
2562 // Defer code generation to first use when possible, e.g. if this is an inline
2563 // function. If the global must always be emitted, do it eagerly if possible
2564 // to benefit from cache locality.
2565 if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
2566 // Emit the definition if it can't be deferred.
2567 EmitGlobalDefinition(GD);
2568 return;
2569 }
2570
2571 // Check if this must be emitted as declare variant.
2572 if (LangOpts.OpenMP && isa<FunctionDecl>(Global) && OpenMPRuntime &&
2573 OpenMPRuntime->emitDeclareVariant(GD, /*IsForDefinition=*/false))
2574 return;
2575
2576 // If we're deferring emission of a C++ variable with an
2577 // initializer, remember the order in which it appeared in the file.
2578 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
2579 cast<VarDecl>(Global)->hasInit()) {
2580 DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
2581 CXXGlobalInits.push_back(nullptr);
2582 }
2583
2584 StringRef MangledName = getMangledName(GD);
2585 if (GetGlobalValue(MangledName) != nullptr) {
2586 // The value has already been used and should therefore be emitted.
2587 addDeferredDeclToEmit(GD);
2588 } else if (MustBeEmitted(Global)) {
2589 // The value must be emitted, but cannot be emitted eagerly.
2590 assert(!MayBeEmittedEagerly(Global));
2591 addDeferredDeclToEmit(GD);
2592 } else {
2593 // Otherwise, remember that we saw a deferred decl with this name. The
2594 // first use of the mangled name will cause it to move into
2595 // DeferredDeclsToEmit.
2596 DeferredDecls[MangledName] = GD;
2597 }
2598 }
2599
2600 // Check if T is a class type with a destructor that's not dllimport.
HasNonDllImportDtor(QualType T)2601 static bool HasNonDllImportDtor(QualType T) {
2602 if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
2603 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
2604 if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
2605 return true;
2606
2607 return false;
2608 }
2609
2610 namespace {
2611 struct FunctionIsDirectlyRecursive
2612 : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> {
2613 const StringRef Name;
2614 const Builtin::Context &BI;
FunctionIsDirectlyRecursive__anonff7355e90611::FunctionIsDirectlyRecursive2615 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C)
2616 : Name(N), BI(C) {}
2617
VisitCallExpr__anonff7355e90611::FunctionIsDirectlyRecursive2618 bool VisitCallExpr(const CallExpr *E) {
2619 const FunctionDecl *FD = E->getDirectCallee();
2620 if (!FD)
2621 return false;
2622 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
2623 if (Attr && Name == Attr->getLabel())
2624 return true;
2625 unsigned BuiltinID = FD->getBuiltinID();
2626 if (!BuiltinID || !BI.isLibFunction(BuiltinID))
2627 return false;
2628 StringRef BuiltinName = BI.getName(BuiltinID);
2629 if (BuiltinName.startswith("__builtin_") &&
2630 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
2631 return true;
2632 }
2633 return false;
2634 }
2635
VisitStmt__anonff7355e90611::FunctionIsDirectlyRecursive2636 bool VisitStmt(const Stmt *S) {
2637 for (const Stmt *Child : S->children())
2638 if (Child && this->Visit(Child))
2639 return true;
2640 return false;
2641 }
2642 };
2643
2644 // Make sure we're not referencing non-imported vars or functions.
2645 struct DLLImportFunctionVisitor
2646 : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
2647 bool SafeToInline = true;
2648
shouldVisitImplicitCode__anonff7355e90611::DLLImportFunctionVisitor2649 bool shouldVisitImplicitCode() const { return true; }
2650
VisitVarDecl__anonff7355e90611::DLLImportFunctionVisitor2651 bool VisitVarDecl(VarDecl *VD) {
2652 if (VD->getTLSKind()) {
2653 // A thread-local variable cannot be imported.
2654 SafeToInline = false;
2655 return SafeToInline;
2656 }
2657
2658 // A variable definition might imply a destructor call.
2659 if (VD->isThisDeclarationADefinition())
2660 SafeToInline = !HasNonDllImportDtor(VD->getType());
2661
2662 return SafeToInline;
2663 }
2664
VisitCXXBindTemporaryExpr__anonff7355e90611::DLLImportFunctionVisitor2665 bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
2666 if (const auto *D = E->getTemporary()->getDestructor())
2667 SafeToInline = D->hasAttr<DLLImportAttr>();
2668 return SafeToInline;
2669 }
2670
VisitDeclRefExpr__anonff7355e90611::DLLImportFunctionVisitor2671 bool VisitDeclRefExpr(DeclRefExpr *E) {
2672 ValueDecl *VD = E->getDecl();
2673 if (isa<FunctionDecl>(VD))
2674 SafeToInline = VD->hasAttr<DLLImportAttr>();
2675 else if (VarDecl *V = dyn_cast<VarDecl>(VD))
2676 SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
2677 return SafeToInline;
2678 }
2679
VisitCXXConstructExpr__anonff7355e90611::DLLImportFunctionVisitor2680 bool VisitCXXConstructExpr(CXXConstructExpr *E) {
2681 SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
2682 return SafeToInline;
2683 }
2684
VisitCXXMemberCallExpr__anonff7355e90611::DLLImportFunctionVisitor2685 bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
2686 CXXMethodDecl *M = E->getMethodDecl();
2687 if (!M) {
2688 // Call through a pointer to member function. This is safe to inline.
2689 SafeToInline = true;
2690 } else {
2691 SafeToInline = M->hasAttr<DLLImportAttr>();
2692 }
2693 return SafeToInline;
2694 }
2695
VisitCXXDeleteExpr__anonff7355e90611::DLLImportFunctionVisitor2696 bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
2697 SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
2698 return SafeToInline;
2699 }
2700
VisitCXXNewExpr__anonff7355e90611::DLLImportFunctionVisitor2701 bool VisitCXXNewExpr(CXXNewExpr *E) {
2702 SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
2703 return SafeToInline;
2704 }
2705 };
2706 }
2707
2708 // isTriviallyRecursive - Check if this function calls another
2709 // decl that, because of the asm attribute or the other decl being a builtin,
2710 // ends up pointing to itself.
2711 bool
isTriviallyRecursive(const FunctionDecl * FD)2712 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
2713 StringRef Name;
2714 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
2715 // asm labels are a special kind of mangling we have to support.
2716 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
2717 if (!Attr)
2718 return false;
2719 Name = Attr->getLabel();
2720 } else {
2721 Name = FD->getName();
2722 }
2723
2724 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
2725 const Stmt *Body = FD->getBody();
2726 return Body ? Walker.Visit(Body) : false;
2727 }
2728
shouldEmitFunction(GlobalDecl GD)2729 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
2730 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
2731 return true;
2732 const auto *F = cast<FunctionDecl>(GD.getDecl());
2733 if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
2734 return false;
2735
2736 if (F->hasAttr<DLLImportAttr>()) {
2737 // Check whether it would be safe to inline this dllimport function.
2738 DLLImportFunctionVisitor Visitor;
2739 Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
2740 if (!Visitor.SafeToInline)
2741 return false;
2742
2743 if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
2744 // Implicit destructor invocations aren't captured in the AST, so the
2745 // check above can't see them. Check for them manually here.
2746 for (const Decl *Member : Dtor->getParent()->decls())
2747 if (isa<FieldDecl>(Member))
2748 if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
2749 return false;
2750 for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
2751 if (HasNonDllImportDtor(B.getType()))
2752 return false;
2753 }
2754 }
2755
2756 // PR9614. Avoid cases where the source code is lying to us. An available
2757 // externally function should have an equivalent function somewhere else,
2758 // but a function that calls itself is clearly not equivalent to the real
2759 // implementation.
2760 // This happens in glibc's btowc and in some configure checks.
2761 return !isTriviallyRecursive(F);
2762 }
2763
shouldOpportunisticallyEmitVTables()2764 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
2765 return CodeGenOpts.OptimizationLevel > 0;
2766 }
2767
EmitMultiVersionFunctionDefinition(GlobalDecl GD,llvm::GlobalValue * GV)2768 void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
2769 llvm::GlobalValue *GV) {
2770 const auto *FD = cast<FunctionDecl>(GD.getDecl());
2771
2772 if (FD->isCPUSpecificMultiVersion()) {
2773 auto *Spec = FD->getAttr<CPUSpecificAttr>();
2774 for (unsigned I = 0; I < Spec->cpus_size(); ++I)
2775 EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
2776 // Requires multiple emits.
2777 } else
2778 EmitGlobalFunctionDefinition(GD, GV);
2779 }
2780
emitOpenMPDeviceFunctionRedefinition(GlobalDecl OldGD,GlobalDecl NewGD,llvm::GlobalValue * GV)2781 void CodeGenModule::emitOpenMPDeviceFunctionRedefinition(
2782 GlobalDecl OldGD, GlobalDecl NewGD, llvm::GlobalValue *GV) {
2783 assert(getLangOpts().OpenMP && getLangOpts().OpenMPIsDevice &&
2784 OpenMPRuntime && "Expected OpenMP device mode.");
2785 const auto *D = cast<FunctionDecl>(OldGD.getDecl());
2786
2787 // Compute the function info and LLVM type.
2788 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(OldGD);
2789 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
2790
2791 // Get or create the prototype for the function.
2792 if (!GV || (GV->getType()->getElementType() != Ty)) {
2793 GV = cast<llvm::GlobalValue>(GetOrCreateLLVMFunction(
2794 getMangledName(OldGD), Ty, GlobalDecl(), /*ForVTable=*/false,
2795 /*DontDefer=*/true, /*IsThunk=*/false, llvm::AttributeList(),
2796 ForDefinition));
2797 SetFunctionAttributes(OldGD, cast<llvm::Function>(GV),
2798 /*IsIncompleteFunction=*/false,
2799 /*IsThunk=*/false);
2800 }
2801 // We need to set linkage and visibility on the function before
2802 // generating code for it because various parts of IR generation
2803 // want to propagate this information down (e.g. to local static
2804 // declarations).
2805 auto *Fn = cast<llvm::Function>(GV);
2806 setFunctionLinkage(OldGD, Fn);
2807
2808 // FIXME: this is redundant with part of
2809 // setFunctionDefinitionAttributes
2810 setGVProperties(Fn, OldGD);
2811
2812 MaybeHandleStaticInExternC(D, Fn);
2813
2814 maybeSetTrivialComdat(*D, *Fn);
2815
2816 CodeGenFunction(*this).GenerateCode(NewGD, Fn, FI);
2817
2818 setNonAliasAttributes(OldGD, Fn);
2819 SetLLVMFunctionAttributesForDefinition(D, Fn);
2820
2821 if (D->hasAttr<AnnotateAttr>())
2822 AddGlobalAnnotations(D, Fn);
2823 }
2824
EmitGlobalDefinition(GlobalDecl GD,llvm::GlobalValue * GV)2825 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
2826 const auto *D = cast<ValueDecl>(GD.getDecl());
2827
2828 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
2829 Context.getSourceManager(),
2830 "Generating code for declaration");
2831
2832 if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
2833 // At -O0, don't generate IR for functions with available_externally
2834 // linkage.
2835 if (!shouldEmitFunction(GD))
2836 return;
2837
2838 llvm::TimeTraceScope TimeScope("CodeGen Function", [&]() {
2839 std::string Name;
2840 llvm::raw_string_ostream OS(Name);
2841 FD->getNameForDiagnostic(OS, getContext().getPrintingPolicy(),
2842 /*Qualified=*/true);
2843 return Name;
2844 });
2845
2846 if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
2847 // Make sure to emit the definition(s) before we emit the thunks.
2848 // This is necessary for the generation of certain thunks.
2849 if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
2850 ABI->emitCXXStructor(GD);
2851 else if (FD->isMultiVersion())
2852 EmitMultiVersionFunctionDefinition(GD, GV);
2853 else
2854 EmitGlobalFunctionDefinition(GD, GV);
2855
2856 if (Method->isVirtual())
2857 getVTables().EmitThunks(GD);
2858
2859 return;
2860 }
2861
2862 if (FD->isMultiVersion())
2863 return EmitMultiVersionFunctionDefinition(GD, GV);
2864 return EmitGlobalFunctionDefinition(GD, GV);
2865 }
2866
2867 if (const auto *VD = dyn_cast<VarDecl>(D))
2868 return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
2869
2870 llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
2871 }
2872
2873 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
2874 llvm::Function *NewFn);
2875
2876 static unsigned
TargetMVPriority(const TargetInfo & TI,const CodeGenFunction::MultiVersionResolverOption & RO)2877 TargetMVPriority(const TargetInfo &TI,
2878 const CodeGenFunction::MultiVersionResolverOption &RO) {
2879 unsigned Priority = 0;
2880 for (StringRef Feat : RO.Conditions.Features)
2881 Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
2882
2883 if (!RO.Conditions.Architecture.empty())
2884 Priority = std::max(
2885 Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
2886 return Priority;
2887 }
2888
emitMultiVersionFunctions()2889 void CodeGenModule::emitMultiVersionFunctions() {
2890 for (GlobalDecl GD : MultiVersionFuncs) {
2891 SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
2892 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2893 getContext().forEachMultiversionedFunctionVersion(
2894 FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
2895 GlobalDecl CurGD{
2896 (CurFD->isDefined() ? CurFD->getDefinition() : CurFD)};
2897 StringRef MangledName = getMangledName(CurGD);
2898 llvm::Constant *Func = GetGlobalValue(MangledName);
2899 if (!Func) {
2900 if (CurFD->isDefined()) {
2901 EmitGlobalFunctionDefinition(CurGD, nullptr);
2902 Func = GetGlobalValue(MangledName);
2903 } else {
2904 const CGFunctionInfo &FI =
2905 getTypes().arrangeGlobalDeclaration(GD);
2906 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
2907 Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
2908 /*DontDefer=*/false, ForDefinition);
2909 }
2910 assert(Func && "This should have just been created");
2911 }
2912
2913 const auto *TA = CurFD->getAttr<TargetAttr>();
2914 llvm::SmallVector<StringRef, 8> Feats;
2915 TA->getAddedFeatures(Feats);
2916
2917 Options.emplace_back(cast<llvm::Function>(Func),
2918 TA->getArchitecture(), Feats);
2919 });
2920
2921 llvm::Function *ResolverFunc;
2922 const TargetInfo &TI = getTarget();
2923
2924 if (TI.supportsIFunc() || FD->isTargetMultiVersion()) {
2925 ResolverFunc = cast<llvm::Function>(
2926 GetGlobalValue((getMangledName(GD) + ".resolver").str()));
2927 ResolverFunc->setLinkage(llvm::Function::WeakODRLinkage);
2928 } else {
2929 ResolverFunc = cast<llvm::Function>(GetGlobalValue(getMangledName(GD)));
2930 }
2931
2932 if (supportsCOMDAT())
2933 ResolverFunc->setComdat(
2934 getModule().getOrInsertComdat(ResolverFunc->getName()));
2935
2936 llvm::stable_sort(
2937 Options, [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
2938 const CodeGenFunction::MultiVersionResolverOption &RHS) {
2939 return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
2940 });
2941 CodeGenFunction CGF(*this);
2942 CGF.EmitMultiVersionResolver(ResolverFunc, Options);
2943 }
2944 }
2945
emitCPUDispatchDefinition(GlobalDecl GD)2946 void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
2947 const auto *FD = cast<FunctionDecl>(GD.getDecl());
2948 assert(FD && "Not a FunctionDecl?");
2949 const auto *DD = FD->getAttr<CPUDispatchAttr>();
2950 assert(DD && "Not a cpu_dispatch Function?");
2951 llvm::Type *DeclTy = getTypes().ConvertType(FD->getType());
2952
2953 if (const auto *CXXFD = dyn_cast<CXXMethodDecl>(FD)) {
2954 const CGFunctionInfo &FInfo = getTypes().arrangeCXXMethodDeclaration(CXXFD);
2955 DeclTy = getTypes().GetFunctionType(FInfo);
2956 }
2957
2958 StringRef ResolverName = getMangledName(GD);
2959
2960 llvm::Type *ResolverType;
2961 GlobalDecl ResolverGD;
2962 if (getTarget().supportsIFunc())
2963 ResolverType = llvm::FunctionType::get(
2964 llvm::PointerType::get(DeclTy,
2965 Context.getTargetAddressSpace(FD->getType())),
2966 false);
2967 else {
2968 ResolverType = DeclTy;
2969 ResolverGD = GD;
2970 }
2971
2972 auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
2973 ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
2974 ResolverFunc->setLinkage(llvm::Function::WeakODRLinkage);
2975 if (supportsCOMDAT())
2976 ResolverFunc->setComdat(
2977 getModule().getOrInsertComdat(ResolverFunc->getName()));
2978
2979 SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
2980 const TargetInfo &Target = getTarget();
2981 unsigned Index = 0;
2982 for (const IdentifierInfo *II : DD->cpus()) {
2983 // Get the name of the target function so we can look it up/create it.
