CodeGenModule.cpp revision a9b21d22bb9337649723a8477b5cb15f83451e7d
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 "CGDebugInfo.h" 16#include "CodeGenFunction.h" 17#include "CodeGenTBAA.h" 18#include "CGCall.h" 19#include "CGCUDARuntime.h" 20#include "CGCXXABI.h" 21#include "CGObjCRuntime.h" 22#include "CGOpenCLRuntime.h" 23#include "TargetInfo.h" 24#include "clang/Frontend/CodeGenOptions.h" 25#include "clang/AST/ASTContext.h" 26#include "clang/AST/CharUnits.h" 27#include "clang/AST/DeclObjC.h" 28#include "clang/AST/DeclCXX.h" 29#include "clang/AST/DeclTemplate.h" 30#include "clang/AST/Mangle.h" 31#include "clang/AST/RecordLayout.h" 32#include "clang/AST/RecursiveASTVisitor.h" 33#include "clang/Basic/Builtins.h" 34#include "clang/Basic/Diagnostic.h" 35#include "clang/Basic/SourceManager.h" 36#include "clang/Basic/TargetInfo.h" 37#include "clang/Basic/ConvertUTF.h" 38#include "llvm/CallingConv.h" 39#include "llvm/Module.h" 40#include "llvm/Intrinsics.h" 41#include "llvm/LLVMContext.h" 42#include "llvm/ADT/Triple.h" 43#include "llvm/Target/Mangler.h" 44#include "llvm/Target/TargetData.h" 45#include "llvm/Support/CallSite.h" 46#include "llvm/Support/ErrorHandling.h" 47using namespace clang; 48using namespace CodeGen; 49 50static const char AnnotationSection[] = "llvm.metadata"; 51 52static CGCXXABI &createCXXABI(CodeGenModule &CGM) { 53 switch (CGM.getContext().getTargetInfo().getCXXABI()) { 54 case CXXABI_ARM: return *CreateARMCXXABI(CGM); 55 case CXXABI_Itanium: return *CreateItaniumCXXABI(CGM); 56 case CXXABI_Microsoft: return *CreateMicrosoftCXXABI(CGM); 57 } 58 59 llvm_unreachable("invalid C++ ABI kind"); 60} 61 62 63CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 64 llvm::Module &M, const llvm::TargetData &TD, 65 DiagnosticsEngine &diags) 66 : Context(C), Features(C.getLangOptions()), CodeGenOpts(CGO), TheModule(M), 67 TheTargetData(TD), TheTargetCodeGenInfo(0), Diags(diags), 68 ABI(createCXXABI(*this)), 69 Types(*this), 70 TBAA(0), 71 VTables(*this), ObjCRuntime(0), OpenCLRuntime(0), CUDARuntime(0), 72 DebugInfo(0), ARCData(0), NoObjCARCExceptionsMetadata(0), 73 RRData(0), CFConstantStringClassRef(0), 74 ConstantStringClassRef(0), NSConstantStringType(0), 75 VMContext(M.getContext()), 76 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), 77 BlockObjectAssign(0), BlockObjectDispose(0), 78 BlockDescriptorType(0), GenericBlockLiteralType(0) { 79 80 // Initialize the type cache. 81 llvm::LLVMContext &LLVMContext = M.getContext(); 82 VoidTy = llvm::Type::getVoidTy(LLVMContext); 83 Int8Ty = llvm::Type::getInt8Ty(LLVMContext); 84 Int16Ty = llvm::Type::getInt16Ty(LLVMContext); 85 Int32Ty = llvm::Type::getInt32Ty(LLVMContext); 86 Int64Ty = llvm::Type::getInt64Ty(LLVMContext); 87 FloatTy = llvm::Type::getFloatTy(LLVMContext); 88 DoubleTy = llvm::Type::getDoubleTy(LLVMContext); 89 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0); 90 PointerAlignInBytes = 91 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity(); 92 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth()); 93 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits); 94 Int8PtrTy = Int8Ty->getPointerTo(0); 95 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0); 96 97 if (Features.ObjC1) 98 createObjCRuntime(); 99 if (Features.OpenCL) 100 createOpenCLRuntime(); 101 if (Features.CUDA) 102 createCUDARuntime(); 103 104 // Enable TBAA unless it's suppressed. 105 if (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0) 106 TBAA = new CodeGenTBAA(Context, VMContext, getLangOptions(), 107 ABI.getMangleContext()); 108 109 // If debug info or coverage generation is enabled, create the CGDebugInfo 110 // object. 111 if (CodeGenOpts.DebugInfo || CodeGenOpts.EmitGcovArcs || 112 CodeGenOpts.EmitGcovNotes) 113 DebugInfo = new CGDebugInfo(*this); 114 115 Block.GlobalUniqueCount = 0; 116 117 if (C.getLangOptions().ObjCAutoRefCount) 118 ARCData = new ARCEntrypoints(); 119 RRData = new RREntrypoints(); 120} 121 122CodeGenModule::~CodeGenModule() { 123 delete ObjCRuntime; 124 delete OpenCLRuntime; 125 delete CUDARuntime; 126 delete TheTargetCodeGenInfo; 127 delete &ABI; 128 delete TBAA; 129 delete DebugInfo; 130 delete ARCData; 131 delete RRData; 132} 133 134void CodeGenModule::createObjCRuntime() { 135 if (!Features.NeXTRuntime) 136 ObjCRuntime = CreateGNUObjCRuntime(*this); 137 else 138 ObjCRuntime = CreateMacObjCRuntime(*this); 139} 140 141void CodeGenModule::createOpenCLRuntime() { 142 OpenCLRuntime = new CGOpenCLRuntime(*this); 143} 144 145void CodeGenModule::createCUDARuntime() { 146 CUDARuntime = CreateNVCUDARuntime(*this); 147} 148 149void CodeGenModule::Release() { 150 EmitDeferred(); 151 EmitCXXGlobalInitFunc(); 152 EmitCXXGlobalDtorFunc(); 153 if (ObjCRuntime) 154 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) 155 AddGlobalCtor(ObjCInitFunction); 156 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 157 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 158 EmitGlobalAnnotations(); 159 EmitLLVMUsed(); 160 161 SimplifyPersonality(); 162 163 if (getCodeGenOpts().EmitDeclMetadata) 164 EmitDeclMetadata(); 165 166 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 167 EmitCoverageFile(); 168 169 if (DebugInfo) 170 DebugInfo->finalize(); 171} 172 173void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 174 // Make sure that this type is translated. 175 Types.UpdateCompletedType(TD); 176 if (DebugInfo) 177 DebugInfo->UpdateCompletedType(TD); 178} 179 180llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 181 if (!TBAA) 182 return 0; 183 return TBAA->getTBAAInfo(QTy); 184} 185 186void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 187 llvm::MDNode *TBAAInfo) { 188 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 189} 190 191bool CodeGenModule::isTargetDarwin() const { 192 return getContext().getTargetInfo().getTriple().isOSDarwin(); 193} 194 195void CodeGenModule::Error(SourceLocation loc, StringRef error) { 196 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); 197 getDiags().Report(Context.getFullLoc(loc), diagID); 198} 199 200/// ErrorUnsupported - Print out an error that codegen doesn't support the 201/// specified stmt yet. 202void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 203 bool OmitOnError) { 204 if (OmitOnError && getDiags().hasErrorOccurred()) 205 return; 206 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 207 "cannot compile this %0 yet"); 208 std::string Msg = Type; 209 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 210 << Msg << S->getSourceRange(); 211} 212 213/// ErrorUnsupported - Print out an error that codegen doesn't support the 214/// specified decl yet. 215void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 216 bool OmitOnError) { 217 if (OmitOnError && getDiags().hasErrorOccurred()) 218 return; 219 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 220 "cannot compile this %0 yet"); 221 std::string Msg = Type; 222 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 223} 224 225llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 226 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 227} 228 229void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 230 const NamedDecl *D) const { 231 // Internal definitions always have default visibility. 232 if (GV->hasLocalLinkage()) { 233 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 234 return; 235 } 236 237 // Set visibility for definitions. 238 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 239 if (LV.visibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 240 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 241} 242 243/// Set the symbol visibility of type information (vtable and RTTI) 244/// associated with the given type. 245void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 246 const CXXRecordDecl *RD, 247 TypeVisibilityKind TVK) const { 248 setGlobalVisibility(GV, RD); 249 250 if (!CodeGenOpts.HiddenWeakVTables) 251 return; 252 253 // We never want to drop the visibility for RTTI names. 254 if (TVK == TVK_ForRTTIName) 255 return; 256 257 // We want to drop the visibility to hidden for weak type symbols. 258 // This isn't possible if there might be unresolved references 259 // elsewhere that rely on this symbol being visible. 260 261 // This should be kept roughly in sync with setThunkVisibility 262 // in CGVTables.cpp. 263 264 // Preconditions. 265 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 266 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 267 return; 268 269 // Don't override an explicit visibility attribute. 270 if (RD->getExplicitVisibility()) 271 return; 272 273 switch (RD->getTemplateSpecializationKind()) { 274 // We have to disable the optimization if this is an EI definition 275 // because there might be EI declarations in other shared objects. 276 case TSK_ExplicitInstantiationDefinition: 277 case TSK_ExplicitInstantiationDeclaration: 278 return; 279 280 // Every use of a non-template class's type information has to emit it. 281 case TSK_Undeclared: 282 break; 283 284 // In theory, implicit instantiations can ignore the possibility of 285 // an explicit instantiation declaration because there necessarily 286 // must be an EI definition somewhere with default visibility. In 287 // practice, it's possible to have an explicit instantiation for 288 // an arbitrary template class, and linkers aren't necessarily able 289 // to deal with mixed-visibility symbols. 290 case TSK_ExplicitSpecialization: 291 case TSK_ImplicitInstantiation: 292 if (!CodeGenOpts.HiddenWeakTemplateVTables) 293 return; 294 break; 295 } 296 297 // If there's a key function, there may be translation units 298 // that don't have the key function's definition. But ignore 299 // this if we're emitting RTTI under -fno-rtti. 300 if (!(TVK != TVK_ForRTTI) || Features.RTTI) { 301 if (Context.getKeyFunction(RD)) 302 return; 303 } 304 305 // Otherwise, drop the visibility to hidden. 306 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 307 GV->setUnnamedAddr(true); 308} 309 310StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 311 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 312 313 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 314 if (!Str.empty()) 315 return Str; 316 317 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 318 IdentifierInfo *II = ND->getIdentifier(); 319 assert(II && "Attempt to mangle unnamed decl."); 320 321 Str = II->getName(); 322 return Str; 323 } 324 325 SmallString<256> Buffer; 326 llvm::raw_svector_ostream Out(Buffer); 327 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 328 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 329 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 330 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 331 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND)) 332 getCXXABI().getMangleContext().mangleBlock(BD, Out); 333 else 334 getCXXABI().getMangleContext().mangleName(ND, Out); 335 336 // Allocate space for the mangled name. 337 Out.flush(); 338 size_t Length = Buffer.size(); 339 char *Name = MangledNamesAllocator.Allocate<char>(Length); 340 std::copy(Buffer.begin(), Buffer.end(), Name); 341 342 Str = StringRef(Name, Length); 343 344 return Str; 345} 346 347void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 348 const BlockDecl *BD) { 349 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 350 const Decl *D = GD.getDecl(); 351 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 352 if (D == 0) 353 MangleCtx.mangleGlobalBlock(BD, Out); 354 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 355 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 356 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 357 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 358 else 359 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 360} 361 362llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 363 return getModule().getNamedValue(Name); 364} 365 366/// AddGlobalCtor - Add a function to the list that will be called before 367/// main() runs. 368void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 369 // FIXME: Type coercion of void()* types. 