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 "CGOpenMPRuntimeAMDGCN.h"
23 #include "CGOpenMPRuntimeNVPTX.h"
24 #include "CodeGenFunction.h"
25 #include "CodeGenPGO.h"
26 #include "ConstantEmitter.h"
27 #include "CoverageMappingGen.h"
28 #include "TargetInfo.h"
29 #include "clang/AST/ASTContext.h"
30 #include "clang/AST/CharUnits.h"
31 #include "clang/AST/DeclCXX.h"
32 #include "clang/AST/DeclObjC.h"
33 #include "clang/AST/DeclTemplate.h"
34 #include "clang/AST/Mangle.h"
35 #include "clang/AST/RecordLayout.h"
36 #include "clang/AST/RecursiveASTVisitor.h"
37 #include "clang/AST/StmtVisitor.h"
38 #include "clang/Basic/Builtins.h"
39 #include "clang/Basic/CharInfo.h"
40 #include "clang/Basic/CodeGenOptions.h"
41 #include "clang/Basic/Diagnostic.h"
42 #include "clang/Basic/FileManager.h"
43 #include "clang/Basic/Module.h"
44 #include "clang/Basic/SourceManager.h"
45 #include "clang/Basic/TargetInfo.h"
46 #include "clang/Basic/Version.h"
47 #include "clang/CodeGen/ConstantInitBuilder.h"
48 #include "clang/Frontend/FrontendDiagnostic.h"
49 #include "llvm/ADT/StringSwitch.h"
50 #include "llvm/ADT/Triple.h"
51 #include "llvm/Analysis/TargetLibraryInfo.h"
52 #include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
53 #include "llvm/IR/CallingConv.h"
54 #include "llvm/IR/DataLayout.h"
55 #include "llvm/IR/Intrinsics.h"
56 #include "llvm/IR/LLVMContext.h"
57 #include "llvm/IR/Module.h"
58 #include "llvm/IR/ProfileSummary.h"
59 #include "llvm/ProfileData/InstrProfReader.h"
60 #include "llvm/Support/CodeGen.h"
61 #include "llvm/Support/CommandLine.h"
62 #include "llvm/Support/ConvertUTF.h"
63 #include "llvm/Support/ErrorHandling.h"
64 #include "llvm/Support/MD5.h"
65 #include "llvm/Support/TimeProfiler.h"
66
67 using namespace clang;
68 using namespace CodeGen;
69
70 static llvm::cl::opt<bool> LimitedCoverage(
71 "limited-coverage-experimental", llvm::cl::ZeroOrMore, llvm::cl::Hidden,
72 llvm::cl::desc("Emit limited coverage mapping information (experimental)"),
73 llvm::cl::init(false));
74
75 static const char AnnotationSection[] = "llvm.metadata";
76
createCXXABI(CodeGenModule & CGM)77 static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
78 switch (CGM.getTarget().getCXXABI().getKind()) {
79 case TargetCXXABI::AppleARM64:
80 case TargetCXXABI::Fuchsia:
81 case TargetCXXABI::GenericAArch64:
82 case TargetCXXABI::GenericARM:
83 case TargetCXXABI::iOS:
84 case TargetCXXABI::WatchOS:
85 case TargetCXXABI::GenericMIPS:
86 case TargetCXXABI::GenericItanium:
87 case TargetCXXABI::WebAssembly:
88 case TargetCXXABI::XL:
89 return CreateItaniumCXXABI(CGM);
90 case TargetCXXABI::Microsoft:
91 return CreateMicrosoftCXXABI(CGM);
92 }
93
94 llvm_unreachable("invalid C++ ABI kind");
95 }
96
CodeGenModule(ASTContext & C,const HeaderSearchOptions & HSO,const PreprocessorOptions & PPO,const CodeGenOptions & CGO,llvm::Module & M,DiagnosticsEngine & diags,CoverageSourceInfo * CoverageInfo)97 CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
98 const PreprocessorOptions &PPO,
99 const CodeGenOptions &CGO, llvm::Module &M,
100 DiagnosticsEngine &diags,
101 CoverageSourceInfo *CoverageInfo)
102 : Context(C), LangOpts(C.getLangOpts()), HeaderSearchOpts(HSO),
103 PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
104 Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
105 VMContext(M.getContext()), Types(*this), VTables(*this),
106 SanitizerMD(new SanitizerMetadata(*this)) {
107
108 // Initialize the type cache.
109 llvm::LLVMContext &LLVMContext = M.getContext();
110 VoidTy = llvm::Type::getVoidTy(LLVMContext);
111 Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
112 Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
113 Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
114 Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
115 HalfTy = llvm::Type::getHalfTy(LLVMContext);
116 BFloatTy = llvm::Type::getBFloatTy(LLVMContext);
117 FloatTy = llvm::Type::getFloatTy(LLVMContext);
118 DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
119 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
120 PointerAlignInBytes =
121 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
122 SizeSizeInBytes =
123 C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
124 IntAlignInBytes =
125 C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
126 CharTy =
127 llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getCharWidth());
128 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
129 IntPtrTy = llvm::IntegerType::get(LLVMContext,
130 C.getTargetInfo().getMaxPointerWidth());
131 Int8PtrTy = Int8Ty->getPointerTo(0);
132 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
133 AllocaInt8PtrTy = Int8Ty->getPointerTo(
134 M.getDataLayout().getAllocaAddrSpace());
135 ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
136
137 RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
138
139 if (LangOpts.ObjC)
140 createObjCRuntime();
141 if (LangOpts.OpenCL)
142 createOpenCLRuntime();
143 if (LangOpts.OpenMP)
144 createOpenMPRuntime();
145 if (LangOpts.CUDA)
146 createCUDARuntime();
147
148 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
149 if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
150 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
151 TBAA.reset(new CodeGenTBAA(Context, TheModule, CodeGenOpts, getLangOpts(),
152 getCXXABI().getMangleContext()));
153
154 // If debug info or coverage generation is enabled, create the CGDebugInfo
155 // object.
156 if (CodeGenOpts.getDebugInfo() != codegenoptions::NoDebugInfo ||
157 CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)
158 DebugInfo.reset(new CGDebugInfo(*this));
159
160 Block.GlobalUniqueCount = 0;
161
162 if (C.getLangOpts().ObjC)
163 ObjCData.reset(new ObjCEntrypoints());
164
165 if (CodeGenOpts.hasProfileClangUse()) {
166 auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
167 CodeGenOpts.ProfileInstrumentUsePath, CodeGenOpts.ProfileRemappingFile);
168 if (auto E = ReaderOrErr.takeError()) {
169 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
170 "Could not read profile %0: %1");
171 llvm::handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EI) {
172 getDiags().Report(DiagID) << CodeGenOpts.ProfileInstrumentUsePath
173 << EI.message();
174 });
175 } else
176 PGOReader = std::move(ReaderOrErr.get());
177 }
178
179 // If coverage mapping generation is enabled, create the
180 // CoverageMappingModuleGen object.
181 if (CodeGenOpts.CoverageMapping)
182 CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
183 }
184
~CodeGenModule()185 CodeGenModule::~CodeGenModule() {}
186
createObjCRuntime()187 void CodeGenModule::createObjCRuntime() {
188 // This is just isGNUFamily(), but we want to force implementors of
189 // new ABIs to decide how best to do this.
190 switch (LangOpts.ObjCRuntime.getKind()) {
191 case ObjCRuntime::GNUstep:
192 case ObjCRuntime::GCC:
193 case ObjCRuntime::ObjFW:
194 ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
195 return;
196
197 case ObjCRuntime::FragileMacOSX:
198 case ObjCRuntime::MacOSX:
199 case ObjCRuntime::iOS:
200 case ObjCRuntime::WatchOS:
201 ObjCRuntime.reset(CreateMacObjCRuntime(*this));
202 return;
203 }
204 llvm_unreachable("bad runtime kind");
205 }
206
createOpenCLRuntime()207 void CodeGenModule::createOpenCLRuntime() {
208 OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
209 }
210
createOpenMPRuntime()211 void CodeGenModule::createOpenMPRuntime() {
212 // Select a specialized code generation class based on the target, if any.
213 // If it does not exist use the default implementation.
214 switch (getTriple().getArch()) {
215 case llvm::Triple::nvptx:
216 case llvm::Triple::nvptx64:
217 assert(getLangOpts().OpenMPIsDevice &&
218 "OpenMP NVPTX is only prepared to deal with device code.");
219 OpenMPRuntime.reset(new CGOpenMPRuntimeNVPTX(*this));
220 break;
221 case llvm::Triple::amdgcn:
222 assert(getLangOpts().OpenMPIsDevice &&
223 "OpenMP AMDGCN is only prepared to deal with device code.");
224 OpenMPRuntime.reset(new CGOpenMPRuntimeAMDGCN(*this));
225 break;
226 default:
227 if (LangOpts.OpenMPSimd)
228 OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
229 else
230 OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
231 break;
232 }
233 }
234
createCUDARuntime()235 void CodeGenModule::createCUDARuntime() {
236 CUDARuntime.reset(CreateNVCUDARuntime(*this));
237 }
238
addReplacement(StringRef Name,llvm::Constant * C)239 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
240 Replacements[Name] = C;
241 }
242
applyReplacements()243 void CodeGenModule::applyReplacements() {
244 for (auto &I : Replacements) {
245 StringRef MangledName = I.first();
246 llvm::Constant *Replacement = I.second;
247 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
248 if (!Entry)
249 continue;
250 auto *OldF = cast<llvm::Function>(Entry);
251 auto *NewF = dyn_cast<llvm::Function>(Replacement);
252 if (!NewF) {
253 if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
254 NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
255 } else {
256 auto *CE = cast<llvm::ConstantExpr>(Replacement);
257 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
258 CE->getOpcode() == llvm::Instruction::GetElementPtr);
259 NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
260 }
261 }
262
263 // Replace old with new, but keep the old order.
264 OldF->replaceAllUsesWith(Replacement);
265 if (NewF) {
266 NewF->removeFromParent();
267 OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
268 NewF);
269 }
270 OldF->eraseFromParent();
271 }
272 }
273
addGlobalValReplacement(llvm::GlobalValue * GV,llvm::Constant * C)274 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
275 GlobalValReplacements.push_back(std::make_pair(GV, C));
276 }
277
applyGlobalValReplacements()278 void CodeGenModule::applyGlobalValReplacements() {
279 for (auto &I : GlobalValReplacements) {
280 llvm::GlobalValue *GV = I.first;
281 llvm::Constant *C = I.second;
282
283 GV->replaceAllUsesWith(C);
284 GV->eraseFromParent();
285 }
286 }
287
288 // This is only used in aliases that we created and we know they have a
289 // linear structure.
getAliasedGlobal(const llvm::GlobalIndirectSymbol & GIS)290 static const llvm::GlobalObject *getAliasedGlobal(
291 const llvm::GlobalIndirectSymbol &GIS) {
292 llvm::SmallPtrSet<const llvm::GlobalIndirectSymbol*, 4> Visited;
293 const llvm::Constant *C = &GIS;
294 for (;;) {
295 C = C->stripPointerCasts();
296 if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
297 return GO;
298 // stripPointerCasts will not walk over weak aliases.
299 auto *GIS2 = dyn_cast<llvm::GlobalIndirectSymbol>(C);
300 if (!GIS2)
301 return nullptr;
302 if (!Visited.insert(GIS2).second)
303 return nullptr;
304 C = GIS2->getIndirectSymbol();
305 }
306 }
307
checkAliases()308 void CodeGenModule::checkAliases() {
309 // Check if the constructed aliases are well formed. It is really unfortunate
310 // that we have to do this in CodeGen, but we only construct mangled names
311 // and aliases during codegen.
312 bool Error = false;
313 DiagnosticsEngine &Diags = getDiags();
314 for (const GlobalDecl &GD : Aliases) {
315 const auto *D = cast<ValueDecl>(GD.getDecl());
316 SourceLocation Location;
317 bool IsIFunc = D->hasAttr<IFuncAttr>();
318 if (const Attr *A = D->getDefiningAttr())
319 Location = A->getLocation();
320 else
321 llvm_unreachable("Not an alias or ifunc?");
322 StringRef MangledName = getMangledName(GD);
323 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
324 auto *Alias = cast<llvm::GlobalIndirectSymbol>(Entry);
325 const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
326 if (!GV) {
327 Error = true;
328 Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
329 } else if (GV->isDeclaration()) {
330 Error = true;
331 Diags.Report(Location, diag::err_alias_to_undefined)
332 << IsIFunc << IsIFunc;
333 } else if (IsIFunc) {
334 // Check resolver function type.
335 llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(
336 GV->getType()->getPointerElementType());
337 assert(FTy);
338 if (!FTy->getReturnType()->isPointerTy())
339 Diags.Report(Location, diag::err_ifunc_resolver_return);
340 }
341
342 llvm::Constant *Aliasee = Alias->getIndirectSymbol();
343 llvm::GlobalValue *AliaseeGV;
344 if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
345 AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
346 else
347 AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
348
349 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
350 StringRef AliasSection = SA->getName();
351 if (AliasSection != AliaseeGV->getSection())
352 Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
353 << AliasSection << IsIFunc << IsIFunc;
354 }
355
356 // We have to handle alias to weak aliases in here. LLVM itself disallows
357 // this since the object semantics would not match the IL one. For
358 // compatibility with gcc we implement it by just pointing the alias
359 // to its aliasee's aliasee. We also warn, since the user is probably
360 // expecting the link to be weak.
361 if (auto GA = dyn_cast<llvm::GlobalIndirectSymbol>(AliaseeGV)) {
362 if (GA->isInterposable()) {
363 Diags.Report(Location, diag::warn_alias_to_weak_alias)
364 << GV->getName() << GA->getName() << IsIFunc;
365 Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
366 GA->getIndirectSymbol(), Alias->getType());
367 Alias->setIndirectSymbol(Aliasee);
368 }
369 }
370 }
371 if (!Error)
372 return;
373
374 for (const GlobalDecl &GD : Aliases) {
375 StringRef MangledName = getMangledName(GD);
376 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
377 auto *Alias = cast<llvm::GlobalIndirectSymbol>(Entry);
378 Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
379 Alias->eraseFromParent();
380 }
381 }
382
clear()383 void CodeGenModule::clear() {
384 DeferredDeclsToEmit.clear();
385 if (OpenMPRuntime)
386 OpenMPRuntime->clear();
387 }
388
reportDiagnostics(DiagnosticsEngine & Diags,StringRef MainFile)389 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
390 StringRef MainFile) {
391 if (!hasDiagnostics())
392 return;
393 if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
394 if (MainFile.empty())
395 MainFile = "<stdin>";
396 Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
397 } else {
398 if (Mismatched > 0)
399 Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
400
401 if (Missing > 0)
402 Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
403 }
404 }
405
setVisibilityFromDLLStorageClass(const clang::LangOptions & LO,llvm::Module & M)406 static void setVisibilityFromDLLStorageClass(const clang::LangOptions &LO,
407 llvm::Module &M) {
408 if (!LO.VisibilityFromDLLStorageClass)
409 return;
410
411 llvm::GlobalValue::VisibilityTypes DLLExportVisibility =
412 CodeGenModule::GetLLVMVisibility(LO.getDLLExportVisibility());
413 llvm::GlobalValue::VisibilityTypes NoDLLStorageClassVisibility =
414 CodeGenModule::GetLLVMVisibility(LO.getNoDLLStorageClassVisibility());
415 llvm::GlobalValue::VisibilityTypes ExternDeclDLLImportVisibility =
416 CodeGenModule::GetLLVMVisibility(LO.getExternDeclDLLImportVisibility());
417 llvm::GlobalValue::VisibilityTypes ExternDeclNoDLLStorageClassVisibility =
418 CodeGenModule::GetLLVMVisibility(
419 LO.getExternDeclNoDLLStorageClassVisibility());
420
421 for (llvm::GlobalValue &GV : M.global_values()) {
422 if (GV.hasAppendingLinkage() || GV.hasLocalLinkage())
423 continue;
424
425 // Reset DSO locality before setting the visibility. This removes
426 // any effects that visibility options and annotations may have
427 // had on the DSO locality. Setting the visibility will implicitly set
428 // appropriate globals to DSO Local; however, this will be pessimistic
429 // w.r.t. to the normal compiler IRGen.
430 GV.setDSOLocal(false);
431
432 if (GV.isDeclarationForLinker()) {
433 GV.setVisibility(GV.getDLLStorageClass() ==
434 llvm::GlobalValue::DLLImportStorageClass
435 ? ExternDeclDLLImportVisibility
436 : ExternDeclNoDLLStorageClassVisibility);
437 } else {
438 GV.setVisibility(GV.getDLLStorageClass() ==
439 llvm::GlobalValue::DLLExportStorageClass
440 ? DLLExportVisibility
441 : NoDLLStorageClassVisibility);
442 }
443
444 GV.setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
445 }
446 }
447
Release()448 void CodeGenModule::Release() {
449 EmitDeferred();
450 EmitVTablesOpportunistically();
451 applyGlobalValReplacements();
452 applyReplacements();
453 checkAliases();
454 emitMultiVersionFunctions();
455 EmitCXXGlobalInitFunc();
456 EmitCXXGlobalCleanUpFunc();
457 registerGlobalDtorsWithAtExit();
458 EmitCXXThreadLocalInitFunc();
459 if (ObjCRuntime)
460 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
461 AddGlobalCtor(ObjCInitFunction);
462 if (Context.getLangOpts().CUDA && !Context.getLangOpts().CUDAIsDevice &&
463 CUDARuntime) {
464 if (llvm::Function *CudaCtorFunction =
465 CUDARuntime->makeModuleCtorFunction())
466 AddGlobalCtor(CudaCtorFunction);
467 }
468 if (OpenMPRuntime) {
469 if (llvm::Function *OpenMPRequiresDirectiveRegFun =
470 OpenMPRuntime->emitRequiresDirectiveRegFun()) {
471 AddGlobalCtor(OpenMPRequiresDirectiveRegFun, 0);
472 }
473 OpenMPRuntime->createOffloadEntriesAndInfoMetadata();
474 OpenMPRuntime->clear();
475 }
476 if (PGOReader) {
477 getModule().setProfileSummary(
478 PGOReader->getSummary(/* UseCS */ false).getMD(VMContext),
479 llvm::ProfileSummary::PSK_Instr);
480 if (PGOStats.hasDiagnostics())
481 PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
482 }
483 EmitCtorList(GlobalCtors, "llvm.global_ctors");
484 EmitCtorList(GlobalDtors, "llvm.global_dtors");
485 EmitGlobalAnnotations();
486 EmitStaticExternCAliases();
487 EmitDeferredUnusedCoverageMappings();
488 if (CoverageMapping)
489 CoverageMapping->emit();
490 if (CodeGenOpts.SanitizeCfiCrossDso) {
491 CodeGenFunction(*this).EmitCfiCheckFail();
492 CodeGenFunction(*this).EmitCfiCheckStub();
493 }
494 emitAtAvailableLinkGuard();
495 if (Context.getTargetInfo().getTriple().isWasm() &&
496 !Context.getTargetInfo().getTriple().isOSEmscripten()) {
497 EmitMainVoidAlias();
498 }
499 emitLLVMUsed();
500 if (SanStats)
501 SanStats->finish();
502
503 if (CodeGenOpts.Autolink &&
504 (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
505 EmitModuleLinkOptions();
506 }
507
508 // On ELF we pass the dependent library specifiers directly to the linker
509 // without manipulating them. This is in contrast to other platforms where
510 // they are mapped to a specific linker option by the compiler. This
511 // difference is a result of the greater variety of ELF linkers and the fact
512 // that ELF linkers tend to handle libraries in a more complicated fashion
513 // than on other platforms. This forces us to defer handling the dependent
514 // libs to the linker.
515 //
516 // CUDA/HIP device and host libraries are different. Currently there is no
517 // way to differentiate dependent libraries for host or device. Existing
518 // usage of #pragma comment(lib, *) is intended for host libraries on
519 // Windows. Therefore emit llvm.dependent-libraries only for host.
520 if (!ELFDependentLibraries.empty() && !Context.getLangOpts().CUDAIsDevice) {
521 auto *NMD = getModule().getOrInsertNamedMetadata("llvm.dependent-libraries");
522 for (auto *MD : ELFDependentLibraries)
523 NMD->addOperand(MD);
524 }
525
526 // Record mregparm value now so it is visible through rest of codegen.
527 if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
528 getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
529 CodeGenOpts.NumRegisterParameters);
530
531 if (CodeGenOpts.DwarfVersion) {
532 getModule().addModuleFlag(llvm::Module::Max, "Dwarf Version",
533 CodeGenOpts.DwarfVersion);
534 }
535
536 if (Context.getLangOpts().SemanticInterposition)
537 // Require various optimization to respect semantic interposition.
538 getModule().setSemanticInterposition(1);
539
540 if (CodeGenOpts.EmitCodeView) {
541 // Indicate that we want CodeView in the metadata.
542 getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
543 }
544 if (CodeGenOpts.CodeViewGHash) {
545 getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
546 }
547 if (CodeGenOpts.ControlFlowGuard) {
548 // Function ID tables and checks for Control Flow Guard (cfguard=2).
549 getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 2);
550 } else if (CodeGenOpts.ControlFlowGuardNoChecks) {
551 // Function ID tables for Control Flow Guard (cfguard=1).
552 getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 1);
553 }
554 if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
555 // We don't support LTO with 2 with different StrictVTablePointers
556 // FIXME: we could support it by stripping all the information introduced
557 // by StrictVTablePointers.
558
559 getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
560
561 llvm::Metadata *Ops[2] = {
562 llvm::MDString::get(VMContext, "StrictVTablePointers"),
563 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
564 llvm::Type::getInt32Ty(VMContext), 1))};
565
566 getModule().addModuleFlag(llvm::Module::Require,
567 "StrictVTablePointersRequirement",
568 llvm::MDNode::get(VMContext, Ops));
569 }
570 if (getModuleDebugInfo())
571 // We support a single version in the linked module. The LLVM
572 // parser will drop debug info with a different version number
573 // (and warn about it, too).
574 getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
575 llvm::DEBUG_METADATA_VERSION);
576
577 // We need to record the widths of enums and wchar_t, so that we can generate
578 // the correct build attributes in the ARM backend. wchar_size is also used by
579 // TargetLibraryInfo.
580 uint64_t WCharWidth =
581 Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
582 getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
583
584 llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
585 if ( Arch == llvm::Triple::arm
586 || Arch == llvm::Triple::armeb
587 || Arch == llvm::Triple::thumb
588 || Arch == llvm::Triple::thumbeb) {
589 // The minimum width of an enum in bytes
590 uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
591 getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
592 }
593
594 if (Arch == llvm::Triple::riscv32 || Arch == llvm::Triple::riscv64) {
595 StringRef ABIStr = Target.getABI();
596 llvm::LLVMContext &Ctx = TheModule.getContext();
597 getModule().addModuleFlag(llvm::Module::Error, "target-abi",
598 llvm::MDString::get(Ctx, ABIStr));
599 }
600
601 if (CodeGenOpts.SanitizeCfiCrossDso) {
602 // Indicate that we want cross-DSO control flow integrity checks.
603 getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
604 }
605
606 if (CodeGenOpts.WholeProgramVTables) {
607 // Indicate whether VFE was enabled for this module, so that the
608 // vcall_visibility metadata added under whole program vtables is handled
609 // appropriately in the optimizer.
610 getModule().addModuleFlag(llvm::Module::Error, "Virtual Function Elim",
611 CodeGenOpts.VirtualFunctionElimination);
612 }
613
614 if (LangOpts.Sanitize.has(SanitizerKind::CFIICall)) {
615 getModule().addModuleFlag(llvm::Module::Override,
616 "CFI Canonical Jump Tables",
617 CodeGenOpts.SanitizeCfiCanonicalJumpTables);
618 }
619
620 if (CodeGenOpts.CFProtectionReturn &&
621 Target.checkCFProtectionReturnSupported(getDiags())) {
622 // Indicate that we want to instrument return control flow protection.
623 getModule().addModuleFlag(llvm::Module::Override, "cf-protection-return",
624 1);
625 }
626
627 if (CodeGenOpts.CFProtectionBranch &&
628 Target.checkCFProtectionBranchSupported(getDiags())) {
629 // Indicate that we want to instrument branch control flow protection.
630 getModule().addModuleFlag(llvm::Module::Override, "cf-protection-branch",
631 1);
632 }
633
634 if (Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_32 ||
635 Arch == llvm::Triple::aarch64_be) {
636 getModule().addModuleFlag(llvm::Module::Error,
637 "branch-target-enforcement",
638 LangOpts.BranchTargetEnforcement);
639
640 getModule().addModuleFlag(llvm::Module::Error, "sign-return-address",
641 LangOpts.hasSignReturnAddress());
642
643 getModule().addModuleFlag(llvm::Module::Error, "sign-return-address-all",
644 LangOpts.isSignReturnAddressScopeAll());
645
646 getModule().addModuleFlag(llvm::Module::Error,
647 "sign-return-address-with-bkey",
648 !LangOpts.isSignReturnAddressWithAKey());
649 }
650
651 if (!CodeGenOpts.MemoryProfileOutput.empty()) {
652 llvm::LLVMContext &Ctx = TheModule.getContext();
653 getModule().addModuleFlag(
654 llvm::Module::Error, "MemProfProfileFilename",
655 llvm::MDString::get(Ctx, CodeGenOpts.MemoryProfileOutput));
656 }
657
658 if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
659 // Indicate whether __nvvm_reflect should be configured to flush denormal
660 // floating point values to 0. (This corresponds to its "__CUDA_FTZ"
661 // property.)
662 getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
663 CodeGenOpts.FP32DenormalMode.Output !=
664 llvm::DenormalMode::IEEE);
665 }
666
667 // Emit OpenCL specific module metadata: OpenCL/SPIR version.
668 if (LangOpts.OpenCL) {
669 EmitOpenCLMetadata();
670 // Emit SPIR version.
671 if (getTriple().isSPIR()) {
672 // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
673 // opencl.spir.version named metadata.
674 // C++ is backwards compatible with OpenCL v2.0.
675 auto Version = LangOpts.OpenCLCPlusPlus ? 200 : LangOpts.OpenCLVersion;
676 llvm::Metadata *SPIRVerElts[] = {
677 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
678 Int32Ty, Version / 100)),
679 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
680 Int32Ty, (Version / 100 > 1) ? 0 : 2))};
681 llvm::NamedMDNode *SPIRVerMD =
682 TheModule.getOrInsertNamedMetadata("opencl.spir.version");
683 llvm::LLVMContext &Ctx = TheModule.getContext();
684 SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
685 }
686 }
687
688 if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
689 assert(PLevel < 3 && "Invalid PIC Level");
690 getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
691 if (Context.getLangOpts().PIE)
692 getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
693 }
694
695 if (getCodeGenOpts().CodeModel.size() > 0) {
696 unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
697 .Case("tiny", llvm::CodeModel::Tiny)
698 .Case("small", llvm::CodeModel::Small)
699 .Case("kernel", llvm::CodeModel::Kernel)
700 .Case("medium", llvm::CodeModel::Medium)
701 .Case("large", llvm::CodeModel::Large)
702 .Default(~0u);
703 if (CM != ~0u) {
704 llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
705 getModule().setCodeModel(codeModel);
706 }
707 }
708
709 if (CodeGenOpts.NoPLT)
710 getModule().setRtLibUseGOT();
711
712 SimplifyPersonality();
713
714 if (getCodeGenOpts().EmitDeclMetadata)
715 EmitDeclMetadata();
716
717 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
718 EmitCoverageFile();
719
720 if (CGDebugInfo *DI = getModuleDebugInfo())
721 DI->finalize();
722
723 if (getCodeGenOpts().EmitVersionIdentMetadata)
724 EmitVersionIdentMetadata();
725
726 if (!getCodeGenOpts().RecordCommandLine.empty())
727 EmitCommandLineMetadata();
728
729 getTargetCodeGenInfo().emitTargetMetadata(*this, MangledDeclNames);
730
731 EmitBackendOptionsMetadata(getCodeGenOpts());
732
733 // Set visibility from DLL storage class
734 // We do this at the end of LLVM IR generation; after any operation
735 // that might affect the DLL storage class or the visibility, and
736 // before anything that might act on these.
737 setVisibilityFromDLLStorageClass(LangOpts, getModule());
738 }
739
EmitOpenCLMetadata()740 void CodeGenModule::EmitOpenCLMetadata() {
741 // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
742 // opencl.ocl.version named metadata node.
743 // C++ is backwards compatible with OpenCL v2.0.
744 // FIXME: We might need to add CXX version at some point too?
745 auto Version = LangOpts.OpenCLCPlusPlus ? 200 : LangOpts.OpenCLVersion;
746 llvm::Metadata *OCLVerElts[] = {
747 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
748 Int32Ty, Version / 100)),
749 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
750 Int32Ty, (Version % 100) / 10))};
751 llvm::NamedMDNode *OCLVerMD =
752 TheModule.getOrInsertNamedMetadata("opencl.ocl.version");
753 llvm::LLVMContext &Ctx = TheModule.getContext();
754 OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
755 }
756
EmitBackendOptionsMetadata(const CodeGenOptions CodeGenOpts)757 void CodeGenModule::EmitBackendOptionsMetadata(
758 const CodeGenOptions CodeGenOpts) {
759 switch (getTriple().getArch()) {
760 default:
761 break;
762 case llvm::Triple::riscv32:
763 case llvm::Triple::riscv64:
764 getModule().addModuleFlag(llvm::Module::Error, "SmallDataLimit",
765 CodeGenOpts.SmallDataLimit);
766 break;
767 }
768 }
769
UpdateCompletedType(const TagDecl * TD)770 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
771 // Make sure that this type is translated.
772 Types.UpdateCompletedType(TD);
773 }
774
RefreshTypeCacheForClass(const CXXRecordDecl * RD)775 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
776 // Make sure that this type is translated.
777 Types.RefreshTypeCacheForClass(RD);
778 }
779
getTBAATypeInfo(QualType QTy)780 llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
781 if (!TBAA)
782 return nullptr;
783 return TBAA->getTypeInfo(QTy);
784 }
785
getTBAAAccessInfo(QualType AccessType)786 TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
787 if (!TBAA)
788 return TBAAAccessInfo();
789 if (getLangOpts().CUDAIsDevice) {
790 // As CUDA builtin surface/texture types are replaced, skip generating TBAA
791 // access info.
