1 //===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This coordinates the per-module state used while generating code.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "CodeGenModule.h"
15 #include "CGBlocks.h"
16 #include "CGCUDARuntime.h"
17 #include "CGCXXABI.h"
18 #include "CGCall.h"
19 #include "CGDebugInfo.h"
20 #include "CGObjCRuntime.h"
21 #include "CGOpenCLRuntime.h"
22 #include "CGOpenMPRuntime.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/Basic/Builtins.h"
38 #include "clang/Basic/CharInfo.h"
39 #include "clang/Basic/CodeGenOptions.h"
40 #include "clang/Basic/Diagnostic.h"
41 #include "clang/Basic/Module.h"
42 #include "clang/Basic/SourceManager.h"
43 #include "clang/Basic/TargetInfo.h"
44 #include "clang/Basic/Version.h"
45 #include "clang/CodeGen/ConstantInitBuilder.h"
46 #include "clang/Frontend/FrontendDiagnostic.h"
47 #include "llvm/ADT/StringSwitch.h"
48 #include "llvm/ADT/Triple.h"
49 #include "llvm/Analysis/TargetLibraryInfo.h"
50 #include "llvm/IR/CallSite.h"
51 #include "llvm/IR/CallingConv.h"
52 #include "llvm/IR/DataLayout.h"
53 #include "llvm/IR/Intrinsics.h"
54 #include "llvm/IR/LLVMContext.h"
55 #include "llvm/IR/Module.h"
56 #include "llvm/ProfileData/InstrProfReader.h"
57 #include "llvm/Support/CodeGen.h"
58 #include "llvm/Support/ConvertUTF.h"
59 #include "llvm/Support/ErrorHandling.h"
60 #include "llvm/Support/MD5.h"
61
62 using namespace clang;
63 using namespace CodeGen;
64
65 static llvm::cl::opt<bool> LimitedCoverage(
66 "limited-coverage-experimental", llvm::cl::ZeroOrMore, llvm::cl::Hidden,
67 llvm::cl::desc("Emit limited coverage mapping information (experimental)"),
68 llvm::cl::init(false));
69
70 static const char AnnotationSection[] = "llvm.metadata";
71
createCXXABI(CodeGenModule & CGM)72 static CGCXXABI *createCXXABI(CodeGenModule &CGM) {
73 switch (CGM.getTarget().getCXXABI().getKind()) {
74 case TargetCXXABI::GenericAArch64:
75 case TargetCXXABI::GenericARM:
76 case TargetCXXABI::iOS:
77 case TargetCXXABI::iOS64:
78 case TargetCXXABI::WatchOS:
79 case TargetCXXABI::GenericMIPS:
80 case TargetCXXABI::GenericItanium:
81 case TargetCXXABI::WebAssembly:
82 return CreateItaniumCXXABI(CGM);
83 case TargetCXXABI::Microsoft:
84 return CreateMicrosoftCXXABI(CGM);
85 }
86
87 llvm_unreachable("invalid C++ ABI kind");
88 }
89
CodeGenModule(ASTContext & C,const HeaderSearchOptions & HSO,const PreprocessorOptions & PPO,const CodeGenOptions & CGO,llvm::Module & M,DiagnosticsEngine & diags,CoverageSourceInfo * CoverageInfo)90 CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
91 const PreprocessorOptions &PPO,
92 const CodeGenOptions &CGO, llvm::Module &M,
93 DiagnosticsEngine &diags,
94 CoverageSourceInfo *CoverageInfo)
95 : Context(C), LangOpts(C.getLangOpts()), HeaderSearchOpts(HSO),
96 PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags),
97 Target(C.getTargetInfo()), ABI(createCXXABI(*this)),
98 VMContext(M.getContext()), Types(*this), VTables(*this),
99 SanitizerMD(new SanitizerMetadata(*this)) {
100
101 // Initialize the type cache.
102 llvm::LLVMContext &LLVMContext = M.getContext();
103 VoidTy = llvm::Type::getVoidTy(LLVMContext);
104 Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
105 Int16Ty = llvm::Type::getInt16Ty(LLVMContext);
106 Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
107 Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
108 HalfTy = llvm::Type::getHalfTy(LLVMContext);
109 FloatTy = llvm::Type::getFloatTy(LLVMContext);
110 DoubleTy = llvm::Type::getDoubleTy(LLVMContext);
111 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
112 PointerAlignInBytes =
113 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
114 SizeSizeInBytes =
115 C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
116 IntAlignInBytes =
117 C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
118 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
119 IntPtrTy = llvm::IntegerType::get(LLVMContext,
120 C.getTargetInfo().getMaxPointerWidth());
121 Int8PtrTy = Int8Ty->getPointerTo(0);
122 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
123 AllocaInt8PtrTy = Int8Ty->getPointerTo(
124 M.getDataLayout().getAllocaAddrSpace());
125 ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace();
126
127 RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
128
129 if (LangOpts.ObjC)
130 createObjCRuntime();
131 if (LangOpts.OpenCL)
132 createOpenCLRuntime();
133 if (LangOpts.OpenMP)
134 createOpenMPRuntime();
135 if (LangOpts.CUDA)
136 createCUDARuntime();
137
138 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
139 if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
140 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
141 TBAA.reset(new CodeGenTBAA(Context, TheModule, CodeGenOpts, getLangOpts(),
142 getCXXABI().getMangleContext()));
143
144 // If debug info or coverage generation is enabled, create the CGDebugInfo
145 // object.
146 if (CodeGenOpts.getDebugInfo() != codegenoptions::NoDebugInfo ||
147 CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes)
148 DebugInfo.reset(new CGDebugInfo(*this));
149
150 Block.GlobalUniqueCount = 0;
151
152 if (C.getLangOpts().ObjC)
153 ObjCData.reset(new ObjCEntrypoints());
154
155 if (CodeGenOpts.hasProfileClangUse()) {
156 auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
157 CodeGenOpts.ProfileInstrumentUsePath, CodeGenOpts.ProfileRemappingFile);
158 if (auto E = ReaderOrErr.takeError()) {
159 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
160 "Could not read profile %0: %1");
161 llvm::handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EI) {
162 getDiags().Report(DiagID) << CodeGenOpts.ProfileInstrumentUsePath
163 << EI.message();
164 });
165 } else
166 PGOReader = std::move(ReaderOrErr.get());
167 }
168
169 // If coverage mapping generation is enabled, create the
170 // CoverageMappingModuleGen object.
171 if (CodeGenOpts.CoverageMapping)
172 CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo));
173 }
174
~CodeGenModule()175 CodeGenModule::~CodeGenModule() {}
176
createObjCRuntime()177 void CodeGenModule::createObjCRuntime() {
178 // This is just isGNUFamily(), but we want to force implementors of
179 // new ABIs to decide how best to do this.
180 switch (LangOpts.ObjCRuntime.getKind()) {
181 case ObjCRuntime::GNUstep:
182 case ObjCRuntime::GCC:
183 case ObjCRuntime::ObjFW:
184 ObjCRuntime.reset(CreateGNUObjCRuntime(*this));
185 return;
186
187 case ObjCRuntime::FragileMacOSX:
188 case ObjCRuntime::MacOSX:
189 case ObjCRuntime::iOS:
190 case ObjCRuntime::WatchOS:
191 ObjCRuntime.reset(CreateMacObjCRuntime(*this));
192 return;
193 }
194 llvm_unreachable("bad runtime kind");
195 }
196
createOpenCLRuntime()197 void CodeGenModule::createOpenCLRuntime() {
198 OpenCLRuntime.reset(new CGOpenCLRuntime(*this));
199 }
200
createOpenMPRuntime()201 void CodeGenModule::createOpenMPRuntime() {
202 // Select a specialized code generation class based on the target, if any.
203 // If it does not exist use the default implementation.
204 switch (getTriple().getArch()) {
205 case llvm::Triple::nvptx:
206 case llvm::Triple::nvptx64:
207 assert(getLangOpts().OpenMPIsDevice &&
208 "OpenMP NVPTX is only prepared to deal with device code.");
209 OpenMPRuntime.reset(new CGOpenMPRuntimeNVPTX(*this));
210 break;
211 default:
212 if (LangOpts.OpenMPSimd)
213 OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this));
214 else
215 OpenMPRuntime.reset(new CGOpenMPRuntime(*this));
216 break;
217 }
218 }
219
createCUDARuntime()220 void CodeGenModule::createCUDARuntime() {
221 CUDARuntime.reset(CreateNVCUDARuntime(*this));
222 }
223
addReplacement(StringRef Name,llvm::Constant * C)224 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) {
225 Replacements[Name] = C;
226 }
227
applyReplacements()228 void CodeGenModule::applyReplacements() {
229 for (auto &I : Replacements) {
230 StringRef MangledName = I.first();
231 llvm::Constant *Replacement = I.second;
232 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
233 if (!Entry)
234 continue;
235 auto *OldF = cast<llvm::Function>(Entry);
236 auto *NewF = dyn_cast<llvm::Function>(Replacement);
237 if (!NewF) {
238 if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) {
239 NewF = dyn_cast<llvm::Function>(Alias->getAliasee());
240 } else {
241 auto *CE = cast<llvm::ConstantExpr>(Replacement);
242 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
243 CE->getOpcode() == llvm::Instruction::GetElementPtr);
244 NewF = dyn_cast<llvm::Function>(CE->getOperand(0));
245 }
246 }
247
248 // Replace old with new, but keep the old order.
249 OldF->replaceAllUsesWith(Replacement);
250 if (NewF) {
251 NewF->removeFromParent();
252 OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(),
253 NewF);
254 }
255 OldF->eraseFromParent();
256 }
257 }
258
addGlobalValReplacement(llvm::GlobalValue * GV,llvm::Constant * C)259 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) {
260 GlobalValReplacements.push_back(std::make_pair(GV, C));
261 }
262
applyGlobalValReplacements()263 void CodeGenModule::applyGlobalValReplacements() {
264 for (auto &I : GlobalValReplacements) {
265 llvm::GlobalValue *GV = I.first;
266 llvm::Constant *C = I.second;
267
268 GV->replaceAllUsesWith(C);
269 GV->eraseFromParent();
270 }
271 }
272
273 // This is only used in aliases that we created and we know they have a
274 // linear structure.
getAliasedGlobal(const llvm::GlobalIndirectSymbol & GIS)275 static const llvm::GlobalObject *getAliasedGlobal(
276 const llvm::GlobalIndirectSymbol &GIS) {
277 llvm::SmallPtrSet<const llvm::GlobalIndirectSymbol*, 4> Visited;
278 const llvm::Constant *C = &GIS;
279 for (;;) {
280 C = C->stripPointerCasts();
281 if (auto *GO = dyn_cast<llvm::GlobalObject>(C))
282 return GO;
283 // stripPointerCasts will not walk over weak aliases.
284 auto *GIS2 = dyn_cast<llvm::GlobalIndirectSymbol>(C);
285 if (!GIS2)
286 return nullptr;
287 if (!Visited.insert(GIS2).second)
288 return nullptr;
289 C = GIS2->getIndirectSymbol();
290 }
291 }
292
checkAliases()293 void CodeGenModule::checkAliases() {
294 // Check if the constructed aliases are well formed. It is really unfortunate
295 // that we have to do this in CodeGen, but we only construct mangled names
296 // and aliases during codegen.
297 bool Error = false;
298 DiagnosticsEngine &Diags = getDiags();
299 for (const GlobalDecl &GD : Aliases) {
300 const auto *D = cast<ValueDecl>(GD.getDecl());
301 SourceLocation Location;
302 bool IsIFunc = D->hasAttr<IFuncAttr>();
303 if (const Attr *A = D->getDefiningAttr())
304 Location = A->getLocation();
305 else
306 llvm_unreachable("Not an alias or ifunc?");
307 StringRef MangledName = getMangledName(GD);
308 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
309 auto *Alias = cast<llvm::GlobalIndirectSymbol>(Entry);
310 const llvm::GlobalValue *GV = getAliasedGlobal(*Alias);
311 if (!GV) {
312 Error = true;
313 Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc;
314 } else if (GV->isDeclaration()) {
315 Error = true;
316 Diags.Report(Location, diag::err_alias_to_undefined)
317 << IsIFunc << IsIFunc;
318 } else if (IsIFunc) {
319 // Check resolver function type.
320 llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(
321 GV->getType()->getPointerElementType());
322 assert(FTy);
323 if (!FTy->getReturnType()->isPointerTy())
324 Diags.Report(Location, diag::err_ifunc_resolver_return);
325 }
326
327 llvm::Constant *Aliasee = Alias->getIndirectSymbol();
328 llvm::GlobalValue *AliaseeGV;
329 if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee))
330 AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0));
331 else
332 AliaseeGV = cast<llvm::GlobalValue>(Aliasee);
333
334 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
335 StringRef AliasSection = SA->getName();
336 if (AliasSection != AliaseeGV->getSection())
337 Diags.Report(SA->getLocation(), diag::warn_alias_with_section)
338 << AliasSection << IsIFunc << IsIFunc;
339 }
340
341 // We have to handle alias to weak aliases in here. LLVM itself disallows
342 // this since the object semantics would not match the IL one. For
343 // compatibility with gcc we implement it by just pointing the alias
344 // to its aliasee's aliasee. We also warn, since the user is probably
345 // expecting the link to be weak.
346 if (auto GA = dyn_cast<llvm::GlobalIndirectSymbol>(AliaseeGV)) {
347 if (GA->isInterposable()) {
348 Diags.Report(Location, diag::warn_alias_to_weak_alias)
349 << GV->getName() << GA->getName() << IsIFunc;
350 Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
351 GA->getIndirectSymbol(), Alias->getType());
352 Alias->setIndirectSymbol(Aliasee);
353 }
354 }
355 }
356 if (!Error)
357 return;
358
359 for (const GlobalDecl &GD : Aliases) {
360 StringRef MangledName = getMangledName(GD);
361 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
362 auto *Alias = dyn_cast<llvm::GlobalIndirectSymbol>(Entry);
363 Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType()));
364 Alias->eraseFromParent();
365 }
366 }
367
clear()368 void CodeGenModule::clear() {
369 DeferredDeclsToEmit.clear();
370 if (OpenMPRuntime)
371 OpenMPRuntime->clear();
372 }
373
reportDiagnostics(DiagnosticsEngine & Diags,StringRef MainFile)374 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags,
375 StringRef MainFile) {
376 if (!hasDiagnostics())
377 return;
378 if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) {
379 if (MainFile.empty())
380 MainFile = "<stdin>";
381 Diags.Report(diag::warn_profile_data_unprofiled) << MainFile;
382 } else {
383 if (Mismatched > 0)
384 Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched;
385
386 if (Missing > 0)
387 Diags.Report(diag::warn_profile_data_missing) << Visited << Missing;
388 }
389 }
390
Release()391 void CodeGenModule::Release() {
392 EmitDeferred();
393 EmitVTablesOpportunistically();
394 applyGlobalValReplacements();
395 applyReplacements();
396 checkAliases();
397 emitMultiVersionFunctions();
398 EmitCXXGlobalInitFunc();
399 EmitCXXGlobalDtorFunc();
400 registerGlobalDtorsWithAtExit();
401 EmitCXXThreadLocalInitFunc();
402 if (ObjCRuntime)
403 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
404 AddGlobalCtor(ObjCInitFunction);
405 if (Context.getLangOpts().CUDA && !Context.getLangOpts().CUDAIsDevice &&
406 CUDARuntime) {
407 if (llvm::Function *CudaCtorFunction =
408 CUDARuntime->makeModuleCtorFunction())
409 AddGlobalCtor(CudaCtorFunction);
410 }
411 if (OpenMPRuntime) {
412 if (llvm::Function *OpenMPRegistrationFunction =
413 OpenMPRuntime->emitRegistrationFunction()) {
414 auto ComdatKey = OpenMPRegistrationFunction->hasComdat() ?
415 OpenMPRegistrationFunction : nullptr;
416 AddGlobalCtor(OpenMPRegistrationFunction, 0, ComdatKey);
417 }
418 OpenMPRuntime->clear();
419 }
420 if (PGOReader) {
421 getModule().setProfileSummary(PGOReader->getSummary().getMD(VMContext));
422 if (PGOStats.hasDiagnostics())
423 PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
424 }
425 EmitCtorList(GlobalCtors, "llvm.global_ctors");
426 EmitCtorList(GlobalDtors, "llvm.global_dtors");
427 EmitGlobalAnnotations();
428 EmitStaticExternCAliases();
429 EmitDeferredUnusedCoverageMappings();
430 if (CoverageMapping)
431 CoverageMapping->emit();
432 if (CodeGenOpts.SanitizeCfiCrossDso) {
433 CodeGenFunction(*this).EmitCfiCheckFail();
434 CodeGenFunction(*this).EmitCfiCheckStub();
435 }
436 emitAtAvailableLinkGuard();
437 emitLLVMUsed();
438 if (SanStats)
439 SanStats->finish();
440
441 if (CodeGenOpts.Autolink &&
442 (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) {
443 EmitModuleLinkOptions();
444 }
445
446 // Record mregparm value now so it is visible through rest of codegen.
447 if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
448 getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters",
449 CodeGenOpts.NumRegisterParameters);
450
451 if (CodeGenOpts.DwarfVersion) {
452 // We actually want the latest version when there are conflicts.
453 // We can change from Warning to Latest if such mode is supported.
454 getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version",
455 CodeGenOpts.DwarfVersion);
456 }
457 if (CodeGenOpts.EmitCodeView) {
458 // Indicate that we want CodeView in the metadata.
459 getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
460 }
461 if (CodeGenOpts.CodeViewGHash) {
462 getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
463 }
464 if (CodeGenOpts.ControlFlowGuard) {
465 // We want function ID tables for Control Flow Guard.
466 getModule().addModuleFlag(llvm::Module::Warning, "cfguardtable", 1);
467 }
468 if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
469 // We don't support LTO with 2 with different StrictVTablePointers
470 // FIXME: we could support it by stripping all the information introduced
471 // by StrictVTablePointers.
472
473 getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1);
474
475 llvm::Metadata *Ops[2] = {
476 llvm::MDString::get(VMContext, "StrictVTablePointers"),
477 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
478 llvm::Type::getInt32Ty(VMContext), 1))};
479
480 getModule().addModuleFlag(llvm::Module::Require,
481 "StrictVTablePointersRequirement",
482 llvm::MDNode::get(VMContext, Ops));
483 }
484 if (DebugInfo)
485 // We support a single version in the linked module. The LLVM
486 // parser will drop debug info with a different version number
487 // (and warn about it, too).
488 getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version",
489 llvm::DEBUG_METADATA_VERSION);
490
491 // We need to record the widths of enums and wchar_t, so that we can generate
492 // the correct build attributes in the ARM backend. wchar_size is also used by
493 // TargetLibraryInfo.
494 uint64_t WCharWidth =
495 Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
496 getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
497
498 llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch();
499 if ( Arch == llvm::Triple::arm
500 || Arch == llvm::Triple::armeb
501 || Arch == llvm::Triple::thumb
502 || Arch == llvm::Triple::thumbeb) {
503 // The minimum width of an enum in bytes
504 uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4;
505 getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth);
506 }
507
508 if (CodeGenOpts.SanitizeCfiCrossDso) {
509 // Indicate that we want cross-DSO control flow integrity checks.
510 getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
511 }
512
513 if (CodeGenOpts.CFProtectionReturn &&
514 Target.checkCFProtectionReturnSupported(getDiags())) {
515 // Indicate that we want to instrument return control flow protection.
516 getModule().addModuleFlag(llvm::Module::Override, "cf-protection-return",
517 1);
518 }
519
520 if (CodeGenOpts.CFProtectionBranch &&
521 Target.checkCFProtectionBranchSupported(getDiags())) {
522 // Indicate that we want to instrument branch control flow protection.
523 getModule().addModuleFlag(llvm::Module::Override, "cf-protection-branch",
524 1);
525 }
526
527 if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) {
528 // Indicate whether __nvvm_reflect should be configured to flush denormal
529 // floating point values to 0. (This corresponds to its "__CUDA_FTZ"
530 // property.)
531 getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz",
532 CodeGenOpts.FlushDenorm ? 1 : 0);
533 }
534
535 // Emit OpenCL specific module metadata: OpenCL/SPIR version.
536 if (LangOpts.OpenCL) {
537 EmitOpenCLMetadata();
538 // Emit SPIR version.
539 if (getTriple().getArch() == llvm::Triple::spir ||
540 getTriple().getArch() == llvm::Triple::spir64) {
541 // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the
542 // opencl.spir.version named metadata.
543 llvm::Metadata *SPIRVerElts[] = {
544 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
545 Int32Ty, LangOpts.OpenCLVersion / 100)),
546 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
547 Int32Ty, (LangOpts.OpenCLVersion / 100 > 1) ? 0 : 2))};
548 llvm::NamedMDNode *SPIRVerMD =
549 TheModule.getOrInsertNamedMetadata("opencl.spir.version");
550 llvm::LLVMContext &Ctx = TheModule.getContext();
551 SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts));
552 }
553 }
554
555 if (uint32_t PLevel = Context.getLangOpts().PICLevel) {
556 assert(PLevel < 3 && "Invalid PIC Level");
557 getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel));
558 if (Context.getLangOpts().PIE)
559 getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
560 }
561
562 if (getCodeGenOpts().CodeModel.size() > 0) {
563 unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
564 .Case("tiny", llvm::CodeModel::Tiny)
565 .Case("small", llvm::CodeModel::Small)
566 .Case("kernel", llvm::CodeModel::Kernel)
567 .Case("medium", llvm::CodeModel::Medium)
568 .Case("large", llvm::CodeModel::Large)
569 .Default(~0u);
570 if (CM != ~0u) {
571 llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
572 getModule().setCodeModel(codeModel);
573 }
574 }
575
576 if (CodeGenOpts.NoPLT)
577 getModule().setRtLibUseGOT();
578
579 SimplifyPersonality();
580
581 if (getCodeGenOpts().EmitDeclMetadata)
582 EmitDeclMetadata();
583
584 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
585 EmitCoverageFile();
586
587 if (DebugInfo)
588 DebugInfo->finalize();
589
590 if (getCodeGenOpts().EmitVersionIdentMetadata)
591 EmitVersionIdentMetadata();
592
593 if (!getCodeGenOpts().RecordCommandLine.empty())
594 EmitCommandLineMetadata();
595
596 EmitTargetMetadata();
597 }
598
EmitOpenCLMetadata()599 void CodeGenModule::EmitOpenCLMetadata() {
600 // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the
601 // opencl.ocl.version named metadata node.
602 llvm::Metadata *OCLVerElts[] = {
603 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
604 Int32Ty, LangOpts.OpenCLVersion / 100)),
605 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
606 Int32Ty, (LangOpts.OpenCLVersion % 100) / 10))};
607 llvm::NamedMDNode *OCLVerMD =
608 TheModule.getOrInsertNamedMetadata("opencl.ocl.version");
609 llvm::LLVMContext &Ctx = TheModule.getContext();
610 OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts));
611 }
612
UpdateCompletedType(const TagDecl * TD)613 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
614 // Make sure that this type is translated.
615 Types.UpdateCompletedType(TD);
616 }
617
RefreshTypeCacheForClass(const CXXRecordDecl * RD)618 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) {
619 // Make sure that this type is translated.
620 Types.RefreshTypeCacheForClass(RD);
621 }
622
getTBAATypeInfo(QualType QTy)623 llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) {
624 if (!TBAA)
625 return nullptr;
626 return TBAA->getTypeInfo(QTy);
627 }
628
getTBAAAccessInfo(QualType AccessType)629 TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
630 if (!TBAA)
631 return TBAAAccessInfo();
632 return TBAA->getAccessInfo(AccessType);
633 }
634
635 TBAAAccessInfo
getTBAAVTablePtrAccessInfo(llvm::Type * VTablePtrType)636 CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) {
637 if (!TBAA)
638 return TBAAAccessInfo();
639 return TBAA->getVTablePtrAccessInfo(VTablePtrType);
640 }
641
getTBAAStructInfo(QualType QTy)642 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
643 if (!TBAA)
644 return nullptr;
645 return TBAA->getTBAAStructInfo(QTy);
646 }
647
getTBAABaseTypeInfo(QualType QTy)648 llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) {
649 if (!TBAA)
650 return nullptr;
651 return TBAA->getBaseTypeInfo(QTy);
652 }
653
getTBAAAccessTagInfo(TBAAAccessInfo Info)654 llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
655 if (!TBAA)
656 return nullptr;
657 return TBAA->getAccessTagInfo(Info);
658 }
659
mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,TBAAAccessInfo TargetInfo)660 TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo,
661 TBAAAccessInfo TargetInfo) {
662 if (!TBAA)
663 return TBAAAccessInfo();
664 return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo);
665 }
666
667 TBAAAccessInfo
mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,TBAAAccessInfo InfoB)668 CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA,
669 TBAAAccessInfo InfoB) {
670 if (!TBAA)
671 return TBAAAccessInfo();
672 return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB);
673 }
674
675 TBAAAccessInfo
mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,TBAAAccessInfo SrcInfo)676 CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo,
677 TBAAAccessInfo SrcInfo) {
678 if (!TBAA)
679 return TBAAAccessInfo();
680 return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo);
681 }
682
DecorateInstructionWithTBAA(llvm::Instruction * Inst,TBAAAccessInfo TBAAInfo)683 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
684 TBAAAccessInfo TBAAInfo) {
685 if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
686 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
687 }
688
DecorateInstructionWithInvariantGroup(llvm::Instruction * I,const CXXRecordDecl * RD)689 void CodeGenModule::DecorateInstructionWithInvariantGroup(
690 llvm::Instruction *I, const CXXRecordDecl *RD) {
691 I->setMetadata(llvm::LLVMContext::MD_invariant_group,
692 llvm::MDNode::get(getLLVMContext(), {}));
693 }
694
Error(SourceLocation loc,StringRef message)695 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
696 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
697 getDiags().Report(Context.getFullLoc(loc), diagID) << message;
698 }
699
700 /// ErrorUnsupported - Print out an error that codegen doesn't support the
701 /// specified stmt yet.
ErrorUnsupported(const Stmt * S,const char * Type)702 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
703 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
704 "cannot compile this %0 yet");
705 std::string Msg = Type;
706 getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID)
707 << Msg << S->getSourceRange();
708 }
709
710 /// ErrorUnsupported - Print out an error that codegen doesn't support the
711 /// specified decl yet.
ErrorUnsupported(const Decl * D,const char * Type)712 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) {
713 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
714 "cannot compile this %0 yet");
715 std::string Msg = Type;
716 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
717 }
718
getSize(CharUnits size)719 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
720 return llvm::ConstantInt::get(SizeTy, size.getQuantity());
721 }
722
setGlobalVisibility(llvm::GlobalValue * GV,const NamedDecl * D) const723 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
724 const NamedDecl *D) const {
725 if (GV->hasDLLImportStorageClass())
726 return;
727 // Internal definitions always have default visibility.
