1 //===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This coordinates the per-module state used while generating code. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "CodeGenModule.h" 14 #include "CGBlocks.h" 15 #include "CGCUDARuntime.h" 16 #include "CGCXXABI.h" 17 #include "CGCall.h" 18 #include "CGDebugInfo.h" 19 #include "CGObjCRuntime.h" 20 #include "CGOpenCLRuntime.h" 21 #include "CGOpenMPRuntime.h" 22 #include "CGOpenMPRuntimeNVPTX.h" 23 #include "CodeGenFunction.h" 24 #include "CodeGenPGO.h" 25 #include "ConstantEmitter.h" 26 #include "CoverageMappingGen.h" 27 #include "TargetInfo.h" 28 #include "clang/AST/ASTContext.h" 29 #include "clang/AST/CharUnits.h" 30 #include "clang/AST/DeclCXX.h" 31 #include "clang/AST/DeclObjC.h" 32 #include "clang/AST/DeclTemplate.h" 33 #include "clang/AST/Mangle.h" 34 #include "clang/AST/RecordLayout.h" 35 #include "clang/AST/RecursiveASTVisitor.h" 36 #include "clang/AST/StmtVisitor.h" 37 #include "clang/Basic/Builtins.h" 38 #include "clang/Basic/CharInfo.h" 39 #include "clang/Basic/CodeGenOptions.h" 40 #include "clang/Basic/Diagnostic.h" 41 #include "clang/Basic/Module.h" 42 #include "clang/Basic/SourceManager.h" 43 #include "clang/Basic/TargetInfo.h" 44 #include "clang/Basic/Version.h" 45 #include "clang/CodeGen/ConstantInitBuilder.h" 46 #include "clang/Frontend/FrontendDiagnostic.h" 47 #include "llvm/ADT/StringSwitch.h" 48 #include "llvm/ADT/Triple.h" 49 #include "llvm/Analysis/TargetLibraryInfo.h" 50 #include "llvm/IR/CallingConv.h" 51 #include "llvm/IR/DataLayout.h" 52 #include "llvm/IR/Intrinsics.h" 53 #include "llvm/IR/LLVMContext.h" 54 #include "llvm/IR/Module.h" 55 #include "llvm/ProfileData/InstrProfReader.h" 56 #include "llvm/Support/CodeGen.h" 57 #include "llvm/Support/ConvertUTF.h" 58 #include "llvm/Support/ErrorHandling.h" 59 #include "llvm/Support/MD5.h" 60 61 using namespace clang; 62 using namespace CodeGen; 63 64 static llvm::cl::opt<bool> LimitedCoverage( 65 "limited-coverage-experimental", llvm::cl::ZeroOrMore, llvm::cl::Hidden, 66 llvm::cl::desc("Emit limited coverage mapping information (experimental)"), 67 llvm::cl::init(false)); 68 69 static const char AnnotationSection[] = "llvm.metadata"; 70 71 static CGCXXABI *createCXXABI(CodeGenModule &CGM) { 72 switch (CGM.getTarget().getCXXABI().getKind()) { 73 case TargetCXXABI::GenericAArch64: 74 case TargetCXXABI::GenericARM: 75 case TargetCXXABI::iOS: 76 case TargetCXXABI::iOS64: 77 case TargetCXXABI::WatchOS: 78 case TargetCXXABI::GenericMIPS: 79 case TargetCXXABI::GenericItanium: 80 case TargetCXXABI::WebAssembly: 81 return CreateItaniumCXXABI(CGM); 82 case TargetCXXABI::Microsoft: 83 return CreateMicrosoftCXXABI(CGM); 84 } 85 86 llvm_unreachable("invalid C++ ABI kind"); 87 } 88 89 CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO, 90 const PreprocessorOptions &PPO, 91 const CodeGenOptions &CGO, llvm::Module &M, 92 DiagnosticsEngine &diags, 93 CoverageSourceInfo *CoverageInfo) 94 : Context(C), LangOpts(C.getLangOpts()), HeaderSearchOpts(HSO), 95 PreprocessorOpts(PPO), CodeGenOpts(CGO), TheModule(M), Diags(diags), 96 Target(C.getTargetInfo()), ABI(createCXXABI(*this)), 97 VMContext(M.getContext()), Types(*this), VTables(*this), 98 SanitizerMD(new SanitizerMetadata(*this)) { 99 100 // Initialize the type cache. 101 llvm::LLVMContext &LLVMContext = M.getContext(); 102 VoidTy = llvm::Type::getVoidTy(LLVMContext); 103 Int8Ty = llvm::Type::getInt8Ty(LLVMContext); 104 Int16Ty = llvm::Type::getInt16Ty(LLVMContext); 105 Int32Ty = llvm::Type::getInt32Ty(LLVMContext); 106 Int64Ty = llvm::Type::getInt64Ty(LLVMContext); 107 HalfTy = llvm::Type::getHalfTy(LLVMContext); 108 FloatTy = llvm::Type::getFloatTy(LLVMContext); 109 DoubleTy = llvm::Type::getDoubleTy(LLVMContext); 110 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0); 111 PointerAlignInBytes = 112 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity(); 113 SizeSizeInBytes = 114 C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity(); 115 IntAlignInBytes = 116 C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity(); 117 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth()); 118 IntPtrTy = llvm::IntegerType::get(LLVMContext, 119 C.getTargetInfo().getMaxPointerWidth()); 120 Int8PtrTy = Int8Ty->getPointerTo(0); 121 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0); 122 AllocaInt8PtrTy = Int8Ty->getPointerTo( 123 M.getDataLayout().getAllocaAddrSpace()); 124 ASTAllocaAddressSpace = getTargetCodeGenInfo().getASTAllocaAddressSpace(); 125 126 RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC(); 127 128 if (LangOpts.ObjC) 129 createObjCRuntime(); 130 if (LangOpts.OpenCL) 131 createOpenCLRuntime(); 132 if (LangOpts.OpenMP) 133 createOpenMPRuntime(); 134 if (LangOpts.CUDA) 135 createCUDARuntime(); 136 137 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0. 138 if (LangOpts.Sanitize.has(SanitizerKind::Thread) || 139 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0)) 140 TBAA.reset(new CodeGenTBAA(Context, TheModule, CodeGenOpts, getLangOpts(), 141 getCXXABI().getMangleContext())); 142 143 // If debug info or coverage generation is enabled, create the CGDebugInfo 144 // object. 145 if (CodeGenOpts.getDebugInfo() != codegenoptions::NoDebugInfo || 146 CodeGenOpts.EmitGcovArcs || CodeGenOpts.EmitGcovNotes) 147 DebugInfo.reset(new CGDebugInfo(*this)); 148 149 Block.GlobalUniqueCount = 0; 150 151 if (C.getLangOpts().ObjC) 152 ObjCData.reset(new ObjCEntrypoints()); 153 154 if (CodeGenOpts.hasProfileClangUse()) { 155 auto ReaderOrErr = llvm::IndexedInstrProfReader::create( 156 CodeGenOpts.ProfileInstrumentUsePath, CodeGenOpts.ProfileRemappingFile); 157 if (auto E = ReaderOrErr.takeError()) { 158 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error, 159 "Could not read profile %0: %1"); 160 llvm::handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EI) { 161 getDiags().Report(DiagID) << CodeGenOpts.ProfileInstrumentUsePath 162 << EI.message(); 163 }); 164 } else 165 PGOReader = std::move(ReaderOrErr.get()); 166 } 167 168 // If coverage mapping generation is enabled, create the 169 // CoverageMappingModuleGen object. 170 if (CodeGenOpts.CoverageMapping) 171 CoverageMapping.reset(new CoverageMappingModuleGen(*this, *CoverageInfo)); 172 } 173 174 CodeGenModule::~CodeGenModule() {} 175 176 void CodeGenModule::createObjCRuntime() { 177 // This is just isGNUFamily(), but we want to force implementors of 178 // new ABIs to decide how best to do this. 179 switch (LangOpts.ObjCRuntime.getKind()) { 180 case ObjCRuntime::GNUstep: 181 case ObjCRuntime::GCC: 182 case ObjCRuntime::ObjFW: 183 ObjCRuntime.reset(CreateGNUObjCRuntime(*this)); 184 return; 185 186 case ObjCRuntime::FragileMacOSX: 187 case ObjCRuntime::MacOSX: 188 case ObjCRuntime::iOS: 189 case ObjCRuntime::WatchOS: 190 ObjCRuntime.reset(CreateMacObjCRuntime(*this)); 191 return; 192 } 193 llvm_unreachable("bad runtime kind"); 194 } 195 196 void CodeGenModule::createOpenCLRuntime() { 197 OpenCLRuntime.reset(new CGOpenCLRuntime(*this)); 198 } 199 200 void CodeGenModule::createOpenMPRuntime() { 201 // Select a specialized code generation class based on the target, if any. 202 // If it does not exist use the default implementation. 203 switch (getTriple().getArch()) { 204 case llvm::Triple::nvptx: 205 case llvm::Triple::nvptx64: 206 assert(getLangOpts().OpenMPIsDevice && 207 "OpenMP NVPTX is only prepared to deal with device code."); 208 OpenMPRuntime.reset(new CGOpenMPRuntimeNVPTX(*this)); 209 break; 210 default: 211 if (LangOpts.OpenMPSimd) 212 OpenMPRuntime.reset(new CGOpenMPSIMDRuntime(*this)); 213 else 214 OpenMPRuntime.reset(new CGOpenMPRuntime(*this)); 215 break; 216 } 217 } 218 219 void CodeGenModule::createCUDARuntime() { 220 CUDARuntime.reset(CreateNVCUDARuntime(*this)); 221 } 222 223 void CodeGenModule::addReplacement(StringRef Name, llvm::Constant *C) { 224 Replacements[Name] = C; 225 } 226 227 void CodeGenModule::applyReplacements() { 228 for (auto &I : Replacements) { 229 StringRef MangledName = I.first(); 230 llvm::Constant *Replacement = I.second; 231 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 232 if (!Entry) 233 continue; 234 auto *OldF = cast<llvm::Function>(Entry); 235 auto *NewF = dyn_cast<llvm::Function>(Replacement); 236 if (!NewF) { 237 if (auto *Alias = dyn_cast<llvm::GlobalAlias>(Replacement)) { 238 NewF = dyn_cast<llvm::Function>(Alias->getAliasee()); 239 } else { 240 auto *CE = cast<llvm::ConstantExpr>(Replacement); 241 assert(CE->getOpcode() == llvm::Instruction::BitCast || 242 CE->getOpcode() == llvm::Instruction::GetElementPtr); 243 NewF = dyn_cast<llvm::Function>(CE->getOperand(0)); 244 } 245 } 246 247 // Replace old with new, but keep the old order. 248 OldF->replaceAllUsesWith(Replacement); 249 if (NewF) { 250 NewF->removeFromParent(); 251 OldF->getParent()->getFunctionList().insertAfter(OldF->getIterator(), 252 NewF); 253 } 254 OldF->eraseFromParent(); 255 } 256 } 257 258 void CodeGenModule::addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C) { 259 GlobalValReplacements.push_back(std::make_pair(GV, C)); 260 } 261 262 void CodeGenModule::applyGlobalValReplacements() { 263 for (auto &I : GlobalValReplacements) { 264 llvm::GlobalValue *GV = I.first; 265 llvm::Constant *C = I.second; 266 267 GV->replaceAllUsesWith(C); 268 GV->eraseFromParent(); 269 } 270 } 271 272 // This is only used in aliases that we created and we know they have a 273 // linear structure. 274 static const llvm::GlobalObject *getAliasedGlobal( 275 const llvm::GlobalIndirectSymbol &GIS) { 276 llvm::SmallPtrSet<const llvm::GlobalIndirectSymbol*, 4> Visited; 277 const llvm::Constant *C = &GIS; 278 for (;;) { 279 C = C->stripPointerCasts(); 280 if (auto *GO = dyn_cast<llvm::GlobalObject>(C)) 281 return GO; 282 // stripPointerCasts will not walk over weak aliases. 283 auto *GIS2 = dyn_cast<llvm::GlobalIndirectSymbol>(C); 284 if (!GIS2) 285 return nullptr; 286 if (!Visited.insert(GIS2).second) 287 return nullptr; 288 C = GIS2->getIndirectSymbol(); 289 } 290 } 291 292 void CodeGenModule::checkAliases() { 293 // Check if the constructed aliases are well formed. It is really unfortunate 294 // that we have to do this in CodeGen, but we only construct mangled names 295 // and aliases during codegen. 296 bool Error = false; 297 DiagnosticsEngine &Diags = getDiags(); 298 for (const GlobalDecl &GD : Aliases) { 299 const auto *D = cast<ValueDecl>(GD.getDecl()); 300 SourceLocation Location; 301 bool IsIFunc = D->hasAttr<IFuncAttr>(); 302 if (const Attr *A = D->getDefiningAttr()) 303 Location = A->getLocation(); 304 else 305 llvm_unreachable("Not an alias or ifunc?"); 306 StringRef MangledName = getMangledName(GD); 307 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 308 auto *Alias = cast<llvm::GlobalIndirectSymbol>(Entry); 309 const llvm::GlobalValue *GV = getAliasedGlobal(*Alias); 310 if (!GV) { 311 Error = true; 312 Diags.Report(Location, diag::err_cyclic_alias) << IsIFunc; 313 } else if (GV->isDeclaration()) { 314 Error = true; 315 Diags.Report(Location, diag::err_alias_to_undefined) 316 << IsIFunc << IsIFunc; 317 } else if (IsIFunc) { 318 // Check resolver function type. 319 llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>( 320 GV->getType()->getPointerElementType()); 321 assert(FTy); 322 if (!FTy->getReturnType()->isPointerTy()) 323 Diags.Report(Location, diag::err_ifunc_resolver_return); 324 } 325 326 llvm::Constant *Aliasee = Alias->getIndirectSymbol(); 327 llvm::GlobalValue *AliaseeGV; 328 if (auto CE = dyn_cast<llvm::ConstantExpr>(Aliasee)) 329 AliaseeGV = cast<llvm::GlobalValue>(CE->getOperand(0)); 330 else 331 AliaseeGV = cast<llvm::GlobalValue>(Aliasee); 332 333 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) { 334 StringRef AliasSection = SA->getName(); 335 if (AliasSection != AliaseeGV->getSection()) 336 Diags.Report(SA->getLocation(), diag::warn_alias_with_section) 337 << AliasSection << IsIFunc << IsIFunc; 338 } 339 340 // We have to handle alias to weak aliases in here. LLVM itself disallows 341 // this since the object semantics would not match the IL one. For 342 // compatibility with gcc we implement it by just pointing the alias 343 // to its aliasee's aliasee. We also warn, since the user is probably 344 // expecting the link to be weak. 345 if (auto GA = dyn_cast<llvm::GlobalIndirectSymbol>(AliaseeGV)) { 346 if (GA->isInterposable()) { 347 Diags.Report(Location, diag::warn_alias_to_weak_alias) 348 << GV->getName() << GA->getName() << IsIFunc; 349 Aliasee = llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast( 350 GA->getIndirectSymbol(), Alias->getType()); 351 Alias->setIndirectSymbol(Aliasee); 352 } 353 } 354 } 355 if (!Error) 356 return; 357 358 for (const GlobalDecl &GD : Aliases) { 359 StringRef MangledName = getMangledName(GD); 360 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 361 auto *Alias = dyn_cast<llvm::GlobalIndirectSymbol>(Entry); 362 Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType())); 363 Alias->eraseFromParent(); 364 } 365 } 366 367 void CodeGenModule::clear() { 368 DeferredDeclsToEmit.clear(); 369 if (OpenMPRuntime) 370 OpenMPRuntime->clear(); 371 } 372 373 void InstrProfStats::reportDiagnostics(DiagnosticsEngine &Diags, 374 StringRef MainFile) { 375 if (!hasDiagnostics()) 376 return; 377 if (VisitedInMainFile > 0 && VisitedInMainFile == MissingInMainFile) { 378 if (MainFile.empty()) 379 MainFile = "<stdin>"; 380 Diags.Report(diag::warn_profile_data_unprofiled) << MainFile; 381 } else { 382 if (Mismatched > 0) 383 Diags.Report(diag::warn_profile_data_out_of_date) << Visited << Mismatched; 384 385 if (Missing > 0) 386 Diags.Report(diag::warn_profile_data_missing) << Visited << Missing; 387 } 388 } 389 390 void CodeGenModule::Release() { 391 EmitDeferred(); 392 EmitVTablesOpportunistically(); 393 applyGlobalValReplacements(); 394 applyReplacements(); 395 checkAliases(); 396 emitMultiVersionFunctions(); 397 EmitCXXGlobalInitFunc(); 398 EmitCXXGlobalDtorFunc(); 399 registerGlobalDtorsWithAtExit(); 400 EmitCXXThreadLocalInitFunc(); 401 if (ObjCRuntime) 402 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) 403 AddGlobalCtor(ObjCInitFunction); 404 if (Context.getLangOpts().CUDA && !Context.getLangOpts().CUDAIsDevice && 405 CUDARuntime) { 406 if (llvm::Function *CudaCtorFunction = 407 CUDARuntime->makeModuleCtorFunction()) 408 AddGlobalCtor(CudaCtorFunction); 409 } 410 if (OpenMPRuntime) { 411 if (llvm::Function *OpenMPRegistrationFunction = 412 OpenMPRuntime->emitRegistrationFunction()) { 413 auto ComdatKey = OpenMPRegistrationFunction->hasComdat() ? 414 OpenMPRegistrationFunction : nullptr; 415 AddGlobalCtor(OpenMPRegistrationFunction, 0, ComdatKey); 416 } 417 OpenMPRuntime->clear(); 418 } 419 if (PGOReader) { 420 getModule().setProfileSummary(PGOReader->getSummary().getMD(VMContext)); 421 if (PGOStats.hasDiagnostics()) 422 PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName); 423 } 424 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 425 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 426 EmitGlobalAnnotations(); 427 EmitStaticExternCAliases(); 428 EmitDeferredUnusedCoverageMappings(); 429 if (CoverageMapping) 430 CoverageMapping->emit(); 431 if (CodeGenOpts.SanitizeCfiCrossDso) { 432 CodeGenFunction(*this).EmitCfiCheckFail(); 433 CodeGenFunction(*this).EmitCfiCheckStub(); 434 } 435 emitAtAvailableLinkGuard(); 436 emitLLVMUsed(); 437 if (SanStats) 438 SanStats->finish(); 439 440 if (CodeGenOpts.Autolink && 441 (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) { 442 EmitModuleLinkOptions(); 443 } 444 445 // Record mregparm value now so it is visible through rest of codegen. 446 if (Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86) 447 getModule().addModuleFlag(llvm::Module::Error, "NumRegisterParameters", 448 CodeGenOpts.NumRegisterParameters); 449 450 if (CodeGenOpts.DwarfVersion) { 451 // We actually want the latest version when there are conflicts. 452 // We can change from Warning to Latest if such mode is supported. 453 getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version", 454 CodeGenOpts.DwarfVersion); 455 } 456 if (CodeGenOpts.EmitCodeView) { 457 // Indicate that we want CodeView in the metadata. 458 getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1); 459 } 460 if (CodeGenOpts.CodeViewGHash) { 461 getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1); 462 } 463 if (CodeGenOpts.ControlFlowGuard) { 464 // We want function ID tables for Control Flow Guard. 465 getModule().addModuleFlag(llvm::Module::Warning, "cfguardtable", 1); 466 } 467 if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) { 468 // We don't support LTO with 2 with different StrictVTablePointers 469 // FIXME: we could support it by stripping all the information introduced 470 // by StrictVTablePointers. 471 472 getModule().addModuleFlag(llvm::Module::Error, "StrictVTablePointers",1); 473 474 llvm::Metadata *Ops[2] = { 475 llvm::MDString::get(VMContext, "StrictVTablePointers"), 476 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( 477 llvm::Type::getInt32Ty(VMContext), 1))}; 478 479 getModule().addModuleFlag(llvm::Module::Require, 480 "StrictVTablePointersRequirement", 481 llvm::MDNode::get(VMContext, Ops)); 482 } 483 if (DebugInfo) 484 // We support a single version in the linked module. The LLVM 485 // parser will drop debug info with a different version number 486 // (and warn about it, too). 487 getModule().addModuleFlag(llvm::Module::Warning, "Debug Info Version", 488 llvm::DEBUG_METADATA_VERSION); 489 490 // We need to record the widths of enums and wchar_t, so that we can generate 491 // the correct build attributes in the ARM backend. wchar_size is also used by 492 // TargetLibraryInfo. 493 uint64_t WCharWidth = 494 Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity(); 495 getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth); 496 497 llvm::Triple::ArchType Arch = Context.getTargetInfo().getTriple().getArch(); 498 if ( Arch == llvm::Triple::arm 499 || Arch == llvm::Triple::armeb 500 || Arch == llvm::Triple::thumb 501 || Arch == llvm::Triple::thumbeb) { 502 // The minimum width of an enum in bytes 503 uint64_t EnumWidth = Context.getLangOpts().ShortEnums ? 1 : 4; 504 getModule().addModuleFlag(llvm::Module::Error, "min_enum_size", EnumWidth); 505 } 506 507 if (CodeGenOpts.SanitizeCfiCrossDso) { 508 // Indicate that we want cross-DSO control flow integrity checks. 509 getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1); 510 } 511 512 if (CodeGenOpts.CFProtectionReturn && 513 Target.checkCFProtectionReturnSupported(getDiags())) { 514 // Indicate that we want to instrument return control flow protection. 515 getModule().addModuleFlag(llvm::Module::Override, "cf-protection-return", 516 1); 517 } 518 519 if (CodeGenOpts.CFProtectionBranch && 520 Target.checkCFProtectionBranchSupported(getDiags())) { 521 // Indicate that we want to instrument branch control flow protection. 522 getModule().addModuleFlag(llvm::Module::Override, "cf-protection-branch", 523 1); 524 } 525 526 if (LangOpts.CUDAIsDevice && getTriple().isNVPTX()) { 527 // Indicate whether __nvvm_reflect should be configured to flush denormal 528 // floating point values to 0. (This corresponds to its "__CUDA_FTZ" 529 // property.) 530 getModule().addModuleFlag(llvm::Module::Override, "nvvm-reflect-ftz", 531 CodeGenOpts.FlushDenorm ? 1 : 0); 532 } 533 534 // Emit OpenCL specific module metadata: OpenCL/SPIR version. 535 if (LangOpts.OpenCL) { 536 EmitOpenCLMetadata(); 537 // Emit SPIR version. 538 if (getTriple().getArch() == llvm::Triple::spir || 539 getTriple().getArch() == llvm::Triple::spir64) { 540 // SPIR v2.0 s2.12 - The SPIR version used by the module is stored in the 541 // opencl.spir.version named metadata. 542 llvm::Metadata *SPIRVerElts[] = { 543 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( 544 Int32Ty, LangOpts.OpenCLVersion / 100)), 545 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( 546 Int32Ty, (LangOpts.OpenCLVersion / 100 > 1) ? 0 : 2))}; 547 llvm::NamedMDNode *SPIRVerMD = 548 TheModule.getOrInsertNamedMetadata("opencl.spir.version"); 549 llvm::LLVMContext &Ctx = TheModule.getContext(); 550 SPIRVerMD->addOperand(llvm::MDNode::get(Ctx, SPIRVerElts)); 551 } 552 } 553 554 if (uint32_t PLevel = Context.getLangOpts().PICLevel) { 555 assert(PLevel < 3 && "Invalid PIC Level"); 556 getModule().setPICLevel(static_cast<llvm::PICLevel::Level>(PLevel)); 557 if (Context.getLangOpts().PIE) 558 getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel)); 559 } 560 561 if (getCodeGenOpts().CodeModel.size() > 0) { 562 unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel) 563 .Case("tiny", llvm::CodeModel::Tiny) 564 .Case("small", llvm::CodeModel::Small) 565 .Case("kernel", llvm::CodeModel::Kernel) 566 .Case("medium", llvm::CodeModel::Medium) 567 .Case("large", llvm::CodeModel::Large) 568 .Default(~0u); 569 if (CM != ~0u) { 570 llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM); 571 getModule().setCodeModel(codeModel); 572 } 573 } 574 575 if (CodeGenOpts.NoPLT) 576 getModule().setRtLibUseGOT(); 577 578 SimplifyPersonality(); 579 580 if (getCodeGenOpts().EmitDeclMetadata) 581 EmitDeclMetadata(); 582 583 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 584 EmitCoverageFile(); 585 586 if (DebugInfo) 587 DebugInfo->finalize(); 588 589 if (getCodeGenOpts().EmitVersionIdentMetadata) 590 EmitVersionIdentMetadata(); 591 592 if (!getCodeGenOpts().RecordCommandLine.empty()) 593 EmitCommandLineMetadata(); 594 595 EmitTargetMetadata(); 596 } 597 598 void CodeGenModule::EmitOpenCLMetadata() { 599 // SPIR v2.0 s2.13 - The OpenCL version used by the module is stored in the 600 // opencl.ocl.version named metadata node. 601 llvm::Metadata *OCLVerElts[] = { 602 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( 603 Int32Ty, LangOpts.OpenCLVersion / 100)), 604 llvm::ConstantAsMetadata::get(llvm::ConstantInt::get( 605 Int32Ty, (LangOpts.OpenCLVersion % 100) / 10))}; 606 llvm::NamedMDNode *OCLVerMD = 607 TheModule.getOrInsertNamedMetadata("opencl.ocl.version"); 608 llvm::LLVMContext &Ctx = TheModule.getContext(); 609 OCLVerMD->addOperand(llvm::MDNode::get(Ctx, OCLVerElts)); 610 } 611 612 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 613 // Make sure that this type is translated. 614 Types.UpdateCompletedType(TD); 615 } 616 617 void CodeGenModule::RefreshTypeCacheForClass(const CXXRecordDecl *RD) { 618 // Make sure that this type is translated. 619 Types.RefreshTypeCacheForClass(RD); 620 } 621 622 llvm::MDNode *CodeGenModule::getTBAATypeInfo(QualType QTy) { 623 if (!TBAA) 624 return nullptr; 625 return TBAA->getTypeInfo(QTy); 626 } 627 628 TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) { 629 if (!TBAA) 630 return TBAAAccessInfo(); 631 return TBAA->getAccessInfo(AccessType); 632 } 633 634 TBAAAccessInfo 635 CodeGenModule::getTBAAVTablePtrAccessInfo(llvm::Type *VTablePtrType) { 636 if (!TBAA) 637 return TBAAAccessInfo(); 638 return TBAA->getVTablePtrAccessInfo(VTablePtrType); 639 } 640 641 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) { 642 if (!TBAA) 643 return nullptr; 644 return TBAA->getTBAAStructInfo(QTy); 645 } 646 647 llvm::MDNode *CodeGenModule::getTBAABaseTypeInfo(QualType QTy) { 648 if (!TBAA) 649 return nullptr; 650 return TBAA->getBaseTypeInfo(QTy); 651 } 652 653 llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) { 654 if (!TBAA) 655 return nullptr; 656 return TBAA->getAccessTagInfo(Info); 657 } 658 659 TBAAAccessInfo CodeGenModule::mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo, 660 TBAAAccessInfo TargetInfo) { 661 if (!TBAA) 662 return TBAAAccessInfo(); 663 return TBAA->mergeTBAAInfoForCast(SourceInfo, TargetInfo); 664 } 665 666 TBAAAccessInfo 667 CodeGenModule::mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA, 668 TBAAAccessInfo InfoB) { 669 if (!TBAA) 670 return TBAAAccessInfo(); 671 return TBAA->mergeTBAAInfoForConditionalOperator(InfoA, InfoB); 672 } 673 674 TBAAAccessInfo 675 CodeGenModule::mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo, 676 TBAAAccessInfo SrcInfo) { 677 if (!TBAA) 678 return TBAAAccessInfo(); 679 return TBAA->mergeTBAAInfoForConditionalOperator(DestInfo, SrcInfo); 680 } 681 682 void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst, 683 TBAAAccessInfo TBAAInfo) { 684 if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo)) 685 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag); 686 } 687 688 void CodeGenModule::DecorateInstructionWithInvariantGroup( 689 llvm::Instruction *I, const CXXRecordDecl *RD) { 690 I->setMetadata(llvm::LLVMContext::MD_invariant_group, 691 llvm::MDNode::get(getLLVMContext(), {})); 692 } 693 694 void CodeGenModule::Error(SourceLocation loc, StringRef message) { 695 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0"); 696 getDiags().Report(Context.getFullLoc(loc), diagID) << message; 697 } 698 699 /// ErrorUnsupported - Print out an error that codegen doesn't support the 700 /// specified stmt yet. 701 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) { 702 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 703 "cannot compile this %0 yet"); 704 std::string Msg = Type; 705 getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID) 706 << Msg << S->getSourceRange(); 707 } 708 709 /// ErrorUnsupported - Print out an error that codegen doesn't support the 710 /// specified decl yet. 711 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) { 712 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 713 "cannot compile this %0 yet"); 714 std::string Msg = Type; 715 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 716 } 717 718 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 719 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 720 } 721 722 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 723 const NamedDecl *D) const { 724 if (GV->hasDLLImportStorageClass()) 725 return; 726 // Internal definitions always have default visibility. 727 if (GV->hasLocalLinkage()) { 728 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 729 return; 730 } 731 if (!D) 732 return; 733 // Set visibility for definitions, and for declarations if requested globally 734 // or set explicitly. 