792 if (AccessType->isCUDADeviceBuiltinSurfaceType()) {
793 if (getTargetCodeGenInfo().getCUDADeviceBuiltinSurfaceDeviceType() !=
794 nullptr)
795 return TBAAAccessInfo();
796 } else if (AccessType->isCUDADeviceBuiltinTextureType()) {
797 if (getTargetCodeGenInfo().getCUDADeviceBuiltinTextureDeviceType() !=
798 nullptr)
799 return TBAAAccessInfo();
800 }
801 }
802 return TBAA->getAccessInfo(AccessType);
803 }
804
805 TBAAAccessInfo
getTBAAVTablePtrAccessInfo(llvm::Type * VTablePtrType)806 CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
807 if (!TBAA)
808 return TBAAAccessInfo();
809 return TBAA->getVTablePtrAccessInfo(VTablePtrType);
810 }
811
getTBAAStructInfo(QualType QTy)812 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
813 if (!TBAA)
814 return nullptr;
815 return TBAA->getTBAAStructInfo(QTy);
816 }
817
getTBAABaseTypeInfo(QualType QTy)818 llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
819 if (!TBAA)
820 return nullptr;
821 return TBAA->getBaseTypeInfo(QTy);
822 }
823
getTBAAAccessTagInfo(TBAAAccessInfo Info)824 llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
825 if (!TBAA)
826 return nullptr;
827 return TBAA->getAccessTagInfo(Info);
828 }
829
mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,TBAAAccessInfo TargetInfo)830 TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
831 TBAAAccessInfo TargetInfo) {
832 if (!TBAA)
833 return TBAAAccessInfo();
834 return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
835 }
836
837 TBAAAccessInfo
mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,TBAAAccessInfo InfoB)838 CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
839 TBAAAccessInfo InfoB) {
840 if (!TBAA)
841 return TBAAAccessInfo();
842 return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
843 }
844
845 TBAAAccessInfo
mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,TBAAAccessInfo SrcInfo)846 CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
847 TBAAAccessInfo SrcInfo) {
848 if (!TBAA)
849 return TBAAAccessInfo();
850 return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
851 }
852
DecorateInstructionWithTBAA(llvm::Instruction * Inst,TBAAAccessInfo TBAAInfo)853 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
854 TBAAAccessInfo TBAAInfo) {
855 if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
856 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
857 }
858
DecorateInstructionWithInvariantGroup(llvm::Instruction * I,const CXXRecordDecl * RD)859 void CodeGenModule::DecorateInstructionWithInvariantGroup(
860 llvm::Instruction *I, const CXXRecordDecl *RD) {
861 I->setMetadata(llvm::LLVMContext::MD_invariant_group,
862 llvm::MDNode::get(getLLVMContext(), {}));
863 }
864
Error(SourceLocation loc,StringRef message)865 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
866 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
867 getDiags().Report(Context.getFullLoc(loc), diagID) << message;
868 }
869
870 /// ErrorUnsupported - Print out an error that codegen doesn't support the
871 /// specified stmt yet.
ErrorUnsupported(const Stmt * S,const char * Type)872 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
873 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
874 "cannot compile this %0 yet");
875 std::string Msg = Type;
876 getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID)
877 << Msg << S->getSourceRange();
878 }
879
880 /// ErrorUnsupported - Print out an error that codegen doesn't support the
881 /// specified decl yet.
ErrorUnsupported(const Decl * D,const char * Type)882 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
883 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
884 "cannot compile this %0 yet");
885 std::string Msg = Type;
886 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
887 }
888
getSize(CharUnits size)889 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
890 return llvm::ConstantInt::get(SizeTy, size.getQuantity());
891 }
892
setGlobalVisibility(llvm::GlobalValue * GV,const NamedDecl * D) const893 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
894 const NamedDecl *D) const {
895 if (GV->hasDLLImportStorageClass())
896 return;
897 // Internal definitions always have default visibility.
898 if (GV->hasLocalLinkage()) {
899 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
900 return;
901 }
902 if (!D)
903 return;
904 // Set visibility for definitions, and for declarations if requested globally
905 // or set explicitly.
906 LinkageInfo LV = D->getLinkageAndVisibility();
907 if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls ||
908 !GV->isDeclarationForLinker())
909 GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
910 }
911
shouldAssumeDSOLocal(const CodeGenModule & CGM,llvm::GlobalValue * GV)912 static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
913 llvm::GlobalValue *GV) {
914 if (GV->hasLocalLinkage())
915 return true;
916
917 if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
918 return true;
919
920 // DLLImport explicitly marks the GV as external.
921 if (GV->hasDLLImportStorageClass())
922 return false;
923
924 const llvm::Triple &TT = CGM.getTriple();
925 if (TT.isWindowsGNUEnvironment()) {
926 // In MinGW, variables without DLLImport can still be automatically
927 // imported from a DLL by the linker; don't mark variables that
928 // potentially could come from another DLL as DSO local.
929 if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
930 !GV->isThreadLocal())
931 return false;
932 }
933
934 // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
935 // remain unresolved in the link, they can be resolved to zero, which is
936 // outside the current DSO.
937 if (TT.isOSBinFormatCOFF() && GV->hasExternalWeakLinkage())
938 return false;
939
940 // Every other GV is local on COFF.
941 // Make an exception for windows OS in the triple: Some firmware builds use
942 // *-win32-macho triples. This (accidentally?) produced windows relocations
943 // without GOT tables in older clang versions; Keep this behaviour.
944 // FIXME: even thread local variables?
945 if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
946 return true;
947
948 const auto &CGOpts = CGM.getCodeGenOpts();
949 llvm::Reloc::Model RM = CGOpts.RelocationModel;
950 const auto &LOpts = CGM.getLangOpts();
951
952 if (TT.isOSBinFormatMachO()) {
953 if (RM == llvm::Reloc::Static)
954 return true;
955 return GV->isStrongDefinitionForLinker();
956 }
957
958 // Only handle COFF and ELF for now.
959 if (!TT.isOSBinFormatELF())
960 return false;
961
962 if (RM != llvm::Reloc::Static && !LOpts.PIE) {
963 // On ELF, if -fno-semantic-interposition is specified and the target
964 // supports local aliases, there will be neither CC1
965 // -fsemantic-interposition nor -fhalf-no-semantic-interposition. Set
966 // dso_local if using a local alias is preferable (can avoid GOT
967 // indirection).
968 if (!GV->canBenefitFromLocalAlias())
969 return false;
970 return !(CGM.getLangOpts().SemanticInterposition ||
971 CGM.getLangOpts().HalfNoSemanticInterposition);
972 }
973
974 // A definition cannot be preempted from an executable.
975 if (!GV->isDeclarationForLinker())
976 return true;
977
978 // Most PIC code sequences that assume that a symbol is local cannot produce a
979 // 0 if it turns out the symbol is undefined. While this is ABI and relocation
980 // depended, it seems worth it to handle it here.
981 if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
982 return false;
983
984 // PowerPC64 prefers TOC indirection to avoid copy relocations.
985 if (TT.isPPC64())
986 return false;
987
988 if (CGOpts.DirectAccessExternalData) {
989 // If -fdirect-access-external-data (default for -fno-pic), set dso_local
990 // for non-thread-local variables. If the symbol is not defined in the
991 // executable, a copy relocation will be needed at link time. dso_local is
992 // excluded for thread-local variables because they generally don't support
993 // copy relocations.
994 if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
995 if (!Var->isThreadLocal())
996 return true;
997
998 // -fno-pic sets dso_local on a function declaration to allow direct
999 // accesses when taking its address (similar to a data symbol). If the
1000 // function is not defined in the executable, a canonical PLT entry will be
1001 // needed at link time. -fno-direct-access-external-data can avoid the
1002 // canonical PLT entry. We don't generalize this condition to -fpie/-fpic as
1003 // it could just cause trouble without providing perceptible benefits.
1004 if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
1005 return true;
1006 }
1007
1008 // If we can use copy relocations we can assume it is local.
1009
1010 // Otherwise don't assume it is local.
1011 return false;
1012 }
1013
setDSOLocal(llvm::GlobalValue * GV) const1014 void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
1015 GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
1016 }
1017
setDLLImportDLLExport(llvm::GlobalValue * GV,GlobalDecl GD) const1018 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1019 GlobalDecl GD) const {
1020 const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
1021 // C++ destructors have a few C++ ABI specific special cases.
1022 if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
1023 getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
1024 return;
1025 }
1026 setDLLImportDLLExport(GV, D);
1027 }
1028
setDLLImportDLLExport(llvm::GlobalValue * GV,const NamedDecl * D) const1029 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
1030 const NamedDecl *D) const {
1031 if (D && D->isExternallyVisible()) {
1032 if (D->hasAttr<DLLImportAttr>())
1033 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
1034 else if (D->hasAttr<DLLExportAttr>() && !GV->isDeclarationForLinker())
1035 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
1036 }
1037 }
1038
setGVProperties(llvm::GlobalValue * GV,GlobalDecl GD) const1039 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1040 GlobalDecl GD) const {
1041 setDLLImportDLLExport(GV, GD);
1042 setGVPropertiesAux(GV, dyn_cast<NamedDecl>(GD.getDecl()));
1043 }
1044
setGVProperties(llvm::GlobalValue * GV,const NamedDecl * D) const1045 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
1046 const NamedDecl *D) const {
1047 setDLLImportDLLExport(GV, D);
1048 setGVPropertiesAux(GV, D);
1049 }
1050
setGVPropertiesAux(llvm::GlobalValue * GV,const NamedDecl * D) const1051 void CodeGenModule::setGVPropertiesAux(llvm::GlobalValue *GV,
1052 const NamedDecl *D) const {
1053 setGlobalVisibility(GV, D);
1054 setDSOLocal(GV);
1055 GV->setPartition(CodeGenOpts.SymbolPartition);
1056 }
1057
GetLLVMTLSModel(StringRef S)1058 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
1059 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
1060 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
1061 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
1062 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
1063 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
1064 }
1065
1066 llvm::GlobalVariable::ThreadLocalMode
GetDefaultLLVMTLSModel() const1067 CodeGenModule::GetDefaultLLVMTLSModel() const {
1068 switch (CodeGenOpts.getDefaultTLSModel()) {
1069 case CodeGenOptions::GeneralDynamicTLSModel:
1070 return llvm::GlobalVariable::GeneralDynamicTLSModel;
1071 case CodeGenOptions::LocalDynamicTLSModel:
1072 return llvm::GlobalVariable::LocalDynamicTLSModel;
1073 case CodeGenOptions::InitialExecTLSModel:
1074 return llvm::GlobalVariable::InitialExecTLSModel;
1075 case CodeGenOptions::LocalExecTLSModel:
1076 return llvm::GlobalVariable::LocalExecTLSModel;
1077 }
1078 llvm_unreachable("Invalid TLS model!");
1079 }
1080
setTLSMode(llvm::GlobalValue * GV,const VarDecl & D) const1081 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
1082 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
1083
1084 llvm::GlobalValue::ThreadLocalMode TLM;
1085 TLM = GetDefaultLLVMTLSModel();
1086
1087 // Override the TLS model if it is explicitly specified.
1088 if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
1089 TLM = GetLLVMTLSModel(Attr->getModel());
1090 }
1091
1092 GV->setThreadLocalMode(TLM);
1093 }
1094
getCPUSpecificMangling(const CodeGenModule & CGM,StringRef Name)1095 static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
1096 StringRef Name) {
1097 const TargetInfo &Target = CGM.getTarget();
1098 return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
1099 }
1100
AppendCPUSpecificCPUDispatchMangling(const CodeGenModule & CGM,const CPUSpecificAttr * Attr,unsigned CPUIndex,raw_ostream & Out)1101 static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
1102 const CPUSpecificAttr *Attr,
1103 unsigned CPUIndex,
1104 raw_ostream &Out) {
1105 // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
1106 // supported.
1107 if (Attr)
1108 Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
1109 else if (CGM.getTarget().supportsIFunc())
1110 Out << ".resolver";
1111 }
1112
AppendTargetMangling(const CodeGenModule & CGM,const TargetAttr * Attr,raw_ostream & Out)1113 static void AppendTargetMangling(const CodeGenModule &CGM,
1114 const TargetAttr *Attr, raw_ostream &Out) {
1115 if (Attr->isDefaultVersion())
1116 return;
1117
1118 Out << '.';
1119 const TargetInfo &Target = CGM.getTarget();
1120 ParsedTargetAttr Info =
1121 Attr->parse([&Target](StringRef LHS, StringRef RHS) {
1122 // Multiversioning doesn't allow "no-${feature}", so we can
1123 // only have "+" prefixes here.
1124 assert(LHS.startswith("+") && RHS.startswith("+") &&
1125 "Features should always have a prefix.");
1126 return Target.multiVersionSortPriority(LHS.substr(1)) >
1127 Target.multiVersionSortPriority(RHS.substr(1));
1128 });
1129
1130 bool IsFirst = true;
1131
1132 if (!Info.Architecture.empty()) {
1133 IsFirst = false;
1134 Out << "arch_" << Info.Architecture;
1135 }
1136
1137 for (StringRef Feat : Info.Features) {
1138 if (!IsFirst)
1139 Out << '_';
1140 IsFirst = false;
1141 Out << Feat.substr(1);
1142 }
1143 }
1144
getMangledNameImpl(const CodeGenModule & CGM,GlobalDecl GD,const NamedDecl * ND,bool OmitMultiVersionMangling=false)1145 static std::string getMangledNameImpl(const CodeGenModule &CGM, GlobalDecl GD,
1146 const NamedDecl *ND,
1147 bool OmitMultiVersionMangling = false) {
1148 SmallString<256> Buffer;
1149 llvm::raw_svector_ostream Out(Buffer);
1150 MangleContext &MC = CGM.getCXXABI().getMangleContext();
1151 if (MC.shouldMangleDeclName(ND))
1152 MC.mangleName(GD.getWithDecl(ND), Out);
1153 else {
1154 IdentifierInfo *II = ND->getIdentifier();
1155 assert(II && "Attempt to mangle unnamed decl.");
1156 const auto *FD = dyn_cast<FunctionDecl>(ND);
1157
1158 if (FD &&
1159 FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
1160 Out << "__regcall3__" << II->getName();
1161 } else if (FD && FD->hasAttr<CUDAGlobalAttr>() &&
1162 GD.getKernelReferenceKind() == KernelReferenceKind::Stub) {
1163 Out << "__device_stub__" << II->getName();
1164 } else {
1165 Out << II->getName();
1166 }
1167 }
1168
1169 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
1170 if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
1171 switch (FD->getMultiVersionKind()) {
1172 case MultiVersionKind::CPUDispatch:
1173 case MultiVersionKind::CPUSpecific:
1174 AppendCPUSpecificCPUDispatchMangling(CGM,
1175 FD->getAttr<CPUSpecificAttr>(),
1176 GD.getMultiVersionIndex(), Out);
1177 break;
1178 case MultiVersionKind::Target:
1179 AppendTargetMangling(CGM, FD->getAttr<TargetAttr>(), Out);
1180 break;
1181 case MultiVersionKind::None:
1182 llvm_unreachable("None multiversion type isn't valid here");
1183 }
1184 }
1185
1186 return std::string(Out.str());
1187 }
1188
UpdateMultiVersionNames(GlobalDecl GD,const FunctionDecl * FD)1189 void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
1190 const FunctionDecl *FD) {
1191 if (!FD->isMultiVersion())
1192 return;
1193
1194 // Get the name of what this would be without the 'target' attribute. This
1195 // allows us to lookup the version that was emitted when this wasn't a
1196 // multiversion function.
1197 std::string NonTargetName =
1198 getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
1199 GlobalDecl OtherGD;
1200 if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
1201 assert(OtherGD.getCanonicalDecl()
1202 .getDecl()
1203 ->getAsFunction()
1204 ->isMultiVersion() &&
1205 "Other GD should now be a multiversioned function");
1206 // OtherFD is the version of this function that was mangled BEFORE
1207 // becoming a MultiVersion function. It potentially needs to be updated.
1208 const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
1209 .getDecl()
1210 ->getAsFunction()
1211 ->getMostRecentDecl();
1212 std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
1213 // This is so that if the initial version was already the 'default'
1214 // version, we don't try to update it.
1215 if (OtherName != NonTargetName) {
1216 // Remove instead of erase, since others may have stored the StringRef
1217 // to this.
1218 const auto ExistingRecord = Manglings.find(NonTargetName);
1219 if (ExistingRecord != std::end(Manglings))
1220 Manglings.remove(&(*ExistingRecord));
1221 auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
1222 MangledDeclNames[OtherGD.getCanonicalDecl()] = Result.first->first();
1223 if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
1224 Entry->setName(OtherName);
1225 }
1226 }
1227 }
1228
getMangledName(GlobalDecl GD)1229 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
1230 GlobalDecl CanonicalGD = GD.getCanonicalDecl();
1231
1232 // Some ABIs don't have constructor variants. Make sure that base and
1233 // complete constructors get mangled the same.
1234 if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
1235 if (!getTarget().getCXXABI().hasConstructorVariants()) {
1236 CXXCtorType OrigCtorType = GD.getCtorType();
1237 assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
1238 if (OrigCtorType == Ctor_Base)
1239 CanonicalGD = GlobalDecl(CD, Ctor_Complete);
1240 }
1241 }
1242
1243 auto FoundName = MangledDeclNames.find(CanonicalGD);
1244 if (FoundName != MangledDeclNames.end())
1245 return FoundName->second;
1246
1247 // Keep the first result in the case of a mangling collision.
1248 const auto *ND = cast<NamedDecl>(GD.getDecl());
1249 std::string MangledName = getMangledNameImpl(*this, GD, ND);
1250
1251 // Ensure either we have different ABIs between host and device compilations,
1252 // says host compilation following MSVC ABI but device compilation follows
1253 // Itanium C++ ABI or, if they follow the same ABI, kernel names after
1254 // mangling should be the same after name stubbing. The later checking is
1255 // very important as the device kernel name being mangled in host-compilation
1256 // is used to resolve the device binaries to be executed. Inconsistent naming
1257 // result in undefined behavior. Even though we cannot check that naming
1258 // directly between host- and device-compilations, the host- and
1259 // device-mangling in host compilation could help catching certain ones.
1260 assert(!isa<FunctionDecl>(ND) || !ND->hasAttr<CUDAGlobalAttr>() ||
1261 getLangOpts().CUDAIsDevice ||
1262 (getContext().getAuxTargetInfo() &&
1263 (getContext().getAuxTargetInfo()->getCXXABI() !=
1264 getContext().getTargetInfo().getCXXABI())) ||
1265 getCUDARuntime().getDeviceSideName(ND) ==
1266 getMangledNameImpl(
1267 *this,
1268 GD.getWithKernelReferenceKind(KernelReferenceKind::Kernel),
1269 ND));
1270
1271 auto Result = Manglings.insert(std::make_pair(MangledName, GD));
1272 return MangledDeclNames[CanonicalGD] = Result.first->first();
1273 }
1274
getBlockMangledName(GlobalDecl GD,const BlockDecl * BD)1275 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
1276 const BlockDecl *BD) {
1277 MangleContext &MangleCtx = getCXXABI().getMangleContext();
1278 const Decl *D = GD.getDecl();
1279
1280 SmallString<256> Buffer;
1281 llvm::raw_svector_ostream Out(Buffer);
1282 if (!D)
1283 MangleCtx.mangleGlobalBlock(BD,
1284 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
1285 else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
1286 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
1287 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
1288 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
1289 else
1290 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
1291
1292 auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
1293 return Result.first->first();
1294 }
1295
GetGlobalValue(StringRef Name)1296 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
1297 return getModule().getNamedValue(Name);
1298 }
1299
1300 /// AddGlobalCtor - Add a function to the list that will be called before
1301 /// main() runs.
AddGlobalCtor(llvm::Function * Ctor,int Priority,llvm::Constant * AssociatedData)1302 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
1303 llvm::Constant *AssociatedData) {
1304 // FIXME: Type coercion of void()* types.
1305 GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData));
1306 }
1307
1308 /// AddGlobalDtor - Add a function to the list that will be called
1309 /// when the module is unloaded.
AddGlobalDtor(llvm::Function * Dtor,int Priority,bool IsDtorAttrFunc)1310 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority,
1311 bool IsDtorAttrFunc) {
1312 if (CodeGenOpts.RegisterGlobalDtorsWithAtExit &&
1313 (!getContext().getTargetInfo().getTriple().isOSAIX() || IsDtorAttrFunc)) {
1314 DtorsUsingAtExit[Priority].push_back(Dtor);
1315 return;
1316 }
1317
1318 // FIXME: Type coercion of void()* types.
1319 GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
1320 }
1321
EmitCtorList(CtorList & Fns,const char * GlobalName)1322 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
1323 if (Fns.empty()) return;
1324
1325 // Ctor function type is void()*.
1326 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
1327 llvm::Type *CtorPFTy = llvm::PointerType::get(CtorFTy,
1328 TheModule.getDataLayout().getProgramAddressSpace());
1329
1330 // Get the type of a ctor entry, { i32, void ()*, i8* }.
1331 llvm::StructType *CtorStructTy = llvm::StructType::get(
1332 Int32Ty, CtorPFTy, VoidPtrTy);
1333
1334 // Construct the constructor and destructor arrays.
1335 ConstantInitBuilder builder(*this);
1336 auto ctors = builder.beginArray(CtorStructTy);
1337 for (const auto &I : Fns) {
1338 auto ctor = ctors.beginStruct(CtorStructTy);
1339 ctor.addInt(Int32Ty, I.Priority);
1340 ctor.add(llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy));
1341 if (I.AssociatedData)
1342 ctor.add(llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy));
1343 else
1344 ctor.addNullPointer(VoidPtrTy);
1345 ctor.finishAndAddTo(ctors);
1346 }
1347
1348 auto list =
1349 ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
1350 /*constant*/ false,
1351 llvm::GlobalValue::AppendingLinkage);
1352
1353 // The LTO linker doesn't seem to like it when we set an alignment
1354 // on appending variables. Take it off as a workaround.
1355 list->setAlignment(llvm::None);
1356
1357 Fns.clear();
1358 }
1359
1360 llvm::GlobalValue::LinkageTypes
getFunctionLinkage(GlobalDecl GD)1361 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
1362 const auto *D = cast<FunctionDecl>(GD.getDecl());
1363
1364 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
1365
1366 if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
1367 return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
1368
1369 if (isa<CXXConstructorDecl>(D) &&
1370 cast<CXXConstructorDecl>(D)->isInheritingConstructor() &&
1371 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
1372 // Our approach to inheriting constructors is fundamentally different from
1373 // that used by the MS ABI, so keep our inheriting constructor thunks
1374 // internal rather than trying to pick an unambiguous mangling for them.
1375 return llvm::GlobalValue::InternalLinkage;
1376 }
1377
1378 return getLLVMLinkageForDeclarator(D, Linkage, /*IsConstantVariable=*/false);
1379 }
1380
CreateCrossDsoCfiTypeId(llvm::Metadata * MD)1381 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
1382 llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
1383 if (!MDS) return nullptr;
1384
1385 return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
1386 }
1387
SetLLVMFunctionAttributes(GlobalDecl GD,const CGFunctionInfo & Info,llvm::Function * F)1388 void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
1389 const CGFunctionInfo &Info,
1390 llvm::Function *F) {
1391 unsigned CallingConv;
1392 llvm::AttributeList PAL;
1393 ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv, false);
1394 F->setAttributes(PAL);
1395 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
1396 }
1397
removeImageAccessQualifier(std::string & TyName)1398 static void removeImageAccessQualifier(std::string& TyName) {
1399 std::string ReadOnlyQual("__read_only");
1400 std::string::size_type ReadOnlyPos = TyName.find(ReadOnlyQual);
1401 if (ReadOnlyPos != std::string::npos)
1402 // "+ 1" for the space after access qualifier.
1403 TyName.erase(ReadOnlyPos, ReadOnlyQual.size() + 1);
1404 else {
1405 std::string WriteOnlyQual("__write_only");
1406 std::string::size_type WriteOnlyPos = TyName.find(WriteOnlyQual);
1407 if (WriteOnlyPos != std::string::npos)
1408 TyName.erase(WriteOnlyPos, WriteOnlyQual.size() + 1);
1409 else {
1410 std::string ReadWriteQual("__read_write");
1411 std::string::size_type ReadWritePos = TyName.find(ReadWriteQual);
1412 if (ReadWritePos != std::string::npos)
1413 TyName.erase(ReadWritePos, ReadWriteQual.size() + 1);
1414 }
1415 }
1416 }
1417
1418 // Returns the address space id that should be produced to the
1419 // kernel_arg_addr_space metadata. This is always fixed to the ids
1420 // as specified in the SPIR 2.0 specification in order to differentiate
1421 // for example in clGetKernelArgInfo() implementation between the address
1422 // spaces with targets without unique mapping to the OpenCL address spaces
1423 // (basically all single AS CPUs).
ArgInfoAddressSpace(LangAS AS)1424 static unsigned ArgInfoAddressSpace(LangAS AS) {
1425 switch (AS) {
1426 case LangAS::opencl_global:
1427 return 1;
1428 case LangAS::opencl_constant:
1429 return 2;
1430 case LangAS::opencl_local:
1431 return 3;
1432 case LangAS::opencl_generic:
1433 return 4; // Not in SPIR 2.0 specs.
1434 case LangAS::opencl_global_device:
1435 return 5;
1436 case LangAS::opencl_global_host:
1437 return 6;
1438 default:
1439 return 0; // Assume private.
1440 }
1441 }
1442
GenOpenCLArgMetadata(llvm::Function * Fn,const FunctionDecl * FD,CodeGenFunction * CGF)1443 void CodeGenModule::GenOpenCLArgMetadata(llvm::Function *Fn,
1444 const FunctionDecl *FD,
1445 CodeGenFunction *CGF) {
1446 assert(((FD && CGF) || (!FD && !CGF)) &&
1447 "Incorrect use - FD and CGF should either be both null or not!");
1448 // Create MDNodes that represent the kernel arg metadata.
1449 // Each MDNode is a list in the form of "key", N number of values which is
1450 // the same number of values as their are kernel arguments.
1451
1452 const PrintingPolicy &Policy = Context.getPrintingPolicy();
1453
1454 // MDNode for the kernel argument address space qualifiers.
1455 SmallVector<llvm::Metadata *, 8> addressQuals;
1456
1457 // MDNode for the kernel argument access qualifiers (images only).
1458 SmallVector<llvm::Metadata *, 8> accessQuals;
1459
1460 // MDNode for the kernel argument type names.
1461 SmallVector<llvm::Metadata *, 8> argTypeNames;
1462
1463 // MDNode for the kernel argument base type names.
1464 SmallVector<llvm::Metadata *, 8> argBaseTypeNames;
1465
1466 // MDNode for the kernel argument type qualifiers.
1467 SmallVector<llvm::Metadata *, 8> argTypeQuals;
1468
1469 // MDNode for the kernel argument names.
1470 SmallVector<llvm::Metadata *, 8> argNames;
1471
1472 if (FD && CGF)
1473 for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) {
1474 const ParmVarDecl *parm = FD->getParamDecl(i);
1475 QualType ty = parm->getType();
1476 std::string typeQuals;
1477
1478 if (ty->isPointerType()) {
1479 QualType pointeeTy = ty->getPointeeType();
1480
1481 // Get address qualifier.
1482 addressQuals.push_back(
1483 llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(
1484 ArgInfoAddressSpace(pointeeTy.getAddressSpace()))));
1485
1486 // Get argument type name.
1487 std::string typeName =
1488 pointeeTy.getUnqualifiedType().getAsString(Policy) + "*";
1489
1490 // Turn "unsigned type" to "utype"
1491 std::string::size_type pos = typeName.find("unsigned");
1492 if (pointeeTy.isCanonical() && pos != std::string::npos)
1493 typeName.erase(pos + 1, 8);
1494
1495 argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
1496
1497 std::string baseTypeName =
1498 pointeeTy.getUnqualifiedType().getCanonicalType().getAsString(
1499 Policy) +
1500 "*";
1501
1502 // Turn "unsigned type" to "utype"
1503 pos = baseTypeName.find("unsigned");
1504 if (pos != std::string::npos)
1505 baseTypeName.erase(pos + 1, 8);
1506
1507 argBaseTypeNames.push_back(
1508 llvm::MDString::get(VMContext, baseTypeName));
1509
1510 // Get argument type qualifiers:
1511 if (ty.isRestrictQualified())
1512 typeQuals = "restrict";
1513 if (pointeeTy.isConstQualified() ||
1514 (pointeeTy.getAddressSpace() == LangAS::opencl_constant))
1515 typeQuals += typeQuals.empty() ? "const" : " const";
1516 if (pointeeTy.isVolatileQualified())
1517 typeQuals += typeQuals.empty() ? "volatile" : " volatile";
1518 } else {
1519 uint32_t AddrSpc = 0;
1520 bool isPipe = ty->isPipeType();
1521 if (ty->isImageType() || isPipe)
1522 AddrSpc = ArgInfoAddressSpace(LangAS::opencl_global);
1523
1524 addressQuals.push_back(
1525 llvm::ConstantAsMetadata::get(CGF->Builder.getInt32(AddrSpc)));
1526
1527 // Get argument type name.
1528 std::string typeName;
1529 if (isPipe)
1530 typeName = ty.getCanonicalType()
1531 ->castAs<PipeType>()
1532 ->getElementType()
1533 .getAsString(Policy);
1534 else
1535 typeName = ty.getUnqualifiedType().getAsString(Policy);
1536
1537 // Turn "unsigned type" to "utype"
1538 std::string::size_type pos = typeName.find("unsigned");
1539 if (ty.isCanonical() && pos != std::string::npos)
1540 typeName.erase(pos + 1, 8);
1541
1542 std::string baseTypeName;
1543 if (isPipe)
1544 baseTypeName = ty.getCanonicalType()
1545 ->castAs<PipeType>()
1546 ->getElementType()
1547 .getCanonicalType()
1548 .getAsString(Policy);
1549 else
1550 baseTypeName =
1551 ty.getUnqualifiedType().getCanonicalType().getAsString(Policy);
1552
1553 // Remove access qualifiers on images
1554 // (as they are inseparable from type in clang implementation,
1555 // but OpenCL spec provides a special query to get access qualifier
1556 // via clGetKernelArgInfo with CL_KERNEL_ARG_ACCESS_QUALIFIER):
1557 if (ty->isImageType()) {
1558 removeImageAccessQualifier(typeName);
1559 removeImageAccessQualifier(baseTypeName);
1560 }
1561
1562 argTypeNames.push_back(llvm::MDString::get(VMContext, typeName));
1563
1564 // Turn "unsigned type" to "utype"
1565 pos = baseTypeName.find("unsigned");
1566 if (pos != std::string::npos)
1567 baseTypeName.erase(pos + 1, 8);
1568
1569 argBaseTypeNames.push_back(
1570 llvm::MDString::get(VMContext, baseTypeName));
1571
1572 if (isPipe)
1573 typeQuals = "pipe";
1574 }
1575
1576 argTypeQuals.push_back(llvm::MDString::get(VMContext, typeQuals));
1577
1578 // Get image and pipe access qualifier:
1579 if (ty->isImageType() || ty->isPipeType()) {
1580 const Decl *PDecl = parm;
1581 if (auto *TD = dyn_cast<TypedefType>(ty))
1582 PDecl = TD->getDecl();
1583 const OpenCLAccessAttr *A = PDecl->getAttr<OpenCLAccessAttr>();
1584 if (A && A->isWriteOnly())
1585 accessQuals.push_back(llvm::MDString::get(VMContext, "write_only"));
1586 else if (A && A->isReadWrite())
1587 accessQuals.push_back(llvm::MDString::get(VMContext, "read_write"));
1588 else
1589 accessQuals.push_back(llvm::MDString::get(VMContext, "read_only"));
1590 } else
1591 accessQuals.push_back(llvm::MDString::get(VMContext, "none"));
1592
1593 // Get argument name.
