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/Basic/Version.h" 39#include "clang/Frontend/CodeGenOptions.h" 40#include "clang/Sema/SemaDiagnostic.h" 41#include "llvm/ADT/APSInt.h" 42#include "llvm/ADT/Triple.h" 43#include "llvm/IR/CallingConv.h" 44#include "llvm/IR/DataLayout.h" 45#include "llvm/IR/Intrinsics.h" 46#include "llvm/IR/LLVMContext.h" 47#include "llvm/IR/Module.h" 48#include "llvm/Support/CallSite.h" 49#include "llvm/Support/ConvertUTF.h" 50#include "llvm/Support/ErrorHandling.h" 51#include "llvm/Target/Mangler.h" 52 53using namespace clang; 54using namespace CodeGen; 55 56static const char AnnotationSection[] = "llvm.metadata"; 57 58static CGCXXABI &createCXXABI(CodeGenModule &CGM) { 59 switch (CGM.getTarget().getCXXABI().getKind()) { 60 case TargetCXXABI::GenericAArch64: 61 case TargetCXXABI::GenericARM: 62 case TargetCXXABI::iOS: 63 case TargetCXXABI::GenericItanium: 64 return *CreateItaniumCXXABI(CGM); 65 case TargetCXXABI::Microsoft: 66 return *CreateMicrosoftCXXABI(CGM); 67 } 68 69 llvm_unreachable("invalid C++ ABI kind"); 70} 71 72CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 73 llvm::Module &M, const llvm::DataLayout &TD, 74 DiagnosticsEngine &diags) 75 : Context(C), LangOpts(C.getLangOpts()), CodeGenOpts(CGO), TheModule(M), 76 Diags(diags), TheDataLayout(TD), Target(C.getTargetInfo()), 77 ABI(createCXXABI(*this)), VMContext(M.getContext()), TBAA(0), 78 TheTargetCodeGenInfo(0), Types(*this), VTables(*this), ObjCRuntime(0), 79 OpenCLRuntime(0), CUDARuntime(0), DebugInfo(0), ARCData(0), 80 NoObjCARCExceptionsMetadata(0), RRData(0), CFConstantStringClassRef(0), 81 ConstantStringClassRef(0), NSConstantStringType(0), 82 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), BlockObjectAssign(0), 83 BlockObjectDispose(0), BlockDescriptorType(0), GenericBlockLiteralType(0), 84 LifetimeStartFn(0), LifetimeEndFn(0), 85 SanitizerBlacklist( 86 llvm::SpecialCaseList::createOrDie(CGO.SanitizerBlacklistFile)), 87 SanOpts(SanitizerBlacklist->isIn(M) ? SanitizerOptions::Disabled 88 : 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::applyReplacements() { 176 for (ReplacementsTy::iterator I = Replacements.begin(), 177 E = Replacements.end(); 178 I != E; ++I) { 179 StringRef MangledName = I->first(); 180 llvm::Constant *Replacement = I->second; 181 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 182 if (!Entry) 183 continue; 184 llvm::Function *OldF = cast<llvm::Function>(Entry); 185 llvm::Function *NewF = dyn_cast<llvm::Function>(Replacement); 186 if (!NewF) { 187 llvm::ConstantExpr *CE = cast<llvm::ConstantExpr>(Replacement); 188 assert(CE->getOpcode() == llvm::Instruction::BitCast || 189 CE->getOpcode() == llvm::Instruction::GetElementPtr); 190 NewF = dyn_cast<llvm::Function>(CE->getOperand(0)); 191 } 192 193 // Replace old with new, but keep the old order. 194 OldF->replaceAllUsesWith(Replacement); 195 if (NewF) { 196 NewF->removeFromParent(); 197 OldF->getParent()->getFunctionList().insertAfter(OldF, NewF); 198 } 199 OldF->eraseFromParent(); 200 } 201} 202 203void CodeGenModule::checkAliases() { 204 bool Error = false; 205 for (std::vector<GlobalDecl>::iterator I = Aliases.begin(), 206 E = Aliases.end(); I != E; ++I) { 207 const GlobalDecl &GD = *I; 208 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 209 const AliasAttr *AA = D->getAttr<AliasAttr>(); 210 StringRef MangledName = getMangledName(GD); 211 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 212 llvm::GlobalAlias *Alias = cast<llvm::GlobalAlias>(Entry); 213 llvm::GlobalValue *GV = Alias->getAliasedGlobal(); 214 if (GV->isDeclaration()) { 215 Error = true; 216 getDiags().Report(AA->getLocation(), diag::err_alias_to_undefined); 217 } else if (!Alias->resolveAliasedGlobal(/*stopOnWeak*/ false)) { 218 Error = true; 219 getDiags().Report(AA->getLocation(), diag::err_cyclic_alias); 220 } 221 } 222 if (!Error) 223 return; 224 225 for (std::vector<GlobalDecl>::iterator I = Aliases.begin(), 226 E = Aliases.end(); I != E; ++I) { 227 const GlobalDecl &GD = *I; 228 StringRef MangledName = getMangledName(GD); 229 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 230 llvm::GlobalAlias *Alias = cast<llvm::GlobalAlias>(Entry); 231 Alias->replaceAllUsesWith(llvm::UndefValue::get(Alias->getType())); 232 Alias->eraseFromParent(); 233 } 234} 235 236void CodeGenModule::Release() { 237 EmitDeferred(); 238 applyReplacements(); 239 checkAliases(); 240 EmitCXXGlobalInitFunc(); 241 EmitCXXGlobalDtorFunc(); 242 EmitCXXThreadLocalInitFunc(); 243 if (ObjCRuntime) 244 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) 245 AddGlobalCtor(ObjCInitFunction); 246 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 247 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 248 EmitGlobalAnnotations(); 249 EmitStaticExternCAliases(); 250 EmitLLVMUsed(); 251 252 if (CodeGenOpts.Autolink && 253 (Context.getLangOpts().Modules || !LinkerOptionsMetadata.empty())) { 254 EmitModuleLinkOptions(); 255 } 256 if (CodeGenOpts.DwarfVersion) 257 // We actually want the latest version when there are conflicts. 258 // We can change from Warning to Latest if such mode is supported. 259 getModule().addModuleFlag(llvm::Module::Warning, "Dwarf Version", 260 CodeGenOpts.DwarfVersion); 261 if (DebugInfo) 262 // We support a single version in the linked module: error out when 263 // modules do not have the same version. We are going to implement dropping 264 // debug info when the version number is not up-to-date. Once that is 265 // done, the bitcode linker is not going to see modules with different 266 // version numbers. 267 getModule().addModuleFlag(llvm::Module::Error, "Debug Info Version", 268 llvm::DEBUG_METADATA_VERSION); 269 270 SimplifyPersonality(); 271 272 if (getCodeGenOpts().EmitDeclMetadata) 273 EmitDeclMetadata(); 274 275 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 276 EmitCoverageFile(); 277 278 if (DebugInfo) 279 DebugInfo->finalize(); 280 281 EmitVersionIdentMetadata(); 282} 283 284void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 285 // Make sure that this type is translated. 286 Types.UpdateCompletedType(TD); 287} 288 289llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 290 if (!TBAA) 291 return 0; 292 return TBAA->getTBAAInfo(QTy); 293} 294 295llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() { 296 if (!TBAA) 297 return 0; 298 return TBAA->getTBAAInfoForVTablePtr(); 299} 300 301llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) { 302 if (!TBAA) 303 return 0; 304 return TBAA->getTBAAStructInfo(QTy); 305} 306 307llvm::MDNode *CodeGenModule::getTBAAStructTypeInfo(QualType QTy) { 308 if (!TBAA) 309 return 0; 310 return TBAA->getTBAAStructTypeInfo(QTy); 311} 312 313llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy, 314 llvm::MDNode *AccessN, 315 uint64_t O) { 316 if (!TBAA) 317 return 0; 318 return TBAA->getTBAAStructTagInfo(BaseTy, AccessN, O); 319} 320 321/// Decorate the instruction with a TBAA tag. For both scalar TBAA 322/// and struct-path aware TBAA, the tag has the same format: 323/// base type, access type and offset. 324/// When ConvertTypeToTag is true, we create a tag based on the scalar type. 325void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 326 llvm::MDNode *TBAAInfo, 327 bool ConvertTypeToTag) { 328 if (ConvertTypeToTag && TBAA) 329 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, 330 TBAA->getTBAAScalarTagInfo(TBAAInfo)); 331 else 332 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 333} 334 335void CodeGenModule::Error(SourceLocation loc, StringRef error) { 336 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); 337 getDiags().Report(Context.getFullLoc(loc), diagID); 338} 339 340/// ErrorUnsupported - Print out an error that codegen doesn't support the 341/// specified stmt yet. 342void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) { 343 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 344 "cannot compile this %0 yet"); 345 std::string Msg = Type; 346 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 347 << Msg << S->getSourceRange(); 348} 349 350/// ErrorUnsupported - Print out an error that codegen doesn't support the 351/// specified decl yet. 352void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type) { 353 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 354 "cannot compile this %0 yet"); 355 std::string Msg = Type; 356 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 357} 358 359llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 360 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 361} 362 363void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 364 const NamedDecl *D) const { 365 // Internal definitions always have default visibility. 366 if (GV->hasLocalLinkage()) { 367 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 368 return; 369 } 370 371 // Set visibility for definitions. 372 LinkageInfo LV = D->getLinkageAndVisibility(); 373 if (LV.isVisibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 374 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 375} 376 377static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) { 378 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S) 379 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel) 380 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel) 381 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel) 382 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel); 383} 384 385static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel( 386 CodeGenOptions::TLSModel M) { 387 switch (M) { 388 case CodeGenOptions::GeneralDynamicTLSModel: 389 return llvm::GlobalVariable::GeneralDynamicTLSModel; 390 case CodeGenOptions::LocalDynamicTLSModel: 391 return llvm::GlobalVariable::LocalDynamicTLSModel; 392 case CodeGenOptions::InitialExecTLSModel: 393 return llvm::GlobalVariable::InitialExecTLSModel; 394 case CodeGenOptions::LocalExecTLSModel: 395 return llvm::GlobalVariable::LocalExecTLSModel; 396 } 397 llvm_unreachable("Invalid TLS model!"); 398} 399 400void CodeGenModule::setTLSMode(llvm::GlobalVariable *GV, 401 const VarDecl &D) const { 402 assert(D.getTLSKind() && "setting TLS mode on non-TLS var!"); 403 404 llvm::GlobalVariable::ThreadLocalMode TLM; 405 TLM = GetLLVMTLSModel(CodeGenOpts.getDefaultTLSModel()); 406 407 // Override the TLS model if it is explicitly specified. 408 if (D.hasAttr<TLSModelAttr>()) { 409 const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>(); 410 TLM = GetLLVMTLSModel(Attr->getModel()); 411 } 412 413 GV->setThreadLocalMode(TLM); 414} 415 416/// Set the symbol visibility of type information (vtable and RTTI) 417/// associated with the given type. 418void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 419 const CXXRecordDecl *RD, 420 TypeVisibilityKind TVK) const { 421 setGlobalVisibility(GV, RD); 422 423 if (!CodeGenOpts.HiddenWeakVTables) 424 return; 425 426 // We never want to drop the visibility for RTTI names. 427 if (TVK == TVK_ForRTTIName) 428 return; 429 430 // We want to drop the visibility to hidden for weak type symbols. 431 // This isn't possible if there might be unresolved references 432 // elsewhere that rely on this symbol being visible. 433 434 // This should be kept roughly in sync with setThunkVisibility 435 // in CGVTables.cpp. 436 437 // Preconditions. 438 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 439 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 440 return; 441 442 // Don't override an explicit visibility attribute. 443 if (RD->getExplicitVisibility(NamedDecl::VisibilityForType)) 444 return; 445 446 switch (RD->getTemplateSpecializationKind()) { 447 // We have to disable the optimization if this is an EI definition 448 // because there might be EI declarations in other shared objects. 449 case TSK_ExplicitInstantiationDefinition: 450 case TSK_ExplicitInstantiationDeclaration: 451 return; 452 453 // Every use of a non-template class's type information has to emit it. 454 case TSK_Undeclared: 455 break; 456 457 // In theory, implicit instantiations can ignore the possibility of 458 // an explicit instantiation declaration because there necessarily 459 // must be an EI definition somewhere with default visibility. In 460 // practice, it's possible to have an explicit instantiation for 461 // an arbitrary template class, and linkers aren't necessarily able 462 // to deal with mixed-visibility symbols. 463 case TSK_ExplicitSpecialization: 464 case TSK_ImplicitInstantiation: 465 return; 466 } 467 468 // If there's a key function, there may be translation units 469 // that don't have the key function's definition. But ignore 470 // this if we're emitting RTTI under -fno-rtti. 471 if (!(TVK != TVK_ForRTTI) || LangOpts.RTTI) { 472 // FIXME: what should we do if we "lose" the key function during 473 // the emission of the file? 474 if (Context.getCurrentKeyFunction(RD)) 475 return; 476 } 477 478 // Otherwise, drop the visibility to hidden. 479 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 480 GV->setUnnamedAddr(true); 481} 482 483StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 484 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 485 486 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 487 if (!Str.empty()) 488 return Str; 489 490 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 491 IdentifierInfo *II = ND->getIdentifier(); 492 assert(II && "Attempt to mangle unnamed decl."); 493 494 Str = II->getName(); 495 return Str; 496 } 497 498 SmallString<256> Buffer; 499 llvm::raw_svector_ostream Out(Buffer); 500 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 501 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 502 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 503 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 504 else 505 getCXXABI().getMangleContext().mangleName(ND, Out); 506 507 // Allocate space for the mangled name. 508 Out.flush(); 509 size_t Length = Buffer.size(); 510 char *Name = MangledNamesAllocator.Allocate<char>(Length); 511 std::copy(Buffer.begin(), Buffer.end(), Name); 512 513 Str = StringRef(Name, Length); 514 515 return Str; 516} 517 518void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 519 const BlockDecl *BD) { 520 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 521 const Decl *D = GD.getDecl(); 522 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 523 if (D == 0) 524 MangleCtx.mangleGlobalBlock(BD, 525 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out); 526 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 527 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 528 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 529 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 530 else 531 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 532} 533 534llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 535 return getModule().getNamedValue(Name); 536} 537 538/// AddGlobalCtor - Add a function to the list that will be called before 539/// main() runs. 540void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 541 // FIXME: Type coercion of void()* types. 