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 } 193 194 SimplifyPersonality(); 195 196 if (getCodeGenOpts().EmitDeclMetadata) 197 EmitDeclMetadata(); 198 199 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 200 EmitCoverageFile(); 201 202 if (DebugInfo) 203 DebugInfo->finalize(); 204 } 205 206 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 207 // Make sure that this type is translated. 208 Types.UpdateCompletedType(TD); 209 } 210 211 llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 212 if (!TBAA) 213 return 0; 214 return TBAA->getTBAAInfo(QTy); 215 } 216 217 llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() { 218 if (!TBAA) 219 return 0; 220 return TBAA->getTBAAInfoForVTablePtr(); 221 } 222 223 llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) { 224 if (!TBAA) 225 return 0; 226 return TBAA->getTBAAStructInfo(QTy); 227 } 228 229 llvm::MDNode *CodeGenModule::getTBAAStructTypeInfo(QualType QTy) { 230 if (!TBAA) 231 return 0; 232 return TBAA->getTBAAStructTypeInfo(QTy); 233 } 234 235 llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy, 236 llvm::MDNode *AccessN, 237 uint64_t O) { 238 if (!TBAA) 239 return 0; 240 return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O); 241 } 242 243 /// Decorate the instruction with a TBAA tag. For scalar TBAA, the tag 244 /// is the same as the type. For struct-path aware TBAA, the tag 245 /// is different from the type: base type, access type and offset. 246 /// When ConvertTypeToTag is true, we create a tag based on the scalar type. 247 void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 248 llvm::MDNode *TBAAInfo, 249 bool ConvertTypeToTag) { 250 if (ConvertTypeToTag && TBAA && CodeGenOpts.StructPathTBAA) 251 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, 252 TBAA->getTBAAScalarTagInfo(TBAAInfo)); 253 else 254 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 255 } 256 257 void CodeGenModule::Error(SourceLocation loc, StringRef error) { 258 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); 259 getDiags().Report(Context.getFullLoc(loc), diagID); 260 } 261 262 /// ErrorUnsupported - Print out an error that codegen doesn't support the 263 /// specified stmt yet. 264 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 265 bool OmitOnError) { 266 if (OmitOnError && getDiags().hasErrorOccurred()) 267 return; 268 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 269 "cannot compile this %0 yet"); 270 std::string Msg = Type; 271 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 272 << Msg << S->getSourceRange(); 273 } 274 275 /// ErrorUnsupported - Print out an error that codegen doesn't support the 276 /// specified decl yet. 277 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 278 bool OmitOnError) { 279 if (OmitOnError && getDiags().hasErrorOccurred()) 280 return; 281 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 282 "cannot compile this %0 yet"); 283 std::string Msg = Type; 284 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 285 } 286 287 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 288 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 289 } 290 291 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 292 const NamedDecl *D) const { 293 // Internal definitions always have default visibility. 294 if (GV->hasLocalLinkage()) { 295 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 296 return; 297 } 298 299 // Set visibility for definitions. 300 LinkageInfo LV = D->getLinkageAndVisibility(); 301 if (LV.isVisibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 302 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 303 } 304 305 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) { 306 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S) 307 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel) 308 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel) 309 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel) 310 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel); 311 } 312 313 static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel( 314 CodeGenOptions::TLSModel M) { 315 switch (M) { 316 case CodeGenOptions::GeneralDynamicTLSModel: 317 return llvm::GlobalVariable::GeneralDynamicTLSModel; 318 case CodeGenOptions::LocalDynamicTLSModel: 319 return llvm::GlobalVariable::LocalDynamicTLSModel; 320 case CodeGenOptions::InitialExecTLSModel: 321 return llvm::GlobalVariable::InitialExecTLSModel; 322 case CodeGenOptions::LocalExecTLSModel: 323 return llvm::GlobalVariable::LocalExecTLSModel; 324 } 325 llvm_unreachable("Invalid TLS model!"); 326 } 327 328 void CodeGenModule::setTLSMode(llvm::GlobalVariable *GV, 329 const VarDecl &D) const { 330 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!"); 331 332 llvm::GlobalVariable::ThreadLocalMode TLM; 333 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel()); 334 335 // Override the TLS model if it is explicitly specified. 336 if (D.hasAttr<TLSModelAttr>()) { 337 const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>(); 338 TLM = GetLLVMTLSModel(Attr->getModel()); 339 } 340 341 GV->setThreadLocalMode(TLM); 342 } 343 344 /// Set the symbol visibility of type information (vtable and RTTI) 345 /// associated with the given type. 346 void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 347 const CXXRecordDecl *RD, 348 TypeVisibilityKind TVK) const { 349 setGlobalVisibility(GV, RD); 350 351 if (!CodeGenOpts.HiddenWeakVTables) 352 return; 353 354 // We never want to drop the visibility for RTTI names. 355 if (TVK == TVK_ForRTTIName) 356 return; 357 358 // We want to drop the visibility to hidden for weak type symbols. 359 // This isn't possible if there might be unresolved references 360 // elsewhere that rely on this symbol being visible. 361 362 // This should be kept roughly in sync with setThunkVisibility 363 // in CGVTables.cpp. 364 365 // Preconditions. 366 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 367 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 368 return; 369 370 // Don't override an explicit visibility attribute. 371 if (RD->getExplicitVisibility(NamedDecl::VisibilityForType)) 372 return; 373 374 switch (RD->getTemplateSpecializationKind()) { 375 // We have to disable the optimization if this is an EI definition 376 // because there might be EI declarations in other shared objects. 377 case TSK_ExplicitInstantiationDefinition: 378 case TSK_ExplicitInstantiationDeclaration: 379 return; 380 381 // Every use of a non-template class's type information has to emit it. 382 case TSK_Undeclared: 383 break; 384 385 // In theory, implicit instantiations can ignore the possibility of 386 // an explicit instantiation declaration because there necessarily 387 // must be an EI definition somewhere with default visibility. In 388 // practice, it's possible to have an explicit instantiation for 389 // an arbitrary template class, and linkers aren't necessarily able 390 // to deal with mixed-visibility symbols. 391 case TSK_ExplicitSpecialization: 392 case TSK_ImplicitInstantiation: 393 return; 394 } 395 396 // If there's a key function, there may be translation units 397 // that don't have the key function's definition. But ignore 398 // this if we're emitting RTTI under -fno-rtti. 399 if (!(TVK != TVK_ForRTTI) || LangOpts.RTTI) { 400 // FIXME: what should we do if we "lose" the key function during 401 // the emission of the file? 402 if (Context.getCurrentKeyFunction(RD)) 403 return; 404 } 405 406 // Otherwise, drop the visibility to hidden. 407 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 408 GV->setUnnamedAddr(true); 409 } 410 411 StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 412 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 413 414 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 415 if (!Str.empty()) 416 return Str; 417 418 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 419 IdentifierInfo *II = ND->getIdentifier(); 420 assert(II && "Attempt to mangle unnamed decl."); 421 422 Str = II->getName(); 423 return Str; 424 } 425 426 SmallString<256> Buffer; 427 llvm::raw_svector_ostream Out(Buffer); 428 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 429 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 430 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 431 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 432 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND)) 433 getCXXABI().getMangleContext().mangleBlock(BD, Out, 434 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl())); 435 else 436 getCXXABI().getMangleContext().mangleName(ND, Out); 437 438 // Allocate space for the mangled name. 439 Out.flush(); 440 size_t Length = Buffer.size(); 441 char *Name = MangledNamesAllocator.Allocate<char>(Length); 442 std::copy(Buffer.begin(), Buffer.end(), Name); 443 444 Str = StringRef(Name, Length); 445 446 return Str; 447 } 448 449 void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 450 const BlockDecl *BD) { 451 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 452 const Decl *D = GD.getDecl(); 453 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 454 if (D == 0) 455 MangleCtx.mangleGlobalBlock(BD, 456 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out); 457 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 458 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 459 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 460 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 461 else 462 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 463 } 464 465 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 466 return getModule().getNamedValue(Name); 467 } 468 469 /// AddGlobalCtor - Add a function to the list that will be called before 470 /// main() runs. 471 void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 472 // FIXME: Type coercion of void()* types. 473 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 474 } 475 476 /// AddGlobalDtor - Add a function to the list that will be called 477 /// when the module is unloaded. 478 void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 479 // FIXME: Type coercion of void()* types. 480 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 481 } 482 483 void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 484 // Ctor function type is void()*. 485 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 486 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 487 488 // Get the type of a ctor entry, { i32, void ()* }. 489 llvm::StructType *CtorStructTy = 490 llvm::StructType::get(Int32Ty, llvm::PointerType::getUnqual(CtorFTy), NULL); 491 492 // Construct the constructor and destructor arrays. 493 SmallVector<llvm::Constant*, 8> Ctors; 494 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 495 llvm::Constant *S[] = { 496 llvm::ConstantInt::get(Int32Ty, I->second, false), 497 llvm::ConstantExpr::getBitCast(I->first, CtorPFTy) 498 }; 499 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 500 } 501 502 if (!Ctors.empty()) { 503 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 504 new llvm::GlobalVariable(TheModule, AT, false, 505 llvm::GlobalValue::AppendingLinkage, 506 llvm::ConstantArray::get(AT, Ctors), 507 GlobalName); 508 } 509 } 510 511 llvm::GlobalValue::LinkageTypes 512 CodeGenModule::getFunctionLinkage(GlobalDecl GD) { 513 return getFunctionLinkage(cast<FunctionDecl>(GD.getDecl())); 514 } 515 516 llvm::GlobalValue::LinkageTypes 517 CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 518 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 519 520 if (Linkage == GVA_Internal) 521 return llvm::Function::InternalLinkage; 522 523 if (D->hasAttr<DLLExportAttr>()) 524 return llvm::Function::DLLExportLinkage; 525 526 if (D->hasAttr<WeakAttr>()) 527 return llvm::Function::WeakAnyLinkage; 528 529 // In C99 mode, 'inline' functions are guaranteed to have a strong 530 // definition somewhere else, so we can use available_externally linkage. 531 if (Linkage == GVA_C99Inline) 532 return llvm::Function::AvailableExternallyLinkage; 533 534 // Note that Apple's kernel linker doesn't support symbol 535 // coalescing, so we need to avoid linkonce and weak linkages there. 536 // Normally, this means we just map to internal, but for explicit 537 // instantiations we'll map to external. 538 539 // In C++, the compiler has to emit a definition in every translation unit 540 // that references the function. We should use linkonce_odr because 541 // a) if all references in this translation unit are optimized away, we 542 // don't need to codegen it. b) if the function persists, it needs to be 543 // merged with other definitions. c) C++ has the ODR, so we know the 544 // definition is dependable. 545 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 546 return !Context.getLangOpts().AppleKext 547 ? llvm::Function::LinkOnceODRLinkage 548 : llvm::Function::InternalLinkage; 549 550 // An explicit instantiation of a template has weak linkage, since 551 // explicit instantiations can occur in multiple translation units 552 // and must all be equivalent. However, we are not allowed to 553 // throw away these explicit instantiations. 554 if (Linkage == GVA_ExplicitTemplateInstantiation) 555 return !Context.getLangOpts().AppleKext 556 ? llvm::Function::WeakODRLinkage 557 : llvm::Function::ExternalLinkage; 558 559 // Otherwise, we have strong external linkage. 