1594 argNames.push_back(llvm::MDString::get(VMContext, parm->getName()));
1595 }
1596
1597 Fn->setMetadata("kernel_arg_addr_space",
1598 llvm::MDNode::get(VMContext, addressQuals));
1599 Fn->setMetadata("kernel_arg_access_qual",
1600 llvm::MDNode::get(VMContext, accessQuals));
1601 Fn->setMetadata("kernel_arg_type",
1602 llvm::MDNode::get(VMContext, argTypeNames));
1603 Fn->setMetadata("kernel_arg_base_type",
1604 llvm::MDNode::get(VMContext, argBaseTypeNames));
1605 Fn->setMetadata("kernel_arg_type_qual",
1606 llvm::MDNode::get(VMContext, argTypeQuals));
1607 if (getCodeGenOpts().EmitOpenCLArgMetadata)
1608 Fn->setMetadata("kernel_arg_name",
1609 llvm::MDNode::get(VMContext, argNames));
1610 }
1611
1612 /// Determines whether the language options require us to model
1613 /// unwind exceptions. We treat -fexceptions as mandating this
1614 /// except under the fragile ObjC ABI with only ObjC exceptions
1615 /// enabled. This means, for example, that C with -fexceptions
1616 /// enables this.
hasUnwindExceptions(const LangOptions & LangOpts)1617 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
1618 // If exceptions are completely disabled, obviously this is false.
1619 if (!LangOpts.Exceptions) return false;
1620
1621 // If C++ exceptions are enabled, this is true.
1622 if (LangOpts.CXXExceptions) return true;
1623
1624 // If ObjC exceptions are enabled, this depends on the ABI.
1625 if (LangOpts.ObjCExceptions) {
1626 return LangOpts.ObjCRuntime.hasUnwindExceptions();
1627 }
1628
1629 return true;
1630 }
1631
requiresMemberFunctionPointerTypeMetadata(CodeGenModule & CGM,const CXXMethodDecl * MD)1632 static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM,
1633 const CXXMethodDecl *MD) {
1634 // Check that the type metadata can ever actually be used by a call.
1635 if (!CGM.getCodeGenOpts().LTOUnit ||
1636 !CGM.HasHiddenLTOVisibility(MD->getParent()))
1637 return false;
1638
1639 // Only functions whose address can be taken with a member function pointer
1640 // need this sort of type metadata.
1641 return !MD->isStatic() && !MD->isVirtual() && !isa<CXXConstructorDecl>(MD) &&
1642 !isa<CXXDestructorDecl>(MD);
1643 }
1644
1645 std::vector<const CXXRecordDecl *>
getMostBaseClasses(const CXXRecordDecl * RD)1646 CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
1647 llvm::SetVector<const CXXRecordDecl *> MostBases;
1648
1649 std::function<void (const CXXRecordDecl *)> CollectMostBases;
1650 CollectMostBases = [&](const CXXRecordDecl *RD) {
1651 if (RD->getNumBases() == 0)
1652 MostBases.insert(RD);
1653 for (const CXXBaseSpecifier &B : RD->bases())
1654 CollectMostBases(B.getType()->getAsCXXRecordDecl());
1655 };
1656 CollectMostBases(RD);
1657 return MostBases.takeVector();
1658 }
1659
SetLLVMFunctionAttributesForDefinition(const Decl * D,llvm::Function * F)1660 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
1661 llvm::Function *F) {
1662 llvm::AttrBuilder B;
1663
1664 if (CodeGenOpts.UnwindTables)
1665 B.addAttribute(llvm::Attribute::UWTable);
1666
1667 if (CodeGenOpts.StackClashProtector)
1668 B.addAttribute("probe-stack", "inline-asm");
1669
1670 if (!hasUnwindExceptions(LangOpts))
1671 B.addAttribute(llvm::Attribute::NoUnwind);
1672
1673 if (!D || !D->hasAttr<NoStackProtectorAttr>()) {
1674 if (LangOpts.getStackProtector() == LangOptions::SSPOn)
1675 B.addAttribute(llvm::Attribute::StackProtect);
1676 else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
1677 B.addAttribute(llvm::Attribute::StackProtectStrong);
1678 else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
1679 B.addAttribute(llvm::Attribute::StackProtectReq);
1680 }
1681
1682 if (!D) {
1683 // If we don't have a declaration to control inlining, the function isn't
1684 // explicitly marked as alwaysinline for semantic reasons, and inlining is
1685 // disabled, mark the function as noinline.
1686 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
1687 CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
1688 B.addAttribute(llvm::Attribute::NoInline);
1689
1690 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1691 return;
1692 }
1693
1694 // Track whether we need to add the optnone LLVM attribute,
1695 // starting with the default for this optimization level.
1696 bool ShouldAddOptNone =
1697 !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
1698 // We can't add optnone in the following cases, it won't pass the verifier.
1699 ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
1700 ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
1701
1702 // Add optnone, but do so only if the function isn't always_inline.
1703 if ((ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) &&
1704 !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1705 B.addAttribute(llvm::Attribute::OptimizeNone);
1706
1707 // OptimizeNone implies noinline; we should not be inlining such functions.
1708 B.addAttribute(llvm::Attribute::NoInline);
1709
1710 // We still need to handle naked functions even though optnone subsumes
1711 // much of their semantics.
1712 if (D->hasAttr<NakedAttr>())
1713 B.addAttribute(llvm::Attribute::Naked);
1714
1715 // OptimizeNone wins over OptimizeForSize and MinSize.
1716 F->removeFnAttr(llvm::Attribute::OptimizeForSize);
1717 F->removeFnAttr(llvm::Attribute::MinSize);
1718 } else if (D->hasAttr<NakedAttr>()) {
1719 // Naked implies noinline: we should not be inlining such functions.
1720 B.addAttribute(llvm::Attribute::Naked);
1721 B.addAttribute(llvm::Attribute::NoInline);
1722 } else if (D->hasAttr<NoDuplicateAttr>()) {
1723 B.addAttribute(llvm::Attribute::NoDuplicate);
1724 } else if (D->hasAttr<NoInlineAttr>() && !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1725 // Add noinline if the function isn't always_inline.
1726 B.addAttribute(llvm::Attribute::NoInline);
1727 } else if (D->hasAttr<AlwaysInlineAttr>() &&
1728 !F->hasFnAttribute(llvm::Attribute::NoInline)) {
1729 // (noinline wins over always_inline, and we can't specify both in IR)
1730 B.addAttribute(llvm::Attribute::AlwaysInline);
1731 } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
1732 // If we're not inlining, then force everything that isn't always_inline to
1733 // carry an explicit noinline attribute.
1734 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
1735 B.addAttribute(llvm::Attribute::NoInline);
1736 } else {
1737 // Otherwise, propagate the inline hint attribute and potentially use its
1738 // absence to mark things as noinline.
1739 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
1740 // Search function and template pattern redeclarations for inline.
1741 auto CheckForInline = [](const FunctionDecl *FD) {
1742 auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
1743 return Redecl->isInlineSpecified();
1744 };
1745 if (any_of(FD->redecls(), CheckRedeclForInline))
1746 return true;
1747 const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
1748 if (!Pattern)
1749 return false;
1750 return any_of(Pattern->redecls(), CheckRedeclForInline);
1751 };
1752 if (CheckForInline(FD)) {
1753 B.addAttribute(llvm::Attribute::InlineHint);
1754 } else if (CodeGenOpts.getInlining() ==
1755 CodeGenOptions::OnlyHintInlining &&
1756 !FD->isInlined() &&
1757 !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1758 B.addAttribute(llvm::Attribute::NoInline);
1759 }
1760 }
1761 }
1762
1763 // Add other optimization related attributes if we are optimizing this
1764 // function.
1765 if (!D->hasAttr<OptimizeNoneAttr>()) {
1766 if (D->hasAttr<ColdAttr>()) {
1767 if (!ShouldAddOptNone)
1768 B.addAttribute(llvm::Attribute::OptimizeForSize);
1769 B.addAttribute(llvm::Attribute::Cold);
1770 }
1771 if (D->hasAttr<HotAttr>())
1772 B.addAttribute(llvm::Attribute::Hot);
1773 if (D->hasAttr<MinSizeAttr>())
1774 B.addAttribute(llvm::Attribute::MinSize);
1775 }
1776
1777 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1778
1779 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
1780 if (alignment)
1781 F->setAlignment(llvm::Align(alignment));
1782
1783 if (!D->hasAttr<AlignedAttr>())
1784 if (LangOpts.FunctionAlignment)
1785 F->setAlignment(llvm::Align(1ull << LangOpts.FunctionAlignment));
1786
1787 // Some C++ ABIs require 2-byte alignment for member functions, in order to
1788 // reserve a bit for differentiating between virtual and non-virtual member
1789 // functions. If the current target's C++ ABI requires this and this is a
1790 // member function, set its alignment accordingly.
1791 if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
1792 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
1793 F->setAlignment(llvm::Align(2));
1794 }
1795
1796 // In the cross-dso CFI mode with canonical jump tables, we want !type
1797 // attributes on definitions only.
1798 if (CodeGenOpts.SanitizeCfiCrossDso &&
1799 CodeGenOpts.SanitizeCfiCanonicalJumpTables) {
1800 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
1801 // Skip available_externally functions. They won't be codegen'ed in the
1802 // current module anyway.
1803 if (getContext().GetGVALinkageForFunction(FD) != GVA_AvailableExternally)
1804 CreateFunctionTypeMetadataForIcall(FD, F);
1805 }
1806 }
1807
1808 // Emit type metadata on member functions for member function pointer checks.
1809 // These are only ever necessary on definitions; we're guaranteed that the
1810 // definition will be present in the LTO unit as a result of LTO visibility.
1811 auto *MD = dyn_cast<CXXMethodDecl>(D);
1812 if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
1813 for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
1814 llvm::Metadata *Id =
1815 CreateMetadataIdentifierForType(Context.getMemberPointerType(
1816 MD->getType(), Context.getRecordType(Base).getTypePtr()));
1817 F->addTypeMetadata(0, Id);
1818 }
1819 }
1820 }
1821
setLLVMFunctionFEnvAttributes(const FunctionDecl * D,llvm::Function * F)1822 void CodeGenModule::setLLVMFunctionFEnvAttributes(const FunctionDecl *D,
1823 llvm::Function *F) {
1824 if (D->hasAttr<StrictFPAttr>()) {
1825 llvm::AttrBuilder FuncAttrs;
1826 FuncAttrs.addAttribute("strictfp");
1827 F->addAttributes(llvm::AttributeList::FunctionIndex, FuncAttrs);
1828 }
1829 }
1830
SetCommonAttributes(GlobalDecl GD,llvm::GlobalValue * GV)1831 void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
1832 const Decl *D = GD.getDecl();
1833 if (dyn_cast_or_null<NamedDecl>(D))
1834 setGVProperties(GV, GD);
1835 else
1836 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1837
1838 if (D && D->hasAttr<UsedAttr>())
1839 addUsedGlobal(GV);
1840
1841 if (CodeGenOpts.KeepStaticConsts && D && isa<VarDecl>(D)) {
1842 const auto *VD = cast<VarDecl>(D);
1843 if (VD->getType().isConstQualified() &&
1844 VD->getStorageDuration() == SD_Static)
1845 addUsedGlobal(GV);
1846 }
1847 }
1848
GetCPUAndFeaturesAttributes(GlobalDecl GD,llvm::AttrBuilder & Attrs)1849 bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
1850 llvm::AttrBuilder &Attrs) {
1851 // Add target-cpu and target-features attributes to functions. If
1852 // we have a decl for the function and it has a target attribute then
1853 // parse that and add it to the feature set.
1854 StringRef TargetCPU = getTarget().getTargetOpts().CPU;
1855 StringRef TuneCPU = getTarget().getTargetOpts().TuneCPU;
1856 std::vector<std::string> Features;
1857 const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
1858 FD = FD ? FD->getMostRecentDecl() : FD;
1859 const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
1860 const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
1861 bool AddedAttr = false;
1862 if (TD || SD) {
1863 llvm::StringMap<bool> FeatureMap;
1864 getContext().getFunctionFeatureMap(FeatureMap, GD);
1865
1866 // Produce the canonical string for this set of features.
1867 for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
1868 Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
1869
1870 // Now add the target-cpu and target-features to the function.
1871 // While we populated the feature map above, we still need to
1872 // get and parse the target attribute so we can get the cpu for
1873 // the function.
1874 if (TD) {
1875 ParsedTargetAttr ParsedAttr = TD->parse();
1876 if (!ParsedAttr.Architecture.empty() &&
1877 getTarget().isValidCPUName(ParsedAttr.Architecture)) {
1878 TargetCPU = ParsedAttr.Architecture;
1879 TuneCPU = ""; // Clear the tune CPU.
1880 }
1881 if (!ParsedAttr.Tune.empty() &&
1882 getTarget().isValidCPUName(ParsedAttr.Tune))
1883 TuneCPU = ParsedAttr.Tune;
1884 }
1885 } else {
1886 // Otherwise just add the existing target cpu and target features to the
1887 // function.
1888 Features = getTarget().getTargetOpts().Features;
1889 }
1890
1891 if (!TargetCPU.empty()) {
1892 Attrs.addAttribute("target-cpu", TargetCPU);
1893 AddedAttr = true;
1894 }
1895 if (!TuneCPU.empty()) {
1896 Attrs.addAttribute("tune-cpu", TuneCPU);
1897 AddedAttr = true;
1898 }
1899 if (!Features.empty()) {
1900 llvm::sort(Features);
1901 Attrs.addAttribute("target-features", llvm::join(Features, ","));
1902 AddedAttr = true;
1903 }
1904
1905 return AddedAttr;
1906 }
1907
setNonAliasAttributes(GlobalDecl GD,llvm::GlobalObject * GO)1908 void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
1909 llvm::GlobalObject *GO) {
1910 const Decl *D = GD.getDecl();
1911 SetCommonAttributes(GD, GO);
1912
1913 if (D) {
1914 if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
1915 if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
1916 GV->addAttribute("bss-section", SA->getName());
1917 if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
1918 GV->addAttribute("data-section", SA->getName());
1919 if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
1920 GV->addAttribute("rodata-section", SA->getName());
1921 if (auto *SA = D->getAttr<PragmaClangRelroSectionAttr>())
1922 GV->addAttribute("relro-section", SA->getName());
1923 }
1924
1925 if (auto *F = dyn_cast<llvm::Function>(GO)) {
1926 if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
1927 if (!D->getAttr<SectionAttr>())
1928 F->addFnAttr("implicit-section-name", SA->getName());
1929
1930 llvm::AttrBuilder Attrs;
1931 if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
1932 // We know that GetCPUAndFeaturesAttributes will always have the
1933 // newest set, since it has the newest possible FunctionDecl, so the
1934 // new ones should replace the old.
1935 llvm::AttrBuilder RemoveAttrs;
1936 RemoveAttrs.addAttribute("target-cpu");
1937 RemoveAttrs.addAttribute("target-features");
1938 RemoveAttrs.addAttribute("tune-cpu");
1939 F->removeAttributes(llvm::AttributeList::FunctionIndex, RemoveAttrs);
1940 F->addAttributes(llvm::AttributeList::FunctionIndex, Attrs);
1941 }
1942 }
1943
1944 if (const auto *CSA = D->getAttr<CodeSegAttr>())
1945 GO->setSection(CSA->getName());
1946 else if (const auto *SA = D->getAttr<SectionAttr>())
1947 GO->setSection(SA->getName());
1948 }
1949
1950 getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
1951 }
1952
SetInternalFunctionAttributes(GlobalDecl GD,llvm::Function * F,const CGFunctionInfo & FI)1953 void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
1954 llvm::Function *F,
1955 const CGFunctionInfo &FI) {
1956 const Decl *D = GD.getDecl();
1957 SetLLVMFunctionAttributes(GD, FI, F);
1958 SetLLVMFunctionAttributesForDefinition(D, F);
1959
1960 F->setLinkage(llvm::Function::InternalLinkage);
1961
1962 setNonAliasAttributes(GD, F);
1963 }
1964
setLinkageForGV(llvm::GlobalValue * GV,const NamedDecl * ND)1965 static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
1966 // Set linkage and visibility in case we never see a definition.
1967 LinkageInfo LV = ND->getLinkageAndVisibility();
1968 // Don't set internal linkage on declarations.
1969 // "extern_weak" is overloaded in LLVM; we probably should have
1970 // separate linkage types for this.
1971 if (isExternallyVisible(LV.getLinkage()) &&
1972 (ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
1973 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
1974 }
1975
CreateFunctionTypeMetadataForIcall(const FunctionDecl * FD,llvm::Function * F)1976 void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
1977 llvm::Function *F) {
1978 // Only if we are checking indirect calls.
1979 if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
1980 return;
1981
1982 // Non-static class methods are handled via vtable or member function pointer
1983 // checks elsewhere.
1984 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
1985 return;
1986
1987 llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
1988 F->addTypeMetadata(0, MD);
1989 F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
1990
1991 // Emit a hash-based bit set entry for cross-DSO calls.
1992 if (CodeGenOpts.SanitizeCfiCrossDso)
1993 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
1994 F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
1995 }
1996
SetFunctionAttributes(GlobalDecl GD,llvm::Function * F,bool IsIncompleteFunction,bool IsThunk)1997 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
1998 bool IsIncompleteFunction,
1999 bool IsThunk) {
2000
2001 if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) {
2002 // If this is an intrinsic function, set the function's attributes
2003 // to the intrinsic's attributes.
2004 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID));
2005 return;
2006 }
2007
2008 const auto *FD = cast<FunctionDecl>(GD.getDecl());
2009
2010 if (!IsIncompleteFunction)
2011 SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F);
2012
2013 // Add the Returned attribute for "this", except for iOS 5 and earlier
2014 // where substantial code, including the libstdc++ dylib, was compiled with
2015 // GCC and does not actually return "this".
2016 if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
2017 !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
2018 assert(!F->arg_empty() &&
2019 F->arg_begin()->getType()
2020 ->canLosslesslyBitCastTo(F->getReturnType()) &&
2021 "unexpected this return");
2022 F->addAttribute(1, llvm::Attribute::Returned);
2023 }
2024
2025 // Only a few attributes are set on declarations; these may later be
2026 // overridden by a definition.
2027
2028 setLinkageForGV(F, FD);
2029 setGVProperties(F, FD);
2030
2031 // Setup target-specific attributes.
2032 if (!IsIncompleteFunction && F->isDeclaration())
2033 getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
2034
2035 if (const auto *CSA = FD->getAttr<CodeSegAttr>())
2036 F->setSection(CSA->getName());
2037 else if (const auto *SA = FD->getAttr<SectionAttr>())
2038 F->setSection(SA->getName());
2039
2040 // If we plan on emitting this inline builtin, we can't treat it as a builtin.
2041 if (FD->isInlineBuiltinDeclaration()) {
2042 const FunctionDecl *FDBody;
2043 bool HasBody = FD->hasBody(FDBody);
2044 (void)HasBody;
2045 assert(HasBody && "Inline builtin declarations should always have an "
2046 "available body!");
2047 if (shouldEmitFunction(FDBody))
2048 F->addAttribute(llvm::AttributeList::FunctionIndex,
2049 llvm::Attribute::NoBuiltin);
2050 }
2051
2052 if (FD->isReplaceableGlobalAllocationFunction()) {
2053 // A replaceable global allocation function does not act like a builtin by
2054 // default, only if it is invoked by a new-expression or delete-expression.
2055 F->addAttribute(llvm::AttributeList::FunctionIndex,
2056 llvm::Attribute::NoBuiltin);
2057 }
2058
2059 if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
2060 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2061 else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
2062 if (MD->isVirtual())
2063 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2064
2065 // Don't emit entries for function declarations in the cross-DSO mode. This
2066 // is handled with better precision by the receiving DSO. But if jump tables
2067 // are non-canonical then we need type metadata in order to produce the local
2068 // jump table.
2069 if (!CodeGenOpts.SanitizeCfiCrossDso ||
2070 !CodeGenOpts.SanitizeCfiCanonicalJumpTables)
2071 CreateFunctionTypeMetadataForIcall(FD, F);
2072
2073 if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
2074 getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
2075
2076 if (const auto *CB = FD->getAttr<CallbackAttr>()) {
2077 // Annotate the callback behavior as metadata:
2078 // - The callback callee (as argument number).
2079 // - The callback payloads (as argument numbers).
2080 llvm::LLVMContext &Ctx = F->getContext();
2081 llvm::MDBuilder MDB(Ctx);
2082
2083 // The payload indices are all but the first one in the encoding. The first
2084 // identifies the callback callee.
2085 int CalleeIdx = *CB->encoding_begin();
2086 ArrayRef<int> PayloadIndices(CB->encoding_begin() + 1, CB->encoding_end());
2087 F->addMetadata(llvm::LLVMContext::MD_callback,
2088 *llvm::MDNode::get(Ctx, {MDB.createCallbackEncoding(
2089 CalleeIdx, PayloadIndices,
2090 /* VarArgsArePassed */ false)}));
2091 }
2092 }
2093
addUsedGlobal(llvm::GlobalValue * GV)2094 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
2095 assert((isa<llvm::Function>(GV) || !GV->isDeclaration()) &&
2096 "Only globals with definition can force usage.");
2097 LLVMUsed.emplace_back(GV);
2098 }
2099
addCompilerUsedGlobal(llvm::GlobalValue * GV)2100 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
2101 assert(!GV->isDeclaration() &&
2102 "Only globals with definition can force usage.");
2103 LLVMCompilerUsed.emplace_back(GV);
2104 }
2105
emitUsed(CodeGenModule & CGM,StringRef Name,std::vector<llvm::WeakTrackingVH> & List)2106 static void emitUsed(CodeGenModule &CGM, StringRef Name,
2107 std::vector<llvm::WeakTrackingVH> &List) {
2108 // Don't create llvm.used if there is no need.
2109 if (List.empty())
2110 return;
2111
2112 // Convert List to what ConstantArray needs.
2113 SmallVector<llvm::Constant*, 8> UsedArray;
2114 UsedArray.resize(List.size());
2115 for (unsigned i = 0, e = List.size(); i != e; ++i) {
2116 UsedArray[i] =
2117 llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
2118 cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
2119 }
2120
2121 if (UsedArray.empty())
2122 return;
2123 llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
2124
2125 auto *GV = new llvm::GlobalVariable(
2126 CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
2127 llvm::ConstantArray::get(ATy, UsedArray), Name);
2128
2129 GV->setSection("llvm.metadata");
2130 }
2131
emitLLVMUsed()2132 void CodeGenModule::emitLLVMUsed() {
2133 emitUsed(*this, "llvm.used", LLVMUsed);
2134 emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
2135 }
2136
AppendLinkerOptions(StringRef Opts)2137 void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
2138 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
2139 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
2140 }
2141
AddDetectMismatch(StringRef Name,StringRef Value)2142 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
2143 llvm::SmallString<32> Opt;
2144 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
2145 if (Opt.empty())
2146 return;
2147 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
2148 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
2149 }
2150
AddDependentLib(StringRef Lib)2151 void CodeGenModule::AddDependentLib(StringRef Lib) {
2152 auto &C = getLLVMContext();
2153 if (getTarget().getTriple().isOSBinFormatELF()) {
2154 ELFDependentLibraries.push_back(
2155 llvm::MDNode::get(C, llvm::MDString::get(C, Lib)));
2156 return;
2157 }
2158
2159 llvm::SmallString<24> Opt;
2160 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
2161 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
2162 LinkerOptionsMetadata.push_back(llvm::MDNode::get(C, MDOpts));
2163 }
2164
2165 /// Add link options implied by the given module, including modules
2166 /// it depends on, using a postorder walk.
addLinkOptionsPostorder(CodeGenModule & CGM,Module * Mod,SmallVectorImpl<llvm::MDNode * > & Metadata,llvm::SmallPtrSet<Module *,16> & Visited)2167 static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
2168 SmallVectorImpl<llvm::MDNode *> &Metadata,
2169 llvm::SmallPtrSet<Module *, 16> &Visited) {
2170 // Import this module's parent.
2171 if (Mod->Parent && Visited.insert(Mod->Parent).second) {
2172 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
2173 }
2174
2175 // Import this module's dependencies.
2176 for (unsigned I = Mod->Imports.size(); I > 0; --I) {
2177 if (Visited.insert(Mod->Imports[I - 1]).second)
2178 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited);
2179 }
2180
2181 // Add linker options to link against the libraries/frameworks
2182 // described by this module.
2183 llvm::LLVMContext &Context = CGM.getLLVMContext();
2184 bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
2185
2186 // For modules that use export_as for linking, use that module
2187 // name instead.
2188 if (Mod->UseExportAsModuleLinkName)
2189 return;
2190
2191 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) {
2192 // Link against a framework. Frameworks are currently Darwin only, so we
2193 // don't to ask TargetCodeGenInfo for the spelling of the linker option.
2194 if (Mod->LinkLibraries[I-1].IsFramework) {
2195 llvm::Metadata *Args[2] = {
2196 llvm::MDString::get(Context, "-framework"),
2197 llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library)};
2198
2199 Metadata.push_back(llvm::MDNode::get(Context, Args));
2200 continue;
2201 }
2202
2203 // Link against a library.
2204 if (IsELF) {
2205 llvm::Metadata *Args[2] = {
2206 llvm::MDString::get(Context, "lib"),
2207 llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library),
2208 };
2209 Metadata.push_back(llvm::MDNode::get(Context, Args));
2210 } else {
2211 llvm::SmallString<24> Opt;
2212 CGM.getTargetCodeGenInfo().getDependentLibraryOption(
2213 Mod->LinkLibraries[I - 1].Library, Opt);
2214 auto *OptString = llvm::MDString::get(Context, Opt);
2215 Metadata.push_back(llvm::MDNode::get(Context, OptString));
2216 }
2217 }
2218 }
2219
EmitModuleLinkOptions()2220 void CodeGenModule::EmitModuleLinkOptions() {
2221 // Collect the set of all of the modules we want to visit to emit link
2222 // options, which is essentially the imported modules and all of their
2223 // non-explicit child modules.
2224 llvm::SetVector<clang::Module *> LinkModules;
2225 llvm::SmallPtrSet<clang::Module *, 16> Visited;
2226 SmallVector<clang::Module *, 16> Stack;
2227
2228 // Seed the stack with imported modules.
2229 for (Module *M : ImportedModules) {
2230 // Do not add any link flags when an implementation TU of a module imports
2231 // a header of that same module.
2232 if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
2233 !getLangOpts().isCompilingModule())
2234 continue;
2235 if (Visited.insert(M).second)
2236 Stack.push_back(M);
2237 }
2238
2239 // Find all of the modules to import, making a little effort to prune
2240 // non-leaf modules.
2241 while (!Stack.empty()) {
2242 clang::Module *Mod = Stack.pop_back_val();
2243
2244 bool AnyChildren = false;
2245
2246 // Visit the submodules of this module.
2247 for (const auto &SM : Mod->submodules()) {
2248 // Skip explicit children; they need to be explicitly imported to be
2249 // linked against.
2250 if (SM->IsExplicit)
2251 continue;
2252
2253 if (Visited.insert(SM).second) {
2254 Stack.push_back(SM);
2255 AnyChildren = true;
2256 }
2257 }
2258
2259 // We didn't find any children, so add this module to the list of
2260 // modules to link against.
2261 if (!AnyChildren) {
2262 LinkModules.insert(Mod);
2263 }
2264 }
2265
2266 // Add link options for all of the imported modules in reverse topological
2267 // order. We don't do anything to try to order import link flags with respect
2268 // to linker options inserted by things like #pragma comment().
2269 SmallVector<llvm::MDNode *, 16> MetadataArgs;
2270 Visited.clear();
2271 for (Module *M : LinkModules)
2272 if (Visited.insert(M).second)
2273 addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
2274 std::reverse(MetadataArgs.begin(), MetadataArgs.end());
2275 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
2276
2277 // Add the linker options metadata flag.
2278 auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
2279 for (auto *MD : LinkerOptionsMetadata)
2280 NMD->addOperand(MD);
2281 }
2282
EmitDeferred()2283 void CodeGenModule::EmitDeferred() {
2284 // Emit deferred declare target declarations.
2285 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
2286 getOpenMPRuntime().emitDeferredTargetDecls();
2287
2288 // Emit code for any potentially referenced deferred decls. Since a
2289 // previously unused static decl may become used during the generation of code
2290 // for a static function, iterate until no changes are made.
2291
2292 if (!DeferredVTables.empty()) {
2293 EmitDeferredVTables();
2294
2295 // Emitting a vtable doesn't directly cause more vtables to
2296 // become deferred, although it can cause functions to be
2297 // emitted that then need those vtables.
2298 assert(DeferredVTables.empty());
2299 }
2300
2301 // Emit CUDA/HIP static device variables referenced by host code only.
2302 if (getLangOpts().CUDA)
2303 for (auto V : getContext().CUDAStaticDeviceVarReferencedByHost)
2304 DeferredDeclsToEmit.push_back(V);
2305
2306 // Stop if we're out of both deferred vtables and deferred declarations.
2307 if (DeferredDeclsToEmit.empty())
2308 return;
2309
2310 // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
2311 // work, it will not interfere with this.
2312 std::vector<GlobalDecl> CurDeclsToEmit;
2313 CurDeclsToEmit.swap(DeferredDeclsToEmit);
2314
2315 for (GlobalDecl &D : CurDeclsToEmit) {
2316 // We should call GetAddrOfGlobal with IsForDefinition set to true in order
2317 // to get GlobalValue with exactly the type we need, not something that
2318 // might had been created for another decl with the same mangled name but
2319 // different type.
2320 llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
2321 GetAddrOfGlobal(D, ForDefinition));
2322
2323 // In case of different address spaces, we may still get a cast, even with
2324 // IsForDefinition equal to true. Query mangled names table to get
2325 // GlobalValue.
2326 if (!GV)
2327 GV = GetGlobalValue(getMangledName(D));
2328
2329 // Make sure GetGlobalValue returned non-null.
2330 assert(GV);
2331
2332 // Check to see if we've already emitted this. This is necessary
2333 // for a couple of reasons: first, decls can end up in the
2334 // deferred-decls queue multiple times, and second, decls can end
2335 // up with definitions in unusual ways (e.g. by an extern inline
2336 // function acquiring a strong function redefinition). Just
2337 // ignore these cases.
