CodeGenModule.cpp revision 491306a83c4f0f49f95a3bcbca8580cb98a91c7a
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 "CGCXXABI.h" 20#include "CGObjCRuntime.h" 21#include "CGOpenCLRuntime.h" 22#include "TargetInfo.h" 23#include "clang/Frontend/CodeGenOptions.h" 24#include "clang/AST/ASTContext.h" 25#include "clang/AST/CharUnits.h" 26#include "clang/AST/DeclObjC.h" 27#include "clang/AST/DeclCXX.h" 28#include "clang/AST/DeclTemplate.h" 29#include "clang/AST/Mangle.h" 30#include "clang/AST/RecordLayout.h" 31#include "clang/Basic/Diagnostic.h" 32#include "clang/Basic/SourceManager.h" 33#include "clang/Basic/TargetInfo.h" 34#include "clang/Basic/ConvertUTF.h" 35#include "llvm/CallingConv.h" 36#include "llvm/Module.h" 37#include "llvm/Intrinsics.h" 38#include "llvm/LLVMContext.h" 39#include "llvm/ADT/Triple.h" 40#include "llvm/Target/Mangler.h" 41#include "llvm/Target/TargetData.h" 42#include "llvm/Support/CallSite.h" 43#include "llvm/Support/ErrorHandling.h" 44using namespace clang; 45using namespace CodeGen; 46 47static const char AnnotationSection[] = "llvm.metadata"; 48 49static CGCXXABI &createCXXABI(CodeGenModule &CGM) { 50 switch (CGM.getContext().getTargetInfo().getCXXABI()) { 51 case CXXABI_ARM: return *CreateARMCXXABI(CGM); 52 case CXXABI_Itanium: return *CreateItaniumCXXABI(CGM); 53 case CXXABI_Microsoft: return *CreateMicrosoftCXXABI(CGM); 54 } 55 56 llvm_unreachable("invalid C++ ABI kind"); 57 return *CreateItaniumCXXABI(CGM); 58} 59 60 61CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 62 llvm::Module &M, const llvm::TargetData &TD, 63 DiagnosticsEngine &diags) 64 : Context(C), Features(C.getLangOptions()), CodeGenOpts(CGO), TheModule(M), 65 TheTargetData(TD), TheTargetCodeGenInfo(0), Diags(diags), 66 ABI(createCXXABI(*this)), 67 Types(C, M, TD, getTargetCodeGenInfo().getABIInfo(), ABI, CGO), 68 TBAA(0), 69 VTables(*this), ObjCRuntime(0), OpenCLRuntime(0), DebugInfo(0), ARCData(0), 70 RRData(0), CFConstantStringClassRef(0), ConstantStringClassRef(0), 71 NSConstantStringType(0), 72 VMContext(M.getContext()), 73 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), 74 BlockObjectAssign(0), BlockObjectDispose(0), 75 BlockDescriptorType(0), GenericBlockLiteralType(0) { 76 if (Features.ObjC1) 77 createObjCRuntime(); 78 if (Features.OpenCL) 79 createOpenCLRuntime(); 80 81 // Enable TBAA unless it's suppressed. 82 if (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0) 83 TBAA = new CodeGenTBAA(Context, VMContext, getLangOptions(), 84 ABI.getMangleContext()); 85 86 // If debug info or coverage generation is enabled, create the CGDebugInfo 87 // object. 88 if (CodeGenOpts.DebugInfo || CodeGenOpts.EmitGcovArcs || 89 CodeGenOpts.EmitGcovNotes) 90 DebugInfo = new CGDebugInfo(*this); 91 92 Block.GlobalUniqueCount = 0; 93 94 if (C.getLangOptions().ObjCAutoRefCount) 95 ARCData = new ARCEntrypoints(); 96 RRData = new RREntrypoints(); 97 98 // Initialize the type cache. 99 llvm::LLVMContext &LLVMContext = M.getContext(); 100 VoidTy = llvm::Type::getVoidTy(LLVMContext); 101 Int8Ty = llvm::Type::getInt8Ty(LLVMContext); 102 Int32Ty = llvm::Type::getInt32Ty(LLVMContext); 103 Int64Ty = llvm::Type::getInt64Ty(LLVMContext); 104 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0); 105 PointerAlignInBytes = 106 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity(); 107 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth()); 108 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits); 109 Int8PtrTy = Int8Ty->getPointerTo(0); 110 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0); 111} 112 113CodeGenModule::~CodeGenModule() { 114 delete ObjCRuntime; 115 delete OpenCLRuntime; 116 delete &ABI; 117 delete TBAA; 118 delete DebugInfo; 119 delete ARCData; 120 delete RRData; 121} 122 123void CodeGenModule::createObjCRuntime() { 124 if (!Features.NeXTRuntime) 125 ObjCRuntime = CreateGNUObjCRuntime(*this); 126 else 127 ObjCRuntime = CreateMacObjCRuntime(*this); 128} 129 130void CodeGenModule::createOpenCLRuntime() { 131 OpenCLRuntime = new CGOpenCLRuntime(*this); 132} 133 134void CodeGenModule::Release() { 135 EmitDeferred(); 136 EmitCXXGlobalInitFunc(); 137 EmitCXXGlobalDtorFunc(); 138 if (ObjCRuntime) 139 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) 140 AddGlobalCtor(ObjCInitFunction); 141 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 142 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 143 EmitGlobalAnnotations(); 144 EmitLLVMUsed(); 145 146 SimplifyPersonality(); 147 148 if (getCodeGenOpts().EmitDeclMetadata) 149 EmitDeclMetadata(); 150 151 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 152 EmitCoverageFile(); 153 154 if (DebugInfo) 155 DebugInfo->finalize(); 156} 157 158void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 159 // Make sure that this type is translated. 