CodeGenModule.cpp revision 4d68ed5f03ad1235946377eb32b5c4d0412f2e48
1//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This coordinates the per-module state used while generating code. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenModule.h" 15#include "CGDebugInfo.h" 16#include "CodeGenFunction.h" 17#include "CodeGenTBAA.h" 18#include "CGCall.h" 19#include "CGCUDARuntime.h" 20#include "CGCXXABI.h" 21#include "CGObjCRuntime.h" 22#include "CGOpenCLRuntime.h" 23#include "TargetInfo.h" 24#include "clang/Frontend/CodeGenOptions.h" 25#include "clang/AST/ASTContext.h" 26#include "clang/AST/CharUnits.h" 27#include "clang/AST/DeclObjC.h" 28#include "clang/AST/DeclCXX.h" 29#include "clang/AST/DeclTemplate.h" 30#include "clang/AST/Mangle.h" 31#include "clang/AST/RecordLayout.h" 32#include "clang/AST/RecursiveASTVisitor.h" 33#include "clang/Basic/Builtins.h" 34#include "clang/Basic/Diagnostic.h" 35#include "clang/Basic/SourceManager.h" 36#include "clang/Basic/TargetInfo.h" 37#include "clang/Basic/ConvertUTF.h" 38#include "llvm/CallingConv.h" 39#include "llvm/Module.h" 40#include "llvm/Intrinsics.h" 41#include "llvm/LLVMContext.h" 42#include "llvm/ADT/APSInt.h" 43#include "llvm/ADT/Triple.h" 44#include "llvm/Target/Mangler.h" 45#include "llvm/DataLayout.h" 46#include "llvm/Support/CallSite.h" 47#include "llvm/Support/ErrorHandling.h" 48using namespace clang; 49using namespace CodeGen; 50 51static const char AnnotationSection[] = "llvm.metadata"; 52 53static CGCXXABI &createCXXABI(CodeGenModule &CGM) { 54 switch (CGM.getContext().getTargetInfo().getCXXABI()) { 55 case CXXABI_ARM: return *CreateARMCXXABI(CGM); 56 case CXXABI_Itanium: return *CreateItaniumCXXABI(CGM); 57 case CXXABI_Microsoft: return *CreateMicrosoftCXXABI(CGM); 58 } 59 60 llvm_unreachable("invalid C++ ABI kind"); 61} 62 63 64CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 65 llvm::Module &M, const llvm::DataLayout &TD, 66 DiagnosticsEngine &diags) 67 : Context(C), LangOpts(C.getLangOpts()), CodeGenOpts(CGO), TheModule(M), 68 TheDataLayout(TD), TheTargetCodeGenInfo(0), Diags(diags), 69 ABI(createCXXABI(*this)), 70 Types(*this), 71 TBAA(0), 72 VTables(*this), ObjCRuntime(0), OpenCLRuntime(0), CUDARuntime(0), 73 DebugInfo(0), ARCData(0), NoObjCARCExceptionsMetadata(0), 74 RRData(0), CFConstantStringClassRef(0), 75 ConstantStringClassRef(0), NSConstantStringType(0), 76 VMContext(M.getContext()), 77 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), 78 BlockObjectAssign(0), BlockObjectDispose(0), 79 BlockDescriptorType(0), GenericBlockLiteralType(0) { 80 81 // Initialize the type cache. 82 llvm::LLVMContext &LLVMContext = M.getContext(); 83 VoidTy = llvm::Type::getVoidTy(LLVMContext); 84 Int8Ty = llvm::Type::getInt8Ty(LLVMContext); 85 Int16Ty = llvm::Type::getInt16Ty(LLVMContext); 86 Int32Ty = llvm::Type::getInt32Ty(LLVMContext); 87 Int64Ty = llvm::Type::getInt64Ty(LLVMContext); 88 FloatTy = llvm::Type::getFloatTy(LLVMContext); 89 DoubleTy = llvm::Type::getDoubleTy(LLVMContext); 90 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0); 91 PointerAlignInBytes = 92 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity(); 93 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth()); 94 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits); 95 Int8PtrTy = Int8Ty->getPointerTo(0); 96 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0); 97 98 if (LangOpts.ObjC1) 99 createObjCRuntime(); 100 if (LangOpts.OpenCL) 101 createOpenCLRuntime(); 102 if (LangOpts.CUDA) 103 createCUDARuntime(); 104 105 // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0. 106 if (LangOpts.ThreadSanitizer || 107 (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0)) 108 TBAA = new CodeGenTBAA(Context, VMContext, CodeGenOpts, getLangOpts(), 109 ABI.getMangleContext()); 110 111 // If debug info or coverage generation is enabled, create the CGDebugInfo 112 // object. 113 if (CodeGenOpts.DebugInfo != CodeGenOptions::NoDebugInfo || 114 CodeGenOpts.EmitGcovArcs || 115 CodeGenOpts.EmitGcovNotes) 116 DebugInfo = new CGDebugInfo(*this); 117 118 Block.GlobalUniqueCount = 0; 119 120 if (C.getLangOpts().ObjCAutoRefCount) 121 ARCData = new ARCEntrypoints(); 122 RRData = new RREntrypoints(); 123} 124 125CodeGenModule::~CodeGenModule() { 126 delete ObjCRuntime; 127 delete OpenCLRuntime; 128 delete CUDARuntime; 129 delete TheTargetCodeGenInfo; 130 delete &ABI; 131 delete TBAA; 132 delete DebugInfo; 133 delete ARCData; 134 delete RRData; 135} 136 137void CodeGenModule::createObjCRuntime() { 138 // This is just isGNUFamily(), but we want to force implementors of 139 // new ABIs to decide how best to do this. 140 switch (LangOpts.ObjCRuntime.getKind()) { 141 case ObjCRuntime::GNUstep: 142 case ObjCRuntime::GCC: 143 case ObjCRuntime::ObjFW: 144 ObjCRuntime = CreateGNUObjCRuntime(*this); 145 return; 146 147 case ObjCRuntime::FragileMacOSX: 148 case ObjCRuntime::MacOSX: 149 case ObjCRuntime::iOS: 150 ObjCRuntime = CreateMacObjCRuntime(*this); 151 return; 152 } 153 llvm_unreachable("bad runtime kind"); 154} 155 156void CodeGenModule::createOpenCLRuntime() { 157 OpenCLRuntime = new CGOpenCLRuntime(*this); 158} 159 160void CodeGenModule::createCUDARuntime() { 161 CUDARuntime = CreateNVCUDARuntime(*this); 162} 163 164void CodeGenModule::Release() { 165 EmitDeferred(); 166 EmitCXXGlobalInitFunc(); 167 EmitCXXGlobalDtorFunc(); 168 if (ObjCRuntime) 169 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) 170 AddGlobalCtor(ObjCInitFunction); 171 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 172 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 173 EmitGlobalAnnotations(); 174 EmitLLVMUsed(); 175 176 SimplifyPersonality(); 177 178 if (getCodeGenOpts().EmitDeclMetadata) 179 EmitDeclMetadata(); 180 181 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 182 EmitCoverageFile(); 183 184 if (DebugInfo) 185 DebugInfo->finalize(); 186} 187 188void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 189 // Make sure that this type is translated. 190 Types.UpdateCompletedType(TD); 191} 192 193llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 194 if (!TBAA) 195 return 0; 196 return TBAA->getTBAAInfo(QTy); 197} 198 199llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() { 200 if (!TBAA) 201 return 0; 202 return TBAA->getTBAAInfoForVTablePtr(); 203} 204 205llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) { 206 if (!TBAA) 207 return 0; 208 return TBAA->getTBAAStructInfo(QTy); 209} 210 211void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 212 llvm::MDNode *TBAAInfo) { 213 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 214} 215 216bool CodeGenModule::isTargetDarwin() const { 217 return getContext().getTargetInfo().getTriple().isOSDarwin(); 218} 219 220void CodeGenModule::Error(SourceLocation loc, StringRef error) { 221 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); 222 getDiags().Report(Context.getFullLoc(loc), diagID); 223} 224 225/// ErrorUnsupported - Print out an error that codegen doesn't support the 226/// specified stmt yet. 227void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 228 bool OmitOnError) { 229 if (OmitOnError && getDiags().hasErrorOccurred()) 230 return; 231 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 232 "cannot compile this %0 yet"); 233 std::string Msg = Type; 234 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 235 << Msg << S->getSourceRange(); 236} 237 238/// ErrorUnsupported - Print out an error that codegen doesn't support the 239/// specified decl yet. 240void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 241 bool OmitOnError) { 242 if (OmitOnError && getDiags().hasErrorOccurred()) 243 return; 244 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 245 "cannot compile this %0 yet"); 246 std::string Msg = Type; 247 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 248} 249 250llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 251 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 252} 253 254void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 255 const NamedDecl *D) const { 256 // Internal definitions always have default visibility. 257 if (GV->hasLocalLinkage()) { 258 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 259 return; 260 } 261 262 // Set visibility for definitions. 263 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 264 if (LV.visibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 265 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 266} 267 268static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel(StringRef S) { 269 return llvm::StringSwitch<llvm::GlobalVariable::ThreadLocalMode>(S) 270 .Case("global-dynamic", llvm::GlobalVariable::GeneralDynamicTLSModel) 271 .Case("local-dynamic", llvm::GlobalVariable::LocalDynamicTLSModel) 272 .Case("initial-exec", llvm::GlobalVariable::InitialExecTLSModel) 273 .Case("local-exec", llvm::GlobalVariable::LocalExecTLSModel); 274} 275 276static llvm::GlobalVariable::ThreadLocalMode GetLLVMTLSModel( 277 CodeGenOptions::TLSModel M) { 278 switch (M) { 279 case CodeGenOptions::GeneralDynamicTLSModel: 280 return llvm::GlobalVariable::GeneralDynamicTLSModel; 281 case CodeGenOptions::LocalDynamicTLSModel: 282 return llvm::GlobalVariable::LocalDynamicTLSModel; 283 case CodeGenOptions::InitialExecTLSModel: 284 return llvm::GlobalVariable::InitialExecTLSModel; 285 case CodeGenOptions::LocalExecTLSModel: 286 return llvm::GlobalVariable::LocalExecTLSModel; 287 } 288 llvm_unreachable("Invalid TLS model!"); 289} 290 291void CodeGenModule::setTLSMode(llvm::GlobalVariable *GV, 292 const VarDecl &D) const { 293 assert(D.isThreadSpecified() && "setting TLS mode on non-TLS var!"); 294 295 llvm::GlobalVariable::ThreadLocalMode TLM; 296 TLM = GetLLVMTLSModel(CodeGenOpts.DefaultTLSModel); 297 298 // Override the TLS model if it is explicitly specified. 299 if (D.hasAttr<TLSModelAttr>()) { 300 const TLSModelAttr *Attr = D.getAttr<TLSModelAttr>(); 301 TLM = GetLLVMTLSModel(Attr->getModel()); 302 } 303 304 GV->setThreadLocalMode(TLM); 305} 306 307/// Set the symbol visibility of type information (vtable and RTTI) 308/// associated with the given type. 309void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 310 const CXXRecordDecl *RD, 311 TypeVisibilityKind TVK) const { 312 setGlobalVisibility(GV, RD); 313 314 if (!CodeGenOpts.HiddenWeakVTables) 315 return; 316 317 // We never want to drop the visibility for RTTI names. 318 if (TVK == TVK_ForRTTIName) 319 return; 320 321 // We want to drop the visibility to hidden for weak type symbols. 322 // This isn't possible if there might be unresolved references 323 // elsewhere that rely on this symbol being visible. 324 325 // This should be kept roughly in sync with setThunkVisibility 326 // in CGVTables.cpp. 327 328 // Preconditions. 329 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 330 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 331 return; 332 333 // Don't override an explicit visibility attribute. 334 if (RD->getExplicitVisibility()) 335 return; 336 337 switch (RD->getTemplateSpecializationKind()) { 338 // We have to disable the optimization if this is an EI definition 339 // because there might be EI declarations in other shared objects. 340 case TSK_ExplicitInstantiationDefinition: 341 case TSK_ExplicitInstantiationDeclaration: 342 return; 343 344 // Every use of a non-template class's type information has to emit it. 345 case TSK_Undeclared: 346 break; 347 348 // In theory, implicit instantiations can ignore the possibility of 349 // an explicit instantiation declaration because there necessarily 350 // must be an EI definition somewhere with default visibility. In 351 // practice, it's possible to have an explicit instantiation for 352 // an arbitrary template class, and linkers aren't necessarily able 353 // to deal with mixed-visibility symbols. 354 case TSK_ExplicitSpecialization: 355 case TSK_ImplicitInstantiation: 356 if (!CodeGenOpts.HiddenWeakTemplateVTables) 357 return; 358 break; 359 } 360 361 // If there's a key function, there may be translation units 362 // that don't have the key function's definition. But ignore 363 // this if we're emitting RTTI under -fno-rtti. 364 if (!(TVK != TVK_ForRTTI) || LangOpts.RTTI) { 365 if (Context.getKeyFunction(RD)) 366 return; 367 } 368 369 // Otherwise, drop the visibility to hidden. 