735 LinkageInfo LV = D->getLinkageAndVisibility(); 736 if (LV.isVisibilityExplicit() || getLangOpts().SetVisibilityForExternDecls || 737 !GV->isDeclarationForLinker()) 738 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 739 } 740 741 static bool shouldAssumeDSOLocal(const CodeGenModule &CGM, 742 llvm::GlobalValue *GV) { 743 if (GV->hasLocalLinkage()) 744 return true; 745 746 if (!GV->hasDefaultVisibility() && !GV->hasExternalWeakLinkage()) 747 return true; 748 749 // DLLImport explicitly marks the GV as external. 750 if (GV->hasDLLImportStorageClass()) 751 return false; 752 753 const llvm::Triple &TT = CGM.getTriple(); 754 if (TT.isWindowsGNUEnvironment()) { 755 // In MinGW, variables without DLLImport can still be automatically 756 // imported from a DLL by the linker; don't mark variables that 757 // potentially could come from another DLL as DSO local. 758 if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) && 759 !GV->isThreadLocal()) 760 return false; 761 } 762 // Every other GV is local on COFF. 763 // Make an exception for windows OS in the triple: Some firmware builds use 764 // *-win32-macho triples. This (accidentally?) produced windows relocations 765 // without GOT tables in older clang versions; Keep this behaviour. 766 // FIXME: even thread local variables? 767 if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO())) 768 return true; 769 770 // Only handle COFF and ELF for now. 771 if (!TT.isOSBinFormatELF()) 772 return false; 773 774 // If this is not an executable, don't assume anything is local. 775 const auto &CGOpts = CGM.getCodeGenOpts(); 776 llvm::Reloc::Model RM = CGOpts.RelocationModel; 777 const auto &LOpts = CGM.getLangOpts(); 778 if (RM != llvm::Reloc::Static && !LOpts.PIE) 779 return false; 780 781 // A definition cannot be preempted from an executable. 782 if (!GV->isDeclarationForLinker()) 783 return true; 784 785 // Most PIC code sequences that assume that a symbol is local cannot produce a 786 // 0 if it turns out the symbol is undefined. While this is ABI and relocation 787 // depended, it seems worth it to handle it here. 788 if (RM == llvm::Reloc::PIC_ && GV->hasExternalWeakLinkage()) 789 return false; 790 791 // PPC has no copy relocations and cannot use a plt entry as a symbol address. 792 llvm::Triple::ArchType Arch = TT.getArch(); 793 if (Arch == llvm::Triple::ppc || Arch == llvm::Triple::ppc64 || 794 Arch == llvm::Triple::ppc64le) 795 return false; 796 797 // If we can use copy relocations we can assume it is local. 798 if (auto *Var = dyn_cast<llvm::GlobalVariable>(GV)) 799 if (!Var->isThreadLocal() && 800 (RM == llvm::Reloc::Static || CGOpts.PIECopyRelocations)) 801 return true; 802 803 // If we can use a plt entry as the symbol address we can assume it 804 // is local. 805 // FIXME: This should work for PIE, but the gold linker doesn't support it. 806 if (isa<llvm::Function>(GV) && !CGOpts.NoPLT && RM == llvm::Reloc::Static) 807 return true; 808 809 // Otherwise don't assue it is local. 810 return false; 811 } 812 813 void CodeGenModule::setDSOLocal(llvm::GlobalValue *GV) const { 814 GV->setDSOLocal(shouldAssumeDSOLocal(*this, GV)); 815 } 816 817 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV, 818 GlobalDecl GD) const { 819 const auto *D = dyn_cast<NamedDecl>(GD.getDecl()); 820 // C++ destructors have a few C++ ABI specific special cases. 821 if (const auto *Dtor = dyn_cast_or_null<CXXDestructorDecl>(D)) { 822 getCXXABI().setCXXDestructorDLLStorage(GV, Dtor, GD.getDtorType()); 823 return; 824 } 825 setDLLImportDLLExport(GV, D); 826 } 827 828 void CodeGenModule::setDLLImportDLLExport(llvm::GlobalValue *GV, 829 const NamedDecl *D) const { 830 if (D && D->isExternallyVisible()) { 831 if (D->hasAttr<DLLImportAttr>()) 832 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass); 833 else if (D->hasAttr<DLLExportAttr>() && !GV->isDeclarationForLinker()) 834 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass); 835 } 836 } 837 838 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV, 839 GlobalDecl GD) const { 840 setDLLImportDLLExport(GV, GD); 841 setGlobalVisibilityAndLocal(GV, dyn_cast<NamedDecl>(GD.getDecl())); 842 } 843 844 void CodeGenModule::setGVProperties(llvm::GlobalValue *GV, 845 const NamedDecl *D) const { 846 setDLLImportDLLExport(GV, D); 847 setGlobalVisibilityAndLocal(GV, D); 848 } 849 850 void CodeGenModule::setGlobalVisibilityAndLocal(llvm::GlobalValue *GV, 851 const NamedDecl *D) const { 852 setGlobalVisibility(GV, D); 853 setDSOLocal(GV); 854 } 855 856 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) { 857 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S) 858 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel) 859 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel) 860 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel) 861 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel); 862 } 863 864 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel( 865 CodeGenOptions::TLSModel M) { 866 switch (M) { 867 case CodeGenOptions::GeneralDynamicTLSModel: 868 return llvm::GlobalVariable::GeneralDynamicTLSModel; 869 case CodeGenOptions::LocalDynamicTLSModel: 870 return llvm::GlobalVariable::LocalDynamicTLSModel; 871 case CodeGenOptions::InitialExecTLSModel: 872 return llvm::GlobalVariable::InitialExecTLSModel; 873 case CodeGenOptions::LocalExecTLSModel: 874 return llvm::GlobalVariable::LocalExecTLSModel; 875 } 876 llvm_unreachable("Invalid TLS model!"); 877 } 878 879 void CodeGenModule::setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const { 880 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!"); 881 882 llvm::GlobalValue::ThreadLocalMode TLM; 883 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel()); 884 885 // Override the TLS model if it is explicitly specified. 886 if (const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>()) { 887 TLM = GetLLVMTLSModel(Attr->getModel()); 888 } 889 890 GV->setThreadLocalMode(TLM); 891 } 892 893 static std::string getCPUSpecificMangling(const CodeGenModule &CGM, 894 StringRef Name) { 895 const TargetInfo &Target = CGM.getTarget(); 896 return (Twine('.') + Twine(Target.CPUSpecificManglingCharacter(Name))).str(); 897 } 898 899 static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM, 900 const CPUSpecificAttr *Attr, 901 unsigned CPUIndex, 902 raw_ostream &Out) { 903 // cpu_specific gets the current name, dispatch gets the resolver if IFunc is 904 // supported. 905 if (Attr) 906 Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName()); 907 else if (CGM.getTarget().supportsIFunc()) 908 Out << ".resolver"; 909 } 910 911 static void AppendTargetMangling(const CodeGenModule &CGM, 912 const TargetAttr *Attr, raw_ostream &Out) { 913 if (Attr->isDefaultVersion()) 914 return; 915 916 Out << '.'; 917 const TargetInfo &Target = CGM.getTarget(); 918 TargetAttr::ParsedTargetAttr Info = 919 Attr->parse([&Target](StringRef LHS, StringRef RHS) { 920 // Multiversioning doesn't allow "no-${feature}", so we can 921 // only have "+" prefixes here. 922 assert(LHS.startswith("+") && RHS.startswith("+") && 923 "Features should always have a prefix."); 924 return Target.multiVersionSortPriority(LHS.substr(1)) > 925 Target.multiVersionSortPriority(RHS.substr(1)); 926 }); 927 928 bool IsFirst = true; 929 930 if (!Info.Architecture.empty()) { 931 IsFirst = false; 932 Out << "arch_" << Info.Architecture; 933 } 934 935 for (StringRef Feat : Info.Features) { 936 if (!IsFirst) 937 Out << '_'; 938 IsFirst = false; 939 Out << Feat.substr(1); 940 } 941 } 942 943 static std::string getMangledNameImpl(const CodeGenModule &CGM, GlobalDecl GD, 944 const NamedDecl *ND, 945 bool OmitMultiVersionMangling = false) { 946 SmallString<256> Buffer; 947 llvm::raw_svector_ostream Out(Buffer); 948 MangleContext &MC = CGM.getCXXABI().getMangleContext(); 949 if (MC.shouldMangleDeclName(ND)) { 950 llvm::raw_svector_ostream Out(Buffer); 951 if (const auto *D = dyn_cast<CXXConstructorDecl>(ND)) 952 MC.mangleCXXCtor(D, GD.getCtorType(), Out); 953 else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND)) 954 MC.mangleCXXDtor(D, GD.getDtorType(), Out); 955 else 956 MC.mangleName(ND, Out); 957 } else { 958 IdentifierInfo *II = ND->getIdentifier(); 959 assert(II && "Attempt to mangle unnamed decl."); 960 const auto *FD = dyn_cast<FunctionDecl>(ND); 961 962 if (FD && 963 FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) { 964 llvm::raw_svector_ostream Out(Buffer); 965 Out << "__regcall3__" << II->getName(); 966 } else { 967 Out << II->getName(); 968 } 969 } 970 971 if (const auto *FD = dyn_cast<FunctionDecl>(ND)) 972 if (FD->isMultiVersion() && !OmitMultiVersionMangling) { 973 switch (FD->getMultiVersionKind()) { 974 case MultiVersionKind::CPUDispatch: 975 case MultiVersionKind::CPUSpecific: 976 AppendCPUSpecificCPUDispatchMangling(CGM, 977 FD->getAttr<CPUSpecificAttr>(), 978 GD.getMultiVersionIndex(), Out); 979 break; 980 case MultiVersionKind::Target: 981 AppendTargetMangling(CGM, FD->getAttr<TargetAttr>(), Out); 982 break; 983 case MultiVersionKind::None: 984 llvm_unreachable("None multiversion type isn't valid here"); 985 } 986 } 987 988 return Out.str(); 989 } 990 991 void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD, 992 const FunctionDecl *FD) { 993 if (!FD->isMultiVersion()) 994 return; 995 996 // Get the name of what this would be without the 'target' attribute. This 997 // allows us to lookup the version that was emitted when this wasn't a 998 // multiversion function. 999 std::string NonTargetName = 1000 getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true); 1001 GlobalDecl OtherGD; 1002 if (lookupRepresentativeDecl(NonTargetName, OtherGD)) { 1003 assert(OtherGD.getCanonicalDecl() 1004 .getDecl() 1005 ->getAsFunction() 1006 ->isMultiVersion() && 1007 "Other GD should now be a multiversioned function"); 1008 // OtherFD is the version of this function that was mangled BEFORE 1009 // becoming a MultiVersion function. It potentially needs to be updated. 1010 const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl() 1011 .getDecl() 1012 ->getAsFunction() 1013 ->getMostRecentDecl(); 1014 std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD); 1015 // This is so that if the initial version was already the 'default' 1016 // version, we don't try to update it. 1017 if (OtherName != NonTargetName) { 1018 // Remove instead of erase, since others may have stored the StringRef 1019 // to this. 1020 const auto ExistingRecord = Manglings.find(NonTargetName); 1021 if (ExistingRecord != std::end(Manglings)) 1022 Manglings.remove(&(*ExistingRecord)); 1023 auto Result = Manglings.insert(std::make_pair(OtherName, OtherGD)); 1024 MangledDeclNames[OtherGD.getCanonicalDecl()] = Result.first->first(); 1025 if (llvm::GlobalValue *Entry = GetGlobalValue(NonTargetName)) 1026 Entry->setName(OtherName); 1027 } 1028 } 1029 } 1030 1031 StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 1032 GlobalDecl CanonicalGD = GD.getCanonicalDecl(); 1033 1034 // Some ABIs don't have constructor variants. Make sure that base and 1035 // complete constructors get mangled the same. 1036 if (const auto *CD = dyn_cast<CXXConstructorDecl>(CanonicalGD.getDecl())) { 1037 if (!getTarget().getCXXABI().hasConstructorVariants()) { 1038 CXXCtorType OrigCtorType = GD.getCtorType(); 1039 assert(OrigCtorType == Ctor_Base || OrigCtorType == Ctor_Complete); 1040 if (OrigCtorType == Ctor_Base) 1041 CanonicalGD = GlobalDecl(CD, Ctor_Complete); 1042 } 1043 } 1044 1045 auto FoundName = MangledDeclNames.find(CanonicalGD); 1046 if (FoundName != MangledDeclNames.end()) 1047 return FoundName->second; 1048 1049 // Keep the first result in the case of a mangling collision. 1050 const auto *ND = cast<NamedDecl>(GD.getDecl()); 1051 auto Result = 1052 Manglings.insert(std::make_pair(getMangledNameImpl(*this, GD, ND), GD)); 1053 return MangledDeclNames[CanonicalGD] = Result.first->first(); 1054 } 1055 1056 StringRef CodeGenModule::getBlockMangledName(GlobalDecl GD, 1057 const BlockDecl *BD) { 1058 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 1059 const Decl *D = GD.getDecl(); 1060 1061 SmallString<256> Buffer; 1062 llvm::raw_svector_ostream Out(Buffer); 1063 if (!D) 1064 MangleCtx.mangleGlobalBlock(BD, 1065 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out); 1066 else if (const auto *CD = dyn_cast<CXXConstructorDecl>(D)) 1067 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 1068 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(D)) 1069 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 1070 else 1071 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 1072 1073 auto Result = Manglings.insert(std::make_pair(Out.str(), BD)); 1074 return Result.first->first(); 1075 } 1076 1077 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 1078 return getModule().getNamedValue(Name); 1079 } 1080 1081 /// AddGlobalCtor - Add a function to the list that will be called before 1082 /// main() runs. 1083 void CodeGenModule::AddGlobalCtor(llvm::Function *Ctor, int Priority, 1084 llvm::Constant *AssociatedData) { 1085 // FIXME: Type coercion of void()* types. 1086 GlobalCtors.push_back(Structor(Priority, Ctor, AssociatedData)); 1087 } 1088 1089 /// AddGlobalDtor - Add a function to the list that will be called 1090 /// when the module is unloaded. 1091 void CodeGenModule::AddGlobalDtor(llvm::Function *Dtor, int Priority) { 1092 if (CodeGenOpts.RegisterGlobalDtorsWithAtExit) { 1093 DtorsUsingAtExit[Priority].push_back(Dtor); 1094 return; 1095 } 1096 1097 // FIXME: Type coercion of void()* types. 1098 GlobalDtors.push_back(Structor(Priority, Dtor, nullptr)); 1099 } 1100 1101 void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) { 1102 if (Fns.empty()) return; 1103 1104 // Ctor function type is void()*. 1105 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 1106 llvm::Type *CtorPFTy = llvm::PointerType::get(CtorFTy, 1107 TheModule.getDataLayout().getProgramAddressSpace()); 1108 1109 // Get the type of a ctor entry, { i32, void ()*, i8* }. 1110 llvm::StructType *CtorStructTy = llvm::StructType::get( 1111 Int32Ty, CtorPFTy, VoidPtrTy); 1112 1113 // Construct the constructor and destructor arrays. 1114 ConstantInitBuilder builder(*this); 1115 auto ctors = builder.beginArray(CtorStructTy); 1116 for (const auto &I : Fns) { 1117 auto ctor = ctors.beginStruct(CtorStructTy); 1118 ctor.addInt(Int32Ty, I.Priority); 1119 ctor.add(llvm::ConstantExpr::getBitCast(I.Initializer, CtorPFTy)); 1120 if (I.AssociatedData) 1121 ctor.add(llvm::ConstantExpr::getBitCast(I.AssociatedData, VoidPtrTy)); 1122 else 1123 ctor.addNullPointer(VoidPtrTy); 1124 ctor.finishAndAddTo(ctors); 1125 } 1126 1127 auto list = 1128 ctors.finishAndCreateGlobal(GlobalName, getPointerAlign(), 1129 /*constant*/ false, 1130 llvm::GlobalValue::AppendingLinkage); 1131 1132 // The LTO linker doesn't seem to like it when we set an alignment 1133 // on appending variables. Take it off as a workaround. 1134 list->setAlignment(0); 1135 1136 Fns.clear(); 1137 } 1138 1139 llvm::GlobalValue::LinkageTypes 1140 CodeGenModule::getFunctionLinkage(GlobalDecl GD) { 1141 const auto *D = cast<FunctionDecl>(GD.getDecl()); 1142 1143 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 1144 1145 if (const auto *Dtor = dyn_cast<CXXDestructorDecl>(D)) 1146 return getCXXABI().getCXXDestructorLinkage(Linkage, Dtor, GD.getDtorType()); 1147 1148 if (isa<CXXConstructorDecl>(D) && 1149 cast<CXXConstructorDecl>(D)->isInheritingConstructor() && 1150 Context.getTargetInfo().getCXXABI().isMicrosoft()) { 1151 // Our approach to inheriting constructors is fundamentally different from 1152 // that used by the MS ABI, so keep our inheriting constructor thunks 1153 // internal rather than trying to pick an unambiguous mangling for them. 1154 return llvm::GlobalValue::InternalLinkage; 1155 } 1156 1157 return getLLVMLinkageForDeclarator(D, Linkage, /*isConstantVariable=*/false); 1158 } 1159 1160 llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) { 1161 llvm::MDString *MDS = dyn_cast<llvm::MDString>(MD); 1162 if (!MDS) return nullptr; 1163 1164 return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString())); 1165 } 1166 1167 void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD, 1168 const CGFunctionInfo &Info, 1169 llvm::Function *F) { 1170 unsigned CallingConv; 1171 llvm::AttributeList PAL; 1172 ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv, false); 1173 F->setAttributes(PAL); 1174 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 1175 } 1176 1177 /// Determines whether the language options require us to model 1178 /// unwind exceptions. We treat -fexceptions as mandating this 1179 /// except under the fragile ObjC ABI with only ObjC exceptions 1180 /// enabled. This means, for example, that C with -fexceptions 1181 /// enables this. 1182 static bool hasUnwindExceptions(const LangOptions &LangOpts) { 1183 // If exceptions are completely disabled, obviously this is false. 1184 if (!LangOpts.Exceptions) return false; 1185 1186 // If C++ exceptions are enabled, this is true. 1187 if (LangOpts.CXXExceptions) return true; 1188 1189 // If ObjC exceptions are enabled, this depends on the ABI. 1190 if (LangOpts.ObjCExceptions) { 1191 return LangOpts.ObjCRuntime.hasUnwindExceptions(); 1192 } 1193 1194 return true; 1195 } 1196 1197 static bool requiresMemberFunctionPointerTypeMetadata(CodeGenModule &CGM, 1198 const CXXMethodDecl *MD) { 1199 // Check that the type metadata can ever actually be used by a call. 1200 if (!CGM.getCodeGenOpts().LTOUnit || 1201 !CGM.HasHiddenLTOVisibility(MD->getParent())) 1202 return false; 1203 1204 // Only functions whose address can be taken with a member function pointer 1205 // need this sort of type metadata. 1206 return !MD->isStatic() && !MD->isVirtual() && !isa<CXXConstructorDecl>(MD) && 1207 !isa<CXXDestructorDecl>(MD); 1208 } 1209 1210 std::vector<const CXXRecordDecl *> 1211 CodeGenModule::getMostBaseClasses(const CXXRecordDecl *RD) { 1212 llvm::SetVector<const CXXRecordDecl *> MostBases; 1213 1214 std::function<void (const CXXRecordDecl *)> CollectMostBases; 1215 CollectMostBases = [&](const CXXRecordDecl *RD) { 1216 if (RD->getNumBases() == 0) 1217 MostBases.insert(RD); 1218 for (const CXXBaseSpecifier &B : RD->bases()) 1219 CollectMostBases(B.getType()->getAsCXXRecordDecl()); 1220 }; 1221 CollectMostBases(RD); 1222 return MostBases.takeVector(); 1223 } 1224 1225 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 1226 llvm::Function *F) { 1227 llvm::AttrBuilder B; 1228 1229 if (CodeGenOpts.UnwindTables) 1230 B.addAttribute(llvm::Attribute::UWTable); 1231 1232 if (!hasUnwindExceptions(LangOpts)) 1233 B.addAttribute(llvm::Attribute::NoUnwind); 1234 1235 if (!D || !D->hasAttr<NoStackProtectorAttr>()) { 1236 if (LangOpts.getStackProtector() == LangOptions::SSPOn) 1237 B.addAttribute(llvm::Attribute::StackProtect); 1238 else if (LangOpts.getStackProtector() == LangOptions::SSPStrong) 1239 B.addAttribute(llvm::Attribute::StackProtectStrong); 1240 else if (LangOpts.getStackProtector() == LangOptions::SSPReq) 1241 B.addAttribute(llvm::Attribute::StackProtectReq); 1242 } 1243 1244 if (!D) { 1245 // If we don't have a declaration to control inlining, the function isn't 1246 // explicitly marked as alwaysinline for semantic reasons, and inlining is 1247 // disabled, mark the function as noinline. 1248 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline) && 1249 CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) 1250 B.addAttribute(llvm::Attribute::NoInline); 1251 1252 F->addAttributes(llvm::AttributeList::FunctionIndex, B); 1253 return; 1254 } 1255 1256 // Track whether we need to add the optnone LLVM attribute, 1257 // starting with the default for this optimization level. 1258 bool ShouldAddOptNone = 1259 !CodeGenOpts.DisableO0ImplyOptNone && CodeGenOpts.OptimizationLevel == 0; 1260 // We can't add optnone in the following cases, it won't pass the verifier. 1261 ShouldAddOptNone &= !D->hasAttr<MinSizeAttr>(); 1262 ShouldAddOptNone &= !F->hasFnAttribute(llvm::Attribute::AlwaysInline); 1263 ShouldAddOptNone &= !D->hasAttr<AlwaysInlineAttr>(); 1264 1265 if (ShouldAddOptNone || D->hasAttr<OptimizeNoneAttr>()) { 1266 B.addAttribute(llvm::Attribute::OptimizeNone); 1267 1268 // OptimizeNone implies noinline; we should not be inlining such functions. 1269 B.addAttribute(llvm::Attribute::NoInline); 1270 assert(!F->hasFnAttribute(llvm::Attribute::AlwaysInline) && 1271 "OptimizeNone and AlwaysInline on same function!"); 1272 1273 // We still need to handle naked functions even though optnone subsumes 1274 // much of their semantics. 1275 if (D->hasAttr<NakedAttr>()) 1276 B.addAttribute(llvm::Attribute::Naked); 1277 1278 // OptimizeNone wins over OptimizeForSize and MinSize. 1279 F->removeFnAttr(llvm::Attribute::OptimizeForSize); 1280 F->removeFnAttr(llvm::Attribute::MinSize); 1281 } else if (D->hasAttr<NakedAttr>()) { 1282 // Naked implies noinline: we should not be inlining such functions. 1283 B.addAttribute(llvm::Attribute::Naked); 1284 B.addAttribute(llvm::Attribute::NoInline); 1285 } else if (D->hasAttr<NoDuplicateAttr>()) { 1286 B.addAttribute(llvm::Attribute::NoDuplicate); 1287 } else if (D->hasAttr<NoInlineAttr>()) { 1288 B.addAttribute(llvm::Attribute::NoInline); 1289 } else if (D->hasAttr<AlwaysInlineAttr>() && 1290 !F->hasFnAttribute(llvm::Attribute::NoInline)) { 1291 // (noinline wins over always_inline, and we can't specify both in IR) 1292 B.addAttribute(llvm::Attribute::AlwaysInline); 1293 } else if (CodeGenOpts.getInlining() == CodeGenOptions::OnlyAlwaysInlining) { 1294 // If we're not inlining, then force everything that isn't always_inline to 1295 // carry an explicit noinline attribute. 1296 if (!F->hasFnAttribute(llvm::Attribute::AlwaysInline)) 1297 B.addAttribute(llvm::Attribute::NoInline); 1298 } else { 1299 // Otherwise, propagate the inline hint attribute and potentially use its 1300 // absence to mark things as noinline. 1301 if (auto *FD = dyn_cast<FunctionDecl>(D)) { 1302 // Search function and template pattern redeclarations for inline. 1303 auto CheckForInline = [](const FunctionDecl *FD) { 1304 auto CheckRedeclForInline = [](const FunctionDecl *Redecl) { 1305 return Redecl->isInlineSpecified(); 1306 }; 1307 if (any_of(FD->redecls(), CheckRedeclForInline)) 1308 return true; 1309 const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern(); 1310 if (!Pattern) 1311 return false; 1312 return any_of(Pattern->redecls(), CheckRedeclForInline); 1313 }; 1314 if (CheckForInline(FD)) { 1315 B.addAttribute(llvm::Attribute::InlineHint); 1316 } else if (CodeGenOpts.getInlining() == 1317 CodeGenOptions::OnlyHintInlining && 1318 !FD->isInlined() && 1319 !F->hasFnAttribute(llvm::Attribute::AlwaysInline)) { 1320 B.addAttribute(llvm::Attribute::NoInline); 1321 } 1322 } 1323 } 1324 1325 // Add other optimization related attributes if we are optimizing this 1326 // function. 1327 if (!D->hasAttr<OptimizeNoneAttr>()) { 1328 if (D->hasAttr<ColdAttr>()) { 1329 if (!ShouldAddOptNone) 1330 B.addAttribute(llvm::Attribute::OptimizeForSize); 1331 B.addAttribute(llvm::Attribute::Cold); 1332 } 1333 1334 if (D->hasAttr<MinSizeAttr>()) 1335 B.addAttribute(llvm::Attribute::MinSize); 1336 } 1337 1338 F->addAttributes(llvm::AttributeList::FunctionIndex, B); 1339 1340 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 1341 if (alignment) 1342 F->setAlignment(alignment); 1343 1344 if (!D->hasAttr<AlignedAttr>()) 1345 if (LangOpts.FunctionAlignment) 1346 F->setAlignment(1 << LangOpts.FunctionAlignment); 1347 1348 // Some C++ ABIs require 2-byte alignment for member functions, in order to 1349 // reserve a bit for differentiating between virtual and non-virtual member 1350 // functions. If the current target's C++ ABI requires this and this is a 1351 // member function, set its alignment accordingly. 1352 if (getTarget().getCXXABI().areMemberFunctionsAligned()) { 1353 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 1354 F->setAlignment(2); 1355 } 1356 1357 // In the cross-dso CFI mode, we want !type attributes on definitions only. 1358 if (CodeGenOpts.SanitizeCfiCrossDso) 1359 if (auto *FD = dyn_cast<FunctionDecl>(D)) 1360 CreateFunctionTypeMetadataForIcall(FD, F); 1361 1362 // Emit type metadata on member functions for member function pointer checks. 1363 // These are only ever necessary on definitions; we're guaranteed that the 1364 // definition will be present in the LTO unit as a result of LTO visibility. 1365 auto *MD = dyn_cast<CXXMethodDecl>(D); 1366 if (MD && requiresMemberFunctionPointerTypeMetadata(*this, MD)) { 1367 for (const CXXRecordDecl *Base : getMostBaseClasses(MD->getParent())) { 1368 llvm::Metadata *Id = 1369 CreateMetadataIdentifierForType(Context.getMemberPointerType( 1370 MD->getType(), Context.getRecordType(Base).getTypePtr())); 1371 F->addTypeMetadata(0, Id); 1372 } 1373 } 1374 } 1375 1376 void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) { 1377 const Decl *D = GD.getDecl(); 1378 if (dyn_cast_or_null<NamedDecl>(D)) 1379 setGVProperties(GV, GD); 1380 else 1381 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 1382 1383 if (D && D->hasAttr<UsedAttr>()) 1384 addUsedGlobal(GV); 1385 1386 if (CodeGenOpts.KeepStaticConsts && D && isa<VarDecl>(D)) { 1387 const auto *VD = cast<VarDecl>(D); 1388 if (VD->getType().isConstQualified() && 1389 VD->getStorageDuration() == SD_Static) 1390 addUsedGlobal(GV); 1391 } 1392 } 1393 1394 bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD, 1395 llvm::AttrBuilder &Attrs) { 1396 // Add target-cpu and target-features attributes to functions. If 1397 // we have a decl for the function and it has a target attribute then 1398 // parse that and add it to the feature set. 1399 StringRef TargetCPU = getTarget().getTargetOpts().CPU; 1400 std::vector<std::string> Features; 1401 const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl()); 1402 FD = FD ? FD->getMostRecentDecl() : FD; 1403 const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr; 1404 const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr; 1405 bool AddedAttr = false; 1406 if (TD || SD) { 1407 llvm::StringMap<bool> FeatureMap; 1408 getFunctionFeatureMap(FeatureMap, GD); 1409 1410 // Produce the canonical string for this set of features. 