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/Frontend/CodeGenOptions.h" 39 #include "llvm/ADT/APSInt.h" 40 #include "llvm/ADT/Triple.h" 41 #include "llvm/IR/CallingConv.h" 42 #include "llvm/IR/DataLayout.h" 43 #include "llvm/IR/Intrinsics.h" 44 #include "llvm/IR/LLVMContext.h" 45 #include "llvm/IR/Module.h" 46 #include "llvm/Support/CallSite.h" 47 #include "llvm/Support/ConvertUTF.h" 48 #include "llvm/Support/ErrorHandling.h" 49 #include "llvm/Target/Mangler.h" 50 51 using namespace clang; 52 using namespace CodeGen; 53 54 static const char AnnotationSection[] = "llvm.metadata"; 55 56 static CGCXXABI &createCXXABI(CodeGenModule &CGM) { 57 switch (CGM.getTarget().getCXXABI().getKind()) { 58 case TargetCXXABI::GenericAArch64: 59 case TargetCXXABI::GenericARM: 60 case TargetCXXABI::iOS: 61 case TargetCXXABI::GenericItanium: 62 return *CreateItaniumCXXABI(CGM); 63 case TargetCXXABI::Microsoft: 64 return *CreateMicrosoftCXXABI(CGM); 65 } 66 67 llvm_unreachable("invalid C++ ABI kind"); 68 } 69 70 71 CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 72 llvm::Module &M, const llvm::DataLayout &TD, 73 DiagnosticsEngine &diags) 74 : Context(C), LangOpts(C.getLangOpts()), CodeGenOpts(CGO), TheModule(M), 75 Diags(diags), TheDataLayout(TD), Target(C.getTargetInfo()), 76 ABI(createCXXABI(*this)), VMContext(M.getContext()), TBAA(0), 77 TheTargetCodeGenInfo(0), Types(*this), VTables(*this), 78 ObjCRuntime(0), OpenCLRuntime(0), CUDARuntime(0), 79 DebugInfo(0), ARCData(0), NoObjCARCExceptionsMetadata(0), 80 RRData(0), CFConstantStringClassRef(0), 81 ConstantStringClassRef(0), NSConstantStringType(0), 82 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), 83 BlockObjectAssign(0), BlockObjectDispose(0), 84 BlockDescriptorType(0), GenericBlockLiteralType(0), 85 LifetimeStartFn(0), LifetimeEndFn(0), 86 SanitizerBlacklist(CGO.SanitizerBlacklistFile), 87 SanOpts(SanitizerBlacklist.isIn(M) ? 88 SanitizerOptions::Disabled : 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::Release() { 176 EmitDeferred(); 177 EmitCXXGlobalInitFunc(); 178 EmitCXXGlobalDtorFunc(); 179 EmitCXXThreadLocalInitFunc(); 180 if (ObjCRuntime) 181 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) 182 AddGlobalCtor(ObjCInitFunction); 183 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 184 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 185 EmitGlobalAnnotations(); 186 EmitStaticExternCAliases(); 187 EmitLLVMUsed(); 188 189 if (CodeGenOpts.Autolink && 190 (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) { 191 EmitModuleLinkOptions(); 192 } 193 if (CodeGenOpts.DwarfVersion) 194 // We actually want the latest version when there are conflicts. 195 // We can change from Warning to Latest if such mode is supported. 196 getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version", 197 CodeGenOpts.DwarfVersion); 198 199 SimplifyPersonality(); 200 201 if (getCodeGenOpts().EmitDeclMetadata) 202 EmitDeclMetadata(); 203 204 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 205 EmitCoverageFile(); 206 207 if (DebugInfo) 208 DebugInfo->finalize(); 209 } 210 211 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 212 // Make sure that this type is translated. 213 Types.UpdateCompletedType(TD); 214 } 215 216 llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 217 if (!TBAA) 218 return 0; 219 return TBAA->getTBAAInfo(QTy); 220 } 221 222 llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() { 223 if (!TBAA) 224 return 0; 225 return TBAA->getTBAAInfoForVTablePtr(); 226 } 227 228 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) { 229 if (!TBAA) 230 return 0; 231 return TBAA->getTBAAStructInfo(QTy); 232 } 233 234 llvm::MDNode *CodeGenModule::getTBAAStructTypeInfo(QualType QTy) { 235 if (!TBAA) 236 return 0; 237 return TBAA->getTBAAStructTypeInfo(QTy); 238 } 239 240 llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy, 241 llvm::MDNode *AccessN, 242 uint64_t O) { 243 if (!TBAA) 244 return 0; 245 return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O); 246 } 247 248 /// Decorate the instruction with a TBAA tag. For scalar TBAA, the tag 249 /// is the same as the type. For struct-path aware TBAA, the tag 250 /// is different from the type: base type, access type and offset. 251 /// When ConvertTypeToTag is true, we create a tag based on the scalar type. 252 void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 253 llvm::MDNode *TBAAInfo, 254 bool ConvertTypeToTag) { 255 if (ConvertTypeToTag && TBAA && CodeGenOpts.StructPathTBAA) 256 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, 257 TBAA->getTBAAScalarTagInfo(TBAAInfo)); 258 else 259 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 260 } 261 262 void CodeGenModule::Error(SourceLocation loc, StringRef error) { 263 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); 264 getDiags().Report(Context.getFullLoc(loc), diagID); 265 } 266 267 /// ErrorUnsupported - Print out an error that codegen doesn't support the 268 /// specified stmt yet. 269 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 270 bool OmitOnError) { 271 if (OmitOnError && getDiags().hasErrorOccurred()) 272 return; 273 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 274 "cannot compile this %0 yet"); 275 std::string Msg = Type; 276 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 277 << Msg << S->getSourceRange(); 278 } 279 280 /// ErrorUnsupported - Print out an error that codegen doesn't support the 281 /// specified decl yet. 282 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 283 bool OmitOnError) { 284 if (OmitOnError && getDiags().hasErrorOccurred()) 285 return; 286 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 287 "cannot compile this %0 yet"); 288 std::string Msg = Type; 289 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 290 } 291 292 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 293 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 294 } 295 296 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 297 const NamedDecl *D) const { 298 // Internal definitions always have default visibility. 299 if (GV->hasLocalLinkage()) { 300 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 301 return; 302 } 303 304 // Set visibility for definitions. 305 LinkageInfo LV = D->getLinkageAndVisibility(); 306 if (LV.isVisibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 307 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 308 } 309 310 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) { 311 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S) 312 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel) 313 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel) 314 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel) 315 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel); 316 } 317 318 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel( 319 CodeGenOptions::TLSModel M) { 320 switch (M) { 321 case CodeGenOptions::GeneralDynamicTLSModel: 322 return llvm::GlobalVariable::GeneralDynamicTLSModel; 323 case CodeGenOptions::LocalDynamicTLSModel: 324 return llvm::GlobalVariable::LocalDynamicTLSModel; 325 case CodeGenOptions::InitialExecTLSModel: 326 return llvm::GlobalVariable::InitialExecTLSModel; 327 case CodeGenOptions::LocalExecTLSModel: 328 return llvm::GlobalVariable::LocalExecTLSModel; 329 } 330 llvm_unreachable("Invalid TLS model!"); 331 } 332 333 void CodeGenModule::setTLSMode(llvm::GlobalVariable *GV, 334 const VarDecl &D) const { 335 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!"); 336 337 llvm::GlobalVariable::ThreadLocalMode TLM; 338 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel()); 339 340 // Override the TLS model if it is explicitly specified. 341 if (D.hasAttr<TLSModelAttr>()) { 342 const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>(); 343 TLM = GetLLVMTLSModel(Attr->getModel()); 344 } 345 346 GV->setThreadLocalMode(TLM); 347 } 348 349 /// Set the symbol visibility of type information (vtable and RTTI) 350 /// associated with the given type. 351 void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 352 const CXXRecordDecl *RD, 353 TypeVisibilityKind TVK) const { 354 setGlobalVisibility(GV, RD); 355 356 if (!CodeGenOpts.HiddenWeakVTables) 357 return; 358 359 // We never want to drop the visibility for RTTI names. 360 if (TVK == TVK_ForRTTIName) 361 return; 362 363 // We want to drop the visibility to hidden for weak type symbols. 364 // This isn't possible if there might be unresolved references 365 // elsewhere that rely on this symbol being visible. 366 367 // This should be kept roughly in sync with setThunkVisibility 368 // in CGVTables.cpp. 369 370 // Preconditions. 371 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 372 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 373 return; 374 375 // Don't override an explicit visibility attribute. 376 if (RD->getExplicitVisibility(NamedDecl::VisibilityForType)) 377 return; 378 379 switch (RD->getTemplateSpecializationKind()) { 380 // We have to disable the optimization if this is an EI definition 381 // because there might be EI declarations in other shared objects. 382 case TSK_ExplicitInstantiationDefinition: 383 case TSK_ExplicitInstantiationDeclaration: 384 return; 385 386 // Every use of a non-template class's type information has to emit it. 387 case TSK_Undeclared: 388 break; 389 390 // In theory, implicit instantiations can ignore the possibility of 391 // an explicit instantiation declaration because there necessarily 392 // must be an EI definition somewhere with default visibility. In 393 // practice, it's possible to have an explicit instantiation for 394 // an arbitrary template class, and linkers aren't necessarily able 395 // to deal with mixed-visibility symbols. 396 case TSK_ExplicitSpecialization: 397 case TSK_ImplicitInstantiation: 398 return; 399 } 400 401 // If there's a key function, there may be translation units 402 // that don't have the key function's definition. But ignore 403 // this if we're emitting RTTI under -fno-rtti. 404 if (!(TVK != TVK_ForRTTI) || LangOpts.RTTI) { 405 // FIXME: what should we do if we "lose" the key function during 406 // the emission of the file? 407 if (Context.getCurrentKeyFunction(RD)) 408 return; 409 } 410 411 // Otherwise, drop the visibility to hidden. 412 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 413 GV->setUnnamedAddr(true); 414 } 415 416 StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 417 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 418 419 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 420 if (!Str.empty()) 421 return Str; 422 423 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 424 IdentifierInfo *II = ND->getIdentifier(); 425 assert(II && "Attempt to mangle unnamed decl."); 426 427 Str = II->getName(); 428 return Str; 429 } 430 431 SmallString<256> Buffer; 432 llvm::raw_svector_ostream Out(Buffer); 433 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 434 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 435 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 436 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 437 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND)) 438 getCXXABI().getMangleContext().mangleBlock(BD, Out, 439 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl())); 440 else 441 getCXXABI().getMangleContext().mangleName(ND, Out); 442 443 // Allocate space for the mangled name. 444 Out.flush(); 445 size_t Length = Buffer.size(); 446 char *Name = MangledNamesAllocator.Allocate<char>(Length); 447 std::copy(Buffer.begin(), Buffer.end(), Name); 448 449 Str = StringRef(Name, Length); 450 451 return Str; 452 } 453 454 void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 455 const BlockDecl *BD) { 456 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 457 const Decl *D = GD.getDecl(); 458 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 459 if (D == 0) 460 MangleCtx.mangleGlobalBlock(BD, 461 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out); 462 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 463 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 464 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 465 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 466 else 467 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 468 } 469 470 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 471 return getModule().getNamedValue(Name); 472 } 473 474 /// AddGlobalCtor - Add a function to the list that will be called before 475 /// main() runs. 476 void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 477 // FIXME: Type coercion of void()* types. 478 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 479 } 480 481 /// AddGlobalDtor - Add a function to the list that will be called 482 /// when the module is unloaded. 483 void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 484 // FIXME: Type coercion of void()* types. 485 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 486 } 487 488 void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 489 // Ctor function type is void()*. 490 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 491 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 492 493 // Get the type of a ctor entry, { i32, void ()* }. 494 llvm::StructType *CtorStructTy = 495 llvm::StructType::get(Int32Ty, llvm::PointerType::getUnqual(CtorFTy), NULL); 496 497 // Construct the constructor and destructor arrays. 