1 //===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This coordinates the per-module state used while generating code. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "CodeGenModule.h" 15 #include "CGCUDARuntime.h" 16 #include "CGCXXABI.h" 17 #include "CGCall.h" 18 #include "CGDebugInfo.h" 19 #include "CGObjCRuntime.h" 20 #include "CGOpenCLRuntime.h" 21 #include "CodeGenFunction.h" 22 #include "CodeGenTBAA.h" 23 #include "TargetInfo.h" 24 #include "clang/AST/ASTContext.h" 25 #include "clang/AST/CharUnits.h" 26 #include "clang/AST/DeclCXX.h" 27 #include "clang/AST/DeclObjC.h" 28 #include "clang/AST/DeclTemplate.h" 29 #include "clang/AST/Mangle.h" 30 #include "clang/AST/RecordLayout.h" 31 #include "clang/AST/RecursiveASTVisitor.h" 32 #include "clang/Basic/Builtins.h" 33 #include "clang/Basic/CharInfo.h" 34 #include "clang/Basic/Diagnostic.h" 35 #include "clang/Basic/Module.h" 36 #include "clang/Basic/SourceManager.h" 37 #include "clang/Basic/TargetInfo.h" 38 #include "clang/Basic/Version.h" 39 #include "clang/Frontend/CodeGenOptions.h" 40 #include "clang/Sema/SemaDiagnostic.h" 41 #include "llvm/ADT/APSInt.h" 42 #include "llvm/ADT/Triple.h" 43 #include "llvm/IR/CallingConv.h" 44 #include "llvm/IR/DataLayout.h" 45 #include "llvm/IR/Intrinsics.h" 46 #include "llvm/IR/LLVMContext.h" 47 #include "llvm/IR/Module.h" 48 #include "llvm/Support/CallSite.h" 49 #include "llvm/Support/ConvertUTF.h" 50 #include "llvm/Support/ErrorHandling.h" 51 #include "llvm/Target/Mangler.h" 52 53 using namespace clang; 54 using namespace CodeGen; 55 56 static const char AnnotationSection[] = "llvm.metadata"; 57 58 static CGCXXABI &createCXXABI(CodeGenModule &CGM) { 59 switch (CGM.getTarget().getCXXABI().getKind()) { 60 case TargetCXXABI::GenericAArch64: 61 case TargetCXXABI::GenericARM: 62 case TargetCXXABI::iOS: 63 case TargetCXXABI::GenericItanium: 64 return *CreateItaniumCXXABI(CGM); 65 case TargetCXXABI::Microsoft: 66 return *CreateMicrosoftCXXABI(CGM); 67 } 68 69 llvm_unreachable("invalid C++ ABI kind"); 70 } 71 72 CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 73 llvm::Module &M, const llvm::DataLayout &TD, 74 DiagnosticsEngine &diags) 75 : Context(C), LangOpts(C.getLangOpts()), CodeGenOpts(CGO), TheModule(M), 76 Diags(diags), TheDataLayout(TD), Target(C.getTargetInfo()), 77 ABI(createCXXABI(*this)), VMContext(M.getContext()), TBAA(0), 78 TheTargetCodeGenInfo(0), Types(*this), VTables(*this), ObjCRuntime(0), 79 OpenCLRuntime(0), CUDARuntime(0), DebugInfo(0), ARCData(0), 80 NoObjCARCExceptionsMetadata(0), RRData(0), CFConstantStringClassRef(0), 81 ConstantStringClassRef(0), NSConstantStringType(0), 82 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), BlockObjectAssign(0), 83 BlockObjectDispose(0), BlockDescriptorType(0), GenericBlockLiteralType(0), 84 LifetimeStartFn(0), LifetimeEndFn(0), 85 SanitizerBlacklist( 86 llvm::SpecialCaseList::createOrDie(CGO.SanitizerBlacklistFile)), 87 SanOpts(SanitizerBlacklist->isIn(M) ? SanitizerOptions::Disabled 88 : LangOpts.Sanitize) { 89 90 // Initialize the type cache. 91 llvm::LLVMContext &LLVMContext = M.getContext(); 92 VoidTy = llvm::Type::getVoidTy(LLVMContext); 93 Int8Ty = llvm::Type::getInt8Ty(LLVMContext); 94 Int16Ty = llvm::Type::getInt16Ty(LLVMContext); 95 Int32Ty = llvm::Type::getInt32Ty(LLVMContext); 96 Int64Ty = llvm::Type::getInt64Ty(LLVMContext); 97 FloatTy = llvm::Type::getFloatTy(LLVMContext); 98 DoubleTy = llvm::Type::getDoubleTy(LLVMContext); 99 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0); 100 PointerAlignInBytes = 101 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity(); 102 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth()); 103 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits); 104 Int8PtrTy = Int8Ty->getPointerTo(0); 105 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0); 106 107 RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC(); 108 109 if (LangOpts.ObjC1) 110 createObjCRuntime(); 111 if (LangOpts.OpenCL) 112 createOpenCLRuntime(); 113 if (LangOpts.CUDA) 114 createCUDARuntime(); 115 116 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0. 117 if (SanOpts.Thread || 118 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0)) 119 TBAA = new CodeGenTBAA(Context, VMContext, CodeGenOpts, getLangOpts(), 120 ABI.getMangleContext()); 121 122 // If debug info or coverage generation is enabled, create the CGDebugInfo 123 // object. 124 if (CodeGenOpts.getDebugInfo() != CodeGenOptions::NoDebugInfo || 125 CodeGenOpts.EmitGcovArcs || 126 CodeGenOpts.EmitGcovNotes) 127 DebugInfo = new CGDebugInfo(*this); 128 129 Block.GlobalUniqueCount = 0; 130 131 if (C.getLangOpts().ObjCAutoRefCount) 132 ARCData = new ARCEntrypoints(); 133 RRData = new RREntrypoints(); 134 } 135 136 CodeGenModule::~CodeGenModule() { 137 delete ObjCRuntime; 138 delete OpenCLRuntime; 139 delete CUDARuntime; 140 delete TheTargetCodeGenInfo; 141 delete &ABI; 142 delete TBAA; 143 delete DebugInfo; 144 delete ARCData; 145 delete RRData; 146 } 147 148 void CodeGenModule::createObjCRuntime() { 149 // This is just isGNUFamily(), but we want to force implementors of 150 // new ABIs to decide how best to do this. 151 switch (LangOpts.ObjCRuntime.getKind()) { 152 case ObjCRuntime::GNUstep: 153 case ObjCRuntime::GCC: 154 case ObjCRuntime::ObjFW: 155 ObjCRuntime = CreateGNUObjCRuntime(*this); 156 return; 157 158 case ObjCRuntime::FragileMacOSX: 159 case ObjCRuntime::MacOSX: 160 case ObjCRuntime::iOS: 161 ObjCRuntime = CreateMacObjCRuntime(*this); 162 return; 163 } 164 llvm_unreachable("bad runtime kind"); 165 } 166 167 void CodeGenModule::createOpenCLRuntime() { 168 OpenCLRuntime = new CGOpenCLRuntime(*this); 169 } 170 171 void CodeGenModule::createCUDARuntime() { 172 CUDARuntime = CreateNVCUDARuntime(*this); 173 } 174 175 void CodeGenModule::applyReplacements() { 176 for (ReplacementsTy::iterator I = Replacements.begin(), 177 E = Replacements.end(); 178 I != E; ++I) { 179 StringRef MangledName = I->first(); 180 llvm::Constant *Replacement = I->second; 181 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 182 if (!Entry) 183 continue; 184 llvm::Function *OldF = cast<llvm::Function>(Entry); 185 llvm::Function *NewF = dyn_cast<llvm::Function>(Replacement); 186 if (!NewF) { 187 llvm::ConstantExpr *CE = cast<llvm::ConstantExpr>(Replacement); 188 assert(CE->getOpcode() == llvm::Instruction::BitCast || 189 CE->getOpcode() == llvm::Instruction::GetElementPtr); 190 NewF = dyn_cast<llvm::Function>(CE->getOperand(0)); 191 } 192 193 // Replace old with new, but keep the old order. 194 OldF->replaceAllUsesWith(Replacement); 195 if (NewF) { 196 NewF->removeFromParent(); 197 OldF->getParent()->getFunctionList().insertAfter(OldF, NewF); 198 } 199 OldF->eraseFromParent(); 200 } 201 } 202 203 void CodeGenModule::checkAliases() { 204 bool Error = false; 205 for (std::vector<GlobalDecl>::iterator I = Aliases.begin(), 206 E = Aliases.end(); I != E; ++I) { 207 const GlobalDecl &GD = *I; 208 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 209 const AliasAttr *AA = D->getAttr<AliasAttr>(); 210 StringRef MangledName = getMangledName(GD); 211 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 212 llvm::GlobalAlias *Alias = cast<llvm::GlobalAlias>(Entry); 213 llvm::GlobalValue *GV = Alias->getAliasedGlobal(); 214 if (GV->isDeclaration()) { 215 Error = true; 216 getDiags().Report(AA->getLocation(), diag::err_alias_to_undefined); 217 } else if (!Alias->resolveAliasedGlobal(/*stopOnWeak*/ false)) { 218 Error = true; 219 getDiags().Report(AA->getLocation(), diag::err_cyclic_alias); 220 } 221 } 222 if (!Error) 223 return; 224 225 for (std::vector<GlobalDecl>::iterator I = Aliases.begin(), 226 E = Aliases.end(); I != E; ++I) { 227 const GlobalDecl &GD = *I; 228 StringRef MangledName = getMangledName(GD); 229 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 230 llvm::GlobalAlias *Alias = cast<llvm::GlobalAlias>(Entry); 231 Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType())); 232 Alias->eraseFromParent(); 233 } 234 } 235 236 void CodeGenModule::Release() { 237 EmitDeferred(); 238 applyReplacements(); 239 checkAliases(); 240 EmitCXXGlobalInitFunc(); 241 EmitCXXGlobalDtorFunc(); 242 EmitCXXThreadLocalInitFunc(); 243 if (ObjCRuntime) 244 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) 245 AddGlobalCtor(ObjCInitFunction); 246 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 247 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 248 EmitGlobalAnnotations(); 249 EmitStaticExternCAliases(); 250 EmitLLVMUsed(); 251 252 if (CodeGenOpts.Autolink && 253 (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) { 254 EmitModuleLinkOptions(); 255 } 256 if (CodeGenOpts.DwarfVersion) 257 // We actually want the latest version when there are conflicts. 258 // We can change from Warning to Latest if such mode is supported. 259 getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version", 260 CodeGenOpts.DwarfVersion); 261 262 SimplifyPersonality(); 263 264 if (getCodeGenOpts().EmitDeclMetadata) 265 EmitDeclMetadata(); 266 267 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 268 EmitCoverageFile(); 269 270 if (DebugInfo) 271 DebugInfo->finalize(); 272 273 EmitVersionIdentMetadata(); 274 } 275 276 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 277 // Make sure that this type is translated. 278 Types.UpdateCompletedType(TD); 279 } 280 281 llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 282 if (!TBAA) 283 return 0; 284 return TBAA->getTBAAInfo(QTy); 285 } 286 287 llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() { 288 if (!TBAA) 289 return 0; 290 return TBAA->getTBAAInfoForVTablePtr(); 291 } 292 293 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) { 294 if (!TBAA) 295 return 0; 296 return TBAA->getTBAAStructInfo(QTy); 297 } 298 299 llvm::MDNode *CodeGenModule::getTBAAStructTypeInfo(QualType QTy) { 300 if (!TBAA) 301 return 0; 302 return TBAA->getTBAAStructTypeInfo(QTy); 303 } 304 305 llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy, 306 llvm::MDNode *AccessN, 307 uint64_t O) { 308 if (!TBAA) 309 return 0; 310 return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O); 311 } 312 313 /// Decorate the instruction with a TBAA tag. For both scalar TBAA 314 /// and struct-path aware TBAA, the tag has the same format: 315 /// base type, access type and offset. 316 /// When ConvertTypeToTag is true, we create a tag based on the scalar type. 317 void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 318 llvm::MDNode *TBAAInfo, 319 bool ConvertTypeToTag) { 320 if (ConvertTypeToTag && TBAA) 321 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, 322 TBAA->getTBAAScalarTagInfo(TBAAInfo)); 323 else 324 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 325 } 326 327 void CodeGenModule::Error(SourceLocation loc, StringRef error) { 328 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); 329 getDiags().Report(Context.getFullLoc(loc), diagID); 330 } 331 332 /// ErrorUnsupported - Print out an error that codegen doesn't support the 333 /// specified stmt yet. 334 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) { 335 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 336 "cannot compile this %0 yet"); 337 std::string Msg = Type; 338 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 339 << Msg << S->getSourceRange(); 340 } 341 342 /// ErrorUnsupported - Print out an error that codegen doesn't support the 343 /// specified decl yet. 344 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) { 345 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 346 "cannot compile this %0 yet"); 347 std::string Msg = Type; 348 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 349 } 350 351 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 352 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 353 } 354 355 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 356 const NamedDecl *D) const { 357 // Internal definitions always have default visibility. 358 if (GV->hasLocalLinkage()) { 359 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 360 return; 361 } 362 363 // Set visibility for definitions. 364 LinkageInfo LV = D->getLinkageAndVisibility(); 365 if (LV.isVisibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 366 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 367 } 368 369 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) { 370 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S) 371 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel) 372 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel) 373 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel) 374 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel); 375 } 376 377 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel( 378 CodeGenOptions::TLSModel M) { 379 switch (M) { 380 case CodeGenOptions::GeneralDynamicTLSModel: 381 return llvm::GlobalVariable::GeneralDynamicTLSModel; 382 case CodeGenOptions::LocalDynamicTLSModel: 383 return llvm::GlobalVariable::LocalDynamicTLSModel; 384 case CodeGenOptions::InitialExecTLSModel: 385 return llvm::GlobalVariable::InitialExecTLSModel; 386 case CodeGenOptions::LocalExecTLSModel: 387 return llvm::GlobalVariable::LocalExecTLSModel; 388 } 389 llvm_unreachable("Invalid TLS model!"); 390 } 391 392 void CodeGenModule::setTLSMode(llvm::GlobalVariable *GV, 393 const VarDecl &D) const { 394 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!"); 395 396 llvm::GlobalVariable::ThreadLocalMode TLM; 397 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel()); 398 399 // Override the TLS model if it is explicitly specified. 400 if (D.hasAttr<TLSModelAttr>()) { 401 const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>(); 402 TLM = GetLLVMTLSModel(Attr->getModel()); 403 } 404 405 GV->setThreadLocalMode(TLM); 406 } 407 408 /// Set the symbol visibility of type information (vtable and RTTI) 409 /// associated with the given type. 410 void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 411 const CXXRecordDecl *RD, 412 TypeVisibilityKind TVK) const { 413 setGlobalVisibility(GV, RD); 414 415 if (!CodeGenOpts.HiddenWeakVTables) 416 return; 417 418 // We never want to drop the visibility for RTTI names. 419 if (TVK == TVK_ForRTTIName) 420 return; 421 422 // We want to drop the visibility to hidden for weak type symbols. 423 // This isn't possible if there might be unresolved references 424 // elsewhere that rely on this symbol being visible. 425 426 // This should be kept roughly in sync with setThunkVisibility 427 // in CGVTables.cpp. 428 429 // Preconditions. 