1411 for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap) 1412 Features.push_back((Entry.getValue() ? "+" : "-") + Entry.getKey().str()); 1413 1414 // Now add the target-cpu and target-features to the function. 1415 // While we populated the feature map above, we still need to 1416 // get and parse the target attribute so we can get the cpu for 1417 // the function. 1418 if (TD) { 1419 TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse(); 1420 if (ParsedAttr.Architecture != "" && 1421 getTarget().isValidCPUName(ParsedAttr.Architecture)) 1422 TargetCPU = ParsedAttr.Architecture; 1423 } 1424 } else { 1425 // Otherwise just add the existing target cpu and target features to the 1426 // function. 1427 Features = getTarget().getTargetOpts().Features; 1428 } 1429 1430 if (TargetCPU != "") { 1431 Attrs.addAttribute("target-cpu", TargetCPU); 1432 AddedAttr = true; 1433 } 1434 if (!Features.empty()) { 1435 llvm::sort(Features); 1436 Attrs.addAttribute("target-features", llvm::join(Features, ",")); 1437 AddedAttr = true; 1438 } 1439 1440 return AddedAttr; 1441 } 1442 1443 void CodeGenModule::setNonAliasAttributes(GlobalDecl GD, 1444 llvm::GlobalObject *GO) { 1445 const Decl *D = GD.getDecl(); 1446 SetCommonAttributes(GD, GO); 1447 1448 if (D) { 1449 if (auto *GV = dyn_cast<llvm::GlobalVariable>(GO)) { 1450 if (auto *SA = D->getAttr<PragmaClangBSSSectionAttr>()) 1451 GV->addAttribute("bss-section", SA->getName()); 1452 if (auto *SA = D->getAttr<PragmaClangDataSectionAttr>()) 1453 GV->addAttribute("data-section", SA->getName()); 1454 if (auto *SA = D->getAttr<PragmaClangRodataSectionAttr>()) 1455 GV->addAttribute("rodata-section", SA->getName()); 1456 } 1457 1458 if (auto *F = dyn_cast<llvm::Function>(GO)) { 1459 if (auto *SA = D->getAttr<PragmaClangTextSectionAttr>()) 1460 if (!D->getAttr<SectionAttr>()) 1461 F->addFnAttr("implicit-section-name", SA->getName()); 1462 1463 llvm::AttrBuilder Attrs; 1464 if (GetCPUAndFeaturesAttributes(GD, Attrs)) { 1465 // We know that GetCPUAndFeaturesAttributes will always have the 1466 // newest set, since it has the newest possible FunctionDecl, so the 1467 // new ones should replace the old. 1468 F->removeFnAttr("target-cpu"); 1469 F->removeFnAttr("target-features"); 1470 F->addAttributes(llvm::AttributeList::FunctionIndex, Attrs); 1471 } 1472 } 1473 1474 if (const auto *CSA = D->getAttr<CodeSegAttr>()) 1475 GO->setSection(CSA->getName()); 1476 else if (const auto *SA = D->getAttr<SectionAttr>()) 1477 GO->setSection(SA->getName()); 1478 } 1479 1480 getTargetCodeGenInfo().setTargetAttributes(D, GO, *this); 1481 } 1482 1483 void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD, 1484 llvm::Function *F, 1485 const CGFunctionInfo &FI) { 1486 const Decl *D = GD.getDecl(); 1487 SetLLVMFunctionAttributes(GD, FI, F); 1488 SetLLVMFunctionAttributesForDefinition(D, F); 1489 1490 F->setLinkage(llvm::Function::InternalLinkage); 1491 1492 setNonAliasAttributes(GD, F); 1493 } 1494 1495 static void setLinkageForGV(llvm::GlobalValue *GV, const NamedDecl *ND) { 1496 // Set linkage and visibility in case we never see a definition. 1497 LinkageInfo LV = ND->getLinkageAndVisibility(); 1498 // Don't set internal linkage on declarations. 1499 // "extern_weak" is overloaded in LLVM; we probably should have 1500 // separate linkage types for this. 1501 if (isExternallyVisible(LV.getLinkage()) && 1502 (ND->hasAttr<WeakAttr>() || ND->isWeakImported())) 1503 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1504 } 1505 1506 void CodeGenModule::CreateFunctionTypeMetadataForIcall(const FunctionDecl *FD, 1507 llvm::Function *F) { 1508 // Only if we are checking indirect calls. 1509 if (!LangOpts.Sanitize.has(SanitizerKind::CFIICall)) 1510 return; 1511 1512 // Non-static class methods are handled via vtable or member function pointer 1513 // checks elsewhere. 1514 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 1515 return; 1516 1517 // Additionally, if building with cross-DSO support... 1518 if (CodeGenOpts.SanitizeCfiCrossDso) { 1519 // Skip available_externally functions. They won't be codegen'ed in the 1520 // current module anyway. 1521 if (getContext().GetGVALinkageForFunction(FD) == GVA_AvailableExternally) 1522 return; 1523 } 1524 1525 llvm::Metadata *MD = CreateMetadataIdentifierForType(FD->getType()); 1526 F->addTypeMetadata(0, MD); 1527 F->addTypeMetadata(0, CreateMetadataIdentifierGeneralized(FD->getType())); 1528 1529 // Emit a hash-based bit set entry for cross-DSO calls. 1530 if (CodeGenOpts.SanitizeCfiCrossDso) 1531 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD)) 1532 F->addTypeMetadata(0, llvm::ConstantAsMetadata::get(CrossDsoTypeId)); 1533 } 1534 1535 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F, 1536 bool IsIncompleteFunction, 1537 bool IsThunk) { 1538 1539 if (llvm::Intrinsic::ID IID = F->getIntrinsicID()) { 1540 // If this is an intrinsic function, set the function's attributes 1541 // to the intrinsic's attributes. 1542 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), IID)); 1543 return; 1544 } 1545 1546 const auto *FD = cast<FunctionDecl>(GD.getDecl()); 1547 1548 if (!IsIncompleteFunction) { 1549 SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F); 1550 // Setup target-specific attributes. 1551 if (F->isDeclaration()) 1552 getTargetCodeGenInfo().setTargetAttributes(FD, F, *this); 1553 } 1554 1555 // Add the Returned attribute for "this", except for iOS 5 and earlier 1556 // where substantial code, including the libstdc++ dylib, was compiled with 1557 // GCC and does not actually return "this". 1558 if (!IsThunk && getCXXABI().HasThisReturn(GD) && 1559 !(getTriple().isiOS() && getTriple().isOSVersionLT(6))) { 1560 assert(!F->arg_empty() && 1561 F->arg_begin()->getType() 1562 ->canLosslesslyBitCastTo(F->getReturnType()) && 1563 "unexpected this return"); 1564 F->addAttribute(1, llvm::Attribute::Returned); 1565 } 1566 1567 // Only a few attributes are set on declarations; these may later be 1568 // overridden by a definition. 1569 1570 setLinkageForGV(F, FD); 1571 setGVProperties(F, FD); 1572 1573 if (const auto *CSA = FD->getAttr<CodeSegAttr>()) 1574 F->setSection(CSA->getName()); 1575 else if (const auto *SA = FD->getAttr<SectionAttr>()) 1576 F->setSection(SA->getName()); 1577 1578 if (FD->isReplaceableGlobalAllocationFunction()) { 1579 // A replaceable global allocation function does not act like a builtin by 1580 // default, only if it is invoked by a new-expression or delete-expression. 1581 F->addAttribute(llvm::AttributeList::FunctionIndex, 1582 llvm::Attribute::NoBuiltin); 1583 1584 // A sane operator new returns a non-aliasing pointer. 1585 // FIXME: Also add NonNull attribute to the return value 1586 // for the non-nothrow forms? 1587 auto Kind = FD->getDeclName().getCXXOverloadedOperator(); 1588 if (getCodeGenOpts().AssumeSaneOperatorNew && 1589 (Kind == OO_New || Kind == OO_Array_New)) 1590 F->addAttribute(llvm::AttributeList::ReturnIndex, 1591 llvm::Attribute::NoAlias); 1592 } 1593 1594 if (isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD)) 1595 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); 1596 else if (const auto *MD = dyn_cast<CXXMethodDecl>(FD)) 1597 if (MD->isVirtual()) 1598 F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); 1599 1600 // Don't emit entries for function declarations in the cross-DSO mode. This 1601 // is handled with better precision by the receiving DSO. 1602 if (!CodeGenOpts.SanitizeCfiCrossDso) 1603 CreateFunctionTypeMetadataForIcall(FD, F); 1604 1605 if (getLangOpts().OpenMP && FD->hasAttr<OMPDeclareSimdDeclAttr>()) 1606 getOpenMPRuntime().emitDeclareSimdFunction(FD, F); 1607 1608 if (const auto *CB = FD->getAttr<CallbackAttr>()) { 1609 // Annotate the callback behavior as metadata: 1610 // - The callback callee (as argument number). 1611 // - The callback payloads (as argument numbers). 1612 llvm::LLVMContext &Ctx = F->getContext(); 1613 llvm::MDBuilder MDB(Ctx); 1614 1615 // The payload indices are all but the first one in the encoding. The first 1616 // identifies the callback callee. 1617 int CalleeIdx = *CB->encoding_begin(); 1618 ArrayRef<int> PayloadIndices(CB->encoding_begin() + 1, CB->encoding_end()); 1619 F->addMetadata(llvm::LLVMContext::MD_callback, 1620 *llvm::MDNode::get(Ctx, {MDB.createCallbackEncoding( 1621 CalleeIdx, PayloadIndices, 1622 /* VarArgsArePassed */ false)})); 1623 } 1624 } 1625 1626 void CodeGenModule::addUsedGlobal(llvm::GlobalValue *GV) { 1627 assert(!GV->isDeclaration() && 1628 "Only globals with definition can force usage."); 1629 LLVMUsed.emplace_back(GV); 1630 } 1631 1632 void CodeGenModule::addCompilerUsedGlobal(llvm::GlobalValue *GV) { 1633 assert(!GV->isDeclaration() && 1634 "Only globals with definition can force usage."); 1635 LLVMCompilerUsed.emplace_back(GV); 1636 } 1637 1638 static void emitUsed(CodeGenModule &CGM, StringRef Name, 1639 std::vector<llvm::WeakTrackingVH> &List) { 1640 // Don't create llvm.used if there is no need. 1641 if (List.empty()) 1642 return; 1643 1644 // Convert List to what ConstantArray needs. 1645 SmallVector<llvm::Constant*, 8> UsedArray; 1646 UsedArray.resize(List.size()); 1647 for (unsigned i = 0, e = List.size(); i != e; ++i) { 1648 UsedArray[i] = 1649 llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast( 1650 cast<llvm::Constant>(&*List[i]), CGM.Int8PtrTy); 1651 } 1652 1653 if (UsedArray.empty()) 1654 return; 1655 llvm::ArrayType *ATy = llvm::ArrayType::get(CGM.Int8PtrTy, UsedArray.size()); 1656 1657 auto *GV = new llvm::GlobalVariable( 1658 CGM.getModule(), ATy, false, llvm::GlobalValue::AppendingLinkage, 1659 llvm::ConstantArray::get(ATy, UsedArray), Name); 1660 1661 GV->setSection("llvm.metadata"); 1662 } 1663 1664 void CodeGenModule::emitLLVMUsed() { 1665 emitUsed(*this, "llvm.used", LLVMUsed); 1666 emitUsed(*this, "llvm.compiler.used", LLVMCompilerUsed); 1667 } 1668 1669 void CodeGenModule::AppendLinkerOptions(StringRef Opts) { 1670 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opts); 1671 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 1672 } 1673 1674 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) { 1675 llvm::SmallString<32> Opt; 1676 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt); 1677 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); 1678 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 1679 } 1680 1681 void CodeGenModule::AddELFLibDirective(StringRef Lib) { 1682 auto &C = getLLVMContext(); 1683 LinkerOptionsMetadata.push_back(llvm::MDNode::get( 1684 C, {llvm::MDString::get(C, "lib"), llvm::MDString::get(C, Lib)})); 1685 } 1686 1687 void CodeGenModule::AddDependentLib(StringRef Lib) { 1688 llvm::SmallString<24> Opt; 1689 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt); 1690 auto *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); 1691 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 1692 } 1693 1694 /// Add link options implied by the given module, including modules 1695 /// it depends on, using a postorder walk. 1696 static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod, 1697 SmallVectorImpl<llvm::MDNode *> &Metadata, 1698 llvm::SmallPtrSet<Module *, 16> &Visited) { 1699 // Import this module's parent. 1700 if (Mod->Parent && Visited.insert(Mod->Parent).second) { 1701 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited); 1702 } 1703 1704 // Import this module's dependencies. 1705 for (unsigned I = Mod->Imports.size(); I > 0; --I) { 1706 if (Visited.insert(Mod->Imports[I - 1]).second) 1707 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited); 1708 } 1709 1710 // Add linker options to link against the libraries/frameworks 1711 // described by this module. 1712 llvm::LLVMContext &Context = CGM.getLLVMContext(); 1713 bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF(); 1714 bool IsPS4 = CGM.getTarget().getTriple().isPS4(); 1715 1716 // For modules that use export_as for linking, use that module 1717 // name instead. 1718 if (Mod->UseExportAsModuleLinkName) 1719 return; 1720 1721 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) { 1722 // Link against a framework. Frameworks are currently Darwin only, so we 1723 // don't to ask TargetCodeGenInfo for the spelling of the linker option. 1724 if (Mod->LinkLibraries[I-1].IsFramework) { 1725 llvm::Metadata *Args[2] = { 1726 llvm::MDString::get(Context, "-framework"), 1727 llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library)}; 1728 1729 Metadata.push_back(llvm::MDNode::get(Context, Args)); 1730 continue; 1731 } 1732 1733 // Link against a library. 1734 if (IsELF && !IsPS4) { 1735 llvm::Metadata *Args[2] = { 1736 llvm::MDString::get(Context, "lib"), 1737 llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library), 1738 }; 1739 Metadata.push_back(llvm::MDNode::get(Context, Args)); 1740 } else { 1741 llvm::SmallString<24> Opt; 1742 CGM.getTargetCodeGenInfo().getDependentLibraryOption( 1743 Mod->LinkLibraries[I - 1].Library, Opt); 1744 auto *OptString = llvm::MDString::get(Context, Opt); 1745 Metadata.push_back(llvm::MDNode::get(Context, OptString)); 1746 } 1747 } 1748 } 1749 1750 void CodeGenModule::EmitModuleLinkOptions() { 1751 // Collect the set of all of the modules we want to visit to emit link 1752 // options, which is essentially the imported modules and all of their 1753 // non-explicit child modules. 1754 llvm::SetVector<clang::Module *> LinkModules; 1755 llvm::SmallPtrSet<clang::Module *, 16> Visited; 1756 SmallVector<clang::Module *, 16> Stack; 1757 1758 // Seed the stack with imported modules. 1759 for (Module *M : ImportedModules) { 1760 // Do not add any link flags when an implementation TU of a module imports 1761 // a header of that same module. 1762 if (M->getTopLevelModuleName() == getLangOpts().CurrentModule && 1763 !getLangOpts().isCompilingModule()) 1764 continue; 1765 if (Visited.insert(M).second) 1766 Stack.push_back(M); 1767 } 1768 1769 // Find all of the modules to import, making a little effort to prune 1770 // non-leaf modules. 1771 while (!Stack.empty()) { 1772 clang::Module *Mod = Stack.pop_back_val(); 1773 1774 bool AnyChildren = false; 1775 1776 // Visit the submodules of this module. 1777 for (const auto &SM : Mod->submodules()) { 1778 // Skip explicit children; they need to be explicitly imported to be 1779 // linked against. 1780 if (SM->IsExplicit) 1781 continue; 1782 1783 if (Visited.insert(SM).second) { 1784 Stack.push_back(SM); 1785 AnyChildren = true; 1786 } 1787 } 1788 1789 // We didn't find any children, so add this module to the list of 1790 // modules to link against. 1791 if (!AnyChildren) { 1792 LinkModules.insert(Mod); 1793 } 1794 } 1795 1796 // Add link options for all of the imported modules in reverse topological 1797 // order. We don't do anything to try to order import link flags with respect 1798 // to linker options inserted by things like #pragma comment(). 1799 SmallVector<llvm::MDNode *, 16> MetadataArgs; 1800 Visited.clear(); 1801 for (Module *M : LinkModules) 1802 if (Visited.insert(M).second) 1803 addLinkOptionsPostorder(*this, M, MetadataArgs, Visited); 1804 std::reverse(MetadataArgs.begin(), MetadataArgs.end()); 1805 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end()); 1806 1807 // Add the linker options metadata flag. 1808 auto *NMD = getModule().getOrInsertNamedMetadata("llvm.linker.options"); 1809 for (auto *MD : LinkerOptionsMetadata) 1810 NMD->addOperand(MD); 1811 } 1812 1813 void CodeGenModule::EmitDeferred() { 1814 // Emit deferred declare target declarations. 1815 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd) 1816 getOpenMPRuntime().emitDeferredTargetDecls(); 1817 1818 // Emit code for any potentially referenced deferred decls. Since a 1819 // previously unused static decl may become used during the generation of code 1820 // for a static function, iterate until no changes are made. 1821 1822 if (!DeferredVTables.empty()) { 1823 EmitDeferredVTables(); 1824 1825 // Emitting a vtable doesn't directly cause more vtables to 1826 // become deferred, although it can cause functions to be 1827 // emitted that then need those vtables. 1828 assert(DeferredVTables.empty()); 1829 } 1830 1831 // Stop if we're out of both deferred vtables and deferred declarations. 1832 if (DeferredDeclsToEmit.empty()) 1833 return; 1834 1835 // Grab the list of decls to emit. If EmitGlobalDefinition schedules more 1836 // work, it will not interfere with this. 1837 std::vector<GlobalDecl> CurDeclsToEmit; 1838 CurDeclsToEmit.swap(DeferredDeclsToEmit); 1839 1840 for (GlobalDecl &D : CurDeclsToEmit) { 1841 // We should call GetAddrOfGlobal with IsForDefinition set to true in order 1842 // to get GlobalValue with exactly the type we need, not something that 1843 // might had been created for another decl with the same mangled name but 1844 // different type. 1845 llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>( 1846 GetAddrOfGlobal(D, ForDefinition)); 1847 1848 // In case of different address spaces, we may still get a cast, even with 1849 // IsForDefinition equal to true. Query mangled names table to get 1850 // GlobalValue. 1851 if (!GV) 1852 GV = GetGlobalValue(getMangledName(D)); 1853 1854 // Make sure GetGlobalValue returned non-null. 1855 assert(GV); 1856 1857 // Check to see if we've already emitted this. This is necessary 1858 // for a couple of reasons: first, decls can end up in the 1859 // deferred-decls queue multiple times, and second, decls can end 1860 // up with definitions in unusual ways (e.g. by an extern inline 1861 // function acquiring a strong function redefinition). Just 1862 // ignore these cases. 1863 if (!GV->isDeclaration()) 1864 continue; 1865 1866 // Otherwise, emit the definition and move on to the next one. 1867 EmitGlobalDefinition(D, GV); 1868 1869 // If we found out that we need to emit more decls, do that recursively. 1870 // This has the advantage that the decls are emitted in a DFS and related 1871 // ones are close together, which is convenient for testing. 1872 if (!DeferredVTables.empty() || !DeferredDeclsToEmit.empty()) { 1873 EmitDeferred(); 1874 assert(DeferredVTables.empty() && DeferredDeclsToEmit.empty()); 1875 } 1876 } 1877 } 1878 1879 void CodeGenModule::EmitVTablesOpportunistically() { 1880 // Try to emit external vtables as available_externally if they have emitted 1881 // all inlined virtual functions. It runs after EmitDeferred() and therefore 1882 // is not allowed to create new references to things that need to be emitted 1883 // lazily. Note that it also uses fact that we eagerly emitting RTTI. 1884 1885 assert((OpportunisticVTables.empty() || shouldOpportunisticallyEmitVTables()) 1886 && "Only emit opportunistic vtables with optimizations"); 1887 1888 for (const CXXRecordDecl *RD : OpportunisticVTables) { 1889 assert(getVTables().isVTableExternal(RD) && 1890 "This queue should only contain external vtables"); 1891 if (getCXXABI().canSpeculativelyEmitVTable(RD)) 1892 VTables.GenerateClassData(RD); 1893 } 1894 OpportunisticVTables.clear(); 1895 } 1896 1897 void CodeGenModule::EmitGlobalAnnotations() { 1898 if (Annotations.empty()) 1899 return; 1900 1901 // Create a new global variable for the ConstantStruct in the Module. 1902 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 1903 Annotations[0]->getType(), Annotations.size()), Annotations); 1904 auto *gv = new llvm::GlobalVariable(getModule(), Array->getType(), false, 1905 llvm::GlobalValue::AppendingLinkage, 1906 Array, "llvm.global.annotations"); 1907 gv->setSection(AnnotationSection); 1908 } 1909 1910 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) { 1911 llvm::Constant *&AStr = AnnotationStrings[Str]; 1912 if (AStr) 1913 return AStr; 1914 1915 // Not found yet, create a new global. 1916 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); 1917 auto *gv = 1918 new llvm::GlobalVariable(getModule(), s->getType(), true, 1919 llvm::GlobalValue::PrivateLinkage, s, ".str"); 1920 gv->setSection(AnnotationSection); 1921 gv->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); 1922 AStr = gv; 1923 return gv; 1924 } 1925 1926 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 1927 SourceManager &SM = getContext().getSourceManager(); 1928 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 1929 if (PLoc.isValid()) 1930 return EmitAnnotationString(PLoc.getFilename()); 1931 return EmitAnnotationString(SM.getBufferName(Loc)); 1932 } 1933 1934 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 1935 SourceManager &SM = getContext().getSourceManager(); 1936 PresumedLoc PLoc = SM.getPresumedLoc(L); 1937 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 1938 SM.getExpansionLineNumber(L); 1939 return llvm::ConstantInt::get(Int32Ty, LineNo); 1940 } 1941 1942 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 1943 const AnnotateAttr *AA, 1944 SourceLocation L) { 1945 // Get the globals for file name, annotation, and the line number. 1946 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 1947 *UnitGV = EmitAnnotationUnit(L), 1948 *LineNoCst = EmitAnnotationLineNo(L); 1949 1950 // Create the ConstantStruct for the global annotation. 1951 llvm::Constant *Fields[4] = { 1952 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 1953 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 1954 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 1955 LineNoCst 1956 }; 1957 return llvm::ConstantStruct::getAnon(Fields); 1958 } 1959 1960 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 1961 llvm::GlobalValue *GV) { 1962 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 1963 // Get the struct elements for these annotations. 1964 for (const auto *I : D->specific_attrs<AnnotateAttr>()) 1965 Annotations.push_back(EmitAnnotateAttr(GV, I, D->getLocation())); 1966 } 1967 1968 bool CodeGenModule::isInSanitizerBlacklist(SanitizerMask Kind, 1969 llvm::Function *Fn, 1970 SourceLocation Loc) const { 1971 const auto &SanitizerBL = getContext().getSanitizerBlacklist(); 1972 // Blacklist by function name. 1973 if (SanitizerBL.isBlacklistedFunction(Kind, Fn->getName())) 1974 return true; 1975 // Blacklist by location. 1976 if (Loc.isValid()) 1977 return SanitizerBL.isBlacklistedLocation(Kind, Loc); 1978 // If location is unknown, this may be a compiler-generated function. Assume 1979 // it's located in the main file. 1980 auto &SM = Context.getSourceManager(); 1981 if (const auto *MainFile = SM.getFileEntryForID(SM.getMainFileID())) { 1982 return SanitizerBL.isBlacklistedFile(Kind, MainFile->getName()); 1983 } 1984 return false; 1985 } 1986 1987 bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV, 1988 SourceLocation Loc, QualType Ty, 1989 StringRef Category) const { 1990 // For now globals can be blacklisted only in ASan and KASan. 1991 const SanitizerMask EnabledAsanMask = LangOpts.Sanitize.Mask & 1992 (SanitizerKind::Address | SanitizerKind::KernelAddress | 1993 SanitizerKind::HWAddress | SanitizerKind::KernelHWAddress); 1994 if (!EnabledAsanMask) 1995 return false; 1996 const auto &SanitizerBL = getContext().getSanitizerBlacklist(); 1997 if (SanitizerBL.isBlacklistedGlobal(EnabledAsanMask, GV->getName(), Category)) 1998 return true; 1999 if (SanitizerBL.isBlacklistedLocation(EnabledAsanMask, Loc, Category)) 2000 return true; 2001 // Check global type. 2002 if (!Ty.isNull()) { 2003 // Drill down the array types: if global variable of a fixed type is 2004 // blacklisted, we also don't instrument arrays of them. 2005 while (auto AT = dyn_cast<ArrayType>(Ty.getTypePtr())) 2006 Ty = AT->getElementType(); 2007 Ty = Ty.getCanonicalType().getUnqualifiedType(); 2008 // We allow to blacklist only record types (classes, structs etc.) 2009 if (Ty->isRecordType()) { 2010 std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy()); 2011 if (SanitizerBL.isBlacklistedType(EnabledAsanMask, TypeStr, Category)) 2012 return true; 2013 } 2014 } 2015 return false; 2016 } 2017 2018 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc, 2019 StringRef Category) const { 2020 const auto &XRayFilter = getContext().getXRayFilter(); 2021 using ImbueAttr = XRayFunctionFilter::ImbueAttribute; 2022 auto Attr = ImbueAttr::NONE; 2023 if (Loc.isValid()) 2024 Attr = XRayFilter.shouldImbueLocation(Loc, Category); 2025 if (Attr == ImbueAttr::NONE) 2026 Attr = XRayFilter.shouldImbueFunction(Fn->getName()); 2027 switch (Attr) { 2028 case ImbueAttr::NONE: 2029 return false; 2030 case ImbueAttr::ALWAYS: 2031 Fn->addFnAttr("function-instrument", "xray-always"); 2032 break; 2033 case ImbueAttr::ALWAYS_ARG1: 2034 Fn->addFnAttr("function-instrument", "xray-always"); 2035 Fn->addFnAttr("xray-log-args", "1"); 2036 break; 2037 case ImbueAttr::NEVER: 2038 Fn->addFnAttr("function-instrument", "xray-never"); 2039 break; 2040 } 2041 return true; 2042 } 2043 2044 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) { 2045 // Never defer when EmitAllDecls is specified. 2046 if (LangOpts.EmitAllDecls) 2047 return true; 2048 2049 if (CodeGenOpts.KeepStaticConsts) { 2050 const auto *VD = dyn_cast<VarDecl>(Global); 2051 if (VD && VD->getType().isConstQualified() && 2052 VD->getStorageDuration() == SD_Static) 2053 return true; 2054 } 2055 2056 return getContext().DeclMustBeEmitted(Global); 2057 } 2058 2059 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) { 2060 if (const auto *FD = dyn_cast<FunctionDecl>(Global)) 2061 if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation) 2062 // Implicit template instantiations may change linkage if they are later 2063 // explicitly instantiated, so they should not be emitted eagerly. 2064 return false; 2065 if (const auto *VD = dyn_cast<VarDecl>(Global)) 2066 if (Context.getInlineVariableDefinitionKind(VD) == 2067 ASTContext::InlineVariableDefinitionKind::WeakUnknown) 2068 // A definition of an inline constexpr static data member may change 2069 // linkage later if it's redeclared outside the class. 2070 return false; 2071 // If OpenMP is enabled and threadprivates must be generated like TLS, delay 2072 // codegen for global variables, because they may be marked as threadprivate. 2073 if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS && 2074 getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) && 2075 !isTypeConstant(Global->getType(), false) && 2076 !