728 if (GV->hasLocalLinkage()) {
729 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
730 return;
731 }
732 if (!D)
733 return;
734 // Set visibility for definitions.
735 LinkageInfo LV = D->getLinkageAndVisibility();
736 if (LV.isVisibilityExplicit() || !GV->isDeclarationForLinker())
737 GV->setVisibility(GetLLVMVisibility(LV.getVisibility()));
738 }
739
shouldAssumeDSOLocal(const CodeGenModule & CGM,llvm::GlobalValue * GV)740 static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
741 llvm::GlobalValue *GV) {
742 if (GV->hasLocalLinkage())
743 return true;
744
745 if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage())
746 return true;
747
748 // DLLImport explicitly marks the GV as external.
749 if (GV->hasDLLImportStorageClass())
750 return false;
751
752 const llvm::Triple &TT = CGM.getTriple();
753 if (TT.isWindowsGNUEnvironment()) {
754 // In MinGW, variables without DLLImport can still be automatically
755 // imported from a DLL by the linker; don't mark variables that
756 // potentially could come from another DLL as DSO local.
757 if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
758 !GV->isThreadLocal())
759 return false;
760 }
761 // Every other GV is local on COFF.
762 // Make an exception for windows OS in the triple: Some firmware builds use
763 // *-win32-macho triples. This (accidentally?) produced windows relocations
764 // without GOT tables in older clang versions; Keep this behaviour.
765 // FIXME: even thread local variables?
766 if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
767 return true;
768
769 // Only handle COFF and ELF for now.
770 if (!TT.isOSBinFormatELF())
771 return false;
772
773 // If this is not an executable, don't assume anything is local.
774 const auto &CGOpts = CGM.getCodeGenOpts();
775 llvm::Reloc::Model RM = CGOpts.RelocationModel;
776 const auto &LOpts = CGM.getLangOpts();
777 if (RM != llvm::Reloc::Static && !LOpts.PIE)
778 return false;
779
780 // A definition cannot be preempted from an executable.
781 if (!GV->isDeclarationForLinker())
782 return true;
783
784 // Most PIC code sequences that assume that a symbol is local cannot produce a
785 // 0 if it turns out the symbol is undefined. While this is ABI and relocation
786 // depended, it seems worth it to handle it here.
787 if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage())
788 return false;
789
790 // PPC has no copy relocations and cannot use a plt entry as a symbol address.
791 llvm::Triple::ArchType Arch = TT.getArch();
792 if (Arch == llvm::Triple::ppc || Arch == llvm::Triple::ppc64 ||
793 Arch == llvm::Triple::ppc64le)
794 return false;
795
796 // If we can use copy relocations we can assume it is local.
797 if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV))
798 if (!Var->isThreadLocal() &&
799 (RM == llvm::Reloc::Static || CGOpts.PIECopyRelocations))
800 return true;
801
802 // If we can use a plt entry as the symbol address we can assume it
803 // is local.
804 // FIXME: This should work for PIE, but the gold linker doesn't support it.
805 if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static)
806 return true;
807
808 // Otherwise don't assue it is local.
809 return false;
810 }
811
setDSOLocal(llvm::GlobalValue * GV) const812 void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const {
813 GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV));
814 }
815
setDLLImportDLLExport(llvm::GlobalValue * GV,GlobalDecl GD) const816 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
817 GlobalDecl GD) const {
818 const auto *D = dyn_cast<NamedDecl>(GD.getDecl());
819 // C++ destructors have a few C++ ABI specific special cases.
820 if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) {
821 getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType());
822 return;
823 }
824 setDLLImportDLLExport(GV, D);
825 }
826
setDLLImportDLLExport(llvm::GlobalValue * GV,const NamedDecl * D) const827 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV,
828 const NamedDecl *D) const {
829 if (D && D->isExternallyVisible()) {
830 if (D->hasAttr<DLLImportAttr>())
831 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
832 else if (D->hasAttr<DLLExportAttr>() && !GV->isDeclarationForLinker())
833 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
834 }
835 }
836
setGVProperties(llvm::GlobalValue * GV,GlobalDecl GD) const837 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
838 GlobalDecl GD) const {
839 setDLLImportDLLExport(GV, GD);
840 setGlobalVisibilityAndLocal(GV, dyn_cast<NamedDecl>(GD.getDecl()));
841 }
842
setGVProperties(llvm::GlobalValue * GV,const NamedDecl * D) const843 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV,
844 const NamedDecl *D) const {
845 setDLLImportDLLExport(GV, D);
846 setGlobalVisibilityAndLocal(GV, D);
847 }
848
setGlobalVisibilityAndLocal(llvm::GlobalValue * GV,const NamedDecl * D) const849 void CodeGenModule::setGlobalVisibilityAndLocal(llvm::GlobalValue *GV,
850 const NamedDecl *D) const {
851 setGlobalVisibility(GV, D);
852 setDSOLocal(GV);
853 }
854
GetLLVMTLSModel(StringRef S)855 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) {
856 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S)
857 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel)
858 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel)
859 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel)
860 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel);
861 }
862
GetLLVMTLSModel(CodeGenOptions::TLSModel M)863 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(
864 CodeGenOptions::TLSModel M) {
865 switch (M) {
866 case CodeGenOptions::GeneralDynamicTLSModel:
867 return llvm::GlobalVariable::GeneralDynamicTLSModel;
868 case CodeGenOptions::LocalDynamicTLSModel:
869 return llvm::GlobalVariable::LocalDynamicTLSModel;
870 case CodeGenOptions::InitialExecTLSModel:
871 return llvm::GlobalVariable::InitialExecTLSModel;
872 case CodeGenOptions::LocalExecTLSModel:
873 return llvm::GlobalVariable::LocalExecTLSModel;
874 }
875 llvm_unreachable("Invalid TLS model!");
876 }
877
setTLSMode(llvm::GlobalValue * GV,const VarDecl & D) const878 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const {
879 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!");
880
881 llvm::GlobalValue::ThreadLocalMode TLM;
882 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel());
883
884 // Override the TLS model if it is explicitly specified.
885 if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) {
886 TLM = GetLLVMTLSModel(Attr->getModel());
887 }
888
889 GV->setThreadLocalMode(TLM);
890 }
891
getCPUSpecificMangling(const CodeGenModule & CGM,StringRef Name)892 static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
893 StringRef Name) {
894 const TargetInfo &Target = CGM.getTarget();
895 return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str();
896 }
897
AppendCPUSpecificCPUDispatchMangling(const CodeGenModule & CGM,const CPUSpecificAttr * Attr,unsigned CPUIndex,raw_ostream & Out)898 static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
899 const CPUSpecificAttr *Attr,
900 unsigned CPUIndex,
901 raw_ostream &Out) {
902 // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
903 // supported.
904 if (Attr)
905 Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
906 else if (CGM.getTarget().supportsIFunc())
907 Out << ".resolver";
908 }
909
AppendTargetMangling(const CodeGenModule & CGM,const TargetAttr * Attr,raw_ostream & Out)910 static void AppendTargetMangling(const CodeGenModule &CGM,
911 const TargetAttr *Attr, raw_ostream &Out) {
912 if (Attr->isDefaultVersion())
913 return;
914
915 Out << '.';
916 const TargetInfo &Target = CGM.getTarget();
917 TargetAttr::ParsedTargetAttr Info =
918 Attr->parse([&Target](StringRef LHS, StringRef RHS) {
919 // Multiversioning doesn't allow "no-${feature}", so we can
920 // only have "+" prefixes here.
921 assert(LHS.startswith("+") && RHS.startswith("+") &&
922 "Features should always have a prefix.");
923 return Target.multiVersionSortPriority(LHS.substr(1)) >
924 Target.multiVersionSortPriority(RHS.substr(1));
925 });
926
927 bool IsFirst = true;
928
929 if (!Info.Architecture.empty()) {
930 IsFirst = false;
931 Out << "arch_" << Info.Architecture;
932 }
933
934 for (StringRef Feat : Info.Features) {
935 if (!IsFirst)
936 Out << '_';
937 IsFirst = false;
938 Out << Feat.substr(1);
939 }
940 }
941
getMangledNameImpl(const CodeGenModule & CGM,GlobalDecl GD,const NamedDecl * ND,bool OmitMultiVersionMangling=false)942 static std::string getMangledNameImpl(const CodeGenModule &CGM, GlobalDecl GD,
943 const NamedDecl *ND,
944 bool OmitMultiVersionMangling = false) {
945 SmallString<256> Buffer;
946 llvm::raw_svector_ostream Out(Buffer);
947 MangleContext &MC = CGM.getCXXABI().getMangleContext();
948 if (MC.shouldMangleDeclName(ND)) {
949 llvm::raw_svector_ostream Out(Buffer);
950 if (const auto *D = dyn_cast<CXXConstructorDecl>(ND))
951 MC.mangleCXXCtor(D, GD.getCtorType(), Out);
952 else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND))
953 MC.mangleCXXDtor(D, GD.getDtorType(), Out);
954 else
955 MC.mangleName(ND, Out);
956 } else {
957 IdentifierInfo *II = ND->getIdentifier();
958 assert(II && "Attempt to mangle unnamed decl.");
959 const auto *FD = dyn_cast<FunctionDecl>(ND);
960
961 if (FD &&
962 FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
963 llvm::raw_svector_ostream Out(Buffer);
964 Out << "__regcall3__" << II->getName();
965 } else {
966 Out << II->getName();
967 }
968 }
969
970 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
971 if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
972 switch (FD->getMultiVersionKind()) {
973 case MultiVersionKind::CPUDispatch:
974 case MultiVersionKind::CPUSpecific:
975 AppendCPUSpecificCPUDispatchMangling(CGM,
976 FD->getAttr<CPUSpecificAttr>(),
977 GD.getMultiVersionIndex(), Out);
978 break;
979 case MultiVersionKind::Target:
980 AppendTargetMangling(CGM, FD->getAttr<TargetAttr>(), Out);
981 break;
982 case MultiVersionKind::None:
983 llvm_unreachable("None multiversion type isn't valid here");
984 }
985 }
986
987 return Out.str();
988 }
989
UpdateMultiVersionNames(GlobalDecl GD,const FunctionDecl * FD)990 void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
991 const FunctionDecl *FD) {
992 if (!FD->isMultiVersion())
993 return;
994
995 // Get the name of what this would be without the 'target' attribute. This
996 // allows us to lookup the version that was emitted when this wasn't a
997 // multiversion function.
998 std::string NonTargetName =
999 getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
1000 GlobalDecl OtherGD;
1001 if (lookupRepresentativeDecl(NonTargetName, OtherGD)) {
1002 assert(OtherGD.getCanonicalDecl()
1003 .getDecl()
1004 ->getAsFunction()
1005 ->isMultiVersion() &&
1006 "Other GD should now be a multiversioned function");
1007 // OtherFD is the version of this function that was mangled BEFORE
1008 // becoming a MultiVersion function. It potentially needs to be updated.
1009 const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
1010 .getDecl()
1011 ->getAsFunction()
1012 ->getMostRecentDecl();
1013 std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
1014 // This is so that if the initial version was already the 'default'
1015 // version, we don't try to update it.
1016 if (OtherName != NonTargetName) {
1017 // Remove instead of erase, since others may have stored the StringRef
1018 // to this.
1019 const auto ExistingRecord = Manglings.find(NonTargetName);
1020 if (ExistingRecord != std::end(Manglings))
1021 Manglings.remove(&(*ExistingRecord));
1022 auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD));
1023 MangledDeclNames[OtherGD.getCanonicalDecl()] = Result.first->first();
1024 if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName))
1025 Entry->setName(OtherName);
1026 }
1027 }
1028 }
1029
getMangledName(GlobalDecl GD)1030 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
1031 GlobalDecl CanonicalGD = GD.getCanonicalDecl();
1032
1033 // Some ABIs don't have constructor variants. Make sure that base and
1034 // complete constructors get mangled the same.
1035 if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) {
1036 if (!getTarget().getCXXABI().hasConstructorVariants()) {
1037 CXXCtorType OrigCtorType = GD.getCtorType();
1038 assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete);
1039 if (OrigCtorType == Ctor_Base)
1040 CanonicalGD = GlobalDecl(CD, Ctor_Complete);
1041 }
1042 }
1043
1044 auto FoundName = MangledDeclNames.find(CanonicalGD);
1045 if (FoundName != MangledDeclNames.end())
1046 return FoundName->second;
1047
1048 // Keep the first result in the case of a mangling collision.
1049 const auto *ND = cast<NamedDecl>(GD.getDecl());
1050 auto Result =
1051 Manglings.insert(std::make_pair(getMangledNameImpl(*this, GD, ND), GD));
1052 return MangledDeclNames[CanonicalGD] = Result.first->first();
1053 }
1054
getBlockMangledName(GlobalDecl GD,const BlockDecl * BD)1055 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD,
1056 const BlockDecl *BD) {
1057 MangleContext &MangleCtx = getCXXABI().getMangleContext();
1058 const Decl *D = GD.getDecl();
1059
1060 SmallString<256> Buffer;
1061 llvm::raw_svector_ostream Out(Buffer);
1062 if (!D)
1063 MangleCtx.mangleGlobalBlock(BD,
1064 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out);
1065 else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D))
1066 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
1067 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D))
1068 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
1069 else
1070 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
1071
1072 auto Result = Manglings.insert(std::make_pair(Out.str(), BD));
1073 return Result.first->first();
1074 }
1075
GetGlobalValue(StringRef Name)1076 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
1077 return getModule().getNamedValue(Name);
1078 }
1079
1080 /// AddGlobalCtor - Add a function to the list that will be called before
1081 /// main() runs.
AddGlobalCtor(llvm::Function * Ctor,int Priority,llvm::Constant * AssociatedData)1082 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority,
1083 llvm::Constant *AssociatedData) {
1084 // FIXME: Type coercion of void()* types.
1085 GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData));
1086 }
1087
1088 /// AddGlobalDtor - Add a function to the list that will be called
1089 /// when the module is unloaded.
AddGlobalDtor(llvm::Function * Dtor,int Priority)1090 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority) {
1091 if (CodeGenOpts.RegisterGlobalDtorsWithAtExit) {
1092 DtorsUsingAtExit[Priority].push_back(Dtor);
1093 return;
1094 }
1095
1096 // FIXME: Type coercion of void()* types.
1097 GlobalDtors.push_back(Structor(Priority, Dtor, nullptr));
1098 }
1099
EmitCtorList(CtorList & Fns,const char * GlobalName)1100 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
1101 if (Fns.empty()) return;
1102
1103 // Ctor function type is void()*.
1104 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
1105 llvm::Type *CtorPFTy = llvm::PointerType::get(CtorFTy,
1106 TheModule.getDataLayout().getProgramAddressSpace());
1107
1108 // Get the type of a ctor entry, { i32, void ()*, i8* }.
1109 llvm::StructType *CtorStructTy = llvm::StructType::get(
1110 Int32Ty, CtorPFTy, VoidPtrTy);
1111
1112 // Construct the constructor and destructor arrays.
1113 ConstantInitBuilder builder(*this);
1114 auto ctors = builder.beginArray(CtorStructTy);
1115 for (const auto &I : Fns) {
1116 auto ctor = ctors.beginStruct(CtorStructTy);
1117 ctor.addInt(Int32Ty, I.Priority);
1118 ctor.add(llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy));
1119 if (I.AssociatedData)
1120 ctor.add(llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy));
1121 else
1122 ctor.addNullPointer(VoidPtrTy);
1123 ctor.finishAndAddTo(ctors);
1124 }
1125
1126 auto list =
1127 ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(),
1128 /*constant*/ false,
1129 llvm::GlobalValue::AppendingLinkage);
1130
1131 // The LTO linker doesn't seem to like it when we set an alignment
1132 // on appending variables. Take it off as a workaround.
1133 list->setAlignment(0);
1134
1135 Fns.clear();
1136 }
1137
1138 llvm::GlobalValue::LinkageTypes
getFunctionLinkage(GlobalDecl GD)1139 CodeGenModule::getFunctionLinkage(GlobalDecl GD) {
1140 const auto *D = cast<FunctionDecl>(GD.getDecl());
1141
1142 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
1143
1144 if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D))
1145 return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType());
1146
1147 if (isa<CXXConstructorDecl>(D) &&
1148 cast<CXXConstructorDecl>(D)->isInheritingConstructor() &&
1149 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
1150 // Our approach to inheriting constructors is fundamentally different from
1151 // that used by the MS ABI, so keep our inheriting constructor thunks
1152 // internal rather than trying to pick an unambiguous mangling for them.
1153 return llvm::GlobalValue::InternalLinkage;
1154 }
1155
1156 return getLLVMLinkageForDeclarator(D, Linkage, /*isConstantVariable=*/false);
1157 }
1158
CreateCrossDsoCfiTypeId(llvm::Metadata * MD)1159 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
1160 llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD);
1161 if (!MDS) return nullptr;
1162
1163 return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
1164 }
1165
SetLLVMFunctionAttributes(GlobalDecl GD,const CGFunctionInfo & Info,llvm::Function * F)1166 void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
1167 const CGFunctionInfo &Info,
1168 llvm::Function *F) {
1169 unsigned CallingConv;
1170 llvm::AttributeList PAL;
1171 ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv, false);
1172 F->setAttributes(PAL);
1173 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
1174 }
1175
1176 /// Determines whether the language options require us to model
1177 /// unwind exceptions. We treat -fexceptions as mandating this
1178 /// except under the fragile ObjC ABI with only ObjC exceptions
1179 /// enabled. This means, for example, that C with -fexceptions
1180 /// enables this.
hasUnwindExceptions(const LangOptions & LangOpts)1181 static bool hasUnwindExceptions(const LangOptions &LangOpts) {
1182 // If exceptions are completely disabled, obviously this is false.
1183 if (!LangOpts.Exceptions) return false;
1184
1185 // If C++ exceptions are enabled, this is true.
1186 if (LangOpts.CXXExceptions) return true;
1187
1188 // If ObjC exceptions are enabled, this depends on the ABI.
1189 if (LangOpts.ObjCExceptions) {
1190 return LangOpts.ObjCRuntime.hasUnwindExceptions();
1191 }
1192
1193 return true;
1194 }
1195
requiresMemberFunctionPointerTypeMetadata(CodeGenModule & CGM,const CXXMethodDecl * MD)1196 static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM,
1197 const CXXMethodDecl *MD) {
1198 // Check that the type metadata can ever actually be used by a call.
1199 if (!CGM.getCodeGenOpts().LTOUnit ||
1200 !CGM.HasHiddenLTOVisibility(MD->getParent()))
1201 return false;
1202
1203 // Only functions whose address can be taken with a member function pointer
1204 // need this sort of type metadata.
1205 return !MD->isStatic() && !MD->isVirtual() && !isa<CXXConstructorDecl>(MD) &&
1206 !isa<CXXDestructorDecl>(MD);
1207 }
1208
1209 std::vector<const CXXRecordDecl *>
getMostBaseClasses(const CXXRecordDecl * RD)1210 CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) {
1211 llvm::SetVector<const CXXRecordDecl *> MostBases;
1212
1213 std::function<void (const CXXRecordDecl *)> CollectMostBases;
1214 CollectMostBases = [&](const CXXRecordDecl *RD) {
1215 if (RD->getNumBases() == 0)
1216 MostBases.insert(RD);
1217 for (const CXXBaseSpecifier &B : RD->bases())
1218 CollectMostBases(B.getType()->getAsCXXRecordDecl());
1219 };
1220 CollectMostBases(RD);
1221 return MostBases.takeVector();
1222 }
1223
SetLLVMFunctionAttributesForDefinition(const Decl * D,llvm::Function * F)1224 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
1225 llvm::Function *F) {
1226 llvm::AttrBuilder B;
1227
1228 if (CodeGenOpts.UnwindTables)
1229 B.addAttribute(llvm::Attribute::UWTable);
1230
1231 if (!hasUnwindExceptions(LangOpts))
1232 B.addAttribute(llvm::Attribute::NoUnwind);
1233
1234 if (!D || !D->hasAttr<NoStackProtectorAttr>()) {
1235 if (LangOpts.getStackProtector() == LangOptions::SSPOn)
1236 B.addAttribute(llvm::Attribute::StackProtect);
1237 else if (LangOpts.getStackProtector() == LangOptions::SSPStrong)
1238 B.addAttribute(llvm::Attribute::StackProtectStrong);
1239 else if (LangOpts.getStackProtector() == LangOptions::SSPReq)
1240 B.addAttribute(llvm::Attribute::StackProtectReq);
1241 }
1242
1243 if (!D) {
1244 // If we don't have a declaration to control inlining, the function isn't
1245 // explicitly marked as alwaysinline for semantic reasons, and inlining is
1246 // disabled, mark the function as noinline.
1247 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
1248 CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining)
1249 B.addAttribute(llvm::Attribute::NoInline);
1250
1251 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1252 return;
1253 }
1254
1255 // Track whether we need to add the optnone LLVM attribute,
1256 // starting with the default for this optimization level.
1257 bool ShouldAddOptNone =
1258 !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0;
1259 // We can't add optnone in the following cases, it won't pass the verifier.
1260 ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>();
1261 ShouldAddOptNone &= !F->hasFnAttribute(llvm::Attribute::AlwaysInline);
1262 ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>();
1263
1264 if (ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) {
1265 B.addAttribute(llvm::Attribute::OptimizeNone);
1266
1267 // OptimizeNone implies noinline; we should not be inlining such functions.
1268 B.addAttribute(llvm::Attribute::NoInline);
1269 assert(!F->hasFnAttribute(llvm::Attribute::AlwaysInline) &&
1270 "OptimizeNone and AlwaysInline on same function!");
1271
1272 // We still need to handle naked functions even though optnone subsumes
1273 // much of their semantics.
1274 if (D->hasAttr<NakedAttr>())
1275 B.addAttribute(llvm::Attribute::Naked);
1276
1277 // OptimizeNone wins over OptimizeForSize and MinSize.
1278 F->removeFnAttr(llvm::Attribute::OptimizeForSize);
1279 F->removeFnAttr(llvm::Attribute::MinSize);
1280 } else if (D->hasAttr<NakedAttr>()) {
1281 // Naked implies noinline: we should not be inlining such functions.
1282 B.addAttribute(llvm::Attribute::Naked);
1283 B.addAttribute(llvm::Attribute::NoInline);
1284 } else if (D->hasAttr<NoDuplicateAttr>()) {
1285 B.addAttribute(llvm::Attribute::NoDuplicate);
1286 } else if (D->hasAttr<NoInlineAttr>()) {
1287 B.addAttribute(llvm::Attribute::NoInline);
1288 } else if (D->hasAttr<AlwaysInlineAttr>() &&
1289 !F->hasFnAttribute(llvm::Attribute::NoInline)) {
1290 // (noinline wins over always_inline, and we can't specify both in IR)
1291 B.addAttribute(llvm::Attribute::AlwaysInline);
1292 } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) {
1293 // If we're not inlining, then force everything that isn't always_inline to
1294 // carry an explicit noinline attribute.
1295 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline))
1296 B.addAttribute(llvm::Attribute::NoInline);
1297 } else {
1298 // Otherwise, propagate the inline hint attribute and potentially use its
1299 // absence to mark things as noinline.
1300 if (auto *FD = dyn_cast<FunctionDecl>(D)) {
1301 // Search function and template pattern redeclarations for inline.
1302 auto CheckForInline = [](const FunctionDecl *FD) {
1303 auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
1304 return Redecl->isInlineSpecified();
1305 };
1306 if (any_of(FD->redecls(), CheckRedeclForInline))
1307 return true;
1308 const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
1309 if (!Pattern)
1310 return false;
1311 return any_of(Pattern->redecls(), CheckRedeclForInline);
1312 };
1313 if (CheckForInline(FD)) {
1314 B.addAttribute(llvm::Attribute::InlineHint);
1315 } else if (CodeGenOpts.getInlining() ==
1316 CodeGenOptions::OnlyHintInlining &&
1317 !FD->isInlined() &&
1318 !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) {
1319 B.addAttribute(llvm::Attribute::NoInline);
1320 }
1321 }
1322 }
1323
1324 // Add other optimization related attributes if we are optimizing this
1325 // function.
1326 if (!D->hasAttr<OptimizeNoneAttr>()) {
1327 if (D->hasAttr<ColdAttr>()) {
1328 if (!ShouldAddOptNone)
1329 B.addAttribute(llvm::Attribute::OptimizeForSize);
1330 B.addAttribute(llvm::Attribute::Cold);
1331 }
1332
1333 if (D->hasAttr<MinSizeAttr>())
1334 B.addAttribute(llvm::Attribute::MinSize);
1335 }
1336
1337 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
1338
1339 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
1340 if (alignment)
1341 F->setAlignment(alignment);
1342
1343 if (!D->hasAttr<AlignedAttr>())
1344 if (LangOpts.FunctionAlignment)
1345 F->setAlignment(1 << LangOpts.FunctionAlignment);
1346
1347 // Some C++ ABIs require 2-byte alignment for member functions, in order to
1348 // reserve a bit for differentiating between virtual and non-virtual member
1349 // functions. If the current target's C++ ABI requires this and this is a
1350 // member function, set its alignment accordingly.
1351 if (getTarget().getCXXABI().areMemberFunctionsAligned()) {
1352 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
1353 F->setAlignment(2);
1354 }
1355
1356 // In the cross-dso CFI mode, we want !type attributes on definitions only.
1357 if (CodeGenOpts.SanitizeCfiCrossDso)
1358 if (auto *FD = dyn_cast<FunctionDecl>(D))
1359 CreateFunctionTypeMetadataForIcall(FD, F);
1360
1361 // Emit type metadata on member functions for member function pointer checks.
1362 // These are only ever necessary on definitions; we're guaranteed that the
1363 // definition will be present in the LTO unit as a result of LTO visibility.
1364 auto *MD = dyn_cast<CXXMethodDecl>(D);
1365 if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) {
1366 for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) {
1367 llvm::Metadata *Id =
1368 CreateMetadataIdentifierForType(Context.getMemberPointerType(
1369 MD->getType(), Context.getRecordType(Base).getTypePtr()));
1370 F->addTypeMetadata(0, Id);
1371 }
1372 }
1373 }
1374
SetCommonAttributes(GlobalDecl GD,llvm::GlobalValue * GV)1375 void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
1376 const Decl *D = GD.getDecl();
1377 if (dyn_cast_or_null<NamedDecl>(D))
1378 setGVProperties(GV, GD);
1379 else
1380 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
1381
1382 if (D && D->hasAttr<UsedAttr>())
1383 addUsedGlobal(GV);
1384
1385 if (CodeGenOpts.KeepStaticConsts && D && isa<VarDecl>(D)) {
1386 const auto *VD = cast<VarDecl>(D);
1387 if (VD->getType().isConstQualified() &&
1388 VD->getStorageDuration() == SD_Static)
1389 addUsedGlobal(GV);
1390 }
1391 }
1392
GetCPUAndFeaturesAttributes(GlobalDecl GD,llvm::AttrBuilder & Attrs)1393 bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
1394 llvm::AttrBuilder &Attrs) {
1395 // Add target-cpu and target-features attributes to functions. If
1396 // we have a decl for the function and it has a target attribute then
1397 // parse that and add it to the feature set.