542 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 543} 544 545/// AddGlobalDtor - Add a function to the list that will be called 546/// when the module is unloaded. 547void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 548 // FIXME: Type coercion of void()* types. 549 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 550} 551 552void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 553 // Ctor function type is void()*. 554 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 555 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 556 557 // Get the type of a ctor entry, { i32, void ()* }. 558 llvm::StructType *CtorStructTy = 559 llvm::StructType::get(Int32Ty, llvm::PointerType::getUnqual(CtorFTy), NULL); 560 561 // Construct the constructor and destructor arrays. 562 SmallVector<llvm::Constant*, 8> Ctors; 563 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 564 llvm::Constant *S[] = { 565 llvm::ConstantInt::get(Int32Ty, I->second, false), 566 llvm::ConstantExpr::getBitCast(I->first, CtorPFTy) 567 }; 568 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 569 } 570 571 if (!Ctors.empty()) { 572 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 573 new llvm::GlobalVariable(TheModule, AT, false, 574 llvm::GlobalValue::AppendingLinkage, 575 llvm::ConstantArray::get(AT, Ctors), 576 GlobalName); 577 } 578} 579 580llvm::GlobalValue::LinkageTypes 581CodeGenModule::getFunctionLinkage(GlobalDecl GD) { 582 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 583 584 if (isa<CXXDestructorDecl>(D) && 585 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D), 586 GD.getDtorType())) 587 return llvm::Function::LinkOnceODRLinkage; 588 589 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 590 591 if (Linkage == GVA_Internal) 592 return llvm::Function::InternalLinkage; 593 594 if (D->hasAttr<DLLExportAttr>()) 595 return llvm::Function::DLLExportLinkage; 596 597 if (D->hasAttr<WeakAttr>()) 598 return llvm::Function::WeakAnyLinkage; 599 600 // In C99 mode, 'inline' functions are guaranteed to have a strong 601 // definition somewhere else, so we can use available_externally linkage. 602 if (Linkage == GVA_C99Inline) 603 return llvm::Function::AvailableExternallyLinkage; 604 605 // Note that Apple's kernel linker doesn't support symbol 606 // coalescing, so we need to avoid linkonce and weak linkages there. 607 // Normally, this means we just map to internal, but for explicit 608 // instantiations we'll map to external. 609 610 // In C++, the compiler has to emit a definition in every translation unit 611 // that references the function. We should use linkonce_odr because 612 // a) if all references in this translation unit are optimized away, we 613 // don't need to codegen it. b) if the function persists, it needs to be 614 // merged with other definitions. c) C++ has the ODR, so we know the 615 // definition is dependable. 616 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 617 return !Context.getLangOpts().AppleKext 618 ? llvm::Function::LinkOnceODRLinkage 619 : llvm::Function::InternalLinkage; 620 621 // An explicit instantiation of a template has weak linkage, since 622 // explicit instantiations can occur in multiple translation units 623 // and must all be equivalent. However, we are not allowed to 624 // throw away these explicit instantiations. 625 if (Linkage == GVA_ExplicitTemplateInstantiation) 626 return !Context.getLangOpts().AppleKext 627 ? llvm::Function::WeakODRLinkage 628 : llvm::Function::ExternalLinkage; 629 630 // Otherwise, we have strong external linkage. 631 assert(Linkage == GVA_StrongExternal); 632 return llvm::Function::ExternalLinkage; 633} 634 635 636/// SetFunctionDefinitionAttributes - Set attributes for a global. 637/// 638/// FIXME: This is currently only done for aliases and functions, but not for 639/// variables (these details are set in EmitGlobalVarDefinition for variables). 640void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 641 llvm::GlobalValue *GV) { 642 SetCommonAttributes(D, GV); 643} 644 645void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 646 const CGFunctionInfo &Info, 647 llvm::Function *F) { 648 unsigned CallingConv; 649 AttributeListType AttributeList; 650 ConstructAttributeList(Info, D, AttributeList, CallingConv, false); 651 F->setAttributes(llvm::AttributeSet::get(getLLVMContext(), AttributeList)); 652 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 653} 654 655/// Determines whether the language options require us to model 656/// unwind exceptions. We treat -fexceptions as mandating this 657/// except under the fragile ObjC ABI with only ObjC exceptions 658/// enabled. This means, for example, that C with -fexceptions 659/// enables this. 660static bool hasUnwindExceptions(const LangOptions &LangOpts) { 661 // If exceptions are completely disabled, obviously this is false. 662 if (!LangOpts.Exceptions) return false; 663 664 // If C++ exceptions are enabled, this is true. 665 if (LangOpts.CXXExceptions) return true; 666 667 // If ObjC exceptions are enabled, this depends on the ABI. 668 if (LangOpts.ObjCExceptions) { 669 return LangOpts.ObjCRuntime.hasUnwindExceptions(); 670 } 671 672 return true; 673} 674 675void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 676 llvm::Function *F) { 677 llvm::AttrBuilder B; 678 679 if (CodeGenOpts.UnwindTables) 680 B.addAttribute(llvm::Attribute::UWTable); 681 682 if (!hasUnwindExceptions(LangOpts)) 683 B.addAttribute(llvm::Attribute::NoUnwind); 684 685 if (D->hasAttr<NakedAttr>()) { 686 // Naked implies noinline: we should not be inlining such functions. 687 B.addAttribute(llvm::Attribute::Naked); 688 B.addAttribute(llvm::Attribute::NoInline); 689 } else if (D->hasAttr<NoInlineAttr>()) { 690 B.addAttribute(llvm::Attribute::NoInline); 691 } else if ((D->hasAttr<AlwaysInlineAttr>() || 692 D->hasAttr<ForceInlineAttr>()) && 693 !F->getAttributes().hasAttribute(llvm::AttributeSet::FunctionIndex, 694 llvm::Attribute::NoInline)) { 695 // (noinline wins over always_inline, and we can't specify both in IR) 696 B.addAttribute(llvm::Attribute::AlwaysInline); 697 } 698 699 if (D->hasAttr<ColdAttr>()) { 700 B.addAttribute(llvm::Attribute::OptimizeForSize); 701 B.addAttribute(llvm::Attribute::Cold); 702 } 703 704 if (D->hasAttr<MinSizeAttr>()) 705 B.addAttribute(llvm::Attribute::MinSize); 706 707 if (LangOpts.getStackProtector() == LangOptions::SSPOn) 708 B.addAttribute(llvm::Attribute::StackProtect); 709 else if (LangOpts.getStackProtector() == LangOptions::SSPReq) 710 B.addAttribute(llvm::Attribute::StackProtectReq); 711 712 // Add sanitizer attributes if function is not blacklisted. 713 if (!SanitizerBlacklist->isIn(*F)) { 714 // When AddressSanitizer is enabled, set SanitizeAddress attribute 715 // unless __attribute__((no_sanitize_address)) is used. 716 if (SanOpts.Address && !D->hasAttr<NoSanitizeAddressAttr>()) 717 B.addAttribute(llvm::Attribute::SanitizeAddress); 718 // Same for ThreadSanitizer and __attribute__((no_sanitize_thread)) 719 if (SanOpts.Thread && !D->hasAttr<NoSanitizeThreadAttr>()) { 720 B.addAttribute(llvm::Attribute::SanitizeThread); 721 } 722 // Same for MemorySanitizer and __attribute__((no_sanitize_memory)) 723 if (SanOpts.Memory && !D->hasAttr<NoSanitizeMemoryAttr>()) 724 B.addAttribute(llvm::Attribute::SanitizeMemory); 725 } 726 727 F->addAttributes(llvm::AttributeSet::FunctionIndex, 728 llvm::AttributeSet::get( 729 F->getContext(), llvm::AttributeSet::FunctionIndex, B)); 730 731 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 732 F->setUnnamedAddr(true); 733 else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) 734 if (MD->isVirtual()) 735 F->setUnnamedAddr(true); 736 737 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 738 if (alignment) 739 F->setAlignment(alignment); 740 741 // C++ ABI requires 2-byte alignment for member functions. 742 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 743 F->setAlignment(2); 744} 745 746void CodeGenModule::SetCommonAttributes(const Decl *D, 747 llvm::GlobalValue *GV) { 748 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 749 setGlobalVisibility(GV, ND); 750 else 751 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 752 753 if (D->hasAttr<UsedAttr>()) 754 AddUsedGlobal(GV); 755 756 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 757 GV->setSection(SA->getName()); 758 759 // Alias cannot have attributes. Filter them here. 760 if (!isa<llvm::GlobalAlias>(GV)) 761 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 762} 763 764void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 765 llvm::Function *F, 766 const CGFunctionInfo &FI) { 767 SetLLVMFunctionAttributes(D, FI, F); 768 SetLLVMFunctionAttributesForDefinition(D, F); 769 770 F->setLinkage(llvm::Function::InternalLinkage); 771 772 SetCommonAttributes(D, F); 773} 774 775void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 776 llvm::Function *F, 777 bool IsIncompleteFunction) { 778 if (unsigned IID = F->getIntrinsicID()) { 779 // If this is an intrinsic function, set the function's attributes 780 // to the intrinsic's attributes. 781 F->setAttributes(llvm::Intrinsic::getAttributes(getLLVMContext(), 782 (llvm::Intrinsic::ID)IID)); 783 return; 784 } 785 786 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 787 788 if (!IsIncompleteFunction) 789 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F); 790 791 if (getCXXABI().HasThisReturn(GD)) { 792 assert(!F->arg_empty() && 793 F->arg_begin()->getType() 794 ->canLosslesslyBitCastTo(F->getReturnType()) && 795 "unexpected this return"); 796 F->addAttribute(1, llvm::Attribute::Returned); 797 } 798 799 // Only a few attributes are set on declarations; these may later be 800 // overridden by a definition. 801 802 if (FD->hasAttr<DLLImportAttr>()) { 803 F->setLinkage(llvm::Function::DLLImportLinkage); 804 } else if (FD->hasAttr<WeakAttr>() || 805 FD->isWeakImported()) { 806 // "extern_weak" is overloaded in LLVM; we probably should have 807 // separate linkage types for this. 808 F->setLinkage(llvm::Function::ExternalWeakLinkage); 809 } else { 810 F->setLinkage(llvm::Function::ExternalLinkage); 811 812 LinkageInfo LV = FD->getLinkageAndVisibility(); 813 if (LV.getLinkage() == ExternalLinkage && LV.isVisibilityExplicit()) { 814 F->setVisibility(GetLLVMVisibility(LV.getVisibility())); 815 } 816 } 817 818 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 819 F->setSection(SA->getName()); 820 821 // A replaceable global allocation function does not act like a builtin by 822 // default, only if it is invoked by a new-expression or delete-expression. 823 if (FD->isReplaceableGlobalAllocationFunction()) 824 F->addAttribute(llvm::AttributeSet::FunctionIndex, 825 llvm::Attribute::NoBuiltin); 826} 827 828void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 829 assert(!GV->isDeclaration() && 830 "Only globals with definition can force usage."); 831 LLVMUsed.push_back(GV); 832} 833 834void CodeGenModule::EmitLLVMUsed() { 835 // Don't create llvm.used if there is no need. 836 if (LLVMUsed.empty()) 837 return; 838 839 // Convert LLVMUsed to what ConstantArray needs. 840 SmallVector<llvm::Constant*, 8> UsedArray; 841 UsedArray.resize(LLVMUsed.size()); 842 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 843 UsedArray[i] = 844 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 845 Int8PtrTy); 846 } 847 848 if (UsedArray.empty()) 849 return; 850 llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size()); 851 852 llvm::GlobalVariable *GV = 853 new llvm::GlobalVariable(getModule(), ATy, false, 854 llvm::GlobalValue::AppendingLinkage, 855 llvm::ConstantArray::get(ATy, UsedArray), 856 "llvm.used"); 857 858 GV->setSection("llvm.metadata"); 859} 860 861void CodeGenModule::AppendLinkerOptions(StringRef Opts) { 862 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opts); 863 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 864} 865 866void CodeGenModule::AddDetectMismatch(StringRef Name, StringRef Value) { 867 llvm::SmallString<32> Opt; 868 getTargetCodeGenInfo().getDetectMismatchOption(Name, Value, Opt); 869 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); 870 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 871} 872 873void CodeGenModule::AddDependentLib(StringRef Lib) { 874 llvm::SmallString<24> Opt; 875 getTargetCodeGenInfo().getDependentLibraryOption(Lib, Opt); 876 llvm::Value *MDOpts = llvm::MDString::get(getLLVMContext(), Opt); 877 LinkerOptionsMetadata.push_back(llvm::MDNode::get(getLLVMContext(), MDOpts)); 878} 879 880/// \brief Add link options implied by the given module, including modules 881/// it depends on, using a postorder walk. 882static void addLinkOptionsPostorder(CodeGenModule &CGM, 883 Module *Mod, 884 SmallVectorImpl<llvm::Value *> &Metadata, 885 llvm::SmallPtrSet<Module *, 16> &Visited) { 886 // Import this module's parent. 887 if (Mod->Parent && Visited.insert(Mod->Parent)) { 888 addLinkOptionsPostorder(CGM, Mod->Parent, Metadata, Visited); 889 } 890 891 // Import this module's dependencies. 892 for (unsigned I = Mod->Imports.size(); I > 0; --I) { 893 if (Visited.insert(Mod->Imports[I-1])) 894 addLinkOptionsPostorder(CGM, Mod->Imports[I-1], Metadata, Visited); 895 } 896 897 // Add linker options to link against the libraries/frameworks 898 // described by this module. 