370 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 371} 372 373/// AddGlobalDtor - Add a function to the list that will be called 374/// when the module is unloaded. 375void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 376 // FIXME: Type coercion of void()* types. 377 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 378} 379 380void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 381 // Ctor function type is void()*. 382 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 383 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 384 385 // Get the type of a ctor entry, { i32, void ()* }. 386 llvm::StructType *CtorStructTy = 387 llvm::StructType::get(Int32Ty, llvm::PointerType::getUnqual(CtorFTy), NULL); 388 389 // Construct the constructor and destructor arrays. 390 SmallVector<llvm::Constant*, 8> Ctors; 391 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 392 llvm::Constant *S[] = { 393 llvm::ConstantInt::get(Int32Ty, I->second, false), 394 llvm::ConstantExpr::getBitCast(I->first, CtorPFTy) 395 }; 396 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 397 } 398 399 if (!Ctors.empty()) { 400 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 401 new llvm::GlobalVariable(TheModule, AT, false, 402 llvm::GlobalValue::AppendingLinkage, 403 llvm::ConstantArray::get(AT, Ctors), 404 GlobalName); 405 } 406} 407 408llvm::GlobalValue::LinkageTypes 409CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 410 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 411 412 if (Linkage == GVA_Internal) 413 return llvm::Function::InternalLinkage; 414 415 if (D->hasAttr<DLLExportAttr>()) 416 return llvm::Function::DLLExportLinkage; 417 418 if (D->hasAttr<WeakAttr>()) 419 return llvm::Function::WeakAnyLinkage; 420 421 // In C99 mode, 'inline' functions are guaranteed to have a strong 422 // definition somewhere else, so we can use available_externally linkage. 423 if (Linkage == GVA_C99Inline) 424 return llvm::Function::AvailableExternallyLinkage; 425 426 // Note that Apple's kernel linker doesn't support symbol 427 // coalescing, so we need to avoid linkonce and weak linkages there. 428 // Normally, this means we just map to internal, but for explicit 429 // instantiations we'll map to external. 430 431 // In C++, the compiler has to emit a definition in every translation unit 432 // that references the function. We should use linkonce_odr because 433 // a) if all references in this translation unit are optimized away, we 434 // don't need to codegen it. b) if the function persists, it needs to be 435 // merged with other definitions. c) C++ has the ODR, so we know the 436 // definition is dependable. 437 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 438 return !Context.getLangOptions().AppleKext 439 ? llvm::Function::LinkOnceODRLinkage 440 : llvm::Function::InternalLinkage; 441 442 // An explicit instantiation of a template has weak linkage, since 443 // explicit instantiations can occur in multiple translation units 444 // and must all be equivalent. However, we are not allowed to 445 // throw away these explicit instantiations. 446 if (Linkage == GVA_ExplicitTemplateInstantiation) 447 return !Context.getLangOptions().AppleKext 448 ? llvm::Function::WeakODRLinkage 449 : llvm::Function::ExternalLinkage; 450 451 // Otherwise, we have strong external linkage. 452 assert(Linkage == GVA_StrongExternal); 453 return llvm::Function::ExternalLinkage; 454} 455 456 457/// SetFunctionDefinitionAttributes - Set attributes for a global. 458/// 459/// FIXME: This is currently only done for aliases and functions, but not for 460/// variables (these details are set in EmitGlobalVarDefinition for variables). 461void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 462 llvm::GlobalValue *GV) { 463 SetCommonAttributes(D, GV); 464} 465 466void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 467 const CGFunctionInfo &Info, 468 llvm::Function *F) { 469 unsigned CallingConv; 470 AttributeListType AttributeList; 471 ConstructAttributeList(Info, D, AttributeList, CallingConv); 472 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 473 AttributeList.size())); 474 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 475} 476 477/// Determines whether the language options require us to model 478/// unwind exceptions. We treat -fexceptions as mandating this 479/// except under the fragile ObjC ABI with only ObjC exceptions 480/// enabled. This means, for example, that C with -fexceptions 481/// enables this. 482static bool hasUnwindExceptions(const LangOptions &Features) { 483 // If exceptions are completely disabled, obviously this is false. 484 if (!Features.Exceptions) return false; 485 486 // If C++ exceptions are enabled, this is true. 487 if (Features.CXXExceptions) return true; 488 489 // If ObjC exceptions are enabled, this depends on the ABI. 490 if (Features.ObjCExceptions) { 491 if (!Features.ObjCNonFragileABI) return false; 492 } 493 494 return true; 495} 496 497void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 498 llvm::Function *F) { 499 if (CodeGenOpts.UnwindTables) 500 F->setHasUWTable(); 501 502 if (!hasUnwindExceptions(Features)) 503 F->addFnAttr(llvm::Attribute::NoUnwind); 504 505 if (D->hasAttr<NakedAttr>()) { 506 // Naked implies noinline: we should not be inlining such functions. 507 F->addFnAttr(llvm::Attribute::Naked); 508 F->addFnAttr(llvm::Attribute::NoInline); 509 } 510 511 if (D->hasAttr<NoInlineAttr>()) 512 F->addFnAttr(llvm::Attribute::NoInline); 513 514 // (noinline wins over always_inline, and we can't specify both in IR) 515 if (D->hasAttr<AlwaysInlineAttr>() && 516 !F->hasFnAttr(llvm::Attribute::NoInline)) 517 F->addFnAttr(llvm::Attribute::AlwaysInline); 518 519 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 520 F->setUnnamedAddr(true); 521 522 if (Features.getStackProtector() == LangOptions::SSPOn) 523 F->addFnAttr(llvm::Attribute::StackProtect); 524 else if (Features.getStackProtector() == LangOptions::SSPReq) 525 F->addFnAttr(llvm::Attribute::StackProtectReq); 526 527 if (Features.AddressSanitizer) { 528 // When AddressSanitizer is enabled, set AddressSafety attribute 529 // unless __attribute__((no_address_safety_analysis)) is used. 530 if (!D->hasAttr<NoAddressSafetyAnalysisAttr>()) 531 F->addFnAttr(llvm::Attribute::AddressSafety); 532 } 533 534 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 535 if (alignment) 536 F->setAlignment(alignment); 537 538 // C++ ABI requires 2-byte alignment for member functions. 539 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 540 F->setAlignment(2); 541} 542 543void CodeGenModule::SetCommonAttributes(const Decl *D, 544 llvm::GlobalValue *GV) { 545 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 546 setGlobalVisibility(GV, ND); 547 else 548 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 549 550 if (D->hasAttr<UsedAttr>()) 551 AddUsedGlobal(GV); 552 553 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 554 GV->setSection(SA->getName()); 555 556 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 557} 558 559void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 560 llvm::Function *F, 561 const CGFunctionInfo &FI) { 562 SetLLVMFunctionAttributes(D, FI, F); 563 SetLLVMFunctionAttributesForDefinition(D, F); 564 565 F->setLinkage(llvm::Function::InternalLinkage); 566 567 SetCommonAttributes(D, F); 568} 569 570void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 571 llvm::Function *F, 572 bool IsIncompleteFunction) { 573 if (unsigned IID = F->getIntrinsicID()) { 574 // If this is an intrinsic function, set the function's attributes 575 // to the intrinsic's attributes. 576 F->setAttributes(llvm::Intrinsic::getAttributes((llvm::Intrinsic::ID)IID)); 577 return; 578 } 579 580 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 581 582 if (!IsIncompleteFunction) 583 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F); 584 585 // Only a few attributes are set on declarations; these may later be 586 // overridden by a definition. 587 588 if (FD->hasAttr<DLLImportAttr>()) { 589 F->setLinkage(llvm::Function::DLLImportLinkage); 590 } else if (FD->hasAttr<WeakAttr>() || 591 FD->isWeakImported()) { 592 // "extern_weak" is overloaded in LLVM; we probably should have 593 // separate linkage types for this. 594 F->setLinkage(llvm::Function::ExternalWeakLinkage); 595 } else { 596 F->setLinkage(llvm::Function::ExternalLinkage); 597 598 NamedDecl::LinkageInfo LV = FD->getLinkageAndVisibility(); 599 if (LV.linkage() == ExternalLinkage && LV.visibilityExplicit()) { 600 F->setVisibility(GetLLVMVisibility(LV.visibility())); 601 } 602 } 603 604 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 605 F->setSection(SA->getName()); 606} 607 608void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 609 assert(!GV->isDeclaration() && 610 "Only globals with definition can force usage."); 611 LLVMUsed.push_back(GV); 612} 613 614void CodeGenModule::EmitLLVMUsed() { 615 // Don't create llvm.used if there is no need. 616 if (LLVMUsed.empty()) 617 return; 618 619 // Convert LLVMUsed to what ConstantArray needs. 620 SmallVector<llvm::Constant*, 8> UsedArray; 621 UsedArray.resize(LLVMUsed.size()); 622 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 623 UsedArray[i] = 624 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 625 Int8PtrTy); 626 } 627 628 if (UsedArray.empty()) 629 return; 630 llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size()); 631 632 llvm::GlobalVariable *GV = 633 new llvm::GlobalVariable(getModule(), ATy, false, 634 llvm::GlobalValue::AppendingLinkage, 635 llvm::ConstantArray::get(ATy, UsedArray), 636 "llvm.used"); 637 638 GV->setSection("llvm.metadata"); 639} 640 641void CodeGenModule::EmitDeferred() { 642 // Emit code for any potentially referenced deferred decls. Since a 643 // previously unused static decl may become used during the generation of code 644 // for a static function, iterate until no changes are made. 645 646 while (!DeferredDeclsToEmit.empty() || !DeferredVTables.empty()) { 647 if (!DeferredVTables.empty()) { 648 const CXXRecordDecl *RD = DeferredVTables.back(); 649 DeferredVTables.pop_back(); 650 getVTables().GenerateClassData(getVTableLinkage(RD), RD); 651 continue; 652 } 653 654 GlobalDecl D = DeferredDeclsToEmit.back(); 655 DeferredDeclsToEmit.pop_back(); 656 657 // Check to see if we've already emitted this. This is necessary 658 // for a couple of reasons: first, decls can end up in the 659 // deferred-decls queue multiple times, and second, decls can end 660 // up with definitions in unusual ways (e.g. by an extern inline 661 // function acquiring a strong function redefinition). Just 662 // ignore these cases. 