370 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 371 GV->setUnnamedAddr(true); 372} 373 374StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 375 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 376 377 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 378 if (!Str.empty()) 379 return Str; 380 381 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 382 IdentifierInfo *II = ND->getIdentifier(); 383 assert(II && "Attempt to mangle unnamed decl."); 384 385 Str = II->getName(); 386 return Str; 387 } 388 389 SmallString<256> Buffer; 390 llvm::raw_svector_ostream Out(Buffer); 391 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 392 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 393 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 394 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 395 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND)) 396 getCXXABI().getMangleContext().mangleBlock(BD, Out, 397 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl())); 398 else 399 getCXXABI().getMangleContext().mangleName(ND, Out); 400 401 // Allocate space for the mangled name. 402 Out.flush(); 403 size_t Length = Buffer.size(); 404 char *Name = MangledNamesAllocator.Allocate<char>(Length); 405 std::copy(Buffer.begin(), Buffer.end(), Name); 406 407 Str = StringRef(Name, Length); 408 409 return Str; 410} 411 412void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 413 const BlockDecl *BD) { 414 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 415 const Decl *D = GD.getDecl(); 416 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 417 if (D == 0) 418 MangleCtx.mangleGlobalBlock(BD, 419 dyn_cast_or_null<VarDecl>(initializedGlobalDecl.getDecl()), Out); 420 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 421 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 422 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 423 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 424 else 425 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 426} 427 428llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 429 return getModule().getNamedValue(Name); 430} 431 432/// AddGlobalCtor - Add a function to the list that will be called before 433/// main() runs. 434void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 435 // FIXME: Type coercion of void()* types. 436 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 437} 438 439/// AddGlobalDtor - Add a function to the list that will be called 440/// when the module is unloaded. 441void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 442 // FIXME: Type coercion of void()* types. 443 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 444} 445 446void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 447 // Ctor function type is void()*. 448 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 449 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 450 451 // Get the type of a ctor entry, { i32, void ()* }. 452 llvm::StructType *CtorStructTy = 453 llvm::StructType::get(Int32Ty, llvm::PointerType::getUnqual(CtorFTy), NULL); 454 455 // Construct the constructor and destructor arrays. 456 SmallVector<llvm::Constant*, 8> Ctors; 457 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 458 llvm::Constant *S[] = { 459 llvm::ConstantInt::get(Int32Ty, I->second, false), 460 llvm::ConstantExpr::getBitCast(I->first, CtorPFTy) 461 }; 462 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 463 } 464 465 if (!Ctors.empty()) { 466 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 467 new llvm::GlobalVariable(TheModule, AT, false, 468 llvm::GlobalValue::AppendingLinkage, 469 llvm::ConstantArray::get(AT, Ctors), 470 GlobalName); 471 } 472} 473 474llvm::GlobalValue::LinkageTypes 475CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 476 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 477 478 if (Linkage == GVA_Internal) 479 return llvm::Function::InternalLinkage; 480 481 if (D->hasAttr<DLLExportAttr>()) 482 return llvm::Function::DLLExportLinkage; 483 484 if (D->hasAttr<WeakAttr>()) 485 return llvm::Function::WeakAnyLinkage; 486 487 // In C99 mode, 'inline' functions are guaranteed to have a strong 488 // definition somewhere else, so we can use available_externally linkage. 489 if (Linkage == GVA_C99Inline) 490 return llvm::Function::AvailableExternallyLinkage; 491 492 // Note that Apple's kernel linker doesn't support symbol 493 // coalescing, so we need to avoid linkonce and weak linkages there. 494 // Normally, this means we just map to internal, but for explicit 495 // instantiations we'll map to external. 496 497 // In C++, the compiler has to emit a definition in every translation unit 498 // that references the function. We should use linkonce_odr because 499 // a) if all references in this translation unit are optimized away, we 500 // don't need to codegen it. b) if the function persists, it needs to be 501 // merged with other definitions. c) C++ has the ODR, so we know the 502 // definition is dependable. 503 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 504 return !Context.getLangOpts().AppleKext 505 ? llvm::Function::LinkOnceODRLinkage 506 : llvm::Function::InternalLinkage; 507 508 // An explicit instantiation of a template has weak linkage, since 509 // explicit instantiations can occur in multiple translation units 510 // and must all be equivalent. However, we are not allowed to 511 // throw away these explicit instantiations. 512 if (Linkage == GVA_ExplicitTemplateInstantiation) 513 return !Context.getLangOpts().AppleKext 514 ? llvm::Function::WeakODRLinkage 515 : llvm::Function::ExternalLinkage; 516 517 // Otherwise, we have strong external linkage. 518 assert(Linkage == GVA_StrongExternal); 519 return llvm::Function::ExternalLinkage; 520} 521 522 523/// SetFunctionDefinitionAttributes - Set attributes for a global. 524/// 525/// FIXME: This is currently only done for aliases and functions, but not for 526/// variables (these details are set in EmitGlobalVarDefinition for variables). 527void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 528 llvm::GlobalValue *GV) { 529 SetCommonAttributes(D, GV); 530} 531 532void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 533 const CGFunctionInfo &Info, 534 llvm::Function *F) { 535 unsigned CallingConv; 536 AttributeListType AttributeList; 537 ConstructAttributeList(Info, D, AttributeList, CallingConv); 538 F->setAttributes(llvm::AttrListPtr::get(AttributeList)); 539 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 540} 541 542/// Determines whether the language options require us to model 543/// unwind exceptions. We treat -fexceptions as mandating this 544/// except under the fragile ObjC ABI with only ObjC exceptions 545/// enabled. This means, for example, that C with -fexceptions 546/// enables this. 547static bool hasUnwindExceptions(const LangOptions &LangOpts) { 548 // If exceptions are completely disabled, obviously this is false. 549 if (!LangOpts.Exceptions) return false; 550 551 // If C++ exceptions are enabled, this is true. 552 if (LangOpts.CXXExceptions) return true; 553 554 // If ObjC exceptions are enabled, this depends on the ABI. 555 if (LangOpts.ObjCExceptions) { 556 return LangOpts.ObjCRuntime.hasUnwindExceptions(); 557 } 558 559 return true; 560} 561 562void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 563 llvm::Function *F) { 564 if (CodeGenOpts.UnwindTables) 565 F->setHasUWTable(); 566 567 if (!hasUnwindExceptions(LangOpts)) 568 F->addFnAttr(llvm::Attributes::NoUnwind); 569 570 if (D->hasAttr<NakedAttr>()) { 571 // Naked implies noinline: we should not be inlining such functions. 572 F->addFnAttr(llvm::Attributes::Naked); 573 F->addFnAttr(llvm::Attributes::NoInline); 574 } 575 576 if (D->hasAttr<NoInlineAttr>()) 577 F->addFnAttr(llvm::Attributes::NoInline); 578 579 // (noinline wins over always_inline, and we can't specify both in IR) 580 if ((D->hasAttr<AlwaysInlineAttr>() || D->hasAttr<ForceInlineAttr>()) && 581 !F->getFnAttributes().hasAttribute(llvm::Attributes::NoInline)) 582 F->addFnAttr(llvm::Attributes::AlwaysInline); 583 584 // FIXME: Communicate hot and cold attributes to LLVM more directly. 585 if (D->hasAttr<ColdAttr>()) 586 F->addFnAttr(llvm::Attributes::OptimizeForSize); 587 588 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 589 F->setUnnamedAddr(true); 590 591 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) 592 if (MD->isVirtual()) 593 F->setUnnamedAddr(true); 594 595 if (LangOpts.getStackProtector() == LangOptions::SSPOn) 596 F->addFnAttr(llvm::Attributes::StackProtect); 597 else if (LangOpts.getStackProtector() == LangOptions::SSPReq) 598 F->addFnAttr(llvm::Attributes::StackProtectReq); 599 600 if (LangOpts.AddressSanitizer) { 601 // When AddressSanitizer is enabled, set AddressSafety attribute 602 // unless __attribute__((no_address_safety_analysis)) is used. 603 if (!D->hasAttr<NoAddressSafetyAnalysisAttr>()) 604 F->addFnAttr(llvm::Attributes::AddressSafety); 605 } 606 607 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 608 if (alignment) 609 F->setAlignment(alignment); 610 611 // C++ ABI requires 2-byte alignment for member functions. 612 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 613 F->setAlignment(2); 614} 615 616void CodeGenModule::SetCommonAttributes(const Decl *D, 617 llvm::GlobalValue *GV) { 618 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 619 setGlobalVisibility(GV, ND); 620 else 621 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 622 623 if (D->hasAttr<UsedAttr>()) 624 AddUsedGlobal(GV); 625 626 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 627 GV->setSection(SA->getName()); 628 629 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 630} 631 632void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 633 llvm::Function *F, 634 const CGFunctionInfo &FI) { 635 SetLLVMFunctionAttributes(D, FI, F); 636 SetLLVMFunctionAttributesForDefinition(D, F); 637 638 F->setLinkage(llvm::Function::InternalLinkage); 639 640 SetCommonAttributes(D, F); 641} 642 643void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 644 llvm::Function *F, 645 bool IsIncompleteFunction) { 646 if (unsigned IID = F->getIntrinsicID()) { 647 // If this is an intrinsic function, set the function's attributes 648 // to the intrinsic's attributes. 649 F->setAttributes(llvm::Intrinsic::getAttributes((llvm::Intrinsic::ID)IID)); 650 return; 651 } 652 653 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 654 655 if (!IsIncompleteFunction) 656 SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F); 657 658 // Only a few attributes are set on declarations; these may later be 659 // overridden by a definition. 660 661 if (FD->hasAttr<DLLImportAttr>()) { 662 F->setLinkage(llvm::Function::DLLImportLinkage); 663 } else if (FD->hasAttr<WeakAttr>() || 664 FD->isWeakImported()) { 665 // "extern_weak" is overloaded in LLVM; we probably should have 666 // separate linkage types for this. 667 F->setLinkage(llvm::Function::ExternalWeakLinkage); 668 } else { 669 F->setLinkage(llvm::Function::ExternalLinkage); 670 671 NamedDecl::LinkageInfo LV = FD->getLinkageAndVisibility(); 672 if (LV.linkage() == ExternalLinkage && LV.visibilityExplicit()) { 673 F->setVisibility(GetLLVMVisibility(LV.visibility())); 674 } 675 } 676 677 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 678 F->setSection(SA->getName()); 679} 680 681void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 682 assert(!GV->isDeclaration() && 683 "Only globals with definition can force usage."); 684 LLVMUsed.push_back(GV); 685} 686 687void CodeGenModule::EmitLLVMUsed() { 688 // Don't create llvm.used if there is no need. 689 if (LLVMUsed.empty()) 690 return; 691 692 // Convert LLVMUsed to what ConstantArray needs. 693 SmallVector<llvm::Constant*, 8> UsedArray; 694 UsedArray.resize(LLVMUsed.size()); 695 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 696 UsedArray[i] = 697 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 698 Int8PtrTy); 699 } 700 701 if (UsedArray.empty()) 702 return; 703 llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size()); 704 705 llvm::GlobalVariable *GV = 706 new llvm::GlobalVariable(getModule(), ATy, false, 707 llvm::GlobalValue::AppendingLinkage, 708 llvm::ConstantArray::get(ATy, UsedArray), 709 "llvm.used"); 710 711 GV->setSection("llvm.metadata"); 712} 713 714void CodeGenModule::EmitDeferred() { 715 // Emit code for any potentially referenced deferred decls. Since a 716 // previously unused static decl may become used during the generation of code 717 // for a static function, iterate until no changes are made. 718 719 while (!DeferredDeclsToEmit.empty() || !DeferredVTables.empty()) { 720 if (!DeferredVTables.empty()) { 721 const CXXRecordDecl *RD = DeferredVTables.back(); 722 DeferredVTables.pop_back(); 723 getCXXABI().EmitVTables(RD); 724 continue; 725 } 726 727 GlobalDecl D = DeferredDeclsToEmit.back(); 728 DeferredDeclsToEmit.pop_back(); 729 730 // Check to see if we've already emitted this. This is necessary 731 // for a couple of reasons: first, decls can end up in the 732 // deferred-decls queue multiple times, and second, decls can end 733 // up with definitions in unusual ways (e.g. by an extern inline 734 // function acquiring a strong function redefinition). Just 735 // ignore these cases. 