560 assert(Linkage == GVA_StrongExternal); 561 return llvm::Function::ExternalLinkage; 562 } 563 564 565 /// SetFunctionDefinitionAttributes - Set attributes for a global. 566 /// 567 /// FIXME: This is currently only done for aliases and functions, but not for 568 /// variables (these details are set in EmitGlobalVarDefinition for variables). 569 void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 570 llvm::GlobalValue *GV) { 571 SetCommonAttributes(D, GV); 572 } 573 574 void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 575 const CGFunctionInfo &Info, 576 llvm::Function *F) { 577 unsigned CallingConv; 578 AttributeListType AttributeList; 579 ConstructAttributeList(Info, D, AttributeList, CallingConv, false); 580 F->setAttributes(llvm::AttributeSet::get(getLLVMContext(), AttributeList)); 581 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 582 } 583 584 /// Determines whether the language options require us to model 585 /// unwind exceptions. We treat -fexceptions as mandating this 586 /// except under the fragile ObjC ABI with only ObjC exceptions 587 /// enabled. This means, for example, that C with -fexceptions 588 /// enables this. 589 static bool hasUnwindExceptions(const LangOptions &LangOpts) { 590 // If exceptions are completely disabled, obviously this is false. 591 if (!LangOpts.Exceptions) return false; 592 593 // If C++ exceptions are enabled, this is true. 594 if (LangOpts.CXXExceptions) return true; 595 596 // If ObjC exceptions are enabled, this depends on the ABI. 597 if (LangOpts.ObjCExceptions) { 598 return LangOpts.ObjCRuntime.hasUnwindExceptions(); 599 } 600 601 return true; 602 } 603 604 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 605 llvm::Function *F) { 606 llvm::AttrBuilder B; 607 608 if (CodeGenOpts.UnwindTables) 609 B.addAttribute(llvm::Attribute::UWTable); 610 611 if (!hasUnwindExceptions(LangOpts)) 612 B.addAttribute(llvm::Attribute::NoUnwind); 613 614 if (D->hasAttr<NakedAttr>()) { 615 // Naked implies noinline: we should not be inlining such functions. 616 B.addAttribute(llvm::Attribute::Naked); 617 B.addAttribute(llvm::Attribute::NoInline); 618 } else if (D->hasAttr<NoInlineAttr>()) { 619 B.addAttribute(llvm::Attribute::NoInline); 620 } else if ((D->hasAttr<AlwaysInlineAttr>() || 621 D->hasAttr<ForceInlineAttr>()) && 622 !F->getAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex, 623 llvm::Attribute::NoInline)) { 624 // (noinline wins over always_inline, and we can't specify both in IR) 625 B.addAttribute(llvm::Attribute::AlwaysInline); 626 } 627 628 if (D->hasAttr<ColdAttr>()) { 629 B.addAttribute(llvm::Attribute::OptimizeForSize); 630 B.addAttribute(llvm::Attribute::Cold); 631 } 632 633 if (D->hasAttr<MinSizeAttr>()) 634 B.addAttribute(llvm::Attribute::MinSize); 635 636 if (LangOpts.getStackProtector() == LangOptions::SSPOn) 637 B.addAttribute(llvm::Attribute::StackProtect); 638 else if (LangOpts.getStackProtector() == LangOptions::SSPReq) 639 B.addAttribute(llvm::Attribute::StackProtectReq); 640 641 // Add sanitizer attributes if function is not blacklisted. 642 if (!SanitizerBlacklist.isIn(*F)) { 643 // When AddressSanitizer is enabled, set SanitizeAddress attribute 644 // unless __attribute__((no_sanitize_address)) is used. 645 if (SanOpts.Address && !D->hasAttr<NoSanitizeAddressAttr>()) 646 B.addAttribute(llvm::Attribute::SanitizeAddress); 647 // Same for ThreadSanitizer and __attribute__((no_sanitize_thread)) 648 if (SanOpts.Thread && !D->hasAttr<NoSanitizeThreadAttr>()) { 649 B.addAttribute(llvm::Attribute::SanitizeThread); 650 } 651 // Same for MemorySanitizer and __attribute__((no_sanitize_memory)) 652 if (SanOpts.Memory && !D->hasAttr<NoSanitizeMemoryAttr>()) 653 B.addAttribute(llvm::Attribute::SanitizeMemory); 654 } 655 656 F->addAttributes(llvm::AttributeSet::FunctionIndex, 657 llvm::AttributeSet::get( 658 F->getContext(), llvm::AttributeSet::FunctionIndex, B)); 659 660 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 661 F->setUnnamedAddr(true); 662 else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) 663 if (MD->isVirtual()) 664 F->setUnnamedAddr(true); 665 666 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 667 if (alignment) 668 F->setAlignment(alignment); 669 670 // C++ ABI requires 2-byte alignment for member functions. 671 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 672 F->setAlignment(2); 673 } 674 675 void CodeGenModule::SetCommonAttributes(const Decl *D, 676 llvm::GlobalValue *GV) { 677 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 678 setGlobalVisibility(GV, ND); 679 else 680 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 681 682 if (D->hasAttr<UsedAttr>()) 683 AddUsedGlobal(GV); 684 685 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 686 GV->setSection(SA->getName()); 687 688 // Alias cannot have attributes. Filter them here. 689 if (!isa<llvm::GlobalAlias>(GV)) 690 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 691 } 692 693 void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 694 llvm::Function *F, 695 const CGFunctionInfo &FI) { 696 SetLLVMFunctionAttributes(D, FI, F); 697 SetLLVMFunctionAttributesForDefinition(D, F); 698 699 F->setLinkage(llvm::Function::InternalLinkage); 700 701 SetCommonAttributes(D, F); 702 } 703 704 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 705 llvm::Function *F, 706 bool IsIncompleteFunction) { 707 if (unsigned IID = F->getIntrinsicID()) { 708 // If this is an intrinsic function, set the function's attributes 709 // to the intrinsic's attributes. 710 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), 711 (llvm::Intrinsic::ID)IID)); 712 return; 713 } 714 715 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 716 717 if (!IsIncompleteFunction) 718 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F); 719 720 if (getCXXABI().HasThisReturn(GD)) { 721 llvm::Type *RetTy = F->getReturnType(); 722 assert(!F->arg_empty() && 723 F->arg_begin()->getType()->canLosslesslyBitCastTo(RetTy) && 724 "unexpected this return"); 725 F->addAttribute(1, llvm::Attribute::Returned); 726 } 727 728 // Only a few attributes are set on declarations; these may later be 729 // overridden by a definition. 730 731 if (FD->hasAttr<DLLImportAttr>()) { 732 F->setLinkage(llvm::Function::DLLImportLinkage); 733 } else if (FD->hasAttr<WeakAttr>() || 734 FD->isWeakImported()) { 735 // "extern_weak" is overloaded in LLVM; we probably should have 736 // separate linkage types for this. 737 F->setLinkage(llvm::Function::ExternalWeakLinkage); 738 } else { 739 F->setLinkage(llvm::Function::ExternalLinkage); 740 741 LinkageInfo LV = FD->getLinkageAndVisibility(); 742 if (LV.getLinkage() == ExternalLinkage && LV.isVisibilityExplicit()) { 743 F->setVisibility(GetLLVMVisibility(LV.getVisibility())); 744 } 745 } 746 747 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 748 F->setSection(SA->getName()); 749 } 750 751 void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 752 assert(!GV->isDeclaration() && 753 "Only globals with definition can force usage."); 754 LLVMUsed.push_back(GV); 755 } 756 757 void CodeGenModule::EmitLLVMUsed() { 758 // Don't create llvm.used if there is no need. 759 if (LLVMUsed.empty()) 760 return; 761 762 // Convert LLVMUsed to what ConstantArray needs. 763 SmallVector<llvm::Constant*, 8> UsedArray; 764 UsedArray.resize(LLVMUsed.size()); 765 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 766 UsedArray[i] = 767 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 768 Int8PtrTy); 769 } 770 771 if (UsedArray.empty()) 772 return; 773 llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size()); 774 775 llvm::GlobalVariable *GV = 776 new llvm::GlobalVariable(getModule(), ATy, false, 777 llvm::GlobalValue::AppendingLinkage, 778 llvm::ConstantArray::get(ATy, UsedArray), 779 "llvm.used"); 780 781 GV->setSection("llvm.metadata"); 782 } 783 784 void CodeGenModule::AppendLinkerOptions(StringRef Opts) { 785 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opts); 786 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 787 } 788 789 void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) { 790 llvm::SmallString<32> Opt; 791 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt); 792 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); 793 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 794 } 795 796 void CodeGenModule::AddDependentLib(StringRef Lib) { 797 llvm::SmallString<24> Opt; 798 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt); 799 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); 800 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 801 } 802 803 /// \brief Add link options implied by the given module, including modules 804 /// it depends on, using a postorder walk. 805 static void addLinkOptionsPostorder(CodeGenModule &CGM, 806 Module *Mod, 807 SmallVectorImpl<llvm::Value *> &Metadata, 808 llvm::SmallPtrSet<Module *, 16> &Visited) { 809 // Import this module's parent. 810 if (Mod->Parent && Visited.insert(Mod->Parent)) { 811 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited); 812 } 813 814 // Import this module's dependencies. 815 for (unsigned I = Mod->Imports.size(); I > 0; --I) { 816 if (Visited.insert(Mod->Imports[I-1])) 817 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited); 818 } 819 820 // Add linker options to link against the libraries/frameworks 821 // described by this module. 822 llvm::LLVMContext &Context = CGM.getLLVMContext(); 823 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) { 824 // Link against a framework. Frameworks are currently Darwin only, so we 825 // don't to ask TargetCodeGenInfo for the spelling of the linker option. 826 if (Mod->LinkLibraries[I-1].IsFramework) { 827 llvm::Value *Args[2] = { 828 llvm::MDString::get(Context, "-framework"), 829 llvm::MDString::get(Context, Mod->LinkLibraries[I-1].Library) 830 }; 831 832 Metadata.push_back(llvm::MDNode::get(Context, Args)); 833 continue; 834 } 835 836 // Link against a library. 837 llvm::SmallString<24> Opt; 838 CGM.getTargetCodeGenInfo().getDependentLibraryOption( 839 Mod->LinkLibraries[I-1].Library, Opt); 840 llvm::Value *OptString = llvm::MDString::get(Context, Opt); 841 Metadata.push_back(llvm::MDNode::get(Context, OptString)); 842 } 843 } 844 845 void CodeGenModule::EmitModuleLinkOptions() { 846 // Collect the set of all of the modules we want to visit to emit link 847 // options, which is essentially the imported modules and all of their 848 // non-explicit child modules. 849 llvm::SetVector<clang::Module *> LinkModules; 850 llvm::SmallPtrSet<clang::Module *, 16> Visited; 851 SmallVector<clang::Module *, 16> Stack; 852 853 // Seed the stack with imported modules. 854 for (llvm::SetVector<clang::Module *>::iterator M = ImportedModules.begin(), 855 MEnd = ImportedModules.end(); 856 M != MEnd; ++M) { 857 if (Visited.insert(*M)) 858 Stack.push_back(*M); 859 } 860 861 // Find all of the modules to import, making a little effort to prune 862 // non-leaf modules. 863 while (!Stack.empty()) { 864 clang::Module *Mod = Stack.back(); 865 Stack.pop_back(); 866 867 bool AnyChildren = false; 868 869 // Visit the submodules of this module. 870 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(), 871 SubEnd = Mod->submodule_end(); 872 Sub != SubEnd; ++Sub) { 873 // Skip explicit children; they need to be explicitly imported to be 874 // linked against. 875 if ((*Sub)->IsExplicit) 876 continue; 877 878 if (Visited.insert(*Sub)) { 879 Stack.push_back(*Sub); 880 AnyChildren = true; 881 } 882 } 883 884 // We didn't find any children, so add this module to the list of 885 // modules to link against. 886 if (!AnyChildren) { 887 LinkModules.insert(Mod); 888 } 889 } 890 891 // Add link options for all of the imported modules in reverse topological 892 // order. We don't do anything to try to order import link flags with respect 893 // to linker options inserted by things like #pragma comment(). 894 SmallVector<llvm::Value *, 16> MetadataArgs; 895 Visited.clear(); 896 for (llvm::SetVector<clang::Module *>::iterator M = LinkModules.begin(), 897 MEnd = LinkModules.end(); 898 M != MEnd; ++M) { 899 if (Visited.insert(*M)) 900 addLinkOptionsPostorder(*this, *M, MetadataArgs, Visited); 901 } 902 std::reverse(MetadataArgs.begin(), MetadataArgs.end()); 903 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end()); 904 905 // Add the linker options metadata flag. 906 getModule().addModuleFlag(llvm::Module::AppendUnique, "Linker Options", 907 llvm::MDNode::get(getLLVMContext(), 908 LinkerOptionsMetadata)); 909 } 910 911 void CodeGenModule::EmitDeferred() { 912 // Emit code for any potentially referenced deferred decls. Since a 913 // previously unused static decl may become used during the generation of code 914 // for a static function, iterate until no changes are made. 915 916 while (true) { 917 if (!DeferredVTables.empty()) { 918 EmitDeferredVTables(); 919 920 // Emitting a v-table doesn't directly cause more v-tables to 921 // become deferred, although it can cause functions to be 922 // emitted that then need those v-tables. 923 assert(DeferredVTables.empty()); 924 } 925 926 // Stop if we're out of both deferred v-tables and deferred declarations. 