160 Types.UpdateCompletedType(TD); 161 if (DebugInfo) 162 DebugInfo->UpdateCompletedType(TD); 163} 164 165llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 166 if (!TBAA) 167 return 0; 168 return TBAA->getTBAAInfo(QTy); 169} 170 171void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 172 llvm::MDNode *TBAAInfo) { 173 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 174} 175 176bool CodeGenModule::isTargetDarwin() const { 177 return getContext().getTargetInfo().getTriple().isOSDarwin(); 178} 179 180void CodeGenModule::Error(SourceLocation loc, StringRef error) { 181 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); 182 getDiags().Report(Context.getFullLoc(loc), diagID); 183} 184 185/// ErrorUnsupported - Print out an error that codegen doesn't support the 186/// specified stmt yet. 187void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 188 bool OmitOnError) { 189 if (OmitOnError && getDiags().hasErrorOccurred()) 190 return; 191 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 192 "cannot compile this %0 yet"); 193 std::string Msg = Type; 194 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 195 << Msg << S->getSourceRange(); 196} 197 198/// ErrorUnsupported - Print out an error that codegen doesn't support the 199/// specified decl yet. 200void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 201 bool OmitOnError) { 202 if (OmitOnError && getDiags().hasErrorOccurred()) 203 return; 204 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 205 "cannot compile this %0 yet"); 206 std::string Msg = Type; 207 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 208} 209 210llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 211 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 212} 213 214void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 215 const NamedDecl *D) const { 216 // Internal definitions always have default visibility. 217 if (GV->hasLocalLinkage()) { 218 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 219 return; 220 } 221 222 // Set visibility for definitions. 223 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 224 if (LV.visibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 225 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 226} 227 228/// Set the symbol visibility of type information (vtable and RTTI) 229/// associated with the given type. 230void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 231 const CXXRecordDecl *RD, 232 TypeVisibilityKind TVK) const { 233 setGlobalVisibility(GV, RD); 234 235 if (!CodeGenOpts.HiddenWeakVTables) 236 return; 237 238 // We never want to drop the visibility for RTTI names. 239 if (TVK == TVK_ForRTTIName) 240 return; 241 242 // We want to drop the visibility to hidden for weak type symbols. 243 // This isn't possible if there might be unresolved references 244 // elsewhere that rely on this symbol being visible. 245 246 // This should be kept roughly in sync with setThunkVisibility 247 // in CGVTables.cpp. 248 249 // Preconditions. 250 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 251 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 252 return; 253 254 // Don't override an explicit visibility attribute. 255 if (RD->getExplicitVisibility()) 256 return; 257 258 switch (RD->getTemplateSpecializationKind()) { 259 // We have to disable the optimization if this is an EI definition 260 // because there might be EI declarations in other shared objects. 261 case TSK_ExplicitInstantiationDefinition: 262 case TSK_ExplicitInstantiationDeclaration: 263 return; 264 265 // Every use of a non-template class's type information has to emit it. 266 case TSK_Undeclared: 267 break; 268 269 // In theory, implicit instantiations can ignore the possibility of 270 // an explicit instantiation declaration because there necessarily 271 // must be an EI definition somewhere with default visibility. In 272 // practice, it's possible to have an explicit instantiation for 273 // an arbitrary template class, and linkers aren't necessarily able 274 // to deal with mixed-visibility symbols. 