899 llvm::LLVMContext &Context = CGM.getLLVMContext(); 900 for (unsigned I = Mod->LinkLibraries.size(); I > 0; --I) { 901 // Link against a framework. Frameworks are currently Darwin only, so we 902 // don't to ask TargetCodeGenInfo for the spelling of the linker option. 903 if (Mod->LinkLibraries[I-1].IsFramework) { 904 llvm::Value *Args[2] = { 905 llvm::MDString::get(Context, "-framework"), 906 llvm::MDString::get(Context, Mod->LinkLibraries[I-1].Library) 907 }; 908 909 Metadata.push_back(llvm::MDNode::get(Context, Args)); 910 continue; 911 } 912 913 // Link against a library. 914 llvm::SmallString<24> Opt; 915 CGM.getTargetCodeGenInfo().getDependentLibraryOption( 916 Mod->LinkLibraries[I-1].Library, Opt); 917 llvm::Value *OptString = llvm::MDString::get(Context, Opt); 918 Metadata.push_back(llvm::MDNode::get(Context, OptString)); 919 } 920} 921 922void CodeGenModule::EmitModuleLinkOptions() { 923 // Collect the set of all of the modules we want to visit to emit link 924 // options, which is essentially the imported modules and all of their 925 // non-explicit child modules. 926 llvm::SetVector<clang::Module *> LinkModules; 927 llvm::SmallPtrSet<clang::Module *, 16> Visited; 928 SmallVector<clang::Module *, 16> Stack; 929 930 // Seed the stack with imported modules. 931 for (llvm::SetVector<clang::Module *>::iterator M = ImportedModules.begin(), 932 MEnd = ImportedModules.end(); 933 M != MEnd; ++M) { 934 if (Visited.insert(*M)) 935 Stack.push_back(*M); 936 } 937 938 // Find all of the modules to import, making a little effort to prune 939 // non-leaf modules. 940 while (!Stack.empty()) { 941 clang::Module *Mod = Stack.pop_back_val(); 942 943 bool AnyChildren = false; 944 945 // Visit the submodules of this module. 946 for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(), 947 SubEnd = Mod->submodule_end(); 948 Sub != SubEnd; ++Sub) { 949 // Skip explicit children; they need to be explicitly imported to be 950 // linked against. 951 if ((*Sub)->IsExplicit) 952 continue; 953 954 if (Visited.insert(*Sub)) { 955 Stack.push_back(*Sub); 956 AnyChildren = true; 957 } 958 } 959 960 // We didn't find any children, so add this module to the list of 961 // modules to link against. 962 if (!AnyChildren) { 963 LinkModules.insert(Mod); 964 } 965 } 966 967 // Add link options for all of the imported modules in reverse topological 968 // order. We don't do anything to try to order import link flags with respect 969 // to linker options inserted by things like #pragma comment(). 970 SmallVector<llvm::Value *, 16> MetadataArgs; 971 Visited.clear(); 972 for (llvm::SetVector<clang::Module *>::iterator M = LinkModules.begin(), 973 MEnd = LinkModules.end(); 974 M != MEnd; ++M) { 975 if (Visited.insert(*M)) 976 addLinkOptionsPostorder(*this, *M, MetadataArgs, Visited); 977 } 978 std::reverse(MetadataArgs.begin(), MetadataArgs.end()); 979 LinkerOptionsMetadata.append(MetadataArgs.begin(), MetadataArgs.end()); 980 981 // Add the linker options metadata flag. 982 getModule().addModuleFlag(llvm::Module::AppendUnique, "Linker Options", 983 llvm::MDNode::get(getLLVMContext(), 984 LinkerOptionsMetadata)); 985} 986 987void CodeGenModule::EmitDeferred() { 988 // Emit code for any potentially referenced deferred decls. Since a 989 // previously unused static decl may become used during the generation of code 990 // for a static function, iterate until no changes are made. 991 992 while (true) { 993 if (!DeferredVTables.empty()) { 994 EmitDeferredVTables(); 995 996 // Emitting a v-table doesn't directly cause more v-tables to 997 // become deferred, although it can cause functions to be 998 // emitted that then need those v-tables. 999 assert(DeferredVTables.empty()); 1000 } 1001 1002 // Stop if we're out of both deferred v-tables and deferred declarations. 1003 if (DeferredDeclsToEmit.empty()) break; 1004 1005 GlobalDecl D = DeferredDeclsToEmit.back(); 1006 DeferredDeclsToEmit.pop_back(); 1007 1008 // Check to see if we've already emitted this. This is necessary 1009 // for a couple of reasons: first, decls can end up in the 1010 // deferred-decls queue multiple times, and second, decls can end 1011 // up with definitions in unusual ways (e.g. by an extern inline 1012 // function acquiring a strong function redefinition). Just 1013 // ignore these cases. 1014 // 1015 // TODO: That said, looking this up multiple times is very wasteful. 1016 StringRef Name = getMangledName(D); 1017 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 1018 assert(CGRef && "Deferred decl wasn't referenced?"); 1019 1020 if (!CGRef->isDeclaration()) 1021 continue; 1022 1023 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 1024 // purposes an alias counts as a definition. 1025 if (isa<llvm::GlobalAlias>(CGRef)) 1026 continue; 1027 1028 // Otherwise, emit the definition and move on to the next one. 1029 EmitGlobalDefinition(D); 1030 } 1031} 1032 1033void CodeGenModule::EmitGlobalAnnotations() { 1034 if (Annotations.empty()) 1035 return; 1036 1037 // Create a new global variable for the ConstantStruct in the Module. 1038 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 1039 Annotations[0]->getType(), Annotations.size()), Annotations); 1040 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), 1041 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, 1042 "llvm.global.annotations"); 1043 gv->setSection(AnnotationSection); 1044} 1045 1046llvm::Constant *CodeGenModule::EmitAnnotationString(StringRef Str) { 1047 llvm::Constant *&AStr = AnnotationStrings[Str]; 1048 if (AStr) 1049 return AStr; 1050 1051 // Not found yet, create a new global. 1052 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); 1053 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), 1054 true, llvm::GlobalValue::PrivateLinkage, s, ".str"); 1055 gv->setSection(AnnotationSection); 1056 gv->setUnnamedAddr(true); 1057 AStr = gv; 1058 return gv; 1059} 1060 1061llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 1062 SourceManager &SM = getContext().getSourceManager(); 1063 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 1064 if (PLoc.isValid()) 1065 return EmitAnnotationString(PLoc.getFilename()); 1066 return EmitAnnotationString(SM.getBufferName(Loc)); 1067} 1068 1069llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 1070 SourceManager &SM = getContext().getSourceManager(); 1071 PresumedLoc PLoc = SM.getPresumedLoc(L); 1072 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 1073 SM.getExpansionLineNumber(L); 1074 return llvm::ConstantInt::get(Int32Ty, LineNo); 1075} 1076 1077llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 1078 const AnnotateAttr *AA, 1079 SourceLocation L) { 1080 // Get the globals for file name, annotation, and the line number. 1081 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 1082 *UnitGV = EmitAnnotationUnit(L), 1083 *LineNoCst = EmitAnnotationLineNo(L); 1084 1085 // Create the ConstantStruct for the global annotation. 1086 llvm::Constant *Fields[4] = { 1087 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 1088 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 1089 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 1090 LineNoCst 1091 }; 1092 return llvm::ConstantStruct::getAnon(Fields); 1093} 1094 1095void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 1096 llvm::GlobalValue *GV) { 1097 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 1098 // Get the struct elements for these annotations. 1099 for (specific_attr_iterator<AnnotateAttr> 1100 ai = D->specific_attr_begin<AnnotateAttr>(), 1101 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) 1102 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); 1103} 1104 1105bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 1106 // Never defer when EmitAllDecls is specified. 1107 if (LangOpts.EmitAllDecls) 1108 return false; 1109 1110 return !getContext().DeclMustBeEmitted(Global); 1111} 1112 1113llvm::Constant *CodeGenModule::GetAddrOfUuidDescriptor( 1114 const CXXUuidofExpr* E) { 1115 // Sema has verified that IIDSource has a __declspec(uuid()), and that its 1116 // well-formed. 1117 StringRef Uuid = E->getUuidAsStringRef(Context); 1118 std::string Name = "_GUID_" + Uuid.lower(); 1119 std::replace(Name.begin(), Name.end(), '-', '_'); 1120 1121 // Look for an existing global. 1122 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name)) 1123 return GV; 1124 1125 llvm::Constant *Init = EmitUuidofInitializer(Uuid, E->getType()); 1126 assert(Init && "failed to initialize as constant"); 1127 1128 llvm::GlobalVariable *GV = new llvm::GlobalVariable( 1129 getModule(), Init->getType(), 1130 /*isConstant=*/true, llvm::GlobalValue::LinkOnceODRLinkage, Init, Name); 1131 return GV; 1132} 1133 1134llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 1135 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 1136 assert(AA && "No alias?"); 1137 1138 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 1139 1140 // See if there is already something with the target's name in the module. 1141 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 1142 if (Entry) { 1143 unsigned AS = getContext().getTargetAddressSpace(VD->getType()); 1144 return llvm::ConstantExpr::getBitCast(Entry, DeclTy->getPointerTo(AS)); 1145 } 1146 1147 llvm::Constant *Aliasee; 1148 if (isa<llvm::FunctionType>(DeclTy)) 1149 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, 1150 GlobalDecl(cast<FunctionDecl>(VD)), 1151 /*ForVTable=*/false); 1152 else 1153 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1154 llvm::PointerType::getUnqual(DeclTy), 0); 1155 1156 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 1157 F->setLinkage(llvm::Function::ExternalWeakLinkage); 1158 WeakRefReferences.insert(F); 1159 1160 return Aliasee; 1161} 1162 1163void CodeGenModule::EmitGlobal(GlobalDecl GD) { 1164 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 1165 1166 // Weak references don't produce any output by themselves. 1167 if (Global->hasAttr<WeakRefAttr>()) 1168 return; 1169 1170 // If this is an alias definition (which otherwise looks like a declaration) 1171 // emit it now. 1172 if (Global->hasAttr<AliasAttr>()) 1173 return EmitAliasDefinition(GD); 1174 1175 // If this is CUDA, be selective about which declarations we emit. 1176 if (LangOpts.CUDA) { 1177 if (CodeGenOpts.CUDAIsDevice) { 1178 if (!Global->hasAttr<CUDADeviceAttr>() && 1179 !Global->hasAttr<CUDAGlobalAttr>() && 1180 !Global->hasAttr<CUDAConstantAttr>() && 1181 !Global->hasAttr<CUDASharedAttr>()) 1182 return; 1183 } else { 1184 if (!Global->hasAttr<CUDAHostAttr>() && ( 1185 Global->hasAttr<CUDADeviceAttr>() || 1186 Global->hasAttr<CUDAConstantAttr>() || 1187 Global->hasAttr<CUDASharedAttr>())) 1188 return; 1189 } 1190 } 1191 1192 // Ignore declarations, they will be emitted on their first use. 1193 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 1194 // Forward declarations are emitted lazily on first use. 1195 if (!FD->doesThisDeclarationHaveABody()) { 1196 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 1197 return; 1198 1199 const FunctionDecl *InlineDefinition = 0; 1200 FD->getBody(InlineDefinition); 1201 1202 StringRef MangledName = getMangledName(GD); 1203 DeferredDecls.erase(MangledName); 1204 EmitGlobalDefinition(InlineDefinition); 1205 return; 1206 } 1207 } else { 1208 const VarDecl *VD = cast<VarDecl>(Global); 1209 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 1210 1211 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 1212 return; 1213 } 1214 1215 // Defer code generation when possible if this is a static definition, inline 1216 // function etc. These we only want to emit if they are used. 1217 if (!MayDeferGeneration(Global)) { 1218 // Emit the definition if it can't be deferred. 1219 EmitGlobalDefinition(GD); 1220 return; 1221 } 1222 1223 // If we're deferring emission of a C++ variable with an 1224 // initializer, remember the order in which it appeared in the file. 1225 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) && 1226 cast<VarDecl>(Global)->hasInit()) { 1227 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 1228 CXXGlobalInits.push_back(0); 1229 } 1230 1231 // If the value has already been used, add it directly to the 1232 // DeferredDeclsToEmit list. 1233 StringRef MangledName = getMangledName(GD); 1234 if (GetGlobalValue(MangledName)) 1235 DeferredDeclsToEmit.push_back(GD); 1236 else { 1237 // Otherwise, remember that we saw a deferred decl with this name. The 1238 // first use of the mangled name will cause it to move into 1239 // DeferredDeclsToEmit. 1240 DeferredDecls[MangledName] = GD; 1241 } 1242} 1243 1244namespace { 1245 struct FunctionIsDirectlyRecursive : 1246 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> { 1247 const StringRef Name; 1248 const Builtin::Context &BI; 1249 bool Result; 1250 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) : 1251 Name(N), BI(C), Result(false) { 1252 } 1253 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; 1254 1255 bool TraverseCallExpr(CallExpr *E) { 1256 const FunctionDecl *FD = E->getDirectCallee(); 1257 if (!FD) 1258 return true; 1259 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1260 if (Attr && Name == Attr->getLabel()) { 1261 Result = true; 1262 return false; 1263 } 1264 unsigned BuiltinID = FD->getBuiltinID(); 1265 if (!BuiltinID) 1266 return true; 1267 StringRef BuiltinName = BI.GetName(BuiltinID); 1268 if (BuiltinName.startswith("__builtin_") && 1269 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { 1270 Result = true; 1271 return false; 1272 } 1273 return true; 1274 } 1275 }; 1276} 1277 1278// isTriviallyRecursive - Check if this function calls another 1279// decl that, because of the asm attribute or the other decl being a builtin, 1280// ends up pointing to itself. 1281bool 1282CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { 1283 StringRef Name; 1284 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { 1285 // asm labels are a special kind of mangling we have to support. 