663 // 664 // TODO: That said, looking this up multiple times is very wasteful. 665 StringRef Name = getMangledName(D); 666 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 667 assert(CGRef && "Deferred decl wasn't referenced?"); 668 669 if (!CGRef->isDeclaration()) 670 continue; 671 672 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 673 // purposes an alias counts as a definition. 674 if (isa<llvm::GlobalAlias>(CGRef)) 675 continue; 676 677 // Otherwise, emit the definition and move on to the next one. 678 EmitGlobalDefinition(D); 679 } 680} 681 682void CodeGenModule::EmitGlobalAnnotations() { 683 if (Annotations.empty()) 684 return; 685 686 // Create a new global variable for the ConstantStruct in the Module. 687 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 688 Annotations[0]->getType(), Annotations.size()), Annotations); 689 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), 690 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, 691 "llvm.global.annotations"); 692 gv->setSection(AnnotationSection); 693} 694 695llvm::Constant *CodeGenModule::EmitAnnotationString(llvm::StringRef Str) { 696 llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str); 697 if (i != AnnotationStrings.end()) 698 return i->second; 699 700 // Not found yet, create a new global. 701 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); 702 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), 703 true, llvm::GlobalValue::PrivateLinkage, s, ".str"); 704 gv->setSection(AnnotationSection); 705 gv->setUnnamedAddr(true); 706 AnnotationStrings[Str] = gv; 707 return gv; 708} 709 710llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 711 SourceManager &SM = getContext().getSourceManager(); 712 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 713 if (PLoc.isValid()) 714 return EmitAnnotationString(PLoc.getFilename()); 715 return EmitAnnotationString(SM.getBufferName(Loc)); 716} 717 718llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 719 SourceManager &SM = getContext().getSourceManager(); 720 PresumedLoc PLoc = SM.getPresumedLoc(L); 721 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 722 SM.getExpansionLineNumber(L); 723 return llvm::ConstantInt::get(Int32Ty, LineNo); 724} 725 726llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 727 const AnnotateAttr *AA, 728 SourceLocation L) { 729 // Get the globals for file name, annotation, and the line number. 730 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 731 *UnitGV = EmitAnnotationUnit(L), 732 *LineNoCst = EmitAnnotationLineNo(L); 733 734 // Create the ConstantStruct for the global annotation. 735 llvm::Constant *Fields[4] = { 736 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 737 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 738 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 739 LineNoCst 740 }; 741 return llvm::ConstantStruct::getAnon(Fields); 742} 743 744void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 745 llvm::GlobalValue *GV) { 746 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 747 // Get the struct elements for these annotations. 748 for (specific_attr_iterator<AnnotateAttr> 749 ai = D->specific_attr_begin<AnnotateAttr>(), 750 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) 751 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); 752} 753 754bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 755 // Never defer when EmitAllDecls is specified. 756 if (Features.EmitAllDecls) 757 return false; 758 759 return !getContext().DeclMustBeEmitted(Global); 760} 761 762llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 763 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 764 assert(AA && "No alias?"); 765 766 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 767 768 // See if there is already something with the target's name in the module. 769 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 770 771 llvm::Constant *Aliasee; 772 if (isa<llvm::FunctionType>(DeclTy)) 773 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 774 /*ForVTable=*/false); 775 else 776 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 777 llvm::PointerType::getUnqual(DeclTy), 0); 778 if (!Entry) { 779 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 780 F->setLinkage(llvm::Function::ExternalWeakLinkage); 781 WeakRefReferences.insert(F); 782 } 783 784 return Aliasee; 785} 786 787void CodeGenModule::EmitGlobal(GlobalDecl GD) { 788 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 789 790 // Weak references don't produce any output by themselves. 791 if (Global->hasAttr<WeakRefAttr>()) 792 return; 793 794 // If this is an alias definition (which otherwise looks like a declaration) 795 // emit it now. 796 if (Global->hasAttr<AliasAttr>()) 797 return EmitAliasDefinition(GD); 798 799 // If this is CUDA, be selective about which declarations we emit. 800 if (Features.CUDA) { 801 if (CodeGenOpts.CUDAIsDevice) { 802 if (!Global->hasAttr<CUDADeviceAttr>() && 803 !Global->hasAttr<CUDAGlobalAttr>() && 804 !Global->hasAttr<CUDAConstantAttr>() && 805 !Global->hasAttr<CUDASharedAttr>()) 806 return; 807 } else { 808 if (!Global->hasAttr<CUDAHostAttr>() && ( 809 Global->hasAttr<CUDADeviceAttr>() || 810 Global->hasAttr<CUDAConstantAttr>() || 811 Global->hasAttr<CUDASharedAttr>())) 812 return; 813 } 814 } 815 816 // Ignore declarations, they will be emitted on their first use. 817 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 818 // Forward declarations are emitted lazily on first use. 819 if (!FD->doesThisDeclarationHaveABody()) { 820 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 821 return; 822 823 const FunctionDecl *InlineDefinition = 0; 824 FD->getBody(InlineDefinition); 825 826 StringRef MangledName = getMangledName(GD); 827 llvm::StringMap<GlobalDecl>::iterator DDI = 828 DeferredDecls.find(MangledName); 829 if (DDI != DeferredDecls.end()) 830 DeferredDecls.erase(DDI); 831 EmitGlobalDefinition(InlineDefinition); 832 return; 833 } 834 } else { 835 const VarDecl *VD = cast<VarDecl>(Global); 836 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 837 838 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 839 return; 840 } 841 842 // Defer code generation when possible if this is a static definition, inline 843 // function etc. These we only want to emit if they are used. 844 if (!MayDeferGeneration(Global)) { 845 // Emit the definition if it can't be deferred. 846 EmitGlobalDefinition(GD); 847 return; 848 } 849 850 // If we're deferring emission of a C++ variable with an 851 // initializer, remember the order in which it appeared in the file. 852 if (getLangOptions().CPlusPlus && isa<VarDecl>(Global) && 853 cast<VarDecl>(Global)->hasInit()) { 854 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 855 CXXGlobalInits.push_back(0); 856 } 857 858 // If the value has already been used, add it directly to the 859 // DeferredDeclsToEmit list. 860 StringRef MangledName = getMangledName(GD); 861 if (GetGlobalValue(MangledName)) 862 DeferredDeclsToEmit.push_back(GD); 863 else { 864 // Otherwise, remember that we saw a deferred decl with this name. The 865 // first use of the mangled name will cause it to move into 866 // DeferredDeclsToEmit. 867 DeferredDecls[MangledName] = GD; 868 } 869} 870 871namespace { 872 struct FunctionIsDirectlyRecursive : 873 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> { 874 const StringRef Name; 875 const Builtin::Context &BI; 876 bool Result; 877 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) : 878 Name(N), BI(C), Result(false) { 879 } 880 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; 881 882 bool TraverseCallExpr(CallExpr *E) { 883 const FunctionDecl *FD = E->getDirectCallee(); 884 if (!FD) 885 return true; 886 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 887 if (Attr && Name == Attr->getLabel()) { 888 Result = true; 889 return false; 890 } 891 unsigned BuiltinID = FD->getBuiltinID(); 892 if (!BuiltinID) 893 return true; 894 StringRef BuiltinName = BI.GetName(BuiltinID); 895 if (BuiltinName.startswith("__builtin_") && 896 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { 897 Result = true; 898 return false; 899 } 900 return true; 901 } 902 }; 903} 904 905// isTriviallyRecursive - Check if this function calls another 906// decl that, because of the asm attribute or the other decl being a builtin, 907// ends up pointing to itself. 908bool 909CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { 910 StringRef Name; 911 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { 912 // asm labels are a special kind of mangling we have to support. 913 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 914 if (!Attr) 915 return false; 916 Name = Attr->getLabel(); 917 } else { 918 Name = FD->getName(); 919 } 920 921 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); 922 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD)); 923 return Walker.Result; 924} 925 926bool 927CodeGenModule::shouldEmitFunction(const FunctionDecl *F) { 928 if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage) 929 return true; 930 if (CodeGenOpts.OptimizationLevel == 0 && 931 !F->hasAttr<AlwaysInlineAttr>()) 932 return false; 933 // PR9614. Avoid cases where the source code is lying to us. An available 934 // externally function should have an equivalent function somewhere else, 935 // but a function that calls itself is clearly not equivalent to the real 936 // implementation. 937 // This happens in glibc's btowc and in some configure checks. 938 return !isTriviallyRecursive(F); 939} 940 941void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 942 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 943 944 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 945 Context.getSourceManager(), 946 "Generating code for declaration"); 947 948 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 949 // At -O0, don't generate IR for functions with available_externally 950 // linkage. 951 if (!shouldEmitFunction(Function)) 952 return; 953 954 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 955 // Make sure to emit the definition(s) before we emit the thunks. 956 // This is necessary for the generation of certain thunks. 957 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 958 EmitCXXConstructor(CD, GD.getCtorType()); 959 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 960 EmitCXXDestructor(DD, GD.getDtorType()); 961 else 962 EmitGlobalFunctionDefinition(GD); 963 964 if (Method->isVirtual()) 965 getVTables().EmitThunks(GD); 966 967 return; 968 } 969 970 return EmitGlobalFunctionDefinition(GD); 971 } 972 973 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 974 return EmitGlobalVarDefinition(VD); 975 976 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 977} 978 979/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 980/// module, create and return an llvm Function with the specified type. If there 981/// is something in the module with the specified name, return it potentially 982/// bitcasted to the right type. 983/// 984/// If D is non-null, it specifies a decl that correspond to this. This is used 985/// to set the attributes on the function when it is first created. 