CodeGenModule.cpp revision 71efba0bbafaefab14419fbd284efff5f7acade7
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(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 const Builtin::Context &BI; 867 bool Result; 868 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) : 869 Name(N), BI(C), Result(false) { 870 } 871 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; 872 873 bool TraverseCallExpr(CallExpr *E) { 874 const FunctionDecl *FD = E->getDirectCallee(); 875 if (!FD) 876 return true; 877 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 878 if (Attr && Name == Attr->getLabel()) { 879 Result = true; 880 return false; 881 } 882 unsigned BuiltinID = FD->getBuiltinID(); 883 if (!BuiltinID) 884 return true; 885 StringRef BuiltinName = BI.GetName(BuiltinID); 886 if (BuiltinName.startswith("__builtin_") && 887 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { 888 Result = true; 889 return false; 890 } 891 return true; 892 } 893 }; 894} 895 896// isTriviallyRecursive - Check if this function calls another 897// decl that, because of the asm attribute or the other decl being a builtin, 898// ends up pointing to itself. 899bool 900CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { 901 StringRef Name; 902 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { 903 // asm labels are a special kind of mangling we have to support. 904 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 905 if (!Attr) 906 return false; 907 Name = Attr->getLabel(); 908 } else { 909 Name = FD->getName(); 910 } 911 912 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); 913 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD)); 914 return Walker.Result; 915} 916 917bool 918CodeGenModule::shouldEmitFunction(const FunctionDecl *F) { 919 if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage) 920 return true; 921 if (CodeGenOpts.OptimizationLevel == 0 && 922 !F->hasAttr<AlwaysInlineAttr>()) 923 return false; 924 // PR9614. Avoid cases where the source code is lying to us. An available 925 // externally function should have an equivalent function somewhere else, 926 // but a function that calls itself is clearly not equivalent to the real 927 // implementation. 928 // This happens in glibc's btowc and in some configure checks. 929 return !isTriviallyRecursive(F); 930} 931 932void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 933 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 934 935 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 936 Context.getSourceManager(), 937 "Generating code for declaration"); 938 939 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 940 // At -O0, don't generate IR for functions with available_externally 941 // linkage. 942 if (!shouldEmitFunction(Function)) 943 return; 944 945 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 946 // Make sure to emit the definition(s) before we emit the thunks. 947 // This is necessary for the generation of certain thunks. 948 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 949 EmitCXXConstructor(CD, GD.getCtorType()); 950 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 951 EmitCXXDestructor(DD, GD.getDtorType()); 952 else 953 EmitGlobalFunctionDefinition(GD); 954 955 if (Method->isVirtual()) 956 getVTables().EmitThunks(GD); 957 958 return; 959 } 960 961 return EmitGlobalFunctionDefinition(GD); 962 } 963 964 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 965 return EmitGlobalVarDefinition(VD); 966 967 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 968} 969 970/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 971/// module, create and return an llvm Function with the specified type. If there 972/// is something in the module with the specified name, return it potentially 973/// bitcasted to the right type. 974/// 975/// If D is non-null, it specifies a decl that correspond to this. This is used 976/// to set the attributes on the function when it is first created. 977llvm::Constant * 978CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 979 llvm::Type *Ty, 980 GlobalDecl D, bool ForVTable, 981 llvm::Attributes ExtraAttrs) { 982 // Lookup the entry, lazily creating it if necessary. 983 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 984 if (Entry) { 985 if (WeakRefReferences.count(Entry)) { 986 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 987 if (FD && !FD->hasAttr<WeakAttr>()) 988 Entry->setLinkage(llvm::Function::ExternalLinkage); 989 990 WeakRefReferences.erase(Entry); 991 } 992 993 if (Entry->getType()->getElementType() == Ty) 994 return Entry; 995 996 // Make sure the result is of the correct type. 997 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 998 } 999 1000 // This function doesn't have a complete type (for example, the return 1001 // type is an incomplete struct). Use a fake type instead, and make 1002 // sure not to try to set attributes. 1003 bool IsIncompleteFunction = false; 1004 1005 llvm::FunctionType *FTy; 1006 if (isa<llvm::FunctionType>(Ty)) { 1007 FTy = cast<llvm::FunctionType>(Ty); 1008 } else { 1009 FTy = llvm::FunctionType::get(VoidTy, false); 1010 IsIncompleteFunction = true; 1011 } 1012 1013 llvm::Function *F = llvm::Function::Create(FTy, 1014 llvm::Function::ExternalLinkage, 1015 MangledName, &getModule()); 1016 assert(F->getName() == MangledName && "name was uniqued!"); 1017 if (D.getDecl()) 1018 SetFunctionAttributes(D, F, IsIncompleteFunction); 1019 if (ExtraAttrs != llvm::Attribute::None) 1020 F->addFnAttr(ExtraAttrs); 1021 1022 if (Features.AddressSanitizer) { 1023 // When AddressSanitizer is enabled, set AddressSafety attribute 1024 // unless __attribute__((no_address_safety_analysis)) is used. 1025 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 1026 if (!FD || !FD->hasAttr<NoAddressSafetyAnalysisAttr>()) 1027 F->addFnAttr(llvm::Attribute::AddressSafety); 1028 } 1029 1030 // This is the first use or definition of a mangled name. If there is a 1031 // deferred decl with this name, remember that we need to emit it at the end 1032 // of the file. 1033 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1034 if (DDI != DeferredDecls.end()) { 1035 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1036 // list, and remove it from DeferredDecls (since we don't need it anymore). 1037 DeferredDeclsToEmit.push_back(DDI->second); 1038 DeferredDecls.erase(DDI); 1039 1040 // Otherwise, there are cases we have to worry about where we're 1041 // using a declaration for which we must emit a definition but where 1042 // we might not find a top-level definition: 1043 // - member functions defined inline in their classes 1044 // - friend functions defined inline in some class 1045 // - special member functions with implicit definitions 1046 // If we ever change our AST traversal to walk into class methods, 1047 // this will be unnecessary. 1048 // 1049 // We also don't emit a definition for a function if it's going to be an entry 1050 // in a vtable, unless it's already marked as used. 1051 } else if (getLangOptions().CPlusPlus && D.getDecl()) { 1052 // Look for a declaration that's lexically in a record. 