2984 std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
2985 getCPUSpecificMangling(*this, II->getName());
2986
2987 llvm::Constant *Func = GetGlobalValue(MangledName);
2988
2989 if (!Func) {
2990 GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
2991 if (ExistingDecl.getDecl() &&
2992 ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
2993 EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
2994 Func = GetGlobalValue(MangledName);
2995 } else {
2996 if (!ExistingDecl.getDecl())
2997 ExistingDecl = GD.getWithMultiVersionIndex(Index);
2998
2999 Func = GetOrCreateLLVMFunction(
3000 MangledName, DeclTy, ExistingDecl,
3001 /*ForVTable=*/false, /*DontDefer=*/true,
3002 /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
3003 }
3004 }
3005
3006 llvm::SmallVector<StringRef, 32> Features;
3007 Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
3008 llvm::transform(Features, Features.begin(),
3009 [](StringRef Str) { return Str.substr(1); });
3010 Features.erase(std::remove_if(
3011 Features.begin(), Features.end(), [&Target](StringRef Feat) {
3012 return !Target.validateCpuSupports(Feat);
3013 }), Features.end());
3014 Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
3015 ++Index;
3016 }
3017
3018 llvm::sort(
3019 Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
3020 const CodeGenFunction::MultiVersionResolverOption &RHS) {
3021 return CodeGenFunction::GetX86CpuSupportsMask(LHS.Conditions.Features) >
3022 CodeGenFunction::GetX86CpuSupportsMask(RHS.Conditions.Features);
3023 });
3024
3025 // If the list contains multiple 'default' versions, such as when it contains
3026 // 'pentium' and 'generic', don't emit the call to the generic one (since we
3027 // always run on at least a 'pentium'). We do this by deleting the 'least
3028 // advanced' (read, lowest mangling letter).
3029 while (Options.size() > 1 &&
3030 CodeGenFunction::GetX86CpuSupportsMask(
3031 (Options.end() - 2)->Conditions.Features) == 0) {
3032 StringRef LHSName = (Options.end() - 2)->Function->getName();
3033 StringRef RHSName = (Options.end() - 1)->Function->getName();
3034 if (LHSName.compare(RHSName) < 0)
3035 Options.erase(Options.end() - 2);
3036 else
3037 Options.erase(Options.end() - 1);
3038 }
3039
3040 CodeGenFunction CGF(*this);
3041 CGF.EmitMultiVersionResolver(ResolverFunc, Options);
3042
3043 if (getTarget().supportsIFunc()) {
3044 std::string AliasName = getMangledNameImpl(
3045 *this, GD, FD, /*OmitMultiVersionMangling=*/true);
3046 llvm::Constant *AliasFunc = GetGlobalValue(AliasName);
3047 if (!AliasFunc) {
3048 auto *IFunc = cast<llvm::GlobalIFunc>(GetOrCreateLLVMFunction(
3049 AliasName, DeclTy, GD, /*ForVTable=*/false, /*DontDefer=*/true,
3050 /*IsThunk=*/false, llvm::AttributeList(), NotForDefinition));
3051 auto *GA = llvm::GlobalAlias::create(
3052 DeclTy, 0, getFunctionLinkage(GD), AliasName, IFunc, &getModule());
3053 GA->setLinkage(llvm::Function::WeakODRLinkage);
3054 SetCommonAttributes(GD, GA);
3055 }
3056 }
3057 }
3058
3059 /// If a dispatcher for the specified mangled name is not in the module, create
3060 /// and return an llvm Function with the specified type.
GetOrCreateMultiVersionResolver(GlobalDecl GD,llvm::Type * DeclTy,const FunctionDecl * FD)3061 llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(
3062 GlobalDecl GD, llvm::Type *DeclTy, const FunctionDecl *FD) {
3063 std::string MangledName =
3064 getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
3065
3066 // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
3067 // a separate resolver).
3068 std::string ResolverName = MangledName;
3069 if (getTarget().supportsIFunc())
3070 ResolverName += ".ifunc";
3071 else if (FD->isTargetMultiVersion())
3072 ResolverName += ".resolver";
3073
3074 // If this already exists, just return that one.
3075 if (llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName))
3076 return ResolverGV;
3077
3078 // Since this is the first time we've created this IFunc, make sure
3079 // that we put this multiversioned function into the list to be
3080 // replaced later if necessary (target multiversioning only).
3081 if (!FD->isCPUDispatchMultiVersion() && !FD->isCPUSpecificMultiVersion())
3082 MultiVersionFuncs.push_back(GD);
3083
3084 if (getTarget().supportsIFunc()) {
3085 llvm::Type *ResolverType = llvm::FunctionType::get(
3086 llvm::PointerType::get(
3087 DeclTy, getContext().getTargetAddressSpace(FD->getType())),
3088 false);
3089 llvm::Constant *Resolver = GetOrCreateLLVMFunction(
3090 MangledName + ".resolver", ResolverType, GlobalDecl{},
3091 /*ForVTable=*/false);
3092 llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
3093 DeclTy, 0, llvm::Function::WeakODRLinkage, "", Resolver, &getModule());
3094 GIF->setName(ResolverName);
3095 SetCommonAttributes(FD, GIF);
3096
3097 return GIF;
3098 }
3099
3100 llvm::Constant *Resolver = GetOrCreateLLVMFunction(
3101 ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
3102 assert(isa<llvm::GlobalValue>(Resolver) &&
3103 "Resolver should be created for the first time");
3104 SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
3105 return Resolver;
3106 }
3107
3108 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
3109 /// module, create and return an llvm Function with the specified type. If there
3110 /// is something in the module with the specified name, return it potentially
3111 /// bitcasted to the right type.
3112 ///
3113 /// If D is non-null, it specifies a decl that correspond to this. This is used
3114 /// 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)3115 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
3116 StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
3117 bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
3118 ForDefinition_t IsForDefinition) {
3119 const Decl *D = GD.getDecl();
3120
3121 // Any attempts to use a MultiVersion function should result in retrieving
3122 // the iFunc instead. Name Mangling will handle the rest of the changes.
3123 if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
3124 // For the device mark the function as one that should be emitted.
3125 if (getLangOpts().OpenMPIsDevice && OpenMPRuntime &&
3126 !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
3127 !DontDefer && !IsForDefinition) {
3128 if (const FunctionDecl *FDDef = FD->getDefinition()) {
3129 GlobalDecl GDDef;
3130 if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
3131 GDDef = GlobalDecl(CD, GD.getCtorType());
3132 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
3133 GDDef = GlobalDecl(DD, GD.getDtorType());
3134 else
3135 GDDef = GlobalDecl(FDDef);
3136 EmitGlobal(GDDef);
3137 }
3138 }
3139 // Check if this must be emitted as declare variant and emit reference to
3140 // the the declare variant function.
3141 if (LangOpts.OpenMP && OpenMPRuntime)
3142 (void)OpenMPRuntime->emitDeclareVariant(GD, /*IsForDefinition=*/true);
3143
3144 if (FD->isMultiVersion()) {
3145 const auto *TA = FD->getAttr<TargetAttr>();
3146 if (TA && TA->isDefaultVersion())
3147 UpdateMultiVersionNames(GD, FD);
3148 if (!IsForDefinition)
3149 return GetOrCreateMultiVersionResolver(GD, Ty, FD);
3150 }
3151 }
3152
3153 // Lookup the entry, lazily creating it if necessary.
3154 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3155 if (Entry) {
3156 if (WeakRefReferences.erase(Entry)) {
3157 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
3158 if (FD && !FD->hasAttr<WeakAttr>())
3159 Entry->setLinkage(llvm::Function::ExternalLinkage);
3160 }
3161
3162 // Handle dropped DLL attributes.
3163 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>()) {
3164 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3165 setDSOLocal(Entry);
3166 }
3167
3168 // If there are two attempts to define the same mangled name, issue an
3169 // error.
3170 if (IsForDefinition && !Entry->isDeclaration()) {
3171 GlobalDecl OtherGD;
3172 // Check that GD is not yet in DiagnosedConflictingDefinitions is required
3173 // to make sure that we issue an error only once.
3174 if (lookupRepresentativeDecl(MangledName, OtherGD) &&
3175 (GD.getCanonicalDecl().getDecl() !=
3176 OtherGD.getCanonicalDecl().getDecl()) &&
3177 DiagnosedConflictingDefinitions.insert(GD).second) {
3178 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3179 << MangledName;
3180 getDiags().Report(OtherGD.getDecl()->getLocation(),
3181 diag::note_previous_definition);
3182 }
3183 }
3184
3185 if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
3186 (Entry->getType()->getElementType() == Ty)) {
3187 return Entry;
3188 }
3189
3190 // Make sure the result is of the correct type.
3191 // (If function is requested for a definition, we always need to create a new
3192 // function, not just return a bitcast.)
3193 if (!IsForDefinition)
3194 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
3195 }
3196
3197 // This function doesn't have a complete type (for example, the return
3198 // type is an incomplete struct). Use a fake type instead, and make
3199 // sure not to try to set attributes.
3200 bool IsIncompleteFunction = false;
3201
3202 llvm::FunctionType *FTy;
3203 if (isa<llvm::FunctionType>(Ty)) {
3204 FTy = cast<llvm::FunctionType>(Ty);
3205 } else {
3206 FTy = llvm::FunctionType::get(VoidTy, false);
3207 IsIncompleteFunction = true;
3208 }
3209
3210 llvm::Function *F =
3211 llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
3212 Entry ? StringRef() : MangledName, &getModule());
3213
3214 // If we already created a function with the same mangled name (but different
3215 // type) before, take its name and add it to the list of functions to be
3216 // replaced with F at the end of CodeGen.
3217 //
3218 // This happens if there is a prototype for a function (e.g. "int f()") and
3219 // then a definition of a different type (e.g. "int f(int x)").
3220 if (Entry) {
3221 F->takeName(Entry);
3222
3223 // This might be an implementation of a function without a prototype, in
3224 // which case, try to do special replacement of calls which match the new
3225 // prototype. The really key thing here is that we also potentially drop
3226 // arguments from the call site so as to make a direct call, which makes the
3227 // inliner happier and suppresses a number of optimizer warnings (!) about
3228 // dropping arguments.
3229 if (!Entry->use_empty()) {
3230 ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
3231 Entry->removeDeadConstantUsers();
3232 }
3233
3234 llvm::Constant *BC = llvm::ConstantExpr::getBitCast(
3235 F, Entry->getType()->getElementType()->getPointerTo());
3236 addGlobalValReplacement(Entry, BC);
3237 }
3238
3239 assert(F->getName() == MangledName && "name was uniqued!");
3240 if (D)
3241 SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
3242 if (ExtraAttrs.hasAttributes(llvm::AttributeList::FunctionIndex)) {
3243 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex);
3244 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
3245 }
3246
3247 if (!DontDefer) {
3248 // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
3249 // each other bottoming out with the base dtor. Therefore we emit non-base
3250 // dtors on usage, even if there is no dtor definition in the TU.
3251 if (D && isa<CXXDestructorDecl>(D) &&
3252 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
3253 GD.getDtorType()))
3254 addDeferredDeclToEmit(GD);
3255
3256 // This is the first use or definition of a mangled name. If there is a
3257 // deferred decl with this name, remember that we need to emit it at the end
3258 // of the file.
3259 auto DDI = DeferredDecls.find(MangledName);
3260 if (DDI != DeferredDecls.end()) {
3261 // Move the potentially referenced deferred decl to the
3262 // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
3263 // don't need it anymore).
3264 addDeferredDeclToEmit(DDI->second);
3265 DeferredDecls.erase(DDI);
3266
3267 // Otherwise, there are cases we have to worry about where we're
3268 // using a declaration for which we must emit a definition but where
3269 // we might not find a top-level definition:
3270 // - member functions defined inline in their classes
3271 // - friend functions defined inline in some class
3272 // - special member functions with implicit definitions
3273 // If we ever change our AST traversal to walk into class methods,
3274 // this will be unnecessary.
3275 //
3276 // We also don't emit a definition for a function if it's going to be an
3277 // entry in a vtable, unless it's already marked as used.
3278 } else if (getLangOpts().CPlusPlus && D) {
3279 // Look for a declaration that's lexically in a record.
3280 for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
3281 FD = FD->getPreviousDecl()) {
3282 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
3283 if (FD->doesThisDeclarationHaveABody()) {
3284 addDeferredDeclToEmit(GD.getWithDecl(FD));
3285 break;
3286 }
3287 }
3288 }
3289 }
3290 }
3291
3292 // Make sure the result is of the requested type.
3293 if (!IsIncompleteFunction) {
3294 assert(F->getType()->getElementType() == Ty);
3295 return F;
3296 }
3297
3298 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
3299 return llvm::ConstantExpr::getBitCast(F, PTy);
3300 }
3301
3302 /// GetAddrOfFunction - Return the address of the given function. If Ty is
3303 /// non-null, then this function will use the specified type if it has to
3304 /// create it (this occurs when we see a definition of the function).
GetAddrOfFunction(GlobalDecl GD,llvm::Type * Ty,bool ForVTable,bool DontDefer,ForDefinition_t IsForDefinition)3305 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
3306 llvm::Type *Ty,
3307 bool ForVTable,
3308 bool DontDefer,
3309 ForDefinition_t IsForDefinition) {
3310 // If there was no specific requested type, just convert it now.
3311 if (!Ty) {
3312 const auto *FD = cast<FunctionDecl>(GD.getDecl());
3313 Ty = getTypes().ConvertType(FD->getType());
3314 }
3315
3316 // Devirtualized destructor calls may come through here instead of via
3317 // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
3318 // of the complete destructor when necessary.
3319 if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
3320 if (getTarget().getCXXABI().isMicrosoft() &&
3321 GD.getDtorType() == Dtor_Complete &&
3322 DD->getParent()->getNumVBases() == 0)
3323 GD = GlobalDecl(DD, Dtor_Base);
3324 }
3325
3326 StringRef MangledName = getMangledName(GD);
3327 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
3328 /*IsThunk=*/false, llvm::AttributeList(),
3329 IsForDefinition);
3330 }
3331
3332 static const FunctionDecl *
GetRuntimeFunctionDecl(ASTContext & C,StringRef Name)3333 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
3334 TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
3335 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
3336
3337 IdentifierInfo &CII = C.Idents.get(Name);
3338 for (const auto &Result : DC->lookup(&CII))
3339 if (const auto FD = dyn_cast<FunctionDecl>(Result))
3340 return FD;
3341
3342 if (!C.getLangOpts().CPlusPlus)
3343 return nullptr;
3344
3345 // Demangle the premangled name from getTerminateFn()
3346 IdentifierInfo &CXXII =
3347 (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
3348 ? C.Idents.get("terminate")
3349 : C.Idents.get(Name);
3350
3351 for (const auto &N : {"__cxxabiv1", "std"}) {
3352 IdentifierInfo &NS = C.Idents.get(N);
3353 for (const auto &Result : DC->lookup(&NS)) {
3354 NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
3355 if (auto LSD = dyn_cast<LinkageSpecDecl>(Result))
3356 for (const auto &Result : LSD->lookup(&NS))
3357 if ((ND = dyn_cast<NamespaceDecl>(Result)))
3358 break;
3359
3360 if (ND)
3361 for (const auto &Result : ND->lookup(&CXXII))
3362 if (const auto *FD = dyn_cast<FunctionDecl>(Result))
3363 return FD;
3364 }
3365 }
3366
3367 return nullptr;
3368 }
3369
3370 /// CreateRuntimeFunction - Create a new runtime function with the specified
3371 /// type and name.