275 case TSK_ExplicitSpecialization: 276 case TSK_ImplicitInstantiation: 277 if (!CodeGenOpts.HiddenWeakTemplateVTables) 278 return; 279 break; 280 } 281 282 // If there's a key function, there may be translation units 283 // that don't have the key function's definition. But ignore 284 // this if we're emitting RTTI under -fno-rtti. 285 if (!(TVK != TVK_ForRTTI) || Features.RTTI) { 286 if (Context.getKeyFunction(RD)) 287 return; 288 } 289 290 // Otherwise, drop the visibility to hidden. 291 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 292 GV->setUnnamedAddr(true); 293} 294 295StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 296 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 297 298 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 299 if (!Str.empty()) 300 return Str; 301 302 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 303 IdentifierInfo *II = ND->getIdentifier(); 304 assert(II && "Attempt to mangle unnamed decl."); 305 306 Str = II->getName(); 307 return Str; 308 } 309 310 llvm::SmallString<256> Buffer; 311 llvm::raw_svector_ostream Out(Buffer); 312 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 313 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 314 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 315 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 316 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND)) 317 getCXXABI().getMangleContext().mangleBlock(BD, Out); 318 else 319 getCXXABI().getMangleContext().mangleName(ND, Out); 320 321 // Allocate space for the mangled name. 322 Out.flush(); 323 size_t Length = Buffer.size(); 324 char *Name = MangledNamesAllocator.Allocate<char>(Length); 325 std::copy(Buffer.begin(), Buffer.end(), Name); 326 327 Str = StringRef(Name, Length); 328 329 return Str; 330} 331 332void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 333 const BlockDecl *BD) { 334 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 335 const Decl *D = GD.getDecl(); 336 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 337 if (D == 0) 338 MangleCtx.mangleGlobalBlock(BD, Out); 339 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 340 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 341 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 342 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 343 else 344 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 345} 346 347llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 348 return getModule().getNamedValue(Name); 349} 350 351/// AddGlobalCtor - Add a function to the list that will be called before 352/// main() runs. 353void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 354 // FIXME: Type coercion of void()* types. 355 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 356} 357 358/// AddGlobalDtor - Add a function to the list that will be called 359/// when the module is unloaded. 360void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 361 // FIXME: Type coercion of void()* types. 362 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 363} 364 365void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 366 // Ctor function type is void()*. 367 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 368 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 369 370 // Get the type of a ctor entry, { i32, void ()* }. 371 llvm::StructType *CtorStructTy = 372 llvm::StructType::get(llvm::Type::getInt32Ty(VMContext), 373 llvm::PointerType::getUnqual(CtorFTy), NULL); 374 375 // Construct the constructor and destructor arrays. 376 std::vector<llvm::Constant*> Ctors; 377 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 378 std::vector<llvm::Constant*> S; 379 S.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 380 I->second, false)); 381 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy)); 382 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 383 } 384 385 if (!Ctors.empty()) { 386 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 387 new llvm::GlobalVariable(TheModule, AT, false, 388 llvm::GlobalValue::AppendingLinkage, 389 llvm::ConstantArray::get(AT, Ctors), 390 GlobalName); 391 } 392} 393 394llvm::GlobalValue::LinkageTypes 395CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 396 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 397 398 if (Linkage == GVA_Internal) 399 return llvm::Function::InternalLinkage; 400 401 if (D->hasAttr<DLLExportAttr>()) 402 return llvm::Function::DLLExportLinkage; 403 404 if (D->hasAttr<WeakAttr>()) 405 return llvm::Function::WeakAnyLinkage; 406 407 // In C99 mode, 'inline' functions are guaranteed to have a strong 408 // definition somewhere else, so we can use available_externally linkage. 