CodeGenModule.cpp revision 228379
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/Diagnostic.h" 34#include "clang/Basic/SourceManager.h" 35#include "clang/Basic/TargetInfo.h" 36#include "clang/Basic/ConvertUTF.h" 37#include "llvm/CallingConv.h" 38#include "llvm/Module.h" 39#include "llvm/Intrinsics.h" 40#include "llvm/LLVMContext.h" 41#include "llvm/ADT/Triple.h" 42#include "llvm/Target/Mangler.h" 43#include "llvm/Target/TargetData.h" 44#include "llvm/Support/CallSite.h" 45#include "llvm/Support/ErrorHandling.h" 46using namespace clang; 47using namespace CodeGen; 48 49static const char AnnotationSection[] = "llvm.metadata"; 50 51static CGCXXABI &createCXXABI(CodeGenModule &CGM) { 52 switch (CGM.getContext().getTargetInfo().getCXXABI()) { 53 case CXXABI_ARM: return *CreateARMCXXABI(CGM); 54 case CXXABI_Itanium: return *CreateItaniumCXXABI(CGM); 55 case CXXABI_Microsoft: return *CreateMicrosoftCXXABI(CGM); 56 } 57 58 llvm_unreachable("invalid C++ ABI kind"); 59 return *CreateItaniumCXXABI(CGM); 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(C, M, TD, getTargetCodeGenInfo().getABIInfo(), ABI, CGO), 70 TBAA(0), 71 VTables(*this), ObjCRuntime(0), OpenCLRuntime(0), CUDARuntime(0), 72 DebugInfo(0), ARCData(0), RRData(0), CFConstantStringClassRef(0), 73 ConstantStringClassRef(0), NSConstantStringType(0), 74 VMContext(M.getContext()), 75 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), 76 BlockObjectAssign(0), BlockObjectDispose(0), 77 BlockDescriptorType(0), GenericBlockLiteralType(0) { 78 if (Features.ObjC1) 79 createObjCRuntime(); 80 if (Features.OpenCL) 81 createOpenCLRuntime(); 82 if (Features.CUDA) 83 createCUDARuntime(); 84 85 // Enable TBAA unless it's suppressed. 86 if (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0) 87 TBAA = new CodeGenTBAA(Context, VMContext, getLangOptions(), 88 ABI.getMangleContext()); 89 90 // If debug info or coverage generation is enabled, create the CGDebugInfo 91 // object. 92 if (CodeGenOpts.DebugInfo || CodeGenOpts.EmitGcovArcs || 93 CodeGenOpts.EmitGcovNotes) 94 DebugInfo = new CGDebugInfo(*this); 95 96 Block.GlobalUniqueCount = 0; 97 98 if (C.getLangOptions().ObjCAutoRefCount) 99 ARCData = new ARCEntrypoints(); 100 RRData = new RREntrypoints(); 101 102 // Initialize the type cache. 103 llvm::LLVMContext &LLVMContext = M.getContext(); 104 VoidTy = llvm::Type::getVoidTy(LLVMContext); 105 Int8Ty = llvm::Type::getInt8Ty(LLVMContext); 106 Int32Ty = llvm::Type::getInt32Ty(LLVMContext); 107 Int64Ty = llvm::Type::getInt64Ty(LLVMContext); 108 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0); 109 PointerAlignInBytes = 110 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity(); 111 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth()); 112 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits); 113 Int8PtrTy = Int8Ty->getPointerTo(0); 114 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0); 115} 116 117CodeGenModule::~CodeGenModule() { 118 delete ObjCRuntime; 119 delete OpenCLRuntime; 120 delete CUDARuntime; 121 delete TheTargetCodeGenInfo; 122 delete &ABI; 123 delete TBAA; 124 delete DebugInfo; 125 delete ARCData; 126 delete RRData; 127} 128 129void CodeGenModule::createObjCRuntime() { 130 if (!Features.NeXTRuntime) 131 ObjCRuntime = CreateGNUObjCRuntime(*this); 132 else 133 ObjCRuntime = CreateMacObjCRuntime(*this); 134} 135 136void CodeGenModule::createOpenCLRuntime() { 137 OpenCLRuntime = new CGOpenCLRuntime(*this); 138} 139 140void CodeGenModule::createCUDARuntime() { 141 CUDARuntime = CreateNVCUDARuntime(*this); 142} 143 144void CodeGenModule::Release() { 145 EmitDeferred(); 146 EmitCXXGlobalInitFunc(); 147 EmitCXXGlobalDtorFunc(); 148 if (ObjCRuntime) 149 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) 150 AddGlobalCtor(ObjCInitFunction); 151 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 152 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 153 EmitGlobalAnnotations(); 154 EmitLLVMUsed(); 155 156 SimplifyPersonality(); 157 158 if (getCodeGenOpts().EmitDeclMetadata) 159 EmitDeclMetadata(); 160 161 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 162 EmitCoverageFile(); 163 164 if (DebugInfo) 165 DebugInfo->finalize(); 166} 167 168void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 169 // Make sure that this type is translated. 170 Types.UpdateCompletedType(TD); 171 if (DebugInfo) 172 DebugInfo->UpdateCompletedType(TD); 173} 174 175llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 176 if (!TBAA) 177 return 0; 178 return TBAA->getTBAAInfo(QTy); 179} 180 181void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 182 llvm::MDNode *TBAAInfo) { 183 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 184} 185 186bool CodeGenModule::isTargetDarwin() const { 187 return getContext().getTargetInfo().getTriple().isOSDarwin(); 188} 189 190void CodeGenModule::Error(SourceLocation loc, StringRef error) { 191 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); 192 getDiags().Report(Context.getFullLoc(loc), diagID); 193} 194 195/// ErrorUnsupported - Print out an error that codegen doesn't support the 196/// specified stmt yet. 197void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 198 bool OmitOnError) { 199 if (OmitOnError && getDiags().hasErrorOccurred()) 200 return; 201 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 202 "cannot compile this %0 yet"); 203 std::string Msg = Type; 204 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 205 << Msg << S->getSourceRange(); 206} 207 208/// ErrorUnsupported - Print out an error that codegen doesn't support the 209/// specified decl yet. 210void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 211 bool OmitOnError) { 212 if (OmitOnError && getDiags().hasErrorOccurred()) 213 return; 214 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 215 "cannot compile this %0 yet"); 216 std::string Msg = Type; 217 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 218} 219 220llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 221 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 222} 223 224void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 225 const NamedDecl *D) const { 226 // Internal definitions always have default visibility. 227 if (GV->hasLocalLinkage()) { 228 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 229 return; 230 } 231 232 // Set visibility for definitions. 233 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 234 if (LV.visibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 235 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 236} 237 238/// Set the symbol visibility of type information (vtable and RTTI) 239/// associated with the given type. 240void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 241 const CXXRecordDecl *RD, 242 TypeVisibilityKind TVK) const { 243 setGlobalVisibility(GV, RD); 244 245 if (!CodeGenOpts.HiddenWeakVTables) 246 return; 247 248 // We never want to drop the visibility for RTTI names. 249 if (TVK == TVK_ForRTTIName) 250 return; 251 252 // We want to drop the visibility to hidden for weak type symbols. 253 // This isn't possible if there might be unresolved references 254 // elsewhere that rely on this symbol being visible. 255 256 // This should be kept roughly in sync with setThunkVisibility 257 // in CGVTables.cpp. 258 259 // Preconditions. 260 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 261 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 262 return; 263 264 // Don't override an explicit visibility attribute. 265 if (RD->getExplicitVisibility()) 266 return; 267 268 switch (RD->getTemplateSpecializationKind()) { 269 // We have to disable the optimization if this is an EI definition 270 // because there might be EI declarations in other shared objects. 271 case TSK_ExplicitInstantiationDefinition: 272 case TSK_ExplicitInstantiationDeclaration: 273 return; 274 275 // Every use of a non-template class's type information has to emit it. 276 case TSK_Undeclared: 277 break; 278 279 // In theory, implicit instantiations can ignore the possibility of 280 // an explicit instantiation declaration because there necessarily 281 // must be an EI definition somewhere with default visibility. In 282 // practice, it's possible to have an explicit instantiation for 283 // an arbitrary template class, and linkers aren't necessarily able 284 // to deal with mixed-visibility symbols. 285 case TSK_ExplicitSpecialization: 286 case TSK_ImplicitInstantiation: 287 if (!CodeGenOpts.HiddenWeakTemplateVTables) 288 return; 289 break; 290 } 291 292 // If there's a key function, there may be translation units 293 // that don't have the key function's definition. But ignore 294 // this if we're emitting RTTI under -fno-rtti. 295 if (!(TVK != TVK_ForRTTI) || Features.RTTI) { 296 if (Context.getKeyFunction(RD)) 297 return; 298 } 299 300 // Otherwise, drop the visibility to hidden. 301 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 302 GV->setUnnamedAddr(true); 303} 304 305StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 306 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 307 308 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 309 if (!Str.empty()) 310 return Str; 311 312 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 313 IdentifierInfo *II = ND->getIdentifier(); 314 assert(II && "Attempt to mangle unnamed decl."); 315 316 Str = II->getName(); 317 return Str; 318 } 319 320 llvm::SmallString<256> Buffer; 321 llvm::raw_svector_ostream Out(Buffer); 322 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 323 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 324 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 325 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 326 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND)) 327 getCXXABI().getMangleContext().mangleBlock(BD, Out); 328 else 329 getCXXABI().getMangleContext().mangleName(ND, Out); 330 331 // Allocate space for the mangled name. 332 Out.flush(); 333 size_t Length = Buffer.size(); 334 char *Name = MangledNamesAllocator.Allocate<char>(Length); 335 std::copy(Buffer.begin(), Buffer.end(), Name); 336 337 Str = StringRef(Name, Length); 338 339 return Str; 340} 341 342void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 343 const BlockDecl *BD) { 344 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 345 const Decl *D = GD.getDecl(); 346 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 347 if (D == 0) 348 MangleCtx.mangleGlobalBlock(BD, Out); 349 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 350 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 351 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 352 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 353 else 354 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 355} 356 357llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 358 return getModule().getNamedValue(Name); 359} 360 361/// AddGlobalCtor - Add a function to the list that will be called before 362/// main() runs. 363void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 364 // FIXME: Type coercion of void()* types. 