736 // 737 // TODO: That said, looking this up multiple times is very wasteful. 738 StringRef Name = getMangledName(D); 739 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 740 assert(CGRef && "Deferred decl wasn't referenced?"); 741 742 if (!CGRef->isDeclaration()) 743 continue; 744 745 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 746 // purposes an alias counts as a definition. 747 if (isa<llvm::GlobalAlias>(CGRef)) 748 continue; 749 750 // Otherwise, emit the definition and move on to the next one. 751 EmitGlobalDefinition(D); 752 } 753} 754 755void CodeGenModule::EmitGlobalAnnotations() { 756 if (Annotations.empty()) 757 return; 758 759 // Create a new global variable for the ConstantStruct in the Module. 760 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 761 Annotations[0]->getType(), Annotations.size()), Annotations); 762 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), 763 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, 764 "llvm.global.annotations"); 765 gv->setSection(AnnotationSection); 766} 767 768llvm::Constant *CodeGenModule::EmitAnnotationString(llvm::StringRef Str) { 769 llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str); 770 if (i != AnnotationStrings.end()) 771 return i->second; 772 773 // Not found yet, create a new global. 774 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); 775 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), 776 true, llvm::GlobalValue::PrivateLinkage, s, ".str"); 777 gv->setSection(AnnotationSection); 778 gv->setUnnamedAddr(true); 779 AnnotationStrings[Str] = gv; 780 return gv; 781} 782 783llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 784 SourceManager &SM = getContext().getSourceManager(); 785 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 786 if (PLoc.isValid()) 787 return EmitAnnotationString(PLoc.getFilename()); 788 return EmitAnnotationString(SM.getBufferName(Loc)); 789} 790 791llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 792 SourceManager &SM = getContext().getSourceManager(); 793 PresumedLoc PLoc = SM.getPresumedLoc(L); 794 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 795 SM.getExpansionLineNumber(L); 796 return llvm::ConstantInt::get(Int32Ty, LineNo); 797} 798 799llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 800 const AnnotateAttr *AA, 801 SourceLocation L) { 802 // Get the globals for file name, annotation, and the line number. 803 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 804 *UnitGV = EmitAnnotationUnit(L), 805 *LineNoCst = EmitAnnotationLineNo(L); 806 807 // Create the ConstantStruct for the global annotation. 808 llvm::Constant *Fields[4] = { 809 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 810 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 811 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 812 LineNoCst 813 }; 814 return llvm::ConstantStruct::getAnon(Fields); 815} 816 817void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 818 llvm::GlobalValue *GV) { 819 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 820 // Get the struct elements for these annotations. 821 for (specific_attr_iterator<AnnotateAttr> 822 ai = D->specific_attr_begin<AnnotateAttr>(), 823 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) 824 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); 825} 826 827bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 828 // Never defer when EmitAllDecls is specified. 829 if (LangOpts.EmitAllDecls) 830 return false; 831 832 return !getContext().DeclMustBeEmitted(Global); 833} 834 835llvm::Constant *CodeGenModule::GetAddrOfUuidDescriptor( 836 const CXXUuidofExpr* E) { 837 // Sema has verified that IIDSource has a __declspec(uuid()), and that its 838 // well-formed. 839 StringRef Uuid; 840 if (E->isTypeOperand()) 841 Uuid = CXXUuidofExpr::GetUuidAttrOfType(E->getTypeOperand())->getGuid(); 842 else { 843 // Special case: __uuidof(0) means an all-zero GUID. 844 Expr *Op = E->getExprOperand(); 845 if (!Op->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 846 Uuid = CXXUuidofExpr::GetUuidAttrOfType(Op->getType())->getGuid(); 847 else 848 Uuid = "00000000-0000-0000-0000-000000000000"; 849 } 850 std::string Name = "__uuid_" + Uuid.str(); 851 852 // Look for an existing global. 853 if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name)) 854 return GV; 855 856 llvm::Constant *Init = EmitUuidofInitializer(Uuid, E->getType()); 857 assert(Init && "failed to initialize as constant"); 858 859 // GUIDs are assumed to be 16 bytes, spread over 4-2-2-8 bytes. However, the 860 // first field is declared as "long", which for many targets is 8 bytes. 861 // Those architectures are not supported. (With the MS abi, long is always 4 862 // bytes.) 863 llvm::Type *GuidType = getTypes().ConvertType(E->getType()); 864 if (Init->getType() != GuidType) { 865 DiagnosticsEngine &Diags = getDiags(); 866 unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error, 867 "__uuidof codegen is not supported on this architecture"); 868 Diags.Report(E->getExprLoc(), DiagID) << E->getSourceRange(); 869 Init = llvm::UndefValue::get(GuidType); 870 } 871 872 llvm::GlobalVariable *GV = new llvm::GlobalVariable(getModule(), GuidType, 873 /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, Init, Name); 874 GV->setUnnamedAddr(true); 875 return GV; 876} 877 878llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 879 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 880 assert(AA && "No alias?"); 881 882 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 883 884 // See if there is already something with the target's name in the module. 885 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 886 887 llvm::Constant *Aliasee; 888 if (isa<llvm::FunctionType>(DeclTy)) 889 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, 890 GlobalDecl(cast<FunctionDecl>(VD)), 891 /*ForVTable=*/false); 892 else 893 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 894 llvm::PointerType::getUnqual(DeclTy), 0); 895 if (!Entry) { 896 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 897 F->setLinkage(llvm::Function::ExternalWeakLinkage); 898 WeakRefReferences.insert(F); 899 } 900 901 return Aliasee; 902} 903 904void CodeGenModule::EmitGlobal(GlobalDecl GD) { 905 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 906 907 // Weak references don't produce any output by themselves. 908 if (Global->hasAttr<WeakRefAttr>()) 909 return; 910 911 // If this is an alias definition (which otherwise looks like a declaration) 912 // emit it now. 913 if (Global->hasAttr<AliasAttr>()) 914 return EmitAliasDefinition(GD); 915 916 // If this is CUDA, be selective about which declarations we emit. 917 if (LangOpts.CUDA) { 918 if (CodeGenOpts.CUDAIsDevice) { 919 if (!Global->hasAttr<CUDADeviceAttr>() && 920 !Global->hasAttr<CUDAGlobalAttr>() && 921 !Global->hasAttr<CUDAConstantAttr>() && 922 !Global->hasAttr<CUDASharedAttr>()) 923 return; 924 } else { 925 if (!Global->hasAttr<CUDAHostAttr>() && ( 926 Global->hasAttr<CUDADeviceAttr>() || 927 Global->hasAttr<CUDAConstantAttr>() || 928 Global->hasAttr<CUDASharedAttr>())) 929 return; 930 } 931 } 932 933 // Ignore declarations, they will be emitted on their first use. 934 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 935 // Forward declarations are emitted lazily on first use. 936 if (!FD->doesThisDeclarationHaveABody()) { 937 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 938 return; 939 940 const FunctionDecl *InlineDefinition = 0; 941 FD->getBody(InlineDefinition); 942 943 StringRef MangledName = getMangledName(GD); 944 DeferredDecls.erase(MangledName); 945 EmitGlobalDefinition(InlineDefinition); 946 return; 947 } 948 } else { 949 const VarDecl *VD = cast<VarDecl>(Global); 950 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 951 952 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 953 return; 954 } 955 956 // Defer code generation when possible if this is a static definition, inline 957 // function etc. These we only want to emit if they are used. 958 if (!MayDeferGeneration(Global)) { 959 // Emit the definition if it can't be deferred. 960 EmitGlobalDefinition(GD); 961 return; 962 } 963 964 // If we're deferring emission of a C++ variable with an 965 // initializer, remember the order in which it appeared in the file. 966 if (getLangOpts().CPlusPlus && isa<VarDecl>(Global) && 967 cast<VarDecl>(Global)->hasInit()) { 968 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 969 CXXGlobalInits.push_back(0); 970 } 971 972 // If the value has already been used, add it directly to the 973 // DeferredDeclsToEmit list. 974 StringRef MangledName = getMangledName(GD); 975 if (GetGlobalValue(MangledName)) 976 DeferredDeclsToEmit.push_back(GD); 977 else { 978 // Otherwise, remember that we saw a deferred decl with this name. The 979 // first use of the mangled name will cause it to move into 980 // DeferredDeclsToEmit. 981 DeferredDecls[MangledName] = GD; 982 } 983} 984 985namespace { 986 struct FunctionIsDirectlyRecursive : 987 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> { 988 const StringRef Name; 989 const Builtin::Context &BI; 990 bool Result; 991 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) : 992 Name(N), BI(C), Result(false) { 993 } 994 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; 995 996 bool TraverseCallExpr(CallExpr *E) { 997 const FunctionDecl *FD = E->getDirectCallee(); 998 if (!FD) 999 return true; 1000 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1001 if (Attr && Name == Attr->getLabel()) { 1002 Result = true; 1003 return false; 1004 } 1005 unsigned BuiltinID = FD->getBuiltinID(); 1006 if (!BuiltinID) 1007 return true; 1008 StringRef BuiltinName = BI.GetName(BuiltinID); 1009 if (BuiltinName.startswith("__builtin_") && 1010 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { 1011 Result = true; 1012 return false; 1013 } 1014 return true; 1015 } 1016 }; 1017} 1018 1019// isTriviallyRecursive - Check if this function calls another 1020// decl that, because of the asm attribute or the other decl being a builtin, 1021// ends up pointing to itself. 1022bool 1023CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { 1024 StringRef Name; 1025 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { 1026 // asm labels are a special kind of mangling we have to support. 1027 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 1028 if (!Attr) 1029 return false; 1030 Name = Attr->getLabel(); 1031 } else { 1032 Name = FD->getName(); 1033 } 1034 1035 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); 1036 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD)); 1037 return Walker.Result; 1038} 1039 1040bool 1041CodeGenModule::shouldEmitFunction(const FunctionDecl *F) { 1042 if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage) 1043 return true; 1044 if (CodeGenOpts.OptimizationLevel == 0 && 1045 !F->hasAttr<AlwaysInlineAttr>() && !F->hasAttr<ForceInlineAttr>()) 1046 return false; 1047 // PR9614. Avoid cases where the source code is lying to us. An available 1048 // externally function should have an equivalent function somewhere else, 1049 // but a function that calls itself is clearly not equivalent to the real 1050 // implementation. 1051 // This happens in glibc's btowc and in some configure checks. 1052 return !isTriviallyRecursive(F); 1053} 1054 1055void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 1056 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1057 1058 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 1059 Context.getSourceManager(), 1060 "Generating code for declaration"); 1061 1062 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 1063 // At -O0, don't generate IR for functions with available_externally 1064 // linkage. 1065 if (!shouldEmitFunction(Function)) 1066 return; 1067 1068 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 1069 // Make sure to emit the definition(s) before we emit the thunks. 1070 // This is necessary for the generation of certain thunks. 1071 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 1072 EmitCXXConstructor(CD, GD.getCtorType()); 1073 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 1074 EmitCXXDestructor(DD, GD.getDtorType()); 1075 else 1076 EmitGlobalFunctionDefinition(GD); 1077 1078 if (Method->isVirtual()) 1079 getVTables().EmitThunks(GD); 1080 1081 return; 1082 } 1083 1084 return EmitGlobalFunctionDefinition(GD); 1085 } 1086 1087 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 1088 return EmitGlobalVarDefinition(VD); 1089 1090 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 1091} 1092 1093/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 1094/// module, create and return an llvm Function with the specified type. If there 1095/// is something in the module with the specified name, return it potentially 1096/// bitcasted to the right type. 1097/// 1098/// If D is non-null, it specifies a decl that correspond to this. This is used 1099/// to set the attributes on the function when it is first created. 