430 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 431 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 432 return; 433 434 // Don't override an explicit visibility attribute. 435 if (RD->getExplicitVisibility(NamedDecl::VisibilityForType)) 436 return; 437 438 switch (RD->getTemplateSpecializationKind()) { 439 // We have to disable the optimization if this is an EI definition 440 // because there might be EI declarations in other shared objects. 441 case TSK_ExplicitInstantiationDefinition: 442 case TSK_ExplicitInstantiationDeclaration: 443 return; 444 445 // Every use of a non-template class's type information has to emit it. 446 case TSK_Undeclared: 447 break; 448 449 // In theory, implicit instantiations can ignore the possibility of 450 // an explicit instantiation declaration because there necessarily 451 // must be an EI definition somewhere with default visibility. In 452 // practice, it's possible to have an explicit instantiation for 453 // an arbitrary template class, and linkers aren't necessarily able 454 // to deal with mixed-visibility symbols. 455 case TSK_ExplicitSpecialization: 456 case TSK_ImplicitInstantiation: 457 return; 458 } 459 460 // If there's a key function, there may be translation units 461 // that don't have the key function's definition. But ignore 462 // this if we're emitting RTTI under -fno-rtti. 463 if (!(TVK != TVK_ForRTTI) || LangOpts.RTTI) { 464 // FIXME: what should we do if we "lose" the key function during 465 // the emission of the file? 466 if (Context.getCurrentKeyFunction(RD)) 467 return; 468 } 469 470 // Otherwise, drop the visibility to hidden. 471 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 472 GV->setUnnamedAddr(true); 473 } 474 475 StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 476 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 477 478 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 479 if (!Str.empty()) 480 return Str; 481 482 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 483 IdentifierInfo *II = ND->getIdentifier(); 484 assert(II && "Attempt to mangle unnamed decl."); 485 486 Str = II->getName(); 487 return Str; 488 } 489 490 SmallString<256> Buffer; 491 llvm::raw_svector_ostream Out(Buffer); 492 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 493 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 494 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 495 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 496 else 497 getCXXABI().getMangleContext().mangleName(ND, Out); 498 499 // Allocate space for the mangled name. 500 Out.flush(); 501 size_t Length = Buffer.size(); 502 char *Name = MangledNamesAllocator.Allocate<char>(Length); 503 std::copy(Buffer.begin(), Buffer.end(), Name); 504 505 Str = StringRef(Name, Length); 506 507 return Str; 508 } 509 510 void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 511 const BlockDecl *BD) { 512 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 513 const Decl *D = GD.getDecl(); 514 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 515 if (D == 0) 516 MangleCtx.mangleGlobalBlock(BD, 517 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out); 518 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 519 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 520 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 521 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 522 else 523 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 524 } 525 526 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 527 return getModule().getNamedValue(Name); 528 } 529 530 /// AddGlobalCtor - Add a function to the list that will be called before 531 /// main() runs. 532 void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 533 // FIXME: Type coercion of void()* types. 534 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 535 } 536 537 /// AddGlobalDtor - Add a function to the list that will be called 538 /// when the module is unloaded. 539 void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 540 // FIXME: Type coercion of void()* types. 541 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 542 } 543 544 void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 545 // Ctor function type is void()*. 546 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 547 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 548 549 // Get the type of a ctor entry, { i32, void ()* }. 550 llvm::StructType *CtorStructTy = 551 llvm::StructType::get(Int32Ty, llvm::PointerType::getUnqual(CtorFTy), NULL); 552 553 // Construct the constructor and destructor arrays. 554 SmallVector<llvm::Constant*, 8> Ctors; 555 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 556 llvm::Constant *S[] = { 557 llvm::ConstantInt::get(Int32Ty, I->second, false), 558 llvm::ConstantExpr::getBitCast(I->first, CtorPFTy) 559 }; 560 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 561 } 562 563 if (!Ctors.empty()) { 564 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 565 new llvm::GlobalVariable(TheModule, AT, false, 566 llvm::GlobalValue::AppendingLinkage, 567 llvm::ConstantArray::get(AT, Ctors), 568 GlobalName); 569 } 570 } 571 572 llvm::GlobalValue::LinkageTypes 573 CodeGenModule::getFunctionLinkage(GlobalDecl GD) { 574 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 575 576 if (isa<CXXDestructorDecl>(D) && 577 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D), 578 GD.getDtorType())) 579 return llvm::Function::LinkOnceODRLinkage; 580 581 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 582 583 if (Linkage == GVA_Internal) 584 return llvm::Function::InternalLinkage; 585 586 if (D->hasAttr<DLLExportAttr>()) 587 return llvm::Function::DLLExportLinkage; 588 589 if (D->hasAttr<WeakAttr>()) 590 return llvm::Function::WeakAnyLinkage; 591 592 // In C99 mode, 'inline' functions are guaranteed to have a strong 593 // definition somewhere else, so we can use available_externally linkage. 594 if (Linkage == GVA_C99Inline) 595 return llvm::Function::AvailableExternallyLinkage; 596 597 // Note that Apple's kernel linker doesn't support symbol 598 // coalescing, so we need to avoid linkonce and weak linkages there. 599 // Normally, this means we just map to internal, but for explicit 600 // instantiations we'll map to external. 601 602 // In C++, the compiler has to emit a definition in every translation unit 603 // that references the function. We should use linkonce_odr because 604 // a) if all references in this translation unit are optimized away, we 605 // don't need to codegen it. b) if the function persists, it needs to be 606 // merged with other definitions. c) C++ has the ODR, so we know the 607 // definition is dependable. 608 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 609 return !Context.getLangOpts().AppleKext 610 ? llvm::Function::LinkOnceODRLinkage 611 : llvm::Function::InternalLinkage; 612 613 // An explicit instantiation of a template has weak linkage, since 614 // explicit instantiations can occur in multiple translation units 615 // and must all be equivalent. However, we are not allowed to 616 // throw away these explicit instantiations. 617 if (Linkage == GVA_ExplicitTemplateInstantiation) 618 return !Context.getLangOpts().AppleKext 619 ? llvm::Function::WeakODRLinkage 620 : llvm::Function::ExternalLinkage; 621 622 // Otherwise, we have strong external linkage. 623 assert(Linkage == GVA_StrongExternal); 624 return llvm::Function::ExternalLinkage; 625 } 626 627 628 /// SetFunctionDefinitionAttributes - Set attributes for a global. 629 /// 630 /// FIXME: This is currently only done for aliases and functions, but not for 631 /// variables (these details are set in EmitGlobalVarDefinition for variables). 632 void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 633 llvm::GlobalValue *GV) { 634 SetCommonAttributes(D, GV); 635 } 636 637 void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 638 const CGFunctionInfo &Info, 639 llvm::Function *F) { 640 unsigned CallingConv; 641 AttributeListType AttributeList; 642 ConstructAttributeList(Info, D, AttributeList, CallingConv, false); 643 F->setAttributes(llvm::AttributeSet::get(getLLVMContext(), AttributeList)); 644 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 645 } 646 647 /// Determines whether the language options require us to model 648 /// unwind exceptions. We treat -fexceptions as mandating this 649 /// except under the fragile ObjC ABI with only ObjC exceptions 650 /// enabled. This means, for example, that C with -fexceptions 651 /// enables this. 652 static bool hasUnwindExceptions(const LangOptions &LangOpts) { 653 // If exceptions are completely disabled, obviously this is false. 654 if (!LangOpts.Exceptions) return false; 655 656 // If C++ exceptions are enabled, this is true. 657 if (LangOpts.CXXExceptions) return true; 658 659 // If ObjC exceptions are enabled, this depends on the ABI. 660 if (LangOpts.ObjCExceptions) { 661 return LangOpts.ObjCRuntime.hasUnwindExceptions(); 662 } 663 664 return true; 665 } 666 667 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 668 llvm::Function *F) { 669 llvm::AttrBuilder B; 670 671 if (CodeGenOpts.UnwindTables) 672 B.addAttribute(llvm::Attribute::UWTable); 673 674 if (!hasUnwindExceptions(LangOpts)) 675 B.addAttribute(llvm::Attribute::NoUnwind); 676 677 if (D->hasAttr<NakedAttr>()) { 678 // Naked implies noinline: we should not be inlining such functions. 679 B.addAttribute(llvm::Attribute::Naked); 680 B.addAttribute(llvm::Attribute::NoInline); 681 } else if (D->hasAttr<NoInlineAttr>()) { 682 B.addAttribute(llvm::Attribute::NoInline); 683 } else if ((D->hasAttr<AlwaysInlineAttr>() || 684 D->hasAttr<ForceInlineAttr>()) && 685 !F->getAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex, 686 llvm::Attribute::NoInline)) { 687 // (noinline wins over always_inline, and we can't specify both in IR) 688 B.addAttribute(llvm::Attribute::AlwaysInline); 689 } 690 691 if (D->hasAttr<ColdAttr>()) { 692 B.addAttribute(llvm::Attribute::OptimizeForSize); 693 B.addAttribute(llvm::Attribute::Cold); 694 } 695 696 if (D->hasAttr<MinSizeAttr>()) 697 B.addAttribute(llvm::Attribute::MinSize); 698 699 if (LangOpts.getStackProtector() == LangOptions::SSPOn) 700 B.addAttribute(llvm::Attribute::StackProtect); 701 else if (LangOpts.getStackProtector() == LangOptions::SSPReq) 702 B.addAttribute(llvm::Attribute::StackProtectReq); 703 704 // Add sanitizer attributes if function is not blacklisted. 705 if (!SanitizerBlacklist->isIn(*F)) { 706 // When AddressSanitizer is enabled, set SanitizeAddress attribute 707 // unless __attribute__((no_sanitize_address)) is used. 708 if (SanOpts.Address && !D->hasAttr<NoSanitizeAddressAttr>()) 709 B.addAttribute(llvm::Attribute::SanitizeAddress); 710 // Same for ThreadSanitizer and __attribute__((no_sanitize_thread)) 711 if (SanOpts.Thread && !D->hasAttr<NoSanitizeThreadAttr>()) { 712 B.addAttribute(llvm::Attribute::SanitizeThread); 713 } 714 // Same for MemorySanitizer and __attribute__((no_sanitize_memory)) 715 if (SanOpts.Memory && !D->hasAttr<NoSanitizeMemoryAttr>()) 716 B.addAttribute(llvm::Attribute::SanitizeMemory); 717 } 718 719 F->addAttributes(llvm::AttributeSet::FunctionIndex, 720 llvm::AttributeSet::get( 721 F->getContext(), llvm::AttributeSet::FunctionIndex, B)); 722 723 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 724 F->setUnnamedAddr(true); 725 else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) 726 if (MD->isVirtual()) 727 F->setUnnamedAddr(true); 728 729 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 730 if (alignment) 731 F->setAlignment(alignment); 732 733 // C++ ABI requires 2-byte alignment for member functions. 734 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 735 F->setAlignment(2); 736 } 737 738 void CodeGenModule::SetCommonAttributes(const Decl *D, 739 llvm::GlobalValue *GV) { 740 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 741 setGlobalVisibility(GV, ND); 742 else 743 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 744 745 if (D->hasAttr<UsedAttr>()) 746 AddUsedGlobal(GV); 747 748 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 749 GV->setSection(SA->getName()); 750 751 // Alias cannot have attributes. Filter them here. 752 if (!isa<llvm::GlobalAlias>(GV)) 753 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 754 } 755 756 void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 757 llvm::Function *F, 758 const CGFunctionInfo &FI) { 759 SetLLVMFunctionAttributes(D, FI, F); 760 SetLLVMFunctionAttributesForDefinition(D, F); 761 762 F->setLinkage(llvm::Function::InternalLinkage); 763 764 SetCommonAttributes(D, F); 765 } 766 767 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 768 llvm::Function *F, 769 bool IsIncompleteFunction) { 770 if (unsigned IID = F->getIntrinsicID()) { 771 // If this is an intrinsic function, set the function's attributes 772 // to the intrinsic's attributes. 773 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), 774 (llvm::Intrinsic::ID)IID)); 775 return; 776 } 777 778 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 779 780 if (!IsIncompleteFunction) 781 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F); 782 783 if (getCXXABI().HasThisReturn(GD)) { 784 assert(!F->arg_empty() && 785 F->arg_begin()->getType() 786 ->canLosslesslyBitCastTo(F->getReturnType()) && 787 "unexpected this return"); 788 F->addAttribute(1, llvm::Attribute::Returned); 789 } 790 791 // Only a few attributes are set on declarations; these may later be 792 // overridden by a definition. 793 794 if (FD->hasAttr<DLLImportAttr>()) { 795 F->setLinkage(llvm::Function::DLLImportLinkage); 796 } else if (FD->hasAttr<WeakAttr>() || 797 FD->isWeakImported()) { 798 // "extern_weak" is overloaded in LLVM; we probably should have 799 // separate linkage types for this. 800 F->setLinkage(llvm::Function::ExternalWeakLinkage); 801 } else { 802 F->setLinkage(llvm::Function::ExternalLinkage); 803 804 LinkageInfo LV = FD->getLinkageAndVisibility(); 805 if (LV.getLinkage() == ExternalLinkage && LV.isVisibilityExplicit()) { 806 F->setVisibility(GetLLVMVisibility(LV.getVisibility())); 807 } 808 } 809 810 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 811 F->setSection(SA->getName()); 812 813 // A replaceable global allocation function does not act like a builtin by 814 // default, only if it is invoked by a new-expression or delete-expression. 