927 if (DeferredDeclsToEmit.empty()) break; 928 929 GlobalDecl D = DeferredDeclsToEmit.back(); 930 DeferredDeclsToEmit.pop_back(); 931 932 // Check to see if we've already emitted this. This is necessary 933 // for a couple of reasons: first, decls can end up in the 934 // deferred-decls queue multiple times, and second, decls can end 935 // up with definitions in unusual ways (e.g. by an extern inline 936 // function acquiring a strong function redefinition). Just 937 // ignore these cases. 938 // 939 // TODO: That said, looking this up multiple times is very wasteful. 940 StringRef Name = getMangledName(D); 941 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 942 assert(CGRef && "Deferred decl wasn't referenced?"); 943 944 if (!CGRef->isDeclaration()) 945 continue; 946 947 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 948 // purposes an alias counts as a definition. 949 if (isa<llvm::GlobalAlias>(CGRef)) 950 continue; 951 952 // Otherwise, emit the definition and move on to the next one. 953 EmitGlobalDefinition(D); 954 } 955 } 956 957 void CodeGenModule::EmitGlobalAnnotations() { 958 if (Annotations.empty()) 959 return; 960 961 // Create a new global variable for the ConstantStruct in the Module. 962 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 963 Annotations[0]->getType(), Annotations.size()), Annotations); 964 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), 965 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, 966 "llvm.global.annotations"); 967 gv->setSection(AnnotationSection); 968 } 969 970 llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) { 971 llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str); 972 if (i != AnnotationStrings.end()) 973 return i->second; 974 975 // Not found yet, create a new global. 976 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); 977 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), 978 true, llvm::GlobalValue::PrivateLinkage, s, ".str"); 979 gv->setSection(AnnotationSection); 980 gv->setUnnamedAddr(true); 981 AnnotationStrings[Str] = gv; 982 return gv; 983 } 984 985 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 986 SourceManager &SM = getContext().getSourceManager(); 987 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 988 if (PLoc.isValid()) 989 return EmitAnnotationString(PLoc.getFilename()); 990 return EmitAnnotationString(SM.getBufferName(Loc)); 991 } 992 993 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 994 SourceManager &SM = getContext().getSourceManager(); 995 PresumedLoc PLoc = SM.getPresumedLoc(L); 996 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 997 SM.getExpansionLineNumber(L); 998 return llvm::ConstantInt::get(Int32Ty, LineNo); 999 } 1000 1001 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 1002 const AnnotateAttr *AA, 1003 SourceLocation L) { 1004 // Get the globals for file name, annotation, and the line number. 1005 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 1006 *UnitGV = EmitAnnotationUnit(L), 1007 *LineNoCst = EmitAnnotationLineNo(L); 1008 1009 // Create the ConstantStruct for the global annotation. 1010 llvm::Constant *Fields[4] = { 1011 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 1012 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 1013 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 1014 LineNoCst 1015 }; 1016 return llvm::ConstantStruct::getAnon(Fields); 1017 } 1018 1019 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 1020 llvm::GlobalValue *GV) { 1021 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 1022 // Get the struct elements for these annotations. 1023 for (specific_attr_iterator<AnnotateAttr> 1024 ai = D->specific_attr_begin<AnnotateAttr>(), 1025 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) 1026 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); 1027 } 1028 1029 bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 1030 // Never defer when EmitAllDecls is specified. 1031 if (LangOpts.EmitAllDecls) 1032 return false; 1033 1034 return !getContext().DeclMustBeEmitted(Global); 1035 } 1036 1037 llvm::Constant *CodeGenModule::GetAddrOfUuidDescriptor( 1038 const CXXUuidofExpr* E) { 1039 // Sema has verified that IIDSource has a __declspec(uuid()), and that its 1040 // well-formed. 1041 StringRef Uuid; 1042 if (E->isTypeOperand()) 1043 Uuid = CXXUuidofExpr::GetUuidAttrOfType(E->getTypeOperand())->getGuid(); 1044 else { 1045 // Special case: __uuidof(0) means an all-zero GUID. 1046 Expr *Op = E->getExprOperand(); 1047 if (!Op->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 1048 Uuid = CXXUuidofExpr::GetUuidAttrOfType(Op->getType())->getGuid(); 1049 else 1050 Uuid = "00000000-0000-0000-0000-000000000000"; 1051 } 1052 std::string Name = "__uuid_" + Uuid.str(); 1053 1054 // Look for an existing global. 1055 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name)) 1056 return GV; 1057 1058 llvm::Constant *Init = EmitUuidofInitializer(Uuid, E->getType()); 1059 assert(Init && "failed to initialize as constant"); 1060 1061 // GUIDs are assumed to be 16 bytes, spread over 4-2-2-8 bytes. However, the 1062 // first field is declared as "long", which for many targets is 8 bytes. 1063 // Those architectures are not supported. (With the MS abi, long is always 4 1064 // bytes.) 1065 llvm::Type *GuidType = getTypes().ConvertType(E->getType()); 1066 if (Init->getType() != GuidType) { 1067 DiagnosticsEngine &Diags = getDiags(); 1068 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error, 1069 "__uuidof codegen is not supported on this architecture"); 1070 Diags.Report(E->getExprLoc(), DiagID) << E->getSourceRange(); 1071 Init = llvm::UndefValue::get(GuidType); 1072 } 1073 1074 llvm::GlobalVariable *GV = new llvm::GlobalVariable(getModule(), GuidType, 1075 /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, Init, Name); 1076 GV->setUnnamedAddr(true); 1077 return GV; 1078 } 1079 1080 llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 1081 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 1082 assert(AA && "No alias?"); 1083 1084 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 1085 1086 // See if there is already something with the target's name in the module. 1087 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 1088 if (Entry) { 1089 unsigned AS = getContext().getTargetAddressSpace(VD->getType()); 1090 return llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS)); 1091 } 1092 1093 llvm::Constant *Aliasee; 1094 if (isa<llvm::FunctionType>(DeclTy)) 1095 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, 1096 GlobalDecl(cast<FunctionDecl>(VD)), 1097 /*ForVTable=*/false); 1098 else 1099 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1100 llvm::PointerType::getUnqual(DeclTy), 0); 1101 1102 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 1103 F->setLinkage(llvm::Function::ExternalWeakLinkage); 1104 WeakRefReferences.insert(F); 1105 1106 return Aliasee; 1107 } 1108 1109 void CodeGenModule::EmitGlobal(GlobalDecl GD) { 1110 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 1111 1112 // Weak references don't produce any output by themselves. 1113 if (Global->hasAttr<WeakRefAttr>()) 1114 return; 1115 1116 // If this is an alias definition (which otherwise looks like a declaration) 1117 // emit it now. 1118 if (Global->hasAttr<AliasAttr>()) 1119 return EmitAliasDefinition(GD); 1120 1121 // If this is CUDA, be selective about which declarations we emit. 1122 if (LangOpts.CUDA) { 1123 if (CodeGenOpts.CUDAIsDevice) { 1124 if (!Global->hasAttr<CUDADeviceAttr>() && 1125 !Global->hasAttr<CUDAGlobalAttr>() && 1126 !Global->hasAttr<CUDAConstantAttr>() && 1127 !Global->hasAttr<CUDASharedAttr>()) 1128 return; 1129 } else { 1130 if (!Global->hasAttr<CUDAHostAttr>() && ( 1131 Global->hasAttr<CUDADeviceAttr>() || 1132 Global->hasAttr<CUDAConstantAttr>() || 1133 Global->hasAttr<CUDASharedAttr>())) 1134 return; 1135 } 1136 } 1137 1138 // Ignore declarations, they will be emitted on their first use. 1139 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 1140 // Forward declarations are emitted lazily on first use. 1141 if (!FD->doesThisDeclarationHaveABody()) { 1142 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 1143 return; 1144 1145 const FunctionDecl *InlineDefinition = 0; 1146 FD->getBody(InlineDefinition); 1147 1148 StringRef MangledName = getMangledName(GD); 1149 DeferredDecls.erase(MangledName); 1150 EmitGlobalDefinition(InlineDefinition); 1151 return; 1152 } 1153 } else { 1154 const VarDecl *VD = cast<VarDecl>(Global); 1155 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 1156 1157 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 1158 return; 1159 } 1160 1161 // Defer code generation when possible if this is a static definition, inline 1162 // function etc. These we only want to emit if they are used. 1163 if (!MayDeferGeneration(Global)) { 1164 // Emit the definition if it can't be deferred. 1165 EmitGlobalDefinition(GD); 1166 return; 1167 } 1168 1169 // If we're deferring emission of a C++ variable with an 1170 // initializer, remember the order in which it appeared in the file. 1171 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) && 1172 cast<VarDecl>(Global)->hasInit()) { 1173 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 1174 CXXGlobalInits.push_back(0); 1175 } 1176 1177 // If the value has already been used, add it directly to the 1178 // DeferredDeclsToEmit list. 1179 StringRef MangledName = getMangledName(GD); 1180 if (GetGlobalValue(MangledName)) 1181 DeferredDeclsToEmit.push_back(GD); 1182 else { 1183 // Otherwise, remember that we saw a deferred decl with this name. The 1184 // first use of the mangled name will cause it to move into 1185 // DeferredDeclsToEmit. 1186 DeferredDecls[MangledName] = GD; 1187 } 1188 } 1189 1190 namespace { 1191 struct FunctionIsDirectlyRecursive : 1192 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> { 1193 const StringRef Name; 1194 const Builtin::Context &BI; 1195 bool Result; 1196 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) : 1197 Name(N), BI(C), Result(false) { 1198 } 1199 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; 1200 1201 bool TraverseCallExpr(CallExpr *E) { 1202 const FunctionDecl *FD = E->getDirectCallee(); 1203 if (!FD) 1204 return true; 1205 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1206 if (Attr && Name == Attr->getLabel()) { 1207 Result = true; 1208 return false; 1209 } 1210 unsigned BuiltinID = FD->getBuiltinID(); 1211 if (!BuiltinID) 1212 return true; 1213 StringRef BuiltinName = BI.GetName(BuiltinID); 1214 if (BuiltinName.startswith("__builtin_") && 1215 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { 1216 Result = true; 1217 return false; 1218 } 1219 return true; 1220 } 1221 }; 1222 } 1223 1224 // isTriviallyRecursive - Check if this function calls another 1225 // decl that, because of the asm attribute or the other decl being a builtin, 1226 // ends up pointing to itself. 1227 bool 1228 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { 1229 StringRef Name; 1230 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { 1231 // asm labels are a special kind of mangling we have to support. 1232 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1233 if (!Attr) 1234 return false; 1235 Name = Attr->getLabel(); 1236 } else { 1237 Name = FD->getName(); 1238 } 1239 1240 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); 1241 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD)); 1242 return Walker.Result; 1243 } 1244 1245 bool 1246 CodeGenModule::shouldEmitFunction(GlobalDecl GD) { 1247 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage) 1248 return true; 1249 const FunctionDecl *F = cast<FunctionDecl>(GD.getDecl()); 1250 if (CodeGenOpts.OptimizationLevel == 0 && 1251 !F->hasAttr<AlwaysInlineAttr>() && !F->hasAttr<ForceInlineAttr>()) 1252 return false; 1253 // PR9614. Avoid cases where the source code is lying to us. An available 1254 // externally function should have an equivalent function somewhere else, 1255 // but a function that calls itself is clearly not equivalent to the real 1256 // implementation. 1257 // This happens in glibc's btowc and in some configure checks. 1258 return !isTriviallyRecursive(F); 1259 } 1260 1261 /// If the type for the method's class was generated by 1262 /// CGDebugInfo::createContextChain(), the cache contains only a 1263 /// limited DIType without any declarations. Since EmitFunctionStart() 1264 /// needs to find the canonical declaration for each method, we need 1265 /// to construct the complete type prior to emitting the method. 1266 void CodeGenModule::CompleteDIClassType(const CXXMethodDecl* D) { 1267 if (!D->isInstance()) 1268 return; 1269 1270 if (CGDebugInfo *DI = getModuleDebugInfo()) 1271 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) { 1272 const PointerType *ThisPtr = 1273 cast<PointerType>(D->getThisType(getContext())); 1274 DI->getOrCreateRecordType(ThisPtr->getPointeeType(), D->getLocation()); 1275 } 1276 } 1277 1278 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 1279 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1280 1281 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 1282 Context.getSourceManager(), 1283 "Generating code for declaration"); 1284 1285 if (isa<FunctionDecl>(D)) { 1286 // At -O0, don't generate IR for functions with available_externally 1287 // linkage. 