986llvm::Constant * 987CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 988 llvm::Type *Ty, 989 GlobalDecl D, bool ForVTable, 990 llvm::Attributes ExtraAttrs) { 991 // Lookup the entry, lazily creating it if necessary. 992 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 993 if (Entry) { 994 if (WeakRefReferences.count(Entry)) { 995 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 996 if (FD && !FD->hasAttr<WeakAttr>()) 997 Entry->setLinkage(llvm::Function::ExternalLinkage); 998 999 WeakRefReferences.erase(Entry); 1000 } 1001 1002 if (Entry->getType()->getElementType() == Ty) 1003 return Entry; 1004 1005 // Make sure the result is of the correct type. 1006 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 1007 } 1008 1009 // This function doesn't have a complete type (for example, the return 1010 // type is an incomplete struct). Use a fake type instead, and make 1011 // sure not to try to set attributes. 1012 bool IsIncompleteFunction = false; 1013 1014 llvm::FunctionType *FTy; 1015 if (isa<llvm::FunctionType>(Ty)) { 1016 FTy = cast<llvm::FunctionType>(Ty); 1017 } else { 1018 FTy = llvm::FunctionType::get(VoidTy, false); 1019 IsIncompleteFunction = true; 1020 } 1021 1022 llvm::Function *F = llvm::Function::Create(FTy, 1023 llvm::Function::ExternalLinkage, 1024 MangledName, &getModule()); 1025 assert(F->getName() == MangledName && "name was uniqued!"); 1026 if (D.getDecl()) 1027 SetFunctionAttributes(D, F, IsIncompleteFunction); 1028 if (ExtraAttrs != llvm::Attribute::None) 1029 F->addFnAttr(ExtraAttrs); 1030 1031 // This is the first use or definition of a mangled name. If there is a 1032 // deferred decl with this name, remember that we need to emit it at the end 1033 // of the file. 1034 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1035 if (DDI != DeferredDecls.end()) { 1036 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1037 // list, and remove it from DeferredDecls (since we don't need it anymore). 1038 DeferredDeclsToEmit.push_back(DDI->second); 1039 DeferredDecls.erase(DDI); 1040 1041 // Otherwise, there are cases we have to worry about where we're 1042 // using a declaration for which we must emit a definition but where 1043 // we might not find a top-level definition: 1044 // - member functions defined inline in their classes 1045 // - friend functions defined inline in some class 1046 // - special member functions with implicit definitions 1047 // If we ever change our AST traversal to walk into class methods, 1048 // this will be unnecessary. 1049 // 1050 // We also don't emit a definition for a function if it's going to be an entry 1051 // in a vtable, unless it's already marked as used. 1052 } else if (getLangOptions().CPlusPlus && D.getDecl()) { 1053 // Look for a declaration that's lexically in a record. 1054 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); 1055 do { 1056 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 1057 if (FD->isImplicit() && !ForVTable) { 1058 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 1059 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1060 break; 1061 } else if (FD->doesThisDeclarationHaveABody()) { 1062 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1063 break; 1064 } 1065 } 1066 FD = FD->getPreviousDecl(); 1067 } while (FD); 1068 } 1069 1070 // Make sure the result is of the requested type. 1071 if (!IsIncompleteFunction) { 1072 assert(F->getType()->getElementType() == Ty); 1073 return F; 1074 } 1075 1076 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1077 return llvm::ConstantExpr::getBitCast(F, PTy); 1078} 1079 1080/// GetAddrOfFunction - Return the address of the given function. If Ty is 1081/// non-null, then this function will use the specified type if it has to 1082/// create it (this occurs when we see a definition of the function). 1083llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 1084 llvm::Type *Ty, 1085 bool ForVTable) { 1086 // If there was no specific requested type, just convert it now. 1087 if (!Ty) 1088 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 1089 1090 StringRef MangledName = getMangledName(GD); 1091 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 1092} 1093 1094/// CreateRuntimeFunction - Create a new runtime function with the specified 1095/// type and name. 1096llvm::Constant * 1097CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 1098 StringRef Name, 1099 llvm::Attributes ExtraAttrs) { 1100 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 1101 ExtraAttrs); 1102} 1103 1104/// isTypeConstant - Determine whether an object of this type can be emitted 1105/// as a constant. 1106/// 1107/// If ExcludeCtor is true, the duration when the object's constructor runs 1108/// will not be considered. The caller will need to verify that the object is 1109/// not written to during its construction. 1110bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) { 1111 if (!Ty.isConstant(Context) && !Ty->isReferenceType()) 1112 return false; 1113 1114 if (Context.getLangOptions().CPlusPlus) { 1115 if (const CXXRecordDecl *Record 1116 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl()) 1117 return ExcludeCtor && !Record->hasMutableFields() && 1118 Record->hasTrivialDestructor(); 1119 } 1120 1121 return true; 1122} 1123 1124/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1125/// create and return an llvm GlobalVariable with the specified type. If there 1126/// is something in the module with the specified name, return it potentially 1127/// bitcasted to the right type. 1128/// 1129/// If D is non-null, it specifies a decl that correspond to this. This is used 1130/// to set the attributes on the global when it is first created. 1131llvm::Constant * 1132CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1133 llvm::PointerType *Ty, 1134 const VarDecl *D, 1135 bool UnnamedAddr) { 1136 // Lookup the entry, lazily creating it if necessary. 1137 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1138 if (Entry) { 1139 if (WeakRefReferences.count(Entry)) { 1140 if (D && !D->hasAttr<WeakAttr>()) 1141 Entry->setLinkage(llvm::Function::ExternalLinkage); 1142 1143 WeakRefReferences.erase(Entry); 1144 } 1145 1146 if (UnnamedAddr) 1147 Entry->setUnnamedAddr(true); 1148 1149 if (Entry->getType() == Ty) 1150 return Entry; 1151 1152 // Make sure the result is of the correct type. 1153 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1154 } 1155 1156 // This is the first use or definition of a mangled name. If there is a 1157 // deferred decl with this name, remember that we need to emit it at the end 1158 // of the file. 1159 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1160 if (DDI != DeferredDecls.end()) { 1161 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1162 // list, and remove it from DeferredDecls (since we don't need it anymore). 1163 DeferredDeclsToEmit.push_back(DDI->second); 1164 DeferredDecls.erase(DDI); 1165 } 1166 1167 llvm::GlobalVariable *GV = 1168 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1169 llvm::GlobalValue::ExternalLinkage, 1170 0, MangledName, 0, 1171 false, Ty->getAddressSpace()); 1172 1173 // Handle things which are present even on external declarations. 1174 if (D) { 1175 // FIXME: This code is overly simple and should be merged with other global 1176 // handling. 1177 GV->setConstant(isTypeConstant(D->getType(), false)); 1178 1179 // Set linkage and visibility in case we never see a definition. 1180 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 1181 if (LV.linkage() != ExternalLinkage) { 1182 // Don't set internal linkage on declarations. 1183 } else { 1184 if (D->hasAttr<DLLImportAttr>()) 1185 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1186 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1187 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1188 1189 // Set visibility on a declaration only if it's explicit. 1190 if (LV.visibilityExplicit()) 1191 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 1192 } 1193 1194 GV->setThreadLocal(D->isThreadSpecified()); 1195 } 1196 1197 return GV; 1198} 1199 1200 1201llvm::GlobalVariable * 1202CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1203 llvm::Type *Ty, 1204 llvm::GlobalValue::LinkageTypes Linkage) { 1205 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1206 llvm::GlobalVariable *OldGV = 0; 1207 1208 1209 if (GV) { 1210 // Check if the variable has the right type. 1211 if (GV->getType()->getElementType() == Ty) 1212 return GV; 1213 1214 // Because C++ name mangling, the only way we can end up with an already 1215 // existing global with the same name is if it has been declared extern "C". 1216 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1217 OldGV = GV; 1218 } 1219 1220 // Create a new variable. 1221 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1222 Linkage, 0, Name); 1223 1224 if (OldGV) { 1225 // Replace occurrences of the old variable if needed. 1226 GV->takeName(OldGV); 1227 1228 if (!OldGV->use_empty()) { 1229 llvm::Constant *NewPtrForOldDecl = 1230 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1231 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1232 } 1233 1234 OldGV->eraseFromParent(); 1235 } 1236 1237 return GV; 1238} 1239 1240/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1241/// given global variable. If Ty is non-null and if the global doesn't exist, 1242/// then it will be greated with the specified type instead of whatever the 1243/// normal requested type would be. 1244llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1245 llvm::Type *Ty) { 1246 assert(D->hasGlobalStorage() && "Not a global variable"); 1247 QualType ASTTy = D->getType(); 1248 if (Ty == 0) 1249 Ty = getTypes().ConvertTypeForMem(ASTTy); 1250 1251 llvm::PointerType *PTy = 1252 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1253 1254 StringRef MangledName = getMangledName(D); 1255 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1256} 1257 1258/// CreateRuntimeVariable - Create a new runtime global variable with the 1259/// specified type and name. 1260llvm::Constant * 1261CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1262 StringRef Name) { 1263 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1264 true); 1265} 1266 1267void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1268 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1269 1270 if (MayDeferGeneration(D)) { 1271 // If we have not seen a reference to this variable yet, place it 1272 // into the deferred declarations table to be emitted if needed 1273 // later. 1274 StringRef MangledName = getMangledName(D); 1275 if (!GetGlobalValue(MangledName)) { 1276 DeferredDecls[MangledName] = D; 1277 return; 1278 } 1279 } 1280 1281 // The tentative definition is the only definition. 