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global)) 2077 return false; 2078 2079 return true; 2080 } 2081 2082 ConstantAddress CodeGenModule::GetAddrOfUuidDescriptor( 2083 const CXXUuidofExpr* E) { 2084 // Sema has verified that IIDSource has a __declspec(uuid()), and that its 2085 // well-formed. 2086 StringRef Uuid = E->getUuidStr(); 2087 std::string Name = "_GUID_" + Uuid.lower(); 2088 std::replace(Name.begin(), Name.end(), '-', '_'); 2089 2090 // The UUID descriptor should be pointer aligned. 2091 CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes); 2092 2093 // Look for an existing global. 2094 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name)) 2095 return ConstantAddress(GV, Alignment); 2096 2097 llvm::Constant *Init = EmitUuidofInitializer(Uuid); 2098 assert(Init && "failed to initialize as constant"); 2099 2100 auto *GV = new llvm::GlobalVariable( 2101 getModule(), Init->getType(), 2102 /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name); 2103 if (supportsCOMDAT()) 2104 GV->setComdat(TheModule.getOrInsertComdat(GV->getName())); 2105 setDSOLocal(GV); 2106 return ConstantAddress(GV, Alignment); 2107 } 2108 2109 ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 2110 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 2111 assert(AA && "No alias?"); 2112 2113 CharUnits Alignment = getContext().getDeclAlign(VD); 2114 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 2115 2116 // See if there is already something with the target's name in the module. 2117 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 2118 if (Entry) { 2119 unsigned AS = getContext().getTargetAddressSpace(VD->getType()); 2120 auto Ptr = llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS)); 2121 return ConstantAddress(Ptr, Alignment); 2122 } 2123 2124 llvm::Constant *Aliasee; 2125 if (isa<llvm::FunctionType>(DeclTy)) 2126 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, 2127 GlobalDecl(cast<FunctionDecl>(VD)), 2128 /*ForVTable=*/false); 2129 else 2130 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 2131 llvm::PointerType::getUnqual(DeclTy), 2132 nullptr); 2133 2134 auto *F = cast<llvm::GlobalValue>(Aliasee); 2135 F->setLinkage(llvm::Function::ExternalWeakLinkage); 2136 WeakRefReferences.insert(F); 2137 2138 return ConstantAddress(Aliasee, Alignment); 2139 } 2140 2141 void CodeGenModule::EmitGlobal(GlobalDecl GD) { 2142 const auto *Global = cast<ValueDecl>(GD.getDecl()); 2143 2144 // Weak references don't produce any output by themselves. 2145 if (Global->hasAttr<WeakRefAttr>()) 2146 return; 2147 2148 // If this is an alias definition (which otherwise looks like a declaration) 2149 // emit it now. 2150 if (Global->hasAttr<AliasAttr>()) 2151 return EmitAliasDefinition(GD); 2152 2153 // IFunc like an alias whose value is resolved at runtime by calling resolver. 2154 if (Global->hasAttr<IFuncAttr>()) 2155 return emitIFuncDefinition(GD); 2156 2157 // If this is a cpu_dispatch multiversion function, emit the resolver. 2158 if (Global->hasAttr<CPUDispatchAttr>()) 2159 return emitCPUDispatchDefinition(GD); 2160 2161 // If this is CUDA, be selective about which declarations we emit. 2162 if (LangOpts.CUDA) { 2163 if (LangOpts.CUDAIsDevice) { 2164 if (!Global->hasAttr<CUDADeviceAttr>() && 2165 !Global->hasAttr<CUDAGlobalAttr>() && 2166 !Global->hasAttr<CUDAConstantAttr>() && 2167 !Global->hasAttr<CUDASharedAttr>()) 2168 return; 2169 } else { 2170 // We need to emit host-side 'shadows' for all global 2171 // device-side variables because the CUDA runtime needs their 2172 // size and host-side address in order to provide access to 2173 // their device-side incarnations. 2174 2175 // So device-only functions are the only things we skip. 2176 if (isa<FunctionDecl>(Global) && !Global->hasAttr<CUDAHostAttr>() && 2177 Global->hasAttr<CUDADeviceAttr>()) 2178 return; 2179 2180 assert((isa<FunctionDecl>(Global) || isa<VarDecl>(Global)) && 2181 "Expected Variable or Function"); 2182 } 2183 } 2184 2185 if (LangOpts.OpenMP) { 2186 // If this is OpenMP device, check if it is legal to emit this global 2187 // normally. 2188 if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD)) 2189 return; 2190 if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) { 2191 if (MustBeEmitted(Global)) 2192 EmitOMPDeclareReduction(DRD); 2193 return; 2194 } else if (auto *DMD = dyn_cast<OMPDeclareMapperDecl>(Global)) { 2195 if (MustBeEmitted(Global)) 2196 EmitOMPDeclareMapper(DMD); 2197 return; 2198 } 2199 } 2200 2201 // Ignore declarations, they will be emitted on their first use. 2202 if (const auto *FD = dyn_cast<FunctionDecl>(Global)) { 2203 // Forward declarations are emitted lazily on first use. 2204 if (!FD->doesThisDeclarationHaveABody()) { 2205 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 2206 return; 2207 2208 StringRef MangledName = getMangledName(GD); 2209 2210 // Compute the function info and LLVM type. 2211 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); 2212 llvm::Type *Ty = getTypes().GetFunctionType(FI); 2213 2214 GetOrCreateLLVMFunction(MangledName, Ty, GD, /*ForVTable=*/false, 2215 /*DontDefer=*/false); 2216 return; 2217 } 2218 } else { 2219 const auto *VD = cast<VarDecl>(Global); 2220 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 2221 if (VD->isThisDeclarationADefinition() != VarDecl::Definition && 2222 !Context.isMSStaticDataMemberInlineDefinition(VD)) { 2223 if (LangOpts.OpenMP) { 2224 // Emit declaration of the must-be-emitted declare target variable. 2225 if (llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res = 2226 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) { 2227 if (*Res == OMPDeclareTargetDeclAttr::MT_To) { 2228 (void)GetAddrOfGlobalVar(VD); 2229 } else { 2230 assert(*Res == OMPDeclareTargetDeclAttr::MT_Link && 2231 "link claue expected."); 2232 (void)getOpenMPRuntime().getAddrOfDeclareTargetLink(VD); 2233 } 2234 return; 2235 } 2236 } 2237 // If this declaration may have caused an inline variable definition to 2238 // change linkage, make sure that it's emitted. 2239 if (Context.getInlineVariableDefinitionKind(VD) == 2240 ASTContext::InlineVariableDefinitionKind::Strong) 2241 GetAddrOfGlobalVar(VD); 2242 return; 2243 } 2244 } 2245 2246 // Defer code generation to first use when possible, e.g. if this is an inline 2247 // function. If the global must always be emitted, do it eagerly if possible 2248 // to benefit from cache locality. 2249 if (MustBeEmitted(Global) && MayBeEmittedEagerly(Global)) { 2250 // Emit the definition if it can't be deferred. 2251 EmitGlobalDefinition(GD); 2252 return; 2253 } 2254 2255 // If we're deferring emission of a C++ variable with an 2256 // initializer, remember the order in which it appeared in the file. 2257 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) && 2258 cast<VarDecl>(Global)->hasInit()) { 2259 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 2260 CXXGlobalInits.push_back(nullptr); 2261 } 2262 2263 StringRef MangledName = getMangledName(GD); 2264 if (GetGlobalValue(MangledName) != nullptr) { 2265 // The value has already been used and should therefore be emitted. 2266 addDeferredDeclToEmit(GD); 2267 } else if (MustBeEmitted(Global)) { 2268 // The value must be emitted, but cannot be emitted eagerly. 2269 assert(!MayBeEmittedEagerly(Global)); 2270 addDeferredDeclToEmit(GD); 2271 } else { 2272 // Otherwise, remember that we saw a deferred decl with this name. The 2273 // first use of the mangled name will cause it to move into 2274 // DeferredDeclsToEmit. 2275 DeferredDecls[MangledName] = GD; 2276 } 2277 } 2278 2279 // Check if T is a class type with a destructor that's not dllimport. 2280 static bool HasNonDllImportDtor(QualType T) { 2281 if (const auto *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>()) 2282 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) 2283 if (RD->getDestructor() && !RD->getDestructor()->hasAttr<DLLImportAttr>()) 2284 return true; 2285 2286 return false; 2287 } 2288 2289 namespace { 2290 struct FunctionIsDirectlyRecursive 2291 : public ConstStmtVisitor<FunctionIsDirectlyRecursive, bool> { 2292 const StringRef Name; 2293 const Builtin::Context &BI; 2294 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) 2295 : Name(N), BI(C) {} 2296 2297 bool VisitCallExpr(const CallExpr *E) { 2298 const FunctionDecl *FD = E->getDirectCallee(); 2299 if (!FD) 2300 return false; 2301 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 2302 if (Attr && Name == Attr->getLabel()) 2303 return true; 2304 unsigned BuiltinID = FD->getBuiltinID(); 2305 if (!BuiltinID || !BI.isLibFunction(BuiltinID)) 2306 return false; 2307 StringRef BuiltinName = BI.getName(BuiltinID); 2308 if (BuiltinName.startswith("__builtin_") && 2309 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { 2310 return true; 2311 } 2312 return false; 2313 } 2314 2315 bool VisitStmt(const Stmt *S) { 2316 for (const Stmt *Child : S->children()) 2317 if (Child && this->Visit(Child)) 2318 return true; 2319 return false; 2320 } 2321 }; 2322 2323 // Make sure we're not referencing non-imported vars or functions. 2324 struct DLLImportFunctionVisitor 2325 : public RecursiveASTVisitor<DLLImportFunctionVisitor> { 2326 bool SafeToInline = true; 2327 2328 bool shouldVisitImplicitCode() const { return true; } 2329 2330 bool VisitVarDecl(VarDecl *VD) { 2331 if (VD->getTLSKind()) { 2332 // A thread-local variable cannot be imported. 2333 SafeToInline = false; 2334 return SafeToInline; 2335 } 2336 2337 // A variable definition might imply a destructor call. 2338 if (VD->isThisDeclarationADefinition()) 2339 SafeToInline = !HasNonDllImportDtor(VD->getType()); 2340 2341 return SafeToInline; 2342 } 2343 2344 bool VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) { 2345 if (const auto *D = E->getTemporary()->getDestructor()) 2346 SafeToInline = D->hasAttr<DLLImportAttr>(); 2347 return SafeToInline; 2348 } 2349 2350 bool VisitDeclRefExpr(DeclRefExpr *E) { 2351 ValueDecl *VD = E->getDecl(); 2352 if (isa<FunctionDecl>(VD)) 2353 SafeToInline = VD->hasAttr<DLLImportAttr>(); 2354 else if (VarDecl *V = dyn_cast<VarDecl>(VD)) 2355 SafeToInline = !V->hasGlobalStorage() || V->hasAttr<DLLImportAttr>(); 2356 return SafeToInline; 2357 } 2358 2359 bool VisitCXXConstructExpr(CXXConstructExpr *E) { 2360 SafeToInline = E->getConstructor()->hasAttr<DLLImportAttr>(); 2361 return SafeToInline; 2362 } 2363 2364 bool VisitCXXMemberCallExpr(CXXMemberCallExpr *E) { 2365 CXXMethodDecl *M = E->getMethodDecl(); 2366 if (!M) { 2367 // Call through a pointer to member function. This is safe to inline. 2368 SafeToInline = true; 2369 } else { 2370 SafeToInline = M->hasAttr<DLLImportAttr>(); 2371 } 2372 return SafeToInline; 2373 } 2374 2375 bool VisitCXXDeleteExpr(CXXDeleteExpr *E) { 2376 SafeToInline = E->getOperatorDelete()->hasAttr<DLLImportAttr>(); 2377 return SafeToInline; 2378 } 2379 2380 bool VisitCXXNewExpr(CXXNewExpr *E) { 2381 SafeToInline = E->getOperatorNew()->hasAttr<DLLImportAttr>(); 2382 return SafeToInline; 2383 } 2384 }; 2385 } 2386 2387 // isTriviallyRecursive - Check if this function calls another 2388 // decl that, because of the asm attribute or the other decl being a builtin, 2389 // ends up pointing to itself. 2390 bool 2391 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { 2392 StringRef Name; 2393 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { 2394 // asm labels are a special kind of mangling we have to support. 2395 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 2396 if (!Attr) 2397 return false; 2398 Name = Attr->getLabel(); 2399 } else { 2400 Name = FD->getName(); 2401 } 2402 2403 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); 2404 const Stmt *Body = FD->getBody(); 2405 return Body ? Walker.Visit(Body) : false; 2406 } 2407 2408 bool CodeGenModule::shouldEmitFunction(GlobalDecl GD) { 2409 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage) 2410 return true; 2411 const auto *F = cast<FunctionDecl>(GD.getDecl()); 2412 if (CodeGenOpts.OptimizationLevel == 0 && !F->hasAttr<AlwaysInlineAttr>()) 2413 return false; 2414 2415 if (F->hasAttr<DLLImportAttr>()) { 2416 // Check whether it would be safe to inline this dllimport function. 2417 DLLImportFunctionVisitor Visitor; 2418 Visitor.TraverseFunctionDecl(const_cast<FunctionDecl*>(F)); 2419 if (!Visitor.SafeToInline) 2420 return false; 2421 2422 if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(F)) { 2423 // Implicit destructor invocations aren't captured in the AST, so the 2424 // check above can't see them. Check for them manually here. 2425 for (const Decl *Member : Dtor->getParent()->decls()) 2426 if (isa<FieldDecl>(Member)) 2427 if (HasNonDllImportDtor(cast<FieldDecl>(Member)->getType())) 2428 return false; 2429 for (const CXXBaseSpecifier &B : Dtor->getParent()->bases()) 2430 if (HasNonDllImportDtor(B.getType())) 2431 return false; 2432 } 2433 } 2434 2435 // PR9614. Avoid cases where the source code is lying to us. An available 2436 // externally function should have an equivalent function somewhere else, 2437 // but a function that calls itself is clearly not equivalent to the real 2438 // implementation. 2439 // This happens in glibc's btowc and in some configure checks. 2440 return !isTriviallyRecursive(F); 2441 } 2442 2443 bool CodeGenModule::shouldOpportunisticallyEmitVTables() { 2444 return CodeGenOpts.OptimizationLevel > 0; 2445 } 2446 2447 void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD, 2448 llvm::GlobalValue *GV) { 2449 const auto *FD = cast<FunctionDecl>(GD.getDecl()); 2450 2451 if (FD->isCPUSpecificMultiVersion()) { 2452 auto *Spec = FD->getAttr<CPUSpecificAttr>(); 2453 for (unsigned I = 0; I < Spec->cpus_size(); ++I) 2454 EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr); 2455 // Requires multiple emits. 2456 } else 2457 EmitGlobalFunctionDefinition(GD, GV); 2458 } 2459 2460 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) { 2461 const auto *D = cast<ValueDecl>(GD.getDecl()); 2462 2463 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 2464 Context.getSourceManager(), 2465 "Generating code for declaration"); 2466 2467 if (const auto *FD = dyn_cast<FunctionDecl>(D)) { 2468 // At -O0, don't generate IR for functions with available_externally 2469 // linkage. 2470 if (!shouldEmitFunction(GD)) 2471 return; 2472 2473 if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) { 2474 // Make sure to emit the definition(s) before we emit the thunks. 2475 // This is necessary for the generation of certain thunks. 2476 if (const auto *CD = dyn_cast<CXXConstructorDecl>(Method)) 2477 ABI->emitCXXStructor(CD, getFromCtorType(GD.getCtorType())); 2478 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(Method)) 2479 ABI->emitCXXStructor(DD, getFromDtorType(GD.getDtorType())); 2480 else if (FD->isMultiVersion()) 2481 EmitMultiVersionFunctionDefinition(GD, GV); 2482 else 2483 EmitGlobalFunctionDefinition(GD, GV); 2484 2485 if (Method->isVirtual()) 2486 getVTables().EmitThunks(GD); 2487 2488 return; 2489 } 2490 2491 if (FD->isMultiVersion()) 2492 return EmitMultiVersionFunctionDefinition(GD, GV); 2493 return EmitGlobalFunctionDefinition(GD, GV); 2494 } 2495 2496 if (const auto *VD = dyn_cast<VarDecl>(D)) 2497 return EmitGlobalVarDefinition(VD, !VD->hasDefinition()); 2498 2499 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 2500 } 2501 2502 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 2503 llvm::Function *NewFn); 2504 2505 static unsigned 2506 TargetMVPriority(const TargetInfo &TI, 2507 const CodeGenFunction::MultiVersionResolverOption &RO) { 2508 unsigned Priority = 0; 2509 for (StringRef Feat : RO.Conditions.Features) 2510 Priority = std::max(Priority, TI.multiVersionSortPriority(Feat)); 2511 2512 if (!RO.Conditions.Architecture.empty()) 2513 Priority = std::max( 2514 Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture)); 2515 return Priority; 2516 } 2517 2518 void CodeGenModule::emitMultiVersionFunctions() { 2519 for (GlobalDecl GD : MultiVersionFuncs) { 2520 SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options; 2521 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 2522 getContext().forEachMultiversionedFunctionVersion( 2523 FD, [this, &GD, &Options](const FunctionDecl *CurFD) { 2524 GlobalDecl CurGD{ 2525 (CurFD->isDefined() ? CurFD->getDefinition() : CurFD)}; 2526 StringRef MangledName = getMangledName(CurGD); 2527 llvm::Constant *Func = GetGlobalValue(MangledName); 2528 if (!Func) { 2529 if (CurFD->isDefined()) { 2530 EmitGlobalFunctionDefinition(CurGD, nullptr); 2531 Func = GetGlobalValue(MangledName); 2532 } else { 2533 const CGFunctionInfo &FI = 2534 getTypes().arrangeGlobalDeclaration(GD); 2535 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); 2536 Func = GetAddrOfFunction(CurGD, Ty, /*ForVTable=*/false, 2537 /*DontDefer=*/false, ForDefinition); 2538 } 2539 assert(Func && "This should have just been created"); 2540 } 2541 2542 const auto *TA = CurFD->getAttr<TargetAttr>(); 2543 llvm::SmallVector<StringRef, 8> Feats; 2544 TA->getAddedFeatures(Feats); 2545 2546 Options.emplace_back(cast<llvm::Function>(Func), 2547 TA->getArchitecture(), Feats); 2548 }); 2549 2550 llvm::Function *ResolverFunc; 2551 const TargetInfo &TI = getTarget(); 2552 2553 if (TI.supportsIFunc() || FD->isTargetMultiVersion()) 2554 ResolverFunc = cast<llvm::Function>( 2555 GetGlobalValue((getMangledName(GD) + ".resolver").str())); 2556 else 2557 ResolverFunc = cast<llvm::Function>(GetGlobalValue(getMangledName(GD))); 2558 2559 if (supportsCOMDAT()) 2560 ResolverFunc->setComdat( 2561 getModule().getOrInsertComdat(ResolverFunc->getName())); 2562 2563 std::stable_sort( 2564 Options.begin(), Options.end(), 2565 [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS, 2566 const CodeGenFunction::MultiVersionResolverOption &RHS) { 2567 return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS); 2568 }); 2569 CodeGenFunction CGF(*this); 2570 CGF.EmitMultiVersionResolver(ResolverFunc, Options); 2571 } 2572 } 2573 2574 void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) { 2575 const auto *FD = cast<FunctionDecl>(GD.getDecl()); 2576 assert(FD && "Not a FunctionDecl?"); 2577 const auto *DD = FD->getAttr<CPUDispatchAttr>(); 2578 assert(DD && "Not a cpu_dispatch Function?"); 2579 llvm::Type *DeclTy = getTypes().ConvertType(FD->getType()); 2580 2581 if (const auto *CXXFD = dyn_cast<CXXMethodDecl>(FD)) { 2582 const CGFunctionInfo &FInfo = getTypes().arrangeCXXMethodDeclaration(CXXFD); 2583 DeclTy = getTypes().GetFunctionType(FInfo); 2584 } 2585 2586 StringRef ResolverName = getMangledName(GD); 2587 2588 llvm::Type *ResolverType; 2589 GlobalDecl ResolverGD; 2590 if (getTarget().supportsIFunc()) 2591 ResolverType = llvm::FunctionType::get( 2592 llvm::PointerType::get(DeclTy, 2593 Context.getTargetAddressSpace(FD->getType())), 2594 false); 2595 else { 2596 ResolverType = DeclTy; 2597 ResolverGD = GD; 2598 } 2599 2600 auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction( 2601 ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false)); 2602 2603 SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options; 2604 const TargetInfo &Target = getTarget(); 2605 unsigned Index = 0; 2606 for (const IdentifierInfo *II : DD->cpus()) { 2607 // Get the name of the target function so we can look it up/create it. 2608 std::string MangledName = getMangledNameImpl(*this, GD, FD, true) + 2609 getCPUSpecificMangling(*this, II->getName()); 2610 2611 llvm::Constant *Func = GetGlobalValue(MangledName); 2612 2613 if (!Func) { 2614 GlobalDecl ExistingDecl = Manglings.lookup(MangledName); 2615 if (ExistingDecl.getDecl() && 2616 ExistingDecl.getDecl()->getAsFunction()->isDefined()) { 2617 EmitGlobalFunctionDefinition(ExistingDecl, nullptr); 2618 Func = GetGlobalValue(MangledName); 2619 } else { 2620 if (!ExistingDecl.getDecl()) 2621 ExistingDecl = GD.getWithMultiVersionIndex(Index); 2622 2623 Func = GetOrCreateLLVMFunction( 2624 MangledName, DeclTy, ExistingDecl, 2625 /*ForVTable=*/false, /*DontDefer=*/true, 2626 /*IsThunk=*/false, llvm::AttributeList(), ForDefinition); 2627 } 2628 } 2629 2630 llvm::SmallVector<StringRef, 32> Features; 2631 Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features); 2632 llvm::transform(Features, Features.begin(), 2633 [](StringRef Str) { return Str.substr(1); }); 2634 Features.erase(std::remove_if( 2635 Features.begin(), Features.end(), [&Target](StringRef Feat) { 2636 return !Target.validateCpuSupports(Feat); 2637 }), Features.end()); 2638 Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features); 2639 ++Index; 2640 } 2641 2642 llvm::sort( 2643 Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS, 2644 const CodeGenFunction::MultiVersionResolverOption &RHS) { 2645 return CodeGenFunction::GetX86CpuSupportsMask(LHS.Conditions.Features) > 2646 CodeGenFunction::GetX86CpuSupportsMask(RHS.Conditions.Features); 2647 }); 2648 2649 // If the list contains multiple 'default' versions, such as when it contains 2650 // 'pentium' and 'generic', don't emit the call to the generic one (since we 2651 // always run on at least a 'pentium'). We do this by deleting the 'least 2652 // advanced' (read, lowest mangling letter). 2653 while (Options.size() > 1 && 2654 CodeGenFunction::GetX86CpuSupportsMask( 2655 (Options.end() - 2)->Conditions.Features) == 0) { 2656 StringRef LHSName = (Options.end() - 2)->Function->getName(); 2657 StringRef RHSName = (Options.end() - 1)->Function->getName(); 2658 if (LHSName.compare(RHSName) < 0) 2659 Options.erase(Options.end() - 2); 2660 else 2661 Options.erase(Options.end() - 1); 2662 } 2663 2664 CodeGenFunction CGF(*this); 2665 CGF.EmitMultiVersionResolver(ResolverFunc, Options); 2666 } 2667 2668 /// If a dispatcher for the specified mangled name is not in the module, create 2669 /// and return an llvm Function with the specified type. 2670 llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver( 2671 GlobalDecl GD, llvm::Type *DeclTy, const FunctionDecl *FD) { 2672 std::string MangledName = 2673 getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true); 2674 2675 // Holds the name of the resolver, in ifunc mode this is the ifunc (which has 2676 // a separate resolver). 2677 std::string ResolverName = MangledName; 2678 if (getTarget().supportsIFunc()) 2679 ResolverName += ".ifunc"; 2680 else if (FD->isTargetMultiVersion()) 2681 ResolverName += ".resolver"; 2682 2683 // If this already exists, just return that one. 2684 if (llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName)) 2685 return ResolverGV; 2686 2687 // Since this is the first time we've created this IFunc, make sure 2688 // that we put this multiversioned function into the list to be 2689 // replaced later if necessary (target multiversioning only). 2690 if (!FD->isCPUDispatchMultiVersion() && !FD->isCPUSpecificMultiVersion()) 2691 MultiVersionFuncs.push_back(GD); 2692 2693 if (getTarget().supportsIFunc()) { 2694 llvm::Type *ResolverType = llvm::FunctionType::get( 2695 llvm::PointerType::get( 2696 DeclTy, getContext().getTargetAddressSpace(FD->getType())), 2697 false); 2698 llvm::Constant *Resolver = GetOrCreateLLVMFunction( 2699 MangledName + ".resolver", ResolverType, GlobalDecl{}, 2700 /*ForVTable=*/false); 2701 llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create( 2702 DeclTy, 0, llvm::Function::ExternalLinkage, "", Resolver, &getModule()); 2703 GIF->setName(ResolverName); 2704 SetCommonAttributes(FD, GIF); 2705 2706 return GIF; 2707 } 2708 2709 llvm::Constant *Resolver = GetOrCreateLLVMFunction( 2710 ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false); 2711 assert(isa<llvm::GlobalValue>(Resolver) && 2712 "Resolver should be created for the first time"); 2713 SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver)); 2714 return Resolver; 2715 } 2716 2717 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the 2718 /// module, create and return an llvm Function with the specified type. If there 2719 /// is something in the module with the specified name, return it potentially 2720 /// bitcasted to the right type. 2721 /// 2722 /// If D is non-null, it specifies a decl that correspond to this. This is used 2723 /// to set the attributes on the function when it is first created. 2724 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction( 2725 StringRef MangledName, llvm::Type *Ty, GlobalDecl GD, bool ForVTable, 2726 bool DontDefer, bool IsThunk, llvm::AttributeList ExtraAttrs, 2727 ForDefinition_t IsForDefinition) { 2728 const Decl *D = GD.getDecl(); 2729 2730 // Any attempts to use a MultiVersion function should result in retrieving 2731 // the iFunc instead. Name Mangling will handle the rest of the changes. 2732 if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D)) { 2733 // For the device mark the function as one that should be emitted. 2734 if (getLangOpts().OpenMPIsDevice && OpenMPRuntime && 2735 !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() && 2736 !DontDefer && !IsForDefinition) { 2737 if (const FunctionDecl *FDDef = FD->getDefinition()) { 2738 GlobalDecl GDDef; 2739 if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef)) 2740 GDDef = GlobalDecl(CD, GD.getCtorType()); 2741 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef)) 2742 GDDef = GlobalDecl(DD, GD.getDtorType()); 2743 else 2744 GDDef = GlobalDecl(FDDef); 2745 EmitGlobal(GDDef); 2746 } 2747 } 2748 2749 if (FD->isMultiVersion()) { 2750 const auto *TA = FD->getAttr<TargetAttr>(); 2751 if (TA && TA->isDefaultVersion()) 2752 UpdateMultiVersionNames(GD, FD); 2753 if (!IsForDefinition) 2754 return GetOrCreateMultiVersionResolver(GD, Ty, FD); 2755 } 2756 } 2757 2758 // Lookup the entry, lazily creating it if necessary. 2759 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 2760 if (Entry) { 2761 if (WeakRefReferences.erase(Entry)) { 2762 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D); 2763 if (FD && !FD->hasAttr<WeakAttr>()) 2764 Entry->setLinkage(llvm::Function::ExternalLinkage); 2765 } 2766 2767 // Handle dropped DLL attributes. 2768 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>()) { 2769 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass); 2770 setDSOLocal(Entry); 2771 } 2772 2773 // If there are two attempts to define the same mangled name, issue an 2774 // error. 