3372 llvm::FunctionCallee
CreateRuntimeFunction(llvm::FunctionType * FTy,StringRef Name,llvm::AttributeList ExtraAttrs,bool Local,bool AssumeConvergent)3373 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
3374 llvm::AttributeList ExtraAttrs, bool Local,
3375 bool AssumeConvergent) {
3376 if (AssumeConvergent) {
3377 ExtraAttrs =
3378 ExtraAttrs.addAttribute(VMContext, llvm::AttributeList::FunctionIndex,
3379 llvm::Attribute::Convergent);
3380 }
3381
3382 llvm::Constant *C =
3383 GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
3384 /*DontDefer=*/false, /*IsThunk=*/false,
3385 ExtraAttrs);
3386
3387 if (auto *F = dyn_cast<llvm::Function>(C)) {
3388 if (F->empty()) {
3389 F->setCallingConv(getRuntimeCC());
3390
3391 // In Windows Itanium environments, try to mark runtime functions
3392 // dllimport. For Mingw and MSVC, don't. We don't really know if the user
3393 // will link their standard library statically or dynamically. Marking
3394 // functions imported when they are not imported can cause linker errors
3395 // and warnings.
3396 if (!Local && getTriple().isWindowsItaniumEnvironment() &&
3397 !getCodeGenOpts().LTOVisibilityPublicStd) {
3398 const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
3399 if (!FD || FD->hasAttr<DLLImportAttr>()) {
3400 F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
3401 F->setLinkage(llvm::GlobalValue::ExternalLinkage);
3402 }
3403 }
3404 setDSOLocal(F);
3405 }
3406 }
3407
3408 return {FTy, C};
3409 }
3410
3411 /// isTypeConstant - Determine whether an object of this type can be emitted
3412 /// as a constant.
3413 ///
3414 /// If ExcludeCtor is true, the duration when the object's constructor runs
3415 /// will not be considered. The caller will need to verify that the object is
3416 /// not written to during its construction.
isTypeConstant(QualType Ty,bool ExcludeCtor)3417 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
3418 if (!Ty.isConstant(Context) && !Ty->isReferenceType())
3419 return false;
3420
3421 if (Context.getLangOpts().CPlusPlus) {
3422 if (const CXXRecordDecl *Record
3423 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
3424 return ExcludeCtor && !Record->hasMutableFields() &&
3425 Record->hasTrivialDestructor();
3426 }
3427
3428 return true;
3429 }
3430
3431 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
3432 /// create and return an llvm GlobalVariable with the specified type. If there
3433 /// is something in the module with the specified name, return it potentially
3434 /// bitcasted to the right type.
3435 ///
3436 /// If D is non-null, it specifies a decl that correspond to this. This is used
3437 /// to set the attributes on the global when it is first created.
3438 ///
3439 /// If IsForDefinition is true, it is guaranteed that an actual global with
3440 /// type Ty will be returned, not conversion of a variable with the same
3441 /// mangled name but some other type.
3442 llvm::Constant *
GetOrCreateLLVMGlobal(StringRef MangledName,llvm::PointerType * Ty,const VarDecl * D,ForDefinition_t IsForDefinition)3443 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
3444 llvm::PointerType *Ty,
3445 const VarDecl *D,
3446 ForDefinition_t IsForDefinition) {
3447 // Lookup the entry, lazily creating it if necessary.
3448 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3449 if (Entry) {
3450 if (WeakRefReferences.erase(Entry)) {
3451 if (D && !D->hasAttr<WeakAttr>())
3452 Entry->setLinkage(llvm::Function::ExternalLinkage);
3453 }
3454
3455 // Handle dropped DLL attributes.
3456 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
3457 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3458
3459 if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
3460 getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
3461
3462 if (Entry->getType() == Ty)
3463 return Entry;
3464
3465 // If there are two attempts to define the same mangled name, issue an
3466 // error.
3467 if (IsForDefinition && !Entry->isDeclaration()) {
3468 GlobalDecl OtherGD;
3469 const VarDecl *OtherD;
3470
3471 // Check that D is not yet in DiagnosedConflictingDefinitions is required
3472 // to make sure that we issue an error only once.
3473 if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
3474 (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
3475 (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
3476 OtherD->hasInit() &&
3477 DiagnosedConflictingDefinitions.insert(D).second) {
3478 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3479 << MangledName;
3480 getDiags().Report(OtherGD.getDecl()->getLocation(),
3481 diag::note_previous_definition);
3482 }
3483 }
3484
3485 // Make sure the result is of the correct type.
3486 if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace())
3487 return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty);
3488
3489 // (If global is requested for a definition, we always need to create a new
3490 // global, not just return a bitcast.)
3491 if (!IsForDefinition)
3492 return llvm::ConstantExpr::getBitCast(Entry, Ty);
3493 }
3494
3495 auto AddrSpace = GetGlobalVarAddressSpace(D);
3496 auto TargetAddrSpace = getContext().getTargetAddressSpace(AddrSpace);
3497
3498 auto *GV = new llvm::GlobalVariable(
3499 getModule(), Ty->getElementType(), false,
3500 llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr,
3501 llvm::GlobalVariable::NotThreadLocal, TargetAddrSpace);
3502
3503 // If we already created a global with the same mangled name (but different
3504 // type) before, take its name and remove it from its parent.
3505 if (Entry) {
3506 GV->takeName(Entry);
3507
3508 if (!Entry->use_empty()) {
3509 llvm::Constant *NewPtrForOldDecl =
3510 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
3511 Entry->replaceAllUsesWith(NewPtrForOldDecl);
3512 }
3513
3514 Entry->eraseFromParent();
3515 }
3516
3517 // This is the first use or definition of a mangled name. If there is a
3518 // deferred decl with this name, remember that we need to emit it at the end
3519 // of the file.
3520 auto DDI = DeferredDecls.find(MangledName);
3521 if (DDI != DeferredDecls.end()) {
3522 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
3523 // list, and remove it from DeferredDecls (since we don't need it anymore).
3524 addDeferredDeclToEmit(DDI->second);
3525 DeferredDecls.erase(DDI);
3526 }
3527
3528 // Handle things which are present even on external declarations.
3529 if (D) {
3530 if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
3531 getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
3532
3533 // FIXME: This code is overly simple and should be merged with other global
3534 // handling.
3535 GV->setConstant(isTypeConstant(D->getType(), false));
3536
3537 GV->setAlignment(getContext().getDeclAlign(D).getAsAlign());
3538
3539 setLinkageForGV(GV, D);
3540
3541 if (D->getTLSKind()) {
3542 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
3543 CXXThreadLocals.push_back(D);
3544 setTLSMode(GV, *D);
3545 }
3546
3547 setGVProperties(GV, D);
3548
3549 // If required by the ABI, treat declarations of static data members with
3550 // inline initializers as definitions.
3551 if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
3552 EmitGlobalVarDefinition(D);
3553 }
3554
3555 // Emit section information for extern variables.
3556 if (D->hasExternalStorage()) {
3557 if (const SectionAttr *SA = D->getAttr<SectionAttr>())
3558 GV->setSection(SA->getName());
3559 }
3560
3561 // Handle XCore specific ABI requirements.
3562 if (getTriple().getArch() == llvm::Triple::xcore &&
3563 D->getLanguageLinkage() == CLanguageLinkage &&
3564 D->getType().isConstant(Context) &&
3565 isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
3566 GV->setSection(".cp.rodata");
3567
3568 // Check if we a have a const declaration with an initializer, we may be
3569 // able to emit it as available_externally to expose it's value to the
3570 // optimizer.
3571 if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
3572 D->getType().isConstQualified() && !GV->hasInitializer() &&
3573 !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
3574 const auto *Record =
3575 Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
3576 bool HasMutableFields = Record && Record->hasMutableFields();
3577 if (!HasMutableFields) {
3578 const VarDecl *InitDecl;
3579 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
3580 if (InitExpr) {
3581 ConstantEmitter emitter(*this);
3582 llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
3583 if (Init) {
3584 auto *InitType = Init->getType();
3585 if (GV->getType()->getElementType() != InitType) {
3586 // The type of the initializer does not match the definition.
3587 // This happens when an initializer has a different type from
3588 // the type of the global (because of padding at the end of a
3589 // structure for instance).
3590 GV->setName(StringRef());
3591 // Make a new global with the correct type, this is now guaranteed
3592 // to work.
3593 auto *NewGV = cast<llvm::GlobalVariable>(
3594 GetAddrOfGlobalVar(D, InitType, IsForDefinition)
3595 ->stripPointerCasts());
3596
3597 // Erase the old global, since it is no longer used.
3598 GV->eraseFromParent();
3599 GV = NewGV;
3600 } else {
3601 GV->setInitializer(Init);
3602 GV->setConstant(true);
3603 GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
3604 }
3605 emitter.finalize(GV);
3606 }
3607 }
3608 }
3609 }
3610 }
3611
3612 if (GV->isDeclaration())
3613 getTargetCodeGenInfo().setTargetAttributes(D, GV, *this);
3614
3615 LangAS ExpectedAS =
3616 D ? D->getType().getAddressSpace()
3617 : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
3618 assert(getContext().getTargetAddressSpace(ExpectedAS) ==
3619 Ty->getPointerAddressSpace());
3620 if (AddrSpace != ExpectedAS)
3621 return getTargetCodeGenInfo().performAddrSpaceCast(*this, GV, AddrSpace,
3622 ExpectedAS, Ty);
3623
3624 return GV;
3625 }
3626
3627 llvm::Constant *
GetAddrOfGlobal(GlobalDecl GD,ForDefinition_t IsForDefinition)3628 CodeGenModule::GetAddrOfGlobal(GlobalDecl GD,
3629 ForDefinition_t IsForDefinition) {
3630 const Decl *D = GD.getDecl();
3631 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
3632 return getAddrOfCXXStructor(GD, /*FnInfo=*/nullptr, /*FnType=*/nullptr,
3633 /*DontDefer=*/false, IsForDefinition);
3634 else if (isa<CXXMethodDecl>(D)) {
3635 auto FInfo = &getTypes().arrangeCXXMethodDeclaration(
3636 cast<CXXMethodDecl>(D));
3637 auto Ty = getTypes().GetFunctionType(*FInfo);
3638 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
3639 IsForDefinition);
3640 } else if (isa<FunctionDecl>(D)) {
3641 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
3642 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
3643 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
3644 IsForDefinition);
3645 } else
3646 return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr,
3647 IsForDefinition);
3648 }
3649
CreateOrReplaceCXXRuntimeVariable(StringRef Name,llvm::Type * Ty,llvm::GlobalValue::LinkageTypes Linkage,unsigned Alignment)3650 llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
3651 StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
3652 unsigned Alignment) {
3653 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
3654 llvm::GlobalVariable *OldGV = nullptr;
3655
3656 if (GV) {
3657 // Check if the variable has the right type.
3658 if (GV->getType()->getElementType() == Ty)
3659 return GV;
3660
3661 // Because C++ name mangling, the only way we can end up with an already
3662 // existing global with the same name is if it has been declared extern "C".
3663 assert(GV->isDeclaration() && "Declaration has wrong type!");
3664 OldGV = GV;
3665 }
3666
3667 // Create a new variable.
3668 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
3669 Linkage, nullptr, Name);
3670
3671 if (OldGV) {
3672 // Replace occurrences of the old variable if needed.
3673 GV->takeName(OldGV);
3674
3675 if (!OldGV->use_empty()) {
3676 llvm::Constant *NewPtrForOldDecl =
3677 llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
3678 OldGV->replaceAllUsesWith(NewPtrForOldDecl);
3679 }
3680
3681 OldGV->eraseFromParent();
3682 }
3683
3684 if (supportsCOMDAT() && GV->isWeakForLinker() &&
3685 !GV->hasAvailableExternallyLinkage())
3686 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3687
3688 GV->setAlignment(llvm::MaybeAlign(Alignment));
3689
3690 return GV;
3691 }
3692
3693 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
3694 /// given global variable. If Ty is non-null and if the global doesn't exist,
3695 /// then it will be created with the specified type instead of whatever the
3696 /// normal requested type would be. If IsForDefinition is true, it is guaranteed
3697 /// that an actual global with type Ty will be returned, not conversion of a
3698 /// variable with the same mangled name but some other type.
GetAddrOfGlobalVar(const VarDecl * D,llvm::Type * Ty,ForDefinition_t IsForDefinition)3699 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
3700 llvm::Type *Ty,
3701 ForDefinition_t IsForDefinition) {
3702 assert(D->hasGlobalStorage() && "Not a global variable");
3703 QualType ASTTy = D->getType();
3704 if (!Ty)
3705 Ty = getTypes().ConvertTypeForMem(ASTTy);
3706
3707 llvm::PointerType *PTy =
3708 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
3709
3710 StringRef MangledName = getMangledName(D);
3711 return GetOrCreateLLVMGlobal(MangledName, PTy, D, IsForDefinition);
3712 }
3713
3714 /// CreateRuntimeVariable - Create a new runtime global variable with the
3715 /// specified type and name.
3716 llvm::Constant *
CreateRuntimeVariable(llvm::Type * Ty,StringRef Name)3717 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
3718 StringRef Name) {
3719 auto PtrTy =
3720 getContext().getLangOpts().OpenCL
3721 ? llvm::PointerType::get(
3722 Ty, getContext().getTargetAddressSpace(LangAS::opencl_global))
3723 : llvm::PointerType::getUnqual(Ty);
3724 auto *Ret = GetOrCreateLLVMGlobal(Name, PtrTy, nullptr);
3725 setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
3726 return Ret;
3727 }
3728
EmitTentativeDefinition(const VarDecl * D)3729 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
3730 assert(!D->getInit() && "Cannot emit definite definitions here!");
3731
3732 StringRef MangledName = getMangledName(D);
3733 llvm::GlobalValue *GV = GetGlobalValue(MangledName);
3734
3735 // We already have a definition, not declaration, with the same mangled name.
3736 // Emitting of declaration is not required (and actually overwrites emitted
3737 // definition).
3738 if (GV && !GV->isDeclaration())
3739 return;
3740
3741 // If we have not seen a reference to this variable yet, place it into the
3742 // deferred declarations table to be emitted if needed later.
3743 if (!MustBeEmitted(D) && !GV) {
3744 DeferredDecls[MangledName] = D;
3745 return;
3746 }
3747
3748 // The tentative definition is the only definition.
3749 EmitGlobalVarDefinition(D);
3750 }
3751
EmitExternalDeclaration(const VarDecl * D)3752 void CodeGenModule::EmitExternalDeclaration(const VarDecl *D) {
3753 EmitExternalVarDeclaration(D);
3754 }
3755
GetTargetTypeStoreSize(llvm::Type * Ty) const3756 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
3757 return Context.toCharUnitsFromBits(
3758 getDataLayout().getTypeStoreSizeInBits(Ty));
3759 }
3760
GetGlobalVarAddressSpace(const VarDecl * D)3761 LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
3762 LangAS AddrSpace = LangAS::Default;
3763 if (LangOpts.OpenCL) {
3764 AddrSpace = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
3765 assert(AddrSpace == LangAS::opencl_global ||
3766 AddrSpace == LangAS::opencl_constant ||
3767 AddrSpace == LangAS::opencl_local ||
3768 AddrSpace >= LangAS::FirstTargetAddressSpace);
3769 return AddrSpace;
3770 }
3771
3772 if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
3773 if (D && D->hasAttr<CUDAConstantAttr>())
3774 return LangAS::cuda_constant;
3775 else if (D && D->hasAttr<CUDASharedAttr>())
3776 return LangAS::cuda_shared;
3777 else if (D && D->hasAttr<CUDADeviceAttr>())
3778 return LangAS::cuda_device;
3779 else if (D && D->getType().isConstQualified())
3780 return LangAS::cuda_constant;
3781 else
3782 return LangAS::cuda_device;
3783 }
3784
3785 if (LangOpts.OpenMP) {
3786 LangAS AS;
3787 if (OpenMPRuntime->hasAllocateAttributeForGlobalVar(D, AS))
3788 return AS;
3789 }
3790 return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
3791 }
3792
getStringLiteralAddressSpace() const3793 LangAS CodeGenModule::getStringLiteralAddressSpace() const {
3794 // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
3795 if (LangOpts.OpenCL)
3796 return LangAS::opencl_constant;
3797 if (auto AS = getTarget().getConstantAddressSpace())
3798 return AS.getValue();
3799 return LangAS::Default;
3800 }
3801
3802 // In address space agnostic languages, string literals are in default address
3803 // space in AST. However, certain targets (e.g. amdgcn) request them to be
3804 // emitted in constant address space in LLVM IR. To be consistent with other
3805 // parts of AST, string literal global variables in constant address space
3806 // need to be casted to default address space before being put into address
3807 // map and referenced by other part of CodeGen.
