CodeGenModule.cpp revision b80a16eadd0dacabfc1c32412e243ccb99dd664d
1//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This coordinates the per-module state used while generating code. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenModule.h" 15#include "CGCUDARuntime.h" 16#include "CGCXXABI.h" 17#include "CGCall.h" 18#include "CGDebugInfo.h" 19#include "CGObjCRuntime.h" 20#include "CGOpenCLRuntime.h" 21#include "CodeGenFunction.h" 22#include "CodeGenTBAA.h" 23#include "TargetInfo.h" 24#include "clang/AST/ASTContext.h" 25#include "clang/AST/CharUnits.h" 26#include "clang/AST/DeclCXX.h" 27#include "clang/AST/DeclObjC.h" 28#include "clang/AST/DeclTemplate.h" 29#include "clang/AST/Mangle.h" 30#include "clang/AST/RecordLayout.h" 31#include "clang/AST/RecursiveASTVisitor.h" 32#include "clang/Basic/Builtins.h" 33#include "clang/Basic/CharInfo.h" 34#include "clang/Basic/Diagnostic.h" 35#include "clang/Basic/Module.h" 36#include "clang/Basic/SourceManager.h" 37#include "clang/Basic/TargetInfo.h" 38#include "clang/Frontend/CodeGenOptions.h" 39#include "llvm/ADT/APSInt.h" 40#include "llvm/ADT/Triple.h" 41#include "llvm/IR/CallingConv.h" 42#include "llvm/IR/DataLayout.h" 43#include "llvm/IR/Intrinsics.h" 44#include "llvm/IR/LLVMContext.h" 45#include "llvm/IR/Module.h" 46#include "llvm/Support/CallSite.h" 47#include "llvm/Support/ConvertUTF.h" 48#include "llvm/Support/ErrorHandling.h" 49#include "llvm/Target/Mangler.h" 50 51using namespace clang; 52using namespace CodeGen; 53 54static const char AnnotationSection[] = "llvm.metadata"; 55 56static CGCXXABI &createCXXABI(CodeGenModule &CGM) { 57 switch (CGM.getTarget().getCXXABI().getKind()) { 58 case TargetCXXABI::GenericAArch64: 59 case TargetCXXABI::GenericARM: 60 case TargetCXXABI::iOS: 61 case TargetCXXABI::GenericItanium: 62 return *CreateItaniumCXXABI(CGM); 63 case TargetCXXABI::Microsoft: 64 return *CreateMicrosoftCXXABI(CGM); 65 } 66 67 llvm_unreachable("invalid C++ ABI kind"); 68} 69 70 71CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 72 llvm::Module &M, const llvm::DataLayout &TD, 73 DiagnosticsEngine &diags) 74 : Context(C), LangOpts(C.getLangOpts()), CodeGenOpts(CGO), TheModule(M), 75 Diags(diags), TheDataLayout(TD), Target(C.getTargetInfo()), 76 ABI(createCXXABI(*this)), VMContext(M.getContext()), TBAA(0), 77 TheTargetCodeGenInfo(0), Types(*this), VTables(*this), 78 ObjCRuntime(0), OpenCLRuntime(0), CUDARuntime(0), 79 DebugInfo(0), ARCData(0), NoObjCARCExceptionsMetadata(0), 80 RRData(0), CFConstantStringClassRef(0), 81 ConstantStringClassRef(0), NSConstantStringType(0), 82 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), 83 BlockObjectAssign(0), BlockObjectDispose(0), 84 BlockDescriptorType(0), GenericBlockLiteralType(0), 85 LifetimeStartFn(0), LifetimeEndFn(0), 86 SanitizerBlacklist(CGO.SanitizerBlacklistFile), 87 SanOpts(SanitizerBlacklist.isIn(M) ? 88 SanitizerOptions::Disabled : LangOpts.Sanitize) { 89 90 // Initialize the type cache. 91 llvm::LLVMContext &LLVMContext = M.getContext(); 92 VoidTy = llvm::Type::getVoidTy(LLVMContext); 93 Int8Ty = llvm::Type::getInt8Ty(LLVMContext); 94 Int16Ty = llvm::Type::getInt16Ty(LLVMContext); 95 Int32Ty = llvm::Type::getInt32Ty(LLVMContext); 96 Int64Ty = llvm::Type::getInt64Ty(LLVMContext); 97 FloatTy = llvm::Type::getFloatTy(LLVMContext); 98 DoubleTy = llvm::Type::getDoubleTy(LLVMContext); 99 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0); 100 PointerAlignInBytes = 101 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity(); 102 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth()); 103 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits); 104 Int8PtrTy = Int8Ty->getPointerTo(0); 105 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0); 106 107 RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC(); 108 109 if (LangOpts.ObjC1) 110 createObjCRuntime(); 111 if (LangOpts.OpenCL) 112 createOpenCLRuntime(); 113 if (LangOpts.CUDA) 114 createCUDARuntime(); 115 116 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0. 117 if (SanOpts.Thread || 118 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0)) 119 TBAA = new CodeGenTBAA(Context, VMContext, CodeGenOpts, getLangOpts(), 120 ABI.getMangleContext()); 121 122 // If debug info or coverage generation is enabled, create the CGDebugInfo 123 // object. 124 if (CodeGenOpts.getDebugInfo() != CodeGenOptions::NoDebugInfo || 125 CodeGenOpts.EmitGcovArcs || 126 CodeGenOpts.EmitGcovNotes) 127 DebugInfo = new CGDebugInfo(*this); 128 129 Block.GlobalUniqueCount = 0; 130 131 if (C.getLangOpts().ObjCAutoRefCount) 132 ARCData = new ARCEntrypoints(); 133 RRData = new RREntrypoints(); 134} 135 136CodeGenModule::~CodeGenModule() { 137 delete ObjCRuntime; 138 delete OpenCLRuntime; 139 delete CUDARuntime; 140 delete TheTargetCodeGenInfo; 141 delete &ABI; 142 delete TBAA; 143 delete DebugInfo; 144 delete ARCData; 145 delete RRData; 146} 147 148void CodeGenModule::createObjCRuntime() { 149 // This is just isGNUFamily(), but we want to force implementors of 150 // new ABIs to decide how best to do this. 151 switch (LangOpts.ObjCRuntime.getKind()) { 152 case ObjCRuntime::GNUstep: 153 case ObjCRuntime::GCC: 154 case ObjCRuntime::ObjFW: 155 ObjCRuntime = CreateGNUObjCRuntime(*this); 156 return; 157 158 case ObjCRuntime::FragileMacOSX: 159 case ObjCRuntime::MacOSX: 160 case ObjCRuntime::iOS: 161 ObjCRuntime = CreateMacObjCRuntime(*this); 162 return; 163 } 164 llvm_unreachable("bad runtime kind"); 165} 166 167void CodeGenModule::createOpenCLRuntime() { 168 OpenCLRuntime = new CGOpenCLRuntime(*this); 169} 170 171void CodeGenModule::createCUDARuntime() { 172 CUDARuntime = CreateNVCUDARuntime(*this); 173} 174 175void CodeGenModule::Release() { 176 EmitDeferred(); 177 EmitCXXGlobalInitFunc(); 178 EmitCXXGlobalDtorFunc(); 179 EmitCXXThreadLocalInitFunc(); 180 if (ObjCRuntime) 181 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) 182 AddGlobalCtor(ObjCInitFunction); 183 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 184 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 185 EmitGlobalAnnotations(); 186 EmitStaticExternCAliases(); 187 EmitLLVMUsed(); 188 189 if (CodeGenOpts.Autolink && Context.getLangOpts().Modules) { 190 EmitModuleLinkOptions(); 191 } 192 193 SimplifyPersonality(); 194 195 if (getCodeGenOpts().EmitDeclMetadata) 196 EmitDeclMetadata(); 197 198 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 199 EmitCoverageFile(); 200 201 if (DebugInfo) 202 DebugInfo->finalize(); 203} 204 205void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 206 // Make sure that this type is translated. 207 Types.UpdateCompletedType(TD); 208} 209 210llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 211 if (!TBAA) 212 return 0; 213 return TBAA->getTBAAInfo(QTy); 214} 215 216llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() { 217 if (!TBAA) 218 return 0; 219 return TBAA->getTBAAInfoForVTablePtr(); 220} 221 222llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) { 223 if (!TBAA) 224 return 0; 225 return TBAA->getTBAAStructInfo(QTy); 226} 227 228llvm::MDNode *CodeGenModule::getTBAAStructTypeInfo(QualType QTy) { 229 if (!TBAA) 230 return 0; 231 return TBAA->getTBAAStructTypeInfo(QTy); 232} 233 234llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy, 235 llvm::MDNode *AccessN, 236 uint64_t O) { 237 if (!TBAA) 238 return 0; 239 return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O); 240} 241 242/// Decorate the instruction with a TBAA tag. For scalar TBAA, the tag 243/// is the same as the type. For struct-path aware TBAA, the tag 244/// is different from the type: base type, access type and offset. 245/// When ConvertTypeToTag is true, we create a tag based on the scalar type. 246void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 247 llvm::MDNode *TBAAInfo, 248 bool ConvertTypeToTag) { 249 if (ConvertTypeToTag && TBAA && CodeGenOpts.StructPathTBAA) 250 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, 251 TBAA->getTBAAScalarTagInfo(TBAAInfo)); 252 else 253 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 254} 255 256void CodeGenModule::Error(SourceLocation loc, StringRef error) { 257 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); 258 getDiags().Report(Context.getFullLoc(loc), diagID); 259} 260 261/// ErrorUnsupported - Print out an error that codegen doesn't support the 262/// specified stmt yet. 263void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 264 bool OmitOnError) { 265 if (OmitOnError && getDiags().hasErrorOccurred()) 266 return; 267 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 268 "cannot compile this %0 yet"); 269 std::string Msg = Type; 270 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 271 << Msg << S->getSourceRange(); 272} 273 274/// ErrorUnsupported - Print out an error that codegen doesn't support the 275/// specified decl yet. 276void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 277 bool OmitOnError) { 278 if (OmitOnError && getDiags().hasErrorOccurred()) 279 return; 280 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 281 "cannot compile this %0 yet"); 282 std::string Msg = Type; 283 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 284} 285 286llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 287 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 288} 289 290void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 291 const NamedDecl *D) const { 292 // Internal definitions always have default visibility. 293 if (GV->hasLocalLinkage()) { 294 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 295 return; 296 } 297 298 // Set visibility for definitions. 299 LinkageInfo LV = D->getLinkageAndVisibility(); 300 if (LV.isVisibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 301 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 302} 303 304static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) { 305 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S) 306 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel) 307 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel) 308 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel) 309 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel); 310} 311 312static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel( 313 CodeGenOptions::TLSModel M) { 314 switch (M) { 315 case CodeGenOptions::GeneralDynamicTLSModel: 316 return llvm::GlobalVariable::GeneralDynamicTLSModel; 317 case CodeGenOptions::LocalDynamicTLSModel: 318 return llvm::GlobalVariable::LocalDynamicTLSModel; 319 case CodeGenOptions::InitialExecTLSModel: 320 return llvm::GlobalVariable::InitialExecTLSModel; 321 case CodeGenOptions::LocalExecTLSModel: 322 return llvm::GlobalVariable::LocalExecTLSModel; 323 } 324 llvm_unreachable("Invalid TLS model!"); 325} 326 327void CodeGenModule::setTLSMode(llvm::GlobalVariable *GV, 328 const VarDecl &D) const { 329 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!"); 330 331 llvm::GlobalVariable::ThreadLocalMode TLM; 332 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel()); 333 334 // Override the TLS model if it is explicitly specified. 335 if (D.hasAttr<TLSModelAttr>()) { 336 const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>(); 337 TLM = GetLLVMTLSModel(Attr->getModel()); 338 } 339 340 GV->setThreadLocalMode(TLM); 341} 342 343/// Set the symbol visibility of type information (vtable and RTTI) 344/// associated with the given type. 345void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 346 const CXXRecordDecl *RD, 347 TypeVisibilityKind TVK) const { 348 setGlobalVisibility(GV, RD); 349 350 if (!CodeGenOpts.HiddenWeakVTables) 351 return; 352 353 // We never want to drop the visibility for RTTI names. 354 if (TVK == TVK_ForRTTIName) 355 return; 356 357 // We want to drop the visibility to hidden for weak type symbols. 358 // This isn't possible if there might be unresolved references 359 // elsewhere that rely on this symbol being visible. 360 361 // This should be kept roughly in sync with setThunkVisibility 362 // in CGVTables.cpp. 363 364 // Preconditions. 365 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 366 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 367 return; 368 369 // Don't override an explicit visibility attribute. 370 if (RD->getExplicitVisibility(NamedDecl::VisibilityForType)) 371 return; 372 373 switch (RD->getTemplateSpecializationKind()) { 374 // We have to disable the optimization if this is an EI definition 375 // because there might be EI declarations in other shared objects. 376 case TSK_ExplicitInstantiationDefinition: 377 case TSK_ExplicitInstantiationDeclaration: 378 return; 379 380 // Every use of a non-template class's type information has to emit it. 381 case TSK_Undeclared: 382 break; 383 384 // In theory, implicit instantiations can ignore the possibility of 385 // an explicit instantiation declaration because there necessarily 386 // must be an EI definition somewhere with default visibility. In 387 // practice, it's possible to have an explicit instantiation for 388 // an arbitrary template class, and linkers aren't necessarily able 389 // to deal with mixed-visibility symbols. 390 case TSK_ExplicitSpecialization: 391 case TSK_ImplicitInstantiation: 392 return; 393 } 394 395 // If there's a key function, there may be translation units 396 // that don't have the key function's definition. But ignore 397 // this if we're emitting RTTI under -fno-rtti. 398 if (!(TVK != TVK_ForRTTI) || LangOpts.RTTI) { 399 // FIXME: what should we do if we "lose" the key function during 400 // the emission of the file? 401 if (Context.getCurrentKeyFunction(RD)) 402 return; 403 } 404 405 // Otherwise, drop the visibility to hidden. 