2775 if (IsForDefinition && !Entry->isDeclaration()) { 2776 GlobalDecl OtherGD; 2777 // Check that GD is not yet in DiagnosedConflictingDefinitions is required 2778 // to make sure that we issue an error only once. 2779 if (lookupRepresentativeDecl(MangledName, OtherGD) && 2780 (GD.getCanonicalDecl().getDecl() != 2781 OtherGD.getCanonicalDecl().getDecl()) && 2782 DiagnosedConflictingDefinitions.insert(GD).second) { 2783 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name) 2784 << MangledName; 2785 getDiags().Report(OtherGD.getDecl()->getLocation(), 2786 diag::note_previous_definition); 2787 } 2788 } 2789 2790 if ((isa<llvm::Function>(Entry) || isa<llvm::GlobalAlias>(Entry)) && 2791 (Entry->getType()->getElementType() == Ty)) { 2792 return Entry; 2793 } 2794 2795 // Make sure the result is of the correct type. 2796 // (If function is requested for a definition, we always need to create a new 2797 // function, not just return a bitcast.) 2798 if (!IsForDefinition) 2799 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 2800 } 2801 2802 // This function doesn't have a complete type (for example, the return 2803 // type is an incomplete struct). Use a fake type instead, and make 2804 // sure not to try to set attributes. 2805 bool IsIncompleteFunction = false; 2806 2807 llvm::FunctionType *FTy; 2808 if (isa<llvm::FunctionType>(Ty)) { 2809 FTy = cast<llvm::FunctionType>(Ty); 2810 } else { 2811 FTy = llvm::FunctionType::get(VoidTy, false); 2812 IsIncompleteFunction = true; 2813 } 2814 2815 llvm::Function *F = 2816 llvm::Function::Create(FTy, llvm::Function::ExternalLinkage, 2817 Entry ? StringRef() : MangledName, &getModule()); 2818 2819 // If we already created a function with the same mangled name (but different 2820 // type) before, take its name and add it to the list of functions to be 2821 // replaced with F at the end of CodeGen. 2822 // 2823 // This happens if there is a prototype for a function (e.g. "int f()") and 2824 // then a definition of a different type (e.g. "int f(int x)"). 2825 if (Entry) { 2826 F->takeName(Entry); 2827 2828 // This might be an implementation of a function without a prototype, in 2829 // which case, try to do special replacement of calls which match the new 2830 // prototype. The really key thing here is that we also potentially drop 2831 // arguments from the call site so as to make a direct call, which makes the 2832 // inliner happier and suppresses a number of optimizer warnings (!) about 2833 // dropping arguments. 2834 if (!Entry->use_empty()) { 2835 ReplaceUsesOfNonProtoTypeWithRealFunction(Entry, F); 2836 Entry->removeDeadConstantUsers(); 2837 } 2838 2839 llvm::Constant *BC = llvm::ConstantExpr::getBitCast( 2840 F, Entry->getType()->getElementType()->getPointerTo()); 2841 addGlobalValReplacement(Entry, BC); 2842 } 2843 2844 assert(F->getName() == MangledName && "name was uniqued!"); 2845 if (D) 2846 SetFunctionAttributes(GD, F, IsIncompleteFunction, IsThunk); 2847 if (ExtraAttrs.hasAttributes(llvm::AttributeList::FunctionIndex)) { 2848 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeList::FunctionIndex); 2849 F->addAttributes(llvm::AttributeList::FunctionIndex, B); 2850 } 2851 2852 if (!DontDefer) { 2853 // All MSVC dtors other than the base dtor are linkonce_odr and delegate to 2854 // each other bottoming out with the base dtor. Therefore we emit non-base 2855 // dtors on usage, even if there is no dtor definition in the TU. 2856 if (D && isa<CXXDestructorDecl>(D) && 2857 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D), 2858 GD.getDtorType())) 2859 addDeferredDeclToEmit(GD); 2860 2861 // This is the first use or definition of a mangled name. If there is a 2862 // deferred decl with this name, remember that we need to emit it at the end 2863 // of the file. 2864 auto DDI = DeferredDecls.find(MangledName); 2865 if (DDI != DeferredDecls.end()) { 2866 // Move the potentially referenced deferred decl to the 2867 // DeferredDeclsToEmit list, and remove it from DeferredDecls (since we 2868 // don't need it anymore). 2869 addDeferredDeclToEmit(DDI->second); 2870 DeferredDecls.erase(DDI); 2871 2872 // Otherwise, there are cases we have to worry about where we're 2873 // using a declaration for which we must emit a definition but where 2874 // we might not find a top-level definition: 2875 // - member functions defined inline in their classes 2876 // - friend functions defined inline in some class 2877 // - special member functions with implicit definitions 2878 // If we ever change our AST traversal to walk into class methods, 2879 // this will be unnecessary. 2880 // 2881 // We also don't emit a definition for a function if it's going to be an 2882 // entry in a vtable, unless it's already marked as used. 2883 } else if (getLangOpts().CPlusPlus && D) { 2884 // Look for a declaration that's lexically in a record. 2885 for (const auto *FD = cast<FunctionDecl>(D)->getMostRecentDecl(); FD; 2886 FD = FD->getPreviousDecl()) { 2887 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 2888 if (FD->doesThisDeclarationHaveABody()) { 2889 addDeferredDeclToEmit(GD.getWithDecl(FD)); 2890 break; 2891 } 2892 } 2893 } 2894 } 2895 } 2896 2897 // Make sure the result is of the requested type. 2898 if (!IsIncompleteFunction) { 2899 assert(F->getType()->getElementType() == Ty); 2900 return F; 2901 } 2902 2903 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 2904 return llvm::ConstantExpr::getBitCast(F, PTy); 2905 } 2906 2907 /// GetAddrOfFunction - Return the address of the given function. If Ty is 2908 /// non-null, then this function will use the specified type if it has to 2909 /// create it (this occurs when we see a definition of the function). 2910 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 2911 llvm::Type *Ty, 2912 bool ForVTable, 2913 bool DontDefer, 2914 ForDefinition_t IsForDefinition) { 2915 // If there was no specific requested type, just convert it now. 2916 if (!Ty) { 2917 const auto *FD = cast<FunctionDecl>(GD.getDecl()); 2918 Ty = getTypes().ConvertType(FD->getType()); 2919 } 2920 2921 // Devirtualized destructor calls may come through here instead of via 2922 // getAddrOfCXXStructor. Make sure we use the MS ABI base destructor instead 2923 // of the complete destructor when necessary. 2924 if (const auto *DD = dyn_cast<CXXDestructorDecl>(GD.getDecl())) { 2925 if (getTarget().getCXXABI().isMicrosoft() && 2926 GD.getDtorType() == Dtor_Complete && 2927 DD->getParent()->getNumVBases() == 0) 2928 GD = GlobalDecl(DD, Dtor_Base); 2929 } 2930 2931 StringRef MangledName = getMangledName(GD); 2932 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable, DontDefer, 2933 /*IsThunk=*/false, llvm::AttributeList(), 2934 IsForDefinition); 2935 } 2936 2937 static const FunctionDecl * 2938 GetRuntimeFunctionDecl(ASTContext &C, StringRef Name) { 2939 TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl(); 2940 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl); 2941 2942 IdentifierInfo &CII = C.Idents.get(Name); 2943 for (const auto &Result : DC->lookup(&CII)) 2944 if (const auto FD = dyn_cast<FunctionDecl>(Result)) 2945 return FD; 2946 2947 if (!C.getLangOpts().CPlusPlus) 2948 return nullptr; 2949 2950 // Demangle the premangled name from getTerminateFn() 2951 IdentifierInfo &CXXII = 2952 (Name == "_ZSt9terminatev" || Name == "?terminate@@YAXXZ") 2953 ? C.Idents.get("terminate") 2954 : C.Idents.get(Name); 2955 2956 for (const auto &N : {"__cxxabiv1", "std"}) { 2957 IdentifierInfo &NS = C.Idents.get(N); 2958 for (const auto &Result : DC->lookup(&NS)) { 2959 NamespaceDecl *ND = dyn_cast<NamespaceDecl>(Result); 2960 if (auto LSD = dyn_cast<LinkageSpecDecl>(Result)) 2961 for (const auto &Result : LSD->lookup(&NS)) 2962 if ((ND = dyn_cast<NamespaceDecl>(Result))) 2963 break; 2964 2965 if (ND) 2966 for (const auto &Result : ND->lookup(&CXXII)) 2967 if (const auto *FD = dyn_cast<FunctionDecl>(Result)) 2968 return FD; 2969 } 2970 } 2971 2972 return nullptr; 2973 } 2974 2975 /// CreateRuntimeFunction - Create a new runtime function with the specified 2976 /// type and name. 2977 llvm::FunctionCallee 2978 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, StringRef Name, 2979 llvm::AttributeList ExtraAttrs, 2980 bool Local) { 2981 llvm::Constant *C = 2982 GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 2983 /*DontDefer=*/false, /*IsThunk=*/false, 2984 ExtraAttrs); 2985 2986 if (auto *F = dyn_cast<llvm::Function>(C)) { 2987 if (F->empty()) { 2988 F->setCallingConv(getRuntimeCC()); 2989 2990 if (!Local && getTriple().isOSBinFormatCOFF() && 2991 !getCodeGenOpts().LTOVisibilityPublicStd && 2992 !getTriple().isWindowsGNUEnvironment()) { 2993 const FunctionDecl *FD = GetRuntimeFunctionDecl(Context, Name); 2994 if (!FD || FD->hasAttr<DLLImportAttr>()) { 2995 F->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass); 2996 F->setLinkage(llvm::GlobalValue::ExternalLinkage); 2997 } 2998 } 2999 setDSOLocal(F); 3000 } 3001 } 3002 3003 return {FTy, C}; 3004 } 3005 3006 /// isTypeConstant - Determine whether an object of this type can be emitted 3007 /// as a constant. 3008 /// 3009 /// If ExcludeCtor is true, the duration when the object's constructor runs 3010 /// will not be considered. The caller will need to verify that the object is 3011 /// not written to during its construction. 3012 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) { 3013 if (!Ty.isConstant(Context) && !Ty->isReferenceType()) 3014 return false; 3015 3016 if (Context.getLangOpts().CPlusPlus) { 3017 if (const CXXRecordDecl *Record 3018 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl()) 3019 return ExcludeCtor && !Record->hasMutableFields() && 3020 Record->hasTrivialDestructor(); 3021 } 3022 3023 return true; 3024 } 3025 3026 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 3027 /// create and return an llvm GlobalVariable with the specified type. If there 3028 /// is something in the module with the specified name, return it potentially 3029 /// bitcasted to the right type. 3030 /// 3031 /// If D is non-null, it specifies a decl that correspond to this. This is used 3032 /// to set the attributes on the global when it is first created. 3033 /// 3034 /// If IsForDefinition is true, it is guaranteed that an actual global with 3035 /// type Ty will be returned, not conversion of a variable with the same 3036 /// mangled name but some other type. 3037 llvm::Constant * 3038 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 3039 llvm::PointerType *Ty, 3040 const VarDecl *D, 3041 ForDefinition_t IsForDefinition) { 3042 // Lookup the entry, lazily creating it if necessary. 3043 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 3044 if (Entry) { 3045 if (WeakRefReferences.erase(Entry)) { 3046 if (D && !D->hasAttr<WeakAttr>()) 3047 Entry->setLinkage(llvm::Function::ExternalLinkage); 3048 } 3049 3050 // Handle dropped DLL attributes. 3051 if (D && !D->hasAttr<DLLImportAttr>() && !D->hasAttr<DLLExportAttr>()) 3052 Entry->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass); 3053 3054 if (LangOpts.OpenMP && !LangOpts.OpenMPSimd && D) 3055 getOpenMPRuntime().registerTargetGlobalVariable(D, Entry); 3056 3057 if (Entry->getType() == Ty) 3058 return Entry; 3059 3060 // If there are two attempts to define the same mangled name, issue an 3061 // error. 3062 if (IsForDefinition && !Entry->isDeclaration()) { 3063 GlobalDecl OtherGD; 3064 const VarDecl *OtherD; 3065 3066 // Check that D is not yet in DiagnosedConflictingDefinitions is required 3067 // to make sure that we issue an error only once. 3068 if (D && lookupRepresentativeDecl(MangledName, OtherGD) && 3069 (D->getCanonicalDecl() != OtherGD.getCanonicalDecl().getDecl()) && 3070 (OtherD = dyn_cast<VarDecl>(OtherGD.getDecl())) && 3071 OtherD->hasInit() && 3072 DiagnosedConflictingDefinitions.insert(D).second) { 3073 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name) 3074 << MangledName; 3075 getDiags().Report(OtherGD.getDecl()->getLocation(), 3076 diag::note_previous_definition); 3077 } 3078 } 3079 3080 // Make sure the result is of the correct type. 3081 if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace()) 3082 return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty); 3083 3084 // (If global is requested for a definition, we always need to create a new 3085 // global, not just return a bitcast.) 3086 if (!IsForDefinition) 3087 return llvm::ConstantExpr::getBitCast(Entry, Ty); 3088 } 3089 3090 auto AddrSpace = GetGlobalVarAddressSpace(D); 3091 auto TargetAddrSpace = getContext().getTargetAddressSpace(AddrSpace); 3092 3093 auto *GV = new llvm::GlobalVariable( 3094 getModule(), Ty->getElementType(), false, 3095 llvm::GlobalValue::ExternalLinkage, nullptr, MangledName, nullptr, 3096 llvm::GlobalVariable::NotThreadLocal, TargetAddrSpace); 3097 3098 // If we already created a global with the same mangled name (but different 3099 // type) before, take its name and remove it from its parent. 3100 if (Entry) { 3101 GV->takeName(Entry); 3102 3103 if (!Entry->use_empty()) { 3104 llvm::Constant *NewPtrForOldDecl = 3105 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 3106 Entry->replaceAllUsesWith(NewPtrForOldDecl); 3107 } 3108 3109 Entry->eraseFromParent(); 3110 } 3111 3112 // This is the first use or definition of a mangled name. If there is a 3113 // deferred decl with this name, remember that we need to emit it at the end 3114 // of the file. 3115 auto DDI = DeferredDecls.find(MangledName); 3116 if (DDI != DeferredDecls.end()) { 3117 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 3118 // list, and remove it from DeferredDecls (since we don't need it anymore). 3119 addDeferredDeclToEmit(DDI->second); 3120 DeferredDecls.erase(DDI); 3121 } 3122 3123 // Handle things which are present even on external declarations. 3124 if (D) { 3125 if (LangOpts.OpenMP && !LangOpts.OpenMPSimd) 3126 getOpenMPRuntime().registerTargetGlobalVariable(D, GV); 3127 3128 // FIXME: This code is overly simple and should be merged with other global 3129 // handling. 3130 GV->setConstant(isTypeConstant(D->getType(), false)); 3131 3132 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 3133 3134 setLinkageForGV(GV, D); 3135 3136 if (D->getTLSKind()) { 3137 if (D->getTLSKind() == VarDecl::TLS_Dynamic) 3138 CXXThreadLocals.push_back(D); 3139 setTLSMode(GV, *D); 3140 } 3141 3142 setGVProperties(GV, D); 3143 3144 // If required by the ABI, treat declarations of static data members with 3145 // inline initializers as definitions. 3146 if (getContext().isMSStaticDataMemberInlineDefinition(D)) { 3147 EmitGlobalVarDefinition(D); 3148 } 3149 3150 // Emit section information for extern variables. 3151 if (D->hasExternalStorage()) { 3152 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 3153 GV->setSection(SA->getName()); 3154 } 3155 3156 // Handle XCore specific ABI requirements. 3157 if (getTriple().getArch() == llvm::Triple::xcore && 3158 D->getLanguageLinkage() == CLanguageLinkage && 3159 D->getType().isConstant(Context) && 3160 isExternallyVisible(D->getLinkageAndVisibility().getLinkage())) 3161 GV->setSection(".cp.rodata"); 3162 3163 // Check if we a have a const declaration with an initializer, we may be 3164 // able to emit it as available_externally to expose it's value to the 3165 // optimizer. 3166 if (Context.getLangOpts().CPlusPlus && GV->hasExternalLinkage() && 3167 D->getType().isConstQualified() && !GV->hasInitializer() && 3168 !D->hasDefinition() && D->hasInit() && !D->hasAttr<DLLImportAttr>()) { 3169 const auto *Record = 3170 Context.getBaseElementType(D->getType())->getAsCXXRecordDecl(); 3171 bool HasMutableFields = Record && Record->hasMutableFields(); 3172 if (!HasMutableFields) { 3173 const VarDecl *InitDecl; 3174 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 3175 if (InitExpr) { 3176 ConstantEmitter emitter(*this); 3177 llvm::Constant *Init = emitter.tryEmitForInitializer(*InitDecl); 3178 if (Init) { 3179 auto *InitType = Init->getType(); 3180 if (GV->getType()->getElementType() != InitType) { 3181 // The type of the initializer does not match the definition. 3182 // This happens when an initializer has a different type from 3183 // the type of the global (because of padding at the end of a 3184 // structure for instance). 3185 GV->setName(StringRef()); 3186 // Make a new global with the correct type, this is now guaranteed 3187 // to work. 3188 auto *NewGV = cast<llvm::GlobalVariable>( 3189 GetAddrOfGlobalVar(D, InitType, IsForDefinition)); 3190 3191 // Erase the old global, since it is no longer used. 3192 GV->eraseFromParent(); 3193 GV = NewGV; 3194 } else { 3195 GV->setInitializer(Init); 3196 GV->setConstant(true); 3197 GV->setLinkage(llvm::GlobalValue::AvailableExternallyLinkage); 3198 } 3199 emitter.finalize(GV); 3200 } 3201 } 3202 } 3203 } 3204 } 3205 3206 LangAS ExpectedAS = 3207 D ? D->getType().getAddressSpace() 3208 : (LangOpts.OpenCL ? LangAS::opencl_global : LangAS::Default); 3209 assert(getContext().getTargetAddressSpace(ExpectedAS) == 3210 Ty->getPointerAddressSpace()); 3211 if (AddrSpace != ExpectedAS) 3212 return getTargetCodeGenInfo().performAddrSpaceCast(*this, GV, AddrSpace, 3213 ExpectedAS, Ty); 3214 3215 return GV; 3216 } 3217 3218 llvm::Constant * 3219 CodeGenModule::GetAddrOfGlobal(GlobalDecl GD, 3220 ForDefinition_t IsForDefinition) { 3221 const Decl *D = GD.getDecl(); 3222 if (isa<CXXConstructorDecl>(D)) 3223 return getAddrOfCXXStructor(cast<CXXConstructorDecl>(D), 3224 getFromCtorType(GD.getCtorType()), 3225 /*FnInfo=*/nullptr, /*FnType=*/nullptr, 3226 /*DontDefer=*/false, IsForDefinition); 3227 else if (isa<CXXDestructorDecl>(D)) 3228 return getAddrOfCXXStructor(cast<CXXDestructorDecl>(D), 3229 getFromDtorType(GD.getDtorType()), 3230 /*FnInfo=*/nullptr, /*FnType=*/nullptr, 3231 /*DontDefer=*/false, IsForDefinition); 3232 else if (isa<CXXMethodDecl>(D)) { 3233 auto FInfo = &getTypes().arrangeCXXMethodDeclaration( 3234 cast<CXXMethodDecl>(D)); 3235 auto Ty = getTypes().GetFunctionType(*FInfo); 3236 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false, 3237 IsForDefinition); 3238 } else if (isa<FunctionDecl>(D)) { 3239 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); 3240 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); 3241 return GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, /*DontDefer=*/false, 3242 IsForDefinition); 3243 } else 3244 return GetAddrOfGlobalVar(cast<VarDecl>(D), /*Ty=*/nullptr, 3245 IsForDefinition); 3246 } 3247 3248 llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable( 3249 StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage, 3250 unsigned Alignment) { 3251 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 3252 llvm::GlobalVariable *OldGV = nullptr; 3253 3254 if (GV) { 3255 // Check if the variable has the right type. 3256 if (GV->getType()->getElementType() == Ty) 3257 return GV; 3258 3259 // Because C++ name mangling, the only way we can end up with an already 3260 // existing global with the same name is if it has been declared extern "C". 3261 assert(GV->isDeclaration() && "Declaration has wrong type!"); 3262 OldGV = GV; 3263 } 3264 3265 // Create a new variable. 3266 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 3267 Linkage, nullptr, Name); 3268 3269 if (OldGV) { 3270 // Replace occurrences of the old variable if needed. 3271 GV->takeName(OldGV); 3272 3273 if (!OldGV->use_empty()) { 3274 llvm::Constant *NewPtrForOldDecl = 3275 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 3276 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 3277 } 3278 3279 OldGV->eraseFromParent(); 3280 } 3281 3282 if (supportsCOMDAT() && GV->isWeakForLinker() && 3283 !GV->hasAvailableExternallyLinkage()) 3284 GV->setComdat(TheModule.getOrInsertComdat(GV->getName())); 3285 3286 GV->setAlignment(Alignment); 3287 3288 return GV; 3289 } 3290 3291 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 3292 /// given global variable. If Ty is non-null and if the global doesn't exist, 3293 /// then it will be created with the specified type instead of whatever the 3294 /// normal requested type would be. If IsForDefinition is true, it is guaranteed 3295 /// that an actual global with type Ty will be returned, not conversion of a 3296 /// variable with the same mangled name but some other type. 3297 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 3298 llvm::Type *Ty, 3299 ForDefinition_t IsForDefinition) { 3300 assert(D->hasGlobalStorage() && "Not a global variable"); 3301 QualType ASTTy = D->getType(); 3302 if (!Ty) 3303 Ty = getTypes().ConvertTypeForMem(ASTTy); 3304 3305 llvm::PointerType *PTy = 3306 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 3307 3308 StringRef MangledName = getMangledName(D); 3309 return GetOrCreateLLVMGlobal(MangledName, PTy, D, IsForDefinition); 3310 } 3311 3312 /// CreateRuntimeVariable - Create a new runtime global variable with the 3313 /// specified type and name. 3314 llvm::Constant * 3315 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 3316 StringRef Name) { 3317 auto *Ret = 3318 GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), nullptr); 3319 setDSOLocal(cast<llvm::GlobalValue>(Ret->stripPointerCasts())); 3320 return Ret; 3321 } 3322 3323 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 3324 assert(!D->getInit() && "Cannot emit definite definitions here!"); 3325 3326 StringRef MangledName = getMangledName(D); 3327 llvm::GlobalValue *GV = GetGlobalValue(MangledName); 3328 3329 // We already have a definition, not declaration, with the same mangled name. 3330 // Emitting of declaration is not required (and actually overwrites emitted 3331 // definition). 3332 if (GV && !GV->isDeclaration()) 3333 return; 3334 3335 // If we have not seen a reference to this variable yet, place it into the 3336 // deferred declarations table to be emitted if needed later. 3337 if (!MustBeEmitted(D) && !GV) { 3338 DeferredDecls[MangledName] = D; 3339 return; 3340 } 3341 3342 // The tentative definition is the only definition. 3343 EmitGlobalVarDefinition(D); 3344 } 3345 3346 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 3347 return Context.toCharUnitsFromBits( 3348 getDataLayout().getTypeStoreSizeInBits(Ty)); 3349 } 3350 3351 LangAS CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D) { 3352 LangAS AddrSpace = LangAS::Default; 3353 if (LangOpts.OpenCL) { 3354 AddrSpace = D ? D->getType().getAddressSpace() : LangAS::opencl_global; 3355 assert(AddrSpace == LangAS::opencl_global || 3356 AddrSpace == LangAS::opencl_constant || 3357 AddrSpace == LangAS::opencl_local || 3358 AddrSpace >= LangAS::FirstTargetAddressSpace); 3359 return AddrSpace; 3360 } 3361 3362 if (LangOpts.CUDA && LangOpts.CUDAIsDevice) { 3363 if (D && D->hasAttr<CUDAConstantAttr>()) 3364 return LangAS::cuda_constant; 3365 else if (D && D->hasAttr<CUDASharedAttr>()) 3366 return LangAS::cuda_shared; 3367 else if (D && D->hasAttr<CUDADeviceAttr>()) 3368 return LangAS::cuda_device; 3369 else if (D && D->getType().isConstQualified()) 3370 return LangAS::cuda_constant; 3371 else 3372 return LangAS::cuda_device; 3373 } 3374 3375 return getTargetCodeGenInfo().getGlobalVarAddressSpace(*this, D); 3376 } 3377 3378 LangAS CodeGenModule::getStringLiteralAddressSpace() const { 3379 // OpenCL v1.2 s6.5.3: a string literal is in the constant address space. 3380 if (LangOpts.OpenCL) 3381 return LangAS::opencl_constant; 3382 if (auto AS = getTarget().getConstantAddressSpace()) 3383 return AS.getValue(); 3384 return LangAS::Default; 3385 } 3386 3387 // In address space agnostic languages, string literals are in default address 3388 // space in AST. However, certain targets (e.g. amdgcn) request them to be 3389 // emitted in constant address space in LLVM IR. To be consistent with other 3390 // parts of AST, string literal global variables in constant address space 3391 // need to be casted to default address space before being put into address 3392 // map and referenced by other part of CodeGen. 3393 // In OpenCL, string literals are in constant address space in AST, therefore 3394 // they should not be casted to default address space. 3395 static llvm::Constant * 3396 castStringLiteralToDefaultAddressSpace(CodeGenModule &CGM, 3397 llvm::GlobalVariable *GV) { 3398 llvm::Constant *Cast = GV; 3399 if (!CGM.getLangOpts().OpenCL) { 3400 if (auto AS = CGM.getTarget().getConstantAddressSpace()) { 3401 if (AS != LangAS::Default) 3402 Cast = CGM.getTargetCodeGenInfo().performAddrSpaceCast( 3403 CGM, GV, AS.getValue(), LangAS::Default, 3404 GV->getValueType()->getPointerTo( 3405 CGM.getContext().getTargetAddressSpace(LangAS::Default))); 3406 } 3407 } 3408 return Cast; 3409 } 3410 3411 template<typename SomeDecl> 3412 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D, 3413 llvm::GlobalValue *GV) { 3414 if (!getLangOpts().CPlusPlus) 3415 return; 3416 3417 // Must have 'used' attribute, or else inline assembly can't rely on 3418 // the name existing. 3419 if (!D->template hasAttr<UsedAttr>()) 3420 return; 3421 3422 // Must have internal linkage and an ordinary name. 3423 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage) 3424 return; 3425 3426 // Must be in an extern "C" context. Entities declared directly within 3427 // a record are not extern "C" even if the record is in such a context. 3428 const SomeDecl *First = D->getFirstDecl(); 3429 if (First->getDeclContext()->isRecord() || !First->isInExternCContext()) 3430 return; 3431 3432 // OK, this is an internal linkage entity inside an extern "C" linkage 3433 // specification. Make a note of that so we can give it the "expected" 3434 // mangled name if nothing else is using that name. 3435 std::pair<StaticExternCMap::iterator, bool> R = 3436 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV)); 3437 3438 // If we have multiple internal linkage entities with the same name 3439 // in extern "C" regions, none of them gets that name. 3440 if (!R.second) 3441 R.first->second = nullptr; 3442 } 3443 3444 static bool shouldBeInCOMDAT(CodeGenModule &CGM, const Decl &D) { 3445 if (!CGM.supportsCOMDAT()) 3446 return false; 3447 3448 if (D.hasAttr<SelectAnyAttr>()) 3449 return true; 3450 3451 GVALinkage Linkage; 3452 if (auto *VD = dyn_cast<VarDecl>(&D)) 3453 Linkage = CGM.getContext().GetGVALinkageForVariable(VD); 3454 else 3455 Linkage = CGM.getContext().GetGVALinkageForFunction(cast<FunctionDecl>(&D)); 3456 3457 switch (Linkage) { 3458 case GVA_Internal: 3459 case GVA_AvailableExternally: 3460 case GVA_StrongExternal: 3461 return false; 3462 case GVA_DiscardableODR: 3463 case GVA_StrongODR: 3464 return true; 3465 } 3466 llvm_unreachable("No such linkage"); 3467 } 3468 3469 void CodeGenModule::maybeSetTrivialComdat(const Decl &D, 3470 llvm::GlobalObject &GO) { 3471 if (!shouldBeInCOMDAT(*this, D)) 3472 return; 3473 GO.setComdat(TheModule.getOrInsertComdat(GO.getName())); 3474 } 3475 3476 /// Pass IsTentative as true if you want to create a tentative definition. 