365 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 366} 367 368/// AddGlobalDtor - Add a function to the list that will be called 369/// when the module is unloaded. 370void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 371 // FIXME: Type coercion of void()* types. 372 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 373} 374 375void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 376 // Ctor function type is void()*. 377 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 378 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 379 380 // Get the type of a ctor entry, { i32, void ()* }. 381 llvm::StructType *CtorStructTy = 382 llvm::StructType::get(llvm::Type::getInt32Ty(VMContext), 383 llvm::PointerType::getUnqual(CtorFTy), NULL); 384 385 // Construct the constructor and destructor arrays. 386 std::vector<llvm::Constant*> Ctors; 387 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 388 std::vector<llvm::Constant*> S; 389 S.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 390 I->second, false)); 391 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy)); 392 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 393 } 394 395 if (!Ctors.empty()) { 396 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 397 new llvm::GlobalVariable(TheModule, AT, false, 398 llvm::GlobalValue::AppendingLinkage, 399 llvm::ConstantArray::get(AT, Ctors), 400 GlobalName); 401 } 402} 403 404llvm::GlobalValue::LinkageTypes 405CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 406 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 407 408 if (Linkage == GVA_Internal) 409 return llvm::Function::InternalLinkage; 410 411 if (D->hasAttr<DLLExportAttr>()) 412 return llvm::Function::DLLExportLinkage; 413 414 if (D->hasAttr<WeakAttr>()) 415 return llvm::Function::WeakAnyLinkage; 416 417 // In C99 mode, 'inline' functions are guaranteed to have a strong 418 // definition somewhere else, so we can use available_externally linkage. 419 if (Linkage == GVA_C99Inline) 420 return llvm::Function::AvailableExternallyLinkage; 421 422 // Note that Apple's kernel linker doesn't support symbol 423 // coalescing, so we need to avoid linkonce and weak linkages there. 424 // Normally, this means we just map to internal, but for explicit 425 // instantiations we'll map to external. 426 427 // In C++, the compiler has to emit a definition in every translation unit 428 // that references the function. We should use linkonce_odr because 429 // a) if all references in this translation unit are optimized away, we 430 // don't need to codegen it. b) if the function persists, it needs to be 431 // merged with other definitions. c) C++ has the ODR, so we know the 432 // definition is dependable. 433 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 434 return !Context.getLangOptions().AppleKext 435 ? llvm::Function::LinkOnceODRLinkage 436 : llvm::Function::InternalLinkage; 437 438 // An explicit instantiation of a template has weak linkage, since 439 // explicit instantiations can occur in multiple translation units 440 // and must all be equivalent. However, we are not allowed to 441 // throw away these explicit instantiations. 442 if (Linkage == GVA_ExplicitTemplateInstantiation) 443 return !Context.getLangOptions().AppleKext 444 ? llvm::Function::WeakODRLinkage 445 : llvm::Function::ExternalLinkage; 446 447 // Otherwise, we have strong external linkage. 448 assert(Linkage == GVA_StrongExternal); 449 return llvm::Function::ExternalLinkage; 450} 451 452 453/// SetFunctionDefinitionAttributes - Set attributes for a global. 454/// 455/// FIXME: This is currently only done for aliases and functions, but not for 456/// variables (these details are set in EmitGlobalVarDefinition for variables). 457void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 458 llvm::GlobalValue *GV) { 459 SetCommonAttributes(D, GV); 460} 461 462void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 463 const CGFunctionInfo &Info, 464 llvm::Function *F) { 465 unsigned CallingConv; 466 AttributeListType AttributeList; 467 ConstructAttributeList(Info, D, AttributeList, CallingConv); 468 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 469 AttributeList.size())); 470 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 471} 472 473/// Determines whether the language options require us to model 474/// unwind exceptions. We treat -fexceptions as mandating this 475/// except under the fragile ObjC ABI with only ObjC exceptions 476/// enabled. This means, for example, that C with -fexceptions 477/// enables this. 478static bool hasUnwindExceptions(const LangOptions &Features) { 479 // If exceptions are completely disabled, obviously this is false. 480 if (!Features.Exceptions) return false; 481 482 // If C++ exceptions are enabled, this is true. 483 if (Features.CXXExceptions) return true; 484 485 // If ObjC exceptions are enabled, this depends on the ABI. 486 if (Features.ObjCExceptions) { 487 if (!Features.ObjCNonFragileABI) return false; 488 } 489 490 return true; 491} 492 493void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 494 llvm::Function *F) { 495 if (CodeGenOpts.UnwindTables) 496 F->setHasUWTable(); 497 498 if (!hasUnwindExceptions(Features)) 499 F->addFnAttr(llvm::Attribute::NoUnwind); 500 501 if (D->hasAttr<NakedAttr>()) { 502 // Naked implies noinline: we should not be inlining such functions. 503 F->addFnAttr(llvm::Attribute::Naked); 504 F->addFnAttr(llvm::Attribute::NoInline); 505 } 506 507 if (D->hasAttr<NoInlineAttr>()) 508 F->addFnAttr(llvm::Attribute::NoInline); 509 510 // (noinline wins over always_inline, and we can't specify both in IR) 511 if (D->hasAttr<AlwaysInlineAttr>() && 512 !F->hasFnAttr(llvm::Attribute::NoInline)) 513 F->addFnAttr(llvm::Attribute::AlwaysInline); 514 515 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 516 F->setUnnamedAddr(true); 517 518 if (Features.getStackProtector() == LangOptions::SSPOn) 519 F->addFnAttr(llvm::Attribute::StackProtect); 520 else if (Features.getStackProtector() == LangOptions::SSPReq) 521 F->addFnAttr(llvm::Attribute::StackProtectReq); 522 523 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 524 if (alignment) 525 F->setAlignment(alignment); 526 527 // C++ ABI requires 2-byte alignment for member functions. 528 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 529 F->setAlignment(2); 530} 531 532void CodeGenModule::SetCommonAttributes(const Decl *D, 533 llvm::GlobalValue *GV) { 534 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 535 setGlobalVisibility(GV, ND); 536 else 537 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 538 539 if (D->hasAttr<UsedAttr>()) 540 AddUsedGlobal(GV); 541 542 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 543 GV->setSection(SA->getName()); 544 545 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 546} 547 548void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 549 llvm::Function *F, 550 const CGFunctionInfo &FI) { 551 SetLLVMFunctionAttributes(D, FI, F); 552 SetLLVMFunctionAttributesForDefinition(D, F); 553 554 F->setLinkage(llvm::Function::InternalLinkage); 555 556 SetCommonAttributes(D, F); 557} 558 559void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 560 llvm::Function *F, 561 bool IsIncompleteFunction) { 562 if (unsigned IID = F->getIntrinsicID()) { 563 // If this is an intrinsic function, set the function's attributes 564 // to the intrinsic's attributes. 565 F->setAttributes(llvm::Intrinsic::getAttributes((llvm::Intrinsic::ID)IID)); 566 return; 567 } 568 569 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 570 571 if (!IsIncompleteFunction) 572 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(GD), F); 573 574 // Only a few attributes are set on declarations; these may later be 575 // overridden by a definition. 576 577 if (FD->hasAttr<DLLImportAttr>()) { 578 F->setLinkage(llvm::Function::DLLImportLinkage); 579 } else if (FD->hasAttr<WeakAttr>() || 580 FD->isWeakImported()) { 581 // "extern_weak" is overloaded in LLVM; we probably should have 582 // separate linkage types for this. 583 F->setLinkage(llvm::Function::ExternalWeakLinkage); 584 } else { 585 F->setLinkage(llvm::Function::ExternalLinkage); 586 587 NamedDecl::LinkageInfo LV = FD->getLinkageAndVisibility(); 588 if (LV.linkage() == ExternalLinkage && LV.visibilityExplicit()) { 589 F->setVisibility(GetLLVMVisibility(LV.visibility())); 590 } 591 } 592 593 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 594 F->setSection(SA->getName()); 595} 596 597void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 598 assert(!GV->isDeclaration() && 599 "Only globals with definition can force usage."); 600 LLVMUsed.push_back(GV); 601} 602 603void CodeGenModule::EmitLLVMUsed() { 604 // Don't create llvm.used if there is no need. 605 if (LLVMUsed.empty()) 606 return; 607 608 llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext); 609 610 // Convert LLVMUsed to what ConstantArray needs. 611 std::vector<llvm::Constant*> UsedArray; 612 UsedArray.resize(LLVMUsed.size()); 613 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 614 UsedArray[i] = 615 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 616 i8PTy); 617 } 618 619 if (UsedArray.empty()) 620 return; 621 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, UsedArray.size()); 622 623 llvm::GlobalVariable *GV = 624 new llvm::GlobalVariable(getModule(), ATy, false, 625 llvm::GlobalValue::AppendingLinkage, 626 llvm::ConstantArray::get(ATy, UsedArray), 627 "llvm.used"); 628 629 GV->setSection("llvm.metadata"); 630} 631 632void CodeGenModule::EmitDeferred() { 633 // Emit code for any potentially referenced deferred decls. Since a 634 // previously unused static decl may become used during the generation of code 635 // for a static function, iterate until no changes are made. 636 637 while (!DeferredDeclsToEmit.empty() || !DeferredVTables.empty()) { 638 if (!DeferredVTables.empty()) { 639 const CXXRecordDecl *RD = DeferredVTables.back(); 640 DeferredVTables.pop_back(); 641 getVTables().GenerateClassData(getVTableLinkage(RD), RD); 642 continue; 643 } 644 645 GlobalDecl D = DeferredDeclsToEmit.back(); 646 DeferredDeclsToEmit.pop_back(); 647 648 // Check to see if we've already emitted this. This is necessary 649 // for a couple of reasons: first, decls can end up in the 650 // deferred-decls queue multiple times, and second, decls can end 651 // up with definitions in unusual ways (e.g. by an extern inline 652 // function acquiring a strong function redefinition). Just 653 // ignore these cases. 654 // 655 // TODO: That said, looking this up multiple times is very wasteful. 