2338 if (!GV->isDeclaration())
2339 continue;
2340
2341 // If this is OpenMP, check if it is legal to emit this global normally.
2342 if (LangOpts.OpenMP && OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(D))
2343 continue;
2344
2345 // Otherwise, emit the definition and move on to the next one.
2346 EmitGlobalDefinition(D, GV);
2347
2348 // If we found out that we need to emit more decls, do that recursively.
2349 // This has the advantage that the decls are emitted in a DFS and related
2350 // ones are close together, which is convenient for testing.
2351 if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
2352 EmitDeferred();
2353 assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
2354 }
2355 }
2356 }
2357
EmitVTablesOpportunistically()2358 void CodeGenModule::EmitVTablesOpportunistically() {
2359 // Try to emit external vtables as available_externally if they have emitted
2360 // all inlined virtual functions. It runs after EmitDeferred() and therefore
2361 // is not allowed to create new references to things that need to be emitted
2362 // lazily. Note that it also uses fact that we eagerly emitting RTTI.
2363
2364 assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
2365 && "Only emit opportunistic vtables with optimizations");
2366
2367 for (const CXXRecordDecl *RD : OpportunisticVTables) {
2368 assert(getVTables().isVTableExternal(RD) &&
2369 "This queue should only contain external vtables");
2370 if (getCXXABI().canSpeculativelyEmitVTable(RD))
2371 VTables.GenerateClassData(RD);
2372 }
2373 OpportunisticVTables.clear();
2374 }
2375
EmitGlobalAnnotations()2376 void CodeGenModule::EmitGlobalAnnotations() {
2377 if (Annotations.empty())
2378 return;
2379
2380 // Create a new global variable for the ConstantStruct in the Module.
2381 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
2382 Annotations[0]->getType(), Annotations.size()), Annotations);
2383 auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
2384 llvm::GlobalValue::AppendingLinkage,
2385 Array, "llvm.global.annotations");
2386 gv->setSection(AnnotationSection);
2387 }
2388
EmitAnnotationString(StringRef Str)2389 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
2390 llvm::Constant *&AStr = AnnotationStrings[Str];
2391 if (AStr)
2392 return AStr;
2393
2394 // Not found yet, create a new global.
2395 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
2396 auto *gv =
2397 new llvm::GlobalVariable(getModule(), s->getType(), true,
2398 llvm::GlobalValue::PrivateLinkage, s, ".str");
2399 gv->setSection(AnnotationSection);
2400 gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2401 AStr = gv;
2402 return gv;
2403 }
2404
EmitAnnotationUnit(SourceLocation Loc)2405 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
2406 SourceManager &SM = getContext().getSourceManager();
2407 PresumedLoc PLoc = SM.getPresumedLoc(Loc);
2408 if (PLoc.isValid())
2409 return EmitAnnotationString(PLoc.getFilename());
2410 return EmitAnnotationString(SM.getBufferName(Loc));
2411 }
2412
EmitAnnotationLineNo(SourceLocation L)2413 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
2414 SourceManager &SM = getContext().getSourceManager();
2415 PresumedLoc PLoc = SM.getPresumedLoc(L);
2416 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
2417 SM.getExpansionLineNumber(L);
2418 return llvm::ConstantInt::get(Int32Ty, LineNo);
2419 }
2420
EmitAnnotationArgs(const AnnotateAttr * Attr)2421 llvm::Constant *CodeGenModule::EmitAnnotationArgs(const AnnotateAttr *Attr) {
2422 ArrayRef<Expr *> Exprs = {Attr->args_begin(), Attr->args_size()};
2423 if (Exprs.empty())
2424 return llvm::ConstantPointerNull::get(Int8PtrTy);
2425
2426 llvm::FoldingSetNodeID ID;
2427 for (Expr *E : Exprs) {
2428 ID.Add(cast<clang::ConstantExpr>(E)->getAPValueResult());
2429 }
2430 llvm::Constant *&Lookup = AnnotationArgs[ID.ComputeHash()];
2431 if (Lookup)
2432 return Lookup;
2433
2434 llvm::SmallVector<llvm::Constant *, 4> LLVMArgs;
2435 LLVMArgs.reserve(Exprs.size());
2436 ConstantEmitter ConstEmiter(*this);
2437 llvm::transform(Exprs, std::back_inserter(LLVMArgs), [&](const Expr *E) {
2438 const auto *CE = cast<clang::ConstantExpr>(E);
2439 return ConstEmiter.emitAbstract(CE->getBeginLoc(), CE->getAPValueResult(),
2440 CE->getType());
2441 });
2442 auto *Struct = llvm::ConstantStruct::getAnon(LLVMArgs);
2443 auto *GV = new llvm::GlobalVariable(getModule(), Struct->getType(), true,
2444 llvm::GlobalValue::PrivateLinkage, Struct,
2445 ".args");
2446 GV->setSection(AnnotationSection);
2447 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2448 auto *Bitcasted = llvm::ConstantExpr::getBitCast(GV, Int8PtrTy);
2449
2450 Lookup = Bitcasted;
2451 return Bitcasted;
2452 }
2453
EmitAnnotateAttr(llvm::GlobalValue * GV,const AnnotateAttr * AA,SourceLocation L)2454 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
2455 const AnnotateAttr *AA,
2456 SourceLocation L) {
2457 // Get the globals for file name, annotation, and the line number.
2458 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
2459 *UnitGV = EmitAnnotationUnit(L),
2460 *LineNoCst = EmitAnnotationLineNo(L),
2461 *Args = EmitAnnotationArgs(AA);
2462
2463 llvm::Constant *ASZeroGV = GV;
2464 if (GV->getAddressSpace() != 0) {
2465 ASZeroGV = llvm::ConstantExpr::getAddrSpaceCast(
2466 GV, GV->getValueType()->getPointerTo(0));
2467 }
2468
2469 // Create the ConstantStruct for the global annotation.
2470 llvm::Constant *Fields[] = {
2471 llvm::ConstantExpr::getBitCast(ASZeroGV, Int8PtrTy),
2472 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
2473 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
2474 LineNoCst,
2475 Args,
2476 };
2477 return llvm::ConstantStruct::getAnon(Fields);
2478 }
2479
AddGlobalAnnotations(const ValueDecl * D,llvm::GlobalValue * GV)2480 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
2481 llvm::GlobalValue *GV) {
2482 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
2483 // Get the struct elements for these annotations.
2484 for (const auto *I : D->specific_attrs<AnnotateAttr>())
2485 Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
2486 }
2487
isInSanitizerBlacklist(SanitizerMask Kind,llvm::Function * Fn,SourceLocation Loc) const2488 bool CodeGenModule::isInSanitizerBlacklist(SanitizerMask Kind,
2489 llvm::Function *Fn,
2490 SourceLocation Loc) const {
2491 const auto &SanitizerBL = getContext().getSanitizerBlacklist();
2492 // Blacklist by function name.
2493 if (SanitizerBL.isBlacklistedFunction(Kind, Fn->getName()))
2494 return true;
2495 // Blacklist by location.
2496 if (Loc.isValid())
2497 return SanitizerBL.isBlacklistedLocation(Kind, Loc);
2498 // If location is unknown, this may be a compiler-generated function. Assume
2499 // it's located in the main file.
2500 auto &SM = Context.getSourceManager();
2501 if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
2502 return SanitizerBL.isBlacklistedFile(Kind, MainFile->getName());
2503 }
2504 return false;
2505 }
2506
isInSanitizerBlacklist(llvm::GlobalVariable * GV,SourceLocation Loc,QualType Ty,StringRef Category) const2507 bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
2508 SourceLocation Loc, QualType Ty,
2509 StringRef Category) const {
2510 // For now globals can be blacklisted only in ASan and KASan.
2511 const SanitizerMask EnabledAsanMask =
2512 LangOpts.Sanitize.Mask &
2513 (SanitizerKind::Address | SanitizerKind::KernelAddress |
2514 SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress |
2515 SanitizerKind::MemTag);
2516 if (!EnabledAsanMask)
2517 return false;
2518 const auto &SanitizerBL = getContext().getSanitizerBlacklist();
2519 if (SanitizerBL.isBlacklistedGlobal(EnabledAsanMask, GV->getName(), Category))
2520 return true;
2521 if (SanitizerBL.isBlacklistedLocation(EnabledAsanMask, Loc, Category))
2522 return true;
2523 // Check global type.
2524 if (!Ty.isNull()) {
2525 // Drill down the array types: if global variable of a fixed type is
2526 // blacklisted, we also don't instrument arrays of them.
2527 while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
2528 Ty = AT->getElementType();
2529 Ty = Ty.getCanonicalType().getUnqualifiedType();
2530 // We allow to blacklist only record types (classes, structs etc.)
2531 if (Ty->isRecordType()) {
2532 std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
2533 if (SanitizerBL.isBlacklistedType(EnabledAsanMask, TypeStr, Category))
2534 return true;
2535 }
2536 }
2537 return false;
2538 }
2539
imbueXRayAttrs(llvm::Function * Fn,SourceLocation Loc,StringRef Category) const2540 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
2541 StringRef Category) const {
2542 const auto &XRayFilter = getContext().getXRayFilter();
2543 using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
2544 auto Attr = ImbueAttr::NONE;
2545 if (Loc.isValid())
2546 Attr = XRayFilter.shouldImbueLocation(Loc, Category);
2547 if (Attr == ImbueAttr::NONE)
2548 Attr = XRayFilter.shouldImbueFunction(Fn->getName());
2549 switch (Attr) {
2550 case ImbueAttr::NONE:
2551 return false;
2552 case ImbueAttr::ALWAYS:
2553 Fn->addFnAttr("function-instrument", "xray-always");
2554 break;
2555 case ImbueAttr::ALWAYS_ARG1:
2556 Fn->addFnAttr("function-instrument", "xray-always");
2557 Fn->addFnAttr("xray-log-args", "1");
2558 break;
2559 case ImbueAttr::NEVER:
2560 Fn->addFnAttr("function-instrument", "xray-never");
2561 break;
2562 }
2563 return true;
2564 }
2565
isProfileInstrExcluded(llvm::Function * Fn,SourceLocation Loc) const2566 bool CodeGenModule::isProfileInstrExcluded(llvm::Function *Fn,
2567 SourceLocation Loc) const {
2568 const auto &ProfileList = getContext().getProfileList();
2569 // If the profile list is empty, then instrument everything.
2570 if (ProfileList.isEmpty())
2571 return false;
2572 CodeGenOptions::ProfileInstrKind Kind = getCodeGenOpts().getProfileInstr();
2573 // First, check the function name.
2574 Optional<bool> V = ProfileList.isFunctionExcluded(Fn->getName(), Kind);
2575 if (V.hasValue())
2576 return *V;
2577 // Next, check the source location.
2578 if (Loc.isValid()) {
2579 Optional<bool> V = ProfileList.isLocationExcluded(Loc, Kind);
2580 if (V.hasValue())
2581 return *V;
2582 }
2583 // If location is unknown, this may be a compiler-generated function. Assume
2584 // it's located in the main file.
2585 auto &SM = Context.getSourceManager();
2586 if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
2587 Optional<bool> V = ProfileList.isFileExcluded(MainFile->getName(), Kind);
2588 if (V.hasValue())
2589 return *V;
2590 }
2591 return ProfileList.getDefault();
2592 }
2593
MustBeEmitted(const ValueDecl * Global)2594 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
2595 // Never defer when EmitAllDecls is specified.
2596 if (LangOpts.EmitAllDecls)
2597 return true;
2598
2599 if (CodeGenOpts.KeepStaticConsts) {
2600 const auto *VD = dyn_cast<VarDecl>(Global);
2601 if (VD && VD->getType().isConstQualified() &&
2602 VD->getStorageDuration() == SD_Static)
2603 return true;
2604 }
2605
2606 return getContext().DeclMustBeEmitted(Global);
2607 }
2608
MayBeEmittedEagerly(const ValueDecl * Global)2609 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
2610 if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
2611 if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
2612 // Implicit template instantiations may change linkage if they are later
2613 // explicitly instantiated, so they should not be emitted eagerly.
2614 return false;
2615 // In OpenMP 5.0 function may be marked as device_type(nohost) and we should
2616 // not emit them eagerly unless we sure that the function must be emitted on
2617 // the host.
2618 if (LangOpts.OpenMP >= 50 && !LangOpts.OpenMPSimd &&
2619 !LangOpts.OpenMPIsDevice &&
2620 !OMPDeclareTargetDeclAttr::getDeviceType(FD) &&
2621 !FD->isUsed(/*CheckUsedAttr=*/false) && !FD->isReferenced())
2622 return false;
2623 }
2624 if (const auto *VD = dyn_cast<VarDecl>(Global))
2625 if (Context.getInlineVariableDefinitionKind(VD) ==
2626 ASTContext::InlineVariableDefinitionKind::WeakUnknown)
2627 // A definition of an inline constexpr static data member may change
2628 // linkage later if it's redeclared outside the class.
2629 return false;
2630 // If OpenMP is enabled and threadprivates must be generated like TLS, delay
2631 // codegen for global variables, because they may be marked as threadprivate.
2632 if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
2633 getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
2634 !isTypeConstant(Global->getType(), false) &&
2635 !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
2636 return false;
2637
2638 return true;
2639 }
2640
GetAddrOfMSGuidDecl(const MSGuidDecl * GD)2641 ConstantAddress CodeGenModule::GetAddrOfMSGuidDecl(const MSGuidDecl *GD) {
2642 StringRef Name = getMangledName(GD);
2643
2644 // The UUID descriptor should be pointer aligned.
2645 CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
2646
2647 // Look for an existing global.
2648 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
2649 return ConstantAddress(GV, Alignment);
2650
2651 ConstantEmitter Emitter(*this);
2652 llvm::Constant *Init;
2653
2654 APValue &V = GD->getAsAPValue();
2655 if (!V.isAbsent()) {
2656 // If possible, emit the APValue version of the initializer. In particular,
2657 // this gets the type of the constant right.
2658 Init = Emitter.emitForInitializer(
2659 GD->getAsAPValue(), GD->getType().getAddressSpace(), GD->getType());
2660 } else {
2661 // As a fallback, directly construct the constant.
2662 // FIXME: This may get padding wrong under esoteric struct layout rules.
2663 // MSVC appears to create a complete type 'struct __s_GUID' that it
2664 // presumably uses to represent these constants.
2665 MSGuidDecl::Parts Parts = GD->getParts();
2666 llvm::Constant *Fields[4] = {
2667 llvm::ConstantInt::get(Int32Ty, Parts.Part1),
2668 llvm::ConstantInt::get(Int16Ty, Parts.Part2),
2669 llvm::ConstantInt::get(Int16Ty, Parts.Part3),
2670 llvm::ConstantDataArray::getRaw(
2671 StringRef(reinterpret_cast<char *>(Parts.Part4And5), 8), 8,
2672 Int8Ty)};
2673 Init = llvm::ConstantStruct::getAnon(Fields);
2674 }
2675
2676 auto *GV = new llvm::GlobalVariable(
2677 getModule(), Init->getType(),
2678 /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
2679 if (supportsCOMDAT())
2680 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
2681 setDSOLocal(GV);
2682
2683 llvm::Constant *Addr = GV;
2684 if (!V.isAbsent()) {
2685 Emitter.finalize(GV);
2686 } else {
2687 llvm::Type *Ty = getTypes().ConvertTypeForMem(GD->getType());
2688 Addr = llvm::ConstantExpr::getBitCast(
2689 GV, Ty->getPointerTo(GV->getAddressSpace()));
2690 }
2691 return ConstantAddress(Addr, Alignment);
2692 }
2693
GetAddrOfTemplateParamObject(const TemplateParamObjectDecl * TPO)2694 ConstantAddress CodeGenModule::GetAddrOfTemplateParamObject(
2695 const TemplateParamObjectDecl *TPO) {
2696 StringRef Name = getMangledName(TPO);
2697 CharUnits Alignment = getNaturalTypeAlignment(TPO->getType());
2698
2699 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
2700 return ConstantAddress(GV, Alignment);
2701
2702 ConstantEmitter Emitter(*this);
2703 llvm::Constant *Init = Emitter.emitForInitializer(
2704 TPO->getValue(), TPO->getType().getAddressSpace(), TPO->getType());
2705
2706 if (!Init) {
2707 ErrorUnsupported(TPO, "template parameter object");
2708 return ConstantAddress::invalid();
2709 }
2710
2711 auto *GV = new llvm::GlobalVariable(
2712 getModule(), Init->getType(),
2713 /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
2714 if (supportsCOMDAT())
2715 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
2716 Emitter.finalize(GV);
2717
2718 return ConstantAddress(GV, Alignment);
2719 }
2720
GetWeakRefReference(const ValueDecl * VD)2721 ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
2722 const AliasAttr *AA = VD->getAttr<AliasAttr>();
2723 assert(AA && "No alias?");
2724
2725 CharUnits Alignment = getContext().getDeclAlign(VD);
2726 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
2727
2728 // See if there is already something with the target's name in the module.
2729 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
2730 if (Entry) {
2731 unsigned AS = getContext().getTargetAddressSpace(VD->getType());
2732 auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
2733 return ConstantAddress(Ptr, Alignment);
2734 }
2735
2736 llvm::Constant *Aliasee;
2737 if (isa<llvm::FunctionType>(DeclTy))
2738 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
2739 GlobalDecl(cast<FunctionDecl>(VD)),
2740 /*ForVTable=*/false);
2741 else
2742 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
2743 llvm::PointerType::getUnqual(DeclTy),
2744 nullptr);
2745
2746 auto *F = cast<llvm::GlobalValue>(Aliasee);
2747 F->setLinkage(llvm::Function::ExternalWeakLinkage);
2748 WeakRefReferences.insert(F);
2749
2750 return ConstantAddress(Aliasee, Alignment);
2751 }
2752
EmitGlobal(GlobalDecl GD)2753 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
2754 const auto *Global = cast<ValueDecl>(GD.getDecl());
2755
2756 // Weak references don't produce any output by themselves.
2757 if (Global->hasAttr<WeakRefAttr>())
2758 return;
2759
2760 // If this is an alias definition (which otherwise looks like a declaration)
2761 // emit it now.
2762 if (Global->hasAttr<AliasAttr>())
2763 return EmitAliasDefinition(GD);
2764
2765 // IFunc like an alias whose value is resolved at runtime by calling resolver.
2766 if (Global->hasAttr<IFuncAttr>())
2767 return emitIFuncDefinition(GD);
2768
2769 // If this is a cpu_dispatch multiversion function, emit the resolver.
2770 if (Global->hasAttr<CPUDispatchAttr>())
2771 return emitCPUDispatchDefinition(GD);
2772
2773 // If this is CUDA, be selective about which declarations we emit.
2774 if (LangOpts.CUDA) {
2775 if (LangOpts.CUDAIsDevice) {
2776 if (!Global->hasAttr<CUDADeviceAttr>() &&
2777 !Global->hasAttr<CUDAGlobalAttr>() &&
2778 !Global->hasAttr<CUDAConstantAttr>() &&
2779 !Global->hasAttr<CUDASharedAttr>() &&
2780 !Global->getType()->isCUDADeviceBuiltinSurfaceType() &&
2781 !Global->getType()->isCUDADeviceBuiltinTextureType())
2782 return;
2783 } else {
2784 // We need to emit host-side 'shadows' for all global
2785 // device-side variables because the CUDA runtime needs their
2786 // size and host-side address in order to provide access to
2787 // their device-side incarnations.
2788
2789 // So device-only functions are the only things we skip.
2790 if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
2791 Global->hasAttr<CUDADeviceAttr>())
2792 return;
2793
2794 assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
2795 "Expected Variable or Function");
2796 }
2797 }
2798
2799 if (LangOpts.OpenMP) {
2800 // If this is OpenMP, check if it is legal to emit this global normally.
2801 if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
2802 return;
2803 if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
2804 if (MustBeEmitted(Global))
2805 EmitOMPDeclareReduction(DRD);
2806 return;
2807 } else if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) {
2808 if (MustBeEmitted(Global))
2809 EmitOMPDeclareMapper(DMD);
2810 return;
2811 }
2812 }
2813
2814 // Ignore declarations, they will be emitted on their first use.
2815 if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
2816 // Forward declarations are emitted lazily on first use.
2817 if (!FD->doesThisDeclarationHaveABody()) {
2818 if (!FD->doesDeclarationForceExternallyVisibleDefinition())
2819 return;
2820
2821 StringRef MangledName = getMangledName(GD);
2822
2823 // Compute the function info and LLVM type.
2824 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
2825 llvm::Type *Ty = getTypes().GetFunctionType(FI);
2826
2827 GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
2828 /*DontDefer=*/false);
2829 return;
2830 }
2831 } else {
2832 const auto *VD = cast<VarDecl>(Global);
2833 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
2834 if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
2835 !Context.isMSStaticDataMemberInlineDefinition(VD)) {
2836 if (LangOpts.OpenMP) {
2837 // Emit declaration of the must-be-emitted declare target variable.
2838 if (llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
2839 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
2840 bool UnifiedMemoryEnabled =
2841 getOpenMPRuntime().hasRequiresUnifiedSharedMemory();
2842 if (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2843 !UnifiedMemoryEnabled) {
2844 (void)GetAddrOfGlobalVar(VD);
2845 } else {
2846 assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2847 (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2848 UnifiedMemoryEnabled)) &&
2849 "Link clause or to clause with unified memory expected.");
2850 (void)getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2851 }
2852
2853 return;
2854 }
2855 }
2856 // If this declaration may have caused an inline variable definition to
2857 // change linkage, make sure that it's emitted.
2858 if (Context.getInlineVariableDefinitionKind(VD) ==
2859 ASTContext::InlineVariableDefinitionKind::Strong)
2860 GetAddrOfGlobalVar(VD);
2861 return;
2862 }
2863 }
2864
2865 // Defer code generation to first use when possible, e.g. if this is an inline
2866 // function. If the global must always be emitted, do it eagerly if possible
2867 // to benefit from cache locality.
2868 if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
2869 // Emit the definition if it can't be deferred.
2870 EmitGlobalDefinition(GD);
2871 return;
2872 }
2873
2874 // If we're deferring emission of a C++ variable with an
2875 // initializer, remember the order in which it appeared in the file.
2876 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
2877 cast<VarDecl>(Global)->hasInit()) {
2878 DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
2879 CXXGlobalInits.push_back(nullptr);
2880 }
2881
2882 StringRef MangledName = getMangledName(GD);
2883 if (GetGlobalValue(MangledName) != nullptr) {
2884 // The value has already been used and should therefore be emitted.
2885 addDeferredDeclToEmit(GD);
2886 } else if (MustBeEmitted(Global)) {
2887 // The value must be emitted, but cannot be emitted eagerly.
2888 assert(!MayBeEmittedEagerly(Global));
2889 addDeferredDeclToEmit(GD);
2890 } else {
2891 // Otherwise, remember that we saw a deferred decl with this name. The
2892 // first use of the mangled name will cause it to move into
2893 // DeferredDeclsToEmit.
2894 DeferredDecls[MangledName] = GD;
2895 }
2896 }
2897
2898 // Check if T is a class type with a destructor that's not dllimport.
HasNonDllImportDtor(QualType T)2899 static bool HasNonDllImportDtor(QualType T) {
2900 if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
2901 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
2902 if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
2903 return true;
2904
2905 return false;
2906 }
2907
2908 namespace {
2909 struct FunctionIsDirectlyRecursive
2910 : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> {
2911 const StringRef Name;
2912 const Builtin::Context &BI;
FunctionIsDirectlyRecursive__anon052bd7050711::FunctionIsDirectlyRecursive2913 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C)
2914 : Name(N), BI(C) {}
2915
VisitCallExpr__anon052bd7050711::FunctionIsDirectlyRecursive2916 bool VisitCallExpr(const CallExpr *E) {
2917 const FunctionDecl *FD = E->getDirectCallee();
2918 if (!FD)
2919 return false;
2920 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
2921 if (Attr && Name == Attr->getLabel())
2922 return true;
2923 unsigned BuiltinID = FD->getBuiltinID();
2924 if (!BuiltinID || !BI.isLibFunction(BuiltinID))
2925 return false;
2926 StringRef BuiltinName = BI.getName(BuiltinID);
2927 if (BuiltinName.startswith("__builtin_") &&
2928 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
2929 return true;
2930 }
2931 return false;
2932 }
2933
VisitStmt__anon052bd7050711::FunctionIsDirectlyRecursive2934 bool VisitStmt(const Stmt *S) {
2935 for (const Stmt *Child : S->children())
2936 if (Child && this->Visit(Child))
2937 return true;
2938 return false;
2939 }
2940 };
2941
2942 // Make sure we're not referencing non-imported vars or functions.
2943 struct DLLImportFunctionVisitor
2944 : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
2945 bool SafeToInline = true;
2946
shouldVisitImplicitCode__anon052bd7050711::DLLImportFunctionVisitor2947 bool shouldVisitImplicitCode() const { return true; }
2948
VisitVarDecl__anon052bd7050711::DLLImportFunctionVisitor2949 bool VisitVarDecl(VarDecl *VD) {
2950 if (VD->getTLSKind()) {
2951 // A thread-local variable cannot be imported.
2952 SafeToInline = false;
2953 return SafeToInline;
2954 }
2955
2956 // A variable definition might imply a destructor call.
2957 if (VD->isThisDeclarationADefinition())
2958 SafeToInline = !HasNonDllImportDtor(VD->getType());
2959
2960 return SafeToInline;
2961 }
2962
VisitCXXBindTemporaryExpr__anon052bd7050711::DLLImportFunctionVisitor2963 bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
2964 if (const auto *D = E->getTemporary()->getDestructor())
2965 SafeToInline = D->hasAttr<DLLImportAttr>();
2966 return SafeToInline;
2967 }
2968
VisitDeclRefExpr__anon052bd7050711::DLLImportFunctionVisitor2969 bool VisitDeclRefExpr(DeclRefExpr *E) {
2970 ValueDecl *VD = E->getDecl();
2971 if (isa<FunctionDecl>(VD))
2972 SafeToInline = VD->hasAttr<DLLImportAttr>();
2973 else if (VarDecl *V = dyn_cast<VarDecl>(VD))
2974 SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
2975 return SafeToInline;
2976 }
2977
VisitCXXConstructExpr__anon052bd7050711::DLLImportFunctionVisitor2978 bool VisitCXXConstructExpr(CXXConstructExpr *E) {
2979 SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
2980 return SafeToInline;
2981 }
2982
VisitCXXMemberCallExpr__anon052bd7050711::DLLImportFunctionVisitor2983 bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
2984 CXXMethodDecl *M = E->getMethodDecl();
2985 if (!M) {
2986 // Call through a pointer to member function. This is safe to inline.
2987 SafeToInline = true;
2988 } else {
2989 SafeToInline = M->hasAttr<DLLImportAttr>();
2990 }
2991 return SafeToInline;
2992 }
2993
VisitCXXDeleteExpr__anon052bd7050711::DLLImportFunctionVisitor2994 bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
2995 SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
2996 return SafeToInline;
2997 }
2998
VisitCXXNewExpr__anon052bd7050711::DLLImportFunctionVisitor2999 bool VisitCXXNewExpr(CXXNewExpr *E) {
3000 SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
3001 return SafeToInline;
3002 }
3003 };
3004 }
3005
3006 // isTriviallyRecursive - Check if this function calls another
3007 // decl that, because of the asm attribute or the other decl being a builtin,
3008 // ends up pointing to itself.
3009 bool
isTriviallyRecursive(const FunctionDecl * FD)3010 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
3011 StringRef Name;
3012 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
3013 // asm labels are a special kind of mangling we have to support.
3014 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
3015 if (!Attr)
3016 return false;
3017 Name = Attr->getLabel();
3018 } else {
3019 Name = FD->getName();
3020 }
3021
3022 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
3023 const Stmt *Body = FD->getBody();
3024 return Body ? Walker.Visit(Body) : false;
3025 }
3026
shouldEmitFunction(GlobalDecl GD)3027 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
3028 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
3029 return true;
3030 const auto *F = cast<FunctionDecl>(GD.getDecl());
3031 if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
3032 return false;
3033
3034 if (F->hasAttr<DLLImportAttr>()) {
3035 // Check whether it would be safe to inline this dllimport function.
3036 DLLImportFunctionVisitor Visitor;
3037 Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
3038 if (!Visitor.SafeToInline)
3039 return false;
3040
3041 if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
3042 // Implicit destructor invocations aren't captured in the AST, so the
3043 // check above can't see them. Check for them manually here.
3044 for (const Decl *Member : Dtor->getParent()->decls())
3045 if (isa<FieldDecl>(Member))
3046 if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
3047 return false;
3048 for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
3049 if (HasNonDllImportDtor(B.getType()))
3050 return false;
3051 }
3052 }
3053
3054 // PR9614. Avoid cases where the source code is lying to us. An available
3055 // externally function should have an equivalent function somewhere else,
3056 // but a function that calls itself through asm label/`__builtin_` trickery is
3057 // clearly not equivalent to the real implementation.
3058 // This happens in glibc's btowc and in some configure checks.
3059 return !isTriviallyRecursive(F);
3060 }
3061
shouldOpportunisticallyEmitVTables()3062 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
3063 return CodeGenOpts.OptimizationLevel > 0;
3064 }
3065
EmitMultiVersionFunctionDefinition(GlobalDecl GD,llvm::GlobalValue * GV)3066 void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
3067 llvm::GlobalValue *GV) {
3068 const auto *FD = cast<FunctionDecl>(GD.getDecl());
3069
3070 if (FD->isCPUSpecificMultiVersion()) {
3071 auto *Spec = FD->getAttr<CPUSpecificAttr>();
3072 for (unsigned I = 0; I < Spec->cpus_size(); ++I)
3073 EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
3074 // Requires multiple emits.
3075 } else
3076 EmitGlobalFunctionDefinition(GD, GV);
3077 }
3078
EmitGlobalDefinition(GlobalDecl GD,llvm::GlobalValue * GV)3079 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
3080 const auto *D = cast<ValueDecl>(GD.getDecl());
3081
3082 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
3083 Context.getSourceManager(),
3084 "Generating code for declaration");
3085
3086 if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
3087 // At -O0, don't generate IR for functions with available_externally
3088 // linkage.
3089 if (!shouldEmitFunction(GD))
3090 return;
3091
3092 llvm::TimeTraceScope TimeScope("CodeGen Function", [&]() {
3093 std::string Name;
3094 llvm::raw_string_ostream OS(Name);
3095 FD->getNameForDiagnostic(OS, getContext().getPrintingPolicy(),
3096 /*Qualified=*/true);
3097 return Name;
3098 });
3099
3100 if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
3101 // Make sure to emit the definition(s) before we emit the thunks.
3102 // This is necessary for the generation of certain thunks.