815 if (FD->isReplaceableGlobalAllocationFunction()) 816 F->addAttribute(llvm::AttributeSet::FunctionIndex, 817 llvm::Attribute::NoBuiltin); 818 } 819 820 void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 821 assert(!GV->isDeclaration() && 822 "Only globals with definition can force usage."); 823 LLVMUsed.push_back(GV); 824 } 825 826 void CodeGenModule::EmitLLVMUsed() { 827 // Don't create llvm.used if there is no need. 828 if (LLVMUsed.empty()) 829 return; 830 831 // Convert LLVMUsed to what ConstantArray needs. 832 SmallVector<llvm::Constant*, 8> UsedArray; 833 UsedArray.resize(LLVMUsed.size()); 834 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 835 UsedArray[i] = 836 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 837 Int8PtrTy); 838 } 839 840 if (UsedArray.empty()) 841 return; 842 llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size()); 843 844 llvm::GlobalVariable *GV = 845 new llvm::GlobalVariable(getModule(), ATy, false, 846 llvm::GlobalValue::AppendingLinkage, 847 llvm::ConstantArray::get(ATy, UsedArray), 848 "llvm.used"); 849 850 GV->setSection("llvm.metadata"); 851 } 852 853 void CodeGenModule::AppendLinkerOptions(StringRef Opts) { 854 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opts); 855 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 856 } 857 858 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) { 859 llvm::SmallString<32> Opt; 860 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt); 861 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); 862 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 863 } 864 865 void CodeGenModule::AddDependentLib(StringRef Lib) { 866 llvm::SmallString<24> Opt; 867 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt); 868 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); 869 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 870 } 871 872 /// \brief Add link options implied by the given module, including modules 873 /// it depends on, using a postorder walk. 874 static void addLinkOptionsPostorder(CodeGenModule &CGM, 875 Module *Mod, 876 SmallVectorImpl<llvm::Value *> &Metadata, 877 llvm::SmallPtrSet<Module *, 16> &Visited) { 878 // Import this module's parent. 879 if (Mod->Parent && Visited.insert(Mod->Parent)) { 880 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited); 881 } 882 883 // Import this module's dependencies. 884 for (unsigned I = Mod->Imports.size(); I > 0; --I) { 885 if (Visited.insert(Mod->Imports[I-1])) 886 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited); 887 } 888 889 // Add linker options to link against the libraries/frameworks 890 // described by this module. 891 llvm::LLVMContext &Context = CGM.getLLVMContext(); 892 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) { 893 // Link against a framework. Frameworks are currently Darwin only, so we 894 // don't to ask TargetCodeGenInfo for the spelling of the linker option. 895 if (Mod->LinkLibraries[I-1].IsFramework) { 896 llvm::Value *Args[2] = { 897 llvm::MDString::get(Context, "-framework"), 898 llvm::MDString::get(Context, Mod->LinkLibraries[I-1].Library) 899 }; 900 901 Metadata.push_back(llvm::MDNode::get(Context, Args)); 902 continue; 903 } 904 905 // Link against a library. 906 llvm::SmallString<24> Opt; 907 CGM.getTargetCodeGenInfo().getDependentLibraryOption( 908 Mod->LinkLibraries[I-1].Library, Opt); 909 llvm::Value *OptString = llvm::MDString::get(Context, Opt); 910 Metadata.push_back(llvm::MDNode::get(Context, OptString)); 911 } 912 } 913 914 void CodeGenModule::EmitModuleLinkOptions() { 915 // Collect the set of all of the modules we want to visit to emit link 916 // options, which is essentially the imported modules and all of their 917 // non-explicit child modules. 918 llvm::SetVector<clang::Module *> LinkModules; 919 llvm::SmallPtrSet<clang::Module *, 16> Visited; 920 SmallVector<clang::Module *, 16> Stack; 921 922 // Seed the stack with imported modules. 923 for (llvm::SetVector<clang::Module *>::iterator M = ImportedModules.begin(), 924 MEnd = ImportedModules.end(); 925 M != MEnd; ++M) { 926 if (Visited.insert(*M)) 927 Stack.push_back(*M); 928 } 929 930 // Find all of the modules to import, making a little effort to prune 931 // non-leaf modules. 932 while (!Stack.empty()) { 933 clang::Module *Mod = Stack.pop_back_val(); 934 935 bool AnyChildren = false; 936 937 // Visit the submodules of this module. 938 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(), 939 SubEnd = Mod->submodule_end(); 940 Sub != SubEnd; ++Sub) { 941 // Skip explicit children; they need to be explicitly imported to be 942 // linked against. 943 if ((*Sub)->IsExplicit) 944 continue; 945 946 if (Visited.insert(*Sub)) { 947 Stack.push_back(*Sub); 948 AnyChildren = true; 949 } 950 } 951 952 // We didn't find any children, so add this module to the list of 953 // modules to link against. 954 if (!AnyChildren) { 955 LinkModules.insert(Mod); 956 } 957 } 958 959 // Add link options for all of the imported modules in reverse topological 960 // order. We don't do anything to try to order import link flags with respect 961 // to linker options inserted by things like #pragma comment(). 962 SmallVector<llvm::Value *, 16> MetadataArgs; 963 Visited.clear(); 964 for (llvm::SetVector<clang::Module *>::iterator M = LinkModules.begin(), 965 MEnd = LinkModules.end(); 966 M != MEnd; ++M) { 967 if (Visited.insert(*M)) 968 addLinkOptionsPostorder(*this, *M, MetadataArgs, Visited); 969 } 970 std::reverse(MetadataArgs.begin(), MetadataArgs.end()); 971 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end()); 972 973 // Add the linker options metadata flag. 974 getModule().addModuleFlag(llvm::Module::AppendUnique, "Linker Options", 975 llvm::MDNode::get(getLLVMContext(), 976 LinkerOptionsMetadata)); 977 } 978 979 void CodeGenModule::EmitDeferred() { 980 // Emit code for any potentially referenced deferred decls. Since a 981 // previously unused static decl may become used during the generation of code 982 // for a static function, iterate until no changes are made. 983 984 while (true) { 985 if (!DeferredVTables.empty()) { 986 EmitDeferredVTables(); 987 988 // Emitting a v-table doesn't directly cause more v-tables to 989 // become deferred, although it can cause functions to be 990 // emitted that then need those v-tables. 991 assert(DeferredVTables.empty()); 992 } 993 994 // Stop if we're out of both deferred v-tables and deferred declarations. 995 if (DeferredDeclsToEmit.empty()) break; 996 997 GlobalDecl D = DeferredDeclsToEmit.back(); 998 DeferredDeclsToEmit.pop_back(); 999 1000 // Check to see if we've already emitted this. This is necessary 1001 // for a couple of reasons: first, decls can end up in the 1002 // deferred-decls queue multiple times, and second, decls can end 1003 // up with definitions in unusual ways (e.g. by an extern inline 1004 // function acquiring a strong function redefinition). Just 1005 // ignore these cases. 1006 // 1007 // TODO: That said, looking this up multiple times is very wasteful. 1008 StringRef Name = getMangledName(D); 1009 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 1010 assert(CGRef && "Deferred decl wasn't referenced?"); 1011 1012 if (!CGRef->isDeclaration()) 1013 continue; 1014 1015 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 1016 // purposes an alias counts as a definition. 1017 if (isa<llvm::GlobalAlias>(CGRef)) 1018 continue; 1019 1020 // Otherwise, emit the definition and move on to the next one. 1021 EmitGlobalDefinition(D); 1022 } 1023 } 1024 1025 void CodeGenModule::EmitGlobalAnnotations() { 1026 if (Annotations.empty()) 1027 return; 1028 1029 // Create a new global variable for the ConstantStruct in the Module. 1030 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 1031 Annotations[0]->getType(), Annotations.size()), Annotations); 1032 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), 1033 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, 1034 "llvm.global.annotations"); 1035 gv->setSection(AnnotationSection); 1036 } 1037 1038 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) { 1039 llvm::Constant *&AStr = AnnotationStrings[Str]; 1040 if (AStr) 1041 return AStr; 1042 1043 // Not found yet, create a new global. 1044 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); 1045 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), 1046 true, llvm::GlobalValue::PrivateLinkage, s, ".str"); 1047 gv->setSection(AnnotationSection); 1048 gv->setUnnamedAddr(true); 1049 AStr = gv; 1050 return gv; 1051 } 1052 1053 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 1054 SourceManager &SM = getContext().getSourceManager(); 1055 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 1056 if (PLoc.isValid()) 1057 return EmitAnnotationString(PLoc.getFilename()); 1058 return EmitAnnotationString(SM.getBufferName(Loc)); 1059 } 1060 1061 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 1062 SourceManager &SM = getContext().getSourceManager(); 1063 PresumedLoc PLoc = SM.getPresumedLoc(L); 1064 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 1065 SM.getExpansionLineNumber(L); 1066 return llvm::ConstantInt::get(Int32Ty, LineNo); 1067 } 1068 1069 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 1070 const AnnotateAttr *AA, 1071 SourceLocation L) { 1072 // Get the globals for file name, annotation, and the line number. 1073 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 1074 *UnitGV = EmitAnnotationUnit(L), 1075 *LineNoCst = EmitAnnotationLineNo(L); 1076 1077 // Create the ConstantStruct for the global annotation. 1078 llvm::Constant *Fields[4] = { 1079 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 1080 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 1081 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 1082 LineNoCst 1083 }; 1084 return llvm::ConstantStruct::getAnon(Fields); 1085 } 1086 1087 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 1088 llvm::GlobalValue *GV) { 1089 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 1090 // Get the struct elements for these annotations. 1091 for (specific_attr_iterator<AnnotateAttr> 1092 ai = D->specific_attr_begin<AnnotateAttr>(), 1093 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) 1094 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); 1095 } 1096 1097 bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 1098 // Never defer when EmitAllDecls is specified. 1099 if (LangOpts.EmitAllDecls) 1100 return false; 1101 1102 return !getContext().DeclMustBeEmitted(Global); 1103 } 1104 1105 llvm::Constant *CodeGenModule::GetAddrOfUuidDescriptor( 1106 const CXXUuidofExpr* E) { 1107 // Sema has verified that IIDSource has a __declspec(uuid()), and that its 1108 // well-formed. 1109 StringRef Uuid = E->getUuidAsStringRef(Context); 1110 std::string Name = "_GUID_" + Uuid.lower(); 1111 std::replace(Name.begin(), Name.end(), '-', '_'); 1112 1113 // Look for an existing global. 1114 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name)) 1115 return GV; 1116 1117 llvm::Constant *Init = EmitUuidofInitializer(Uuid, E->getType()); 1118 assert(Init && "failed to initialize as constant"); 1119 1120 llvm::GlobalVariable *GV = new llvm::GlobalVariable( 1121 getModule(), Init->getType(), 1122 /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name); 1123 return GV; 1124 } 1125 1126 llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 1127 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 1128 assert(AA && "No alias?"); 1129 1130 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 1131 1132 // See if there is already something with the target's name in the module. 1133 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 1134 if (Entry) { 1135 unsigned AS = getContext().getTargetAddressSpace(VD->getType()); 1136 return llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS)); 1137 } 1138 1139 llvm::Constant *Aliasee; 1140 if (isa<llvm::FunctionType>(DeclTy)) 1141 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, 1142 GlobalDecl(cast<FunctionDecl>(VD)), 1143 /*ForVTable=*/false); 1144 else 1145 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1146 llvm::PointerType::getUnqual(DeclTy), 0); 1147 1148 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 1149 F->setLinkage(llvm::Function::ExternalWeakLinkage); 1150 WeakRefReferences.insert(F); 1151 1152 return Aliasee; 1153 } 1154 1155 void CodeGenModule::EmitGlobal(GlobalDecl GD) { 1156 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 1157 1158 // Weak references don't produce any output by themselves. 1159 if (Global->hasAttr<WeakRefAttr>()) 1160 return; 1161 1162 // If this is an alias definition (which otherwise looks like a declaration) 1163 // emit it now. 1164 if (Global->hasAttr<AliasAttr>()) 1165 return EmitAliasDefinition(GD); 1166 1167 // If this is CUDA, be selective about which declarations we emit. 1168 if (LangOpts.CUDA) { 1169 if (CodeGenOpts.CUDAIsDevice) { 1170 if (!Global->hasAttr<CUDADeviceAttr>() && 1171 !Global->hasAttr<CUDAGlobalAttr>() && 1172 !Global->hasAttr<CUDAConstantAttr>() && 1173 !Global->hasAttr<CUDASharedAttr>()) 1174 return; 1175 } else { 1176 if (!Global->hasAttr<CUDAHostAttr>() && ( 1177 Global->hasAttr<CUDADeviceAttr>() || 1178 Global->hasAttr<CUDAConstantAttr>() || 1179 Global->hasAttr<CUDASharedAttr>())) 1180 return; 1181 } 1182 } 1183 1184 // Ignore declarations, they will be emitted on their first use. 1185 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 1186 // Forward declarations are emitted lazily on first use. 1187 if (!FD->doesThisDeclarationHaveABody()) { 1188 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 1189 return; 1190 1191 const FunctionDecl *InlineDefinition = 0; 1192 FD->getBody(InlineDefinition); 1193 1194 StringRef MangledName = getMangledName(GD); 1195 DeferredDecls.erase(MangledName); 1196 EmitGlobalDefinition(InlineDefinition); 1197 return; 1198 } 1199 } else { 1200 const VarDecl *VD = cast<VarDecl>(Global); 1201 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 1202 1203 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 1204 return; 1205 } 1206 1207 // Defer code generation when possible if this is a static definition, inline 1208 // function etc. These we only want to emit if they are used. 1209 if (!MayDeferGeneration(Global)) { 1210 // Emit the definition if it can't be deferred. 1211 EmitGlobalDefinition(GD); 1212 return; 1213 } 1214 1215 // If we're deferring emission of a C++ variable with an 1216 // initializer, remember the order in which it appeared in the file. 1217 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) && 1218 cast<VarDecl>(Global)->hasInit()) { 1219 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 1220 CXXGlobalInits.push_back(0); 1221 } 1222 1223 // If the value has already been used, add it directly to the 1224 // DeferredDeclsToEmit list. 1225 StringRef MangledName = getMangledName(GD); 1226 if (GetGlobalValue(MangledName)) 1227 DeferredDeclsToEmit.push_back(GD); 1228 else { 1229 // Otherwise, remember that we saw a deferred decl with this name. The 1230 // first use of the mangled name will cause it to move into 1231 // DeferredDeclsToEmit. 