1288 if (!shouldEmitFunction(GD)) 1289 return; 1290 1291 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 1292 CompleteDIClassType(Method); 1293 // Make sure to emit the definition(s) before we emit the thunks. 1294 // This is necessary for the generation of certain thunks. 1295 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 1296 EmitCXXConstructor(CD, GD.getCtorType()); 1297 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 1298 EmitCXXDestructor(DD, GD.getDtorType()); 1299 else 1300 EmitGlobalFunctionDefinition(GD); 1301 1302 if (Method->isVirtual()) 1303 getVTables().EmitThunks(GD); 1304 1305 return; 1306 } 1307 1308 return EmitGlobalFunctionDefinition(GD); 1309 } 1310 1311 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 1312 return EmitGlobalVarDefinition(VD); 1313 1314 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 1315 } 1316 1317 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the 1318 /// module, create and return an llvm Function with the specified type. If there 1319 /// is something in the module with the specified name, return it potentially 1320 /// bitcasted to the right type. 1321 /// 1322 /// If D is non-null, it specifies a decl that correspond to this. This is used 1323 /// to set the attributes on the function when it is first created. 1324 llvm::Constant * 1325 CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 1326 llvm::Type *Ty, 1327 GlobalDecl D, bool ForVTable, 1328 llvm::AttributeSet ExtraAttrs) { 1329 // Lookup the entry, lazily creating it if necessary. 1330 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1331 if (Entry) { 1332 if (WeakRefReferences.erase(Entry)) { 1333 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 1334 if (FD && !FD->hasAttr<WeakAttr>()) 1335 Entry->setLinkage(llvm::Function::ExternalLinkage); 1336 } 1337 1338 if (Entry->getType()->getElementType() == Ty) 1339 return Entry; 1340 1341 // Make sure the result is of the correct type. 1342 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 1343 } 1344 1345 // This function doesn't have a complete type (for example, the return 1346 // type is an incomplete struct). Use a fake type instead, and make 1347 // sure not to try to set attributes. 1348 bool IsIncompleteFunction = false; 1349 1350 llvm::FunctionType *FTy; 1351 if (isa<llvm::FunctionType>(Ty)) { 1352 FTy = cast<llvm::FunctionType>(Ty); 1353 } else { 1354 FTy = llvm::FunctionType::get(VoidTy, false); 1355 IsIncompleteFunction = true; 1356 } 1357 1358 llvm::Function *F = llvm::Function::Create(FTy, 1359 llvm::Function::ExternalLinkage, 1360 MangledName, &getModule()); 1361 assert(F->getName() == MangledName && "name was uniqued!"); 1362 if (D.getDecl()) 1363 SetFunctionAttributes(D, F, IsIncompleteFunction); 1364 if (ExtraAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) { 1365 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeSet::FunctionIndex); 1366 F->addAttributes(llvm::AttributeSet::FunctionIndex, 1367 llvm::AttributeSet::get(VMContext, 1368 llvm::AttributeSet::FunctionIndex, 1369 B)); 1370 } 1371 1372 // This is the first use or definition of a mangled name. If there is a 1373 // deferred decl with this name, remember that we need to emit it at the end 1374 // of the file. 1375 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1376 if (DDI != DeferredDecls.end()) { 1377 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1378 // list, and remove it from DeferredDecls (since we don't need it anymore). 1379 DeferredDeclsToEmit.push_back(DDI->second); 1380 DeferredDecls.erase(DDI); 1381 1382 // Otherwise, there are cases we have to worry about where we're 1383 // using a declaration for which we must emit a definition but where 1384 // we might not find a top-level definition: 1385 // - member functions defined inline in their classes 1386 // - friend functions defined inline in some class 1387 // - special member functions with implicit definitions 1388 // If we ever change our AST traversal to walk into class methods, 1389 // this will be unnecessary. 1390 // 1391 // We also don't emit a definition for a function if it's going to be an entry 1392 // in a vtable, unless it's already marked as used. 1393 } else if (getLangOpts().CPlusPlus && D.getDecl()) { 1394 // Look for a declaration that's lexically in a record. 1395 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); 1396 FD = FD->getMostRecentDecl(); 1397 do { 1398 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 1399 if (FD->isImplicit() && !ForVTable) { 1400 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 1401 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1402 break; 1403 } else if (FD->doesThisDeclarationHaveABody()) { 1404 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1405 break; 1406 } 1407 } 1408 FD = FD->getPreviousDecl(); 1409 } while (FD); 1410 } 1411 1412 // Make sure the result is of the requested type. 1413 if (!IsIncompleteFunction) { 1414 assert(F->getType()->getElementType() == Ty); 1415 return F; 1416 } 1417 1418 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1419 return llvm::ConstantExpr::getBitCast(F, PTy); 1420 } 1421 1422 /// GetAddrOfFunction - Return the address of the given function. If Ty is 1423 /// non-null, then this function will use the specified type if it has to 1424 /// create it (this occurs when we see a definition of the function). 1425 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 1426 llvm::Type *Ty, 1427 bool ForVTable) { 1428 // If there was no specific requested type, just convert it now. 1429 if (!Ty) 1430 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 1431 1432 StringRef MangledName = getMangledName(GD); 1433 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 1434 } 1435 1436 /// CreateRuntimeFunction - Create a new runtime function with the specified 1437 /// type and name. 1438 llvm::Constant * 1439 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 1440 StringRef Name, 1441 llvm::AttributeSet ExtraAttrs) { 1442 llvm::Constant *C 1443 = GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 1444 ExtraAttrs); 1445 if (llvm::Function *F = dyn_cast<llvm::Function>(C)) 1446 if (F->empty()) 1447 F->setCallingConv(getRuntimeCC()); 1448 return C; 1449 } 1450 1451 /// isTypeConstant - Determine whether an object of this type can be emitted 1452 /// as a constant. 1453 /// 1454 /// If ExcludeCtor is true, the duration when the object's constructor runs 1455 /// will not be considered. The caller will need to verify that the object is 1456 /// not written to during its construction. 1457 bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) { 1458 if (!Ty.isConstant(Context) && !Ty->isReferenceType()) 1459 return false; 1460 1461 if (Context.getLangOpts().CPlusPlus) { 1462 if (const CXXRecordDecl *Record 1463 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl()) 1464 return ExcludeCtor && !Record->hasMutableFields() && 1465 Record->hasTrivialDestructor(); 1466 } 1467 1468 return true; 1469 } 1470 1471 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1472 /// create and return an llvm GlobalVariable with the specified type. If there 1473 /// is something in the module with the specified name, return it potentially 1474 /// bitcasted to the right type. 1475 /// 1476 /// If D is non-null, it specifies a decl that correspond to this. This is used 1477 /// to set the attributes on the global when it is first created. 1478 llvm::Constant * 1479 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1480 llvm::PointerType *Ty, 1481 const VarDecl *D, 1482 bool UnnamedAddr) { 1483 // Lookup the entry, lazily creating it if necessary. 1484 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1485 if (Entry) { 1486 if (WeakRefReferences.erase(Entry)) { 1487 if (D && !D->hasAttr<WeakAttr>()) 1488 Entry->setLinkage(llvm::Function::ExternalLinkage); 1489 } 1490 1491 if (UnnamedAddr) 1492 Entry->setUnnamedAddr(true); 1493 1494 if (Entry->getType() == Ty) 1495 return Entry; 1496 1497 // Make sure the result is of the correct type. 1498 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1499 } 1500 1501 // This is the first use or definition of a mangled name. If there is a 1502 // deferred decl with this name, remember that we need to emit it at the end 1503 // of the file. 1504 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1505 if (DDI != DeferredDecls.end()) { 1506 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1507 // list, and remove it from DeferredDecls (since we don't need it anymore). 1508 DeferredDeclsToEmit.push_back(DDI->second); 1509 DeferredDecls.erase(DDI); 1510 } 1511 1512 unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace()); 1513 llvm::GlobalVariable *GV = 1514 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1515 llvm::GlobalValue::ExternalLinkage, 1516 0, MangledName, 0, 1517 llvm::GlobalVariable::NotThreadLocal, AddrSpace); 1518 1519 // Handle things which are present even on external declarations. 1520 if (D) { 1521 // FIXME: This code is overly simple and should be merged with other global 1522 // handling. 1523 GV->setConstant(isTypeConstant(D->getType(), false)); 1524 1525 // Set linkage and visibility in case we never see a definition. 1526 LinkageInfo LV = D->getLinkageAndVisibility(); 1527 if (LV.getLinkage() != ExternalLinkage) { 1528 // Don't set internal linkage on declarations. 1529 } else { 1530 if (D->hasAttr<DLLImportAttr>()) 1531 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1532 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1533 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1534 1535 // Set visibility on a declaration only if it's explicit. 1536 if (LV.isVisibilityExplicit()) 1537 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 1538 } 1539 1540 if (D->getTLSKind()) { 1541 if (D->getTLSKind() == VarDecl::TLS_Dynamic) 1542 CXXThreadLocals.push_back(std::make_pair(D, GV)); 1543 setTLSMode(GV, *D); 1544 } 1545 } 1546 1547 if (AddrSpace != Ty->getAddressSpace()) 1548 return llvm::ConstantExpr::getBitCast(GV, Ty); 1549 else 1550 return GV; 1551 } 1552 1553 1554 llvm::GlobalVariable * 1555 CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1556 llvm::Type *Ty, 1557 llvm::GlobalValue::LinkageTypes Linkage) { 1558 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1559 llvm::GlobalVariable *OldGV = 0; 1560 1561 1562 if (GV) { 1563 // Check if the variable has the right type. 1564 if (GV->getType()->getElementType() == Ty) 1565 return GV; 1566 1567 // Because C++ name mangling, the only way we can end up with an already 1568 // existing global with the same name is if it has been declared extern "C". 1569 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1570 OldGV = GV; 1571 } 1572 1573 // Create a new variable. 1574 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1575 Linkage, 0, Name); 1576 1577 if (OldGV) { 1578 // Replace occurrences of the old variable if needed. 1579 GV->takeName(OldGV); 1580 1581 if (!OldGV->use_empty()) { 1582 llvm::Constant *NewPtrForOldDecl = 1583 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1584 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1585 } 1586 1587 OldGV->eraseFromParent(); 1588 } 1589 1590 return GV; 1591 } 1592 1593 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1594 /// given global variable. If Ty is non-null and if the global doesn't exist, 1595 /// then it will be created with the specified type instead of whatever the 1596 /// normal requested type would be. 1597 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1598 llvm::Type *Ty) { 1599 assert(D->hasGlobalStorage() && "Not a global variable"); 1600 QualType ASTTy = D->getType(); 1601 if (Ty == 0) 1602 Ty = getTypes().ConvertTypeForMem(ASTTy); 1603 1604 llvm::PointerType *PTy = 1605 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1606 1607 StringRef MangledName = getMangledName(D); 1608 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1609 } 1610 1611 /// CreateRuntimeVariable - Create a new runtime global variable with the 1612 /// specified type and name. 1613 llvm::Constant * 1614 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1615 StringRef Name) { 1616 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1617 true); 1618 } 1619 1620 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1621 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1622 1623 if (MayDeferGeneration(D)) { 1624 // If we have not seen a reference to this variable yet, place it 1625 // into the deferred declarations table to be emitted if needed 1626 // later. 1627 StringRef MangledName = getMangledName(D); 1628 if (!GetGlobalValue(MangledName)) { 1629 DeferredDecls[MangledName] = D; 1630 return; 1631 } 1632 } 1633 1634 // The tentative definition is the only definition. 1635 EmitGlobalVarDefinition(D); 1636 } 1637 1638 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1639 return Context.toCharUnitsFromBits( 1640 TheDataLayout.getTypeStoreSizeInBits(Ty)); 1641 } 1642 1643 unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D, 1644 unsigned AddrSpace) { 1645 if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) { 1646 if (D->hasAttr<CUDAConstantAttr>()) 1647 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_constant); 1648 else if (D->hasAttr<CUDASharedAttr>()) 1649 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_shared); 1650 else 1651 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_device); 1652 } 1653 1654 return AddrSpace; 1655 } 1656 1657 template<typename SomeDecl> 1658 void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D, 1659 llvm::GlobalValue *GV) { 1660 if (!getLangOpts().CPlusPlus) 1661 return; 1662 1663 // Must have 'used' attribute, or else inline assembly can't rely on 1664 // the name existing. 