1053 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); 1054 do { 1055 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 1056 if (FD->isImplicit() && !ForVTable) { 1057 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 1058 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1059 break; 1060 } else if (FD->doesThisDeclarationHaveABody()) { 1061 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1062 break; 1063 } 1064 } 1065 FD = FD->getPreviousDecl(); 1066 } while (FD); 1067 } 1068 1069 // Make sure the result is of the requested type. 1070 if (!IsIncompleteFunction) { 1071 assert(F->getType()->getElementType() == Ty); 1072 return F; 1073 } 1074 1075 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1076 return llvm::ConstantExpr::getBitCast(F, PTy); 1077} 1078 1079/// GetAddrOfFunction - Return the address of the given function. If Ty is 1080/// non-null, then this function will use the specified type if it has to 1081/// create it (this occurs when we see a definition of the function). 1082llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 1083 llvm::Type *Ty, 1084 bool ForVTable) { 1085 // If there was no specific requested type, just convert it now. 1086 if (!Ty) 1087 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 1088 1089 StringRef MangledName = getMangledName(GD); 1090 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 1091} 1092 1093/// CreateRuntimeFunction - Create a new runtime function with the specified 1094/// type and name. 1095llvm::Constant * 1096CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 1097 StringRef Name, 1098 llvm::Attributes ExtraAttrs) { 1099 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 1100 ExtraAttrs); 1101} 1102 1103static bool DeclIsConstantGlobal(ASTContext &Context, const VarDecl *D, 1104 bool ConstantInit) { 1105 if (!D->getType().isConstant(Context) && !D->getType()->isReferenceType()) 1106 return false; 1107 1108 if (Context.getLangOptions().CPlusPlus) { 1109 if (const RecordType *Record 1110 = Context.getBaseElementType(D->getType())->getAs<RecordType>()) 1111 return ConstantInit && 1112 cast<CXXRecordDecl>(Record->getDecl())->isPOD() && 1113 !cast<CXXRecordDecl>(Record->getDecl())->hasMutableFields(); 1114 } 1115 1116 return true; 1117} 1118 1119/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1120/// create and return an llvm GlobalVariable with the specified type. If there 1121/// is something in the module with the specified name, return it potentially 1122/// bitcasted to the right type. 1123/// 1124/// If D is non-null, it specifies a decl that correspond to this. This is used 1125/// to set the attributes on the global when it is first created. 1126llvm::Constant * 1127CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1128 llvm::PointerType *Ty, 1129 const VarDecl *D, 1130 bool UnnamedAddr) { 1131 // Lookup the entry, lazily creating it if necessary. 1132 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1133 if (Entry) { 1134 if (WeakRefReferences.count(Entry)) { 1135 if (D && !D->hasAttr<WeakAttr>()) 1136 Entry->setLinkage(llvm::Function::ExternalLinkage); 1137 1138 WeakRefReferences.erase(Entry); 1139 } 1140 1141 if (UnnamedAddr) 1142 Entry->setUnnamedAddr(true); 1143 1144 if (Entry->getType() == Ty) 1145 return Entry; 1146 1147 // Make sure the result is of the correct type. 1148 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1149 } 1150 1151 // This is the first use or definition of a mangled name. If there is a 1152 // deferred decl with this name, remember that we need to emit it at the end 1153 // of the file. 1154 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1155 if (DDI != DeferredDecls.end()) { 1156 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1157 // list, and remove it from DeferredDecls (since we don't need it anymore). 1158 DeferredDeclsToEmit.push_back(DDI->second); 1159 DeferredDecls.erase(DDI); 1160 } 1161 1162 llvm::GlobalVariable *GV = 1163 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1164 llvm::GlobalValue::ExternalLinkage, 1165 0, MangledName, 0, 1166 false, Ty->getAddressSpace()); 1167 1168 // Handle things which are present even on external declarations. 1169 if (D) { 1170 // FIXME: This code is overly simple and should be merged with other global 1171 // handling. 1172 GV->setConstant(DeclIsConstantGlobal(Context, D, false)); 1173 1174 // Set linkage and visibility in case we never see a definition. 1175 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 1176 if (LV.linkage() != ExternalLinkage) { 1177 // Don't set internal linkage on declarations. 1178 } else { 1179 if (D->hasAttr<DLLImportAttr>()) 1180 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1181 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1182 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1183 1184 // Set visibility on a declaration only if it's explicit. 1185 if (LV.visibilityExplicit()) 1186 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 1187 } 1188 1189 GV->setThreadLocal(D->isThreadSpecified()); 1190 } 1191 1192 return GV; 1193} 1194 1195 1196llvm::GlobalVariable * 1197CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1198 llvm::Type *Ty, 1199 llvm::GlobalValue::LinkageTypes Linkage) { 1200 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1201 llvm::GlobalVariable *OldGV = 0; 1202 1203 1204 if (GV) { 1205 // Check if the variable has the right type. 1206 if (GV->getType()->getElementType() == Ty) 1207 return GV; 1208 1209 // Because C++ name mangling, the only way we can end up with an already 1210 // existing global with the same name is if it has been declared extern "C". 1211 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1212 OldGV = GV; 1213 } 1214 1215 // Create a new variable. 1216 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1217 Linkage, 0, Name); 1218 1219 if (OldGV) { 1220 // Replace occurrences of the old variable if needed. 1221 GV->takeName(OldGV); 1222 1223 if (!OldGV->use_empty()) { 1224 llvm::Constant *NewPtrForOldDecl = 1225 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1226 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1227 } 1228 1229 OldGV->eraseFromParent(); 1230 } 1231 1232 return GV; 1233} 1234 1235/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1236/// given global variable. If Ty is non-null and if the global doesn't exist, 1237/// then it will be greated with the specified type instead of whatever the 1238/// normal requested type would be. 1239llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1240 llvm::Type *Ty) { 1241 assert(D->hasGlobalStorage() && "Not a global variable"); 1242 QualType ASTTy = D->getType(); 1243 if (Ty == 0) 1244 Ty = getTypes().ConvertTypeForMem(ASTTy); 1245 1246 llvm::PointerType *PTy = 1247 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1248 1249 StringRef MangledName = getMangledName(D); 1250 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1251} 1252 1253/// CreateRuntimeVariable - Create a new runtime global variable with the 1254/// specified type and name. 1255llvm::Constant * 1256CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1257 StringRef Name) { 1258 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1259 true); 1260} 1261 1262void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1263 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1264 1265 if (MayDeferGeneration(D)) { 1266 // If we have not seen a reference to this variable yet, place it 1267 // into the deferred declarations table to be emitted if needed 1268 // later. 1269 StringRef MangledName = getMangledName(D); 1270 if (!GetGlobalValue(MangledName)) { 1271 DeferredDecls[MangledName] = D; 1272 return; 1273 } 1274 } 1275 1276 // The tentative definition is the only definition. 