1398 StringRef TargetCPU = getTarget().getTargetOpts().CPU;
1399 std::vector<std::string> Features;
1400 const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
1401 FD = FD ? FD->getMostRecentDecl() : FD;
1402 const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
1403 const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
1404 bool AddedAttr = false;
1405 if (TD || SD) {
1406 llvm::StringMap<bool> FeatureMap;
1407 getFunctionFeatureMap(FeatureMap, GD);
1408
1409 // Produce the canonical string for this set of features.
1410 for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
1411 Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str());
1412
1413 // Now add the target-cpu and target-features to the function.
1414 // While we populated the feature map above, we still need to
1415 // get and parse the target attribute so we can get the cpu for
1416 // the function.
1417 if (TD) {
1418 TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
1419 if (ParsedAttr.Architecture != "" &&
1420 getTarget().isValidCPUName(ParsedAttr.Architecture))
1421 TargetCPU = ParsedAttr.Architecture;
1422 }
1423 } else {
1424 // Otherwise just add the existing target cpu and target features to the
1425 // function.
1426 Features = getTarget().getTargetOpts().Features;
1427 }
1428
1429 if (TargetCPU != "") {
1430 Attrs.addAttribute("target-cpu", TargetCPU);
1431 AddedAttr = true;
1432 }
1433 if (!Features.empty()) {
1434 llvm::sort(Features);
1435 Attrs.addAttribute("target-features", llvm::join(Features, ","));
1436 AddedAttr = true;
1437 }
1438
1439 return AddedAttr;
1440 }
1441
setNonAliasAttributes(GlobalDecl GD,llvm::GlobalObject * GO)1442 void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
1443 llvm::GlobalObject *GO) {
1444 const Decl *D = GD.getDecl();
1445 SetCommonAttributes(GD, GO);
1446
1447 if (D) {
1448 if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) {
1449 if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>())
1450 GV->addAttribute("bss-section", SA->getName());
1451 if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>())
1452 GV->addAttribute("data-section", SA->getName());
1453 if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>())
1454 GV->addAttribute("rodata-section", SA->getName());
1455 }
1456
1457 if (auto *F = dyn_cast<llvm::Function>(GO)) {
1458 if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>())
1459 if (!D->getAttr<SectionAttr>())
1460 F->addFnAttr("implicit-section-name", SA->getName());
1461
1462 llvm::AttrBuilder Attrs;
1463 if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
1464 // We know that GetCPUAndFeaturesAttributes will always have the
1465 // newest set, since it has the newest possible FunctionDecl, so the
1466 // new ones should replace the old.
1467 F->removeFnAttr("target-cpu");
1468 F->removeFnAttr("target-features");
1469 F->addAttributes(llvm::AttributeList::FunctionIndex, Attrs);
1470 }
1471 }
1472
1473 if (const auto *CSA = D->getAttr<CodeSegAttr>())
1474 GO->setSection(CSA->getName());
1475 else if (const auto *SA = D->getAttr<SectionAttr>())
1476 GO->setSection(SA->getName());
1477 }
1478
1479 getTargetCodeGenInfo().setTargetAttributes(D, GO, *this);
1480 }
1481
SetInternalFunctionAttributes(GlobalDecl GD,llvm::Function * F,const CGFunctionInfo & FI)1482 void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
1483 llvm::Function *F,
1484 const CGFunctionInfo &FI) {
1485 const Decl *D = GD.getDecl();
1486 SetLLVMFunctionAttributes(GD, FI, F);
1487 SetLLVMFunctionAttributesForDefinition(D, F);
1488
1489 F->setLinkage(llvm::Function::InternalLinkage);
1490
1491 setNonAliasAttributes(GD, F);
1492 }
1493
setLinkageForGV(llvm::GlobalValue * GV,const NamedDecl * ND)1494 static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) {
1495 // Set linkage and visibility in case we never see a definition.
1496 LinkageInfo LV = ND->getLinkageAndVisibility();
1497 // Don't set internal linkage on declarations.
1498 // "extern_weak" is overloaded in LLVM; we probably should have
1499 // separate linkage types for this.
1500 if (isExternallyVisible(LV.getLinkage()) &&
1501 (ND->hasAttr<WeakAttr>() || ND->isWeakImported()))
1502 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
1503 }
1504
CreateFunctionTypeMetadataForIcall(const FunctionDecl * FD,llvm::Function * F)1505 void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD,
1506 llvm::Function *F) {
1507 // Only if we are checking indirect calls.
1508 if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall))
1509 return;
1510
1511 // Non-static class methods are handled via vtable or member function pointer
1512 // checks elsewhere.
1513 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic())
1514 return;
1515
1516 // Additionally, if building with cross-DSO support...
1517 if (CodeGenOpts.SanitizeCfiCrossDso) {
1518 // Skip available_externally functions. They won't be codegen'ed in the
1519 // current module anyway.
1520 if (getContext().GetGVALinkageForFunction(FD) == GVA_AvailableExternally)
1521 return;
1522 }
1523
1524 llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType());
1525 F->addTypeMetadata(0, MD);
1526 F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType()));
1527
1528 // Emit a hash-based bit set entry for cross-DSO calls.
1529 if (CodeGenOpts.SanitizeCfiCrossDso)
1530 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
1531 F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId));
1532 }
1533
SetFunctionAttributes(GlobalDecl GD,llvm::Function * F,bool IsIncompleteFunction,bool IsThunk)1534 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
1535 bool IsIncompleteFunction,
1536 bool IsThunk) {
1537
1538 if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) {
1539 // If this is an intrinsic function, set the function's attributes
1540 // to the intrinsic's attributes.
1541 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID));
1542 return;
1543 }
1544
1545 const auto *FD = cast<FunctionDecl>(GD.getDecl());
1546
1547 if (!IsIncompleteFunction) {
1548 SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F);
1549 // Setup target-specific attributes.
1550 if (F->isDeclaration())
1551 getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
1552 }
1553
1554 // Add the Returned attribute for "this", except for iOS 5 and earlier
1555 // where substantial code, including the libstdc++ dylib, was compiled with
1556 // GCC and does not actually return "this".
1557 if (!IsThunk && getCXXABI().HasThisReturn(GD) &&
1558 !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) {
1559 assert(!F->arg_empty() &&
1560 F->arg_begin()->getType()
1561 ->canLosslesslyBitCastTo(F->getReturnType()) &&
1562 "unexpected this return");
1563 F->addAttribute(1, llvm::Attribute::Returned);
1564 }
1565
1566 // Only a few attributes are set on declarations; these may later be
1567 // overridden by a definition.
1568
1569 setLinkageForGV(F, FD);
1570 setGVProperties(F, FD);
1571
1572 if (const auto *CSA = FD->getAttr<CodeSegAttr>())
1573 F->setSection(CSA->getName());
1574 else if (const auto *SA = FD->getAttr<SectionAttr>())
1575 F->setSection(SA->getName());
1576
1577 if (FD->isReplaceableGlobalAllocationFunction()) {
1578 // A replaceable global allocation function does not act like a builtin by
1579 // default, only if it is invoked by a new-expression or delete-expression.
1580 F->addAttribute(llvm::AttributeList::FunctionIndex,
1581 llvm::Attribute::NoBuiltin);
1582
1583 // A sane operator new returns a non-aliasing pointer.
1584 // FIXME: Also add NonNull attribute to the return value
1585 // for the non-nothrow forms?
1586 auto Kind = FD->getDeclName().getCXXOverloadedOperator();
1587 if (getCodeGenOpts().AssumeSaneOperatorNew &&
1588 (Kind == OO_New || Kind == OO_Array_New))
1589 F->addAttribute(llvm::AttributeList::ReturnIndex,
1590 llvm::Attribute::NoAlias);
1591 }
1592
1593 if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD))
1594 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1595 else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD))
1596 if (MD->isVirtual())
1597 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1598
1599 // Don't emit entries for function declarations in the cross-DSO mode. This
1600 // is handled with better precision by the receiving DSO.
1601 if (!CodeGenOpts.SanitizeCfiCrossDso)
1602 CreateFunctionTypeMetadataForIcall(FD, F);
1603
1604 if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>())
1605 getOpenMPRuntime().emitDeclareSimdFunction(FD, F);
1606 }
1607
addUsedGlobal(llvm::GlobalValue * GV)1608 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) {
1609 assert(!GV->isDeclaration() &&
1610 "Only globals with definition can force usage.");
1611 LLVMUsed.emplace_back(GV);
1612 }
1613
addCompilerUsedGlobal(llvm::GlobalValue * GV)1614 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) {
1615 assert(!GV->isDeclaration() &&
1616 "Only globals with definition can force usage.");
1617 LLVMCompilerUsed.emplace_back(GV);
1618 }
1619
emitUsed(CodeGenModule & CGM,StringRef Name,std::vector<llvm::WeakTrackingVH> & List)1620 static void emitUsed(CodeGenModule &CGM, StringRef Name,
1621 std::vector<llvm::WeakTrackingVH> &List) {
1622 // Don't create llvm.used if there is no need.
1623 if (List.empty())
1624 return;
1625
1626 // Convert List to what ConstantArray needs.
1627 SmallVector<llvm::Constant*, 8> UsedArray;
1628 UsedArray.resize(List.size());
1629 for (unsigned i = 0, e = List.size(); i != e; ++i) {
1630 UsedArray[i] =
1631 llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
1632 cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy);
1633 }
1634
1635 if (UsedArray.empty())
1636 return;
1637 llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size());
1638
1639 auto *GV = new llvm::GlobalVariable(
1640 CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage,
1641 llvm::ConstantArray::get(ATy, UsedArray), Name);
1642
1643 GV->setSection("llvm.metadata");
1644 }
1645
emitLLVMUsed()1646 void CodeGenModule::emitLLVMUsed() {
1647 emitUsed(*this, "llvm.used", LLVMUsed);
1648 emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed);
1649 }
1650
AppendLinkerOptions(StringRef Opts)1651 void CodeGenModule::AppendLinkerOptions(StringRef Opts) {
1652 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts);
1653 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1654 }
1655
AddDetectMismatch(StringRef Name,StringRef Value)1656 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) {
1657 llvm::SmallString<32> Opt;
1658 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt);
1659 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
1660 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1661 }
1662
AddELFLibDirective(StringRef Lib)1663 void CodeGenModule::AddELFLibDirective(StringRef Lib) {
1664 auto &C = getLLVMContext();
1665 LinkerOptionsMetadata.push_back(llvm::MDNode::get(
1666 C, {llvm::MDString::get(C, "lib"), llvm::MDString::get(C, Lib)}));
1667 }
1668
AddDependentLib(StringRef Lib)1669 void CodeGenModule::AddDependentLib(StringRef Lib) {
1670 llvm::SmallString<24> Opt;
1671 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt);
1672 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt);
1673 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts));
1674 }
1675
1676 /// Add link options implied by the given module, including modules
1677 /// it depends on, using a postorder walk.
addLinkOptionsPostorder(CodeGenModule & CGM,Module * Mod,SmallVectorImpl<llvm::MDNode * > & Metadata,llvm::SmallPtrSet<Module *,16> & Visited)1678 static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
1679 SmallVectorImpl<llvm::MDNode *> &Metadata,
1680 llvm::SmallPtrSet<Module *, 16> &Visited) {
1681 // Import this module's parent.
1682 if (Mod->Parent && Visited.insert(Mod->Parent).second) {
1683 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited);
1684 }
1685
1686 // Import this module's dependencies.
1687 for (unsigned I = Mod->Imports.size(); I > 0; --I) {
1688 if (Visited.insert(Mod->Imports[I - 1]).second)
1689 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited);
1690 }
1691
1692 // Add linker options to link against the libraries/frameworks
1693 // described by this module.
1694 llvm::LLVMContext &Context = CGM.getLLVMContext();
1695 bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
1696 bool IsPS4 = CGM.getTarget().getTriple().isPS4();
1697
1698 // For modules that use export_as for linking, use that module
1699 // name instead.
1700 if (Mod->UseExportAsModuleLinkName)
1701 return;
1702
1703 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) {
1704 // Link against a framework. Frameworks are currently Darwin only, so we
1705 // don't to ask TargetCodeGenInfo for the spelling of the linker option.
1706 if (Mod->LinkLibraries[I-1].IsFramework) {
1707 llvm::Metadata *Args[2] = {
1708 llvm::MDString::get(Context, "-framework"),
1709 llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library)};
1710
1711 Metadata.push_back(llvm::MDNode::get(Context, Args));
1712 continue;
1713 }
1714
1715 // Link against a library.
1716 if (IsELF && !IsPS4) {
1717 llvm::Metadata *Args[2] = {
1718 llvm::MDString::get(Context, "lib"),
1719 llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library),
1720 };
1721 Metadata.push_back(llvm::MDNode::get(Context, Args));
1722 } else {
1723 llvm::SmallString<24> Opt;
1724 CGM.getTargetCodeGenInfo().getDependentLibraryOption(
1725 Mod->LinkLibraries[I - 1].Library, Opt);
1726 auto *OptString = llvm::MDString::get(Context, Opt);
1727 Metadata.push_back(llvm::MDNode::get(Context, OptString));
1728 }
1729 }
1730 }
1731
EmitModuleLinkOptions()1732 void CodeGenModule::EmitModuleLinkOptions() {
1733 // Collect the set of all of the modules we want to visit to emit link
1734 // options, which is essentially the imported modules and all of their
1735 // non-explicit child modules.
1736 llvm::SetVector<clang::Module *> LinkModules;
1737 llvm::SmallPtrSet<clang::Module *, 16> Visited;
1738 SmallVector<clang::Module *, 16> Stack;
1739
1740 // Seed the stack with imported modules.
1741 for (Module *M : ImportedModules) {
1742 // Do not add any link flags when an implementation TU of a module imports
1743 // a header of that same module.
1744 if (M->getTopLevelModuleName() == getLangOpts().CurrentModule &&
1745 !getLangOpts().isCompilingModule())
1746 continue;
1747 if (Visited.insert(M).second)
1748 Stack.push_back(M);
1749 }
1750
1751 // Find all of the modules to import, making a little effort to prune
1752 // non-leaf modules.
1753 while (!Stack.empty()) {
1754 clang::Module *Mod = Stack.pop_back_val();
1755
1756 bool AnyChildren = false;
1757
1758 // Visit the submodules of this module.
1759 for (const auto &SM : Mod->submodules()) {
1760 // Skip explicit children; they need to be explicitly imported to be
1761 // linked against.
1762 if (SM->IsExplicit)
1763 continue;
1764
1765 if (Visited.insert(SM).second) {
1766 Stack.push_back(SM);
1767 AnyChildren = true;
1768 }
1769 }
1770
1771 // We didn't find any children, so add this module to the list of
1772 // modules to link against.
1773 if (!AnyChildren) {
1774 LinkModules.insert(Mod);
1775 }
1776 }
1777
1778 // Add link options for all of the imported modules in reverse topological
1779 // order. We don't do anything to try to order import link flags with respect
1780 // to linker options inserted by things like #pragma comment().
1781 SmallVector<llvm::MDNode *, 16> MetadataArgs;
1782 Visited.clear();
1783 for (Module *M : LinkModules)
1784 if (Visited.insert(M).second)
1785 addLinkOptionsPostorder(*this, M, MetadataArgs, Visited);
1786 std::reverse(MetadataArgs.begin(), MetadataArgs.end());
1787 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end());
1788
1789 // Add the linker options metadata flag.
1790 auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options");
1791 for (auto *MD : LinkerOptionsMetadata)
1792 NMD->addOperand(MD);
1793 }
1794
EmitDeferred()1795 void CodeGenModule::EmitDeferred() {
1796 // Emit deferred declare target declarations.
1797 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
1798 getOpenMPRuntime().emitDeferredTargetDecls();
1799
1800 // Emit code for any potentially referenced deferred decls. Since a
1801 // previously unused static decl may become used during the generation of code
1802 // for a static function, iterate until no changes are made.
1803
1804 if (!DeferredVTables.empty()) {
1805 EmitDeferredVTables();
1806
1807 // Emitting a vtable doesn't directly cause more vtables to
1808 // become deferred, although it can cause functions to be
1809 // emitted that then need those vtables.
1810 assert(DeferredVTables.empty());
1811 }
1812
1813 // Stop if we're out of both deferred vtables and deferred declarations.
1814 if (DeferredDeclsToEmit.empty())
1815 return;
1816
1817 // Grab the list of decls to emit. If EmitGlobalDefinition schedules more
1818 // work, it will not interfere with this.
1819 std::vector<GlobalDecl> CurDeclsToEmit;
1820 CurDeclsToEmit.swap(DeferredDeclsToEmit);
1821
1822 for (GlobalDecl &D : CurDeclsToEmit) {
1823 // We should call GetAddrOfGlobal with IsForDefinition set to true in order
1824 // to get GlobalValue with exactly the type we need, not something that
1825 // might had been created for another decl with the same mangled name but
1826 // different type.
1827 llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(
1828 GetAddrOfGlobal(D, ForDefinition));
1829
1830 // In case of different address spaces, we may still get a cast, even with
1831 // IsForDefinition equal to true. Query mangled names table to get
1832 // GlobalValue.
1833 if (!GV)
1834 GV = GetGlobalValue(getMangledName(D));
1835
1836 // Make sure GetGlobalValue returned non-null.
1837 assert(GV);
1838
1839 // Check to see if we've already emitted this. This is necessary
1840 // for a couple of reasons: first, decls can end up in the
1841 // deferred-decls queue multiple times, and second, decls can end
1842 // up with definitions in unusual ways (e.g. by an extern inline
1843 // function acquiring a strong function redefinition). Just
1844 // ignore these cases.
1845 if (!GV->isDeclaration())
1846 continue;
1847
1848 // Otherwise, emit the definition and move on to the next one.
1849 EmitGlobalDefinition(D, GV);
1850
1851 // If we found out that we need to emit more decls, do that recursively.
1852 // This has the advantage that the decls are emitted in a DFS and related
1853 // ones are close together, which is convenient for testing.
1854 if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) {
1855 EmitDeferred();
1856 assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty());
1857 }
1858 }
1859 }
1860
EmitVTablesOpportunistically()1861 void CodeGenModule::EmitVTablesOpportunistically() {
1862 // Try to emit external vtables as available_externally if they have emitted
1863 // all inlined virtual functions. It runs after EmitDeferred() and therefore
1864 // is not allowed to create new references to things that need to be emitted
1865 // lazily. Note that it also uses fact that we eagerly emitting RTTI.
1866
1867 assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables())
1868 && "Only emit opportunistic vtables with optimizations");
1869
1870 for (const CXXRecordDecl *RD : OpportunisticVTables) {
1871 assert(getVTables().isVTableExternal(RD) &&
1872 "This queue should only contain external vtables");
1873 if (getCXXABI().canSpeculativelyEmitVTable(RD))
1874 VTables.GenerateClassData(RD);
1875 }
1876 OpportunisticVTables.clear();
1877 }
1878
EmitGlobalAnnotations()1879 void CodeGenModule::EmitGlobalAnnotations() {
1880 if (Annotations.empty())
1881 return;
1882
1883 // Create a new global variable for the ConstantStruct in the Module.
1884 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
1885 Annotations[0]->getType(), Annotations.size()), Annotations);
1886 auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false,
1887 llvm::GlobalValue::AppendingLinkage,
1888 Array, "llvm.global.annotations");
1889 gv->setSection(AnnotationSection);
1890 }
1891
EmitAnnotationString(StringRef Str)1892 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) {
1893 llvm::Constant *&AStr = AnnotationStrings[Str];
1894 if (AStr)
1895 return AStr;
1896
1897 // Not found yet, create a new global.
1898 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str);
1899 auto *gv =
1900 new llvm::GlobalVariable(getModule(), s->getType(), true,
1901 llvm::GlobalValue::PrivateLinkage, s, ".str");
1902 gv->setSection(AnnotationSection);
1903 gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1904 AStr = gv;
1905 return gv;
1906 }
1907
EmitAnnotationUnit(SourceLocation Loc)1908 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
1909 SourceManager &SM = getContext().getSourceManager();
1910 PresumedLoc PLoc = SM.getPresumedLoc(Loc);
1911 if (PLoc.isValid())
1912 return EmitAnnotationString(PLoc.getFilename());
1913 return EmitAnnotationString(SM.getBufferName(Loc));
1914 }
1915
EmitAnnotationLineNo(SourceLocation L)1916 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
1917 SourceManager &SM = getContext().getSourceManager();
1918 PresumedLoc PLoc = SM.getPresumedLoc(L);
1919 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
1920 SM.getExpansionLineNumber(L);
1921 return llvm::ConstantInt::get(Int32Ty, LineNo);
1922 }
1923
EmitAnnotateAttr(llvm::GlobalValue * GV,const AnnotateAttr * AA,SourceLocation L)1924 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
1925 const AnnotateAttr *AA,
1926 SourceLocation L) {
1927 // Get the globals for file name, annotation, and the line number.
1928 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
1929 *UnitGV = EmitAnnotationUnit(L),
1930 *LineNoCst = EmitAnnotationLineNo(L);
1931
1932 // Create the ConstantStruct for the global annotation.
1933 llvm::Constant *Fields[4] = {
1934 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy),
1935 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
1936 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
1937 LineNoCst
1938 };
1939 return llvm::ConstantStruct::getAnon(Fields);
1940 }
1941
AddGlobalAnnotations(const ValueDecl * D,llvm::GlobalValue * GV)1942 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
1943 llvm::GlobalValue *GV) {
1944 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
1945 // Get the struct elements for these annotations.
1946 for (const auto *I : D->specific_attrs<AnnotateAttr>())
1947 Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation()));
1948 }
1949
isInSanitizerBlacklist(SanitizerMask Kind,llvm::Function * Fn,SourceLocation Loc) const1950 bool CodeGenModule::isInSanitizerBlacklist(SanitizerMask Kind,
1951 llvm::Function *Fn,
1952 SourceLocation Loc) const {
1953 const auto &SanitizerBL = getContext().getSanitizerBlacklist();
1954 // Blacklist by function name.
1955 if (SanitizerBL.isBlacklistedFunction(Kind, Fn->getName()))
1956 return true;
1957 // Blacklist by location.
1958 if (Loc.isValid())
1959 return SanitizerBL.isBlacklistedLocation(Kind, Loc);
1960 // If location is unknown, this may be a compiler-generated function. Assume
1961 // it's located in the main file.
1962 auto &SM = Context.getSourceManager();
1963 if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1964 return SanitizerBL.isBlacklistedFile(Kind, MainFile->getName());
1965 }
1966 return false;
1967 }
1968
isInSanitizerBlacklist(llvm::GlobalVariable * GV,SourceLocation Loc,QualType Ty,StringRef Category) const1969 bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
1970 SourceLocation Loc, QualType Ty,
1971 StringRef Category) const {
1972 // For now globals can be blacklisted only in ASan and KASan.
1973 const SanitizerMask EnabledAsanMask = LangOpts.Sanitize.Mask &
1974 (SanitizerKind::Address | SanitizerKind::KernelAddress |
1975 SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress);
1976 if (!EnabledAsanMask)
1977 return false;
1978 const auto &SanitizerBL = getContext().getSanitizerBlacklist();
1979 if (SanitizerBL.isBlacklistedGlobal(EnabledAsanMask, GV->getName(), Category))
1980 return true;
1981 if (SanitizerBL.isBlacklistedLocation(EnabledAsanMask, Loc, Category))
1982 return true;
1983 // Check global type.
1984 if (!Ty.isNull()) {
1985 // Drill down the array types: if global variable of a fixed type is
1986 // blacklisted, we also don't instrument arrays of them.
1987 while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr()))
1988 Ty = AT->getElementType();
1989 Ty = Ty.getCanonicalType().getUnqualifiedType();
1990 // We allow to blacklist only record types (classes, structs etc.)
1991 if (Ty->isRecordType()) {
1992 std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy());
1993 if (SanitizerBL.isBlacklistedType(EnabledAsanMask, TypeStr, Category))
1994 return true;
1995 }
1996 }
1997 return false;
1998 }
1999
imbueXRayAttrs(llvm::Function * Fn,SourceLocation Loc,StringRef Category) const2000 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
2001 StringRef Category) const {
2002 const auto &XRayFilter = getContext().getXRayFilter();
2003 using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
2004 auto Attr = ImbueAttr::NONE;
2005 if (Loc.isValid())
2006 Attr = XRayFilter.shouldImbueLocation(Loc, Category);
2007 if (Attr == ImbueAttr::NONE)
2008 Attr = XRayFilter.shouldImbueFunction(Fn->getName());
2009 switch (Attr) {
2010 case ImbueAttr::NONE:
2011 return false;
2012 case ImbueAttr::ALWAYS:
2013 Fn->addFnAttr("function-instrument", "xray-always");
2014 break;
2015 case ImbueAttr::ALWAYS_ARG1:
2016 Fn->addFnAttr("function-instrument", "xray-always");
2017 Fn->addFnAttr("xray-log-args", "1");
2018 break;
2019 case ImbueAttr::NEVER:
2020 Fn->addFnAttr("function-instrument", "xray-never");
2021 break;
2022 }
2023 return true;
2024 }
2025
MustBeEmitted(const ValueDecl * Global)2026 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
2027 // Never defer when EmitAllDecls is specified.
2028 if (LangOpts.EmitAllDecls)
2029 return true;
2030
2031 if (CodeGenOpts.KeepStaticConsts) {
2032 const auto *VD = dyn_cast<VarDecl>(Global);
2033 if (VD && VD->getType().isConstQualified() &&
2034 VD->getStorageDuration() == SD_Static)
2035 return true;
2036 }
2037
2038 return getContext().DeclMustBeEmitted(Global);
2039 }
2040
MayBeEmittedEagerly(const ValueDecl * Global)2041 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
2042 if (const auto *FD = dyn_cast<FunctionDecl>(Global))
2043 if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
2044 // Implicit template instantiations may change linkage if they are later
2045 // explicitly instantiated, so they should not be emitted eagerly.
2046 return false;
2047 if (const auto *VD = dyn_cast<VarDecl>(Global))
2048 if (Context.getInlineVariableDefinitionKind(VD) ==
2049 ASTContext::InlineVariableDefinitionKind::WeakUnknown)
2050 // A definition of an inline constexpr static data member may change
2051 // linkage later if it's redeclared outside the class.
2052 return false;
2053 // If OpenMP is enabled and threadprivates must be generated like TLS, delay
2054 // codegen for global variables, because they may be marked as threadprivate.