3808 // In OpenCL, string literals are in constant address space in AST, therefore
3809 // they should not be casted to default address space.
3810 static llvm::Constant *
castStringLiteralToDefaultAddressSpace(CodeGenModule & CGM,llvm::GlobalVariable * GV)3811 castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM,
3812 llvm::GlobalVariable *GV) {
3813 llvm::Constant *Cast = GV;
3814 if (!CGM.getLangOpts().OpenCL) {
3815 if (auto AS = CGM.getTarget().getConstantAddressSpace()) {
3816 if (AS != LangAS::Default)
3817 Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast(
3818 CGM, GV, AS.getValue(), LangAS::Default,
3819 GV->getValueType()->getPointerTo(
3820 CGM.getContext().getTargetAddressSpace(LangAS::Default)));
3821 }
3822 }
3823 return Cast;
3824 }
3825
3826 template<typename SomeDecl>
MaybeHandleStaticInExternC(const SomeDecl * D,llvm::GlobalValue * GV)3827 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
3828 llvm::GlobalValue *GV) {
3829 if (!getLangOpts().CPlusPlus)
3830 return;
3831
3832 // Must have 'used' attribute, or else inline assembly can't rely on
3833 // the name existing.
3834 if (!D->template hasAttr<UsedAttr>())
3835 return;
3836
3837 // Must have internal linkage and an ordinary name.
3838 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage)
3839 return;
3840
3841 // Must be in an extern "C" context. Entities declared directly within
3842 // a record are not extern "C" even if the record is in such a context.
3843 const SomeDecl *First = D->getFirstDecl();
3844 if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
3845 return;
3846
3847 // OK, this is an internal linkage entity inside an extern "C" linkage
3848 // specification. Make a note of that so we can give it the "expected"
3849 // mangled name if nothing else is using that name.
3850 std::pair<StaticExternCMap::iterator, bool> R =
3851 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
3852
3853 // If we have multiple internal linkage entities with the same name
3854 // in extern "C" regions, none of them gets that name.
3855 if (!R.second)
3856 R.first->second = nullptr;
3857 }
3858
shouldBeInCOMDAT(CodeGenModule & CGM,const Decl & D)3859 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
3860 if (!CGM.supportsCOMDAT())
3861 return false;
3862
3863 // Do not set COMDAT attribute for CUDA/HIP stub functions to prevent
3864 // them being "merged" by the COMDAT Folding linker optimization.
3865 if (D.hasAttr<CUDAGlobalAttr>())
3866 return false;
3867
3868 if (D.hasAttr<SelectAnyAttr>())
3869 return true;
3870
3871 GVALinkage Linkage;
3872 if (auto *VD = dyn_cast<VarDecl>(&D))
3873 Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
3874 else
3875 Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
3876
3877 switch (Linkage) {
3878 case GVA_Internal:
3879 case GVA_AvailableExternally:
3880 case GVA_StrongExternal:
3881 return false;
3882 case GVA_DiscardableODR:
3883 case GVA_StrongODR:
3884 return true;
3885 }
3886 llvm_unreachable("No such linkage");
3887 }
3888
maybeSetTrivialComdat(const Decl & D,llvm::GlobalObject & GO)3889 void CodeGenModule::maybeSetTrivialComdat(const Decl &D,
3890 llvm::GlobalObject &GO) {
3891 if (!shouldBeInCOMDAT(*this, D))
3892 return;
3893 GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
3894 }
3895
3896 /// Pass IsTentative as true if you want to create a tentative definition.
EmitGlobalVarDefinition(const VarDecl * D,bool IsTentative)3897 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
3898 bool IsTentative) {
3899 // OpenCL global variables of sampler type are translated to function calls,
3900 // therefore no need to be translated.
3901 QualType ASTTy = D->getType();
3902 if (getLangOpts().OpenCL && ASTTy->isSamplerT())
3903 return;
3904
3905 // If this is OpenMP device, check if it is legal to emit this global
3906 // normally.
3907 if (LangOpts.OpenMPIsDevice && OpenMPRuntime &&
3908 OpenMPRuntime->emitTargetGlobalVariable(D))
3909 return;
3910
3911 llvm::Constant *Init = nullptr;
3912 bool NeedsGlobalCtor = false;
3913 bool NeedsGlobalDtor =
3914 D->needsDestruction(getContext()) == QualType::DK_cxx_destructor;
3915
3916 const VarDecl *InitDecl;
3917 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
3918
3919 Optional<ConstantEmitter> emitter;
3920
3921 // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
3922 // as part of their declaration." Sema has already checked for
3923 // error cases, so we just need to set Init to UndefValue.
3924 bool IsCUDASharedVar =
3925 getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
3926 // Shadows of initialized device-side global variables are also left
3927 // undefined.
3928 bool IsCUDAShadowVar =
3929 !getLangOpts().CUDAIsDevice &&
3930 (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
3931 D->hasAttr<CUDASharedAttr>());
3932 // HIP pinned shadow of initialized host-side global variables are also
3933 // left undefined.
3934 bool IsHIPPinnedShadowVar =
3935 getLangOpts().CUDAIsDevice && D->hasAttr<HIPPinnedShadowAttr>();
3936 if (getLangOpts().CUDA &&
3937 (IsCUDASharedVar || IsCUDAShadowVar || IsHIPPinnedShadowVar))
3938 Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
3939 else if (!InitExpr) {
3940 // This is a tentative definition; tentative definitions are
3941 // implicitly initialized with { 0 }.
3942 //
3943 // Note that tentative definitions are only emitted at the end of
3944 // a translation unit, so they should never have incomplete
3945 // type. In addition, EmitTentativeDefinition makes sure that we
3946 // never attempt to emit a tentative definition if a real one
3947 // exists. A use may still exists, however, so we still may need
3948 // to do a RAUW.
3949 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
3950 Init = EmitNullConstant(D->getType());
3951 } else {
3952 initializedGlobalDecl = GlobalDecl(D);
3953 emitter.emplace(*this);
3954 Init = emitter->tryEmitForInitializer(*InitDecl);
3955
3956 if (!Init) {
3957 QualType T = InitExpr->getType();
3958 if (D->getType()->isReferenceType())
3959 T = D->getType();
3960
3961 if (getLangOpts().CPlusPlus) {
3962 Init = EmitNullConstant(T);
3963 NeedsGlobalCtor = true;
3964 } else {
3965 ErrorUnsupported(D, "static initializer");
3966 Init = llvm::UndefValue::get(getTypes().ConvertType(T));
3967 }
3968 } else {
3969 // We don't need an initializer, so remove the entry for the delayed
3970 // initializer position (just in case this entry was delayed) if we
3971 // also don't need to register a destructor.
3972 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
3973 DelayedCXXInitPosition.erase(D);
3974 }
3975 }
3976
3977 llvm::Type* InitType = Init->getType();
3978 llvm::Constant *Entry =
3979 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
3980
3981 // Strip off pointer casts if we got them.
3982 Entry = Entry->stripPointerCasts();
3983
3984 // Entry is now either a Function or GlobalVariable.
3985 auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
3986
3987 // We have a definition after a declaration with the wrong type.
3988 // We must make a new GlobalVariable* and update everything that used OldGV
3989 // (a declaration or tentative definition) with the new GlobalVariable*
3990 // (which will be a definition).
3991 //
3992 // This happens if there is a prototype for a global (e.g.
3993 // "extern int x[];") and then a definition of a different type (e.g.
3994 // "int x[10];"). This also happens when an initializer has a different type
3995 // from the type of the global (this happens with unions).
3996 if (!GV || GV->getType()->getElementType() != InitType ||
3997 GV->getType()->getAddressSpace() !=
3998 getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
3999
4000 // Move the old entry aside so that we'll create a new one.
4001 Entry->setName(StringRef());
4002
4003 // Make a new global with the correct type, this is now guaranteed to work.
4004 GV = cast<llvm::GlobalVariable>(
4005 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative))
4006 ->stripPointerCasts());
4007
4008 // Replace all uses of the old global with the new global
4009 llvm::Constant *NewPtrForOldDecl =
4010 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
4011 Entry->replaceAllUsesWith(NewPtrForOldDecl);
4012
4013 // Erase the old global, since it is no longer used.
4014 cast<llvm::GlobalValue>(Entry)->eraseFromParent();
4015 }
4016
4017 MaybeHandleStaticInExternC(D, GV);
4018
4019 if (D->hasAttr<AnnotateAttr>())
4020 AddGlobalAnnotations(D, GV);
4021
4022 // Set the llvm linkage type as appropriate.
4023 llvm::GlobalValue::LinkageTypes Linkage =
4024 getLLVMLinkageVarDefinition(D, GV->isConstant());
4025
4026 // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
4027 // the device. [...]"
4028 // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
4029 // __device__, declares a variable that: [...]
4030 // Is accessible from all the threads within the grid and from the host
4031 // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
4032 // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
4033 if (GV && LangOpts.CUDA) {
4034 if (LangOpts.CUDAIsDevice) {
4035 if (Linkage != llvm::GlobalValue::InternalLinkage &&
4036 (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()))
4037 GV->setExternallyInitialized(true);
4038 } else {
4039 // Host-side shadows of external declarations of device-side
4040 // global variables become internal definitions. These have to
4041 // be internal in order to prevent name conflicts with global
4042 // host variables with the same name in a different TUs.
4043 if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
4044 D->hasAttr<HIPPinnedShadowAttr>()) {
4045 Linkage = llvm::GlobalValue::InternalLinkage;
4046
4047 // Shadow variables and their properties must be registered
4048 // with CUDA runtime.
4049 unsigned Flags = 0;
4050 if (!D->hasDefinition())
4051 Flags |= CGCUDARuntime::ExternDeviceVar;
4052 if (D->hasAttr<CUDAConstantAttr>())
4053 Flags |= CGCUDARuntime::ConstantDeviceVar;
4054 // Extern global variables will be registered in the TU where they are
4055 // defined.
4056 if (!D->hasExternalStorage())
4057 getCUDARuntime().registerDeviceVar(D, *GV, Flags);
4058 } else if (D->hasAttr<CUDASharedAttr>())
4059 // __shared__ variables are odd. Shadows do get created, but
4060 // they are not registered with the CUDA runtime, so they
4061 // can't really be used to access their device-side
4062 // counterparts. It's not clear yet whether it's nvcc's bug or
4063 // a feature, but we've got to do the same for compatibility.
4064 Linkage = llvm::GlobalValue::InternalLinkage;
4065 }
4066 }
4067
4068 if (!IsHIPPinnedShadowVar)
4069 GV->setInitializer(Init);
4070 if (emitter) emitter->finalize(GV);
4071
4072 // If it is safe to mark the global 'constant', do so now.
4073 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
4074 isTypeConstant(D->getType(), true));
4075
4076 // If it is in a read-only section, mark it 'constant'.
4077 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
4078 const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
4079 if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
4080 GV->setConstant(true);
4081 }
4082
4083 GV->setAlignment(getContext().getDeclAlign(D).getAsAlign());
4084
4085 // On Darwin, if the normal linkage of a C++ thread_local variable is
4086 // LinkOnce or Weak, we keep the normal linkage to prevent multiple
4087 // copies within a linkage unit; otherwise, the backing variable has
4088 // internal linkage and all accesses should just be calls to the
4089 // Itanium-specified entry point, which has the normal linkage of the
4090 // variable. This is to preserve the ability to change the implementation
4091 // behind the scenes.
4092 if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic &&
4093 Context.getTargetInfo().getTriple().isOSDarwin() &&
4094 !llvm::GlobalVariable::isLinkOnceLinkage(Linkage) &&
4095 !llvm::GlobalVariable::isWeakLinkage(Linkage))
4096 Linkage = llvm::GlobalValue::InternalLinkage;
4097
4098 GV->setLinkage(Linkage);
4099 if (D->hasAttr<DLLImportAttr>())
4100 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
4101 else if (D->hasAttr<DLLExportAttr>())
4102 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
4103 else
4104 GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
4105
4106 if (Linkage == llvm::GlobalVariable::CommonLinkage) {
4107 // common vars aren't constant even if declared const.
4108 GV->setConstant(false);
4109 // Tentative definition of global variables may be initialized with
4110 // non-zero null pointers. In this case they should have weak linkage
4111 // since common linkage must have zero initializer and must not have
4112 // explicit section therefore cannot have non-zero initial value.
4113 if (!GV->getInitializer()->isNullValue())
4114 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
4115 }
4116
4117 setNonAliasAttributes(D, GV);
4118
4119 if (D->getTLSKind() && !GV->isThreadLocal()) {
4120 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
4121 CXXThreadLocals.push_back(D);
4122 setTLSMode(GV, *D);
4123 }
4124
4125 maybeSetTrivialComdat(*D, *GV);
4126
4127 // Emit the initializer function if necessary.
4128 if (NeedsGlobalCtor || NeedsGlobalDtor)
4129 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
4130
4131 SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor);
4132
4133 // Emit global variable debug information.
4134 if (CGDebugInfo *DI = getModuleDebugInfo())
4135 if (getCodeGenOpts().hasReducedDebugInfo())
4136 DI->EmitGlobalVariable(GV, D);
4137 }
4138
EmitExternalVarDeclaration(const VarDecl * D)4139 void CodeGenModule::EmitExternalVarDeclaration(const VarDecl *D) {
4140 if (CGDebugInfo *DI = getModuleDebugInfo())
4141 if (getCodeGenOpts().hasReducedDebugInfo()) {
4142 QualType ASTTy = D->getType();
4143 llvm::Type *Ty = getTypes().ConvertTypeForMem(D->getType());
4144 llvm::PointerType *PTy =
4145 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
4146 llvm::Constant *GV = GetOrCreateLLVMGlobal(D->getName(), PTy, D);
4147 DI->EmitExternalVariable(
4148 cast<llvm::GlobalVariable>(GV->stripPointerCasts()), D);
4149 }
4150 }
4151
isVarDeclStrongDefinition(const ASTContext & Context,CodeGenModule & CGM,const VarDecl * D,bool NoCommon)4152 static bool isVarDeclStrongDefinition(const ASTContext &Context,
4153 CodeGenModule &CGM, const VarDecl *D,
4154 bool NoCommon) {
4155 // Don't give variables common linkage if -fno-common was specified unless it
4156 // was overridden by a NoCommon attribute.
4157 if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
4158 return true;
4159
4160 // C11 6.9.2/2:
4161 // A declaration of an identifier for an object that has file scope without
4162 // an initializer, and without a storage-class specifier or with the
4163 // storage-class specifier static, constitutes a tentative definition.
4164 if (D->getInit() || D->hasExternalStorage())
4165 return true;
4166
4167 // A variable cannot be both common and exist in a section.
4168 if (D->hasAttr<SectionAttr>())
4169 return true;
4170
4171 // A variable cannot be both common and exist in a section.
4172 // We don't try to determine which is the right section in the front-end.
4173 // If no specialized section name is applicable, it will resort to default.
4174 if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
4175 D->hasAttr<PragmaClangDataSectionAttr>() ||
4176 D->hasAttr<PragmaClangRelroSectionAttr>() ||
4177 D->hasAttr<PragmaClangRodataSectionAttr>())
4178 return true;
4179
4180 // Thread local vars aren't considered common linkage.