1277 EmitGlobalVarDefinition(D); 1278} 1279 1280void CodeGenModule::EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired) { 1281 if (DefinitionRequired) 1282 getVTables().GenerateClassData(getVTableLinkage(Class), Class); 1283} 1284 1285llvm::GlobalVariable::LinkageTypes 1286CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) { 1287 if (RD->getLinkage() != ExternalLinkage) 1288 return llvm::GlobalVariable::InternalLinkage; 1289 1290 if (const CXXMethodDecl *KeyFunction 1291 = RD->getASTContext().getKeyFunction(RD)) { 1292 // If this class has a key function, use that to determine the linkage of 1293 // the vtable. 1294 const FunctionDecl *Def = 0; 1295 if (KeyFunction->hasBody(Def)) 1296 KeyFunction = cast<CXXMethodDecl>(Def); 1297 1298 switch (KeyFunction->getTemplateSpecializationKind()) { 1299 case TSK_Undeclared: 1300 case TSK_ExplicitSpecialization: 1301 // When compiling with optimizations turned on, we emit all vtables, 1302 // even if the key function is not defined in the current translation 1303 // unit. If this is the case, use available_externally linkage. 1304 if (!Def && CodeGenOpts.OptimizationLevel) 1305 return llvm::GlobalVariable::AvailableExternallyLinkage; 1306 1307 if (KeyFunction->isInlined()) 1308 return !Context.getLangOptions().AppleKext ? 1309 llvm::GlobalVariable::LinkOnceODRLinkage : 1310 llvm::Function::InternalLinkage; 1311 1312 return llvm::GlobalVariable::ExternalLinkage; 1313 1314 case TSK_ImplicitInstantiation: 1315 return !Context.getLangOptions().AppleKext ? 1316 llvm::GlobalVariable::LinkOnceODRLinkage : 1317 llvm::Function::InternalLinkage; 1318 1319 case TSK_ExplicitInstantiationDefinition: 1320 return !Context.getLangOptions().AppleKext ? 1321 llvm::GlobalVariable::WeakODRLinkage : 1322 llvm::Function::InternalLinkage; 1323 1324 case TSK_ExplicitInstantiationDeclaration: 1325 // FIXME: Use available_externally linkage. However, this currently 1326 // breaks LLVM's build due to undefined symbols. 1327 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1328 return !Context.getLangOptions().AppleKext ? 1329 llvm::GlobalVariable::LinkOnceODRLinkage : 1330 llvm::Function::InternalLinkage; 1331 } 1332 } 1333 1334 if (Context.getLangOptions().AppleKext) 1335 return llvm::Function::InternalLinkage; 1336 1337 switch (RD->getTemplateSpecializationKind()) { 1338 case TSK_Undeclared: 1339 case TSK_ExplicitSpecialization: 1340 case TSK_ImplicitInstantiation: 1341 // FIXME: Use available_externally linkage. However, this currently 1342 // breaks LLVM's build due to undefined symbols. 1343 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1344 case TSK_ExplicitInstantiationDeclaration: 1345 return llvm::GlobalVariable::LinkOnceODRLinkage; 1346 1347 case TSK_ExplicitInstantiationDefinition: 1348 return llvm::GlobalVariable::WeakODRLinkage; 1349 } 1350 1351 llvm_unreachable("Invalid TemplateSpecializationKind!"); 1352} 1353 1354CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1355 return Context.toCharUnitsFromBits( 1356 TheTargetData.getTypeStoreSizeInBits(Ty)); 1357} 1358 1359void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1360 llvm::Constant *Init = 0; 1361 QualType ASTTy = D->getType(); 1362 bool NonConstInit = false; 1363 1364 const VarDecl *InitDecl; 1365 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 1366 1367 if (!InitExpr) { 1368 // This is a tentative definition; tentative definitions are 1369 // implicitly initialized with { 0 }. 1370 // 1371 // Note that tentative definitions are only emitted at the end of 1372 // a translation unit, so they should never have incomplete 1373 // type. In addition, EmitTentativeDefinition makes sure that we 1374 // never attempt to emit a tentative definition if a real one 1375 // exists. A use may still exists, however, so we still may need 1376 // to do a RAUW. 1377 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1378 Init = EmitNullConstant(D->getType()); 1379 } else { 1380 Init = EmitConstantInit(*InitDecl); 1381 if (!Init) { 1382 QualType T = InitExpr->getType(); 1383 if (D->getType()->isReferenceType()) 1384 T = D->getType(); 1385 1386 if (getLangOptions().CPlusPlus) { 1387 Init = EmitNullConstant(T); 1388 NonConstInit = true; 1389 } else { 1390 ErrorUnsupported(D, "static initializer"); 1391 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1392 } 1393 } else { 1394 // We don't need an initializer, so remove the entry for the delayed 1395 // initializer position (just in case this entry was delayed). 1396 if (getLangOptions().CPlusPlus) 1397 DelayedCXXInitPosition.erase(D); 1398 } 1399 } 1400 1401 llvm::Type* InitType = Init->getType(); 1402 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1403 1404 // Strip off a bitcast if we got one back. 1405 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1406 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1407 // all zero index gep. 1408 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1409 Entry = CE->getOperand(0); 1410 } 1411 1412 // Entry is now either a Function or GlobalVariable. 1413 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1414 1415 // We have a definition after a declaration with the wrong type. 1416 // We must make a new GlobalVariable* and update everything that used OldGV 1417 // (a declaration or tentative definition) with the new GlobalVariable* 1418 // (which will be a definition). 1419 // 1420 // This happens if there is a prototype for a global (e.g. 1421 // "extern int x[];") and then a definition of a different type (e.g. 1422 // "int x[10];"). This also happens when an initializer has a different type 1423 // from the type of the global (this happens with unions). 1424 if (GV == 0 || 1425 GV->getType()->getElementType() != InitType || 1426 GV->getType()->getAddressSpace() != 1427 getContext().getTargetAddressSpace(ASTTy)) { 1428 1429 // Move the old entry aside so that we'll create a new one. 1430 Entry->setName(StringRef()); 1431 1432 // Make a new global with the correct type, this is now guaranteed to work. 1433 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1434 1435 // Replace all uses of the old global with the new global 1436 llvm::Constant *NewPtrForOldDecl = 1437 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1438 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1439 1440 // Erase the old global, since it is no longer used. 1441 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1442 } 1443 1444 if (D->hasAttr<AnnotateAttr>()) 1445 AddGlobalAnnotations(D, GV); 1446 1447 GV->setInitializer(Init); 1448 1449 // If it is safe to mark the global 'constant', do so now. 1450 GV->setConstant(false); 1451 if (!NonConstInit && DeclIsConstantGlobal(Context, D, true)) 1452 GV->setConstant(true); 1453 1454 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1455 1456 // Set the llvm linkage type as appropriate. 1457 llvm::GlobalValue::LinkageTypes Linkage = 1458 GetLLVMLinkageVarDefinition(D, GV); 1459 GV->setLinkage(Linkage); 1460 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1461 // common vars aren't constant even if declared const. 1462 GV->setConstant(false); 1463 1464 SetCommonAttributes(D, GV); 1465 1466 // Emit the initializer function if necessary. 1467 if (NonConstInit) 1468 EmitCXXGlobalVarDeclInitFunc(D, GV); 1469 1470 // Emit global variable debug information. 