498 SmallVector<llvm::Constant*, 8> Ctors; 499 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 500 llvm::Constant *S[] = { 501 llvm::ConstantInt::get(Int32Ty, I->second, false), 502 llvm::ConstantExpr::getBitCast(I->first, CtorPFTy) 503 }; 504 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 505 } 506 507 if (!Ctors.empty()) { 508 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 509 new llvm::GlobalVariable(TheModule, AT, false, 510 llvm::GlobalValue::AppendingLinkage, 511 llvm::ConstantArray::get(AT, Ctors), 512 GlobalName); 513 } 514 } 515 516 llvm::GlobalValue::LinkageTypes 517 CodeGenModule::getFunctionLinkage(GlobalDecl GD) { 518 return getFunctionLinkage(cast<FunctionDecl>(GD.getDecl())); 519 } 520 521 llvm::GlobalValue::LinkageTypes 522 CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 523 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 524 525 if (Linkage == GVA_Internal) 526 return llvm::Function::InternalLinkage; 527 528 if (D->hasAttr<DLLExportAttr>()) 529 return llvm::Function::DLLExportLinkage; 530 531 if (D->hasAttr<WeakAttr>()) 532 return llvm::Function::WeakAnyLinkage; 533 534 // In C99 mode, 'inline' functions are guaranteed to have a strong 535 // definition somewhere else, so we can use available_externally linkage. 536 if (Linkage == GVA_C99Inline) 537 return llvm::Function::AvailableExternallyLinkage; 538 539 // Note that Apple's kernel linker doesn't support symbol 540 // coalescing, so we need to avoid linkonce and weak linkages there. 541 // Normally, this means we just map to internal, but for explicit 542 // instantiations we'll map to external. 543 544 // In C++, the compiler has to emit a definition in every translation unit 545 // that references the function. We should use linkonce_odr because 546 // a) if all references in this translation unit are optimized away, we 547 // don't need to codegen it. b) if the function persists, it needs to be 548 // merged with other definitions. c) C++ has the ODR, so we know the 549 // definition is dependable. 550 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 551 return !Context.getLangOpts().AppleKext 552 ? llvm::Function::LinkOnceODRLinkage 553 : llvm::Function::InternalLinkage; 554 555 // An explicit instantiation of a template has weak linkage, since 556 // explicit instantiations can occur in multiple translation units 557 // and must all be equivalent. However, we are not allowed to 558 // throw away these explicit instantiations. 559 if (Linkage == GVA_ExplicitTemplateInstantiation) 560 return !Context.getLangOpts().AppleKext 561 ? llvm::Function::WeakODRLinkage 562 : llvm::Function::ExternalLinkage; 563 564 // Otherwise, we have strong external linkage. 565 assert(Linkage == GVA_StrongExternal); 566 return llvm::Function::ExternalLinkage; 567 } 568 569 570 /// SetFunctionDefinitionAttributes - Set attributes for a global. 571 /// 572 /// FIXME: This is currently only done for aliases and functions, but not for 573 /// variables (these details are set in EmitGlobalVarDefinition for variables). 574 void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 575 llvm::GlobalValue *GV) { 576 SetCommonAttributes(D, GV); 577 } 578 579 void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 580 const CGFunctionInfo &Info, 581 llvm::Function *F) { 582 unsigned CallingConv; 583 AttributeListType AttributeList; 584 ConstructAttributeList(Info, D, AttributeList, CallingConv, false); 585 F->setAttributes(llvm::AttributeSet::get(getLLVMContext(), AttributeList)); 586 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 587 } 588 589 /// Determines whether the language options require us to model 590 /// unwind exceptions. We treat -fexceptions as mandating this 591 /// except under the fragile ObjC ABI with only ObjC exceptions 592 /// enabled. This means, for example, that C with -fexceptions 593 /// enables this. 594 static bool hasUnwindExceptions(const LangOptions &LangOpts) { 595 // If exceptions are completely disabled, obviously this is false. 596 if (!LangOpts.Exceptions) return false; 597 598 // If C++ exceptions are enabled, this is true. 599 if (LangOpts.CXXExceptions) return true; 600 601 // If ObjC exceptions are enabled, this depends on the ABI. 602 if (LangOpts.ObjCExceptions) { 603 return LangOpts.ObjCRuntime.hasUnwindExceptions(); 604 } 605 606 return true; 607 } 608 609 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 610 llvm::Function *F) { 611 llvm::AttrBuilder B; 612 613 if (CodeGenOpts.UnwindTables) 614 B.addAttribute(llvm::Attribute::UWTable); 615 616 if (!hasUnwindExceptions(LangOpts)) 617 B.addAttribute(llvm::Attribute::NoUnwind); 618 619 if (D->hasAttr<NakedAttr>()) { 620 // Naked implies noinline: we should not be inlining such functions. 621 B.addAttribute(llvm::Attribute::Naked); 622 B.addAttribute(llvm::Attribute::NoInline); 623 } else if (D->hasAttr<NoInlineAttr>()) { 624 B.addAttribute(llvm::Attribute::NoInline); 625 } else if ((D->hasAttr<AlwaysInlineAttr>() || 626 D->hasAttr<ForceInlineAttr>()) && 627 !F->getAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex, 628 llvm::Attribute::NoInline)) { 629 // (noinline wins over always_inline, and we can't specify both in IR) 630 B.addAttribute(llvm::Attribute::AlwaysInline); 631 } 632 633 if (D->hasAttr<ColdAttr>()) { 634 B.addAttribute(llvm::Attribute::OptimizeForSize); 635 B.addAttribute(llvm::Attribute::Cold); 636 } 637 638 if (D->hasAttr<MinSizeAttr>()) 639 B.addAttribute(llvm::Attribute::MinSize); 640 641 if (LangOpts.getStackProtector() == LangOptions::SSPOn) 642 B.addAttribute(llvm::Attribute::StackProtect); 643 else if (LangOpts.getStackProtector() == LangOptions::SSPReq) 644 B.addAttribute(llvm::Attribute::StackProtectReq); 645 646 // Add sanitizer attributes if function is not blacklisted. 647 if (!SanitizerBlacklist.isIn(*F)) { 648 // When AddressSanitizer is enabled, set SanitizeAddress attribute 649 // unless __attribute__((no_sanitize_address)) is used. 650 if (SanOpts.Address && !D->hasAttr<NoSanitizeAddressAttr>()) 651 B.addAttribute(llvm::Attribute::SanitizeAddress); 652 // Same for ThreadSanitizer and __attribute__((no_sanitize_thread)) 653 if (SanOpts.Thread && !D->hasAttr<NoSanitizeThreadAttr>()) { 654 B.addAttribute(llvm::Attribute::SanitizeThread); 655 } 656 // Same for MemorySanitizer and __attribute__((no_sanitize_memory)) 657 if (SanOpts.Memory && !D->hasAttr<NoSanitizeMemoryAttr>()) 658 B.addAttribute(llvm::Attribute::SanitizeMemory); 659 } 660 661 F->addAttributes(llvm::AttributeSet::FunctionIndex, 662 llvm::AttributeSet::get( 663 F->getContext(), llvm::AttributeSet::FunctionIndex, B)); 664 665 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 666 F->setUnnamedAddr(true); 667 else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) 668 if (MD->isVirtual()) 669 F->setUnnamedAddr(true); 670 671 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 672 if (alignment) 673 F->setAlignment(alignment); 674 675 // C++ ABI requires 2-byte alignment for member functions. 676 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 677 F->setAlignment(2); 678 } 679 680 void CodeGenModule::SetCommonAttributes(const Decl *D, 681 llvm::GlobalValue *GV) { 682 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 683 setGlobalVisibility(GV, ND); 684 else 685 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 686 687 if (D->hasAttr<UsedAttr>()) 688 AddUsedGlobal(GV); 689 690 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 691 GV->setSection(SA->getName()); 692 693 // Alias cannot have attributes. Filter them here. 694 if (!isa<llvm::GlobalAlias>(GV)) 695 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 696 } 697 698 void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 699 llvm::Function *F, 700 const CGFunctionInfo &FI) { 701 SetLLVMFunctionAttributes(D, FI, F); 702 SetLLVMFunctionAttributesForDefinition(D, F); 703 704 F->setLinkage(llvm::Function::InternalLinkage); 705 706 SetCommonAttributes(D, F); 707 } 708 709 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 710 llvm::Function *F, 711 bool IsIncompleteFunction) { 712 if (unsigned IID = F->getIntrinsicID()) { 713 // If this is an intrinsic function, set the function's attributes 714 // to the intrinsic's attributes. 715 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), 716 (llvm::Intrinsic::ID)IID)); 717 return; 718 } 719 720 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 721 722 if (!IsIncompleteFunction) 723 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F); 724 725 // Only a few attributes are set on declarations; these may later be 726 // overridden by a definition. 727 728 if (FD->hasAttr<DLLImportAttr>()) { 729 F->setLinkage(llvm::Function::DLLImportLinkage); 730 } else if (FD->hasAttr<WeakAttr>() || 731 FD->isWeakImported()) { 732 // "extern_weak" is overloaded in LLVM; we probably should have 733 // separate linkage types for this. 734 F->setLinkage(llvm::Function::ExternalWeakLinkage); 735 } else { 736 F->setLinkage(llvm::Function::ExternalLinkage); 737 738 LinkageInfo LV = FD->getLinkageAndVisibility(); 739 if (LV.getLinkage() == ExternalLinkage && LV.isVisibilityExplicit()) { 740 F->setVisibility(GetLLVMVisibility(LV.getVisibility())); 741 } 742 } 743 744 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 745 F->setSection(SA->getName()); 746 } 747 748 void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 749 assert(!GV->isDeclaration() && 750 "Only globals with definition can force usage."); 751 LLVMUsed.push_back(GV); 752 } 753 754 void CodeGenModule::EmitLLVMUsed() { 755 // Don't create llvm.used if there is no need. 756 if (LLVMUsed.empty()) 757 return; 758 759 // Convert LLVMUsed to what ConstantArray needs. 760 SmallVector<llvm::Constant*, 8> UsedArray; 761 UsedArray.resize(LLVMUsed.size()); 762 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 763 UsedArray[i] = 764 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 765 Int8PtrTy); 766 } 767 768 if (UsedArray.empty()) 769 return; 770 llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size()); 771 772 llvm::GlobalVariable *GV = 773 new llvm::GlobalVariable(getModule(), ATy, false, 774 llvm::GlobalValue::AppendingLinkage, 775 llvm::ConstantArray::get(ATy, UsedArray), 776 "llvm.used"); 777 778 GV->setSection("llvm.metadata"); 779 } 780 781 void CodeGenModule::AppendLinkerOptions(StringRef Opts) { 782 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opts); 783 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 784 } 785 786 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) { 787 llvm::SmallString<32> Opt; 788 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt); 789 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); 790 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 791 } 792 793 void CodeGenModule::AddDependentLib(StringRef Lib) { 794 llvm::SmallString<24> Opt; 795 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt); 796 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); 797 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 798 } 799 800 /// \brief Add link options implied by the given module, including modules 801 /// it depends on, using a postorder walk. 802 static void addLinkOptionsPostorder(CodeGenModule &CGM, 803 Module *Mod, 804 SmallVectorImpl<llvm::Value *> &Metadata, 805 llvm::SmallPtrSet<Module *, 16> &Visited) { 806 // Import this module's parent. 807 if (Mod->Parent && Visited.insert(Mod->Parent)) { 808 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited); 809 } 810 811 // Import this module's dependencies. 812 for (unsigned I = Mod->Imports.size(); I > 0; --I) { 813 if (Visited.insert(Mod->Imports[I-1])) 814 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited); 815 } 816 817 // Add linker options to link against the libraries/frameworks 818 // described by this module. 819 llvm::LLVMContext &Context = CGM.getLLVMContext(); 820 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) { 821 // Link against a framework. Frameworks are currently Darwin only, so we 822 // don't to ask TargetCodeGenInfo for the spelling of the linker option. 823 if (Mod->LinkLibraries[I-1].IsFramework) { 824 llvm::Value *Args[2] = { 825 llvm::MDString::get(Context, "-framework"), 826 llvm::MDString::get(Context, Mod->LinkLibraries[I-1].Library) 827 }; 828 829 Metadata.push_back(llvm::MDNode::get(Context, Args)); 830 continue; 831 } 832 833 // Link against a library. 834 llvm::SmallString<24> Opt; 835 CGM.getTargetCodeGenInfo().getDependentLibraryOption( 836 Mod->LinkLibraries[I-1].Library, Opt); 837 llvm::Value *OptString = llvm::MDString::get(Context, Opt); 838 Metadata.push_back(llvm::MDNode::get(Context, OptString)); 839 } 840 } 841 842 void CodeGenModule::EmitModuleLinkOptions() { 843 // Collect the set of all of the modules we want to visit to emit link 844 // options, which is essentially the imported modules and all of their 845 // non-explicit child modules. 846 llvm::SetVector<clang::Module *> LinkModules; 847 llvm::SmallPtrSet<clang::Module *, 16> Visited; 848 SmallVector<clang::Module *, 16> Stack; 849 850 // Seed the stack with imported modules. 851 for (llvm::SetVector<clang::Module *>::iterator M = ImportedModules.begin(), 852 MEnd = ImportedModules.end(); 853 M != MEnd; ++M) { 854 if (Visited.insert(*M)) 855 Stack.push_back(*M); 856 } 857 858 // Find all of the modules to import, making a little effort to prune 859 // non-leaf modules. 860 while (!Stack.empty()) { 861 clang::Module *Mod = Stack.back(); 862 Stack.pop_back(); 863 864 bool AnyChildren = false; 865 866 // Visit the submodules of this module. 867 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(), 868 SubEnd = Mod->submodule_end(); 869 Sub != SubEnd; ++Sub) { 870 // Skip explicit children; they need to be explicitly imported to be 871 // linked against. 