409 if (Linkage == GVA_C99Inline) 410 return llvm::Function::AvailableExternallyLinkage; 411 412 // Note that Apple's kernel linker doesn't support symbol 413 // coalescing, so we need to avoid linkonce and weak linkages there. 414 // Normally, this means we just map to internal, but for explicit 415 // instantiations we'll map to external. 416 417 // In C++, the compiler has to emit a definition in every translation unit 418 // that references the function. We should use linkonce_odr because 419 // a) if all references in this translation unit are optimized away, we 420 // don't need to codegen it. b) if the function persists, it needs to be 421 // merged with other definitions. c) C++ has the ODR, so we know the 422 // definition is dependable. 423 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 424 return !Context.getLangOptions().AppleKext 425 ? llvm::Function::LinkOnceODRLinkage 426 : llvm::Function::InternalLinkage; 427 428 // An explicit instantiation of a template has weak linkage, since 429 // explicit instantiations can occur in multiple translation units 430 // and must all be equivalent. However, we are not allowed to 431 // throw away these explicit instantiations. 432 if (Linkage == GVA_ExplicitTemplateInstantiation) 433 return !Context.getLangOptions().AppleKext 434 ? llvm::Function::WeakODRLinkage 435 : llvm::Function::ExternalLinkage; 436 437 // Otherwise, we have strong external linkage. 438 assert(Linkage == GVA_StrongExternal); 439 return llvm::Function::ExternalLinkage; 440} 441 442 443/// SetFunctionDefinitionAttributes - Set attributes for a global. 444/// 445/// FIXME: This is currently only done for aliases and functions, but not for 446/// variables (these details are set in EmitGlobalVarDefinition for variables). 447void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 448 llvm::GlobalValue *GV) { 449 SetCommonAttributes(D, GV); 450} 451 452void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 453 const CGFunctionInfo &Info, 454 llvm::Function *F) { 455 unsigned CallingConv; 456 AttributeListType AttributeList; 457 ConstructAttributeList(Info, D, AttributeList, CallingConv); 458 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 459 AttributeList.size())); 460 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 461} 462 463/// Determines whether the language options require us to model 464/// unwind exceptions. We treat -fexceptions as mandating this 465/// except under the fragile ObjC ABI with only ObjC exceptions 466/// enabled. This means, for example, that C with -fexceptions 467/// enables this. 468static bool hasUnwindExceptions(const LangOptions &Features) { 469 // If exceptions are completely disabled, obviously this is false. 470 if (!Features.Exceptions) return false; 471 472 // If C++ exceptions are enabled, this is true. 473 if (Features.CXXExceptions) return true; 474 475 // If ObjC exceptions are enabled, this depends on the ABI. 476 if (Features.ObjCExceptions) { 477 if (!Features.ObjCNonFragileABI) return false; 478 } 479 480 return true; 481} 482 483void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 484 llvm::Function *F) { 485 if (CodeGenOpts.UnwindTables) 486 F->setHasUWTable(); 487 488 if (!hasUnwindExceptions(Features)) 489 F->addFnAttr(llvm::Attribute::NoUnwind); 490 491 if (D->hasAttr<NakedAttr>()) { 492 // Naked implies noinline: we should not be inlining such functions. 493 F->addFnAttr(llvm::Attribute::Naked); 494 F->addFnAttr(llvm::Attribute::NoInline); 495 } 496 497 if (D->hasAttr<NoInlineAttr>()) 498 F->addFnAttr(llvm::Attribute::NoInline); 499 500 // (noinline wins over always_inline, and we can't specify both in IR) 501 if (D->hasAttr<AlwaysInlineAttr>() && 502 !F->hasFnAttr(llvm::Attribute::NoInline)) 503 F->addFnAttr(llvm::Attribute::AlwaysInline); 504 505 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 506 F->setUnnamedAddr(true); 507 508 if (Features.getStackProtector() == LangOptions::SSPOn) 509 F->addFnAttr(llvm::Attribute::StackProtect); 510 else if (Features.getStackProtector() == LangOptions::SSPReq) 511 F->addFnAttr(llvm::Attribute::StackProtectReq); 512 513 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 514 if (alignment) 515 F->setAlignment(alignment); 516 517 // C++ ABI requires 2-byte alignment for member functions. 