1282 EmitGlobalVarDefinition(D); 1283} 1284 1285void CodeGenModule::EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired) { 1286 if (DefinitionRequired) 1287 getVTables().GenerateClassData(getVTableLinkage(Class), Class); 1288} 1289 1290llvm::GlobalVariable::LinkageTypes 1291CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) { 1292 if (RD->getLinkage() != ExternalLinkage) 1293 return llvm::GlobalVariable::InternalLinkage; 1294 1295 if (const CXXMethodDecl *KeyFunction 1296 = RD->getASTContext().getKeyFunction(RD)) { 1297 // If this class has a key function, use that to determine the linkage of 1298 // the vtable. 1299 const FunctionDecl *Def = 0; 1300 if (KeyFunction->hasBody(Def)) 1301 KeyFunction = cast<CXXMethodDecl>(Def); 1302 1303 switch (KeyFunction->getTemplateSpecializationKind()) { 1304 case TSK_Undeclared: 1305 case TSK_ExplicitSpecialization: 1306 // When compiling with optimizations turned on, we emit all vtables, 1307 // even if the key function is not defined in the current translation 1308 // unit. If this is the case, use available_externally linkage. 1309 if (!Def && CodeGenOpts.OptimizationLevel) 1310 return llvm::GlobalVariable::AvailableExternallyLinkage; 1311 1312 if (KeyFunction->isInlined()) 1313 return !Context.getLangOptions().AppleKext ? 1314 llvm::GlobalVariable::LinkOnceODRLinkage : 1315 llvm::Function::InternalLinkage; 1316 1317 return llvm::GlobalVariable::ExternalLinkage; 1318 1319 case TSK_ImplicitInstantiation: 1320 return !Context.getLangOptions().AppleKext ? 1321 llvm::GlobalVariable::LinkOnceODRLinkage : 1322 llvm::Function::InternalLinkage; 1323 1324 case TSK_ExplicitInstantiationDefinition: 1325 return !Context.getLangOptions().AppleKext ? 1326 llvm::GlobalVariable::WeakODRLinkage : 1327 llvm::Function::InternalLinkage; 1328 1329 case TSK_ExplicitInstantiationDeclaration: 1330 // FIXME: Use available_externally linkage. However, this currently 1331 // breaks LLVM's build due to undefined symbols. 1332 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1333 return !Context.getLangOptions().AppleKext ? 1334 llvm::GlobalVariable::LinkOnceODRLinkage : 1335 llvm::Function::InternalLinkage; 1336 } 1337 } 1338 1339 if (Context.getLangOptions().AppleKext) 1340 return llvm::Function::InternalLinkage; 1341 1342 switch (RD->getTemplateSpecializationKind()) { 1343 case TSK_Undeclared: 1344 case TSK_ExplicitSpecialization: 1345 case TSK_ImplicitInstantiation: 1346 // FIXME: Use available_externally linkage. However, this currently 1347 // breaks LLVM's build due to undefined symbols. 1348 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1349 case TSK_ExplicitInstantiationDeclaration: 1350 return llvm::GlobalVariable::LinkOnceODRLinkage; 1351 1352 case TSK_ExplicitInstantiationDefinition: 1353 return llvm::GlobalVariable::WeakODRLinkage; 1354 } 1355 1356 llvm_unreachable("Invalid TemplateSpecializationKind!"); 1357} 1358 1359CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1360 return Context.toCharUnitsFromBits( 1361 TheTargetData.getTypeStoreSizeInBits(Ty)); 1362} 1363 1364void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1365 llvm::Constant *Init = 0; 1366 QualType ASTTy = D->getType(); 1367 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 1368 bool NeedsGlobalCtor = false; 1369 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor(); 1370 1371 const VarDecl *InitDecl; 1372 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 1373 1374 if (!InitExpr) { 1375 // This is a tentative definition; tentative definitions are 1376 // implicitly initialized with { 0 }. 1377 // 1378 // Note that tentative definitions are only emitted at the end of 1379 // a translation unit, so they should never have incomplete 1380 // type. In addition, EmitTentativeDefinition makes sure that we 1381 // never attempt to emit a tentative definition if a real one 1382 // exists. A use may still exists, however, so we still may need 1383 // to do a RAUW. 1384 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1385 Init = EmitNullConstant(D->getType()); 1386 } else { 1387 Init = EmitConstantInit(*InitDecl); 1388 if (!Init) { 1389 QualType T = InitExpr->getType(); 1390 if (D->getType()->isReferenceType()) 1391 T = D->getType(); 1392 1393 if (getLangOptions().CPlusPlus) { 1394 Init = EmitNullConstant(T); 1395 NeedsGlobalCtor = true; 1396 } else { 1397 ErrorUnsupported(D, "static initializer"); 1398 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1399 } 1400 } else { 1401 // We don't need an initializer, so remove the entry for the delayed 1402 // initializer position (just in case this entry was delayed) if we 1403 // also don't need to register a destructor. 1404 if (getLangOptions().CPlusPlus && !NeedsGlobalDtor) 1405 DelayedCXXInitPosition.erase(D); 1406 } 1407 } 1408 1409 llvm::Type* InitType = Init->getType(); 1410 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1411 1412 // Strip off a bitcast if we got one back. 1413 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1414 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1415 // all zero index gep. 1416 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1417 Entry = CE->getOperand(0); 1418 } 1419 1420 // Entry is now either a Function or GlobalVariable. 1421 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1422 1423 // We have a definition after a declaration with the wrong type. 1424 // We must make a new GlobalVariable* and update everything that used OldGV 1425 // (a declaration or tentative definition) with the new GlobalVariable* 1426 // (which will be a definition). 1427 // 1428 // This happens if there is a prototype for a global (e.g. 1429 // "extern int x[];") and then a definition of a different type (e.g. 1430 // "int x[10];"). This also happens when an initializer has a different type 1431 // from the type of the global (this happens with unions). 1432 if (GV == 0 || 1433 GV->getType()->getElementType() != InitType || 1434 GV->getType()->getAddressSpace() != 1435 getContext().getTargetAddressSpace(ASTTy)) { 1436 1437 // Move the old entry aside so that we'll create a new one. 1438 Entry->setName(StringRef()); 1439 1440 // Make a new global with the correct type, this is now guaranteed to work. 1441 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1442 1443 // Replace all uses of the old global with the new global 1444 llvm::Constant *NewPtrForOldDecl = 1445 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1446 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1447 1448 // Erase the old global, since it is no longer used. 1449 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1450 } 1451 1452 if (D->hasAttr<AnnotateAttr>()) 1453 AddGlobalAnnotations(D, GV); 1454 1455 GV->setInitializer(Init); 1456 1457 // If it is safe to mark the global 'constant', do so now. 1458 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor && 1459 isTypeConstant(D->getType(), true)); 1460 1461 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1462 1463 // Set the llvm linkage type as appropriate. 1464 llvm::GlobalValue::LinkageTypes Linkage = 1465 GetLLVMLinkageVarDefinition(D, GV); 1466 GV->setLinkage(Linkage); 1467 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1468 // common vars aren't constant even if declared const. 1469 GV->setConstant(false); 1470 1471 SetCommonAttributes(D, GV); 1472 1473 // Emit the initializer function if necessary. 1474 if (NeedsGlobalCtor || NeedsGlobalDtor) 1475 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); 1476 1477 // Emit global variable debug information. 1478 if (CGDebugInfo *DI = getModuleDebugInfo()) 1479 DI->EmitGlobalVariable(GV, D); 1480} 1481 1482llvm::GlobalValue::LinkageTypes 1483CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, 1484 llvm::GlobalVariable *GV) { 1485 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1486 if (Linkage == GVA_Internal) 1487 return llvm::Function::InternalLinkage; 1488 else if (D->hasAttr<DLLImportAttr>()) 1489 return llvm::Function::DLLImportLinkage; 1490 else if (D->hasAttr<DLLExportAttr>()) 1491 return llvm::Function::DLLExportLinkage; 1492 else if (D->hasAttr<WeakAttr>()) { 1493 if (GV->isConstant()) 1494 return llvm::GlobalVariable::WeakODRLinkage; 1495 else 1496 return llvm::GlobalVariable::WeakAnyLinkage; 1497 } else if (Linkage == GVA_TemplateInstantiation || 1498 Linkage == GVA_ExplicitTemplateInstantiation) 1499 return llvm::GlobalVariable::WeakODRLinkage; 1500 else if (!getLangOptions().CPlusPlus && 1501 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1502 D->getAttr<CommonAttr>()) && 1503 !D->hasExternalStorage() && !D->getInit() && 1504 !D->getAttr<SectionAttr>() && !D->isThreadSpecified() && 1505 !D->getAttr<WeakImportAttr>()) { 1506 // Thread local vars aren't considered common linkage. 1507 return llvm::GlobalVariable::CommonLinkage; 1508 } 1509 return llvm::GlobalVariable::ExternalLinkage; 1510} 1511 1512/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1513/// implement a function with no prototype, e.g. "int foo() {}". If there are 1514/// existing call uses of the old function in the module, this adjusts them to 1515/// call the new function directly. 1516/// 1517/// This is not just a cleanup: the always_inline pass requires direct calls to 1518/// functions to be able to inline them. If there is a bitcast in the way, it 1519/// won't inline them. Instcombine normally deletes these calls, but it isn't 1520/// run at -O0. 1521static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1522 llvm::Function *NewFn) { 1523 // If we're redefining a global as a function, don't transform it. 1524 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1525 if (OldFn == 0) return; 1526 1527 llvm::Type *NewRetTy = NewFn->getReturnType(); 1528 SmallVector<llvm::Value*, 4> ArgList; 1529 1530 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1531 UI != E; ) { 1532 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1533 llvm::Value::use_iterator I = UI++; // Increment before the CI is erased. 1534 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*I); 1535 if (!CI) continue; // FIXME: when we allow Invoke, just do CallSite CS(*I) 1536 llvm::CallSite CS(CI); 1537 if (!CI || !CS.isCallee(I)) continue; 1538 1539 // If the return types don't match exactly, and if the call isn't dead, then 1540 // we can't transform this call. 1541 if (CI->getType() != NewRetTy && !CI->use_empty()) 1542 continue; 1543 1544 // Get the attribute list. 1545 llvm::SmallVector<llvm::AttributeWithIndex, 8> AttrVec; 1546 llvm::AttrListPtr AttrList = CI->getAttributes(); 1547 1548 // Get any return attributes. 1549 llvm::Attributes RAttrs = AttrList.getRetAttributes(); 1550 1551 // Add the return attributes. 1552 if (RAttrs) 1553 AttrVec.push_back(llvm::AttributeWithIndex::get(0, RAttrs)); 1554 1555 // If the function was passed too few arguments, don't transform. If extra 1556 // arguments were passed, we silently drop them. If any of the types 1557 // mismatch, we don't transform. 1558 unsigned ArgNo = 0; 1559 bool DontTransform = false; 1560 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1561 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1562 if (CS.arg_size() == ArgNo || 1563 CS.getArgument(ArgNo)->getType() != AI->getType()) { 1564 DontTransform = true; 1565 break; 1566 } 1567 1568 // Add any parameter attributes. 