406 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 407 GV->setUnnamedAddr(true); 408} 409 410StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 411 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 412 413 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 414 if (!Str.empty()) 415 return Str; 416 417 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 418 IdentifierInfo *II = ND->getIdentifier(); 419 assert(II && "Attempt to mangle unnamed decl."); 420 421 Str = II->getName(); 422 return Str; 423 } 424 425 SmallString<256> Buffer; 426 llvm::raw_svector_ostream Out(Buffer); 427 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 428 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 429 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 430 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 431 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND)) 432 getCXXABI().getMangleContext().mangleBlock(BD, Out, 433 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl())); 434 else 435 getCXXABI().getMangleContext().mangleName(ND, Out); 436 437 // Allocate space for the mangled name. 438 Out.flush(); 439 size_t Length = Buffer.size(); 440 char *Name = MangledNamesAllocator.Allocate<char>(Length); 441 std::copy(Buffer.begin(), Buffer.end(), Name); 442 443 Str = StringRef(Name, Length); 444 445 return Str; 446} 447 448void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 449 const BlockDecl *BD) { 450 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 451 const Decl *D = GD.getDecl(); 452 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 453 if (D == 0) 454 MangleCtx.mangleGlobalBlock(BD, 455 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out); 456 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 457 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 458 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 459 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 460 else 461 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 462} 463 464llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 465 return getModule().getNamedValue(Name); 466} 467 468/// AddGlobalCtor - Add a function to the list that will be called before 469/// main() runs. 470void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 471 // FIXME: Type coercion of void()* types. 472 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 473} 474 475/// AddGlobalDtor - Add a function to the list that will be called 476/// when the module is unloaded. 477void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 478 // FIXME: Type coercion of void()* types. 479 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 480} 481 482void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 483 // Ctor function type is void()*. 484 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 485 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 486 487 // Get the type of a ctor entry, { i32, void ()* }. 488 llvm::StructType *CtorStructTy = 489 llvm::StructType::get(Int32Ty, llvm::PointerType::getUnqual(CtorFTy), NULL); 490 491 // Construct the constructor and destructor arrays. 492 SmallVector<llvm::Constant*, 8> Ctors; 493 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 494 llvm::Constant *S[] = { 495 llvm::ConstantInt::get(Int32Ty, I->second, false), 496 llvm::ConstantExpr::getBitCast(I->first, CtorPFTy) 497 }; 498 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 499 } 500 501 if (!Ctors.empty()) { 502 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 503 new llvm::GlobalVariable(TheModule, AT, false, 504 llvm::GlobalValue::AppendingLinkage, 505 llvm::ConstantArray::get(AT, Ctors), 506 GlobalName); 507 } 508} 509 510llvm::GlobalValue::LinkageTypes 511CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 512 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 513 514 if (Linkage == GVA_Internal) 515 return llvm::Function::InternalLinkage; 516 517 if (D->hasAttr<DLLExportAttr>()) 518 return llvm::Function::DLLExportLinkage; 519 520 if (D->hasAttr<WeakAttr>()) 521 return llvm::Function::WeakAnyLinkage; 522 523 // In C99 mode, 'inline' functions are guaranteed to have a strong 524 // definition somewhere else, so we can use available_externally linkage. 525 if (Linkage == GVA_C99Inline) 526 return llvm::Function::AvailableExternallyLinkage; 527 528 // Note that Apple's kernel linker doesn't support symbol 529 // coalescing, so we need to avoid linkonce and weak linkages there. 530 // Normally, this means we just map to internal, but for explicit 531 // instantiations we'll map to external. 532 533 // In C++, the compiler has to emit a definition in every translation unit 534 // that references the function. We should use linkonce_odr because 535 // a) if all references in this translation unit are optimized away, we 536 // don't need to codegen it. b) if the function persists, it needs to be 537 // merged with other definitions. c) C++ has the ODR, so we know the 538 // definition is dependable. 539 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 540 return !Context.getLangOpts().AppleKext 541 ? llvm::Function::LinkOnceODRLinkage 542 : llvm::Function::InternalLinkage; 543 544 // An explicit instantiation of a template has weak linkage, since 545 // explicit instantiations can occur in multiple translation units 546 // and must all be equivalent. However, we are not allowed to 547 // throw away these explicit instantiations. 548 if (Linkage == GVA_ExplicitTemplateInstantiation) 549 return !Context.getLangOpts().AppleKext 550 ? llvm::Function::WeakODRLinkage 551 : llvm::Function::ExternalLinkage; 552 553 // Otherwise, we have strong external linkage. 554 assert(Linkage == GVA_StrongExternal); 555 return llvm::Function::ExternalLinkage; 556} 557 558 559/// SetFunctionDefinitionAttributes - Set attributes for a global. 560/// 561/// FIXME: This is currently only done for aliases and functions, but not for 562/// variables (these details are set in EmitGlobalVarDefinition for variables). 563void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 564 llvm::GlobalValue *GV) { 565 SetCommonAttributes(D, GV); 566} 567 568void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 569 const CGFunctionInfo &Info, 570 llvm::Function *F) { 571 unsigned CallingConv; 572 AttributeListType AttributeList; 573 ConstructAttributeList(Info, D, AttributeList, CallingConv, false); 574 F->setAttributes(llvm::AttributeSet::get(getLLVMContext(), AttributeList)); 575 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 576} 577 578/// Determines whether the language options require us to model 579/// unwind exceptions. We treat -fexceptions as mandating this 580/// except under the fragile ObjC ABI with only ObjC exceptions 581/// enabled. This means, for example, that C with -fexceptions 582/// enables this. 583static bool hasUnwindExceptions(const LangOptions &LangOpts) { 584 // If exceptions are completely disabled, obviously this is false. 585 if (!LangOpts.Exceptions) return false; 586 587 // If C++ exceptions are enabled, this is true. 588 if (LangOpts.CXXExceptions) return true; 589 590 // If ObjC exceptions are enabled, this depends on the ABI. 591 if (LangOpts.ObjCExceptions) { 592 return LangOpts.ObjCRuntime.hasUnwindExceptions(); 593 } 594 595 return true; 596} 597 598void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 599 llvm::Function *F) { 600 if (CodeGenOpts.UnwindTables) 601 F->setHasUWTable(); 602 603 if (!hasUnwindExceptions(LangOpts)) 604 F->addFnAttr(llvm::Attribute::NoUnwind); 605 606 if (D->hasAttr<NakedAttr>()) { 607 // Naked implies noinline: we should not be inlining such functions. 608 F->addFnAttr(llvm::Attribute::Naked); 609 F->addFnAttr(llvm::Attribute::NoInline); 610 } 611 612 if (D->hasAttr<NoInlineAttr>()) 613 F->addFnAttr(llvm::Attribute::NoInline); 614 615 // (noinline wins over always_inline, and we can't specify both in IR) 616 if ((D->hasAttr<AlwaysInlineAttr>() || D->hasAttr<ForceInlineAttr>()) && 617 !F->getAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex, 618 llvm::Attribute::NoInline)) 619 F->addFnAttr(llvm::Attribute::AlwaysInline); 620 621 // FIXME: Communicate hot and cold attributes to LLVM more directly. 622 if (D->hasAttr<ColdAttr>()) 623 F->addFnAttr(llvm::Attribute::OptimizeForSize); 624 625 if (D->hasAttr<MinSizeAttr>()) 626 F->addFnAttr(llvm::Attribute::MinSize); 627 628 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 629 F->setUnnamedAddr(true); 630 631 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) 632 if (MD->isVirtual()) 633 F->setUnnamedAddr(true); 634 635 if (LangOpts.getStackProtector() == LangOptions::SSPOn) 636 F->addFnAttr(llvm::Attribute::StackProtect); 637 else if (LangOpts.getStackProtector() == LangOptions::SSPReq) 638 F->addFnAttr(llvm::Attribute::StackProtectReq); 639 640 // Add sanitizer attributes if function is not blacklisted. 641 if (!SanitizerBlacklist.isIn(*F)) { 642 // When AddressSanitizer is enabled, set SanitizeAddress attribute 643 // unless __attribute__((no_sanitize_address)) is used. 644 if (SanOpts.Address && !D->hasAttr<NoSanitizeAddressAttr>()) 645 F->addFnAttr(llvm::Attribute::SanitizeAddress); 646 // Same for ThreadSanitizer and __attribute__((no_sanitize_thread)) 647 if (SanOpts.Thread && !D->hasAttr<NoSanitizeThreadAttr>()) { 648 F->addFnAttr(llvm::Attribute::SanitizeThread); 649 } 650 // Same for MemorySanitizer and __attribute__((no_sanitize_memory)) 651 if (SanOpts.Memory && !D->hasAttr<NoSanitizeMemoryAttr>()) 652 F->addFnAttr(llvm::Attribute::SanitizeMemory); 653 } 654 655 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 656 if (alignment) 657 F->setAlignment(alignment); 658 659 // C++ ABI requires 2-byte alignment for member functions. 660 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 661 F->setAlignment(2); 662} 663 664void CodeGenModule::SetCommonAttributes(const Decl *D, 665 llvm::GlobalValue *GV) { 666 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 667 setGlobalVisibility(GV, ND); 668 else 669 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 670 671 if (D->hasAttr<UsedAttr>()) 672 AddUsedGlobal(GV); 673 674 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 675 GV->setSection(SA->getName()); 676 677 // Alias cannot have attributes. Filter them here. 678 if (!isa<llvm::GlobalAlias>(GV)) 679 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 680} 681 682void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 683 llvm::Function *F, 684 const CGFunctionInfo &FI) { 685 SetLLVMFunctionAttributes(D, FI, F); 686 SetLLVMFunctionAttributesForDefinition(D, F); 687 688 F->setLinkage(llvm::Function::InternalLinkage); 689 690 SetCommonAttributes(D, F); 691} 692 693void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 694 llvm::Function *F, 695 bool IsIncompleteFunction) { 696 if (unsigned IID = F->getIntrinsicID()) { 697 // If this is an intrinsic function, set the function's attributes 698 // to the intrinsic's attributes. 699 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), 700 (llvm::Intrinsic::ID)IID)); 701 return; 702 } 703 704 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 705 706 if (!IsIncompleteFunction) 707 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F); 708 709 // Only a few attributes are set on declarations; these may later be 710 // overridden by a definition. 711 712 if (FD->hasAttr<DLLImportAttr>()) { 713 F->setLinkage(llvm::Function::DLLImportLinkage); 714 } else if (FD->hasAttr<WeakAttr>() || 715 FD->isWeakImported()) { 716 // "extern_weak" is overloaded in LLVM; we probably should have 717 // separate linkage types for this. 718 F->setLinkage(llvm::Function::ExternalWeakLinkage); 719 } else { 720 F->setLinkage(llvm::Function::ExternalLinkage); 721 722 LinkageInfo LV = FD->getLinkageAndVisibility(); 723 if (LV.getLinkage() == ExternalLinkage && LV.isVisibilityExplicit()) { 724 F->setVisibility(GetLLVMVisibility(LV.getVisibility())); 725 } 726 } 727 728 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 729 F->setSection(SA->getName()); 730} 731 732void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 733 assert(!GV->isDeclaration() && 734 "Only globals with definition can force usage."); 735 LLVMUsed.push_back(GV); 736} 737 738void CodeGenModule::EmitLLVMUsed() { 739 // Don't create llvm.used if there is no need. 740 if (LLVMUsed.empty()) 741 return; 742 743 // Convert LLVMUsed to what ConstantArray needs. 744 SmallVector<llvm::Constant*, 8> UsedArray; 745 UsedArray.resize(LLVMUsed.size()); 746 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 747 UsedArray[i] = 748 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 749 Int8PtrTy); 750 } 751 752 if (UsedArray.empty()) 753 return; 754 llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size()); 755 756 llvm::GlobalVariable *GV = 757 new llvm::GlobalVariable(getModule(), ATy, false, 758 llvm::GlobalValue::AppendingLinkage, 759 llvm::ConstantArray::get(ATy, UsedArray), 760 "llvm.used"); 761 762 GV->setSection("llvm.metadata"); 763} 764 765/// \brief Add link options implied by the given module, including modules 766/// it depends on, using a postorder walk. 767static void addLinkOptionsPostorder(llvm::LLVMContext &Context, 768 Module *Mod, 769 SmallVectorImpl<llvm::Value *> &Metadata, 770 llvm::SmallPtrSet<Module *, 16> &Visited) { 771 // Import this module's parent. 772 if (Mod->Parent && Visited.insert(Mod->Parent)) { 773 addLinkOptionsPostorder(Context, Mod->Parent, Metadata, Visited); 774 } 775 776 // Import this module's dependencies. 777 for (unsigned I = Mod->Imports.size(); I > 0; --I) { 778 if (Visited.insert(Mod->Imports[I-1])) 779 addLinkOptionsPostorder(Context, Mod->Imports[I-1], Metadata, Visited); 780 } 781 782 // Add linker options to link against the libraries/frameworks 783 // described by this module. 784 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) { 785 // FIXME: -lfoo is Unix-centric and -framework Foo is Darwin-centric. 786 // We need to know more about the linker to know how to encode these 787 // options propertly. 