656 StringRef Name = getMangledName(D); 657 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 658 assert(CGRef && "Deferred decl wasn't referenced?"); 659 660 if (!CGRef->isDeclaration()) 661 continue; 662 663 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 664 // purposes an alias counts as a definition. 665 if (isa<llvm::GlobalAlias>(CGRef)) 666 continue; 667 668 // Otherwise, emit the definition and move on to the next one. 669 EmitGlobalDefinition(D); 670 } 671} 672 673void CodeGenModule::EmitGlobalAnnotations() { 674 if (Annotations.empty()) 675 return; 676 677 // Create a new global variable for the ConstantStruct in the Module. 678 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 679 Annotations[0]->getType(), Annotations.size()), Annotations); 680 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), 681 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, 682 "llvm.global.annotations"); 683 gv->setSection(AnnotationSection); 684} 685 686llvm::Constant *CodeGenModule::EmitAnnotationString(llvm::StringRef Str) { 687 llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str); 688 if (i != AnnotationStrings.end()) 689 return i->second; 690 691 // Not found yet, create a new global. 692 llvm::Constant *s = llvm::ConstantArray::get(getLLVMContext(), Str, true); 693 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), 694 true, llvm::GlobalValue::PrivateLinkage, s, ".str"); 695 gv->setSection(AnnotationSection); 696 gv->setUnnamedAddr(true); 697 AnnotationStrings[Str] = gv; 698 return gv; 699} 700 701llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 702 SourceManager &SM = getContext().getSourceManager(); 703 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 704 if (PLoc.isValid()) 705 return EmitAnnotationString(PLoc.getFilename()); 706 return EmitAnnotationString(SM.getBufferName(Loc)); 707} 708 709llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 710 SourceManager &SM = getContext().getSourceManager(); 711 PresumedLoc PLoc = SM.getPresumedLoc(L); 712 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 713 SM.getExpansionLineNumber(L); 714 return llvm::ConstantInt::get(Int32Ty, LineNo); 715} 716 717llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 718 const AnnotateAttr *AA, 719 SourceLocation L) { 720 // Get the globals for file name, annotation, and the line number. 721 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 722 *UnitGV = EmitAnnotationUnit(L), 723 *LineNoCst = EmitAnnotationLineNo(L); 724 725 // Create the ConstantStruct for the global annotation. 726 llvm::Constant *Fields[4] = { 727 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 728 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 729 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 730 LineNoCst 731 }; 732 return llvm::ConstantStruct::getAnon(Fields); 733} 734 735void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 736 llvm::GlobalValue *GV) { 737 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 738 // Get the struct elements for these annotations. 739 for (specific_attr_iterator<AnnotateAttr> 740 ai = D->specific_attr_begin<AnnotateAttr>(), 741 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) 742 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); 743} 744 745bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 746 // Never defer when EmitAllDecls is specified. 747 if (Features.EmitAllDecls) 748 return false; 749 750 return !getContext().DeclMustBeEmitted(Global); 751} 752 753llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 754 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 755 assert(AA && "No alias?"); 756 757 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 758 759 // See if there is already something with the target's name in the module. 760 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 761 762 llvm::Constant *Aliasee; 763 if (isa<llvm::FunctionType>(DeclTy)) 764 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 765 /*ForVTable=*/false); 766 else 767 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 768 llvm::PointerType::getUnqual(DeclTy), 0); 769 if (!Entry) { 770 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 771 F->setLinkage(llvm::Function::ExternalWeakLinkage); 772 WeakRefReferences.insert(F); 773 } 774 775 return Aliasee; 776} 777 778void CodeGenModule::EmitGlobal(GlobalDecl GD) { 779 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 780 781 // Weak references don't produce any output by themselves. 782 if (Global->hasAttr<WeakRefAttr>()) 783 return; 784 785 // If this is an alias definition (which otherwise looks like a declaration) 786 // emit it now. 787 if (Global->hasAttr<AliasAttr>()) 788 return EmitAliasDefinition(GD); 789 790 // If this is CUDA, be selective about which declarations we emit. 791 if (Features.CUDA) { 792 if (CodeGenOpts.CUDAIsDevice) { 793 if (!Global->hasAttr<CUDADeviceAttr>() && 794 !Global->hasAttr<CUDAGlobalAttr>() && 795 !Global->hasAttr<CUDAConstantAttr>() && 796 !Global->hasAttr<CUDASharedAttr>()) 797 return; 798 } else { 799 if (!Global->hasAttr<CUDAHostAttr>() && ( 800 Global->hasAttr<CUDADeviceAttr>() || 801 Global->hasAttr<CUDAConstantAttr>() || 802 Global->hasAttr<CUDASharedAttr>())) 803 return; 804 } 805 } 806 807 // Ignore declarations, they will be emitted on their first use. 808 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 809 // Forward declarations are emitted lazily on first use. 810 if (!FD->doesThisDeclarationHaveABody()) { 811 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 812 return; 813 814 const FunctionDecl *InlineDefinition = 0; 815 FD->getBody(InlineDefinition); 816 817 StringRef MangledName = getMangledName(GD); 818 llvm::StringMap<GlobalDecl>::iterator DDI = 819 DeferredDecls.find(MangledName); 820 if (DDI != DeferredDecls.end()) 821 DeferredDecls.erase(DDI); 822 EmitGlobalDefinition(InlineDefinition); 823 return; 824 } 825 } else { 826 const VarDecl *VD = cast<VarDecl>(Global); 827 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 828 829 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 830 return; 831 } 832 833 // Defer code generation when possible if this is a static definition, inline 834 // function etc. These we only want to emit if they are used. 835 if (!MayDeferGeneration(Global)) { 836 // Emit the definition if it can't be deferred. 837 EmitGlobalDefinition(GD); 838 return; 839 } 840 841 // If we're deferring emission of a C++ variable with an 842 // initializer, remember the order in which it appeared in the file. 843 if (getLangOptions().CPlusPlus && isa<VarDecl>(Global) && 844 cast<VarDecl>(Global)->hasInit()) { 845 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 846 CXXGlobalInits.push_back(0); 847 } 848 849 // If the value has already been used, add it directly to the 850 // DeferredDeclsToEmit list. 851 StringRef MangledName = getMangledName(GD); 852 if (GetGlobalValue(MangledName)) 853 DeferredDeclsToEmit.push_back(GD); 854 else { 855 // Otherwise, remember that we saw a deferred decl with this name. The 856 // first use of the mangled name will cause it to move into 857 // DeferredDeclsToEmit. 858 DeferredDecls[MangledName] = GD; 859 } 860} 861 862namespace { 863 struct FunctionIsDirectlyRecursive : 864 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> { 865 const StringRef Name; 866 bool Result; 867 FunctionIsDirectlyRecursive(const FunctionDecl *F) : 868 Name(F->getName()), Result(false) { 869 } 870 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; 871 872 bool TraverseCallExpr(CallExpr *E) { 873 const Decl *D = E->getCalleeDecl(); 874 if (!D) 875 return true; 876 AsmLabelAttr *Attr = D->getAttr<AsmLabelAttr>(); 877 if (!Attr) 878 return true; 879 if (Name == Attr->getLabel()) { 880 Result = true; 881 return false; 882 } 883 return true; 884 } 885 }; 886} 887 888// isTriviallyRecursiveViaAsm - Check if this function calls another 889// decl that, because of the asm attribute, ends up pointing to itself. 890bool 891CodeGenModule::isTriviallyRecursiveViaAsm(const FunctionDecl *F) { 892 if (getCXXABI().getMangleContext().shouldMangleDeclName(F)) 893 return false; 894 895 FunctionIsDirectlyRecursive Walker(F); 896 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(F)); 897 return Walker.Result; 898} 899 900bool 901CodeGenModule::shouldEmitFunction(const FunctionDecl *F) { 902 if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage) 903 return true; 904 if (CodeGenOpts.OptimizationLevel == 0 && 905 !F->hasAttr<AlwaysInlineAttr>()) 906 return false; 907 // PR9614. Avoid cases where the source code is lying to us. An available 908 // externally function should have an equivalent function somewhere else, 909 // but a function that calls itself is clearly not equivalent to the real 910 // implementation. 911 // This happens in glibc's btowc and in some configure checks. 912 return !isTriviallyRecursiveViaAsm(F); 913} 914 915void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 916 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 917 918 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 919 Context.getSourceManager(), 920 "Generating code for declaration"); 921 922 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 923 // At -O0, don't generate IR for functions with available_externally 924 // linkage. 925 if (!shouldEmitFunction(Function)) 926 return; 927 928 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 929 // Make sure to emit the definition(s) before we emit the thunks. 930 // This is necessary for the generation of certain thunks. 931 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 932 EmitCXXConstructor(CD, GD.getCtorType()); 933 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 934 EmitCXXDestructor(DD, GD.getDtorType()); 935 else 936 EmitGlobalFunctionDefinition(GD); 937 938 if (Method->isVirtual()) 939 getVTables().EmitThunks(GD); 940 941 return; 942 } 943 944 return EmitGlobalFunctionDefinition(GD); 945 } 946 947 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 948 return EmitGlobalVarDefinition(VD); 949 950 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 951} 952 953/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 954/// module, create and return an llvm Function with the specified type. If there 955/// is something in the module with the specified name, return it potentially 956/// bitcasted to the right type. 957/// 958/// If D is non-null, it specifies a decl that correspond to this. This is used 959/// to set the attributes on the function when it is first created. 960llvm::Constant * 961CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 962 llvm::Type *Ty, 963 GlobalDecl D, bool ForVTable, 964 llvm::Attributes ExtraAttrs) { 965 // Lookup the entry, lazily creating it if necessary. 