4181 if (D->getTLSKind())
4182 return true;
4183
4184 // Tentative definitions marked with WeakImportAttr are true definitions.
4185 if (D->hasAttr<WeakImportAttr>())
4186 return true;
4187
4188 // A variable cannot be both common and exist in a comdat.
4189 if (shouldBeInCOMDAT(CGM, *D))
4190 return true;
4191
4192 // Declarations with a required alignment do not have common linkage in MSVC
4193 // mode.
4194 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
4195 if (D->hasAttr<AlignedAttr>())
4196 return true;
4197 QualType VarType = D->getType();
4198 if (Context.isAlignmentRequired(VarType))
4199 return true;
4200
4201 if (const auto *RT = VarType->getAs<RecordType>()) {
4202 const RecordDecl *RD = RT->getDecl();
4203 for (const FieldDecl *FD : RD->fields()) {
4204 if (FD->isBitField())
4205 continue;
4206 if (FD->hasAttr<AlignedAttr>())
4207 return true;
4208 if (Context.isAlignmentRequired(FD->getType()))
4209 return true;
4210 }
4211 }
4212 }
4213
4214 // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
4215 // common symbols, so symbols with greater alignment requirements cannot be
4216 // common.
4217 // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
4218 // alignments for common symbols via the aligncomm directive, so this
4219 // restriction only applies to MSVC environments.
4220 if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
4221 Context.getTypeAlignIfKnown(D->getType()) >
4222 Context.toBits(CharUnits::fromQuantity(32)))
4223 return true;
4224
4225 return false;
4226 }
4227
getLLVMLinkageForDeclarator(const DeclaratorDecl * D,GVALinkage Linkage,bool IsConstantVariable)4228 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
4229 const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) {
4230 if (Linkage == GVA_Internal)
4231 return llvm::Function::InternalLinkage;
4232
4233 if (D->hasAttr<WeakAttr>()) {
4234 if (IsConstantVariable)
4235 return llvm::GlobalVariable::WeakODRLinkage;
4236 else
4237 return llvm::GlobalVariable::WeakAnyLinkage;
4238 }
4239
4240 if (const auto *FD = D->getAsFunction())
4241 if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
4242 return llvm::GlobalVariable::LinkOnceAnyLinkage;
4243
4244 // We are guaranteed to have a strong definition somewhere else,
4245 // so we can use available_externally linkage.
4246 if (Linkage == GVA_AvailableExternally)
4247 return llvm::GlobalValue::AvailableExternallyLinkage;
4248
4249 // Note that Apple's kernel linker doesn't support symbol
4250 // coalescing, so we need to avoid linkonce and weak linkages there.
4251 // Normally, this means we just map to internal, but for explicit
4252 // instantiations we'll map to external.
4253
4254 // In C++, the compiler has to emit a definition in every translation unit
4255 // that references the function. We should use linkonce_odr because
4256 // a) if all references in this translation unit are optimized away, we
4257 // don't need to codegen it. b) if the function persists, it needs to be
4258 // merged with other definitions. c) C++ has the ODR, so we know the
4259 // definition is dependable.
4260 if (Linkage == GVA_DiscardableODR)
4261 return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
4262 : llvm::Function::InternalLinkage;
4263
4264 // An explicit instantiation of a template has weak linkage, since
4265 // explicit instantiations can occur in multiple translation units
4266 // and must all be equivalent. However, we are not allowed to
4267 // throw away these explicit instantiations.
4268 //
4269 // We don't currently support CUDA device code spread out across multiple TUs,
4270 // so say that CUDA templates are either external (for kernels) or internal.
4271 // This lets llvm perform aggressive inter-procedural optimizations.
4272 if (Linkage == GVA_StrongODR) {
4273 if (Context.getLangOpts().AppleKext)
4274 return llvm::Function::ExternalLinkage;
4275 if (Context.getLangOpts().CUDA && Context.getLangOpts().CUDAIsDevice)
4276 return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
4277 : llvm::Function::InternalLinkage;
4278 return llvm::Function::WeakODRLinkage;
4279 }
4280
4281 // C++ doesn't have tentative definitions and thus cannot have common
4282 // linkage.
4283 if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
4284 !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
4285 CodeGenOpts.NoCommon))
4286 return llvm::GlobalVariable::CommonLinkage;
4287
4288 // selectany symbols are externally visible, so use weak instead of
4289 // linkonce. MSVC optimizes away references to const selectany globals, so
4290 // all definitions should be the same and ODR linkage should be used.
4291 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
4292 if (D->hasAttr<SelectAnyAttr>())
4293 return llvm::GlobalVariable::WeakODRLinkage;
4294
4295 // Otherwise, we have strong external linkage.
4296 assert(Linkage == GVA_StrongExternal);
4297 return llvm::GlobalVariable::ExternalLinkage;
4298 }
4299
getLLVMLinkageVarDefinition(const VarDecl * VD,bool IsConstant)4300 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition(
4301 const VarDecl *VD, bool IsConstant) {
4302 GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
4303 return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant);
4304 }
4305
4306 /// Replace the uses of a function that was declared with a non-proto type.
4307 /// We want to silently drop extra arguments from call sites
replaceUsesOfNonProtoConstant(llvm::Constant * old,llvm::Function * newFn)4308 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
4309 llvm::Function *newFn) {
4310 // Fast path.
4311 if (old->use_empty()) return;
4312
4313 llvm::Type *newRetTy = newFn->getReturnType();
4314 SmallVector<llvm::Value*, 4> newArgs;
4315 SmallVector<llvm::OperandBundleDef, 1> newBundles;
4316
4317 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
4318 ui != ue; ) {
4319 llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
4320 llvm::User *user = use->getUser();
4321
4322 // Recognize and replace uses of bitcasts. Most calls to
4323 // unprototyped functions will use bitcasts.
4324 if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
4325 if (bitcast->getOpcode() == llvm::Instruction::BitCast)
4326 replaceUsesOfNonProtoConstant(bitcast, newFn);
4327 continue;
4328 }
4329
4330 // Recognize calls to the function.
4331 llvm::CallBase *callSite = dyn_cast<llvm::CallBase>(user);
4332 if (!callSite) continue;
4333 if (!callSite->isCallee(&*use))
4334 continue;
4335
4336 // If the return types don't match exactly, then we can't
4337 // transform this call unless it's dead.
4338 if (callSite->getType() != newRetTy && !callSite->use_empty())
4339 continue;
4340
4341 // Get the call site's attribute list.
4342 SmallVector<llvm::AttributeSet, 8> newArgAttrs;
4343 llvm::AttributeList oldAttrs = callSite->getAttributes();
4344
4345 // If the function was passed too few arguments, don't transform.
4346 unsigned newNumArgs = newFn->arg_size();
4347 if (callSite->arg_size() < newNumArgs)
4348 continue;
4349
4350 // If extra arguments were passed, we silently drop them.
4351 // If any of the types mismatch, we don't transform.
4352 unsigned argNo = 0;
4353 bool dontTransform = false;
4354 for (llvm::Argument &A : newFn->args()) {
4355 if (callSite->getArgOperand(argNo)->getType() != A.getType()) {
4356 dontTransform = true;
4357 break;
4358 }
4359
4360 // Add any parameter attributes.
4361 newArgAttrs.push_back(oldAttrs.getParamAttributes(argNo));
4362 argNo++;
4363 }
4364 if (dontTransform)
4365 continue;
4366
4367 // Okay, we can transform this. Create the new call instruction and copy
4368 // over the required information.
4369 newArgs.append(callSite->arg_begin(), callSite->arg_begin() + argNo);
4370
4371 // Copy over any operand bundles.
4372 callSite->getOperandBundlesAsDefs(newBundles);
4373
4374 llvm::CallBase *newCall;
4375 if (dyn_cast<llvm::CallInst>(callSite)) {
4376 newCall =
4377 llvm::CallInst::Create(newFn, newArgs, newBundles, "", callSite);
4378 } else {
4379 auto *oldInvoke = cast<llvm::InvokeInst>(callSite);
4380 newCall = llvm::InvokeInst::Create(newFn, oldInvoke->getNormalDest(),
4381 oldInvoke->getUnwindDest(), newArgs,
4382 newBundles, "", callSite);
4383 }
4384 newArgs.clear(); // for the next iteration
4385
4386 if (!newCall->getType()->isVoidTy())
4387 newCall->takeName(callSite);
4388 newCall->setAttributes(llvm::AttributeList::get(
4389 newFn->getContext(), oldAttrs.getFnAttributes(),
4390 oldAttrs.getRetAttributes(), newArgAttrs));
4391 newCall->setCallingConv(callSite->getCallingConv());
4392
4393 // Finally, remove the old call, replacing any uses with the new one.
4394 if (!callSite->use_empty())
4395 callSite->replaceAllUsesWith(newCall);
4396
4397 // Copy debug location attached to CI.
4398 if (callSite->getDebugLoc())
4399 newCall->setDebugLoc(callSite->getDebugLoc());
4400
4401 callSite->eraseFromParent();
4402 }
4403 }
4404
4405 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
4406 /// implement a function with no prototype, e.g. "int foo() {}". If there are
4407 /// existing call uses of the old function in the module, this adjusts them to
4408 /// call the new function directly.
4409 ///
4410 /// This is not just a cleanup: the always_inline pass requires direct calls to
4411 /// functions to be able to inline them. If there is a bitcast in the way, it
4412 /// won't inline them. Instcombine normally deletes these calls, but it isn't
4413 /// run at -O0.
ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue * Old,llvm::Function * NewFn)4414 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
4415 llvm::Function *NewFn) {
4416 // If we're redefining a global as a function, don't transform it.
4417 if (!isa<llvm::Function>(Old)) return;
4418
4419 replaceUsesOfNonProtoConstant(Old, NewFn);
4420 }
4421
HandleCXXStaticMemberVarInstantiation(VarDecl * VD)4422 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
4423 auto DK = VD->isThisDeclarationADefinition();
4424 if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
4425 return;
4426
4427 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
4428 // If we have a definition, this might be a deferred decl. If the
4429 // instantiation is explicit, make sure we emit it at the end.
4430 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
4431 GetAddrOfGlobalVar(VD);
4432
4433 EmitTopLevelDecl(VD);
4434 }
4435
EmitGlobalFunctionDefinition(GlobalDecl GD,llvm::GlobalValue * GV)4436 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
4437 llvm::GlobalValue *GV) {
4438 // Check if this must be emitted as declare variant.
4439 if (LangOpts.OpenMP && OpenMPRuntime &&
4440 OpenMPRuntime->emitDeclareVariant(GD, /*IsForDefinition=*/true))
4441 return;
4442
4443 const auto *D = cast<FunctionDecl>(GD.getDecl());
4444
4445 // Compute the function info and LLVM type.
4446 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4447 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4448
4449 // Get or create the prototype for the function.
4450 if (!GV || (GV->getType()->getElementType() != Ty))
4451 GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
4452 /*DontDefer=*/true,
4453 ForDefinition));
4454
4455 // Already emitted.
4456 if (!GV->isDeclaration())
4457 return;
4458
4459 // We need to set linkage and visibility on the function before
4460 // generating code for it because various parts of IR generation
4461 // want to propagate this information down (e.g. to local static
4462 // declarations).
4463 auto *Fn = cast<llvm::Function>(GV);
4464 setFunctionLinkage(GD, Fn);
4465
4466 // FIXME: this is redundant with part of setFunctionDefinitionAttributes
4467 setGVProperties(Fn, GD);
4468
4469 MaybeHandleStaticInExternC(D, Fn);
4470
4471
4472 maybeSetTrivialComdat(*D, *Fn);
4473
4474 CodeGenFunction(*this).GenerateCode(D, Fn, FI);
4475
4476 setNonAliasAttributes(GD, Fn);
4477 SetLLVMFunctionAttributesForDefinition(D, Fn);
4478
4479 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
4480 AddGlobalCtor(Fn, CA->getPriority());
4481 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
4482 AddGlobalDtor(Fn, DA->getPriority());
4483 if (D->hasAttr<AnnotateAttr>())
4484 AddGlobalAnnotations(D, Fn);
4485 }
4486
EmitAliasDefinition(GlobalDecl GD)4487 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
4488 const auto *D = cast<ValueDecl>(GD.getDecl());
4489 const AliasAttr *AA = D->getAttr<AliasAttr>();
4490 assert(AA && "Not an alias?");
4491
4492 StringRef MangledName = getMangledName(GD);
4493
4494 if (AA->getAliasee() == MangledName) {
4495 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4496 return;
4497 }
4498
4499 // If there is a definition in the module, then it wins over the alias.
4500 // This is dubious, but allow it to be safe. Just ignore the alias.
4501 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4502 if (Entry && !Entry->isDeclaration())
4503 return;
4504
4505 Aliases.push_back(GD);
4506
4507 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4508
4509 // Create a reference to the named value. This ensures that it is emitted
4510 // if a deferred decl.
4511 llvm::Constant *Aliasee;
4512 llvm::GlobalValue::LinkageTypes LT;
4513 if (isa<llvm::FunctionType>(DeclTy)) {
4514 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
4515 /*ForVTable=*/false);
4516 LT = getFunctionLinkage(GD);
4517 } else {
4518 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
4519 llvm::PointerType::getUnqual(DeclTy),
4520 /*D=*/nullptr);
4521 LT = getLLVMLinkageVarDefinition(cast<VarDecl>(GD.getDecl()),
4522 D->getType().isConstQualified());
4523 }
4524
4525 // Create the new alias itself, but don't set a name yet.
4526 auto *GA =
4527 llvm::GlobalAlias::create(DeclTy, 0, LT, "", Aliasee, &getModule());
4528
4529 if (Entry) {
4530 if (GA->getAliasee() == Entry) {
4531 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4532 return;
4533 }
4534
4535 assert(Entry->isDeclaration());
4536
4537 // If there is a declaration in the module, then we had an extern followed
4538 // by the alias, as in:
4539 // extern int test6();
4540 // ...
4541 // int test6() __attribute__((alias("test7")));
4542 //
4543 // Remove it and replace uses of it with the alias.
4544 GA->takeName(Entry);
4545
4546 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
4547 Entry->getType()));
4548 Entry->eraseFromParent();
4549 } else {
4550 GA->setName(MangledName);
4551 }
4552
4553 // Set attributes which are particular to an alias; this is a
4554 // specialization of the attributes which may be set on a global
4555 // variable/function.
4556 if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
4557 D->isWeakImported()) {
4558 GA->setLinkage(llvm::Function::WeakAnyLinkage);
4559 }
4560
4561 if (const auto *VD = dyn_cast<VarDecl>(D))
4562 if (VD->getTLSKind())
4563 setTLSMode(GA, *VD);
4564
4565 SetCommonAttributes(GD, GA);
4566 }
4567
emitIFuncDefinition(GlobalDecl GD)4568 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
4569 const auto *D = cast<ValueDecl>(GD.getDecl());
4570 const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
4571 assert(IFA && "Not an ifunc?");
4572
4573 StringRef MangledName = getMangledName(GD);
4574
4575 if (IFA->getResolver() == MangledName) {
4576 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4577 return;
4578 }
4579
4580 // Report an error if some definition overrides ifunc.
4581 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4582 if (Entry && !Entry->isDeclaration()) {
4583 GlobalDecl OtherGD;
4584 if (lookupRepresentativeDecl(MangledName, OtherGD) &&
4585 DiagnosedConflictingDefinitions.insert(GD).second) {
4586 Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
4587 << MangledName;
4588 Diags.Report(OtherGD.getDecl()->getLocation(),
4589 diag::note_previous_definition);
4590 }
4591 return;
4592 }
4593
4594 Aliases.push_back(GD);
4595
4596 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4597 llvm::Constant *Resolver =
4598 GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD,
4599 /*ForVTable=*/false);
4600 llvm::GlobalIFunc *GIF =
4601 llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage,
4602 "", Resolver, &getModule());
4603 if (Entry) {
4604 if (GIF->getResolver() == Entry) {
4605 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4606 return;
4607 }
4608 assert(Entry->isDeclaration());
4609
4610 // If there is a declaration in the module, then we had an extern followed
4611 // by the ifunc, as in:
4612 // extern int test();
4613 // ...