3477 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D, 3478 bool IsTentative) { 3479 // OpenCL global variables of sampler type are translated to function calls, 3480 // therefore no need to be translated. 3481 QualType ASTTy = D->getType(); 3482 if (getLangOpts().OpenCL && ASTTy->isSamplerT()) 3483 return; 3484 3485 // If this is OpenMP device, check if it is legal to emit this global 3486 // normally. 3487 if (LangOpts.OpenMPIsDevice && OpenMPRuntime && 3488 OpenMPRuntime->emitTargetGlobalVariable(D)) 3489 return; 3490 3491 llvm::Constant *Init = nullptr; 3492 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 3493 bool NeedsGlobalCtor = false; 3494 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor(); 3495 3496 const VarDecl *InitDecl; 3497 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 3498 3499 Optional<ConstantEmitter> emitter; 3500 3501 // CUDA E.2.4.1 "__shared__ variables cannot have an initialization 3502 // as part of their declaration." Sema has already checked for 3503 // error cases, so we just need to set Init to UndefValue. 3504 bool IsCUDASharedVar = 3505 getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>(); 3506 // Shadows of initialized device-side global variables are also left 3507 // undefined. 3508 bool IsCUDAShadowVar = 3509 !getLangOpts().CUDAIsDevice && 3510 (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() || 3511 D->hasAttr<CUDASharedAttr>()); 3512 if (getLangOpts().CUDA && (IsCUDASharedVar || IsCUDAShadowVar)) 3513 Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy)); 3514 else if (!InitExpr) { 3515 // This is a tentative definition; tentative definitions are 3516 // implicitly initialized with { 0 }. 3517 // 3518 // Note that tentative definitions are only emitted at the end of 3519 // a translation unit, so they should never have incomplete 3520 // type. In addition, EmitTentativeDefinition makes sure that we 3521 // never attempt to emit a tentative definition if a real one 3522 // exists. A use may still exists, however, so we still may need 3523 // to do a RAUW. 3524 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 3525 Init = EmitNullConstant(D->getType()); 3526 } else { 3527 initializedGlobalDecl = GlobalDecl(D); 3528 emitter.emplace(*this); 3529 Init = emitter->tryEmitForInitializer(*InitDecl); 3530 3531 if (!Init) { 3532 QualType T = InitExpr->getType(); 3533 if (D->getType()->isReferenceType()) 3534 T = D->getType(); 3535 3536 if (getLangOpts().CPlusPlus) { 3537 Init = EmitNullConstant(T); 3538 NeedsGlobalCtor = true; 3539 } else { 3540 ErrorUnsupported(D, "static initializer"); 3541 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 3542 } 3543 } else { 3544 // We don't need an initializer, so remove the entry for the delayed 3545 // initializer position (just in case this entry was delayed) if we 3546 // also don't need to register a destructor. 3547 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor) 3548 DelayedCXXInitPosition.erase(D); 3549 } 3550 } 3551 3552 llvm::Type* InitType = Init->getType(); 3553 llvm::Constant *Entry = 3554 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative)); 3555 3556 // Strip off a bitcast if we got one back. 3557 if (auto *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 3558 assert(CE->getOpcode() == llvm::Instruction::BitCast || 3559 CE->getOpcode() == llvm::Instruction::AddrSpaceCast || 3560 // All zero index gep. 3561 CE->getOpcode() == llvm::Instruction::GetElementPtr); 3562 Entry = CE->getOperand(0); 3563 } 3564 3565 // Entry is now either a Function or GlobalVariable. 3566 auto *GV = dyn_cast<llvm::GlobalVariable>(Entry); 3567 3568 // We have a definition after a declaration with the wrong type. 3569 // We must make a new GlobalVariable* and update everything that used OldGV 3570 // (a declaration or tentative definition) with the new GlobalVariable* 3571 // (which will be a definition). 3572 // 3573 // This happens if there is a prototype for a global (e.g. 3574 // "extern int x[];") and then a definition of a different type (e.g. 3575 // "int x[10];"). This also happens when an initializer has a different type 3576 // from the type of the global (this happens with unions). 3577 if (!GV || GV->getType()->getElementType() != InitType || 3578 GV->getType()->getAddressSpace() != 3579 getContext().getTargetAddressSpace(GetGlobalVarAddressSpace(D))) { 3580 3581 // Move the old entry aside so that we'll create a new one. 3582 Entry->setName(StringRef()); 3583 3584 // Make a new global with the correct type, this is now guaranteed to work. 3585 GV = cast<llvm::GlobalVariable>( 3586 GetAddrOfGlobalVar(D, InitType, ForDefinition_t(!IsTentative))); 3587 3588 // Replace all uses of the old global with the new global 3589 llvm::Constant *NewPtrForOldDecl = 3590 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 3591 Entry->replaceAllUsesWith(NewPtrForOldDecl); 3592 3593 // Erase the old global, since it is no longer used. 3594 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 3595 } 3596 3597 MaybeHandleStaticInExternC(D, GV); 3598 3599 if (D->hasAttr<AnnotateAttr>()) 3600 AddGlobalAnnotations(D, GV); 3601 3602 // Set the llvm linkage type as appropriate. 3603 llvm::GlobalValue::LinkageTypes Linkage = 3604 getLLVMLinkageVarDefinition(D, GV->isConstant()); 3605 3606 // CUDA B.2.1 "The __device__ qualifier declares a variable that resides on 3607 // the device. [...]" 3608 // CUDA B.2.2 "The __constant__ qualifier, optionally used together with 3609 // __device__, declares a variable that: [...] 3610 // Is accessible from all the threads within the grid and from the host 3611 // through the runtime library (cudaGetSymbolAddress() / cudaGetSymbolSize() 3612 // / cudaMemcpyToSymbol() / cudaMemcpyFromSymbol())." 3613 if (GV && LangOpts.CUDA) { 3614 if (LangOpts.CUDAIsDevice) { 3615 if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()) 3616 GV->setExternallyInitialized(true); 3617 } else { 3618 // Host-side shadows of external declarations of device-side 3619 // global variables become internal definitions. These have to 3620 // be internal in order to prevent name conflicts with global 3621 // host variables with the same name in a different TUs. 3622 if (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>()) { 3623 Linkage = llvm::GlobalValue::InternalLinkage; 3624 3625 // Shadow variables and their properties must be registered 3626 // with CUDA runtime. 3627 unsigned Flags = 0; 3628 if (!D->hasDefinition()) 3629 Flags |= CGCUDARuntime::ExternDeviceVar; 3630 if (D->hasAttr<CUDAConstantAttr>()) 3631 Flags |= CGCUDARuntime::ConstantDeviceVar; 3632 // Extern global variables will be registered in the TU where they are 3633 // defined. 3634 if (!D->hasExternalStorage()) 3635 getCUDARuntime().registerDeviceVar(*GV, Flags); 3636 } else if (D->hasAttr<CUDASharedAttr>()) 3637 // __shared__ variables are odd. Shadows do get created, but 3638 // they are not registered with the CUDA runtime, so they 3639 // can't really be used to access their device-side 3640 // counterparts. It's not clear yet whether it's nvcc's bug or 3641 // a feature, but we've got to do the same for compatibility. 3642 Linkage = llvm::GlobalValue::InternalLinkage; 3643 } 3644 } 3645 3646 GV->setInitializer(Init); 3647 if (emitter) emitter->finalize(GV); 3648 3649 // If it is safe to mark the global 'constant', do so now. 3650 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor && 3651 isTypeConstant(D->getType(), true)); 3652 3653 // If it is in a read-only section, mark it 'constant'. 3654 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) { 3655 const ASTContext::SectionInfo &SI = Context.SectionInfos[SA->getName()]; 3656 if ((SI.SectionFlags & ASTContext::PSF_Write) == 0) 3657 GV->setConstant(true); 3658 } 3659 3660 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 3661 3662 3663 // On Darwin, if the normal linkage of a C++ thread_local variable is 3664 // LinkOnce or Weak, we keep the normal linkage to prevent multiple 3665 // copies within a linkage unit; otherwise, the backing variable has 3666 // internal linkage and all accesses should just be calls to the 3667 // Itanium-specified entry point, which has the normal linkage of the 3668 // variable. This is to preserve the ability to change the implementation 3669 // behind the scenes. 3670 if (!D->isStaticLocal() && D->getTLSKind() == VarDecl::TLS_Dynamic && 3671 Context.getTargetInfo().getTriple().isOSDarwin() && 3672 !llvm::GlobalVariable::isLinkOnceLinkage(Linkage) && 3673 !llvm::GlobalVariable::isWeakLinkage(Linkage)) 3674 Linkage = llvm::GlobalValue::InternalLinkage; 3675 3676 GV->setLinkage(Linkage); 3677 if (D->hasAttr<DLLImportAttr>()) 3678 GV->setDLLStorageClass(llvm::GlobalVariable::DLLImportStorageClass); 3679 else if (D->hasAttr<DLLExportAttr>()) 3680 GV->setDLLStorageClass(llvm::GlobalVariable::DLLExportStorageClass); 3681 else 3682 GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass); 3683 3684 if (Linkage == llvm::GlobalVariable::CommonLinkage) { 3685 // common vars aren't constant even if declared const. 3686 GV->setConstant(false); 3687 // Tentative definition of global variables may be initialized with 3688 // non-zero null pointers. In this case they should have weak linkage 3689 // since common linkage must have zero initializer and must not have 3690 // explicit section therefore cannot have non-zero initial value. 3691 if (!GV->getInitializer()->isNullValue()) 3692 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 3693 } 3694 3695 setNonAliasAttributes(D, GV); 3696 3697 if (D->getTLSKind() && !GV->isThreadLocal()) { 3698 if (D->getTLSKind() == VarDecl::TLS_Dynamic) 3699 CXXThreadLocals.push_back(D); 3700 setTLSMode(GV, *D); 3701 } 3702 3703 maybeSetTrivialComdat(*D, *GV); 3704 3705 // Emit the initializer function if necessary. 3706 if (NeedsGlobalCtor || NeedsGlobalDtor) 3707 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); 3708 3709 SanitizerMD->reportGlobalToASan(GV, *D, NeedsGlobalCtor); 3710 3711 // Emit global variable debug information. 3712 if (CGDebugInfo *DI = getModuleDebugInfo()) 3713 if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo) 3714 DI->EmitGlobalVariable(GV, D); 3715 } 3716 3717 static bool isVarDeclStrongDefinition(const ASTContext &Context, 3718 CodeGenModule &CGM, const VarDecl *D, 3719 bool NoCommon) { 3720 // Don't give variables common linkage if -fno-common was specified unless it 3721 // was overridden by a NoCommon attribute. 3722 if ((NoCommon || D->hasAttr<NoCommonAttr>()) && !D->hasAttr<CommonAttr>()) 3723 return true; 3724 3725 // C11 6.9.2/2: 3726 // A declaration of an identifier for an object that has file scope without 3727 // an initializer, and without a storage-class specifier or with the 3728 // storage-class specifier static, constitutes a tentative definition. 3729 if (D->getInit() || D->hasExternalStorage()) 3730 return true; 3731 3732 // A variable cannot be both common and exist in a section. 3733 if (D->hasAttr<SectionAttr>()) 3734 return true; 3735 3736 // A variable cannot be both common and exist in a section. 3737 // We don't try to determine which is the right section in the front-end. 3738 // If no specialized section name is applicable, it will resort to default. 3739 if (D->hasAttr<PragmaClangBSSSectionAttr>() || 3740 D->hasAttr<PragmaClangDataSectionAttr>() || 3741 D->hasAttr<PragmaClangRodataSectionAttr>()) 3742 return true; 3743 3744 // Thread local vars aren't considered common linkage. 3745 if (D->getTLSKind()) 3746 return true; 3747 3748 // Tentative definitions marked with WeakImportAttr are true definitions. 3749 if (D->hasAttr<WeakImportAttr>()) 3750 return true; 3751 3752 // A variable cannot be both common and exist in a comdat. 3753 if (shouldBeInCOMDAT(CGM, *D)) 3754 return true; 3755 3756 // Declarations with a required alignment do not have common linkage in MSVC 3757 // mode. 3758 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { 3759 if (D->hasAttr<AlignedAttr>()) 3760 return true; 3761 QualType VarType = D->getType(); 3762 if (Context.isAlignmentRequired(VarType)) 3763 return true; 3764 3765 if (const auto *RT = VarType->getAs<RecordType>()) { 3766 const RecordDecl *RD = RT->getDecl(); 3767 for (const FieldDecl *FD : RD->fields()) { 3768 if (FD->isBitField()) 3769 continue; 3770 if (FD->hasAttr<AlignedAttr>()) 3771 return true; 3772 if (Context.isAlignmentRequired(FD->getType())) 3773 return true; 3774 } 3775 } 3776 } 3777 3778 // Microsoft's link.exe doesn't support alignments greater than 32 for common 3779 // symbols, so symbols with greater alignment requirements cannot be common. 3780 // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two 3781 // alignments for common symbols via the aligncomm directive, so this 3782 // restriction only applies to MSVC environments. 3783 if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() && 3784 Context.getTypeAlignIfKnown(D->getType()) > 32) 3785 return true; 3786 3787 return false; 3788 } 3789 3790 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator( 3791 const DeclaratorDecl *D, GVALinkage Linkage, bool IsConstantVariable) { 3792 if (Linkage == GVA_Internal) 3793 return llvm::Function::InternalLinkage; 3794 3795 if (D->hasAttr<WeakAttr>()) { 3796 if (IsConstantVariable) 3797 return llvm::GlobalVariable::WeakODRLinkage; 3798 else 3799 return llvm::GlobalVariable::WeakAnyLinkage; 3800 } 3801 3802 if (const auto *FD = D->getAsFunction()) 3803 if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally) 3804 return llvm::GlobalVariable::LinkOnceAnyLinkage; 3805 3806 // We are guaranteed to have a strong definition somewhere else, 3807 // so we can use available_externally linkage. 3808 if (Linkage == GVA_AvailableExternally) 3809 return llvm::GlobalValue::AvailableExternallyLinkage; 3810 3811 // Note that Apple's kernel linker doesn't support symbol 3812 // coalescing, so we need to avoid linkonce and weak linkages there. 3813 // Normally, this means we just map to internal, but for explicit 3814 // instantiations we'll map to external. 3815 3816 // In C++, the compiler has to emit a definition in every translation unit 3817 // that references the function. We should use linkonce_odr because 3818 // a) if all references in this translation unit are optimized away, we 3819 // don't need to codegen it. b) if the function persists, it needs to be 3820 // merged with other definitions. c) C++ has the ODR, so we know the 3821 // definition is dependable. 3822 if (Linkage == GVA_DiscardableODR) 3823 return !Context.getLangOpts().AppleKext ? llvm::Function::LinkOnceODRLinkage 3824 : llvm::Function::InternalLinkage; 3825 3826 // An explicit instantiation of a template has weak linkage, since 3827 // explicit instantiations can occur in multiple translation units 3828 // and must all be equivalent. However, we are not allowed to 3829 // throw away these explicit instantiations. 3830 // 3831 // We don't currently support CUDA device code spread out across multiple TUs, 3832 // so say that CUDA templates are either external (for kernels) or internal. 3833 // This lets llvm perform aggressive inter-procedural optimizations. 3834 if (Linkage == GVA_StrongODR) { 3835 if (Context.getLangOpts().AppleKext) 3836 return llvm::Function::ExternalLinkage; 3837 if (Context.getLangOpts().CUDA && Context.getLangOpts().CUDAIsDevice) 3838 return D->hasAttr<CUDAGlobalAttr>() ? llvm::Function::ExternalLinkage 3839 : llvm::Function::InternalLinkage; 3840 return llvm::Function::WeakODRLinkage; 3841 } 3842 3843 // C++ doesn't have tentative definitions and thus cannot have common 3844 // linkage. 3845 if (!getLangOpts().CPlusPlus && isa<VarDecl>(D) && 3846 !isVarDeclStrongDefinition(Context, *this, cast<VarDecl>(D), 3847 CodeGenOpts.NoCommon)) 3848 return llvm::GlobalVariable::CommonLinkage; 3849 3850 // selectany symbols are externally visible, so use weak instead of 3851 // linkonce. MSVC optimizes away references to const selectany globals, so 3852 // all definitions should be the same and ODR linkage should be used. 3853 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx 3854 if (D->hasAttr<SelectAnyAttr>()) 3855 return llvm::GlobalVariable::WeakODRLinkage; 3856 3857 // Otherwise, we have strong external linkage. 3858 assert(Linkage == GVA_StrongExternal); 3859 return llvm::GlobalVariable::ExternalLinkage; 3860 } 3861 3862 llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageVarDefinition( 3863 const VarDecl *VD, bool IsConstant) { 3864 GVALinkage Linkage = getContext().GetGVALinkageForVariable(VD); 3865 return getLLVMLinkageForDeclarator(VD, Linkage, IsConstant); 3866 } 3867 3868 /// Replace the uses of a function that was declared with a non-proto type. 3869 /// We want to silently drop extra arguments from call sites 3870 static void replaceUsesOfNonProtoConstant(llvm::Constant *old, 3871 llvm::Function *newFn) { 3872 // Fast path. 3873 if (old->use_empty()) return; 3874 3875 llvm::Type *newRetTy = newFn->getReturnType(); 3876 SmallVector<llvm::Value*, 4> newArgs; 3877 SmallVector<llvm::OperandBundleDef, 1> newBundles; 3878 3879 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end(); 3880 ui != ue; ) { 3881 llvm::Value::use_iterator use = ui++; // Increment before the use is erased. 3882 llvm::User *user = use->getUser(); 3883 3884 // Recognize and replace uses of bitcasts. Most calls to 3885 // unprototyped functions will use bitcasts. 3886 if (auto *bitcast = dyn_cast<llvm::ConstantExpr>(user)) { 3887 if (bitcast->getOpcode() == llvm::Instruction::BitCast) 3888 replaceUsesOfNonProtoConstant(bitcast, newFn); 3889 continue; 3890 } 3891 3892 // Recognize calls to the function. 3893 llvm::CallBase *callSite = dyn_cast<llvm::CallBase>(user); 3894 if (!callSite) continue; 3895 if (!callSite->isCallee(&*use)) 3896 continue; 3897 3898 // If the return types don't match exactly, then we can't 3899 // transform this call unless it's dead. 3900 if (callSite->getType() != newRetTy && !callSite->use_empty()) 3901 continue; 3902 3903 // Get the call site's attribute list. 3904 SmallVector<llvm::AttributeSet, 8> newArgAttrs; 3905 llvm::AttributeList oldAttrs = callSite->getAttributes(); 3906 3907 // If the function was passed too few arguments, don't transform. 3908 unsigned newNumArgs = newFn->arg_size(); 3909 if (callSite->arg_size() < newNumArgs) 3910 continue; 3911 3912 // If extra arguments were passed, we silently drop them. 3913 // If any of the types mismatch, we don't transform. 3914 unsigned argNo = 0; 3915 bool dontTransform = false; 3916 for (llvm::Argument &A : newFn->args()) { 3917 if (callSite->getArgOperand(argNo)->getType() != A.getType()) { 3918 dontTransform = true; 3919 break; 3920 } 3921 3922 // Add any parameter attributes. 3923 newArgAttrs.push_back(oldAttrs.getParamAttributes(argNo)); 3924 argNo++; 3925 } 3926 if (dontTransform) 3927 continue; 3928 3929 // Okay, we can transform this. Create the new call instruction and copy 3930 // over the required information. 3931 newArgs.append(callSite->arg_begin(), callSite->arg_begin() + argNo); 3932 3933 // Copy over any operand bundles. 3934 callSite->getOperandBundlesAsDefs(newBundles); 3935 3936 llvm::CallBase *newCall; 3937 if (dyn_cast<llvm::CallInst>(callSite)) { 3938 newCall = 3939 llvm::CallInst::Create(newFn, newArgs, newBundles, "", callSite); 3940 } else { 3941 auto *oldInvoke = cast<llvm::InvokeInst>(callSite); 3942 newCall = llvm::InvokeInst::Create(newFn, oldInvoke->getNormalDest(), 3943 oldInvoke->getUnwindDest(), newArgs, 3944 newBundles, "", callSite); 3945 } 3946 newArgs.clear(); // for the next iteration 3947 3948 if (!newCall->getType()->isVoidTy()) 3949 newCall->takeName(callSite); 3950 newCall->setAttributes(llvm::AttributeList::get( 3951 newFn->getContext(), oldAttrs.getFnAttributes(), 3952 oldAttrs.getRetAttributes(), newArgAttrs)); 3953 newCall->setCallingConv(callSite->getCallingConv()); 3954 3955 // Finally, remove the old call, replacing any uses with the new one. 3956 if (!callSite->use_empty()) 3957 callSite->replaceAllUsesWith(newCall); 3958 3959 // Copy debug location attached to CI. 3960 if (callSite->getDebugLoc()) 3961 newCall->setDebugLoc(callSite->getDebugLoc()); 3962 3963 callSite->eraseFromParent(); 3964 } 3965 } 3966 3967 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 3968 /// implement a function with no prototype, e.g. "int foo() {}". If there are 3969 /// existing call uses of the old function in the module, this adjusts them to 3970 /// call the new function directly. 3971 /// 3972 /// This is not just a cleanup: the always_inline pass requires direct calls to 3973 /// functions to be able to inline them. If there is a bitcast in the way, it 3974 /// won't inline them. Instcombine normally deletes these calls, but it isn't 3975 /// run at -O0. 3976 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 3977 llvm::Function *NewFn) { 3978 // If we're redefining a global as a function, don't transform it. 3979 if (!isa<llvm::Function>(Old)) return; 3980 3981 replaceUsesOfNonProtoConstant(Old, NewFn); 3982 } 3983 3984 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) { 3985 auto DK = VD->isThisDeclarationADefinition(); 3986 if (DK == VarDecl::Definition && VD->hasAttr<DLLImportAttr>()) 3987 return; 3988 3989 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind(); 3990 // If we have a definition, this might be a deferred decl. If the 3991 // instantiation is explicit, make sure we emit it at the end. 3992 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition) 3993 GetAddrOfGlobalVar(VD); 3994 3995 EmitTopLevelDecl(VD); 3996 } 3997 3998 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD, 3999 llvm::GlobalValue *GV) { 4000 const auto *D = cast<FunctionDecl>(GD.getDecl()); 4001 4002 // Compute the function info and LLVM type. 4003 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); 4004 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); 4005 4006 // Get or create the prototype for the function. 4007 if (!GV || (GV->getType()->getElementType() != Ty)) 4008 GV = cast<llvm::GlobalValue>(GetAddrOfFunction(GD, Ty, /*ForVTable=*/false, 4009 /*DontDefer=*/true, 4010 ForDefinition)); 4011 4012 // Already emitted. 4013 if (!GV->isDeclaration()) 4014 return; 4015 4016 // We need to set linkage and visibility on the function before 4017 // generating code for it because various parts of IR generation 4018 // want to propagate this information down (e.g. to local static 4019 // declarations). 4020 auto *Fn = cast<llvm::Function>(GV); 4021 setFunctionLinkage(GD, Fn); 4022 4023 // FIXME: this is redundant with part of setFunctionDefinitionAttributes 4024 setGVProperties(Fn, GD); 4025 4026 MaybeHandleStaticInExternC(D, Fn); 4027 4028 4029 maybeSetTrivialComdat(*D, *Fn); 4030 4031 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 4032 4033 setNonAliasAttributes(GD, Fn); 4034 SetLLVMFunctionAttributesForDefinition(D, Fn); 4035 4036 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 4037 AddGlobalCtor(Fn, CA->getPriority()); 4038 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 4039 AddGlobalDtor(Fn, DA->getPriority()); 4040 if (D->hasAttr<AnnotateAttr>()) 4041 AddGlobalAnnotations(D, Fn); 4042 } 4043 4044 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 4045 const auto *D = cast<ValueDecl>(GD.getDecl()); 4046 const AliasAttr *AA = D->getAttr<AliasAttr>(); 4047 assert(AA && "Not an alias?"); 4048 4049 StringRef MangledName = getMangledName(GD); 4050 4051 if (AA->getAliasee() == MangledName) { 4052 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0; 4053 return; 4054 } 4055 4056 // If there is a definition in the module, then it wins over the alias. 4057 // This is dubious, but allow it to be safe. Just ignore the alias. 4058 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 4059 if (Entry && !Entry->isDeclaration()) 4060 return; 4061 4062 Aliases.push_back(GD); 4063 4064 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 4065 4066 // Create a reference to the named value. This ensures that it is emitted 4067 // if a deferred decl. 4068 llvm::Constant *Aliasee; 4069 if (isa<llvm::FunctionType>(DeclTy)) 4070 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD, 4071 /*ForVTable=*/false); 4072 else 4073 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 4074 llvm::PointerType::getUnqual(DeclTy), 4075 /*D=*/nullptr); 4076 4077 // Create the new alias itself, but don't set a name yet. 4078 auto *GA = llvm::GlobalAlias::create( 4079 DeclTy, 0, llvm::Function::ExternalLinkage, "", Aliasee, &getModule()); 4080 4081 if (Entry) { 4082 if (GA->getAliasee() == Entry) { 4083 Diags.Report(AA->getLocation(), diag::err_cyclic_alias) << 0; 4084 return; 4085 } 4086 4087 assert(Entry->isDeclaration()); 4088 4089 // If there is a declaration in the module, then we had an extern followed 4090 // by the alias, as in: 4091 // extern int test6(); 4092 // ... 4093 // int test6() __attribute__((alias("test7"))); 4094 // 4095 // Remove it and replace uses of it with the alias. 4096 GA->takeName(Entry); 4097 4098 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 4099 Entry->getType())); 4100 Entry->eraseFromParent(); 4101 } else { 4102 GA->setName(MangledName); 4103 } 4104 4105 // Set attributes which are particular to an alias; this is a 4106 // specialization of the attributes which may be set on a global 4107 // variable/function. 