2055 if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
2056 getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
2057 !isTypeConstant(Global->getType(), false) &&
2058 !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
2059 return false;
2060
2061 return true;
2062 }
2063
GetAddrOfUuidDescriptor(const CXXUuidofExpr * E)2064 ConstantAddress CodeGenModule::GetAddrOfUuidDescriptor(
2065 const CXXUuidofExpr* E) {
2066 // Sema has verified that IIDSource has a __declspec(uuid()), and that its
2067 // well-formed.
2068 StringRef Uuid = E->getUuidStr();
2069 std::string Name = "_GUID_" + Uuid.lower();
2070 std::replace(Name.begin(), Name.end(), '-', '_');
2071
2072 // The UUID descriptor should be pointer aligned.
2073 CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
2074
2075 // Look for an existing global.
2076 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))
2077 return ConstantAddress(GV, Alignment);
2078
2079 llvm::Constant *Init = EmitUuidofInitializer(Uuid);
2080 assert(Init && "failed to initialize as constant");
2081
2082 auto *GV = new llvm::GlobalVariable(
2083 getModule(), Init->getType(),
2084 /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name);
2085 if (supportsCOMDAT())
2086 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
2087 setDSOLocal(GV);
2088 return ConstantAddress(GV, Alignment);
2089 }
2090
GetWeakRefReference(const ValueDecl * VD)2091 ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
2092 const AliasAttr *AA = VD->getAttr<AliasAttr>();
2093 assert(AA && "No alias?");
2094
2095 CharUnits Alignment = getContext().getDeclAlign(VD);
2096 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
2097
2098 // See if there is already something with the target's name in the module.
2099 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
2100 if (Entry) {
2101 unsigned AS = getContext().getTargetAddressSpace(VD->getType());
2102 auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS));
2103 return ConstantAddress(Ptr, Alignment);
2104 }
2105
2106 llvm::Constant *Aliasee;
2107 if (isa<llvm::FunctionType>(DeclTy))
2108 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy,
2109 GlobalDecl(cast<FunctionDecl>(VD)),
2110 /*ForVTable=*/false);
2111 else
2112 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
2113 llvm::PointerType::getUnqual(DeclTy),
2114 nullptr);
2115
2116 auto *F = cast<llvm::GlobalValue>(Aliasee);
2117 F->setLinkage(llvm::Function::ExternalWeakLinkage);
2118 WeakRefReferences.insert(F);
2119
2120 return ConstantAddress(Aliasee, Alignment);
2121 }
2122
EmitGlobal(GlobalDecl GD)2123 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
2124 const auto *Global = cast<ValueDecl>(GD.getDecl());
2125
2126 // Weak references don't produce any output by themselves.
2127 if (Global->hasAttr<WeakRefAttr>())
2128 return;
2129
2130 // If this is an alias definition (which otherwise looks like a declaration)
2131 // emit it now.
2132 if (Global->hasAttr<AliasAttr>())
2133 return EmitAliasDefinition(GD);
2134
2135 // IFunc like an alias whose value is resolved at runtime by calling resolver.
2136 if (Global->hasAttr<IFuncAttr>())
2137 return emitIFuncDefinition(GD);
2138
2139 // If this is a cpu_dispatch multiversion function, emit the resolver.
2140 if (Global->hasAttr<CPUDispatchAttr>())
2141 return emitCPUDispatchDefinition(GD);
2142
2143 // If this is CUDA, be selective about which declarations we emit.
2144 if (LangOpts.CUDA) {
2145 if (LangOpts.CUDAIsDevice) {
2146 if (!Global->hasAttr<CUDADeviceAttr>() &&
2147 !Global->hasAttr<CUDAGlobalAttr>() &&
2148 !Global->hasAttr<CUDAConstantAttr>() &&
2149 !Global->hasAttr<CUDASharedAttr>())
2150 return;
2151 } else {
2152 // We need to emit host-side 'shadows' for all global
2153 // device-side variables because the CUDA runtime needs their
2154 // size and host-side address in order to provide access to
2155 // their device-side incarnations.
2156
2157 // So device-only functions are the only things we skip.
2158 if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() &&
2159 Global->hasAttr<CUDADeviceAttr>())
2160 return;
2161
2162 assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) &&
2163 "Expected Variable or Function");
2164 }
2165 }
2166
2167 if (LangOpts.OpenMP) {
2168 // If this is OpenMP device, check if it is legal to emit this global
2169 // normally.
2170 if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
2171 return;
2172 if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {
2173 if (MustBeEmitted(Global))
2174 EmitOMPDeclareReduction(DRD);
2175 return;
2176 }
2177 }
2178
2179 // Ignore declarations, they will be emitted on their first use.
2180 if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
2181 // Forward declarations are emitted lazily on first use.
2182 if (!FD->doesThisDeclarationHaveABody()) {
2183 if (!FD->doesDeclarationForceExternallyVisibleDefinition())
2184 return;
2185
2186 StringRef MangledName = getMangledName(GD);
2187
2188 // Compute the function info and LLVM type.
2189 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
2190 llvm::Type *Ty = getTypes().GetFunctionType(FI);
2191
2192 GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false,
2193 /*DontDefer=*/false);
2194 return;
2195 }
2196 } else {
2197 const auto *VD = cast<VarDecl>(Global);
2198 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
2199 if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
2200 !Context.isMSStaticDataMemberInlineDefinition(VD)) {
2201 if (LangOpts.OpenMP) {
2202 // Emit declaration of the must-be-emitted declare target variable.
2203 if (llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
2204 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
2205 if (*Res == OMPDeclareTargetDeclAttr::MT_To) {
2206 (void)GetAddrOfGlobalVar(VD);
2207 } else {
2208 assert(*Res == OMPDeclareTargetDeclAttr::MT_Link &&
2209 "link claue expected.");
2210 (void)getOpenMPRuntime().getAddrOfDeclareTargetLink(VD);
2211 }
2212 return;
2213 }
2214 }
2215 // If this declaration may have caused an inline variable definition to
2216 // change linkage, make sure that it's emitted.
2217 if (Context.getInlineVariableDefinitionKind(VD) ==
2218 ASTContext::InlineVariableDefinitionKind::Strong)
2219 GetAddrOfGlobalVar(VD);
2220 return;
2221 }
2222 }
2223
2224 // Defer code generation to first use when possible, e.g. if this is an inline
2225 // function. If the global must always be emitted, do it eagerly if possible
2226 // to benefit from cache locality.
2227 if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) {
2228 // Emit the definition if it can't be deferred.
2229 EmitGlobalDefinition(GD);
2230 return;
2231 }
2232
2233 // If we're deferring emission of a C++ variable with an
2234 // initializer, remember the order in which it appeared in the file.
2235 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) &&
2236 cast<VarDecl>(Global)->hasInit()) {
2237 DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
2238 CXXGlobalInits.push_back(nullptr);
2239 }
2240
2241 StringRef MangledName = getMangledName(GD);
2242 if (GetGlobalValue(MangledName) != nullptr) {
2243 // The value has already been used and should therefore be emitted.
2244 addDeferredDeclToEmit(GD);
2245 } else if (MustBeEmitted(Global)) {
2246 // The value must be emitted, but cannot be emitted eagerly.
2247 assert(!MayBeEmittedEagerly(Global));
2248 addDeferredDeclToEmit(GD);
2249 } else {
2250 // Otherwise, remember that we saw a deferred decl with this name. The
2251 // first use of the mangled name will cause it to move into
2252 // DeferredDeclsToEmit.
2253 DeferredDecls[MangledName] = GD;
2254 }
2255 }
2256
2257 // Check if T is a class type with a destructor that's not dllimport.
HasNonDllImportDtor(QualType T)2258 static bool HasNonDllImportDtor(QualType T) {
2259 if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>())
2260 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
2261 if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>())
2262 return true;
2263
2264 return false;
2265 }
2266
2267 namespace {
2268 struct FunctionIsDirectlyRecursive :
2269 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> {
2270 const StringRef Name;
2271 const Builtin::Context &BI;
2272 bool Result;
FunctionIsDirectlyRecursive__anona59ec6a70611::FunctionIsDirectlyRecursive2273 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) :
2274 Name(N), BI(C), Result(false) {
2275 }
2276 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base;
2277
TraverseCallExpr__anona59ec6a70611::FunctionIsDirectlyRecursive2278 bool TraverseCallExpr(CallExpr *E) {
2279 const FunctionDecl *FD = E->getDirectCallee();
2280 if (!FD)
2281 return true;
2282 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
2283 if (Attr && Name == Attr->getLabel()) {
2284 Result = true;
2285 return false;
2286 }
2287 unsigned BuiltinID = FD->getBuiltinID();
2288 if (!BuiltinID || !BI.isLibFunction(BuiltinID))
2289 return true;
2290 StringRef BuiltinName = BI.getName(BuiltinID);
2291 if (BuiltinName.startswith("__builtin_") &&
2292 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) {
2293 Result = true;
2294 return false;
2295 }
2296 return true;
2297 }
2298 };
2299
2300 // Make sure we're not referencing non-imported vars or functions.
2301 struct DLLImportFunctionVisitor
2302 : public RecursiveASTVisitor<DLLImportFunctionVisitor> {
2303 bool SafeToInline = true;
2304
shouldVisitImplicitCode__anona59ec6a70611::DLLImportFunctionVisitor2305 bool shouldVisitImplicitCode() const { return true; }
2306
VisitVarDecl__anona59ec6a70611::DLLImportFunctionVisitor2307 bool VisitVarDecl(VarDecl *VD) {
2308 if (VD->getTLSKind()) {
2309 // A thread-local variable cannot be imported.
2310 SafeToInline = false;
2311 return SafeToInline;
2312 }
2313
2314 // A variable definition might imply a destructor call.
2315 if (VD->isThisDeclarationADefinition())
2316 SafeToInline = !HasNonDllImportDtor(VD->getType());
2317
2318 return SafeToInline;
2319 }
2320
VisitCXXBindTemporaryExpr__anona59ec6a70611::DLLImportFunctionVisitor2321 bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) {
2322 if (const auto *D = E->getTemporary()->getDestructor())
2323 SafeToInline = D->hasAttr<DLLImportAttr>();
2324 return SafeToInline;
2325 }
2326
VisitDeclRefExpr__anona59ec6a70611::DLLImportFunctionVisitor2327 bool VisitDeclRefExpr(DeclRefExpr *E) {
2328 ValueDecl *VD = E->getDecl();
2329 if (isa<FunctionDecl>(VD))
2330 SafeToInline = VD->hasAttr<DLLImportAttr>();
2331 else if (VarDecl *V = dyn_cast<VarDecl>(VD))
2332 SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>();
2333 return SafeToInline;
2334 }
2335
VisitCXXConstructExpr__anona59ec6a70611::DLLImportFunctionVisitor2336 bool VisitCXXConstructExpr(CXXConstructExpr *E) {
2337 SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>();
2338 return SafeToInline;
2339 }
2340
VisitCXXMemberCallExpr__anona59ec6a70611::DLLImportFunctionVisitor2341 bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
2342 CXXMethodDecl *M = E->getMethodDecl();
2343 if (!M) {
2344 // Call through a pointer to member function. This is safe to inline.
2345 SafeToInline = true;
2346 } else {
2347 SafeToInline = M->hasAttr<DLLImportAttr>();
2348 }
2349 return SafeToInline;
2350 }
2351
VisitCXXDeleteExpr__anona59ec6a70611::DLLImportFunctionVisitor2352 bool VisitCXXDeleteExpr(CXXDeleteExpr *E) {
2353 SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>();
2354 return SafeToInline;
2355 }
2356
VisitCXXNewExpr__anona59ec6a70611::DLLImportFunctionVisitor2357 bool VisitCXXNewExpr(CXXNewExpr *E) {
2358 SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>();
2359 return SafeToInline;
2360 }
2361 };
2362 }
2363
2364 // isTriviallyRecursive - Check if this function calls another
2365 // decl that, because of the asm attribute or the other decl being a builtin,
2366 // ends up pointing to itself.
2367 bool
isTriviallyRecursive(const FunctionDecl * FD)2368 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) {
2369 StringRef Name;
2370 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) {
2371 // asm labels are a special kind of mangling we have to support.
2372 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>();
2373 if (!Attr)
2374 return false;
2375 Name = Attr->getLabel();
2376 } else {
2377 Name = FD->getName();
2378 }
2379
2380 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo);
2381 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD));
2382 return Walker.Result;
2383 }
2384
shouldEmitFunction(GlobalDecl GD)2385 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) {
2386 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage)
2387 return true;
2388 const auto *F = cast<FunctionDecl>(GD.getDecl());
2389 if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>())
2390 return false;
2391
2392 if (F->hasAttr<DLLImportAttr>()) {
2393 // Check whether it would be safe to inline this dllimport function.
2394 DLLImportFunctionVisitor Visitor;
2395 Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
2396 if (!Visitor.SafeToInline)
2397 return false;
2398
2399 if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) {
2400 // Implicit destructor invocations aren't captured in the AST, so the
2401 // check above can't see them. Check for them manually here.
2402 for (const Decl *Member : Dtor->getParent()->decls())
2403 if (isa<FieldDecl>(Member))
2404 if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType()))
2405 return false;
2406 for (const CXXBaseSpecifier &B : Dtor->getParent()->bases())
2407 if (HasNonDllImportDtor(B.getType()))
2408 return false;
2409 }
2410 }
2411
2412 // PR9614. Avoid cases where the source code is lying to us. An available
2413 // externally function should have an equivalent function somewhere else,
2414 // but a function that calls itself is clearly not equivalent to the real
2415 // implementation.
2416 // This happens in glibc's btowc and in some configure checks.
2417 return !isTriviallyRecursive(F);
2418 }
2419
shouldOpportunisticallyEmitVTables()2420 bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
2421 return CodeGenOpts.OptimizationLevel > 0;
2422 }
2423
EmitMultiVersionFunctionDefinition(GlobalDecl GD,llvm::GlobalValue * GV)2424 void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
2425 llvm::GlobalValue *GV) {
2426 const auto *FD = cast<FunctionDecl>(GD.getDecl());
2427
2428 if (FD->isCPUSpecificMultiVersion()) {
2429 auto *Spec = FD->getAttr<CPUSpecificAttr>();
2430 for (unsigned I = 0; I < Spec->cpus_size(); ++I)
2431 EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
2432 // Requires multiple emits.
2433 } else
2434 EmitGlobalFunctionDefinition(GD, GV);
2435 }
2436
EmitGlobalDefinition(GlobalDecl GD,llvm::GlobalValue * GV)2437 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
2438 const auto *D = cast<ValueDecl>(GD.getDecl());
2439
2440 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
2441 Context.getSourceManager(),
2442 "Generating code for declaration");
2443
2444 if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
2445 // At -O0, don't generate IR for functions with available_externally
2446 // linkage.
2447 if (!shouldEmitFunction(GD))
2448 return;
2449
2450 if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
2451 // Make sure to emit the definition(s) before we emit the thunks.
2452 // This is necessary for the generation of certain thunks.
2453 if (const auto *CD = dyn_cast<CXXConstructorDecl>(Method))
2454 ABI->emitCXXStructor(CD, getFromCtorType(GD.getCtorType()));
2455 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(Method))
2456 ABI->emitCXXStructor(DD, getFromDtorType(GD.getDtorType()));
2457 else if (FD->isMultiVersion())
2458 EmitMultiVersionFunctionDefinition(GD, GV);
2459 else
2460 EmitGlobalFunctionDefinition(GD, GV);
2461
2462 if (Method->isVirtual())
2463 getVTables().EmitThunks(GD);
2464
2465 return;
2466 }
2467
2468 if (FD->isMultiVersion())
2469 return EmitMultiVersionFunctionDefinition(GD, GV);
2470 return EmitGlobalFunctionDefinition(GD, GV);
2471 }
2472
2473 if (const auto *VD = dyn_cast<VarDecl>(D))
2474 return EmitGlobalVarDefinition(VD, !VD->hasDefinition());
2475
2476 llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
2477 }
2478
2479 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
2480 llvm::Function *NewFn);
2481
2482 static unsigned
TargetMVPriority(const TargetInfo & TI,const CodeGenFunction::MultiVersionResolverOption & RO)2483 TargetMVPriority(const TargetInfo &TI,
2484 const CodeGenFunction::MultiVersionResolverOption &RO) {
2485 unsigned Priority = 0;
2486 for (StringRef Feat : RO.Conditions.Features)
2487 Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
2488
2489 if (!RO.Conditions.Architecture.empty())
2490 Priority = std::max(
2491 Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
2492 return Priority;
2493 }
2494
emitMultiVersionFunctions()2495 void CodeGenModule::emitMultiVersionFunctions() {
2496 for (GlobalDecl GD : MultiVersionFuncs) {
2497 SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
2498 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2499 getContext().forEachMultiversionedFunctionVersion(
2500 FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
2501 GlobalDecl CurGD{
2502 (CurFD->isDefined() ? CurFD->getDefinition() : CurFD)};
2503 StringRef MangledName = getMangledName(CurGD);
2504 llvm::Constant *Func = GetGlobalValue(MangledName);
2505 if (!Func) {
2506 if (CurFD->isDefined()) {
2507 EmitGlobalFunctionDefinition(CurGD, nullptr);
2508 Func = GetGlobalValue(MangledName);
2509 } else {
2510 const CGFunctionInfo &FI =
2511 getTypes().arrangeGlobalDeclaration(GD);
2512 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
2513 Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false,
2514 /*DontDefer=*/false, ForDefinition);
2515 }
2516 assert(Func && "This should have just been created");
2517 }
2518
2519 const auto *TA = CurFD->getAttr<TargetAttr>();
2520 llvm::SmallVector<StringRef, 8> Feats;
2521 TA->getAddedFeatures(Feats);
2522
2523 Options.emplace_back(cast<llvm::Function>(Func),
2524 TA->getArchitecture(), Feats);
2525 });
2526
2527 llvm::Function *ResolverFunc;
2528 const TargetInfo &TI = getTarget();
2529
2530 if (TI.supportsIFunc() || FD->isTargetMultiVersion())
2531 ResolverFunc = cast<llvm::Function>(
2532 GetGlobalValue((getMangledName(GD) + ".resolver").str()));
2533 else
2534 ResolverFunc = cast<llvm::Function>(GetGlobalValue(getMangledName(GD)));
2535
2536 if (supportsCOMDAT())
2537 ResolverFunc->setComdat(
2538 getModule().getOrInsertComdat(ResolverFunc->getName()));
2539
2540 std::stable_sort(
2541 Options.begin(), Options.end(),
2542 [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
2543 const CodeGenFunction::MultiVersionResolverOption &RHS) {
2544 return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
2545 });
2546 CodeGenFunction CGF(*this);
2547 CGF.EmitMultiVersionResolver(ResolverFunc, Options);
2548 }
2549 }
2550
emitCPUDispatchDefinition(GlobalDecl GD)2551 void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
2552 const auto *FD = cast<FunctionDecl>(GD.getDecl());
2553 assert(FD && "Not a FunctionDecl?");
2554 const auto *DD = FD->getAttr<CPUDispatchAttr>();
2555 assert(DD && "Not a cpu_dispatch Function?");
2556 QualType CanonTy = Context.getCanonicalType(FD->getType());
2557 llvm::Type *DeclTy = getTypes().ConvertFunctionType(CanonTy, FD);
2558
2559 if (const auto *CXXFD = dyn_cast<CXXMethodDecl>(FD)) {
2560 const CGFunctionInfo &FInfo = getTypes().arrangeCXXMethodDeclaration(CXXFD);
2561 DeclTy = getTypes().GetFunctionType(FInfo);
2562 }
2563
2564 StringRef ResolverName = getMangledName(GD);
2565
2566 llvm::Type *ResolverType;
2567 GlobalDecl ResolverGD;
2568 if (getTarget().supportsIFunc())
2569 ResolverType = llvm::FunctionType::get(
2570 llvm::PointerType::get(DeclTy,
2571 Context.getTargetAddressSpace(FD->getType())),
2572 false);
2573 else {
2574 ResolverType = DeclTy;
2575 ResolverGD = GD;
2576 }
2577
2578 auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
2579 ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
2580
2581 SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
2582 const TargetInfo &Target = getTarget();
2583 unsigned Index = 0;
2584 for (const IdentifierInfo *II : DD->cpus()) {
2585 // Get the name of the target function so we can look it up/create it.
2586 std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
2587 getCPUSpecificMangling(*this, II->getName());
2588
2589 llvm::Constant *Func = GetGlobalValue(MangledName);
2590
2591 if (!Func) {
2592 GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
2593 if (ExistingDecl.getDecl() &&
2594 ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
2595 EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
2596 Func = GetGlobalValue(MangledName);
2597 } else {
2598 if (!ExistingDecl.getDecl())
2599 ExistingDecl = GD.getWithMultiVersionIndex(Index);
2600
2601 Func = GetOrCreateLLVMFunction(
2602 MangledName, DeclTy, ExistingDecl,
2603 /*ForVTable=*/false, /*DontDefer=*/true,
2604 /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
2605 }
2606 }
2607
2608 llvm::SmallVector<StringRef, 32> Features;
2609 Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
2610 llvm::transform(Features, Features.begin(),
2611 [](StringRef Str) { return Str.substr(1); });
2612 Features.erase(std::remove_if(
2613 Features.begin(), Features.end(), [&Target](StringRef Feat) {
2614 return !Target.validateCpuSupports(Feat);
2615 }), Features.end());
2616 Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
2617 ++Index;
2618 }
2619
2620 llvm::sort(
2621 Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
2622 const CodeGenFunction::MultiVersionResolverOption &RHS) {
2623 return CodeGenFunction::GetX86CpuSupportsMask(LHS.Conditions.Features) >
2624 CodeGenFunction::GetX86CpuSupportsMask(RHS.Conditions.Features);
2625 });
2626
2627 // If the list contains multiple 'default' versions, such as when it contains
2628 // 'pentium' and 'generic', don't emit the call to the generic one (since we
2629 // always run on at least a 'pentium'). We do this by deleting the 'least
2630 // advanced' (read, lowest mangling letter).
2631 while (Options.size() > 1 &&
2632 CodeGenFunction::GetX86CpuSupportsMask(
2633 (Options.end() - 2)->Conditions.Features) == 0) {
2634 StringRef LHSName = (Options.end() - 2)->Function->getName();
2635 StringRef RHSName = (Options.end() - 1)->Function->getName();
2636 if (LHSName.compare(RHSName) < 0)
2637 Options.erase(Options.end() - 2);
2638 else
2639 Options.erase(Options.end() - 1);
2640 }
2641
2642 CodeGenFunction CGF(*this);
2643 CGF.EmitMultiVersionResolver(ResolverFunc, Options);
2644 }
2645
2646 /// If a dispatcher for the specified mangled name is not in the module, create
2647 /// and return an llvm Function with the specified type.
GetOrCreateMultiVersionResolver(GlobalDecl GD,llvm::Type * DeclTy,const FunctionDecl * FD)2648 llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(
2649 GlobalDecl GD, llvm::Type *DeclTy, const FunctionDecl *FD) {
2650 std::string MangledName =
2651 getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
2652
2653 // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
2654 // a separate resolver).
2655 std::string ResolverName = MangledName;
2656 if (getTarget().supportsIFunc())
2657 ResolverName += ".ifunc";
2658 else if (FD->isTargetMultiVersion())
2659 ResolverName += ".resolver";
2660
2661 // If this already exists, just return that one.
2662 if (llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName))
2663 return ResolverGV;
2664
2665 // Since this is the first time we've created this IFunc, make sure
2666 // that we put this multiversioned function into the list to be
2667 // replaced later if necessary (target multiversioning only).
2668 if (!FD->isCPUDispatchMultiVersion() && !FD->isCPUSpecificMultiVersion())
2669 MultiVersionFuncs.push_back(GD);
2670
2671 if (getTarget().supportsIFunc()) {
2672 llvm::Type *ResolverType = llvm::FunctionType::get(
2673 llvm::PointerType::get(
2674 DeclTy, getContext().getTargetAddressSpace(FD->getType())),
2675 false);
2676 llvm::Constant *Resolver = GetOrCreateLLVMFunction(
2677 MangledName + ".resolver", ResolverType, GlobalDecl{},
2678 /*ForVTable=*/false);
2679 llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
2680 DeclTy, 0, llvm::Function::ExternalLinkage, "", Resolver, &getModule());
2681 GIF->setName(ResolverName);
2682 SetCommonAttributes(FD, GIF);
2683
2684 return GIF;
2685 }
2686
2687 llvm::Constant *Resolver = GetOrCreateLLVMFunction(
2688 ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
2689 assert(isa<llvm::GlobalValue>(Resolver) &&
2690 "Resolver should be created for the first time");
2691 SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
2692 return Resolver;
2693 }
2694
2695 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
2696 /// module, create and return an llvm Function with the specified type. If there
2697 /// is something in the module with the specified name, return it potentially
2698 /// bitcasted to the right type.
2699 ///
2700 /// If D is non-null, it specifies a decl that correspond to this. This is used
2701 /// 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)2702 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
2703 StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable,
2704 bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs,
2705 ForDefinition_t IsForDefinition) {
2706 const Decl *D = GD.getDecl();
2707
2708 // Any attempts to use a MultiVersion function should result in retrieving
2709 // the iFunc instead. Name Mangling will handle the rest of the changes.
2710 if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) {
2711 // For the device mark the function as one that should be emitted.
2712 if (getLangOpts().OpenMPIsDevice && OpenMPRuntime &&
2713 !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
2714 !DontDefer && !IsForDefinition) {
2715 if (const FunctionDecl *FDDef = FD->getDefinition()) {
2716 GlobalDecl GDDef;
2717 if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
2718 GDDef = GlobalDecl(CD, GD.getCtorType());
2719 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
2720 GDDef = GlobalDecl(DD, GD.getDtorType());
2721 else
2722 GDDef = GlobalDecl(FDDef);
2723 EmitGlobal(GDDef);
2724 }
2725 }
2726
2727 if (FD->isMultiVersion()) {
2728 const auto *TA = FD->getAttr<TargetAttr>();
2729 if (TA && TA->isDefaultVersion())
2730 UpdateMultiVersionNames(GD, FD);
2731 if (!IsForDefinition)
2732 return GetOrCreateMultiVersionResolver(GD, Ty, FD);
2733 }
2734 }
2735
2736 // Lookup the entry, lazily creating it if necessary.
2737 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
2738 if (Entry) {
2739 if (WeakRefReferences.erase(Entry)) {
2740 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D);
2741 if (FD && !FD->hasAttr<WeakAttr>())
2742 Entry->setLinkage(llvm::Function::ExternalLinkage);
2743 }
2744
2745 // Handle dropped DLL attributes.
2746 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>()) {
2747 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
2748 setDSOLocal(Entry);
2749 }
2750
2751 // If there are two attempts to define the same mangled name, issue an
2752 // error.