966 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 967 if (Entry) { 968 if (WeakRefReferences.count(Entry)) { 969 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 970 if (FD && !FD->hasAttr<WeakAttr>()) 971 Entry->setLinkage(llvm::Function::ExternalLinkage); 972 973 WeakRefReferences.erase(Entry); 974 } 975 976 if (Entry->getType()->getElementType() == Ty) 977 return Entry; 978 979 // Make sure the result is of the correct type. 980 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 981 } 982 983 // This function doesn't have a complete type (for example, the return 984 // type is an incomplete struct). Use a fake type instead, and make 985 // sure not to try to set attributes. 986 bool IsIncompleteFunction = false; 987 988 llvm::FunctionType *FTy; 989 if (isa<llvm::FunctionType>(Ty)) { 990 FTy = cast<llvm::FunctionType>(Ty); 991 } else { 992 FTy = llvm::FunctionType::get(VoidTy, false); 993 IsIncompleteFunction = true; 994 } 995 996 llvm::Function *F = llvm::Function::Create(FTy, 997 llvm::Function::ExternalLinkage, 998 MangledName, &getModule()); 999 assert(F->getName() == MangledName && "name was uniqued!"); 1000 if (D.getDecl()) 1001 SetFunctionAttributes(D, F, IsIncompleteFunction); 1002 if (ExtraAttrs != llvm::Attribute::None) 1003 F->addFnAttr(ExtraAttrs); 1004 1005 // This is the first use or definition of a mangled name. If there is a 1006 // deferred decl with this name, remember that we need to emit it at the end 1007 // of the file. 1008 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1009 if (DDI != DeferredDecls.end()) { 1010 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1011 // list, and remove it from DeferredDecls (since we don't need it anymore). 1012 DeferredDeclsToEmit.push_back(DDI->second); 1013 DeferredDecls.erase(DDI); 1014 1015 // Otherwise, there are cases we have to worry about where we're 1016 // using a declaration for which we must emit a definition but where 1017 // we might not find a top-level definition: 1018 // - member functions defined inline in their classes 1019 // - friend functions defined inline in some class 1020 // - special member functions with implicit definitions 1021 // If we ever change our AST traversal to walk into class methods, 1022 // this will be unnecessary. 1023 // 1024 // We also don't emit a definition for a function if it's going to be an entry 1025 // in a vtable, unless it's already marked as used. 1026 } else if (getLangOptions().CPlusPlus && D.getDecl()) { 1027 // Look for a declaration that's lexically in a record. 1028 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); 1029 do { 1030 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 1031 if (FD->isImplicit() && !ForVTable) { 1032 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 1033 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1034 break; 1035 } else if (FD->doesThisDeclarationHaveABody()) { 1036 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1037 break; 1038 } 1039 } 1040 FD = FD->getPreviousDeclaration(); 1041 } while (FD); 1042 } 1043 1044 // Make sure the result is of the requested type. 1045 if (!IsIncompleteFunction) { 1046 assert(F->getType()->getElementType() == Ty); 1047 return F; 1048 } 1049 1050 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1051 return llvm::ConstantExpr::getBitCast(F, PTy); 1052} 1053 1054/// GetAddrOfFunction - Return the address of the given function. If Ty is 1055/// non-null, then this function will use the specified type if it has to 1056/// create it (this occurs when we see a definition of the function). 1057llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 1058 llvm::Type *Ty, 1059 bool ForVTable) { 1060 // If there was no specific requested type, just convert it now. 1061 if (!Ty) 1062 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 1063 1064 StringRef MangledName = getMangledName(GD); 1065 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 1066} 1067 1068/// CreateRuntimeFunction - Create a new runtime function with the specified 1069/// type and name. 1070llvm::Constant * 1071CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 1072 StringRef Name, 1073 llvm::Attributes ExtraAttrs) { 1074 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 1075 ExtraAttrs); 1076} 1077 1078static bool DeclIsConstantGlobal(ASTContext &Context, const VarDecl *D, 1079 bool ConstantInit) { 1080 if (!D->getType().isConstant(Context) && !D->getType()->isReferenceType()) 1081 return false; 1082 1083 if (Context.getLangOptions().CPlusPlus) { 1084 if (const RecordType *Record 1085 = Context.getBaseElementType(D->getType())->getAs<RecordType>()) 1086 return ConstantInit && 1087 cast<CXXRecordDecl>(Record->getDecl())->isPOD() && 1088 !cast<CXXRecordDecl>(Record->getDecl())->hasMutableFields(); 1089 } 1090 1091 return true; 1092} 1093 1094/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1095/// create and return an llvm GlobalVariable with the specified type. If there 1096/// is something in the module with the specified name, return it potentially 1097/// bitcasted to the right type. 1098/// 1099/// If D is non-null, it specifies a decl that correspond to this. This is used 1100/// to set the attributes on the global when it is first created. 1101llvm::Constant * 1102CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1103 llvm::PointerType *Ty, 1104 const VarDecl *D, 1105 bool UnnamedAddr) { 1106 // Lookup the entry, lazily creating it if necessary. 1107 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1108 if (Entry) { 1109 if (WeakRefReferences.count(Entry)) { 1110 if (D && !D->hasAttr<WeakAttr>()) 1111 Entry->setLinkage(llvm::Function::ExternalLinkage); 1112 1113 WeakRefReferences.erase(Entry); 1114 } 1115 1116 if (UnnamedAddr) 1117 Entry->setUnnamedAddr(true); 1118 1119 if (Entry->getType() == Ty) 1120 return Entry; 1121 1122 // Make sure the result is of the correct type. 1123 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1124 } 1125 1126 // This is the first use or definition of a mangled name. If there is a 1127 // deferred decl with this name, remember that we need to emit it at the end 1128 // of the file. 1129 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1130 if (DDI != DeferredDecls.end()) { 1131 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1132 // list, and remove it from DeferredDecls (since we don't need it anymore). 1133 DeferredDeclsToEmit.push_back(DDI->second); 1134 DeferredDecls.erase(DDI); 1135 } 1136 1137 llvm::GlobalVariable *GV = 1138 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1139 llvm::GlobalValue::ExternalLinkage, 1140 0, MangledName, 0, 1141 false, Ty->getAddressSpace()); 1142 1143 // Handle things which are present even on external declarations. 1144 if (D) { 1145 // FIXME: This code is overly simple and should be merged with other global 1146 // handling. 1147 GV->setConstant(DeclIsConstantGlobal(Context, D, false)); 1148 1149 // Set linkage and visibility in case we never see a definition. 1150 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 1151 if (LV.linkage() != ExternalLinkage) { 1152 // Don't set internal linkage on declarations. 1153 } else { 1154 if (D->hasAttr<DLLImportAttr>()) 1155 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1156 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1157 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1158 1159 // Set visibility on a declaration only if it's explicit. 1160 if (LV.visibilityExplicit()) 1161 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 1162 } 1163 1164 GV->setThreadLocal(D->isThreadSpecified()); 1165 } 1166 1167 return GV; 1168} 1169 1170 1171llvm::GlobalVariable * 1172CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1173 llvm::Type *Ty, 1174 llvm::GlobalValue::LinkageTypes Linkage) { 1175 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1176 llvm::GlobalVariable *OldGV = 0; 1177 1178 1179 if (GV) { 1180 // Check if the variable has the right type. 1181 if (GV->getType()->getElementType() == Ty) 1182 return GV; 1183 1184 // Because C++ name mangling, the only way we can end up with an already 1185 // existing global with the same name is if it has been declared extern "C". 1186 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1187 OldGV = GV; 1188 } 1189 1190 // Create a new variable. 1191 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1192 Linkage, 0, Name); 1193 1194 if (OldGV) { 1195 // Replace occurrences of the old variable if needed. 1196 GV->takeName(OldGV); 1197 1198 if (!OldGV->use_empty()) { 1199 llvm::Constant *NewPtrForOldDecl = 1200 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1201 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1202 } 1203 1204 OldGV->eraseFromParent(); 1205 } 1206 1207 return GV; 1208} 1209 1210/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1211/// given global variable. If Ty is non-null and if the global doesn't exist, 1212/// then it will be greated with the specified type instead of whatever the 1213/// normal requested type would be. 1214llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1215 llvm::Type *Ty) { 1216 assert(D->hasGlobalStorage() && "Not a global variable"); 1217 QualType ASTTy = D->getType(); 1218 if (Ty == 0) 1219 Ty = getTypes().ConvertTypeForMem(ASTTy); 1220 1221 llvm::PointerType *PTy = 1222 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1223 1224 StringRef MangledName = getMangledName(D); 1225 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1226} 1227 1228/// CreateRuntimeVariable - Create a new runtime global variable with the 1229/// specified type and name. 1230llvm::Constant * 1231CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1232 StringRef Name) { 1233 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1234 true); 1235} 1236 1237void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1238 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1239 1240 if (MayDeferGeneration(D)) { 1241 // If we have not seen a reference to this variable yet, place it 1242 // into the deferred declarations table to be emitted if needed 1243 // later. 1244 StringRef MangledName = getMangledName(D); 1245 if (!GetGlobalValue(MangledName)) { 1246 DeferredDecls[MangledName] = D; 1247 return; 1248 } 1249 } 1250 1251 // The tentative definition is the only definition. 1252 EmitGlobalVarDefinition(D); 1253} 1254 1255void CodeGenModule::EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired) { 1256 if (DefinitionRequired) 1257 getVTables().GenerateClassData(getVTableLinkage(Class), Class); 1258} 1259 1260llvm::GlobalVariable::LinkageTypes 1261CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) { 1262 if (RD->getLinkage() != ExternalLinkage) 1263 return llvm::GlobalVariable::InternalLinkage; 1264 1265 if (const CXXMethodDecl *KeyFunction 1266 = RD->getASTContext().getKeyFunction(RD)) { 1267 // If this class has a key function, use that to determine the linkage of 1268 // the vtable. 