1471 if (CGDebugInfo *DI = getModuleDebugInfo()) 1472 DI->EmitGlobalVariable(GV, D); 1473} 1474 1475llvm::GlobalValue::LinkageTypes 1476CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, 1477 llvm::GlobalVariable *GV) { 1478 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1479 if (Linkage == GVA_Internal) 1480 return llvm::Function::InternalLinkage; 1481 else if (D->hasAttr<DLLImportAttr>()) 1482 return llvm::Function::DLLImportLinkage; 1483 else if (D->hasAttr<DLLExportAttr>()) 1484 return llvm::Function::DLLExportLinkage; 1485 else if (D->hasAttr<WeakAttr>()) { 1486 if (GV->isConstant()) 1487 return llvm::GlobalVariable::WeakODRLinkage; 1488 else 1489 return llvm::GlobalVariable::WeakAnyLinkage; 1490 } else if (Linkage == GVA_TemplateInstantiation || 1491 Linkage == GVA_ExplicitTemplateInstantiation) 1492 return llvm::GlobalVariable::WeakODRLinkage; 1493 else if (!getLangOptions().CPlusPlus && 1494 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1495 D->getAttr<CommonAttr>()) && 1496 !D->hasExternalStorage() && !D->getInit() && 1497 !D->getAttr<SectionAttr>() && !D->isThreadSpecified() && 1498 !D->getAttr<WeakImportAttr>()) { 1499 // Thread local vars aren't considered common linkage. 1500 return llvm::GlobalVariable::CommonLinkage; 1501 } 1502 return llvm::GlobalVariable::ExternalLinkage; 1503} 1504 1505/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1506/// implement a function with no prototype, e.g. "int foo() {}". If there are 1507/// existing call uses of the old function in the module, this adjusts them to 1508/// call the new function directly. 1509/// 1510/// This is not just a cleanup: the always_inline pass requires direct calls to 1511/// functions to be able to inline them. If there is a bitcast in the way, it 1512/// won't inline them. Instcombine normally deletes these calls, but it isn't 1513/// run at -O0. 1514static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1515 llvm::Function *NewFn) { 1516 // If we're redefining a global as a function, don't transform it. 1517 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1518 if (OldFn == 0) return; 1519 1520 llvm::Type *NewRetTy = NewFn->getReturnType(); 1521 SmallVector<llvm::Value*, 4> ArgList; 1522 1523 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1524 UI != E; ) { 1525 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1526 llvm::Value::use_iterator I = UI++; // Increment before the CI is erased. 1527 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*I); 1528 if (!CI) continue; // FIXME: when we allow Invoke, just do CallSite CS(*I) 1529 llvm::CallSite CS(CI); 1530 if (!CI || !CS.isCallee(I)) continue; 1531 1532 // If the return types don't match exactly, and if the call isn't dead, then 1533 // we can't transform this call. 1534 if (CI->getType() != NewRetTy && !CI->use_empty()) 1535 continue; 1536 1537 // Get the attribute list. 1538 llvm::SmallVector<llvm::AttributeWithIndex, 8> AttrVec; 1539 llvm::AttrListPtr AttrList = CI->getAttributes(); 1540 1541 // Get any return attributes. 1542 llvm::Attributes RAttrs = AttrList.getRetAttributes(); 1543 1544 // Add the return attributes. 1545 if (RAttrs) 1546 AttrVec.push_back(llvm::AttributeWithIndex::get(0, RAttrs)); 1547 1548 // If the function was passed too few arguments, don't transform. If extra 1549 // arguments were passed, we silently drop them. If any of the types 1550 // mismatch, we don't transform. 1551 unsigned ArgNo = 0; 1552 bool DontTransform = false; 1553 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1554 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1555 if (CS.arg_size() == ArgNo || 1556 CS.getArgument(ArgNo)->getType() != AI->getType()) { 1557 DontTransform = true; 1558 break; 1559 } 1560 1561 // Add any parameter attributes. 1562 if (llvm::Attributes PAttrs = AttrList.getParamAttributes(ArgNo + 1)) 1563 AttrVec.push_back(llvm::AttributeWithIndex::get(ArgNo + 1, PAttrs)); 1564 } 1565 if (DontTransform) 1566 continue; 1567 1568 if (llvm::Attributes FnAttrs = AttrList.getFnAttributes()) 1569 AttrVec.push_back(llvm::AttributeWithIndex::get(~0, FnAttrs)); 1570 1571 // Okay, we can transform this. Create the new call instruction and copy 1572 // over the required information. 1573 ArgList.append(CS.arg_begin(), CS.arg_begin() + ArgNo); 1574 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList, "", CI); 1575 ArgList.clear(); 1576 if (!NewCall->getType()->isVoidTy()) 1577 NewCall->takeName(CI); 1578 NewCall->setAttributes(llvm::AttrListPtr::get(AttrVec.begin(), 1579 AttrVec.end())); 1580 NewCall->setCallingConv(CI->getCallingConv()); 1581 1582 // Finally, remove the old call, replacing any uses with the new one. 1583 if (!CI->use_empty()) 1584 CI->replaceAllUsesWith(NewCall); 1585 1586 // Copy debug location attached to CI. 1587 if (!CI->getDebugLoc().isUnknown()) 1588 NewCall->setDebugLoc(CI->getDebugLoc()); 1589 CI->eraseFromParent(); 1590 } 1591} 1592 1593 1594void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1595 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1596 1597 // Compute the function info and LLVM type. 1598 const CGFunctionInfo &FI = getTypes().getFunctionInfo(GD); 1599 bool variadic = false; 1600 if (const FunctionProtoType *fpt = D->getType()->getAs<FunctionProtoType>()) 1601 variadic = fpt->isVariadic(); 1602 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI, variadic); 1603 1604 // Get or create the prototype for the function. 1605 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1606 1607 // Strip off a bitcast if we got one back. 1608 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1609 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1610 Entry = CE->getOperand(0); 1611 } 1612 1613 1614 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1615 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1616 1617 // If the types mismatch then we have to rewrite the definition. 1618 assert(OldFn->isDeclaration() && 1619 "Shouldn't replace non-declaration"); 1620 1621 // F is the Function* for the one with the wrong type, we must make a new 1622 // Function* and update everything that used F (a declaration) with the new 1623 // Function* (which will be a definition). 1624 // 1625 // This happens if there is a prototype for a function 1626 // (e.g. "int f()") and then a definition of a different type 1627 // (e.g. "int f(int x)"). Move the old function aside so that it 1628 // doesn't interfere with GetAddrOfFunction. 1629 OldFn->setName(StringRef()); 1630 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1631 1632 // If this is an implementation of a function without a prototype, try to 1633 // replace any existing uses of the function (which may be calls) with uses 1634 // of the new function 1635 if (D->getType()->isFunctionNoProtoType()) { 1636 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1637 OldFn->removeDeadConstantUsers(); 1638 } 1639 1640 // Replace uses of F with the Function we will endow with a body. 1641 if (!Entry->use_empty()) { 1642 llvm::Constant *NewPtrForOldDecl = 1643 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1644 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1645 } 1646 1647 // Ok, delete the old function now, which is dead. 1648 OldFn->eraseFromParent(); 1649 1650 Entry = NewFn; 1651 } 1652 1653 // We need to set linkage and visibility on the function before 1654 // generating code for it because various parts of IR generation 1655 // want to propagate this information down (e.g. to local static 1656 // declarations). 