1569 if (llvm::Attributes PAttrs = AttrList.getParamAttributes(ArgNo + 1)) 1570 AttrVec.push_back(llvm::AttributeWithIndex::get(ArgNo + 1, PAttrs)); 1571 } 1572 if (DontTransform) 1573 continue; 1574 1575 if (llvm::Attributes FnAttrs = AttrList.getFnAttributes()) 1576 AttrVec.push_back(llvm::AttributeWithIndex::get(~0, FnAttrs)); 1577 1578 // Okay, we can transform this. Create the new call instruction and copy 1579 // over the required information. 1580 ArgList.append(CS.arg_begin(), CS.arg_begin() + ArgNo); 1581 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList, "", CI); 1582 ArgList.clear(); 1583 if (!NewCall->getType()->isVoidTy()) 1584 NewCall->takeName(CI); 1585 NewCall->setAttributes(llvm::AttrListPtr::get(AttrVec.begin(), 1586 AttrVec.end())); 1587 NewCall->setCallingConv(CI->getCallingConv()); 1588 1589 // Finally, remove the old call, replacing any uses with the new one. 1590 if (!CI->use_empty()) 1591 CI->replaceAllUsesWith(NewCall); 1592 1593 // Copy debug location attached to CI. 1594 if (!CI->getDebugLoc().isUnknown()) 1595 NewCall->setDebugLoc(CI->getDebugLoc()); 1596 CI->eraseFromParent(); 1597 } 1598} 1599 1600 1601void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1602 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1603 1604 // Compute the function info and LLVM type. 1605 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); 1606 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); 1607 1608 // Get or create the prototype for the function. 1609 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1610 1611 // Strip off a bitcast if we got one back. 1612 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1613 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1614 Entry = CE->getOperand(0); 1615 } 1616 1617 1618 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1619 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1620 1621 // If the types mismatch then we have to rewrite the definition. 1622 assert(OldFn->isDeclaration() && 1623 "Shouldn't replace non-declaration"); 1624 1625 // F is the Function* for the one with the wrong type, we must make a new 1626 // Function* and update everything that used F (a declaration) with the new 1627 // Function* (which will be a definition). 1628 // 1629 // This happens if there is a prototype for a function 1630 // (e.g. "int f()") and then a definition of a different type 1631 // (e.g. "int f(int x)"). Move the old function aside so that it 1632 // doesn't interfere with GetAddrOfFunction. 1633 OldFn->setName(StringRef()); 1634 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1635 1636 // If this is an implementation of a function without a prototype, try to 1637 // replace any existing uses of the function (which may be calls) with uses 1638 // of the new function 1639 if (D->getType()->isFunctionNoProtoType()) { 1640 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1641 OldFn->removeDeadConstantUsers(); 1642 } 1643 1644 // Replace uses of F with the Function we will endow with a body. 1645 if (!Entry->use_empty()) { 1646 llvm::Constant *NewPtrForOldDecl = 1647 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1648 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1649 } 1650 1651 // Ok, delete the old function now, which is dead. 1652 OldFn->eraseFromParent(); 1653 1654 Entry = NewFn; 1655 } 1656 1657 // We need to set linkage and visibility on the function before 1658 // generating code for it because various parts of IR generation 1659 // want to propagate this information down (e.g. to local static 1660 // declarations). 1661 llvm::Function *Fn = cast<llvm::Function>(Entry); 1662 setFunctionLinkage(D, Fn); 1663 1664 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 1665 setGlobalVisibility(Fn, D); 1666 1667 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 1668 1669 SetFunctionDefinitionAttributes(D, Fn); 1670 SetLLVMFunctionAttributesForDefinition(D, Fn); 1671 1672 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1673 AddGlobalCtor(Fn, CA->getPriority()); 1674 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1675 AddGlobalDtor(Fn, DA->getPriority()); 1676 if (D->hasAttr<AnnotateAttr>()) 1677 AddGlobalAnnotations(D, Fn); 1678} 1679 1680void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 1681 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1682 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1683 assert(AA && "Not an alias?"); 1684 1685 StringRef MangledName = getMangledName(GD); 1686 1687 // If there is a definition in the module, then it wins over the alias. 1688 // This is dubious, but allow it to be safe. Just ignore the alias. 1689 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1690 if (Entry && !Entry->isDeclaration()) 1691 return; 1692 1693 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1694 1695 // Create a reference to the named value. This ensures that it is emitted 1696 // if a deferred decl. 1697 llvm::Constant *Aliasee; 1698 if (isa<llvm::FunctionType>(DeclTy)) 1699 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 1700 /*ForVTable=*/false); 1701 else 1702 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1703 llvm::PointerType::getUnqual(DeclTy), 0); 1704 1705 // Create the new alias itself, but don't set a name yet. 1706 llvm::GlobalValue *GA = 1707 new llvm::GlobalAlias(Aliasee->getType(), 1708 llvm::Function::ExternalLinkage, 1709 "", Aliasee, &getModule()); 1710 1711 if (Entry) { 1712 assert(Entry->isDeclaration()); 1713 1714 // If there is a declaration in the module, then we had an extern followed 1715 // by the alias, as in: 1716 // extern int test6(); 1717 // ... 1718 // int test6() __attribute__((alias("test7"))); 1719 // 1720 // Remove it and replace uses of it with the alias. 1721 GA->takeName(Entry); 1722 1723 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1724 Entry->getType())); 1725 Entry->eraseFromParent(); 1726 } else { 1727 GA->setName(MangledName); 1728 } 1729 1730 // Set attributes which are particular to an alias; this is a 1731 // specialization of the attributes which may be set on a global 1732 // variable/function. 1733 if (D->hasAttr<DLLExportAttr>()) { 1734 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1735 // The dllexport attribute is ignored for undefined symbols. 1736 if (FD->hasBody()) 1737 GA->setLinkage(llvm::Function::DLLExportLinkage); 1738 } else { 1739 GA->setLinkage(llvm::Function::DLLExportLinkage); 1740 } 1741 } else if (D->hasAttr<WeakAttr>() || 1742 D->hasAttr<WeakRefAttr>() || 1743 D->isWeakImported()) { 1744 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1745 } 1746 1747 SetCommonAttributes(D, GA); 1748} 1749 1750llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 1751 ArrayRef<llvm::Type*> Tys) { 1752 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 1753 Tys); 1754} 1755 1756static llvm::StringMapEntry<llvm::Constant*> & 1757GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1758 const StringLiteral *Literal, 1759 bool TargetIsLSB, 1760 bool &IsUTF16, 1761 unsigned &StringLength) { 1762 StringRef String = Literal->getString(); 1763 unsigned NumBytes = String.size(); 1764 1765 // Check for simple case. 1766 if (!Literal->containsNonAsciiOrNull()) { 1767 StringLength = NumBytes; 1768 return Map.GetOrCreateValue(String); 1769 } 1770 1771 // Otherwise, convert the UTF8 literals into a byte string. 1772 SmallVector<UTF16, 128> ToBuf(NumBytes); 1773 const UTF8 *FromPtr = (UTF8 *)String.data(); 1774 UTF16 *ToPtr = &ToBuf[0]; 1775 1776 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 1777 &ToPtr, ToPtr + NumBytes, 1778 strictConversion); 1779 1780 // ConvertUTF8toUTF16 returns the length in ToPtr. 1781 StringLength = ToPtr - &ToBuf[0]; 1782 1783 // Render the UTF-16 string into a byte array and convert to the target byte 1784 // order. 1785 // 1786 // FIXME: This isn't something we should need to do here. 1787 SmallString<128> AsBytes; 1788 AsBytes.reserve(StringLength * 2); 1789 for (unsigned i = 0; i != StringLength; ++i) { 1790 unsigned short Val = ToBuf[i]; 1791 if (TargetIsLSB) { 1792 AsBytes.push_back(Val & 0xFF); 1793 AsBytes.push_back(Val >> 8); 1794 } else { 1795 AsBytes.push_back(Val >> 8); 1796 AsBytes.push_back(Val & 0xFF); 1797 } 1798 } 1799 // Append one extra null character, the second is automatically added by our 1800 // caller. 1801 AsBytes.push_back(0); 1802 1803 IsUTF16 = true; 1804 return Map.GetOrCreateValue(StringRef(AsBytes.data(), AsBytes.size())); 1805} 1806 1807static llvm::StringMapEntry<llvm::Constant*> & 1808GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1809 const StringLiteral *Literal, 1810 unsigned &StringLength) 1811{ 1812 StringRef String = Literal->getString(); 1813 StringLength = String.size(); 1814 return Map.GetOrCreateValue(String); 1815} 1816 1817llvm::Constant * 1818CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 1819 unsigned StringLength = 0; 1820 bool isUTF16 = false; 1821 llvm::StringMapEntry<llvm::Constant*> &Entry = 1822 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1823 getTargetData().isLittleEndian(), 1824 isUTF16, StringLength); 1825 1826 if (llvm::Constant *C = Entry.getValue()) 1827 return C; 1828 1829 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 1830 llvm::Constant *Zeros[] = { Zero, Zero }; 1831 1832 // If we don't already have it, get __CFConstantStringClassReference. 1833 if (!CFConstantStringClassRef) { 1834 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1835 Ty = llvm::ArrayType::get(Ty, 0); 1836 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1837 "__CFConstantStringClassReference"); 1838 // Decay array -> ptr 1839 CFConstantStringClassRef = 1840 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1841 } 1842 1843 QualType CFTy = getContext().getCFConstantStringType(); 1844 1845 llvm::StructType *STy = 1846 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1847 1848 llvm::Constant *Fields[4]; 1849 1850 // Class pointer. 1851 Fields[0] = CFConstantStringClassRef; 1852 1853 // Flags. 1854 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1855 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 1856 llvm::ConstantInt::get(Ty, 0x07C8); 1857 1858 // String pointer. 1859 llvm::Constant *C = llvm::ConstantDataArray::getString(VMContext, 1860 Entry.getKey()); 1861 1862 llvm::GlobalValue::LinkageTypes Linkage; 1863 if (isUTF16) 1864 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1865 Linkage = llvm::GlobalValue::InternalLinkage; 1866 else 1867 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 1868 // when using private linkage. It is not clear if this is a bug in ld 1869 // or a reasonable new restriction. 1870 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 1871 1872 // Note: -fwritable-strings doesn't make the backing store strings of 1873 // CFStrings writable. (See <rdar://problem/10657500>) 1874 llvm::GlobalVariable *GV = 1875 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, 1876 Linkage, C, ".str"); 1877 GV->setUnnamedAddr(true); 1878 if (isUTF16) { 1879 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 1880 GV->setAlignment(Align.getQuantity()); 1881 } else { 1882 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 1883 GV->setAlignment(Align.getQuantity()); 1884 } 1885 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1886 1887 // String length. 