1269 const FunctionDecl *Def = 0; 1270 if (KeyFunction->hasBody(Def)) 1271 KeyFunction = cast<CXXMethodDecl>(Def); 1272 1273 switch (KeyFunction->getTemplateSpecializationKind()) { 1274 case TSK_Undeclared: 1275 case TSK_ExplicitSpecialization: 1276 // When compiling with optimizations turned on, we emit all vtables, 1277 // even if the key function is not defined in the current translation 1278 // unit. If this is the case, use available_externally linkage. 1279 if (!Def && CodeGenOpts.OptimizationLevel) 1280 return llvm::GlobalVariable::AvailableExternallyLinkage; 1281 1282 if (KeyFunction->isInlined()) 1283 return !Context.getLangOptions().AppleKext ? 1284 llvm::GlobalVariable::LinkOnceODRLinkage : 1285 llvm::Function::InternalLinkage; 1286 1287 return llvm::GlobalVariable::ExternalLinkage; 1288 1289 case TSK_ImplicitInstantiation: 1290 return !Context.getLangOptions().AppleKext ? 1291 llvm::GlobalVariable::LinkOnceODRLinkage : 1292 llvm::Function::InternalLinkage; 1293 1294 case TSK_ExplicitInstantiationDefinition: 1295 return !Context.getLangOptions().AppleKext ? 1296 llvm::GlobalVariable::WeakODRLinkage : 1297 llvm::Function::InternalLinkage; 1298 1299 case TSK_ExplicitInstantiationDeclaration: 1300 // FIXME: Use available_externally linkage. However, this currently 1301 // breaks LLVM's build due to undefined symbols. 1302 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1303 return !Context.getLangOptions().AppleKext ? 1304 llvm::GlobalVariable::LinkOnceODRLinkage : 1305 llvm::Function::InternalLinkage; 1306 } 1307 } 1308 1309 if (Context.getLangOptions().AppleKext) 1310 return llvm::Function::InternalLinkage; 1311 1312 switch (RD->getTemplateSpecializationKind()) { 1313 case TSK_Undeclared: 1314 case TSK_ExplicitSpecialization: 1315 case TSK_ImplicitInstantiation: 1316 // FIXME: Use available_externally linkage. However, this currently 1317 // breaks LLVM's build due to undefined symbols. 1318 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1319 case TSK_ExplicitInstantiationDeclaration: 1320 return llvm::GlobalVariable::LinkOnceODRLinkage; 1321 1322 case TSK_ExplicitInstantiationDefinition: 1323 return llvm::GlobalVariable::WeakODRLinkage; 1324 } 1325 1326 // Silence GCC warning. 1327 return llvm::GlobalVariable::LinkOnceODRLinkage; 1328} 1329 1330CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1331 return Context.toCharUnitsFromBits( 1332 TheTargetData.getTypeStoreSizeInBits(Ty)); 1333} 1334 1335void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1336 llvm::Constant *Init = 0; 1337 QualType ASTTy = D->getType(); 1338 bool NonConstInit = false; 1339 1340 const Expr *InitExpr = D->getAnyInitializer(); 1341 1342 if (!InitExpr) { 1343 // This is a tentative definition; tentative definitions are 1344 // implicitly initialized with { 0 }. 1345 // 1346 // Note that tentative definitions are only emitted at the end of 1347 // a translation unit, so they should never have incomplete 1348 // type. In addition, EmitTentativeDefinition makes sure that we 1349 // never attempt to emit a tentative definition if a real one 1350 // exists. A use may still exists, however, so we still may need 1351 // to do a RAUW. 1352 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1353 Init = EmitNullConstant(D->getType()); 1354 } else { 1355 Init = EmitConstantExpr(InitExpr, D->getType()); 1356 if (!Init) { 1357 QualType T = InitExpr->getType(); 1358 if (D->getType()->isReferenceType()) 1359 T = D->getType(); 1360 1361 if (getLangOptions().CPlusPlus) { 1362 Init = EmitNullConstant(T); 1363 NonConstInit = true; 1364 } else { 1365 ErrorUnsupported(D, "static initializer"); 1366 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1367 } 1368 } else { 1369 // We don't need an initializer, so remove the entry for the delayed 1370 // initializer position (just in case this entry was delayed). 1371 if (getLangOptions().CPlusPlus) 1372 DelayedCXXInitPosition.erase(D); 1373 } 1374 } 1375 1376 llvm::Type* InitType = Init->getType(); 1377 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1378 1379 // Strip off a bitcast if we got one back. 1380 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1381 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1382 // all zero index gep. 1383 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1384 Entry = CE->getOperand(0); 1385 } 1386 1387 // Entry is now either a Function or GlobalVariable. 1388 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1389 1390 // We have a definition after a declaration with the wrong type. 1391 // We must make a new GlobalVariable* and update everything that used OldGV 1392 // (a declaration or tentative definition) with the new GlobalVariable* 1393 // (which will be a definition). 1394 // 1395 // This happens if there is a prototype for a global (e.g. 1396 // "extern int x[];") and then a definition of a different type (e.g. 1397 // "int x[10];"). This also happens when an initializer has a different type 1398 // from the type of the global (this happens with unions). 1399 if (GV == 0 || 1400 GV->getType()->getElementType() != InitType || 1401 GV->getType()->getAddressSpace() != 1402 getContext().getTargetAddressSpace(ASTTy)) { 1403 1404 // Move the old entry aside so that we'll create a new one. 1405 Entry->setName(StringRef()); 1406 1407 // Make a new global with the correct type, this is now guaranteed to work. 1408 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1409 1410 // Replace all uses of the old global with the new global 1411 llvm::Constant *NewPtrForOldDecl = 1412 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1413 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1414 1415 // Erase the old global, since it is no longer used. 1416 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1417 } 1418 1419 if (D->hasAttr<AnnotateAttr>()) 1420 AddGlobalAnnotations(D, GV); 1421 1422 GV->setInitializer(Init); 1423 1424 // If it is safe to mark the global 'constant', do so now. 1425 GV->setConstant(false); 1426 if (!NonConstInit && DeclIsConstantGlobal(Context, D, true)) 1427 GV->setConstant(true); 1428 1429 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1430 1431 // Set the llvm linkage type as appropriate. 1432 llvm::GlobalValue::LinkageTypes Linkage = 1433 GetLLVMLinkageVarDefinition(D, GV); 1434 GV->setLinkage(Linkage); 1435 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1436 // common vars aren't constant even if declared const. 1437 GV->setConstant(false); 1438 1439 SetCommonAttributes(D, GV); 1440 1441 // Emit the initializer function if necessary. 1442 if (NonConstInit) 1443 EmitCXXGlobalVarDeclInitFunc(D, GV); 1444 1445 // Emit global variable debug information. 1446 if (CGDebugInfo *DI = getModuleDebugInfo()) 1447 DI->EmitGlobalVariable(GV, D); 1448} 1449 1450llvm::GlobalValue::LinkageTypes 1451CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, 1452 llvm::GlobalVariable *GV) { 1453 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1454 if (Linkage == GVA_Internal) 1455 return llvm::Function::InternalLinkage; 1456 else if (D->hasAttr<DLLImportAttr>()) 1457 return llvm::Function::DLLImportLinkage; 1458 else if (D->hasAttr<DLLExportAttr>()) 1459 return llvm::Function::DLLExportLinkage; 1460 else if (D->hasAttr<WeakAttr>()) { 1461 if (GV->isConstant()) 1462 return llvm::GlobalVariable::WeakODRLinkage; 1463 else 1464 return llvm::GlobalVariable::WeakAnyLinkage; 1465 } else if (Linkage == GVA_TemplateInstantiation || 1466 Linkage == GVA_ExplicitTemplateInstantiation) 1467 return llvm::GlobalVariable::WeakODRLinkage; 1468 else if (!getLangOptions().CPlusPlus && 1469 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1470 D->getAttr<CommonAttr>()) && 1471 !D->hasExternalStorage() && !D->getInit() && 1472 !D->getAttr<SectionAttr>() && !D->isThreadSpecified() && 1473 !D->getAttr<WeakImportAttr>()) { 1474 // Thread local vars aren't considered common linkage. 1475 return llvm::GlobalVariable::CommonLinkage; 1476 } 1477 return llvm::GlobalVariable::ExternalLinkage; 1478} 1479 1480/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1481/// implement a function with no prototype, e.g. "int foo() {}". If there are 1482/// existing call uses of the old function in the module, this adjusts them to 1483/// call the new function directly. 1484/// 1485/// This is not just a cleanup: the always_inline pass requires direct calls to 1486/// functions to be able to inline them. If there is a bitcast in the way, it 1487/// won't inline them. Instcombine normally deletes these calls, but it isn't 1488/// run at -O0. 1489static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1490 llvm::Function *NewFn) { 1491 // If we're redefining a global as a function, don't transform it. 1492 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1493 if (OldFn == 0) return; 1494 1495 llvm::Type *NewRetTy = NewFn->getReturnType(); 1496 SmallVector<llvm::Value*, 4> ArgList; 1497 1498 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1499 UI != E; ) { 1500 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1501 llvm::Value::use_iterator I = UI++; // Increment before the CI is erased. 1502 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*I); 1503 if (!CI) continue; // FIXME: when we allow Invoke, just do CallSite CS(*I) 1504 llvm::CallSite CS(CI); 1505 if (!CI || !CS.isCallee(I)) continue; 1506 1507 // If the return types don't match exactly, and if the call isn't dead, then 1508 // we can't transform this call. 1509 if (CI->getType() != NewRetTy && !CI->use_empty()) 1510 continue; 1511 1512 // Get the attribute list. 1513 llvm::SmallVector<llvm::AttributeWithIndex, 8> AttrVec; 1514 llvm::AttrListPtr AttrList = CI->getAttributes(); 1515 1516 // Get any return attributes. 1517 llvm::Attributes RAttrs = AttrList.getRetAttributes(); 1518 1519 // Add the return attributes. 1520 if (RAttrs) 1521 AttrVec.push_back(llvm::AttributeWithIndex::get(0, RAttrs)); 1522 1523 // If the function was passed too few arguments, don't transform. If extra 1524 // arguments were passed, we silently drop them. If any of the types 1525 // mismatch, we don't transform. 1526 unsigned ArgNo = 0; 1527 bool DontTransform = false; 1528 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1529 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1530 if (CS.arg_size() == ArgNo || 1531 CS.getArgument(ArgNo)->getType() != AI->getType()) { 1532 DontTransform = true; 1533 break; 1534 } 1535 1536 // Add any parameter attributes. 1537 if (llvm::Attributes PAttrs = AttrList.getParamAttributes(ArgNo + 1)) 1538 AttrVec.push_back(llvm::AttributeWithIndex::get(ArgNo + 1, PAttrs)); 1539 } 1540 if (DontTransform) 1541 continue; 1542 1543 if (llvm::Attributes FnAttrs = AttrList.getFnAttributes()) 1544 AttrVec.push_back(llvm::AttributeWithIndex::get(~0, FnAttrs)); 1545 1546 // Okay, we can transform this. Create the new call instruction and copy 1547 // over the required information. 