1657 llvm::Function *Fn = cast<llvm::Function>(Entry); 1658 setFunctionLinkage(D, Fn); 1659 1660 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 1661 setGlobalVisibility(Fn, D); 1662 1663 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 1664 1665 SetFunctionDefinitionAttributes(D, Fn); 1666 SetLLVMFunctionAttributesForDefinition(D, Fn); 1667 1668 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1669 AddGlobalCtor(Fn, CA->getPriority()); 1670 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1671 AddGlobalDtor(Fn, DA->getPriority()); 1672 if (D->hasAttr<AnnotateAttr>()) 1673 AddGlobalAnnotations(D, Fn); 1674} 1675 1676void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 1677 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1678 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1679 assert(AA && "Not an alias?"); 1680 1681 StringRef MangledName = getMangledName(GD); 1682 1683 // If there is a definition in the module, then it wins over the alias. 1684 // This is dubious, but allow it to be safe. Just ignore the alias. 1685 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1686 if (Entry && !Entry->isDeclaration()) 1687 return; 1688 1689 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1690 1691 // Create a reference to the named value. This ensures that it is emitted 1692 // if a deferred decl. 1693 llvm::Constant *Aliasee; 1694 if (isa<llvm::FunctionType>(DeclTy)) 1695 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 1696 /*ForVTable=*/false); 1697 else 1698 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1699 llvm::PointerType::getUnqual(DeclTy), 0); 1700 1701 // Create the new alias itself, but don't set a name yet. 1702 llvm::GlobalValue *GA = 1703 new llvm::GlobalAlias(Aliasee->getType(), 1704 llvm::Function::ExternalLinkage, 1705 "", Aliasee, &getModule()); 1706 1707 if (Entry) { 1708 assert(Entry->isDeclaration()); 1709 1710 // If there is a declaration in the module, then we had an extern followed 1711 // by the alias, as in: 1712 // extern int test6(); 1713 // ... 1714 // int test6() __attribute__((alias("test7"))); 1715 // 1716 // Remove it and replace uses of it with the alias. 1717 GA->takeName(Entry); 1718 1719 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1720 Entry->getType())); 1721 Entry->eraseFromParent(); 1722 } else { 1723 GA->setName(MangledName); 1724 } 1725 1726 // Set attributes which are particular to an alias; this is a 1727 // specialization of the attributes which may be set on a global 1728 // variable/function. 1729 if (D->hasAttr<DLLExportAttr>()) { 1730 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1731 // The dllexport attribute is ignored for undefined symbols. 1732 if (FD->hasBody()) 1733 GA->setLinkage(llvm::Function::DLLExportLinkage); 1734 } else { 1735 GA->setLinkage(llvm::Function::DLLExportLinkage); 1736 } 1737 } else if (D->hasAttr<WeakAttr>() || 1738 D->hasAttr<WeakRefAttr>() || 1739 D->isWeakImported()) { 1740 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1741 } 1742 1743 SetCommonAttributes(D, GA); 1744} 1745 1746llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 1747 ArrayRef<llvm::Type*> Tys) { 1748 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 1749 Tys); 1750} 1751 1752static llvm::StringMapEntry<llvm::Constant*> & 1753GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1754 const StringLiteral *Literal, 1755 bool TargetIsLSB, 1756 bool &IsUTF16, 1757 unsigned &StringLength) { 1758 StringRef String = Literal->getString(); 1759 unsigned NumBytes = String.size(); 1760 1761 // Check for simple case. 1762 if (!Literal->containsNonAsciiOrNull()) { 1763 StringLength = NumBytes; 1764 return Map.GetOrCreateValue(String); 1765 } 1766 1767 // Otherwise, convert the UTF8 literals into a byte string. 1768 SmallVector<UTF16, 128> ToBuf(NumBytes); 1769 const UTF8 *FromPtr = (UTF8 *)String.data(); 1770 UTF16 *ToPtr = &ToBuf[0]; 1771 1772 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 1773 &ToPtr, ToPtr + NumBytes, 1774 strictConversion); 1775 1776 // ConvertUTF8toUTF16 returns the length in ToPtr. 1777 StringLength = ToPtr - &ToBuf[0]; 1778 1779 // Render the UTF-16 string into a byte array and convert to the target byte 1780 // order. 1781 // 1782 // FIXME: This isn't something we should need to do here. 1783 llvm::SmallString<128> AsBytes; 1784 AsBytes.reserve(StringLength * 2); 1785 for (unsigned i = 0; i != StringLength; ++i) { 1786 unsigned short Val = ToBuf[i]; 1787 if (TargetIsLSB) { 1788 AsBytes.push_back(Val & 0xFF); 1789 AsBytes.push_back(Val >> 8); 1790 } else { 1791 AsBytes.push_back(Val >> 8); 1792 AsBytes.push_back(Val & 0xFF); 1793 } 1794 } 1795 // Append one extra null character, the second is automatically added by our 1796 // caller. 1797 AsBytes.push_back(0); 1798 1799 IsUTF16 = true; 1800 return Map.GetOrCreateValue(StringRef(AsBytes.data(), AsBytes.size())); 1801} 1802 1803static llvm::StringMapEntry<llvm::Constant*> & 1804GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1805 const StringLiteral *Literal, 1806 unsigned &StringLength) 1807{ 1808 StringRef String = Literal->getString(); 1809 StringLength = String.size(); 1810 return Map.GetOrCreateValue(String); 1811} 1812 1813llvm::Constant * 1814CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 1815 unsigned StringLength = 0; 1816 bool isUTF16 = false; 1817 llvm::StringMapEntry<llvm::Constant*> &Entry = 1818 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1819 getTargetData().isLittleEndian(), 1820 isUTF16, StringLength); 1821 1822 if (llvm::Constant *C = Entry.getValue()) 1823 return C; 1824 1825 llvm::Constant *Zero = 1826 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1827 llvm::Constant *Zeros[] = { Zero, Zero }; 1828 1829 // If we don't already have it, get __CFConstantStringClassReference. 1830 if (!CFConstantStringClassRef) { 1831 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1832 Ty = llvm::ArrayType::get(Ty, 0); 1833 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1834 "__CFConstantStringClassReference"); 1835 // Decay array -> ptr 1836 CFConstantStringClassRef = 1837 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1838 } 1839 1840 QualType CFTy = getContext().getCFConstantStringType(); 1841 1842 llvm::StructType *STy = 1843 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1844 1845 llvm::Constant *Fields[4]; 1846 1847 // Class pointer. 1848 Fields[0] = CFConstantStringClassRef; 1849 1850 // Flags. 1851 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1852 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 1853 llvm::ConstantInt::get(Ty, 0x07C8); 1854 1855 // String pointer. 1856 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1857 1858 llvm::GlobalValue::LinkageTypes Linkage; 1859 if (isUTF16) 1860 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1861 Linkage = llvm::GlobalValue::InternalLinkage; 1862 else 1863 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 1864 // when using private linkage. It is not clear if this is a bug in ld 1865 // or a reasonable new restriction. 1866 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 1867 1868 // Note: -fwritable-strings doesn't make the backing store strings of 1869 // CFStrings writable. (See <rdar://problem/10657500>) 1870 llvm::GlobalVariable *GV = 1871 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, 1872 Linkage, C, ".str"); 1873 GV->setUnnamedAddr(true); 1874 if (isUTF16) { 1875 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 1876 GV->setAlignment(Align.getQuantity()); 1877 } else { 1878 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 1879 GV->setAlignment(Align.getQuantity()); 1880 } 1881 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1882 1883 // String length. 