1286 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1287 if (!Attr) 1288 return false; 1289 Name = Attr->getLabel(); 1290 } else { 1291 Name = FD->getName(); 1292 } 1293 1294 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); 1295 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD)); 1296 return Walker.Result; 1297} 1298 1299bool 1300CodeGenModule::shouldEmitFunction(GlobalDecl GD) { 1301 if (getFunctionLinkage(GD) != llvm::Function::AvailableExternallyLinkage) 1302 return true; 1303 const FunctionDecl *F = cast<FunctionDecl>(GD.getDecl()); 1304 if (CodeGenOpts.OptimizationLevel == 0 && 1305 !F->hasAttr<AlwaysInlineAttr>() && !F->hasAttr<ForceInlineAttr>()) 1306 return false; 1307 // PR9614. Avoid cases where the source code is lying to us. An available 1308 // externally function should have an equivalent function somewhere else, 1309 // but a function that calls itself is clearly not equivalent to the real 1310 // implementation. 1311 // This happens in glibc's btowc and in some configure checks. 1312 return !isTriviallyRecursive(F); 1313} 1314 1315/// If the type for the method's class was generated by 1316/// CGDebugInfo::createContextChain(), the cache contains only a 1317/// limited DIType without any declarations. Since EmitFunctionStart() 1318/// needs to find the canonical declaration for each method, we need 1319/// to construct the complete type prior to emitting the method. 1320void CodeGenModule::CompleteDIClassType(const CXXMethodDecl* D) { 1321 if (!D->isInstance()) 1322 return; 1323 1324 if (CGDebugInfo *DI = getModuleDebugInfo()) 1325 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) { 1326 const PointerType *ThisPtr = 1327 cast<PointerType>(D->getThisType(getContext())); 1328 DI->getOrCreateRecordType(ThisPtr->getPointeeType(), D->getLocation()); 1329 } 1330} 1331 1332void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 1333 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1334 1335 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 1336 Context.getSourceManager(), 1337 "Generating code for declaration"); 1338 1339 if (isa<FunctionDecl>(D)) { 1340 // At -O0, don't generate IR for functions with available_externally 1341 // linkage. 1342 if (!shouldEmitFunction(GD)) 1343 return; 1344 1345 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 1346 CompleteDIClassType(Method); 1347 // Make sure to emit the definition(s) before we emit the thunks. 1348 // This is necessary for the generation of certain thunks. 1349 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 1350 EmitCXXConstructor(CD, GD.getCtorType()); 1351 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 1352 EmitCXXDestructor(DD, GD.getDtorType()); 1353 else 1354 EmitGlobalFunctionDefinition(GD); 1355 1356 if (Method->isVirtual()) 1357 getVTables().EmitThunks(GD); 1358 1359 return; 1360 } 1361 1362 return EmitGlobalFunctionDefinition(GD); 1363 } 1364 1365 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 1366 return EmitGlobalVarDefinition(VD); 1367 1368 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 1369} 1370 1371/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 1372/// module, create and return an llvm Function with the specified type. If there 1373/// is something in the module with the specified name, return it potentially 1374/// bitcasted to the right type. 1375/// 1376/// If D is non-null, it specifies a decl that correspond to this. This is used 1377/// to set the attributes on the function when it is first created. 1378llvm::Constant * 1379CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 1380 llvm::Type *Ty, 1381 GlobalDecl GD, bool ForVTable, 1382 llvm::AttributeSet ExtraAttrs) { 1383 const Decl *D = GD.getDecl(); 1384 1385 // Lookup the entry, lazily creating it if necessary. 1386 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1387 if (Entry) { 1388 if (WeakRefReferences.erase(Entry)) { 1389 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D); 1390 if (FD && !FD->hasAttr<WeakAttr>()) 1391 Entry->setLinkage(llvm::Function::ExternalLinkage); 1392 } 1393 1394 if (Entry->getType()->getElementType() == Ty) 1395 return Entry; 1396 1397 // Make sure the result is of the correct type. 1398 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 1399 } 1400 1401 // All MSVC dtors other than the base dtor are linkonce_odr and delegate to 1402 // each other bottoming out with the base dtor. Therefore we emit non-base 1403 // dtors on usage, even if there is no dtor definition in the TU. 1404 if (D && isa<CXXDestructorDecl>(D) && 1405 getCXXABI().useThunkForDtorVariant(cast<CXXDestructorDecl>(D), 1406 GD.getDtorType())) 1407 DeferredDeclsToEmit.push_back(GD); 1408 1409 // This function doesn't have a complete type (for example, the return 1410 // type is an incomplete struct). Use a fake type instead, and make 1411 // sure not to try to set attributes. 1412 bool IsIncompleteFunction = false; 1413 1414 llvm::FunctionType *FTy; 1415 if (isa<llvm::FunctionType>(Ty)) { 1416 FTy = cast<llvm::FunctionType>(Ty); 1417 } else { 1418 FTy = llvm::FunctionType::get(VoidTy, false); 1419 IsIncompleteFunction = true; 1420 } 1421 1422 llvm::Function *F = llvm::Function::Create(FTy, 1423 llvm::Function::ExternalLinkage, 1424 MangledName, &getModule()); 1425 assert(F->getName() == MangledName && "name was uniqued!"); 1426 if (D) 1427 SetFunctionAttributes(GD, F, IsIncompleteFunction); 1428 if (ExtraAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) { 1429 llvm::AttrBuilder B(ExtraAttrs, llvm::AttributeSet::FunctionIndex); 1430 F->addAttributes(llvm::AttributeSet::FunctionIndex, 1431 llvm::AttributeSet::get(VMContext, 1432 llvm::AttributeSet::FunctionIndex, 1433 B)); 1434 } 1435 1436 // This is the first use or definition of a mangled name. If there is a 1437 // deferred decl with this name, remember that we need to emit it at the end 1438 // of the file. 1439 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1440 if (DDI != DeferredDecls.end()) { 1441 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1442 // list, and remove it from DeferredDecls (since we don't need it anymore). 1443 DeferredDeclsToEmit.push_back(DDI->second); 1444 DeferredDecls.erase(DDI); 1445 1446 // Otherwise, if this is a sized deallocation function, emit a weak definition 1447 // for it at the end of the translation unit. 1448 } else if (D && cast<FunctionDecl>(D) 1449 ->getCorrespondingUnsizedGlobalDeallocationFunction()) { 1450 DeferredDeclsToEmit.push_back(GD); 1451 1452 // Otherwise, there are cases we have to worry about where we're 1453 // using a declaration for which we must emit a definition but where 1454 // we might not find a top-level definition: 1455 // - member functions defined inline in their classes 1456 // - friend functions defined inline in some class 1457 // - special member functions with implicit definitions 1458 // If we ever change our AST traversal to walk into class methods, 1459 // this will be unnecessary. 1460 // 1461 // We also don't emit a definition for a function if it's going to be an entry 1462 // in a vtable, unless it's already marked as used. 1463 } else if (getLangOpts().CPlusPlus && D) { 1464 // Look for a declaration that's lexically in a record. 1465 const FunctionDecl *FD = cast<FunctionDecl>(D); 1466 FD = FD->getMostRecentDecl(); 1467 do { 1468 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 1469 if (FD->isImplicit() && !ForVTable) { 1470 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 1471 DeferredDeclsToEmit.push_back(GD.getWithDecl(FD)); 1472 break; 1473 } else if (FD->doesThisDeclarationHaveABody()) { 1474 DeferredDeclsToEmit.push_back(GD.getWithDecl(FD)); 1475 break; 1476 } 1477 } 1478 FD = FD->getPreviousDecl(); 1479 } while (FD); 1480 } 1481 1482 // Make sure the result is of the requested type. 1483 if (!IsIncompleteFunction) { 1484 assert(F->getType()->getElementType() == Ty); 1485 return F; 1486 } 1487 1488 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1489 return llvm::ConstantExpr::getBitCast(F, PTy); 1490} 1491 1492/// GetAddrOfFunction - Return the address of the given function. If Ty is 1493/// non-null, then this function will use the specified type if it has to 1494/// create it (this occurs when we see a definition of the function). 1495llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 1496 llvm::Type *Ty, 1497 bool ForVTable) { 1498 // If there was no specific requested type, just convert it now. 1499 if (!Ty) 1500 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 1501 1502 StringRef MangledName = getMangledName(GD); 1503 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 1504} 1505 1506/// CreateRuntimeFunction - Create a new runtime function with the specified 1507/// type and name. 1508llvm::Constant * 1509CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 1510 StringRef Name, 1511 llvm::AttributeSet ExtraAttrs) { 1512 llvm::Constant *C 1513 = GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 1514 ExtraAttrs); 1515 if (llvm::Function *F = dyn_cast<llvm::Function>(C)) 1516 if (F->empty()) 1517 F->setCallingConv(getRuntimeCC()); 1518 return C; 1519} 1520 1521/// isTypeConstant - Determine whether an object of this type can be emitted 1522/// as a constant. 1523/// 1524/// If ExcludeCtor is true, the duration when the object's constructor runs 1525/// will not be considered. The caller will need to verify that the object is 1526/// not written to during its construction. 1527bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) { 1528 if (!Ty.isConstant(Context) && !Ty->isReferenceType()) 1529 return false; 1530 1531 if (Context.getLangOpts().CPlusPlus) { 1532 if (const CXXRecordDecl *Record 1533 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl()) 1534 return ExcludeCtor && !Record->hasMutableFields() && 1535 Record->hasTrivialDestructor(); 1536 } 1537 1538 return true; 1539} 1540 1541/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1542/// create and return an llvm GlobalVariable with the specified type. If there 1543/// is something in the module with the specified name, return it potentially 1544/// bitcasted to the right type. 1545/// 1546/// If D is non-null, it specifies a decl that correspond to this. This is used 1547/// to set the attributes on the global when it is first created. 1548llvm::Constant * 1549CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1550 llvm::PointerType *Ty, 1551 const VarDecl *D, 1552 bool UnnamedAddr) { 1553 // Lookup the entry, lazily creating it if necessary. 1554 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1555 if (Entry) { 1556 if (WeakRefReferences.erase(Entry)) { 1557 if (D && !D->hasAttr<WeakAttr>()) 1558 Entry->setLinkage(llvm::Function::ExternalLinkage); 1559 } 1560 1561 if (UnnamedAddr) 1562 Entry->setUnnamedAddr(true); 1563 1564 if (Entry->getType() == Ty) 1565 return Entry; 1566 1567 // Make sure the result is of the correct type. 1568 if (Entry->getType()->getAddressSpace() != Ty->getAddressSpace()) 1569 return llvm::ConstantExpr::getAddrSpaceCast(Entry, Ty); 1570 1571 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1572 } 1573 1574 // This is the first use or definition of a mangled name. If there is a 1575 // deferred decl with this name, remember that we need to emit it at the end 1576 // of the file. 1577 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1578 if (DDI != DeferredDecls.end()) { 1579 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1580 // list, and remove it from DeferredDecls (since we don't need it anymore). 1581 DeferredDeclsToEmit.push_back(DDI->second); 1582 DeferredDecls.erase(DDI); 1583 } 1584 1585 unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace()); 1586 llvm::GlobalVariable *GV = 1587 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1588 llvm::GlobalValue::ExternalLinkage, 1589 0, MangledName, 0, 1590 llvm::GlobalVariable::NotThreadLocal, AddrSpace); 1591 1592 // Handle things which are present even on external declarations. 1593 if (D) { 1594 // FIXME: This code is overly simple and should be merged with other global 1595 // handling. 1596 GV->setConstant(isTypeConstant(D->getType(), false)); 1597 1598 // Set linkage and visibility in case we never see a definition. 1599 LinkageInfo LV = D->getLinkageAndVisibility(); 1600 if (LV.getLinkage() != ExternalLinkage) { 1601 // Don't set internal linkage on declarations. 1602 } else { 1603 if (D->hasAttr<DLLImportAttr>()) 1604 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1605 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1606 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1607 1608 // Set visibility on a declaration only if it's explicit. 1609 if (LV.isVisibilityExplicit()) 1610 GV->setVisibility(GetLLVMVisibility(LV.getVisibility())); 1611 } 1612 1613 if (D->getTLSKind()) { 1614 if (D->getTLSKind() == VarDecl::TLS_Dynamic) 1615 CXXThreadLocals.push_back(std::make_pair(D, GV)); 1616 setTLSMode(GV, *D); 1617 } 1618 1619 // If required by the ABI, treat declarations of static data members with 1620 // inline initializers as definitions. 1621 if (getCXXABI().isInlineInitializedStaticDataMemberLinkOnce() && 1622 D->isStaticDataMember() && D->hasInit() && 1623 !D->isThisDeclarationADefinition()) 1624 EmitGlobalVarDefinition(D); 1625 } 1626 1627 if (AddrSpace != Ty->getAddressSpace()) 1628 return llvm::ConstantExpr::getAddrSpaceCast(GV, Ty); 1629 1630 return GV; 1631} 1632 1633 1634llvm::GlobalVariable * 1635CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1636 llvm::Type *Ty, 1637 llvm::GlobalValue::LinkageTypes Linkage) { 1638 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1639 llvm::GlobalVariable *OldGV = 0; 1640 1641 1642 if (GV) { 1643 // Check if the variable has the right type. 1644 if (GV->getType()->getElementType() == Ty) 1645 return GV; 1646 1647 // Because C++ name mangling, the only way we can end up with an already 1648 // existing global with the same name is if it has been declared extern "C". 1649 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1650 OldGV = GV; 1651 } 1652 1653 // Create a new variable. 1654 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1655 Linkage, 0, Name); 1656 1657 if (OldGV) { 1658 // Replace occurrences of the old variable if needed. 