1548 ArgList.append(CS.arg_begin(), CS.arg_begin() + ArgNo); 1549 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList, "", CI); 1550 ArgList.clear(); 1551 if (!NewCall->getType()->isVoidTy()) 1552 NewCall->takeName(CI); 1553 NewCall->setAttributes(llvm::AttrListPtr::get(AttrVec.begin(), 1554 AttrVec.end())); 1555 NewCall->setCallingConv(CI->getCallingConv()); 1556 1557 // Finally, remove the old call, replacing any uses with the new one. 1558 if (!CI->use_empty()) 1559 CI->replaceAllUsesWith(NewCall); 1560 1561 // Copy debug location attached to CI. 1562 if (!CI->getDebugLoc().isUnknown()) 1563 NewCall->setDebugLoc(CI->getDebugLoc()); 1564 CI->eraseFromParent(); 1565 } 1566} 1567 1568 1569void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1570 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1571 1572 // Compute the function info and LLVM type. 1573 const CGFunctionInfo &FI = getTypes().getFunctionInfo(GD); 1574 bool variadic = false; 1575 if (const FunctionProtoType *fpt = D->getType()->getAs<FunctionProtoType>()) 1576 variadic = fpt->isVariadic(); 1577 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI, variadic); 1578 1579 // Get or create the prototype for the function. 1580 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1581 1582 // Strip off a bitcast if we got one back. 1583 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1584 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1585 Entry = CE->getOperand(0); 1586 } 1587 1588 1589 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1590 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1591 1592 // If the types mismatch then we have to rewrite the definition. 1593 assert(OldFn->isDeclaration() && 1594 "Shouldn't replace non-declaration"); 1595 1596 // F is the Function* for the one with the wrong type, we must make a new 1597 // Function* and update everything that used F (a declaration) with the new 1598 // Function* (which will be a definition). 1599 // 1600 // This happens if there is a prototype for a function 1601 // (e.g. "int f()") and then a definition of a different type 1602 // (e.g. "int f(int x)"). Move the old function aside so that it 1603 // doesn't interfere with GetAddrOfFunction. 1604 OldFn->setName(StringRef()); 1605 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1606 1607 // If this is an implementation of a function without a prototype, try to 1608 // replace any existing uses of the function (which may be calls) with uses 1609 // of the new function 1610 if (D->getType()->isFunctionNoProtoType()) { 1611 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1612 OldFn->removeDeadConstantUsers(); 1613 } 1614 1615 // Replace uses of F with the Function we will endow with a body. 1616 if (!Entry->use_empty()) { 1617 llvm::Constant *NewPtrForOldDecl = 1618 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1619 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1620 } 1621 1622 // Ok, delete the old function now, which is dead. 1623 OldFn->eraseFromParent(); 1624 1625 Entry = NewFn; 1626 } 1627 1628 // We need to set linkage and visibility on the function before 1629 // generating code for it because various parts of IR generation 1630 // want to propagate this information down (e.g. to local static 1631 // declarations). 1632 llvm::Function *Fn = cast<llvm::Function>(Entry); 1633 setFunctionLinkage(D, Fn); 1634 1635 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 1636 setGlobalVisibility(Fn, D); 1637 1638 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 1639 1640 SetFunctionDefinitionAttributes(D, Fn); 1641 SetLLVMFunctionAttributesForDefinition(D, Fn); 1642 1643 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1644 AddGlobalCtor(Fn, CA->getPriority()); 1645 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1646 AddGlobalDtor(Fn, DA->getPriority()); 1647 if (D->hasAttr<AnnotateAttr>()) 1648 AddGlobalAnnotations(D, Fn); 1649} 1650 1651void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 1652 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1653 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1654 assert(AA && "Not an alias?"); 1655 1656 StringRef MangledName = getMangledName(GD); 1657 1658 // If there is a definition in the module, then it wins over the alias. 1659 // This is dubious, but allow it to be safe. Just ignore the alias. 1660 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1661 if (Entry && !Entry->isDeclaration()) 1662 return; 1663 1664 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1665 1666 // Create a reference to the named value. This ensures that it is emitted 1667 // if a deferred decl. 1668 llvm::Constant *Aliasee; 1669 if (isa<llvm::FunctionType>(DeclTy)) 1670 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 1671 /*ForVTable=*/false); 1672 else 1673 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1674 llvm::PointerType::getUnqual(DeclTy), 0); 1675 1676 // Create the new alias itself, but don't set a name yet. 1677 llvm::GlobalValue *GA = 1678 new llvm::GlobalAlias(Aliasee->getType(), 1679 llvm::Function::ExternalLinkage, 1680 "", Aliasee, &getModule()); 1681 1682 if (Entry) { 1683 assert(Entry->isDeclaration()); 1684 1685 // If there is a declaration in the module, then we had an extern followed 1686 // by the alias, as in: 1687 // extern int test6(); 1688 // ... 1689 // int test6() __attribute__((alias("test7"))); 1690 // 1691 // Remove it and replace uses of it with the alias. 1692 GA->takeName(Entry); 1693 1694 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1695 Entry->getType())); 1696 Entry->eraseFromParent(); 1697 } else { 1698 GA->setName(MangledName); 1699 } 1700 1701 // Set attributes which are particular to an alias; this is a 1702 // specialization of the attributes which may be set on a global 1703 // variable/function. 1704 if (D->hasAttr<DLLExportAttr>()) { 1705 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1706 // The dllexport attribute is ignored for undefined symbols. 1707 if (FD->hasBody()) 1708 GA->setLinkage(llvm::Function::DLLExportLinkage); 1709 } else { 1710 GA->setLinkage(llvm::Function::DLLExportLinkage); 1711 } 1712 } else if (D->hasAttr<WeakAttr>() || 1713 D->hasAttr<WeakRefAttr>() || 1714 D->isWeakImported()) { 1715 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1716 } 1717 1718 SetCommonAttributes(D, GA); 1719} 1720 1721llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 1722 ArrayRef<llvm::Type*> Tys) { 1723 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 1724 Tys); 1725} 1726 1727static llvm::StringMapEntry<llvm::Constant*> & 1728GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1729 const StringLiteral *Literal, 1730 bool TargetIsLSB, 1731 bool &IsUTF16, 1732 unsigned &StringLength) { 1733 StringRef String = Literal->getString(); 1734 unsigned NumBytes = String.size(); 1735 1736 // Check for simple case. 1737 if (!Literal->containsNonAsciiOrNull()) { 1738 StringLength = NumBytes; 1739 return Map.GetOrCreateValue(String); 1740 } 1741 1742 // Otherwise, convert the UTF8 literals into a byte string. 1743 SmallVector<UTF16, 128> ToBuf(NumBytes); 1744 const UTF8 *FromPtr = (UTF8 *)String.data(); 1745 UTF16 *ToPtr = &ToBuf[0]; 1746 1747 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 1748 &ToPtr, ToPtr + NumBytes, 1749 strictConversion); 1750 1751 // ConvertUTF8toUTF16 returns the length in ToPtr. 1752 StringLength = ToPtr - &ToBuf[0]; 1753 1754 // Render the UTF-16 string into a byte array and convert to the target byte 1755 // order. 1756 // 1757 // FIXME: This isn't something we should need to do here. 1758 llvm::SmallString<128> AsBytes; 1759 AsBytes.reserve(StringLength * 2); 1760 for (unsigned i = 0; i != StringLength; ++i) { 1761 unsigned short Val = ToBuf[i]; 1762 if (TargetIsLSB) { 1763 AsBytes.push_back(Val & 0xFF); 1764 AsBytes.push_back(Val >> 8); 1765 } else { 1766 AsBytes.push_back(Val >> 8); 1767 AsBytes.push_back(Val & 0xFF); 1768 } 1769 } 1770 // Append one extra null character, the second is automatically added by our 1771 // caller. 1772 AsBytes.push_back(0); 1773 1774 IsUTF16 = true; 1775 return Map.GetOrCreateValue(StringRef(AsBytes.data(), AsBytes.size())); 1776} 1777 1778static llvm::StringMapEntry<llvm::Constant*> & 1779GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1780 const StringLiteral *Literal, 1781 unsigned &StringLength) 1782{ 1783 StringRef String = Literal->getString(); 1784 StringLength = String.size(); 1785 return Map.GetOrCreateValue(String); 1786} 1787 1788llvm::Constant * 1789CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 1790 unsigned StringLength = 0; 1791 bool isUTF16 = false; 1792 llvm::StringMapEntry<llvm::Constant*> &Entry = 1793 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1794 getTargetData().isLittleEndian(), 1795 isUTF16, StringLength); 1796 1797 if (llvm::Constant *C = Entry.getValue()) 1798 return C; 1799 1800 llvm::Constant *Zero = 1801 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1802 llvm::Constant *Zeros[] = { Zero, Zero }; 1803 1804 // If we don't already have it, get __CFConstantStringClassReference. 1805 if (!CFConstantStringClassRef) { 1806 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1807 Ty = llvm::ArrayType::get(Ty, 0); 1808 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1809 "__CFConstantStringClassReference"); 1810 // Decay array -> ptr 1811 CFConstantStringClassRef = 1812 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1813 } 1814 1815 QualType CFTy = getContext().getCFConstantStringType(); 1816 1817 llvm::StructType *STy = 1818 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1819 1820 std::vector<llvm::Constant*> Fields(4); 1821 1822 // Class pointer. 1823 Fields[0] = CFConstantStringClassRef; 1824 1825 // Flags. 1826 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1827 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 1828 llvm::ConstantInt::get(Ty, 0x07C8); 1829 1830 // String pointer. 1831 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1832 1833 llvm::GlobalValue::LinkageTypes Linkage; 1834 bool isConstant; 1835 if (isUTF16) { 1836 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1837 Linkage = llvm::GlobalValue::InternalLinkage; 1838 // Note: -fwritable-strings doesn't make unicode CFStrings writable, but 1839 // does make plain ascii ones writable. 1840 isConstant = true; 1841 } else { 1842 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 1843 // when using private linkage. It is not clear if this is a bug in ld 1844 // or a reasonable new restriction. 1845 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 1846 isConstant = !Features.WritableStrings; 1847 } 1848 1849 llvm::GlobalVariable *GV = 1850 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1851 ".str"); 1852 GV->setUnnamedAddr(true); 1853 if (isUTF16) { 1854 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 1855 GV->setAlignment(Align.getQuantity()); 1856 } else { 1857 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 1858 GV->setAlignment(Align.getQuantity()); 1859 } 1860 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1861 1862 // String length. 