1665 if (!D->template hasAttr<UsedAttr>()) 1666 return; 1667 1668 // Must have internal linkage and an ordinary name. 1669 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage) 1670 return; 1671 1672 // Must be in an extern "C" context. Entities declared directly within 1673 // a record are not extern "C" even if the record is in such a context. 1674 const SomeDecl *First = D->getFirstDeclaration(); 1675 if (First->getDeclContext()->isRecord() || !First->isInExternCContext()) 1676 return; 1677 1678 // OK, this is an internal linkage entity inside an extern "C" linkage 1679 // specification. Make a note of that so we can give it the "expected" 1680 // mangled name if nothing else is using that name. 1681 std::pair<StaticExternCMap::iterator, bool> R = 1682 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV)); 1683 1684 // If we have multiple internal linkage entities with the same name 1685 // in extern "C" regions, none of them gets that name. 1686 if (!R.second) 1687 R.first->second = 0; 1688 } 1689 1690 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1691 llvm::Constant *Init = 0; 1692 QualType ASTTy = D->getType(); 1693 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 1694 bool NeedsGlobalCtor = false; 1695 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor(); 1696 1697 const VarDecl *InitDecl; 1698 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 1699 1700 if (!InitExpr) { 1701 // This is a tentative definition; tentative definitions are 1702 // implicitly initialized with { 0 }. 1703 // 1704 // Note that tentative definitions are only emitted at the end of 1705 // a translation unit, so they should never have incomplete 1706 // type. In addition, EmitTentativeDefinition makes sure that we 1707 // never attempt to emit a tentative definition if a real one 1708 // exists. A use may still exists, however, so we still may need 1709 // to do a RAUW. 1710 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1711 Init = EmitNullConstant(D->getType()); 1712 } else { 1713 initializedGlobalDecl = GlobalDecl(D); 1714 Init = EmitConstantInit(*InitDecl); 1715 1716 if (!Init) { 1717 QualType T = InitExpr->getType(); 1718 if (D->getType()->isReferenceType()) 1719 T = D->getType(); 1720 1721 if (getLangOpts().CPlusPlus) { 1722 Init = EmitNullConstant(T); 1723 NeedsGlobalCtor = true; 1724 } else { 1725 ErrorUnsupported(D, "static initializer"); 1726 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1727 } 1728 } else { 1729 // We don't need an initializer, so remove the entry for the delayed 1730 // initializer position (just in case this entry was delayed) if we 1731 // also don't need to register a destructor. 1732 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor) 1733 DelayedCXXInitPosition.erase(D); 1734 } 1735 } 1736 1737 llvm::Type* InitType = Init->getType(); 1738 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1739 1740 // Strip off a bitcast if we got one back. 1741 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1742 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1743 // all zero index gep. 1744 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1745 Entry = CE->getOperand(0); 1746 } 1747 1748 // Entry is now either a Function or GlobalVariable. 1749 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1750 1751 // We have a definition after a declaration with the wrong type. 1752 // We must make a new GlobalVariable* and update everything that used OldGV 1753 // (a declaration or tentative definition) with the new GlobalVariable* 1754 // (which will be a definition). 1755 // 1756 // This happens if there is a prototype for a global (e.g. 1757 // "extern int x[];") and then a definition of a different type (e.g. 1758 // "int x[10];"). This also happens when an initializer has a different type 1759 // from the type of the global (this happens with unions). 1760 if (GV == 0 || 1761 GV->getType()->getElementType() != InitType || 1762 GV->getType()->getAddressSpace() != 1763 GetGlobalVarAddressSpace(D, getContext().getTargetAddressSpace(ASTTy))) { 1764 1765 // Move the old entry aside so that we'll create a new one. 1766 Entry->setName(StringRef()); 1767 1768 // Make a new global with the correct type, this is now guaranteed to work. 1769 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1770 1771 // Replace all uses of the old global with the new global 1772 llvm::Constant *NewPtrForOldDecl = 1773 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1774 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1775 1776 // Erase the old global, since it is no longer used. 1777 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1778 } 1779 1780 MaybeHandleStaticInExternC(D, GV); 1781 1782 if (D->hasAttr<AnnotateAttr>()) 1783 AddGlobalAnnotations(D, GV); 1784 1785 GV->setInitializer(Init); 1786 1787 // If it is safe to mark the global 'constant', do so now. 1788 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor && 1789 isTypeConstant(D->getType(), true)); 1790 1791 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1792 1793 // Set the llvm linkage type as appropriate. 1794 llvm::GlobalValue::LinkageTypes Linkage = 1795 GetLLVMLinkageVarDefinition(D, GV); 1796 GV->setLinkage(Linkage); 1797 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1798 // common vars aren't constant even if declared const. 1799 GV->setConstant(false); 1800 1801 SetCommonAttributes(D, GV); 1802 1803 // Emit the initializer function if necessary. 1804 if (NeedsGlobalCtor || NeedsGlobalDtor) 1805 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); 1806 1807 // If we are compiling with ASan, add metadata indicating dynamically 1808 // initialized globals. 1809 if (SanOpts.Address && NeedsGlobalCtor) { 1810 llvm::Module &M = getModule(); 1811 1812 llvm::NamedMDNode *DynamicInitializers = 1813 M.getOrInsertNamedMetadata("llvm.asan.dynamically_initialized_globals"); 1814 llvm::Value *GlobalToAdd[] = { GV }; 1815 llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalToAdd); 1816 DynamicInitializers->addOperand(ThisGlobal); 1817 } 1818 1819 // Emit global variable debug information. 1820 if (CGDebugInfo *DI = getModuleDebugInfo()) 1821 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) 1822 DI->EmitGlobalVariable(GV, D); 1823 } 1824 1825 llvm::GlobalValue::LinkageTypes 1826 CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, 1827 llvm::GlobalVariable *GV) { 1828 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1829 if (Linkage == GVA_Internal) 1830 return llvm::Function::InternalLinkage; 1831 else if (D->hasAttr<DLLImportAttr>()) 1832 return llvm::Function::DLLImportLinkage; 1833 else if (D->hasAttr<DLLExportAttr>()) 1834 return llvm::Function::DLLExportLinkage; 1835 else if (D->hasAttr<SelectAnyAttr>()) { 1836 // selectany symbols are externally visible, so use weak instead of 1837 // linkonce. MSVC optimizes away references to const selectany globals, so 1838 // all definitions should be the same and ODR linkage should be used. 1839 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx 1840 return llvm::GlobalVariable::WeakODRLinkage; 1841 } else if (D->hasAttr<WeakAttr>()) { 1842 if (GV->isConstant()) 1843 return llvm::GlobalVariable::WeakODRLinkage; 1844 else 1845 return llvm::GlobalVariable::WeakAnyLinkage; 1846 } else if (Linkage == GVA_TemplateInstantiation || 1847 Linkage == GVA_ExplicitTemplateInstantiation) 1848 return llvm::GlobalVariable::WeakODRLinkage; 1849 else if (!getLangOpts().CPlusPlus && 1850 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1851 D->getAttr<CommonAttr>()) && 1852 !D->hasExternalStorage() && !D->getInit() && 1853 !D->getAttr<SectionAttr>() && !D->getTLSKind() && 1854 !D->getAttr<WeakImportAttr>()) { 1855 // Thread local vars aren't considered common linkage. 1856 return llvm::GlobalVariable::CommonLinkage; 1857 } else if (D->getTLSKind() == VarDecl::TLS_Dynamic && 1858 getTarget().getTriple().isMacOSX()) 1859 // On Darwin, the backing variable for a C++11 thread_local variable always 1860 // has internal linkage; all accesses should just be calls to the 1861 // Itanium-specified entry point, which has the normal linkage of the 1862 // variable. 1863 return llvm::GlobalValue::InternalLinkage; 1864 return llvm::GlobalVariable::ExternalLinkage; 1865 } 1866 1867 /// Replace the uses of a function that was declared with a non-proto type. 1868 /// We want to silently drop extra arguments from call sites 1869 static void replaceUsesOfNonProtoConstant(llvm::Constant *old, 1870 llvm::Function *newFn) { 1871 // Fast path. 1872 if (old->use_empty()) return; 1873 1874 llvm::Type *newRetTy = newFn->getReturnType(); 1875 SmallVector<llvm::Value*, 4> newArgs; 1876 1877 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end(); 1878 ui != ue; ) { 1879 llvm::Value::use_iterator use = ui++; // Increment before the use is erased. 1880 llvm::User *user = *use; 1881 1882 // Recognize and replace uses of bitcasts. Most calls to 1883 // unprototyped functions will use bitcasts. 1884 if (llvm::ConstantExpr *bitcast = dyn_cast<llvm::ConstantExpr>(user)) { 1885 if (bitcast->getOpcode() == llvm::Instruction::BitCast) 1886 replaceUsesOfNonProtoConstant(bitcast, newFn); 1887 continue; 1888 } 1889 1890 // Recognize calls to the function. 1891 llvm::CallSite callSite(user); 1892 if (!callSite) continue; 1893 if (!callSite.isCallee(use)) continue; 1894 1895 // If the return types don't match exactly, then we can't 1896 // transform this call unless it's dead. 1897 if (callSite->getType() != newRetTy && !callSite->use_empty()) 1898 continue; 1899 1900 // Get the call site's attribute list. 1901 SmallVector<llvm::AttributeSet, 8> newAttrs; 1902 llvm::AttributeSet oldAttrs = callSite.getAttributes(); 1903 1904 // Collect any return attributes from the call. 1905 if (oldAttrs.hasAttributes(llvm::AttributeSet::ReturnIndex)) 1906 newAttrs.push_back( 1907 llvm::AttributeSet::get(newFn->getContext(), 1908 oldAttrs.getRetAttributes())); 1909 1910 // If the function was passed too few arguments, don't transform. 1911 unsigned newNumArgs = newFn->arg_size(); 1912 if (callSite.arg_size() < newNumArgs) continue; 1913 1914 // If extra arguments were passed, we silently drop them. 1915 // If any of the types mismatch, we don't transform. 1916 unsigned argNo = 0; 1917 bool dontTransform = false; 1918 for (llvm::Function::arg_iterator ai = newFn->arg_begin(), 1919 ae = newFn->arg_end(); ai != ae; ++ai, ++argNo) { 1920 if (callSite.getArgument(argNo)->getType() != ai->getType()) { 1921 dontTransform = true; 1922 break; 1923 } 1924 1925 // Add any parameter attributes. 1926 if (oldAttrs.hasAttributes(argNo + 1)) 1927 newAttrs. 1928 push_back(llvm:: 1929 AttributeSet::get(newFn->getContext(), 1930 oldAttrs.getParamAttributes(argNo + 1))); 1931 } 1932 if (dontTransform) 1933 continue; 1934 1935 if (oldAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) 1936 newAttrs.push_back(llvm::AttributeSet::get(newFn->getContext(), 1937 oldAttrs.getFnAttributes())); 1938 1939 // Okay, we can transform this. Create the new call instruction and copy 1940 // over the required information. 1941 newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo); 1942 1943 llvm::CallSite newCall; 1944 if (callSite.isCall()) { 1945 newCall = llvm::CallInst::Create(newFn, newArgs, "", 1946 callSite.getInstruction()); 1947 } else { 1948 llvm::InvokeInst *oldInvoke = 1949 cast<llvm::InvokeInst>(callSite.getInstruction()); 1950 newCall = llvm::InvokeInst::Create(newFn, 1951 oldInvoke->getNormalDest(), 1952 oldInvoke->getUnwindDest(), 1953 newArgs, "", 1954 callSite.getInstruction()); 1955 } 1956 newArgs.clear(); // for the next iteration 1957 1958 if (!newCall->getType()->isVoidTy()) 1959 newCall->takeName(callSite.getInstruction()); 1960 newCall.setAttributes( 1961 llvm::AttributeSet::get(newFn->getContext(), newAttrs)); 1962 newCall.setCallingConv(callSite.getCallingConv()); 1963 1964 // Finally, remove the old call, replacing any uses with the new one. 1965 if (!callSite->use_empty()) 1966 callSite->replaceAllUsesWith(newCall.getInstruction()); 1967 1968 // Copy debug location attached to CI. 1969 if (!callSite->getDebugLoc().isUnknown()) 1970 newCall->setDebugLoc(callSite->getDebugLoc()); 1971 callSite->eraseFromParent(); 1972 } 1973 } 1974 1975 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1976 /// implement a function with no prototype, e.g. "int foo() {}". If there are 1977 /// existing call uses of the old function in the module, this adjusts them to 1978 /// call the new function directly. 1979 /// 1980 /// This is not just a cleanup: the always_inline pass requires direct calls to 1981 /// functions to be able to inline them. If there is a bitcast in the way, it 1982 /// won't inline them. Instcombine normally deletes these calls, but it isn't 1983 /// run at -O0. 