1888 Ty = getTypes().ConvertType(getContext().LongTy); 1889 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 1890 1891 // The struct. 1892 C = llvm::ConstantStruct::get(STy, Fields); 1893 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1894 llvm::GlobalVariable::PrivateLinkage, C, 1895 "_unnamed_cfstring_"); 1896 if (const char *Sect = getContext().getTargetInfo().getCFStringSection()) 1897 GV->setSection(Sect); 1898 Entry.setValue(GV); 1899 1900 return GV; 1901} 1902 1903static RecordDecl * 1904CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 1905 DeclContext *DC, IdentifierInfo *Id) { 1906 SourceLocation Loc; 1907 if (Ctx.getLangOptions().CPlusPlus) 1908 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 1909 else 1910 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 1911} 1912 1913llvm::Constant * 1914CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 1915 unsigned StringLength = 0; 1916 llvm::StringMapEntry<llvm::Constant*> &Entry = 1917 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 1918 1919 if (llvm::Constant *C = Entry.getValue()) 1920 return C; 1921 1922 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 1923 llvm::Constant *Zeros[] = { Zero, Zero }; 1924 1925 // If we don't already have it, get _NSConstantStringClassReference. 1926 if (!ConstantStringClassRef) { 1927 std::string StringClass(getLangOptions().ObjCConstantStringClass); 1928 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1929 llvm::Constant *GV; 1930 if (Features.ObjCNonFragileABI) { 1931 std::string str = 1932 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 1933 : "OBJC_CLASS_$_" + StringClass; 1934 GV = getObjCRuntime().GetClassGlobal(str); 1935 // Make sure the result is of the correct type. 1936 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1937 ConstantStringClassRef = 1938 llvm::ConstantExpr::getBitCast(GV, PTy); 1939 } else { 1940 std::string str = 1941 StringClass.empty() ? "_NSConstantStringClassReference" 1942 : "_" + StringClass + "ClassReference"; 1943 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 1944 GV = CreateRuntimeVariable(PTy, str); 1945 // Decay array -> ptr 1946 ConstantStringClassRef = 1947 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1948 } 1949 } 1950 1951 if (!NSConstantStringType) { 1952 // Construct the type for a constant NSString. 1953 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 1954 Context.getTranslationUnitDecl(), 1955 &Context.Idents.get("__builtin_NSString")); 1956 D->startDefinition(); 1957 1958 QualType FieldTypes[3]; 1959 1960 // const int *isa; 1961 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 1962 // const char *str; 1963 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 1964 // unsigned int length; 1965 FieldTypes[2] = Context.UnsignedIntTy; 1966 1967 // Create fields 1968 for (unsigned i = 0; i < 3; ++i) { 1969 FieldDecl *Field = FieldDecl::Create(Context, D, 1970 SourceLocation(), 1971 SourceLocation(), 0, 1972 FieldTypes[i], /*TInfo=*/0, 1973 /*BitWidth=*/0, 1974 /*Mutable=*/false, 1975 /*HasInit=*/false); 1976 Field->setAccess(AS_public); 1977 D->addDecl(Field); 1978 } 1979 1980 D->completeDefinition(); 1981 QualType NSTy = Context.getTagDeclType(D); 1982 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 1983 } 1984 1985 llvm::Constant *Fields[3]; 1986 1987 // Class pointer. 1988 Fields[0] = ConstantStringClassRef; 1989 1990 // String pointer. 1991 llvm::Constant *C = 1992 llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 1993 1994 llvm::GlobalValue::LinkageTypes Linkage; 1995 bool isConstant; 1996 Linkage = llvm::GlobalValue::PrivateLinkage; 1997 isConstant = !Features.WritableStrings; 1998 1999 llvm::GlobalVariable *GV = 2000 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 2001 ".str"); 2002 GV->setUnnamedAddr(true); 2003 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2004 GV->setAlignment(Align.getQuantity()); 2005 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2006 2007 // String length. 2008 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2009 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 2010 2011 // The struct. 2012 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 2013 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2014 llvm::GlobalVariable::PrivateLinkage, C, 2015 "_unnamed_nsstring_"); 2016 // FIXME. Fix section. 2017 if (const char *Sect = 2018 Features.ObjCNonFragileABI 2019 ? getContext().getTargetInfo().getNSStringNonFragileABISection() 2020 : getContext().getTargetInfo().getNSStringSection()) 2021 GV->setSection(Sect); 2022 Entry.setValue(GV); 2023 2024 return GV; 2025} 2026 2027QualType CodeGenModule::getObjCFastEnumerationStateType() { 2028 if (ObjCFastEnumerationStateType.isNull()) { 2029 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2030 Context.getTranslationUnitDecl(), 2031 &Context.Idents.get("__objcFastEnumerationState")); 2032 D->startDefinition(); 2033 2034 QualType FieldTypes[] = { 2035 Context.UnsignedLongTy, 2036 Context.getPointerType(Context.getObjCIdType()), 2037 Context.getPointerType(Context.UnsignedLongTy), 2038 Context.getConstantArrayType(Context.UnsignedLongTy, 2039 llvm::APInt(32, 5), ArrayType::Normal, 0) 2040 }; 2041 2042 for (size_t i = 0; i < 4; ++i) { 2043 FieldDecl *Field = FieldDecl::Create(Context, 2044 D, 2045 SourceLocation(), 2046 SourceLocation(), 0, 2047 FieldTypes[i], /*TInfo=*/0, 2048 /*BitWidth=*/0, 2049 /*Mutable=*/false, 2050 /*HasInit=*/false); 2051 Field->setAccess(AS_public); 2052 D->addDecl(Field); 2053 } 2054 2055 D->completeDefinition(); 2056 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 2057 } 2058 2059 return ObjCFastEnumerationStateType; 2060} 2061 2062llvm::Constant * 2063CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { 2064 assert(!E->getType()->isPointerType() && "Strings are always arrays"); 2065 2066 // Don't emit it as the address of the string, emit the string data itself 2067 // as an inline array. 2068 if (E->getCharByteWidth() == 1) { 2069 SmallString<64> Str(E->getString()); 2070 2071 // Resize the string to the right size, which is indicated by its type. 2072 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType()); 2073 Str.resize(CAT->getSize().getZExtValue()); 2074 return llvm::ConstantDataArray::getString(VMContext, Str, false); 2075 } 2076 2077 llvm::ArrayType *AType = 2078 cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); 2079 llvm::Type *ElemTy = AType->getElementType(); 2080 unsigned NumElements = AType->getNumElements(); 2081 2082 // Wide strings have either 2-byte or 4-byte elements. 2083 if (ElemTy->getPrimitiveSizeInBits() == 16) { 2084 SmallVector<uint16_t, 32> Elements; 2085 Elements.reserve(NumElements); 2086 2087 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2088 Elements.push_back(E->getCodeUnit(i)); 2089 Elements.resize(NumElements); 2090 return llvm::ConstantDataArray::get(VMContext, Elements); 2091 } 2092 2093 assert(ElemTy->getPrimitiveSizeInBits() == 32); 2094 SmallVector<uint32_t, 32> Elements; 2095 Elements.reserve(NumElements); 2096 2097 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2098 Elements.push_back(E->getCodeUnit(i)); 2099 Elements.resize(NumElements); 2100 return llvm::ConstantDataArray::get(VMContext, Elements); 2101} 2102 2103/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 2104/// constant array for the given string literal. 2105llvm::Constant * 2106CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 2107 CharUnits Align = getContext().getTypeAlignInChars(S->getType()); 2108 if (S->isAscii() || S->isUTF8()) { 2109 SmallString<64> Str(S->getString()); 2110 2111 // Resize the string to the right size, which is indicated by its type. 2112 const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType()); 2113 Str.resize(CAT->getSize().getZExtValue()); 2114 return GetAddrOfConstantString(Str, /*GlobalName*/ 0, Align.getQuantity()); 2115 } 2116 2117 // FIXME: the following does not memoize wide strings. 2118 llvm::Constant *C = GetConstantArrayFromStringLiteral(S); 2119 llvm::GlobalVariable *GV = 2120 new llvm::GlobalVariable(getModule(),C->getType(), 2121 !Features.WritableStrings, 2122 llvm::GlobalValue::PrivateLinkage, 2123 C,".str"); 2124 2125 GV->setAlignment(Align.getQuantity()); 2126 GV->setUnnamedAddr(true); 2127 return GV; 2128} 2129 2130/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2131/// array for the given ObjCEncodeExpr node. 2132llvm::Constant * 2133CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2134 std::string Str; 2135 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2136 2137 return GetAddrOfConstantCString(Str); 2138} 2139 2140 2141/// GenerateWritableString -- Creates storage for a string literal. 2142static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2143 bool constant, 2144 CodeGenModule &CGM, 2145 const char *GlobalName, 2146 unsigned Alignment) { 2147 // Create Constant for this string literal. Don't add a '\0'. 2148 llvm::Constant *C = 2149 llvm::ConstantDataArray::getString(CGM.getLLVMContext(), str, false); 2150 2151 // Create a global variable for this string 2152 llvm::GlobalVariable *GV = 2153 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 2154 llvm::GlobalValue::PrivateLinkage, 2155 C, GlobalName); 2156 GV->setAlignment(Alignment); 2157 GV->setUnnamedAddr(true); 2158 return GV; 2159} 2160 2161/// GetAddrOfConstantString - Returns a pointer to a character array 2162/// containing the literal. This contents are exactly that of the 2163/// given string, i.e. it will not be null terminated automatically; 2164/// see GetAddrOfConstantCString. Note that whether the result is 2165/// actually a pointer to an LLVM constant depends on 2166/// Feature.WriteableStrings. 2167/// 2168/// The result has pointer to array type. 2169llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2170 const char *GlobalName, 2171 unsigned Alignment) { 2172 // Get the default prefix if a name wasn't specified. 2173 if (!GlobalName) 2174 GlobalName = ".str"; 2175 2176 // Don't share any string literals if strings aren't constant. 2177 if (Features.WritableStrings) 2178 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2179 2180 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2181 ConstantStringMap.GetOrCreateValue(Str); 2182 2183 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2184 if (Alignment > GV->getAlignment()) { 2185 GV->setAlignment(Alignment); 2186 } 2187 return GV; 2188 } 2189 2190 // Create a global variable for this. 2191 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, 2192 Alignment); 2193 Entry.setValue(GV); 2194 return GV; 2195} 2196 2197/// GetAddrOfConstantCString - Returns a pointer to a character 2198/// array containing the literal and a terminating '\0' 2199/// character. The result has pointer to array type. 2200llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2201 const char *GlobalName, 2202 unsigned Alignment) { 2203 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2204 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2205} 2206 2207/// EmitObjCPropertyImplementations - Emit information for synthesized 2208/// properties for an implementation. 