1100llvm::Constant * 1101CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 1102 llvm::Type *Ty, 1103 GlobalDecl D, bool ForVTable, 1104 llvm::Attributes ExtraAttrs) { 1105 // Lookup the entry, lazily creating it if necessary. 1106 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1107 if (Entry) { 1108 if (WeakRefReferences.erase(Entry)) { 1109 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 1110 if (FD && !FD->hasAttr<WeakAttr>()) 1111 Entry->setLinkage(llvm::Function::ExternalLinkage); 1112 } 1113 1114 if (Entry->getType()->getElementType() == Ty) 1115 return Entry; 1116 1117 // Make sure the result is of the correct type. 1118 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 1119 } 1120 1121 // This function doesn't have a complete type (for example, the return 1122 // type is an incomplete struct). Use a fake type instead, and make 1123 // sure not to try to set attributes. 1124 bool IsIncompleteFunction = false; 1125 1126 llvm::FunctionType *FTy; 1127 if (isa<llvm::FunctionType>(Ty)) { 1128 FTy = cast<llvm::FunctionType>(Ty); 1129 } else { 1130 FTy = llvm::FunctionType::get(VoidTy, false); 1131 IsIncompleteFunction = true; 1132 } 1133 1134 llvm::Function *F = llvm::Function::Create(FTy, 1135 llvm::Function::ExternalLinkage, 1136 MangledName, &getModule()); 1137 assert(F->getName() == MangledName && "name was uniqued!"); 1138 if (D.getDecl()) 1139 SetFunctionAttributes(D, F, IsIncompleteFunction); 1140 if (ExtraAttrs.hasAttributes()) 1141 F->addAttribute(~0, ExtraAttrs); 1142 1143 // This is the first use or definition of a mangled name. If there is a 1144 // deferred decl with this name, remember that we need to emit it at the end 1145 // of the file. 1146 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1147 if (DDI != DeferredDecls.end()) { 1148 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1149 // list, and remove it from DeferredDecls (since we don't need it anymore). 1150 DeferredDeclsToEmit.push_back(DDI->second); 1151 DeferredDecls.erase(DDI); 1152 1153 // Otherwise, there are cases we have to worry about where we're 1154 // using a declaration for which we must emit a definition but where 1155 // we might not find a top-level definition: 1156 // - member functions defined inline in their classes 1157 // - friend functions defined inline in some class 1158 // - special member functions with implicit definitions 1159 // If we ever change our AST traversal to walk into class methods, 1160 // this will be unnecessary. 1161 // 1162 // We also don't emit a definition for a function if it's going to be an entry 1163 // in a vtable, unless it's already marked as used. 1164 } else if (getLangOpts().CPlusPlus && D.getDecl()) { 1165 // Look for a declaration that's lexically in a record. 1166 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); 1167 FD = FD->getMostRecentDecl(); 1168 do { 1169 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 1170 if (FD->isImplicit() && !ForVTable) { 1171 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 1172 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1173 break; 1174 } else if (FD->doesThisDeclarationHaveABody()) { 1175 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1176 break; 1177 } 1178 } 1179 FD = FD->getPreviousDecl(); 1180 } while (FD); 1181 } 1182 1183 // Make sure the result is of the requested type. 1184 if (!IsIncompleteFunction) { 1185 assert(F->getType()->getElementType() == Ty); 1186 return F; 1187 } 1188 1189 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1190 return llvm::ConstantExpr::getBitCast(F, PTy); 1191} 1192 1193/// GetAddrOfFunction - Return the address of the given function. If Ty is 1194/// non-null, then this function will use the specified type if it has to 1195/// create it (this occurs when we see a definition of the function). 1196llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 1197 llvm::Type *Ty, 1198 bool ForVTable) { 1199 // If there was no specific requested type, just convert it now. 1200 if (!Ty) 1201 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 1202 1203 StringRef MangledName = getMangledName(GD); 1204 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 1205} 1206 1207/// CreateRuntimeFunction - Create a new runtime function with the specified 1208/// type and name. 1209llvm::Constant * 1210CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 1211 StringRef Name, 1212 llvm::Attributes ExtraAttrs) { 1213 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 1214 ExtraAttrs); 1215} 1216 1217/// isTypeConstant - Determine whether an object of this type can be emitted 1218/// as a constant. 1219/// 1220/// If ExcludeCtor is true, the duration when the object's constructor runs 1221/// will not be considered. The caller will need to verify that the object is 1222/// not written to during its construction. 1223bool CodeGenModule::isTypeConstant(QualType Ty, bool ExcludeCtor) { 1224 if (!Ty.isConstant(Context) && !Ty->isReferenceType()) 1225 return false; 1226 1227 if (Context.getLangOpts().CPlusPlus) { 1228 if (const CXXRecordDecl *Record 1229 = Context.getBaseElementType(Ty)->getAsCXXRecordDecl()) 1230 return ExcludeCtor && !Record->hasMutableFields() && 1231 Record->hasTrivialDestructor(); 1232 } 1233 1234 return true; 1235} 1236 1237/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1238/// create and return an llvm GlobalVariable with the specified type. If there 1239/// is something in the module with the specified name, return it potentially 1240/// bitcasted to the right type. 1241/// 1242/// If D is non-null, it specifies a decl that correspond to this. This is used 1243/// to set the attributes on the global when it is first created. 1244llvm::Constant * 1245CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1246 llvm::PointerType *Ty, 1247 const VarDecl *D, 1248 bool UnnamedAddr) { 1249 // Lookup the entry, lazily creating it if necessary. 1250 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1251 if (Entry) { 1252 if (WeakRefReferences.erase(Entry)) { 1253 if (D && !D->hasAttr<WeakAttr>()) 1254 Entry->setLinkage(llvm::Function::ExternalLinkage); 1255 } 1256 1257 if (UnnamedAddr) 1258 Entry->setUnnamedAddr(true); 1259 1260 if (Entry->getType() == Ty) 1261 return Entry; 1262 1263 // Make sure the result is of the correct type. 1264 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1265 } 1266 1267 // This is the first use or definition of a mangled name. If there is a 1268 // deferred decl with this name, remember that we need to emit it at the end 1269 // of the file. 1270 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1271 if (DDI != DeferredDecls.end()) { 1272 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1273 // list, and remove it from DeferredDecls (since we don't need it anymore). 1274 DeferredDeclsToEmit.push_back(DDI->second); 1275 DeferredDecls.erase(DDI); 1276 } 1277 1278 unsigned AddrSpace = GetGlobalVarAddressSpace(D, Ty->getAddressSpace()); 1279 llvm::GlobalVariable *GV = 1280 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1281 llvm::GlobalValue::ExternalLinkage, 1282 0, MangledName, 0, 1283 llvm::GlobalVariable::NotThreadLocal, AddrSpace); 1284 1285 // Handle things which are present even on external declarations. 1286 if (D) { 1287 // FIXME: This code is overly simple and should be merged with other global 1288 // handling. 1289 GV->setConstant(isTypeConstant(D->getType(), false)); 1290 1291 // Set linkage and visibility in case we never see a definition. 1292 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 1293 if (LV.linkage() != ExternalLinkage) { 1294 // Don't set internal linkage on declarations. 1295 } else { 1296 if (D->hasAttr<DLLImportAttr>()) 1297 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1298 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1299 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1300 1301 // Set visibility on a declaration only if it's explicit. 1302 if (LV.visibilityExplicit()) 1303 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 1304 } 1305 1306 if (D->isThreadSpecified()) 1307 setTLSMode(GV, *D); 1308 } 1309 1310 if (AddrSpace != Ty->getAddressSpace()) 1311 return llvm::ConstantExpr::getBitCast(GV, Ty); 1312 else 1313 return GV; 1314} 1315 1316 1317llvm::GlobalVariable * 1318CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1319 llvm::Type *Ty, 1320 llvm::GlobalValue::LinkageTypes Linkage) { 1321 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1322 llvm::GlobalVariable *OldGV = 0; 1323 1324 1325 if (GV) { 1326 // Check if the variable has the right type. 1327 if (GV->getType()->getElementType() == Ty) 1328 return GV; 1329 1330 // Because C++ name mangling, the only way we can end up with an already 1331 // existing global with the same name is if it has been declared extern "C". 1332 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1333 OldGV = GV; 1334 } 1335 1336 // Create a new variable. 1337 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1338 Linkage, 0, Name); 1339 1340 if (OldGV) { 1341 // Replace occurrences of the old variable if needed. 1342 GV->takeName(OldGV); 1343 1344 if (!OldGV->use_empty()) { 1345 llvm::Constant *NewPtrForOldDecl = 1346 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1347 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1348 } 1349 1350 OldGV->eraseFromParent(); 1351 } 1352 1353 return GV; 1354} 1355 1356/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1357/// given global variable. If Ty is non-null and if the global doesn't exist, 1358/// then it will be created with the specified type instead of whatever the 1359/// normal requested type would be. 1360llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1361 llvm::Type *Ty) { 1362 assert(D->hasGlobalStorage() && "Not a global variable"); 1363 QualType ASTTy = D->getType(); 1364 if (Ty == 0) 1365 Ty = getTypes().ConvertTypeForMem(ASTTy); 1366 1367 llvm::PointerType *PTy = 1368 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1369 1370 StringRef MangledName = getMangledName(D); 1371 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1372} 1373 1374/// CreateRuntimeVariable - Create a new runtime global variable with the 1375/// specified type and name. 1376llvm::Constant * 1377CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1378 StringRef Name) { 1379 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1380 true); 1381} 1382 1383void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1384 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1385 1386 if (MayDeferGeneration(D)) { 1387 // If we have not seen a reference to this variable yet, place it 1388 // into the deferred declarations table to be emitted if needed 1389 // later. 1390 StringRef MangledName = getMangledName(D); 1391 if (!GetGlobalValue(MangledName)) { 1392 DeferredDecls[MangledName] = D; 1393 return; 1394 } 1395 } 1396 1397 // The tentative definition is the only definition. 1398 EmitGlobalVarDefinition(D); 1399} 1400 1401void CodeGenModule::EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired) { 1402 if (DefinitionRequired) 1403 getCXXABI().EmitVTables(Class); 1404} 1405 1406llvm::GlobalVariable::LinkageTypes 1407CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) { 1408 if (RD->getLinkage() != ExternalLinkage) 1409 return llvm::GlobalVariable::InternalLinkage; 1410 1411 if (const CXXMethodDecl *KeyFunction 1412 = RD->getASTContext().getKeyFunction(RD)) { 1413 // If this class has a key function, use that to determine the linkage of 1414 // the vtable. 1415 const FunctionDecl *Def = 0; 1416 if (KeyFunction->hasBody(Def)) 1417 KeyFunction = cast<CXXMethodDecl>(Def); 1418 1419 switch (KeyFunction->getTemplateSpecializationKind()) { 1420 case TSK_Undeclared: 1421 case TSK_ExplicitSpecialization: 1422 // When compiling with optimizations turned on, we emit all vtables, 1423 // even if the key function is not defined in the current translation 1424 // unit. If this is the case, use available_externally linkage. 1425 if (!Def && CodeGenOpts.OptimizationLevel) 1426 return llvm::GlobalVariable::AvailableExternallyLinkage; 1427 1428 if (KeyFunction->isInlined()) 1429 return !Context.getLangOpts().AppleKext ? 1430 llvm::GlobalVariable::LinkOnceODRLinkage : 1431 llvm::Function::InternalLinkage; 1432 1433 return llvm::GlobalVariable::ExternalLinkage; 1434 1435 case TSK_ImplicitInstantiation: 1436 return !Context.getLangOpts().AppleKext ? 1437 llvm::GlobalVariable::LinkOnceODRLinkage : 1438 llvm::Function::InternalLinkage; 1439 1440 case TSK_ExplicitInstantiationDefinition: 1441 return !Context.getLangOpts().AppleKext ? 