872 if ((*Sub)->IsExplicit) 873 continue; 874 875 if (Visited.insert(*Sub)) { 876 Stack.push_back(*Sub); 877 AnyChildren = true; 878 } 879 } 880 881 // We didn't find any children, so add this module to the list of 882 // modules to link against. 883 if (!AnyChildren) { 884 LinkModules.insert(Mod); 885 } 886 } 887 888 // Add link options for all of the imported modules in reverse topological 889 // order. We don't do anything to try to order import link flags with respect 890 // to linker options inserted by things like #pragma comment(). 891 SmallVector<llvm::Value *, 16> MetadataArgs; 892 Visited.clear(); 893 for (llvm::SetVector<clang::Module *>::iterator M = LinkModules.begin(), 894 MEnd = LinkModules.end(); 895 M != MEnd; ++M) { 896 if (Visited.insert(*M)) 897 addLinkOptionsPostorder(*this, *M, MetadataArgs, Visited); 898 } 899 std::reverse(MetadataArgs.begin(), MetadataArgs.end()); 900 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end()); 901 902 // Add the linker options metadata flag. 903 getModule().addModuleFlag(llvm::Module::AppendUnique, "Linker Options", 904 llvm::MDNode::get(getLLVMContext(), 905 LinkerOptionsMetadata)); 906 } 907 908 void CodeGenModule::EmitDeferred() { 909 // Emit code for any potentially referenced deferred decls. Since a 910 // previously unused static decl may become used during the generation of code 911 // for a static function, iterate until no changes are made. 912 913 while (true) { 914 if (!DeferredVTables.empty()) { 915 EmitDeferredVTables(); 916 917 // Emitting a v-table doesn't directly cause more v-tables to 918 // become deferred, although it can cause functions to be 919 // emitted that then need those v-tables. 920 assert(DeferredVTables.empty()); 921 } 922 923 // Stop if we're out of both deferred v-tables and deferred declarations. 924 if (DeferredDeclsToEmit.empty()) break; 925 926 GlobalDecl D = DeferredDeclsToEmit.back(); 927 DeferredDeclsToEmit.pop_back(); 928 929 // Check to see if we've already emitted this. This is necessary 930 // for a couple of reasons: first, decls can end up in the 931 // deferred-decls queue multiple times, and second, decls can end 932 // up with definitions in unusual ways (e.g. by an extern inline 933 // function acquiring a strong function redefinition). Just 934 // ignore these cases. 935 // 936 // TODO: That said, looking this up multiple times is very wasteful. 937 StringRef Name = getMangledName(D); 938 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 939 assert(CGRef && "Deferred decl wasn't referenced?"); 940 941 if (!CGRef->isDeclaration()) 942 continue; 943 944 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 945 // purposes an alias counts as a definition. 946 if (isa<llvm::GlobalAlias>(CGRef)) 947 continue; 948 949 // Otherwise, emit the definition and move on to the next one. 950 EmitGlobalDefinition(D); 951 } 952 } 953 954 void CodeGenModule::EmitGlobalAnnotations() { 955 if (Annotations.empty()) 956 return; 957 958 // Create a new global variable for the ConstantStruct in the Module. 959 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 960 Annotations[0]->getType(), Annotations.size()), Annotations); 961 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), 962 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, 963 "llvm.global.annotations"); 964 gv->setSection(AnnotationSection); 965 } 966 967 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) { 968 llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str); 969 if (i != AnnotationStrings.end()) 970 return i->second; 971 972 // Not found yet, create a new global. 973 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); 974 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), 975 true, llvm::GlobalValue::PrivateLinkage, s, ".str"); 976 gv->setSection(AnnotationSection); 977 gv->setUnnamedAddr(true); 978 AnnotationStrings[Str] = gv; 979 return gv; 980 } 981 982 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 983 SourceManager &SM = getContext().getSourceManager(); 984 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 985 if (PLoc.isValid()) 986 return EmitAnnotationString(PLoc.getFilename()); 987 return EmitAnnotationString(SM.getBufferName(Loc)); 988 } 989 990 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 991 SourceManager &SM = getContext().getSourceManager(); 992 PresumedLoc PLoc = SM.getPresumedLoc(L); 993 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 994 SM.getExpansionLineNumber(L); 995 return llvm::ConstantInt::get(Int32Ty, LineNo); 996 } 997 998 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 999 const AnnotateAttr *AA, 1000 SourceLocation L) { 1001 // Get the globals for file name, annotation, and the line number. 1002 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 1003 *UnitGV = EmitAnnotationUnit(L), 1004 *LineNoCst = EmitAnnotationLineNo(L); 1005 1006 // Create the ConstantStruct for the global annotation. 1007 llvm::Constant *Fields[4] = { 1008 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 1009 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 1010 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 1011 LineNoCst 1012 }; 1013 return llvm::ConstantStruct::getAnon(Fields); 1014 } 1015 1016 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 1017 llvm::GlobalValue *GV) { 1018 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 1019 // Get the struct elements for these annotations. 1020 for (specific_attr_iterator<AnnotateAttr> 1021 ai = D->specific_attr_begin<AnnotateAttr>(), 1022 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) 1023 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); 1024 } 1025 1026 bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 1027 // Never defer when EmitAllDecls is specified. 1028 if (LangOpts.EmitAllDecls) 1029 return false; 1030 1031 return !getContext().DeclMustBeEmitted(Global); 1032 } 1033 1034 llvm::Constant *CodeGenModule::GetAddrOfUuidDescriptor( 1035 const CXXUuidofExpr* E) { 1036 // Sema has verified that IIDSource has a __declspec(uuid()), and that its 1037 // well-formed. 1038 StringRef Uuid; 1039 if (E->isTypeOperand()) 1040 Uuid = CXXUuidofExpr::GetUuidAttrOfType(E->getTypeOperand())->getGuid(); 1041 else { 1042 // Special case: __uuidof(0) means an all-zero GUID. 1043 Expr *Op = E->getExprOperand(); 1044 if (!Op->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 1045 Uuid = CXXUuidofExpr::GetUuidAttrOfType(Op->getType())->getGuid(); 1046 else 1047 Uuid = "00000000-0000-0000-0000-000000000000"; 1048 } 1049 std::string Name = "__uuid_" + Uuid.str(); 1050 1051 // Look for an existing global. 1052 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name)) 1053 return GV; 1054 1055 llvm::Constant *Init = EmitUuidofInitializer(Uuid, E->getType()); 1056 assert(Init && "failed to initialize as constant"); 1057 1058 // GUIDs are assumed to be 16 bytes, spread over 4-2-2-8 bytes. However, the 1059 // first field is declared as "long", which for many targets is 8 bytes. 1060 // Those architectures are not supported. (With the MS abi, long is always 4 1061 // bytes.) 1062 llvm::Type *GuidType = getTypes().ConvertType(E->getType()); 1063 if (Init->getType() != GuidType) { 1064 DiagnosticsEngine &Diags = getDiags(); 1065 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error, 1066 "__uuidof codegen is not supported on this architecture"); 1067 Diags.Report(E->getExprLoc(), DiagID) << E->getSourceRange(); 1068 Init = llvm::UndefValue::get(GuidType); 1069 } 1070 1071 llvm::GlobalVariable *GV = new llvm::GlobalVariable(getModule(), GuidType, 1072 /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, Init, Name); 1073 GV->setUnnamedAddr(true); 1074 return GV; 1075 } 1076 1077 llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 1078 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 1079 assert(AA && "No alias?"); 1080 1081 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 1082 1083 // See if there is already something with the target's name in the module. 1084 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 1085 if (Entry) { 1086 unsigned AS = getContext().getTargetAddressSpace(VD->getType()); 1087 return llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS)); 1088 } 1089 1090 llvm::Constant *Aliasee; 1091 if (isa<llvm::FunctionType>(DeclTy)) 1092 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, 1093 GlobalDecl(cast<FunctionDecl>(VD)), 1094 /*ForVTable=*/false); 1095 else 1096 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1097 llvm::PointerType::getUnqual(DeclTy), 0); 1098 1099 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 1100 F->setLinkage(llvm::Function::ExternalWeakLinkage); 1101 WeakRefReferences.insert(F); 1102 1103 return Aliasee; 1104 } 1105 1106 void CodeGenModule::EmitGlobal(GlobalDecl GD) { 1107 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 1108 1109 // Weak references don't produce any output by themselves. 1110 if (Global->hasAttr<WeakRefAttr>()) 1111 return; 1112 1113 // If this is an alias definition (which otherwise looks like a declaration) 1114 // emit it now. 1115 if (Global->hasAttr<AliasAttr>()) 1116 return EmitAliasDefinition(GD); 1117 1118 // If this is CUDA, be selective about which declarations we emit. 1119 if (LangOpts.CUDA) { 1120 if (CodeGenOpts.CUDAIsDevice) { 1121 if (!Global->hasAttr<CUDADeviceAttr>() && 1122 !Global->hasAttr<CUDAGlobalAttr>() && 1123 !Global->hasAttr<CUDAConstantAttr>() && 1124 !Global->hasAttr<CUDASharedAttr>()) 1125 return; 1126 } else { 1127 if (!Global->hasAttr<CUDAHostAttr>() && ( 1128 Global->hasAttr<CUDADeviceAttr>() || 1129 Global->hasAttr<CUDAConstantAttr>() || 1130 Global->hasAttr<CUDASharedAttr>())) 1131 return; 1132 } 1133 } 1134 1135 // Ignore declarations, they will be emitted on their first use. 1136 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 1137 // Forward declarations are emitted lazily on first use. 1138 if (!FD->doesThisDeclarationHaveABody()) { 1139 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 1140 return; 1141 1142 const FunctionDecl *InlineDefinition = 0; 1143 FD->getBody(InlineDefinition); 1144 1145 StringRef MangledName = getMangledName(GD); 1146 DeferredDecls.erase(MangledName); 1147 EmitGlobalDefinition(InlineDefinition); 1148 return; 1149 } 1150 } else { 1151 const VarDecl *VD = cast<VarDecl>(Global); 1152 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 1153 1154 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 1155 return; 1156 } 1157 1158 // Defer code generation when possible if this is a static definition, inline 1159 // function etc. These we only want to emit if they are used. 1160 if (!MayDeferGeneration(Global)) { 1161 // Emit the definition if it can't be deferred. 1162 EmitGlobalDefinition(GD); 1163 return; 1164 } 1165 1166 // If we're deferring emission of a C++ variable with an 1167 // initializer, remember the order in which it appeared in the file. 1168 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) && 1169 cast<VarDecl>(Global)->hasInit()) { 1170 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 1171 CXXGlobalInits.push_back(0); 1172 } 1173 1174 // If the value has already been used, add it directly to the 1175 // DeferredDeclsToEmit list. 1176 StringRef MangledName = getMangledName(GD); 1177 if (GetGlobalValue(MangledName)) 1178 DeferredDeclsToEmit.push_back(GD); 1179 else { 1180 // Otherwise, remember that we saw a deferred decl with this name. The 1181 // first use of the mangled name will cause it to move into 1182 // DeferredDeclsToEmit. 1183 DeferredDecls[MangledName] = GD; 1184 } 1185 } 1186 1187 namespace { 1188 struct FunctionIsDirectlyRecursive : 1189 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> { 1190 const StringRef Name; 1191 const Builtin::Context &BI; 1192 bool Result; 1193 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) : 1194 Name(N), BI(C), Result(false) { 1195 } 1196 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; 1197 1198 bool TraverseCallExpr(CallExpr *E) { 1199 const FunctionDecl *FD = E->getDirectCallee(); 1200 if (!FD) 1201 return true; 1202 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1203 if (Attr && Name == Attr->getLabel()) { 1204 Result = true; 1205 return false; 1206 } 1207 unsigned BuiltinID = FD->getBuiltinID(); 1208 if (!BuiltinID) 1209 return true; 1210 StringRef BuiltinName = BI.GetName(BuiltinID); 1211 if (BuiltinName.startswith("__builtin_") && 1212 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { 1213 Result = true; 1214 return false; 1215 } 1216 return true; 1217 } 1218 }; 1219 } 1220 1221 // isTriviallyRecursive - Check if this function calls another 1222 // decl that, because of the asm attribute or the other decl being a builtin, 1223 // ends up pointing to itself. 1224 bool 1225 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { 1226 StringRef Name; 1227 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { 1228 // asm labels are a special kind of mangling we have to support. 1229 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1230 if (!Attr) 1231 return false; 1232 Name = Attr->getLabel(); 1233 } else { 1234 Name = FD->getName(); 1235 } 1236 1237 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); 1238 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD)); 1239 return Walker.Result; 1240 } 1241 1242 bool 1243 CodeGenModule::shouldEmitFunction(GlobalDecl GD) { 1244 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage) 1245 return true; 1246 const FunctionDecl *F = cast<FunctionDecl>(GD.getDecl()); 1247 if (CodeGenOpts.OptimizationLevel == 0 && 1248 !F->hasAttr<AlwaysInlineAttr>() && !F->hasAttr<ForceInlineAttr>()) 1249 return false; 1250 // PR9614. Avoid cases where the source code is lying to us. An available 1251 // externally function should have an equivalent function somewhere else, 1252 // but a function that calls itself is clearly not equivalent to the real 1253 // implementation. 