2753 if (IsForDefinition && !Entry->isDeclaration()) {
2754 GlobalDecl OtherGD;
2755 // Check that GD is not yet in DiagnosedConflictingDefinitions is required
2756 // to make sure that we issue an error only once.
2757 if (lookupRepresentativeDecl(MangledName, OtherGD) &&
2758 (GD.getCanonicalDecl().getDecl() !=
2759 OtherGD.getCanonicalDecl().getDecl()) &&
2760 DiagnosedConflictingDefinitions.insert(GD).second) {
2761 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
2762 << MangledName;
2763 getDiags().Report(OtherGD.getDecl()->getLocation(),
2764 diag::note_previous_definition);
2765 }
2766 }
2767
2768 if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) &&
2769 (Entry->getType()->getElementType() == Ty)) {
2770 return Entry;
2771 }
2772
2773 // Make sure the result is of the correct type.
2774 // (If function is requested for a definition, we always need to create a new
2775 // function, not just return a bitcast.)
2776 if (!IsForDefinition)
2777 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
2778 }
2779
2780 // This function doesn't have a complete type (for example, the return
2781 // type is an incomplete struct). Use a fake type instead, and make
2782 // sure not to try to set attributes.
2783 bool IsIncompleteFunction = false;
2784
2785 llvm::FunctionType *FTy;
2786 if (isa<llvm::FunctionType>(Ty)) {
2787 FTy = cast<llvm::FunctionType>(Ty);
2788 } else {
2789 FTy = llvm::FunctionType::get(VoidTy, false);
2790 IsIncompleteFunction = true;
2791 }
2792
2793 llvm::Function *F =
2794 llvm::Function::Create(FTy, llvm::Function::ExternalLinkage,
2795 Entry ? StringRef() : MangledName, &getModule());
2796
2797 // If we already created a function with the same mangled name (but different
2798 // type) before, take its name and add it to the list of functions to be
2799 // replaced with F at the end of CodeGen.
2800 //
2801 // This happens if there is a prototype for a function (e.g. "int f()") and
2802 // then a definition of a different type (e.g. "int f(int x)").
2803 if (Entry) {
2804 F->takeName(Entry);
2805
2806 // This might be an implementation of a function without a prototype, in
2807 // which case, try to do special replacement of calls which match the new
2808 // prototype. The really key thing here is that we also potentially drop
2809 // arguments from the call site so as to make a direct call, which makes the
2810 // inliner happier and suppresses a number of optimizer warnings (!) about
2811 // dropping arguments.
2812 if (!Entry->use_empty()) {
2813 ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F);
2814 Entry->removeDeadConstantUsers();
2815 }
2816
2817 llvm::Constant *BC = llvm::ConstantExpr::getBitCast(
2818 F, Entry->getType()->getElementType()->getPointerTo());
2819 addGlobalValReplacement(Entry, BC);
2820 }
2821
2822 assert(F->getName() == MangledName && "name was uniqued!");
2823 if (D)
2824 SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk);
2825 if (ExtraAttrs.hasAttributes(llvm::AttributeList::FunctionIndex)) {
2826 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex);
2827 F->addAttributes(llvm::AttributeList::FunctionIndex, B);
2828 }
2829
2830 if (!DontDefer) {
2831 // All MSVC dtors other than the base dtor are linkonce_odr and delegate to
2832 // each other bottoming out with the base dtor. Therefore we emit non-base
2833 // dtors on usage, even if there is no dtor definition in the TU.
2834 if (D && isa<CXXDestructorDecl>(D) &&
2835 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D),
2836 GD.getDtorType()))
2837 addDeferredDeclToEmit(GD);
2838
2839 // This is the first use or definition of a mangled name. If there is a
2840 // deferred decl with this name, remember that we need to emit it at the end
2841 // of the file.
2842 auto DDI = DeferredDecls.find(MangledName);
2843 if (DDI != DeferredDecls.end()) {
2844 // Move the potentially referenced deferred decl to the
2845 // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we
2846 // don't need it anymore).
2847 addDeferredDeclToEmit(DDI->second);
2848 DeferredDecls.erase(DDI);
2849
2850 // Otherwise, there are cases we have to worry about where we're
2851 // using a declaration for which we must emit a definition but where
2852 // we might not find a top-level definition:
2853 // - member functions defined inline in their classes
2854 // - friend functions defined inline in some class
2855 // - special member functions with implicit definitions
2856 // If we ever change our AST traversal to walk into class methods,
2857 // this will be unnecessary.
2858 //
2859 // We also don't emit a definition for a function if it's going to be an
2860 // entry in a vtable, unless it's already marked as used.
2861 } else if (getLangOpts().CPlusPlus && D) {
2862 // Look for a declaration that's lexically in a record.
2863 for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD;
2864 FD = FD->getPreviousDecl()) {
2865 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
2866 if (FD->doesThisDeclarationHaveABody()) {
2867 addDeferredDeclToEmit(GD.getWithDecl(FD));
2868 break;
2869 }
2870 }
2871 }
2872 }
2873 }
2874
2875 // Make sure the result is of the requested type.
2876 if (!IsIncompleteFunction) {
2877 assert(F->getType()->getElementType() == Ty);
2878 return F;
2879 }
2880
2881 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
2882 return llvm::ConstantExpr::getBitCast(F, PTy);
2883 }
2884
2885 /// GetAddrOfFunction - Return the address of the given function. If Ty is
2886 /// non-null, then this function will use the specified type if it has to
2887 /// 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)2888 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
2889 llvm::Type *Ty,
2890 bool ForVTable,
2891 bool DontDefer,
2892 ForDefinition_t IsForDefinition) {
2893 // If there was no specific requested type, just convert it now.
2894 if (!Ty) {
2895 const auto *FD = cast<FunctionDecl>(GD.getDecl());
2896 auto CanonTy = Context.getCanonicalType(FD->getType());
2897 Ty = getTypes().ConvertFunctionType(CanonTy, FD);
2898 }
2899
2900 // Devirtualized destructor calls may come through here instead of via
2901 // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead
2902 // of the complete destructor when necessary.
2903 if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) {
2904 if (getTarget().getCXXABI().isMicrosoft() &&
2905 GD.getDtorType() == Dtor_Complete &&
2906 DD->getParent()->getNumVBases() == 0)
2907 GD = GlobalDecl(DD, Dtor_Base);
2908 }
2909
2910 StringRef MangledName = getMangledName(GD);
2911 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer,
2912 /*IsThunk=*/false, llvm::AttributeList(),
2913 IsForDefinition);
2914 }
2915
2916 static const FunctionDecl *
GetRuntimeFunctionDecl(ASTContext & C,StringRef Name)2917 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) {
2918 TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
2919 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
2920
2921 IdentifierInfo &CII = C.Idents.get(Name);
2922 for (const auto &Result : DC->lookup(&CII))
2923 if (const auto FD = dyn_cast<FunctionDecl>(Result))
2924 return FD;
2925
2926 if (!C.getLangOpts().CPlusPlus)
2927 return nullptr;
2928
2929 // Demangle the premangled name from getTerminateFn()
2930 IdentifierInfo &CXXII =
2931 (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ")
2932 ? C.Idents.get("terminate")
2933 : C.Idents.get(Name);
2934
2935 for (const auto &N : {"__cxxabiv1", "std"}) {
2936 IdentifierInfo &NS = C.Idents.get(N);
2937 for (const auto &Result : DC->lookup(&NS)) {
2938 NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result);
2939 if (auto LSD = dyn_cast<LinkageSpecDecl>(Result))
2940 for (const auto &Result : LSD->lookup(&NS))
2941 if ((ND = dyn_cast<NamespaceDecl>(Result)))
2942 break;
2943
2944 if (ND)
2945 for (const auto &Result : ND->lookup(&CXXII))
2946 if (const auto *FD = dyn_cast<FunctionDecl>(Result))
2947 return FD;
2948 }
2949 }
2950
2951 return nullptr;
2952 }
2953
2954 /// CreateRuntimeFunction - Create a new runtime function with the specified
2955 /// type and name.
2956 llvm::Constant *
CreateRuntimeFunction(llvm::FunctionType * FTy,StringRef Name,llvm::AttributeList ExtraAttrs,bool Local)2957 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name,
2958 llvm::AttributeList ExtraAttrs,
2959 bool Local) {
2960 llvm::Constant *C =
2961 GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
2962 /*DontDefer=*/false, /*IsThunk=*/false,
2963 ExtraAttrs);
2964
2965 if (auto *F = dyn_cast<llvm::Function>(C)) {
2966 if (F->empty()) {
2967 F->setCallingConv(getRuntimeCC());
2968
2969 if (!Local && getTriple().isOSBinFormatCOFF() &&
2970 !getCodeGenOpts().LTOVisibilityPublicStd &&
2971 !getTriple().isWindowsGNUEnvironment()) {
2972 const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name);
2973 if (!FD || FD->hasAttr<DLLImportAttr>()) {
2974 F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2975 F->setLinkage(llvm::GlobalValue::ExternalLinkage);
2976 }
2977 }
2978 setDSOLocal(F);
2979 }
2980 }
2981
2982 return C;
2983 }
2984
2985 /// CreateBuiltinFunction - Create a new builtin function with the specified
2986 /// type and name.
2987 llvm::Constant *
CreateBuiltinFunction(llvm::FunctionType * FTy,StringRef Name,llvm::AttributeList ExtraAttrs)2988 CodeGenModule::CreateBuiltinFunction(llvm::FunctionType *FTy, StringRef Name,
2989 llvm::AttributeList ExtraAttrs) {
2990 return CreateRuntimeFunction(FTy, Name, ExtraAttrs, true);
2991 }
2992
2993 /// isTypeConstant - Determine whether an object of this type can be emitted
2994 /// as a constant.
2995 ///
2996 /// If ExcludeCtor is true, the duration when the object's constructor runs
2997 /// will not be considered. The caller will need to verify that the object is
2998 /// not written to during its construction.
isTypeConstant(QualType Ty,bool ExcludeCtor)2999 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) {
3000 if (!Ty.isConstant(Context) && !Ty->isReferenceType())
3001 return false;
3002
3003 if (Context.getLangOpts().CPlusPlus) {
3004 if (const CXXRecordDecl *Record
3005 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl())
3006 return ExcludeCtor && !Record->hasMutableFields() &&
3007 Record->hasTrivialDestructor();
3008 }
3009
3010 return true;
3011 }
3012
3013 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
3014 /// create and return an llvm GlobalVariable with the specified type. If there
3015 /// is something in the module with the specified name, return it potentially
3016 /// bitcasted to the right type.
3017 ///
3018 /// If D is non-null, it specifies a decl that correspond to this. This is used
3019 /// to set the attributes on the global when it is first created.
3020 ///
3021 /// If IsForDefinition is true, it is guaranteed that an actual global with
3022 /// type Ty will be returned, not conversion of a variable with the same
3023 /// mangled name but some other type.
3024 llvm::Constant *
GetOrCreateLLVMGlobal(StringRef MangledName,llvm::PointerType * Ty,const VarDecl * D,ForDefinition_t IsForDefinition)3025 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
3026 llvm::PointerType *Ty,
3027 const VarDecl *D,
3028 ForDefinition_t IsForDefinition) {
3029 // Lookup the entry, lazily creating it if necessary.
3030 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
3031 if (Entry) {
3032 if (WeakRefReferences.erase(Entry)) {
3033 if (D && !D->hasAttr<WeakAttr>())
3034 Entry->setLinkage(llvm::Function::ExternalLinkage);
3035 }
3036
3037 // Handle dropped DLL attributes.
3038 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>())
3039 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
3040
3041 if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D)
3042 getOpenMPRuntime().registerTargetGlobalVariable(D, Entry);
3043
3044 if (Entry->getType() == Ty)
3045 return Entry;
3046
3047 // If there are two attempts to define the same mangled name, issue an
3048 // error.
3049 if (IsForDefinition && !Entry->isDeclaration()) {
3050 GlobalDecl OtherGD;
3051 const VarDecl *OtherD;
3052
3053 // Check that D is not yet in DiagnosedConflictingDefinitions is required
3054 // to make sure that we issue an error only once.
3055 if (D && lookupRepresentativeDecl(MangledName, OtherGD) &&
3056 (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) &&
3057 (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) &&
3058 OtherD->hasInit() &&
3059 DiagnosedConflictingDefinitions.insert(D).second) {
3060 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name)
3061 << MangledName;
3062 getDiags().Report(OtherGD.getDecl()->getLocation(),
3063 diag::note_previous_definition);
3064 }
3065 }
3066
3067 // Make sure the result is of the correct type.
3068 if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace())
3069 return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty);
3070
3071 // (If global is requested for a definition, we always need to create a new
3072 // global, not just return a bitcast.)
3073 if (!IsForDefinition)
3074 return llvm::ConstantExpr::getBitCast(Entry, Ty);
3075 }
3076
3077 auto AddrSpace = GetGlobalVarAddressSpace(D);
3078 auto TargetAddrSpace = getContext().getTargetAddressSpace(AddrSpace);
3079
3080 auto *GV = new llvm::GlobalVariable(
3081 getModule(), Ty->getElementType(), false,
3082 llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr,
3083 llvm::GlobalVariable::NotThreadLocal, TargetAddrSpace);
3084
3085 // If we already created a global with the same mangled name (but different
3086 // type) before, take its name and remove it from its parent.
3087 if (Entry) {
3088 GV->takeName(Entry);
3089
3090 if (!Entry->use_empty()) {
3091 llvm::Constant *NewPtrForOldDecl =
3092 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
3093 Entry->replaceAllUsesWith(NewPtrForOldDecl);
3094 }
3095
3096 Entry->eraseFromParent();
3097 }
3098
3099 // This is the first use or definition of a mangled name. If there is a
3100 // deferred decl with this name, remember that we need to emit it at the end
3101 // of the file.
3102 auto DDI = DeferredDecls.find(MangledName);
3103 if (DDI != DeferredDecls.end()) {
3104 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
3105 // list, and remove it from DeferredDecls (since we don't need it anymore).
3106 addDeferredDeclToEmit(DDI->second);
3107 DeferredDecls.erase(DDI);
3108 }
3109
3110 // Handle things which are present even on external declarations.
3111 if (D) {
3112 if (LangOpts.OpenMP && !LangOpts.OpenMPSimd)
3113 getOpenMPRuntime().registerTargetGlobalVariable(D, GV);
3114
3115 // FIXME: This code is overly simple and should be merged with other global
3116 // handling.
3117 GV->setConstant(isTypeConstant(D->getType(), false));
3118
3119 GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
3120
3121 setLinkageForGV(GV, D);
3122
3123 if (D->getTLSKind()) {
3124 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
3125 CXXThreadLocals.push_back(D);
3126 setTLSMode(GV, *D);
3127 }
3128
3129 setGVProperties(GV, D);
3130
3131 // If required by the ABI, treat declarations of static data members with
3132 // inline initializers as definitions.
3133 if (getContext().isMSStaticDataMemberInlineDefinition(D)) {
3134 EmitGlobalVarDefinition(D);
3135 }
3136
3137 // Emit section information for extern variables.
3138 if (D->hasExternalStorage()) {
3139 if (const SectionAttr *SA = D->getAttr<SectionAttr>())
3140 GV->setSection(SA->getName());
3141 }
3142
3143 // Handle XCore specific ABI requirements.
3144 if (getTriple().getArch() == llvm::Triple::xcore &&
3145 D->getLanguageLinkage() == CLanguageLinkage &&
3146 D->getType().isConstant(Context) &&
3147 isExternallyVisible(D->getLinkageAndVisibility().getLinkage()))
3148 GV->setSection(".cp.rodata");
3149
3150 // Check if we a have a const declaration with an initializer, we may be
3151 // able to emit it as available_externally to expose it's value to the
3152 // optimizer.
3153 if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() &&
3154 D->getType().isConstQualified() && !GV->hasInitializer() &&
3155 !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) {
3156 const auto *Record =
3157 Context.getBaseElementType(D->getType())->getAsCXXRecordDecl();
3158 bool HasMutableFields = Record && Record->hasMutableFields();
3159 if (!HasMutableFields) {
3160 const VarDecl *InitDecl;
3161 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
3162 if (InitExpr) {
3163 ConstantEmitter emitter(*this);
3164 llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl);
3165 if (Init) {
3166 auto *InitType = Init->getType();
3167 if (GV->getType()->getElementType() != InitType) {
3168 // The type of the initializer does not match the definition.
3169 // This happens when an initializer has a different type from
3170 // the type of the global (because of padding at the end of a
3171 // structure for instance).
3172 GV->setName(StringRef());
3173 // Make a new global with the correct type, this is now guaranteed
3174 // to work.
3175 auto *NewGV = cast<llvm::GlobalVariable>(
3176 GetAddrOfGlobalVar(D, InitType, IsForDefinition));
3177
3178 // Erase the old global, since it is no longer used.
3179 GV->eraseFromParent();
3180 GV = NewGV;
3181 } else {
3182 GV->setInitializer(Init);
3183 GV->setConstant(true);
3184 GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage);
3185 }
3186 emitter.finalize(GV);
3187 }
3188 }
3189 }
3190 }
3191 }
3192
3193 LangAS ExpectedAS =
3194 D ? D->getType().getAddressSpace()
3195 : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default);
3196 assert(getContext().getTargetAddressSpace(ExpectedAS) ==
3197 Ty->getPointerAddressSpace());
3198 if (AddrSpace != ExpectedAS)
3199 return getTargetCodeGenInfo().performAddrSpaceCast(*this, GV, AddrSpace,
3200 ExpectedAS, Ty);
3201
3202 return GV;
3203 }
3204
3205 llvm::Constant *
GetAddrOfGlobal(GlobalDecl GD,ForDefinition_t IsForDefinition)3206 CodeGenModule::GetAddrOfGlobal(GlobalDecl GD,
3207 ForDefinition_t IsForDefinition) {
3208 const Decl *D = GD.getDecl();
3209 if (isa<CXXConstructorDecl>(D))
3210 return getAddrOfCXXStructor(cast<CXXConstructorDecl>(D),
3211 getFromCtorType(GD.getCtorType()),
3212 /*FnInfo=*/nullptr, /*FnType=*/nullptr,
3213 /*DontDefer=*/false, IsForDefinition);
3214 else if (isa<CXXDestructorDecl>(D))
3215 return getAddrOfCXXStructor(cast<CXXDestructorDecl>(D),
3216 getFromDtorType(GD.getDtorType()),
3217 /*FnInfo=*/nullptr, /*FnType=*/nullptr,
3218 /*DontDefer=*/false, IsForDefinition);
3219 else if (isa<CXXMethodDecl>(D)) {
3220 auto FInfo = &getTypes().arrangeCXXMethodDeclaration(
3221 cast<CXXMethodDecl>(D));
3222 auto Ty = getTypes().GetFunctionType(*FInfo);
3223 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
3224 IsForDefinition);
3225 } else if (isa<FunctionDecl>(D)) {
3226 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
3227 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
3228 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false,
3229 IsForDefinition);
3230 } else
3231 return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr,
3232 IsForDefinition);
3233 }
3234
CreateOrReplaceCXXRuntimeVariable(StringRef Name,llvm::Type * Ty,llvm::GlobalValue::LinkageTypes Linkage,unsigned Alignment)3235 llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
3236 StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
3237 unsigned Alignment) {
3238 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
3239 llvm::GlobalVariable *OldGV = nullptr;
3240
3241 if (GV) {
3242 // Check if the variable has the right type.
3243 if (GV->getType()->getElementType() == Ty)
3244 return GV;
3245
3246 // Because C++ name mangling, the only way we can end up with an already
3247 // existing global with the same name is if it has been declared extern "C".
3248 assert(GV->isDeclaration() && "Declaration has wrong type!");
3249 OldGV = GV;
3250 }
3251
3252 // Create a new variable.
3253 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
3254 Linkage, nullptr, Name);
3255
3256 if (OldGV) {
3257 // Replace occurrences of the old variable if needed.
3258 GV->takeName(OldGV);
3259
3260 if (!OldGV->use_empty()) {
3261 llvm::Constant *NewPtrForOldDecl =
3262 llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
3263 OldGV->replaceAllUsesWith(NewPtrForOldDecl);
3264 }
3265
3266 OldGV->eraseFromParent();
3267 }
3268
3269 if (supportsCOMDAT() && GV->isWeakForLinker() &&
3270 !GV->hasAvailableExternallyLinkage())
3271 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
3272
3273 GV->setAlignment(Alignment);
3274
3275 return GV;
3276 }
3277
3278 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
3279 /// given global variable. If Ty is non-null and if the global doesn't exist,
3280 /// then it will be created with the specified type instead of whatever the
3281 /// normal requested type would be. If IsForDefinition is true, it is guaranteed
3282 /// that an actual global with type Ty will be returned, not conversion of a
3283 /// variable with the same mangled name but some other type.
GetAddrOfGlobalVar(const VarDecl * D,llvm::Type * Ty,ForDefinition_t IsForDefinition)3284 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
3285 llvm::Type *Ty,
3286 ForDefinition_t IsForDefinition) {
3287 assert(D->hasGlobalStorage() && "Not a global variable");
3288 QualType ASTTy = D->getType();
3289 if (!Ty)
3290 Ty = getTypes().ConvertTypeForMem(ASTTy);
3291
3292 llvm::PointerType *PTy =
3293 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
3294
3295 StringRef MangledName = getMangledName(D);
3296 return GetOrCreateLLVMGlobal(MangledName, PTy, D, IsForDefinition);
3297 }
3298
3299 /// CreateRuntimeVariable - Create a new runtime global variable with the
3300 /// specified type and name.
3301 llvm::Constant *
CreateRuntimeVariable(llvm::Type * Ty,StringRef Name)3302 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
3303 StringRef Name) {
3304 auto *Ret =
3305 GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), nullptr);
3306 setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts()));
3307 return Ret;
3308 }
3309
EmitTentativeDefinition(const VarDecl * D)3310 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
3311 assert(!D->getInit() && "Cannot emit definite definitions here!");
3312
3313 StringRef MangledName = getMangledName(D);
3314 llvm::GlobalValue *GV = GetGlobalValue(MangledName);
3315
3316 // We already have a definition, not declaration, with the same mangled name.
3317 // Emitting of declaration is not required (and actually overwrites emitted
3318 // definition).
3319 if (GV && !GV->isDeclaration())
3320 return;
3321
3322 // If we have not seen a reference to this variable yet, place it into the
3323 // deferred declarations table to be emitted if needed later.
3324 if (!MustBeEmitted(D) && !GV) {
3325 DeferredDecls[MangledName] = D;
3326 return;
3327 }
3328
3329 // The tentative definition is the only definition.
3330 EmitGlobalVarDefinition(D);
3331 }
3332
GetTargetTypeStoreSize(llvm::Type * Ty) const3333 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
3334 return Context.toCharUnitsFromBits(
3335 getDataLayout().getTypeStoreSizeInBits(Ty));
3336 }
3337
GetGlobalVarAddressSpace(const VarDecl * D)3338 LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) {
3339 LangAS AddrSpace = LangAS::Default;
3340 if (LangOpts.OpenCL) {
3341 AddrSpace = D ? D->getType().getAddressSpace() : LangAS::opencl_global;
3342 assert(AddrSpace == LangAS::opencl_global ||
3343 AddrSpace == LangAS::opencl_constant ||
3344 AddrSpace == LangAS::opencl_local ||
3345 AddrSpace >= LangAS::FirstTargetAddressSpace);
3346 return AddrSpace;
3347 }
3348
3349 if (LangOpts.CUDA && LangOpts.CUDAIsDevice) {
3350 if (D && D->hasAttr<CUDAConstantAttr>())
3351 return LangAS::cuda_constant;
3352 else if (D && D->hasAttr<CUDASharedAttr>())
3353 return LangAS::cuda_shared;
3354 else if (D && D->hasAttr<CUDADeviceAttr>())
3355 return LangAS::cuda_device;
3356 else if (D && D->getType().isConstQualified())
3357 return LangAS::cuda_constant;
3358 else
3359 return LangAS::cuda_device;
3360 }
3361
3362 return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D);
3363 }
3364
getStringLiteralAddressSpace() const3365 LangAS CodeGenModule::getStringLiteralAddressSpace() const {
3366 // OpenCL v1.2 s6.5.3: a string literal is in the constant address space.
3367 if (LangOpts.OpenCL)
3368 return LangAS::opencl_constant;
3369 if (auto AS = getTarget().getConstantAddressSpace())
3370 return AS.getValue();
3371 return LangAS::Default;
3372 }
3373
3374 // In address space agnostic languages, string literals are in default address
3375 // space in AST. However, certain targets (e.g. amdgcn) request them to be
3376 // emitted in constant address space in LLVM IR. To be consistent with other
3377 // parts of AST, string literal global variables in constant address space
3378 // need to be casted to default address space before being put into address
3379 // map and referenced by other part of CodeGen.
3380 // In OpenCL, string literals are in constant address space in AST, therefore
3381 // they should not be casted to default address space.
3382 static llvm::Constant *
castStringLiteralToDefaultAddressSpace(CodeGenModule & CGM,llvm::GlobalVariable * GV)3383 castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM,
3384 llvm::GlobalVariable *GV) {
3385 llvm::Constant *Cast = GV;
3386 if (!CGM.getLangOpts().OpenCL) {
3387 if (auto AS = CGM.getTarget().getConstantAddressSpace()) {
3388 if (AS != LangAS::Default)
3389 Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast(
3390 CGM, GV, AS.getValue(), LangAS::Default,
3391 GV->getValueType()->getPointerTo(
3392 CGM.getContext().getTargetAddressSpace(LangAS::Default)));
3393 }
3394 }
3395 return Cast;
3396 }
3397
3398 template<typename SomeDecl>
MaybeHandleStaticInExternC(const SomeDecl * D,llvm::GlobalValue * GV)3399 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D,
3400 llvm::GlobalValue *GV) {
3401 if (!getLangOpts().CPlusPlus)
3402 return;
3403
3404 // Must have 'used' attribute, or else inline assembly can't rely on
3405 // the name existing.
3406 if (!D->template hasAttr<UsedAttr>())
3407 return;
3408
3409 // Must have internal linkage and an ordinary name.
3410 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage)
3411 return;
3412
3413 // Must be in an extern "C" context. Entities declared directly within
3414 // a record are not extern "C" even if the record is in such a context.
3415 const SomeDecl *First = D->getFirstDecl();
3416 if (First->getDeclContext()->isRecord() || !First->isInExternCContext())
3417 return;
3418
3419 // OK, this is an internal linkage entity inside an extern "C" linkage
3420 // specification. Make a note of that so we can give it the "expected"
3421 // mangled name if nothing else is using that name.
3422 std::pair<StaticExternCMap::iterator, bool> R =
3423 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV));
3424
3425 // If we have multiple internal linkage entities with the same name
3426 // in extern "C" regions, none of them gets that name.