1442 llvm::GlobalVariable::WeakODRLinkage : 1443 llvm::Function::InternalLinkage; 1444 1445 case TSK_ExplicitInstantiationDeclaration: 1446 // FIXME: Use available_externally linkage. However, this currently 1447 // breaks LLVM's build due to undefined symbols. 1448 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1449 return !Context.getLangOpts().AppleKext ? 1450 llvm::GlobalVariable::LinkOnceODRLinkage : 1451 llvm::Function::InternalLinkage; 1452 } 1453 } 1454 1455 if (Context.getLangOpts().AppleKext) 1456 return llvm::Function::InternalLinkage; 1457 1458 switch (RD->getTemplateSpecializationKind()) { 1459 case TSK_Undeclared: 1460 case TSK_ExplicitSpecialization: 1461 case TSK_ImplicitInstantiation: 1462 // FIXME: Use available_externally linkage. However, this currently 1463 // breaks LLVM's build due to undefined symbols. 1464 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1465 case TSK_ExplicitInstantiationDeclaration: 1466 return llvm::GlobalVariable::LinkOnceODRLinkage; 1467 1468 case TSK_ExplicitInstantiationDefinition: 1469 return llvm::GlobalVariable::WeakODRLinkage; 1470 } 1471 1472 llvm_unreachable("Invalid TemplateSpecializationKind!"); 1473} 1474 1475CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1476 return Context.toCharUnitsFromBits( 1477 TheDataLayout.getTypeStoreSizeInBits(Ty)); 1478} 1479 1480llvm::Constant * 1481CodeGenModule::MaybeEmitGlobalStdInitializerListInitializer(const VarDecl *D, 1482 const Expr *rawInit) { 1483 ArrayRef<ExprWithCleanups::CleanupObject> cleanups; 1484 if (const ExprWithCleanups *withCleanups = 1485 dyn_cast<ExprWithCleanups>(rawInit)) { 1486 cleanups = withCleanups->getObjects(); 1487 rawInit = withCleanups->getSubExpr(); 1488 } 1489 1490 const InitListExpr *init = dyn_cast<InitListExpr>(rawInit); 1491 if (!init || !init->initializesStdInitializerList() || 1492 init->getNumInits() == 0) 1493 return 0; 1494 1495 ASTContext &ctx = getContext(); 1496 unsigned numInits = init->getNumInits(); 1497 // FIXME: This check is here because we would otherwise silently miscompile 1498 // nested global std::initializer_lists. Better would be to have a real 1499 // implementation. 1500 for (unsigned i = 0; i < numInits; ++i) { 1501 const InitListExpr *inner = dyn_cast<InitListExpr>(init->getInit(i)); 1502 if (inner && inner->initializesStdInitializerList()) { 1503 ErrorUnsupported(inner, "nested global std::initializer_list"); 1504 return 0; 1505 } 1506 } 1507 1508 // Synthesize a fake VarDecl for the array and initialize that. 1509 QualType elementType = init->getInit(0)->getType(); 1510 llvm::APInt numElements(ctx.getTypeSize(ctx.getSizeType()), numInits); 1511 QualType arrayType = ctx.getConstantArrayType(elementType, numElements, 1512 ArrayType::Normal, 0); 1513 1514 IdentifierInfo *name = &ctx.Idents.get(D->getNameAsString() + "__initlist"); 1515 TypeSourceInfo *sourceInfo = ctx.getTrivialTypeSourceInfo( 1516 arrayType, D->getLocation()); 1517 VarDecl *backingArray = VarDecl::Create(ctx, const_cast<DeclContext*>( 1518 D->getDeclContext()), 1519 D->getLocStart(), D->getLocation(), 1520 name, arrayType, sourceInfo, 1521 SC_Static, SC_Static); 1522 1523 // Now clone the InitListExpr to initialize the array instead. 1524 // Incredible hack: we want to use the existing InitListExpr here, so we need 1525 // to tell it that it no longer initializes a std::initializer_list. 1526 ArrayRef<Expr*> Inits(const_cast<InitListExpr*>(init)->getInits(), 1527 init->getNumInits()); 1528 Expr *arrayInit = new (ctx) InitListExpr(ctx, init->getLBraceLoc(), Inits, 1529 init->getRBraceLoc()); 1530 arrayInit->setType(arrayType); 1531 1532 if (!cleanups.empty()) 1533 arrayInit = ExprWithCleanups::Create(ctx, arrayInit, cleanups); 1534 1535 backingArray->setInit(arrayInit); 1536 1537 // Emit the definition of the array. 1538 EmitGlobalVarDefinition(backingArray); 1539 1540 // Inspect the initializer list to validate it and determine its type. 1541 // FIXME: doing this every time is probably inefficient; caching would be nice 1542 RecordDecl *record = init->getType()->castAs<RecordType>()->getDecl(); 1543 RecordDecl::field_iterator field = record->field_begin(); 1544 if (field == record->field_end()) { 1545 ErrorUnsupported(D, "weird std::initializer_list"); 1546 return 0; 1547 } 1548 QualType elementPtr = ctx.getPointerType(elementType.withConst()); 1549 // Start pointer. 1550 if (!ctx.hasSameType(field->getType(), elementPtr)) { 1551 ErrorUnsupported(D, "weird std::initializer_list"); 1552 return 0; 1553 } 1554 ++field; 1555 if (field == record->field_end()) { 1556 ErrorUnsupported(D, "weird std::initializer_list"); 1557 return 0; 1558 } 1559 bool isStartEnd = false; 1560 if (ctx.hasSameType(field->getType(), elementPtr)) { 1561 // End pointer. 1562 isStartEnd = true; 1563 } else if(!ctx.hasSameType(field->getType(), ctx.getSizeType())) { 1564 ErrorUnsupported(D, "weird std::initializer_list"); 1565 return 0; 1566 } 1567 1568 // Now build an APValue representing the std::initializer_list. 1569 APValue initListValue(APValue::UninitStruct(), 0, 2); 1570 APValue &startField = initListValue.getStructField(0); 1571 APValue::LValuePathEntry startOffsetPathEntry; 1572 startOffsetPathEntry.ArrayIndex = 0; 1573 startField = APValue(APValue::LValueBase(backingArray), 1574 CharUnits::fromQuantity(0), 1575 llvm::makeArrayRef(startOffsetPathEntry), 1576 /*IsOnePastTheEnd=*/false, 0); 1577 1578 if (isStartEnd) { 1579 APValue &endField = initListValue.getStructField(1); 1580 APValue::LValuePathEntry endOffsetPathEntry; 1581 endOffsetPathEntry.ArrayIndex = numInits; 1582 endField = APValue(APValue::LValueBase(backingArray), 1583 ctx.getTypeSizeInChars(elementType) * numInits, 1584 llvm::makeArrayRef(endOffsetPathEntry), 1585 /*IsOnePastTheEnd=*/true, 0); 1586 } else { 1587 APValue &sizeField = initListValue.getStructField(1); 1588 sizeField = APValue(llvm::APSInt(numElements)); 1589 } 1590 1591 // Emit the constant for the initializer_list. 1592 llvm::Constant *llvmInit = 1593 EmitConstantValueForMemory(initListValue, D->getType()); 1594 assert(llvmInit && "failed to initialize as constant"); 1595 return llvmInit; 1596} 1597 1598unsigned CodeGenModule::GetGlobalVarAddressSpace(const VarDecl *D, 1599 unsigned AddrSpace) { 1600 if (LangOpts.CUDA && CodeGenOpts.CUDAIsDevice) { 1601 if (D->hasAttr<CUDAConstantAttr>()) 1602 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_constant); 1603 else if (D->hasAttr<CUDASharedAttr>()) 1604 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_shared); 1605 else 1606 AddrSpace = getContext().getTargetAddressSpace(LangAS::cuda_device); 1607 } 1608 1609 return AddrSpace; 1610} 1611 1612void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1613 llvm::Constant *Init = 0; 1614 QualType ASTTy = D->getType(); 1615 CXXRecordDecl *RD = ASTTy->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 1616 bool NeedsGlobalCtor = false; 1617 bool NeedsGlobalDtor = RD && !RD->hasTrivialDestructor(); 1618 1619 const VarDecl *InitDecl; 1620 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 1621 1622 if (!InitExpr) { 1623 // This is a tentative definition; tentative definitions are 1624 // implicitly initialized with { 0 }. 1625 // 1626 // Note that tentative definitions are only emitted at the end of 1627 // a translation unit, so they should never have incomplete 1628 // type. In addition, EmitTentativeDefinition makes sure that we 1629 // never attempt to emit a tentative definition if a real one 1630 // exists. A use may still exists, however, so we still may need 1631 // to do a RAUW. 1632 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1633 Init = EmitNullConstant(D->getType()); 1634 } else { 1635 // If this is a std::initializer_list, emit the special initializer. 1636 Init = MaybeEmitGlobalStdInitializerListInitializer(D, InitExpr); 1637 // An empty init list will perform zero-initialization, which happens 1638 // to be exactly what we want. 1639 // FIXME: It does so in a global constructor, which is *not* what we 1640 // want. 1641 1642 if (!Init) { 1643 initializedGlobalDecl = GlobalDecl(D); 1644 Init = EmitConstantInit(*InitDecl); 1645 } 1646 if (!Init) { 1647 QualType T = InitExpr->getType(); 1648 if (D->getType()->isReferenceType()) 1649 T = D->getType(); 1650 1651 if (getLangOpts().CPlusPlus) { 1652 Init = EmitNullConstant(T); 1653 NeedsGlobalCtor = true; 1654 } else { 1655 ErrorUnsupported(D, "static initializer"); 1656 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1657 } 1658 } else { 1659 // We don't need an initializer, so remove the entry for the delayed 1660 // initializer position (just in case this entry was delayed) if we 1661 // also don't need to register a destructor. 1662 if (getLangOpts().CPlusPlus && !NeedsGlobalDtor) 1663 DelayedCXXInitPosition.erase(D); 1664 } 1665 } 1666 1667 llvm::Type* InitType = Init->getType(); 1668 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1669 1670 // Strip off a bitcast if we got one back. 1671 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1672 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1673 // all zero index gep. 1674 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1675 Entry = CE->getOperand(0); 1676 } 1677 1678 // Entry is now either a Function or GlobalVariable. 1679 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1680 1681 // We have a definition after a declaration with the wrong type. 1682 // We must make a new GlobalVariable* and update everything that used OldGV 1683 // (a declaration or tentative definition) with the new GlobalVariable* 1684 // (which will be a definition). 1685 // 1686 // This happens if there is a prototype for a global (e.g. 1687 // "extern int x[];") and then a definition of a different type (e.g. 1688 // "int x[10];"). This also happens when an initializer has a different type 1689 // from the type of the global (this happens with unions). 1690 if (GV == 0 || 1691 GV->getType()->getElementType() != InitType || 1692 GV->getType()->getAddressSpace() != 1693 GetGlobalVarAddressSpace(D, getContext().getTargetAddressSpace(ASTTy))) { 1694 1695 // Move the old entry aside so that we'll create a new one. 1696 Entry->setName(StringRef()); 1697 1698 // Make a new global with the correct type, this is now guaranteed to work. 1699 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1700 1701 // Replace all uses of the old global with the new global 1702 llvm::Constant *NewPtrForOldDecl = 1703 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1704 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1705 1706 // Erase the old global, since it is no longer used. 1707 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1708 } 1709 1710 if (D->hasAttr<AnnotateAttr>()) 1711 AddGlobalAnnotations(D, GV); 1712 1713 GV->setInitializer(Init); 1714 1715 // If it is safe to mark the global 'constant', do so now. 1716 GV->setConstant(!NeedsGlobalCtor && !NeedsGlobalDtor && 1717 isTypeConstant(D->getType(), true)); 1718 1719 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1720 1721 // Set the llvm linkage type as appropriate. 1722 llvm::GlobalValue::LinkageTypes Linkage = 1723 GetLLVMLinkageVarDefinition(D, GV); 1724 GV->setLinkage(Linkage); 1725 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1726 // common vars aren't constant even if declared const. 1727 GV->setConstant(false); 1728 1729 SetCommonAttributes(D, GV); 1730 1731 // Emit the initializer function if necessary. 1732 if (NeedsGlobalCtor || NeedsGlobalDtor) 1733 EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); 1734 1735 // If we are compiling with ASan, add metadata indicating dynamically 1736 // initialized globals. 1737 if (LangOpts.AddressSanitizer && NeedsGlobalCtor) { 1738 llvm::Module &M = getModule(); 1739 1740 llvm::NamedMDNode *DynamicInitializers = 1741 M.getOrInsertNamedMetadata("llvm.asan.dynamically_initialized_globals"); 1742 llvm::Value *GlobalToAdd[] = { GV }; 1743 llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalToAdd); 1744 DynamicInitializers->addOperand(ThisGlobal); 1745 } 1746 1747 // Emit global variable debug information. 1748 if (CGDebugInfo *DI = getModuleDebugInfo()) 1749 if (getCodeGenOpts().DebugInfo >= CodeGenOptions::LimitedDebugInfo) 1750 DI->EmitGlobalVariable(GV, D); 1751} 1752 1753llvm::GlobalValue::LinkageTypes 1754CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, 1755 llvm::GlobalVariable *GV) { 1756 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1757 if (Linkage == GVA_Internal) 1758 return llvm::Function::InternalLinkage; 1759 else if (D->hasAttr<DLLImportAttr>()) 1760 return llvm::Function::DLLImportLinkage; 1761 else if (D->hasAttr<DLLExportAttr>()) 1762 return llvm::Function::DLLExportLinkage; 1763 else if (D->hasAttr<WeakAttr>()) { 1764 if (GV->isConstant()) 1765 return llvm::GlobalVariable::WeakODRLinkage; 1766 else 1767 return llvm::GlobalVariable::WeakAnyLinkage; 1768 } else if (Linkage == GVA_TemplateInstantiation || 1769 Linkage == GVA_ExplicitTemplateInstantiation) 1770 return llvm::GlobalVariable::WeakODRLinkage; 1771 else if (!getLangOpts().CPlusPlus && 1772 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1773 D->getAttr<CommonAttr>()) && 1774 !D->hasExternalStorage() && !D->getInit() && 1775 !D->getAttr<SectionAttr>() && !D->isThreadSpecified() && 1776 !D->getAttr<WeakImportAttr>()) { 1777 // Thread local vars aren't considered common linkage. 