518 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 519 F->setAlignment(2); 520} 521 522void CodeGenModule::SetCommonAttributes(const Decl *D, 523 llvm::GlobalValue *GV) { 524 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 525 setGlobalVisibility(GV, ND); 526 else 527 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 528 529 if (D->hasAttr<UsedAttr>()) 530 AddUsedGlobal(GV); 531 532 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 533 GV->setSection(SA->getName()); 534 535 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 536} 537 538void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 539 llvm::Function *F, 540 const CGFunctionInfo &FI) { 541 SetLLVMFunctionAttributes(D, FI, F); 542 SetLLVMFunctionAttributesForDefinition(D, F); 543 544 F->setLinkage(llvm::Function::InternalLinkage); 545 546 SetCommonAttributes(D, F); 547} 548 549void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 550 llvm::Function *F, 551 bool IsIncompleteFunction) { 552 if (unsigned IID = F->getIntrinsicID()) { 553 // If this is an intrinsic function, set the function's attributes 554 // to the intrinsic's attributes. 555 F->setAttributes(llvm::Intrinsic::getAttributes((llvm::Intrinsic::ID)IID)); 556 return; 557 } 558 559 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 560 561 if (!IsIncompleteFunction) 562 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(GD), F); 563 564 // Only a few attributes are set on declarations; these may later be 565 // overridden by a definition. 566 567 if (FD->hasAttr<DLLImportAttr>()) { 568 F->setLinkage(llvm::Function::DLLImportLinkage); 569 } else if (FD->hasAttr<WeakAttr>() || 570 FD->isWeakImported()) { 571 // "extern_weak" is overloaded in LLVM; we probably should have 572 // separate linkage types for this. 573 F->setLinkage(llvm::Function::ExternalWeakLinkage); 574 } else { 575 F->setLinkage(llvm::Function::ExternalLinkage); 576 577 NamedDecl::LinkageInfo LV = FD->getLinkageAndVisibility(); 578 if (LV.linkage() == ExternalLinkage && LV.visibilityExplicit()) { 579 F->setVisibility(GetLLVMVisibility(LV.visibility())); 580 } 581 } 582 583 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 584 F->setSection(SA->getName()); 585} 586 587void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 588 assert(!GV->isDeclaration() && 589 "Only globals with definition can force usage."); 590 LLVMUsed.push_back(GV); 591} 592 593void CodeGenModule::EmitLLVMUsed() { 594 // Don't create llvm.used if there is no need. 595 if (LLVMUsed.empty()) 596 return; 597 598 llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext); 599 600 // Convert LLVMUsed to what ConstantArray needs. 601 std::vector<llvm::Constant*> UsedArray; 602 UsedArray.resize(LLVMUsed.size()); 603 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 604 UsedArray[i] = 605 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 606 i8PTy); 607 } 608 609 if (UsedArray.empty()) 610 return; 611 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, UsedArray.size()); 612 613 llvm::GlobalVariable *GV = 614 new llvm::GlobalVariable(getModule(), ATy, false, 615 llvm::GlobalValue::AppendingLinkage, 616 llvm::ConstantArray::get(ATy, UsedArray), 617 "llvm.used"); 618 619 GV->setSection("llvm.metadata"); 620} 621 622void CodeGenModule::EmitDeferred() { 623 // Emit code for any potentially referenced deferred decls. Since a 624 // previously unused static decl may become used during the generation of code 625 // for a static function, iterate until no changes are made. 626 627 while (!DeferredDeclsToEmit.empty() || !DeferredVTables.empty()) { 628 if (!DeferredVTables.empty()) { 629 const CXXRecordDecl *RD = DeferredVTables.back(); 630 DeferredVTables.pop_back(); 631 getVTables().GenerateClassData(getVTableLinkage(RD), RD); 632 continue; 633 } 634 635 GlobalDecl D = DeferredDeclsToEmit.back(); 636 DeferredDeclsToEmit.pop_back(); 637 638 // Check to see if we've already emitted this. This is necessary 639 // for a couple of reasons: first, decls can end up in the 640 // deferred-decls queue multiple times, and second, decls can end 641 // up with definitions in unusual ways (e.g. by an extern inline 642 // function acquiring a strong function redefinition). Just 643 // ignore these cases. 