1884 Ty = getTypes().ConvertType(getContext().LongTy); 1885 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 1886 1887 // The struct. 1888 C = llvm::ConstantStruct::get(STy, Fields); 1889 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1890 llvm::GlobalVariable::PrivateLinkage, C, 1891 "_unnamed_cfstring_"); 1892 if (const char *Sect = getContext().getTargetInfo().getCFStringSection()) 1893 GV->setSection(Sect); 1894 Entry.setValue(GV); 1895 1896 return GV; 1897} 1898 1899static RecordDecl * 1900CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 1901 DeclContext *DC, IdentifierInfo *Id) { 1902 SourceLocation Loc; 1903 if (Ctx.getLangOptions().CPlusPlus) 1904 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 1905 else 1906 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 1907} 1908 1909llvm::Constant * 1910CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 1911 unsigned StringLength = 0; 1912 llvm::StringMapEntry<llvm::Constant*> &Entry = 1913 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 1914 1915 if (llvm::Constant *C = Entry.getValue()) 1916 return C; 1917 1918 llvm::Constant *Zero = 1919 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1920 llvm::Constant *Zeros[] = { Zero, Zero }; 1921 1922 // If we don't already have it, get _NSConstantStringClassReference. 1923 if (!ConstantStringClassRef) { 1924 std::string StringClass(getLangOptions().ObjCConstantStringClass); 1925 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1926 llvm::Constant *GV; 1927 if (Features.ObjCNonFragileABI) { 1928 std::string str = 1929 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 1930 : "OBJC_CLASS_$_" + StringClass; 1931 GV = getObjCRuntime().GetClassGlobal(str); 1932 // Make sure the result is of the correct type. 1933 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1934 ConstantStringClassRef = 1935 llvm::ConstantExpr::getBitCast(GV, PTy); 1936 } else { 1937 std::string str = 1938 StringClass.empty() ? "_NSConstantStringClassReference" 1939 : "_" + StringClass + "ClassReference"; 1940 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 1941 GV = CreateRuntimeVariable(PTy, str); 1942 // Decay array -> ptr 1943 ConstantStringClassRef = 1944 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1945 } 1946 } 1947 1948 if (!NSConstantStringType) { 1949 // Construct the type for a constant NSString. 1950 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 1951 Context.getTranslationUnitDecl(), 1952 &Context.Idents.get("__builtin_NSString")); 1953 D->startDefinition(); 1954 1955 QualType FieldTypes[3]; 1956 1957 // const int *isa; 1958 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 1959 // const char *str; 1960 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 1961 // unsigned int length; 1962 FieldTypes[2] = Context.UnsignedIntTy; 1963 1964 // Create fields 1965 for (unsigned i = 0; i < 3; ++i) { 1966 FieldDecl *Field = FieldDecl::Create(Context, D, 1967 SourceLocation(), 1968 SourceLocation(), 0, 1969 FieldTypes[i], /*TInfo=*/0, 1970 /*BitWidth=*/0, 1971 /*Mutable=*/false, 1972 /*HasInit=*/false); 1973 Field->setAccess(AS_public); 1974 D->addDecl(Field); 1975 } 1976 1977 D->completeDefinition(); 1978 QualType NSTy = Context.getTagDeclType(D); 1979 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 1980 } 1981 1982 llvm::Constant *Fields[3]; 1983 1984 // Class pointer. 1985 Fields[0] = ConstantStringClassRef; 1986 1987 // String pointer. 1988 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1989 1990 llvm::GlobalValue::LinkageTypes Linkage; 1991 bool isConstant; 1992 Linkage = llvm::GlobalValue::PrivateLinkage; 1993 isConstant = !Features.WritableStrings; 1994 1995 llvm::GlobalVariable *GV = 1996 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1997 ".str"); 1998 GV->setUnnamedAddr(true); 1999 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2000 GV->setAlignment(Align.getQuantity()); 2001 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2002 2003 // String length. 2004 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2005 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 2006 2007 // The struct. 2008 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 2009 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2010 llvm::GlobalVariable::PrivateLinkage, C, 2011 "_unnamed_nsstring_"); 2012 // FIXME. Fix section. 2013 if (const char *Sect = 2014 Features.ObjCNonFragileABI 2015 ? getContext().getTargetInfo().getNSStringNonFragileABISection() 2016 : getContext().getTargetInfo().getNSStringSection()) 2017 GV->setSection(Sect); 2018 Entry.setValue(GV); 2019 2020 return GV; 2021} 2022 2023QualType CodeGenModule::getObjCFastEnumerationStateType() { 2024 if (ObjCFastEnumerationStateType.isNull()) { 2025 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2026 Context.getTranslationUnitDecl(), 2027 &Context.Idents.get("__objcFastEnumerationState")); 2028 D->startDefinition(); 2029 2030 QualType FieldTypes[] = { 2031 Context.UnsignedLongTy, 2032 Context.getPointerType(Context.getObjCIdType()), 2033 Context.getPointerType(Context.UnsignedLongTy), 2034 Context.getConstantArrayType(Context.UnsignedLongTy, 2035 llvm::APInt(32, 5), ArrayType::Normal, 0) 2036 }; 2037 2038 for (size_t i = 0; i < 4; ++i) { 2039 FieldDecl *Field = FieldDecl::Create(Context, 2040 D, 2041 SourceLocation(), 2042 SourceLocation(), 0, 2043 FieldTypes[i], /*TInfo=*/0, 2044 /*BitWidth=*/0, 2045 /*Mutable=*/false, 2046 /*HasInit=*/false); 2047 Field->setAccess(AS_public); 2048 D->addDecl(Field); 2049 } 2050 2051 D->completeDefinition(); 2052 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 2053 } 2054 2055 return ObjCFastEnumerationStateType; 2056} 2057 2058/// GetStringForStringLiteral - Return the appropriate bytes for a 2059/// string literal, properly padded to match the literal type. 2060std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 2061 assert((E->isAscii() || E->isUTF8()) 2062 && "Use GetConstantArrayFromStringLiteral for wide strings"); 2063 const ASTContext &Context = getContext(); 2064 const ConstantArrayType *CAT = 2065 Context.getAsConstantArrayType(E->getType()); 2066 assert(CAT && "String isn't pointer or array!"); 2067 2068 // Resize the string to the right size. 2069 uint64_t RealLen = CAT->getSize().getZExtValue(); 2070 2071 std::string Str = E->getString().str(); 2072 Str.resize(RealLen, '\0'); 2073 2074 return Str; 2075} 2076 2077llvm::Constant * 2078CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { 2079 assert(!E->getType()->isPointerType() && "Strings are always arrays"); 2080 2081 // Don't emit it as the address of the string, emit the string data itself 2082 // as an inline array. 2083 if (E->getCharByteWidth()==1) { 2084 return llvm::ConstantArray::get(VMContext, 2085 GetStringForStringLiteral(E), false); 2086 } else { 2087 llvm::ArrayType *AType = 2088 cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); 2089 llvm::Type *ElemTy = AType->getElementType(); 2090 unsigned NumElements = AType->getNumElements(); 2091 std::vector<llvm::Constant*> Elts; 2092 Elts.reserve(NumElements); 2093 2094 for(unsigned i=0;i<E->getLength();++i) { 2095 unsigned value = E->getCodeUnit(i); 2096 llvm::Constant *C = llvm::ConstantInt::get(ElemTy,value,false); 2097 Elts.push_back(C); 2098 } 2099 for(unsigned i=E->getLength();i<NumElements;++i) { 2100 llvm::Constant *C = llvm::ConstantInt::get(ElemTy,0,false); 2101 Elts.push_back(C); 2102 } 2103 2104 return llvm::ConstantArray::get(AType, Elts); 2105 } 2106 2107} 2108 2109/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 2110/// constant array for the given string literal. 