1863 Ty = getTypes().ConvertType(getContext().LongTy); 1864 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 1865 1866 // The struct. 1867 C = llvm::ConstantStruct::get(STy, Fields); 1868 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1869 llvm::GlobalVariable::PrivateLinkage, C, 1870 "_unnamed_cfstring_"); 1871 if (const char *Sect = getContext().getTargetInfo().getCFStringSection()) 1872 GV->setSection(Sect); 1873 Entry.setValue(GV); 1874 1875 return GV; 1876} 1877 1878static RecordDecl * 1879CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 1880 DeclContext *DC, IdentifierInfo *Id) { 1881 SourceLocation Loc; 1882 if (Ctx.getLangOptions().CPlusPlus) 1883 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 1884 else 1885 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 1886} 1887 1888llvm::Constant * 1889CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 1890 unsigned StringLength = 0; 1891 llvm::StringMapEntry<llvm::Constant*> &Entry = 1892 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 1893 1894 if (llvm::Constant *C = Entry.getValue()) 1895 return C; 1896 1897 llvm::Constant *Zero = 1898 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1899 llvm::Constant *Zeros[] = { Zero, Zero }; 1900 1901 // If we don't already have it, get _NSConstantStringClassReference. 1902 if (!ConstantStringClassRef) { 1903 std::string StringClass(getLangOptions().ObjCConstantStringClass); 1904 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1905 llvm::Constant *GV; 1906 if (Features.ObjCNonFragileABI) { 1907 std::string str = 1908 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 1909 : "OBJC_CLASS_$_" + StringClass; 1910 GV = getObjCRuntime().GetClassGlobal(str); 1911 // Make sure the result is of the correct type. 1912 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1913 ConstantStringClassRef = 1914 llvm::ConstantExpr::getBitCast(GV, PTy); 1915 } else { 1916 std::string str = 1917 StringClass.empty() ? "_NSConstantStringClassReference" 1918 : "_" + StringClass + "ClassReference"; 1919 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 1920 GV = CreateRuntimeVariable(PTy, str); 1921 // Decay array -> ptr 1922 ConstantStringClassRef = 1923 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1924 } 1925 } 1926 1927 if (!NSConstantStringType) { 1928 // Construct the type for a constant NSString. 1929 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 1930 Context.getTranslationUnitDecl(), 1931 &Context.Idents.get("__builtin_NSString")); 1932 D->startDefinition(); 1933 1934 QualType FieldTypes[3]; 1935 1936 // const int *isa; 1937 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 1938 // const char *str; 1939 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 1940 // unsigned int length; 1941 FieldTypes[2] = Context.UnsignedIntTy; 1942 1943 // Create fields 1944 for (unsigned i = 0; i < 3; ++i) { 1945 FieldDecl *Field = FieldDecl::Create(Context, D, 1946 SourceLocation(), 1947 SourceLocation(), 0, 1948 FieldTypes[i], /*TInfo=*/0, 1949 /*BitWidth=*/0, 1950 /*Mutable=*/false, 1951 /*HasInit=*/false); 1952 Field->setAccess(AS_public); 1953 D->addDecl(Field); 1954 } 1955 1956 D->completeDefinition(); 1957 QualType NSTy = Context.getTagDeclType(D); 1958 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 1959 } 1960 1961 std::vector<llvm::Constant*> Fields(3); 1962 1963 // Class pointer. 1964 Fields[0] = ConstantStringClassRef; 1965 1966 // String pointer. 1967 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1968 1969 llvm::GlobalValue::LinkageTypes Linkage; 1970 bool isConstant; 1971 Linkage = llvm::GlobalValue::PrivateLinkage; 1972 isConstant = !Features.WritableStrings; 1973 1974 llvm::GlobalVariable *GV = 1975 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1976 ".str"); 1977 GV->setUnnamedAddr(true); 1978 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 1979 GV->setAlignment(Align.getQuantity()); 1980 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1981 1982 // String length. 1983 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1984 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 1985 1986 // The struct. 1987 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 1988 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1989 llvm::GlobalVariable::PrivateLinkage, C, 1990 "_unnamed_nsstring_"); 1991 // FIXME. Fix section. 1992 if (const char *Sect = 1993 Features.ObjCNonFragileABI 1994 ? getContext().getTargetInfo().getNSStringNonFragileABISection() 1995 : getContext().getTargetInfo().getNSStringSection()) 1996 GV->setSection(Sect); 1997 Entry.setValue(GV); 1998 1999 return GV; 2000} 2001 2002QualType CodeGenModule::getObjCFastEnumerationStateType() { 2003 if (ObjCFastEnumerationStateType.isNull()) { 2004 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2005 Context.getTranslationUnitDecl(), 2006 &Context.Idents.get("__objcFastEnumerationState")); 2007 D->startDefinition(); 2008 2009 QualType FieldTypes[] = { 2010 Context.UnsignedLongTy, 2011 Context.getPointerType(Context.getObjCIdType()), 2012 Context.getPointerType(Context.UnsignedLongTy), 2013 Context.getConstantArrayType(Context.UnsignedLongTy, 2014 llvm::APInt(32, 5), ArrayType::Normal, 0) 2015 }; 2016 2017 for (size_t i = 0; i < 4; ++i) { 2018 FieldDecl *Field = FieldDecl::Create(Context, 2019 D, 2020 SourceLocation(), 2021 SourceLocation(), 0, 2022 FieldTypes[i], /*TInfo=*/0, 2023 /*BitWidth=*/0, 2024 /*Mutable=*/false, 2025 /*HasInit=*/false); 2026 Field->setAccess(AS_public); 2027 D->addDecl(Field); 2028 } 2029 2030 D->completeDefinition(); 2031 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 2032 } 2033 2034 return ObjCFastEnumerationStateType; 2035} 2036 2037/// GetStringForStringLiteral - Return the appropriate bytes for a 2038/// string literal, properly padded to match the literal type. 2039std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 2040 const ASTContext &Context = getContext(); 2041 const ConstantArrayType *CAT = 2042 Context.getAsConstantArrayType(E->getType()); 2043 assert(CAT && "String isn't pointer or array!"); 2044 2045 // Resize the string to the right size. 2046 uint64_t RealLen = CAT->getSize().getZExtValue(); 2047 2048 switch (E->getKind()) { 2049 case StringLiteral::Ascii: 2050 case StringLiteral::UTF8: 2051 break; 2052 case StringLiteral::Wide: 2053 RealLen *= Context.getTargetInfo().getWCharWidth() / Context.getCharWidth(); 2054 break; 2055 case StringLiteral::UTF16: 2056 RealLen *= Context.getTargetInfo().getChar16Width() / Context.getCharWidth(); 2057 break; 2058 case StringLiteral::UTF32: 2059 RealLen *= Context.getTargetInfo().getChar32Width() / Context.getCharWidth(); 2060 break; 2061 } 2062 2063 std::string Str = E->getString().str(); 2064 Str.resize(RealLen, '\0'); 2065 2066 return Str; 2067} 2068 2069/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 2070/// constant array for the given string literal. 2071llvm::Constant * 2072CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 2073 // FIXME: This can be more efficient. 2074 // FIXME: We shouldn't need to bitcast the constant in the wide string case. 2075 CharUnits Align = getContext().getTypeAlignInChars(S->getType()); 2076 llvm::Constant *C = GetAddrOfConstantString(GetStringForStringLiteral(S), 2077 /* GlobalName */ 0, 2078 Align.getQuantity()); 2079 if (S->isWide() || S->isUTF16() || S->isUTF32()) { 2080 llvm::Type *DestTy = 2081 llvm::PointerType::getUnqual(getTypes().ConvertType(S->getType())); 2082 C = llvm::ConstantExpr::getBitCast(C, DestTy); 2083 } 2084 return C; 2085} 2086 2087/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2088/// array for the given ObjCEncodeExpr node. 2089llvm::Constant * 2090CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2091 std::string Str; 2092 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2093 2094 return GetAddrOfConstantCString(Str); 2095} 2096 2097 2098/// GenerateWritableString -- Creates storage for a string literal. 2099static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2100 bool constant, 2101 CodeGenModule &CGM, 2102 const char *GlobalName, 2103 unsigned Alignment) { 2104 // Create Constant for this string literal. Don't add a '\0'. 2105 llvm::Constant *C = 2106 llvm::ConstantArray::get(CGM.getLLVMContext(), str, false); 2107 2108 // Create a global variable for this string 2109 llvm::GlobalVariable *GV = 2110 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 2111 llvm::GlobalValue::PrivateLinkage, 2112 C, GlobalName); 2113 GV->setAlignment(Alignment); 2114 GV->setUnnamedAddr(true); 2115 return GV; 2116} 2117 2118/// GetAddrOfConstantString - Returns a pointer to a character array 2119/// containing the literal. This contents are exactly that of the 2120/// given string, i.e. it will not be null terminated automatically; 2121/// see GetAddrOfConstantCString. Note that whether the result is 2122/// actually a pointer to an LLVM constant depends on 2123/// Feature.WriteableStrings. 2124/// 2125/// The result has pointer to array type. 2126llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2127 const char *GlobalName, 2128 unsigned Alignment) { 2129 bool IsConstant = !Features.WritableStrings; 2130 2131 // Get the default prefix if a name wasn't specified. 2132 if (!GlobalName) 2133 GlobalName = ".str"; 2134 2135 // Don't share any string literals if strings aren't constant. 2136 if (!IsConstant) 2137 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2138 2139 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2140 ConstantStringMap.GetOrCreateValue(Str); 2141 2142 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2143 if (Alignment > GV->getAlignment()) { 2144 GV->setAlignment(Alignment); 2145 } 2146 return GV; 2147 } 2148 2149 // Create a global variable for this. 2150 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, Alignment); 2151 Entry.setValue(GV); 2152 return GV; 2153} 2154 2155/// GetAddrOfConstantCString - Returns a pointer to a character 2156/// array containing the literal and a terminating '\0' 2157/// character. The result has pointer to array type. 2158llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2159 const char *GlobalName, 2160 unsigned Alignment) { 2161 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2162 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2163} 2164 2165/// EmitObjCPropertyImplementations - Emit information for synthesized 2166/// properties for an implementation. 2167void CodeGenModule::EmitObjCPropertyImplementations(const 2168 ObjCImplementationDecl *D) { 2169 for (ObjCImplementationDecl::propimpl_iterator 2170 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2171 ObjCPropertyImplDecl *PID = *i; 2172 2173 // Dynamic is just for type-checking. 