1254 // This happens in glibc's btowc and in some configure checks. 1255 return !isTriviallyRecursive(F); 1256 } 1257 1258 /// If the type for the method's class was generated by 1259 /// CGDebugInfo::createContextChain(), the cache contains only a 1260 /// limited DIType without any declarations. Since EmitFunctionStart() 1261 /// needs to find the canonical declaration for each method, we need 1262 /// to construct the complete type prior to emitting the method. 1263 void CodeGenModule::CompleteDIClassType(const CXXMethodDecl* D) { 1264 if (!D->isInstance()) 1265 return; 1266 1267 if (CGDebugInfo *DI = getModuleDebugInfo()) 1268 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) { 1269 const PointerType *ThisPtr = 1270 cast<PointerType>(D->getThisType(getContext())); 1271 DI->getOrCreateRecordType(ThisPtr->getPointeeType(), D->getLocation()); 1272 } 1273 } 1274 1275 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 1276 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1277 1278 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 1279 Context.getSourceManager(), 1280 "Generating code for declaration"); 1281 1282 if (isa<FunctionDecl>(D)) { 1283 // At -O0, don't generate IR for functions with available_externally 1284 // linkage. 1285 if (!shouldEmitFunction(GD)) 1286 return; 1287 1288 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 1289 CompleteDIClassType(Method); 1290 // Make sure to emit the definition(s) before we emit the thunks. 1291 // This is necessary for the generation of certain thunks. 1292 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 1293 EmitCXXConstructor(CD, GD.getCtorType()); 1294 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 1295 EmitCXXDestructor(DD, GD.getDtorType()); 1296 else 1297 EmitGlobalFunctionDefinition(GD); 1298 1299 if (Method->isVirtual()) 1300 getVTables().EmitThunks(GD); 1301 1302 return; 1303 } 1304 1305 return EmitGlobalFunctionDefinition(GD); 1306 } 1307 1308 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 1309 return EmitGlobalVarDefinition(VD); 1310 1311 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 1312 } 1313 1314 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the 1315 /// module, create and return an llvm Function with the specified type. If there 1316 /// is something in the module with the specified name, return it potentially 1317 /// bitcasted to the right type. 1318 /// 1319 /// If D is non-null, it specifies a decl that correspond to this. This is used 1320 /// to set the attributes on the function when it is first created. 1321 llvm::Constant * 1322 CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 1323 llvm::Type *Ty, 1324 GlobalDecl D, bool ForVTable, 1325 llvm::AttributeSet ExtraAttrs) { 1326 // Lookup the entry, lazily creating it if necessary. 1327 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1328 if (Entry) { 1329 if (WeakRefReferences.erase(Entry)) { 1330 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 1331 if (FD && !FD->hasAttr<WeakAttr>()) 1332 Entry->setLinkage(llvm::Function::ExternalLinkage); 1333 } 1334 1335 if (Entry->getType()->getElementType() == Ty) 1336 return Entry; 1337 1338 // Make sure the result is of the correct type. 1339 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 1340 } 1341 1342 // This function doesn't have a complete type (for example, the return 1343 // type is an incomplete struct). Use a fake type instead, and make 1344 // sure not to try to set attributes. 1345 bool IsIncompleteFunction = false; 1346 1347 llvm::FunctionType *FTy; 1348 if (isa<llvm::FunctionType>(Ty)) { 1349 FTy = cast<llvm::FunctionType>(Ty); 1350 } else { 1351 FTy = llvm::FunctionType::get(VoidTy, false); 1352 IsIncompleteFunction = true; 1353 } 1354 1355 llvm::Function *F = llvm::Function::Create(FTy, 1356 llvm::Function::ExternalLinkage, 1357 MangledName, &getModule()); 1358 assert(F->getName() == MangledName && "name was uniqued!"); 1359 if (D.getDecl()) 1360 SetFunctionAttributes(D, F, IsIncompleteFunction); 1361 if (ExtraAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) { 1362 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeSet::FunctionIndex); 1363 F->addAttributes(llvm::AttributeSet::FunctionIndex, 1364 llvm::AttributeSet::get(VMContext, 1365 llvm::AttributeSet::FunctionIndex, 1366 B)); 1367 } 1368 1369 // This is the first use or definition of a mangled name. If there is a 1370 // deferred decl with this name, remember that we need to emit it at the end 1371 // of the file. 1372 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1373 if (DDI != DeferredDecls.end()) { 1374 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1375 // list, and remove it from DeferredDecls (since we don't need it anymore). 1376 DeferredDeclsToEmit.push_back(DDI->second); 1377 DeferredDecls.erase(DDI); 1378 1379 // Otherwise, there are cases we have to worry about where we're 1380 // using a declaration for which we must emit a definition but where 1381 // we might not find a top-level definition: 1382 // - member functions defined inline in their classes 1383 // - friend functions defined inline in some class 1384 // - special member functions with implicit definitions 1385 // If we ever change our AST traversal to walk into class methods, 1386 // this will be unnecessary. 1387 // 1388 // We also don't emit a definition for a function if it's going to be an entry 1389 // in a vtable, unless it's already marked as used. 1390 } else if (getLangOpts().CPlusPlus && D.getDecl()) { 1391 // Look for a declaration that's lexically in a record. 1392 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); 1393 FD = FD->getMostRecentDecl(); 1394 do { 1395 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 1396 if (FD->isImplicit() && !ForVTable) { 1397 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 1398 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1399 break; 1400 } else if (FD->doesThisDeclarationHaveABody()) { 1401 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1402 break; 1403 } 1404 } 1405 FD = FD->getPreviousDecl(); 1406 } while (FD); 1407 } 1408 1409 // Make sure the result is of the requested type. 1410 if (!IsIncompleteFunction) { 1411 assert(F->getType()->getElementType() == Ty); 1412 return F; 1413 } 1414 1415 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1416 return llvm::ConstantExpr::getBitCast(F, PTy); 1417 } 1418 1419 /// GetAddrOfFunction - Return the address of the given function. If Ty is 1420 /// non-null, then this function will use the specified type if it has to 1421 /// create it (this occurs when we see a definition of the function). 1422 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 1423 llvm::Type *Ty, 1424 bool ForVTable) { 1425 // If there was no specific requested type, just convert it now. 1426 if (!Ty) 1427 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 1428 1429 StringRef MangledName = getMangledName(GD); 1430 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 1431 } 1432 1433 /// CreateRuntimeFunction - Create a new runtime function with the specified 1434 /// type and name. 1435 llvm::Constant * 1436 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 1437 StringRef Name, 1438 llvm::AttributeSet ExtraAttrs) { 1439 llvm::Constant *C 1440 = GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 1441 ExtraAttrs); 1442 if (llvm::Function *F = dyn_cast<llvm::Function>(C)) 1443 if (F->empty()) 1444 F->setCallingConv(getRuntimeCC()); 1445 return C; 1446 } 1447 1448 /// isTypeConstant - Determine whether an object of this type can be emitted 1449 /// as a constant. 1450 /// 1451 /// If ExcludeCtor is true, the duration when the object's constructor runs 1452 /// will not be considered. The caller will need to verify that the object is 1453 /// not written to during its construction. 1454 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) { 1455 if (!Ty.isConstant(Context) && !Ty->isReferenceType()) 1456 return false; 1457 1458 if (Context.getLangOpts().CPlusPlus) { 1459 if (const CXXRecordDecl *Record 1460 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl()) 1461 return ExcludeCtor && !Record->hasMutableFields() && 1462 Record->hasTrivialDestructor(); 1463 } 1464 1465 return true; 1466 } 1467 1468 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1469 /// create and return an llvm GlobalVariable with the specified type. If there 1470 /// is something in the module with the specified name, return it potentially 1471 /// bitcasted to the right type. 1472 /// 1473 /// If D is non-null, it specifies a decl that correspond to this. This is used 1474 /// to set the attributes on the global when it is first created. 1475 llvm::Constant * 1476 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1477 llvm::PointerType *Ty, 1478 const VarDecl *D, 1479 bool UnnamedAddr) { 1480 // Lookup the entry, lazily creating it if necessary. 1481 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1482 if (Entry) { 1483 if (WeakRefReferences.erase(Entry)) { 1484 if (D && !D->hasAttr<WeakAttr>()) 1485 Entry->setLinkage(llvm::Function::ExternalLinkage); 1486 } 1487 1488 if (UnnamedAddr) 1489 Entry->setUnnamedAddr(true); 1490 1491 if (Entry->getType() == Ty) 1492 return Entry; 1493 1494 // Make sure the result is of the correct type. 1495 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1496 } 1497 1498 // This is the first use or definition of a mangled name. If there is a 1499 // deferred decl with this name, remember that we need to emit it at the end 1500 // of the file. 1501 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1502 if (DDI != DeferredDecls.end()) { 1503 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1504 // list, and remove it from DeferredDecls (since we don't need it anymore). 1505 DeferredDeclsToEmit.push_back(DDI->second); 1506 DeferredDecls.erase(DDI); 1507 } 1508 1509 unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace()); 1510 llvm::GlobalVariable *GV = 1511 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1512 llvm::GlobalValue::ExternalLinkage, 1513 0, MangledName, 0, 1514 llvm::GlobalVariable::NotThreadLocal, AddrSpace); 1515 1516 // Handle things which are present even on external declarations. 1517 if (D) { 1518 // FIXME: This code is overly simple and should be merged with other global 1519 // handling. 1520 GV->setConstant(isTypeConstant(D->getType(), false)); 1521 1522 // Set linkage and visibility in case we never see a definition. 1523 LinkageInfo LV = D->getLinkageAndVisibility(); 1524 if (LV.getLinkage() != ExternalLinkage) { 1525 // Don't set internal linkage on declarations. 1526 } else { 1527 if (D->hasAttr<DLLImportAttr>()) 1528 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1529 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1530 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1531 1532 // Set visibility on a declaration only if it's explicit. 1533 if (LV.isVisibilityExplicit()) 1534 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 1535 } 1536 1537 if (D->getTLSKind()) { 1538 if (D->getTLSKind() == VarDecl::TLS_Dynamic) 1539 CXXThreadLocals.push_back(std::make_pair(D, GV)); 1540 setTLSMode(GV, *D); 1541 } 1542 } 1543 1544 if (AddrSpace != Ty->getAddressSpace()) 1545 return llvm::ConstantExpr::getBitCast(GV, Ty); 1546 else 1547 return GV; 1548 } 1549 1550 1551 llvm::GlobalVariable * 1552 CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1553 llvm::Type *Ty, 1554 llvm::GlobalValue::LinkageTypes Linkage) { 1555 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1556 llvm::GlobalVariable *OldGV = 0; 1557 1558 1559 if (GV) { 1560 // Check if the variable has the right type. 1561 if (GV->getType()->getElementType() == Ty) 1562 return GV; 1563 1564 // Because C++ name mangling, the only way we can end up with an already 1565 // existing global with the same name is if it has been declared extern "C". 1566 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1567 OldGV = GV; 1568 } 1569 1570 // Create a new variable. 1571 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1572 Linkage, 0, Name); 1573 1574 if (OldGV) { 1575 // Replace occurrences of the old variable if needed. 1576 GV->takeName(OldGV); 1577 1578 if (!OldGV->use_empty()) { 1579 llvm::Constant *NewPtrForOldDecl = 1580 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1581 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1582 } 1583 1584 OldGV->eraseFromParent(); 1585 } 1586 1587 return GV; 1588 } 1589 1590 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1591 /// given global variable. If Ty is non-null and if the global doesn't exist, 1592 /// then it will be created with the specified type instead of whatever the 1593 /// normal requested type would be. 1594 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1595 llvm::Type *Ty) { 1596 assert(D->hasGlobalStorage() && "Not a global variable"); 1597 QualType ASTTy = D->getType(); 1598 if (Ty == 0) 1599 Ty = getTypes().ConvertTypeForMem(ASTTy); 1600 1601 llvm::PointerType *PTy = 1602 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1603 1604 StringRef MangledName = getMangledName(D); 1605 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1606 } 1607 1608 /// CreateRuntimeVariable - Create a new runtime global variable with the 1609 /// specified type and name. 1610 llvm::Constant * 1611 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1612 StringRef Name) { 1613 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1614 true); 1615 } 1616 1617 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1618 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1619 1620 if (MayDeferGeneration(D)) { 1621 // If we have not seen a reference to this variable yet, place it 1622 // into the deferred declarations table to be emitted if needed 1623 // later. 