4614 // int test() __attribute__((ifunc("resolver")));
4615 //
4616 // Remove it and replace uses of it with the ifunc.
4617 GIF->takeName(Entry);
4618
4619 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
4620 Entry->getType()));
4621 Entry->eraseFromParent();
4622 } else
4623 GIF->setName(MangledName);
4624
4625 SetCommonAttributes(GD, GIF);
4626 }
4627
getIntrinsic(unsigned IID,ArrayRef<llvm::Type * > Tys)4628 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
4629 ArrayRef<llvm::Type*> Tys) {
4630 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
4631 Tys);
4632 }
4633
4634 static llvm::StringMapEntry<llvm::GlobalVariable *> &
GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable * > & Map,const StringLiteral * Literal,bool TargetIsLSB,bool & IsUTF16,unsigned & StringLength)4635 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
4636 const StringLiteral *Literal, bool TargetIsLSB,
4637 bool &IsUTF16, unsigned &StringLength) {
4638 StringRef String = Literal->getString();
4639 unsigned NumBytes = String.size();
4640
4641 // Check for simple case.
4642 if (!Literal->containsNonAsciiOrNull()) {
4643 StringLength = NumBytes;
4644 return *Map.insert(std::make_pair(String, nullptr)).first;
4645 }
4646
4647 // Otherwise, convert the UTF8 literals into a string of shorts.
4648 IsUTF16 = true;
4649
4650 SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
4651 const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
4652 llvm::UTF16 *ToPtr = &ToBuf[0];
4653
4654 (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
4655 ToPtr + NumBytes, llvm::strictConversion);
4656
4657 // ConvertUTF8toUTF16 returns the length in ToPtr.
4658 StringLength = ToPtr - &ToBuf[0];
4659
4660 // Add an explicit null.
4661 *ToPtr = 0;
4662 return *Map.insert(std::make_pair(
4663 StringRef(reinterpret_cast<const char *>(ToBuf.data()),
4664 (StringLength + 1) * 2),
4665 nullptr)).first;
4666 }
4667
4668 ConstantAddress
GetAddrOfConstantCFString(const StringLiteral * Literal)4669 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
4670 unsigned StringLength = 0;
4671 bool isUTF16 = false;
4672 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
4673 GetConstantCFStringEntry(CFConstantStringMap, Literal,
4674 getDataLayout().isLittleEndian(), isUTF16,
4675 StringLength);
4676
4677 if (auto *C = Entry.second)
4678 return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment()));
4679
4680 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
4681 llvm::Constant *Zeros[] = { Zero, Zero };
4682
4683 const ASTContext &Context = getContext();
4684 const llvm::Triple &Triple = getTriple();
4685
4686 const auto CFRuntime = getLangOpts().CFRuntime;
4687 const bool IsSwiftABI =
4688 static_cast<unsigned>(CFRuntime) >=
4689 static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
4690 const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
4691
4692 // If we don't already have it, get __CFConstantStringClassReference.
4693 if (!CFConstantStringClassRef) {
4694 const char *CFConstantStringClassName = "__CFConstantStringClassReference";
4695 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
4696 Ty = llvm::ArrayType::get(Ty, 0);
4697
4698 switch (CFRuntime) {
4699 default: break;
4700 case LangOptions::CoreFoundationABI::Swift: LLVM_FALLTHROUGH;
4701 case LangOptions::CoreFoundationABI::Swift5_0:
4702 CFConstantStringClassName =
4703 Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
4704 : "$s10Foundation19_NSCFConstantStringCN";
4705 Ty = IntPtrTy;
4706 break;
4707 case LangOptions::CoreFoundationABI::Swift4_2:
4708 CFConstantStringClassName =
4709 Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
4710 : "$S10Foundation19_NSCFConstantStringCN";
4711 Ty = IntPtrTy;
4712 break;
4713 case LangOptions::CoreFoundationABI::Swift4_1:
4714 CFConstantStringClassName =
4715 Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
4716 : "__T010Foundation19_NSCFConstantStringCN";
4717 Ty = IntPtrTy;
4718 break;
4719 }
4720
4721 llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
4722
4723 if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
4724 llvm::GlobalValue *GV = nullptr;
4725
4726 if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
4727 IdentifierInfo &II = Context.Idents.get(GV->getName());
4728 TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
4729 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
4730
4731 const VarDecl *VD = nullptr;
4732 for (const auto &Result : DC->lookup(&II))
4733 if ((VD = dyn_cast<VarDecl>(Result)))
4734 break;
4735
4736 if (Triple.isOSBinFormatELF()) {
4737 if (!VD)
4738 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
4739 } else {
4740 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
4741 if (!VD || !VD->hasAttr<DLLExportAttr>())
4742 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
4743 else
4744 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
4745 }
4746
4747 setDSOLocal(GV);
4748 }
4749 }
4750
4751 // Decay array -> ptr
4752 CFConstantStringClassRef =
4753 IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty)
4754 : llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros);
4755 }
4756
4757 QualType CFTy = Context.getCFConstantStringType();
4758
4759 auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
4760
4761 ConstantInitBuilder Builder(*this);
4762 auto Fields = Builder.beginStruct(STy);
4763
4764 // Class pointer.
4765 Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
4766
4767 // Flags.
4768 if (IsSwiftABI) {
4769 Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
4770 Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
4771 } else {
4772 Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
4773 }
4774
4775 // String pointer.
4776 llvm::Constant *C = nullptr;
4777 if (isUTF16) {
4778 auto Arr = llvm::makeArrayRef(
4779 reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
4780 Entry.first().size() / 2);
4781 C = llvm::ConstantDataArray::get(VMContext, Arr);
4782 } else {
4783 C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
4784 }
4785
4786 // Note: -fwritable-strings doesn't make the backing store strings of
4787 // CFStrings writable. (See <rdar://problem/10657500>)
4788 auto *GV =
4789 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
4790 llvm::GlobalValue::PrivateLinkage, C, ".str");
4791 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4792 // Don't enforce the target's minimum global alignment, since the only use
4793 // of the string is via this class initializer.
4794 CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
4795 : Context.getTypeAlignInChars(Context.CharTy);
4796 GV->setAlignment(Align.getAsAlign());
4797
4798 // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
4799 // Without it LLVM can merge the string with a non unnamed_addr one during
4800 // LTO. Doing that changes the section it ends in, which surprises ld64.
4801 if (Triple.isOSBinFormatMachO())
4802 GV->setSection(isUTF16 ? "__TEXT,__ustring"
4803 : "__TEXT,__cstring,cstring_literals");
4804 // Make sure the literal ends up in .rodata to allow for safe ICF and for
4805 // the static linker to adjust permissions to read-only later on.
4806 else if (Triple.isOSBinFormatELF())
4807 GV->setSection(".rodata");
4808
4809 // String.
4810 llvm::Constant *Str =
4811 llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
4812
4813 if (isUTF16)
4814 // Cast the UTF16 string to the correct type.
4815 Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
4816 Fields.add(Str);
4817
4818 // String length.
4819 llvm::IntegerType *LengthTy =
4820 llvm::IntegerType::get(getModule().getContext(),
4821 Context.getTargetInfo().getLongWidth());
4822 if (IsSwiftABI) {
4823 if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
4824 CFRuntime == LangOptions::CoreFoundationABI::Swift4_2)
4825 LengthTy = Int32Ty;
4826 else
4827 LengthTy = IntPtrTy;
4828 }
4829 Fields.addInt(LengthTy, StringLength);
4830
4831 // Swift ABI requires 8-byte alignment to ensure that the _Atomic(uint64_t) is
4832 // properly aligned on 32-bit platforms.
4833 CharUnits Alignment =
4834 IsSwiftABI ? Context.toCharUnitsFromBits(64) : getPointerAlign();
4835
4836 // The struct.
4837 GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
4838 /*isConstant=*/false,
4839 llvm::GlobalVariable::PrivateLinkage);
4840 GV->addAttribute("objc_arc_inert");
4841 switch (Triple.getObjectFormat()) {
4842 case llvm::Triple::UnknownObjectFormat:
4843 llvm_unreachable("unknown file format");
4844 case llvm::Triple::XCOFF:
4845 llvm_unreachable("XCOFF is not yet implemented");
4846 case llvm::Triple::COFF:
4847 case llvm::Triple::ELF:
4848 case llvm::Triple::Wasm:
4849 GV->setSection("cfstring");
4850 break;
4851 case llvm::Triple::MachO:
4852 GV->setSection("__DATA,__cfstring");
4853 break;
4854 }
4855 Entry.second = GV;
4856
4857 return ConstantAddress(GV, Alignment);
4858 }
4859
getExpressionLocationsEnabled() const4860 bool CodeGenModule::getExpressionLocationsEnabled() const {
4861 return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
4862 }
4863
getObjCFastEnumerationStateType()4864 QualType CodeGenModule::getObjCFastEnumerationStateType() {
4865 if (ObjCFastEnumerationStateType.isNull()) {
4866 RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
4867 D->startDefinition();
4868
4869 QualType FieldTypes[] = {
4870 Context.UnsignedLongTy,
4871 Context.getPointerType(Context.getObjCIdType()),
4872 Context.getPointerType(Context.UnsignedLongTy),
4873 Context.getConstantArrayType(Context.UnsignedLongTy,
4874 llvm::APInt(32, 5), nullptr, ArrayType::Normal, 0)
4875 };
4876
4877 for (size_t i = 0; i < 4; ++i) {
4878 FieldDecl *Field = FieldDecl::Create(Context,
4879 D,
4880 SourceLocation(),
4881 SourceLocation(), nullptr,
4882 FieldTypes[i], /*TInfo=*/nullptr,
4883 /*BitWidth=*/nullptr,
4884 /*Mutable=*/false,
4885 ICIS_NoInit);
4886 Field->setAccess(AS_public);
4887 D->addDecl(Field);
4888 }
4889
4890 D->completeDefinition();
4891 ObjCFastEnumerationStateType = Context.getTagDeclType(D);
4892 }
4893
4894 return ObjCFastEnumerationStateType;
4895 }
4896
4897 llvm::Constant *
GetConstantArrayFromStringLiteral(const StringLiteral * E)4898 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
4899 assert(!E->getType()->isPointerType() && "Strings are always arrays");
4900
4901 // Don't emit it as the address of the string, emit the string data itself
4902 // as an inline array.
4903 if (E->getCharByteWidth() == 1) {
4904 SmallString<64> Str(E->getString());
4905
4906 // Resize the string to the right size, which is indicated by its type.
4907 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
4908 Str.resize(CAT->getSize().getZExtValue());
4909 return llvm::ConstantDataArray::getString(VMContext, Str, false);
4910 }
4911
4912 auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
4913 llvm::Type *ElemTy = AType->getElementType();
4914 unsigned NumElements = AType->getNumElements();
4915
4916 // Wide strings have either 2-byte or 4-byte elements.
4917 if (ElemTy->getPrimitiveSizeInBits() == 16) {
4918 SmallVector<uint16_t, 32> Elements;
4919 Elements.reserve(NumElements);
4920
4921 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
4922 Elements.push_back(E->getCodeUnit(i));
4923 Elements.resize(NumElements);
4924 return llvm::ConstantDataArray::get(VMContext, Elements);
4925 }
4926
4927 assert(ElemTy->getPrimitiveSizeInBits() == 32);
4928 SmallVector<uint32_t, 32> Elements;
4929 Elements.reserve(NumElements);
4930
4931 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
4932 Elements.push_back(E->getCodeUnit(i));
4933 Elements.resize(NumElements);
4934 return llvm::ConstantDataArray::get(VMContext, Elements);
4935 }
4936
4937 static llvm::GlobalVariable *
GenerateStringLiteral(llvm::Constant * C,llvm::GlobalValue::LinkageTypes LT,CodeGenModule & CGM,StringRef GlobalName,CharUnits Alignment)4938 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
4939 CodeGenModule &CGM, StringRef GlobalName,
4940 CharUnits Alignment) {
4941 unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
4942 CGM.getStringLiteralAddressSpace());
4943
4944 llvm::Module &M = CGM.getModule();
4945 // Create a global variable for this string
4946 auto *GV = new llvm::GlobalVariable(
4947 M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
4948 nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
4949 GV->setAlignment(Alignment.getAsAlign());
4950 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4951 if (GV->isWeakForLinker()) {
4952 assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
4953 GV->setComdat(M.getOrInsertComdat(GV->getName()));
4954 }
4955 CGM.setDSOLocal(GV);
4956
4957 return GV;
4958 }
4959
4960 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
4961 /// constant array for the given string literal.
4962 ConstantAddress
GetAddrOfConstantStringFromLiteral(const StringLiteral * S,StringRef Name)4963 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
4964 StringRef Name) {
4965 CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType());
4966
4967 llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
4968 llvm::GlobalVariable **Entry = nullptr;
4969 if (!LangOpts.WritableStrings) {
4970 Entry = &ConstantStringMap[C];
4971 if (auto GV = *Entry) {
4972 if (Alignment.getQuantity() > GV->getAlignment())
4973 GV->setAlignment(Alignment.getAsAlign());
4974 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
4975 Alignment);
4976 }
4977 }
4978
4979 SmallString<256> MangledNameBuffer;
4980 StringRef GlobalVariableName;
4981 llvm::GlobalValue::LinkageTypes LT;
4982
4983 // Mangle the string literal if that's how the ABI merges duplicate strings.
4984 // Don't do it if they are writable, since we don't want writes in one TU to
4985 // affect strings in another.
4986 if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
4987 !LangOpts.WritableStrings) {
4988 llvm::raw_svector_ostream Out(MangledNameBuffer);
4989 getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
4990 LT = llvm::GlobalValue::LinkOnceODRLinkage;
4991 GlobalVariableName = MangledNameBuffer;
4992 } else {
4993 LT = llvm::GlobalValue::PrivateLinkage;
4994 GlobalVariableName = Name;
4995 }
4996
4997 auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
4998 if (Entry)
4999 *Entry = GV;
5000
5001 SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>",
5002 QualType());
5003
5004 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5005 Alignment);
5006 }
5007
5008 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
5009 /// array for the given ObjCEncodeExpr node.
5010 ConstantAddress
GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr * E)5011 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
5012 std::string Str;
5013 getContext().getObjCEncodingForType(E->getEncodedType(), Str);
5014
5015 return GetAddrOfConstantCString(Str);
5016 }
5017
5018 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
5019 /// the literal and a terminating '\0' character.
5020 /// The result has pointer to array type.
GetAddrOfConstantCString(const std::string & Str,const char * GlobalName)5021 ConstantAddress CodeGenModule::GetAddrOfConstantCString(
5022 const std::string &Str, const char *GlobalName) {
5023 StringRef StrWithNull(Str.c_str(), Str.size() + 1);
5024 CharUnits Alignment =
5025 getContext().getAlignOfGlobalVarInChars(getContext().CharTy);
5026
5027 llvm::Constant *C =
5028 llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
5029
5030 // Don't share any string literals if strings aren't constant.
5031 llvm::GlobalVariable **Entry = nullptr;
5032 if (!LangOpts.WritableStrings) {
5033 Entry = &ConstantStringMap[C];
5034 if (auto GV = *Entry) {
5035 if (Alignment.getQuantity() > GV->getAlignment())
5036 GV->setAlignment(Alignment.getAsAlign());
5037 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5038 Alignment);
5039 }
5040 }
5041
5042 // Get the default prefix if a name wasn't specified.
5043 if (!GlobalName)
5044 GlobalName = ".str";
5045 // Create a global variable for this.
5046 auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
5047 GlobalName, Alignment);
5048 if (Entry)
5049 *Entry = GV;
5050
5051 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5052 Alignment);
5053 }
5054
GetAddrOfGlobalTemporary(const MaterializeTemporaryExpr * E,const Expr * Init)5055 ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
5056 const MaterializeTemporaryExpr *E, const Expr *Init) {
5057 assert((E->getStorageDuration() == SD_Static ||
5058 E->getStorageDuration() == SD_Thread) && "not a global temporary");
5059 const auto *VD = cast<VarDecl>(E->getExtendingDecl());
5060
5061 // If we're not materializing a subobject of the temporary, keep the
5062 // cv-qualifiers from the type of the MaterializeTemporaryExpr.