1232 DeferredDecls[MangledName] = GD; 1233 } 1234 } 1235 1236 namespace { 1237 struct FunctionIsDirectlyRecursive : 1238 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> { 1239 const StringRef Name; 1240 const Builtin::Context &BI; 1241 bool Result; 1242 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) : 1243 Name(N), BI(C), Result(false) { 1244 } 1245 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; 1246 1247 bool TraverseCallExpr(CallExpr *E) { 1248 const FunctionDecl *FD = E->getDirectCallee(); 1249 if (!FD) 1250 return true; 1251 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1252 if (Attr && Name == Attr->getLabel()) { 1253 Result = true; 1254 return false; 1255 } 1256 unsigned BuiltinID = FD->getBuiltinID(); 1257 if (!BuiltinID) 1258 return true; 1259 StringRef BuiltinName = BI.GetName(BuiltinID); 1260 if (BuiltinName.startswith("__builtin_") && 1261 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { 1262 Result = true; 1263 return false; 1264 } 1265 return true; 1266 } 1267 }; 1268 } 1269 1270 // isTriviallyRecursive - Check if this function calls another 1271 // decl that, because of the asm attribute or the other decl being a builtin, 1272 // ends up pointing to itself. 1273 bool 1274 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { 1275 StringRef Name; 1276 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { 1277 // asm labels are a special kind of mangling we have to support. 1278 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1279 if (!Attr) 1280 return false; 1281 Name = Attr->getLabel(); 1282 } else { 1283 Name = FD->getName(); 1284 } 1285 1286 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); 1287 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD)); 1288 return Walker.Result; 1289 } 1290 1291 bool 1292 CodeGenModule::shouldEmitFunction(GlobalDecl GD) { 1293 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage) 1294 return true; 1295 const FunctionDecl *F = cast<FunctionDecl>(GD.getDecl()); 1296 if (CodeGenOpts.OptimizationLevel == 0 && 1297 !F->hasAttr<AlwaysInlineAttr>() && !F->hasAttr<ForceInlineAttr>()) 1298 return false; 1299 // PR9614. Avoid cases where the source code is lying to us. An available 1300 // externally function should have an equivalent function somewhere else, 1301 // but a function that calls itself is clearly not equivalent to the real 1302 // implementation. 1303 // This happens in glibc's btowc and in some configure checks. 1304 return !isTriviallyRecursive(F); 1305 } 1306 1307 /// If the type for the method's class was generated by 1308 /// CGDebugInfo::createContextChain(), the cache contains only a 1309 /// limited DIType without any declarations. Since EmitFunctionStart() 1310 /// needs to find the canonical declaration for each method, we need 1311 /// to construct the complete type prior to emitting the method. 1312 void CodeGenModule::CompleteDIClassType(const CXXMethodDecl* D) { 1313 if (!D->isInstance()) 1314 return; 1315 1316 if (CGDebugInfo *DI = getModuleDebugInfo()) 1317 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) { 1318 const PointerType *ThisPtr = 1319 cast<PointerType>(D->getThisType(getContext())); 1320 DI->getOrCreateRecordType(ThisPtr->getPointeeType(), D->getLocation()); 1321 } 1322 } 1323 1324 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 1325 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1326 1327 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 1328 Context.getSourceManager(), 1329 "Generating code for declaration"); 1330 1331 if (isa<FunctionDecl>(D)) { 1332 // At -O0, don't generate IR for functions with available_externally 1333 // linkage. 1334 if (!shouldEmitFunction(GD)) 1335 return; 1336 1337 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 1338 CompleteDIClassType(Method); 1339 // Make sure to emit the definition(s) before we emit the thunks. 1340 // This is necessary for the generation of certain thunks. 1341 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 1342 EmitCXXConstructor(CD, GD.getCtorType()); 1343 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 1344 EmitCXXDestructor(DD, GD.getDtorType()); 1345 else 1346 EmitGlobalFunctionDefinition(GD); 1347 1348 if (Method->isVirtual()) 1349 getVTables().EmitThunks(GD); 1350 1351 return; 1352 } 1353 1354 return EmitGlobalFunctionDefinition(GD); 1355 } 1356 1357 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 1358 return EmitGlobalVarDefinition(VD); 1359 1360 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 1361 } 1362 1363 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the 1364 /// module, create and return an llvm Function with the specified type. If there 1365 /// is something in the module with the specified name, return it potentially 1366 /// bitcasted to the right type. 1367 /// 1368 /// If D is non-null, it specifies a decl that correspond to this. This is used 1369 /// to set the attributes on the function when it is first created. 1370 llvm::Constant * 1371 CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 1372 llvm::Type *Ty, 1373 GlobalDecl GD, bool ForVTable, 1374 llvm::AttributeSet ExtraAttrs) { 1375 const Decl *D = GD.getDecl(); 1376 1377 // Lookup the entry, lazily creating it if necessary. 1378 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1379 if (Entry) { 1380 if (WeakRefReferences.erase(Entry)) { 1381 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D); 1382 if (FD && !FD->hasAttr<WeakAttr>()) 1383 Entry->setLinkage(llvm::Function::ExternalLinkage); 1384 } 1385 1386 if (Entry->getType()->getElementType() == Ty) 1387 return Entry; 1388 1389 // Make sure the result is of the correct type. 1390 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 1391 } 1392 1393 // All MSVC dtors other than the base dtor are linkonce_odr and delegate to 1394 // each other bottoming out with the base dtor. Therefore we emit non-base 1395 // dtors on usage, even if there is no dtor definition in the TU. 1396 if (D && isa<CXXDestructorDecl>(D) && 1397 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D), 1398 GD.getDtorType())) 1399 DeferredDeclsToEmit.push_back(GD); 1400 1401 // This function doesn't have a complete type (for example, the return 1402 // type is an incomplete struct). Use a fake type instead, and make 1403 // sure not to try to set attributes. 1404 bool IsIncompleteFunction = false; 1405 1406 llvm::FunctionType *FTy; 1407 if (isa<llvm::FunctionType>(Ty)) { 1408 FTy = cast<llvm::FunctionType>(Ty); 1409 } else { 1410 FTy = llvm::FunctionType::get(VoidTy, false); 1411 IsIncompleteFunction = true; 1412 } 1413 1414 llvm::Function *F = llvm::Function::Create(FTy, 1415 llvm::Function::ExternalLinkage, 1416 MangledName, &getModule()); 1417 assert(F->getName() == MangledName && "name was uniqued!"); 1418 if (D) 1419 SetFunctionAttributes(GD, F, IsIncompleteFunction); 1420 if (ExtraAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) { 1421 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeSet::FunctionIndex); 1422 F->addAttributes(llvm::AttributeSet::FunctionIndex, 1423 llvm::AttributeSet::get(VMContext, 1424 llvm::AttributeSet::FunctionIndex, 1425 B)); 1426 } 1427 1428 // This is the first use or definition of a mangled name. If there is a 1429 // deferred decl with this name, remember that we need to emit it at the end 1430 // of the file. 1431 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1432 if (DDI != DeferredDecls.end()) { 1433 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1434 // list, and remove it from DeferredDecls (since we don't need it anymore). 1435 DeferredDeclsToEmit.push_back(DDI->second); 1436 DeferredDecls.erase(DDI); 1437 1438 // Otherwise, if this is a sized deallocation function, emit a weak definition 1439 // for it at the end of the translation unit. 1440 } else if (D && cast<FunctionDecl>(D) 1441 ->getCorrespondingUnsizedGlobalDeallocationFunction()) { 1442 DeferredDeclsToEmit.push_back(GD); 1443 1444 // Otherwise, there are cases we have to worry about where we're 1445 // using a declaration for which we must emit a definition but where 1446 // we might not find a top-level definition: 1447 // - member functions defined inline in their classes 1448 // - friend functions defined inline in some class 1449 // - special member functions with implicit definitions 1450 // If we ever change our AST traversal to walk into class methods, 1451 // this will be unnecessary. 1452 // 1453 // We also don't emit a definition for a function if it's going to be an entry 1454 // in a vtable, unless it's already marked as used. 1455 } else if (getLangOpts().CPlusPlus && D) { 1456 // Look for a declaration that's lexically in a record. 1457 const FunctionDecl *FD = cast<FunctionDecl>(D); 1458 FD = FD->getMostRecentDecl(); 1459 do { 1460 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 1461 if (FD->isImplicit() && !ForVTable) { 1462 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 1463 DeferredDeclsToEmit.push_back(GD.getWithDecl(FD)); 1464 break; 1465 } else if (FD->doesThisDeclarationHaveABody()) { 1466 DeferredDeclsToEmit.push_back(GD.getWithDecl(FD)); 1467 break; 1468 } 1469 } 1470 FD = FD->getPreviousDecl(); 1471 } while (FD); 1472 } 1473 1474 // Make sure the result is of the requested type. 1475 if (!IsIncompleteFunction) { 1476 assert(F->getType()->getElementType() == Ty); 1477 return F; 1478 } 1479 1480 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1481 return llvm::ConstantExpr::getBitCast(F, PTy); 1482 } 1483 1484 /// GetAddrOfFunction - Return the address of the given function. If Ty is 1485 /// non-null, then this function will use the specified type if it has to 1486 /// create it (this occurs when we see a definition of the function). 1487 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 1488 llvm::Type *Ty, 1489 bool ForVTable) { 1490 // If there was no specific requested type, just convert it now. 1491 if (!Ty) 1492 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 1493 1494 StringRef MangledName = getMangledName(GD); 1495 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 1496 } 1497 1498 /// CreateRuntimeFunction - Create a new runtime function with the specified 1499 /// type and name. 1500 llvm::Constant * 1501 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 1502 StringRef Name, 1503 llvm::AttributeSet ExtraAttrs) { 1504 llvm::Constant *C 1505 = GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 1506 ExtraAttrs); 1507 if (llvm::Function *F = dyn_cast<llvm::Function>(C)) 1508 if (F->empty()) 1509 F->setCallingConv(getRuntimeCC()); 1510 return C; 1511 } 1512 1513 /// isTypeConstant - Determine whether an object of this type can be emitted 1514 /// as a constant. 1515 /// 1516 /// If ExcludeCtor is true, the duration when the object's constructor runs 1517 /// will not be considered. The caller will need to verify that the object is 1518 /// not written to during its construction. 1519 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) { 1520 if (!Ty.isConstant(Context) && !Ty->isReferenceType()) 1521 return false; 1522 1523 if (Context.getLangOpts().CPlusPlus) { 1524 if (const CXXRecordDecl *Record 1525 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl()) 1526 return ExcludeCtor && !Record->hasMutableFields() && 1527 Record->hasTrivialDestructor(); 1528 } 1529 1530 return true; 1531 } 1532 1533 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1534 /// create and return an llvm GlobalVariable with the specified type. If there 1535 /// is something in the module with the specified name, return it potentially 1536 /// bitcasted to the right type. 1537 /// 1538 /// If D is non-null, it specifies a decl that correspond to this. This is used 1539 /// to set the attributes on the global when it is first created. 1540 llvm::Constant * 1541 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1542 llvm::PointerType *Ty, 1543 const VarDecl *D, 1544 bool UnnamedAddr) { 1545 // Lookup the entry, lazily creating it if necessary. 1546 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1547 if (Entry) { 1548 if (WeakRefReferences.erase(Entry)) { 1549 if (D && !D->hasAttr<WeakAttr>()) 1550 Entry->setLinkage(llvm::Function::ExternalLinkage); 1551 } 1552 1553 if (UnnamedAddr) 1554 Entry->setUnnamedAddr(true); 1555 1556 if (Entry->getType() == Ty) 1557 return Entry; 1558 1559 // Make sure the result is of the correct type. 1560 if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace()) 1561 return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty); 1562 1563 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1564 } 1565 1566 // This is the first use or definition of a mangled name. If there is a 1567 // deferred decl with this name, remember that we need to emit it at the end 1568 // of the file. 1569 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1570 if (DDI != DeferredDecls.end()) { 1571 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1572 // list, and remove it from DeferredDecls (since we don't need it anymore). 1573 DeferredDeclsToEmit.push_back(DDI->second); 1574 DeferredDecls.erase(DDI); 1575 } 1576 1577 unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace()); 1578 llvm::GlobalVariable *GV = 1579 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1580 llvm::GlobalValue::ExternalLinkage, 1581 0, MangledName, 0, 1582 llvm::GlobalVariable::NotThreadLocal, AddrSpace); 1583 1584 // Handle things which are present even on external declarations. 1585 if (D) { 1586 // FIXME: This code is overly simple and should be merged with other global 1587 // handling. 1588 GV->setConstant(isTypeConstant(D->getType(), false)); 1589 1590 // Set linkage and visibility in case we never see a definition. 1591 LinkageInfo LV = D->getLinkageAndVisibility(); 1592 if (LV.getLinkage() != ExternalLinkage) { 1593 // Don't set internal linkage on declarations. 1594 } else { 1595 if (D->hasAttr<DLLImportAttr>()) 1596 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1597 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1598 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1599 1600 // Set visibility on a declaration only if it's explicit. 