1624 StringRef MangledName = getMangledName(D); 1625 if (!GetGlobalValue(MangledName)) { 1626 DeferredDecls[MangledName] = D; 1627 return; 1628 } 1629 } 1630 1631 // The tentative definition is the only definition. 1632 EmitGlobalVarDefinition(D); 1633 } 1634 1635 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1636 return Context.toCharUnitsFromBits( 1637 TheDataLayout.getTypeStoreSizeInBits(Ty)); 1638 } 1639 1640 unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D, 1641 unsigned AddrSpace) { 1642 if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) { 1643 if (D->hasAttr<CUDAConstantAttr>()) 1644 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_constant); 1645 else if (D->hasAttr<CUDASharedAttr>()) 1646 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_shared); 1647 else 1648 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_device); 1649 } 1650 1651 return AddrSpace; 1652 } 1653 1654 template<typename SomeDecl> 1655 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D, 1656 llvm::GlobalValue *GV) { 1657 if (!getLangOpts().CPlusPlus) 1658 return; 1659 1660 // Must have 'used' attribute, or else inline assembly can't rely on 1661 // the name existing. 1662 if (!D->template hasAttr<UsedAttr>()) 1663 return; 1664 1665 // Must have internal linkage and an ordinary name. 1666 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage) 1667 return; 1668 1669 // Must be in an extern "C" context. Entities declared directly within 1670 // a record are not extern "C" even if the record is in such a context. 1671 const SomeDecl *First = D->getFirstDeclaration(); 1672 if (First->getDeclContext()->isRecord() || !First->isInExternCContext()) 1673 return; 1674 1675 // OK, this is an internal linkage entity inside an extern "C" linkage 1676 // specification. Make a note of that so we can give it the "expected" 1677 // mangled name if nothing else is using that name. 1678 std::pair<StaticExternCMap::iterator, bool> R = 1679 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV)); 1680 1681 // If we have multiple internal linkage entities with the same name 1682 // in extern "C" regions, none of them gets that name. 1683 if (!R.second) 1684 R.first->second = 0; 1685 } 1686 1687 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1688 llvm::Constant *Init = 0; 1689 QualType ASTTy = D->getType(); 1690 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 1691 bool NeedsGlobalCtor = false; 1692 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor(); 1693 1694 const VarDecl *InitDecl; 1695 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 1696 1697 if (!InitExpr) { 1698 // This is a tentative definition; tentative definitions are 1699 // implicitly initialized with { 0 }. 1700 // 1701 // Note that tentative definitions are only emitted at the end of 1702 // a translation unit, so they should never have incomplete 1703 // type. In addition, EmitTentativeDefinition makes sure that we 1704 // never attempt to emit a tentative definition if a real one 1705 // exists. A use may still exists, however, so we still may need 1706 // to do a RAUW. 1707 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1708 Init = EmitNullConstant(D->getType()); 1709 } else { 1710 initializedGlobalDecl = GlobalDecl(D); 1711 Init = EmitConstantInit(*InitDecl); 1712 1713 if (!Init) { 1714 QualType T = InitExpr->getType(); 1715 if (D->getType()->isReferenceType()) 1716 T = D->getType(); 1717 1718 if (getLangOpts().CPlusPlus) { 1719 Init = EmitNullConstant(T); 1720 NeedsGlobalCtor = true; 1721 } else { 1722 ErrorUnsupported(D, "static initializer"); 1723 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1724 } 1725 } else { 1726 // We don't need an initializer, so remove the entry for the delayed 1727 // initializer position (just in case this entry was delayed) if we 1728 // also don't need to register a destructor. 1729 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor) 1730 DelayedCXXInitPosition.erase(D); 1731 } 1732 } 1733 1734 llvm::Type* InitType = Init->getType(); 1735 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1736 1737 // Strip off a bitcast if we got one back. 1738 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1739 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1740 // all zero index gep. 1741 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1742 Entry = CE->getOperand(0); 1743 } 1744 1745 // Entry is now either a Function or GlobalVariable. 1746 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1747 1748 // We have a definition after a declaration with the wrong type. 1749 // We must make a new GlobalVariable* and update everything that used OldGV 1750 // (a declaration or tentative definition) with the new GlobalVariable* 1751 // (which will be a definition). 1752 // 1753 // This happens if there is a prototype for a global (e.g. 1754 // "extern int x[];") and then a definition of a different type (e.g. 1755 // "int x[10];"). This also happens when an initializer has a different type 1756 // from the type of the global (this happens with unions). 1757 if (GV == 0 || 1758 GV->getType()->getElementType() != InitType || 1759 GV->getType()->getAddressSpace() != 1760 GetGlobalVarAddressSpace(D, getContext().getTargetAddressSpace(ASTTy))) { 1761 1762 // Move the old entry aside so that we'll create a new one. 1763 Entry->setName(StringRef()); 1764 1765 // Make a new global with the correct type, this is now guaranteed to work. 1766 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1767 1768 // Replace all uses of the old global with the new global 1769 llvm::Constant *NewPtrForOldDecl = 1770 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1771 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1772 1773 // Erase the old global, since it is no longer used. 1774 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1775 } 1776 1777 MaybeHandleStaticInExternC(D, GV); 1778 1779 if (D->hasAttr<AnnotateAttr>()) 1780 AddGlobalAnnotations(D, GV); 1781 1782 GV->setInitializer(Init); 1783 1784 // If it is safe to mark the global 'constant', do so now. 1785 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor && 1786 isTypeConstant(D->getType(), true)); 1787 1788 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1789 1790 // Set the llvm linkage type as appropriate. 1791 llvm::GlobalValue::LinkageTypes Linkage = 1792 GetLLVMLinkageVarDefinition(D, GV); 1793 GV->setLinkage(Linkage); 1794 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1795 // common vars aren't constant even if declared const. 1796 GV->setConstant(false); 1797 1798 SetCommonAttributes(D, GV); 1799 1800 // Emit the initializer function if necessary. 1801 if (NeedsGlobalCtor || NeedsGlobalDtor) 1802 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); 1803 1804 // If we are compiling with ASan, add metadata indicating dynamically 1805 // initialized globals. 1806 if (SanOpts.Address && NeedsGlobalCtor) { 1807 llvm::Module &M = getModule(); 1808 1809 llvm::NamedMDNode *DynamicInitializers = 1810 M.getOrInsertNamedMetadata("llvm.asan.dynamically_initialized_globals"); 1811 llvm::Value *GlobalToAdd[] = { GV }; 1812 llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalToAdd); 1813 DynamicInitializers->addOperand(ThisGlobal); 1814 } 1815 1816 // Emit global variable debug information. 1817 if (CGDebugInfo *DI = getModuleDebugInfo()) 1818 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) 1819 DI->EmitGlobalVariable(GV, D); 1820 } 1821 1822 llvm::GlobalValue::LinkageTypes 1823 CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, 1824 llvm::GlobalVariable *GV) { 1825 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1826 if (Linkage == GVA_Internal) 1827 return llvm::Function::InternalLinkage; 1828 else if (D->hasAttr<DLLImportAttr>()) 1829 return llvm::Function::DLLImportLinkage; 1830 else if (D->hasAttr<DLLExportAttr>()) 1831 return llvm::Function::DLLExportLinkage; 1832 else if (D->hasAttr<SelectAnyAttr>()) { 1833 // selectany symbols are externally visible, so use weak instead of 1834 // linkonce. MSVC optimizes away references to const selectany globals, so 1835 // all definitions should be the same and ODR linkage should be used. 1836 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx 1837 return llvm::GlobalVariable::WeakODRLinkage; 1838 } else if (D->hasAttr<WeakAttr>()) { 1839 if (GV->isConstant()) 1840 return llvm::GlobalVariable::WeakODRLinkage; 1841 else 1842 return llvm::GlobalVariable::WeakAnyLinkage; 1843 } else if (Linkage == GVA_TemplateInstantiation || 1844 Linkage == GVA_ExplicitTemplateInstantiation) 1845 return llvm::GlobalVariable::WeakODRLinkage; 1846 else if (!getLangOpts().CPlusPlus && 1847 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1848 D->getAttr<CommonAttr>()) && 1849 !D->hasExternalStorage() && !D->getInit() && 1850 !D->getAttr<SectionAttr>() && !D->getTLSKind() && 1851 !D->getAttr<WeakImportAttr>()) { 1852 // Thread local vars aren't considered common linkage. 1853 return llvm::GlobalVariable::CommonLinkage; 1854 } else if (D->getTLSKind() == VarDecl::TLS_Dynamic && 1855 getTarget().getTriple().isMacOSX()) 1856 // On Darwin, the backing variable for a C++11 thread_local variable always 1857 // has internal linkage; all accesses should just be calls to the 1858 // Itanium-specified entry point, which has the normal linkage of the 1859 // variable. 1860 return llvm::GlobalValue::InternalLinkage; 1861 return llvm::GlobalVariable::ExternalLinkage; 1862 } 1863 1864 /// Replace the uses of a function that was declared with a non-proto type. 1865 /// We want to silently drop extra arguments from call sites 1866 static void replaceUsesOfNonProtoConstant(llvm::Constant *old, 1867 llvm::Function *newFn) { 1868 // Fast path. 1869 if (old->use_empty()) return; 1870 1871 llvm::Type *newRetTy = newFn->getReturnType(); 1872 SmallVector<llvm::Value*, 4> newArgs; 1873 1874 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end(); 1875 ui != ue; ) { 1876 llvm::Value::use_iterator use = ui++; // Increment before the use is erased. 1877 llvm::User *user = *use; 1878 1879 // Recognize and replace uses of bitcasts. Most calls to 1880 // unprototyped functions will use bitcasts. 1881 if (llvm::ConstantExpr *bitcast = dyn_cast<llvm::ConstantExpr>(user)) { 1882 if (bitcast->getOpcode() == llvm::Instruction::BitCast) 1883 replaceUsesOfNonProtoConstant(bitcast, newFn); 1884 continue; 1885 } 1886 1887 // Recognize calls to the function. 1888 llvm::CallSite callSite(user); 1889 if (!callSite) continue; 1890 if (!callSite.isCallee(use)) continue; 1891 1892 // If the return types don't match exactly, then we can't 1893 // transform this call unless it's dead. 1894 if (callSite->getType() != newRetTy && !callSite->use_empty()) 1895 continue; 1896 1897 // Get the call site's attribute list. 1898 SmallVector<llvm::AttributeSet, 8> newAttrs; 1899 llvm::AttributeSet oldAttrs = callSite.getAttributes(); 1900 1901 // Collect any return attributes from the call. 1902 if (oldAttrs.hasAttributes(llvm::AttributeSet::ReturnIndex)) 1903 newAttrs.push_back( 1904 llvm::AttributeSet::get(newFn->getContext(), 1905 oldAttrs.getRetAttributes())); 1906 1907 // If the function was passed too few arguments, don't transform. 1908 unsigned newNumArgs = newFn->arg_size(); 1909 if (callSite.arg_size() < newNumArgs) continue; 1910 1911 // If extra arguments were passed, we silently drop them. 1912 // If any of the types mismatch, we don't transform. 1913 unsigned argNo = 0; 1914 bool dontTransform = false; 1915 for (llvm::Function::arg_iterator ai = newFn->arg_begin(), 1916 ae = newFn->arg_end(); ai != ae; ++ai, ++argNo) { 1917 if (callSite.getArgument(argNo)->getType() != ai->getType()) { 1918 dontTransform = true; 1919 break; 1920 } 1921 1922 // Add any parameter attributes. 1923 if (oldAttrs.hasAttributes(argNo + 1)) 1924 newAttrs. 1925 push_back(llvm:: 1926 AttributeSet::get(newFn->getContext(), 1927 oldAttrs.getParamAttributes(argNo + 1))); 1928 } 1929 if (dontTransform) 1930 continue; 1931 1932 if (oldAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) 1933 newAttrs.push_back(llvm::AttributeSet::get(newFn->getContext(), 1934 oldAttrs.getFnAttributes())); 1935 1936 // Okay, we can transform this. Create the new call instruction and copy 1937 // over the required information. 1938 newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo); 1939 1940 llvm::CallSite newCall; 1941 if (callSite.isCall()) { 1942 newCall = llvm::CallInst::Create(newFn, newArgs, "", 1943 callSite.getInstruction()); 1944 } else { 1945 llvm::InvokeInst *oldInvoke = 1946 cast<llvm::InvokeInst>(callSite.getInstruction()); 1947 newCall = llvm::InvokeInst::Create(newFn, 1948 oldInvoke->getNormalDest(), 1949 oldInvoke->getUnwindDest(), 1950 newArgs, "", 1951 callSite.getInstruction()); 1952 } 1953 newArgs.clear(); // for the next iteration 1954 1955 if (!newCall->getType()->isVoidTy()) 1956 newCall->takeName(callSite.getInstruction()); 1957 newCall.setAttributes( 1958 llvm::AttributeSet::get(newFn->getContext(), newAttrs)); 1959 newCall.setCallingConv(callSite.getCallingConv()); 1960 1961 // Finally, remove the old call, replacing any uses with the new one. 1962 if (!callSite->use_empty()) 1963 callSite->replaceAllUsesWith(newCall.getInstruction()); 1964 1965 // Copy debug location attached to CI. 1966 if (!callSite->getDebugLoc().isUnknown()) 1967 newCall->setDebugLoc(callSite->getDebugLoc()); 1968 callSite->eraseFromParent(); 1969 } 1970 } 1971 1972 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1973 /// implement a function with no prototype, e.g. "int foo() {}". If there are 1974 /// existing call uses of the old function in the module, this adjusts them to 1975 /// call the new function directly. 