1778 return llvm::GlobalVariable::CommonLinkage; 1779 } 1780 return llvm::GlobalVariable::ExternalLinkage; 1781} 1782 1783/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1784/// implement a function with no prototype, e.g. "int foo() {}". If there are 1785/// existing call uses of the old function in the module, this adjusts them to 1786/// call the new function directly. 1787/// 1788/// This is not just a cleanup: the always_inline pass requires direct calls to 1789/// functions to be able to inline them. If there is a bitcast in the way, it 1790/// won't inline them. Instcombine normally deletes these calls, but it isn't 1791/// run at -O0. 1792static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1793 llvm::Function *NewFn) { 1794 // If we're redefining a global as a function, don't transform it. 1795 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1796 if (OldFn == 0) return; 1797 1798 llvm::Type *NewRetTy = NewFn->getReturnType(); 1799 SmallVector<llvm::Value*, 4> ArgList; 1800 1801 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1802 UI != E; ) { 1803 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1804 llvm::Value::use_iterator I = UI++; // Increment before the CI is erased. 1805 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*I); 1806 if (!CI) continue; // FIXME: when we allow Invoke, just do CallSite CS(*I) 1807 llvm::CallSite CS(CI); 1808 if (!CI || !CS.isCallee(I)) continue; 1809 1810 // If the return types don't match exactly, and if the call isn't dead, then 1811 // we can't transform this call. 1812 if (CI->getType() != NewRetTy && !CI->use_empty()) 1813 continue; 1814 1815 // Get the attribute list. 1816 llvm::SmallVector<llvm::AttributeWithIndex, 8> AttrVec; 1817 llvm::AttrListPtr AttrList = CI->getAttributes(); 1818 1819 // Get any return attributes. 1820 llvm::Attributes RAttrs = AttrList.getRetAttributes(); 1821 1822 // Add the return attributes. 1823 if (RAttrs.hasAttributes()) 1824 AttrVec.push_back(llvm::AttributeWithIndex::get(0, RAttrs)); 1825 1826 // If the function was passed too few arguments, don't transform. If extra 1827 // arguments were passed, we silently drop them. If any of the types 1828 // mismatch, we don't transform. 1829 unsigned ArgNo = 0; 1830 bool DontTransform = false; 1831 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1832 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1833 if (CS.arg_size() == ArgNo || 1834 CS.getArgument(ArgNo)->getType() != AI->getType()) { 1835 DontTransform = true; 1836 break; 1837 } 1838 1839 // Add any parameter attributes. 1840 llvm::Attributes PAttrs = AttrList.getParamAttributes(ArgNo + 1); 1841 if (PAttrs.hasAttributes()) 1842 AttrVec.push_back(llvm::AttributeWithIndex::get(ArgNo + 1, PAttrs)); 1843 } 1844 if (DontTransform) 1845 continue; 1846 1847 llvm::Attributes FnAttrs = AttrList.getFnAttributes(); 1848 if (FnAttrs.hasAttributes()) 1849 AttrVec.push_back(llvm::AttributeWithIndex::get(~0, FnAttrs)); 1850 1851 // Okay, we can transform this. Create the new call instruction and copy 1852 // over the required information. 1853 ArgList.append(CS.arg_begin(), CS.arg_begin() + ArgNo); 1854 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList, "", CI); 1855 ArgList.clear(); 1856 if (!NewCall->getType()->isVoidTy()) 1857 NewCall->takeName(CI); 1858 NewCall->setAttributes(llvm::AttrListPtr::get(AttrVec)); 1859 NewCall->setCallingConv(CI->getCallingConv()); 1860 1861 // Finally, remove the old call, replacing any uses with the new one. 1862 if (!CI->use_empty()) 1863 CI->replaceAllUsesWith(NewCall); 1864 1865 // Copy debug location attached to CI. 1866 if (!CI->getDebugLoc().isUnknown()) 1867 NewCall->setDebugLoc(CI->getDebugLoc()); 1868 CI->eraseFromParent(); 1869 } 1870} 1871 1872void CodeGenModule::HandleCXXStaticMemberVarInstantiation(VarDecl *VD) { 1873 TemplateSpecializationKind TSK = VD->getTemplateSpecializationKind(); 1874 // If we have a definition, this might be a deferred decl. If the 1875 // instantiation is explicit, make sure we emit it at the end. 1876 if (VD->getDefinition() && TSK == TSK_ExplicitInstantiationDefinition) 1877 GetAddrOfGlobalVar(VD); 1878} 1879 1880void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1881 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1882 1883 // Compute the function info and LLVM type. 1884 const CGFunctionInfo &FI = getTypes().arrangeGlobalDeclaration(GD); 1885 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI); 1886 1887 // Get or create the prototype for the function. 1888 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1889 1890 // Strip off a bitcast if we got one back. 1891 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1892 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1893 Entry = CE->getOperand(0); 1894 } 1895 1896 1897 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1898 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1899 1900 // If the types mismatch then we have to rewrite the definition. 1901 assert(OldFn->isDeclaration() && 1902 "Shouldn't replace non-declaration"); 1903 1904 // F is the Function* for the one with the wrong type, we must make a new 1905 // Function* and update everything that used F (a declaration) with the new 1906 // Function* (which will be a definition). 1907 // 1908 // This happens if there is a prototype for a function 1909 // (e.g. "int f()") and then a definition of a different type 1910 // (e.g. "int f(int x)"). Move the old function aside so that it 1911 // doesn't interfere with GetAddrOfFunction. 1912 OldFn->setName(StringRef()); 1913 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1914 1915 // If this is an implementation of a function without a prototype, try to 1916 // replace any existing uses of the function (which may be calls) with uses 1917 // of the new function 1918 if (D->getType()->isFunctionNoProtoType()) { 1919 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1920 OldFn->removeDeadConstantUsers(); 1921 } 1922 1923 // Replace uses of F with the Function we will endow with a body. 1924 if (!Entry->use_empty()) { 1925 llvm::Constant *NewPtrForOldDecl = 1926 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1927 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1928 } 1929 1930 // Ok, delete the old function now, which is dead. 1931 OldFn->eraseFromParent(); 1932 1933 Entry = NewFn; 1934 } 1935 1936 // We need to set linkage and visibility on the function before 1937 // generating code for it because various parts of IR generation 1938 // want to propagate this information down (e.g. to local static 1939 // declarations). 1940 llvm::Function *Fn = cast<llvm::Function>(Entry); 1941 setFunctionLinkage(D, Fn); 1942 1943 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 1944 setGlobalVisibility(Fn, D); 1945 1946 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 1947 1948 SetFunctionDefinitionAttributes(D, Fn); 1949 SetLLVMFunctionAttributesForDefinition(D, Fn); 1950 1951 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1952 AddGlobalCtor(Fn, CA->getPriority()); 1953 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1954 AddGlobalDtor(Fn, DA->getPriority()); 1955 if (D->hasAttr<AnnotateAttr>()) 1956 AddGlobalAnnotations(D, Fn); 1957} 1958 1959void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 1960 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1961 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1962 assert(AA && "Not an alias?"); 1963 1964 StringRef MangledName = getMangledName(GD); 1965 1966 // If there is a definition in the module, then it wins over the alias. 1967 // This is dubious, but allow it to be safe. Just ignore the alias. 1968 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1969 if (Entry && !Entry->isDeclaration()) 1970 return; 1971 1972 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1973 1974 // Create a reference to the named value. This ensures that it is emitted 1975 // if a deferred decl. 1976 llvm::Constant *Aliasee; 1977 if (isa<llvm::FunctionType>(DeclTy)) 1978 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GD, 1979 /*ForVTable=*/false); 1980 else 1981 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1982 llvm::PointerType::getUnqual(DeclTy), 0); 1983 1984 // Create the new alias itself, but don't set a name yet. 1985 llvm::GlobalValue *GA = 1986 new llvm::GlobalAlias(Aliasee->getType(), 1987 llvm::Function::ExternalLinkage, 1988 "", Aliasee, &getModule()); 1989 1990 if (Entry) { 1991 assert(Entry->isDeclaration()); 1992 1993 // If there is a declaration in the module, then we had an extern followed 1994 // by the alias, as in: 1995 // extern int test6(); 1996 // ... 1997 // int test6() __attribute__((alias("test7"))); 1998 // 1999 // Remove it and replace uses of it with the alias. 2000 GA->takeName(Entry); 2001 2002 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 2003 Entry->getType())); 2004 Entry->eraseFromParent(); 2005 } else { 2006 GA->setName(MangledName); 2007 } 2008 2009 // Set attributes which are particular to an alias; this is a 2010 // specialization of the attributes which may be set on a global 2011 // variable/function. 2012 if (D->hasAttr<DLLExportAttr>()) { 2013 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2014 // The dllexport attribute is ignored for undefined symbols. 2015 if (FD->hasBody()) 2016 GA->setLinkage(llvm::Function::DLLExportLinkage); 2017 } else { 2018 GA->setLinkage(llvm::Function::DLLExportLinkage); 2019 } 2020 } else if (D->hasAttr<WeakAttr>() || 2021 D->hasAttr<WeakRefAttr>() || 2022 D->isWeakImported()) { 2023 GA->setLinkage(llvm::Function::WeakAnyLinkage); 2024 } 2025 2026 SetCommonAttributes(D, GA); 2027} 2028 2029llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 2030 ArrayRef<llvm::Type*> Tys) { 2031 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 2032 Tys); 2033} 2034 2035static llvm::StringMapEntry<llvm::Constant*> & 2036GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2037 const StringLiteral *Literal, 2038 bool TargetIsLSB, 2039 bool &IsUTF16, 2040 unsigned &StringLength) { 2041 StringRef String = Literal->getString(); 2042 unsigned NumBytes = String.size(); 2043 2044 // Check for simple case. 2045 if (!Literal->containsNonAsciiOrNull()) { 2046 StringLength = NumBytes; 2047 return Map.GetOrCreateValue(String); 2048 } 2049 2050 // Otherwise, convert the UTF8 literals into a string of shorts. 2051 IsUTF16 = true; 2052 2053 SmallVector<UTF16, 128> ToBuf(NumBytes + 1); // +1 for ending nulls. 2054 const UTF8 *FromPtr = (const UTF8 *)String.data(); 2055 UTF16 *ToPtr = &ToBuf[0]; 2056 2057 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 2058 &ToPtr, ToPtr + NumBytes, 2059 strictConversion); 2060 2061 // ConvertUTF8toUTF16 returns the length in ToPtr. 2062 StringLength = ToPtr - &ToBuf[0]; 2063 2064 // Add an explicit null. 2065 *ToPtr = 0; 2066 return Map. 2067 GetOrCreateValue(StringRef(reinterpret_cast<const char *>(ToBuf.data()), 2068 (StringLength + 1) * 2)); 2069} 2070 2071static llvm::StringMapEntry<llvm::Constant*> & 2072GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 2073 const StringLiteral *Literal, 2074 unsigned &StringLength) { 2075 StringRef String = Literal->getString(); 2076 StringLength = String.size(); 2077 return Map.GetOrCreateValue(String); 2078} 2079 2080llvm::Constant * 2081CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 2082 unsigned StringLength = 0; 2083 bool isUTF16 = false; 2084 llvm::StringMapEntry<llvm::Constant*> &Entry = 2085 GetConstantCFStringEntry(CFConstantStringMap, Literal, 2086 getDataLayout().isLittleEndian(), 2087 isUTF16, StringLength); 2088 2089 if (llvm::Constant *C = Entry.getValue()) 2090 return C; 2091 2092 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2093 llvm::Constant *Zeros[] = { Zero, Zero }; 2094 2095 // If we don't already have it, get __CFConstantStringClassReference. 2096 if (!CFConstantStringClassRef) { 2097 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2098 Ty = llvm::ArrayType::get(Ty, 0); 2099 llvm::Constant *GV = CreateRuntimeVariable(Ty, 2100 "__CFConstantStringClassReference"); 2101 // Decay array -> ptr 2102 CFConstantStringClassRef = 2103 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2104 } 2105 2106 QualType CFTy = getContext().getCFConstantStringType(); 2107 2108 llvm::StructType *STy = 2109 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 2110 2111 llvm::Constant *Fields[4]; 2112 2113 // Class pointer. 