788 789 // Link against a framework. 790 if (Mod->LinkLibraries[I-1].IsFramework) { 791 llvm::Value *Args[2] = { 792 llvm::MDString::get(Context, "-framework"), 793 llvm::MDString::get(Context, Mod->LinkLibraries[I-1].Library) 794 }; 795 796 Metadata.push_back(llvm::MDNode::get(Context, Args)); 797 continue; 798 } 799 800 // Link against a library. 801 llvm::Value *OptString 802 = llvm::MDString::get(Context, 803 "-l" + Mod->LinkLibraries[I-1].Library); 804 Metadata.push_back(llvm::MDNode::get(Context, OptString)); 805 } 806} 807 808void CodeGenModule::EmitModuleLinkOptions() { 809 // Collect the set of all of the modules we want to visit to emit link 810 // options, which is essentially the imported modules and all of their 811 // non-explicit child modules. 812 llvm::SetVector<clang::Module *> LinkModules; 813 llvm::SmallPtrSet<clang::Module *, 16> Visited; 814 SmallVector<clang::Module *, 16> Stack; 815 816 // Seed the stack with imported modules. 817 for (llvm::SetVector<clang::Module *>::iterator M = ImportedModules.begin(), 818 MEnd = ImportedModules.end(); 819 M != MEnd; ++M) { 820 if (Visited.insert(*M)) 821 Stack.push_back(*M); 822 } 823 824 // Find all of the modules to import, making a little effort to prune 825 // non-leaf modules. 826 while (!Stack.empty()) { 827 clang::Module *Mod = Stack.back(); 828 Stack.pop_back(); 829 830 bool AnyChildren = false; 831 832 // Visit the submodules of this module. 833 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(), 834 SubEnd = Mod->submodule_end(); 835 Sub != SubEnd; ++Sub) { 836 // Skip explicit children; they need to be explicitly imported to be 837 // linked against. 838 if ((*Sub)->IsExplicit) 839 continue; 840 841 if (Visited.insert(*Sub)) { 842 Stack.push_back(*Sub); 843 AnyChildren = true; 844 } 845 } 846 847 // We didn't find any children, so add this module to the list of 848 // modules to link against. 849 if (!AnyChildren) { 850 LinkModules.insert(Mod); 851 } 852 } 853 854 // Add link options for all of the imported modules in reverse topological 855 // order. 856 SmallVector<llvm::Value *, 16> MetadataArgs; 857 Visited.clear(); 858 for (llvm::SetVector<clang::Module *>::iterator M = LinkModules.begin(), 859 MEnd = LinkModules.end(); 860 M != MEnd; ++M) { 861 if (Visited.insert(*M)) 862 addLinkOptionsPostorder(getLLVMContext(), *M, MetadataArgs, Visited); 863 } 864 std::reverse(MetadataArgs.begin(), MetadataArgs.end()); 865 866 // Add the linker options metadata flag. 867 getModule().addModuleFlag(llvm::Module::AppendUnique, "Linker Options", 868 llvm::MDNode::get(getLLVMContext(), MetadataArgs)); 869} 870 871void CodeGenModule::EmitDeferred() { 872 // Emit code for any potentially referenced deferred decls. Since a 873 // previously unused static decl may become used during the generation of code 874 // for a static function, iterate until no changes are made. 875 876 while (true) { 877 if (!DeferredVTables.empty()) { 878 EmitDeferredVTables(); 879 880 // Emitting a v-table doesn't directly cause more v-tables to 881 // become deferred, although it can cause functions to be 882 // emitted that then need those v-tables. 883 assert(DeferredVTables.empty()); 884 } 885 886 // Stop if we're out of both deferred v-tables and deferred declarations. 887 if (DeferredDeclsToEmit.empty()) break; 888 889 GlobalDecl D = DeferredDeclsToEmit.back(); 890 DeferredDeclsToEmit.pop_back(); 891 892 // Check to see if we've already emitted this. This is necessary 893 // for a couple of reasons: first, decls can end up in the 894 // deferred-decls queue multiple times, and second, decls can end 895 // up with definitions in unusual ways (e.g. by an extern inline 896 // function acquiring a strong function redefinition). Just 897 // ignore these cases. 898 // 899 // TODO: That said, looking this up multiple times is very wasteful. 900 StringRef Name = getMangledName(D); 901 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 902 assert(CGRef && "Deferred decl wasn't referenced?"); 903 904 if (!CGRef->isDeclaration()) 905 continue; 906 907 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 908 // purposes an alias counts as a definition. 909 if (isa<llvm::GlobalAlias>(CGRef)) 910 continue; 911 912 // Otherwise, emit the definition and move on to the next one. 913 EmitGlobalDefinition(D); 914 } 915} 916 917void CodeGenModule::EmitGlobalAnnotations() { 918 if (Annotations.empty()) 919 return; 920 921 // Create a new global variable for the ConstantStruct in the Module. 922 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 923 Annotations[0]->getType(), Annotations.size()), Annotations); 924 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), 925 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, 926 "llvm.global.annotations"); 927 gv->setSection(AnnotationSection); 928} 929 930llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) { 931 llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str); 932 if (i != AnnotationStrings.end()) 933 return i->second; 934 935 // Not found yet, create a new global. 936 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); 937 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), 938 true, llvm::GlobalValue::PrivateLinkage, s, ".str"); 939 gv->setSection(AnnotationSection); 940 gv->setUnnamedAddr(true); 941 AnnotationStrings[Str] = gv; 942 return gv; 943} 944 945llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 946 SourceManager &SM = getContext().getSourceManager(); 947 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 948 if (PLoc.isValid()) 949 return EmitAnnotationString(PLoc.getFilename()); 950 return EmitAnnotationString(SM.getBufferName(Loc)); 951} 952 953llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 954 SourceManager &SM = getContext().getSourceManager(); 955 PresumedLoc PLoc = SM.getPresumedLoc(L); 956 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 957 SM.getExpansionLineNumber(L); 958 return llvm::ConstantInt::get(Int32Ty, LineNo); 959} 960 961llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 962 const AnnotateAttr *AA, 963 SourceLocation L) { 964 // Get the globals for file name, annotation, and the line number. 965 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 966 *UnitGV = EmitAnnotationUnit(L), 967 *LineNoCst = EmitAnnotationLineNo(L); 968 969 // Create the ConstantStruct for the global annotation. 970 llvm::Constant *Fields[4] = { 971 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 972 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 973 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 974 LineNoCst 975 }; 976 return llvm::ConstantStruct::getAnon(Fields); 977} 978 979void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 980 llvm::GlobalValue *GV) { 981 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 982 // Get the struct elements for these annotations. 983 for (specific_attr_iterator<AnnotateAttr> 984 ai = D->specific_attr_begin<AnnotateAttr>(), 985 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) 986 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); 987} 988 989bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 990 // Never defer when EmitAllDecls is specified. 991 if (LangOpts.EmitAllDecls) 992 return false; 993 994 return !getContext().DeclMustBeEmitted(Global); 995} 996 997llvm::Constant *CodeGenModule::GetAddrOfUuidDescriptor( 998 const CXXUuidofExpr* E) { 999 // Sema has verified that IIDSource has a __declspec(uuid()), and that its 1000 // well-formed. 1001 StringRef Uuid; 1002 if (E->isTypeOperand()) 1003 Uuid = CXXUuidofExpr::GetUuidAttrOfType(E->getTypeOperand())->getGuid(); 1004 else { 1005 // Special case: __uuidof(0) means an all-zero GUID. 1006 Expr *Op = E->getExprOperand(); 1007 if (!Op->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 1008 Uuid = CXXUuidofExpr::GetUuidAttrOfType(Op->getType())->getGuid(); 1009 else 1010 Uuid = "00000000-0000-0000-0000-000000000000"; 1011 } 1012 std::string Name = "__uuid_" + Uuid.str(); 1013 1014 // Look for an existing global. 1015 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name)) 1016 return GV; 1017 1018 llvm::Constant *Init = EmitUuidofInitializer(Uuid, E->getType()); 1019 assert(Init && "failed to initialize as constant"); 1020 1021 // GUIDs are assumed to be 16 bytes, spread over 4-2-2-8 bytes. However, the 1022 // first field is declared as "long", which for many targets is 8 bytes. 1023 // Those architectures are not supported. (With the MS abi, long is always 4 1024 // bytes.) 1025 llvm::Type *GuidType = getTypes().ConvertType(E->getType()); 1026 if (Init->getType() != GuidType) { 1027 DiagnosticsEngine &Diags = getDiags(); 1028 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error, 1029 "__uuidof codegen is not supported on this architecture"); 1030 Diags.Report(E->getExprLoc(), DiagID) << E->getSourceRange(); 1031 Init = llvm::UndefValue::get(GuidType); 1032 } 1033 1034 llvm::GlobalVariable *GV = new llvm::GlobalVariable(getModule(), GuidType, 1035 /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, Init, Name); 1036 GV->setUnnamedAddr(true); 1037 return GV; 1038} 1039 1040llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 1041 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 1042 assert(AA && "No alias?"); 1043 1044 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 1045 1046 // See if there is already something with the target's name in the module. 1047 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 1048 if (Entry) { 1049 unsigned AS = getContext().getTargetAddressSpace(VD->getType()); 1050 return llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS)); 1051 } 1052 1053 llvm::Constant *Aliasee; 1054 if (isa<llvm::FunctionType>(DeclTy)) 1055 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, 1056 GlobalDecl(cast<FunctionDecl>(VD)), 1057 /*ForVTable=*/false); 1058 else 1059 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1060 llvm::PointerType::getUnqual(DeclTy), 0); 1061 1062 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 1063 F->setLinkage(llvm::Function::ExternalWeakLinkage); 1064 WeakRefReferences.insert(F); 1065 1066 return Aliasee; 1067} 1068 1069void CodeGenModule::EmitGlobal(GlobalDecl GD) { 1070 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 1071 1072 // Weak references don't produce any output by themselves. 1073 if (Global->hasAttr<WeakRefAttr>()) 1074 return; 1075 1076 // If this is an alias definition (which otherwise looks like a declaration) 1077 // emit it now. 1078 if (Global->hasAttr<AliasAttr>()) 1079 return EmitAliasDefinition(GD); 1080 1081 // If this is CUDA, be selective about which declarations we emit. 1082 if (LangOpts.CUDA) { 1083 if (CodeGenOpts.CUDAIsDevice) { 1084 if (!Global->hasAttr<CUDADeviceAttr>() && 1085 !Global->hasAttr<CUDAGlobalAttr>() && 1086 !Global->hasAttr<CUDAConstantAttr>() && 1087 !Global->hasAttr<CUDASharedAttr>()) 1088 return; 1089 } else { 1090 if (!Global->hasAttr<CUDAHostAttr>() && ( 1091 Global->hasAttr<CUDADeviceAttr>() || 1092 Global->hasAttr<CUDAConstantAttr>() || 1093 Global->hasAttr<CUDASharedAttr>())) 1094 return; 1095 } 1096 } 1097 1098 // Ignore declarations, they will be emitted on their first use. 1099 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 1100 // Forward declarations are emitted lazily on first use. 1101 if (!FD->doesThisDeclarationHaveABody()) { 1102 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 1103 return; 1104 1105 const FunctionDecl *InlineDefinition = 0; 1106 FD->getBody(InlineDefinition); 1107 1108 StringRef MangledName = getMangledName(GD); 1109 DeferredDecls.erase(MangledName); 1110 EmitGlobalDefinition(InlineDefinition); 1111 return; 1112 } 1113 } else { 1114 const VarDecl *VD = cast<VarDecl>(Global); 1115 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 1116 1117 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 1118 return; 1119 } 1120 1121 // Defer code generation when possible if this is a static definition, inline 1122 // function etc. These we only want to emit if they are used. 1123 if (!MayDeferGeneration(Global)) { 1124 // Emit the definition if it can't be deferred. 1125 EmitGlobalDefinition(GD); 1126 return; 1127 } 1128 1129 // If we're deferring emission of a C++ variable with an 1130 // initializer, remember the order in which it appeared in the file. 1131 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) && 1132 cast<VarDecl>(Global)->hasInit()) { 1133 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 1134 CXXGlobalInits.push_back(0); 1135 } 1136 1137 // If the value has already been used, add it directly to the 1138 // DeferredDeclsToEmit list. 1139 StringRef MangledName = getMangledName(GD); 1140 if (GetGlobalValue(MangledName)) 1141 DeferredDeclsToEmit.push_back(GD); 1142 else { 1143 // Otherwise, remember that we saw a deferred decl with this name. The 1144 // first use of the mangled name will cause it to move into 1145 // DeferredDeclsToEmit. 1146 DeferredDecls[MangledName] = GD; 1147 } 1148} 1149 1150namespace { 1151 struct FunctionIsDirectlyRecursive : 1152 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> { 1153 const StringRef Name; 1154 const Builtin::Context &BI; 1155 bool Result; 1156 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) : 1157 Name(N), BI(C), Result(false) { 1158 } 1159 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; 1160 1161 bool TraverseCallExpr(CallExpr *E) { 1162 const FunctionDecl *FD = E->getDirectCallee(); 1163 if (!FD) 1164 return true; 1165 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1166 if (Attr && Name == Attr->getLabel()) { 1167 Result = true; 1168 return false; 1169 } 1170 unsigned BuiltinID = FD->getBuiltinID(); 1171 if (!BuiltinID) 1172 return true; 1173 StringRef BuiltinName = BI.GetName(BuiltinID); 1174 if (BuiltinName.startswith("__builtin_") && 1175 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { 1176 Result = true; 1177 return false; 1178 } 1179 return true; 1180 } 1181 }; 1182} 1183 1184// isTriviallyRecursive - Check if this function calls another 1185// decl that, because of the asm attribute or the other decl being a builtin, 1186// ends up pointing to itself. 