644 // 645 // TODO: That said, looking this up multiple times is very wasteful. 646 StringRef Name = getMangledName(D); 647 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 648 assert(CGRef && "Deferred decl wasn't referenced?"); 649 650 if (!CGRef->isDeclaration()) 651 continue; 652 653 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 654 // purposes an alias counts as a definition. 655 if (isa<llvm::GlobalAlias>(CGRef)) 656 continue; 657 658 // Otherwise, emit the definition and move on to the next one. 659 EmitGlobalDefinition(D); 660 } 661} 662 663void CodeGenModule::EmitGlobalAnnotations() { 664 if (Annotations.empty()) 665 return; 666 667 // Create a new global variable for the ConstantStruct in the Module. 668 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 669 Annotations[0]->getType(), Annotations.size()), Annotations); 670 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), 671 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, 672 "llvm.global.annotations"); 673 gv->setSection(AnnotationSection); 674} 675 676llvm::Constant *CodeGenModule::EmitAnnotationString(llvm::StringRef Str) { 677 llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str); 678 if (i != AnnotationStrings.end()) 679 return i->second; 680 681 // Not found yet, create a new global. 682 llvm::Constant *s = llvm::ConstantArray::get(getLLVMContext(), Str, true); 683 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), 684 true, llvm::GlobalValue::PrivateLinkage, s, ".str"); 685 gv->setSection(AnnotationSection); 686 gv->setUnnamedAddr(true); 687 AnnotationStrings[Str] = gv; 688 return gv; 689} 690 691llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 692 SourceManager &SM = getContext().getSourceManager(); 693 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 694 if (PLoc.isValid()) 695 return EmitAnnotationString(PLoc.getFilename()); 696 return EmitAnnotationString(SM.getBufferName(Loc)); 697} 698 699llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 700 SourceManager &SM = getContext().getSourceManager(); 701 PresumedLoc PLoc = SM.getPresumedLoc(L); 702 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 703 SM.getExpansionLineNumber(L); 704 return llvm::ConstantInt::get(Int32Ty, LineNo); 705} 706 707llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 708 const AnnotateAttr *AA, 709 SourceLocation L) { 710 // Get the globals for file name, annotation, and the line number. 711 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 712 *UnitGV = EmitAnnotationUnit(L), 713 *LineNoCst = EmitAnnotationLineNo(L); 714 715 // Create the ConstantStruct for the global annotation. 716 llvm::Constant *Fields[4] = { 717 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 718 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 719 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 720 LineNoCst 721 }; 722 return llvm::ConstantStruct::getAnon(Fields); 723} 724 725void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 726 llvm::GlobalValue *GV) { 727 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 728 // Get the struct elements for these annotations. 729 for (specific_attr_iterator<AnnotateAttr> 730 ai = D->specific_attr_begin<AnnotateAttr>(), 731 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) 732 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); 733} 734 735bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 736 // Never defer when EmitAllDecls is specified. 737 if (Features.EmitAllDecls) 738 return false; 739 740 return !getContext().DeclMustBeEmitted(Global); 741} 742 743llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 744 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 745 assert(AA && "No alias?"); 746 747 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 748 749 // See if there is already something with the target's name in the module. 