3103 if (isa<CXXConstructorDecl>(Method) || isa<CXXDestructorDecl>(Method))
3104 ABI->emitCXXStructor(GD);
3105 else if (FD->isMultiVersion())
3106 EmitMultiVersionFunctionDefinition(GD, GV);
3107 else
3108 EmitGlobalFunctionDefinition(GD, GV);
3109
3110 if (Method->isVirtual())
3111 getVTables().EmitThunks(GD);
3112
3113 return;
3114 }
3115
3116 if (FD->isMultiVersion())
3117 return EmitMultiVersionFunctionDefinition(GD, GV);
3118 return EmitGlobalFunctionDefinition(GD, GV);
3119 }
3120
3121 if (const auto *VD = dyn_cast<VarDecl>(D))
3122 return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
3123
3124 llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
3125 }
3126
3127 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
3128 llvm::Function *NewFn);
3129
3130 static unsigned
TargetMVPriority(const TargetInfo & TI,const CodeGenFunction::MultiVersionResolverOption & RO)3131 TargetMVPriority(const TargetInfo &TI,
3132 const CodeGenFunction::MultiVersionResolverOption &RO) {
3133 unsigned Priority = 0;
3134 for (StringRef Feat : RO.Conditions.Features)
3135 Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
3136
3137 if (!RO.Conditions.Architecture.empty())
3138 Priority = std::max(
3139 Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
3140 return Priority;
3141 }
3142
emitMultiVersionFunctions()3143 void CodeGenModule::emitMultiVersionFunctions() {
3144 for (GlobalDecl GD : MultiVersionFuncs) {
3145 SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
3146 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
3147 getContext().forEachMultiversionedFunctionVersion(
3148 FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
3149 GlobalDecl CurGD{
3150 (CurFD->isDefined() ? CurFD->getDefinition() : CurFD)};
3151 StringRef MangledName = getMangledName(CurGD);
3152 llvm::Constant *Func = GetGlobalValue(MangledName);
3153 if (!Func) {
3154 if (CurFD->isDefined()) {
3155 EmitGlobalFunctionDefinition(CurGD, nullptr);
3156 Func = GetGlobalValue(MangledName);
3157 } else {
3158 const CGFunctionInfo &FI =
3159 getTypes().arrangeGlobalDeclaration(GD);
3160 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
3161 Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
3162 /*DontDefer=*/false, ForDefinition);
3163 }
3164 assert(Func && "This should have just been created");
3165 }
3166
3167 const auto *TA = CurFD->getAttr<TargetAttr>();
3168 llvm::SmallVector<StringRef, 8> Feats;
3169 TA->getAddedFeatures(Feats);
3170
3171 Options.emplace_back(cast<llvm::Function>(Func),
3172 TA->getArchitecture(), Feats);
3173 });
3174
3175 llvm::Function *ResolverFunc;
3176 const TargetInfo &TI = getTarget();
3177
3178 if (TI.supportsIFunc() || FD->isTargetMultiVersion()) {
3179 ResolverFunc = cast<llvm::Function>(
3180 GetGlobalValue((getMangledName(GD) + ".resolver").str()));
3181 ResolverFunc->setLinkage(llvm::Function::WeakODRLinkage);
3182 } else {
3183 ResolverFunc = cast<llvm::Function>(GetGlobalValue(getMangledName(GD)));
3184 }
3185
3186 if (supportsCOMDAT())
3187 ResolverFunc->setComdat(
3188 getModule().getOrInsertComdat(ResolverFunc->getName()));
3189
3190 llvm::stable_sort(
3191 Options, [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
3192 const CodeGenFunction::MultiVersionResolverOption &RHS) {
3193 return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
3194 });
3195 CodeGenFunction CGF(*this);
3196 CGF.EmitMultiVersionResolver(ResolverFunc, Options);
3197 }
3198 }
3199
emitCPUDispatchDefinition(GlobalDecl GD)3200 void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
3201 const auto *FD = cast<FunctionDecl>(GD.getDecl());
3202 assert(FD && "Not a FunctionDecl?");
3203 const auto *DD = FD->getAttr<CPUDispatchAttr>();
3204 assert(DD && "Not a cpu_dispatch Function?");
3205 llvm::Type *DeclTy = getTypes().ConvertType(FD->getType());
3206
3207 if (const auto *CXXFD = dyn_cast<CXXMethodDecl>(FD)) {
3208 const CGFunctionInfo &FInfo = getTypes().arrangeCXXMethodDeclaration(CXXFD);
3209 DeclTy = getTypes().GetFunctionType(FInfo);
3210 }
3211
3212 StringRef ResolverName = getMangledName(GD);
3213
3214 llvm::Type *ResolverType;
3215 GlobalDecl ResolverGD;
3216 if (getTarget().supportsIFunc())
3217 ResolverType = llvm::FunctionType::get(
3218 llvm::PointerType::get(DeclTy,
3219 Context.getTargetAddressSpace(FD->getType())),
3220 false);
3221 else {
3222 ResolverType = DeclTy;
3223 ResolverGD = GD;
3224 }
3225
3226 auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
3227 ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
3228 ResolverFunc->setLinkage(llvm::Function::WeakODRLinkage);
3229 if (supportsCOMDAT())
3230 ResolverFunc->setComdat(
3231 getModule().getOrInsertComdat(ResolverFunc->getName()));
3232
3233 SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
3234 const TargetInfo &Target = getTarget();
3235 unsigned Index = 0;
3236 for (const IdentifierInfo *II : DD->cpus()) {
3237 // Get the name of the target function so we can look it up/create it.
3238 std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
3239 getCPUSpecificMangling(*this, II->getName());
3240
3241 llvm::Constant *Func = GetGlobalValue(MangledName);
3242
3243 if (!Func) {
3244 GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
3245 if (ExistingDecl.getDecl() &&
3246 ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
3247 EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
3248 Func = GetGlobalValue(MangledName);
3249 } else {
3250 if (!ExistingDecl.getDecl())
3251 ExistingDecl = GD.getWithMultiVersionIndex(Index);
3252
3253 Func = GetOrCreateLLVMFunction(
3254 MangledName, DeclTy, ExistingDecl,
3255 /*ForVTable=*/false, /*DontDefer=*/true,
3256 /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
3257 }
3258 }
3259
3260 llvm::SmallVector<StringRef, 32> Features;
3261 Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
3262 llvm::transform(Features, Features.begin(),
3263 [](StringRef Str) { return Str.substr(1); });
3264 Features.erase(std::remove_if(
3265 Features.begin(), Features.end(), [&Target](StringRef Feat) {
3266 return !Target.validateCpuSupports(Feat);
3267 }), Features.end());
3268 Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
3269 ++Index;
3270 }
3271
3272 llvm::sort(
3273 Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
3274 const CodeGenFunction::MultiVersionResolverOption &RHS) {
3275 return CodeGenFunction::GetX86CpuSupportsMask(LHS.Conditions.Features) >
3276 CodeGenFunction::GetX86CpuSupportsMask(RHS.Conditions.Features);
3277 });
3278
3279 // If the list contains multiple 'default' versions, such as when it contains
3280 // 'pentium' and 'generic', don't emit the call to the generic one (since we
3281 // always run on at least a 'pentium'). We do this by deleting the 'least
3282 // advanced' (read, lowest mangling letter).
3283 while (Options.size() > 1 &&
3284 CodeGenFunction::GetX86CpuSupportsMask(
3285 (Options.end() - 2)->Conditions.Features) == 0) {
3286 StringRef LHSName = (Options.end() - 2)->Function->getName();
3287 StringRef RHSName = (Options.end() - 1)->Function->getName();
3288 if (LHSName.compare(RHSName) < 0)
3289 Options.erase(Options.end() - 2);
3290 else
3291 Options.erase(Options.end() - 1);
3292 }
3293
3294 CodeGenFunction CGF(*this);
3295 CGF.EmitMultiVersionResolver(ResolverFunc, Options);
3296
3297 if (getTarget().supportsIFunc()) {
3298 std::string AliasName = getMangledNameImpl(
3299 *this, GD, FD, /*OmitMultiVersionMangling=*/true);
3300 llvm::Constant *AliasFunc = GetGlobalValue(AliasName);
3301 if (!AliasFunc) {
3302 auto *IFunc = cast<llvm::GlobalIFunc>(GetOrCreateLLVMFunction(
3303 AliasName, DeclTy, GD, /*ForVTable=*/false, /*DontDefer=*/true,
3304 /*IsThunk=*/false, llvm::AttributeList(), NotForDefinition));
3305 auto *GA = llvm::GlobalAlias::create(
3306 DeclTy, 0, getFunctionLinkage(GD), AliasName, IFunc, &getModule());
3307 GA->setLinkage(llvm::Function::WeakODRLinkage);
3308 SetCommonAttributes(GD, GA);
3309 }
3310 }
3311 }
3312
3313 /// If a dispatcher for the specified mangled name is not in the module, create
3314 /// and return an llvm Function with the specified type.
GetOrCreateMultiVersionResolver(GlobalDecl GD,llvm::Type * DeclTy,const FunctionDecl * FD)3315 llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(
3316 GlobalDecl GD, llvm::Type *DeclTy, const FunctionDecl *FD) {
3317 std::string MangledName =
3318 getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
3319
3320 // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
3321 // a separate resolver).
3322 std::string ResolverName = MangledName;
3323 if (getTarget().supportsIFunc())
3324 ResolverName += ".ifunc";
3325 else if (FD->isTargetMultiVersion())
3326 ResolverName += ".resolver";
3327
3328 // If this already exists, just return that one.
3329 if (llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName))
3330 return ResolverGV;
3331
3332 // Since this is the first time we've created this IFunc, make sure
3333 // that we put this multiversioned function into the list to be
3334 // replaced later if necessary (target multiversioning only).
3335 if (!FD->isCPUDispatchMultiVersion() && !FD->isCPUSpecificMultiVersion())
3336 MultiVersionFuncs.push_back(GD);
3337
3338 if (getTarget().supportsIFunc()) {
3339 llvm::Type *ResolverType = llvm::FunctionType::get(
3340 llvm::PointerType::get(
3341 DeclTy, getContext().getTargetAddressSpace(FD->getType())),
3342 false);
3343 llvm::Constant *Resolver = GetOrCreateLLVMFunction(
3344 MangledName + ".resolver", ResolverType, GlobalDecl{},
3345 /*ForVTable=*/false);
3346 llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
3347 DeclTy, 0, llvm::Function::WeakODRLinkage, "", Resolver, &getModule());
3348 GIF->setName(ResolverName);
3349 SetCommonAttributes(FD, GIF);
3350
3351 return GIF;
3352 }
3353
3354 llvm::Constant *Resolver = GetOrCreateLLVMFunction(
3355 ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
3356 assert(isa<llvm::GlobalValue>(Resolver) &&
3357 "Resolver should be created for the first time");
3358 SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
3359 return Resolver;
3360 }
3361
3362 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
3363 /// module, create and return an llvm Function with the specified type. If there
3364 /// is something in the module with the specified name, return it potentially
3365 /// bitcasted to the right type.
3366 ///
3367 /// If D is non-null, it specifies a decl that correspond to this. This is used
3368 /// 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)3369 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
3370 StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
3371 bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
3372 ForDefinition_t IsForDefinition) {
3373 const Decl *D = GD.getDecl();
3374
3375 // Any attempts to use a MultiVersion function should result in retrieving
3376 // the iFunc instead. Name Mangling will handle the rest of the changes.
3377 if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
3378 // For the device mark the function as one that should be emitted.
3379 if (getLangOpts().OpenMPIsDevice && OpenMPRuntime &&
3380 !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
3381 !DontDefer && !IsForDefinition) {
3382 if (const FunctionDecl *FDDef = FD->getDefinition()) {
3383 GlobalDecl GDDef;
3384 if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
3385 GDDef = GlobalDecl(CD, GD.getCtorType());
3386 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
3387 GDDef = GlobalDecl(DD, GD.getDtorType());
3388 else
3389 GDDef = GlobalDecl(FDDef);
3390 EmitGlobal(GDDef);
3391 }
3392 }
3393
3394 if (FD->isMultiVersion()) {
3395 if (FD->hasAttr<TargetAttr>())
3396 UpdateMultiVersionNames(GD, FD);
3397 if (!IsForDefinition)
3398 return GetOrCreateMultiVersionResolver(GD, Ty, FD);
3399 }
3400 }
3401
3402 // Lookup the entry, lazily creating it if necessary.
3403 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3404 if (Entry) {
3405 if (WeakRefReferences.erase(Entry)) {
3406 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
3407 if (FD && !FD->hasAttr<WeakAttr>())
3408 Entry->setLinkage(llvm::Function::ExternalLinkage);
3409 }
3410
3411 // Handle dropped DLL attributes.
3412 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>()) {
3413 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3414 setDSOLocal(Entry);
3415 }
3416
3417 // If there are two attempts to define the same mangled name, issue an
3418 // error.
3419 if (IsForDefinition && !Entry->isDeclaration()) {
3420 GlobalDecl OtherGD;
3421 // Check that GD is not yet in DiagnosedConflictingDefinitions is required
3422 // to make sure that we issue an error only once.
3423 if (lookupRepresentativeDecl(MangledName, OtherGD) &&
3424 (GD.getCanonicalDecl().getDecl() !=
3425 OtherGD.getCanonicalDecl().getDecl()) &&
3426 DiagnosedConflictingDefinitions.insert(GD).second) {
3427 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3428 << MangledName;
3429 getDiags().Report(OtherGD.getDecl()->getLocation(),
3430 diag::note_previous_definition);
3431 }
3432 }
3433
3434 if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
3435 (Entry->getValueType() == Ty)) {
3436 return Entry;
3437 }
3438
3439 // Make sure the result is of the correct type.
3440 // (If function is requested for a definition, we always need to create a new
3441 // function, not just return a bitcast.)
3442 if (!IsForDefinition)
3443 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
3444 }
3445
3446 // This function doesn't have a complete type (for example, the return
3447 // type is an incomplete struct). Use a fake type instead, and make
3448 // sure not to try to set attributes.
3449 bool IsIncompleteFunction = false;
3450
3451 llvm::FunctionType *FTy;
3452 if (isa<llvm::FunctionType>(Ty)) {
3453 FTy = cast<llvm::FunctionType>(Ty);
3454 } else {
3455 FTy = llvm::FunctionType::get(VoidTy, false);
3456 IsIncompleteFunction = true;
3457 }
3458
3459 llvm::Function *F =
3460 llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
3461 Entry ? StringRef() : MangledName, &getModule());
3462
3463 // If we already created a function with the same mangled name (but different
3464 // type) before, take its name and add it to the list of functions to be
3465 // replaced with F at the end of CodeGen.
3466 //
3467 // This happens if there is a prototype for a function (e.g. "int f()") and
3468 // then a definition of a different type (e.g. "int f(int x)").
3469 if (Entry) {
3470 F->takeName(Entry);
3471
3472 // This might be an implementation of a function without a prototype, in
3473 // which case, try to do special replacement of calls which match the new
3474 // prototype. The really key thing here is that we also potentially drop
3475 // arguments from the call site so as to make a direct call, which makes the
3476 // inliner happier and suppresses a number of optimizer warnings (!) about
3477 // dropping arguments.
3478 if (!Entry->use_empty()) {
3479 ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
3480 Entry->removeDeadConstantUsers();
3481 }
3482
3483 llvm::Constant *BC = llvm::ConstantExpr::getBitCast(
3484 F, Entry->getValueType()->getPointerTo());
3485 addGlobalValReplacement(Entry, BC);
3486 }
3487
3488 assert(F->getName() == MangledName && "name was uniqued!");
3489 if (D)
3490 SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
3491 if (ExtraAttrs.hasAttributes(llvm::AttributeList::FunctionIndex)) {
3492 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex);
3493 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
3494 }
3495
3496 if (!DontDefer) {
3497 // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
3498 // each other bottoming out with the base dtor. Therefore we emit non-base
3499 // dtors on usage, even if there is no dtor definition in the TU.
3500 if (D && isa<CXXDestructorDecl>(D) &&
3501 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
3502 GD.getDtorType()))
3503 addDeferredDeclToEmit(GD);
3504
3505 // This is the first use or definition of a mangled name. If there is a
3506 // deferred decl with this name, remember that we need to emit it at the end
3507 // of the file.
3508 auto DDI = DeferredDecls.find(MangledName);
3509 if (DDI != DeferredDecls.end()) {
3510 // Move the potentially referenced deferred decl to the
3511 // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
3512 // don't need it anymore).
3513 addDeferredDeclToEmit(DDI->second);
3514 DeferredDecls.erase(DDI);
3515
3516 // Otherwise, there are cases we have to worry about where we're
3517 // using a declaration for which we must emit a definition but where
3518 // we might not find a top-level definition:
3519 // - member functions defined inline in their classes
3520 // - friend functions defined inline in some class
3521 // - special member functions with implicit definitions
3522 // If we ever change our AST traversal to walk into class methods,
3523 // this will be unnecessary.
3524 //
3525 // We also don't emit a definition for a function if it's going to be an
3526 // entry in a vtable, unless it's already marked as used.
3527 } else if (getLangOpts().CPlusPlus && D) {
3528 // Look for a declaration that's lexically in a record.
3529 for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
3530 FD = FD->getPreviousDecl()) {
3531 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
3532 if (FD->doesThisDeclarationHaveABody()) {
3533 addDeferredDeclToEmit(GD.getWithDecl(FD));
3534 break;
3535 }
3536 }
3537 }
3538 }
3539 }
3540
3541 // Make sure the result is of the requested type.
3542 if (!IsIncompleteFunction) {
3543 assert(F->getFunctionType() == Ty);
3544 return F;
3545 }
3546
3547 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
3548 return llvm::ConstantExpr::getBitCast(F, PTy);
3549 }
3550
3551 /// GetAddrOfFunction - Return the address of the given function. If Ty is
3552 /// non-null, then this function will use the specified type if it has to
3553 /// 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)3554 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
3555 llvm::Type *Ty,
3556 bool ForVTable,
3557 bool DontDefer,
3558 ForDefinition_t IsForDefinition) {
3559 assert(!cast<FunctionDecl>(GD.getDecl())->isConsteval() &&
3560 "consteval function should never be emitted");
3561 // If there was no specific requested type, just convert it now.
3562 if (!Ty) {
3563 const auto *FD = cast<FunctionDecl>(GD.getDecl());
3564 Ty = getTypes().ConvertType(FD->getType());
3565 }
3566
3567 // Devirtualized destructor calls may come through here instead of via
3568 // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
3569 // of the complete destructor when necessary.
3570 if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
3571 if (getTarget().getCXXABI().isMicrosoft() &&
3572 GD.getDtorType() == Dtor_Complete &&
3573 DD->getParent()->getNumVBases() == 0)
3574 GD = GlobalDecl(DD, Dtor_Base);
3575 }
3576
3577 StringRef MangledName = getMangledName(GD);
3578 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
3579 /*IsThunk=*/false, llvm::AttributeList(),
3580 IsForDefinition);
3581 }
3582
3583 static const FunctionDecl *
GetRuntimeFunctionDecl(ASTContext & C,StringRef Name)3584 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
3585 TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
3586 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
3587
3588 IdentifierInfo &CII = C.Idents.get(Name);
3589 for (const auto &Result : DC->lookup(&CII))
3590 if (const auto FD = dyn_cast<FunctionDecl>(Result))
3591 return FD;
3592
3593 if (!C.getLangOpts().CPlusPlus)
3594 return nullptr;
3595
3596 // Demangle the premangled name from getTerminateFn()
3597 IdentifierInfo &CXXII =
3598 (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
3599 ? C.Idents.get("terminate")
3600 : C.Idents.get(Name);
3601
3602 for (const auto &N : {"__cxxabiv1", "std"}) {
3603 IdentifierInfo &NS = C.Idents.get(N);
3604 for (const auto &Result : DC->lookup(&NS)) {
3605 NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
3606 if (auto LSD = dyn_cast<LinkageSpecDecl>(Result))
3607 for (const auto &Result : LSD->lookup(&NS))
3608 if ((ND = dyn_cast<NamespaceDecl>(Result)))
3609 break;
3610
3611 if (ND)
3612 for (const auto &Result : ND->lookup(&CXXII))
3613 if (const auto *FD = dyn_cast<FunctionDecl>(Result))
3614 return FD;
3615 }
3616 }
3617
3618 return nullptr;
3619 }
3620
3621 /// CreateRuntimeFunction - Create a new runtime function with the specified
3622 /// type and name.
3623 llvm::FunctionCallee
CreateRuntimeFunction(llvm::FunctionType * FTy,StringRef Name,llvm::AttributeList ExtraAttrs,bool Local,bool AssumeConvergent)3624 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
3625 llvm::AttributeList ExtraAttrs, bool Local,
3626 bool AssumeConvergent) {
3627 if (AssumeConvergent) {
3628 ExtraAttrs =
3629 ExtraAttrs.addAttribute(VMContext, llvm::AttributeList::FunctionIndex,
3630 llvm::Attribute::Convergent);
3631 }
3632
3633 llvm::Constant *C =
3634 GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
3635 /*DontDefer=*/false, /*IsThunk=*/false,
3636 ExtraAttrs);
3637
3638 if (auto *F = dyn_cast<llvm::Function>(C)) {
3639 if (F->empty()) {
3640 F->setCallingConv(getRuntimeCC());
3641
3642 // In Windows Itanium environments, try to mark runtime functions
3643 // dllimport. For Mingw and MSVC, don't. We don't really know if the user
3644 // will link their standard library statically or dynamically. Marking
3645 // functions imported when they are not imported can cause linker errors
3646 // and warnings.
3647 if (!Local && getTriple().isWindowsItaniumEnvironment() &&
3648 !getCodeGenOpts().LTOVisibilityPublicStd) {
3649 const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
3650 if (!FD || FD->hasAttr<DLLImportAttr>()) {
3651 F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
3652 F->setLinkage(llvm::GlobalValue::ExternalLinkage);
3653 }
3654 }
3655 setDSOLocal(F);
3656 }
3657 }
3658
3659 return {FTy, C};
3660 }
3661
3662 /// isTypeConstant - Determine whether an object of this type can be emitted
3663 /// as a constant.
3664 ///
3665 /// If ExcludeCtor is true, the duration when the object's constructor runs
3666 /// will not be considered. The caller will need to verify that the object is
3667 /// not written to during its construction.
isTypeConstant(QualType Ty,bool ExcludeCtor)3668 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
3669 if (!Ty.isConstant(Context) && !Ty->isReferenceType())
3670 return false;
3671
3672 if (Context.getLangOpts().CPlusPlus) {
3673 if (const CXXRecordDecl *Record
3674 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
3675 return ExcludeCtor && !Record->hasMutableFields() &&
3676 Record->hasTrivialDestructor();
3677 }
3678
3679 return true;
3680 }
3681
3682 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
3683 /// create and return an llvm GlobalVariable with the specified type. If there
3684 /// is something in the module with the specified name, return it potentially
3685 /// bitcasted to the right type.
3686 ///
3687 /// If D is non-null, it specifies a decl that correspond to this. This is used
3688 /// to set the attributes on the global when it is first created.
3689 ///
3690 /// If IsForDefinition is true, it is guaranteed that an actual global with
3691 /// type Ty will be returned, not conversion of a variable with the same
3692 /// mangled name but some other type.
3693 llvm::Constant *
GetOrCreateLLVMGlobal(StringRef MangledName,llvm::PointerType * Ty,const VarDecl * D,ForDefinition_t IsForDefinition)3694 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
3695 llvm::PointerType *Ty,
3696 const VarDecl *D,
3697 ForDefinition_t IsForDefinition) {
3698 // Lookup the entry, lazily creating it if necessary.
3699 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3700 if (Entry) {
3701 if (WeakRefReferences.erase(Entry)) {
3702 if (D && !D->hasAttr<WeakAttr>())
3703 Entry->setLinkage(llvm::Function::ExternalLinkage);
3704 }
3705
3706 // Handle dropped DLL attributes.
3707 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
3708 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3709
3710 if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
3711 getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
3712
3713 if (Entry->getType() == Ty)
3714 return Entry;
3715
3716 // If there are two attempts to define the same mangled name, issue an
3717 // error.
3718 if (IsForDefinition && !Entry->isDeclaration()) {
3719 GlobalDecl OtherGD;
3720 const VarDecl *OtherD;
3721
3722 // Check that D is not yet in DiagnosedConflictingDefinitions is required
3723 // to make sure that we issue an error only once.
3724 if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
3725 (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
3726 (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
3727 OtherD->hasInit() &&
3728 DiagnosedConflictingDefinitions.insert(D).second) {
3729 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3730 << MangledName;
3731 getDiags().Report(OtherGD.getDecl()->getLocation(),
3732 diag::note_previous_definition);
3733 }
3734 }
3735
3736 // Make sure the result is of the correct type.
3737 if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace())
3738 return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty);
3739
3740 // (If global is requested for a definition, we always need to create a new
3741 // global, not just return a bitcast.)
3742 if (!IsForDefinition)
3743 return llvm::ConstantExpr::getBitCast(Entry, Ty);
3744 }
3745
3746 auto AddrSpace = GetGlobalVarAddressSpace(D);
3747 auto TargetAddrSpace = getContext().getTargetAddressSpace(AddrSpace);
3748
3749 auto *GV = new llvm::GlobalVariable(
3750 getModule(), Ty->getElementType(), false,
3751 llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr,
3752 llvm::GlobalVariable::NotThreadLocal, TargetAddrSpace);
3753
3754 // If we already created a global with the same mangled name (but different
3755 // type) before, take its name and remove it from its parent.
3756 if (Entry) {
3757 GV->takeName(Entry);
3758
3759 if (!Entry->use_empty()) {
3760 llvm::Constant *NewPtrForOldDecl =
3761 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
3762 Entry->replaceAllUsesWith(NewPtrForOldDecl);
3763 }
3764
3765 Entry->eraseFromParent();
3766 }
3767
3768 // This is the first use or definition of a mangled name. If there is a
3769 // deferred decl with this name, remember that we need to emit it at the end
3770 // of the file.
3771 auto DDI = DeferredDecls.find(MangledName);
3772 if (DDI != DeferredDecls.end()) {
3773 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
3774 // list, and remove it from DeferredDecls (since we don't need it anymore).
3775 addDeferredDeclToEmit(DDI->second);
3776 DeferredDecls.erase(DDI);
3777 }
3778
3779 // Handle things which are present even on external declarations.
3780 if (D) {
3781 if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
3782 getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
3783
3784 // FIXME: This code is overly simple and should be merged with other global
3785 // handling.
3786 GV->setConstant(isTypeConstant(D->getType(), false));
3787
3788 GV->setAlignment(getContext().getDeclAlign(D).getAsAlign());
3789
3790 setLinkageForGV(GV, D);
3791
3792 if (D->getTLSKind()) {
3793 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
3794 CXXThreadLocals.push_back(D);
3795 setTLSMode(GV, *D);
3796 }
3797
3798 setGVProperties(GV, D);
3799
3800 // If required by the ABI, treat declarations of static data members with
3801 // inline initializers as definitions.
3802 if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
3803 EmitGlobalVarDefinition(D);
3804 }
3805
3806 // Emit section information for extern variables.
3807 if (D->hasExternalStorage()) {
3808 if (const SectionAttr *SA = D->getAttr<SectionAttr>())
3809 GV->setSection(SA->getName());
3810 }
3811
3812 // Handle XCore specific ABI requirements.
3813 if (getTriple().getArch() == llvm::Triple::xcore &&
3814 D->getLanguageLinkage() == CLanguageLinkage &&
3815 D->getType().isConstant(Context) &&
3816 isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
3817 GV->setSection(".cp.rodata");
3818
3819 // Check if we a have a const declaration with an initializer, we may be
3820 // able to emit it as available_externally to expose it's value to the
3821 // optimizer.
3822 if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
3823 D->getType().isConstQualified() && !GV->hasInitializer() &&
3824 !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
3825 const auto *Record =
3826 Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
3827 bool HasMutableFields = Record && Record->hasMutableFields();
3828 if (!HasMutableFields) {
3829 const VarDecl *InitDecl;
3830 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
3831 if (InitExpr) {
3832 ConstantEmitter emitter(*this);
3833 llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
3834 if (Init) {
3835 auto *InitType = Init->getType();
3836 if (GV->getValueType() != InitType) {
3837 // The type of the initializer does not match the definition.
3838 // This happens when an initializer has a different type from
3839 // the type of the global (because of padding at the end of a
3840 // structure for instance).
3841 GV->setName(StringRef());
3842 // Make a new global with the correct type, this is now guaranteed
3843 // to work.
3844 auto *NewGV = cast<llvm::GlobalVariable>(
3845 GetAddrOfGlobalVar(D, InitType, IsForDefinition)
3846 ->stripPointerCasts());
3847
3848 // Erase the old global, since it is no longer used.
3849 GV->eraseFromParent();
3850 GV = NewGV;
3851 } else {
3852 GV->setInitializer(Init);
3853 GV->setConstant(true);
3854 GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
3855 }
3856 emitter.finalize(GV);
3857 }
3858 }
3859 }
3860 }
3861 }
3862
3863 if (GV->isDeclaration())
3864 getTargetCodeGenInfo().setTargetAttributes(D, GV, *this);
3865
3866 LangAS ExpectedAS =
3867 D ? D->getType().getAddressSpace()
3868 : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
3869 assert(getContext().getTargetAddressSpace(ExpectedAS) ==
3870 Ty->getPointerAddressSpace());
3871 if (AddrSpace != ExpectedAS)
3872 return getTargetCodeGenInfo().performAddrSpaceCast(*this, GV, AddrSpace,
3873 ExpectedAS, Ty);
3874
3875 return GV;
3876 }
3877
3878 llvm::Constant *
GetAddrOfGlobal(GlobalDecl GD,ForDefinition_t IsForDefinition)3879 CodeGenModule::GetAddrOfGlobal(GlobalDecl GD, ForDefinition_t IsForDefinition) {
3880 const Decl *D = GD.getDecl();
3881
3882 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
3883 return getAddrOfCXXStructor(GD, /*FnInfo=*/nullptr, /*FnType=*/nullptr,
3884 /*DontDefer=*/false, IsForDefinition);
3885
3886 if (isa<CXXMethodDecl>(D)) {
3887 auto FInfo =
3888 &getTypes().arrangeCXXMethodDeclaration(cast<CXXMethodDecl>(D));
3889 auto Ty = getTypes().GetFunctionType(*FInfo);
3890 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
3891 IsForDefinition);
3892 }
3893
3894 if (isa<FunctionDecl>(D)) {
3895 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
3896 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
3897 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
3898 IsForDefinition);
3899 }
3900
3901 return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr, IsForDefinition);
3902 }
3903
CreateOrReplaceCXXRuntimeVariable(StringRef Name,llvm::Type * Ty,llvm::GlobalValue::LinkageTypes Linkage,unsigned Alignment)3904 llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
3905 StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
3906 unsigned Alignment) {
3907 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
3908 llvm::GlobalVariable *OldGV = nullptr;
3909
3910 if (GV) {
3911 // Check if the variable has the right type.