1187bool 1188CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { 1189 StringRef Name; 1190 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { 1191 // asm labels are a special kind of mangling we have to support. 1192 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1193 if (!Attr) 1194 return false; 1195 Name = Attr->getLabel(); 1196 } else { 1197 Name = FD->getName(); 1198 } 1199 1200 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); 1201 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD)); 1202 return Walker.Result; 1203} 1204 1205bool 1206CodeGenModule::shouldEmitFunction(const FunctionDecl *F) { 1207 if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage) 1208 return true; 1209 if (CodeGenOpts.OptimizationLevel == 0 && 1210 !F->hasAttr<AlwaysInlineAttr>() && !F->hasAttr<ForceInlineAttr>()) 1211 return false; 1212 // PR9614. Avoid cases where the source code is lying to us. An available 1213 // externally function should have an equivalent function somewhere else, 1214 // but a function that calls itself is clearly not equivalent to the real 1215 // implementation. 1216 // This happens in glibc's btowc and in some configure checks. 1217 return !isTriviallyRecursive(F); 1218} 1219 1220void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 1221 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1222 1223 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 1224 Context.getSourceManager(), 1225 "Generating code for declaration"); 1226 1227 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 1228 // At -O0, don't generate IR for functions with available_externally 1229 // linkage. 1230 if (!shouldEmitFunction(Function)) 1231 return; 1232 1233 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 1234 // Make sure to emit the definition(s) before we emit the thunks. 1235 // This is necessary for the generation of certain thunks. 1236 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 1237 EmitCXXConstructor(CD, GD.getCtorType()); 1238 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 1239 EmitCXXDestructor(DD, GD.getDtorType()); 1240 else 1241 EmitGlobalFunctionDefinition(GD); 1242 1243 if (Method->isVirtual()) 1244 getVTables().EmitThunks(GD); 1245 1246 return; 1247 } 1248 1249 return EmitGlobalFunctionDefinition(GD); 1250 } 1251 1252 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 1253 return EmitGlobalVarDefinition(VD); 1254 1255 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 1256} 1257 1258/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 1259/// module, create and return an llvm Function with the specified type. If there 1260/// is something in the module with the specified name, return it potentially 1261/// bitcasted to the right type. 1262/// 1263/// If D is non-null, it specifies a decl that correspond to this. This is used 1264/// to set the attributes on the function when it is first created. 1265llvm::Constant * 1266CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 1267 llvm::Type *Ty, 1268 GlobalDecl D, bool ForVTable, 1269 llvm::AttributeSet ExtraAttrs) { 1270 // Lookup the entry, lazily creating it if necessary. 1271 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1272 if (Entry) { 1273 if (WeakRefReferences.erase(Entry)) { 1274 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 1275 if (FD && !FD->hasAttr<WeakAttr>()) 1276 Entry->setLinkage(llvm::Function::ExternalLinkage); 1277 } 1278 1279 if (Entry->getType()->getElementType() == Ty) 1280 return Entry; 1281 1282 // Make sure the result is of the correct type. 1283 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 1284 } 1285 1286 // This function doesn't have a complete type (for example, the return 1287 // type is an incomplete struct). Use a fake type instead, and make 1288 // sure not to try to set attributes. 1289 bool IsIncompleteFunction = false; 1290 1291 llvm::FunctionType *FTy; 1292 if (isa<llvm::FunctionType>(Ty)) { 1293 FTy = cast<llvm::FunctionType>(Ty); 1294 } else { 1295 FTy = llvm::FunctionType::get(VoidTy, false); 1296 IsIncompleteFunction = true; 1297 } 1298 1299 llvm::Function *F = llvm::Function::Create(FTy, 1300 llvm::Function::ExternalLinkage, 1301 MangledName, &getModule()); 1302 assert(F->getName() == MangledName && "name was uniqued!"); 1303 if (D.getDecl()) 1304 SetFunctionAttributes(D, F, IsIncompleteFunction); 1305 if (ExtraAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) { 1306 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeSet::FunctionIndex); 1307 F->addAttributes(llvm::AttributeSet::FunctionIndex, 1308 llvm::AttributeSet::get(VMContext, 1309 llvm::AttributeSet::FunctionIndex, 1310 B)); 1311 } 1312 1313 // This is the first use or definition of a mangled name. If there is a 1314 // deferred decl with this name, remember that we need to emit it at the end 1315 // of the file. 1316 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1317 if (DDI != DeferredDecls.end()) { 1318 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1319 // list, and remove it from DeferredDecls (since we don't need it anymore). 1320 DeferredDeclsToEmit.push_back(DDI->second); 1321 DeferredDecls.erase(DDI); 1322 1323 // Otherwise, there are cases we have to worry about where we're 1324 // using a declaration for which we must emit a definition but where 1325 // we might not find a top-level definition: 1326 // - member functions defined inline in their classes 1327 // - friend functions defined inline in some class 1328 // - special member functions with implicit definitions 1329 // If we ever change our AST traversal to walk into class methods, 1330 // this will be unnecessary. 1331 // 1332 // We also don't emit a definition for a function if it's going to be an entry 1333 // in a vtable, unless it's already marked as used. 1334 } else if (getLangOpts().CPlusPlus && D.getDecl()) { 1335 // Look for a declaration that's lexically in a record. 1336 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); 1337 FD = FD->getMostRecentDecl(); 1338 do { 1339 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 1340 if (FD->isImplicit() && !ForVTable) { 1341 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 1342 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1343 break; 1344 } else if (FD->doesThisDeclarationHaveABody()) { 1345 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1346 break; 1347 } 1348 } 1349 FD = FD->getPreviousDecl(); 1350 } while (FD); 1351 } 1352 1353 // Make sure the result is of the requested type. 1354 if (!IsIncompleteFunction) { 1355 assert(F->getType()->getElementType() == Ty); 1356 return F; 1357 } 1358 1359 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1360 return llvm::ConstantExpr::getBitCast(F, PTy); 1361} 1362 1363/// GetAddrOfFunction - Return the address of the given function. If Ty is 1364/// non-null, then this function will use the specified type if it has to 1365/// create it (this occurs when we see a definition of the function). 1366llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 1367 llvm::Type *Ty, 1368 bool ForVTable) { 1369 // If there was no specific requested type, just convert it now. 1370 if (!Ty) 1371 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 1372 1373 StringRef MangledName = getMangledName(GD); 1374 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 1375} 1376 1377/// CreateRuntimeFunction - Create a new runtime function with the specified 1378/// type and name. 1379llvm::Constant * 1380CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 1381 StringRef Name, 1382 llvm::AttributeSet ExtraAttrs) { 1383 llvm::Constant *C 1384 = GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 1385 ExtraAttrs); 1386 if (llvm::Function *F = dyn_cast<llvm::Function>(C)) 1387 if (F->empty()) 1388 F->setCallingConv(getRuntimeCC()); 1389 return C; 1390} 1391 1392/// isTypeConstant - Determine whether an object of this type can be emitted 1393/// as a constant. 1394/// 1395/// If ExcludeCtor is true, the duration when the object's constructor runs 1396/// will not be considered. The caller will need to verify that the object is 1397/// not written to during its construction. 1398bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) { 1399 if (!Ty.isConstant(Context) && !Ty->isReferenceType()) 1400 return false; 1401 1402 if (Context.getLangOpts().CPlusPlus) { 1403 if (const CXXRecordDecl *Record 1404 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl()) 1405 return ExcludeCtor && !Record->hasMutableFields() && 1406 Record->hasTrivialDestructor(); 1407 } 1408 1409 return true; 1410} 1411 1412/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1413/// create and return an llvm GlobalVariable with the specified type. If there 1414/// is something in the module with the specified name, return it potentially 1415/// bitcasted to the right type. 1416/// 1417/// If D is non-null, it specifies a decl that correspond to this. This is used 1418/// to set the attributes on the global when it is first created. 1419llvm::Constant * 1420CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1421 llvm::PointerType *Ty, 1422 const VarDecl *D, 1423 bool UnnamedAddr) { 1424 // Lookup the entry, lazily creating it if necessary. 1425 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1426 if (Entry) { 1427 if (WeakRefReferences.erase(Entry)) { 1428 if (D && !D->hasAttr<WeakAttr>()) 1429 Entry->setLinkage(llvm::Function::ExternalLinkage); 1430 } 1431 1432 if (UnnamedAddr) 1433 Entry->setUnnamedAddr(true); 1434 1435 if (Entry->getType() == Ty) 1436 return Entry; 1437 1438 // Make sure the result is of the correct type. 1439 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1440 } 1441 1442 // This is the first use or definition of a mangled name. If there is a 1443 // deferred decl with this name, remember that we need to emit it at the end 1444 // of the file. 1445 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1446 if (DDI != DeferredDecls.end()) { 1447 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1448 // list, and remove it from DeferredDecls (since we don't need it anymore). 1449 DeferredDeclsToEmit.push_back(DDI->second); 1450 DeferredDecls.erase(DDI); 1451 } 1452 1453 unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace()); 1454 llvm::GlobalVariable *GV = 1455 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1456 llvm::GlobalValue::ExternalLinkage, 1457 0, MangledName, 0, 1458 llvm::GlobalVariable::NotThreadLocal, AddrSpace); 1459 1460 // Handle things which are present even on external declarations. 1461 if (D) { 1462 // FIXME: This code is overly simple and should be merged with other global 1463 // handling. 1464 GV->setConstant(isTypeConstant(D->getType(), false)); 1465 1466 // Set linkage and visibility in case we never see a definition. 1467 LinkageInfo LV = D->getLinkageAndVisibility(); 1468 if (LV.getLinkage() != ExternalLinkage) { 1469 // Don't set internal linkage on declarations. 1470 } else { 1471 if (D->hasAttr<DLLImportAttr>()) 1472 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1473 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1474 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1475 1476 // Set visibility on a declaration only if it's explicit. 1477 if (LV.isVisibilityExplicit()) 1478 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 1479 } 1480 1481 if (D->getTLSKind()) { 1482 CXXThreadLocals.push_back(std::make_pair(D, GV)); 1483 setTLSMode(GV, *D); 1484 } 1485 } 1486 1487 if (AddrSpace != Ty->getAddressSpace()) 1488 return llvm::ConstantExpr::getBitCast(GV, Ty); 1489 else 1490 return GV; 1491} 1492 1493 1494llvm::GlobalVariable * 1495CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1496 llvm::Type *Ty, 1497 llvm::GlobalValue::LinkageTypes Linkage) { 1498 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1499 llvm::GlobalVariable *OldGV = 0; 1500 1501 1502 if (GV) { 1503 // Check if the variable has the right type. 1504 if (GV->getType()->getElementType() == Ty) 1505 return GV; 1506 1507 // Because C++ name mangling, the only way we can end up with an already 1508 // existing global with the same name is if it has been declared extern "C". 1509 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1510 OldGV = GV; 1511 } 1512 1513 // Create a new variable. 1514 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1515 Linkage, 0, Name); 1516 1517 if (OldGV) { 1518 // Replace occurrences of the old variable if needed. 1519 GV->takeName(OldGV); 1520 1521 if (!OldGV->use_empty()) { 1522 llvm::Constant *NewPtrForOldDecl = 1523 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1524 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1525 } 1526 1527 OldGV->eraseFromParent(); 1528 } 1529 1530 return GV; 1531} 1532 1533/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1534/// given global variable. If Ty is non-null and if the global doesn't exist, 1535/// then it will be created with the specified type instead of whatever the 1536/// normal requested type would be. 1537llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1538 llvm::Type *Ty) { 1539 assert(D->hasGlobalStorage() && "Not a global variable"); 1540 QualType ASTTy = D->getType(); 1541 if (Ty == 0) 1542 Ty = getTypes().ConvertTypeForMem(ASTTy); 1543 1544 llvm::PointerType *PTy = 1545 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1546 1547 StringRef MangledName = getMangledName(D); 1548 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1549} 1550 1551/// CreateRuntimeVariable - Create a new runtime global variable with the 1552/// specified type and name. 1553llvm::Constant * 1554CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1555 StringRef Name) { 1556 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1557 true); 1558} 1559 1560void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1561 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1562 1563 if (MayDeferGeneration(D)) { 1564 // If we have not seen a reference to this variable yet, place it 1565 // into the deferred declarations table to be emitted if needed 1566 // later. 