5063 QualType MaterializedType = Init->getType();
5064 if (Init == E->getSubExpr())
5065 MaterializedType = E->getType();
5066
5067 CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
5068
5069 if (llvm::Constant *Slot = MaterializedGlobalTemporaryMap[E])
5070 return ConstantAddress(Slot, Align);
5071
5072 // FIXME: If an externally-visible declaration extends multiple temporaries,
5073 // we need to give each temporary the same name in every translation unit (and
5074 // we also need to make the temporaries externally-visible).
5075 SmallString<256> Name;
5076 llvm::raw_svector_ostream Out(Name);
5077 getCXXABI().getMangleContext().mangleReferenceTemporary(
5078 VD, E->getManglingNumber(), Out);
5079
5080 APValue *Value = nullptr;
5081 if (E->getStorageDuration() == SD_Static && VD && VD->evaluateValue()) {
5082 // If the initializer of the extending declaration is a constant
5083 // initializer, we should have a cached constant initializer for this
5084 // temporary. Note that this might have a different value from the value
5085 // computed by evaluating the initializer if the surrounding constant
5086 // expression modifies the temporary.
5087 Value = E->getOrCreateValue(false);
5088 }
5089
5090 // Try evaluating it now, it might have a constant initializer.
5091 Expr::EvalResult EvalResult;
5092 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
5093 !EvalResult.hasSideEffects())
5094 Value = &EvalResult.Val;
5095
5096 LangAS AddrSpace =
5097 VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace();
5098
5099 Optional<ConstantEmitter> emitter;
5100 llvm::Constant *InitialValue = nullptr;
5101 bool Constant = false;
5102 llvm::Type *Type;
5103 if (Value) {
5104 // The temporary has a constant initializer, use it.
5105 emitter.emplace(*this);
5106 InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
5107 MaterializedType);
5108 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value);
5109 Type = InitialValue->getType();
5110 } else {
5111 // No initializer, the initialization will be provided when we
5112 // initialize the declaration which performed lifetime extension.
5113 Type = getTypes().ConvertTypeForMem(MaterializedType);
5114 }
5115
5116 // Create a global variable for this lifetime-extended temporary.
5117 llvm::GlobalValue::LinkageTypes Linkage =
5118 getLLVMLinkageVarDefinition(VD, Constant);
5119 if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
5120 const VarDecl *InitVD;
5121 if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
5122 isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
5123 // Temporaries defined inside a class get linkonce_odr linkage because the
5124 // class can be defined in multiple translation units.
5125 Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
5126 } else {
5127 // There is no need for this temporary to have external linkage if the
5128 // VarDecl has external linkage.
5129 Linkage = llvm::GlobalVariable::InternalLinkage;
5130 }
5131 }
5132 auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
5133 auto *GV = new llvm::GlobalVariable(
5134 getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
5135 /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
5136 if (emitter) emitter->finalize(GV);
5137 setGVProperties(GV, VD);
5138 GV->setAlignment(Align.getAsAlign());
5139 if (supportsCOMDAT() && GV->isWeakForLinker())
5140 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
5141 if (VD->getTLSKind())
5142 setTLSMode(GV, *VD);
5143 llvm::Constant *CV = GV;
5144 if (AddrSpace != LangAS::Default)
5145 CV = getTargetCodeGenInfo().performAddrSpaceCast(
5146 *this, GV, AddrSpace, LangAS::Default,
5147 Type->getPointerTo(
5148 getContext().getTargetAddressSpace(LangAS::Default)));
5149 MaterializedGlobalTemporaryMap[E] = CV;
5150 return ConstantAddress(CV, Align);
5151 }
5152
5153 /// EmitObjCPropertyImplementations - Emit information for synthesized
5154 /// properties for an implementation.
EmitObjCPropertyImplementations(const ObjCImplementationDecl * D)5155 void CodeGenModule::EmitObjCPropertyImplementations(const
5156 ObjCImplementationDecl *D) {
5157 for (const auto *PID : D->property_impls()) {
5158 // Dynamic is just for type-checking.
5159 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
5160 ObjCPropertyDecl *PD = PID->getPropertyDecl();
5161
5162 // Determine which methods need to be implemented, some may have
5163 // been overridden. Note that ::isPropertyAccessor is not the method
5164 // we want, that just indicates if the decl came from a
5165 // property. What we want to know is if the method is defined in
5166 // this implementation.
5167 auto *Getter = PID->getGetterMethodDecl();
5168 if (!Getter || Getter->isSynthesizedAccessorStub())
5169 CodeGenFunction(*this).GenerateObjCGetter(
5170 const_cast<ObjCImplementationDecl *>(D), PID);
5171 auto *Setter = PID->getSetterMethodDecl();
5172 if (!PD->isReadOnly() && (!Setter || Setter->isSynthesizedAccessorStub()))
5173 CodeGenFunction(*this).GenerateObjCSetter(
5174 const_cast<ObjCImplementationDecl *>(D), PID);
5175 }
5176 }
5177 }
5178
needsDestructMethod(ObjCImplementationDecl * impl)5179 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
5180 const ObjCInterfaceDecl *iface = impl->getClassInterface();
5181 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
5182 ivar; ivar = ivar->getNextIvar())
5183 if (ivar->getType().isDestructedType())
5184 return true;
5185
5186 return false;
5187 }
5188
AllTrivialInitializers(CodeGenModule & CGM,ObjCImplementationDecl * D)5189 static bool AllTrivialInitializers(CodeGenModule &CGM,
5190 ObjCImplementationDecl *D) {
5191 CodeGenFunction CGF(CGM);
5192 for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
5193 E = D->init_end(); B != E; ++B) {
5194 CXXCtorInitializer *CtorInitExp = *B;
5195 Expr *Init = CtorInitExp->getInit();
5196 if (!CGF.isTrivialInitializer(Init))
5197 return false;
5198 }
5199 return true;
5200 }
5201
5202 /// EmitObjCIvarInitializations - Emit information for ivar initialization
5203 /// for an implementation.
EmitObjCIvarInitializations(ObjCImplementationDecl * D)5204 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
5205 // We might need a .cxx_destruct even if we don't have any ivar initializers.
5206 if (needsDestructMethod(D)) {
5207 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
5208 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
5209 ObjCMethodDecl *DTORMethod = ObjCMethodDecl::Create(
5210 getContext(), D->getLocation(), D->getLocation(), cxxSelector,
5211 getContext().VoidTy, nullptr, D,
5212 /*isInstance=*/true, /*isVariadic=*/false,
5213 /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
5214 /*isImplicitlyDeclared=*/true,
5215 /*isDefined=*/false, ObjCMethodDecl::Required);
5216 D->addInstanceMethod(DTORMethod);
5217 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
5218 D->setHasDestructors(true);
5219 }
5220
5221 // If the implementation doesn't have any ivar initializers, we don't need
5222 // a .cxx_construct.
5223 if (D->getNumIvarInitializers() == 0 ||
5224 AllTrivialInitializers(*this, D))
5225 return;
5226
5227 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
5228 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
5229 // The constructor returns 'self'.
5230 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(
5231 getContext(), D->getLocation(), D->getLocation(), cxxSelector,
5232 getContext().getObjCIdType(), nullptr, D, /*isInstance=*/true,
5233 /*isVariadic=*/false,
5234 /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
5235 /*isImplicitlyDeclared=*/true,
5236 /*isDefined=*/false, ObjCMethodDecl::Required);
5237 D->addInstanceMethod(CTORMethod);
5238 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
5239 D->setHasNonZeroConstructors(true);
5240 }
5241
5242 // EmitLinkageSpec - Emit all declarations in a linkage spec.
EmitLinkageSpec(const LinkageSpecDecl * LSD)5243 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
5244 if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
5245 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
5246 ErrorUnsupported(LSD, "linkage spec");
5247 return;
5248 }
5249
5250 EmitDeclContext(LSD);
5251 }
5252
EmitDeclContext(const DeclContext * DC)5253 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
5254 for (auto *I : DC->decls()) {
5255 // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
5256 // are themselves considered "top-level", so EmitTopLevelDecl on an
5257 // ObjCImplDecl does not recursively visit them. We need to do that in
5258 // case they're nested inside another construct (LinkageSpecDecl /
5259 // ExportDecl) that does stop them from being considered "top-level".
5260 if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
5261 for (auto *M : OID->methods())
5262 EmitTopLevelDecl(M);
5263 }
5264
5265 EmitTopLevelDecl(I);
5266 }
5267 }
5268
5269 /// EmitTopLevelDecl - Emit code for a single top level declaration.
EmitTopLevelDecl(Decl * D)5270 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
5271 // Ignore dependent declarations.
5272 if (D->isTemplated())
5273 return;
5274
5275 switch (D->getKind()) {
5276 case Decl::CXXConversion:
5277 case Decl::CXXMethod:
5278 case Decl::Function:
5279 EmitGlobal(cast<FunctionDecl>(D));
5280 // Always provide some coverage mapping
5281 // even for the functions that aren't emitted.
5282 AddDeferredUnusedCoverageMapping(D);
5283 break;
5284
5285 case Decl::CXXDeductionGuide:
5286 // Function-like, but does not result in code emission.
5287 break;
5288
5289 case Decl::Var:
5290 case Decl::Decomposition:
5291 case Decl::VarTemplateSpecialization:
5292 EmitGlobal(cast<VarDecl>(D));
5293 if (auto *DD = dyn_cast<DecompositionDecl>(D))
5294 for (auto *B : DD->bindings())
5295 if (auto *HD = B->getHoldingVar())
5296 EmitGlobal(HD);
5297 break;
5298
5299 // Indirect fields from global anonymous structs and unions can be
5300 // ignored; only the actual variable requires IR gen support.
5301 case Decl::IndirectField:
5302 break;
5303
5304 // C++ Decls
5305 case Decl::Namespace:
5306 EmitDeclContext(cast<NamespaceDecl>(D));
5307 break;
5308 case Decl::ClassTemplateSpecialization: {
5309 const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
5310 if (DebugInfo &&
5311 Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition &&
5312 Spec->hasDefinition())
5313 DebugInfo->completeTemplateDefinition(*Spec);
5314 } LLVM_FALLTHROUGH;
5315 case Decl::CXXRecord:
5316 if (DebugInfo) {
5317 if (auto *ES = D->getASTContext().getExternalSource())
5318 if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
5319 DebugInfo->completeUnusedClass(cast<CXXRecordDecl>(*D));
5320 }
5321 // Emit any static data members, they may be definitions.
5322 for (auto *I : cast<CXXRecordDecl>(D)->decls())
5323 if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
5324 EmitTopLevelDecl(I);
5325 break;
5326 // No code generation needed.
5327 case Decl::UsingShadow:
5328 case Decl::ClassTemplate:
5329 case Decl::VarTemplate:
5330 case Decl::Concept:
5331 case Decl::VarTemplatePartialSpecialization:
5332 case Decl::FunctionTemplate:
5333 case Decl::TypeAliasTemplate:
5334 case Decl::Block:
5335 case Decl::Empty:
5336 case Decl::Binding:
5337 break;
5338 case Decl::Using: // using X; [C++]
5339 if (CGDebugInfo *DI = getModuleDebugInfo())
5340 DI->EmitUsingDecl(cast<UsingDecl>(*D));
5341 return;
5342 case Decl::NamespaceAlias:
5343 if (CGDebugInfo *DI = getModuleDebugInfo())
5344 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
5345 return;
5346 case Decl::UsingDirective: // using namespace X; [C++]
5347 if (CGDebugInfo *DI = getModuleDebugInfo())
5348 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
5349 return;
5350 case Decl::CXXConstructor:
5351 getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
5352 break;
5353 case Decl::CXXDestructor:
5354 getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
5355 break;
5356
5357 case Decl::StaticAssert:
5358 // Nothing to do.
5359 break;
5360
5361 // Objective-C Decls
5362
5363 // Forward declarations, no (immediate) code generation.
5364 case Decl::ObjCInterface:
5365 case Decl::ObjCCategory:
5366 break;
5367
5368 case Decl::ObjCProtocol: {
5369 auto *Proto = cast<ObjCProtocolDecl>(D);
5370 if (Proto->isThisDeclarationADefinition())
5371 ObjCRuntime->GenerateProtocol(Proto);
5372 break;
5373 }
5374
5375 case Decl::ObjCCategoryImpl:
5376 // Categories have properties but don't support synthesize so we
5377 // can ignore them here.
5378 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
5379 break;
5380
5381 case Decl::ObjCImplementation: {
5382 auto *OMD = cast<ObjCImplementationDecl>(D);
5383 EmitObjCPropertyImplementations(OMD);
5384 EmitObjCIvarInitializations(OMD);
5385 ObjCRuntime->GenerateClass(OMD);
5386 // Emit global variable debug information.
5387 if (CGDebugInfo *DI = getModuleDebugInfo())
5388 if (getCodeGenOpts().hasReducedDebugInfo())
5389 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
5390 OMD->getClassInterface()), OMD->getLocation());
5391 break;
5392 }
5393 case Decl::ObjCMethod: {
5394 auto *OMD = cast<ObjCMethodDecl>(D);
5395 // If this is not a prototype, emit the body.
5396 if (OMD->getBody())
5397 CodeGenFunction(*this).GenerateObjCMethod(OMD);
5398 break;
5399 }
5400 case Decl::ObjCCompatibleAlias:
5401 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
5402 break;
5403
5404 case Decl::PragmaComment: {
5405 const auto *PCD = cast<PragmaCommentDecl>(D);
5406 switch (PCD->getCommentKind()) {
5407 case PCK_Unknown:
5408 llvm_unreachable("unexpected pragma comment kind");
5409 case PCK_Linker:
5410 AppendLinkerOptions(PCD->getArg());
5411 break;
5412 case PCK_Lib:
5413 AddDependentLib(PCD->getArg());
5414 break;
5415 case PCK_Compiler:
5416 case PCK_ExeStr:
5417 case PCK_User:
5418 break; // We ignore all of these.
5419 }
5420 break;
5421 }
5422
5423 case Decl::PragmaDetectMismatch: {
5424 const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
5425 AddDetectMismatch(PDMD->getName(), PDMD->getValue());
5426 break;
5427 }
5428
5429 case Decl::LinkageSpec:
5430 EmitLinkageSpec(cast<LinkageSpecDecl>(D));
5431 break;
5432
5433 case Decl::FileScopeAsm: {
5434 // File-scope asm is ignored during device-side CUDA compilation.
5435 if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
5436 break;
5437 // File-scope asm is ignored during device-side OpenMP compilation.
5438 if (LangOpts.OpenMPIsDevice)
5439 break;
5440 auto *AD = cast<FileScopeAsmDecl>(D);
5441 getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
5442 break;
5443 }
5444
5445 case Decl::Import: {
5446 auto *Import = cast<ImportDecl>(D);
5447
5448 // If we've already imported this module, we're done.
5449 if (!ImportedModules.insert(Import->getImportedModule()))
5450 break;
5451
5452 // Emit debug information for direct imports.
5453 if (!Import->getImportedOwningModule()) {
5454 if (CGDebugInfo *DI = getModuleDebugInfo())
5455 DI->EmitImportDecl(*Import);
5456 }
5457
5458 // Find all of the submodules and emit the module initializers.
5459 llvm::SmallPtrSet<clang::Module *, 16> Visited;
5460 SmallVector<clang::Module *, 16> Stack;
5461 Visited.insert(Import->getImportedModule());
5462 Stack.push_back(Import->getImportedModule());
5463
5464 while (!Stack.empty()) {
5465 clang::Module *Mod = Stack.pop_back_val();
5466 if (!EmittedModuleInitializers.insert(Mod).second)
5467 continue;
5468
5469 for (auto *D : Context.getModuleInitializers(Mod))
5470 EmitTopLevelDecl(D);
5471
5472 // Visit the submodules of this module.
5473 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
5474 SubEnd = Mod->submodule_end();
5475 Sub != SubEnd; ++Sub) {
5476 // Skip explicit children; they need to be explicitly imported to emit
5477 // the initializers.