1976 /// 1977 /// This is not just a cleanup: the always_inline pass requires direct calls to 1978 /// functions to be able to inline them. If there is a bitcast in the way, it 1979 /// won't inline them. Instcombine normally deletes these calls, but it isn't 1980 /// run at -O0. 1981 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1982 llvm::Function *NewFn) { 1983 // If we're redefining a global as a function, don't transform it. 1984 if (!isa<llvm::Function>(Old)) return; 1985 1986 replaceUsesOfNonProtoConstant(Old, NewFn); 1987 } 1988 1989 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) { 1990 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind(); 1991 // If we have a definition, this might be a deferred decl. If the 1992 // instantiation is explicit, make sure we emit it at the end. 1993 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition) 1994 GetAddrOfGlobalVar(VD); 1995 1996 EmitTopLevelDecl(VD); 1997 } 1998 1999 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 2000 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 2001 2002 // Compute the function info and LLVM type. 2003 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); 2004 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); 2005 2006 // Get or create the prototype for the function. 2007 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 2008 2009 // Strip off a bitcast if we got one back. 2010 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 2011 assert(CE->getOpcode() == llvm::Instruction::BitCast); 2012 Entry = CE->getOperand(0); 2013 } 2014 2015 2016 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 2017 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 2018 2019 // If the types mismatch then we have to rewrite the definition. 2020 assert(OldFn->isDeclaration() && 2021 "Shouldn't replace non-declaration"); 2022 2023 // F is the Function* for the one with the wrong type, we must make a new 2024 // Function* and update everything that used F (a declaration) with the new 2025 // Function* (which will be a definition). 2026 // 2027 // This happens if there is a prototype for a function 2028 // (e.g. "int f()") and then a definition of a different type 2029 // (e.g. "int f(int x)"). Move the old function aside so that it 2030 // doesn't interfere with GetAddrOfFunction. 2031 OldFn->setName(StringRef()); 2032 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 2033 2034 // This might be an implementation of a function without a 2035 // prototype, in which case, try to do special replacement of 2036 // calls which match the new prototype. The really key thing here 2037 // is that we also potentially drop arguments from the call site 2038 // so as to make a direct call, which makes the inliner happier 2039 // and suppresses a number of optimizer warnings (!) about 2040 // dropping arguments. 2041 if (!OldFn->use_empty()) { 2042 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 2043 OldFn->removeDeadConstantUsers(); 2044 } 2045 2046 // Replace uses of F with the Function we will endow with a body. 2047 if (!Entry->use_empty()) { 2048 llvm::Constant *NewPtrForOldDecl = 2049 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 2050 Entry->replaceAllUsesWith(NewPtrForOldDecl); 2051 } 2052 2053 // Ok, delete the old function now, which is dead. 2054 OldFn->eraseFromParent(); 2055 2056 Entry = NewFn; 2057 } 2058 2059 // We need to set linkage and visibility on the function before 2060 // generating code for it because various parts of IR generation 2061 // want to propagate this information down (e.g. to local static 2062 // declarations). 2063 llvm::Function *Fn = cast<llvm::Function>(Entry); 2064 setFunctionLinkage(GD, Fn); 2065 2066 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 2067 setGlobalVisibility(Fn, D); 2068 2069 MaybeHandleStaticInExternC(D, Fn); 2070 2071 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 2072 2073 SetFunctionDefinitionAttributes(D, Fn); 2074 SetLLVMFunctionAttributesForDefinition(D, Fn); 2075 2076 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 2077 AddGlobalCtor(Fn, CA->getPriority()); 2078 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 2079 AddGlobalDtor(Fn, DA->getPriority()); 2080 if (D->hasAttr<AnnotateAttr>()) 2081 AddGlobalAnnotations(D, Fn); 2082 } 2083 2084 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 2085 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 2086 const AliasAttr *AA = D->getAttr<AliasAttr>(); 2087 assert(AA && "Not an alias?"); 2088 2089 StringRef MangledName = getMangledName(GD); 2090 2091 // If there is a definition in the module, then it wins over the alias. 2092 // This is dubious, but allow it to be safe. Just ignore the alias. 2093 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 2094 if (Entry && !Entry->isDeclaration()) 2095 return; 2096 2097 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 2098 2099 // Create a reference to the named value. This ensures that it is emitted 2100 // if a deferred decl. 2101 llvm::Constant *Aliasee; 2102 if (isa<llvm::FunctionType>(DeclTy)) 2103 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD, 2104 /*ForVTable=*/false); 2105 else 2106 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 2107 llvm::PointerType::getUnqual(DeclTy), 0); 2108 2109 // Create the new alias itself, but don't set a name yet. 2110 llvm::GlobalValue *GA = 2111 new llvm::GlobalAlias(Aliasee->getType(), 2112 llvm::Function::ExternalLinkage, 2113 "", Aliasee, &getModule()); 2114 2115 if (Entry) { 2116 assert(Entry->isDeclaration()); 2117 2118 // If there is a declaration in the module, then we had an extern followed 2119 // by the alias, as in: 2120 // extern int test6(); 2121 // ... 2122 // int test6() __attribute__((alias("test7"))); 2123 // 2124 // Remove it and replace uses of it with the alias. 2125 GA->takeName(Entry); 2126 2127 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 2128 Entry->getType())); 2129 Entry->eraseFromParent(); 2130 } else { 2131 GA->setName(MangledName); 2132 } 2133 2134 // Set attributes which are particular to an alias; this is a 2135 // specialization of the attributes which may be set on a global 2136 // variable/function. 2137 if (D->hasAttr<DLLExportAttr>()) { 2138 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2139 // The dllexport attribute is ignored for undefined symbols. 2140 if (FD->hasBody()) 2141 GA->setLinkage(llvm::Function::DLLExportLinkage); 2142 } else { 2143 GA->setLinkage(llvm::Function::DLLExportLinkage); 2144 } 2145 } else if (D->hasAttr<WeakAttr>() || 2146 D->hasAttr<WeakRefAttr>() || 2147 D->isWeakImported()) { 2148 GA->setLinkage(llvm::Function::WeakAnyLinkage); 2149 } 2150 2151 SetCommonAttributes(D, GA); 2152 } 2153 2154 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 2155 ArrayRef<llvm::Type*> Tys) { 2156 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 2157 Tys); 2158 } 2159 2160 static llvm::StringMapEntry<llvm::Constant*> & 2161 GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2162 const StringLiteral *Literal, 2163 bool TargetIsLSB, 2164 bool &IsUTF16, 2165 unsigned &StringLength) { 2166 StringRef String = Literal->getString(); 2167 unsigned NumBytes = String.size(); 2168 2169 // Check for simple case. 2170 if (!Literal->containsNonAsciiOrNull()) { 2171 StringLength = NumBytes; 2172 return Map.GetOrCreateValue(String); 2173 } 2174 2175 // Otherwise, convert the UTF8 literals into a string of shorts. 2176 IsUTF16 = true; 2177 2178 SmallVector<UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls. 2179 const UTF8 *FromPtr = (const UTF8 *)String.data(); 2180 UTF16 *ToPtr = &ToBuf[0]; 2181 2182 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 2183 &ToPtr, ToPtr + NumBytes, 2184 strictConversion); 2185 2186 // ConvertUTF8toUTF16 returns the length in ToPtr. 2187 StringLength = ToPtr - &ToBuf[0]; 2188 2189 // Add an explicit null. 2190 *ToPtr = 0; 2191 return Map. 2192 GetOrCreateValue(StringRef(reinterpret_cast<const char *>(ToBuf.data()), 2193 (StringLength + 1) * 2)); 2194 } 2195 2196 static llvm::StringMapEntry<llvm::Constant*> & 2197 GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2198 const StringLiteral *Literal, 2199 unsigned &StringLength) { 2200 StringRef String = Literal->getString(); 2201 StringLength = String.size(); 2202 return Map.GetOrCreateValue(String); 2203 } 2204 2205 llvm::Constant * 2206 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 2207 unsigned StringLength = 0; 2208 bool isUTF16 = false; 2209 llvm::StringMapEntry<llvm::Constant*> &Entry = 2210 GetConstantCFStringEntry(CFConstantStringMap, Literal, 2211 getDataLayout().isLittleEndian(), 2212 isUTF16, StringLength); 2213 2214 if (llvm::Constant *C = Entry.getValue()) 2215 return C; 2216 2217 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2218 llvm::Constant *Zeros[] = { Zero, Zero }; 2219 llvm::Value *V; 2220 2221 // If we don't already have it, get __CFConstantStringClassReference. 2222 if (!CFConstantStringClassRef) { 2223 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2224 Ty = llvm::ArrayType::get(Ty, 0); 2225 llvm::Constant *GV = CreateRuntimeVariable(Ty, 2226 "__CFConstantStringClassReference"); 2227 // Decay array -> ptr 2228 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2229 CFConstantStringClassRef = V; 2230 } 2231 else 2232 V = CFConstantStringClassRef; 2233 2234 QualType CFTy = getContext().getCFConstantStringType(); 2235 2236 llvm::StructType *STy = 2237 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 2238 2239 llvm::Constant *Fields[4]; 2240 2241 // Class pointer. 2242 Fields[0] = cast<llvm::ConstantExpr>(V); 2243 2244 // Flags. 2245 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2246 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 2247 llvm::ConstantInt::get(Ty, 0x07C8); 2248 2249 // String pointer. 2250 llvm::Constant *C = 0; 2251 if (isUTF16) { 2252 ArrayRef<uint16_t> Arr = 2253 llvm::makeArrayRef<uint16_t>(reinterpret_cast<uint16_t*>( 2254 const_cast<char *>(Entry.getKey().data())), 2255 Entry.getKey().size() / 2); 2256 C = llvm::ConstantDataArray::get(VMContext, Arr); 2257 } else { 2258 C = llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2259 } 2260 2261 llvm::GlobalValue::LinkageTypes Linkage; 2262 if (isUTF16) 2263 // FIXME: why do utf strings get "_" labels instead of "L" labels? 2264 Linkage = llvm::GlobalValue::InternalLinkage; 2265 else 2266 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 2267 // when using private linkage. It is not clear if this is a bug in ld 2268 // or a reasonable new restriction. 2269 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 2270 2271 // Note: -fwritable-strings doesn't make the backing store strings of 2272 // CFStrings writable. (See <rdar://problem/10657500>) 2273 llvm::GlobalVariable *GV = 2274 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, 2275 Linkage, C, ".str"); 2276 GV->setUnnamedAddr(true); 2277 // Don't enforce the target's minimum global alignment, since the only use 2278 // of the string is via this class initializer. 2279 if (isUTF16) { 2280 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 2281 GV->setAlignment(Align.getQuantity()); 2282 } else { 2283 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2284 GV->setAlignment(Align.getQuantity()); 2285 } 2286 2287 // String. 2288 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2289 2290 if (isUTF16) 2291 // Cast the UTF16 string to the correct type. 2292 Fields[2] = llvm::ConstantExpr::getBitCast(Fields[2], Int8PtrTy); 2293 2294 // String length. 2295 Ty = getTypes().ConvertType(getContext().LongTy); 2296 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 2297 2298 // The struct. 2299 C = llvm::ConstantStruct::get(STy, Fields); 2300 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2301 llvm::GlobalVariable::PrivateLinkage, C, 2302 "_unnamed_cfstring_"); 2303 if (const char *Sect = getTarget().getCFStringSection()) 2304 GV->setSection(Sect); 2305 Entry.setValue(GV); 2306 2307 return GV; 2308 } 2309 2310 static RecordDecl * 2311 CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 2312 DeclContext *DC, IdentifierInfo *Id) { 2313 SourceLocation Loc; 2314 if (Ctx.getLangOpts().CPlusPlus) 2315 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2316 else 2317 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2318 } 2319 2320 llvm::Constant * 2321 CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 2322 unsigned StringLength = 0; 2323 llvm::StringMapEntry<llvm::Constant*> &Entry = 2324 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 2325 2326 if (llvm::Constant *C = Entry.getValue()) 2327 return C; 2328 2329 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2330 llvm::Constant *Zeros[] = { Zero, Zero }; 2331 llvm::Value *V; 2332 // If we don't already have it, get _NSConstantStringClassReference. 