4108 if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakRefAttr>() || 4109 D->isWeakImported()) { 4110 GA->setLinkage(llvm::Function::WeakAnyLinkage); 4111 } 4112 4113 if (const auto *VD = dyn_cast<VarDecl>(D)) 4114 if (VD->getTLSKind()) 4115 setTLSMode(GA, *VD); 4116 4117 SetCommonAttributes(GD, GA); 4118 } 4119 4120 void CodeGenModule::emitIFuncDefinition(GlobalDecl GD) { 4121 const auto *D = cast<ValueDecl>(GD.getDecl()); 4122 const IFuncAttr *IFA = D->getAttr<IFuncAttr>(); 4123 assert(IFA && "Not an ifunc?"); 4124 4125 StringRef MangledName = getMangledName(GD); 4126 4127 if (IFA->getResolver() == MangledName) { 4128 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1; 4129 return; 4130 } 4131 4132 // Report an error if some definition overrides ifunc. 4133 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 4134 if (Entry && !Entry->isDeclaration()) { 4135 GlobalDecl OtherGD; 4136 if (lookupRepresentativeDecl(MangledName, OtherGD) && 4137 DiagnosedConflictingDefinitions.insert(GD).second) { 4138 Diags.Report(D->getLocation(), diag::err_duplicate_mangled_name) 4139 << MangledName; 4140 Diags.Report(OtherGD.getDecl()->getLocation(), 4141 diag::note_previous_definition); 4142 } 4143 return; 4144 } 4145 4146 Aliases.push_back(GD); 4147 4148 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 4149 llvm::Constant *Resolver = 4150 GetOrCreateLLVMFunction(IFA->getResolver(), DeclTy, GD, 4151 /*ForVTable=*/false); 4152 llvm::GlobalIFunc *GIF = 4153 llvm::GlobalIFunc::create(DeclTy, 0, llvm::Function::ExternalLinkage, 4154 "", Resolver, &getModule()); 4155 if (Entry) { 4156 if (GIF->getResolver() == Entry) { 4157 Diags.Report(IFA->getLocation(), diag::err_cyclic_alias) << 1; 4158 return; 4159 } 4160 assert(Entry->isDeclaration()); 4161 4162 // If there is a declaration in the module, then we had an extern followed 4163 // by the ifunc, as in: 4164 // extern int test(); 4165 // ... 4166 // int test() __attribute__((ifunc("resolver"))); 4167 // 4168 // Remove it and replace uses of it with the ifunc. 4169 GIF->takeName(Entry); 4170 4171 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GIF, 4172 Entry->getType())); 4173 Entry->eraseFromParent(); 4174 } else 4175 GIF->setName(MangledName); 4176 4177 SetCommonAttributes(GD, GIF); 4178 } 4179 4180 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 4181 ArrayRef<llvm::Type*> Tys) { 4182 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 4183 Tys); 4184 } 4185 4186 static llvm::StringMapEntry<llvm::GlobalVariable *> & 4187 GetConstantCFStringEntry(llvm::StringMap<llvm::GlobalVariable *> &Map, 4188 const StringLiteral *Literal, bool TargetIsLSB, 4189 bool &IsUTF16, unsigned &StringLength) { 4190 StringRef String = Literal->getString(); 4191 unsigned NumBytes = String.size(); 4192 4193 // Check for simple case. 4194 if (!Literal->containsNonAsciiOrNull()) { 4195 StringLength = NumBytes; 4196 return *Map.insert(std::make_pair(String, nullptr)).first; 4197 } 4198 4199 // Otherwise, convert the UTF8 literals into a string of shorts. 4200 IsUTF16 = true; 4201 4202 SmallVector<llvm::UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls. 4203 const llvm::UTF8 *FromPtr = (const llvm::UTF8 *)String.data(); 4204 llvm::UTF16 *ToPtr = &ToBuf[0]; 4205 4206 (void)llvm::ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, &ToPtr, 4207 ToPtr + NumBytes, llvm::strictConversion); 4208 4209 // ConvertUTF8toUTF16 returns the length in ToPtr. 4210 StringLength = ToPtr - &ToBuf[0]; 4211 4212 // Add an explicit null. 4213 *ToPtr = 0; 4214 return *Map.insert(std::make_pair( 4215 StringRef(reinterpret_cast<const char *>(ToBuf.data()), 4216 (StringLength + 1) * 2), 4217 nullptr)).first; 4218 } 4219 4220 ConstantAddress 4221 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 4222 unsigned StringLength = 0; 4223 bool isUTF16 = false; 4224 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 4225 GetConstantCFStringEntry(CFConstantStringMap, Literal, 4226 getDataLayout().isLittleEndian(), isUTF16, 4227 StringLength); 4228 4229 if (auto *C = Entry.second) 4230 return ConstantAddress(C, CharUnits::fromQuantity(C->getAlignment())); 4231 4232 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 4233 llvm::Constant *Zeros[] = { Zero, Zero }; 4234 4235 const ASTContext &Context = getContext(); 4236 const llvm::Triple &Triple = getTriple(); 4237 4238 const auto CFRuntime = getLangOpts().CFRuntime; 4239 const bool IsSwiftABI = 4240 static_cast<unsigned>(CFRuntime) >= 4241 static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift); 4242 const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1; 4243 4244 // If we don't already have it, get __CFConstantStringClassReference. 4245 if (!CFConstantStringClassRef) { 4246 const char *CFConstantStringClassName = "__CFConstantStringClassReference"; 4247 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 4248 Ty = llvm::ArrayType::get(Ty, 0); 4249 4250 switch (CFRuntime) { 4251 default: break; 4252 case LangOptions::CoreFoundationABI::Swift: LLVM_FALLTHROUGH; 4253 case LangOptions::CoreFoundationABI::Swift5_0: 4254 CFConstantStringClassName = 4255 Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN" 4256 : "$s10Foundation19_NSCFConstantStringCN"; 4257 Ty = IntPtrTy; 4258 break; 4259 case LangOptions::CoreFoundationABI::Swift4_2: 4260 CFConstantStringClassName = 4261 Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN" 4262 : "$S10Foundation19_NSCFConstantStringCN"; 4263 Ty = IntPtrTy; 4264 break; 4265 case LangOptions::CoreFoundationABI::Swift4_1: 4266 CFConstantStringClassName = 4267 Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN" 4268 : "__T010Foundation19_NSCFConstantStringCN"; 4269 Ty = IntPtrTy; 4270 break; 4271 } 4272 4273 llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName); 4274 4275 if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) { 4276 llvm::GlobalValue *GV = nullptr; 4277 4278 if ((GV = dyn_cast<llvm::GlobalValue>(C))) { 4279 IdentifierInfo &II = Context.Idents.get(GV->getName()); 4280 TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl(); 4281 DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl); 4282 4283 const VarDecl *VD = nullptr; 4284 for (const auto &Result : DC->lookup(&II)) 4285 if ((VD = dyn_cast<VarDecl>(Result))) 4286 break; 4287 4288 if (Triple.isOSBinFormatELF()) { 4289 if (!VD) 4290 GV->setLinkage(llvm::GlobalValue::ExternalLinkage); 4291 } else { 4292 GV->setLinkage(llvm::GlobalValue::ExternalLinkage); 4293 if (!VD || !VD->hasAttr<DLLExportAttr>()) 4294 GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass); 4295 else 4296 GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass); 4297 } 4298 4299 setDSOLocal(GV); 4300 } 4301 } 4302 4303 // Decay array -> ptr 4304 CFConstantStringClassRef = 4305 IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty) 4306 : llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros); 4307 } 4308 4309 QualType CFTy = Context.getCFConstantStringType(); 4310 4311 auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 4312 4313 ConstantInitBuilder Builder(*this); 4314 auto Fields = Builder.beginStruct(STy); 4315 4316 // Class pointer. 4317 Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef)); 4318 4319 // Flags. 4320 if (IsSwiftABI) { 4321 Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01); 4322 Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8); 4323 } else { 4324 Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8); 4325 } 4326 4327 // String pointer. 4328 llvm::Constant *C = nullptr; 4329 if (isUTF16) { 4330 auto Arr = llvm::makeArrayRef( 4331 reinterpret_cast<uint16_t *>(const_cast<char *>(Entry.first().data())), 4332 Entry.first().size() / 2); 4333 C = llvm::ConstantDataArray::get(VMContext, Arr); 4334 } else { 4335 C = llvm::ConstantDataArray::getString(VMContext, Entry.first()); 4336 } 4337 4338 // Note: -fwritable-strings doesn't make the backing store strings of 4339 // CFStrings writable. (See <rdar://problem/10657500>) 4340 auto *GV = 4341 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, 4342 llvm::GlobalValue::PrivateLinkage, C, ".str"); 4343 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); 4344 // Don't enforce the target's minimum global alignment, since the only use 4345 // of the string is via this class initializer. 4346 CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy) 4347 : Context.getTypeAlignInChars(Context.CharTy); 4348 GV->setAlignment(Align.getQuantity()); 4349 4350 // FIXME: We set the section explicitly to avoid a bug in ld64 224.1. 4351 // Without it LLVM can merge the string with a non unnamed_addr one during 4352 // LTO. Doing that changes the section it ends in, which surprises ld64. 4353 if (Triple.isOSBinFormatMachO()) 4354 GV->setSection(isUTF16 ? "__TEXT,__ustring" 4355 : "__TEXT,__cstring,cstring_literals"); 4356 // Make sure the literal ends up in .rodata to allow for safe ICF and for 4357 // the static linker to adjust permissions to read-only later on. 4358 else if (Triple.isOSBinFormatELF()) 4359 GV->setSection(".rodata"); 4360 4361 // String. 4362 llvm::Constant *Str = 4363 llvm::ConstantExpr::getGetElementPtr(GV->getValueType(), GV, Zeros); 4364 4365 if (isUTF16) 4366 // Cast the UTF16 string to the correct type. 4367 Str = llvm::ConstantExpr::getBitCast(Str, Int8PtrTy); 4368 Fields.add(Str); 4369 4370 // String length. 4371 llvm::IntegerType *LengthTy = 4372 llvm::IntegerType::get(getModule().getContext(), 4373 Context.getTargetInfo().getLongWidth()); 4374 if (IsSwiftABI) { 4375 if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 || 4376 CFRuntime == LangOptions::CoreFoundationABI::Swift4_2) 4377 LengthTy = Int32Ty; 4378 else 4379 LengthTy = IntPtrTy; 4380 } 4381 Fields.addInt(LengthTy, StringLength); 4382 4383 CharUnits Alignment = getPointerAlign(); 4384 4385 // The struct. 4386 GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment, 4387 /*isConstant=*/false, 4388 llvm::GlobalVariable::PrivateLinkage); 4389 switch (Triple.getObjectFormat()) { 4390 case llvm::Triple::UnknownObjectFormat: 4391 llvm_unreachable("unknown file format"); 4392 case llvm::Triple::COFF: 4393 case llvm::Triple::ELF: 4394 case llvm::Triple::Wasm: 4395 GV->setSection("cfstring"); 4396 break; 4397 case llvm::Triple::MachO: 4398 GV->setSection("__DATA,__cfstring"); 4399 break; 4400 } 4401 Entry.second = GV; 4402 4403 return ConstantAddress(GV, Alignment); 4404 } 4405 4406 bool CodeGenModule::getExpressionLocationsEnabled() const { 4407 return !CodeGenOpts.EmitCodeView || CodeGenOpts.DebugColumnInfo; 4408 } 4409 4410 QualType CodeGenModule::getObjCFastEnumerationStateType() { 4411 if (ObjCFastEnumerationStateType.isNull()) { 4412 RecordDecl *D = Context.buildImplicitRecord("__objcFastEnumerationState"); 4413 D->startDefinition(); 4414 4415 QualType FieldTypes[] = { 4416 Context.UnsignedLongTy, 4417 Context.getPointerType(Context.getObjCIdType()), 4418 Context.getPointerType(Context.UnsignedLongTy), 4419 Context.getConstantArrayType(Context.UnsignedLongTy, 4420 llvm::APInt(32, 5), ArrayType::Normal, 0) 4421 }; 4422 4423 for (size_t i = 0; i < 4; ++i) { 4424 FieldDecl *Field = FieldDecl::Create(Context, 4425 D, 4426 SourceLocation(), 4427 SourceLocation(), nullptr, 4428 FieldTypes[i], /*TInfo=*/nullptr, 4429 /*BitWidth=*/nullptr, 4430 /*Mutable=*/false, 4431 ICIS_NoInit); 4432 Field->setAccess(AS_public); 4433 D->addDecl(Field); 4434 } 4435 4436 D->completeDefinition(); 4437 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 4438 } 4439 4440 return ObjCFastEnumerationStateType; 4441 } 4442 4443 llvm::Constant * 4444 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { 4445 assert(!E->getType()->isPointerType() && "Strings are always arrays"); 4446 4447 // Don't emit it as the address of the string, emit the string data itself 4448 // as an inline array. 4449 if (E->getCharByteWidth() == 1) { 4450 SmallString<64> Str(E->getString()); 4451 4452 // Resize the string to the right size, which is indicated by its type. 4453 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType()); 4454 Str.resize(CAT->getSize().getZExtValue()); 4455 return llvm::ConstantDataArray::getString(VMContext, Str, false); 4456 } 4457 4458 auto *AType = cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); 4459 llvm::Type *ElemTy = AType->getElementType(); 4460 unsigned NumElements = AType->getNumElements(); 4461 4462 // Wide strings have either 2-byte or 4-byte elements. 4463 if (ElemTy->getPrimitiveSizeInBits() == 16) { 4464 SmallVector<uint16_t, 32> Elements; 4465 Elements.reserve(NumElements); 4466 4467 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 4468 Elements.push_back(E->getCodeUnit(i)); 4469 Elements.resize(NumElements); 4470 return llvm::ConstantDataArray::get(VMContext, Elements); 4471 } 4472 4473 assert(ElemTy->getPrimitiveSizeInBits() == 32); 4474 SmallVector<uint32_t, 32> Elements; 4475 Elements.reserve(NumElements); 4476 4477 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 4478 Elements.push_back(E->getCodeUnit(i)); 4479 Elements.resize(NumElements); 4480 return llvm::ConstantDataArray::get(VMContext, Elements); 4481 } 4482 4483 static llvm::GlobalVariable * 4484 GenerateStringLiteral(llvm::Constant *C, llvm::GlobalValue::LinkageTypes LT, 4485 CodeGenModule &CGM, StringRef GlobalName, 4486 CharUnits Alignment) { 4487 unsigned AddrSpace = CGM.getContext().getTargetAddressSpace( 4488 CGM.getStringLiteralAddressSpace()); 4489 4490 llvm::Module &M = CGM.getModule(); 4491 // Create a global variable for this string 4492 auto *GV = new llvm::GlobalVariable( 4493 M, C->getType(), !CGM.getLangOpts().WritableStrings, LT, C, GlobalName, 4494 nullptr, llvm::GlobalVariable::NotThreadLocal, AddrSpace); 4495 GV->setAlignment(Alignment.getQuantity()); 4496 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); 4497 if (GV->isWeakForLinker()) { 4498 assert(CGM.supportsCOMDAT() && "Only COFF uses weak string literals"); 4499 GV->setComdat(M.getOrInsertComdat(GV->getName())); 4500 } 4501 CGM.setDSOLocal(GV); 4502 4503 return GV; 4504 } 4505 4506 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a 4507 /// constant array for the given string literal. 4508 ConstantAddress 4509 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S, 4510 StringRef Name) { 4511 CharUnits Alignment = getContext().getAlignOfGlobalVarInChars(S->getType()); 4512 4513 llvm::Constant *C = GetConstantArrayFromStringLiteral(S); 4514 llvm::GlobalVariable **Entry = nullptr; 4515 if (!LangOpts.WritableStrings) { 4516 Entry = &ConstantStringMap[C]; 4517 if (auto GV = *Entry) { 4518 if (Alignment.getQuantity() > GV->getAlignment()) 4519 GV->setAlignment(Alignment.getQuantity()); 4520 return ConstantAddress(GV, Alignment); 4521 } 4522 } 4523 4524 SmallString<256> MangledNameBuffer; 4525 StringRef GlobalVariableName; 4526 llvm::GlobalValue::LinkageTypes LT; 4527 4528 // Mangle the string literal if that's how the ABI merges duplicate strings. 4529 // Don't do it if they are writable, since we don't want writes in one TU to 4530 // affect strings in another. 4531 if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) && 4532 !LangOpts.WritableStrings) { 4533 llvm::raw_svector_ostream Out(MangledNameBuffer); 4534 getCXXABI().getMangleContext().mangleStringLiteral(S, Out); 4535 LT = llvm::GlobalValue::LinkOnceODRLinkage; 4536 GlobalVariableName = MangledNameBuffer; 4537 } else { 4538 LT = llvm::GlobalValue::PrivateLinkage; 4539 GlobalVariableName = Name; 4540 } 4541 4542 auto GV = GenerateStringLiteral(C, LT, *this, GlobalVariableName, Alignment); 4543 if (Entry) 4544 *Entry = GV; 4545 4546 SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>", 4547 QualType()); 4548 4549 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV), 4550 Alignment); 4551 } 4552 4553 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 4554 /// array for the given ObjCEncodeExpr node. 4555 ConstantAddress 4556 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 4557 std::string Str; 4558 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 4559 4560 return GetAddrOfConstantCString(Str); 4561 } 4562 4563 /// GetAddrOfConstantCString - Returns a pointer to a character array containing 4564 /// the literal and a terminating '\0' character. 4565 /// The result has pointer to array type. 4566 ConstantAddress CodeGenModule::GetAddrOfConstantCString( 4567 const std::string &Str, const char *GlobalName) { 4568 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 4569 CharUnits Alignment = 4570 getContext().getAlignOfGlobalVarInChars(getContext().CharTy); 4571 4572 llvm::Constant *C = 4573 llvm::ConstantDataArray::getString(getLLVMContext(), StrWithNull, false); 4574 4575 // Don't share any string literals if strings aren't constant. 4576 llvm::GlobalVariable **Entry = nullptr; 4577 if (!LangOpts.WritableStrings) { 4578 Entry = &ConstantStringMap[C]; 4579 if (auto GV = *Entry) { 4580 if (Alignment.getQuantity() > GV->getAlignment()) 4581 GV->setAlignment(Alignment.getQuantity()); 4582 return ConstantAddress(GV, Alignment); 4583 } 4584 } 4585 4586 // Get the default prefix if a name wasn't specified. 4587 if (!GlobalName) 4588 GlobalName = ".str"; 4589 // Create a global variable for this. 4590 auto GV = GenerateStringLiteral(C, llvm::GlobalValue::PrivateLinkage, *this, 4591 GlobalName, Alignment); 4592 if (Entry) 4593 *Entry = GV; 4594 4595 return ConstantAddress(castStringLiteralToDefaultAddressSpace(*this, GV), 4596 Alignment); 4597 } 4598 4599 ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary( 4600 const MaterializeTemporaryExpr *E, const Expr *Init) { 4601 assert((E->getStorageDuration() == SD_Static || 4602 E->getStorageDuration() == SD_Thread) && "not a global temporary"); 4603 const auto *VD = cast<VarDecl>(E->getExtendingDecl()); 4604 4605 // If we're not materializing a subobject of the temporary, keep the 4606 // cv-qualifiers from the type of the MaterializeTemporaryExpr. 4607 QualType MaterializedType = Init->getType(); 4608 if (Init == E->GetTemporaryExpr()) 4609 MaterializedType = E->getType(); 4610 4611 CharUnits Align = getContext().getTypeAlignInChars(MaterializedType); 4612 4613 if (llvm::Constant *Slot = MaterializedGlobalTemporaryMap[E]) 4614 return ConstantAddress(Slot, Align); 4615 4616 // FIXME: If an externally-visible declaration extends multiple temporaries, 4617 // we need to give each temporary the same name in every translation unit (and 4618 // we also need to make the temporaries externally-visible). 4619 SmallString<256> Name; 4620 llvm::raw_svector_ostream Out(Name); 4621 getCXXABI().getMangleContext().mangleReferenceTemporary( 4622 VD, E->getManglingNumber(), Out); 4623 4624 APValue *Value = nullptr; 4625 if (E->getStorageDuration() == SD_Static) { 4626 // We might have a cached constant initializer for this temporary. Note 4627 // that this might have a different value from the value computed by 4628 // evaluating the initializer if the surrounding constant expression 4629 // modifies the temporary. 4630 Value = getContext().getMaterializedTemporaryValue(E, false); 4631 if (Value && Value->isUninit()) 4632 Value = nullptr; 4633 } 4634 4635 // Try evaluating it now, it might have a constant initializer. 4636 Expr::EvalResult EvalResult; 4637 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) && 4638 !EvalResult.hasSideEffects()) 4639 Value = &EvalResult.Val; 4640 4641 LangAS AddrSpace = 4642 VD ? GetGlobalVarAddressSpace(VD) : MaterializedType.getAddressSpace(); 4643 4644 Optional<ConstantEmitter> emitter; 4645 llvm::Constant *InitialValue = nullptr; 4646 bool Constant = false; 4647 llvm::Type *Type; 4648 if (Value) { 4649 // The temporary has a constant initializer, use it. 4650 emitter.emplace(*this); 4651 InitialValue = emitter->emitForInitializer(*Value, AddrSpace, 4652 MaterializedType); 4653 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value); 4654 Type = InitialValue->getType(); 4655 } else { 4656 // No initializer, the initialization will be provided when we 4657 // initialize the declaration which performed lifetime extension. 4658 Type = getTypes().ConvertTypeForMem(MaterializedType); 4659 } 4660 4661 // Create a global variable for this lifetime-extended temporary. 4662 llvm::GlobalValue::LinkageTypes Linkage = 4663 getLLVMLinkageVarDefinition(VD, Constant); 4664 if (Linkage == llvm::GlobalVariable::ExternalLinkage) { 4665 const VarDecl *InitVD; 4666 if (VD->isStaticDataMember() && VD->getAnyInitializer(InitVD) && 4667 isa<CXXRecordDecl>(InitVD->getLexicalDeclContext())) { 4668 // Temporaries defined inside a class get linkonce_odr linkage because the 4669 // class can be defined in multiple translation units. 4670 Linkage = llvm::GlobalVariable::LinkOnceODRLinkage; 4671 } else { 4672 // There is no need for this temporary to have external linkage if the 4673 // VarDecl has external linkage. 4674 Linkage = llvm::GlobalVariable::InternalLinkage; 4675 } 4676 } 4677 auto TargetAS = getContext().getTargetAddressSpace(AddrSpace); 4678 auto *GV = new llvm::GlobalVariable( 4679 getModule(), Type, Constant, Linkage, InitialValue, Name.c_str(), 4680 /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS); 4681 if (emitter) emitter->finalize(GV); 4682 setGVProperties(GV, VD); 4683 GV->setAlignment(Align.getQuantity()); 4684 if (supportsCOMDAT() && GV->isWeakForLinker()) 4685 GV->setComdat(TheModule.getOrInsertComdat(GV->getName())); 4686 if (VD->getTLSKind()) 4687 setTLSMode(GV, *VD); 4688 llvm::Constant *CV = GV; 4689 if (AddrSpace != LangAS::Default) 4690 CV = getTargetCodeGenInfo().performAddrSpaceCast( 4691 *this, GV, AddrSpace, LangAS::Default, 4692 Type->getPointerTo( 4693 getContext().getTargetAddressSpace(LangAS::Default))); 4694 MaterializedGlobalTemporaryMap[E] = CV; 4695 return ConstantAddress(CV, Align); 4696 } 4697 4698 /// EmitObjCPropertyImplementations - Emit information for synthesized 4699 /// properties for an implementation. 4700 void CodeGenModule::EmitObjCPropertyImplementations(const 4701 ObjCImplementationDecl *D) { 4702 for (const auto *PID : D->property_impls()) { 4703 // Dynamic is just for type-checking. 4704 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 4705 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 4706 4707 // Determine which methods need to be implemented, some may have 4708 // been overridden. Note that ::isPropertyAccessor is not the method 4709 // we want, that just indicates if the decl came from a 4710 // property. What we want to know is if the method is defined in 4711 // this implementation. 4712 if (!D->getInstanceMethod(PD->getGetterName())) 4713 CodeGenFunction(*this).GenerateObjCGetter( 4714 const_cast<ObjCImplementationDecl *>(D), PID); 4715 if (!PD->isReadOnly() && 4716 !D->getInstanceMethod(PD->getSetterName())) 4717 CodeGenFunction(*this).GenerateObjCSetter( 4718 const_cast<ObjCImplementationDecl *>(D), PID); 4719 } 4720 } 4721 } 4722 4723 static bool needsDestructMethod(ObjCImplementationDecl *impl) { 4724 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 4725 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 4726 ivar; ivar = ivar->getNextIvar()) 4727 if (ivar->getType().isDestructedType()) 4728 return true; 4729 4730 return false; 4731 } 4732 4733 static bool AllTrivialInitializers(CodeGenModule &CGM, 4734 ObjCImplementationDecl *D) { 4735 CodeGenFunction CGF(CGM); 4736 for (ObjCImplementationDecl::init_iterator B = D->init_begin(), 4737 E = D->init_end(); B != E; ++B) { 4738 CXXCtorInitializer *CtorInitExp = *B; 4739 Expr *Init = CtorInitExp->getInit(); 4740 if (!CGF.isTrivialInitializer(Init)) 4741 return false; 4742 } 4743 return true; 4744 } 4745 4746 /// EmitObjCIvarInitializations - Emit information for ivar initialization 4747 /// for an implementation. 4748 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 4749 // We might need a .cxx_destruct even if we don't have any ivar initializers. 4750 if (needsDestructMethod(D)) { 4751 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 4752 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 4753 ObjCMethodDecl *DTORMethod = 4754 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 4755 cxxSelector, getContext().VoidTy, nullptr, D, 4756 /*isInstance=*/true, /*isVariadic=*/false, 4757 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true, 4758 /*isDefined=*/false, ObjCMethodDecl::Required); 4759 D->addInstanceMethod(DTORMethod); 4760 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 4761 D->setHasDestructors(true); 4762 } 4763 4764 // If the implementation doesn't have any ivar initializers, we don't need 4765 // a .cxx_construct. 4766 if (D->getNumIvarInitializers() == 0 || 4767 AllTrivialInitializers(*this, D)) 4768 return; 4769 4770 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 4771 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 4772 // The constructor returns 'self'. 4773 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 4774 D->getLocation(), 4775 D->getLocation(), 4776 cxxSelector, 4777 getContext().getObjCIdType(), 4778 nullptr, D, /*isInstance=*/true, 4779 /*isVariadic=*/false, 4780 /*isPropertyAccessor=*/true, 4781 /*isImplicitlyDeclared=*/true, 4782 /*isDefined=*/false, 4783 ObjCMethodDecl::Required); 4784 D->addInstanceMethod(CTORMethod); 4785 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 4786 D->setHasNonZeroConstructors(true); 4787 } 4788 4789 // EmitLinkageSpec - Emit all declarations in a linkage spec. 4790 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 4791 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 4792 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 4793 ErrorUnsupported(LSD, "linkage spec"); 4794 return; 4795 } 4796 4797 EmitDeclContext(LSD); 4798 } 4799 4800 void CodeGenModule::EmitDeclContext(const DeclContext *DC) { 4801 for (auto *I : DC->decls()) { 4802 // Unlike other DeclContexts, the contents of an ObjCImplDecl at TU scope 4803 // are themselves considered "top-level", so EmitTopLevelDecl on an 4804 // ObjCImplDecl does not recursively visit them. We need to do that in 4805 // case they're nested inside another construct (LinkageSpecDecl / 4806 // ExportDecl) that does stop them from being considered "top-level". 4807 if (auto *OID = dyn_cast<ObjCImplDecl>(I)) { 4808 for (auto *M : OID->methods()) 4809 EmitTopLevelDecl(M); 4810 } 4811 4812 EmitTopLevelDecl(I); 4813 } 4814 } 4815 4816 /// EmitTopLevelDecl - Emit code for a single top level declaration. 