3912 if (GV->getValueType() == Ty)
3913 return GV;
3914
3915 // Because C++ name mangling, the only way we can end up with an already
3916 // existing global with the same name is if it has been declared extern "C".
3917 assert(GV->isDeclaration() && "Declaration has wrong type!");
3918 OldGV = GV;
3919 }
3920
3921 // Create a new variable.
3922 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
3923 Linkage, nullptr, Name);
3924
3925 if (OldGV) {
3926 // Replace occurrences of the old variable if needed.
3927 GV->takeName(OldGV);
3928
3929 if (!OldGV->use_empty()) {
3930 llvm::Constant *NewPtrForOldDecl =
3931 llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
3932 OldGV->replaceAllUsesWith(NewPtrForOldDecl);
3933 }
3934
3935 OldGV->eraseFromParent();
3936 }
3937
3938 if (supportsCOMDAT() && GV->isWeakForLinker() &&
3939 !GV->hasAvailableExternallyLinkage())
3940 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3941
3942 GV->setAlignment(llvm::MaybeAlign(Alignment));
3943
3944 return GV;
3945 }
3946
3947 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
3948 /// given global variable. If Ty is non-null and if the global doesn't exist,
3949 /// then it will be created with the specified type instead of whatever the
3950 /// normal requested type would be. If IsForDefinition is true, it is guaranteed
3951 /// that an actual global with type Ty will be returned, not conversion of a
3952 /// variable with the same mangled name but some other type.
GetAddrOfGlobalVar(const VarDecl * D,llvm::Type * Ty,ForDefinition_t IsForDefinition)3953 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
3954 llvm::Type *Ty,
3955 ForDefinition_t IsForDefinition) {
3956 assert(D->hasGlobalStorage() && "Not a global variable");
3957 QualType ASTTy = D->getType();
3958 if (!Ty)
3959 Ty = getTypes().ConvertTypeForMem(ASTTy);
3960
3961 llvm::PointerType *PTy =
3962 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
3963
3964 StringRef MangledName = getMangledName(D);
3965 return GetOrCreateLLVMGlobal(MangledName, PTy, D, IsForDefinition);
3966 }
3967
3968 /// CreateRuntimeVariable - Create a new runtime global variable with the
3969 /// specified type and name.
3970 llvm::Constant *
CreateRuntimeVariable(llvm::Type * Ty,StringRef Name)3971 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
3972 StringRef Name) {
3973 auto PtrTy =
3974 getContext().getLangOpts().OpenCL
3975 ? llvm::PointerType::get(
3976 Ty, getContext().getTargetAddressSpace(LangAS::opencl_global))
3977 : llvm::PointerType::getUnqual(Ty);
3978 auto *Ret = GetOrCreateLLVMGlobal(Name, PtrTy, nullptr);
3979 setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
3980 return Ret;
3981 }
3982
EmitTentativeDefinition(const VarDecl * D)3983 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
3984 assert(!D->getInit() && "Cannot emit definite definitions here!");
3985
3986 StringRef MangledName = getMangledName(D);
3987 llvm::GlobalValue *GV = GetGlobalValue(MangledName);
3988
3989 // We already have a definition, not declaration, with the same mangled name.
3990 // Emitting of declaration is not required (and actually overwrites emitted
3991 // definition).
3992 if (GV && !GV->isDeclaration())
3993 return;
3994
3995 // If we have not seen a reference to this variable yet, place it into the
3996 // deferred declarations table to be emitted if needed later.
3997 if (!MustBeEmitted(D) && !GV) {
3998 DeferredDecls[MangledName] = D;
3999 return;
4000 }
4001
4002 // The tentative definition is the only definition.
4003 EmitGlobalVarDefinition(D);
4004 }
4005
EmitExternalDeclaration(const VarDecl * D)4006 void CodeGenModule::EmitExternalDeclaration(const VarDecl *D) {
4007 EmitExternalVarDeclaration(D);
4008 }
4009
GetTargetTypeStoreSize(llvm::Type * Ty) const4010 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
4011 return Context.toCharUnitsFromBits(
4012 getDataLayout().getTypeStoreSizeInBits(Ty));
4013 }
4014
GetGlobalVarAddressSpace(const VarDecl * D)4015 LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
4016 LangAS AddrSpace = LangAS::Default;
4017 if (LangOpts.OpenCL) {
4018 AddrSpace = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
4019 assert(AddrSpace == LangAS::opencl_global ||
4020 AddrSpace == LangAS::opencl_global_device ||
4021 AddrSpace == LangAS::opencl_global_host ||
4022 AddrSpace == LangAS::opencl_constant ||
4023 AddrSpace == LangAS::opencl_local ||
4024 AddrSpace >= LangAS::FirstTargetAddressSpace);
4025 return AddrSpace;
4026 }
4027
4028 if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
4029 if (D && D->hasAttr<CUDAConstantAttr>())
4030 return LangAS::cuda_constant;
4031 else if (D && D->hasAttr<CUDASharedAttr>())
4032 return LangAS::cuda_shared;
4033 else if (D && D->hasAttr<CUDADeviceAttr>())
4034 return LangAS::cuda_device;
4035 else if (D && D->getType().isConstQualified())
4036 return LangAS::cuda_constant;
4037 else
4038 return LangAS::cuda_device;
4039 }
4040
4041 if (LangOpts.OpenMP) {
4042 LangAS AS;
4043 if (OpenMPRuntime->hasAllocateAttributeForGlobalVar(D, AS))
4044 return AS;
4045 }
4046 return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
4047 }
4048
getStringLiteralAddressSpace() const4049 LangAS CodeGenModule::getStringLiteralAddressSpace() const {
4050 // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
4051 if (LangOpts.OpenCL)
4052 return LangAS::opencl_constant;
4053 if (auto AS = getTarget().getConstantAddressSpace())
4054 return AS.getValue();
4055 return LangAS::Default;
4056 }
4057
4058 // In address space agnostic languages, string literals are in default address
4059 // space in AST. However, certain targets (e.g. amdgcn) request them to be
4060 // emitted in constant address space in LLVM IR. To be consistent with other
4061 // parts of AST, string literal global variables in constant address space
4062 // need to be casted to default address space before being put into address
4063 // map and referenced by other part of CodeGen.
4064 // In OpenCL, string literals are in constant address space in AST, therefore
4065 // they should not be casted to default address space.
4066 static llvm::Constant *
castStringLiteralToDefaultAddressSpace(CodeGenModule & CGM,llvm::GlobalVariable * GV)4067 castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM,
4068 llvm::GlobalVariable *GV) {
4069 llvm::Constant *Cast = GV;
4070 if (!CGM.getLangOpts().OpenCL) {
4071 if (auto AS = CGM.getTarget().getConstantAddressSpace()) {
4072 if (AS != LangAS::Default)
4073 Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast(
4074 CGM, GV, AS.getValue(), LangAS::Default,
4075 GV->getValueType()->getPointerTo(
4076 CGM.getContext().getTargetAddressSpace(LangAS::Default)));
4077 }
4078 }
4079 return Cast;
4080 }
4081
4082 template<typename SomeDecl>
MaybeHandleStaticInExternC(const SomeDecl * D,llvm::GlobalValue * GV)4083 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
4084 llvm::GlobalValue *GV) {
4085 if (!getLangOpts().CPlusPlus)
4086 return;
4087
4088 // Must have 'used' attribute, or else inline assembly can't rely on
4089 // the name existing.
4090 if (!D->template hasAttr<UsedAttr>())
4091 return;
4092
4093 // Must have internal linkage and an ordinary name.
4094 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage)
4095 return;
4096
4097 // Must be in an extern "C" context. Entities declared directly within
4098 // a record are not extern "C" even if the record is in such a context.
4099 const SomeDecl *First = D->getFirstDecl();
4100 if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
4101 return;
4102
4103 // OK, this is an internal linkage entity inside an extern "C" linkage
4104 // specification. Make a note of that so we can give it the "expected"
4105 // mangled name if nothing else is using that name.
4106 std::pair<StaticExternCMap::iterator, bool> R =
4107 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
4108
4109 // If we have multiple internal linkage entities with the same name
4110 // in extern "C" regions, none of them gets that name.
4111 if (!R.second)
4112 R.first->second = nullptr;
4113 }
4114
shouldBeInCOMDAT(CodeGenModule & CGM,const Decl & D)4115 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
4116 if (!CGM.supportsCOMDAT())
4117 return false;
4118
4119 // Do not set COMDAT attribute for CUDA/HIP stub functions to prevent
4120 // them being "merged" by the COMDAT Folding linker optimization.
4121 if (D.hasAttr<CUDAGlobalAttr>())
4122 return false;
4123
4124 if (D.hasAttr<SelectAnyAttr>())
4125 return true;
4126
4127 GVALinkage Linkage;
4128 if (auto *VD = dyn_cast<VarDecl>(&D))
4129 Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
4130 else
4131 Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
4132
4133 switch (Linkage) {
4134 case GVA_Internal:
4135 case GVA_AvailableExternally:
4136 case GVA_StrongExternal:
4137 return false;
4138 case GVA_DiscardableODR:
4139 case GVA_StrongODR:
4140 return true;
4141 }
4142 llvm_unreachable("No such linkage");
4143 }
4144
maybeSetTrivialComdat(const Decl & D,llvm::GlobalObject & GO)4145 void CodeGenModule::maybeSetTrivialComdat(const Decl &D,
4146 llvm::GlobalObject &GO) {
4147 if (!shouldBeInCOMDAT(*this, D))
4148 return;
4149 GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
4150 }
4151
4152 /// Pass IsTentative as true if you want to create a tentative definition.
EmitGlobalVarDefinition(const VarDecl * D,bool IsTentative)4153 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
4154 bool IsTentative) {
4155 // OpenCL global variables of sampler type are translated to function calls,
4156 // therefore no need to be translated.
4157 QualType ASTTy = D->getType();
4158 if (getLangOpts().OpenCL && ASTTy->isSamplerT())
4159 return;
4160
4161 // If this is OpenMP device, check if it is legal to emit this global
4162 // normally.
4163 if (LangOpts.OpenMPIsDevice && OpenMPRuntime &&
4164 OpenMPRuntime->emitTargetGlobalVariable(D))
4165 return;
4166
4167 llvm::Constant *Init = nullptr;
4168 bool NeedsGlobalCtor = false;
4169 bool NeedsGlobalDtor =
4170 D->needsDestruction(getContext()) == QualType::DK_cxx_destructor;
4171
4172 const VarDecl *InitDecl;
4173 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
4174
4175 Optional<ConstantEmitter> emitter;
4176
4177 // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
4178 // as part of their declaration." Sema has already checked for
4179 // error cases, so we just need to set Init to UndefValue.
4180 bool IsCUDASharedVar =
4181 getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
4182 // Shadows of initialized device-side global variables are also left
4183 // undefined.
4184 bool IsCUDAShadowVar =
4185 !getLangOpts().CUDAIsDevice && !D->hasAttr<HIPManagedAttr>() &&
4186 (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
4187 D->hasAttr<CUDASharedAttr>());
4188 bool IsCUDADeviceShadowVar =
4189 getLangOpts().CUDAIsDevice &&
4190 (D->getType()->isCUDADeviceBuiltinSurfaceType() ||
4191 D->getType()->isCUDADeviceBuiltinTextureType() ||
4192 D->hasAttr<HIPManagedAttr>());
4193 // HIP pinned shadow of initialized host-side global variables are also
4194 // left undefined.
4195 if (getLangOpts().CUDA &&
4196 (IsCUDASharedVar || IsCUDAShadowVar || IsCUDADeviceShadowVar))
4197 Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
4198 else if (D->hasAttr<LoaderUninitializedAttr>())
4199 Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
4200 else if (!InitExpr) {
4201 // This is a tentative definition; tentative definitions are
4202 // implicitly initialized with { 0 }.
4203 //
4204 // Note that tentative definitions are only emitted at the end of
4205 // a translation unit, so they should never have incomplete
4206 // type. In addition, EmitTentativeDefinition makes sure that we
4207 // never attempt to emit a tentative definition if a real one
4208 // exists. A use may still exists, however, so we still may need
4209 // to do a RAUW.
4210 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
4211 Init = EmitNullConstant(D->getType());
4212 } else {
4213 initializedGlobalDecl = GlobalDecl(D);
4214 emitter.emplace(*this);
4215 Init = emitter->tryEmitForInitializer(*InitDecl);
4216
4217 if (!Init) {
4218 QualType T = InitExpr->getType();
4219 if (D->getType()->isReferenceType())
4220 T = D->getType();
4221
4222 if (getLangOpts().CPlusPlus) {
4223 Init = EmitNullConstant(T);
4224 NeedsGlobalCtor = true;
4225 } else {
4226 ErrorUnsupported(D, "static initializer");
4227 Init = llvm::UndefValue::get(getTypes().ConvertType(T));
4228 }
4229 } else {
4230 // We don't need an initializer, so remove the entry for the delayed
4231 // initializer position (just in case this entry was delayed) if we
4232 // also don't need to register a destructor.
4233 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
4234 DelayedCXXInitPosition.erase(D);
4235 }
4236 }
4237
4238 llvm::Type* InitType = Init->getType();
4239 llvm::Constant *Entry =
4240 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
4241
4242 // Strip off pointer casts if we got them.
4243 Entry = Entry->stripPointerCasts();
4244
4245 // Entry is now either a Function or GlobalVariable.
4246 auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
4247
4248 // We have a definition after a declaration with the wrong type.
4249 // We must make a new GlobalVariable* and update everything that used OldGV
4250 // (a declaration or tentative definition) with the new GlobalVariable*
4251 // (which will be a definition).
4252 //
4253 // This happens if there is a prototype for a global (e.g.
4254 // "extern int x[];") and then a definition of a different type (e.g.
4255 // "int x[10];"). This also happens when an initializer has a different type
4256 // from the type of the global (this happens with unions).
4257 if (!GV || GV->getValueType() != InitType ||
4258 GV->getType()->getAddressSpace() !=
4259 getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
4260
4261 // Move the old entry aside so that we'll create a new one.
4262 Entry->setName(StringRef());
4263
4264 // Make a new global with the correct type, this is now guaranteed to work.
4265 GV = cast<llvm::GlobalVariable>(
4266 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative))
4267 ->stripPointerCasts());
4268
4269 // Replace all uses of the old global with the new global
4270 llvm::Constant *NewPtrForOldDecl =
4271 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
4272 Entry->replaceAllUsesWith(NewPtrForOldDecl);
4273
4274 // Erase the old global, since it is no longer used.
4275 cast<llvm::GlobalValue>(Entry)->eraseFromParent();
4276 }
4277
4278 MaybeHandleStaticInExternC(D, GV);
4279
4280 if (D->hasAttr<AnnotateAttr>())
4281 AddGlobalAnnotations(D, GV);
4282
4283 // Set the llvm linkage type as appropriate.
4284 llvm::GlobalValue::LinkageTypes Linkage =
4285 getLLVMLinkageVarDefinition(D, GV->isConstant());
4286
4287 // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
4288 // the device. [...]"
4289 // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
4290 // __device__, declares a variable that: [...]
4291 // Is accessible from all the threads within the grid and from the host
4292 // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
4293 // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
4294 if (GV && LangOpts.CUDA) {
4295 if (LangOpts.CUDAIsDevice) {
4296 if (Linkage != llvm::GlobalValue::InternalLinkage &&
4297 (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()))
4298 GV->setExternallyInitialized(true);
4299 } else {
4300 // Host-side shadows of external declarations of device-side
4301 // global variables become internal definitions. These have to
4302 // be internal in order to prevent name conflicts with global
4303 // host variables with the same name in a different TUs.
4304 if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()) {
4305 Linkage = llvm::GlobalValue::InternalLinkage;
4306 // Shadow variables and their properties must be registered with CUDA
4307 // runtime. Skip Extern global variables, which will be registered in
4308 // the TU where they are defined.
4309 //
4310 // Don't register a C++17 inline variable. The local symbol can be
4311 // discarded and referencing a discarded local symbol from outside the
4312 // comdat (__cuda_register_globals) is disallowed by the ELF spec.
4313 // TODO: Reject __device__ constexpr and __device__ inline in Sema.
4314 if (!D->hasExternalStorage() && !D->isInline())
4315 getCUDARuntime().registerDeviceVar(D, *GV, !D->hasDefinition(),
4316 D->hasAttr<CUDAConstantAttr>());
4317 } else if (D->hasAttr<CUDASharedAttr>()) {
4318 // __shared__ variables are odd. Shadows do get created, but
4319 // they are not registered with the CUDA runtime, so they
4320 // can't really be used to access their device-side
4321 // counterparts. It's not clear yet whether it's nvcc's bug or
4322 // a feature, but we've got to do the same for compatibility.
4323 Linkage = llvm::GlobalValue::InternalLinkage;
4324 } else if (D->getType()->isCUDADeviceBuiltinSurfaceType() ||
4325 D->getType()->isCUDADeviceBuiltinTextureType()) {
4326 // Builtin surfaces and textures and their template arguments are
4327 // also registered with CUDA runtime.
4328 Linkage = llvm::GlobalValue::InternalLinkage;
4329 const ClassTemplateSpecializationDecl *TD =
4330 cast<ClassTemplateSpecializationDecl>(
4331 D->getType()->getAs<RecordType>()->getDecl());
4332 const TemplateArgumentList &Args = TD->getTemplateArgs();
4333 if (TD->hasAttr<CUDADeviceBuiltinSurfaceTypeAttr>()) {
4334 assert(Args.size() == 2 &&
4335 "Unexpected number of template arguments of CUDA device "
4336 "builtin surface type.");
4337 auto SurfType = Args[1].getAsIntegral();
4338 if (!D->hasExternalStorage())
4339 getCUDARuntime().registerDeviceSurf(D, *GV, !D->hasDefinition(),
4340 SurfType.getSExtValue());
4341 } else {
4342 assert(Args.size() == 3 &&
4343 "Unexpected number of template arguments of CUDA device "
4344 "builtin texture type.");
4345 auto TexType = Args[1].getAsIntegral();
4346 auto Normalized = Args[2].getAsIntegral();
4347 if (!D->hasExternalStorage())
4348 getCUDARuntime().registerDeviceTex(D, *GV, !D->hasDefinition(),
4349 TexType.getSExtValue(),
4350 Normalized.getZExtValue());
4351 }
4352 }
4353 }
4354 }
4355
4356 GV->setInitializer(Init);
4357 if (emitter)
4358 emitter->finalize(GV);
4359
4360 // If it is safe to mark the global 'constant', do so now.
4361 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
4362 isTypeConstant(D->getType(), true));
4363
4364 // If it is in a read-only section, mark it 'constant'.
4365 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
4366 const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
4367 if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
4368 GV->setConstant(true);
4369 }
4370
4371 GV->setAlignment(getContext().getDeclAlign(D).getAsAlign());
4372
4373 // On Darwin, unlike other Itanium C++ ABI platforms, the thread-wrapper
4374 // function is only defined alongside the variable, not also alongside
4375 // callers. Normally, all accesses to a thread_local go through the
4376 // thread-wrapper in order to ensure initialization has occurred, underlying
4377 // variable will never be used other than the thread-wrapper, so it can be
4378 // converted to internal linkage.
4379 //
4380 // However, if the variable has the 'constinit' attribute, it _can_ be
4381 // referenced directly, without calling the thread-wrapper, so the linkage
4382 // must not be changed.
4383 //
4384 // Additionally, if the variable isn't plain external linkage, e.g. if it's
4385 // weak or linkonce, the de-duplication semantics are important to preserve,
4386 // so we don't change the linkage.
4387 if (D->getTLSKind() == VarDecl::TLS_Dynamic &&
4388 Linkage == llvm::GlobalValue::ExternalLinkage &&
4389 Context.getTargetInfo().getTriple().isOSDarwin() &&
4390 !D->hasAttr<ConstInitAttr>())
4391 Linkage = llvm::GlobalValue::InternalLinkage;
4392
4393 GV->setLinkage(Linkage);
4394 if (D->hasAttr<DLLImportAttr>())
4395 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
4396 else if (D->hasAttr<DLLExportAttr>())
4397 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
4398 else
4399 GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
4400
4401 if (Linkage == llvm::GlobalVariable::CommonLinkage) {
4402 // common vars aren't constant even if declared const.
4403 GV->setConstant(false);
4404 // Tentative definition of global variables may be initialized with
4405 // non-zero null pointers. In this case they should have weak linkage
4406 // since common linkage must have zero initializer and must not have
4407 // explicit section therefore cannot have non-zero initial value.
4408 if (!GV->getInitializer()->isNullValue())
4409 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
4410 }
4411
4412 setNonAliasAttributes(D, GV);
4413
4414 if (D->getTLSKind() && !GV->isThreadLocal()) {
4415 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
4416 CXXThreadLocals.push_back(D);
4417 setTLSMode(GV, *D);
4418 }
4419
4420 maybeSetTrivialComdat(*D, *GV);
4421
4422 // Emit the initializer function if necessary.
4423 if (NeedsGlobalCtor || NeedsGlobalDtor)
4424 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
4425
4426 SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor);
4427
4428 // Emit global variable debug information.
4429 if (CGDebugInfo *DI = getModuleDebugInfo())
4430 if (getCodeGenOpts().hasReducedDebugInfo())
4431 DI->EmitGlobalVariable(GV, D);
4432 }
4433
EmitExternalVarDeclaration(const VarDecl * D)4434 void CodeGenModule::EmitExternalVarDeclaration(const VarDecl *D) {
4435 if (CGDebugInfo *DI = getModuleDebugInfo())
4436 if (getCodeGenOpts().hasReducedDebugInfo()) {
4437 QualType ASTTy = D->getType();
4438 llvm::Type *Ty = getTypes().ConvertTypeForMem(D->getType());
4439 llvm::PointerType *PTy =
4440 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
4441 llvm::Constant *GV = GetOrCreateLLVMGlobal(D->getName(), PTy, D);
4442 DI->EmitExternalVariable(
4443 cast<llvm::GlobalVariable>(GV->stripPointerCasts()), D);
4444 }
4445 }
4446
isVarDeclStrongDefinition(const ASTContext & Context,CodeGenModule & CGM,const VarDecl * D,bool NoCommon)4447 static bool isVarDeclStrongDefinition(const ASTContext &Context,
4448 CodeGenModule &CGM, const VarDecl *D,
4449 bool NoCommon) {
4450 // Don't give variables common linkage if -fno-common was specified unless it
4451 // was overridden by a NoCommon attribute.
4452 if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
4453 return true;
4454
4455 // C11 6.9.2/2:
4456 // A declaration of an identifier for an object that has file scope without
4457 // an initializer, and without a storage-class specifier or with the
4458 // storage-class specifier static, constitutes a tentative definition.
4459 if (D->getInit() || D->hasExternalStorage())
4460 return true;
4461
4462 // A variable cannot be both common and exist in a section.
4463 if (D->hasAttr<SectionAttr>())
4464 return true;
4465
4466 // A variable cannot be both common and exist in a section.
4467 // We don't try to determine which is the right section in the front-end.
4468 // If no specialized section name is applicable, it will resort to default.
4469 if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
4470 D->hasAttr<PragmaClangDataSectionAttr>() ||
4471 D->hasAttr<PragmaClangRelroSectionAttr>() ||
4472 D->hasAttr<PragmaClangRodataSectionAttr>())
4473 return true;
4474
4475 // Thread local vars aren't considered common linkage.
4476 if (D->getTLSKind())
4477 return true;
4478
4479 // Tentative definitions marked with WeakImportAttr are true definitions.
4480 if (D->hasAttr<WeakImportAttr>())
4481 return true;
4482
4483 // A variable cannot be both common and exist in a comdat.
4484 if (shouldBeInCOMDAT(CGM, *D))
4485 return true;
4486
4487 // Declarations with a required alignment do not have common linkage in MSVC
4488 // mode.
4489 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
4490 if (D->hasAttr<AlignedAttr>())
4491 return true;
4492 QualType VarType = D->getType();
4493 if (Context.isAlignmentRequired(VarType))
4494 return true;
4495
4496 if (const auto *RT = VarType->getAs<RecordType>()) {
4497 const RecordDecl *RD = RT->getDecl();
4498 for (const FieldDecl *FD : RD->fields()) {
4499 if (FD->isBitField())
4500 continue;
4501 if (FD->hasAttr<AlignedAttr>())
4502 return true;
4503 if (Context.isAlignmentRequired(FD->getType()))
4504 return true;
4505 }
4506 }
4507 }
4508
4509 // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
4510 // common symbols, so symbols with greater alignment requirements cannot be
4511 // common.
4512 // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
4513 // alignments for common symbols via the aligncomm directive, so this
4514 // restriction only applies to MSVC environments.
4515 if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
4516 Context.getTypeAlignIfKnown(D->getType()) >
4517 Context.toBits(CharUnits::fromQuantity(32)))
4518 return true;
4519
4520 return false;
4521 }
4522
getLLVMLinkageForDeclarator(const DeclaratorDecl * D,GVALinkage Linkage,bool IsConstantVariable)4523 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
4524 const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) {
4525 if (Linkage == GVA_Internal)
4526 return llvm::Function::InternalLinkage;
4527
4528 if (D->hasAttr<WeakAttr>()) {
4529 if (IsConstantVariable)
4530 return llvm::GlobalVariable::WeakODRLinkage;
4531 else
4532 return llvm::GlobalVariable::WeakAnyLinkage;
4533 }
4534
4535 if (const auto *FD = D->getAsFunction())
4536 if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
4537 return llvm::GlobalVariable::LinkOnceAnyLinkage;
4538
4539 // We are guaranteed to have a strong definition somewhere else,
4540 // so we can use available_externally linkage.
4541 if (Linkage == GVA_AvailableExternally)
4542 return llvm::GlobalValue::AvailableExternallyLinkage;
4543
4544 // Note that Apple's kernel linker doesn't support symbol
4545 // coalescing, so we need to avoid linkonce and weak linkages there.
4546 // Normally, this means we just map to internal, but for explicit
4547 // instantiations we'll map to external.
4548
4549 // In C++, the compiler has to emit a definition in every translation unit
4550 // that references the function. We should use linkonce_odr because
4551 // a) if all references in this translation unit are optimized away, we
4552 // don't need to codegen it. b) if the function persists, it needs to be
4553 // merged with other definitions. c) C++ has the ODR, so we know the
4554 // definition is dependable.
4555 if (Linkage == GVA_DiscardableODR)
4556 return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
4557 : llvm::Function::InternalLinkage;
4558
4559 // An explicit instantiation of a template has weak linkage, since
4560 // explicit instantiations can occur in multiple translation units
4561 // and must all be equivalent. However, we are not allowed to
4562 // throw away these explicit instantiations.
4563 //
4564 // CUDA/HIP: For -fno-gpu-rdc case, device code is limited to one TU,
4565 // so say that CUDA templates are either external (for kernels) or internal.
4566 // This lets llvm perform aggressive inter-procedural optimizations. For
4567 // -fgpu-rdc case, device function calls across multiple TU's are allowed,
4568 // therefore we need to follow the normal linkage paradigm.
4569 if (Linkage == GVA_StrongODR) {
4570 if (getLangOpts().AppleKext)
4571 return llvm::Function::ExternalLinkage;
4572 if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
4573 !getLangOpts().GPURelocatableDeviceCode)
4574 return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
4575 : llvm::Function::InternalLinkage;
4576 return llvm::Function::WeakODRLinkage;
4577 }
4578
4579 // C++ doesn't have tentative definitions and thus cannot have common
4580 // linkage.
4581 if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
4582 !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
4583 CodeGenOpts.NoCommon))
4584 return llvm::GlobalVariable::CommonLinkage;
4585
4586 // selectany symbols are externally visible, so use weak instead of
4587 // linkonce. MSVC optimizes away references to const selectany globals, so
4588 // all definitions should be the same and ODR linkage should be used.
4589 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
4590 if (D->hasAttr<SelectAnyAttr>())
4591 return llvm::GlobalVariable::WeakODRLinkage;
4592
4593 // Otherwise, we have strong external linkage.
4594 assert(Linkage == GVA_StrongExternal);
4595 return llvm::GlobalVariable::ExternalLinkage;
4596 }
4597
getLLVMLinkageVarDefinition(const VarDecl * VD,bool IsConstant)4598 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition(
4599 const VarDecl *VD, bool IsConstant) {
4600 GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
4601 return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant);
4602 }
4603
4604 /// Replace the uses of a function that was declared with a non-proto type.
4605 /// We want to silently drop extra arguments from call sites
replaceUsesOfNonProtoConstant(llvm::Constant * old,llvm::Function * newFn)4606 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
4607 llvm::Function *newFn) {
4608 // Fast path.
4609 if (old->use_empty()) return;
4610
4611 llvm::Type *newRetTy = newFn->getReturnType();
4612 SmallVector<llvm::Value*, 4> newArgs;
4613 SmallVector<llvm::OperandBundleDef, 1> newBundles;
4614
4615 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
4616 ui != ue; ) {
4617 llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
4618 llvm::User *user = use->getUser();
4619
4620 // Recognize and replace uses of bitcasts. Most calls to
4621 // unprototyped functions will use bitcasts.
4622 if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
4623 if (bitcast->getOpcode() == llvm::Instruction::BitCast)
4624 replaceUsesOfNonProtoConstant(bitcast, newFn);
4625 continue;
4626 }
4627
4628 // Recognize calls to the function.
4629 llvm::CallBase *callSite = dyn_cast<llvm::CallBase>(user);
4630 if (!callSite) continue;
4631 if (!callSite->isCallee(&*use))
4632 continue;
4633
4634 // If the return types don't match exactly, then we can't
4635 // transform this call unless it's dead.
4636 if (callSite->getType() != newRetTy && !callSite->use_empty())
4637 continue;
4638
4639 // Get the call site's attribute list.
4640 SmallVector<llvm::AttributeSet, 8> newArgAttrs;
4641 llvm::AttributeList oldAttrs = callSite->getAttributes();
4642
4643 // If the function was passed too few arguments, don't transform.
4644 unsigned newNumArgs = newFn->arg_size();
4645 if (callSite->arg_size() < newNumArgs)
4646 continue;
4647
4648 // If extra arguments were passed, we silently drop them.
4649 // If any of the types mismatch, we don't transform.
4650 unsigned argNo = 0;
4651 bool dontTransform = false;
4652 for (llvm::Argument &A : newFn->args()) {
4653 if (callSite->getArgOperand(argNo)->getType() != A.getType()) {
4654 dontTransform = true;
4655 break;
4656 }
4657
4658 // Add any parameter attributes.