1984 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1985 llvm::Function *NewFn) { 1986 // If we're redefining a global as a function, don't transform it. 1987 if (!isa<llvm::Function>(Old)) return; 1988 1989 replaceUsesOfNonProtoConstant(Old, NewFn); 1990 } 1991 1992 void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) { 1993 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind(); 1994 // If we have a definition, this might be a deferred decl. If the 1995 // instantiation is explicit, make sure we emit it at the end. 1996 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition) 1997 GetAddrOfGlobalVar(VD); 1998 1999 EmitTopLevelDecl(VD); 2000 } 2001 2002 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 2003 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 2004 2005 // Compute the function info and LLVM type. 2006 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); 2007 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); 2008 2009 // Get or create the prototype for the function. 2010 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 2011 2012 // Strip off a bitcast if we got one back. 2013 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 2014 assert(CE->getOpcode() == llvm::Instruction::BitCast); 2015 Entry = CE->getOperand(0); 2016 } 2017 2018 2019 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 2020 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 2021 2022 // If the types mismatch then we have to rewrite the definition. 2023 assert(OldFn->isDeclaration() && 2024 "Shouldn't replace non-declaration"); 2025 2026 // F is the Function* for the one with the wrong type, we must make a new 2027 // Function* and update everything that used F (a declaration) with the new 2028 // Function* (which will be a definition). 2029 // 2030 // This happens if there is a prototype for a function 2031 // (e.g. "int f()") and then a definition of a different type 2032 // (e.g. "int f(int x)"). Move the old function aside so that it 2033 // doesn't interfere with GetAddrOfFunction. 2034 OldFn->setName(StringRef()); 2035 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 2036 2037 // This might be an implementation of a function without a 2038 // prototype, in which case, try to do special replacement of 2039 // calls which match the new prototype. The really key thing here 2040 // is that we also potentially drop arguments from the call site 2041 // so as to make a direct call, which makes the inliner happier 2042 // and suppresses a number of optimizer warnings (!) about 2043 // dropping arguments. 2044 if (!OldFn->use_empty()) { 2045 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 2046 OldFn->removeDeadConstantUsers(); 2047 } 2048 2049 // Replace uses of F with the Function we will endow with a body. 2050 if (!Entry->use_empty()) { 2051 llvm::Constant *NewPtrForOldDecl = 2052 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 2053 Entry->replaceAllUsesWith(NewPtrForOldDecl); 2054 } 2055 2056 // Ok, delete the old function now, which is dead. 2057 OldFn->eraseFromParent(); 2058 2059 Entry = NewFn; 2060 } 2061 2062 // We need to set linkage and visibility on the function before 2063 // generating code for it because various parts of IR generation 2064 // want to propagate this information down (e.g. to local static 2065 // declarations). 2066 llvm::Function *Fn = cast<llvm::Function>(Entry); 2067 setFunctionLinkage(GD, Fn); 2068 2069 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 2070 setGlobalVisibility(Fn, D); 2071 2072 MaybeHandleStaticInExternC(D, Fn); 2073 2074 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 2075 2076 SetFunctionDefinitionAttributes(D, Fn); 2077 SetLLVMFunctionAttributesForDefinition(D, Fn); 2078 2079 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 2080 AddGlobalCtor(Fn, CA->getPriority()); 2081 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 2082 AddGlobalDtor(Fn, DA->getPriority()); 2083 if (D->hasAttr<AnnotateAttr>()) 2084 AddGlobalAnnotations(D, Fn); 2085 } 2086 2087 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 2088 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 2089 const AliasAttr *AA = D->getAttr<AliasAttr>(); 2090 assert(AA && "Not an alias?"); 2091 2092 StringRef MangledName = getMangledName(GD); 2093 2094 // If there is a definition in the module, then it wins over the alias. 2095 // This is dubious, but allow it to be safe. Just ignore the alias. 2096 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 2097 if (Entry && !Entry->isDeclaration()) 2098 return; 2099 2100 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 2101 2102 // Create a reference to the named value. This ensures that it is emitted 2103 // if a deferred decl. 2104 llvm::Constant *Aliasee; 2105 if (isa<llvm::FunctionType>(DeclTy)) 2106 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD, 2107 /*ForVTable=*/false); 2108 else 2109 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 2110 llvm::PointerType::getUnqual(DeclTy), 0); 2111 2112 // Create the new alias itself, but don't set a name yet. 2113 llvm::GlobalValue *GA = 2114 new llvm::GlobalAlias(Aliasee->getType(), 2115 llvm::Function::ExternalLinkage, 2116 "", Aliasee, &getModule()); 2117 2118 if (Entry) { 2119 assert(Entry->isDeclaration()); 2120 2121 // If there is a declaration in the module, then we had an extern followed 2122 // by the alias, as in: 2123 // extern int test6(); 2124 // ... 2125 // int test6() __attribute__((alias("test7"))); 2126 // 2127 // Remove it and replace uses of it with the alias. 2128 GA->takeName(Entry); 2129 2130 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 2131 Entry->getType())); 2132 Entry->eraseFromParent(); 2133 } else { 2134 GA->setName(MangledName); 2135 } 2136 2137 // Set attributes which are particular to an alias; this is a 2138 // specialization of the attributes which may be set on a global 2139 // variable/function. 2140 if (D->hasAttr<DLLExportAttr>()) { 2141 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2142 // The dllexport attribute is ignored for undefined symbols. 2143 if (FD->hasBody()) 2144 GA->setLinkage(llvm::Function::DLLExportLinkage); 2145 } else { 2146 GA->setLinkage(llvm::Function::DLLExportLinkage); 2147 } 2148 } else if (D->hasAttr<WeakAttr>() || 2149 D->hasAttr<WeakRefAttr>() || 2150 D->isWeakImported()) { 2151 GA->setLinkage(llvm::Function::WeakAnyLinkage); 2152 } 2153 2154 SetCommonAttributes(D, GA); 2155 } 2156 2157 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 2158 ArrayRef<llvm::Type*> Tys) { 2159 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 2160 Tys); 2161 } 2162 2163 static llvm::StringMapEntry<llvm::Constant*> & 2164 GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2165 const StringLiteral *Literal, 2166 bool TargetIsLSB, 2167 bool &IsUTF16, 2168 unsigned &StringLength) { 2169 StringRef String = Literal->getString(); 2170 unsigned NumBytes = String.size(); 2171 2172 // Check for simple case. 2173 if (!Literal->containsNonAsciiOrNull()) { 2174 StringLength = NumBytes; 2175 return Map.GetOrCreateValue(String); 2176 } 2177 2178 // Otherwise, convert the UTF8 literals into a string of shorts. 2179 IsUTF16 = true; 2180 2181 SmallVector<UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls. 2182 const UTF8 *FromPtr = (const UTF8 *)String.data(); 2183 UTF16 *ToPtr = &ToBuf[0]; 2184 2185 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 2186 &ToPtr, ToPtr + NumBytes, 2187 strictConversion); 2188 2189 // ConvertUTF8toUTF16 returns the length in ToPtr. 2190 StringLength = ToPtr - &ToBuf[0]; 2191 2192 // Add an explicit null. 2193 *ToPtr = 0; 2194 return Map. 2195 GetOrCreateValue(StringRef(reinterpret_cast<const char *>(ToBuf.data()), 2196 (StringLength + 1) * 2)); 2197 } 2198 2199 static llvm::StringMapEntry<llvm::Constant*> & 2200 GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2201 const StringLiteral *Literal, 2202 unsigned &StringLength) { 2203 StringRef String = Literal->getString(); 2204 StringLength = String.size(); 2205 return Map.GetOrCreateValue(String); 2206 } 2207 2208 llvm::Constant * 2209 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 2210 unsigned StringLength = 0; 2211 bool isUTF16 = false; 2212 llvm::StringMapEntry<llvm::Constant*> &Entry = 2213 GetConstantCFStringEntry(CFConstantStringMap, Literal, 2214 getDataLayout().isLittleEndian(), 2215 isUTF16, StringLength); 2216 2217 if (llvm::Constant *C = Entry.getValue()) 2218 return C; 2219 2220 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2221 llvm::Constant *Zeros[] = { Zero, Zero }; 2222 llvm::Value *V; 2223 2224 // If we don't already have it, get __CFConstantStringClassReference. 2225 if (!CFConstantStringClassRef) { 2226 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2227 Ty = llvm::ArrayType::get(Ty, 0); 2228 llvm::Constant *GV = CreateRuntimeVariable(Ty, 2229 "__CFConstantStringClassReference"); 2230 // Decay array -> ptr 2231 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2232 CFConstantStringClassRef = V; 2233 } 2234 else 2235 V = CFConstantStringClassRef; 2236 2237 QualType CFTy = getContext().getCFConstantStringType(); 2238 2239 llvm::StructType *STy = 2240 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 2241 2242 llvm::Constant *Fields[4]; 2243 2244 // Class pointer. 2245 Fields[0] = cast<llvm::ConstantExpr>(V); 2246 2247 // Flags. 2248 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2249 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 2250 llvm::ConstantInt::get(Ty, 0x07C8); 2251 2252 // String pointer. 2253 llvm::Constant *C = 0; 2254 if (isUTF16) { 2255 ArrayRef<uint16_t> Arr = 2256 llvm::makeArrayRef<uint16_t>(reinterpret_cast<uint16_t*>( 2257 const_cast<char *>(Entry.getKey().data())), 2258 Entry.getKey().size() / 2); 2259 C = llvm::ConstantDataArray::get(VMContext, Arr); 2260 } else { 2261 C = llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2262 } 2263 2264 llvm::GlobalValue::LinkageTypes Linkage; 2265 if (isUTF16) 2266 // FIXME: why do utf strings get "_" labels instead of "L" labels? 2267 Linkage = llvm::GlobalValue::InternalLinkage; 2268 else 2269 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 2270 // when using private linkage. It is not clear if this is a bug in ld 2271 // or a reasonable new restriction. 2272 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 2273 2274 // Note: -fwritable-strings doesn't make the backing store strings of 2275 // CFStrings writable. (See <rdar://problem/10657500>) 2276 llvm::GlobalVariable *GV = 2277 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, 2278 Linkage, C, ".str"); 2279 GV->setUnnamedAddr(true); 2280 // Don't enforce the target's minimum global alignment, since the only use 2281 // of the string is via this class initializer. 2282 if (isUTF16) { 2283 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 2284 GV->setAlignment(Align.getQuantity()); 2285 } else { 2286 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2287 GV->setAlignment(Align.getQuantity()); 2288 } 2289 2290 // String. 2291 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2292 2293 if (isUTF16) 2294 // Cast the UTF16 string to the correct type. 2295 Fields[2] = llvm::ConstantExpr::getBitCast(Fields[2], Int8PtrTy); 2296 2297 // String length. 2298 Ty = getTypes().ConvertType(getContext().LongTy); 2299 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 2300 2301 // The struct. 2302 C = llvm::ConstantStruct::get(STy, Fields); 2303 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2304 llvm::GlobalVariable::PrivateLinkage, C, 2305 "_unnamed_cfstring_"); 2306 if (const char *Sect = getTarget().getCFStringSection()) 2307 GV->setSection(Sect); 2308 Entry.setValue(GV); 2309 2310 return GV; 2311 } 2312 2313 static RecordDecl * 2314 CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 2315 DeclContext *DC, IdentifierInfo *Id) { 2316 SourceLocation Loc; 2317 if (Ctx.getLangOpts().CPlusPlus) 2318 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2319 else 2320 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2321 } 2322 2323 llvm::Constant * 2324 CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 2325 unsigned StringLength = 0; 2326 llvm::StringMapEntry<llvm::Constant*> &Entry = 2327 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 2328 2329 if (llvm::Constant *C = Entry.getValue()) 2330 return C; 2331 2332 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2333 llvm::Constant *Zeros[] = { Zero, Zero }; 2334 llvm::Value *V; 2335 // If we don't already have it, get _NSConstantStringClassReference. 2336 if (!ConstantStringClassRef) { 2337 std::string StringClass(getLangOpts().ObjCConstantStringClass); 2338 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2339 llvm::Constant *GV; 2340 if (LangOpts.ObjCRuntime.isNonFragile()) { 2341 std::string str = 2342 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 2343 : "OBJC_CLASS_$_" + StringClass; 2344 GV = getObjCRuntime().GetClassGlobal(str); 2345 // Make sure the result is of the correct type. 2346 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 2347 V = llvm::ConstantExpr::getBitCast(GV, PTy); 2348 ConstantStringClassRef = V; 2349 } else { 2350 std::string str = 2351 StringClass.empty() ? "_NSConstantStringClassReference" 2352 : "_" + StringClass + "ClassReference"; 2353 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 2354 GV = CreateRuntimeVariable(PTy, str); 2355 // Decay array -> ptr 2356 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2357 ConstantStringClassRef = V; 2358 } 2359 } 2360 else 2361 V = ConstantStringClassRef; 2362 2363 if (!NSConstantStringType) { 2364 // Construct the type for a constant NSString. 