3427 if (!R.second)
3428 R.first->second = nullptr;
3429 }
3430
shouldBeInCOMDAT(CodeGenModule & CGM,const Decl & D)3431 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) {
3432 if (!CGM.supportsCOMDAT())
3433 return false;
3434
3435 if (D.hasAttr<SelectAnyAttr>())
3436 return true;
3437
3438 GVALinkage Linkage;
3439 if (auto *VD = dyn_cast<VarDecl>(&D))
3440 Linkage = CGM.getContext().GetGVALinkageForVariable(VD);
3441 else
3442 Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D));
3443
3444 switch (Linkage) {
3445 case GVA_Internal:
3446 case GVA_AvailableExternally:
3447 case GVA_StrongExternal:
3448 return false;
3449 case GVA_DiscardableODR:
3450 case GVA_StrongODR:
3451 return true;
3452 }
3453 llvm_unreachable("No such linkage");
3454 }
3455
maybeSetTrivialComdat(const Decl & D,llvm::GlobalObject & GO)3456 void CodeGenModule::maybeSetTrivialComdat(const Decl &D,
3457 llvm::GlobalObject &GO) {
3458 if (!shouldBeInCOMDAT(*this, D))
3459 return;
3460 GO.setComdat(TheModule.getOrInsertComdat(GO.getName()));
3461 }
3462
3463 /// Pass IsTentative as true if you want to create a tentative definition.
EmitGlobalVarDefinition(const VarDecl * D,bool IsTentative)3464 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
3465 bool IsTentative) {
3466 // OpenCL global variables of sampler type are translated to function calls,
3467 // therefore no need to be translated.
3468 QualType ASTTy = D->getType();
3469 if (getLangOpts().OpenCL && ASTTy->isSamplerT())
3470 return;
3471
3472 // If this is OpenMP device, check if it is legal to emit this global
3473 // normally.
3474 if (LangOpts.OpenMPIsDevice && OpenMPRuntime &&
3475 OpenMPRuntime->emitTargetGlobalVariable(D))
3476 return;
3477
3478 llvm::Constant *Init = nullptr;
3479 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
3480 bool NeedsGlobalCtor = false;
3481 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor();
3482
3483 const VarDecl *InitDecl;
3484 const Expr *InitExpr = D->getAnyInitializer(InitDecl);
3485
3486 Optional<ConstantEmitter> emitter;
3487
3488 // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
3489 // as part of their declaration." Sema has already checked for
3490 // error cases, so we just need to set Init to UndefValue.
3491 bool IsCUDASharedVar =
3492 getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
3493 // Shadows of initialized device-side global variables are also left
3494 // undefined.
3495 bool IsCUDAShadowVar =
3496 !getLangOpts().CUDAIsDevice &&
3497 (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
3498 D->hasAttr<CUDASharedAttr>());
3499 if (getLangOpts().CUDA && (IsCUDASharedVar || IsCUDAShadowVar))
3500 Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
3501 else if (!InitExpr) {
3502 // This is a tentative definition; tentative definitions are
3503 // implicitly initialized with { 0 }.
3504 //
3505 // Note that tentative definitions are only emitted at the end of
3506 // a translation unit, so they should never have incomplete
3507 // type. In addition, EmitTentativeDefinition makes sure that we
3508 // never attempt to emit a tentative definition if a real one
3509 // exists. A use may still exists, however, so we still may need
3510 // to do a RAUW.
3511 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
3512 Init = EmitNullConstant(D->getType());
3513 } else {
3514 initializedGlobalDecl = GlobalDecl(D);
3515 emitter.emplace(*this);
3516 Init = emitter->tryEmitForInitializer(*InitDecl);
3517
3518 if (!Init) {
3519 QualType T = InitExpr->getType();
3520 if (D->getType()->isReferenceType())
3521 T = D->getType();
3522
3523 if (getLangOpts().CPlusPlus) {
3524 Init = EmitNullConstant(T);
3525 NeedsGlobalCtor = true;
3526 } else {
3527 ErrorUnsupported(D, "static initializer");
3528 Init = llvm::UndefValue::get(getTypes().ConvertType(T));
3529 }
3530 } else {
3531 // We don't need an initializer, so remove the entry for the delayed
3532 // initializer position (just in case this entry was delayed) if we
3533 // also don't need to register a destructor.
3534 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor)
3535 DelayedCXXInitPosition.erase(D);
3536 }
3537 }
3538
3539 llvm::Type* InitType = Init->getType();
3540 llvm::Constant *Entry =
3541 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative));
3542
3543 // Strip off a bitcast if we got one back.
3544 if (auto *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
3545 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
3546 CE->getOpcode() == llvm::Instruction::AddrSpaceCast ||
3547 // All zero index gep.
3548 CE->getOpcode() == llvm::Instruction::GetElementPtr);
3549 Entry = CE->getOperand(0);
3550 }
3551
3552 // Entry is now either a Function or GlobalVariable.
3553 auto *GV = dyn_cast<llvm::GlobalVariable>(Entry);
3554
3555 // We have a definition after a declaration with the wrong type.
3556 // We must make a new GlobalVariable* and update everything that used OldGV
3557 // (a declaration or tentative definition) with the new GlobalVariable*
3558 // (which will be a definition).
3559 //
3560 // This happens if there is a prototype for a global (e.g.
3561 // "extern int x[];") and then a definition of a different type (e.g.
3562 // "int x[10];"). This also happens when an initializer has a different type
3563 // from the type of the global (this happens with unions).
3564 if (!GV || GV->getType()->getElementType() != InitType ||
3565 GV->getType()->getAddressSpace() !=
3566 getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) {
3567
3568 // Move the old entry aside so that we'll create a new one.
3569 Entry->setName(StringRef());
3570
3571 // Make a new global with the correct type, this is now guaranteed to work.
3572 GV = cast<llvm::GlobalVariable>(
3573 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative)));
3574
3575 // Replace all uses of the old global with the new global
3576 llvm::Constant *NewPtrForOldDecl =
3577 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
3578 Entry->replaceAllUsesWith(NewPtrForOldDecl);
3579
3580 // Erase the old global, since it is no longer used.
3581 cast<llvm::GlobalValue>(Entry)->eraseFromParent();
3582 }
3583
3584 MaybeHandleStaticInExternC(D, GV);
3585
3586 if (D->hasAttr<AnnotateAttr>())
3587 AddGlobalAnnotations(D, GV);
3588
3589 // Set the llvm linkage type as appropriate.
3590 llvm::GlobalValue::LinkageTypes Linkage =
3591 getLLVMLinkageVarDefinition(D, GV->isConstant());
3592
3593 // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on
3594 // the device. [...]"
3595 // CUDA B.2.2 "The __constant__ qualifier, optionally used together with
3596 // __device__, declares a variable that: [...]
3597 // Is accessible from all the threads within the grid and from the host
3598 // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize()
3599 // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())."
3600 if (GV && LangOpts.CUDA) {
3601 if (LangOpts.CUDAIsDevice) {
3602 if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>())
3603 GV->setExternallyInitialized(true);
3604 } else {
3605 // Host-side shadows of external declarations of device-side
3606 // global variables become internal definitions. These have to
3607 // be internal in order to prevent name conflicts with global
3608 // host variables with the same name in a different TUs.
3609 if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()) {
3610 Linkage = llvm::GlobalValue::InternalLinkage;
3611
3612 // Shadow variables and their properties must be registered
3613 // with CUDA runtime.
3614 unsigned Flags = 0;
3615 if (!D->hasDefinition())
3616 Flags |= CGCUDARuntime::ExternDeviceVar;
3617 if (D->hasAttr<CUDAConstantAttr>())
3618 Flags |= CGCUDARuntime::ConstantDeviceVar;
3619 // Extern global variables will be registered in the TU where they are
3620 // defined.
3621 if (!D->hasExternalStorage())
3622 getCUDARuntime().registerDeviceVar(*GV, Flags);
3623 } else if (D->hasAttr<CUDASharedAttr>())
3624 // __shared__ variables are odd. Shadows do get created, but
3625 // they are not registered with the CUDA runtime, so they
3626 // can't really be used to access their device-side
3627 // counterparts. It's not clear yet whether it's nvcc's bug or
3628 // a feature, but we've got to do the same for compatibility.
3629 Linkage = llvm::GlobalValue::InternalLinkage;
3630 }
3631 }
3632
3633 GV->setInitializer(Init);
3634 if (emitter) emitter->finalize(GV);
3635
3636 // If it is safe to mark the global 'constant', do so now.
3637 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor &&
3638 isTypeConstant(D->getType(), true));
3639
3640 // If it is in a read-only section, mark it 'constant'.
3641 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) {
3642 const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()];
3643 if ((SI.SectionFlags & ASTContext::PSF_Write) == 0)
3644 GV->setConstant(true);
3645 }
3646
3647 GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
3648
3649
3650 // On Darwin, if the normal linkage of a C++ thread_local variable is
3651 // LinkOnce or Weak, we keep the normal linkage to prevent multiple
3652 // copies within a linkage unit; otherwise, the backing variable has
3653 // internal linkage and all accesses should just be calls to the
3654 // Itanium-specified entry point, which has the normal linkage of the
3655 // variable. This is to preserve the ability to change the implementation
3656 // behind the scenes.
3657 if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic &&
3658 Context.getTargetInfo().getTriple().isOSDarwin() &&
3659 !llvm::GlobalVariable::isLinkOnceLinkage(Linkage) &&
3660 !llvm::GlobalVariable::isWeakLinkage(Linkage))
3661 Linkage = llvm::GlobalValue::InternalLinkage;
3662
3663 GV->setLinkage(Linkage);
3664 if (D->hasAttr<DLLImportAttr>())
3665 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass);
3666 else if (D->hasAttr<DLLExportAttr>())
3667 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass);
3668 else
3669 GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass);
3670
3671 if (Linkage == llvm::GlobalVariable::CommonLinkage) {
3672 // common vars aren't constant even if declared const.
3673 GV->setConstant(false);
3674 // Tentative definition of global variables may be initialized with
3675 // non-zero null pointers. In this case they should have weak linkage
3676 // since common linkage must have zero initializer and must not have
3677 // explicit section therefore cannot have non-zero initial value.
3678 if (!GV->getInitializer()->isNullValue())
3679 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage);
3680 }
3681
3682 setNonAliasAttributes(D, GV);
3683
3684 if (D->getTLSKind() && !GV->isThreadLocal()) {
3685 if (D->getTLSKind() == VarDecl::TLS_Dynamic)
3686 CXXThreadLocals.push_back(D);
3687 setTLSMode(GV, *D);
3688 }
3689
3690 maybeSetTrivialComdat(*D, *GV);
3691
3692 // Emit the initializer function if necessary.
3693 if (NeedsGlobalCtor || NeedsGlobalDtor)
3694 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
3695
3696 SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor);
3697
3698 // Emit global variable debug information.
3699 if (CGDebugInfo *DI = getModuleDebugInfo())
3700 if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
3701 DI->EmitGlobalVariable(GV, D);
3702 }
3703
isVarDeclStrongDefinition(const ASTContext & Context,CodeGenModule & CGM,const VarDecl * D,bool NoCommon)3704 static bool isVarDeclStrongDefinition(const ASTContext &Context,
3705 CodeGenModule &CGM, const VarDecl *D,
3706 bool NoCommon) {
3707 // Don't give variables common linkage if -fno-common was specified unless it
3708 // was overridden by a NoCommon attribute.
3709 if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>())
3710 return true;
3711
3712 // C11 6.9.2/2:
3713 // A declaration of an identifier for an object that has file scope without
3714 // an initializer, and without a storage-class specifier or with the
3715 // storage-class specifier static, constitutes a tentative definition.
3716 if (D->getInit() || D->hasExternalStorage())
3717 return true;
3718
3719 // A variable cannot be both common and exist in a section.
3720 if (D->hasAttr<SectionAttr>())
3721 return true;
3722
3723 // A variable cannot be both common and exist in a section.
3724 // We don't try to determine which is the right section in the front-end.
3725 // If no specialized section name is applicable, it will resort to default.
3726 if (D->hasAttr<PragmaClangBSSSectionAttr>() ||
3727 D->hasAttr<PragmaClangDataSectionAttr>() ||
3728 D->hasAttr<PragmaClangRodataSectionAttr>())
3729 return true;
3730
3731 // Thread local vars aren't considered common linkage.
3732 if (D->getTLSKind())
3733 return true;
3734
3735 // Tentative definitions marked with WeakImportAttr are true definitions.
3736 if (D->hasAttr<WeakImportAttr>())
3737 return true;
3738
3739 // A variable cannot be both common and exist in a comdat.
3740 if (shouldBeInCOMDAT(CGM, *D))
3741 return true;
3742
3743 // Declarations with a required alignment do not have common linkage in MSVC
3744 // mode.
3745 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
3746 if (D->hasAttr<AlignedAttr>())
3747 return true;
3748 QualType VarType = D->getType();
3749 if (Context.isAlignmentRequired(VarType))
3750 return true;
3751
3752 if (const auto *RT = VarType->getAs<RecordType>()) {
3753 const RecordDecl *RD = RT->getDecl();
3754 for (const FieldDecl *FD : RD->fields()) {
3755 if (FD->isBitField())
3756 continue;
3757 if (FD->hasAttr<AlignedAttr>())
3758 return true;
3759 if (Context.isAlignmentRequired(FD->getType()))
3760 return true;
3761 }
3762 }
3763 }
3764
3765 // Microsoft's link.exe doesn't support alignments greater than 32 bytes for
3766 // common symbols, so symbols with greater alignment requirements cannot be
3767 // common.
3768 // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
3769 // alignments for common symbols via the aligncomm directive, so this
3770 // restriction only applies to MSVC environments.
3771 if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
3772 Context.getTypeAlignIfKnown(D->getType()) >
3773 Context.toBits(CharUnits::fromQuantity(32)))
3774 return true;
3775
3776 return false;
3777 }
3778
getLLVMLinkageForDeclarator(const DeclaratorDecl * D,GVALinkage Linkage,bool IsConstantVariable)3779 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
3780 const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) {
3781 if (Linkage == GVA_Internal)
3782 return llvm::Function::InternalLinkage;
3783
3784 if (D->hasAttr<WeakAttr>()) {
3785 if (IsConstantVariable)
3786 return llvm::GlobalVariable::WeakODRLinkage;
3787 else
3788 return llvm::GlobalVariable::WeakAnyLinkage;
3789 }
3790
3791 if (const auto *FD = D->getAsFunction())
3792 if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
3793 return llvm::GlobalVariable::LinkOnceAnyLinkage;
3794
3795 // We are guaranteed to have a strong definition somewhere else,
3796 // so we can use available_externally linkage.
3797 if (Linkage == GVA_AvailableExternally)
3798 return llvm::GlobalValue::AvailableExternallyLinkage;
3799
3800 // Note that Apple's kernel linker doesn't support symbol
3801 // coalescing, so we need to avoid linkonce and weak linkages there.
3802 // Normally, this means we just map to internal, but for explicit
3803 // instantiations we'll map to external.
3804
3805 // In C++, the compiler has to emit a definition in every translation unit
3806 // that references the function. We should use linkonce_odr because
3807 // a) if all references in this translation unit are optimized away, we
3808 // don't need to codegen it. b) if the function persists, it needs to be
3809 // merged with other definitions. c) C++ has the ODR, so we know the
3810 // definition is dependable.
3811 if (Linkage == GVA_DiscardableODR)
3812 return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage
3813 : llvm::Function::InternalLinkage;
3814
3815 // An explicit instantiation of a template has weak linkage, since
3816 // explicit instantiations can occur in multiple translation units
3817 // and must all be equivalent. However, we are not allowed to
3818 // throw away these explicit instantiations.
3819 //
3820 // We don't currently support CUDA device code spread out across multiple TUs,
3821 // so say that CUDA templates are either external (for kernels) or internal.
3822 // This lets llvm perform aggressive inter-procedural optimizations.
3823 if (Linkage == GVA_StrongODR) {
3824 if (Context.getLangOpts().AppleKext)
3825 return llvm::Function::ExternalLinkage;
3826 if (Context.getLangOpts().CUDA && Context.getLangOpts().CUDAIsDevice)
3827 return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage
3828 : llvm::Function::InternalLinkage;
3829 return llvm::Function::WeakODRLinkage;
3830 }
3831
3832 // C++ doesn't have tentative definitions and thus cannot have common
3833 // linkage.
3834 if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) &&
3835 !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D),
3836 CodeGenOpts.NoCommon))
3837 return llvm::GlobalVariable::CommonLinkage;
3838
3839 // selectany symbols are externally visible, so use weak instead of
3840 // linkonce. MSVC optimizes away references to const selectany globals, so
3841 // all definitions should be the same and ODR linkage should be used.
3842 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx
3843 if (D->hasAttr<SelectAnyAttr>())
3844 return llvm::GlobalVariable::WeakODRLinkage;
3845
3846 // Otherwise, we have strong external linkage.
3847 assert(Linkage == GVA_StrongExternal);
3848 return llvm::GlobalVariable::ExternalLinkage;
3849 }
3850
getLLVMLinkageVarDefinition(const VarDecl * VD,bool IsConstant)3851 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition(
3852 const VarDecl *VD, bool IsConstant) {
3853 GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD);
3854 return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant);
3855 }
3856
3857 /// Replace the uses of a function that was declared with a non-proto type.
3858 /// We want to silently drop extra arguments from call sites
replaceUsesOfNonProtoConstant(llvm::Constant * old,llvm::Function * newFn)3859 static void replaceUsesOfNonProtoConstant(llvm::Constant *old,
3860 llvm::Function *newFn) {
3861 // Fast path.
3862 if (old->use_empty()) return;
3863
3864 llvm::Type *newRetTy = newFn->getReturnType();
3865 SmallVector<llvm::Value*, 4> newArgs;
3866 SmallVector<llvm::OperandBundleDef, 1> newBundles;
3867
3868 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end();
3869 ui != ue; ) {
3870 llvm::Value::use_iterator use = ui++; // Increment before the use is erased.
3871 llvm::User *user = use->getUser();
3872
3873 // Recognize and replace uses of bitcasts. Most calls to
3874 // unprototyped functions will use bitcasts.
3875 if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) {
3876 if (bitcast->getOpcode() == llvm::Instruction::BitCast)
3877 replaceUsesOfNonProtoConstant(bitcast, newFn);
3878 continue;
3879 }
3880
3881 // Recognize calls to the function.
3882 llvm::CallSite callSite(user);
3883 if (!callSite) continue;
3884 if (!callSite.isCallee(&*use)) continue;
3885
3886 // If the return types don't match exactly, then we can't
3887 // transform this call unless it's dead.
3888 if (callSite->getType() != newRetTy && !callSite->use_empty())
3889 continue;
3890
3891 // Get the call site's attribute list.
3892 SmallVector<llvm::AttributeSet, 8> newArgAttrs;
3893 llvm::AttributeList oldAttrs = callSite.getAttributes();
3894
3895 // If the function was passed too few arguments, don't transform.
3896 unsigned newNumArgs = newFn->arg_size();
3897 if (callSite.arg_size() < newNumArgs) continue;
3898
3899 // If extra arguments were passed, we silently drop them.
3900 // If any of the types mismatch, we don't transform.
3901 unsigned argNo = 0;
3902 bool dontTransform = false;
3903 for (llvm::Argument &A : newFn->args()) {
3904 if (callSite.getArgument(argNo)->getType() != A.getType()) {
3905 dontTransform = true;
3906 break;
3907 }
3908
3909 // Add any parameter attributes.
3910 newArgAttrs.push_back(oldAttrs.getParamAttributes(argNo));
3911 argNo++;
3912 }
3913 if (dontTransform)
3914 continue;
3915
3916 // Okay, we can transform this. Create the new call instruction and copy
3917 // over the required information.
3918 newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo);
3919
3920 // Copy over any operand bundles.
3921 callSite.getOperandBundlesAsDefs(newBundles);
3922
3923 llvm::CallSite newCall;
3924 if (callSite.isCall()) {
3925 newCall = llvm::CallInst::Create(newFn, newArgs, newBundles, "",
3926 callSite.getInstruction());
3927 } else {
3928 auto *oldInvoke = cast<llvm::InvokeInst>(callSite.getInstruction());
3929 newCall = llvm::InvokeInst::Create(newFn,
3930 oldInvoke->getNormalDest(),
3931 oldInvoke->getUnwindDest(),
3932 newArgs, newBundles, "",
3933 callSite.getInstruction());
3934 }
3935 newArgs.clear(); // for the next iteration
3936
3937 if (!newCall->getType()->isVoidTy())
3938 newCall->takeName(callSite.getInstruction());
3939 newCall.setAttributes(llvm::AttributeList::get(
3940 newFn->getContext(), oldAttrs.getFnAttributes(),
3941 oldAttrs.getRetAttributes(), newArgAttrs));
3942 newCall.setCallingConv(callSite.getCallingConv());
3943
3944 // Finally, remove the old call, replacing any uses with the new one.
3945 if (!callSite->use_empty())
3946 callSite->replaceAllUsesWith(newCall.getInstruction());
3947
3948 // Copy debug location attached to CI.
3949 if (callSite->getDebugLoc())
3950 newCall->setDebugLoc(callSite->getDebugLoc());
3951
3952 callSite->eraseFromParent();
3953 }
3954 }
3955
3956 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
3957 /// implement a function with no prototype, e.g. "int foo() {}". If there are
3958 /// existing call uses of the old function in the module, this adjusts them to
3959 /// call the new function directly.
3960 ///
3961 /// This is not just a cleanup: the always_inline pass requires direct calls to
3962 /// functions to be able to inline them. If there is a bitcast in the way, it
3963 /// won't inline them. Instcombine normally deletes these calls, but it isn't
3964 /// run at -O0.
ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue * Old,llvm::Function * NewFn)3965 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
3966 llvm::Function *NewFn) {
3967 // If we're redefining a global as a function, don't transform it.
3968 if (!isa<llvm::Function>(Old)) return;
3969
3970 replaceUsesOfNonProtoConstant(Old, NewFn);
3971 }
3972
HandleCXXStaticMemberVarInstantiation(VarDecl * VD)3973 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) {
3974 auto DK = VD->isThisDeclarationADefinition();
3975 if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>())
3976 return;
3977
3978 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind();
3979 // If we have a definition, this might be a deferred decl. If the
3980 // instantiation is explicit, make sure we emit it at the end.
3981 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition)
3982 GetAddrOfGlobalVar(VD);
3983
3984 EmitTopLevelDecl(VD);
3985 }
3986
EmitGlobalFunctionDefinition(GlobalDecl GD,llvm::GlobalValue * GV)3987 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
3988 llvm::GlobalValue *GV) {
3989 const auto *D = cast<FunctionDecl>(GD.getDecl());
3990
3991 // Compute the function info and LLVM type.
3992 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD);
3993 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI);
3994
3995 // Get or create the prototype for the function.
3996 if (!GV || (GV->getType()->getElementType() != Ty))
3997 GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false,
3998 /*DontDefer=*/true,
3999 ForDefinition));
4000
4001 // Already emitted.
4002 if (!GV->isDeclaration())
4003 return;
4004
4005 // We need to set linkage and visibility on the function before
4006 // generating code for it because various parts of IR generation
4007 // want to propagate this information down (e.g. to local static
4008 // declarations).
4009 auto *Fn = cast<llvm::Function>(GV);
4010 setFunctionLinkage(GD, Fn);
4011
4012 // FIXME: this is redundant with part of setFunctionDefinitionAttributes
4013 setGVProperties(Fn, GD);
4014
4015 MaybeHandleStaticInExternC(D, Fn);
4016
4017
4018 maybeSetTrivialComdat(*D, *Fn);
4019
4020 CodeGenFunction(*this).GenerateCode(D, Fn, FI);
4021
4022 setNonAliasAttributes(GD, Fn);
4023 SetLLVMFunctionAttributesForDefinition(D, Fn);
4024
4025 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
4026 AddGlobalCtor(Fn, CA->getPriority());
4027 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
4028 AddGlobalDtor(Fn, DA->getPriority());
4029 if (D->hasAttr<AnnotateAttr>())
4030 AddGlobalAnnotations(D, Fn);
4031 }
4032
EmitAliasDefinition(GlobalDecl GD)4033 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
4034 const auto *D = cast<ValueDecl>(GD.getDecl());
4035 const AliasAttr *AA = D->getAttr<AliasAttr>();
4036 assert(AA && "Not an alias?");
4037
4038 StringRef MangledName = getMangledName(GD);
4039
4040 if (AA->getAliasee() == MangledName) {
4041 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4042 return;
4043 }
4044
4045 // If there is a definition in the module, then it wins over the alias.
4046 // This is dubious, but allow it to be safe. Just ignore the alias.
4047 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4048 if (Entry && !Entry->isDeclaration())
4049 return;
4050
4051 Aliases.push_back(GD);
4052
4053 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4054
4055 // Create a reference to the named value. This ensures that it is emitted
4056 // if a deferred decl.
4057 llvm::Constant *Aliasee;
4058 if (isa<llvm::FunctionType>(DeclTy))
4059 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD,
4060 /*ForVTable=*/false);
4061 else
4062 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
4063 llvm::PointerType::getUnqual(DeclTy),
4064 /*D=*/nullptr);
4065
4066 // Create the new alias itself, but don't set a name yet.
4067 auto *GA = llvm::GlobalAlias::create(
4068 DeclTy, 0, llvm::Function::ExternalLinkage, "", Aliasee, &getModule());
4069
4070 if (Entry) {
4071 if (GA->getAliasee() == Entry) {
4072 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0;
4073 return;
4074 }
4075
4076 assert(Entry->isDeclaration());
4077
4078 // If there is a declaration in the module, then we had an extern followed
4079 // by the alias, as in:
4080 // extern int test6();
4081 // ...
4082 // int test6() __attribute__((alias("test7")));
4083 //
4084 // Remove it and replace uses of it with the alias.
4085 GA->takeName(Entry);
4086
4087 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
4088 Entry->getType()));
4089 Entry->eraseFromParent();
4090 } else {
4091 GA->setName(MangledName);
4092 }
4093
4094 // Set attributes which are particular to an alias; this is a
4095 // specialization of the attributes which may be set on a global
4096 // variable/function.
4097 if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() ||
4098 D->isWeakImported()) {
4099 GA->setLinkage(llvm::Function::WeakAnyLinkage);
4100 }
4101
4102 if (const auto *VD = dyn_cast<VarDecl>(D))
4103 if (VD->getTLSKind())
4104 setTLSMode(GA, *VD);
4105
4106 SetCommonAttributes(GD, GA);
4107 }
4108
emitIFuncDefinition(GlobalDecl GD)4109 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) {
4110 const auto *D = cast<ValueDecl>(GD.getDecl());
4111 const IFuncAttr *IFA = D->getAttr<IFuncAttr>();
4112 assert(IFA && "Not an ifunc?");
4113
4114 StringRef MangledName = getMangledName(GD);
4115
4116 if (IFA->getResolver() == MangledName) {
4117 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4118 return;
4119 }
4120
4121 // Report an error if some definition overrides ifunc.