1567 StringRef MangledName = getMangledName(D); 1568 if (!GetGlobalValue(MangledName)) { 1569 DeferredDecls[MangledName] = D; 1570 return; 1571 } 1572 } 1573 1574 // The tentative definition is the only definition. 1575 EmitGlobalVarDefinition(D); 1576} 1577 1578CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1579 return Context.toCharUnitsFromBits( 1580 TheDataLayout.getTypeStoreSizeInBits(Ty)); 1581} 1582 1583llvm::Constant * 1584CodeGenModule::MaybeEmitGlobalStdInitializerListInitializer(const VarDecl *D, 1585 const Expr *rawInit) { 1586 ArrayRef<ExprWithCleanups::CleanupObject> cleanups; 1587 if (const ExprWithCleanups *withCleanups = 1588 dyn_cast<ExprWithCleanups>(rawInit)) { 1589 cleanups = withCleanups->getObjects(); 1590 rawInit = withCleanups->getSubExpr(); 1591 } 1592 1593 const InitListExpr *init = dyn_cast<InitListExpr>(rawInit); 1594 if (!init || !init->initializesStdInitializerList() || 1595 init->getNumInits() == 0) 1596 return 0; 1597 1598 ASTContext &ctx = getContext(); 1599 unsigned numInits = init->getNumInits(); 1600 // FIXME: This check is here because we would otherwise silently miscompile 1601 // nested global std::initializer_lists. Better would be to have a real 1602 // implementation. 1603 for (unsigned i = 0; i < numInits; ++i) { 1604 const InitListExpr *inner = dyn_cast<InitListExpr>(init->getInit(i)); 1605 if (inner && inner->initializesStdInitializerList()) { 1606 ErrorUnsupported(inner, "nested global std::initializer_list"); 1607 return 0; 1608 } 1609 } 1610 1611 // Synthesize a fake VarDecl for the array and initialize that. 1612 QualType elementType = init->getInit(0)->getType(); 1613 llvm::APInt numElements(ctx.getTypeSize(ctx.getSizeType()), numInits); 1614 QualType arrayType = ctx.getConstantArrayType(elementType, numElements, 1615 ArrayType::Normal, 0); 1616 1617 IdentifierInfo *name = &ctx.Idents.get(D->getNameAsString() + "__initlist"); 1618 TypeSourceInfo *sourceInfo = ctx.getTrivialTypeSourceInfo( 1619 arrayType, D->getLocation()); 1620 VarDecl *backingArray = VarDecl::Create(ctx, const_cast<DeclContext*>( 1621 D->getDeclContext()), 1622 D->getLocStart(), D->getLocation(), 1623 name, arrayType, sourceInfo, 1624 SC_Static); 1625 backingArray->setTLSKind(D->getTLSKind()); 1626 1627 // Now clone the InitListExpr to initialize the array instead. 1628 // Incredible hack: we want to use the existing InitListExpr here, so we need 1629 // to tell it that it no longer initializes a std::initializer_list. 1630 ArrayRef<Expr*> Inits(const_cast<InitListExpr*>(init)->getInits(), 1631 init->getNumInits()); 1632 Expr *arrayInit = new (ctx) InitListExpr(ctx, init->getLBraceLoc(), Inits, 1633 init->getRBraceLoc()); 1634 arrayInit->setType(arrayType); 1635 1636 if (!cleanups.empty()) 1637 arrayInit = ExprWithCleanups::Create(ctx, arrayInit, cleanups); 1638 1639 backingArray->setInit(arrayInit); 1640 1641 // Emit the definition of the array. 1642 EmitGlobalVarDefinition(backingArray); 1643 1644 // Inspect the initializer list to validate it and determine its type. 1645 // FIXME: doing this every time is probably inefficient; caching would be nice 1646 RecordDecl *record = init->getType()->castAs<RecordType>()->getDecl(); 1647 RecordDecl::field_iterator field = record->field_begin(); 1648 if (field == record->field_end()) { 1649 ErrorUnsupported(D, "weird std::initializer_list"); 1650 return 0; 1651 } 1652 QualType elementPtr = ctx.getPointerType(elementType.withConst()); 1653 // Start pointer. 1654 if (!ctx.hasSameType(field->getType(), elementPtr)) { 1655 ErrorUnsupported(D, "weird std::initializer_list"); 1656 return 0; 1657 } 1658 ++field; 1659 if (field == record->field_end()) { 1660 ErrorUnsupported(D, "weird std::initializer_list"); 1661 return 0; 1662 } 1663 bool isStartEnd = false; 1664 if (ctx.hasSameType(field->getType(), elementPtr)) { 1665 // End pointer. 1666 isStartEnd = true; 1667 } else if(!ctx.hasSameType(field->getType(), ctx.getSizeType())) { 1668 ErrorUnsupported(D, "weird std::initializer_list"); 1669 return 0; 1670 } 1671 1672 // Now build an APValue representing the std::initializer_list. 1673 APValue initListValue(APValue::UninitStruct(), 0, 2); 1674 APValue &startField = initListValue.getStructField(0); 1675 APValue::LValuePathEntry startOffsetPathEntry; 1676 startOffsetPathEntry.ArrayIndex = 0; 1677 startField = APValue(APValue::LValueBase(backingArray), 1678 CharUnits::fromQuantity(0), 1679 llvm::makeArrayRef(startOffsetPathEntry), 1680 /*IsOnePastTheEnd=*/false, 0); 1681 1682 if (isStartEnd) { 1683 APValue &endField = initListValue.getStructField(1); 1684 APValue::LValuePathEntry endOffsetPathEntry; 1685 endOffsetPathEntry.ArrayIndex = numInits; 1686 endField = APValue(APValue::LValueBase(backingArray), 1687 ctx.getTypeSizeInChars(elementType) * numInits, 1688 llvm::makeArrayRef(endOffsetPathEntry), 1689 /*IsOnePastTheEnd=*/true, 0); 1690 } else { 1691 APValue &sizeField = initListValue.getStructField(1); 1692 sizeField = APValue(llvm::APSInt(numElements)); 1693 } 1694 1695 // Emit the constant for the initializer_list. 1696 llvm::Constant *llvmInit = 1697 EmitConstantValueForMemory(initListValue, D->getType()); 1698 assert(llvmInit && "failed to initialize as constant"); 1699 return llvmInit; 1700} 1701 1702unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D, 1703 unsigned AddrSpace) { 1704 if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) { 1705 if (D->hasAttr<CUDAConstantAttr>()) 1706 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_constant); 1707 else if (D->hasAttr<CUDASharedAttr>()) 1708 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_shared); 1709 else 1710 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_device); 1711 } 1712 1713 return AddrSpace; 1714} 1715 1716template<typename SomeDecl> 1717void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D, 1718 llvm::GlobalValue *GV) { 1719 if (!getLangOpts().CPlusPlus) 1720 return; 1721 1722 // Must have 'used' attribute, or else inline assembly can't rely on 1723 // the name existing. 1724 if (!D->template hasAttr<UsedAttr>()) 1725 return; 1726 1727 // Must have internal linkage and an ordinary name. 1728 if (!D->getIdentifier() || D->getLinkage() != InternalLinkage) 1729 return; 1730 1731 // Must be in an extern "C" context. Entities declared directly within 1732 // a record are not extern "C" even if the record is in such a context. 1733 const DeclContext *DC = D->getFirstDeclaration()->getDeclContext(); 1734 if (DC->isRecord() || !DC->isExternCContext()) 1735 return; 1736 1737 // OK, this is an internal linkage entity inside an extern "C" linkage 1738 // specification. Make a note of that so we can give it the "expected" 1739 // mangled name if nothing else is using that name. 1740 std::pair<StaticExternCMap::iterator, bool> R = 1741 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV)); 1742 1743 // If we have multiple internal linkage entities with the same name 1744 // in extern "C" regions, none of them gets that name. 1745 if (!R.second) 1746 R.first->second = 0; 1747} 1748 1749void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1750 llvm::Constant *Init = 0; 1751 QualType ASTTy = D->getType(); 1752 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 1753 bool NeedsGlobalCtor = false; 1754 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor(); 1755 1756 const VarDecl *InitDecl; 1757 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 1758 1759 if (!InitExpr) { 1760 // This is a tentative definition; tentative definitions are 1761 // implicitly initialized with { 0 }. 1762 // 1763 // Note that tentative definitions are only emitted at the end of 1764 // a translation unit, so they should never have incomplete 1765 // type. In addition, EmitTentativeDefinition makes sure that we 1766 // never attempt to emit a tentative definition if a real one 1767 // exists. A use may still exists, however, so we still may need 1768 // to do a RAUW. 1769 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1770 Init = EmitNullConstant(D->getType()); 1771 } else { 1772 // If this is a std::initializer_list, emit the special initializer. 1773 Init = MaybeEmitGlobalStdInitializerListInitializer(D, InitExpr); 1774 // An empty init list will perform zero-initialization, which happens 1775 // to be exactly what we want. 1776 // FIXME: It does so in a global constructor, which is *not* what we 1777 // want. 1778 1779 if (!Init) { 1780 initializedGlobalDecl = GlobalDecl(D); 1781 Init = EmitConstantInit(*InitDecl); 1782 } 1783 if (!Init) { 1784 QualType T = InitExpr->getType(); 1785 if (D->getType()->isReferenceType()) 1786 T = D->getType(); 1787 1788 if (getLangOpts().CPlusPlus) { 1789 Init = EmitNullConstant(T); 1790 NeedsGlobalCtor = true; 1791 } else { 1792 ErrorUnsupported(D, "static initializer"); 1793 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1794 } 1795 } else { 1796 // We don't need an initializer, so remove the entry for the delayed 1797 // initializer position (just in case this entry was delayed) if we 1798 // also don't need to register a destructor. 1799 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor) 1800 DelayedCXXInitPosition.erase(D); 1801 } 1802 } 1803 1804 llvm::Type* InitType = Init->getType(); 1805 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1806 1807 // Strip off a bitcast if we got one back. 1808 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1809 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1810 // all zero index gep. 1811 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1812 Entry = CE->getOperand(0); 1813 } 1814 1815 // Entry is now either a Function or GlobalVariable. 1816 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1817 1818 // We have a definition after a declaration with the wrong type. 1819 // We must make a new GlobalVariable* and update everything that used OldGV 1820 // (a declaration or tentative definition) with the new GlobalVariable* 1821 // (which will be a definition). 1822 // 1823 // This happens if there is a prototype for a global (e.g. 1824 // "extern int x[];") and then a definition of a different type (e.g. 1825 // "int x[10];"). This also happens when an initializer has a different type 1826 // from the type of the global (this happens with unions). 1827 if (GV == 0 || 1828 GV->getType()->getElementType() != InitType || 1829 GV->getType()->getAddressSpace() != 1830 GetGlobalVarAddressSpace(D, getContext().getTargetAddressSpace(ASTTy))) { 1831 1832 // Move the old entry aside so that we'll create a new one. 1833 Entry->setName(StringRef()); 1834 1835 // Make a new global with the correct type, this is now guaranteed to work. 1836 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1837 1838 // Replace all uses of the old global with the new global 1839 llvm::Constant *NewPtrForOldDecl = 1840 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1841 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1842 1843 // Erase the old global, since it is no longer used. 1844 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1845 } 1846 1847 MaybeHandleStaticInExternC(D, GV); 1848 1849 if (D->hasAttr<AnnotateAttr>()) 1850 AddGlobalAnnotations(D, GV); 1851 1852 GV->setInitializer(Init); 1853 1854 // If it is safe to mark the global 'constant', do so now. 1855 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor && 1856 isTypeConstant(D->getType(), true)); 1857 1858 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1859 1860 // Set the llvm linkage type as appropriate. 1861 llvm::GlobalValue::LinkageTypes Linkage = 1862 GetLLVMLinkageVarDefinition(D, GV); 1863 GV->setLinkage(Linkage); 1864 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1865 // common vars aren't constant even if declared const. 1866 GV->setConstant(false); 1867 1868 SetCommonAttributes(D, GV); 1869 1870 // Emit the initializer function if necessary. 1871 if (NeedsGlobalCtor || NeedsGlobalDtor) 1872 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); 1873 1874 // If we are compiling with ASan, add metadata indicating dynamically 1875 // initialized globals. 1876 if (SanOpts.Address && NeedsGlobalCtor) { 1877 llvm::Module &M = getModule(); 1878 1879 llvm::NamedMDNode *DynamicInitializers = 1880 M.getOrInsertNamedMetadata("llvm.asan.dynamically_initialized_globals"); 1881 llvm::Value *GlobalToAdd[] = { GV }; 1882 llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalToAdd); 1883 DynamicInitializers->addOperand(ThisGlobal); 1884 } 1885 1886 // Emit global variable debug information. 1887 if (CGDebugInfo *DI = getModuleDebugInfo()) 1888 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) 1889 DI->EmitGlobalVariable(GV, D); 1890} 1891 1892llvm::GlobalValue::LinkageTypes 1893CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, 1894 llvm::GlobalVariable *GV) { 1895 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1896 if (Linkage == GVA_Internal) 1897 return llvm::Function::InternalLinkage; 1898 else if (D->hasAttr<DLLImportAttr>()) 1899 return llvm::Function::DLLImportLinkage; 1900 else if (D->hasAttr<DLLExportAttr>()) 1901 return llvm::Function::DLLExportLinkage; 1902 else if (D->hasAttr<WeakAttr>()) { 1903 if (GV->isConstant()) 1904 return llvm::GlobalVariable::WeakODRLinkage; 1905 else 1906 return llvm::GlobalVariable::WeakAnyLinkage; 1907 } else if (Linkage == GVA_TemplateInstantiation || 1908 Linkage == GVA_ExplicitTemplateInstantiation) 1909 return llvm::GlobalVariable::WeakODRLinkage; 1910 else if (!getLangOpts().CPlusPlus && 1911 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1912 D->getAttr<CommonAttr>()) && 1913 !D->hasExternalStorage() && !D->getInit() && 1914 !D->getAttr<SectionAttr>() && !D->getTLSKind() && 1915 !D->getAttr<WeakImportAttr>()) { 1916 // Thread local vars aren't considered common linkage. 