2174 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2175 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2176 2177 // Determine which methods need to be implemented, some may have 2178 // been overridden. Note that ::isSynthesized is not the method 2179 // we want, that just indicates if the decl came from a 2180 // property. What we want to know is if the method is defined in 2181 // this implementation. 2182 if (!D->getInstanceMethod(PD->getGetterName())) 2183 CodeGenFunction(*this).GenerateObjCGetter( 2184 const_cast<ObjCImplementationDecl *>(D), PID); 2185 if (!PD->isReadOnly() && 2186 !D->getInstanceMethod(PD->getSetterName())) 2187 CodeGenFunction(*this).GenerateObjCSetter( 2188 const_cast<ObjCImplementationDecl *>(D), PID); 2189 } 2190 } 2191} 2192 2193static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2194 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2195 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2196 ivar; ivar = ivar->getNextIvar()) 2197 if (ivar->getType().isDestructedType()) 2198 return true; 2199 2200 return false; 2201} 2202 2203/// EmitObjCIvarInitializations - Emit information for ivar initialization 2204/// for an implementation. 2205void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2206 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2207 if (needsDestructMethod(D)) { 2208 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2209 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2210 ObjCMethodDecl *DTORMethod = 2211 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2212 cxxSelector, getContext().VoidTy, 0, D, 2213 /*isInstance=*/true, /*isVariadic=*/false, 2214 /*isSynthesized=*/true, /*isImplicitlyDeclared=*/true, 2215 /*isDefined=*/false, ObjCMethodDecl::Required); 2216 D->addInstanceMethod(DTORMethod); 2217 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2218 D->setHasCXXStructors(true); 2219 } 2220 2221 // If the implementation doesn't have any ivar initializers, we don't need 2222 // a .cxx_construct. 2223 if (D->getNumIvarInitializers() == 0) 2224 return; 2225 2226 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2227 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2228 // The constructor returns 'self'. 2229 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2230 D->getLocation(), 2231 D->getLocation(), 2232 cxxSelector, 2233 getContext().getObjCIdType(), 0, 2234 D, /*isInstance=*/true, 2235 /*isVariadic=*/false, 2236 /*isSynthesized=*/true, 2237 /*isImplicitlyDeclared=*/true, 2238 /*isDefined=*/false, 2239 ObjCMethodDecl::Required); 2240 D->addInstanceMethod(CTORMethod); 2241 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2242 D->setHasCXXStructors(true); 2243} 2244 2245/// EmitNamespace - Emit all declarations in a namespace. 2246void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2247 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2248 I != E; ++I) 2249 EmitTopLevelDecl(*I); 2250} 2251 2252// EmitLinkageSpec - Emit all declarations in a linkage spec. 2253void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2254 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2255 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2256 ErrorUnsupported(LSD, "linkage spec"); 2257 return; 2258 } 2259 2260 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2261 I != E; ++I) 2262 EmitTopLevelDecl(*I); 2263} 2264 2265/// EmitTopLevelDecl - Emit code for a single top level declaration. 2266void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2267 // If an error has occurred, stop code generation, but continue 2268 // parsing and semantic analysis (to ensure all warnings and errors 2269 // are emitted). 2270 if (Diags.hasErrorOccurred()) 2271 return; 2272 2273 // Ignore dependent declarations. 2274 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2275 return; 2276 2277 switch (D->getKind()) { 2278 case Decl::CXXConversion: 2279 case Decl::CXXMethod: 2280 case Decl::Function: 2281 // Skip function templates 2282 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2283 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2284 return; 2285 2286 EmitGlobal(cast<FunctionDecl>(D)); 2287 break; 2288 2289 case Decl::Var: 2290 EmitGlobal(cast<VarDecl>(D)); 2291 break; 2292 2293 // Indirect fields from global anonymous structs and unions can be 2294 // ignored; only the actual variable requires IR gen support. 2295 case Decl::IndirectField: 2296 break; 2297 2298 // C++ Decls 2299 case Decl::Namespace: 2300 EmitNamespace(cast<NamespaceDecl>(D)); 2301 break; 2302 // No code generation needed. 2303 case Decl::UsingShadow: 2304 case Decl::Using: 2305 case Decl::UsingDirective: 2306 case Decl::ClassTemplate: 2307 case Decl::FunctionTemplate: 2308 case Decl::TypeAliasTemplate: 2309 case Decl::NamespaceAlias: 2310 case Decl::Block: 2311 break; 2312 case Decl::CXXConstructor: 2313 // Skip function templates 2314 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2315 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2316 return; 2317 2318 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2319 break; 2320 case Decl::CXXDestructor: 2321 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2322 return; 2323 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2324 break; 2325 2326 case Decl::StaticAssert: 2327 // Nothing to do. 2328 break; 2329 2330 // Objective-C Decls 2331 2332 // Forward declarations, no (immediate) code generation. 2333 case Decl::ObjCClass: 2334 case Decl::ObjCForwardProtocol: 2335 case Decl::ObjCInterface: 2336 break; 2337 2338 case Decl::ObjCCategory: { 2339 ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D); 2340 if (CD->IsClassExtension() && CD->hasSynthBitfield()) 2341 Context.ResetObjCLayout(CD->getClassInterface()); 2342 break; 2343 } 2344 2345 case Decl::ObjCProtocol: 2346 ObjCRuntime->GenerateProtocol(cast<ObjCProtocolDecl>(D)); 2347 break; 2348 2349 case Decl::ObjCCategoryImpl: 2350 // Categories have properties but don't support synthesize so we 2351 // can ignore them here. 2352 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2353 break; 2354 2355 case Decl::ObjCImplementation: { 2356 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2357 if (Features.ObjCNonFragileABI2 && OMD->hasSynthBitfield()) 2358 Context.ResetObjCLayout(OMD->getClassInterface()); 2359 EmitObjCPropertyImplementations(OMD); 2360 EmitObjCIvarInitializations(OMD); 2361 ObjCRuntime->GenerateClass(OMD); 2362 break; 2363 } 2364 case Decl::ObjCMethod: { 2365 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 2366 // If this is not a prototype, emit the body. 2367 if (OMD->getBody()) 2368 CodeGenFunction(*this).GenerateObjCMethod(OMD); 2369 break; 2370 } 2371 case Decl::ObjCCompatibleAlias: 2372 // compatibility-alias is a directive and has no code gen. 2373 break; 2374 2375 case Decl::LinkageSpec: 2376 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 2377 break; 2378 2379 case Decl::FileScopeAsm: { 2380 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 2381 StringRef AsmString = AD->getAsmString()->getString(); 2382 2383 const std::string &S = getModule().getModuleInlineAsm(); 2384 if (S.empty()) 2385 getModule().setModuleInlineAsm(AsmString); 2386 else if (*--S.end() == '\n') 2387 getModule().setModuleInlineAsm(S + AsmString.str()); 2388 else 2389 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 2390 break; 2391 } 2392 2393 default: 2394 // Make sure we handled everything we should, every other kind is a 2395 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 2396 // function. Need to recode Decl::Kind to do that easily. 2397 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 2398 } 2399} 2400 2401/// Turns the given pointer into a constant. 2402static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 2403 const void *Ptr) { 2404 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 2405 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 2406 return llvm::ConstantInt::get(i64, PtrInt); 2407} 2408 2409static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 2410 llvm::NamedMDNode *&GlobalMetadata, 2411 GlobalDecl D, 2412 llvm::GlobalValue *Addr) { 2413 if (!GlobalMetadata) 2414 GlobalMetadata = 2415 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 2416 2417 // TODO: should we report variant information for ctors/dtors? 2418 llvm::Value *Ops[] = { 2419 Addr, 2420 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 2421 }; 2422 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 2423} 2424 2425/// Emits metadata nodes associating all the global values in the 2426/// current module with the Decls they came from. This is useful for 2427/// projects using IR gen as a subroutine. 2428/// 2429/// Since there's currently no way to associate an MDNode directly 2430/// with an llvm::GlobalValue, we create a global named metadata 2431/// with the name 'clang.global.decl.ptrs'. 2432void CodeGenModule::EmitDeclMetadata() { 2433 llvm::NamedMDNode *GlobalMetadata = 0; 2434 2435 // StaticLocalDeclMap 2436 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 2437 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 2438 I != E; ++I) { 2439 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 2440 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 2441 } 2442} 2443 2444/// Emits metadata nodes for all the local variables in the current 2445/// function. 2446void CodeGenFunction::EmitDeclMetadata() { 2447 if (LocalDeclMap.empty()) return; 2448 2449 llvm::LLVMContext &Context = getLLVMContext(); 2450 2451 // Find the unique metadata ID for this name. 2452 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 2453 2454 llvm::NamedMDNode *GlobalMetadata = 0; 2455 2456 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 2457 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 2458 const Decl *D = I->first; 2459 llvm::Value *Addr = I->second; 2460 2461 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 2462 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 2463 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 2464 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 2465 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 2466 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 2467 } 2468 } 2469} 2470 2471void CodeGenModule::EmitCoverageFile() { 2472 if (!getCodeGenOpts().CoverageFile.empty()) { 2473 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 2474 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 2475 llvm::LLVMContext &Ctx = TheModule.getContext(); 2476 llvm::MDString *CoverageFile = 2477 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 2478 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 2479 llvm::MDNode *CU = CUNode->getOperand(i); 2480 llvm::Value *node[] = { CoverageFile, CU }; 2481 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 2482 GCov->addOperand(N); 2483 } 2484 } 2485 } 2486} 2487