1601 if (LV.isVisibilityExplicit()) 1602 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 1603 } 1604 1605 if (D->getTLSKind()) { 1606 if (D->getTLSKind() == VarDecl::TLS_Dynamic) 1607 CXXThreadLocals.push_back(std::make_pair(D, GV)); 1608 setTLSMode(GV, *D); 1609 } 1610 1611 // If required by the ABI, treat declarations of static data members with 1612 // inline initializers as definitions. 1613 if (getCXXABI().isInlineInitializedStaticDataMemberLinkOnce() && 1614 D->isStaticDataMember() && D->hasInit() && 1615 !D->isThisDeclarationADefinition()) 1616 EmitGlobalVarDefinition(D); 1617 } 1618 1619 if (AddrSpace != Ty->getAddressSpace()) 1620 return llvm::ConstantExpr::getAddrSpaceCast(GV, Ty); 1621 1622 return GV; 1623 } 1624 1625 1626 llvm::GlobalVariable * 1627 CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1628 llvm::Type *Ty, 1629 llvm::GlobalValue::LinkageTypes Linkage) { 1630 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1631 llvm::GlobalVariable *OldGV = 0; 1632 1633 1634 if (GV) { 1635 // Check if the variable has the right type. 1636 if (GV->getType()->getElementType() == Ty) 1637 return GV; 1638 1639 // Because C++ name mangling, the only way we can end up with an already 1640 // existing global with the same name is if it has been declared extern "C". 1641 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1642 OldGV = GV; 1643 } 1644 1645 // Create a new variable. 1646 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1647 Linkage, 0, Name); 1648 1649 if (OldGV) { 1650 // Replace occurrences of the old variable if needed. 1651 GV->takeName(OldGV); 1652 1653 if (!OldGV->use_empty()) { 1654 llvm::Constant *NewPtrForOldDecl = 1655 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1656 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1657 } 1658 1659 OldGV->eraseFromParent(); 1660 } 1661 1662 return GV; 1663 } 1664 1665 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1666 /// given global variable. If Ty is non-null and if the global doesn't exist, 1667 /// then it will be created with the specified type instead of whatever the 1668 /// normal requested type would be. 1669 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1670 llvm::Type *Ty) { 1671 assert(D->hasGlobalStorage() && "Not a global variable"); 1672 QualType ASTTy = D->getType(); 1673 if (Ty == 0) 1674 Ty = getTypes().ConvertTypeForMem(ASTTy); 1675 1676 llvm::PointerType *PTy = 1677 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1678 1679 StringRef MangledName = getMangledName(D); 1680 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1681 } 1682 1683 /// CreateRuntimeVariable - Create a new runtime global variable with the 1684 /// specified type and name. 1685 llvm::Constant * 1686 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1687 StringRef Name) { 1688 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1689 true); 1690 } 1691 1692 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1693 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1694 1695 if (MayDeferGeneration(D)) { 1696 // If we have not seen a reference to this variable yet, place it 1697 // into the deferred declarations table to be emitted if needed 1698 // later. 1699 StringRef MangledName = getMangledName(D); 1700 if (!GetGlobalValue(MangledName)) { 1701 DeferredDecls[MangledName] = D; 1702 return; 1703 } 1704 } 1705 1706 // The tentative definition is the only definition. 1707 EmitGlobalVarDefinition(D); 1708 } 1709 1710 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1711 return Context.toCharUnitsFromBits( 1712 TheDataLayout.getTypeStoreSizeInBits(Ty)); 1713 } 1714 1715 unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D, 1716 unsigned AddrSpace) { 1717 if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) { 1718 if (D->hasAttr<CUDAConstantAttr>()) 1719 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_constant); 1720 else if (D->hasAttr<CUDASharedAttr>()) 1721 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_shared); 1722 else 1723 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_device); 1724 } 1725 1726 return AddrSpace; 1727 } 1728 1729 template<typename SomeDecl> 1730 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D, 1731 llvm::GlobalValue *GV) { 1732 if (!getLangOpts().CPlusPlus) 1733 return; 1734 1735 // Must have 'used' attribute, or else inline assembly can't rely on 1736 // the name existing. 1737 if (!D->template hasAttr<UsedAttr>()) 1738 return; 1739 1740 // Must have internal linkage and an ordinary name. 1741 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage) 1742 return; 1743 1744 // Must be in an extern "C" context. Entities declared directly within 1745 // a record are not extern "C" even if the record is in such a context. 1746 const SomeDecl *First = D->getFirstDecl(); 1747 if (First->getDeclContext()->isRecord() || !First->isInExternCContext()) 1748 return; 1749 1750 // OK, this is an internal linkage entity inside an extern "C" linkage 1751 // specification. Make a note of that so we can give it the "expected" 1752 // mangled name if nothing else is using that name. 1753 std::pair<StaticExternCMap::iterator, bool> R = 1754 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV)); 1755 1756 // If we have multiple internal linkage entities with the same name 1757 // in extern "C" regions, none of them gets that name. 1758 if (!R.second) 1759 R.first->second = 0; 1760 } 1761 1762 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1763 llvm::Constant *Init = 0; 1764 QualType ASTTy = D->getType(); 1765 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 1766 bool NeedsGlobalCtor = false; 1767 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor(); 1768 1769 const VarDecl *InitDecl; 1770 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 1771 1772 if (!InitExpr) { 1773 // This is a tentative definition; tentative definitions are 1774 // implicitly initialized with { 0 }. 1775 // 1776 // Note that tentative definitions are only emitted at the end of 1777 // a translation unit, so they should never have incomplete 1778 // type. In addition, EmitTentativeDefinition makes sure that we 1779 // never attempt to emit a tentative definition if a real one 1780 // exists. A use may still exists, however, so we still may need 1781 // to do a RAUW. 1782 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1783 Init = EmitNullConstant(D->getType()); 1784 } else { 1785 initializedGlobalDecl = GlobalDecl(D); 1786 Init = EmitConstantInit(*InitDecl); 1787 1788 if (!Init) { 1789 QualType T = InitExpr->getType(); 1790 if (D->getType()->isReferenceType()) 1791 T = D->getType(); 1792 1793 if (getLangOpts().CPlusPlus) { 1794 Init = EmitNullConstant(T); 1795 NeedsGlobalCtor = true; 1796 } else { 1797 ErrorUnsupported(D, "static initializer"); 1798 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1799 } 1800 } else { 1801 // We don't need an initializer, so remove the entry for the delayed 1802 // initializer position (just in case this entry was delayed) if we 1803 // also don't need to register a destructor. 1804 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor) 1805 DelayedCXXInitPosition.erase(D); 1806 } 1807 } 1808 1809 llvm::Type* InitType = Init->getType(); 1810 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1811 1812 // Strip off a bitcast if we got one back. 1813 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1814 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1815 CE->getOpcode() == llvm::Instruction::AddrSpaceCast || 1816 // All zero index gep. 1817 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1818 Entry = CE->getOperand(0); 1819 } 1820 1821 // Entry is now either a Function or GlobalVariable. 1822 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1823 1824 // We have a definition after a declaration with the wrong type. 1825 // We must make a new GlobalVariable* and update everything that used OldGV 1826 // (a declaration or tentative definition) with the new GlobalVariable* 1827 // (which will be a definition). 1828 // 1829 // This happens if there is a prototype for a global (e.g. 1830 // "extern int x[];") and then a definition of a different type (e.g. 1831 // "int x[10];"). This also happens when an initializer has a different type 1832 // from the type of the global (this happens with unions). 1833 if (GV == 0 || 1834 GV->getType()->getElementType() != InitType || 1835 GV->getType()->getAddressSpace() != 1836 GetGlobalVarAddressSpace(D, getContext().getTargetAddressSpace(ASTTy))) { 1837 1838 // Move the old entry aside so that we'll create a new one. 1839 Entry->setName(StringRef()); 1840 1841 // Make a new global with the correct type, this is now guaranteed to work. 1842 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1843 1844 // Replace all uses of the old global with the new global 1845 llvm::Constant *NewPtrForOldDecl = 1846 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1847 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1848 1849 // Erase the old global, since it is no longer used. 1850 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1851 } 1852 1853 MaybeHandleStaticInExternC(D, GV); 1854 1855 if (D->hasAttr<AnnotateAttr>()) 1856 AddGlobalAnnotations(D, GV); 1857 1858 GV->setInitializer(Init); 1859 1860 // If it is safe to mark the global 'constant', do so now. 1861 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor && 1862 isTypeConstant(D->getType(), true)); 1863 1864 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1865 1866 // Set the llvm linkage type as appropriate. 1867 llvm::GlobalValue::LinkageTypes Linkage = 1868 GetLLVMLinkageVarDefinition(D, GV->isConstant()); 1869 GV->setLinkage(Linkage); 1870 1871 // If required by the ABI, give definitions of static data members with inline 1872 // initializers linkonce_odr linkage. 1873 if (getCXXABI().isInlineInitializedStaticDataMemberLinkOnce() && 1874 D->isStaticDataMember() && InitExpr && 1875 !InitDecl->isThisDeclarationADefinition()) 1876 GV->setLinkage(llvm::GlobalVariable::LinkOnceODRLinkage); 1877 1878 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1879 // common vars aren't constant even if declared const. 1880 GV->setConstant(false); 1881 1882 SetCommonAttributes(D, GV); 1883 1884 // Emit the initializer function if necessary. 1885 if (NeedsGlobalCtor || NeedsGlobalDtor) 1886 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); 1887 1888 // If we are compiling with ASan, add metadata indicating dynamically 1889 // initialized globals. 1890 if (SanOpts.Address && NeedsGlobalCtor) { 1891 llvm::Module &M = getModule(); 1892 1893 llvm::NamedMDNode *DynamicInitializers = 1894 M.getOrInsertNamedMetadata("llvm.asan.dynamically_initialized_globals"); 1895 llvm::Value *GlobalToAdd[] = { GV }; 1896 llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalToAdd); 1897 DynamicInitializers->addOperand(ThisGlobal); 1898 } 1899 1900 // Emit global variable debug information. 1901 if (CGDebugInfo *DI = getModuleDebugInfo()) 1902 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) 1903 DI->EmitGlobalVariable(GV, D); 1904 } 1905 1906 llvm::GlobalValue::LinkageTypes 1907 CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, bool isConstant) { 1908 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1909 if (Linkage == GVA_Internal) 1910 return llvm::Function::InternalLinkage; 1911 else if (D->hasAttr<DLLImportAttr>()) 1912 return llvm::Function::DLLImportLinkage; 1913 else if (D->hasAttr<DLLExportAttr>()) 1914 return llvm::Function::DLLExportLinkage; 1915 else if (D->hasAttr<SelectAnyAttr>()) { 1916 // selectany symbols are externally visible, so use weak instead of 1917 // linkonce. MSVC optimizes away references to const selectany globals, so 1918 // all definitions should be the same and ODR linkage should be used. 1919 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx 1920 return llvm::GlobalVariable::WeakODRLinkage; 1921 } else if (D->hasAttr<WeakAttr>()) { 1922 if (isConstant) 1923 return llvm::GlobalVariable::WeakODRLinkage; 1924 else 1925 return llvm::GlobalVariable::WeakAnyLinkage; 1926 } else if (Linkage == GVA_TemplateInstantiation || 1927 Linkage == GVA_ExplicitTemplateInstantiation) 1928 return llvm::GlobalVariable::WeakODRLinkage; 1929 else if (!getLangOpts().CPlusPlus && 1930 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1931 D->getAttr<CommonAttr>()) && 1932 !D->hasExternalStorage() && !D->getInit() && 1933 !D->getAttr<SectionAttr>() && !D->getTLSKind() && 1934 !D->getAttr<WeakImportAttr>()) { 1935 // Thread local vars aren't considered common linkage. 1936 return llvm::GlobalVariable::CommonLinkage; 1937 } else if (D->getTLSKind() == VarDecl::TLS_Dynamic && 1938 getTarget().getTriple().isMacOSX()) 1939 // On Darwin, the backing variable for a C++11 thread_local variable always 1940 // has internal linkage; all accesses should just be calls to the 1941 // Itanium-specified entry point, which has the normal linkage of the 1942 // variable. 1943 return llvm::GlobalValue::InternalLinkage; 1944 return llvm::GlobalVariable::ExternalLinkage; 1945 } 1946 1947 /// Replace the uses of a function that was declared with a non-proto type. 1948 /// We want to silently drop extra arguments from call sites 1949 static void replaceUsesOfNonProtoConstant(llvm::Constant *old, 1950 llvm::Function *newFn) { 1951 // Fast path. 1952 if (old->use_empty()) return; 1953 1954 llvm::Type *newRetTy = newFn->getReturnType(); 1955 SmallVector<llvm::Value*, 4> newArgs; 1956 1957 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end(); 1958 ui != ue; ) { 1959 llvm::Value::use_iterator use = ui++; // Increment before the use is erased. 1960 llvm::User *user = *use; 1961 1962 // Recognize and replace uses of bitcasts. Most calls to 1963 // unprototyped functions will use bitcasts. 1964 if (llvm::ConstantExpr *bitcast = dyn_cast<llvm::ConstantExpr>(user)) { 1965 if (bitcast->getOpcode() == llvm::Instruction::BitCast) 1966 replaceUsesOfNonProtoConstant(bitcast, newFn); 1967 continue; 1968 } 1969 1970 // Recognize calls to the function. 1971 llvm::CallSite callSite(user); 1972 if (!callSite) continue; 1973 if (!callSite.isCallee(use)) continue; 1974 1975 // If the return types don't match exactly, then we can't 1976 // transform this call unless it's dead. 1977 if (callSite->getType() != newRetTy && !callSite->use_empty()) 1978 continue; 1979 1980 // Get the call site's attribute list. 1981 SmallVector<llvm::AttributeSet, 8> newAttrs; 1982 llvm::AttributeSet oldAttrs = callSite.getAttributes(); 1983 1984 // Collect any return attributes from the call. 1985 if (oldAttrs.hasAttributes(llvm::AttributeSet::ReturnIndex)) 1986 newAttrs.push_back( 1987 llvm::AttributeSet::get(newFn->getContext(), 1988 oldAttrs.getRetAttributes())); 1989 1990 // If the function was passed too few arguments, don't transform. 