4659 newArgAttrs.push_back(oldAttrs.getParamAttributes(argNo));
4660 argNo++;
4661 }
4662 if (dontTransform)
4663 continue;
4664
4665 // Okay, we can transform this. Create the new call instruction and copy
4666 // over the required information.
4667 newArgs.append(callSite->arg_begin(), callSite->arg_begin() + argNo);
4668
4669 // Copy over any operand bundles.
4670 callSite->getOperandBundlesAsDefs(newBundles);
4671
4672 llvm::CallBase *newCall;
4673 if (dyn_cast<llvm::CallInst>(callSite)) {
4674 newCall =
4675 llvm::CallInst::Create(newFn, newArgs, newBundles, "", callSite);
4676 } else {
4677 auto *oldInvoke = cast<llvm::InvokeInst>(callSite);
4678 newCall = llvm::InvokeInst::Create(newFn, oldInvoke->getNormalDest(),
4679 oldInvoke->getUnwindDest(), newArgs,
4680 newBundles, "", callSite);
4681 }
4682 newArgs.clear(); // for the next iteration
4683
4684 if (!newCall->getType()->isVoidTy())
4685 newCall->takeName(callSite);
4686 newCall->setAttributes(llvm::AttributeList::get(
4687 newFn->getContext(), oldAttrs.getFnAttributes(),
4688 oldAttrs.getRetAttributes(), newArgAttrs));
4689 newCall->setCallingConv(callSite->getCallingConv());
4690
4691 // Finally, remove the old call, replacing any uses with the new one.
4692 if (!callSite->use_empty())
4693 callSite->replaceAllUsesWith(newCall);
4694
4695 // Copy debug location attached to CI.
4696 if (callSite->getDebugLoc())
4697 newCall->setDebugLoc(callSite->getDebugLoc());
4698
4699 callSite->eraseFromParent();
4700 }
4701 }
4702
4703 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
4704 /// implement a function with no prototype, e.g. "int foo() {}". If there are
4705 /// existing call uses of the old function in the module, this adjusts them to
4706 /// call the new function directly.
4707 ///
4708 /// This is not just a cleanup: the always_inline pass requires direct calls to
4709 /// functions to be able to inline them. If there is a bitcast in the way, it
4710 /// won't inline them. Instcombine normally deletes these calls, but it isn't
4711 /// run at -O0.
ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue * Old,llvm::Function * NewFn)4712 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
4713 llvm::Function *NewFn) {
4714 // If we're redefining a global as a function, don't transform it.
4715 if (!isa<llvm::Function>(Old)) return;
4716
4717 replaceUsesOfNonProtoConstant(Old, NewFn);
4718 }
4719
HandleCXXStaticMemberVarInstantiation(VarDecl * VD)4720 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
4721 auto DK = VD->isThisDeclarationADefinition();
4722 if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
4723 return;
4724
4725 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
4726 // If we have a definition, this might be a deferred decl. If the
4727 // instantiation is explicit, make sure we emit it at the end.
4728 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
4729 GetAddrOfGlobalVar(VD);
4730
4731 EmitTopLevelDecl(VD);
4732 }
4733
EmitGlobalFunctionDefinition(GlobalDecl GD,llvm::GlobalValue * GV)4734 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
4735 llvm::GlobalValue *GV) {
4736 const auto *D = cast<FunctionDecl>(GD.getDecl());
4737
4738 // Compute the function info and LLVM type.
4739 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
4740 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
4741
4742 // Get or create the prototype for the function.
4743 if (!GV || (GV->getValueType() != Ty))
4744 GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
4745 /*DontDefer=*/true,
4746 ForDefinition));
4747
4748 // Already emitted.
4749 if (!GV->isDeclaration())
4750 return;
4751
4752 // We need to set linkage and visibility on the function before
4753 // generating code for it because various parts of IR generation
4754 // want to propagate this information down (e.g. to local static
4755 // declarations).
4756 auto *Fn = cast<llvm::Function>(GV);
4757 setFunctionLinkage(GD, Fn);
4758
4759 // FIXME: this is redundant with part of setFunctionDefinitionAttributes
4760 setGVProperties(Fn, GD);
4761
4762 MaybeHandleStaticInExternC(D, Fn);
4763
4764 maybeSetTrivialComdat(*D, *Fn);
4765
4766 // Set CodeGen attributes that represent floating point environment.
4767 setLLVMFunctionFEnvAttributes(D, Fn);
4768
4769 CodeGenFunction(*this).GenerateCode(GD, Fn, FI);
4770
4771 setNonAliasAttributes(GD, Fn);
4772 SetLLVMFunctionAttributesForDefinition(D, Fn);
4773
4774 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
4775 AddGlobalCtor(Fn, CA->getPriority());
4776 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
4777 AddGlobalDtor(Fn, DA->getPriority(), true);
4778 if (D->hasAttr<AnnotateAttr>())
4779 AddGlobalAnnotations(D, Fn);
4780 }
4781
EmitAliasDefinition(GlobalDecl GD)4782 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
4783 const auto *D = cast<ValueDecl>(GD.getDecl());
4784 const AliasAttr *AA = D->getAttr<AliasAttr>();
4785 assert(AA && "Not an alias?");
4786
4787 StringRef MangledName = getMangledName(GD);
4788
4789 if (AA->getAliasee() == MangledName) {
4790 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4791 return;
4792 }
4793
4794 // If there is a definition in the module, then it wins over the alias.
4795 // This is dubious, but allow it to be safe. Just ignore the alias.
4796 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4797 if (Entry && !Entry->isDeclaration())
4798 return;
4799
4800 Aliases.push_back(GD);
4801
4802 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4803
4804 // Create a reference to the named value. This ensures that it is emitted
4805 // if a deferred decl.
4806 llvm::Constant *Aliasee;
4807 llvm::GlobalValue::LinkageTypes LT;
4808 if (isa<llvm::FunctionType>(DeclTy)) {
4809 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
4810 /*ForVTable=*/false);
4811 LT = getFunctionLinkage(GD);
4812 } else {
4813 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
4814 llvm::PointerType::getUnqual(DeclTy),
4815 /*D=*/nullptr);
4816 if (const auto *VD = dyn_cast<VarDecl>(GD.getDecl()))
4817 LT = getLLVMLinkageVarDefinition(VD, D->getType().isConstQualified());
4818 else
4819 LT = getFunctionLinkage(GD);
4820 }
4821
4822 // Create the new alias itself, but don't set a name yet.
4823 unsigned AS = Aliasee->getType()->getPointerAddressSpace();
4824 auto *GA =
4825 llvm::GlobalAlias::create(DeclTy, AS, LT, "", Aliasee, &getModule());
4826
4827 if (Entry) {
4828 if (GA->getAliasee() == Entry) {
4829 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4830 return;
4831 }
4832
4833 assert(Entry->isDeclaration());
4834
4835 // If there is a declaration in the module, then we had an extern followed
4836 // by the alias, as in:
4837 // extern int test6();
4838 // ...
4839 // int test6() __attribute__((alias("test7")));
4840 //
4841 // Remove it and replace uses of it with the alias.
4842 GA->takeName(Entry);
4843
4844 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
4845 Entry->getType()));
4846 Entry->eraseFromParent();
4847 } else {
4848 GA->setName(MangledName);
4849 }
4850
4851 // Set attributes which are particular to an alias; this is a
4852 // specialization of the attributes which may be set on a global
4853 // variable/function.
4854 if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
4855 D->isWeakImported()) {
4856 GA->setLinkage(llvm::Function::WeakAnyLinkage);
4857 }
4858
4859 if (const auto *VD = dyn_cast<VarDecl>(D))
4860 if (VD->getTLSKind())
4861 setTLSMode(GA, *VD);
4862
4863 SetCommonAttributes(GD, GA);
4864 }
4865
emitIFuncDefinition(GlobalDecl GD)4866 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
4867 const auto *D = cast<ValueDecl>(GD.getDecl());
4868 const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
4869 assert(IFA && "Not an ifunc?");
4870
4871 StringRef MangledName = getMangledName(GD);
4872
4873 if (IFA->getResolver() == MangledName) {
4874 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4875 return;
4876 }
4877
4878 // Report an error if some definition overrides ifunc.
4879 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4880 if (Entry && !Entry->isDeclaration()) {
4881 GlobalDecl OtherGD;
4882 if (lookupRepresentativeDecl(MangledName, OtherGD) &&
4883 DiagnosedConflictingDefinitions.insert(GD).second) {
4884 Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
4885 << MangledName;
4886 Diags.Report(OtherGD.getDecl()->getLocation(),
4887 diag::note_previous_definition);
4888 }
4889 return;
4890 }
4891
4892 Aliases.push_back(GD);
4893
4894 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4895 llvm::Constant *Resolver =
4896 GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD,
4897 /*ForVTable=*/false);
4898 llvm::GlobalIFunc *GIF =
4899 llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage,
4900 "", Resolver, &getModule());
4901 if (Entry) {
4902 if (GIF->getResolver() == Entry) {
4903 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4904 return;
4905 }
4906 assert(Entry->isDeclaration());
4907
4908 // If there is a declaration in the module, then we had an extern followed
4909 // by the ifunc, as in:
4910 // extern int test();
4911 // ...
4912 // int test() __attribute__((ifunc("resolver")));
4913 //
4914 // Remove it and replace uses of it with the ifunc.
4915 GIF->takeName(Entry);
4916
4917 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
4918 Entry->getType()));
4919 Entry->eraseFromParent();
4920 } else
4921 GIF->setName(MangledName);
4922
4923 SetCommonAttributes(GD, GIF);
4924 }
4925
getIntrinsic(unsigned IID,ArrayRef<llvm::Type * > Tys)4926 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
4927 ArrayRef<llvm::Type*> Tys) {
4928 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
4929 Tys);
4930 }
4931
4932 static llvm::StringMapEntry<llvm::GlobalVariable *> &
GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable * > & Map,const StringLiteral * Literal,bool TargetIsLSB,bool & IsUTF16,unsigned & StringLength)4933 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
4934 const StringLiteral *Literal, bool TargetIsLSB,
4935 bool &IsUTF16, unsigned &StringLength) {
4936 StringRef String = Literal->getString();
4937 unsigned NumBytes = String.size();
4938
4939 // Check for simple case.
4940 if (!Literal->containsNonAsciiOrNull()) {
4941 StringLength = NumBytes;
4942 return *Map.insert(std::make_pair(String, nullptr)).first;
4943 }
4944
4945 // Otherwise, convert the UTF8 literals into a string of shorts.
4946 IsUTF16 = true;
4947
4948 SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
4949 const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
4950 llvm::UTF16 *ToPtr = &ToBuf[0];
4951
4952 (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
4953 ToPtr + NumBytes, llvm::strictConversion);
4954
4955 // ConvertUTF8toUTF16 returns the length in ToPtr.
4956 StringLength = ToPtr - &ToBuf[0];
4957
4958 // Add an explicit null.
4959 *ToPtr = 0;
4960 return *Map.insert(std::make_pair(
4961 StringRef(reinterpret_cast<const char *>(ToBuf.data()),
4962 (StringLength + 1) * 2),
4963 nullptr)).first;
4964 }
4965
4966 ConstantAddress
GetAddrOfConstantCFString(const StringLiteral * Literal)4967 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
4968 unsigned StringLength = 0;
4969 bool isUTF16 = false;
4970 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
4971 GetConstantCFStringEntry(CFConstantStringMap, Literal,
4972 getDataLayout().isLittleEndian(), isUTF16,
4973 StringLength);
4974
4975 if (auto *C = Entry.second)
4976 return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment()));
4977
4978 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
4979 llvm::Constant *Zeros[] = { Zero, Zero };
4980
4981 const ASTContext &Context = getContext();
4982 const llvm::Triple &Triple = getTriple();
4983
4984 const auto CFRuntime = getLangOpts().CFRuntime;
4985 const bool IsSwiftABI =
4986 static_cast<unsigned>(CFRuntime) >=
4987 static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
4988 const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
4989
4990 // If we don't already have it, get __CFConstantStringClassReference.
4991 if (!CFConstantStringClassRef) {
4992 const char *CFConstantStringClassName = "__CFConstantStringClassReference";
4993 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
4994 Ty = llvm::ArrayType::get(Ty, 0);
4995
4996 switch (CFRuntime) {
4997 default: break;
4998 case LangOptions::CoreFoundationABI::Swift: LLVM_FALLTHROUGH;
4999 case LangOptions::CoreFoundationABI::Swift5_0:
5000 CFConstantStringClassName =
5001 Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
5002 : "$s10Foundation19_NSCFConstantStringCN";
5003 Ty = IntPtrTy;
5004 break;
5005 case LangOptions::CoreFoundationABI::Swift4_2:
5006 CFConstantStringClassName =
5007 Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
5008 : "$S10Foundation19_NSCFConstantStringCN";
5009 Ty = IntPtrTy;
5010 break;
5011 case LangOptions::CoreFoundationABI::Swift4_1:
5012 CFConstantStringClassName =
5013 Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
5014 : "__T010Foundation19_NSCFConstantStringCN";
5015 Ty = IntPtrTy;
5016 break;
5017 }
5018
5019 llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
5020
5021 if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
5022 llvm::GlobalValue *GV = nullptr;
5023
5024 if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
5025 IdentifierInfo &II = Context.Idents.get(GV->getName());
5026 TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
5027 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
5028
5029 const VarDecl *VD = nullptr;
5030 for (const auto &Result : DC->lookup(&II))
5031 if ((VD = dyn_cast<VarDecl>(Result)))
5032 break;
5033
5034 if (Triple.isOSBinFormatELF()) {
5035 if (!VD)
5036 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
5037 } else {
5038 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
5039 if (!VD || !VD->hasAttr<DLLExportAttr>())
5040 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
5041 else
5042 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
5043 }
5044
5045 setDSOLocal(GV);
5046 }
5047 }
5048
5049 // Decay array -> ptr
5050 CFConstantStringClassRef =
5051 IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty)
5052 : llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros);
5053 }
5054
5055 QualType CFTy = Context.getCFConstantStringType();
5056
5057 auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
5058
5059 ConstantInitBuilder Builder(*this);
5060 auto Fields = Builder.beginStruct(STy);
5061
5062 // Class pointer.
5063 Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
5064
5065 // Flags.
5066 if (IsSwiftABI) {
5067 Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
5068 Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
5069 } else {
5070 Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
5071 }
5072
5073 // String pointer.
5074 llvm::Constant *C = nullptr;
5075 if (isUTF16) {
5076 auto Arr = llvm::makeArrayRef(
5077 reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
5078 Entry.first().size() / 2);
5079 C = llvm::ConstantDataArray::get(VMContext, Arr);
5080 } else {
5081 C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
5082 }
5083
5084 // Note: -fwritable-strings doesn't make the backing store strings of
5085 // CFStrings writable. (See <rdar://problem/10657500>)
5086 auto *GV =
5087 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
5088 llvm::GlobalValue::PrivateLinkage, C, ".str");
5089 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
5090 // Don't enforce the target's minimum global alignment, since the only use
5091 // of the string is via this class initializer.
5092 CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
5093 : Context.getTypeAlignInChars(Context.CharTy);
5094 GV->setAlignment(Align.getAsAlign());
5095
5096 // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
5097 // Without it LLVM can merge the string with a non unnamed_addr one during
5098 // LTO. Doing that changes the section it ends in, which surprises ld64.
5099 if (Triple.isOSBinFormatMachO())
5100 GV->setSection(isUTF16 ? "__TEXT,__ustring"
5101 : "__TEXT,__cstring,cstring_literals");
5102 // Make sure the literal ends up in .rodata to allow for safe ICF and for
5103 // the static linker to adjust permissions to read-only later on.
5104 else if (Triple.isOSBinFormatELF())
5105 GV->setSection(".rodata");
5106
5107 // String.
5108 llvm::Constant *Str =
5109 llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
5110
5111 if (isUTF16)
5112 // Cast the UTF16 string to the correct type.
5113 Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
5114 Fields.add(Str);
5115
5116 // String length.
5117 llvm::IntegerType *LengthTy =
5118 llvm::IntegerType::get(getModule().getContext(),
5119 Context.getTargetInfo().getLongWidth());
5120 if (IsSwiftABI) {
5121 if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
5122 CFRuntime == LangOptions::CoreFoundationABI::Swift4_2)
5123 LengthTy = Int32Ty;
5124 else
5125 LengthTy = IntPtrTy;
5126 }
5127 Fields.addInt(LengthTy, StringLength);
5128
5129 // Swift ABI requires 8-byte alignment to ensure that the _Atomic(uint64_t) is
5130 // properly aligned on 32-bit platforms.
5131 CharUnits Alignment =
5132 IsSwiftABI ? Context.toCharUnitsFromBits(64) : getPointerAlign();
5133
5134 // The struct.
5135 GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
5136 /*isConstant=*/false,
5137 llvm::GlobalVariable::PrivateLinkage);
5138 GV->addAttribute("objc_arc_inert");
5139 switch (Triple.getObjectFormat()) {
5140 case llvm::Triple::UnknownObjectFormat:
5141 llvm_unreachable("unknown file format");
5142 case llvm::Triple::GOFF:
5143 llvm_unreachable("GOFF is not yet implemented");
5144 case llvm::Triple::XCOFF:
5145 llvm_unreachable("XCOFF is not yet implemented");
5146 case llvm::Triple::COFF:
5147 case llvm::Triple::ELF:
5148 case llvm::Triple::Wasm:
5149 GV->setSection("cfstring");
5150 break;
5151 case llvm::Triple::MachO:
5152 GV->setSection("__DATA,__cfstring");
5153 break;
5154 }
5155 Entry.second = GV;
5156
5157 return ConstantAddress(GV, Alignment);
5158 }
5159
getExpressionLocationsEnabled() const5160 bool CodeGenModule::getExpressionLocationsEnabled() const {
5161 return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
5162 }
5163
getObjCFastEnumerationStateType()5164 QualType CodeGenModule::getObjCFastEnumerationStateType() {
5165 if (ObjCFastEnumerationStateType.isNull()) {
5166 RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
5167 D->startDefinition();
5168
5169 QualType FieldTypes[] = {
5170 Context.UnsignedLongTy,
5171 Context.getPointerType(Context.getObjCIdType()),
5172 Context.getPointerType(Context.UnsignedLongTy),
5173 Context.getConstantArrayType(Context.UnsignedLongTy,
5174 llvm::APInt(32, 5), nullptr, ArrayType::Normal, 0)
5175 };
5176
5177 for (size_t i = 0; i < 4; ++i) {
5178 FieldDecl *Field = FieldDecl::Create(Context,
5179 D,
5180 SourceLocation(),
5181 SourceLocation(), nullptr,
5182 FieldTypes[i], /*TInfo=*/nullptr,
5183 /*BitWidth=*/nullptr,
5184 /*Mutable=*/false,
5185 ICIS_NoInit);
5186 Field->setAccess(AS_public);
5187 D->addDecl(Field);
5188 }
5189
5190 D->completeDefinition();
5191 ObjCFastEnumerationStateType = Context.getTagDeclType(D);
5192 }
5193
5194 return ObjCFastEnumerationStateType;
5195 }
5196
5197 llvm::Constant *
GetConstantArrayFromStringLiteral(const StringLiteral * E)5198 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
5199 assert(!E->getType()->isPointerType() && "Strings are always arrays");
5200
5201 // Don't emit it as the address of the string, emit the string data itself
5202 // as an inline array.
5203 if (E->getCharByteWidth() == 1) {
5204 SmallString<64> Str(E->getString());
5205
5206 // Resize the string to the right size, which is indicated by its type.
5207 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
5208 Str.resize(CAT->getSize().getZExtValue());
5209 return llvm::ConstantDataArray::getString(VMContext, Str, false);
5210 }
5211
5212 auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
5213 llvm::Type *ElemTy = AType->getElementType();
5214 unsigned NumElements = AType->getNumElements();
5215
5216 // Wide strings have either 2-byte or 4-byte elements.
5217 if (ElemTy->getPrimitiveSizeInBits() == 16) {
5218 SmallVector<uint16_t, 32> Elements;
5219 Elements.reserve(NumElements);
5220
5221 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
5222 Elements.push_back(E->getCodeUnit(i));
5223 Elements.resize(NumElements);
5224 return llvm::ConstantDataArray::get(VMContext, Elements);
5225 }
5226
5227 assert(ElemTy->getPrimitiveSizeInBits() == 32);
5228 SmallVector<uint32_t, 32> Elements;
5229 Elements.reserve(NumElements);
5230
5231 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
5232 Elements.push_back(E->getCodeUnit(i));
5233 Elements.resize(NumElements);
5234 return llvm::ConstantDataArray::get(VMContext, Elements);
5235 }
5236
5237 static llvm::GlobalVariable *
GenerateStringLiteral(llvm::Constant * C,llvm::GlobalValue::LinkageTypes LT,CodeGenModule & CGM,StringRef GlobalName,CharUnits Alignment)5238 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
5239 CodeGenModule &CGM, StringRef GlobalName,
5240 CharUnits Alignment) {
5241 unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
5242 CGM.getStringLiteralAddressSpace());
5243
5244 llvm::Module &M = CGM.getModule();
5245 // Create a global variable for this string
5246 auto *GV = new llvm::GlobalVariable(
5247 M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
5248 nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
5249 GV->setAlignment(Alignment.getAsAlign());
5250 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
5251 if (GV->isWeakForLinker()) {
5252 assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
5253 GV->setComdat(M.getOrInsertComdat(GV->getName()));
5254 }
5255 CGM.setDSOLocal(GV);
5256
5257 return GV;
5258 }
5259
5260 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
5261 /// constant array for the given string literal.
5262 ConstantAddress
GetAddrOfConstantStringFromLiteral(const StringLiteral * S,StringRef Name)5263 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
5264 StringRef Name) {
5265 CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType());
5266
5267 llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
5268 llvm::GlobalVariable **Entry = nullptr;
5269 if (!LangOpts.WritableStrings) {
5270 Entry = &ConstantStringMap[C];
5271 if (auto GV = *Entry) {
5272 if (Alignment.getQuantity() > GV->getAlignment())
5273 GV->setAlignment(Alignment.getAsAlign());
5274 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5275 Alignment);
5276 }
5277 }
5278
5279 SmallString<256> MangledNameBuffer;
5280 StringRef GlobalVariableName;
5281 llvm::GlobalValue::LinkageTypes LT;
5282
5283 // Mangle the string literal if that's how the ABI merges duplicate strings.
5284 // Don't do it if they are writable, since we don't want writes in one TU to
5285 // affect strings in another.
5286 if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
5287 !LangOpts.WritableStrings) {
5288 llvm::raw_svector_ostream Out(MangledNameBuffer);
5289 getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
5290 LT = llvm::GlobalValue::LinkOnceODRLinkage;
5291 GlobalVariableName = MangledNameBuffer;
5292 } else {
5293 LT = llvm::GlobalValue::PrivateLinkage;
5294 GlobalVariableName = Name;
5295 }
5296
5297 auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
5298 if (Entry)
5299 *Entry = GV;
5300
5301 SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>",
5302 QualType());
5303
5304 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5305 Alignment);
5306 }
5307
5308 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
5309 /// array for the given ObjCEncodeExpr node.
5310 ConstantAddress
GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr * E)5311 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
5312 std::string Str;
5313 getContext().getObjCEncodingForType(E->getEncodedType(), Str);
5314
5315 return GetAddrOfConstantCString(Str);
5316 }
5317
5318 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
5319 /// the literal and a terminating '\0' character.
5320 /// The result has pointer to array type.
GetAddrOfConstantCString(const std::string & Str,const char * GlobalName)5321 ConstantAddress CodeGenModule::GetAddrOfConstantCString(
5322 const std::string &Str, const char *GlobalName) {
5323 StringRef StrWithNull(Str.c_str(), Str.size() + 1);
5324 CharUnits Alignment =
5325 getContext().getAlignOfGlobalVarInChars(getContext().CharTy);
5326
5327 llvm::Constant *C =
5328 llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
5329
5330 // Don't share any string literals if strings aren't constant.
5331 llvm::GlobalVariable **Entry = nullptr;
5332 if (!LangOpts.WritableStrings) {
5333 Entry = &ConstantStringMap[C];
5334 if (auto GV = *Entry) {
5335 if (Alignment.getQuantity() > GV->getAlignment())
5336 GV->setAlignment(Alignment.getAsAlign());
5337 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5338 Alignment);
5339 }
5340 }
5341
5342 // Get the default prefix if a name wasn't specified.
5343 if (!GlobalName)
5344 GlobalName = ".str";
5345 // Create a global variable for this.
5346 auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
5347 GlobalName, Alignment);
5348 if (Entry)
5349 *Entry = GV;
5350
5351 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
5352 Alignment);
5353 }
5354
GetAddrOfGlobalTemporary(const MaterializeTemporaryExpr * E,const Expr * Init)5355 ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
5356 const MaterializeTemporaryExpr *E, const Expr *Init) {
5357 assert((E->getStorageDuration() == SD_Static ||
5358 E->getStorageDuration() == SD_Thread) && "not a global temporary");
5359 const auto *VD = cast<VarDecl>(E->getExtendingDecl());
5360
5361 // If we're not materializing a subobject of the temporary, keep the
5362 // cv-qualifiers from the type of the MaterializeTemporaryExpr.
5363 QualType MaterializedType = Init->getType();
5364 if (Init == E->getSubExpr())
5365 MaterializedType = E->getType();
5366
5367 CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
5368
5369 if (llvm::Constant *Slot = MaterializedGlobalTemporaryMap[E])
5370 return ConstantAddress(Slot, Align);
5371
5372 // FIXME: If an externally-visible declaration extends multiple temporaries,
5373 // we need to give each temporary the same name in every translation unit (and
5374 // we also need to make the temporaries externally-visible).
5375 SmallString<256> Name;
5376 llvm::raw_svector_ostream Out(Name);
5377 getCXXABI().getMangleContext().mangleReferenceTemporary(
5378 VD, E->getManglingNumber(), Out);
5379
5380 APValue *Value = nullptr;
5381 if (E->getStorageDuration() == SD_Static && VD && VD->evaluateValue()) {
5382 // If the initializer of the extending declaration is a constant
5383 // initializer, we should have a cached constant initializer for this
5384 // temporary. Note that this might have a different value from the value
5385 // computed by evaluating the initializer if the surrounding constant
5386 // expression modifies the temporary.
5387 Value = E->getOrCreateValue(false);
5388 }
5389
5390 // Try evaluating it now, it might have a constant initializer.
5391 Expr::EvalResult EvalResult;
5392 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
5393 !EvalResult.hasSideEffects())
5394 Value = &EvalResult.Val;
5395
5396 LangAS AddrSpace =
5397 VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace();
5398
5399 Optional<ConstantEmitter> emitter;
5400 llvm::Constant *InitialValue = nullptr;
5401 bool Constant = false;
5402 llvm::Type *Type;
5403 if (Value) {
5404 // The temporary has a constant initializer, use it.
5405 emitter.emplace(*this);
5406 InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
5407 MaterializedType);
5408 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value);
5409 Type = InitialValue->getType();
5410 } else {
5411 // No initializer, the initialization will be provided when we
5412 // initialize the declaration which performed lifetime extension.
5413 Type = getTypes().ConvertTypeForMem(MaterializedType);
5414 }
5415
5416 // Create a global variable for this lifetime-extended temporary.
5417 llvm::GlobalValue::LinkageTypes Linkage =
5418 getLLVMLinkageVarDefinition(VD, Constant);
5419 if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
5420 const VarDecl *InitVD;
5421 if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
5422 isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
5423 // Temporaries defined inside a class get linkonce_odr linkage because the
5424 // class can be defined in multiple translation units.
5425 Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
5426 } else {
5427 // There is no need for this temporary to have external linkage if the
5428 // VarDecl has external linkage.
5429 Linkage = llvm::GlobalVariable::InternalLinkage;
5430 }
5431 }
5432 auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
5433 auto *GV = new llvm::GlobalVariable(
5434 getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
5435 /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
5436 if (emitter) emitter->finalize(GV);
5437 setGVProperties(GV, VD);
5438 GV->setAlignment(Align.getAsAlign());
5439 if (supportsCOMDAT() && GV->isWeakForLinker())
5440 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
5441 if (VD->getTLSKind())
5442 setTLSMode(GV, *VD);
5443 llvm::Constant *CV = GV;
5444 if (AddrSpace != LangAS::Default)
5445 CV = getTargetCodeGenInfo().performAddrSpaceCast(
5446 *this, GV, AddrSpace, LangAS::Default,
5447 Type->getPointerTo(
5448 getContext().getTargetAddressSpace(LangAS::Default)));
5449 MaterializedGlobalTemporaryMap[E] = CV;
5450 return ConstantAddress(CV, Align);
5451 }
5452
5453 /// EmitObjCPropertyImplementations - Emit information for synthesized
5454 /// properties for an implementation.
EmitObjCPropertyImplementations(const ObjCImplementationDecl * D)5455 void CodeGenModule::EmitObjCPropertyImplementations(const
5456 ObjCImplementationDecl *D) {
5457 for (const auto *PID : D->property_impls()) {
5458 // Dynamic is just for type-checking.
5459 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
5460 ObjCPropertyDecl *PD = PID->getPropertyDecl();
5461
5462 // Determine which methods need to be implemented, some may have
5463 // been overridden. Note that ::isPropertyAccessor is not the method
5464 // we want, that just indicates if the decl came from a
5465 // property. What we want to know is if the method is defined in
5466 // this implementation.
5467 auto *Getter = PID->getGetterMethodDecl();
5468 if (!Getter || Getter->isSynthesizedAccessorStub())
5469 CodeGenFunction(*this).GenerateObjCGetter(
5470 const_cast<ObjCImplementationDecl *>(D), PID);
5471 auto *Setter = PID->getSetterMethodDecl();
5472 if (!PD->isReadOnly() && (!Setter || Setter->isSynthesizedAccessorStub()))
5473 CodeGenFunction(*this).GenerateObjCSetter(
5474 const_cast<ObjCImplementationDecl *>(D), PID);
5475 }
5476 }
5477 }
5478
needsDestructMethod(ObjCImplementationDecl * impl)5479 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
5480 const ObjCInterfaceDecl *iface = impl->getClassInterface();
5481 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
5482 ivar; ivar = ivar->getNextIvar())
5483 if (ivar->getType().isDestructedType())
5484 return true;
5485
5486 return false;
5487 }
5488
AllTrivialInitializers(CodeGenModule & CGM,ObjCImplementationDecl * D)5489 static bool AllTrivialInitializers(CodeGenModule &CGM,
5490 ObjCImplementationDecl *D) {
5491 CodeGenFunction CGF(CGM);
5492 for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
5493 E = D->init_end(); B != E; ++B) {
5494 CXXCtorInitializer *CtorInitExp = *B;
5495 Expr *Init = CtorInitExp->getInit();
5496 if (!CGF.isTrivialInitializer(Init))
5497 return false;
5498 }
5499 return true;
5500 }
5501
5502 /// EmitObjCIvarInitializations - Emit information for ivar initialization
5503 /// for an implementation.