5478 if ((*Sub)->IsExplicit)
5479 continue;
5480
5481 if (Visited.insert(*Sub).second)
5482 Stack.push_back(*Sub);
5483 }
5484 }
5485 break;
5486 }
5487
5488 case Decl::Export:
5489 EmitDeclContext(cast<ExportDecl>(D));
5490 break;
5491
5492 case Decl::OMPThreadPrivate:
5493 EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
5494 break;
5495
5496 case Decl::OMPAllocate:
5497 break;
5498
5499 case Decl::OMPDeclareReduction:
5500 EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
5501 break;
5502
5503 case Decl::OMPDeclareMapper:
5504 EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D));
5505 break;
5506
5507 case Decl::OMPRequires:
5508 EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
5509 break;
5510
5511 default:
5512 // Make sure we handled everything we should, every other kind is a
5513 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
5514 // function. Need to recode Decl::Kind to do that easily.
5515 assert(isa<TypeDecl>(D) && "Unsupported decl kind");
5516 break;
5517 }
5518 }
5519
AddDeferredUnusedCoverageMapping(Decl * D)5520 void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
5521 // Do we need to generate coverage mapping?
5522 if (!CodeGenOpts.CoverageMapping)
5523 return;
5524 switch (D->getKind()) {
5525 case Decl::CXXConversion:
5526 case Decl::CXXMethod:
5527 case Decl::Function:
5528 case Decl::ObjCMethod:
5529 case Decl::CXXConstructor:
5530 case Decl::CXXDestructor: {
5531 if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
5532 return;
5533 SourceManager &SM = getContext().getSourceManager();
5534 if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
5535 return;
5536 auto I = DeferredEmptyCoverageMappingDecls.find(D);
5537 if (I == DeferredEmptyCoverageMappingDecls.end())
5538 DeferredEmptyCoverageMappingDecls[D] = true;
5539 break;
5540 }
5541 default:
5542 break;
5543 };
5544 }
5545
ClearUnusedCoverageMapping(const Decl * D)5546 void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
5547 // Do we need to generate coverage mapping?
5548 if (!CodeGenOpts.CoverageMapping)
5549 return;
5550 if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
5551 if (Fn->isTemplateInstantiation())
5552 ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
5553 }
5554 auto I = DeferredEmptyCoverageMappingDecls.find(D);
5555 if (I == DeferredEmptyCoverageMappingDecls.end())
5556 DeferredEmptyCoverageMappingDecls[D] = false;
5557 else
5558 I->second = false;
5559 }
5560
EmitDeferredUnusedCoverageMappings()5561 void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
5562 // We call takeVector() here to avoid use-after-free.
5563 // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
5564 // we deserialize function bodies to emit coverage info for them, and that
5565 // deserializes more declarations. How should we handle that case?
5566 for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
5567 if (!Entry.second)
5568 continue;
5569 const Decl *D = Entry.first;
5570 switch (D->getKind()) {
5571 case Decl::CXXConversion:
5572 case Decl::CXXMethod:
5573 case Decl::Function:
5574 case Decl::ObjCMethod: {
5575 CodeGenPGO PGO(*this);
5576 GlobalDecl GD(cast<FunctionDecl>(D));
5577 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
5578 getFunctionLinkage(GD));
5579 break;
5580 }
5581 case Decl::CXXConstructor: {
5582 CodeGenPGO PGO(*this);
5583 GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
5584 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
5585 getFunctionLinkage(GD));
5586 break;
5587 }
5588 case Decl::CXXDestructor: {
5589 CodeGenPGO PGO(*this);
5590 GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
5591 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
5592 getFunctionLinkage(GD));
5593 break;
5594 }
5595 default:
5596 break;
5597 };
5598 }
5599 }
5600
5601 /// Turns the given pointer into a constant.
GetPointerConstant(llvm::LLVMContext & Context,const void * Ptr)5602 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
5603 const void *Ptr) {
5604 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
5605 llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
5606 return llvm::ConstantInt::get(i64, PtrInt);
5607 }
5608
EmitGlobalDeclMetadata(CodeGenModule & CGM,llvm::NamedMDNode * & GlobalMetadata,GlobalDecl D,llvm::GlobalValue * Addr)5609 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
5610 llvm::NamedMDNode *&GlobalMetadata,
5611 GlobalDecl D,
5612 llvm::GlobalValue *Addr) {
5613 if (!GlobalMetadata)
5614 GlobalMetadata =
5615 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
5616
5617 // TODO: should we report variant information for ctors/dtors?
5618 llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
5619 llvm::ConstantAsMetadata::get(GetPointerConstant(
5620 CGM.getLLVMContext(), D.getDecl()))};
5621 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
5622 }
5623
5624 /// For each function which is declared within an extern "C" region and marked
5625 /// as 'used', but has internal linkage, create an alias from the unmangled
5626 /// name to the mangled name if possible. People expect to be able to refer
5627 /// to such functions with an unmangled name from inline assembly within the
5628 /// same translation unit.
EmitStaticExternCAliases()5629 void CodeGenModule::EmitStaticExternCAliases() {
5630 if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
5631 return;
5632 for (auto &I : StaticExternCValues) {
5633 IdentifierInfo *Name = I.first;
5634 llvm::GlobalValue *Val = I.second;
5635 if (Val && !getModule().getNamedValue(Name->getName()))
5636 addUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
5637 }
5638 }
5639
lookupRepresentativeDecl(StringRef MangledName,GlobalDecl & Result) const5640 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
5641 GlobalDecl &Result) const {
5642 auto Res = Manglings.find(MangledName);
5643 if (Res == Manglings.end())
5644 return false;
5645 Result = Res->getValue();
5646 return true;
5647 }
5648
5649 /// Emits metadata nodes associating all the global values in the
5650 /// current module with the Decls they came from. This is useful for
5651 /// projects using IR gen as a subroutine.
5652 ///
5653 /// Since there's currently no way to associate an MDNode directly
5654 /// with an llvm::GlobalValue, we create a global named metadata
5655 /// with the name 'clang.global.decl.ptrs'.
EmitDeclMetadata()5656 void CodeGenModule::EmitDeclMetadata() {
5657 llvm::NamedMDNode *GlobalMetadata = nullptr;
5658
5659 for (auto &I : MangledDeclNames) {
5660 llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
5661 // Some mangled names don't necessarily have an associated GlobalValue
5662 // in this module, e.g. if we mangled it for DebugInfo.
5663 if (Addr)
5664 EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
5665 }
5666 }
5667
5668 /// Emits metadata nodes for all the local variables in the current
5669 /// function.
EmitDeclMetadata()5670 void CodeGenFunction::EmitDeclMetadata() {
5671 if (LocalDeclMap.empty()) return;
5672
5673 llvm::LLVMContext &Context = getLLVMContext();
5674
5675 // Find the unique metadata ID for this name.
5676 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
5677
5678 llvm::NamedMDNode *GlobalMetadata = nullptr;
5679
5680 for (auto &I : LocalDeclMap) {
5681 const Decl *D = I.first;
5682 llvm::Value *Addr = I.second.getPointer();
5683 if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
5684 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
5685 Alloca->setMetadata(
5686 DeclPtrKind, llvm::MDNode::get(
5687 Context, llvm::ValueAsMetadata::getConstant(DAddr)));
5688 } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
5689 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
5690 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
5691 }
5692 }
5693 }
5694
EmitVersionIdentMetadata()5695 void CodeGenModule::EmitVersionIdentMetadata() {
5696 llvm::NamedMDNode *IdentMetadata =
5697 TheModule.getOrInsertNamedMetadata("llvm.ident");
5698 std::string Version = getClangFullVersion();
5699 llvm::LLVMContext &Ctx = TheModule.getContext();
5700
5701 llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
5702 IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
5703 }
5704
EmitCommandLineMetadata()5705 void CodeGenModule::EmitCommandLineMetadata() {
5706 llvm::NamedMDNode *CommandLineMetadata =
5707 TheModule.getOrInsertNamedMetadata("llvm.commandline");
5708 std::string CommandLine = getCodeGenOpts().RecordCommandLine;
5709 llvm::LLVMContext &Ctx = TheModule.getContext();
5710
5711 llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
5712 CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
5713 }
5714
EmitTargetMetadata()5715 void CodeGenModule::EmitTargetMetadata() {
5716 // Warning, new MangledDeclNames may be appended within this loop.
5717 // We rely on MapVector insertions adding new elements to the end
5718 // of the container.
5719 // FIXME: Move this loop into the one target that needs it, and only
5720 // loop over those declarations for which we couldn't emit the target
5721 // metadata when we emitted the declaration.
5722 for (unsigned I = 0; I != MangledDeclNames.size(); ++I) {
5723 auto Val = *(MangledDeclNames.begin() + I);
5724 const Decl *D = Val.first.getDecl()->getMostRecentDecl();
5725 llvm::GlobalValue *GV = GetGlobalValue(Val.second);
5726 getTargetCodeGenInfo().emitTargetMD(D, GV, *this);
5727 }
5728 }
5729
EmitCoverageFile()5730 void CodeGenModule::EmitCoverageFile() {
5731 if (getCodeGenOpts().CoverageDataFile.empty() &&
5732 getCodeGenOpts().CoverageNotesFile.empty())
5733 return;
5734
5735 llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
5736 if (!CUNode)
5737 return;
5738
5739 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
5740 llvm::LLVMContext &Ctx = TheModule.getContext();
5741 auto *CoverageDataFile =
5742 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
5743 auto *CoverageNotesFile =
5744 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
5745 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
5746 llvm::MDNode *CU = CUNode->getOperand(i);
5747 llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
5748 GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
5749 }
5750 }
5751
EmitUuidofInitializer(StringRef Uuid)5752 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid) {
5753 // Sema has checked that all uuid strings are of the form
5754 // "12345678-1234-1234-1234-1234567890ab".
5755 assert(Uuid.size() == 36);
5756 for (unsigned i = 0; i < 36; ++i) {
5757 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-');
5758 else assert(isHexDigit(Uuid[i]));
5759 }
5760
5761 // The starts of all bytes of Field3 in Uuid. Field 3 is "1234-1234567890ab".
5762 const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 };
5763
5764 llvm::Constant *Field3[8];
5765 for (unsigned Idx = 0; Idx < 8; ++Idx)
5766 Field3[Idx] = llvm::ConstantInt::get(
5767 Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16);
5768
5769 llvm::Constant *Fields[4] = {
5770 llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16),
5771 llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16),
5772 llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16),
5773 llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3)
5774 };
5775
5776 return llvm::ConstantStruct::getAnon(Fields);
5777 }
5778
GetAddrOfRTTIDescriptor(QualType Ty,bool ForEH)5779 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
5780 bool ForEH) {
5781 // Return a bogus pointer if RTTI is disabled, unless it's for EH.
5782 // FIXME: should we even be calling this method if RTTI is disabled
5783 // and it's not for EH?
5784 if ((!ForEH && !getLangOpts().RTTI) || getLangOpts().CUDAIsDevice)
5785 return llvm::Constant::getNullValue(Int8PtrTy);
5786
5787 if (ForEH && Ty->isObjCObjectPointerType() &&
5788 LangOpts.ObjCRuntime.isGNUFamily())
5789 return ObjCRuntime->GetEHType(Ty);
5790
5791 return getCXXABI().getAddrOfRTTIDescriptor(Ty);
5792 }
5793
EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl * D)5794 void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
5795 // Do not emit threadprivates in simd-only mode.
5796 if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
5797 return;
5798 for (auto RefExpr : D->varlists()) {
5799 auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
5800 bool PerformInit =
5801 VD->getAnyInitializer() &&
5802 !VD->getAnyInitializer()->isConstantInitializer(getContext(),
5803 /*ForRef=*/false);
5804
5805 Address Addr(GetAddrOfGlobalVar(VD), getContext().getDeclAlign(VD));
5806 if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
5807 VD, Addr, RefExpr->getBeginLoc(), PerformInit))
5808 CXXGlobalInits.push_back(InitFunction);
5809 }
5810 }
5811
5812 llvm::Metadata *
CreateMetadataIdentifierImpl(QualType T,MetadataTypeMap & Map,StringRef Suffix)5813 CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
5814 StringRef Suffix) {
5815 llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
5816 if (InternalId)
5817 return InternalId;
5818
5819 if (isExternallyVisible(T->getLinkage())) {
5820 std::string OutName;
5821 llvm::raw_string_ostream Out(OutName);
5822 getCXXABI().getMangleContext().mangleTypeName(T, Out);
5823 Out << Suffix;
5824
5825 InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
5826 } else {
5827 InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
5828 llvm::ArrayRef<llvm::Metadata *>());
5829 }
5830
5831 return InternalId;
5832 }
5833
CreateMetadataIdentifierForType(QualType T)5834 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
5835 return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
5836 }
5837
5838 llvm::Metadata *
CreateMetadataIdentifierForVirtualMemPtrType(QualType T)5839 CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
5840 return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
5841 }
5842
5843 // Generalize pointer types to a void pointer with the qualifiers of the
5844 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
5845 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
5846 // 'void *'.
GeneralizeType(ASTContext & Ctx,QualType Ty)5847 static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
5848 if (!Ty->isPointerType())
5849 return Ty;
5850
5851 return Ctx.getPointerType(
5852 QualType(Ctx.VoidTy).withCVRQualifiers(
5853 Ty->getPointeeType().getCVRQualifiers()));
5854 }
5855
5856 // Apply type generalization to a FunctionType's return and argument types
GeneralizeFunctionType(ASTContext & Ctx,QualType Ty)5857 static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
5858 if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
5859 SmallVector<QualType, 8> GeneralizedParams;
5860 for (auto &Param : FnType->param_types())
5861 GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
5862
5863 return Ctx.getFunctionType(
5864 GeneralizeType(Ctx, FnType->getReturnType()),
5865 GeneralizedParams, FnType->getExtProtoInfo());
5866 }
5867
5868 if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
5869 return Ctx.getFunctionNoProtoType(
5870 GeneralizeType(Ctx, FnType->getReturnType()));
5871
5872 llvm_unreachable("Encountered unknown FunctionType");
5873 }
5874
CreateMetadataIdentifierGeneralized(QualType T)5875 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
5876 return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
5877 GeneralizedMetadataIdMap, ".generalized");
5878 }
5879
5880 /// Returns whether this module needs the "all-vtables" type identifier.
NeedAllVtablesTypeId() const5881 bool CodeGenModule::NeedAllVtablesTypeId() const {
5882 // Returns true if at least one of vtable-based CFI checkers is enabled and
5883 // is not in the trapping mode.
5884 return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
5885 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
5886 (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
5887 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
5888 (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
5889 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
5890 (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
5891 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
5892 }
5893
AddVTableTypeMetadata(llvm::GlobalVariable * VTable,CharUnits Offset,const CXXRecordDecl * RD)5894 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
5895 CharUnits Offset,
5896 const CXXRecordDecl *RD) {
5897 llvm::Metadata *MD =
5898 CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
5899 VTable->addTypeMetadata(Offset.getQuantity(), MD);
5900
5901 if (CodeGenOpts.SanitizeCfiCrossDso)
5902 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
5903 VTable->addTypeMetadata(Offset.getQuantity(),
5904 llvm::ConstantAsMetadata::get(CrossDsoTypeId));
5905
5906 if (NeedAllVtablesTypeId()) {
5907 llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
5908 VTable->addTypeMetadata(Offset.getQuantity(), MD);
5909 }
5910 }
5911
getSanStats()5912 llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
5913 if (!SanStats)
5914 SanStats = std::make_unique<llvm::SanitizerStatReport>(&getModule());
5915
5916 return *SanStats;
5917 }
5918 llvm::Value *
createOpenCLIntToSamplerConversion(const Expr * E,CodeGenFunction & CGF)5919 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
5920 CodeGenFunction &CGF) {
5921 llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
5922 auto SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
5923 auto FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
5924 return CGF.Builder.CreateCall(CreateRuntimeFunction(FTy,
5925 "__translate_sampler_initializer"),
5926 {C});
5927 }
5928