2365 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2366 Context.getTranslationUnitDecl(), 2367 &Context.Idents.get("__builtin_NSString")); 2368 D->startDefinition(); 2369 2370 QualType FieldTypes[3]; 2371 2372 // const int *isa; 2373 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 2374 // const char *str; 2375 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 2376 // unsigned int length; 2377 FieldTypes[2] = Context.UnsignedIntTy; 2378 2379 // Create fields 2380 for (unsigned i = 0; i < 3; ++i) { 2381 FieldDecl *Field = FieldDecl::Create(Context, D, 2382 SourceLocation(), 2383 SourceLocation(), 0, 2384 FieldTypes[i], /*TInfo=*/0, 2385 /*BitWidth=*/0, 2386 /*Mutable=*/false, 2387 ICIS_NoInit); 2388 Field->setAccess(AS_public); 2389 D->addDecl(Field); 2390 } 2391 2392 D->completeDefinition(); 2393 QualType NSTy = Context.getTagDeclType(D); 2394 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 2395 } 2396 2397 llvm::Constant *Fields[3]; 2398 2399 // Class pointer. 2400 Fields[0] = cast<llvm::ConstantExpr>(V); 2401 2402 // String pointer. 2403 llvm::Constant *C = 2404 llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2405 2406 llvm::GlobalValue::LinkageTypes Linkage; 2407 bool isConstant; 2408 Linkage = llvm::GlobalValue::PrivateLinkage; 2409 isConstant = !LangOpts.WritableStrings; 2410 2411 llvm::GlobalVariable *GV = 2412 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 2413 ".str"); 2414 GV->setUnnamedAddr(true); 2415 // Don't enforce the target's minimum global alignment, since the only use 2416 // of the string is via this class initializer. 2417 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2418 GV->setAlignment(Align.getQuantity()); 2419 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2420 2421 // String length. 2422 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2423 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 2424 2425 // The struct. 2426 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 2427 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2428 llvm::GlobalVariable::PrivateLinkage, C, 2429 "_unnamed_nsstring_"); 2430 // FIXME. Fix section. 2431 if (const char *Sect = 2432 LangOpts.ObjCRuntime.isNonFragile() 2433 ? getTarget().getNSStringNonFragileABISection() 2434 : getTarget().getNSStringSection()) 2435 GV->setSection(Sect); 2436 Entry.setValue(GV); 2437 2438 return GV; 2439 } 2440 2441 QualType CodeGenModule::getObjCFastEnumerationStateType() { 2442 if (ObjCFastEnumerationStateType.isNull()) { 2443 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2444 Context.getTranslationUnitDecl(), 2445 &Context.Idents.get("__objcFastEnumerationState")); 2446 D->startDefinition(); 2447 2448 QualType FieldTypes[] = { 2449 Context.UnsignedLongTy, 2450 Context.getPointerType(Context.getObjCIdType()), 2451 Context.getPointerType(Context.UnsignedLongTy), 2452 Context.getConstantArrayType(Context.UnsignedLongTy, 2453 llvm::APInt(32, 5), ArrayType::Normal, 0) 2454 }; 2455 2456 for (size_t i = 0; i < 4; ++i) { 2457 FieldDecl *Field = FieldDecl::Create(Context, 2458 D, 2459 SourceLocation(), 2460 SourceLocation(), 0, 2461 FieldTypes[i], /*TInfo=*/0, 2462 /*BitWidth=*/0, 2463 /*Mutable=*/false, 2464 ICIS_NoInit); 2465 Field->setAccess(AS_public); 2466 D->addDecl(Field); 2467 } 2468 2469 D->completeDefinition(); 2470 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 2471 } 2472 2473 return ObjCFastEnumerationStateType; 2474 } 2475 2476 llvm::Constant * 2477 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { 2478 assert(!E->getType()->isPointerType() && "Strings are always arrays"); 2479 2480 // Don't emit it as the address of the string, emit the string data itself 2481 // as an inline array. 2482 if (E->getCharByteWidth() == 1) { 2483 SmallString<64> Str(E->getString()); 2484 2485 // Resize the string to the right size, which is indicated by its type. 2486 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType()); 2487 Str.resize(CAT->getSize().getZExtValue()); 2488 return llvm::ConstantDataArray::getString(VMContext, Str, false); 2489 } 2490 2491 llvm::ArrayType *AType = 2492 cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); 2493 llvm::Type *ElemTy = AType->getElementType(); 2494 unsigned NumElements = AType->getNumElements(); 2495 2496 // Wide strings have either 2-byte or 4-byte elements. 2497 if (ElemTy->getPrimitiveSizeInBits() == 16) { 2498 SmallVector<uint16_t, 32> Elements; 2499 Elements.reserve(NumElements); 2500 2501 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2502 Elements.push_back(E->getCodeUnit(i)); 2503 Elements.resize(NumElements); 2504 return llvm::ConstantDataArray::get(VMContext, Elements); 2505 } 2506 2507 assert(ElemTy->getPrimitiveSizeInBits() == 32); 2508 SmallVector<uint32_t, 32> Elements; 2509 Elements.reserve(NumElements); 2510 2511 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2512 Elements.push_back(E->getCodeUnit(i)); 2513 Elements.resize(NumElements); 2514 return llvm::ConstantDataArray::get(VMContext, Elements); 2515 } 2516 2517 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a 2518 /// constant array for the given string literal. 2519 llvm::Constant * 2520 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 2521 CharUnits Align = getContext().getAlignOfGlobalVarInChars(S->getType()); 2522 if (S->isAscii() || S->isUTF8()) { 2523 SmallString<64> Str(S->getString()); 2524 2525 // Resize the string to the right size, which is indicated by its type. 2526 const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType()); 2527 Str.resize(CAT->getSize().getZExtValue()); 2528 return GetAddrOfConstantString(Str, /*GlobalName*/ 0, Align.getQuantity()); 2529 } 2530 2531 // FIXME: the following does not memoize wide strings. 2532 llvm::Constant *C = GetConstantArrayFromStringLiteral(S); 2533 llvm::GlobalVariable *GV = 2534 new llvm::GlobalVariable(getModule(),C->getType(), 2535 !LangOpts.WritableStrings, 2536 llvm::GlobalValue::PrivateLinkage, 2537 C,".str"); 2538 2539 GV->setAlignment(Align.getQuantity()); 2540 GV->setUnnamedAddr(true); 2541 return GV; 2542 } 2543 2544 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2545 /// array for the given ObjCEncodeExpr node. 2546 llvm::Constant * 2547 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2548 std::string Str; 2549 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2550 2551 return GetAddrOfConstantCString(Str); 2552 } 2553 2554 2555 /// GenerateWritableString -- Creates storage for a string literal. 2556 static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2557 bool constant, 2558 CodeGenModule &CGM, 2559 const char *GlobalName, 2560 unsigned Alignment) { 2561 // Create Constant for this string literal. Don't add a '\0'. 2562 llvm::Constant *C = 2563 llvm::ConstantDataArray::getString(CGM.getLLVMContext(), str, false); 2564 2565 // Create a global variable for this string 2566 llvm::GlobalVariable *GV = 2567 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 2568 llvm::GlobalValue::PrivateLinkage, 2569 C, GlobalName); 2570 GV->setAlignment(Alignment); 2571 GV->setUnnamedAddr(true); 2572 return GV; 2573 } 2574 2575 /// GetAddrOfConstantString - Returns a pointer to a character array 2576 /// containing the literal. This contents are exactly that of the 2577 /// given string, i.e. it will not be null terminated automatically; 2578 /// see GetAddrOfConstantCString. Note that whether the result is 2579 /// actually a pointer to an LLVM constant depends on 2580 /// Feature.WriteableStrings. 2581 /// 2582 /// The result has pointer to array type. 2583 llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2584 const char *GlobalName, 2585 unsigned Alignment) { 2586 // Get the default prefix if a name wasn't specified. 2587 if (!GlobalName) 2588 GlobalName = ".str"; 2589 2590 if (Alignment == 0) 2591 Alignment = getContext().getAlignOfGlobalVarInChars(getContext().CharTy) 2592 .getQuantity(); 2593 2594 // Don't share any string literals if strings aren't constant. 2595 if (LangOpts.WritableStrings) 2596 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2597 2598 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2599 ConstantStringMap.GetOrCreateValue(Str); 2600 2601 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2602 if (Alignment > GV->getAlignment()) { 2603 GV->setAlignment(Alignment); 2604 } 2605 return GV; 2606 } 2607 2608 // Create a global variable for this. 2609 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, 2610 Alignment); 2611 Entry.setValue(GV); 2612 return GV; 2613 } 2614 2615 /// GetAddrOfConstantCString - Returns a pointer to a character 2616 /// array containing the literal and a terminating '\0' 2617 /// character. The result has pointer to array type. 2618 llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2619 const char *GlobalName, 2620 unsigned Alignment) { 2621 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2622 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2623 } 2624 2625 llvm::Constant *CodeGenModule::GetAddrOfGlobalTemporary( 2626 const MaterializeTemporaryExpr *E, const Expr *Init) { 2627 assert((E->getStorageDuration() == SD_Static || 2628 E->getStorageDuration() == SD_Thread) && "not a global temporary"); 2629 const VarDecl *VD = cast<VarDecl>(E->getExtendingDecl()); 2630 2631 // If we're not materializing a subobject of the temporary, keep the 2632 // cv-qualifiers from the type of the MaterializeTemporaryExpr. 2633 QualType MaterializedType = Init->getType(); 2634 if (Init == E->GetTemporaryExpr()) 2635 MaterializedType = E->getType(); 2636 2637 llvm::Constant *&Slot = MaterializedGlobalTemporaryMap[E]; 2638 if (Slot) 2639 return Slot; 2640 2641 // FIXME: If an externally-visible declaration extends multiple temporaries, 2642 // we need to give each temporary the same name in every translation unit (and 2643 // we also need to make the temporaries externally-visible). 2644 SmallString<256> Name; 2645 llvm::raw_svector_ostream Out(Name); 2646 getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out); 2647 Out.flush(); 2648 2649 APValue *Value = 0; 2650 if (E->getStorageDuration() == SD_Static) { 2651 // We might have a cached constant initializer for this temporary. Note 2652 // that this might have a different value from the value computed by 2653 // evaluating the initializer if the surrounding constant expression 2654 // modifies the temporary. 2655 Value = getContext().getMaterializedTemporaryValue(E, false); 2656 if (Value && Value->isUninit()) 2657 Value = 0; 2658 } 2659 2660 // Try evaluating it now, it might have a constant initializer. 2661 Expr::EvalResult EvalResult; 2662 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) && 2663 !EvalResult.hasSideEffects()) 2664 Value = &EvalResult.Val; 2665 2666 llvm::Constant *InitialValue = 0; 2667 bool Constant = false; 2668 llvm::Type *Type; 2669 if (Value) { 2670 // The temporary has a constant initializer, use it. 2671 InitialValue = EmitConstantValue(*Value, MaterializedType, 0); 2672 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value); 2673 Type = InitialValue->getType(); 2674 } else { 2675 // No initializer, the initialization will be provided when we 2676 // initialize the declaration which performed lifetime extension. 2677 Type = getTypes().ConvertTypeForMem(MaterializedType); 2678 } 2679 2680 // Create a global variable for this lifetime-extended temporary. 2681 llvm::GlobalVariable *GV = 2682 new llvm::GlobalVariable(getModule(), Type, Constant, 2683 llvm::GlobalValue::PrivateLinkage, 2684 InitialValue, Name.c_str()); 2685 GV->setAlignment( 2686 getContext().getTypeAlignInChars(MaterializedType).getQuantity()); 2687 if (VD->getTLSKind()) 2688 setTLSMode(GV, *VD); 2689 Slot = GV; 2690 return GV; 2691 } 2692 2693 /// EmitObjCPropertyImplementations - Emit information for synthesized 2694 /// properties for an implementation. 2695 void CodeGenModule::EmitObjCPropertyImplementations(const 2696 ObjCImplementationDecl *D) { 2697 for (ObjCImplementationDecl::propimpl_iterator 2698 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2699 ObjCPropertyImplDecl *PID = *i; 2700 2701 // Dynamic is just for type-checking. 2702 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2703 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2704 2705 // Determine which methods need to be implemented, some may have 2706 // been overridden. Note that ::isPropertyAccessor is not the method 2707 // we want, that just indicates if the decl came from a 2708 // property. What we want to know is if the method is defined in 2709 // this implementation. 