2209void CodeGenModule::EmitObjCPropertyImplementations(const 2210 ObjCImplementationDecl *D) { 2211 for (ObjCImplementationDecl::propimpl_iterator 2212 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2213 ObjCPropertyImplDecl *PID = *i; 2214 2215 // Dynamic is just for type-checking. 2216 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2217 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2218 2219 // Determine which methods need to be implemented, some may have 2220 // been overridden. Note that ::isSynthesized is not the method 2221 // we want, that just indicates if the decl came from a 2222 // property. What we want to know is if the method is defined in 2223 // this implementation. 2224 if (!D->getInstanceMethod(PD->getGetterName())) 2225 CodeGenFunction(*this).GenerateObjCGetter( 2226 const_cast<ObjCImplementationDecl *>(D), PID); 2227 if (!PD->isReadOnly() && 2228 !D->getInstanceMethod(PD->getSetterName())) 2229 CodeGenFunction(*this).GenerateObjCSetter( 2230 const_cast<ObjCImplementationDecl *>(D), PID); 2231 } 2232 } 2233} 2234 2235static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2236 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2237 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2238 ivar; ivar = ivar->getNextIvar()) 2239 if (ivar->getType().isDestructedType()) 2240 return true; 2241 2242 return false; 2243} 2244 2245/// EmitObjCIvarInitializations - Emit information for ivar initialization 2246/// for an implementation. 2247void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2248 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2249 if (needsDestructMethod(D)) { 2250 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2251 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2252 ObjCMethodDecl *DTORMethod = 2253 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2254 cxxSelector, getContext().VoidTy, 0, D, 2255 /*isInstance=*/true, /*isVariadic=*/false, 2256 /*isSynthesized=*/true, /*isImplicitlyDeclared=*/true, 2257 /*isDefined=*/false, ObjCMethodDecl::Required); 2258 D->addInstanceMethod(DTORMethod); 2259 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2260 D->setHasCXXStructors(true); 2261 } 2262 2263 // If the implementation doesn't have any ivar initializers, we don't need 2264 // a .cxx_construct. 2265 if (D->getNumIvarInitializers() == 0) 2266 return; 2267 2268 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2269 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2270 // The constructor returns 'self'. 2271 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2272 D->getLocation(), 2273 D->getLocation(), 2274 cxxSelector, 2275 getContext().getObjCIdType(), 0, 2276 D, /*isInstance=*/true, 2277 /*isVariadic=*/false, 2278 /*isSynthesized=*/true, 2279 /*isImplicitlyDeclared=*/true, 2280 /*isDefined=*/false, 2281 ObjCMethodDecl::Required); 2282 D->addInstanceMethod(CTORMethod); 2283 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2284 D->setHasCXXStructors(true); 2285} 2286 2287/// EmitNamespace - Emit all declarations in a namespace. 2288void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2289 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2290 I != E; ++I) 2291 EmitTopLevelDecl(*I); 2292} 2293 2294// EmitLinkageSpec - Emit all declarations in a linkage spec. 2295void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2296 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2297 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2298 ErrorUnsupported(LSD, "linkage spec"); 2299 return; 2300 } 2301 2302 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2303 I != E; ++I) 2304 EmitTopLevelDecl(*I); 2305} 2306 2307/// EmitTopLevelDecl - Emit code for a single top level declaration. 2308void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2309 // If an error has occurred, stop code generation, but continue 2310 // parsing and semantic analysis (to ensure all warnings and errors 2311 // are emitted). 2312 if (Diags.hasErrorOccurred()) 2313 return; 2314 2315 // Ignore dependent declarations. 2316 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2317 return; 2318 2319 switch (D->getKind()) { 2320 case Decl::CXXConversion: 2321 case Decl::CXXMethod: 2322 case Decl::Function: 2323 // Skip function templates 2324 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2325 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2326 return; 2327 2328 EmitGlobal(cast<FunctionDecl>(D)); 2329 break; 2330 2331 case Decl::Var: 2332 EmitGlobal(cast<VarDecl>(D)); 2333 break; 2334 2335 // Indirect fields from global anonymous structs and unions can be 2336 // ignored; only the actual variable requires IR gen support. 2337 case Decl::IndirectField: 2338 break; 2339 2340 // C++ Decls 2341 case Decl::Namespace: 2342 EmitNamespace(cast<NamespaceDecl>(D)); 2343 break; 2344 // No code generation needed. 2345 case Decl::UsingShadow: 2346 case Decl::Using: 2347 case Decl::UsingDirective: 2348 case Decl::ClassTemplate: 2349 case Decl::FunctionTemplate: 2350 case Decl::TypeAliasTemplate: 2351 case Decl::NamespaceAlias: 2352 case Decl::Block: 2353 case Decl::Import: 2354 break; 2355 case Decl::CXXConstructor: 2356 // Skip function templates 2357 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2358 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2359 return; 2360 2361 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2362 break; 2363 case Decl::CXXDestructor: 2364 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2365 return; 2366 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2367 break; 2368 2369 case Decl::StaticAssert: 2370 // Nothing to do. 2371 break; 2372 2373 // Objective-C Decls 2374 2375 // Forward declarations, no (immediate) code generation. 2376 case Decl::ObjCInterface: 2377 break; 2378 2379 case Decl::ObjCCategory: { 2380 ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D); 2381 if (CD->IsClassExtension() && CD->hasSynthBitfield()) 2382 Context.ResetObjCLayout(CD->getClassInterface()); 2383 break; 2384 } 2385 2386 case Decl::ObjCProtocol: { 2387 ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D); 2388 if (Proto->isThisDeclarationADefinition()) 2389 ObjCRuntime->GenerateProtocol(Proto); 2390 break; 2391 } 2392 2393 case Decl::ObjCCategoryImpl: 2394 // Categories have properties but don't support synthesize so we 2395 // can ignore them here. 2396 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2397 break; 2398 2399 case Decl::ObjCImplementation: { 2400 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2401 if (Features.ObjCNonFragileABI2 && OMD->hasSynthBitfield()) 2402 Context.ResetObjCLayout(OMD->getClassInterface()); 2403 EmitObjCPropertyImplementations(OMD); 2404 EmitObjCIvarInitializations(OMD); 2405 ObjCRuntime->GenerateClass(OMD); 2406 break; 2407 } 2408 case Decl::ObjCMethod: { 2409 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 2410 // If this is not a prototype, emit the body. 2411 if (OMD->getBody()) 2412 CodeGenFunction(*this).GenerateObjCMethod(OMD); 2413 break; 2414 } 2415 case Decl::ObjCCompatibleAlias: 2416 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D)); 2417 break; 2418 2419 case Decl::LinkageSpec: 2420 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 2421 break; 2422 2423 case Decl::FileScopeAsm: { 2424 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 2425 StringRef AsmString = AD->getAsmString()->getString(); 2426 2427 const std::string &S = getModule().getModuleInlineAsm(); 2428 if (S.empty()) 2429 getModule().setModuleInlineAsm(AsmString); 2430 else if (*--S.end() == '\n') 2431 getModule().setModuleInlineAsm(S + AsmString.str()); 2432 else 2433 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 2434 break; 2435 } 2436 2437 default: 2438 // Make sure we handled everything we should, every other kind is a 2439 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 2440 // function. Need to recode Decl::Kind to do that easily. 2441 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 2442 } 2443} 2444 2445/// Turns the given pointer into a constant. 2446static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 2447 const void *Ptr) { 2448 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 2449 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 2450 return llvm::ConstantInt::get(i64, PtrInt); 2451} 2452 2453static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 2454 llvm::NamedMDNode *&GlobalMetadata, 2455 GlobalDecl D, 2456 llvm::GlobalValue *Addr) { 2457 if (!GlobalMetadata) 2458 GlobalMetadata = 2459 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 2460 2461 // TODO: should we report variant information for ctors/dtors? 2462 llvm::Value *Ops[] = { 2463 Addr, 2464 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 2465 }; 2466 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 2467} 2468 2469/// Emits metadata nodes associating all the global values in the 2470/// current module with the Decls they came from. This is useful for 2471/// projects using IR gen as a subroutine. 2472/// 2473/// Since there's currently no way to associate an MDNode directly 2474/// with an llvm::GlobalValue, we create a global named metadata 2475/// with the name 'clang.global.decl.ptrs'. 2476void CodeGenModule::EmitDeclMetadata() { 2477 llvm::NamedMDNode *GlobalMetadata = 0; 2478 2479 // StaticLocalDeclMap 2480 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 2481 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 2482 I != E; ++I) { 2483 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 2484 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 2485 } 2486} 2487 2488/// Emits metadata nodes for all the local variables in the current 2489/// function. 2490void CodeGenFunction::EmitDeclMetadata() { 2491 if (LocalDeclMap.empty()) return; 2492 2493 llvm::LLVMContext &Context = getLLVMContext(); 2494 2495 // Find the unique metadata ID for this name. 2496 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 2497 2498 llvm::NamedMDNode *GlobalMetadata = 0; 2499 2500 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 2501 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 2502 const Decl *D = I->first; 2503 llvm::Value *Addr = I->second; 2504 2505 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 2506 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 2507 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 2508 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 2509 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 2510 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 2511 } 2512 } 2513} 2514 2515void CodeGenModule::EmitCoverageFile() { 2516 if (!getCodeGenOpts().CoverageFile.empty()) { 2517 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 2518 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 2519 llvm::LLVMContext &Ctx = TheModule.getContext(); 2520 llvm::MDString *CoverageFile = 2521 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 2522 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 2523 llvm::MDNode *CU = CUNode->getOperand(i); 2524 llvm::Value *node[] = { CoverageFile, CU }; 2525 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 2526 GCov->addOperand(N); 2527 } 2528 } 2529 } 2530} 2531