2114 Fields[0] = CFConstantStringClassRef; 2115 2116 // Flags. 2117 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2118 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 2119 llvm::ConstantInt::get(Ty, 0x07C8); 2120 2121 // String pointer. 2122 llvm::Constant *C = 0; 2123 if (isUTF16) { 2124 ArrayRef<uint16_t> Arr = 2125 llvm::makeArrayRef<uint16_t>((uint16_t*)Entry.getKey().data(), 2126 Entry.getKey().size() / 2); 2127 C = llvm::ConstantDataArray::get(VMContext, Arr); 2128 } else { 2129 C = llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2130 } 2131 2132 llvm::GlobalValue::LinkageTypes Linkage; 2133 if (isUTF16) 2134 // FIXME: why do utf strings get "_" labels instead of "L" labels? 2135 Linkage = llvm::GlobalValue::InternalLinkage; 2136 else 2137 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 2138 // when using private linkage. It is not clear if this is a bug in ld 2139 // or a reasonable new restriction. 2140 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 2141 2142 // Note: -fwritable-strings doesn't make the backing store strings of 2143 // CFStrings writable. (See <rdar://problem/10657500>) 2144 llvm::GlobalVariable *GV = 2145 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, 2146 Linkage, C, ".str"); 2147 GV->setUnnamedAddr(true); 2148 if (isUTF16) { 2149 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 2150 GV->setAlignment(Align.getQuantity()); 2151 } else { 2152 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2153 GV->setAlignment(Align.getQuantity()); 2154 } 2155 2156 // String. 2157 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2158 2159 if (isUTF16) 2160 // Cast the UTF16 string to the correct type. 2161 Fields[2] = llvm::ConstantExpr::getBitCast(Fields[2], Int8PtrTy); 2162 2163 // String length. 2164 Ty = getTypes().ConvertType(getContext().LongTy); 2165 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 2166 2167 // The struct. 2168 C = llvm::ConstantStruct::get(STy, Fields); 2169 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2170 llvm::GlobalVariable::PrivateLinkage, C, 2171 "_unnamed_cfstring_"); 2172 if (const char *Sect = getContext().getTargetInfo().getCFStringSection()) 2173 GV->setSection(Sect); 2174 Entry.setValue(GV); 2175 2176 return GV; 2177} 2178 2179static RecordDecl * 2180CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 2181 DeclContext *DC, IdentifierInfo *Id) { 2182 SourceLocation Loc; 2183 if (Ctx.getLangOpts().CPlusPlus) 2184 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2185 else 2186 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 2187} 2188 2189llvm::Constant * 2190CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 2191 unsigned StringLength = 0; 2192 llvm::StringMapEntry<llvm::Constant*> &Entry = 2193 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 2194 2195 if (llvm::Constant *C = Entry.getValue()) 2196 return C; 2197 2198 llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty); 2199 llvm::Constant *Zeros[] = { Zero, Zero }; 2200 2201 // If we don't already have it, get _NSConstantStringClassReference. 2202 if (!ConstantStringClassRef) { 2203 std::string StringClass(getLangOpts().ObjCConstantStringClass); 2204 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 2205 llvm::Constant *GV; 2206 if (LangOpts.ObjCRuntime.isNonFragile()) { 2207 std::string str = 2208 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 2209 : "OBJC_CLASS_$_" + StringClass; 2210 GV = getObjCRuntime().GetClassGlobal(str); 2211 // Make sure the result is of the correct type. 2212 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 2213 ConstantStringClassRef = 2214 llvm::ConstantExpr::getBitCast(GV, PTy); 2215 } else { 2216 std::string str = 2217 StringClass.empty() ? "_NSConstantStringClassReference" 2218 : "_" + StringClass + "ClassReference"; 2219 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 2220 GV = CreateRuntimeVariable(PTy, str); 2221 // Decay array -> ptr 2222 ConstantStringClassRef = 2223 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2224 } 2225 } 2226 2227 if (!NSConstantStringType) { 2228 // Construct the type for a constant NSString. 2229 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2230 Context.getTranslationUnitDecl(), 2231 &Context.Idents.get("__builtin_NSString")); 2232 D->startDefinition(); 2233 2234 QualType FieldTypes[3]; 2235 2236 // const int *isa; 2237 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 2238 // const char *str; 2239 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 2240 // unsigned int length; 2241 FieldTypes[2] = Context.UnsignedIntTy; 2242 2243 // Create fields 2244 for (unsigned i = 0; i < 3; ++i) { 2245 FieldDecl *Field = FieldDecl::Create(Context, D, 2246 SourceLocation(), 2247 SourceLocation(), 0, 2248 FieldTypes[i], /*TInfo=*/0, 2249 /*BitWidth=*/0, 2250 /*Mutable=*/false, 2251 ICIS_NoInit); 2252 Field->setAccess(AS_public); 2253 D->addDecl(Field); 2254 } 2255 2256 D->completeDefinition(); 2257 QualType NSTy = Context.getTagDeclType(D); 2258 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 2259 } 2260 2261 llvm::Constant *Fields[3]; 2262 2263 // Class pointer. 2264 Fields[0] = ConstantStringClassRef; 2265 2266 // String pointer. 2267 llvm::Constant *C = 2268 llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 2269 2270 llvm::GlobalValue::LinkageTypes Linkage; 2271 bool isConstant; 2272 Linkage = llvm::GlobalValue::PrivateLinkage; 2273 isConstant = !LangOpts.WritableStrings; 2274 2275 llvm::GlobalVariable *GV = 2276 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 2277 ".str"); 2278 GV->setUnnamedAddr(true); 2279 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 2280 GV->setAlignment(Align.getQuantity()); 2281 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2282 2283 // String length. 2284 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2285 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 2286 2287 // The struct. 2288 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 2289 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2290 llvm::GlobalVariable::PrivateLinkage, C, 2291 "_unnamed_nsstring_"); 2292 // FIXME. Fix section. 2293 if (const char *Sect = 2294 LangOpts.ObjCRuntime.isNonFragile() 2295 ? getContext().getTargetInfo().getNSStringNonFragileABISection() 2296 : getContext().getTargetInfo().getNSStringSection()) 2297 GV->setSection(Sect); 2298 Entry.setValue(GV); 2299 2300 return GV; 2301} 2302 2303QualType CodeGenModule::getObjCFastEnumerationStateType() { 2304 if (ObjCFastEnumerationStateType.isNull()) { 2305 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2306 Context.getTranslationUnitDecl(), 2307 &Context.Idents.get("__objcFastEnumerationState")); 2308 D->startDefinition(); 2309 2310 QualType FieldTypes[] = { 2311 Context.UnsignedLongTy, 2312 Context.getPointerType(Context.getObjCIdType()), 2313 Context.getPointerType(Context.UnsignedLongTy), 2314 Context.getConstantArrayType(Context.UnsignedLongTy, 2315 llvm::APInt(32, 5), ArrayType::Normal, 0) 2316 }; 2317 2318 for (size_t i = 0; i < 4; ++i) { 2319 FieldDecl *Field = FieldDecl::Create(Context, 2320 D, 2321 SourceLocation(), 2322 SourceLocation(), 0, 2323 FieldTypes[i], /*TInfo=*/0, 2324 /*BitWidth=*/0, 2325 /*Mutable=*/false, 2326 ICIS_NoInit); 2327 Field->setAccess(AS_public); 2328 D->addDecl(Field); 2329 } 2330 2331 D->completeDefinition(); 2332 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 2333 } 2334 2335 return ObjCFastEnumerationStateType; 2336} 2337 2338llvm::Constant * 2339CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { 2340 assert(!E->getType()->isPointerType() && "Strings are always arrays"); 2341 2342 // Don't emit it as the address of the string, emit the string data itself 2343 // as an inline array. 2344 if (E->getCharByteWidth() == 1) { 2345 SmallString<64> Str(E->getString()); 2346 2347 // Resize the string to the right size, which is indicated by its type. 2348 const ConstantArrayType *CAT = Context.getAsConstantArrayType(E->getType()); 2349 Str.resize(CAT->getSize().getZExtValue()); 2350 return llvm::ConstantDataArray::getString(VMContext, Str, false); 2351 } 2352 2353 llvm::ArrayType *AType = 2354 cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); 2355 llvm::Type *ElemTy = AType->getElementType(); 2356 unsigned NumElements = AType->getNumElements(); 2357 2358 // Wide strings have either 2-byte or 4-byte elements. 2359 if (ElemTy->getPrimitiveSizeInBits() == 16) { 2360 SmallVector<uint16_t, 32> Elements; 2361 Elements.reserve(NumElements); 2362 2363 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2364 Elements.push_back(E->getCodeUnit(i)); 2365 Elements.resize(NumElements); 2366 return llvm::ConstantDataArray::get(VMContext, Elements); 2367 } 2368 2369 assert(ElemTy->getPrimitiveSizeInBits() == 32); 2370 SmallVector<uint32_t, 32> Elements; 2371 Elements.reserve(NumElements); 2372 2373 for(unsigned i = 0, e = E->getLength(); i != e; ++i) 2374 Elements.push_back(E->getCodeUnit(i)); 2375 Elements.resize(NumElements); 2376 return llvm::ConstantDataArray::get(VMContext, Elements); 2377} 2378 2379/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 2380/// constant array for the given string literal. 2381llvm::Constant * 2382CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 2383 CharUnits Align = getContext().getTypeAlignInChars(S->getType()); 2384 if (S->isAscii() || S->isUTF8()) { 2385 SmallString<64> Str(S->getString()); 2386 2387 // Resize the string to the right size, which is indicated by its type. 2388 const ConstantArrayType *CAT = Context.getAsConstantArrayType(S->getType()); 2389 Str.resize(CAT->getSize().getZExtValue()); 2390 return GetAddrOfConstantString(Str, /*GlobalName*/ 0, Align.getQuantity()); 2391 } 2392 2393 // FIXME: the following does not memoize wide strings. 2394 llvm::Constant *C = GetConstantArrayFromStringLiteral(S); 2395 llvm::GlobalVariable *GV = 2396 new llvm::GlobalVariable(getModule(),C->getType(), 2397 !LangOpts.WritableStrings, 2398 llvm::GlobalValue::PrivateLinkage, 2399 C,".str"); 2400 2401 GV->setAlignment(Align.getQuantity()); 2402 GV->setUnnamedAddr(true); 2403 return GV; 2404} 2405 2406/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2407/// array for the given ObjCEncodeExpr node. 2408llvm::Constant * 2409CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2410 std::string Str; 2411 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2412 2413 return GetAddrOfConstantCString(Str); 2414} 2415 2416 2417/// GenerateWritableString -- Creates storage for a string literal. 2418static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2419 bool constant, 2420 CodeGenModule &CGM, 2421 const char *GlobalName, 2422 unsigned Alignment) { 2423 // Create Constant for this string literal. Don't add a '\0'. 2424 llvm::Constant *C = 2425 llvm::ConstantDataArray::getString(CGM.getLLVMContext(), str, false); 2426 2427 // Create a global variable for this string 2428 llvm::GlobalVariable *GV = 2429 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 2430 llvm::GlobalValue::PrivateLinkage, 2431 C, GlobalName); 2432 GV->setAlignment(Alignment); 2433 GV->setUnnamedAddr(true); 2434 return GV; 2435} 2436 2437/// GetAddrOfConstantString - Returns a pointer to a character array 2438/// containing the literal. This contents are exactly that of the 2439/// given string, i.e. it will not be null terminated automatically; 2440/// see GetAddrOfConstantCString. Note that whether the result is 2441/// actually a pointer to an LLVM constant depends on 2442/// Feature.WriteableStrings. 2443/// 2444/// The result has pointer to array type. 2445llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2446 const char *GlobalName, 2447 unsigned Alignment) { 2448 // Get the default prefix if a name wasn't specified. 2449 if (!GlobalName) 2450 GlobalName = ".str"; 2451 2452 // Don't share any string literals if strings aren't constant. 2453 if (LangOpts.WritableStrings) 2454 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2455 2456 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2457 ConstantStringMap.GetOrCreateValue(Str); 2458 2459 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2460 if (Alignment > GV->getAlignment()) { 2461 GV->setAlignment(Alignment); 2462 } 2463 return GV; 2464 } 2465 2466 // Create a global variable for this. 2467 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, 2468 Alignment); 2469 Entry.setValue(GV); 2470 return GV; 2471} 2472 2473/// GetAddrOfConstantCString - Returns a pointer to a character 2474/// array containing the literal and a terminating '\0' 2475/// character. The result has pointer to array type. 2476llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2477 const char *GlobalName, 2478 unsigned Alignment) { 2479 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2480 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2481} 2482 2483/// EmitObjCPropertyImplementations - Emit information for synthesized 2484/// properties for an implementation. 