2710 if (!D->getInstanceMethod(PD->getGetterName())) 2711 CodeGenFunction(*this).GenerateObjCGetter( 2712 const_cast<ObjCImplementationDecl *>(D), PID); 2713 if (!PD->isReadOnly() && 2714 !D->getInstanceMethod(PD->getSetterName())) 2715 CodeGenFunction(*this).GenerateObjCSetter( 2716 const_cast<ObjCImplementationDecl *>(D), PID); 2717 } 2718 } 2719 } 2720 2721 static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2722 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2723 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2724 ivar; ivar = ivar->getNextIvar()) 2725 if (ivar->getType().isDestructedType()) 2726 return true; 2727 2728 return false; 2729 } 2730 2731 /// EmitObjCIvarInitializations - Emit information for ivar initialization 2732 /// for an implementation. 2733 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2734 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2735 if (needsDestructMethod(D)) { 2736 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2737 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2738 ObjCMethodDecl *DTORMethod = 2739 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2740 cxxSelector, getContext().VoidTy, 0, D, 2741 /*isInstance=*/true, /*isVariadic=*/false, 2742 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true, 2743 /*isDefined=*/false, ObjCMethodDecl::Required); 2744 D->addInstanceMethod(DTORMethod); 2745 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2746 D->setHasDestructors(true); 2747 } 2748 2749 // If the implementation doesn't have any ivar initializers, we don't need 2750 // a .cxx_construct. 2751 if (D->getNumIvarInitializers() == 0) 2752 return; 2753 2754 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2755 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2756 // The constructor returns 'self'. 2757 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2758 D->getLocation(), 2759 D->getLocation(), 2760 cxxSelector, 2761 getContext().getObjCIdType(), 0, 2762 D, /*isInstance=*/true, 2763 /*isVariadic=*/false, 2764 /*isPropertyAccessor=*/true, 2765 /*isImplicitlyDeclared=*/true, 2766 /*isDefined=*/false, 2767 ObjCMethodDecl::Required); 2768 D->addInstanceMethod(CTORMethod); 2769 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2770 D->setHasNonZeroConstructors(true); 2771 } 2772 2773 /// EmitNamespace - Emit all declarations in a namespace. 2774 void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2775 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2776 I != E; ++I) 2777 EmitTopLevelDecl(*I); 2778 } 2779 2780 // EmitLinkageSpec - Emit all declarations in a linkage spec. 2781 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2782 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2783 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2784 ErrorUnsupported(LSD, "linkage spec"); 2785 return; 2786 } 2787 2788 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2789 I != E; ++I) { 2790 // Meta-data for ObjC class includes references to implemented methods. 2791 // Generate class's method definitions first. 2792 if (ObjCImplDecl *OID = dyn_cast<ObjCImplDecl>(*I)) { 2793 for (ObjCContainerDecl::method_iterator M = OID->meth_begin(), 2794 MEnd = OID->meth_end(); 2795 M != MEnd; ++M) 2796 EmitTopLevelDecl(*M); 2797 } 2798 EmitTopLevelDecl(*I); 2799 } 2800 } 2801 2802 /// EmitTopLevelDecl - Emit code for a single top level declaration. 2803 void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2804 // If an error has occurred, stop code generation, but continue 2805 // parsing and semantic analysis (to ensure all warnings and errors 2806 // are emitted). 2807 if (Diags.hasErrorOccurred()) 2808 return; 2809 2810 // Ignore dependent declarations. 2811 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2812 return; 2813 2814 switch (D->getKind()) { 2815 case Decl::CXXConversion: 2816 case Decl::CXXMethod: 2817 case Decl::Function: 2818 // Skip function templates 2819 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2820 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2821 return; 2822 2823 EmitGlobal(cast<FunctionDecl>(D)); 2824 break; 2825 2826 case Decl::Var: 2827 EmitGlobal(cast<VarDecl>(D)); 2828 break; 2829 2830 // Indirect fields from global anonymous structs and unions can be 2831 // ignored; only the actual variable requires IR gen support. 2832 case Decl::IndirectField: 2833 break; 2834 2835 // C++ Decls 2836 case Decl::Namespace: 2837 EmitNamespace(cast<NamespaceDecl>(D)); 2838 break; 2839 // No code generation needed. 2840 case Decl::UsingShadow: 2841 case Decl::Using: 2842 case Decl::ClassTemplate: 2843 case Decl::FunctionTemplate: 2844 case Decl::TypeAliasTemplate: 2845 case Decl::Block: 2846 case Decl::Empty: 2847 break; 2848 case Decl::NamespaceAlias: 2849 if (CGDebugInfo *DI = getModuleDebugInfo()) 2850 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D)); 2851 return; 2852 case Decl::UsingDirective: // using namespace X; [C++] 2853 if (CGDebugInfo *DI = getModuleDebugInfo()) 2854 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D)); 2855 return; 2856 case Decl::CXXConstructor: 2857 // Skip function templates 2858 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2859 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2860 return; 2861 2862 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2863 break; 2864 case Decl::CXXDestructor: 2865 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2866 return; 2867 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2868 break; 2869 2870 case Decl::StaticAssert: 2871 // Nothing to do. 2872 break; 2873 2874 // Objective-C Decls 2875 2876 // Forward declarations, no (immediate) code generation. 2877 case Decl::ObjCInterface: 2878 case Decl::ObjCCategory: 2879 break; 2880 2881 case Decl::ObjCProtocol: { 2882 ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D); 2883 if (Proto->isThisDeclarationADefinition()) 2884 ObjCRuntime->GenerateProtocol(Proto); 2885 break; 2886 } 2887 2888 case Decl::ObjCCategoryImpl: 2889 // Categories have properties but don't support synthesize so we 2890 // can ignore them here. 2891 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2892 break; 2893 2894 case Decl::ObjCImplementation: { 2895 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2896 EmitObjCPropertyImplementations(OMD); 2897 EmitObjCIvarInitializations(OMD); 2898 ObjCRuntime->GenerateClass(OMD); 2899 // Emit global variable debug information. 2900 if (CGDebugInfo *DI = getModuleDebugInfo()) 2901 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) 2902 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType( 2903 OMD->getClassInterface()), OMD->getLocation()); 2904 break; 2905 } 2906 case Decl::ObjCMethod: { 2907 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 2908 // If this is not a prototype, emit the body. 2909 if (OMD->getBody()) 2910 CodeGenFunction(*this).GenerateObjCMethod(OMD); 2911 break; 2912 } 2913 case Decl::ObjCCompatibleAlias: 2914 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D)); 2915 break; 2916 2917 case Decl::LinkageSpec: 2918 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 2919 break; 2920 2921 case Decl::FileScopeAsm: { 2922 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 2923 StringRef AsmString = AD->getAsmString()->getString(); 2924 2925 const std::string &S = getModule().getModuleInlineAsm(); 2926 if (S.empty()) 2927 getModule().setModuleInlineAsm(AsmString); 2928 else if (S.end()[-1] == '\n') 2929 getModule().setModuleInlineAsm(S + AsmString.str()); 2930 else 2931 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 2932 break; 2933 } 2934 2935 case Decl::Import: { 2936 ImportDecl *Import = cast<ImportDecl>(D); 2937 2938 // Ignore import declarations that come from imported modules. 2939 if (clang::Module *Owner = Import->getOwningModule()) { 2940 if (getLangOpts().CurrentModule.empty() || 2941 Owner->getTopLevelModule()->Name == getLangOpts().CurrentModule) 2942 break; 2943 } 2944 2945 ImportedModules.insert(Import->getImportedModule()); 2946 break; 2947 } 2948 2949 default: 2950 // Make sure we handled everything we should, every other kind is a 2951 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 2952 // function. Need to recode Decl::Kind to do that easily. 2953 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 2954 } 2955 } 2956 2957 /// Turns the given pointer into a constant. 2958 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 2959 const void *Ptr) { 2960 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 2961 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 2962 return llvm::ConstantInt::get(i64, PtrInt); 2963 } 2964 2965 static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 2966 llvm::NamedMDNode *&GlobalMetadata, 2967 GlobalDecl D, 2968 llvm::GlobalValue *Addr) { 2969 if (!GlobalMetadata) 2970 GlobalMetadata = 2971 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 2972 2973 // TODO: should we report variant information for ctors/dtors? 2974 llvm::Value *Ops[] = { 2975 Addr, 2976 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 2977 }; 2978 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 2979 } 2980 2981 /// For each function which is declared within an extern "C" region and marked 2982 /// as 'used', but has internal linkage, create an alias from the unmangled 2983 /// name to the mangled name if possible. People expect to be able to refer 2984 /// to such functions with an unmangled name from inline assembly within the 2985 /// same translation unit. 2986 void CodeGenModule::EmitStaticExternCAliases() { 2987 for (StaticExternCMap::iterator I = StaticExternCValues.begin(), 2988 E = StaticExternCValues.end(); 2989 I != E; ++I) { 2990 IdentifierInfo *Name = I->first; 2991 llvm::GlobalValue *Val = I->second; 2992 if (Val && !getModule().getNamedValue(Name->getName())) 2993 AddUsedGlobal(new llvm::GlobalAlias(Val->getType(), Val->getLinkage(), 2994 Name->getName(), Val, &getModule())); 2995 } 2996 } 2997 2998 /// Emits metadata nodes associating all the global values in the 2999 /// current module with the Decls they came from. This is useful for 3000 /// projects using IR gen as a subroutine. 3001 /// 3002 /// Since there's currently no way to associate an MDNode directly 3003 /// with an llvm::GlobalValue, we create a global named metadata 3004 /// with the name 'clang.global.decl.ptrs'. 3005 void CodeGenModule::EmitDeclMetadata() { 3006 llvm::NamedMDNode *GlobalMetadata = 0; 3007 3008 // StaticLocalDeclMap 3009 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 3010 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 3011 I != E; ++I) { 3012 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 3013 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 3014 } 3015 } 3016 3017 /// Emits metadata nodes for all the local variables in the current 3018 /// function. 3019 void CodeGenFunction::EmitDeclMetadata() { 3020 if (LocalDeclMap.empty()) return; 3021 3022 llvm::LLVMContext &Context = getLLVMContext(); 3023 3024 // Find the unique metadata ID for this name. 3025 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 3026 3027 llvm::NamedMDNode *GlobalMetadata = 0; 3028 3029 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 3030 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 3031 const Decl *D = I->first; 3032 llvm::Value *Addr = I->second; 3033 3034 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 3035 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 3036 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 3037 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 3038 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 3039 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 3040 } 3041 } 3042 } 3043 3044 void CodeGenModule::EmitCoverageFile() { 3045 if (!getCodeGenOpts().CoverageFile.empty()) { 3046 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 3047 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 3048 llvm::LLVMContext &Ctx = TheModule.getContext(); 3049 llvm::MDString *CoverageFile = 3050 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 3051 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 3052 llvm::MDNode *CU = CUNode->getOperand(i); 3053 llvm::Value *node[] = { CoverageFile, CU }; 3054 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 3055 GCov->addOperand(N); 3056 } 3057 } 3058 } 3059 } 3060 3061 llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid, 3062 QualType GuidType) { 3063 // Sema has checked that all uuid strings are of the form 3064 // "12345678-1234-1234-1234-1234567890ab". 3065 assert(Uuid.size() == 36); 3066 const char *Uuidstr = Uuid.data(); 3067 for (int i = 0; i < 36; ++i) { 3068 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuidstr[i] == '-'); 3069 else assert(isHexDigit(Uuidstr[i])); 3070 } 3071 3072 llvm::APInt Field0(32, StringRef(Uuidstr , 8), 16); 3073 llvm::APInt Field1(16, StringRef(Uuidstr + 9, 4), 16); 3074 llvm::APInt Field2(16, StringRef(Uuidstr + 14, 4), 16); 3075 static const int Field3ValueOffsets[] = { 19, 21, 24, 26, 28, 30, 32, 34 }; 3076 3077 APValue InitStruct(APValue::UninitStruct(), /*NumBases=*/0, /*NumFields=*/4); 3078 InitStruct.getStructField(0) = APValue(llvm::APSInt(Field0)); 3079 InitStruct.getStructField(1) = APValue(llvm::APSInt(Field1)); 3080 InitStruct.getStructField(2) = APValue(llvm::APSInt(Field2)); 3081 APValue& Arr = InitStruct.getStructField(3); 3082 Arr = APValue(APValue::UninitArray(), 8, 8); 3083 for (int t = 0; t < 8; ++t) 3084 Arr.getArrayInitializedElt(t) = APValue(llvm::APSInt( 3085 llvm::APInt(8, StringRef(Uuidstr + Field3ValueOffsets[t], 2), 16))); 3086 3087 return EmitConstantValue(InitStruct, GuidType); 3088 } 3089