750 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 751 752 llvm::Constant *Aliasee; 753 if (isa<llvm::FunctionType>(DeclTy)) 754 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 755 /*ForVTable=*/false); 756 else 757 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 758 llvm::PointerType::getUnqual(DeclTy), 0); 759 if (!Entry) { 760 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 761 F->setLinkage(llvm::Function::ExternalWeakLinkage); 762 WeakRefReferences.insert(F); 763 } 764 765 return Aliasee; 766} 767 768void CodeGenModule::EmitGlobal(GlobalDecl GD) { 769 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 770 771 // Weak references don't produce any output by themselves. 772 if (Global->hasAttr<WeakRefAttr>()) 773 return; 774 775 // If this is an alias definition (which otherwise looks like a declaration) 776 // emit it now. 777 if (Global->hasAttr<AliasAttr>()) 778 return EmitAliasDefinition(GD); 779 780 // Ignore declarations, they will be emitted on their first use. 781 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 782 // Forward declarations are emitted lazily on first use. 783 if (!FD->doesThisDeclarationHaveABody()) { 784 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 785 return; 786 787 const FunctionDecl *InlineDefinition = 0; 788 FD->getBody(InlineDefinition); 789 790 StringRef MangledName = getMangledName(GD); 791 llvm::StringMap<GlobalDecl>::iterator DDI = 792 DeferredDecls.find(MangledName); 793 if (DDI != DeferredDecls.end()) 794 DeferredDecls.erase(DDI); 795 EmitGlobalDefinition(InlineDefinition); 796 return; 797 } 798 } else { 799 const VarDecl *VD = cast<VarDecl>(Global); 800 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 801 802 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 803 return; 804 } 805 806 // Defer code generation when possible if this is a static definition, inline 807 // function etc. These we only want to emit if they are used. 808 if (!MayDeferGeneration(Global)) { 809 // Emit the definition if it can't be deferred. 810 EmitGlobalDefinition(GD); 811 return; 812 } 813 814 // If we're deferring emission of a C++ variable with an 815 // initializer, remember the order in which it appeared in the file. 816 if (getLangOptions().CPlusPlus && isa<VarDecl>(Global) && 817 cast<VarDecl>(Global)->hasInit()) { 818 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 819 CXXGlobalInits.push_back(0); 820 } 821 822 // If the value has already been used, add it directly to the 823 // DeferredDeclsToEmit list. 824 StringRef MangledName = getMangledName(GD); 825 if (GetGlobalValue(MangledName)) 826 DeferredDeclsToEmit.push_back(GD); 827 else { 828 // Otherwise, remember that we saw a deferred decl with this name. The 829 // first use of the mangled name will cause it to move into 830 // DeferredDeclsToEmit. 831 DeferredDecls[MangledName] = GD; 832 } 833} 834 835void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 836 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 837 838 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 839 Context.getSourceManager(), 840 "Generating code for declaration"); 841 842 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 843 // At -O0, don't generate IR for functions with available_externally 844 // linkage. 845 if (CodeGenOpts.OptimizationLevel == 0 && 846 !Function->hasAttr<AlwaysInlineAttr>() && 847 getFunctionLinkage(Function) 848 == llvm::Function::AvailableExternallyLinkage) 849 return; 850 851 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 852 // Make sure to emit the definition(s) before we emit the thunks. 853 // This is necessary for the generation of certain thunks. 854 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 855 EmitCXXConstructor(CD, GD.getCtorType()); 856 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 857 EmitCXXDestructor(DD, GD.getDtorType()); 858 else 859 EmitGlobalFunctionDefinition(GD); 860 861 if (Method->isVirtual()) 862 getVTables().EmitThunks(GD); 863 864 return; 865 } 866 867 return EmitGlobalFunctionDefinition(GD); 868 } 869 870 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 871 return EmitGlobalVarDefinition(VD); 872 873 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 874} 875 876/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 877/// module, create and return an llvm Function with the specified type. If there 878/// is something in the module with the specified name, return it potentially 879/// bitcasted to the right type. 880/// 881/// If D is non-null, it specifies a decl that correspond to this. This is used 882/// to set the attributes on the function when it is first created. 