1917 return llvm::GlobalVariable::CommonLinkage; 1918 } 1919 return llvm::GlobalVariable::ExternalLinkage; 1920} 1921 1922/// Replace the uses of a function that was declared with a non-proto type. 1923/// We want to silently drop extra arguments from call sites 1924static void replaceUsesOfNonProtoConstant(llvm::Constant *old, 1925 llvm::Function *newFn) { 1926 // Fast path. 1927 if (old->use_empty()) return; 1928 1929 llvm::Type *newRetTy = newFn->getReturnType(); 1930 SmallVector<llvm::Value*, 4> newArgs; 1931 1932 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end(); 1933 ui != ue; ) { 1934 llvm::Value::use_iterator use = ui++; // Increment before the use is erased. 1935 llvm::User *user = *use; 1936 1937 // Recognize and replace uses of bitcasts. Most calls to 1938 // unprototyped functions will use bitcasts. 1939 if (llvm::ConstantExpr *bitcast = dyn_cast<llvm::ConstantExpr>(user)) { 1940 if (bitcast->getOpcode() == llvm::Instruction::BitCast) 1941 replaceUsesOfNonProtoConstant(bitcast, newFn); 1942 continue; 1943 } 1944 1945 // Recognize calls to the function. 1946 llvm::CallSite callSite(user); 1947 if (!callSite) continue; 1948 if (!callSite.isCallee(use)) continue; 1949 1950 // If the return types don't match exactly, then we can't 1951 // transform this call unless it's dead. 1952 if (callSite->getType() != newRetTy && !callSite->use_empty()) 1953 continue; 1954 1955 // Get the call site's attribute list. 1956 SmallVector<llvm::AttributeSet, 8> newAttrs; 1957 llvm::AttributeSet oldAttrs = callSite.getAttributes(); 1958 1959 // Collect any return attributes from the call. 1960 if (oldAttrs.hasAttributes(llvm::AttributeSet::ReturnIndex)) 1961 newAttrs.push_back( 1962 llvm::AttributeSet::get(newFn->getContext(), 1963 oldAttrs.getRetAttributes())); 1964 1965 // If the function was passed too few arguments, don't transform. 1966 unsigned newNumArgs = newFn->arg_size(); 1967 if (callSite.arg_size() < newNumArgs) continue; 1968 1969 // If extra arguments were passed, we silently drop them. 1970 // If any of the types mismatch, we don't transform. 1971 unsigned argNo = 0; 1972 bool dontTransform = false; 1973 for (llvm::Function::arg_iterator ai = newFn->arg_begin(), 1974 ae = newFn->arg_end(); ai != ae; ++ai, ++argNo) { 1975 if (callSite.getArgument(argNo)->getType() != ai->getType()) { 1976 dontTransform = true; 1977 break; 1978 } 1979 1980 // Add any parameter attributes. 1981 if (oldAttrs.hasAttributes(argNo + 1)) 1982 newAttrs. 1983 push_back(llvm:: 1984 AttributeSet::get(newFn->getContext(), 1985 oldAttrs.getParamAttributes(argNo + 1))); 1986 } 1987 if (dontTransform) 1988 continue; 1989 1990 if (oldAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) 1991 newAttrs.push_back(llvm::AttributeSet::get(newFn->getContext(), 1992 oldAttrs.getFnAttributes())); 1993 1994 // Okay, we can transform this. Create the new call instruction and copy 1995 // over the required information. 1996 newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo); 1997 1998 llvm::CallSite newCall; 1999 if (callSite.isCall()) { 2000 newCall = llvm::CallInst::Create(newFn, newArgs, "", 2001 callSite.getInstruction()); 2002 } else { 2003 llvm::InvokeInst *oldInvoke = 2004 cast<llvm::InvokeInst>(callSite.getInstruction()); 2005 newCall = llvm::InvokeInst::Create(newFn, 2006 oldInvoke->getNormalDest(), 2007 oldInvoke->getUnwindDest(), 2008 newArgs, "", 2009 callSite.getInstruction()); 2010 } 2011 newArgs.clear(); // for the next iteration 2012 2013 if (!newCall->getType()->isVoidTy()) 2014 newCall->takeName(callSite.getInstruction()); 2015 newCall.setAttributes( 2016 llvm::AttributeSet::get(newFn->getContext(), newAttrs)); 2017 newCall.setCallingConv(callSite.getCallingConv()); 2018 2019 // Finally, remove the old call, replacing any uses with the new one. 2020 if (!callSite->use_empty()) 2021 callSite->replaceAllUsesWith(newCall.getInstruction()); 2022 2023 // Copy debug location attached to CI. 2024 if (!callSite->getDebugLoc().isUnknown()) 2025 newCall->setDebugLoc(callSite->getDebugLoc()); 2026 callSite->eraseFromParent(); 2027 } 2028} 2029 2030/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 2031/// implement a function with no prototype, e.g. "int foo() {}". If there are 2032/// existing call uses of the old function in the module, this adjusts them to 2033/// call the new function directly. 2034/// 2035/// This is not just a cleanup: the always_inline pass requires direct calls to 2036/// functions to be able to inline them. If there is a bitcast in the way, it 2037/// won't inline them. Instcombine normally deletes these calls, but it isn't 2038/// run at -O0. 2039static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 2040 llvm::Function *NewFn) { 2041 // If we're redefining a global as a function, don't transform it. 2042 if (!isa<llvm::Function>(Old)) return; 2043 2044 replaceUsesOfNonProtoConstant(Old, NewFn); 2045} 2046 2047void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) { 2048 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind(); 2049 // If we have a definition, this might be a deferred decl. If the 2050 // instantiation is explicit, make sure we emit it at the end. 2051 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition) 2052 GetAddrOfGlobalVar(VD); 2053 2054 EmitTopLevelDecl(VD); 2055} 2056 2057void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 2058 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 2059 2060 // Compute the function info and LLVM type. 2061 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); 2062 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); 2063 2064 // Get or create the prototype for the function. 2065 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 2066 2067 // Strip off a bitcast if we got one back. 2068 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 2069 assert(CE->getOpcode() == llvm::Instruction::BitCast); 2070 Entry = CE->getOperand(0); 2071 } 2072 2073 2074 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 2075 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 2076 2077 // If the types mismatch then we have to rewrite the definition. 2078 assert(OldFn->isDeclaration() && 2079 "Shouldn't replace non-declaration"); 2080 2081 // F is the Function* for the one with the wrong type, we must make a new 2082 // Function* and update everything that used F (a declaration) with the new 2083 // Function* (which will be a definition). 2084 // 2085 // This happens if there is a prototype for a function 2086 // (e.g. "int f()") and then a definition of a different type 2087 // (e.g. "int f(int x)"). Move the old function aside so that it 2088 // doesn't interfere with GetAddrOfFunction. 2089 OldFn->setName(StringRef()); 2090 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 2091 2092 // This might be an implementation of a function without a 2093 // prototype, in which case, try to do special replacement of 2094 // calls which match the new prototype. The really key thing here 2095 // is that we also potentially drop arguments from the call site 2096 // so as to make a direct call, which makes the inliner happier 2097 // and suppresses a number of optimizer warnings (!) about 2098 // dropping arguments. 2099 if (!OldFn->use_empty()) { 2100 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 2101 OldFn->removeDeadConstantUsers(); 2102 } 2103 2104 // Replace uses of F with the Function we will endow with a body. 2105 if (!Entry->use_empty()) { 2106 llvm::Constant *NewPtrForOldDecl = 2107 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 2108 Entry->replaceAllUsesWith(NewPtrForOldDecl); 2109 } 2110 2111 // Ok, delete the old function now, which is dead. 2112 OldFn->eraseFromParent(); 2113 2114 Entry = NewFn; 2115 } 2116 2117 // We need to set linkage and visibility on the function before 2118 // generating code for it because various parts of IR generation 2119 // want to propagate this information down (e.g. to local static 2120 // declarations). 2121 llvm::Function *Fn = cast<llvm::Function>(Entry); 2122 setFunctionLinkage(D, Fn); 2123 2124 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 2125 setGlobalVisibility(Fn, D); 2126 2127 MaybeHandleStaticInExternC(D, Fn); 2128 2129 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 2130 2131 SetFunctionDefinitionAttributes(D, Fn); 2132 SetLLVMFunctionAttributesForDefinition(D, Fn); 2133 2134 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 2135 AddGlobalCtor(Fn, CA->getPriority()); 2136 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 2137 AddGlobalDtor(Fn, DA->getPriority()); 2138 if (D->hasAttr<AnnotateAttr>()) 2139 AddGlobalAnnotations(D, Fn); 2140} 2141 2142void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 2143 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 2144 const AliasAttr *AA = D->getAttr<AliasAttr>(); 2145 assert(AA && "Not an alias?"); 2146 2147 StringRef MangledName = getMangledName(GD); 2148 2149 // If there is a definition in the module, then it wins over the alias. 2150 // This is dubious, but allow it to be safe. Just ignore the alias. 2151 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 2152 if (Entry && !Entry->isDeclaration()) 2153 return; 2154 2155 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 2156 2157 // Create a reference to the named value. This ensures that it is emitted 2158 // if a deferred decl. 2159 llvm::Constant *Aliasee; 2160 if (isa<llvm::FunctionType>(DeclTy)) 2161 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD, 2162 /*ForVTable=*/false); 2163 else 2164 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 2165 llvm::PointerType::getUnqual(DeclTy), 0); 2166 2167 // Create the new alias itself, but don't set a name yet. 2168 llvm::GlobalValue *GA = 2169 new llvm::GlobalAlias(Aliasee->getType(), 2170 llvm::Function::ExternalLinkage, 2171 "", Aliasee, &getModule()); 2172 2173 if (Entry) { 2174 assert(Entry->isDeclaration()); 2175 2176 // If there is a declaration in the module, then we had an extern followed 2177 // by the alias, as in: 2178 // extern int test6(); 2179 // ... 2180 // int test6() __attribute__((alias("test7"))); 2181 // 2182 // Remove it and replace uses of it with the alias. 2183 GA->takeName(Entry); 2184 2185 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 2186 Entry->getType())); 2187 Entry->eraseFromParent(); 2188 } else { 2189 GA->setName(MangledName); 2190 } 2191 2192 // Set attributes which are particular to an alias; this is a 2193 // specialization of the attributes which may be set on a global 2194 // variable/function. 2195 if (D->hasAttr<DLLExportAttr>()) { 2196 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2197 // The dllexport attribute is ignored for undefined symbols. 2198 if (FD->hasBody()) 2199 GA->setLinkage(llvm::Function::DLLExportLinkage); 2200 } else { 2201 GA->setLinkage(llvm::Function::DLLExportLinkage); 2202 } 2203 } else if (D->hasAttr<WeakAttr>() || 2204 D->hasAttr<WeakRefAttr>() || 2205 D->isWeakImported()) { 2206 GA->setLinkage(llvm::Function::WeakAnyLinkage); 2207 } 2208 2209 SetCommonAttributes(D, GA); 2210} 2211 2212llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 2213 ArrayRef<llvm::Type*> Tys) { 2214 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 2215 Tys); 2216} 2217 2218static llvm::StringMapEntry<llvm::Constant*> & 2219GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2220 const StringLiteral *Literal, 2221 bool TargetIsLSB, 2222 bool &IsUTF16, 2223 unsigned &StringLength) { 2224 StringRef String = Literal->getString(); 2225 unsigned NumBytes = String.size(); 2226 2227 // Check for simple case. 2228 if (!Literal->containsNonAsciiOrNull()) { 2229 StringLength = NumBytes; 2230 return Map.GetOrCreateValue(String); 2231 } 2232 2233 // Otherwise, convert the UTF8 literals into a string of shorts. 2234 IsUTF16 = true; 2235 2236 SmallVector<UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls. 2237 const UTF8 *FromPtr = (const UTF8 *)String.data(); 2238 UTF16 *ToPtr = &ToBuf[0]; 2239 2240 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 2241 &ToPtr, ToPtr + NumBytes, 2242 strictConversion); 2243 2244 // ConvertUTF8toUTF16 returns the length in ToPtr. 2245 StringLength = ToPtr - &ToBuf[0]; 2246 2247 // Add an explicit null. 2248 *ToPtr = 0; 2249 return Map. 2250 GetOrCreateValue(StringRef(reinterpret_cast<const char *>(ToBuf.data()), 2251 (StringLength + 1) * 2)); 2252} 2253 2254static llvm::StringMapEntry<llvm::Constant*> & 2255GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2256 const StringLiteral *Literal, 2257 unsigned &StringLength) { 2258 StringRef String = Literal->getString(); 2259 StringLength = String.size(); 2260 return Map.GetOrCreateValue(String); 2261} 2262 2263llvm::Constant * 2264CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 2265 unsigned StringLength = 0; 2266 bool isUTF16 = false; 2267 llvm::StringMapEntry<llvm::Constant*> &Entry = 2268 GetConstantCFStringEntry(CFConstantStringMap, Literal, 2269 getDataLayout().isLittleEndian(), 2270 isUTF16, StringLength); 2271 2272 if (llvm::Constant *C = Entry.getValue()) 2273 return C; 2274 2275 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2276 llvm::Constant *Zeros[] = { Zero, Zero }; 2277 llvm::Value *V; 2278 2279 // If we don't already have it, get __CFConstantStringClassReference. 