4122 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
4123 if (Entry && !Entry->isDeclaration()) {
4124 GlobalDecl OtherGD;
4125 if (lookupRepresentativeDecl(MangledName, OtherGD) &&
4126 DiagnosedConflictingDefinitions.insert(GD).second) {
4127 Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name)
4128 << MangledName;
4129 Diags.Report(OtherGD.getDecl()->getLocation(),
4130 diag::note_previous_definition);
4131 }
4132 return;
4133 }
4134
4135 Aliases.push_back(GD);
4136
4137 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
4138 llvm::Constant *Resolver =
4139 GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD,
4140 /*ForVTable=*/false);
4141 llvm::GlobalIFunc *GIF =
4142 llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage,
4143 "", Resolver, &getModule());
4144 if (Entry) {
4145 if (GIF->getResolver() == Entry) {
4146 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1;
4147 return;
4148 }
4149 assert(Entry->isDeclaration());
4150
4151 // If there is a declaration in the module, then we had an extern followed
4152 // by the ifunc, as in:
4153 // extern int test();
4154 // ...
4155 // int test() __attribute__((ifunc("resolver")));
4156 //
4157 // Remove it and replace uses of it with the ifunc.
4158 GIF->takeName(Entry);
4159
4160 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF,
4161 Entry->getType()));
4162 Entry->eraseFromParent();
4163 } else
4164 GIF->setName(MangledName);
4165
4166 SetCommonAttributes(GD, GIF);
4167 }
4168
getIntrinsic(unsigned IID,ArrayRef<llvm::Type * > Tys)4169 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
4170 ArrayRef<llvm::Type*> Tys) {
4171 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
4172 Tys);
4173 }
4174
4175 static llvm::StringMapEntry<llvm::GlobalVariable *> &
GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable * > & Map,const StringLiteral * Literal,bool TargetIsLSB,bool & IsUTF16,unsigned & StringLength)4176 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map,
4177 const StringLiteral *Literal, bool TargetIsLSB,
4178 bool &IsUTF16, unsigned &StringLength) {
4179 StringRef String = Literal->getString();
4180 unsigned NumBytes = String.size();
4181
4182 // Check for simple case.
4183 if (!Literal->containsNonAsciiOrNull()) {
4184 StringLength = NumBytes;
4185 return *Map.insert(std::make_pair(String, nullptr)).first;
4186 }
4187
4188 // Otherwise, convert the UTF8 literals into a string of shorts.
4189 IsUTF16 = true;
4190
4191 SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls.
4192 const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data();
4193 llvm::UTF16 *ToPtr = &ToBuf[0];
4194
4195 (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr,
4196 ToPtr + NumBytes, llvm::strictConversion);
4197
4198 // ConvertUTF8toUTF16 returns the length in ToPtr.
4199 StringLength = ToPtr - &ToBuf[0];
4200
4201 // Add an explicit null.
4202 *ToPtr = 0;
4203 return *Map.insert(std::make_pair(
4204 StringRef(reinterpret_cast<const char *>(ToBuf.data()),
4205 (StringLength + 1) * 2),
4206 nullptr)).first;
4207 }
4208
4209 ConstantAddress
GetAddrOfConstantCFString(const StringLiteral * Literal)4210 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
4211 unsigned StringLength = 0;
4212 bool isUTF16 = false;
4213 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
4214 GetConstantCFStringEntry(CFConstantStringMap, Literal,
4215 getDataLayout().isLittleEndian(), isUTF16,
4216 StringLength);
4217
4218 if (auto *C = Entry.second)
4219 return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment()));
4220
4221 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
4222 llvm::Constant *Zeros[] = { Zero, Zero };
4223
4224 const ASTContext &Context = getContext();
4225 const llvm::Triple &Triple = getTriple();
4226
4227 const auto CFRuntime = getLangOpts().CFRuntime;
4228 const bool IsSwiftABI =
4229 static_cast<unsigned>(CFRuntime) >=
4230 static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
4231 const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
4232
4233 // If we don't already have it, get __CFConstantStringClassReference.
4234 if (!CFConstantStringClassRef) {
4235 const char *CFConstantStringClassName = "__CFConstantStringClassReference";
4236 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
4237 Ty = llvm::ArrayType::get(Ty, 0);
4238
4239 switch (CFRuntime) {
4240 default: break;
4241 case LangOptions::CoreFoundationABI::Swift: LLVM_FALLTHROUGH;
4242 case LangOptions::CoreFoundationABI::Swift5_0:
4243 CFConstantStringClassName =
4244 Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
4245 : "$s10Foundation19_NSCFConstantStringCN";
4246 Ty = IntPtrTy;
4247 break;
4248 case LangOptions::CoreFoundationABI::Swift4_2:
4249 CFConstantStringClassName =
4250 Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
4251 : "$S10Foundation19_NSCFConstantStringCN";
4252 Ty = IntPtrTy;
4253 break;
4254 case LangOptions::CoreFoundationABI::Swift4_1:
4255 CFConstantStringClassName =
4256 Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
4257 : "__T010Foundation19_NSCFConstantStringCN";
4258 Ty = IntPtrTy;
4259 break;
4260 }
4261
4262 llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
4263
4264 if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
4265 llvm::GlobalValue *GV = nullptr;
4266
4267 if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
4268 IdentifierInfo &II = Context.Idents.get(GV->getName());
4269 TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
4270 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
4271
4272 const VarDecl *VD = nullptr;
4273 for (const auto &Result : DC->lookup(&II))
4274 if ((VD = dyn_cast<VarDecl>(Result)))
4275 break;
4276
4277 if (Triple.isOSBinFormatELF()) {
4278 if (!VD)
4279 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
4280 } else {
4281 GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
4282 if (!VD || !VD->hasAttr<DLLExportAttr>())
4283 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
4284 else
4285 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
4286 }
4287
4288 setDSOLocal(GV);
4289 }
4290 }
4291
4292 // Decay array -> ptr
4293 CFConstantStringClassRef =
4294 IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty)
4295 : llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros);
4296 }
4297
4298 QualType CFTy = Context.getCFConstantStringType();
4299
4300 auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
4301
4302 ConstantInitBuilder Builder(*this);
4303 auto Fields = Builder.beginStruct(STy);
4304
4305 // Class pointer.
4306 Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
4307
4308 // Flags.
4309 if (IsSwiftABI) {
4310 Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
4311 Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
4312 } else {
4313 Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
4314 }
4315
4316 // String pointer.
4317 llvm::Constant *C = nullptr;
4318 if (isUTF16) {
4319 auto Arr = llvm::makeArrayRef(
4320 reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())),
4321 Entry.first().size() / 2);
4322 C = llvm::ConstantDataArray::get(VMContext, Arr);
4323 } else {
4324 C = llvm::ConstantDataArray::getString(VMContext, Entry.first());
4325 }
4326
4327 // Note: -fwritable-strings doesn't make the backing store strings of
4328 // CFStrings writable. (See <rdar://problem/10657500>)
4329 auto *GV =
4330 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true,
4331 llvm::GlobalValue::PrivateLinkage, C, ".str");
4332 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4333 // Don't enforce the target's minimum global alignment, since the only use
4334 // of the string is via this class initializer.
4335 CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
4336 : Context.getTypeAlignInChars(Context.CharTy);
4337 GV->setAlignment(Align.getQuantity());
4338
4339 // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
4340 // Without it LLVM can merge the string with a non unnamed_addr one during
4341 // LTO. Doing that changes the section it ends in, which surprises ld64.
4342 if (Triple.isOSBinFormatMachO())
4343 GV->setSection(isUTF16 ? "__TEXT,__ustring"
4344 : "__TEXT,__cstring,cstring_literals");
4345 // Make sure the literal ends up in .rodata to allow for safe ICF and for
4346 // the static linker to adjust permissions to read-only later on.
4347 else if (Triple.isOSBinFormatELF())
4348 GV->setSection(".rodata");
4349
4350 // String.
4351 llvm::Constant *Str =
4352 llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros);
4353
4354 if (isUTF16)
4355 // Cast the UTF16 string to the correct type.
4356 Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy);
4357 Fields.add(Str);
4358
4359 // String length.
4360 llvm::IntegerType *LengthTy =
4361 llvm::IntegerType::get(getModule().getContext(),
4362 Context.getTargetInfo().getLongWidth());
4363 if (IsSwiftABI) {
4364 if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
4365 CFRuntime == LangOptions::CoreFoundationABI::Swift4_2)
4366 LengthTy = Int32Ty;
4367 else
4368 LengthTy = IntPtrTy;
4369 }
4370 Fields.addInt(LengthTy, StringLength);
4371
4372 CharUnits Alignment = getPointerAlign();
4373
4374 // The struct.
4375 GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
4376 /*isConstant=*/false,
4377 llvm::GlobalVariable::PrivateLinkage);
4378 switch (Triple.getObjectFormat()) {
4379 case llvm::Triple::UnknownObjectFormat:
4380 llvm_unreachable("unknown file format");
4381 case llvm::Triple::COFF:
4382 case llvm::Triple::ELF:
4383 case llvm::Triple::Wasm:
4384 GV->setSection("cfstring");
4385 break;
4386 case llvm::Triple::MachO:
4387 GV->setSection("__DATA,__cfstring");
4388 break;
4389 }
4390 Entry.second = GV;
4391
4392 return ConstantAddress(GV, Alignment);
4393 }
4394
getExpressionLocationsEnabled() const4395 bool CodeGenModule::getExpressionLocationsEnabled() const {
4396 return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo;
4397 }
4398
getObjCFastEnumerationStateType()4399 QualType CodeGenModule::getObjCFastEnumerationStateType() {
4400 if (ObjCFastEnumerationStateType.isNull()) {
4401 RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState");
4402 D->startDefinition();
4403
4404 QualType FieldTypes[] = {
4405 Context.UnsignedLongTy,
4406 Context.getPointerType(Context.getObjCIdType()),
4407 Context.getPointerType(Context.UnsignedLongTy),
4408 Context.getConstantArrayType(Context.UnsignedLongTy,
4409 llvm::APInt(32, 5), ArrayType::Normal, 0)
4410 };
4411
4412 for (size_t i = 0; i < 4; ++i) {
4413 FieldDecl *Field = FieldDecl::Create(Context,
4414 D,
4415 SourceLocation(),
4416 SourceLocation(), nullptr,
4417 FieldTypes[i], /*TInfo=*/nullptr,
4418 /*BitWidth=*/nullptr,
4419 /*Mutable=*/false,
4420 ICIS_NoInit);
4421 Field->setAccess(AS_public);
4422 D->addDecl(Field);
4423 }
4424
4425 D->completeDefinition();
4426 ObjCFastEnumerationStateType = Context.getTagDeclType(D);
4427 }
4428
4429 return ObjCFastEnumerationStateType;
4430 }
4431
4432 llvm::Constant *
GetConstantArrayFromStringLiteral(const StringLiteral * E)4433 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) {
4434 assert(!E->getType()->isPointerType() && "Strings are always arrays");
4435
4436 // Don't emit it as the address of the string, emit the string data itself
4437 // as an inline array.
4438 if (E->getCharByteWidth() == 1) {
4439 SmallString<64> Str(E->getString());
4440
4441 // Resize the string to the right size, which is indicated by its type.
4442 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType());
4443 Str.resize(CAT->getSize().getZExtValue());
4444 return llvm::ConstantDataArray::getString(VMContext, Str, false);
4445 }
4446
4447 auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType()));
4448 llvm::Type *ElemTy = AType->getElementType();
4449 unsigned NumElements = AType->getNumElements();
4450
4451 // Wide strings have either 2-byte or 4-byte elements.
4452 if (ElemTy->getPrimitiveSizeInBits() == 16) {
4453 SmallVector<uint16_t, 32> Elements;
4454 Elements.reserve(NumElements);
4455
4456 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
4457 Elements.push_back(E->getCodeUnit(i));
4458 Elements.resize(NumElements);
4459 return llvm::ConstantDataArray::get(VMContext, Elements);
4460 }
4461
4462 assert(ElemTy->getPrimitiveSizeInBits() == 32);
4463 SmallVector<uint32_t, 32> Elements;
4464 Elements.reserve(NumElements);
4465
4466 for(unsigned i = 0, e = E->getLength(); i != e; ++i)
4467 Elements.push_back(E->getCodeUnit(i));
4468 Elements.resize(NumElements);
4469 return llvm::ConstantDataArray::get(VMContext, Elements);
4470 }
4471
4472 static llvm::GlobalVariable *
GenerateStringLiteral(llvm::Constant * C,llvm::GlobalValue::LinkageTypes LT,CodeGenModule & CGM,StringRef GlobalName,CharUnits Alignment)4473 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT,
4474 CodeGenModule &CGM, StringRef GlobalName,
4475 CharUnits Alignment) {
4476 unsigned AddrSpace = CGM.getContext().getTargetAddressSpace(
4477 CGM.getStringLiteralAddressSpace());
4478
4479 llvm::Module &M = CGM.getModule();
4480 // Create a global variable for this string
4481 auto *GV = new llvm::GlobalVariable(
4482 M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName,
4483 nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace);
4484 GV->setAlignment(Alignment.getQuantity());
4485 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4486 if (GV->isWeakForLinker()) {
4487 assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals");
4488 GV->setComdat(M.getOrInsertComdat(GV->getName()));
4489 }
4490 CGM.setDSOLocal(GV);
4491
4492 return GV;
4493 }
4494
4495 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
4496 /// constant array for the given string literal.
4497 ConstantAddress
GetAddrOfConstantStringFromLiteral(const StringLiteral * S,StringRef Name)4498 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
4499 StringRef Name) {
4500 CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType());
4501
4502 llvm::Constant *C = GetConstantArrayFromStringLiteral(S);
4503 llvm::GlobalVariable **Entry = nullptr;
4504 if (!LangOpts.WritableStrings) {
4505 Entry = &ConstantStringMap[C];
4506 if (auto GV = *Entry) {
4507 if (Alignment.getQuantity() > GV->getAlignment())
4508 GV->setAlignment(Alignment.getQuantity());
4509 return ConstantAddress(GV, Alignment);
4510 }
4511 }
4512
4513 SmallString<256> MangledNameBuffer;
4514 StringRef GlobalVariableName;
4515 llvm::GlobalValue::LinkageTypes LT;
4516
4517 // Mangle the string literal if that's how the ABI merges duplicate strings.
4518 // Don't do it if they are writable, since we don't want writes in one TU to
4519 // affect strings in another.
4520 if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
4521 !LangOpts.WritableStrings) {
4522 llvm::raw_svector_ostream Out(MangledNameBuffer);
4523 getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
4524 LT = llvm::GlobalValue::LinkOnceODRLinkage;
4525 GlobalVariableName = MangledNameBuffer;
4526 } else {
4527 LT = llvm::GlobalValue::PrivateLinkage;
4528 GlobalVariableName = Name;
4529 }
4530
4531 auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment);
4532 if (Entry)
4533 *Entry = GV;
4534
4535 SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>",
4536 QualType());
4537
4538 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
4539 Alignment);
4540 }
4541
4542 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
4543 /// array for the given ObjCEncodeExpr node.
4544 ConstantAddress
GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr * E)4545 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
4546 std::string Str;
4547 getContext().getObjCEncodingForType(E->getEncodedType(), Str);
4548
4549 return GetAddrOfConstantCString(Str);
4550 }
4551
4552 /// GetAddrOfConstantCString - Returns a pointer to a character array containing
4553 /// the literal and a terminating '\0' character.
4554 /// The result has pointer to array type.
GetAddrOfConstantCString(const std::string & Str,const char * GlobalName)4555 ConstantAddress CodeGenModule::GetAddrOfConstantCString(
4556 const std::string &Str, const char *GlobalName) {
4557 StringRef StrWithNull(Str.c_str(), Str.size() + 1);
4558 CharUnits Alignment =
4559 getContext().getAlignOfGlobalVarInChars(getContext().CharTy);
4560
4561 llvm::Constant *C =
4562 llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false);
4563
4564 // Don't share any string literals if strings aren't constant.
4565 llvm::GlobalVariable **Entry = nullptr;
4566 if (!LangOpts.WritableStrings) {
4567 Entry = &ConstantStringMap[C];
4568 if (auto GV = *Entry) {
4569 if (Alignment.getQuantity() > GV->getAlignment())
4570 GV->setAlignment(Alignment.getQuantity());
4571 return ConstantAddress(GV, Alignment);
4572 }
4573 }
4574
4575 // Get the default prefix if a name wasn't specified.
4576 if (!GlobalName)
4577 GlobalName = ".str";
4578 // Create a global variable for this.
4579 auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this,
4580 GlobalName, Alignment);
4581 if (Entry)
4582 *Entry = GV;
4583
4584 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV),
4585 Alignment);
4586 }
4587
GetAddrOfGlobalTemporary(const MaterializeTemporaryExpr * E,const Expr * Init)4588 ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary(
4589 const MaterializeTemporaryExpr *E, const Expr *Init) {
4590 assert((E->getStorageDuration() == SD_Static ||
4591 E->getStorageDuration() == SD_Thread) && "not a global temporary");
4592 const auto *VD = cast<VarDecl>(E->getExtendingDecl());
4593
4594 // If we're not materializing a subobject of the temporary, keep the
4595 // cv-qualifiers from the type of the MaterializeTemporaryExpr.
4596 QualType MaterializedType = Init->getType();
4597 if (Init == E->GetTemporaryExpr())
4598 MaterializedType = E->getType();
4599
4600 CharUnits Align = getContext().getTypeAlignInChars(MaterializedType);
4601
4602 if (llvm::Constant *Slot = MaterializedGlobalTemporaryMap[E])
4603 return ConstantAddress(Slot, Align);
4604
4605 // FIXME: If an externally-visible declaration extends multiple temporaries,
4606 // we need to give each temporary the same name in every translation unit (and
4607 // we also need to make the temporaries externally-visible).
4608 SmallString<256> Name;
4609 llvm::raw_svector_ostream Out(Name);
4610 getCXXABI().getMangleContext().mangleReferenceTemporary(
4611 VD, E->getManglingNumber(), Out);
4612
4613 APValue *Value = nullptr;
4614 if (E->getStorageDuration() == SD_Static) {
4615 // We might have a cached constant initializer for this temporary. Note
4616 // that this might have a different value from the value computed by
4617 // evaluating the initializer if the surrounding constant expression
4618 // modifies the temporary.
4619 Value = getContext().getMaterializedTemporaryValue(E, false);
4620 if (Value && Value->isUninit())
4621 Value = nullptr;
4622 }
4623
4624 // Try evaluating it now, it might have a constant initializer.
4625 Expr::EvalResult EvalResult;
4626 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) &&
4627 !EvalResult.hasSideEffects())
4628 Value = &EvalResult.Val;
4629
4630 LangAS AddrSpace =
4631 VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace();
4632
4633 Optional<ConstantEmitter> emitter;
4634 llvm::Constant *InitialValue = nullptr;
4635 bool Constant = false;
4636 llvm::Type *Type;
4637 if (Value) {
4638 // The temporary has a constant initializer, use it.
4639 emitter.emplace(*this);
4640 InitialValue = emitter->emitForInitializer(*Value, AddrSpace,
4641 MaterializedType);
4642 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value);
4643 Type = InitialValue->getType();
4644 } else {
4645 // No initializer, the initialization will be provided when we
4646 // initialize the declaration which performed lifetime extension.
4647 Type = getTypes().ConvertTypeForMem(MaterializedType);
4648 }
4649
4650 // Create a global variable for this lifetime-extended temporary.
4651 llvm::GlobalValue::LinkageTypes Linkage =
4652 getLLVMLinkageVarDefinition(VD, Constant);
4653 if (Linkage == llvm::GlobalVariable::ExternalLinkage) {
4654 const VarDecl *InitVD;
4655 if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) &&
4656 isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) {
4657 // Temporaries defined inside a class get linkonce_odr linkage because the
4658 // class can be defined in multiple translation units.
4659 Linkage = llvm::GlobalVariable::LinkOnceODRLinkage;
4660 } else {
4661 // There is no need for this temporary to have external linkage if the
4662 // VarDecl has external linkage.
4663 Linkage = llvm::GlobalVariable::InternalLinkage;
4664 }
4665 }
4666 auto TargetAS = getContext().getTargetAddressSpace(AddrSpace);
4667 auto *GV = new llvm::GlobalVariable(
4668 getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(),
4669 /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
4670 if (emitter) emitter->finalize(GV);
4671 setGVProperties(GV, VD);
4672 GV->setAlignment(Align.getQuantity());
4673 if (supportsCOMDAT() && GV->isWeakForLinker())
4674 GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
4675 if (VD->getTLSKind())
4676 setTLSMode(GV, *VD);
4677 llvm::Constant *CV = GV;
4678 if (AddrSpace != LangAS::Default)
4679 CV = getTargetCodeGenInfo().performAddrSpaceCast(
4680 *this, GV, AddrSpace, LangAS::Default,
4681 Type->getPointerTo(
4682 getContext().getTargetAddressSpace(LangAS::Default)));
4683 MaterializedGlobalTemporaryMap[E] = CV;
4684 return ConstantAddress(CV, Align);
4685 }
4686
4687 /// EmitObjCPropertyImplementations - Emit information for synthesized
4688 /// properties for an implementation.
EmitObjCPropertyImplementations(const ObjCImplementationDecl * D)4689 void CodeGenModule::EmitObjCPropertyImplementations(const
4690 ObjCImplementationDecl *D) {
4691 for (const auto *PID : D->property_impls()) {
4692 // Dynamic is just for type-checking.
4693 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
4694 ObjCPropertyDecl *PD = PID->getPropertyDecl();
4695
4696 // Determine which methods need to be implemented, some may have
4697 // been overridden. Note that ::isPropertyAccessor is not the method
4698 // we want, that just indicates if the decl came from a
4699 // property. What we want to know is if the method is defined in
4700 // this implementation.
4701 if (!D->getInstanceMethod(PD->getGetterName()))
4702 CodeGenFunction(*this).GenerateObjCGetter(
4703 const_cast<ObjCImplementationDecl *>(D), PID);
4704 if (!PD->isReadOnly() &&
4705 !D->getInstanceMethod(PD->getSetterName()))
4706 CodeGenFunction(*this).GenerateObjCSetter(
4707 const_cast<ObjCImplementationDecl *>(D), PID);
4708 }
4709 }
4710 }
4711
needsDestructMethod(ObjCImplementationDecl * impl)4712 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
4713 const ObjCInterfaceDecl *iface = impl->getClassInterface();
4714 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
4715 ivar; ivar = ivar->getNextIvar())
4716 if (ivar->getType().isDestructedType())
4717 return true;
4718
4719 return false;
4720 }
4721
AllTrivialInitializers(CodeGenModule & CGM,ObjCImplementationDecl * D)4722 static bool AllTrivialInitializers(CodeGenModule &CGM,
4723 ObjCImplementationDecl *D) {
4724 CodeGenFunction CGF(CGM);
4725 for (ObjCImplementationDecl::init_iterator B = D->init_begin(),
4726 E = D->init_end(); B != E; ++B) {
4727 CXXCtorInitializer *CtorInitExp = *B;
4728 Expr *Init = CtorInitExp->getInit();
4729 if (!CGF.isTrivialInitializer(Init))
4730 return false;
4731 }
4732 return true;
4733 }
4734
4735 /// EmitObjCIvarInitializations - Emit information for ivar initialization
4736 /// for an implementation.
EmitObjCIvarInitializations(ObjCImplementationDecl * D)4737 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
4738 // We might need a .cxx_destruct even if we don't have any ivar initializers.
4739 if (needsDestructMethod(D)) {
4740 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
4741 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
4742 ObjCMethodDecl *DTORMethod =
4743 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(),
4744 cxxSelector, getContext().VoidTy, nullptr, D,
4745 /*isInstance=*/true, /*isVariadic=*/false,
4746 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true,
4747 /*isDefined=*/false, ObjCMethodDecl::Required);
4748 D->addInstanceMethod(DTORMethod);
4749 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
4750 D->setHasDestructors(true);
4751 }
4752
4753 // If the implementation doesn't have any ivar initializers, we don't need
4754 // a .cxx_construct.
4755 if (D->getNumIvarInitializers() == 0 ||
4756 AllTrivialInitializers(*this, D))
4757 return;
4758
4759 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
4760 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
4761 // The constructor returns 'self'.
4762 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(),
4763 D->getLocation(),
4764 D->getLocation(),
4765 cxxSelector,
4766 getContext().getObjCIdType(),
4767 nullptr, D, /*isInstance=*/true,
4768 /*isVariadic=*/false,
4769 /*isPropertyAccessor=*/true,
4770 /*isImplicitlyDeclared=*/true,
4771 /*isDefined=*/false,
4772 ObjCMethodDecl::Required);
4773 D->addInstanceMethod(CTORMethod);
4774 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
4775 D->setHasNonZeroConstructors(true);
4776 }
4777
4778 // EmitLinkageSpec - Emit all declarations in a linkage spec.
EmitLinkageSpec(const LinkageSpecDecl * LSD)4779 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
4780 if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
4781 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
4782 ErrorUnsupported(LSD, "linkage spec");
4783 return;
4784 }
4785
4786 EmitDeclContext(LSD);
4787 }
4788
EmitDeclContext(const DeclContext * DC)4789 void CodeGenModule::EmitDeclContext(const DeclContext *DC) {
4790 for (auto *I : DC->decls()) {
4791 // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope
4792 // are themselves considered "top-level", so EmitTopLevelDecl on an
4793 // ObjCImplDecl does not recursively visit them. We need to do that in
4794 // case they're nested inside another construct (LinkageSpecDecl /
4795 // ExportDecl) that does stop them from being considered "top-level".
4796 if (auto *OID = dyn_cast<ObjCImplDecl>(I)) {
4797 for (auto *M : OID->methods())
4798 EmitTopLevelDecl(M);
4799 }
4800
4801 EmitTopLevelDecl(I);
4802 }
4803 }
4804
4805 /// EmitTopLevelDecl - Emit code for a single top level declaration.
EmitTopLevelDecl(Decl * D)4806 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
4807 // Ignore dependent declarations.
4808 if (D->isTemplated())
4809 return;
4810
4811 switch (D->getKind()) {
4812 case Decl::CXXConversion:
4813 case Decl::CXXMethod:
4814 case Decl::Function:
4815 EmitGlobal(cast<FunctionDecl>(D));
4816 // Always provide some coverage mapping
4817 // even for the functions that aren't emitted.
4818 AddDeferredUnusedCoverageMapping(D);
4819 break;
4820
4821 case Decl::CXXDeductionGuide:
4822 // Function-like, but does not result in code emission.