2333 if (!ConstantStringClassRef) { 2334 std::string StringClass(getLangOpts().ObjCConstantStringClass); 2335 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2336 llvm::Constant *GV; 2337 if (LangOpts.ObjCRuntime.isNonFragile()) { 2338 std::string str = 2339 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 2340 : "OBJC_CLASS_$_" + StringClass; 2341 GV = getObjCRuntime().GetClassGlobal(str); 2342 // Make sure the result is of the correct type. 2343 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 2344 V = llvm::ConstantExpr::getBitCast(GV, PTy); 2345 ConstantStringClassRef = V; 2346 } else { 2347 std::string str = 2348 StringClass.empty() ? "_NSConstantStringClassReference" 2349 : "_" + StringClass + "ClassReference"; 2350 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 2351 GV = CreateRuntimeVariable(PTy, str); 2352 // Decay array -> ptr 2353 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2354 ConstantStringClassRef = V; 2355 } 2356 } 2357 else 2358 V = ConstantStringClassRef; 2359 2360 if (!NSConstantStringType) { 2361 // Construct the type for a constant NSString. 2362 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2363 Context.getTranslationUnitDecl(), 2364 &Context.Idents.get("__builtin_NSString")); 2365 D->startDefinition(); 2366 2367 QualType FieldTypes[3]; 2368 2369 // const int *isa; 2370 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 2371 // const char *str; 2372 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 2373 // unsigned int length; 2374 FieldTypes[2] = Context.UnsignedIntTy; 2375 2376 // Create fields 2377 for (unsigned i = 0; i < 3; ++i) { 2378 FieldDecl *Field = FieldDecl::Create(Context, D, 2379 SourceLocation(), 2380 SourceLocation(), 0, 2381 FieldTypes[i], /*TInfo=*/0, 2382 /*BitWidth=*/0, 2383 /*Mutable=*/false, 2384 ICIS_NoInit); 2385 Field->setAccess(AS_public); 2386 D->addDecl(Field); 2387 } 2388 2389 D->completeDefinition(); 2390 QualType NSTy = Context.getTagDeclType(D); 2391 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 2392 } 2393 2394 llvm::Constant *Fields[3]; 2395 2396 // Class pointer. 2397 Fields[0] = cast<llvm::ConstantExpr>(V); 2398 2399 // String pointer. 2400 llvm::Constant *C = 2401 llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2402 2403 llvm::GlobalValue::LinkageTypes Linkage; 2404 bool isConstant; 2405 Linkage = llvm::GlobalValue::PrivateLinkage; 2406 isConstant = !LangOpts.WritableStrings; 2407 2408 llvm::GlobalVariable *GV = 2409 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 2410 ".str"); 2411 GV->setUnnamedAddr(true); 2412 // Don't enforce the target's minimum global alignment, since the only use 2413 // of the string is via this class initializer. 2414 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2415 GV->setAlignment(Align.getQuantity()); 2416 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2417 2418 // String length. 2419 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2420 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 2421 2422 // The struct. 2423 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 2424 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2425 llvm::GlobalVariable::PrivateLinkage, C, 2426 "_unnamed_nsstring_"); 2427 // FIXME. Fix section. 2428 if (const char *Sect = 2429 LangOpts.ObjCRuntime.isNonFragile() 2430 ? getTarget().getNSStringNonFragileABISection() 2431 : getTarget().getNSStringSection()) 2432 GV->setSection(Sect); 2433 Entry.setValue(GV); 2434 2435 return GV; 2436 } 2437 2438 QualType CodeGenModule::getObjCFastEnumerationStateType() { 2439 if (ObjCFastEnumerationStateType.isNull()) { 2440 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2441 Context.getTranslationUnitDecl(), 2442 &Context.Idents.get("__objcFastEnumerationState")); 2443 D->startDefinition(); 2444 2445 QualType FieldTypes[] = { 2446 Context.UnsignedLongTy, 2447 Context.getPointerType(Context.getObjCIdType()), 2448 Context.getPointerType(Context.UnsignedLongTy), 2449 Context.getConstantArrayType(Context.UnsignedLongTy, 2450 llvm::APInt(32, 5), ArrayType::Normal, 0) 2451 }; 2452 2453 for (size_t i = 0; i < 4; ++i) { 2454 FieldDecl *Field = FieldDecl::Create(Context, 2455 D, 2456 SourceLocation(), 2457 SourceLocation(), 0, 2458 FieldTypes[i], /*TInfo=*/0, 2459 /*BitWidth=*/0, 2460 /*Mutable=*/false, 2461 ICIS_NoInit); 2462 Field->setAccess(AS_public); 2463 D->addDecl(Field); 2464 } 2465 2466 D->completeDefinition(); 2467 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 2468 } 2469 2470 return ObjCFastEnumerationStateType; 2471 } 2472 2473 llvm::Constant * 2474 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { 2475 assert(!E->getType()->isPointerType() && "Strings are always arrays"); 2476 2477 // Don't emit it as the address of the string, emit the string data itself 2478 // as an inline array. 2479 if (E->getCharByteWidth() == 1) { 2480 SmallString<64> Str(E->getString()); 2481 2482 // Resize the string to the right size, which is indicated by its type. 2483 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType()); 2484 Str.resize(CAT->getSize().getZExtValue()); 2485 return llvm::ConstantDataArray::getString(VMContext, Str, false); 2486 } 2487 2488 llvm::ArrayType *AType = 2489 cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); 2490 llvm::Type *ElemTy = AType->getElementType(); 2491 unsigned NumElements = AType->getNumElements(); 2492 2493 // Wide strings have either 2-byte or 4-byte elements. 2494 if (ElemTy->getPrimitiveSizeInBits() == 16) { 2495 SmallVector<uint16_t, 32> Elements; 2496 Elements.reserve(NumElements); 2497 2498 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2499 Elements.push_back(E->getCodeUnit(i)); 2500 Elements.resize(NumElements); 2501 return llvm::ConstantDataArray::get(VMContext, Elements); 2502 } 2503 2504 assert(ElemTy->getPrimitiveSizeInBits() == 32); 2505 SmallVector<uint32_t, 32> Elements; 2506 Elements.reserve(NumElements); 2507 2508 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2509 Elements.push_back(E->getCodeUnit(i)); 2510 Elements.resize(NumElements); 2511 return llvm::ConstantDataArray::get(VMContext, Elements); 2512 } 2513 2514 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a 2515 /// constant array for the given string literal. 2516 llvm::Constant * 2517 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 2518 CharUnits Align = getContext().getAlignOfGlobalVarInChars(S->getType()); 2519 if (S->isAscii() || S->isUTF8()) { 2520 SmallString<64> Str(S->getString()); 2521 2522 // Resize the string to the right size, which is indicated by its type. 2523 const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType()); 2524 Str.resize(CAT->getSize().getZExtValue()); 2525 return GetAddrOfConstantString(Str, /*GlobalName*/ 0, Align.getQuantity()); 2526 } 2527 2528 // FIXME: the following does not memoize wide strings. 2529 llvm::Constant *C = GetConstantArrayFromStringLiteral(S); 2530 llvm::GlobalVariable *GV = 2531 new llvm::GlobalVariable(getModule(),C->getType(), 2532 !LangOpts.WritableStrings, 2533 llvm::GlobalValue::PrivateLinkage, 2534 C,".str"); 2535 2536 GV->setAlignment(Align.getQuantity()); 2537 GV->setUnnamedAddr(true); 2538 return GV; 2539 } 2540 2541 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2542 /// array for the given ObjCEncodeExpr node. 2543 llvm::Constant * 2544 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2545 std::string Str; 2546 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2547 2548 return GetAddrOfConstantCString(Str); 2549 } 2550 2551 2552 /// GenerateWritableString -- Creates storage for a string literal. 2553 static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2554 bool constant, 2555 CodeGenModule &CGM, 2556 const char *GlobalName, 2557 unsigned Alignment) { 2558 // Create Constant for this string literal. Don't add a '\0'. 2559 llvm::Constant *C = 2560 llvm::ConstantDataArray::getString(CGM.getLLVMContext(), str, false); 2561 2562 // Create a global variable for this string 2563 llvm::GlobalVariable *GV = 2564 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 2565 llvm::GlobalValue::PrivateLinkage, 2566 C, GlobalName); 2567 GV->setAlignment(Alignment); 2568 GV->setUnnamedAddr(true); 2569 return GV; 2570 } 2571 2572 /// GetAddrOfConstantString - Returns a pointer to a character array 2573 /// containing the literal. This contents are exactly that of the 2574 /// given string, i.e. it will not be null terminated automatically; 2575 /// see GetAddrOfConstantCString. Note that whether the result is 2576 /// actually a pointer to an LLVM constant depends on 2577 /// Feature.WriteableStrings. 2578 /// 2579 /// The result has pointer to array type. 2580 llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2581 const char *GlobalName, 2582 unsigned Alignment) { 2583 // Get the default prefix if a name wasn't specified. 2584 if (!GlobalName) 2585 GlobalName = ".str"; 2586 2587 if (Alignment == 0) 2588 Alignment = getContext().getAlignOfGlobalVarInChars(getContext().CharTy) 2589 .getQuantity(); 2590 2591 // Don't share any string literals if strings aren't constant. 2592 if (LangOpts.WritableStrings) 2593 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2594 2595 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2596 ConstantStringMap.GetOrCreateValue(Str); 2597 2598 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2599 if (Alignment > GV->getAlignment()) { 2600 GV->setAlignment(Alignment); 2601 } 2602 return GV; 2603 } 2604 2605 // Create a global variable for this. 2606 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, 2607 Alignment); 2608 Entry.setValue(GV); 2609 return GV; 2610 } 2611 2612 /// GetAddrOfConstantCString - Returns a pointer to a character 2613 /// array containing the literal and a terminating '\0' 2614 /// character. The result has pointer to array type. 2615 llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2616 const char *GlobalName, 2617 unsigned Alignment) { 2618 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2619 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2620 } 2621 2622 llvm::Constant *CodeGenModule::GetAddrOfGlobalTemporary( 2623 const MaterializeTemporaryExpr *E, const Expr *Init) { 2624 assert((E->getStorageDuration() == SD_Static || 2625 E->getStorageDuration() == SD_Thread) && "not a global temporary"); 2626 const VarDecl *VD = cast<VarDecl>(E->getExtendingDecl()); 2627 2628 // If we're not materializing a subobject of the temporary, keep the 2629 // cv-qualifiers from the type of the MaterializeTemporaryExpr. 2630 QualType MaterializedType = Init->getType(); 2631 if (Init == E->GetTemporaryExpr()) 2632 MaterializedType = E->getType(); 2633 2634 llvm::Constant *&Slot = MaterializedGlobalTemporaryMap[E]; 2635 if (Slot) 2636 return Slot; 2637 2638 // FIXME: If an externally-visible declaration extends multiple temporaries, 2639 // we need to give each temporary the same name in every translation unit (and 2640 // we also need to make the temporaries externally-visible). 2641 SmallString<256> Name; 2642 llvm::raw_svector_ostream Out(Name); 2643 getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out); 2644 Out.flush(); 2645 2646 APValue *Value = 0; 2647 if (E->getStorageDuration() == SD_Static) { 2648 // We might have a cached constant initializer for this temporary. Note 2649 // that this might have a different value from the value computed by 2650 // evaluating the initializer if the surrounding constant expression 2651 // modifies the temporary. 2652 Value = getContext().getMaterializedTemporaryValue(E, false); 2653 if (Value && Value->isUninit()) 2654 Value = 0; 2655 } 2656 2657 // Try evaluating it now, it might have a constant initializer. 2658 Expr::EvalResult EvalResult; 2659 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) && 2660 !EvalResult.hasSideEffects()) 2661 Value = &EvalResult.Val; 2662 2663 llvm::Constant *InitialValue = 0; 2664 bool Constant = false; 2665 llvm::Type *Type; 2666 if (Value) { 2667 // The temporary has a constant initializer, use it. 2668 InitialValue = EmitConstantValue(*Value, MaterializedType, 0); 2669 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value); 2670 Type = InitialValue->getType(); 2671 } else { 2672 // No initializer, the initialization will be provided when we 2673 // initialize the declaration which performed lifetime extension. 2674 Type = getTypes().ConvertTypeForMem(MaterializedType); 2675 } 2676 2677 // Create a global variable for this lifetime-extended temporary. 2678 llvm::GlobalVariable *GV = 2679 new llvm::GlobalVariable(getModule(), Type, Constant, 2680 llvm::GlobalValue::PrivateLinkage, 2681 InitialValue, Name.c_str()); 2682 GV->setAlignment( 2683 getContext().getTypeAlignInChars(MaterializedType).getQuantity()); 2684 if (VD->getTLSKind()) 2685 setTLSMode(GV, *VD); 2686 Slot = GV; 2687 return GV; 2688 } 2689 2690 /// EmitObjCPropertyImplementations - Emit information for synthesized 2691 /// properties for an implementation. 2692 void CodeGenModule::EmitObjCPropertyImplementations(const 2693 ObjCImplementationDecl *D) { 2694 for (ObjCImplementationDecl::propimpl_iterator 2695 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2696 ObjCPropertyImplDecl *PID = *i; 2697 2698 // Dynamic is just for type-checking. 2699 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2700 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2701 2702 // Determine which methods need to be implemented, some may have 2703 // been overridden. Note that ::isPropertyAccessor is not the method 2704 // we want, that just indicates if the decl came from a 2705 // property. What we want to know is if the method is defined in 2706 // this implementation. 