1659 GV->takeName(OldGV); 1660 1661 if (!OldGV->use_empty()) { 1662 llvm::Constant *NewPtrForOldDecl = 1663 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1664 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1665 } 1666 1667 OldGV->eraseFromParent(); 1668 } 1669 1670 return GV; 1671} 1672 1673/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1674/// given global variable. If Ty is non-null and if the global doesn't exist, 1675/// then it will be created with the specified type instead of whatever the 1676/// normal requested type would be. 1677llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1678 llvm::Type *Ty) { 1679 assert(D->hasGlobalStorage() && "Not a global variable"); 1680 QualType ASTTy = D->getType(); 1681 if (Ty == 0) 1682 Ty = getTypes().ConvertTypeForMem(ASTTy); 1683 1684 llvm::PointerType *PTy = 1685 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1686 1687 StringRef MangledName = getMangledName(D); 1688 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1689} 1690 1691/// CreateRuntimeVariable - Create a new runtime global variable with the 1692/// specified type and name. 1693llvm::Constant * 1694CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1695 StringRef Name) { 1696 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1697 true); 1698} 1699 1700void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1701 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1702 1703 if (MayDeferGeneration(D)) { 1704 // If we have not seen a reference to this variable yet, place it 1705 // into the deferred declarations table to be emitted if needed 1706 // later. 1707 StringRef MangledName = getMangledName(D); 1708 if (!GetGlobalValue(MangledName)) { 1709 DeferredDecls[MangledName] = D; 1710 return; 1711 } 1712 } 1713 1714 // The tentative definition is the only definition. 1715 EmitGlobalVarDefinition(D); 1716} 1717 1718CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1719 return Context.toCharUnitsFromBits( 1720 TheDataLayout.getTypeStoreSizeInBits(Ty)); 1721} 1722 1723unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D, 1724 unsigned AddrSpace) { 1725 if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) { 1726 if (D->hasAttr<CUDAConstantAttr>()) 1727 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_constant); 1728 else if (D->hasAttr<CUDASharedAttr>()) 1729 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_shared); 1730 else 1731 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_device); 1732 } 1733 1734 return AddrSpace; 1735} 1736 1737template<typename SomeDecl> 1738void CodeGenModule::MaybeHandleStaticInExternC(const SomeDecl *D, 1739 llvm::GlobalValue *GV) { 1740 if (!getLangOpts().CPlusPlus) 1741 return; 1742 1743 // Must have 'used' attribute, or else inline assembly can't rely on 1744 // the name existing. 1745 if (!D->template hasAttr<UsedAttr>()) 1746 return; 1747 1748 // Must have internal linkage and an ordinary name. 1749 if (!D->getIdentifier() || D->getFormalLinkage() != InternalLinkage) 1750 return; 1751 1752 // Must be in an extern "C" context. Entities declared directly within 1753 // a record are not extern "C" even if the record is in such a context. 1754 const SomeDecl *First = D->getFirstDecl(); 1755 if (First->getDeclContext()->isRecord() || !First->isInExternCContext()) 1756 return; 1757 1758 // OK, this is an internal linkage entity inside an extern "C" linkage 1759 // specification. Make a note of that so we can give it the "expected" 1760 // mangled name if nothing else is using that name. 1761 std::pair<StaticExternCMap::iterator, bool> R = 1762 StaticExternCValues.insert(std::make_pair(D->getIdentifier(), GV)); 1763 1764 // If we have multiple internal linkage entities with the same name 1765 // in extern "C" regions, none of them gets that name. 1766 if (!R.second) 1767 R.first->second = 0; 1768} 1769 1770void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1771 llvm::Constant *Init = 0; 1772 QualType ASTTy = D->getType(); 1773 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 1774 bool NeedsGlobalCtor = false; 1775 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor(); 1776 1777 const VarDecl *InitDecl; 1778 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 1779 1780 if (!InitExpr) { 1781 // This is a tentative definition; tentative definitions are 1782 // implicitly initialized with { 0 }. 1783 // 1784 // Note that tentative definitions are only emitted at the end of 1785 // a translation unit, so they should never have incomplete 1786 // type. In addition, EmitTentativeDefinition makes sure that we 1787 // never attempt to emit a tentative definition if a real one 1788 // exists. A use may still exists, however, so we still may need 1789 // to do a RAUW. 1790 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1791 Init = EmitNullConstant(D->getType()); 1792 } else { 1793 initializedGlobalDecl = GlobalDecl(D); 1794 Init = EmitConstantInit(*InitDecl); 1795 1796 if (!Init) { 1797 QualType T = InitExpr->getType(); 1798 if (D->getType()->isReferenceType()) 1799 T = D->getType(); 1800 1801 if (getLangOpts().CPlusPlus) { 1802 Init = EmitNullConstant(T); 1803 NeedsGlobalCtor = true; 1804 } else { 1805 ErrorUnsupported(D, "static initializer"); 1806 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1807 } 1808 } else { 1809 // We don't need an initializer, so remove the entry for the delayed 1810 // initializer position (just in case this entry was delayed) if we 1811 // also don't need to register a destructor. 1812 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor) 1813 DelayedCXXInitPosition.erase(D); 1814 } 1815 } 1816 1817 llvm::Type* InitType = Init->getType(); 1818 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1819 1820 // Strip off a bitcast if we got one back. 1821 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1822 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1823 CE->getOpcode() == llvm::Instruction::AddrSpaceCast || 1824 // All zero index gep. 1825 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1826 Entry = CE->getOperand(0); 1827 } 1828 1829 // Entry is now either a Function or GlobalVariable. 1830 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1831 1832 // We have a definition after a declaration with the wrong type. 1833 // We must make a new GlobalVariable* and update everything that used OldGV 1834 // (a declaration or tentative definition) with the new GlobalVariable* 1835 // (which will be a definition). 1836 // 1837 // This happens if there is a prototype for a global (e.g. 1838 // "extern int x[];") and then a definition of a different type (e.g. 1839 // "int x[10];"). This also happens when an initializer has a different type 1840 // from the type of the global (this happens with unions). 1841 if (GV == 0 || 1842 GV->getType()->getElementType() != InitType || 1843 GV->getType()->getAddressSpace() != 1844 GetGlobalVarAddressSpace(D, getContext().getTargetAddressSpace(ASTTy))) { 1845 1846 // Move the old entry aside so that we'll create a new one. 1847 Entry->setName(StringRef()); 1848 1849 // Make a new global with the correct type, this is now guaranteed to work. 1850 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1851 1852 // Replace all uses of the old global with the new global 1853 llvm::Constant *NewPtrForOldDecl = 1854 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1855 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1856 1857 // Erase the old global, since it is no longer used. 1858 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1859 } 1860 1861 MaybeHandleStaticInExternC(D, GV); 1862 1863 if (D->hasAttr<AnnotateAttr>()) 1864 AddGlobalAnnotations(D, GV); 1865 1866 GV->setInitializer(Init); 1867 1868 // If it is safe to mark the global 'constant', do so now. 1869 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor && 1870 isTypeConstant(D->getType(), true)); 1871 1872 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1873 1874 // Set the llvm linkage type as appropriate. 1875 llvm::GlobalValue::LinkageTypes Linkage = 1876 GetLLVMLinkageVarDefinition(D, GV->isConstant()); 1877 GV->setLinkage(Linkage); 1878 1879 // If required by the ABI, give definitions of static data members with inline 1880 // initializers linkonce_odr linkage. 1881 if (getCXXABI().isInlineInitializedStaticDataMemberLinkOnce() && 1882 D->isStaticDataMember() && InitExpr && 1883 !InitDecl->isThisDeclarationADefinition()) 1884 GV->setLinkage(llvm::GlobalVariable::LinkOnceODRLinkage); 1885 1886 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1887 // common vars aren't constant even if declared const. 1888 GV->setConstant(false); 1889 1890 SetCommonAttributes(D, GV); 1891 1892 // Emit the initializer function if necessary. 1893 if (NeedsGlobalCtor || NeedsGlobalDtor) 1894 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); 1895 1896 // If we are compiling with ASan, add metadata indicating dynamically 1897 // initialized globals. 1898 if (SanOpts.Address && NeedsGlobalCtor) { 1899 llvm::Module &M = getModule(); 1900 1901 llvm::NamedMDNode *DynamicInitializers = 1902 M.getOrInsertNamedMetadata("llvm.asan.dynamically_initialized_globals"); 1903 llvm::Value *GlobalToAdd[] = { GV }; 1904 llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalToAdd); 1905 DynamicInitializers->addOperand(ThisGlobal); 1906 } 1907 1908 // Emit global variable debug information. 1909 if (CGDebugInfo *DI = getModuleDebugInfo()) 1910 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) 1911 DI->EmitGlobalVariable(GV, D); 1912} 1913 1914llvm::GlobalValue::LinkageTypes 1915CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, bool isConstant) { 1916 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1917 if (Linkage == GVA_Internal) 1918 return llvm::Function::InternalLinkage; 1919 else if (D->hasAttr<DLLImportAttr>()) 1920 return llvm::Function::DLLImportLinkage; 1921 else if (D->hasAttr<DLLExportAttr>()) 1922 return llvm::Function::DLLExportLinkage; 1923 else if (D->hasAttr<SelectAnyAttr>()) { 1924 // selectany symbols are externally visible, so use weak instead of 1925 // linkonce. MSVC optimizes away references to const selectany globals, so 1926 // all definitions should be the same and ODR linkage should be used. 1927 // http://msdn.microsoft.com/en-us/library/5tkz6s71.aspx 1928 return llvm::GlobalVariable::WeakODRLinkage; 1929 } else if (D->hasAttr<WeakAttr>()) { 1930 if (isConstant) 1931 return llvm::GlobalVariable::WeakODRLinkage; 1932 else 1933 return llvm::GlobalVariable::WeakAnyLinkage; 1934 } else if (Linkage == GVA_TemplateInstantiation || 1935 Linkage == GVA_ExplicitTemplateInstantiation) 1936 return llvm::GlobalVariable::WeakODRLinkage; 1937 else if (!getLangOpts().CPlusPlus && 1938 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1939 D->getAttr<CommonAttr>()) && 1940 !D->hasExternalStorage() && !D->getInit() && 1941 !D->getAttr<SectionAttr>() && !D->getTLSKind() && 1942 !D->getAttr<WeakImportAttr>()) { 1943 // Thread local vars aren't considered common linkage. 1944 return llvm::GlobalVariable::CommonLinkage; 1945 } else if (D->getTLSKind() == VarDecl::TLS_Dynamic && 1946 getTarget().getTriple().isMacOSX()) 1947 // On Darwin, the backing variable for a C++11 thread_local variable always 1948 // has internal linkage; all accesses should just be calls to the 1949 // Itanium-specified entry point, which has the normal linkage of the 1950 // variable. 1951 return llvm::GlobalValue::InternalLinkage; 1952 return llvm::GlobalVariable::ExternalLinkage; 1953} 1954 1955/// Replace the uses of a function that was declared with a non-proto type. 1956/// We want to silently drop extra arguments from call sites 1957static void replaceUsesOfNonProtoConstant(llvm::Constant *old, 1958 llvm::Function *newFn) { 1959 // Fast path. 1960 if (old->use_empty()) return; 1961 1962 llvm::Type *newRetTy = newFn->getReturnType(); 1963 SmallVector<llvm::Value*, 4> newArgs; 1964 1965 for (llvm::Value::use_iterator ui = old->use_begin(), ue = old->use_end(); 1966 ui != ue; ) { 1967 llvm::Value::use_iterator use = ui++; // Increment before the use is erased. 1968 llvm::User *user = *use; 1969 1970 // Recognize and replace uses of bitcasts. Most calls to 1971 // unprototyped functions will use bitcasts. 1972 if (llvm::ConstantExpr *bitcast = dyn_cast<llvm::ConstantExpr>(user)) { 1973 if (bitcast->getOpcode() == llvm::Instruction::BitCast) 1974 replaceUsesOfNonProtoConstant(bitcast, newFn); 1975 continue; 1976 } 1977 1978 // Recognize calls to the function. 1979 llvm::CallSite callSite(user); 1980 if (!callSite) continue; 1981 if (!callSite.isCallee(use)) continue; 1982 1983 // If the return types don't match exactly, then we can't 1984 // transform this call unless it's dead. 1985 if (callSite->getType() != newRetTy && !callSite->use_empty()) 1986 continue; 1987 1988 // Get the call site's attribute list. 1989 SmallVector<llvm::AttributeSet, 8> newAttrs; 1990 llvm::AttributeSet oldAttrs = callSite.getAttributes(); 1991 1992 // Collect any return attributes from the call. 1993 if (oldAttrs.hasAttributes(llvm::AttributeSet::ReturnIndex)) 1994 newAttrs.push_back( 1995 llvm::AttributeSet::get(newFn->getContext(), 1996 oldAttrs.getRetAttributes())); 1997 1998 // If the function was passed too few arguments, don't transform. 1999 unsigned newNumArgs = newFn->arg_size(); 2000 if (callSite.arg_size() < newNumArgs) continue; 2001 2002 // If extra arguments were passed, we silently drop them. 2003 // If any of the types mismatch, we don't transform. 2004 unsigned argNo = 0; 2005 bool dontTransform = false; 2006 for (llvm::Function::arg_iterator ai = newFn->arg_begin(), 2007 ae = newFn->arg_end(); ai != ae; ++ai, ++argNo) { 2008 if (callSite.getArgument(argNo)->getType() != ai->getType()) { 2009 dontTransform = true; 2010 break; 2011 } 2012 2013 // Add any parameter attributes. 2014 if (oldAttrs.hasAttributes(argNo + 1)) 2015 newAttrs. 2016 push_back(llvm:: 2017 AttributeSet::get(newFn->getContext(), 2018 oldAttrs.getParamAttributes(argNo + 1))); 2019 } 2020 if (dontTransform) 2021 continue; 2022 2023 if (oldAttrs.hasAttributes(llvm::AttributeSet::FunctionIndex)) 2024 newAttrs.push_back(llvm::AttributeSet::get(newFn->getContext(), 2025 oldAttrs.getFnAttributes())); 2026 2027 // Okay, we can transform this. Create the new call instruction and copy 2028 // over the required information. 