2280 if (!CFConstantStringClassRef) { 2281 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2282 Ty = llvm::ArrayType::get(Ty, 0); 2283 llvm::Constant *GV = CreateRuntimeVariable(Ty, 2284 "__CFConstantStringClassReference"); 2285 // Decay array -> ptr 2286 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2287 CFConstantStringClassRef = V; 2288 } 2289 else 2290 V = CFConstantStringClassRef; 2291 2292 QualType CFTy = getContext().getCFConstantStringType(); 2293 2294 llvm::StructType *STy = 2295 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 2296 2297 llvm::Constant *Fields[4]; 2298 2299 // Class pointer. 2300 Fields[0] = cast<llvm::ConstantExpr>(V); 2301 2302 // Flags. 2303 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2304 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 2305 llvm::ConstantInt::get(Ty, 0x07C8); 2306 2307 // String pointer. 2308 llvm::Constant *C = 0; 2309 if (isUTF16) { 2310 ArrayRef<uint16_t> Arr = 2311 llvm::makeArrayRef<uint16_t>(reinterpret_cast<uint16_t*>( 2312 const_cast<char *>(Entry.getKey().data())), 2313 Entry.getKey().size() / 2); 2314 C = llvm::ConstantDataArray::get(VMContext, Arr); 2315 } else { 2316 C = llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2317 } 2318 2319 llvm::GlobalValue::LinkageTypes Linkage; 2320 if (isUTF16) 2321 // FIXME: why do utf strings get "_" labels instead of "L" labels? 2322 Linkage = llvm::GlobalValue::InternalLinkage; 2323 else 2324 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 2325 // when using private linkage. It is not clear if this is a bug in ld 2326 // or a reasonable new restriction. 2327 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 2328 2329 // Note: -fwritable-strings doesn't make the backing store strings of 2330 // CFStrings writable. (See <rdar://problem/10657500>) 2331 llvm::GlobalVariable *GV = 2332 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, 2333 Linkage, C, ".str"); 2334 GV->setUnnamedAddr(true); 2335 if (isUTF16) { 2336 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 2337 GV->setAlignment(Align.getQuantity()); 2338 } else { 2339 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2340 GV->setAlignment(Align.getQuantity()); 2341 } 2342 2343 // String. 2344 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2345 2346 if (isUTF16) 2347 // Cast the UTF16 string to the correct type. 2348 Fields[2] = llvm::ConstantExpr::getBitCast(Fields[2], Int8PtrTy); 2349 2350 // String length. 2351 Ty = getTypes().ConvertType(getContext().LongTy); 2352 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 2353 2354 // The struct. 2355 C = llvm::ConstantStruct::get(STy, Fields); 2356 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2357 llvm::GlobalVariable::PrivateLinkage, C, 2358 "_unnamed_cfstring_"); 2359 if (const char *Sect = getTarget().getCFStringSection()) 2360 GV->setSection(Sect); 2361 Entry.setValue(GV); 2362 2363 return GV; 2364} 2365 2366static RecordDecl * 2367CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 2368 DeclContext *DC, IdentifierInfo *Id) { 2369 SourceLocation Loc; 2370 if (Ctx.getLangOpts().CPlusPlus) 2371 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2372 else 2373 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2374} 2375 2376llvm::Constant * 2377CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 2378 unsigned StringLength = 0; 2379 llvm::StringMapEntry<llvm::Constant*> &Entry = 2380 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 2381 2382 if (llvm::Constant *C = Entry.getValue()) 2383 return C; 2384 2385 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2386 llvm::Constant *Zeros[] = { Zero, Zero }; 2387 llvm::Value *V; 2388 // If we don't already have it, get _NSConstantStringClassReference. 2389 if (!ConstantStringClassRef) { 2390 std::string StringClass(getLangOpts().ObjCConstantStringClass); 2391 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2392 llvm::Constant *GV; 2393 if (LangOpts.ObjCRuntime.isNonFragile()) { 2394 std::string str = 2395 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 2396 : "OBJC_CLASS_$_" + StringClass; 2397 GV = getObjCRuntime().GetClassGlobal(str); 2398 // Make sure the result is of the correct type. 2399 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 2400 V = llvm::ConstantExpr::getBitCast(GV, PTy); 2401 ConstantStringClassRef = V; 2402 } else { 2403 std::string str = 2404 StringClass.empty() ? "_NSConstantStringClassReference" 2405 : "_" + StringClass + "ClassReference"; 2406 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 2407 GV = CreateRuntimeVariable(PTy, str); 2408 // Decay array -> ptr 2409 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2410 ConstantStringClassRef = V; 2411 } 2412 } 2413 else 2414 V = ConstantStringClassRef; 2415 2416 if (!NSConstantStringType) { 2417 // Construct the type for a constant NSString. 2418 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2419 Context.getTranslationUnitDecl(), 2420 &Context.Idents.get("__builtin_NSString")); 2421 D->startDefinition(); 2422 2423 QualType FieldTypes[3]; 2424 2425 // const int *isa; 2426 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 2427 // const char *str; 2428 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 2429 // unsigned int length; 2430 FieldTypes[2] = Context.UnsignedIntTy; 2431 2432 // Create fields 2433 for (unsigned i = 0; i < 3; ++i) { 2434 FieldDecl *Field = FieldDecl::Create(Context, D, 2435 SourceLocation(), 2436 SourceLocation(), 0, 2437 FieldTypes[i], /*TInfo=*/0, 2438 /*BitWidth=*/0, 2439 /*Mutable=*/false, 2440 ICIS_NoInit); 2441 Field->setAccess(AS_public); 2442 D->addDecl(Field); 2443 } 2444 2445 D->completeDefinition(); 2446 QualType NSTy = Context.getTagDeclType(D); 2447 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 2448 } 2449 2450 llvm::Constant *Fields[3]; 2451 2452 // Class pointer. 2453 Fields[0] = cast<llvm::ConstantExpr>(V); 2454 2455 // String pointer. 2456 llvm::Constant *C = 2457 llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2458 2459 llvm::GlobalValue::LinkageTypes Linkage; 2460 bool isConstant; 2461 Linkage = llvm::GlobalValue::PrivateLinkage; 2462 isConstant = !LangOpts.WritableStrings; 2463 2464 llvm::GlobalVariable *GV = 2465 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 2466 ".str"); 2467 GV->setUnnamedAddr(true); 2468 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2469 GV->setAlignment(Align.getQuantity()); 2470 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2471 2472 // String length. 2473 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2474 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 2475 2476 // The struct. 2477 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 2478 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2479 llvm::GlobalVariable::PrivateLinkage, C, 2480 "_unnamed_nsstring_"); 2481 // FIXME. Fix section. 2482 if (const char *Sect = 2483 LangOpts.ObjCRuntime.isNonFragile() 2484 ? getTarget().getNSStringNonFragileABISection() 2485 : getTarget().getNSStringSection()) 2486 GV->setSection(Sect); 2487 Entry.setValue(GV); 2488 2489 return GV; 2490} 2491 2492QualType CodeGenModule::getObjCFastEnumerationStateType() { 2493 if (ObjCFastEnumerationStateType.isNull()) { 2494 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2495 Context.getTranslationUnitDecl(), 2496 &Context.Idents.get("__objcFastEnumerationState")); 2497 D->startDefinition(); 2498 2499 QualType FieldTypes[] = { 2500 Context.UnsignedLongTy, 2501 Context.getPointerType(Context.getObjCIdType()), 2502 Context.getPointerType(Context.UnsignedLongTy), 2503 Context.getConstantArrayType(Context.UnsignedLongTy, 2504 llvm::APInt(32, 5), ArrayType::Normal, 0) 2505 }; 2506 2507 for (size_t i = 0; i < 4; ++i) { 2508 FieldDecl *Field = FieldDecl::Create(Context, 2509 D, 2510 SourceLocation(), 2511 SourceLocation(), 0, 2512 FieldTypes[i], /*TInfo=*/0, 2513 /*BitWidth=*/0, 2514 /*Mutable=*/false, 2515 ICIS_NoInit); 2516 Field->setAccess(AS_public); 2517 D->addDecl(Field); 2518 } 2519 2520 D->completeDefinition(); 2521 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 2522 } 2523 2524 return ObjCFastEnumerationStateType; 2525} 2526 2527llvm::Constant * 2528CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { 2529 assert(!E->getType()->isPointerType() && "Strings are always arrays"); 2530 2531 // Don't emit it as the address of the string, emit the string data itself 2532 // as an inline array. 2533 if (E->getCharByteWidth() == 1) { 2534 SmallString<64> Str(E->getString()); 2535 2536 // Resize the string to the right size, which is indicated by its type. 2537 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType()); 2538 Str.resize(CAT->getSize().getZExtValue()); 2539 return llvm::ConstantDataArray::getString(VMContext, Str, false); 2540 } 2541 2542 llvm::ArrayType *AType = 2543 cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); 2544 llvm::Type *ElemTy = AType->getElementType(); 2545 unsigned NumElements = AType->getNumElements(); 2546 2547 // Wide strings have either 2-byte or 4-byte elements. 2548 if (ElemTy->getPrimitiveSizeInBits() == 16) { 2549 SmallVector<uint16_t, 32> Elements; 2550 Elements.reserve(NumElements); 2551 2552 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2553 Elements.push_back(E->getCodeUnit(i)); 2554 Elements.resize(NumElements); 2555 return llvm::ConstantDataArray::get(VMContext, Elements); 2556 } 2557 2558 assert(ElemTy->getPrimitiveSizeInBits() == 32); 2559 SmallVector<uint32_t, 32> Elements; 2560 Elements.reserve(NumElements); 2561 2562 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2563 Elements.push_back(E->getCodeUnit(i)); 2564 Elements.resize(NumElements); 2565 return llvm::ConstantDataArray::get(VMContext, Elements); 2566} 2567 2568/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 2569/// constant array for the given string literal. 2570llvm::Constant * 2571CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 2572 CharUnits Align = getContext().getTypeAlignInChars(S->getType()); 2573 if (S->isAscii() || S->isUTF8()) { 2574 SmallString<64> Str(S->getString()); 2575 2576 // Resize the string to the right size, which is indicated by its type. 2577 const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType()); 2578 Str.resize(CAT->getSize().getZExtValue()); 2579 return GetAddrOfConstantString(Str, /*GlobalName*/ 0, Align.getQuantity()); 2580 } 2581 2582 // FIXME: the following does not memoize wide strings. 2583 llvm::Constant *C = GetConstantArrayFromStringLiteral(S); 2584 llvm::GlobalVariable *GV = 2585 new llvm::GlobalVariable(getModule(),C->getType(), 2586 !LangOpts.WritableStrings, 2587 llvm::GlobalValue::PrivateLinkage, 2588 C,".str"); 2589 2590 GV->setAlignment(Align.getQuantity()); 2591 GV->setUnnamedAddr(true); 2592 return GV; 2593} 2594 2595/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2596/// array for the given ObjCEncodeExpr node. 2597llvm::Constant * 2598CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2599 std::string Str; 2600 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2601 2602 return GetAddrOfConstantCString(Str); 2603} 2604 2605 2606/// GenerateWritableString -- Creates storage for a string literal. 2607static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2608 bool constant, 2609 CodeGenModule &CGM, 2610 const char *GlobalName, 2611 unsigned Alignment) { 2612 // Create Constant for this string literal. Don't add a '\0'. 2613 llvm::Constant *C = 2614 llvm::ConstantDataArray::getString(CGM.getLLVMContext(), str, false); 2615 2616 // Create a global variable for this string 2617 llvm::GlobalVariable *GV = 2618 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 2619 llvm::GlobalValue::PrivateLinkage, 2620 C, GlobalName); 2621 GV->setAlignment(Alignment); 2622 GV->setUnnamedAddr(true); 2623 return GV; 2624} 2625 2626/// GetAddrOfConstantString - Returns a pointer to a character array 2627/// containing the literal. This contents are exactly that of the 2628/// given string, i.e. it will not be null terminated automatically; 2629/// see GetAddrOfConstantCString. Note that whether the result is 2630/// actually a pointer to an LLVM constant depends on 2631/// Feature.WriteableStrings. 2632/// 2633/// The result has pointer to array type. 2634llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2635 const char *GlobalName, 2636 unsigned Alignment) { 2637 // Get the default prefix if a name wasn't specified. 2638 if (!GlobalName) 2639 GlobalName = ".str"; 2640 2641 // Don't share any string literals if strings aren't constant. 2642 if (LangOpts.WritableStrings) 2643 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2644 2645 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2646 ConstantStringMap.GetOrCreateValue(Str); 2647 2648 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2649 if (Alignment > GV->getAlignment()) { 2650 GV->setAlignment(Alignment); 2651 } 2652 return GV; 2653 } 2654 2655 // Create a global variable for this. 2656 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, 2657 Alignment); 2658 Entry.setValue(GV); 2659 return GV; 2660} 2661 2662/// GetAddrOfConstantCString - Returns a pointer to a character 2663/// array containing the literal and a terminating '\0' 2664/// character. The result has pointer to array type. 2665llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2666 const char *GlobalName, 2667 unsigned Alignment) { 2668 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2669 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2670} 2671 2672/// EmitObjCPropertyImplementations - Emit information for synthesized 2673/// properties for an implementation. 2674void CodeGenModule::EmitObjCPropertyImplementations(const 2675 ObjCImplementationDecl *D) { 2676 for (ObjCImplementationDecl::propimpl_iterator 2677 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2678 ObjCPropertyImplDecl *PID = *i; 2679 2680 // Dynamic is just for type-checking. 