1991 unsigned newNumArgs = newFn->arg_size(); 1992 if (callSite.arg_size() < newNumArgs) continue; 1993 1994 // If extra arguments were passed, we silently drop them. 1995 // If any of the types mismatch, we don't transform. 1996 unsigned argNo = 0; 1997 bool dontTransform = false; 1998 for (llvm::Function::arg_iterator ai = newFn->arg_begin(), 1999 ae = newFn->arg_end(); ai != ae; ++ai, ++argNo) { 2000 if (callSite.getArgument(argNo)->getType() != ai->getType()) { 2001 dontTransform = true; 2002 break; 2003 } 2004 2005 // Add any parameter attributes. 2006 if (oldAttrs.hasAttributes(argNo + 1)) 2007 newAttrs. 2008 push_back(llvm:: 2009 AttributeSet::get(newFn->getContext(), 2010 oldAttrs.getParamAttributes(argNo + 1))); 2011 } 2012 if (dontTransform) 2013 continue; 2014 2015 if (oldAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) 2016 newAttrs.push_back(llvm::AttributeSet::get(newFn->getContext(), 2017 oldAttrs.getFnAttributes())); 2018 2019 // Okay, we can transform this. Create the new call instruction and copy 2020 // over the required information. 2021 newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo); 2022 2023 llvm::CallSite newCall; 2024 if (callSite.isCall()) { 2025 newCall = llvm::CallInst::Create(newFn, newArgs, "", 2026 callSite.getInstruction()); 2027 } else { 2028 llvm::InvokeInst *oldInvoke = 2029 cast<llvm::InvokeInst>(callSite.getInstruction()); 2030 newCall = llvm::InvokeInst::Create(newFn, 2031 oldInvoke->getNormalDest(), 2032 oldInvoke->getUnwindDest(), 2033 newArgs, "", 2034 callSite.getInstruction()); 2035 } 2036 newArgs.clear(); // for the next iteration 2037 2038 if (!newCall->getType()->isVoidTy()) 2039 newCall->takeName(callSite.getInstruction()); 2040 newCall.setAttributes( 2041 llvm::AttributeSet::get(newFn->getContext(), newAttrs)); 2042 newCall.setCallingConv(callSite.getCallingConv()); 2043 2044 // Finally, remove the old call, replacing any uses with the new one. 2045 if (!callSite->use_empty()) 2046 callSite->replaceAllUsesWith(newCall.getInstruction()); 2047 2048 // Copy debug location attached to CI. 2049 if (!callSite->getDebugLoc().isUnknown()) 2050 newCall->setDebugLoc(callSite->getDebugLoc()); 2051 callSite->eraseFromParent(); 2052 } 2053 } 2054 2055 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 2056 /// implement a function with no prototype, e.g. "int foo() {}". If there are 2057 /// existing call uses of the old function in the module, this adjusts them to 2058 /// call the new function directly. 2059 /// 2060 /// This is not just a cleanup: the always_inline pass requires direct calls to 2061 /// functions to be able to inline them. If there is a bitcast in the way, it 2062 /// won't inline them. Instcombine normally deletes these calls, but it isn't 2063 /// run at -O0. 2064 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 2065 llvm::Function *NewFn) { 2066 // If we're redefining a global as a function, don't transform it. 2067 if (!isa<llvm::Function>(Old)) return; 2068 2069 replaceUsesOfNonProtoConstant(Old, NewFn); 2070 } 2071 2072 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) { 2073 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind(); 2074 // If we have a definition, this might be a deferred decl. If the 2075 // instantiation is explicit, make sure we emit it at the end. 2076 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition) 2077 GetAddrOfGlobalVar(VD); 2078 2079 EmitTopLevelDecl(VD); 2080 } 2081 2082 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 2083 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 2084 2085 // Compute the function info and LLVM type. 2086 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); 2087 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); 2088 2089 // Get or create the prototype for the function. 2090 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 2091 2092 // Strip off a bitcast if we got one back. 2093 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 2094 assert(CE->getOpcode() == llvm::Instruction::BitCast); 2095 Entry = CE->getOperand(0); 2096 } 2097 2098 if (!cast<llvm::GlobalValue>(Entry)->isDeclaration()) { 2099 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name); 2100 return; 2101 } 2102 2103 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 2104 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 2105 2106 // If the types mismatch then we have to rewrite the definition. 2107 assert(OldFn->isDeclaration() && 2108 "Shouldn't replace non-declaration"); 2109 2110 // F is the Function* for the one with the wrong type, we must make a new 2111 // Function* and update everything that used F (a declaration) with the new 2112 // Function* (which will be a definition). 2113 // 2114 // This happens if there is a prototype for a function 2115 // (e.g. "int f()") and then a definition of a different type 2116 // (e.g. "int f(int x)"). Move the old function aside so that it 2117 // doesn't interfere with GetAddrOfFunction. 2118 OldFn->setName(StringRef()); 2119 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 2120 2121 // This might be an implementation of a function without a 2122 // prototype, in which case, try to do special replacement of 2123 // calls which match the new prototype. The really key thing here 2124 // is that we also potentially drop arguments from the call site 2125 // so as to make a direct call, which makes the inliner happier 2126 // and suppresses a number of optimizer warnings (!) about 2127 // dropping arguments. 2128 if (!OldFn->use_empty()) { 2129 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 2130 OldFn->removeDeadConstantUsers(); 2131 } 2132 2133 // Replace uses of F with the Function we will endow with a body. 2134 if (!Entry->use_empty()) { 2135 llvm::Constant *NewPtrForOldDecl = 2136 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 2137 Entry->replaceAllUsesWith(NewPtrForOldDecl); 2138 } 2139 2140 // Ok, delete the old function now, which is dead. 2141 OldFn->eraseFromParent(); 2142 2143 Entry = NewFn; 2144 } 2145 2146 // We need to set linkage and visibility on the function before 2147 // generating code for it because various parts of IR generation 2148 // want to propagate this information down (e.g. to local static 2149 // declarations). 2150 llvm::Function *Fn = cast<llvm::Function>(Entry); 2151 setFunctionLinkage(GD, Fn); 2152 2153 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 2154 setGlobalVisibility(Fn, D); 2155 2156 MaybeHandleStaticInExternC(D, Fn); 2157 2158 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 2159 2160 SetFunctionDefinitionAttributes(D, Fn); 2161 SetLLVMFunctionAttributesForDefinition(D, Fn); 2162 2163 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 2164 AddGlobalCtor(Fn, CA->getPriority()); 2165 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 2166 AddGlobalDtor(Fn, DA->getPriority()); 2167 if (D->hasAttr<AnnotateAttr>()) 2168 AddGlobalAnnotations(D, Fn); 2169 } 2170 2171 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 2172 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 2173 const AliasAttr *AA = D->getAttr<AliasAttr>(); 2174 assert(AA && "Not an alias?"); 2175 2176 StringRef MangledName = getMangledName(GD); 2177 2178 // If there is a definition in the module, then it wins over the alias. 2179 // This is dubious, but allow it to be safe. Just ignore the alias. 2180 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 2181 if (Entry && !Entry->isDeclaration()) 2182 return; 2183 2184 Aliases.push_back(GD); 2185 2186 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 2187 2188 // Create a reference to the named value. This ensures that it is emitted 2189 // if a deferred decl. 2190 llvm::Constant *Aliasee; 2191 if (isa<llvm::FunctionType>(DeclTy)) 2192 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD, 2193 /*ForVTable=*/false); 2194 else 2195 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 2196 llvm::PointerType::getUnqual(DeclTy), 0); 2197 2198 // Create the new alias itself, but don't set a name yet. 2199 llvm::GlobalValue *GA = 2200 new llvm::GlobalAlias(Aliasee->getType(), 2201 llvm::Function::ExternalLinkage, 2202 "", Aliasee, &getModule()); 2203 2204 if (Entry) { 2205 assert(Entry->isDeclaration()); 2206 2207 // If there is a declaration in the module, then we had an extern followed 2208 // by the alias, as in: 2209 // extern int test6(); 2210 // ... 2211 // int test6() __attribute__((alias("test7"))); 2212 // 2213 // Remove it and replace uses of it with the alias. 2214 GA->takeName(Entry); 2215 2216 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 2217 Entry->getType())); 2218 Entry->eraseFromParent(); 2219 } else { 2220 GA->setName(MangledName); 2221 } 2222 2223 // Set attributes which are particular to an alias; this is a 2224 // specialization of the attributes which may be set on a global 2225 // variable/function. 2226 if (D->hasAttr<DLLExportAttr>()) { 2227 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2228 // The dllexport attribute is ignored for undefined symbols. 2229 if (FD->hasBody()) 2230 GA->setLinkage(llvm::Function::DLLExportLinkage); 2231 } else { 2232 GA->setLinkage(llvm::Function::DLLExportLinkage); 2233 } 2234 } else if (D->hasAttr<WeakAttr>() || 2235 D->hasAttr<WeakRefAttr>() || 2236 D->isWeakImported()) { 2237 GA->setLinkage(llvm::Function::WeakAnyLinkage); 2238 } 2239 2240 SetCommonAttributes(D, GA); 2241 } 2242 2243 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 2244 ArrayRef<llvm::Type*> Tys) { 2245 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 2246 Tys); 2247 } 2248 2249 static llvm::StringMapEntry<llvm::Constant*> & 2250 GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2251 const StringLiteral *Literal, 2252 bool TargetIsLSB, 2253 bool &IsUTF16, 2254 unsigned &StringLength) { 2255 StringRef String = Literal->getString(); 2256 unsigned NumBytes = String.size(); 2257 2258 // Check for simple case. 2259 if (!Literal->containsNonAsciiOrNull()) { 2260 StringLength = NumBytes; 2261 return Map.GetOrCreateValue(String); 2262 } 2263 2264 // Otherwise, convert the UTF8 literals into a string of shorts. 2265 IsUTF16 = true; 2266 2267 SmallVector<UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls. 2268 const UTF8 *FromPtr = (const UTF8 *)String.data(); 2269 UTF16 *ToPtr = &ToBuf[0]; 2270 2271 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 2272 &ToPtr, ToPtr + NumBytes, 2273 strictConversion); 2274 2275 // ConvertUTF8toUTF16 returns the length in ToPtr. 2276 StringLength = ToPtr - &ToBuf[0]; 2277 2278 // Add an explicit null. 2279 *ToPtr = 0; 2280 return Map. 2281 GetOrCreateValue(StringRef(reinterpret_cast<const char *>(ToBuf.data()), 2282 (StringLength + 1) * 2)); 2283 } 2284 2285 static llvm::StringMapEntry<llvm::Constant*> & 2286 GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2287 const StringLiteral *Literal, 2288 unsigned &StringLength) { 2289 StringRef String = Literal->getString(); 2290 StringLength = String.size(); 2291 return Map.GetOrCreateValue(String); 2292 } 2293 2294 llvm::Constant * 2295 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 2296 unsigned StringLength = 0; 2297 bool isUTF16 = false; 2298 llvm::StringMapEntry<llvm::Constant*> &Entry = 2299 GetConstantCFStringEntry(CFConstantStringMap, Literal, 2300 getDataLayout().isLittleEndian(), 2301 isUTF16, StringLength); 2302 2303 if (llvm::Constant *C = Entry.getValue()) 2304 return C; 2305 2306 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2307 llvm::Constant *Zeros[] = { Zero, Zero }; 2308 llvm::Value *V; 2309 2310 // If we don't already have it, get __CFConstantStringClassReference. 2311 if (!CFConstantStringClassRef) { 2312 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2313 Ty = llvm::ArrayType::get(Ty, 0); 2314 llvm::Constant *GV = CreateRuntimeVariable(Ty, 2315 "__CFConstantStringClassReference"); 2316 // Decay array -> ptr 2317 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2318 CFConstantStringClassRef = V; 2319 } 2320 else 2321 V = CFConstantStringClassRef; 2322 2323 QualType CFTy = getContext().getCFConstantStringType(); 2324 2325 llvm::StructType *STy = 2326 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 2327 2328 llvm::Constant *Fields[4]; 2329 2330 // Class pointer. 2331 Fields[0] = cast<llvm::ConstantExpr>(V); 2332 2333 // Flags. 2334 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2335 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 2336 llvm::ConstantInt::get(Ty, 0x07C8); 2337 2338 // String pointer. 2339 llvm::Constant *C = 0; 2340 if (isUTF16) { 2341 ArrayRef<uint16_t> Arr = 2342 llvm::makeArrayRef<uint16_t>(reinterpret_cast<uint16_t*>( 2343 const_cast<char *>(Entry.getKey().data())), 2344 Entry.getKey().size() / 2); 2345 C = llvm::ConstantDataArray::get(VMContext, Arr); 2346 } else { 2347 C = llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2348 } 2349 2350 llvm::GlobalValue::LinkageTypes Linkage; 2351 if (isUTF16) 2352 // FIXME: why do utf strings get "_" labels instead of "L" labels? 2353 Linkage = llvm::GlobalValue::InternalLinkage; 2354 else 2355 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 2356 // when using private linkage. It is not clear if this is a bug in ld 2357 // or a reasonable new restriction. 2358 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 2359 2360 // Note: -fwritable-strings doesn't make the backing store strings of 2361 // CFStrings writable. (See <rdar://problem/10657500>) 2362 llvm::GlobalVariable *GV = 2363 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, 2364 Linkage, C, ".str"); 2365 GV->setUnnamedAddr(true); 2366 // Don't enforce the target's minimum global alignment, since the only use 2367 // of the string is via this class initializer. 2368 if (isUTF16) { 2369 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 2370 GV->setAlignment(Align.getQuantity()); 2371 } else { 2372 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2373 GV->setAlignment(Align.getQuantity()); 2374 } 2375 2376 // String. 2377 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2378 2379 if (isUTF16) 2380 // Cast the UTF16 string to the correct type. 2381 Fields[2] = llvm::ConstantExpr::getBitCast(Fields[2], Int8PtrTy); 2382 2383 // String length. 2384 Ty = getTypes().ConvertType(getContext().LongTy); 2385 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 2386 2387 // The struct. 