2111llvm::Constant * 2112CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 2113 // FIXME: This can be more efficient. 2114 // FIXME: We shouldn't need to bitcast the constant in the wide string case. 2115 CharUnits Align = getContext().getTypeAlignInChars(S->getType()); 2116 if (S->isAscii() || S->isUTF8()) { 2117 return GetAddrOfConstantString(GetStringForStringLiteral(S), 2118 /* GlobalName */ 0, 2119 Align.getQuantity()); 2120 } 2121 2122 // FIXME: the following does not memoize wide strings 2123 llvm::Constant *C = GetConstantArrayFromStringLiteral(S); 2124 llvm::GlobalVariable *GV = 2125 new llvm::GlobalVariable(getModule(),C->getType(), 2126 !Features.WritableStrings, 2127 llvm::GlobalValue::PrivateLinkage, 2128 C,".str"); 2129 2130 GV->setAlignment(Align.getQuantity()); 2131 GV->setUnnamedAddr(true); 2132 2133 return GV; 2134} 2135 2136/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2137/// array for the given ObjCEncodeExpr node. 2138llvm::Constant * 2139CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2140 std::string Str; 2141 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2142 2143 return GetAddrOfConstantCString(Str); 2144} 2145 2146 2147/// GenerateWritableString -- Creates storage for a string literal. 2148static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2149 bool constant, 2150 CodeGenModule &CGM, 2151 const char *GlobalName, 2152 unsigned Alignment) { 2153 // Create Constant for this string literal. Don't add a '\0'. 2154 llvm::Constant *C = 2155 llvm::ConstantArray::get(CGM.getLLVMContext(), str, false); 2156 2157 // Create a global variable for this string 2158 llvm::GlobalVariable *GV = 2159 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 2160 llvm::GlobalValue::PrivateLinkage, 2161 C, GlobalName); 2162 GV->setAlignment(Alignment); 2163 GV->setUnnamedAddr(true); 2164 return GV; 2165} 2166 2167/// GetAddrOfConstantString - Returns a pointer to a character array 2168/// containing the literal. This contents are exactly that of the 2169/// given string, i.e. it will not be null terminated automatically; 2170/// see GetAddrOfConstantCString. Note that whether the result is 2171/// actually a pointer to an LLVM constant depends on 2172/// Feature.WriteableStrings. 2173/// 2174/// The result has pointer to array type. 2175llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2176 const char *GlobalName, 2177 unsigned Alignment) { 2178 bool IsConstant = !Features.WritableStrings; 2179 2180 // Get the default prefix if a name wasn't specified. 2181 if (!GlobalName) 2182 GlobalName = ".str"; 2183 2184 // Don't share any string literals if strings aren't constant. 2185 if (!IsConstant) 2186 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2187 2188 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2189 ConstantStringMap.GetOrCreateValue(Str); 2190 2191 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2192 if (Alignment > GV->getAlignment()) { 2193 GV->setAlignment(Alignment); 2194 } 2195 return GV; 2196 } 2197 2198 // Create a global variable for this. 2199 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, Alignment); 2200 Entry.setValue(GV); 2201 return GV; 2202} 2203 2204/// GetAddrOfConstantCString - Returns a pointer to a character 2205/// array containing the literal and a terminating '\0' 2206/// character. The result has pointer to array type. 2207llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2208 const char *GlobalName, 2209 unsigned Alignment) { 2210 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2211 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2212} 2213 2214/// EmitObjCPropertyImplementations - Emit information for synthesized 2215/// properties for an implementation. 2216void CodeGenModule::EmitObjCPropertyImplementations(const 2217 ObjCImplementationDecl *D) { 2218 for (ObjCImplementationDecl::propimpl_iterator 2219 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2220 ObjCPropertyImplDecl *PID = *i; 2221 2222 // Dynamic is just for type-checking. 2223 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2224 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2225 2226 // Determine which methods need to be implemented, some may have 2227 // been overridden. Note that ::isSynthesized is not the method 2228 // we want, that just indicates if the decl came from a 2229 // property. What we want to know is if the method is defined in 2230 // this implementation. 2231 if (!D->getInstanceMethod(PD->getGetterName())) 2232 CodeGenFunction(*this).GenerateObjCGetter( 2233 const_cast<ObjCImplementationDecl *>(D), PID); 2234 if (!PD->isReadOnly() && 2235 !D->getInstanceMethod(PD->getSetterName())) 2236 CodeGenFunction(*this).GenerateObjCSetter( 2237 const_cast<ObjCImplementationDecl *>(D), PID); 2238 } 2239 } 2240} 2241 2242static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2243 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2244 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2245 ivar; ivar = ivar->getNextIvar()) 2246 if (ivar->getType().isDestructedType()) 2247 return true; 2248 2249 return false; 2250} 2251 2252/// EmitObjCIvarInitializations - Emit information for ivar initialization 2253/// for an implementation. 2254void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2255 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2256 if (needsDestructMethod(D)) { 2257 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2258 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2259 ObjCMethodDecl *DTORMethod = 2260 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2261 cxxSelector, getContext().VoidTy, 0, D, 2262 /*isInstance=*/true, /*isVariadic=*/false, 2263 /*isSynthesized=*/true, /*isImplicitlyDeclared=*/true, 2264 /*isDefined=*/false, ObjCMethodDecl::Required); 2265 D->addInstanceMethod(DTORMethod); 2266 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2267 D->setHasCXXStructors(true); 2268 } 2269 2270 // If the implementation doesn't have any ivar initializers, we don't need 2271 // a .cxx_construct. 2272 if (D->getNumIvarInitializers() == 0) 2273 return; 2274 2275 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2276 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2277 // The constructor returns 'self'. 2278 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2279 D->getLocation(), 2280 D->getLocation(), 2281 cxxSelector, 2282 getContext().getObjCIdType(), 0, 2283 D, /*isInstance=*/true, 2284 /*isVariadic=*/false, 2285 /*isSynthesized=*/true, 2286 /*isImplicitlyDeclared=*/true, 2287 /*isDefined=*/false, 2288 ObjCMethodDecl::Required); 2289 D->addInstanceMethod(CTORMethod); 2290 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2291 D->setHasCXXStructors(true); 2292} 2293 2294/// EmitNamespace - Emit all declarations in a namespace. 2295void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2296 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2297 I != E; ++I) 2298 EmitTopLevelDecl(*I); 2299} 2300 2301// EmitLinkageSpec - Emit all declarations in a linkage spec. 2302void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2303 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2304 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2305 ErrorUnsupported(LSD, "linkage spec"); 2306 return; 2307 } 2308 2309 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2310 I != E; ++I) 2311 EmitTopLevelDecl(*I); 2312} 2313 2314/// EmitTopLevelDecl - Emit code for a single top level declaration. 