4823 break;
4824
4825 case Decl::Var:
4826 case Decl::Decomposition:
4827 case Decl::VarTemplateSpecialization:
4828 EmitGlobal(cast<VarDecl>(D));
4829 if (auto *DD = dyn_cast<DecompositionDecl>(D))
4830 for (auto *B : DD->bindings())
4831 if (auto *HD = B->getHoldingVar())
4832 EmitGlobal(HD);
4833 break;
4834
4835 // Indirect fields from global anonymous structs and unions can be
4836 // ignored; only the actual variable requires IR gen support.
4837 case Decl::IndirectField:
4838 break;
4839
4840 // C++ Decls
4841 case Decl::Namespace:
4842 EmitDeclContext(cast<NamespaceDecl>(D));
4843 break;
4844 case Decl::ClassTemplateSpecialization: {
4845 const auto *Spec = cast<ClassTemplateSpecializationDecl>(D);
4846 if (DebugInfo &&
4847 Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition &&
4848 Spec->hasDefinition())
4849 DebugInfo->completeTemplateDefinition(*Spec);
4850 } LLVM_FALLTHROUGH;
4851 case Decl::CXXRecord:
4852 if (DebugInfo) {
4853 if (auto *ES = D->getASTContext().getExternalSource())
4854 if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
4855 DebugInfo->completeUnusedClass(cast<CXXRecordDecl>(*D));
4856 }
4857 // Emit any static data members, they may be definitions.
4858 for (auto *I : cast<CXXRecordDecl>(D)->decls())
4859 if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I))
4860 EmitTopLevelDecl(I);
4861 break;
4862 // No code generation needed.
4863 case Decl::UsingShadow:
4864 case Decl::ClassTemplate:
4865 case Decl::VarTemplate:
4866 case Decl::VarTemplatePartialSpecialization:
4867 case Decl::FunctionTemplate:
4868 case Decl::TypeAliasTemplate:
4869 case Decl::Block:
4870 case Decl::Empty:
4871 case Decl::Binding:
4872 break;
4873 case Decl::Using: // using X; [C++]
4874 if (CGDebugInfo *DI = getModuleDebugInfo())
4875 DI->EmitUsingDecl(cast<UsingDecl>(*D));
4876 return;
4877 case Decl::NamespaceAlias:
4878 if (CGDebugInfo *DI = getModuleDebugInfo())
4879 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D));
4880 return;
4881 case Decl::UsingDirective: // using namespace X; [C++]
4882 if (CGDebugInfo *DI = getModuleDebugInfo())
4883 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D));
4884 return;
4885 case Decl::CXXConstructor:
4886 getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D));
4887 break;
4888 case Decl::CXXDestructor:
4889 getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D));
4890 break;
4891
4892 case Decl::StaticAssert:
4893 // Nothing to do.
4894 break;
4895
4896 // Objective-C Decls
4897
4898 // Forward declarations, no (immediate) code generation.
4899 case Decl::ObjCInterface:
4900 case Decl::ObjCCategory:
4901 break;
4902
4903 case Decl::ObjCProtocol: {
4904 auto *Proto = cast<ObjCProtocolDecl>(D);
4905 if (Proto->isThisDeclarationADefinition())
4906 ObjCRuntime->GenerateProtocol(Proto);
4907 break;
4908 }
4909
4910 case Decl::ObjCCategoryImpl:
4911 // Categories have properties but don't support synthesize so we
4912 // can ignore them here.
4913 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
4914 break;
4915
4916 case Decl::ObjCImplementation: {
4917 auto *OMD = cast<ObjCImplementationDecl>(D);
4918 EmitObjCPropertyImplementations(OMD);
4919 EmitObjCIvarInitializations(OMD);
4920 ObjCRuntime->GenerateClass(OMD);
4921 // Emit global variable debug information.
4922 if (CGDebugInfo *DI = getModuleDebugInfo())
4923 if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo)
4924 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(
4925 OMD->getClassInterface()), OMD->getLocation());
4926 break;
4927 }
4928 case Decl::ObjCMethod: {
4929 auto *OMD = cast<ObjCMethodDecl>(D);
4930 // If this is not a prototype, emit the body.
4931 if (OMD->getBody())
4932 CodeGenFunction(*this).GenerateObjCMethod(OMD);
4933 break;
4934 }
4935 case Decl::ObjCCompatibleAlias:
4936 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D));
4937 break;
4938
4939 case Decl::PragmaComment: {
4940 const auto *PCD = cast<PragmaCommentDecl>(D);
4941 switch (PCD->getCommentKind()) {
4942 case PCK_Unknown:
4943 llvm_unreachable("unexpected pragma comment kind");
4944 case PCK_Linker:
4945 AppendLinkerOptions(PCD->getArg());
4946 break;
4947 case PCK_Lib:
4948 if (getTarget().getTriple().isOSBinFormatELF() &&
4949 !getTarget().getTriple().isPS4())
4950 AddELFLibDirective(PCD->getArg());
4951 else
4952 AddDependentLib(PCD->getArg());
4953 break;
4954 case PCK_Compiler:
4955 case PCK_ExeStr:
4956 case PCK_User:
4957 break; // We ignore all of these.
4958 }
4959 break;
4960 }
4961
4962 case Decl::PragmaDetectMismatch: {
4963 const auto *PDMD = cast<PragmaDetectMismatchDecl>(D);
4964 AddDetectMismatch(PDMD->getName(), PDMD->getValue());
4965 break;
4966 }
4967
4968 case Decl::LinkageSpec:
4969 EmitLinkageSpec(cast<LinkageSpecDecl>(D));
4970 break;
4971
4972 case Decl::FileScopeAsm: {
4973 // File-scope asm is ignored during device-side CUDA compilation.
4974 if (LangOpts.CUDA && LangOpts.CUDAIsDevice)
4975 break;
4976 // File-scope asm is ignored during device-side OpenMP compilation.
4977 if (LangOpts.OpenMPIsDevice)
4978 break;
4979 auto *AD = cast<FileScopeAsmDecl>(D);
4980 getModule().appendModuleInlineAsm(AD->getAsmString()->getString());
4981 break;
4982 }
4983
4984 case Decl::Import: {
4985 auto *Import = cast<ImportDecl>(D);
4986
4987 // If we've already imported this module, we're done.
4988 if (!ImportedModules.insert(Import->getImportedModule()))
4989 break;
4990
4991 // Emit debug information for direct imports.
4992 if (!Import->getImportedOwningModule()) {
4993 if (CGDebugInfo *DI = getModuleDebugInfo())
4994 DI->EmitImportDecl(*Import);
4995 }
4996
4997 // Find all of the submodules and emit the module initializers.
4998 llvm::SmallPtrSet<clang::Module *, 16> Visited;
4999 SmallVector<clang::Module *, 16> Stack;
5000 Visited.insert(Import->getImportedModule());
5001 Stack.push_back(Import->getImportedModule());
5002
5003 while (!Stack.empty()) {
5004 clang::Module *Mod = Stack.pop_back_val();
5005 if (!EmittedModuleInitializers.insert(Mod).second)
5006 continue;
5007
5008 for (auto *D : Context.getModuleInitializers(Mod))
5009 EmitTopLevelDecl(D);
5010
5011 // Visit the submodules of this module.
5012 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
5013 SubEnd = Mod->submodule_end();
5014 Sub != SubEnd; ++Sub) {
5015 // Skip explicit children; they need to be explicitly imported to emit
5016 // the initializers.
5017 if ((*Sub)->IsExplicit)
5018 continue;
5019
5020 if (Visited.insert(*Sub).second)
5021 Stack.push_back(*Sub);
5022 }
5023 }
5024 break;
5025 }
5026
5027 case Decl::Export:
5028 EmitDeclContext(cast<ExportDecl>(D));
5029 break;
5030
5031 case Decl::OMPThreadPrivate:
5032 EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D));
5033 break;
5034
5035 case Decl::OMPDeclareReduction:
5036 EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
5037 break;
5038
5039 case Decl::OMPRequires:
5040 EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
5041 break;
5042
5043 default:
5044 // Make sure we handled everything we should, every other kind is a
5045 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
5046 // function. Need to recode Decl::Kind to do that easily.
5047 assert(isa<TypeDecl>(D) && "Unsupported decl kind");
5048 break;
5049 }
5050 }
5051
AddDeferredUnusedCoverageMapping(Decl * D)5052 void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
5053 // Do we need to generate coverage mapping?
5054 if (!CodeGenOpts.CoverageMapping)
5055 return;
5056 switch (D->getKind()) {
5057 case Decl::CXXConversion:
5058 case Decl::CXXMethod:
5059 case Decl::Function:
5060 case Decl::ObjCMethod:
5061 case Decl::CXXConstructor:
5062 case Decl::CXXDestructor: {
5063 if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
5064 return;
5065 SourceManager &SM = getContext().getSourceManager();
5066 if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
5067 return;
5068 auto I = DeferredEmptyCoverageMappingDecls.find(D);
5069 if (I == DeferredEmptyCoverageMappingDecls.end())
5070 DeferredEmptyCoverageMappingDecls[D] = true;
5071 break;
5072 }
5073 default:
5074 break;
5075 };
5076 }
5077
ClearUnusedCoverageMapping(const Decl * D)5078 void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) {
5079 // Do we need to generate coverage mapping?
5080 if (!CodeGenOpts.CoverageMapping)
5081 return;
5082 if (const auto *Fn = dyn_cast<FunctionDecl>(D)) {
5083 if (Fn->isTemplateInstantiation())
5084 ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern());
5085 }
5086 auto I = DeferredEmptyCoverageMappingDecls.find(D);
5087 if (I == DeferredEmptyCoverageMappingDecls.end())
5088 DeferredEmptyCoverageMappingDecls[D] = false;
5089 else
5090 I->second = false;
5091 }
5092
EmitDeferredUnusedCoverageMappings()5093 void CodeGenModule::EmitDeferredUnusedCoverageMappings() {
5094 // We call takeVector() here to avoid use-after-free.
5095 // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because
5096 // we deserialize function bodies to emit coverage info for them, and that
5097 // deserializes more declarations. How should we handle that case?
5098 for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) {
5099 if (!Entry.second)
5100 continue;
5101 const Decl *D = Entry.first;
5102 switch (D->getKind()) {
5103 case Decl::CXXConversion:
5104 case Decl::CXXMethod:
5105 case Decl::Function:
5106 case Decl::ObjCMethod: {
5107 CodeGenPGO PGO(*this);
5108 GlobalDecl GD(cast<FunctionDecl>(D));
5109 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
5110 getFunctionLinkage(GD));
5111 break;
5112 }
5113 case Decl::CXXConstructor: {
5114 CodeGenPGO PGO(*this);
5115 GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base);
5116 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
5117 getFunctionLinkage(GD));
5118 break;
5119 }
5120 case Decl::CXXDestructor: {
5121 CodeGenPGO PGO(*this);
5122 GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base);
5123 PGO.emitEmptyCounterMapping(D, getMangledName(GD),
5124 getFunctionLinkage(GD));
5125 break;
5126 }
5127 default:
5128 break;
5129 };
5130 }
5131 }
5132
5133 /// Turns the given pointer into a constant.
GetPointerConstant(llvm::LLVMContext & Context,const void * Ptr)5134 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
5135 const void *Ptr) {
5136 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
5137 llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
5138 return llvm::ConstantInt::get(i64, PtrInt);
5139 }
5140
EmitGlobalDeclMetadata(CodeGenModule & CGM,llvm::NamedMDNode * & GlobalMetadata,GlobalDecl D,llvm::GlobalValue * Addr)5141 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
5142 llvm::NamedMDNode *&GlobalMetadata,
5143 GlobalDecl D,
5144 llvm::GlobalValue *Addr) {
5145 if (!GlobalMetadata)
5146 GlobalMetadata =
5147 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
5148
5149 // TODO: should we report variant information for ctors/dtors?
5150 llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr),
5151 llvm::ConstantAsMetadata::get(GetPointerConstant(
5152 CGM.getLLVMContext(), D.getDecl()))};
5153 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
5154 }
5155
5156 /// For each function which is declared within an extern "C" region and marked
5157 /// as 'used', but has internal linkage, create an alias from the unmangled
5158 /// name to the mangled name if possible. People expect to be able to refer
5159 /// to such functions with an unmangled name from inline assembly within the
5160 /// same translation unit.
EmitStaticExternCAliases()5161 void CodeGenModule::EmitStaticExternCAliases() {
5162 if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases())
5163 return;
5164 for (auto &I : StaticExternCValues) {
5165 IdentifierInfo *Name = I.first;
5166 llvm::GlobalValue *Val = I.second;
5167 if (Val && !getModule().getNamedValue(Name->getName()))
5168 addUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val));
5169 }
5170 }
5171
lookupRepresentativeDecl(StringRef MangledName,GlobalDecl & Result) const5172 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName,
5173 GlobalDecl &Result) const {
5174 auto Res = Manglings.find(MangledName);
5175 if (Res == Manglings.end())
5176 return false;
5177 Result = Res->getValue();
5178 return true;
5179 }
5180
5181 /// Emits metadata nodes associating all the global values in the
5182 /// current module with the Decls they came from. This is useful for
5183 /// projects using IR gen as a subroutine.
5184 ///
5185 /// Since there's currently no way to associate an MDNode directly
5186 /// with an llvm::GlobalValue, we create a global named metadata
5187 /// with the name 'clang.global.decl.ptrs'.
EmitDeclMetadata()5188 void CodeGenModule::EmitDeclMetadata() {
5189 llvm::NamedMDNode *GlobalMetadata = nullptr;
5190
5191 for (auto &I : MangledDeclNames) {
5192 llvm::GlobalValue *Addr = getModule().getNamedValue(I.second);
5193 // Some mangled names don't necessarily have an associated GlobalValue
5194 // in this module, e.g. if we mangled it for DebugInfo.
5195 if (Addr)
5196 EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr);
5197 }
5198 }
5199
5200 /// Emits metadata nodes for all the local variables in the current
5201 /// function.
EmitDeclMetadata()5202 void CodeGenFunction::EmitDeclMetadata() {
5203 if (LocalDeclMap.empty()) return;
5204
5205 llvm::LLVMContext &Context = getLLVMContext();
5206
5207 // Find the unique metadata ID for this name.
5208 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
5209
5210 llvm::NamedMDNode *GlobalMetadata = nullptr;
5211
5212 for (auto &I : LocalDeclMap) {
5213 const Decl *D = I.first;
5214 llvm::Value *Addr = I.second.getPointer();
5215 if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
5216 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
5217 Alloca->setMetadata(
5218 DeclPtrKind, llvm::MDNode::get(
5219 Context, llvm::ValueAsMetadata::getConstant(DAddr)));
5220 } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
5221 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
5222 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
5223 }
5224 }
5225 }
5226
EmitVersionIdentMetadata()5227 void CodeGenModule::EmitVersionIdentMetadata() {
5228 llvm::NamedMDNode *IdentMetadata =
5229 TheModule.getOrInsertNamedMetadata("llvm.ident");
5230 std::string Version = getClangFullVersion();
5231 llvm::LLVMContext &Ctx = TheModule.getContext();
5232
5233 llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)};
5234 IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
5235 }
5236
EmitCommandLineMetadata()5237 void CodeGenModule::EmitCommandLineMetadata() {
5238 llvm::NamedMDNode *CommandLineMetadata =
5239 TheModule.getOrInsertNamedMetadata("llvm.commandline");
5240 std::string CommandLine = getCodeGenOpts().RecordCommandLine;
5241 llvm::LLVMContext &Ctx = TheModule.getContext();
5242
5243 llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
5244 CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
5245 }
5246
EmitTargetMetadata()5247 void CodeGenModule::EmitTargetMetadata() {
5248 // Warning, new MangledDeclNames may be appended within this loop.
5249 // We rely on MapVector insertions adding new elements to the end
5250 // of the container.
5251 // FIXME: Move this loop into the one target that needs it, and only
5252 // loop over those declarations for which we couldn't emit the target
5253 // metadata when we emitted the declaration.
5254 for (unsigned I = 0; I != MangledDeclNames.size(); ++I) {
5255 auto Val = *(MangledDeclNames.begin() + I);
5256 const Decl *D = Val.first.getDecl()->getMostRecentDecl();
5257 llvm::GlobalValue *GV = GetGlobalValue(Val.second);
5258 getTargetCodeGenInfo().emitTargetMD(D, GV, *this);
5259 }
5260 }
5261
EmitCoverageFile()5262 void CodeGenModule::EmitCoverageFile() {
5263 if (getCodeGenOpts().CoverageDataFile.empty() &&
5264 getCodeGenOpts().CoverageNotesFile.empty())
5265 return;
5266
5267 llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu");
5268 if (!CUNode)
5269 return;
5270
5271 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
5272 llvm::LLVMContext &Ctx = TheModule.getContext();
5273 auto *CoverageDataFile =
5274 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile);
5275 auto *CoverageNotesFile =
5276 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile);
5277 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
5278 llvm::MDNode *CU = CUNode->getOperand(i);
5279 llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU};
5280 GCov->addOperand(llvm::MDNode::get(Ctx, Elts));
5281 }
5282 }
5283
EmitUuidofInitializer(StringRef Uuid)5284 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid) {
5285 // Sema has checked that all uuid strings are of the form
5286 // "12345678-1234-1234-1234-1234567890ab".
5287 assert(Uuid.size() == 36);
5288 for (unsigned i = 0; i < 36; ++i) {
5289 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-');
5290 else assert(isHexDigit(Uuid[i]));
5291 }
5292
5293 // The starts of all bytes of Field3 in Uuid. Field 3 is "1234-1234567890ab".
5294 const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 };
5295
5296 llvm::Constant *Field3[8];
5297 for (unsigned Idx = 0; Idx < 8; ++Idx)
5298 Field3[Idx] = llvm::ConstantInt::get(
5299 Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16);
5300
5301 llvm::Constant *Fields[4] = {
5302 llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16),
5303 llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16),
5304 llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16),
5305 llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3)
5306 };
5307
5308 return llvm::ConstantStruct::getAnon(Fields);
5309 }
5310
GetAddrOfRTTIDescriptor(QualType Ty,bool ForEH)5311 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty,
5312 bool ForEH) {
5313 // Return a bogus pointer if RTTI is disabled, unless it's for EH.
5314 // FIXME: should we even be calling this method if RTTI is disabled
5315 // and it's not for EH?
5316 if ((!ForEH && !getLangOpts().RTTI) || getLangOpts().CUDAIsDevice)
5317 return llvm::Constant::getNullValue(Int8PtrTy);
5318
5319 if (ForEH && Ty->isObjCObjectPointerType() &&
5320 LangOpts.ObjCRuntime.isGNUFamily())
5321 return ObjCRuntime->GetEHType(Ty);
5322
5323 return getCXXABI().getAddrOfRTTIDescriptor(Ty);
5324 }
5325
EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl * D)5326 void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
5327 // Do not emit threadprivates in simd-only mode.
5328 if (LangOpts.OpenMP && LangOpts.OpenMPSimd)
5329 return;
5330 for (auto RefExpr : D->varlists()) {
5331 auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl());
5332 bool PerformInit =
5333 VD->getAnyInitializer() &&
5334 !VD->getAnyInitializer()->isConstantInitializer(getContext(),
5335 /*ForRef=*/false);
5336
5337 Address Addr(GetAddrOfGlobalVar(VD), getContext().getDeclAlign(VD));
5338 if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
5339 VD, Addr, RefExpr->getBeginLoc(), PerformInit))
5340 CXXGlobalInits.push_back(InitFunction);
5341 }
5342 }
5343
5344 llvm::Metadata *
CreateMetadataIdentifierImpl(QualType T,MetadataTypeMap & Map,StringRef Suffix)5345 CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map,
5346 StringRef Suffix) {
5347 llvm::Metadata *&InternalId = Map[T.getCanonicalType()];
5348 if (InternalId)
5349 return InternalId;
5350
5351 if (isExternallyVisible(T->getLinkage())) {
5352 std::string OutName;
5353 llvm::raw_string_ostream Out(OutName);
5354 getCXXABI().getMangleContext().mangleTypeName(T, Out);
5355 Out << Suffix;
5356
5357 InternalId = llvm::MDString::get(getLLVMContext(), Out.str());
5358 } else {
5359 InternalId = llvm::MDNode::getDistinct(getLLVMContext(),
5360 llvm::ArrayRef<llvm::Metadata *>());
5361 }
5362
5363 return InternalId;
5364 }
5365
CreateMetadataIdentifierForType(QualType T)5366 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) {
5367 return CreateMetadataIdentifierImpl(T, MetadataIdMap, "");
5368 }
5369
5370 llvm::Metadata *
CreateMetadataIdentifierForVirtualMemPtrType(QualType T)5371 CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) {
5372 return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual");
5373 }
5374
5375 // Generalize pointer types to a void pointer with the qualifiers of the
5376 // originally pointed-to type, e.g. 'const char *' and 'char * const *'
5377 // generalize to 'const void *' while 'char *' and 'const char **' generalize to
5378 // 'void *'.
GeneralizeType(ASTContext & Ctx,QualType Ty)5379 static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) {
5380 if (!Ty->isPointerType())
5381 return Ty;
5382
5383 return Ctx.getPointerType(
5384 QualType(Ctx.VoidTy).withCVRQualifiers(
5385 Ty->getPointeeType().getCVRQualifiers()));
5386 }
5387
5388 // Apply type generalization to a FunctionType's return and argument types
GeneralizeFunctionType(ASTContext & Ctx,QualType Ty)5389 static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) {
5390 if (auto *FnType = Ty->getAs<FunctionProtoType>()) {
5391 SmallVector<QualType, 8> GeneralizedParams;
5392 for (auto &Param : FnType->param_types())
5393 GeneralizedParams.push_back(GeneralizeType(Ctx, Param));
5394
5395 return Ctx.getFunctionType(
5396 GeneralizeType(Ctx, FnType->getReturnType()),
5397 GeneralizedParams, FnType->getExtProtoInfo());
5398 }
5399
5400 if (auto *FnType = Ty->getAs<FunctionNoProtoType>())
5401 return Ctx.getFunctionNoProtoType(
5402 GeneralizeType(Ctx, FnType->getReturnType()));
5403
5404 llvm_unreachable("Encountered unknown FunctionType");
5405 }
5406
CreateMetadataIdentifierGeneralized(QualType T)5407 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) {
5408 return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T),
5409 GeneralizedMetadataIdMap, ".generalized");
5410 }
5411
5412 /// Returns whether this module needs the "all-vtables" type identifier.
NeedAllVtablesTypeId() const5413 bool CodeGenModule::NeedAllVtablesTypeId() const {
5414 // Returns true if at least one of vtable-based CFI checkers is enabled and
5415 // is not in the trapping mode.
5416 return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
5417 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) ||
5418 (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
5419 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) ||
5420 (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
5421 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) ||
5422 (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) &&
5423 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast)));
5424 }
5425
AddVTableTypeMetadata(llvm::GlobalVariable * VTable,CharUnits Offset,const CXXRecordDecl * RD)5426 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable,
5427 CharUnits Offset,
5428 const CXXRecordDecl *RD) {
5429 llvm::Metadata *MD =
5430 CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
5431 VTable->addTypeMetadata(Offset.getQuantity(), MD);
5432
5433 if (CodeGenOpts.SanitizeCfiCrossDso)
5434 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD))
5435 VTable->addTypeMetadata(Offset.getQuantity(),
5436 llvm::ConstantAsMetadata::get(CrossDsoTypeId));
5437
5438 if (NeedAllVtablesTypeId()) {
5439 llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables");
5440 VTable->addTypeMetadata(Offset.getQuantity(), MD);
5441 }
5442 }
5443
filterFunctionTargetAttrs(const TargetAttr * TD)5444 TargetAttr::ParsedTargetAttr CodeGenModule::filterFunctionTargetAttrs(const TargetAttr *TD) {
5445 assert(TD != nullptr);
5446 TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
5447
5448 ParsedAttr.Features.erase(
5449 llvm::remove_if(ParsedAttr.Features,
5450 [&](const std::string &Feat) {
5451 return !Target.isValidFeatureName(
5452 StringRef{Feat}.substr(1));
5453 }),
5454 ParsedAttr.Features.end());
5455 return ParsedAttr;
5456 }
5457
5458
5459 // Fills in the supplied string map with the set of target features for the
5460 // passed in function.
getFunctionFeatureMap(llvm::StringMap<bool> & FeatureMap,GlobalDecl GD)5461 void CodeGenModule::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
5462 GlobalDecl GD) {
5463 StringRef TargetCPU = Target.getTargetOpts().CPU;
5464 const FunctionDecl *FD = GD.getDecl()->getAsFunction();
5465 if (const auto *TD = FD->getAttr<TargetAttr>()) {
5466 TargetAttr::ParsedTargetAttr ParsedAttr = filterFunctionTargetAttrs(TD);
5467
5468 // Make a copy of the features as passed on the command line into the
5469 // beginning of the additional features from the function to override.
5470 ParsedAttr.Features.insert(ParsedAttr.Features.begin(),
5471 Target.getTargetOpts().FeaturesAsWritten.begin(),
5472 Target.getTargetOpts().FeaturesAsWritten.end());
5473
5474 if (ParsedAttr.Architecture != "" &&
5475 Target.isValidCPUName(ParsedAttr.Architecture))
5476 TargetCPU = ParsedAttr.Architecture;
5477
5478 // Now populate the feature map, first with the TargetCPU which is either
5479 // the default or a new one from the target attribute string. Then we'll use
5480 // the passed in features (FeaturesAsWritten) along with the new ones from
5481 // the attribute.
5482 Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU,
5483 ParsedAttr.Features);
5484 } else if (const auto *SD = FD->getAttr<CPUSpecificAttr>()) {
5485 llvm::SmallVector<StringRef, 32> FeaturesTmp;
5486 Target.getCPUSpecificCPUDispatchFeatures(
5487 SD->getCPUName(GD.getMultiVersionIndex())->getName(), FeaturesTmp);
5488 std::vector<std::string> Features(FeaturesTmp.begin(), FeaturesTmp.end());
5489 Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU, Features);
5490 } else {
5491 Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU,
5492 Target.getTargetOpts().Features);
5493 }
5494 }
5495
getSanStats()5496 llvm::SanitizerStatReport &CodeGenModule::getSanStats() {
5497 if (!SanStats)
5498 SanStats = llvm::make_unique<llvm::SanitizerStatReport>(&getModule());
5499
5500 return *SanStats;
5501 }
5502 llvm::Value *
createOpenCLIntToSamplerConversion(const Expr * E,CodeGenFunction & CGF)5503 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E,
5504 CodeGenFunction &CGF) {
5505 llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType());
5506 auto SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr());
5507 auto FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false);
5508 return CGF.Builder.CreateCall(CreateRuntimeFunction(FTy,
5509 "__translate_sampler_initializer"),
5510 {C});
5511 }
5512