2388 C = llvm::ConstantStruct::get(STy, Fields); 2389 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2390 llvm::GlobalVariable::PrivateLinkage, C, 2391 "_unnamed_cfstring_"); 2392 if (const char *Sect = getTarget().getCFStringSection()) 2393 GV->setSection(Sect); 2394 Entry.setValue(GV); 2395 2396 return GV; 2397 } 2398 2399 static RecordDecl * 2400 CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 2401 DeclContext *DC, IdentifierInfo *Id) { 2402 SourceLocation Loc; 2403 if (Ctx.getLangOpts().CPlusPlus) 2404 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2405 else 2406 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2407 } 2408 2409 llvm::Constant * 2410 CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 2411 unsigned StringLength = 0; 2412 llvm::StringMapEntry<llvm::Constant*> &Entry = 2413 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 2414 2415 if (llvm::Constant *C = Entry.getValue()) 2416 return C; 2417 2418 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2419 llvm::Constant *Zeros[] = { Zero, Zero }; 2420 llvm::Value *V; 2421 // If we don't already have it, get _NSConstantStringClassReference. 2422 if (!ConstantStringClassRef) { 2423 std::string StringClass(getLangOpts().ObjCConstantStringClass); 2424 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2425 llvm::Constant *GV; 2426 if (LangOpts.ObjCRuntime.isNonFragile()) { 2427 std::string str = 2428 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 2429 : "OBJC_CLASS_$_" + StringClass; 2430 GV = getObjCRuntime().GetClassGlobal(str); 2431 // Make sure the result is of the correct type. 2432 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 2433 V = llvm::ConstantExpr::getBitCast(GV, PTy); 2434 ConstantStringClassRef = V; 2435 } else { 2436 std::string str = 2437 StringClass.empty() ? "_NSConstantStringClassReference" 2438 : "_" + StringClass + "ClassReference"; 2439 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 2440 GV = CreateRuntimeVariable(PTy, str); 2441 // Decay array -> ptr 2442 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2443 ConstantStringClassRef = V; 2444 } 2445 } 2446 else 2447 V = ConstantStringClassRef; 2448 2449 if (!NSConstantStringType) { 2450 // Construct the type for a constant NSString. 2451 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2452 Context.getTranslationUnitDecl(), 2453 &Context.Idents.get("__builtin_NSString")); 2454 D->startDefinition(); 2455 2456 QualType FieldTypes[3]; 2457 2458 // const int *isa; 2459 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 2460 // const char *str; 2461 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 2462 // unsigned int length; 2463 FieldTypes[2] = Context.UnsignedIntTy; 2464 2465 // Create fields 2466 for (unsigned i = 0; i < 3; ++i) { 2467 FieldDecl *Field = FieldDecl::Create(Context, D, 2468 SourceLocation(), 2469 SourceLocation(), 0, 2470 FieldTypes[i], /*TInfo=*/0, 2471 /*BitWidth=*/0, 2472 /*Mutable=*/false, 2473 ICIS_NoInit); 2474 Field->setAccess(AS_public); 2475 D->addDecl(Field); 2476 } 2477 2478 D->completeDefinition(); 2479 QualType NSTy = Context.getTagDeclType(D); 2480 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 2481 } 2482 2483 llvm::Constant *Fields[3]; 2484 2485 // Class pointer. 2486 Fields[0] = cast<llvm::ConstantExpr>(V); 2487 2488 // String pointer. 2489 llvm::Constant *C = 2490 llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2491 2492 llvm::GlobalValue::LinkageTypes Linkage; 2493 bool isConstant; 2494 Linkage = llvm::GlobalValue::PrivateLinkage; 2495 isConstant = !LangOpts.WritableStrings; 2496 2497 llvm::GlobalVariable *GV = 2498 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 2499 ".str"); 2500 GV->setUnnamedAddr(true); 2501 // Don't enforce the target's minimum global alignment, since the only use 2502 // of the string is via this class initializer. 2503 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2504 GV->setAlignment(Align.getQuantity()); 2505 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2506 2507 // String length. 2508 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2509 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 2510 2511 // The struct. 2512 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 2513 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2514 llvm::GlobalVariable::PrivateLinkage, C, 2515 "_unnamed_nsstring_"); 2516 // FIXME. Fix section. 2517 if (const char *Sect = 2518 LangOpts.ObjCRuntime.isNonFragile() 2519 ? getTarget().getNSStringNonFragileABISection() 2520 : getTarget().getNSStringSection()) 2521 GV->setSection(Sect); 2522 Entry.setValue(GV); 2523 2524 return GV; 2525 } 2526 2527 QualType CodeGenModule::getObjCFastEnumerationStateType() { 2528 if (ObjCFastEnumerationStateType.isNull()) { 2529 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2530 Context.getTranslationUnitDecl(), 2531 &Context.Idents.get("__objcFastEnumerationState")); 2532 D->startDefinition(); 2533 2534 QualType FieldTypes[] = { 2535 Context.UnsignedLongTy, 2536 Context.getPointerType(Context.getObjCIdType()), 2537 Context.getPointerType(Context.UnsignedLongTy), 2538 Context.getConstantArrayType(Context.UnsignedLongTy, 2539 llvm::APInt(32, 5), ArrayType::Normal, 0) 2540 }; 2541 2542 for (size_t i = 0; i < 4; ++i) { 2543 FieldDecl *Field = FieldDecl::Create(Context, 2544 D, 2545 SourceLocation(), 2546 SourceLocation(), 0, 2547 FieldTypes[i], /*TInfo=*/0, 2548 /*BitWidth=*/0, 2549 /*Mutable=*/false, 2550 ICIS_NoInit); 2551 Field->setAccess(AS_public); 2552 D->addDecl(Field); 2553 } 2554 2555 D->completeDefinition(); 2556 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 2557 } 2558 2559 return ObjCFastEnumerationStateType; 2560 } 2561 2562 llvm::Constant * 2563 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { 2564 assert(!E->getType()->isPointerType() && "Strings are always arrays"); 2565 2566 // Don't emit it as the address of the string, emit the string data itself 2567 // as an inline array. 2568 if (E->getCharByteWidth() == 1) { 2569 SmallString<64> Str(E->getString()); 2570 2571 // Resize the string to the right size, which is indicated by its type. 2572 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType()); 2573 Str.resize(CAT->getSize().getZExtValue()); 2574 return llvm::ConstantDataArray::getString(VMContext, Str, false); 2575 } 2576 2577 llvm::ArrayType *AType = 2578 cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); 2579 llvm::Type *ElemTy = AType->getElementType(); 2580 unsigned NumElements = AType->getNumElements(); 2581 2582 // Wide strings have either 2-byte or 4-byte elements. 2583 if (ElemTy->getPrimitiveSizeInBits() == 16) { 2584 SmallVector<uint16_t, 32> Elements; 2585 Elements.reserve(NumElements); 2586 2587 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2588 Elements.push_back(E->getCodeUnit(i)); 2589 Elements.resize(NumElements); 2590 return llvm::ConstantDataArray::get(VMContext, Elements); 2591 } 2592 2593 assert(ElemTy->getPrimitiveSizeInBits() == 32); 2594 SmallVector<uint32_t, 32> Elements; 2595 Elements.reserve(NumElements); 2596 2597 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2598 Elements.push_back(E->getCodeUnit(i)); 2599 Elements.resize(NumElements); 2600 return llvm::ConstantDataArray::get(VMContext, Elements); 2601 } 2602 2603 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a 2604 /// constant array for the given string literal. 2605 llvm::Constant * 2606 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 2607 CharUnits Align = getContext().getAlignOfGlobalVarInChars(S->getType()); 2608 if (S->isAscii() || S->isUTF8()) { 2609 SmallString<64> Str(S->getString()); 2610 2611 // Resize the string to the right size, which is indicated by its type. 2612 const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType()); 2613 Str.resize(CAT->getSize().getZExtValue()); 2614 return GetAddrOfConstantString(Str, /*GlobalName*/ 0, Align.getQuantity()); 2615 } 2616 2617 // FIXME: the following does not memoize wide strings. 2618 llvm::Constant *C = GetConstantArrayFromStringLiteral(S); 2619 llvm::GlobalVariable *GV = 2620 new llvm::GlobalVariable(getModule(),C->getType(), 2621 !LangOpts.WritableStrings, 2622 llvm::GlobalValue::PrivateLinkage, 2623 C,".str"); 2624 2625 GV->setAlignment(Align.getQuantity()); 2626 GV->setUnnamedAddr(true); 2627 return GV; 2628 } 2629 2630 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2631 /// array for the given ObjCEncodeExpr node. 2632 llvm::Constant * 2633 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2634 std::string Str; 2635 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2636 2637 return GetAddrOfConstantCString(Str); 2638 } 2639 2640 2641 /// GenerateWritableString -- Creates storage for a string literal. 2642 static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2643 bool constant, 2644 CodeGenModule &CGM, 2645 const char *GlobalName, 2646 unsigned Alignment) { 2647 // Create Constant for this string literal. Don't add a '\0'. 2648 llvm::Constant *C = 2649 llvm::ConstantDataArray::getString(CGM.getLLVMContext(), str, false); 2650 2651 // OpenCL v1.1 s6.5.3: a string literal is in the constant address space. 2652 unsigned AddrSpace = 0; 2653 if (CGM.getLangOpts().OpenCL) 2654 AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_constant); 2655 2656 // Create a global variable for this string 2657 llvm::GlobalVariable *GV = new llvm::GlobalVariable( 2658 CGM.getModule(), C->getType(), constant, 2659 llvm::GlobalValue::PrivateLinkage, C, GlobalName, 0, 2660 llvm::GlobalVariable::NotThreadLocal, AddrSpace); 2661 GV->setAlignment(Alignment); 2662 GV->setUnnamedAddr(true); 2663 return GV; 2664 } 2665 2666 /// GetAddrOfConstantString - Returns a pointer to a character array 2667 /// containing the literal. This contents are exactly that of the 2668 /// given string, i.e. it will not be null terminated automatically; 2669 /// see GetAddrOfConstantCString. Note that whether the result is 2670 /// actually a pointer to an LLVM constant depends on 2671 /// Feature.WriteableStrings. 2672 /// 2673 /// The result has pointer to array type. 2674 llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2675 const char *GlobalName, 2676 unsigned Alignment) { 2677 // Get the default prefix if a name wasn't specified. 2678 if (!GlobalName) 2679 GlobalName = ".str"; 2680 2681 if (Alignment == 0) 2682 Alignment = getContext().getAlignOfGlobalVarInChars(getContext().CharTy) 2683 .getQuantity(); 2684 2685 // Don't share any string literals if strings aren't constant. 2686 if (LangOpts.WritableStrings) 2687 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2688 2689 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2690 ConstantStringMap.GetOrCreateValue(Str); 2691 2692 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2693 if (Alignment > GV->getAlignment()) { 2694 GV->setAlignment(Alignment); 2695 } 2696 return GV; 2697 } 2698 2699 // Create a global variable for this. 2700 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, 2701 Alignment); 2702 Entry.setValue(GV); 2703 return GV; 2704 } 2705 2706 /// GetAddrOfConstantCString - Returns a pointer to a character 2707 /// array containing the literal and a terminating '\0' 2708 /// character. The result has pointer to array type. 2709 llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2710 const char *GlobalName, 2711 unsigned Alignment) { 2712 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2713 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2714 } 2715 2716 llvm::Constant *CodeGenModule::GetAddrOfGlobalTemporary( 2717 const MaterializeTemporaryExpr *E, const Expr *Init) { 2718 assert((E->getStorageDuration() == SD_Static || 2719 E->getStorageDuration() == SD_Thread) && "not a global temporary"); 2720 const VarDecl *VD = cast<VarDecl>(E->getExtendingDecl()); 2721 2722 // If we're not materializing a subobject of the temporary, keep the 2723 // cv-qualifiers from the type of the MaterializeTemporaryExpr. 2724 QualType MaterializedType = Init->getType(); 2725 if (Init == E->GetTemporaryExpr()) 2726 MaterializedType = E->getType(); 2727 2728 llvm::Constant *&Slot = MaterializedGlobalTemporaryMap[E]; 2729 if (Slot) 2730 return Slot; 2731 2732 // FIXME: If an externally-visible declaration extends multiple temporaries, 2733 // we need to give each temporary the same name in every translation unit (and 2734 // we also need to make the temporaries externally-visible). 2735 SmallString<256> Name; 2736 llvm::raw_svector_ostream Out(Name); 2737 getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out); 2738 Out.flush(); 2739 2740 APValue *Value = 0; 2741 if (E->getStorageDuration() == SD_Static) { 2742 // We might have a cached constant initializer for this temporary. Note 2743 // that this might have a different value from the value computed by 2744 // evaluating the initializer if the surrounding constant expression 2745 // modifies the temporary. 2746 Value = getContext().getMaterializedTemporaryValue(E, false); 2747 if (Value && Value->isUninit()) 2748 Value = 0; 2749 } 2750 2751 // Try evaluating it now, it might have a constant initializer. 2752 Expr::EvalResult EvalResult; 2753 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) && 2754 !EvalResult.hasSideEffects()) 2755 Value = &EvalResult.Val; 2756 2757 llvm::Constant *InitialValue = 0; 2758 bool Constant = false; 2759 llvm::Type *Type; 2760 if (Value) { 2761 // The temporary has a constant initializer, use it. 2762 InitialValue = EmitConstantValue(*Value, MaterializedType, 0); 2763 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value); 2764 Type = InitialValue->getType(); 2765 } else { 2766 // No initializer, the initialization will be provided when we 2767 // initialize the declaration which performed lifetime extension. 2768 Type = getTypes().ConvertTypeForMem(MaterializedType); 2769 } 2770 2771 // Create a global variable for this lifetime-extended temporary. 2772 llvm::GlobalVariable *GV = 2773 new llvm::GlobalVariable(getModule(), Type, Constant, 2774 llvm::GlobalValue::PrivateLinkage, 2775 InitialValue, Name.c_str()); 2776 GV->setAlignment( 2777 getContext().getTypeAlignInChars(MaterializedType).getQuantity()); 2778 if (VD->getTLSKind()) 2779 setTLSMode(GV, *VD); 2780 Slot = GV; 2781 return GV; 2782 } 2783 2784 /// EmitObjCPropertyImplementations - Emit information for synthesized 2785 /// properties for an implementation. 2786 void CodeGenModule::EmitObjCPropertyImplementations(const 2787 ObjCImplementationDecl *D) { 2788 for (ObjCImplementationDecl::propimpl_iterator 2789 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2790 ObjCPropertyImplDecl *PID = *i; 2791 2792 // Dynamic is just for type-checking. 