4817 void CodeGenModule::EmitTopLevelDecl(Decl *D) { 4818 // Ignore dependent declarations. 4819 if (D->isTemplated()) 4820 return; 4821 4822 switch (D->getKind()) { 4823 case Decl::CXXConversion: 4824 case Decl::CXXMethod: 4825 case Decl::Function: 4826 EmitGlobal(cast<FunctionDecl>(D)); 4827 // Always provide some coverage mapping 4828 // even for the functions that aren't emitted. 4829 AddDeferredUnusedCoverageMapping(D); 4830 break; 4831 4832 case Decl::CXXDeductionGuide: 4833 // Function-like, but does not result in code emission. 4834 break; 4835 4836 case Decl::Var: 4837 case Decl::Decomposition: 4838 case Decl::VarTemplateSpecialization: 4839 EmitGlobal(cast<VarDecl>(D)); 4840 if (auto *DD = dyn_cast<DecompositionDecl>(D)) 4841 for (auto *B : DD->bindings()) 4842 if (auto *HD = B->getHoldingVar()) 4843 EmitGlobal(HD); 4844 break; 4845 4846 // Indirect fields from global anonymous structs and unions can be 4847 // ignored; only the actual variable requires IR gen support. 4848 case Decl::IndirectField: 4849 break; 4850 4851 // C++ Decls 4852 case Decl::Namespace: 4853 EmitDeclContext(cast<NamespaceDecl>(D)); 4854 break; 4855 case Decl::ClassTemplateSpecialization: { 4856 const auto *Spec = cast<ClassTemplateSpecializationDecl>(D); 4857 if (DebugInfo && 4858 Spec->getSpecializationKind() == TSK_ExplicitInstantiationDefinition && 4859 Spec->hasDefinition()) 4860 DebugInfo->completeTemplateDefinition(*Spec); 4861 } LLVM_FALLTHROUGH; 4862 case Decl::CXXRecord: 4863 if (DebugInfo) { 4864 if (auto *ES = D->getASTContext().getExternalSource()) 4865 if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never) 4866 DebugInfo->completeUnusedClass(cast<CXXRecordDecl>(*D)); 4867 } 4868 // Emit any static data members, they may be definitions. 4869 for (auto *I : cast<CXXRecordDecl>(D)->decls()) 4870 if (isa<VarDecl>(I) || isa<CXXRecordDecl>(I)) 4871 EmitTopLevelDecl(I); 4872 break; 4873 // No code generation needed. 4874 case Decl::UsingShadow: 4875 case Decl::ClassTemplate: 4876 case Decl::VarTemplate: 4877 case Decl::VarTemplatePartialSpecialization: 4878 case Decl::FunctionTemplate: 4879 case Decl::TypeAliasTemplate: 4880 case Decl::Block: 4881 case Decl::Empty: 4882 case Decl::Binding: 4883 break; 4884 case Decl::Using: // using X; [C++] 4885 if (CGDebugInfo *DI = getModuleDebugInfo()) 4886 DI->EmitUsingDecl(cast<UsingDecl>(*D)); 4887 return; 4888 case Decl::NamespaceAlias: 4889 if (CGDebugInfo *DI = getModuleDebugInfo()) 4890 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D)); 4891 return; 4892 case Decl::UsingDirective: // using namespace X; [C++] 4893 if (CGDebugInfo *DI = getModuleDebugInfo()) 4894 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D)); 4895 return; 4896 case Decl::CXXConstructor: 4897 getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 4898 break; 4899 case Decl::CXXDestructor: 4900 getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 4901 break; 4902 4903 case Decl::StaticAssert: 4904 // Nothing to do. 4905 break; 4906 4907 // Objective-C Decls 4908 4909 // Forward declarations, no (immediate) code generation. 4910 case Decl::ObjCInterface: 4911 case Decl::ObjCCategory: 4912 break; 4913 4914 case Decl::ObjCProtocol: { 4915 auto *Proto = cast<ObjCProtocolDecl>(D); 4916 if (Proto->isThisDeclarationADefinition()) 4917 ObjCRuntime->GenerateProtocol(Proto); 4918 break; 4919 } 4920 4921 case Decl::ObjCCategoryImpl: 4922 // Categories have properties but don't support synthesize so we 4923 // can ignore them here. 4924 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 4925 break; 4926 4927 case Decl::ObjCImplementation: { 4928 auto *OMD = cast<ObjCImplementationDecl>(D); 4929 EmitObjCPropertyImplementations(OMD); 4930 EmitObjCIvarInitializations(OMD); 4931 ObjCRuntime->GenerateClass(OMD); 4932 // Emit global variable debug information. 4933 if (CGDebugInfo *DI = getModuleDebugInfo()) 4934 if (getCodeGenOpts().getDebugInfo() >= codegenoptions::LimitedDebugInfo) 4935 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType( 4936 OMD->getClassInterface()), OMD->getLocation()); 4937 break; 4938 } 4939 case Decl::ObjCMethod: { 4940 auto *OMD = cast<ObjCMethodDecl>(D); 4941 // If this is not a prototype, emit the body. 4942 if (OMD->getBody()) 4943 CodeGenFunction(*this).GenerateObjCMethod(OMD); 4944 break; 4945 } 4946 case Decl::ObjCCompatibleAlias: 4947 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D)); 4948 break; 4949 4950 case Decl::PragmaComment: { 4951 const auto *PCD = cast<PragmaCommentDecl>(D); 4952 switch (PCD->getCommentKind()) { 4953 case PCK_Unknown: 4954 llvm_unreachable("unexpected pragma comment kind"); 4955 case PCK_Linker: 4956 AppendLinkerOptions(PCD->getArg()); 4957 break; 4958 case PCK_Lib: 4959 if (getTarget().getTriple().isOSBinFormatELF() && 4960 !getTarget().getTriple().isPS4()) 4961 AddELFLibDirective(PCD->getArg()); 4962 else 4963 AddDependentLib(PCD->getArg()); 4964 break; 4965 case PCK_Compiler: 4966 case PCK_ExeStr: 4967 case PCK_User: 4968 break; // We ignore all of these. 4969 } 4970 break; 4971 } 4972 4973 case Decl::PragmaDetectMismatch: { 4974 const auto *PDMD = cast<PragmaDetectMismatchDecl>(D); 4975 AddDetectMismatch(PDMD->getName(), PDMD->getValue()); 4976 break; 4977 } 4978 4979 case Decl::LinkageSpec: 4980 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 4981 break; 4982 4983 case Decl::FileScopeAsm: { 4984 // File-scope asm is ignored during device-side CUDA compilation. 4985 if (LangOpts.CUDA && LangOpts.CUDAIsDevice) 4986 break; 4987 // File-scope asm is ignored during device-side OpenMP compilation. 4988 if (LangOpts.OpenMPIsDevice) 4989 break; 4990 auto *AD = cast<FileScopeAsmDecl>(D); 4991 getModule().appendModuleInlineAsm(AD->getAsmString()->getString()); 4992 break; 4993 } 4994 4995 case Decl::Import: { 4996 auto *Import = cast<ImportDecl>(D); 4997 4998 // If we've already imported this module, we're done. 4999 if (!ImportedModules.insert(Import->getImportedModule())) 5000 break; 5001 5002 // Emit debug information for direct imports. 5003 if (!Import->getImportedOwningModule()) { 5004 if (CGDebugInfo *DI = getModuleDebugInfo()) 5005 DI->EmitImportDecl(*Import); 5006 } 5007 5008 // Find all of the submodules and emit the module initializers. 5009 llvm::SmallPtrSet<clang::Module *, 16> Visited; 5010 SmallVector<clang::Module *, 16> Stack; 5011 Visited.insert(Import->getImportedModule()); 5012 Stack.push_back(Import->getImportedModule()); 5013 5014 while (!Stack.empty()) { 5015 clang::Module *Mod = Stack.pop_back_val(); 5016 if (!EmittedModuleInitializers.insert(Mod).second) 5017 continue; 5018 5019 for (auto *D : Context.getModuleInitializers(Mod)) 5020 EmitTopLevelDecl(D); 5021 5022 // Visit the submodules of this module. 5023 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(), 5024 SubEnd = Mod->submodule_end(); 5025 Sub != SubEnd; ++Sub) { 5026 // Skip explicit children; they need to be explicitly imported to emit 5027 // the initializers. 5028 if ((*Sub)->IsExplicit) 5029 continue; 5030 5031 if (Visited.insert(*Sub).second) 5032 Stack.push_back(*Sub); 5033 } 5034 } 5035 break; 5036 } 5037 5038 case Decl::Export: 5039 EmitDeclContext(cast<ExportDecl>(D)); 5040 break; 5041 5042 case Decl::OMPThreadPrivate: 5043 EmitOMPThreadPrivateDecl(cast<OMPThreadPrivateDecl>(D)); 5044 break; 5045 5046 case Decl::OMPDeclareReduction: 5047 EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D)); 5048 break; 5049 5050 case Decl::OMPDeclareMapper: 5051 EmitOMPDeclareMapper(cast<OMPDeclareMapperDecl>(D)); 5052 break; 5053 5054 case Decl::OMPRequires: 5055 EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D)); 5056 break; 5057 5058 default: 5059 // Make sure we handled everything we should, every other kind is a 5060 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 5061 // function. Need to recode Decl::Kind to do that easily. 5062 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 5063 break; 5064 } 5065 } 5066 5067 void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) { 5068 // Do we need to generate coverage mapping? 5069 if (!CodeGenOpts.CoverageMapping) 5070 return; 5071 switch (D->getKind()) { 5072 case Decl::CXXConversion: 5073 case Decl::CXXMethod: 5074 case Decl::Function: 5075 case Decl::ObjCMethod: 5076 case Decl::CXXConstructor: 5077 case Decl::CXXDestructor: { 5078 if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody()) 5079 return; 5080 SourceManager &SM = getContext().getSourceManager(); 5081 if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc())) 5082 return; 5083 auto I = DeferredEmptyCoverageMappingDecls.find(D); 5084 if (I == DeferredEmptyCoverageMappingDecls.end()) 5085 DeferredEmptyCoverageMappingDecls[D] = true; 5086 break; 5087 } 5088 default: 5089 break; 5090 }; 5091 } 5092 5093 void CodeGenModule::ClearUnusedCoverageMapping(const Decl *D) { 5094 // Do we need to generate coverage mapping? 5095 if (!CodeGenOpts.CoverageMapping) 5096 return; 5097 if (const auto *Fn = dyn_cast<FunctionDecl>(D)) { 5098 if (Fn->isTemplateInstantiation()) 5099 ClearUnusedCoverageMapping(Fn->getTemplateInstantiationPattern()); 5100 } 5101 auto I = DeferredEmptyCoverageMappingDecls.find(D); 5102 if (I == DeferredEmptyCoverageMappingDecls.end()) 5103 DeferredEmptyCoverageMappingDecls[D] = false; 5104 else 5105 I->second = false; 5106 } 5107 5108 void CodeGenModule::EmitDeferredUnusedCoverageMappings() { 5109 // We call takeVector() here to avoid use-after-free. 5110 // FIXME: DeferredEmptyCoverageMappingDecls is getting mutated because 5111 // we deserialize function bodies to emit coverage info for them, and that 5112 // deserializes more declarations. How should we handle that case? 5113 for (const auto &Entry : DeferredEmptyCoverageMappingDecls.takeVector()) { 5114 if (!Entry.second) 5115 continue; 5116 const Decl *D = Entry.first; 5117 switch (D->getKind()) { 5118 case Decl::CXXConversion: 5119 case Decl::CXXMethod: 5120 case Decl::Function: 5121 case Decl::ObjCMethod: { 5122 CodeGenPGO PGO(*this); 5123 GlobalDecl GD(cast<FunctionDecl>(D)); 5124 PGO.emitEmptyCounterMapping(D, getMangledName(GD), 5125 getFunctionLinkage(GD)); 5126 break; 5127 } 5128 case Decl::CXXConstructor: { 5129 CodeGenPGO PGO(*this); 5130 GlobalDecl GD(cast<CXXConstructorDecl>(D), Ctor_Base); 5131 PGO.emitEmptyCounterMapping(D, getMangledName(GD), 5132 getFunctionLinkage(GD)); 5133 break; 5134 } 5135 case Decl::CXXDestructor: { 5136 CodeGenPGO PGO(*this); 5137 GlobalDecl GD(cast<CXXDestructorDecl>(D), Dtor_Base); 5138 PGO.emitEmptyCounterMapping(D, getMangledName(GD), 5139 getFunctionLinkage(GD)); 5140 break; 5141 } 5142 default: 5143 break; 5144 }; 5145 } 5146 } 5147 5148 /// Turns the given pointer into a constant. 5149 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 5150 const void *Ptr) { 5151 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 5152 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 5153 return llvm::ConstantInt::get(i64, PtrInt); 5154 } 5155 5156 static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 5157 llvm::NamedMDNode *&GlobalMetadata, 5158 GlobalDecl D, 5159 llvm::GlobalValue *Addr) { 5160 if (!GlobalMetadata) 5161 GlobalMetadata = 5162 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 5163 5164 // TODO: should we report variant information for ctors/dtors? 5165 llvm::Metadata *Ops[] = {llvm::ConstantAsMetadata::get(Addr), 5166 llvm::ConstantAsMetadata::get(GetPointerConstant( 5167 CGM.getLLVMContext(), D.getDecl()))}; 5168 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 5169 } 5170 5171 /// For each function which is declared within an extern "C" region and marked 5172 /// as 'used', but has internal linkage, create an alias from the unmangled 5173 /// name to the mangled name if possible. People expect to be able to refer 5174 /// to such functions with an unmangled name from inline assembly within the 5175 /// same translation unit. 5176 void CodeGenModule::EmitStaticExternCAliases() { 5177 if (!getTargetCodeGenInfo().shouldEmitStaticExternCAliases()) 5178 return; 5179 for (auto &I : StaticExternCValues) { 5180 IdentifierInfo *Name = I.first; 5181 llvm::GlobalValue *Val = I.second; 5182 if (Val && !getModule().getNamedValue(Name->getName())) 5183 addUsedGlobal(llvm::GlobalAlias::create(Name->getName(), Val)); 5184 } 5185 } 5186 5187 bool CodeGenModule::lookupRepresentativeDecl(StringRef MangledName, 5188 GlobalDecl &Result) const { 5189 auto Res = Manglings.find(MangledName); 5190 if (Res == Manglings.end()) 5191 return false; 5192 Result = Res->getValue(); 5193 return true; 5194 } 5195 5196 /// Emits metadata nodes associating all the global values in the 5197 /// current module with the Decls they came from. This is useful for 5198 /// projects using IR gen as a subroutine. 5199 /// 5200 /// Since there's currently no way to associate an MDNode directly 5201 /// with an llvm::GlobalValue, we create a global named metadata 5202 /// with the name 'clang.global.decl.ptrs'. 5203 void CodeGenModule::EmitDeclMetadata() { 5204 llvm::NamedMDNode *GlobalMetadata = nullptr; 5205 5206 for (auto &I : MangledDeclNames) { 5207 llvm::GlobalValue *Addr = getModule().getNamedValue(I.second); 5208 // Some mangled names don't necessarily have an associated GlobalValue 5209 // in this module, e.g. if we mangled it for DebugInfo. 5210 if (Addr) 5211 EmitGlobalDeclMetadata(*this, GlobalMetadata, I.first, Addr); 5212 } 5213 } 5214 5215 /// Emits metadata nodes for all the local variables in the current 5216 /// function. 5217 void CodeGenFunction::EmitDeclMetadata() { 5218 if (LocalDeclMap.empty()) return; 5219 5220 llvm::LLVMContext &Context = getLLVMContext(); 5221 5222 // Find the unique metadata ID for this name. 5223 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 5224 5225 llvm::NamedMDNode *GlobalMetadata = nullptr; 5226 5227 for (auto &I : LocalDeclMap) { 5228 const Decl *D = I.first; 5229 llvm::Value *Addr = I.second.getPointer(); 5230 if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 5231 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 5232 Alloca->setMetadata( 5233 DeclPtrKind, llvm::MDNode::get( 5234 Context, llvm::ValueAsMetadata::getConstant(DAddr))); 5235 } else if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 5236 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 5237 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 5238 } 5239 } 5240 } 5241 5242 void CodeGenModule::EmitVersionIdentMetadata() { 5243 llvm::NamedMDNode *IdentMetadata = 5244 TheModule.getOrInsertNamedMetadata("llvm.ident"); 5245 std::string Version = getClangFullVersion(); 5246 llvm::LLVMContext &Ctx = TheModule.getContext(); 5247 5248 llvm::Metadata *IdentNode[] = {llvm::MDString::get(Ctx, Version)}; 5249 IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode)); 5250 } 5251 5252 void CodeGenModule::EmitCommandLineMetadata() { 5253 llvm::NamedMDNode *CommandLineMetadata = 5254 TheModule.getOrInsertNamedMetadata("llvm.commandline"); 5255 std::string CommandLine = getCodeGenOpts().RecordCommandLine; 5256 llvm::LLVMContext &Ctx = TheModule.getContext(); 5257 5258 llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)}; 5259 CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode)); 5260 } 5261 5262 void CodeGenModule::EmitTargetMetadata() { 5263 // Warning, new MangledDeclNames may be appended within this loop. 5264 // We rely on MapVector insertions adding new elements to the end 5265 // of the container. 5266 // FIXME: Move this loop into the one target that needs it, and only 5267 // loop over those declarations for which we couldn't emit the target 5268 // metadata when we emitted the declaration. 5269 for (unsigned I = 0; I != MangledDeclNames.size(); ++I) { 5270 auto Val = *(MangledDeclNames.begin() + I); 5271 const Decl *D = Val.first.getDecl()->getMostRecentDecl(); 5272 llvm::GlobalValue *GV = GetGlobalValue(Val.second); 5273 getTargetCodeGenInfo().emitTargetMD(D, GV, *this); 5274 } 5275 } 5276 5277 void CodeGenModule::EmitCoverageFile() { 5278 if (getCodeGenOpts().CoverageDataFile.empty() && 5279 getCodeGenOpts().CoverageNotesFile.empty()) 5280 return; 5281 5282 llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu"); 5283 if (!CUNode) 5284 return; 5285 5286 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 5287 llvm::LLVMContext &Ctx = TheModule.getContext(); 5288 auto *CoverageDataFile = 5289 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageDataFile); 5290 auto *CoverageNotesFile = 5291 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageNotesFile); 5292 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 5293 llvm::MDNode *CU = CUNode->getOperand(i); 5294 llvm::Metadata *Elts[] = {CoverageNotesFile, CoverageDataFile, CU}; 5295 GCov->addOperand(llvm::MDNode::get(Ctx, Elts)); 5296 } 5297 } 5298 5299 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid) { 5300 // Sema has checked that all uuid strings are of the form 5301 // "12345678-1234-1234-1234-1234567890ab". 5302 assert(Uuid.size() == 36); 5303 for (unsigned i = 0; i < 36; ++i) { 5304 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-'); 5305 else assert(isHexDigit(Uuid[i])); 5306 } 5307 5308 // The starts of all bytes of Field3 in Uuid. Field 3 is "1234-1234567890ab". 5309 const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 }; 5310 5311 llvm::Constant *Field3[8]; 5312 for (unsigned Idx = 0; Idx < 8; ++Idx) 5313 Field3[Idx] = llvm::ConstantInt::get( 5314 Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16); 5315 5316 llvm::Constant *Fields[4] = { 5317 llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16), 5318 llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16), 5319 llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16), 5320 llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3) 5321 }; 5322 5323 return llvm::ConstantStruct::getAnon(Fields); 5324 } 5325 5326 llvm::Constant *CodeGenModule::GetAddrOfRTTIDescriptor(QualType Ty, 5327 bool ForEH) { 5328 // Return a bogus pointer if RTTI is disabled, unless it's for EH. 5329 // FIXME: should we even be calling this method if RTTI is disabled 5330 // and it's not for EH? 5331 if ((!ForEH && !getLangOpts().RTTI) || getLangOpts().CUDAIsDevice) 5332 return llvm::Constant::getNullValue(Int8PtrTy); 5333 5334 if (ForEH && Ty->isObjCObjectPointerType() && 5335 LangOpts.ObjCRuntime.isGNUFamily()) 5336 return ObjCRuntime->GetEHType(Ty); 5337 5338 return getCXXABI().getAddrOfRTTIDescriptor(Ty); 5339 } 5340 5341 void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) { 5342 // Do not emit threadprivates in simd-only mode. 5343 if (LangOpts.OpenMP && LangOpts.OpenMPSimd) 5344 return; 5345 for (auto RefExpr : D->varlists()) { 5346 auto *VD = cast<VarDecl>(cast<DeclRefExpr>(RefExpr)->getDecl()); 5347 bool PerformInit = 5348 VD->getAnyInitializer() && 5349 !VD->getAnyInitializer()->isConstantInitializer(getContext(), 5350 /*ForRef=*/false); 5351 5352 Address Addr(GetAddrOfGlobalVar(VD), getContext().getDeclAlign(VD)); 5353 if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition( 5354 VD, Addr, RefExpr->getBeginLoc(), PerformInit)) 5355 CXXGlobalInits.push_back(InitFunction); 5356 } 5357 } 5358 5359 llvm::Metadata * 5360 CodeGenModule::CreateMetadataIdentifierImpl(QualType T, MetadataTypeMap &Map, 5361 StringRef Suffix) { 5362 llvm::Metadata *&InternalId = Map[T.getCanonicalType()]; 5363 if (InternalId) 5364 return InternalId; 5365 5366 if (isExternallyVisible(T->getLinkage())) { 5367 std::string OutName; 5368 llvm::raw_string_ostream Out(OutName); 5369 getCXXABI().getMangleContext().mangleTypeName(T, Out); 5370 Out << Suffix; 5371 5372 InternalId = llvm::MDString::get(getLLVMContext(), Out.str()); 5373 } else { 5374 InternalId = llvm::MDNode::getDistinct(getLLVMContext(), 5375 llvm::ArrayRef<llvm::Metadata *>()); 5376 } 5377 5378 return InternalId; 5379 } 5380 5381 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierForType(QualType T) { 5382 return CreateMetadataIdentifierImpl(T, MetadataIdMap, ""); 5383 } 5384 5385 llvm::Metadata * 5386 CodeGenModule::CreateMetadataIdentifierForVirtualMemPtrType(QualType T) { 5387 return CreateMetadataIdentifierImpl(T, VirtualMetadataIdMap, ".virtual"); 5388 } 5389 5390 // Generalize pointer types to a void pointer with the qualifiers of the 5391 // originally pointed-to type, e.g. 'const char *' and 'char * const *' 5392 // generalize to 'const void *' while 'char *' and 'const char **' generalize to 5393 // 'void *'. 5394 static QualType GeneralizeType(ASTContext &Ctx, QualType Ty) { 5395 if (!Ty->isPointerType()) 5396 return Ty; 5397 5398 return Ctx.getPointerType( 5399 QualType(Ctx.VoidTy).withCVRQualifiers( 5400 Ty->getPointeeType().getCVRQualifiers())); 5401 } 5402 5403 // Apply type generalization to a FunctionType's return and argument types 5404 static QualType GeneralizeFunctionType(ASTContext &Ctx, QualType Ty) { 5405 if (auto *FnType = Ty->getAs<FunctionProtoType>()) { 5406 SmallVector<QualType, 8> GeneralizedParams; 5407 for (auto &Param : FnType->param_types()) 5408 GeneralizedParams.push_back(GeneralizeType(Ctx, Param)); 5409 5410 return Ctx.getFunctionType( 5411 GeneralizeType(Ctx, FnType->getReturnType()), 5412 GeneralizedParams, FnType->getExtProtoInfo()); 5413 } 5414 5415 if (auto *FnType = Ty->getAs<FunctionNoProtoType>()) 5416 return Ctx.getFunctionNoProtoType( 5417 GeneralizeType(Ctx, FnType->getReturnType())); 5418 5419 llvm_unreachable("Encountered unknown FunctionType"); 5420 } 5421 5422 llvm::Metadata *CodeGenModule::CreateMetadataIdentifierGeneralized(QualType T) { 5423 return CreateMetadataIdentifierImpl(GeneralizeFunctionType(getContext(), T), 5424 GeneralizedMetadataIdMap, ".generalized"); 5425 } 5426 5427 /// Returns whether this module needs the "all-vtables" type identifier. 5428 bool CodeGenModule::NeedAllVtablesTypeId() const { 5429 // Returns true if at least one of vtable-based CFI checkers is enabled and 5430 // is not in the trapping mode. 5431 return ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) && 5432 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIVCall)) || 5433 (LangOpts.Sanitize.has(SanitizerKind::CFINVCall) && 5434 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFINVCall)) || 5435 (LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) && 5436 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIDerivedCast)) || 5437 (LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast) && 5438 !CodeGenOpts.SanitizeTrap.has(SanitizerKind::CFIUnrelatedCast))); 5439 } 5440 5441 void CodeGenModule::AddVTableTypeMetadata(llvm::GlobalVariable *VTable, 5442 CharUnits Offset, 5443 const CXXRecordDecl *RD) { 5444 llvm::Metadata *MD = 5445 CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0)); 5446 VTable->addTypeMetadata(Offset.getQuantity(), MD); 5447 5448 if (CodeGenOpts.SanitizeCfiCrossDso) 5449 if (auto CrossDsoTypeId = CreateCrossDsoCfiTypeId(MD)) 5450 VTable->addTypeMetadata(Offset.getQuantity(), 5451 llvm::ConstantAsMetadata::get(CrossDsoTypeId)); 5452 5453 if (NeedAllVtablesTypeId()) { 5454 llvm::Metadata *MD = llvm::MDString::get(getLLVMContext(), "all-vtables"); 5455 VTable->addTypeMetadata(Offset.getQuantity(), MD); 5456 } 5457 } 5458 5459 TargetAttr::ParsedTargetAttr CodeGenModule::filterFunctionTargetAttrs(const TargetAttr *TD) { 5460 assert(TD != nullptr); 5461 TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse(); 5462 5463 ParsedAttr.Features.erase( 5464 llvm::remove_if(ParsedAttr.Features, 5465 [&](const std::string &Feat) { 5466 return !Target.isValidFeatureName( 5467 StringRef{Feat}.substr(1)); 5468 }), 5469 ParsedAttr.Features.end()); 5470 return ParsedAttr; 5471 } 5472 5473 5474 // Fills in the supplied string map with the set of target features for the 5475 // passed in function. 5476 void CodeGenModule::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap, 5477 GlobalDecl GD) { 5478 StringRef TargetCPU = Target.getTargetOpts().CPU; 5479 const FunctionDecl *FD = GD.getDecl()->getAsFunction(); 5480 if (const auto *TD = FD->getAttr<TargetAttr>()) { 5481 TargetAttr::ParsedTargetAttr ParsedAttr = filterFunctionTargetAttrs(TD); 5482 5483 // Make a copy of the features as passed on the command line into the 5484 // beginning of the additional features from the function to override. 5485 ParsedAttr.Features.insert(ParsedAttr.Features.begin(), 5486 Target.getTargetOpts().FeaturesAsWritten.begin(), 5487 Target.getTargetOpts().FeaturesAsWritten.end()); 5488 5489 if (ParsedAttr.Architecture != "" && 5490 Target.isValidCPUName(ParsedAttr.Architecture)) 5491 TargetCPU = ParsedAttr.Architecture; 5492 5493 // Now populate the feature map, first with the TargetCPU which is either 5494 // the default or a new one from the target attribute string. Then we'll use 5495 // the passed in features (FeaturesAsWritten) along with the new ones from 5496 // the attribute. 5497 Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU, 5498 ParsedAttr.Features); 5499 } else if (const auto *SD = FD->getAttr<CPUSpecificAttr>()) { 5500 llvm::SmallVector<StringRef, 32> FeaturesTmp; 5501 Target.getCPUSpecificCPUDispatchFeatures( 5502 SD->getCPUName(GD.getMultiVersionIndex())->getName(), FeaturesTmp); 5503 std::vector<std::string> Features(FeaturesTmp.begin(), FeaturesTmp.end()); 5504 Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU, Features); 5505 } else { 5506 Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU, 5507 Target.getTargetOpts().Features); 5508 } 5509 } 5510 5511 llvm::SanitizerStatReport &CodeGenModule::getSanStats() { 5512 if (!SanStats) 5513 SanStats = llvm::make_unique<llvm::SanitizerStatReport>(&getModule()); 5514 5515 return *SanStats; 5516 } 5517 llvm::Value * 5518 CodeGenModule::createOpenCLIntToSamplerConversion(const Expr *E, 5519 CodeGenFunction &CGF) { 5520 llvm::Constant *C = ConstantEmitter(CGF).emitAbstract(E, E->getType()); 5521 auto SamplerT = getOpenCLRuntime().getSamplerType(E->getType().getTypePtr()); 5522 auto FTy = llvm::FunctionType::get(SamplerT, {C->getType()}, false); 5523 return CGF.Builder.CreateCall(CreateRuntimeFunction(FTy, 5524 "__translate_sampler_initializer"), 5525 {C}); 5526 } 5527