2029 newArgs.append(callSite.arg_begin(), callSite.arg_begin() + argNo); 2030 2031 llvm::CallSite newCall; 2032 if (callSite.isCall()) { 2033 newCall = llvm::CallInst::Create(newFn, newArgs, "", 2034 callSite.getInstruction()); 2035 } else { 2036 llvm::InvokeInst *oldInvoke = 2037 cast<llvm::InvokeInst>(callSite.getInstruction()); 2038 newCall = llvm::InvokeInst::Create(newFn, 2039 oldInvoke->getNormalDest(), 2040 oldInvoke->getUnwindDest(), 2041 newArgs, "", 2042 callSite.getInstruction()); 2043 } 2044 newArgs.clear(); // for the next iteration 2045 2046 if (!newCall->getType()->isVoidTy()) 2047 newCall->takeName(callSite.getInstruction()); 2048 newCall.setAttributes( 2049 llvm::AttributeSet::get(newFn->getContext(), newAttrs)); 2050 newCall.setCallingConv(callSite.getCallingConv()); 2051 2052 // Finally, remove the old call, replacing any uses with the new one. 2053 if (!callSite->use_empty()) 2054 callSite->replaceAllUsesWith(newCall.getInstruction()); 2055 2056 // Copy debug location attached to CI. 2057 if (!callSite->getDebugLoc().isUnknown()) 2058 newCall->setDebugLoc(callSite->getDebugLoc()); 2059 callSite->eraseFromParent(); 2060 } 2061} 2062 2063/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 2064/// implement a function with no prototype, e.g. "int foo() {}". If there are 2065/// existing call uses of the old function in the module, this adjusts them to 2066/// call the new function directly. 2067/// 2068/// This is not just a cleanup: the always_inline pass requires direct calls to 2069/// functions to be able to inline them. If there is a bitcast in the way, it 2070/// won't inline them. Instcombine normally deletes these calls, but it isn't 2071/// run at -O0. 2072static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 2073 llvm::Function *NewFn) { 2074 // If we're redefining a global as a function, don't transform it. 2075 if (!isa<llvm::Function>(Old)) return; 2076 2077 replaceUsesOfNonProtoConstant(Old, NewFn); 2078} 2079 2080void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) { 2081 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind(); 2082 // If we have a definition, this might be a deferred decl. If the 2083 // instantiation is explicit, make sure we emit it at the end. 2084 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition) 2085 GetAddrOfGlobalVar(VD); 2086 2087 EmitTopLevelDecl(VD); 2088} 2089 2090void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 2091 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 2092 2093 // Compute the function info and LLVM type. 2094 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); 2095 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); 2096 2097 // Get or create the prototype for the function. 2098 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 2099 2100 // Strip off a bitcast if we got one back. 2101 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 2102 assert(CE->getOpcode() == llvm::Instruction::BitCast); 2103 Entry = CE->getOperand(0); 2104 } 2105 2106 if (!cast<llvm::GlobalValue>(Entry)->isDeclaration()) { 2107 getDiags().Report(D->getLocation(), diag::err_duplicate_mangled_name); 2108 return; 2109 } 2110 2111 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 2112 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 2113 2114 // If the types mismatch then we have to rewrite the definition. 2115 assert(OldFn->isDeclaration() && 2116 "Shouldn't replace non-declaration"); 2117 2118 // F is the Function* for the one with the wrong type, we must make a new 2119 // Function* and update everything that used F (a declaration) with the new 2120 // Function* (which will be a definition). 2121 // 2122 // This happens if there is a prototype for a function 2123 // (e.g. "int f()") and then a definition of a different type 2124 // (e.g. "int f(int x)"). Move the old function aside so that it 2125 // doesn't interfere with GetAddrOfFunction. 2126 OldFn->setName(StringRef()); 2127 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 2128 2129 // This might be an implementation of a function without a 2130 // prototype, in which case, try to do special replacement of 2131 // calls which match the new prototype. The really key thing here 2132 // is that we also potentially drop arguments from the call site 2133 // so as to make a direct call, which makes the inliner happier 2134 // and suppresses a number of optimizer warnings (!) about 2135 // dropping arguments. 2136 if (!OldFn->use_empty()) { 2137 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 2138 OldFn->removeDeadConstantUsers(); 2139 } 2140 2141 // Replace uses of F with the Function we will endow with a body. 2142 if (!Entry->use_empty()) { 2143 llvm::Constant *NewPtrForOldDecl = 2144 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 2145 Entry->replaceAllUsesWith(NewPtrForOldDecl); 2146 } 2147 2148 // Ok, delete the old function now, which is dead. 2149 OldFn->eraseFromParent(); 2150 2151 Entry = NewFn; 2152 } 2153 2154 // We need to set linkage and visibility on the function before 2155 // generating code for it because various parts of IR generation 2156 // want to propagate this information down (e.g. to local static 2157 // declarations). 2158 llvm::Function *Fn = cast<llvm::Function>(Entry); 2159 setFunctionLinkage(GD, Fn); 2160 2161 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 2162 setGlobalVisibility(Fn, D); 2163 2164 MaybeHandleStaticInExternC(D, Fn); 2165 2166 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 2167 2168 SetFunctionDefinitionAttributes(D, Fn); 2169 SetLLVMFunctionAttributesForDefinition(D, Fn); 2170 2171 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 2172 AddGlobalCtor(Fn, CA->getPriority()); 2173 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 2174 AddGlobalDtor(Fn, DA->getPriority()); 2175 if (D->hasAttr<AnnotateAttr>()) 2176 AddGlobalAnnotations(D, Fn); 2177} 2178 2179void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 2180 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 2181 const AliasAttr *AA = D->getAttr<AliasAttr>(); 2182 assert(AA && "Not an alias?"); 2183 2184 StringRef MangledName = getMangledName(GD); 2185 2186 // If there is a definition in the module, then it wins over the alias. 2187 // This is dubious, but allow it to be safe. Just ignore the alias. 2188 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 2189 if (Entry && !Entry->isDeclaration()) 2190 return; 2191 2192 Aliases.push_back(GD); 2193 2194 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 2195 2196 // Create a reference to the named value. This ensures that it is emitted 2197 // if a deferred decl. 2198 llvm::Constant *Aliasee; 2199 if (isa<llvm::FunctionType>(DeclTy)) 2200 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD, 2201 /*ForVTable=*/false); 2202 else 2203 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 2204 llvm::PointerType::getUnqual(DeclTy), 0); 2205 2206 // Create the new alias itself, but don't set a name yet. 2207 llvm::GlobalValue *GA = 2208 new llvm::GlobalAlias(Aliasee->getType(), 2209 llvm::Function::ExternalLinkage, 2210 "", Aliasee, &getModule()); 2211 2212 if (Entry) { 2213 assert(Entry->isDeclaration()); 2214 2215 // If there is a declaration in the module, then we had an extern followed 2216 // by the alias, as in: 2217 // extern int test6(); 2218 // ... 2219 // int test6() __attribute__((alias("test7"))); 2220 // 2221 // Remove it and replace uses of it with the alias. 2222 GA->takeName(Entry); 2223 2224 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 2225 Entry->getType())); 2226 Entry->eraseFromParent(); 2227 } else { 2228 GA->setName(MangledName); 2229 } 2230 2231 // Set attributes which are particular to an alias; this is a 2232 // specialization of the attributes which may be set on a global 2233 // variable/function. 2234 if (D->hasAttr<DLLExportAttr>()) { 2235 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2236 // The dllexport attribute is ignored for undefined symbols. 2237 if (FD->hasBody()) 2238 GA->setLinkage(llvm::Function::DLLExportLinkage); 2239 } else { 2240 GA->setLinkage(llvm::Function::DLLExportLinkage); 2241 } 2242 } else if (D->hasAttr<WeakAttr>() || 2243 D->hasAttr<WeakRefAttr>() || 2244 D->isWeakImported()) { 2245 GA->setLinkage(llvm::Function::WeakAnyLinkage); 2246 } 2247 2248 SetCommonAttributes(D, GA); 2249} 2250 2251llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 2252 ArrayRef<llvm::Type*> Tys) { 2253 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 2254 Tys); 2255} 2256 2257static llvm::StringMapEntry<llvm::Constant*> & 2258GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2259 const StringLiteral *Literal, 2260 bool TargetIsLSB, 2261 bool &IsUTF16, 2262 unsigned &StringLength) { 2263 StringRef String = Literal->getString(); 2264 unsigned NumBytes = String.size(); 2265 2266 // Check for simple case. 2267 if (!Literal->containsNonAsciiOrNull()) { 2268 StringLength = NumBytes; 2269 return Map.GetOrCreateValue(String); 2270 } 2271 2272 // Otherwise, convert the UTF8 literals into a string of shorts. 2273 IsUTF16 = true; 2274 2275 SmallVector<UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls. 2276 const UTF8 *FromPtr = (const UTF8 *)String.data(); 2277 UTF16 *ToPtr = &ToBuf[0]; 2278 2279 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 2280 &ToPtr, ToPtr + NumBytes, 2281 strictConversion); 2282 2283 // ConvertUTF8toUTF16 returns the length in ToPtr. 2284 StringLength = ToPtr - &ToBuf[0]; 2285 2286 // Add an explicit null. 2287 *ToPtr = 0; 2288 return Map. 2289 GetOrCreateValue(StringRef(reinterpret_cast<const char *>(ToBuf.data()), 2290 (StringLength + 1) * 2)); 2291} 2292 2293static llvm::StringMapEntry<llvm::Constant*> & 2294GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2295 const StringLiteral *Literal, 2296 unsigned &StringLength) { 2297 StringRef String = Literal->getString(); 2298 StringLength = String.size(); 2299 return Map.GetOrCreateValue(String); 2300} 2301 2302llvm::Constant * 2303CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 2304 unsigned StringLength = 0; 2305 bool isUTF16 = false; 2306 llvm::StringMapEntry<llvm::Constant*> &Entry = 2307 GetConstantCFStringEntry(CFConstantStringMap, Literal, 2308 getDataLayout().isLittleEndian(), 2309 isUTF16, StringLength); 2310 2311 if (llvm::Constant *C = Entry.getValue()) 2312 return C; 2313 2314 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2315 llvm::Constant *Zeros[] = { Zero, Zero }; 2316 llvm::Value *V; 2317 2318 // If we don't already have it, get __CFConstantStringClassReference. 2319 if (!CFConstantStringClassRef) { 2320 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2321 Ty = llvm::ArrayType::get(Ty, 0); 2322 llvm::Constant *GV = CreateRuntimeVariable(Ty, 2323 "__CFConstantStringClassReference"); 2324 // Decay array -> ptr 2325 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2326 CFConstantStringClassRef = V; 2327 } 2328 else 2329 V = CFConstantStringClassRef; 2330 2331 QualType CFTy = getContext().getCFConstantStringType(); 2332 2333 llvm::StructType *STy = 2334 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 2335 2336 llvm::Constant *Fields[4]; 2337 2338 // Class pointer. 2339 Fields[0] = cast<llvm::ConstantExpr>(V); 2340 2341 // Flags. 2342 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2343 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 2344 llvm::ConstantInt::get(Ty, 0x07C8); 2345 2346 // String pointer. 2347 llvm::Constant *C = 0; 2348 if (isUTF16) { 2349 ArrayRef<uint16_t> Arr = 2350 llvm::makeArrayRef<uint16_t>(reinterpret_cast<uint16_t*>( 2351 const_cast<char *>(Entry.getKey().data())), 2352 Entry.getKey().size() / 2); 2353 C = llvm::ConstantDataArray::get(VMContext, Arr); 2354 } else { 2355 C = llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2356 } 2357 2358 llvm::GlobalValue::LinkageTypes Linkage; 2359 if (isUTF16) 2360 // FIXME: why do utf strings get "_" labels instead of "L" labels? 2361 Linkage = llvm::GlobalValue::InternalLinkage; 2362 else 2363 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 2364 // when using private linkage. It is not clear if this is a bug in ld 2365 // or a reasonable new restriction. 2366 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 2367 2368 // Note: -fwritable-strings doesn't make the backing store strings of 2369 // CFStrings writable. (See <rdar://problem/10657500>) 2370 llvm::GlobalVariable *GV = 2371 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, 2372 Linkage, C, ".str"); 2373 GV->setUnnamedAddr(true); 2374 // Don't enforce the target's minimum global alignment, since the only use 2375 // of the string is via this class initializer. 2376 if (isUTF16) { 2377 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 2378 GV->setAlignment(Align.getQuantity()); 2379 } else { 2380 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2381 GV->setAlignment(Align.getQuantity()); 2382 } 2383 2384 // String. 2385 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2386 2387 if (isUTF16) 2388 // Cast the UTF16 string to the correct type. 2389 Fields[2] = llvm::ConstantExpr::getBitCast(Fields[2], Int8PtrTy); 2390 2391 // String length. 2392 Ty = getTypes().ConvertType(getContext().LongTy); 2393 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 2394 2395 // The struct. 2396 C = llvm::ConstantStruct::get(STy, Fields); 2397 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2398 llvm::GlobalVariable::PrivateLinkage, C, 2399 "_unnamed_cfstring_"); 2400 if (const char *Sect = getTarget().getCFStringSection()) 2401 GV->setSection(Sect); 2402 Entry.setValue(GV); 2403 2404 return GV; 2405} 2406 2407static RecordDecl * 2408CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 2409 DeclContext *DC, IdentifierInfo *Id) { 2410 SourceLocation Loc; 2411 if (Ctx.getLangOpts().CPlusPlus) 2412 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2413 else 2414 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2415} 2416 2417llvm::Constant * 2418CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 2419 unsigned StringLength = 0; 2420 llvm::StringMapEntry<llvm::Constant*> &Entry = 2421 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 2422 2423 if (llvm::Constant *C = Entry.getValue()) 2424 return C; 2425 2426 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2427 llvm::Constant *Zeros[] = { Zero, Zero }; 2428 llvm::Value *V; 2429 // If we don't already have it, get _NSConstantStringClassReference. 