2793 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2794 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2795 2796 // Determine which methods need to be implemented, some may have 2797 // been overridden. Note that ::isPropertyAccessor is not the method 2798 // we want, that just indicates if the decl came from a 2799 // property. What we want to know is if the method is defined in 2800 // this implementation. 2801 if (!D->getInstanceMethod(PD->getGetterName())) 2802 CodeGenFunction(*this).GenerateObjCGetter( 2803 const_cast<ObjCImplementationDecl *>(D), PID); 2804 if (!PD->isReadOnly() && 2805 !D->getInstanceMethod(PD->getSetterName())) 2806 CodeGenFunction(*this).GenerateObjCSetter( 2807 const_cast<ObjCImplementationDecl *>(D), PID); 2808 } 2809 } 2810 } 2811 2812 static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2813 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2814 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2815 ivar; ivar = ivar->getNextIvar()) 2816 if (ivar->getType().isDestructedType()) 2817 return true; 2818 2819 return false; 2820 } 2821 2822 /// EmitObjCIvarInitializations - Emit information for ivar initialization 2823 /// for an implementation. 2824 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2825 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2826 if (needsDestructMethod(D)) { 2827 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2828 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2829 ObjCMethodDecl *DTORMethod = 2830 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2831 cxxSelector, getContext().VoidTy, 0, D, 2832 /*isInstance=*/true, /*isVariadic=*/false, 2833 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true, 2834 /*isDefined=*/false, ObjCMethodDecl::Required); 2835 D->addInstanceMethod(DTORMethod); 2836 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2837 D->setHasDestructors(true); 2838 } 2839 2840 // If the implementation doesn't have any ivar initializers, we don't need 2841 // a .cxx_construct. 2842 if (D->getNumIvarInitializers() == 0) 2843 return; 2844 2845 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2846 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2847 // The constructor returns 'self'. 2848 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2849 D->getLocation(), 2850 D->getLocation(), 2851 cxxSelector, 2852 getContext().getObjCIdType(), 0, 2853 D, /*isInstance=*/true, 2854 /*isVariadic=*/false, 2855 /*isPropertyAccessor=*/true, 2856 /*isImplicitlyDeclared=*/true, 2857 /*isDefined=*/false, 2858 ObjCMethodDecl::Required); 2859 D->addInstanceMethod(CTORMethod); 2860 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2861 D->setHasNonZeroConstructors(true); 2862 } 2863 2864 /// EmitNamespace - Emit all declarations in a namespace. 2865 void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2866 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2867 I != E; ++I) { 2868 if (const VarDecl *VD = dyn_cast<VarDecl>(*I)) 2869 if (VD->getTemplateSpecializationKind() != TSK_ExplicitSpecialization && 2870 VD->getTemplateSpecializationKind() != TSK_Undeclared) 2871 continue; 2872 EmitTopLevelDecl(*I); 2873 } 2874 } 2875 2876 // EmitLinkageSpec - Emit all declarations in a linkage spec. 2877 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2878 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2879 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2880 ErrorUnsupported(LSD, "linkage spec"); 2881 return; 2882 } 2883 2884 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2885 I != E; ++I) { 2886 // Meta-data for ObjC class includes references to implemented methods. 2887 // Generate class's method definitions first. 2888 if (ObjCImplDecl *OID = dyn_cast<ObjCImplDecl>(*I)) { 2889 for (ObjCContainerDecl::method_iterator M = OID->meth_begin(), 2890 MEnd = OID->meth_end(); 2891 M != MEnd; ++M) 2892 EmitTopLevelDecl(*M); 2893 } 2894 EmitTopLevelDecl(*I); 2895 } 2896 } 2897 2898 /// EmitTopLevelDecl - Emit code for a single top level declaration. 2899 void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2900 // Ignore dependent declarations. 2901 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2902 return; 2903 2904 switch (D->getKind()) { 2905 case Decl::CXXConversion: 2906 case Decl::CXXMethod: 2907 case Decl::Function: 2908 // Skip function templates 2909 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2910 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2911 return; 2912 2913 EmitGlobal(cast<FunctionDecl>(D)); 2914 break; 2915 2916 case Decl::Var: 2917 // Skip variable templates 2918 if (cast<VarDecl>(D)->getDescribedVarTemplate()) 2919 return; 2920 case Decl::VarTemplateSpecialization: 2921 EmitGlobal(cast<VarDecl>(D)); 2922 break; 2923 2924 // Indirect fields from global anonymous structs and unions can be 2925 // ignored; only the actual variable requires IR gen support. 2926 case Decl::IndirectField: 2927 break; 2928 2929 // C++ Decls 2930 case Decl::Namespace: 2931 EmitNamespace(cast<NamespaceDecl>(D)); 2932 break; 2933 // No code generation needed. 2934 case Decl::UsingShadow: 2935 case Decl::Using: 2936 case Decl::ClassTemplate: 2937 case Decl::VarTemplate: 2938 case Decl::VarTemplatePartialSpecialization: 2939 case Decl::FunctionTemplate: 2940 case Decl::TypeAliasTemplate: 2941 case Decl::Block: 2942 case Decl::Empty: 2943 break; 2944 case Decl::NamespaceAlias: 2945 if (CGDebugInfo *DI = getModuleDebugInfo()) 2946 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D)); 2947 return; 2948 case Decl::UsingDirective: // using namespace X; [C++] 2949 if (CGDebugInfo *DI = getModuleDebugInfo()) 2950 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D)); 2951 return; 2952 case Decl::CXXConstructor: 2953 // Skip function templates 2954 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2955 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2956 return; 2957 2958 getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2959 break; 2960 case Decl::CXXDestructor: 2961 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2962 return; 2963 getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2964 break; 2965 2966 case Decl::StaticAssert: 2967 // Nothing to do. 2968 break; 2969 2970 // Objective-C Decls 2971 2972 // Forward declarations, no (immediate) code generation. 2973 case Decl::ObjCInterface: 2974 case Decl::ObjCCategory: 2975 break; 2976 2977 case Decl::ObjCProtocol: { 2978 ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D); 2979 if (Proto->isThisDeclarationADefinition()) 2980 ObjCRuntime->GenerateProtocol(Proto); 2981 break; 2982 } 2983 2984 case Decl::ObjCCategoryImpl: 2985 // Categories have properties but don't support synthesize so we 2986 // can ignore them here. 2987 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2988 break; 2989 2990 case Decl::ObjCImplementation: { 2991 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2992 EmitObjCPropertyImplementations(OMD); 2993 EmitObjCIvarInitializations(OMD); 2994 ObjCRuntime->GenerateClass(OMD); 2995 // Emit global variable debug information. 2996 if (CGDebugInfo *DI = getModuleDebugInfo()) 2997 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) 2998 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType( 2999 OMD->getClassInterface()), OMD->getLocation()); 3000 break; 3001 } 3002 case Decl::ObjCMethod: { 3003 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 3004 // If this is not a prototype, emit the body. 3005 if (OMD->getBody()) 3006 CodeGenFunction(*this).GenerateObjCMethod(OMD); 3007 break; 3008 } 3009 case Decl::ObjCCompatibleAlias: 3010 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D)); 3011 break; 3012 3013 case Decl::LinkageSpec: 3014 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 3015 break; 3016 3017 case Decl::FileScopeAsm: { 3018 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 3019 StringRef AsmString = AD->getAsmString()->getString(); 3020 3021 const std::string &S = getModule().getModuleInlineAsm(); 3022 if (S.empty()) 3023 getModule().setModuleInlineAsm(AsmString); 3024 else if (S.end()[-1] == '\n') 3025 getModule().setModuleInlineAsm(S + AsmString.str()); 3026 else 3027 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 3028 break; 3029 } 3030 3031 case Decl::Import: { 3032 ImportDecl *Import = cast<ImportDecl>(D); 3033 3034 // Ignore import declarations that come from imported modules. 3035 if (clang::Module *Owner = Import->getOwningModule()) { 3036 if (getLangOpts().CurrentModule.empty() || 3037 Owner->getTopLevelModule()->Name == getLangOpts().CurrentModule) 3038 break; 3039 } 3040 3041 ImportedModules.insert(Import->getImportedModule()); 3042 break; 3043 } 3044 3045 default: 3046 // Make sure we handled everything we should, every other kind is a 3047 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 3048 // function. Need to recode Decl::Kind to do that easily. 3049 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 3050 } 3051 } 3052 3053 /// Turns the given pointer into a constant. 3054 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 3055 const void *Ptr) { 3056 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 3057 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 3058 return llvm::ConstantInt::get(i64, PtrInt); 3059 } 3060 3061 static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 3062 llvm::NamedMDNode *&GlobalMetadata, 3063 GlobalDecl D, 3064 llvm::GlobalValue *Addr) { 3065 if (!GlobalMetadata) 3066 GlobalMetadata = 3067 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 3068 3069 // TODO: should we report variant information for ctors/dtors? 3070 llvm::Value *Ops[] = { 3071 Addr, 3072 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 3073 }; 3074 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 3075 } 3076 3077 /// For each function which is declared within an extern "C" region and marked 3078 /// as 'used', but has internal linkage, create an alias from the unmangled 3079 /// name to the mangled name if possible. People expect to be able to refer 3080 /// to such functions with an unmangled name from inline assembly within the 3081 /// same translation unit. 3082 void CodeGenModule::EmitStaticExternCAliases() { 3083 for (StaticExternCMap::iterator I = StaticExternCValues.begin(), 3084 E = StaticExternCValues.end(); 3085 I != E; ++I) { 3086 IdentifierInfo *Name = I->first; 3087 llvm::GlobalValue *Val = I->second; 3088 if (Val && !getModule().getNamedValue(Name->getName())) 3089 AddUsedGlobal(new llvm::GlobalAlias(Val->getType(), Val->getLinkage(), 3090 Name->getName(), Val, &getModule())); 3091 } 3092 } 3093 3094 /// Emits metadata nodes associating all the global values in the 3095 /// current module with the Decls they came from. This is useful for 3096 /// projects using IR gen as a subroutine. 3097 /// 3098 /// Since there's currently no way to associate an MDNode directly 3099 /// with an llvm::GlobalValue, we create a global named metadata 3100 /// with the name 'clang.global.decl.ptrs'. 3101 void CodeGenModule::EmitDeclMetadata() { 3102 llvm::NamedMDNode *GlobalMetadata = 0; 3103 3104 // StaticLocalDeclMap 3105 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 3106 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 3107 I != E; ++I) { 3108 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 3109 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 3110 } 3111 } 3112 3113 /// Emits metadata nodes for all the local variables in the current 3114 /// function. 3115 void CodeGenFunction::EmitDeclMetadata() { 3116 if (LocalDeclMap.empty()) return; 3117 3118 llvm::LLVMContext &Context = getLLVMContext(); 3119 3120 // Find the unique metadata ID for this name. 3121 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 3122 3123 llvm::NamedMDNode *GlobalMetadata = 0; 3124 3125 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 3126 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 3127 const Decl *D = I->first; 3128 llvm::Value *Addr = I->second; 3129 3130 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 3131 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 3132 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 3133 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 3134 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 3135 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 3136 } 3137 } 3138 } 3139 3140 void CodeGenModule::EmitVersionIdentMetadata() { 3141 llvm::NamedMDNode *IdentMetadata = 3142 TheModule.getOrInsertNamedMetadata("llvm.ident"); 3143 std::string Version = getClangFullVersion(); 3144 llvm::LLVMContext &Ctx = TheModule.getContext(); 3145 3146 llvm::Value *IdentNode[] = { 3147 llvm::MDString::get(Ctx, Version) 3148 }; 3149 IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode)); 3150 } 3151 3152 void CodeGenModule::EmitCoverageFile() { 3153 if (!getCodeGenOpts().CoverageFile.empty()) { 3154 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 3155 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 3156 llvm::LLVMContext &Ctx = TheModule.getContext(); 3157 llvm::MDString *CoverageFile = 3158 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 3159 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 3160 llvm::MDNode *CU = CUNode->getOperand(i); 3161 llvm::Value *node[] = { CoverageFile, CU }; 3162 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 3163 GCov->addOperand(N); 3164 } 3165 } 3166 } 3167 } 3168 3169 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid, 3170 QualType GuidType) { 3171 // Sema has checked that all uuid strings are of the form 3172 // "12345678-1234-1234-1234-1234567890ab". 3173 assert(Uuid.size() == 36); 3174 for (unsigned i = 0; i < 36; ++i) { 3175 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-'); 3176 else assert(isHexDigit(Uuid[i])); 3177 } 3178 3179 const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 }; 3180 3181 llvm::Constant *Field3[8]; 3182 for (unsigned Idx = 0; Idx < 8; ++Idx) 3183 Field3[Idx] = llvm::ConstantInt::get( 3184 Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16); 3185 3186 llvm::Constant *Fields[4] = { 3187 llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16), 3188 llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16), 3189 llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16), 3190 llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3) 3191 }; 3192 3193 return llvm::ConstantStruct::getAnon(Fields); 3194 } 3195