2707 if (!D->getInstanceMethod(PD->getGetterName())) 2708 CodeGenFunction(*this).GenerateObjCGetter( 2709 const_cast<ObjCImplementationDecl *>(D), PID); 2710 if (!PD->isReadOnly() && 2711 !D->getInstanceMethod(PD->getSetterName())) 2712 CodeGenFunction(*this).GenerateObjCSetter( 2713 const_cast<ObjCImplementationDecl *>(D), PID); 2714 } 2715 } 2716 } 2717 2718 static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2719 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2720 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2721 ivar; ivar = ivar->getNextIvar()) 2722 if (ivar->getType().isDestructedType()) 2723 return true; 2724 2725 return false; 2726 } 2727 2728 /// EmitObjCIvarInitializations - Emit information for ivar initialization 2729 /// for an implementation. 2730 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2731 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2732 if (needsDestructMethod(D)) { 2733 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2734 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2735 ObjCMethodDecl *DTORMethod = 2736 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2737 cxxSelector, getContext().VoidTy, 0, D, 2738 /*isInstance=*/true, /*isVariadic=*/false, 2739 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true, 2740 /*isDefined=*/false, ObjCMethodDecl::Required); 2741 D->addInstanceMethod(DTORMethod); 2742 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2743 D->setHasDestructors(true); 2744 } 2745 2746 // If the implementation doesn't have any ivar initializers, we don't need 2747 // a .cxx_construct. 2748 if (D->getNumIvarInitializers() == 0) 2749 return; 2750 2751 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2752 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2753 // The constructor returns 'self'. 2754 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2755 D->getLocation(), 2756 D->getLocation(), 2757 cxxSelector, 2758 getContext().getObjCIdType(), 0, 2759 D, /*isInstance=*/true, 2760 /*isVariadic=*/false, 2761 /*isPropertyAccessor=*/true, 2762 /*isImplicitlyDeclared=*/true, 2763 /*isDefined=*/false, 2764 ObjCMethodDecl::Required); 2765 D->addInstanceMethod(CTORMethod); 2766 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2767 D->setHasNonZeroConstructors(true); 2768 } 2769 2770 /// EmitNamespace - Emit all declarations in a namespace. 2771 void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2772 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2773 I != E; ++I) 2774 EmitTopLevelDecl(*I); 2775 } 2776 2777 // EmitLinkageSpec - Emit all declarations in a linkage spec. 2778 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2779 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2780 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2781 ErrorUnsupported(LSD, "linkage spec"); 2782 return; 2783 } 2784 2785 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2786 I != E; ++I) { 2787 // Meta-data for ObjC class includes references to implemented methods. 2788 // Generate class's method definitions first. 2789 if (ObjCImplDecl *OID = dyn_cast<ObjCImplDecl>(*I)) { 2790 for (ObjCContainerDecl::method_iterator M = OID->meth_begin(), 2791 MEnd = OID->meth_end(); 2792 M != MEnd; ++M) 2793 EmitTopLevelDecl(*M); 2794 } 2795 EmitTopLevelDecl(*I); 2796 } 2797 } 2798 2799 /// EmitTopLevelDecl - Emit code for a single top level declaration. 2800 void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2801 // If an error has occurred, stop code generation, but continue 2802 // parsing and semantic analysis (to ensure all warnings and errors 2803 // are emitted). 2804 if (Diags.hasErrorOccurred()) 2805 return; 2806 2807 // Ignore dependent declarations. 2808 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2809 return; 2810 2811 switch (D->getKind()) { 2812 case Decl::CXXConversion: 2813 case Decl::CXXMethod: 2814 case Decl::Function: 2815 // Skip function templates 2816 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2817 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2818 return; 2819 2820 EmitGlobal(cast<FunctionDecl>(D)); 2821 break; 2822 2823 case Decl::Var: 2824 EmitGlobal(cast<VarDecl>(D)); 2825 break; 2826 2827 // Indirect fields from global anonymous structs and unions can be 2828 // ignored; only the actual variable requires IR gen support. 2829 case Decl::IndirectField: 2830 break; 2831 2832 // C++ Decls 2833 case Decl::Namespace: 2834 EmitNamespace(cast<NamespaceDecl>(D)); 2835 break; 2836 // No code generation needed. 2837 case Decl::UsingShadow: 2838 case Decl::Using: 2839 case Decl::ClassTemplate: 2840 case Decl::FunctionTemplate: 2841 case Decl::TypeAliasTemplate: 2842 case Decl::Block: 2843 case Decl::Empty: 2844 break; 2845 case Decl::NamespaceAlias: 2846 if (CGDebugInfo *DI = getModuleDebugInfo()) 2847 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D)); 2848 return; 2849 case Decl::UsingDirective: // using namespace X; [C++] 2850 if (CGDebugInfo *DI = getModuleDebugInfo()) 2851 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D)); 2852 return; 2853 case Decl::CXXConstructor: 2854 // Skip function templates 2855 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2856 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2857 return; 2858 2859 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2860 break; 2861 case Decl::CXXDestructor: 2862 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2863 return; 2864 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2865 break; 2866 2867 case Decl::StaticAssert: 2868 // Nothing to do. 2869 break; 2870 2871 // Objective-C Decls 2872 2873 // Forward declarations, no (immediate) code generation. 2874 case Decl::ObjCInterface: 2875 case Decl::ObjCCategory: 2876 break; 2877 2878 case Decl::ObjCProtocol: { 2879 ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D); 2880 if (Proto->isThisDeclarationADefinition()) 2881 ObjCRuntime->GenerateProtocol(Proto); 2882 break; 2883 } 2884 2885 case Decl::ObjCCategoryImpl: 2886 // Categories have properties but don't support synthesize so we 2887 // can ignore them here. 2888 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2889 break; 2890 2891 case Decl::ObjCImplementation: { 2892 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2893 EmitObjCPropertyImplementations(OMD); 2894 EmitObjCIvarInitializations(OMD); 2895 ObjCRuntime->GenerateClass(OMD); 2896 // Emit global variable debug information. 2897 if (CGDebugInfo *DI = getModuleDebugInfo()) 2898 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) 2899 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType( 2900 OMD->getClassInterface()), OMD->getLocation()); 2901 break; 2902 } 2903 case Decl::ObjCMethod: { 2904 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 2905 // If this is not a prototype, emit the body. 2906 if (OMD->getBody()) 2907 CodeGenFunction(*this).GenerateObjCMethod(OMD); 2908 break; 2909 } 2910 case Decl::ObjCCompatibleAlias: 2911 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D)); 2912 break; 2913 2914 case Decl::LinkageSpec: 2915 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 2916 break; 2917 2918 case Decl::FileScopeAsm: { 2919 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 2920 StringRef AsmString = AD->getAsmString()->getString(); 2921 2922 const std::string &S = getModule().getModuleInlineAsm(); 2923 if (S.empty()) 2924 getModule().setModuleInlineAsm(AsmString); 2925 else if (S.end()[-1] == '\n') 2926 getModule().setModuleInlineAsm(S + AsmString.str()); 2927 else 2928 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 2929 break; 2930 } 2931 2932 case Decl::Import: { 2933 ImportDecl *Import = cast<ImportDecl>(D); 2934 2935 // Ignore import declarations that come from imported modules. 2936 if (clang::Module *Owner = Import->getOwningModule()) { 2937 if (getLangOpts().CurrentModule.empty() || 2938 Owner->getTopLevelModule()->Name == getLangOpts().CurrentModule) 2939 break; 2940 } 2941 2942 ImportedModules.insert(Import->getImportedModule()); 2943 break; 2944 } 2945 2946 default: 2947 // Make sure we handled everything we should, every other kind is a 2948 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 2949 // function. Need to recode Decl::Kind to do that easily. 2950 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 2951 } 2952 } 2953 2954 /// Turns the given pointer into a constant. 2955 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 2956 const void *Ptr) { 2957 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 2958 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 2959 return llvm::ConstantInt::get(i64, PtrInt); 2960 } 2961 2962 static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 2963 llvm::NamedMDNode *&GlobalMetadata, 2964 GlobalDecl D, 2965 llvm::GlobalValue *Addr) { 2966 if (!GlobalMetadata) 2967 GlobalMetadata = 2968 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 2969 2970 // TODO: should we report variant information for ctors/dtors? 2971 llvm::Value *Ops[] = { 2972 Addr, 2973 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 2974 }; 2975 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 2976 } 2977 2978 /// For each function which is declared within an extern "C" region and marked 2979 /// as 'used', but has internal linkage, create an alias from the unmangled 2980 /// name to the mangled name if possible. People expect to be able to refer 2981 /// to such functions with an unmangled name from inline assembly within the 2982 /// same translation unit. 2983 void CodeGenModule::EmitStaticExternCAliases() { 2984 for (StaticExternCMap::iterator I = StaticExternCValues.begin(), 2985 E = StaticExternCValues.end(); 2986 I != E; ++I) { 2987 IdentifierInfo *Name = I->first; 2988 llvm::GlobalValue *Val = I->second; 2989 if (Val && !getModule().getNamedValue(Name->getName())) 2990 AddUsedGlobal(new llvm::GlobalAlias(Val->getType(), Val->getLinkage(), 2991 Name->getName(), Val, &getModule())); 2992 } 2993 } 2994 2995 /// Emits metadata nodes associating all the global values in the 2996 /// current module with the Decls they came from. This is useful for 2997 /// projects using IR gen as a subroutine. 2998 /// 2999 /// Since there's currently no way to associate an MDNode directly 3000 /// with an llvm::GlobalValue, we create a global named metadata 3001 /// with the name 'clang.global.decl.ptrs'. 3002 void CodeGenModule::EmitDeclMetadata() { 3003 llvm::NamedMDNode *GlobalMetadata = 0; 3004 3005 // StaticLocalDeclMap 3006 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 3007 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 3008 I != E; ++I) { 3009 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 3010 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 3011 } 3012 } 3013 3014 /// Emits metadata nodes for all the local variables in the current 3015 /// function. 3016 void CodeGenFunction::EmitDeclMetadata() { 3017 if (LocalDeclMap.empty()) return; 3018 3019 llvm::LLVMContext &Context = getLLVMContext(); 3020 3021 // Find the unique metadata ID for this name. 3022 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 3023 3024 llvm::NamedMDNode *GlobalMetadata = 0; 3025 3026 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 3027 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 3028 const Decl *D = I->first; 3029 llvm::Value *Addr = I->second; 3030 3031 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 3032 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 3033 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 3034 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 3035 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 3036 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 3037 } 3038 } 3039 } 3040 3041 void CodeGenModule::EmitCoverageFile() { 3042 if (!getCodeGenOpts().CoverageFile.empty()) { 3043 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 3044 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 3045 llvm::LLVMContext &Ctx = TheModule.getContext(); 3046 llvm::MDString *CoverageFile = 3047 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 3048 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 3049 llvm::MDNode *CU = CUNode->getOperand(i); 3050 llvm::Value *node[] = { CoverageFile, CU }; 3051 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 3052 GCov->addOperand(N); 3053 } 3054 } 3055 } 3056 } 3057 3058 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid, 3059 QualType GuidType) { 3060 // Sema has checked that all uuid strings are of the form 3061 // "12345678-1234-1234-1234-1234567890ab". 3062 assert(Uuid.size() == 36); 3063 const char *Uuidstr = Uuid.data(); 3064 for (int i = 0; i < 36; ++i) { 3065 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuidstr[i] == '-'); 3066 else assert(isHexDigit(Uuidstr[i])); 3067 } 3068 3069 llvm::APInt Field0(32, StringRef(Uuidstr , 8), 16); 3070 llvm::APInt Field1(16, StringRef(Uuidstr + 9, 4), 16); 3071 llvm::APInt Field2(16, StringRef(Uuidstr + 14, 4), 16); 3072 static const int Field3ValueOffsets[] = { 19, 21, 24, 26, 28, 30, 32, 34 }; 3073 3074 APValue InitStruct(APValue::UninitStruct(), /*NumBases=*/0, /*NumFields=*/4); 3075 InitStruct.getStructField(0) = APValue(llvm::APSInt(Field0)); 3076 InitStruct.getStructField(1) = APValue(llvm::APSInt(Field1)); 3077 InitStruct.getStructField(2) = APValue(llvm::APSInt(Field2)); 3078 APValue& Arr = InitStruct.getStructField(3); 3079 Arr = APValue(APValue::UninitArray(), 8, 8); 3080 for (int t = 0; t < 8; ++t) 3081 Arr.getArrayInitializedElt(t) = APValue(llvm::APSInt( 3082 llvm::APInt(8, StringRef(Uuidstr + Field3ValueOffsets[t], 2), 16))); 3083 3084 return EmitConstantValue(InitStruct, GuidType); 3085 } 3086