2485void CodeGenModule::EmitObjCPropertyImplementations(const 2486 ObjCImplementationDecl *D) { 2487 for (ObjCImplementationDecl::propimpl_iterator 2488 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2489 ObjCPropertyImplDecl *PID = *i; 2490 2491 // Dynamic is just for type-checking. 2492 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2493 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2494 2495 // Determine which methods need to be implemented, some may have 2496 // been overridden. Note that ::isPropertyAccessor is not the method 2497 // we want, that just indicates if the decl came from a 2498 // property. What we want to know is if the method is defined in 2499 // this implementation. 2500 if (!D->getInstanceMethod(PD->getGetterName())) 2501 CodeGenFunction(*this).GenerateObjCGetter( 2502 const_cast<ObjCImplementationDecl *>(D), PID); 2503 if (!PD->isReadOnly() && 2504 !D->getInstanceMethod(PD->getSetterName())) 2505 CodeGenFunction(*this).GenerateObjCSetter( 2506 const_cast<ObjCImplementationDecl *>(D), PID); 2507 } 2508 } 2509} 2510 2511static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2512 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2513 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2514 ivar; ivar = ivar->getNextIvar()) 2515 if (ivar->getType().isDestructedType()) 2516 return true; 2517 2518 return false; 2519} 2520 2521/// EmitObjCIvarInitializations - Emit information for ivar initialization 2522/// for an implementation. 2523void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2524 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2525 if (needsDestructMethod(D)) { 2526 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2527 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2528 ObjCMethodDecl *DTORMethod = 2529 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2530 cxxSelector, getContext().VoidTy, 0, D, 2531 /*isInstance=*/true, /*isVariadic=*/false, 2532 /*isPropertyAccessor=*/true, /*isImplicitlyDeclared=*/true, 2533 /*isDefined=*/false, ObjCMethodDecl::Required); 2534 D->addInstanceMethod(DTORMethod); 2535 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2536 D->setHasCXXStructors(true); 2537 } 2538 2539 // If the implementation doesn't have any ivar initializers, we don't need 2540 // a .cxx_construct. 2541 if (D->getNumIvarInitializers() == 0) 2542 return; 2543 2544 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2545 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2546 // The constructor returns 'self'. 2547 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2548 D->getLocation(), 2549 D->getLocation(), 2550 cxxSelector, 2551 getContext().getObjCIdType(), 0, 2552 D, /*isInstance=*/true, 2553 /*isVariadic=*/false, 2554 /*isPropertyAccessor=*/true, 2555 /*isImplicitlyDeclared=*/true, 2556 /*isDefined=*/false, 2557 ObjCMethodDecl::Required); 2558 D->addInstanceMethod(CTORMethod); 2559 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2560 D->setHasCXXStructors(true); 2561} 2562 2563/// EmitNamespace - Emit all declarations in a namespace. 2564void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2565 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2566 I != E; ++I) 2567 EmitTopLevelDecl(*I); 2568} 2569 2570// EmitLinkageSpec - Emit all declarations in a linkage spec. 2571void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2572 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2573 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2574 ErrorUnsupported(LSD, "linkage spec"); 2575 return; 2576 } 2577 2578 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2579 I != E; ++I) 2580 EmitTopLevelDecl(*I); 2581} 2582 2583/// EmitTopLevelDecl - Emit code for a single top level declaration. 2584void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2585 // If an error has occurred, stop code generation, but continue 2586 // parsing and semantic analysis (to ensure all warnings and errors 2587 // are emitted). 2588 if (Diags.hasErrorOccurred()) 2589 return; 2590 2591 // Ignore dependent declarations. 2592 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2593 return; 2594 2595 switch (D->getKind()) { 2596 case Decl::CXXConversion: 2597 case Decl::CXXMethod: 2598 case Decl::Function: 2599 // Skip function templates 2600 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2601 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2602 return; 2603 2604 EmitGlobal(cast<FunctionDecl>(D)); 2605 break; 2606 2607 case Decl::Var: 2608 EmitGlobal(cast<VarDecl>(D)); 2609 break; 2610 2611 // Indirect fields from global anonymous structs and unions can be 2612 // ignored; only the actual variable requires IR gen support. 2613 case Decl::IndirectField: 2614 break; 2615 2616 // C++ Decls 2617 case Decl::Namespace: 2618 EmitNamespace(cast<NamespaceDecl>(D)); 2619 break; 2620 // No code generation needed. 2621 case Decl::UsingShadow: 2622 case Decl::Using: 2623 case Decl::UsingDirective: 2624 case Decl::ClassTemplate: 2625 case Decl::FunctionTemplate: 2626 case Decl::TypeAliasTemplate: 2627 case Decl::NamespaceAlias: 2628 case Decl::Block: 2629 case Decl::Import: 2630 break; 2631 case Decl::CXXConstructor: 2632 // Skip function templates 2633 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2634 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2635 return; 2636 2637 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2638 break; 2639 case Decl::CXXDestructor: 2640 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2641 return; 2642 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2643 break; 2644 2645 case Decl::StaticAssert: 2646 // Nothing to do. 2647 break; 2648 2649 // Objective-C Decls 2650 2651 // Forward declarations, no (immediate) code generation. 2652 case Decl::ObjCInterface: 2653 case Decl::ObjCCategory: 2654 break; 2655 2656 case Decl::ObjCProtocol: { 2657 ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D); 2658 if (Proto->isThisDeclarationADefinition()) 2659 ObjCRuntime->GenerateProtocol(Proto); 2660 break; 2661 } 2662 2663 case Decl::ObjCCategoryImpl: 2664 // Categories have properties but don't support synthesize so we 2665 // can ignore them here. 2666 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2667 break; 2668 2669 case Decl::ObjCImplementation: { 2670 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2671 EmitObjCPropertyImplementations(OMD); 2672 EmitObjCIvarInitializations(OMD); 2673 ObjCRuntime->GenerateClass(OMD); 2674 // Emit global variable debug information. 2675 if (CGDebugInfo *DI = getModuleDebugInfo()) 2676 DI->getOrCreateInterfaceType(getContext().getObjCInterfaceType(OMD->getClassInterface()), 2677 OMD->getLocation()); 2678 2679 break; 2680 } 2681 case Decl::ObjCMethod: { 2682 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 2683 // If this is not a prototype, emit the body. 2684 if (OMD->getBody()) 2685 CodeGenFunction(*this).GenerateObjCMethod(OMD); 2686 break; 2687 } 2688 case Decl::ObjCCompatibleAlias: 2689 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D)); 2690 break; 2691 2692 case Decl::LinkageSpec: 2693 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 2694 break; 2695 2696 case Decl::FileScopeAsm: { 2697 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 2698 StringRef AsmString = AD->getAsmString()->getString(); 2699 2700 const std::string &S = getModule().getModuleInlineAsm(); 2701 if (S.empty()) 2702 getModule().setModuleInlineAsm(AsmString); 2703 else if (S.end()[-1] == '\n') 2704 getModule().setModuleInlineAsm(S + AsmString.str()); 2705 else 2706 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 2707 break; 2708 } 2709 2710 default: 2711 // Make sure we handled everything we should, every other kind is a 2712 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 2713 // function. Need to recode Decl::Kind to do that easily. 2714 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 2715 } 2716} 2717 2718/// Turns the given pointer into a constant. 2719static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 2720 const void *Ptr) { 2721 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 2722 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 2723 return llvm::ConstantInt::get(i64, PtrInt); 2724} 2725 2726static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 2727 llvm::NamedMDNode *&GlobalMetadata, 2728 GlobalDecl D, 2729 llvm::GlobalValue *Addr) { 2730 if (!GlobalMetadata) 2731 GlobalMetadata = 2732 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 2733 2734 // TODO: should we report variant information for ctors/dtors? 2735 llvm::Value *Ops[] = { 2736 Addr, 2737 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 2738 }; 2739 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 2740} 2741 2742/// Emits metadata nodes associating all the global values in the 2743/// current module with the Decls they came from. This is useful for 2744/// projects using IR gen as a subroutine. 2745/// 2746/// Since there's currently no way to associate an MDNode directly 2747/// with an llvm::GlobalValue, we create a global named metadata 2748/// with the name 'clang.global.decl.ptrs'. 2749void CodeGenModule::EmitDeclMetadata() { 2750 llvm::NamedMDNode *GlobalMetadata = 0; 2751 2752 // StaticLocalDeclMap 2753 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 2754 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 2755 I != E; ++I) { 2756 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 2757 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 2758 } 2759} 2760 2761/// Emits metadata nodes for all the local variables in the current 2762/// function. 2763void CodeGenFunction::EmitDeclMetadata() { 2764 if (LocalDeclMap.empty()) return; 2765 2766 llvm::LLVMContext &Context = getLLVMContext(); 2767 2768 // Find the unique metadata ID for this name. 2769 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 2770 2771 llvm::NamedMDNode *GlobalMetadata = 0; 2772 2773 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 2774 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 2775 const Decl *D = I->first; 2776 llvm::Value *Addr = I->second; 2777 2778 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 2779 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 2780 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 2781 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 2782 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 2783 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 2784 } 2785 } 2786} 2787 2788void CodeGenModule::EmitCoverageFile() { 2789 if (!getCodeGenOpts().CoverageFile.empty()) { 2790 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 2791 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 2792 llvm::LLVMContext &Ctx = TheModule.getContext(); 2793 llvm::MDString *CoverageFile = 2794 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 2795 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 2796 llvm::MDNode *CU = CUNode->getOperand(i); 2797 llvm::Value *node[] = { CoverageFile, CU }; 2798 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 2799 GCov->addOperand(N); 2800 } 2801 } 2802 } 2803} 2804 2805llvm::Constant *CodeGenModule::EmitUuidofInitializer(StringRef Uuid, 2806 QualType GuidType) { 2807 // Sema has checked that all uuid strings are of the form 2808 // "12345678-1234-1234-1234-1234567890ab". 2809 assert(Uuid.size() == 36); 2810 const char *Uuidstr = Uuid.data(); 2811 for (int i = 0; i < 36; ++i) { 2812 if (i == 8 || i == 13 || i == 18 || i == 23) assert(Uuidstr[i] == '-'); 2813 else assert(isxdigit(Uuidstr[i])); 2814 } 2815 2816 llvm::APInt Field0(32, StringRef(Uuidstr , 8), 16); 2817 llvm::APInt Field1(16, StringRef(Uuidstr + 9, 4), 16); 2818 llvm::APInt Field2(16, StringRef(Uuidstr + 14, 4), 16); 2819 int Field3ValueOffsets[] = { 19, 21, 24, 26, 28, 30, 32, 34 }; 2820 2821 APValue InitStruct(APValue::UninitStruct(), /*NumBases=*/0, /*NumFields=*/4); 2822 InitStruct.getStructField(0) = APValue(llvm::APSInt(Field0)); 2823 InitStruct.getStructField(1) = APValue(llvm::APSInt(Field1)); 2824 InitStruct.getStructField(2) = APValue(llvm::APSInt(Field2)); 2825 APValue& Arr = InitStruct.getStructField(3); 2826 Arr = APValue(APValue::UninitArray(), 8, 8); 2827 for (int t = 0; t < 8; ++t) 2828 Arr.getArrayInitializedElt(t) = APValue(llvm::APSInt( 2829 llvm::APInt(8, StringRef(Uuidstr + Field3ValueOffsets[t], 2), 16))); 2830 2831 return EmitConstantValue(InitStruct, GuidType); 2832} 2833