2430 if (!ConstantStringClassRef) { 2431 std::string StringClass(getLangOpts().ObjCConstantStringClass); 2432 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2433 llvm::Constant *GV; 2434 if (LangOpts.ObjCRuntime.isNonFragile()) { 2435 std::string str = 2436 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 2437 : "OBJC_CLASS_$_" + StringClass; 2438 GV = getObjCRuntime().GetClassGlobal(str); 2439 // Make sure the result is of the correct type. 2440 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 2441 V = llvm::ConstantExpr::getBitCast(GV, PTy); 2442 ConstantStringClassRef = V; 2443 } else { 2444 std::string str = 2445 StringClass.empty() ? "_NSConstantStringClassReference" 2446 : "_" + StringClass + "ClassReference"; 2447 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 2448 GV = CreateRuntimeVariable(PTy, str); 2449 // Decay array -> ptr 2450 V = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2451 ConstantStringClassRef = V; 2452 } 2453 } 2454 else 2455 V = ConstantStringClassRef; 2456 2457 if (!NSConstantStringType) { 2458 // Construct the type for a constant NSString. 2459 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2460 Context.getTranslationUnitDecl(), 2461 &Context.Idents.get("__builtin_NSString")); 2462 D->startDefinition(); 2463 2464 QualType FieldTypes[3]; 2465 2466 // const int *isa; 2467 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 2468 // const char *str; 2469 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 2470 // unsigned int length; 2471 FieldTypes[2] = Context.UnsignedIntTy; 2472 2473 // Create fields 2474 for (unsigned i = 0; i < 3; ++i) { 2475 FieldDecl *Field = FieldDecl::Create(Context, D, 2476 SourceLocation(), 2477 SourceLocation(), 0, 2478 FieldTypes[i], /*TInfo=*/0, 2479 /*BitWidth=*/0, 2480 /*Mutable=*/false, 2481 ICIS_NoInit); 2482 Field->setAccess(AS_public); 2483 D->addDecl(Field); 2484 } 2485 2486 D->completeDefinition(); 2487 QualType NSTy = Context.getTagDeclType(D); 2488 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 2489 } 2490 2491 llvm::Constant *Fields[3]; 2492 2493 // Class pointer. 2494 Fields[0] = cast<llvm::ConstantExpr>(V); 2495 2496 // String pointer. 2497 llvm::Constant *C = 2498 llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2499 2500 llvm::GlobalValue::LinkageTypes Linkage; 2501 bool isConstant; 2502 Linkage = llvm::GlobalValue::PrivateLinkage; 2503 isConstant = !LangOpts.WritableStrings; 2504 2505 llvm::GlobalVariable *GV = 2506 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 2507 ".str"); 2508 GV->setUnnamedAddr(true); 2509 // Don't enforce the target's minimum global alignment, since the only use 2510 // of the string is via this class initializer. 2511 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2512 GV->setAlignment(Align.getQuantity()); 2513 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2514 2515 // String length. 2516 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2517 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 2518 2519 // The struct. 2520 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 2521 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2522 llvm::GlobalVariable::PrivateLinkage, C, 2523 "_unnamed_nsstring_"); 2524 // FIXME. Fix section. 2525 if (const char *Sect = 2526 LangOpts.ObjCRuntime.isNonFragile() 2527 ? getTarget().getNSStringNonFragileABISection() 2528 : getTarget().getNSStringSection()) 2529 GV->setSection(Sect); 2530 Entry.setValue(GV); 2531 2532 return GV; 2533} 2534 2535QualType CodeGenModule::getObjCFastEnumerationStateType() { 2536 if (ObjCFastEnumerationStateType.isNull()) { 2537 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2538 Context.getTranslationUnitDecl(), 2539 &Context.Idents.get("__objcFastEnumerationState")); 2540 D->startDefinition(); 2541 2542 QualType FieldTypes[] = { 2543 Context.UnsignedLongTy, 2544 Context.getPointerType(Context.getObjCIdType()), 2545 Context.getPointerType(Context.UnsignedLongTy), 2546 Context.getConstantArrayType(Context.UnsignedLongTy, 2547 llvm::APInt(32, 5), ArrayType::Normal, 0) 2548 }; 2549 2550 for (size_t i = 0; i < 4; ++i) { 2551 FieldDecl *Field = FieldDecl::Create(Context, 2552 D, 2553 SourceLocation(), 2554 SourceLocation(), 0, 2555 FieldTypes[i], /*TInfo=*/0, 2556 /*BitWidth=*/0, 2557 /*Mutable=*/false, 2558 ICIS_NoInit); 2559 Field->setAccess(AS_public); 2560 D->addDecl(Field); 2561 } 2562 2563 D->completeDefinition(); 2564 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 2565 } 2566 2567 return ObjCFastEnumerationStateType; 2568} 2569 2570llvm::Constant * 2571CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { 2572 assert(!E->getType()->isPointerType() && "Strings are always arrays"); 2573 2574 // Don't emit it as the address of the string, emit the string data itself 2575 // as an inline array. 2576 if (E->getCharByteWidth() == 1) { 2577 SmallString<64> Str(E->getString()); 2578 2579 // Resize the string to the right size, which is indicated by its type. 2580 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType()); 2581 Str.resize(CAT->getSize().getZExtValue()); 2582 return llvm::ConstantDataArray::getString(VMContext, Str, false); 2583 } 2584 2585 llvm::ArrayType *AType = 2586 cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); 2587 llvm::Type *ElemTy = AType->getElementType(); 2588 unsigned NumElements = AType->getNumElements(); 2589 2590 // Wide strings have either 2-byte or 4-byte elements. 2591 if (ElemTy->getPrimitiveSizeInBits() == 16) { 2592 SmallVector<uint16_t, 32> Elements; 2593 Elements.reserve(NumElements); 2594 2595 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2596 Elements.push_back(E->getCodeUnit(i)); 2597 Elements.resize(NumElements); 2598 return llvm::ConstantDataArray::get(VMContext, Elements); 2599 } 2600 2601 assert(ElemTy->getPrimitiveSizeInBits() == 32); 2602 SmallVector<uint32_t, 32> Elements; 2603 Elements.reserve(NumElements); 2604 2605 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2606 Elements.push_back(E->getCodeUnit(i)); 2607 Elements.resize(NumElements); 2608 return llvm::ConstantDataArray::get(VMContext, Elements); 2609} 2610 2611/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 2612/// constant array for the given string literal. 2613llvm::Constant * 2614CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 2615 CharUnits Align = getContext().getAlignOfGlobalVarInChars(S->getType()); 2616 if (S->isAscii() || S->isUTF8()) { 2617 SmallString<64> Str(S->getString()); 2618 2619 // Resize the string to the right size, which is indicated by its type. 2620 const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType()); 2621 Str.resize(CAT->getSize().getZExtValue()); 2622 return GetAddrOfConstantString(Str, /*GlobalName*/ 0, Align.getQuantity()); 2623 } 2624 2625 // FIXME: the following does not memoize wide strings. 2626 llvm::Constant *C = GetConstantArrayFromStringLiteral(S); 2627 llvm::GlobalVariable *GV = 2628 new llvm::GlobalVariable(getModule(),C->getType(), 2629 !LangOpts.WritableStrings, 2630 llvm::GlobalValue::PrivateLinkage, 2631 C,".str"); 2632 2633 GV->setAlignment(Align.getQuantity()); 2634 GV->setUnnamedAddr(true); 2635 return GV; 2636} 2637 2638/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2639/// array for the given ObjCEncodeExpr node. 2640llvm::Constant * 2641CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2642 std::string Str; 2643 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2644 2645 return GetAddrOfConstantCString(Str); 2646} 2647 2648 2649/// GenerateWritableString -- Creates storage for a string literal. 2650static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2651 bool constant, 2652 CodeGenModule &CGM, 2653 const char *GlobalName, 2654 unsigned Alignment) { 2655 // Create Constant for this string literal. Don't add a '\0'. 2656 llvm::Constant *C = 2657 llvm::ConstantDataArray::getString(CGM.getLLVMContext(), str, false); 2658 2659 // OpenCL v1.1 s6.5.3: a string literal is in the constant address space. 2660 unsigned AddrSpace = 0; 2661 if (CGM.getLangOpts().OpenCL) 2662 AddrSpace = CGM.getContext().getTargetAddressSpace(LangAS::opencl_constant); 2663 2664 // Create a global variable for this string 2665 llvm::GlobalVariable *GV = new llvm::GlobalVariable( 2666 CGM.getModule(), C->getType(), constant, 2667 llvm::GlobalValue::PrivateLinkage, C, GlobalName, 0, 2668 llvm::GlobalVariable::NotThreadLocal, AddrSpace); 2669 GV->setAlignment(Alignment); 2670 GV->setUnnamedAddr(true); 2671 return GV; 2672} 2673 2674/// GetAddrOfConstantString - Returns a pointer to a character array 2675/// containing the literal. This contents are exactly that of the 2676/// given string, i.e. it will not be null terminated automatically; 2677/// see GetAddrOfConstantCString. Note that whether the result is 2678/// actually a pointer to an LLVM constant depends on 2679/// Feature.WriteableStrings. 2680/// 2681/// The result has pointer to array type. 2682llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2683 const char *GlobalName, 2684 unsigned Alignment) { 2685 // Get the default prefix if a name wasn't specified. 2686 if (!GlobalName) 2687 GlobalName = ".str"; 2688 2689 if (Alignment == 0) 2690 Alignment = getContext().getAlignOfGlobalVarInChars(getContext().CharTy) 2691 .getQuantity(); 2692 2693 // Don't share any string literals if strings aren't constant. 2694 if (LangOpts.WritableStrings) 2695 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2696 2697 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2698 ConstantStringMap.GetOrCreateValue(Str); 2699 2700 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2701 if (Alignment > GV->getAlignment()) { 2702 GV->setAlignment(Alignment); 2703 } 2704 return GV; 2705 } 2706 2707 // Create a global variable for this. 2708 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, 2709 Alignment); 2710 Entry.setValue(GV); 2711 return GV; 2712} 2713 2714/// GetAddrOfConstantCString - Returns a pointer to a character 2715/// array containing the literal and a terminating '\0' 2716/// character. The result has pointer to array type. 2717llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2718 const char *GlobalName, 2719 unsigned Alignment) { 2720 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2721 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2722} 2723 2724llvm::Constant *CodeGenModule::GetAddrOfGlobalTemporary( 2725 const MaterializeTemporaryExpr *E, const Expr *Init) { 2726 assert((E->getStorageDuration() == SD_Static || 2727 E->getStorageDuration() == SD_Thread) && "not a global temporary"); 2728 const VarDecl *VD = cast<VarDecl>(E->getExtendingDecl()); 2729 2730 // If we're not materializing a subobject of the temporary, keep the 2731 // cv-qualifiers from the type of the MaterializeTemporaryExpr. 2732 QualType MaterializedType = Init->getType(); 2733 if (Init == E->GetTemporaryExpr()) 2734 MaterializedType = E->getType(); 2735 2736 llvm::Constant *&Slot = MaterializedGlobalTemporaryMap[E]; 2737 if (Slot) 2738 return Slot; 2739 2740 // FIXME: If an externally-visible declaration extends multiple temporaries, 2741 // we need to give each temporary the same name in every translation unit (and 2742 // we also need to make the temporaries externally-visible). 2743 SmallString<256> Name; 2744 llvm::raw_svector_ostream Out(Name); 2745 getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out); 2746 Out.flush(); 2747 2748 APValue *Value = 0; 2749 if (E->getStorageDuration() == SD_Static) { 2750 // We might have a cached constant initializer for this temporary. Note 2751 // that this might have a different value from the value computed by 2752 // evaluating the initializer if the surrounding constant expression 2753 // modifies the temporary. 2754 Value = getContext().getMaterializedTemporaryValue(E, false); 2755 if (Value && Value->isUninit()) 2756 Value = 0; 2757 } 2758 2759 // Try evaluating it now, it might have a constant initializer. 2760 Expr::EvalResult EvalResult; 2761 if (!Value && Init->EvaluateAsRValue(EvalResult, getContext()) && 2762 !EvalResult.hasSideEffects()) 2763 Value = &EvalResult.Val; 2764 2765 llvm::Constant *InitialValue = 0; 2766 bool Constant = false; 2767 llvm::Type *Type; 2768 if (Value) { 2769 // The temporary has a constant initializer, use it. 2770 InitialValue = EmitConstantValue(*Value, MaterializedType, 0); 2771 Constant = isTypeConstant(MaterializedType, /*ExcludeCtor*/Value); 2772 Type = InitialValue->getType(); 2773 } else { 2774 // No initializer, the initialization will be provided when we 2775 // initialize the declaration which performed lifetime extension. 2776 Type = getTypes().ConvertTypeForMem(MaterializedType); 2777 } 2778 2779 // Create a global variable for this lifetime-extended temporary. 2780 llvm::GlobalVariable *GV = 2781 new llvm::GlobalVariable(getModule(), Type, Constant, 2782 llvm::GlobalValue::PrivateLinkage, 2783 InitialValue, Name.c_str()); 2784 GV->setAlignment( 2785 getContext().getTypeAlignInChars(MaterializedType).getQuantity()); 2786 if (VD->getTLSKind()) 2787 setTLSMode(GV, *VD); 2788 Slot = GV; 2789 return GV; 2790} 2791 2792/// EmitObjCPropertyImplementations - Emit information for synthesized 2793/// properties for an implementation. 2794void CodeGenModule::EmitObjCPropertyImplementations(const 2795 ObjCImplementationDecl *D) { 2796 for (ObjCImplementationDecl::propimpl_iterator 2797 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2798 ObjCPropertyImplDecl *PID = *i; 2799 2800 // Dynamic is just for type-checking. 2801 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2802 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2803 2804 // Determine which methods need to be implemented, some may have 2805 // been overridden. Note that ::isPropertyAccessor is not the method 2806 // we want, that just indicates if the decl came from a 2807 // property. What we want to know is if the method is defined in 2808 // this implementation. 