2681 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2682 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2683 2684 // Determine which methods need to be implemented, some may have 2685 // been overridden. Note that ::isPropertyAccessor is not the method 2686 // we want, that just indicates if the decl came from a 2687 // property. What we want to know is if the method is defined in 2688 // this implementation. 2689 if (!D->getInstanceMethod(PD->getGetterName())) 2690 CodeGenFunction(*this).GenerateObjCGetter( 2691 const_cast<ObjCImplementationDecl *>(D), PID); 2692 if (!PD->isReadOnly() && 2693 !D->getInstanceMethod(PD->getSetterName())) 2694 CodeGenFunction(*this).GenerateObjCSetter( 2695 const_cast<ObjCImplementationDecl *>(D), PID); 2696 } 2697 } 2698} 2699 2700static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2701 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2702 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2703 ivar; ivar = ivar->getNextIvar()) 2704 if (ivar->getType().isDestructedType()) 2705 return true; 2706 2707 return false; 2708} 2709 2710/// EmitObjCIvarInitializations - Emit information for ivar initialization 2711/// for an implementation. 2712void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2713 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2714 if (needsDestructMethod(D)) { 2715 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2716 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2717 ObjCMethodDecl *DTORMethod = 2718 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2719 cxxSelector, getContext().VoidTy, 0, D, 2720 /*isInstance=*/true, /*isVariadic=*/false, 2721 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true, 2722 /*isDefined=*/false, ObjCMethodDecl::Required); 2723 D->addInstanceMethod(DTORMethod); 2724 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2725 D->setHasDestructors(true); 2726 } 2727 2728 // If the implementation doesn't have any ivar initializers, we don't need 2729 // a .cxx_construct. 2730 if (D->getNumIvarInitializers() == 0) 2731 return; 2732 2733 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2734 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2735 // The constructor returns 'self'. 2736 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2737 D->getLocation(), 2738 D->getLocation(), 2739 cxxSelector, 2740 getContext().getObjCIdType(), 0, 2741 D, /*isInstance=*/true, 2742 /*isVariadic=*/false, 2743 /*isPropertyAccessor=*/true, 2744 /*isImplicitlyDeclared=*/true, 2745 /*isDefined=*/false, 2746 ObjCMethodDecl::Required); 2747 D->addInstanceMethod(CTORMethod); 2748 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2749 D->setHasNonZeroConstructors(true); 2750} 2751 2752/// EmitNamespace - Emit all declarations in a namespace. 2753void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2754 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2755 I != E; ++I) 2756 EmitTopLevelDecl(*I); 2757} 2758 2759// EmitLinkageSpec - Emit all declarations in a linkage spec. 2760void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2761 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2762 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2763 ErrorUnsupported(LSD, "linkage spec"); 2764 return; 2765 } 2766 2767 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2768 I != E; ++I) { 2769 // Meta-data for ObjC class includes references to implemented methods. 2770 // Generate class's method definitions first. 2771 if (ObjCImplDecl *OID = dyn_cast<ObjCImplDecl>(*I)) { 2772 for (ObjCContainerDecl::method_iterator M = OID->meth_begin(), 2773 MEnd = OID->meth_end(); 2774 M != MEnd; ++M) 2775 EmitTopLevelDecl(*M); 2776 } 2777 EmitTopLevelDecl(*I); 2778 } 2779} 2780 2781/// EmitTopLevelDecl - Emit code for a single top level declaration. 2782void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2783 // If an error has occurred, stop code generation, but continue 2784 // parsing and semantic analysis (to ensure all warnings and errors 2785 // are emitted). 2786 if (Diags.hasErrorOccurred()) 2787 return; 2788 2789 // Ignore dependent declarations. 2790 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2791 return; 2792 2793 switch (D->getKind()) { 2794 case Decl::CXXConversion: 2795 case Decl::CXXMethod: 2796 case Decl::Function: 2797 // Skip function templates 2798 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2799 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2800 return; 2801 2802 EmitGlobal(cast<FunctionDecl>(D)); 2803 break; 2804 2805 case Decl::Var: 2806 EmitGlobal(cast<VarDecl>(D)); 2807 break; 2808 2809 // Indirect fields from global anonymous structs and unions can be 2810 // ignored; only the actual variable requires IR gen support. 2811 case Decl::IndirectField: 2812 break; 2813 2814 // C++ Decls 2815 case Decl::Namespace: 2816 EmitNamespace(cast<NamespaceDecl>(D)); 2817 break; 2818 // No code generation needed. 2819 case Decl::UsingShadow: 2820 case Decl::Using: 2821 case Decl::UsingDirective: 2822 case Decl::ClassTemplate: 2823 case Decl::FunctionTemplate: 2824 case Decl::TypeAliasTemplate: 2825 case Decl::NamespaceAlias: 2826 case Decl::Block: 2827 case Decl::Empty: 2828 break; 2829 case Decl::CXXConstructor: 2830 // Skip function templates 2831 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2832 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2833 return; 2834 2835 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2836 break; 2837 case Decl::CXXDestructor: 2838 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2839 return; 2840 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2841 break; 2842 2843 case Decl::StaticAssert: 2844 // Nothing to do. 2845 break; 2846 2847 // Objective-C Decls 2848 2849 // Forward declarations, no (immediate) code generation. 2850 case Decl::ObjCInterface: 2851 case Decl::ObjCCategory: 2852 break; 2853 2854 case Decl::ObjCProtocol: { 2855 ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D); 2856 if (Proto->isThisDeclarationADefinition()) 2857 ObjCRuntime->GenerateProtocol(Proto); 2858 break; 2859 } 2860 2861 case Decl::ObjCCategoryImpl: 2862 // Categories have properties but don't support synthesize so we 2863 // can ignore them here. 2864 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2865 break; 2866 2867 case Decl::ObjCImplementation: { 2868 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2869 EmitObjCPropertyImplementations(OMD); 2870 EmitObjCIvarInitializations(OMD); 2871 ObjCRuntime->GenerateClass(OMD); 2872 // Emit global variable debug information. 2873 if (CGDebugInfo *DI = getModuleDebugInfo()) 2874 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) 2875 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType( 2876 OMD->getClassInterface()), OMD->getLocation()); 2877 break; 2878 } 2879 case Decl::ObjCMethod: { 2880 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 2881 // If this is not a prototype, emit the body. 2882 if (OMD->getBody()) 2883 CodeGenFunction(*this).GenerateObjCMethod(OMD); 2884 break; 2885 } 2886 case Decl::ObjCCompatibleAlias: 2887 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D)); 2888 break; 2889 2890 case Decl::LinkageSpec: 2891 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 2892 break; 2893 2894 case Decl::FileScopeAsm: { 2895 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 2896 StringRef AsmString = AD->getAsmString()->getString(); 2897 2898 const std::string &S = getModule().getModuleInlineAsm(); 2899 if (S.empty()) 2900 getModule().setModuleInlineAsm(AsmString); 2901 else if (S.end()[-1] == '\n') 2902 getModule().setModuleInlineAsm(S + AsmString.str()); 2903 else 2904 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 2905 break; 2906 } 2907 2908 case Decl::Import: { 2909 ImportDecl *Import = cast<ImportDecl>(D); 2910 2911 // Ignore import declarations that come from imported modules. 2912 if (clang::Module *Owner = Import->getOwningModule()) { 2913 if (getLangOpts().CurrentModule.empty() || 2914 Owner->getTopLevelModule()->Name == getLangOpts().CurrentModule) 2915 break; 2916 } 2917 2918 ImportedModules.insert(Import->getImportedModule()); 2919 break; 2920 } 2921 2922 default: 2923 // Make sure we handled everything we should, every other kind is a 2924 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 2925 // function. Need to recode Decl::Kind to do that easily. 2926 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 2927 } 2928} 2929 2930/// Turns the given pointer into a constant. 2931static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 2932 const void *Ptr) { 2933 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 2934 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 2935 return llvm::ConstantInt::get(i64, PtrInt); 2936} 2937 2938static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 2939 llvm::NamedMDNode *&GlobalMetadata, 2940 GlobalDecl D, 2941 llvm::GlobalValue *Addr) { 2942 if (!GlobalMetadata) 2943 GlobalMetadata = 2944 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 2945 2946 // TODO: should we report variant information for ctors/dtors? 2947 llvm::Value *Ops[] = { 2948 Addr, 2949 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 2950 }; 2951 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 2952} 2953 2954/// For each function which is declared within an extern "C" region and marked 2955/// as 'used', but has internal linkage, create an alias from the unmangled 2956/// name to the mangled name if possible. People expect to be able to refer 2957/// to such functions with an unmangled name from inline assembly within the 2958/// same translation unit. 2959void CodeGenModule::EmitStaticExternCAliases() { 2960 for (StaticExternCMap::iterator I = StaticExternCValues.begin(), 2961 E = StaticExternCValues.end(); 2962 I != E; ++I) { 2963 IdentifierInfo *Name = I->first; 2964 llvm::GlobalValue *Val = I->second; 2965 if (Val && !getModule().getNamedValue(Name->getName())) 2966 AddUsedGlobal(new llvm::GlobalAlias(Val->getType(), Val->getLinkage(), 2967 Name->getName(), Val, &getModule())); 2968 } 2969} 2970 2971/// Emits metadata nodes associating all the global values in the 2972/// current module with the Decls they came from. This is useful for 2973/// projects using IR gen as a subroutine. 2974/// 2975/// Since there's currently no way to associate an MDNode directly 2976/// with an llvm::GlobalValue, we create a global named metadata 2977/// with the name 'clang.global.decl.ptrs'. 2978void CodeGenModule::EmitDeclMetadata() { 2979 llvm::NamedMDNode *GlobalMetadata = 0; 2980 2981 // StaticLocalDeclMap 2982 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 2983 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 2984 I != E; ++I) { 2985 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 2986 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 2987 } 2988} 2989 2990/// Emits metadata nodes for all the local variables in the current 2991/// function. 2992void CodeGenFunction::EmitDeclMetadata() { 2993 if (LocalDeclMap.empty()) return; 2994 2995 llvm::LLVMContext &Context = getLLVMContext(); 2996 2997 // Find the unique metadata ID for this name. 2998 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 2999 3000 llvm::NamedMDNode *GlobalMetadata = 0; 3001 3002 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 3003 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 3004 const Decl *D = I->first; 3005 llvm::Value *Addr = I->second; 3006 3007 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 3008 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 3009 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 3010 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 3011 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 3012 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 3013 } 3014 } 3015} 3016 3017void CodeGenModule::EmitCoverageFile() { 3018 if (!getCodeGenOpts().CoverageFile.empty()) { 3019 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 3020 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 3021 llvm::LLVMContext &Ctx = TheModule.getContext(); 3022 llvm::MDString *CoverageFile = 3023 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 3024 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 3025 llvm::MDNode *CU = CUNode->getOperand(i); 3026 llvm::Value *node[] = { CoverageFile, CU }; 3027 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 3028 GCov->addOperand(N); 3029 } 3030 } 3031 } 3032} 3033 3034llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid, 3035 QualType GuidType) { 3036 // Sema has checked that all uuid strings are of the form 3037 // "12345678-1234-1234-1234-1234567890ab". 3038 assert(Uuid.size() == 36); 3039 const char *Uuidstr = Uuid.data(); 3040 for (int i = 0; i < 36; ++i) { 3041 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuidstr[i] == '-'); 3042 else assert(isHexDigit(Uuidstr[i])); 3043 } 3044 3045 llvm::APInt Field0(32, StringRef(Uuidstr , 8), 16); 3046 llvm::APInt Field1(16, StringRef(Uuidstr + 9, 4), 16); 3047 llvm::APInt Field2(16, StringRef(Uuidstr + 14, 4), 16); 3048 static const int Field3ValueOffsets[] = { 19, 21, 24, 26, 28, 30, 32, 34 }; 3049 3050 APValue InitStruct(APValue::UninitStruct(), /*NumBases=*/0, /*NumFields=*/4); 3051 InitStruct.getStructField(0) = APValue(llvm::APSInt(Field0)); 3052 InitStruct.getStructField(1) = APValue(llvm::APSInt(Field1)); 3053 InitStruct.getStructField(2) = APValue(llvm::APSInt(Field2)); 3054 APValue& Arr = InitStruct.getStructField(3); 3055 Arr = APValue(APValue::UninitArray(), 8, 8); 3056 for (int t = 0; t < 8; ++t) 3057 Arr.getArrayInitializedElt(t) = APValue(llvm::APSInt( 3058 llvm::APInt(8, StringRef(Uuidstr + Field3ValueOffsets[t], 2), 16))); 3059 3060 return EmitConstantValue(InitStruct, GuidType); 3061} 3062