EmitObjCIvarInitializations(ObjCImplementationDecl * D)5504 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
5505 // We might need a .cxx_destruct even if we don't have any ivar initializers.
5506 if (needsDestructMethod(D)) {
5507 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
5508 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
5509 ObjCMethodDecl *DTORMethod = ObjCMethodDecl::Create(
5510 getContext(), D->getLocation(), D->getLocation(), cxxSelector,
5511 getContext().VoidTy, nullptr, D,
5512 /*isInstance=*/true, /*isVariadic=*/false,
5513 /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
5514 /*isImplicitlyDeclared=*/true,
5515 /*isDefined=*/false, ObjCMethodDecl::Required);
5516 D->addInstanceMethod(DTORMethod);
5517 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
5518 D->setHasDestructors(true);
5519 }
5520
5521 // If the implementation doesn't have any ivar initializers, we don't need
5522 // a .cxx_construct.
5523 if (D->getNumIvarInitializers() == 0 ||
5524 AllTrivialInitializers(*this, D))
5525 return;
5526
5527 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
5528 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
5529 // The constructor returns 'self'.
5530 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(
5531 getContext(), D->getLocation(), D->getLocation(), cxxSelector,
5532 getContext().getObjCIdType(), nullptr, D, /*isInstance=*/true,
5533 /*isVariadic=*/false,
5534 /*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
5535 /*isImplicitlyDeclared=*/true,
5536 /*isDefined=*/false, ObjCMethodDecl::Required);
5537 D->addInstanceMethod(CTORMethod);
5538 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
5539 D->setHasNonZeroConstructors(true);
5540 }
5541
5542 // EmitLinkageSpec - Emit all declarations in a linkage spec.
EmitLinkageSpec(const LinkageSpecDecl * LSD)5543 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
5544 if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
5545 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
5546 ErrorUnsupported(LSD, "linkage spec");
5547 return;
5548 }
5549
5550 EmitDeclContext(LSD);
5551 }
5552
EmitDeclContext(const DeclContext * DC)5553 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
5554 for (auto *I : DC->decls()) {
5555 // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
5556 // are themselves considered "top-level", so EmitTopLevelDecl on an
5557 // ObjCImplDecl does not recursively visit them. We need to do that in
5558 // case they're nested inside another construct (LinkageSpecDecl /
5559 // ExportDecl) that does stop them from being considered "top-level".
5560 if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
5561 for (auto *M : OID->methods())
5562 EmitTopLevelDecl(M);
5563 }
5564
5565 EmitTopLevelDecl(I);
5566 }
5567 }
5568
5569 /// EmitTopLevelDecl - Emit code for a single top level declaration.
EmitTopLevelDecl(Decl * D)5570 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
5571 // Ignore dependent declarations.
5572 if (D->isTemplated())
5573 return;
5574
5575 // Consteval function shouldn't be emitted.
5576 if (auto *FD = dyn_cast<FunctionDecl>(D))
5577 if (FD->isConsteval())
5578 return;
5579
5580 switch (D->getKind()) {
5581 case Decl::CXXConversion:
5582 case Decl::CXXMethod:
5583 case Decl::Function:
5584 EmitGlobal(cast<FunctionDecl>(D));
5585 // Always provide some coverage mapping
5586 // even for the functions that aren't emitted.
5587 AddDeferredUnusedCoverageMapping(D);
5588 break;
5589
5590 case Decl::CXXDeductionGuide:
5591 // Function-like, but does not result in code emission.
5592 break;
5593
5594 case Decl::Var:
5595 case Decl::Decomposition:
5596 case Decl::VarTemplateSpecialization:
5597 EmitGlobal(cast<VarDecl>(D));
5598 if (auto *DD = dyn_cast<DecompositionDecl>(D))
5599 for (auto *B : DD->bindings())
5600 if (auto *HD = B->getHoldingVar())
5601 EmitGlobal(HD);
5602 break;
5603
5604 // Indirect fields from global anonymous structs and unions can be
5605 // ignored; only the actual variable requires IR gen support.
5606 case Decl::IndirectField:
5607 break;
5608
5609 // C++ Decls
5610 case Decl::Namespace:
5611 EmitDeclContext(cast<NamespaceDecl>(D));
5612 break;
5613 case Decl::ClassTemplateSpecialization: {
5614 const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
5615 if (CGDebugInfo *DI = getModuleDebugInfo())
5616 if (Spec->getSpecializationKind() ==
5617 TSK_ExplicitInstantiationDefinition &&
5618 Spec->hasDefinition())
5619 DI->completeTemplateDefinition(*Spec);
5620 } LLVM_FALLTHROUGH;
5621 case Decl::CXXRecord: {
5622 CXXRecordDecl *CRD = cast<CXXRecordDecl>(D);
5623 if (CGDebugInfo *DI = getModuleDebugInfo()) {
5624 if (CRD->hasDefinition())
5625 DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
5626 if (auto *ES = D->getASTContext().getExternalSource())
5627 if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
5628 DI->completeUnusedClass(*CRD);
5629 }
5630 // Emit any static data members, they may be definitions.
5631 for (auto *I : CRD->decls())
5632 if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
5633 EmitTopLevelDecl(I);
5634 break;
5635 }
5636 // No code generation needed.
5637 case Decl::UsingShadow:
5638 case Decl::ClassTemplate:
5639 case Decl::VarTemplate:
5640 case Decl::Concept:
5641 case Decl::VarTemplatePartialSpecialization:
5642 case Decl::FunctionTemplate:
5643 case Decl::TypeAliasTemplate:
5644 case Decl::Block:
5645 case Decl::Empty:
5646 case Decl::Binding:
5647 break;
5648 case Decl::Using: // using X; [C++]
5649 if (CGDebugInfo *DI = getModuleDebugInfo())
5650 DI->EmitUsingDecl(cast<UsingDecl>(*D));
5651 break;
5652 case Decl::NamespaceAlias:
5653 if (CGDebugInfo *DI = getModuleDebugInfo())
5654 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
5655 break;
5656 case Decl::UsingDirective: // using namespace X; [C++]
5657 if (CGDebugInfo *DI = getModuleDebugInfo())
5658 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
5659 break;
5660 case Decl::CXXConstructor:
5661 getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
5662 break;
5663 case Decl::CXXDestructor:
5664 getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
5665 break;
5666
5667 case Decl::StaticAssert:
5668 // Nothing to do.
5669 break;
5670
5671 // Objective-C Decls
5672
5673 // Forward declarations, no (immediate) code generation.
5674 case Decl::ObjCInterface:
5675 case Decl::ObjCCategory:
5676 break;
5677
5678 case Decl::ObjCProtocol: {
5679 auto *Proto = cast<ObjCProtocolDecl>(D);
5680 if (Proto->isThisDeclarationADefinition())
5681 ObjCRuntime->GenerateProtocol(Proto);
5682 break;
5683 }
5684
5685 case Decl::ObjCCategoryImpl:
5686 // Categories have properties but don't support synthesize so we
5687 // can ignore them here.
5688 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
5689 break;
5690
5691 case Decl::ObjCImplementation: {
5692 auto *OMD = cast<ObjCImplementationDecl>(D);
5693 EmitObjCPropertyImplementations(OMD);
5694 EmitObjCIvarInitializations(OMD);
5695 ObjCRuntime->GenerateClass(OMD);
5696 // Emit global variable debug information.
5697 if (CGDebugInfo *DI = getModuleDebugInfo())
5698 if (getCodeGenOpts().hasReducedDebugInfo())
5699 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
5700 OMD->getClassInterface()), OMD->getLocation());
5701 break;
5702 }
5703 case Decl::ObjCMethod: {
5704 auto *OMD = cast<ObjCMethodDecl>(D);
5705 // If this is not a prototype, emit the body.
5706 if (OMD->getBody())
5707 CodeGenFunction(*this).GenerateObjCMethod(OMD);
5708 break;
5709 }
5710 case Decl::ObjCCompatibleAlias:
5711 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
5712 break;
5713
5714 case Decl::PragmaComment: {
5715 const auto *PCD = cast<PragmaCommentDecl>(D);
5716 switch (PCD->getCommentKind()) {
5717 case PCK_Unknown:
5718 llvm_unreachable("unexpected pragma comment kind");
5719 case PCK_Linker:
5720 AppendLinkerOptions(PCD->getArg());
5721 break;
5722 case PCK_Lib:
5723 AddDependentLib(PCD->getArg());
5724 break;
5725 case PCK_Compiler:
5726 case PCK_ExeStr:
5727 case PCK_User:
5728 break; // We ignore all of these.
5729 }
5730 break;
5731 }
5732
5733 case Decl::PragmaDetectMismatch: {
5734 const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
5735 AddDetectMismatch(PDMD->getName(), PDMD->getValue());
5736 break;
5737 }
5738
5739 case Decl::LinkageSpec:
5740 EmitLinkageSpec(cast<LinkageSpecDecl>(D));
5741 break;
5742
5743 case Decl::FileScopeAsm: {
5744 // File-scope asm is ignored during device-side CUDA compilation.
5745 if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
5746 break;
5747 // File-scope asm is ignored during device-side OpenMP compilation.
5748 if (LangOpts.OpenMPIsDevice)
5749 break;
5750 auto *AD = cast<FileScopeAsmDecl>(D);
5751 getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
5752 break;
5753 }
5754
5755 case Decl::Import: {
5756 auto *Import = cast<ImportDecl>(D);
5757
5758 // If we've already imported this module, we're done.
5759 if (!ImportedModules.insert(Import->getImportedModule()))
5760 break;
5761
5762 // Emit debug information for direct imports.
5763 if (!Import->getImportedOwningModule()) {
5764 if (CGDebugInfo *DI = getModuleDebugInfo())
5765 DI->EmitImportDecl(*Import);
5766 }
5767
5768 // Find all of the submodules and emit the module initializers.
5769 llvm::SmallPtrSet<clang::Module *, 16> Visited;
5770 SmallVector<clang::Module *, 16> Stack;
5771 Visited.insert(Import->getImportedModule());
5772 Stack.push_back(Import->getImportedModule());
5773
5774 while (!Stack.empty()) {
5775 clang::Module *Mod = Stack.pop_back_val();
5776 if (!EmittedModuleInitializers.insert(Mod).second)
5777 continue;
5778
5779 for (auto *D : Context.getModuleInitializers(Mod))
5780 EmitTopLevelDecl(D);
5781
5782 // Visit the submodules of this module.
5783 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
5784 SubEnd = Mod->submodule_end();
5785 Sub != SubEnd; ++Sub) {
5786 // Skip explicit children; they need to be explicitly imported to emit
5787 // the initializers.
5788 if ((*Sub)->IsExplicit)
5789 continue;
5790
5791 if (Visited.insert(*Sub).second)
5792 Stack.push_back(*Sub);
5793 }
5794 }
5795 break;
5796 }
5797
5798 case Decl::Export:
5799 EmitDeclContext(cast<ExportDecl>(D));
5800 break;
5801
5802 case Decl::OMPThreadPrivate:
5803 EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
5804 break;
5805
5806 case Decl::OMPAllocate:
5807 break;
5808
5809 case Decl::OMPDeclareReduction:
5810 EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
5811 break;
5812
5813 case Decl::OMPDeclareMapper:
5814 EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D));
5815 break;
5816
5817 case Decl::OMPRequires:
5818 EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
5819 break;
5820
5821 case Decl::Typedef:
5822 case Decl::TypeAlias: // using foo = bar; [C++11]
5823 if (CGDebugInfo *DI = getModuleDebugInfo())
5824 DI->EmitAndRetainType(
5825 getContext().getTypedefType(cast<TypedefNameDecl>(D)));
5826 break;
5827
5828 case Decl::Record:
5829 if (CGDebugInfo *DI = getModuleDebugInfo())
5830 if (cast<RecordDecl>(D)->getDefinition())
5831 DI->EmitAndRetainType(getContext().getRecordType(cast<RecordDecl>(D)));
5832 break;
5833
5834 case Decl::Enum:
5835 if (CGDebugInfo *DI = getModuleDebugInfo())
5836 if (cast<EnumDecl>(D)->getDefinition())
5837 DI->EmitAndRetainType(getContext().getEnumType(cast<EnumDecl>(D)));
5838 break;
5839
5840 default:
5841 // Make sure we handled everything we should, every other kind is a
5842 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
5843 // function. Need to recode Decl::Kind to do that easily.
5844 assert(isa<TypeDecl>(D) && "Unsupported decl kind");
5845 break;
5846 }
5847 }
5848
AddDeferredUnusedCoverageMapping(Decl * D)5849 void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
5850 // Do we need to generate coverage mapping?
5851 if (!CodeGenOpts.CoverageMapping)
5852 return;
5853 switch (D->getKind()) {
5854 case Decl::CXXConversion:
5855 case Decl::CXXMethod:
5856 case Decl::Function:
5857 case Decl::ObjCMethod:
5858 case Decl::CXXConstructor:
5859 case Decl::CXXDestructor: {
5860 if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
5861 break;
5862 SourceManager &SM = getContext().getSourceManager();
5863 if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
5864 break;
5865 auto I = DeferredEmptyCoverageMappingDecls.find(D);
5866 if (I == DeferredEmptyCoverageMappingDecls.end())
5867 DeferredEmptyCoverageMappingDecls[D] = true;
5868 break;
5869 }
5870 default:
5871 break;
5872 };
5873 }
5874
ClearUnusedCoverageMapping(const Decl * D)5875 void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
5876 // Do we need to generate coverage mapping?
5877 if (!CodeGenOpts.CoverageMapping)
5878 return;
5879 if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
5880 if (Fn->isTemplateInstantiation())
5881 ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
5882 }
5883 auto I = DeferredEmptyCoverageMappingDecls.find(D);
5884 if (I == DeferredEmptyCoverageMappingDecls.end())
5885 DeferredEmptyCoverageMappingDecls[D] = false;
5886 else
5887 I->second = false;
5888 }
5889
EmitDeferredUnusedCoverageMappings()5890 void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
5891 // We call takeVector() here to avoid use-after-free.
5892 // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
5893 // we deserialize function bodies to emit coverage info for them, and that
5894 // deserializes more declarations. How should we handle that case?
5895 for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
5896 if (!Entry.second)
5897 continue;
5898 const Decl *D = Entry.first;
5899 switch (D->getKind()) {
5900 case Decl::CXXConversion:
5901 case Decl::CXXMethod:
5902 case Decl::Function:
5903 case Decl::ObjCMethod: {
5904 CodeGenPGO PGO(*this);
5905 GlobalDecl GD(cast<FunctionDecl>(D));
5906 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
5907 getFunctionLinkage(GD));
5908 break;
5909 }
5910 case Decl::CXXConstructor: {
5911 CodeGenPGO PGO(*this);
5912 GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
5913 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
5914 getFunctionLinkage(GD));
5915 break;
5916 }
5917 case Decl::CXXDestructor: {
5918 CodeGenPGO PGO(*this);
5919 GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
5920 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
5921 getFunctionLinkage(GD));
5922 break;
5923 }
5924 default:
5925 break;
5926 };
5927 }
5928 }
5929
EmitMainVoidAlias()5930 void CodeGenModule::EmitMainVoidAlias() {
5931 // In order to transition away from "__original_main" gracefully, emit an
5932 // alias for "main" in the no-argument case so that libc can detect when
5933 // new-style no-argument main is in used.
5934 if (llvm::Function *F = getModule().getFunction("main")) {
5935 if (!F->isDeclaration() && F->arg_size() == 0 && !F->isVarArg() &&
5936 F->getReturnType()->isIntegerTy(Context.getTargetInfo().getIntWidth()))
5937 addUsedGlobal(llvm::GlobalAlias::create("__main_void", F));
5938 }
5939 }
5940
5941 /// Turns the given pointer into a constant.
GetPointerConstant(llvm::LLVMContext & Context,const void * Ptr)5942 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
5943 const void *Ptr) {
5944 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
5945 llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
5946 return llvm::ConstantInt::get(i64, PtrInt);
5947 }
5948
EmitGlobalDeclMetadata(CodeGenModule & CGM,llvm::NamedMDNode * & GlobalMetadata,GlobalDecl D,llvm::GlobalValue * Addr)5949 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
5950 llvm::NamedMDNode *&GlobalMetadata,
5951 GlobalDecl D,
5952 llvm::GlobalValue *Addr) {
5953 if (!GlobalMetadata)
5954 GlobalMetadata =
5955 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
5956
5957 // TODO: should we report variant information for ctors/dtors?
5958 llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
5959 llvm::ConstantAsMetadata::get(GetPointerConstant(
5960 CGM.getLLVMContext(), D.getDecl()))};
5961 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
5962 }
5963
5964 /// For each function which is declared within an extern "C" region and marked
5965 /// as 'used', but has internal linkage, create an alias from the unmangled
5966 /// name to the mangled name if possible. People expect to be able to refer
5967 /// to such functions with an unmangled name from inline assembly within the
5968 /// same translation unit.
EmitStaticExternCAliases()5969 void CodeGenModule::EmitStaticExternCAliases() {
5970 if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
5971 return;
5972 for (auto &I : StaticExternCValues) {
5973 IdentifierInfo *Name = I.first;
5974 llvm::GlobalValue *Val = I.second;
5975 if (Val && !getModule().getNamedValue(Name->getName()))
5976 addUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
5977 }
5978 }
5979
lookupRepresentativeDecl(StringRef MangledName,GlobalDecl & Result) const5980 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
5981 GlobalDecl &Result) const {
5982 auto Res = Manglings.find(MangledName);
5983 if (Res == Manglings.end())
5984 return false;
5985 Result = Res->getValue();
5986 return true;
5987 }
5988
5989 /// Emits metadata nodes associating all the global values in the
5990 /// current module with the Decls they came from. This is useful for
5991 /// projects using IR gen as a subroutine.
5992 ///
5993 /// Since there's currently no way to associate an MDNode directly
5994 /// with an llvm::GlobalValue, we create a global named metadata
5995 /// with the name 'clang.global.decl.ptrs'.
EmitDeclMetadata()5996 void CodeGenModule::EmitDeclMetadata() {
5997 llvm::NamedMDNode *GlobalMetadata = nullptr;
5998
5999 for (auto &I : MangledDeclNames) {
6000 llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
6001 // Some mangled names don't necessarily have an associated GlobalValue
6002 // in this module, e.g. if we mangled it for DebugInfo.
6003 if (Addr)
6004 EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
6005 }
6006 }
6007
6008 /// Emits metadata nodes for all the local variables in the current
6009 /// function.
EmitDeclMetadata()6010 void CodeGenFunction::EmitDeclMetadata() {
6011 if (LocalDeclMap.empty()) return;
6012
6013 llvm::LLVMContext &Context = getLLVMContext();
6014
6015 // Find the unique metadata ID for this name.
6016 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
6017
6018 llvm::NamedMDNode *GlobalMetadata = nullptr;
6019
6020 for (auto &I : LocalDeclMap) {
6021 const Decl *D = I.first;
6022 llvm::Value *Addr = I.second.getPointer();
6023 if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
6024 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
6025 Alloca->setMetadata(
6026 DeclPtrKind, llvm::MDNode::get(
6027 Context, llvm::ValueAsMetadata::getConstant(DAddr)));
6028 } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
6029 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
6030 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
6031 }
6032 }
6033 }
6034
EmitVersionIdentMetadata()6035 void CodeGenModule::EmitVersionIdentMetadata() {
6036 llvm::NamedMDNode *IdentMetadata =
6037 TheModule.getOrInsertNamedMetadata("llvm.ident");
6038 std::string Version = getClangFullVersion();
6039 llvm::LLVMContext &Ctx = TheModule.getContext();
6040
6041 llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
6042 IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
6043 }
6044
EmitCommandLineMetadata()6045 void CodeGenModule::EmitCommandLineMetadata() {
6046 llvm::NamedMDNode *CommandLineMetadata =
6047 TheModule.getOrInsertNamedMetadata("llvm.commandline");
6048 std::string CommandLine = getCodeGenOpts().RecordCommandLine;
6049 llvm::LLVMContext &Ctx = TheModule.getContext();
6050
6051 llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
6052 CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
6053 }
6054
EmitCoverageFile()6055 void CodeGenModule::EmitCoverageFile() {
6056 if (getCodeGenOpts().CoverageDataFile.empty() &&
6057 getCodeGenOpts().CoverageNotesFile.empty())
6058 return;
6059
6060 llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
6061 if (!CUNode)
6062 return;
6063
6064 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
6065 llvm::LLVMContext &Ctx = TheModule.getContext();
6066 auto *CoverageDataFile =
6067 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
6068 auto *CoverageNotesFile =
6069 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
6070 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
6071 llvm::MDNode *CU = CUNode->getOperand(i);
6072 llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
6073 GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
6074 }
6075 }
6076
GetAddrOfRTTIDescriptor(QualType Ty,bool ForEH)6077 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
6078 bool ForEH) {
6079 // Return a bogus pointer if RTTI is disabled, unless it's for EH.
6080 // FIXME: should we even be calling this method if RTTI is disabled
6081 // and it's not for EH?
6082 if ((!ForEH && !getLangOpts().RTTI) || getLangOpts().CUDAIsDevice ||
6083 (getLangOpts().OpenMP && getLangOpts().OpenMPIsDevice &&
6084 getTriple().isNVPTX()))
6085 return llvm::Constant::getNullValue(Int8PtrTy);
6086
6087 if (ForEH && Ty->isObjCObjectPointerType() &&
6088 LangOpts.ObjCRuntime.isGNUFamily())
6089 return ObjCRuntime->GetEHType(Ty);
6090
6091 return getCXXABI().getAddrOfRTTIDescriptor(Ty);
6092 }
6093
EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl * D)6094 void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
6095 // Do not emit threadprivates in simd-only mode.
6096 if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
6097 return;
6098 for (auto RefExpr : D->varlists()) {
6099 auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
6100 bool PerformInit =
6101 VD->getAnyInitializer() &&
6102 !VD->getAnyInitializer()->isConstantInitializer(getContext(),
6103 /*ForRef=*/false);
6104
6105 Address Addr(GetAddrOfGlobalVar(VD), getContext().getDeclAlign(VD));
6106 if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
6107 VD, Addr, RefExpr->getBeginLoc(), PerformInit))
6108 CXXGlobalInits.push_back(InitFunction);
6109 }
6110 }
6111
6112 llvm::Metadata *
CreateMetadataIdentifierImpl(QualType T,MetadataTypeMap & Map,StringRef Suffix)6113 CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
6114 StringRef Suffix) {
6115 llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
6116 if (InternalId)
6117 return InternalId;
6118
6119 if (isExternallyVisible(T->getLinkage())) {
6120 std::string OutName;
6121 llvm::raw_string_ostream Out(OutName);
6122 getCXXABI().getMangleContext().mangleTypeName(T, Out);
6123 Out << Suffix;
6124
6125 InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
6126 } else {
6127 InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
6128 llvm::ArrayRef<llvm::Metadata *>());
6129 }
6130
6131 return InternalId;
6132 }
6133
CreateMetadataIdentifierForType(QualType T)6134 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
6135 return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
6136 }
6137
6138 llvm::Metadata *
CreateMetadataIdentifierForVirtualMemPtrType(QualType T)6139 CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
6140 return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
6141 }
6142
6143 // Generalize pointer types to a void pointer with the qualifiers of the
6144 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
6145 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
6146 // 'void *'.
GeneralizeType(ASTContext & Ctx,QualType Ty)6147 static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
6148 if (!Ty->isPointerType())
6149 return Ty;
6150
6151 return Ctx.getPointerType(
6152 QualType(Ctx.VoidTy).withCVRQualifiers(
6153 Ty->getPointeeType().getCVRQualifiers()));
6154 }
6155
6156 // Apply type generalization to a FunctionType's return and argument types
GeneralizeFunctionType(ASTContext & Ctx,QualType Ty)6157 static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
6158 if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
6159 SmallVector<QualType, 8> GeneralizedParams;
6160 for (auto &Param : FnType->param_types())
6161 GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
6162
6163 return Ctx.getFunctionType(
6164 GeneralizeType(Ctx, FnType->getReturnType()),
6165 GeneralizedParams, FnType->getExtProtoInfo());
6166 }
6167
6168 if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
6169 return Ctx.getFunctionNoProtoType(
6170 GeneralizeType(Ctx, FnType->getReturnType()));
6171
6172 llvm_unreachable("Encountered unknown FunctionType");
6173 }
6174
CreateMetadataIdentifierGeneralized(QualType T)6175 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
6176 return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
6177 GeneralizedMetadataIdMap, ".generalized");
6178 }
6179
6180 /// Returns whether this module needs the "all-vtables" type identifier.
NeedAllVtablesTypeId() const6181 bool CodeGenModule::NeedAllVtablesTypeId() const {
6182 // Returns true if at least one of vtable-based CFI checkers is enabled and
6183 // is not in the trapping mode.
6184 return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
6185 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
6186 (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
6187 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
6188 (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
6189 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
6190 (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
6191 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
6192 }
6193
AddVTableTypeMetadata(llvm::GlobalVariable * VTable,CharUnits Offset,const CXXRecordDecl * RD)6194 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
6195 CharUnits Offset,
6196 const CXXRecordDecl *RD) {
6197 llvm::Metadata *MD =
6198 CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
6199 VTable->addTypeMetadata(Offset.getQuantity(), MD);
6200
6201 if (CodeGenOpts.SanitizeCfiCrossDso)
6202 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
6203 VTable->addTypeMetadata(Offset.getQuantity(),
6204 llvm::ConstantAsMetadata::get(CrossDsoTypeId));
6205
6206 if (NeedAllVtablesTypeId()) {
6207 llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
6208 VTable->addTypeMetadata(Offset.getQuantity(), MD);
6209 }
6210 }
6211
getSanStats()6212 llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
6213 if (!SanStats)
6214 SanStats = std::make_unique<llvm::SanitizerStatReport>(&getModule());
6215
6216 return *SanStats;
6217 }
6218
6219 llvm::Value *
createOpenCLIntToSamplerConversion(const Expr * E,CodeGenFunction & CGF)6220 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
6221 CodeGenFunction &CGF) {
6222 llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
6223 auto *SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
6224 auto *FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
6225 auto *Call = CGF.Builder.CreateCall(
6226 CreateRuntimeFunction(FTy, "__translate_sampler_initializer"), {C});
6227 Call->setCallingConv(Call->getCalledFunction()->getCallingConv());
6228 return Call;
6229 }
6230
getNaturalPointeeTypeAlignment(QualType T,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo)6231 CharUnits CodeGenModule::getNaturalPointeeTypeAlignment(
6232 QualType T, LValueBaseInfo *BaseInfo, TBAAAccessInfo *TBAAInfo) {
6233 return getNaturalTypeAlignment(T->getPointeeType(), BaseInfo, TBAAInfo,
6234 /* forPointeeType= */ true);
6235 }
6236
getNaturalTypeAlignment(QualType T,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo,bool forPointeeType)6237 CharUnits CodeGenModule::getNaturalTypeAlignment(QualType T,
6238 LValueBaseInfo *BaseInfo,
6239 TBAAAccessInfo *TBAAInfo,
6240 bool forPointeeType) {
6241 if (TBAAInfo)
6242 *TBAAInfo = getTBAAAccessInfo(T);
6243
6244 // FIXME: This duplicates logic in ASTContext::getTypeAlignIfKnown. But
6245 // that doesn't return the information we need to compute BaseInfo.
6246
6247 // Honor alignment typedef attributes even on incomplete types.
6248 // We also honor them straight for C++ class types, even as pointees;
6249 // there's an expressivity gap here.
6250 if (auto TT = T->getAs<TypedefType>()) {
6251 if (auto Align = TT->getDecl()->getMaxAlignment()) {
6252 if (BaseInfo)
6253 *BaseInfo = LValueBaseInfo(AlignmentSource::AttributedType);
6254 return getContext().toCharUnitsFromBits(Align);
6255 }
6256 }
6257
6258 bool AlignForArray = T->isArrayType();
6259
6260 // Analyze the base element type, so we don't get confused by incomplete
6261 // array types.
6262 T = getContext().getBaseElementType(T);
6263
6264 if (T->isIncompleteType()) {
6265 // We could try to replicate the logic from
6266 // ASTContext::getTypeAlignIfKnown, but nothing uses the alignment if the
6267 // type is incomplete, so it's impossible to test. We could try to reuse
6268 // getTypeAlignIfKnown, but that doesn't return the information we need
6269 // to set BaseInfo. So just ignore the possibility that the alignment is
6270 // greater than one.
6271 if (BaseInfo)
6272 *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
6273 return CharUnits::One();
6274 }
6275
6276 if (BaseInfo)
6277 *BaseInfo = LValueBaseInfo(AlignmentSource::Type);
6278
6279 CharUnits Alignment;
6280 const CXXRecordDecl *RD;
6281 if (T.getQualifiers().hasUnaligned()) {
6282 Alignment = CharUnits::One();
6283 } else if (forPointeeType && !AlignForArray &&
6284 (RD = T->getAsCXXRecordDecl())) {
6285 // For C++ class pointees, we don't know whether we're pointing at a
6286 // base or a complete object, so we generally need to use the
6287 // non-virtual alignment.
6288 Alignment = getClassPointerAlignment(RD);
6289 } else {
6290 Alignment = getContext().getTypeAlignInChars(T);
6291 }
6292
6293 // Cap to the global maximum type alignment unless the alignment
6294 // was somehow explicit on the type.
6295 if (unsigned MaxAlign = getLangOpts().MaxTypeAlign) {
6296 if (Alignment.getQuantity() > MaxAlign &&
6297 !getContext().isAlignmentRequired(T))
6298 Alignment = CharUnits::fromQuantity(MaxAlign);
6299 }
6300 return Alignment;
6301 }
6302
stopAutoInit()6303 bool CodeGenModule::stopAutoInit() {
6304 unsigned StopAfter = getContext().getLangOpts().TrivialAutoVarInitStopAfter;
6305 if (StopAfter) {
6306 // This number is positive only when -ftrivial-auto-var-init-stop-after=* is
6307 // used
6308 if (NumAutoVarInit >= StopAfter) {
6309 return true;
6310 }
6311 if (!NumAutoVarInit) {
6312 unsigned DiagID = getDiags().getCustomDiagID(
6313 DiagnosticsEngine::Warning,
6314 "-ftrivial-auto-var-init-stop-after=%0 has been enabled to limit the "
6315 "number of times ftrivial-auto-var-init=%1 gets applied.");
6316 getDiags().Report(DiagID)
6317 << StopAfter
6318 << (getContext().getLangOpts().getTrivialAutoVarInit() ==
6319 LangOptions::TrivialAutoVarInitKind::Zero
6320 ? "zero"
6321 : "pattern");
6322 }
6323 ++NumAutoVarInit;
6324 }
6325 return false;
6326 }
6327