2315void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2316 // If an error has occurred, stop code generation, but continue 2317 // parsing and semantic analysis (to ensure all warnings and errors 2318 // are emitted). 2319 if (Diags.hasErrorOccurred()) 2320 return; 2321 2322 // Ignore dependent declarations. 2323 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2324 return; 2325 2326 switch (D->getKind()) { 2327 case Decl::CXXConversion: 2328 case Decl::CXXMethod: 2329 case Decl::Function: 2330 // Skip function templates 2331 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2332 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2333 return; 2334 2335 EmitGlobal(cast<FunctionDecl>(D)); 2336 break; 2337 2338 case Decl::Var: 2339 EmitGlobal(cast<VarDecl>(D)); 2340 break; 2341 2342 // Indirect fields from global anonymous structs and unions can be 2343 // ignored; only the actual variable requires IR gen support. 2344 case Decl::IndirectField: 2345 break; 2346 2347 // C++ Decls 2348 case Decl::Namespace: 2349 EmitNamespace(cast<NamespaceDecl>(D)); 2350 break; 2351 // No code generation needed. 2352 case Decl::UsingShadow: 2353 case Decl::Using: 2354 case Decl::UsingDirective: 2355 case Decl::ClassTemplate: 2356 case Decl::FunctionTemplate: 2357 case Decl::TypeAliasTemplate: 2358 case Decl::NamespaceAlias: 2359 case Decl::Block: 2360 case Decl::Import: 2361 break; 2362 case Decl::CXXConstructor: 2363 // Skip function templates 2364 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2365 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2366 return; 2367 2368 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2369 break; 2370 case Decl::CXXDestructor: 2371 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2372 return; 2373 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2374 break; 2375 2376 case Decl::StaticAssert: 2377 // Nothing to do. 2378 break; 2379 2380 // Objective-C Decls 2381 2382 // Forward declarations, no (immediate) code generation. 2383 case Decl::ObjCInterface: 2384 break; 2385 2386 case Decl::ObjCCategory: { 2387 ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D); 2388 if (CD->IsClassExtension() && CD->hasSynthBitfield()) 2389 Context.ResetObjCLayout(CD->getClassInterface()); 2390 break; 2391 } 2392 2393 case Decl::ObjCProtocol: { 2394 ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D); 2395 if (Proto->isThisDeclarationADefinition()) 2396 ObjCRuntime->GenerateProtocol(Proto); 2397 break; 2398 } 2399 2400 case Decl::ObjCCategoryImpl: 2401 // Categories have properties but don't support synthesize so we 2402 // can ignore them here. 2403 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2404 break; 2405 2406 case Decl::ObjCImplementation: { 2407 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2408 if (Features.ObjCNonFragileABI2 && OMD->hasSynthBitfield()) 2409 Context.ResetObjCLayout(OMD->getClassInterface()); 2410 EmitObjCPropertyImplementations(OMD); 2411 EmitObjCIvarInitializations(OMD); 2412 ObjCRuntime->GenerateClass(OMD); 2413 break; 2414 } 2415 case Decl::ObjCMethod: { 2416 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 2417 // If this is not a prototype, emit the body. 2418 if (OMD->getBody()) 2419 CodeGenFunction(*this).GenerateObjCMethod(OMD); 2420 break; 2421 } 2422 case Decl::ObjCCompatibleAlias: 2423 // compatibility-alias is a directive and has no code gen. 2424 break; 2425 2426 case Decl::LinkageSpec: 2427 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 2428 break; 2429 2430 case Decl::FileScopeAsm: { 2431 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 2432 StringRef AsmString = AD->getAsmString()->getString(); 2433 2434 const std::string &S = getModule().getModuleInlineAsm(); 2435 if (S.empty()) 2436 getModule().setModuleInlineAsm(AsmString); 2437 else if (*--S.end() == '\n') 2438 getModule().setModuleInlineAsm(S + AsmString.str()); 2439 else 2440 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 2441 break; 2442 } 2443 2444 default: 2445 // Make sure we handled everything we should, every other kind is a 2446 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 2447 // function. Need to recode Decl::Kind to do that easily. 2448 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 2449 } 2450} 2451 2452/// Turns the given pointer into a constant. 2453static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 2454 const void *Ptr) { 2455 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 2456 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 2457 return llvm::ConstantInt::get(i64, PtrInt); 2458} 2459 2460static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 2461 llvm::NamedMDNode *&GlobalMetadata, 2462 GlobalDecl D, 2463 llvm::GlobalValue *Addr) { 2464 if (!GlobalMetadata) 2465 GlobalMetadata = 2466 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 2467 2468 // TODO: should we report variant information for ctors/dtors? 2469 llvm::Value *Ops[] = { 2470 Addr, 2471 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 2472 }; 2473 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 2474} 2475 2476/// Emits metadata nodes associating all the global values in the 2477/// current module with the Decls they came from. This is useful for 2478/// projects using IR gen as a subroutine. 2479/// 2480/// Since there's currently no way to associate an MDNode directly 2481/// with an llvm::GlobalValue, we create a global named metadata 2482/// with the name 'clang.global.decl.ptrs'. 2483void CodeGenModule::EmitDeclMetadata() { 2484 llvm::NamedMDNode *GlobalMetadata = 0; 2485 2486 // StaticLocalDeclMap 2487 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 2488 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 2489 I != E; ++I) { 2490 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 2491 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 2492 } 2493} 2494 2495/// Emits metadata nodes for all the local variables in the current 2496/// function. 2497void CodeGenFunction::EmitDeclMetadata() { 2498 if (LocalDeclMap.empty()) return; 2499 2500 llvm::LLVMContext &Context = getLLVMContext(); 2501 2502 // Find the unique metadata ID for this name. 2503 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 2504 2505 llvm::NamedMDNode *GlobalMetadata = 0; 2506 2507 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 2508 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 2509 const Decl *D = I->first; 2510 llvm::Value *Addr = I->second; 2511 2512 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 2513 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 2514 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 2515 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 2516 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 2517 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 2518 } 2519 } 2520} 2521 2522void CodeGenModule::EmitCoverageFile() { 2523 if (!getCodeGenOpts().CoverageFile.empty()) { 2524 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 2525 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 2526 llvm::LLVMContext &Ctx = TheModule.getContext(); 2527 llvm::MDString *CoverageFile = 2528 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 2529 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 2530 llvm::MDNode *CU = CUNode->getOperand(i); 2531 llvm::Value *node[] = { CoverageFile, CU }; 2532 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 2533 GCov->addOperand(N); 2534 } 2535 } 2536 } 2537} 2538