2809 if (!D->getInstanceMethod(PD->getGetterName())) 2810 CodeGenFunction(*this).GenerateObjCGetter( 2811 const_cast<ObjCImplementationDecl *>(D), PID); 2812 if (!PD->isReadOnly() && 2813 !D->getInstanceMethod(PD->getSetterName())) 2814 CodeGenFunction(*this).GenerateObjCSetter( 2815 const_cast<ObjCImplementationDecl *>(D), PID); 2816 } 2817 } 2818} 2819 2820static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2821 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2822 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2823 ivar; ivar = ivar->getNextIvar()) 2824 if (ivar->getType().isDestructedType()) 2825 return true; 2826 2827 return false; 2828} 2829 2830/// EmitObjCIvarInitializations - Emit information for ivar initialization 2831/// for an implementation. 2832void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2833 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2834 if (needsDestructMethod(D)) { 2835 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2836 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2837 ObjCMethodDecl *DTORMethod = 2838 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2839 cxxSelector, getContext().VoidTy, 0, D, 2840 /*isInstance=*/true, /*isVariadic=*/false, 2841 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true, 2842 /*isDefined=*/false, ObjCMethodDecl::Required); 2843 D->addInstanceMethod(DTORMethod); 2844 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2845 D->setHasDestructors(true); 2846 } 2847 2848 // If the implementation doesn't have any ivar initializers, we don't need 2849 // a .cxx_construct. 2850 if (D->getNumIvarInitializers() == 0) 2851 return; 2852 2853 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2854 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2855 // The constructor returns 'self'. 2856 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2857 D->getLocation(), 2858 D->getLocation(), 2859 cxxSelector, 2860 getContext().getObjCIdType(), 0, 2861 D, /*isInstance=*/true, 2862 /*isVariadic=*/false, 2863 /*isPropertyAccessor=*/true, 2864 /*isImplicitlyDeclared=*/true, 2865 /*isDefined=*/false, 2866 ObjCMethodDecl::Required); 2867 D->addInstanceMethod(CTORMethod); 2868 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2869 D->setHasNonZeroConstructors(true); 2870} 2871 2872/// EmitNamespace - Emit all declarations in a namespace. 2873void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2874 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2875 I != E; ++I) { 2876 if (const VarDecl *VD = dyn_cast<VarDecl>(*I)) 2877 if (VD->getTemplateSpecializationKind() != TSK_ExplicitSpecialization && 2878 VD->getTemplateSpecializationKind() != TSK_Undeclared) 2879 continue; 2880 EmitTopLevelDecl(*I); 2881 } 2882} 2883 2884// EmitLinkageSpec - Emit all declarations in a linkage spec. 2885void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2886 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2887 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2888 ErrorUnsupported(LSD, "linkage spec"); 2889 return; 2890 } 2891 2892 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2893 I != E; ++I) { 2894 // Meta-data for ObjC class includes references to implemented methods. 2895 // Generate class's method definitions first. 2896 if (ObjCImplDecl *OID = dyn_cast<ObjCImplDecl>(*I)) { 2897 for (ObjCContainerDecl::method_iterator M = OID->meth_begin(), 2898 MEnd = OID->meth_end(); 2899 M != MEnd; ++M) 2900 EmitTopLevelDecl(*M); 2901 } 2902 EmitTopLevelDecl(*I); 2903 } 2904} 2905 2906/// EmitTopLevelDecl - Emit code for a single top level declaration. 2907void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2908 // Ignore dependent declarations. 2909 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2910 return; 2911 2912 switch (D->getKind()) { 2913 case Decl::CXXConversion: 2914 case Decl::CXXMethod: 2915 case Decl::Function: 2916 // Skip function templates 2917 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2918 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2919 return; 2920 2921 EmitGlobal(cast<FunctionDecl>(D)); 2922 break; 2923 2924 case Decl::Var: 2925 // Skip variable templates 2926 if (cast<VarDecl>(D)->getDescribedVarTemplate()) 2927 return; 2928 case Decl::VarTemplateSpecialization: 2929 EmitGlobal(cast<VarDecl>(D)); 2930 break; 2931 2932 // Indirect fields from global anonymous structs and unions can be 2933 // ignored; only the actual variable requires IR gen support. 2934 case Decl::IndirectField: 2935 break; 2936 2937 // C++ Decls 2938 case Decl::Namespace: 2939 EmitNamespace(cast<NamespaceDecl>(D)); 2940 break; 2941 // No code generation needed. 2942 case Decl::UsingShadow: 2943 case Decl::Using: 2944 case Decl::ClassTemplate: 2945 case Decl::VarTemplate: 2946 case Decl::VarTemplatePartialSpecialization: 2947 case Decl::FunctionTemplate: 2948 case Decl::TypeAliasTemplate: 2949 case Decl::Block: 2950 case Decl::Empty: 2951 break; 2952 case Decl::NamespaceAlias: 2953 if (CGDebugInfo *DI = getModuleDebugInfo()) 2954 DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(*D)); 2955 return; 2956 case Decl::UsingDirective: // using namespace X; [C++] 2957 if (CGDebugInfo *DI = getModuleDebugInfo()) 2958 DI->EmitUsingDirective(cast<UsingDirectiveDecl>(*D)); 2959 return; 2960 case Decl::CXXConstructor: 2961 // Skip function templates 2962 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2963 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2964 return; 2965 2966 getCXXABI().EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2967 break; 2968 case Decl::CXXDestructor: 2969 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2970 return; 2971 getCXXABI().EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2972 break; 2973 2974 case Decl::StaticAssert: 2975 // Nothing to do. 2976 break; 2977 2978 // Objective-C Decls 2979 2980 // Forward declarations, no (immediate) code generation. 2981 case Decl::ObjCInterface: 2982 case Decl::ObjCCategory: 2983 break; 2984 2985 case Decl::ObjCProtocol: { 2986 ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D); 2987 if (Proto->isThisDeclarationADefinition()) 2988 ObjCRuntime->GenerateProtocol(Proto); 2989 break; 2990 } 2991 2992 case Decl::ObjCCategoryImpl: 2993 // Categories have properties but don't support synthesize so we 2994 // can ignore them here. 2995 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2996 break; 2997 2998 case Decl::ObjCImplementation: { 2999 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 3000 EmitObjCPropertyImplementations(OMD); 3001 EmitObjCIvarInitializations(OMD); 3002 ObjCRuntime->GenerateClass(OMD); 3003 // Emit global variable debug information. 3004 if (CGDebugInfo *DI = getModuleDebugInfo()) 3005 if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) 3006 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType( 3007 OMD->getClassInterface()), OMD->getLocation()); 3008 break; 3009 } 3010 case Decl::ObjCMethod: { 3011 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 3012 // If this is not a prototype, emit the body. 3013 if (OMD->getBody()) 3014 CodeGenFunction(*this).GenerateObjCMethod(OMD); 3015 break; 3016 } 3017 case Decl::ObjCCompatibleAlias: 3018 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D)); 3019 break; 3020 3021 case Decl::LinkageSpec: 3022 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 3023 break; 3024 3025 case Decl::FileScopeAsm: { 3026 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 3027 StringRef AsmString = AD->getAsmString()->getString(); 3028 3029 const std::string &S = getModule().getModuleInlineAsm(); 3030 if (S.empty()) 3031 getModule().setModuleInlineAsm(AsmString); 3032 else if (S.end()[-1] == '\n') 3033 getModule().setModuleInlineAsm(S + AsmString.str()); 3034 else 3035 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 3036 break; 3037 } 3038 3039 case Decl::Import: { 3040 ImportDecl *Import = cast<ImportDecl>(D); 3041 3042 // Ignore import declarations that come from imported modules. 3043 if (clang::Module *Owner = Import->getOwningModule()) { 3044 if (getLangOpts().CurrentModule.empty() || 3045 Owner->getTopLevelModule()->Name == getLangOpts().CurrentModule) 3046 break; 3047 } 3048 3049 ImportedModules.insert(Import->getImportedModule()); 3050 break; 3051 } 3052 3053 default: 3054 // Make sure we handled everything we should, every other kind is a 3055 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 3056 // function. Need to recode Decl::Kind to do that easily. 3057 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 3058 } 3059} 3060 3061/// Turns the given pointer into a constant. 3062static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 3063 const void *Ptr) { 3064 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 3065 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 3066 return llvm::ConstantInt::get(i64, PtrInt); 3067} 3068 3069static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 3070 llvm::NamedMDNode *&GlobalMetadata, 3071 GlobalDecl D, 3072 llvm::GlobalValue *Addr) { 3073 if (!GlobalMetadata) 3074 GlobalMetadata = 3075 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 3076 3077 // TODO: should we report variant information for ctors/dtors? 3078 llvm::Value *Ops[] = { 3079 Addr, 3080 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 3081 }; 3082 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 3083} 3084 3085/// For each function which is declared within an extern "C" region and marked 3086/// as 'used', but has internal linkage, create an alias from the unmangled 3087/// name to the mangled name if possible. People expect to be able to refer 3088/// to such functions with an unmangled name from inline assembly within the 3089/// same translation unit. 3090void CodeGenModule::EmitStaticExternCAliases() { 3091 for (StaticExternCMap::iterator I = StaticExternCValues.begin(), 3092 E = StaticExternCValues.end(); 3093 I != E; ++I) { 3094 IdentifierInfo *Name = I->first; 3095 llvm::GlobalValue *Val = I->second; 3096 if (Val && !getModule().getNamedValue(Name->getName())) 3097 AddUsedGlobal(new llvm::GlobalAlias(Val->getType(), Val->getLinkage(), 3098 Name->getName(), Val, &getModule())); 3099 } 3100} 3101 3102/// Emits metadata nodes associating all the global values in the 3103/// current module with the Decls they came from. This is useful for 3104/// projects using IR gen as a subroutine. 3105/// 3106/// Since there's currently no way to associate an MDNode directly 3107/// with an llvm::GlobalValue, we create a global named metadata 3108/// with the name 'clang.global.decl.ptrs'. 3109void CodeGenModule::EmitDeclMetadata() { 3110 llvm::NamedMDNode *GlobalMetadata = 0; 3111 3112 // StaticLocalDeclMap 3113 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 3114 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 3115 I != E; ++I) { 3116 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 3117 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 3118 } 3119} 3120 3121/// Emits metadata nodes for all the local variables in the current 3122/// function. 3123void CodeGenFunction::EmitDeclMetadata() { 3124 if (LocalDeclMap.empty()) return; 3125 3126 llvm::LLVMContext &Context = getLLVMContext(); 3127 3128 // Find the unique metadata ID for this name. 3129 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 3130 3131 llvm::NamedMDNode *GlobalMetadata = 0; 3132 3133 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 3134 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 3135 const Decl *D = I->first; 3136 llvm::Value *Addr = I->second; 3137 3138 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 3139 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 3140 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 3141 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 3142 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 3143 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 3144 } 3145 } 3146} 3147 3148void CodeGenModule::EmitVersionIdentMetadata() { 3149 llvm::NamedMDNode *IdentMetadata = 3150 TheModule.getOrInsertNamedMetadata("llvm.ident"); 3151 std::string Version = getClangFullVersion(); 3152 llvm::LLVMContext &Ctx = TheModule.getContext(); 3153 3154 llvm::Value *IdentNode[] = { 3155 llvm::MDString::get(Ctx, Version) 3156 }; 3157 IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode)); 3158} 3159 3160void CodeGenModule::EmitCoverageFile() { 3161 if (!getCodeGenOpts().CoverageFile.empty()) { 3162 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 3163 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 3164 llvm::LLVMContext &Ctx = TheModule.getContext(); 3165 llvm::MDString *CoverageFile = 3166 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 3167 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 3168 llvm::MDNode *CU = CUNode->getOperand(i); 3169 llvm::Value *node[] = { CoverageFile, CU }; 3170 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 3171 GCov->addOperand(N); 3172 } 3173 } 3174 } 3175} 3176 3177llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid, 3178 QualType GuidType) { 3179 // Sema has checked that all uuid strings are of the form 3180 // "12345678-1234-1234-1234-1234567890ab". 3181 assert(Uuid.size() == 36); 3182 for (unsigned i = 0; i < 36; ++i) { 3183 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuid[i] == '-'); 3184 else assert(isHexDigit(Uuid[i])); 3185 } 3186 3187 const unsigned Field3ValueOffsets[8] = { 19, 21, 24, 26, 28, 30, 32, 34 }; 3188 3189 llvm::Constant *Field3[8]; 3190 for (unsigned Idx = 0; Idx < 8; ++Idx) 3191 Field3[Idx] = llvm::ConstantInt::get( 3192 Int8Ty, Uuid.substr(Field3ValueOffsets[Idx], 2), 16); 3193 3194 llvm::Constant *Fields[4] = { 3195 llvm::ConstantInt::get(Int32Ty, Uuid.substr(0, 8), 16), 3196 llvm::ConstantInt::get(Int16Ty, Uuid.substr(9, 4), 16), 3197 llvm::ConstantInt::get(Int16Ty, Uuid.substr(14, 4), 16), 3198 llvm::ConstantArray::get(llvm::ArrayType::get(Int8Ty, 8), Field3) 3199 }; 3200 3201 return llvm::ConstantStruct::getAnon(Fields); 3202} 3203