883llvm::Constant * 884CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 885 llvm::Type *Ty, 886 GlobalDecl D, bool ForVTable, 887 llvm::Attributes ExtraAttrs) { 888 // Lookup the entry, lazily creating it if necessary. 889 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 890 if (Entry) { 891 if (WeakRefReferences.count(Entry)) { 892 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 893 if (FD && !FD->hasAttr<WeakAttr>()) 894 Entry->setLinkage(llvm::Function::ExternalLinkage); 895 896 WeakRefReferences.erase(Entry); 897 } 898 899 if (Entry->getType()->getElementType() == Ty) 900 return Entry; 901 902 // Make sure the result is of the correct type. 903 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 904 } 905 906 // This function doesn't have a complete type (for example, the return 907 // type is an incomplete struct). Use a fake type instead, and make 908 // sure not to try to set attributes. 909 bool IsIncompleteFunction = false; 910 911 llvm::FunctionType *FTy; 912 if (isa<llvm::FunctionType>(Ty)) { 913 FTy = cast<llvm::FunctionType>(Ty); 914 } else { 915 FTy = llvm::FunctionType::get(VoidTy, false); 916 IsIncompleteFunction = true; 917 } 918 919 llvm::Function *F = llvm::Function::Create(FTy, 920 llvm::Function::ExternalLinkage, 921 MangledName, &getModule()); 922 assert(F->getName() == MangledName && "name was uniqued!"); 923 if (D.getDecl()) 924 SetFunctionAttributes(D, F, IsIncompleteFunction); 925 if (ExtraAttrs != llvm::Attribute::None) 926 F->addFnAttr(ExtraAttrs); 927 928 // This is the first use or definition of a mangled name. If there is a 929 // deferred decl with this name, remember that we need to emit it at the end 930 // of the file. 931 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 932 if (DDI != DeferredDecls.end()) { 933 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 934 // list, and remove it from DeferredDecls (since we don't need it anymore). 935 DeferredDeclsToEmit.push_back(DDI->second); 936 DeferredDecls.erase(DDI); 937 938 // Otherwise, there are cases we have to worry about where we're 939 // using a declaration for which we must emit a definition but where 940 // we might not find a top-level definition: 941 // - member functions defined inline in their classes 942 // - friend functions defined inline in some class 943 // - special member functions with implicit definitions 944 // If we ever change our AST traversal to walk into class methods, 945 // this will be unnecessary. 946 // 947 // We also don't emit a definition for a function if it's going to be an entry 948 // in a vtable, unless it's already marked as used. 949 } else if (getLangOptions().CPlusPlus && D.getDecl()) { 950 // Look for a declaration that's lexically in a record. 951 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); 952 do { 953 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 954 if (FD->isImplicit() && !ForVTable) { 955 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 956 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 957 break; 958 } else if (FD->doesThisDeclarationHaveABody()) { 959 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 960 break; 961 } 962 } 963 FD = FD->getPreviousDeclaration(); 964 } while (FD); 965 } 966 967 // Make sure the result is of the requested type. 968 if (!IsIncompleteFunction) { 969 assert(F->getType()->getElementType() == Ty); 970 return F; 971 } 972 973 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 974 return llvm::ConstantExpr::getBitCast(F, PTy); 975} 976 977/// GetAddrOfFunction - Return the address of the given function. If Ty is 978/// non-null, then this function will use the specified type if it has to 979/// create it (this occurs when we see a definition of the function). 980llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 981 llvm::Type *Ty, 982 bool ForVTable) { 983 // If there was no specific requested type, just convert it now. 984 if (!Ty) 985 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 986 987 StringRef MangledName = getMangledName(GD); 988 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 989} 990 991/// CreateRuntimeFunction - Create a new runtime function with the specified 992/// type and name. 993llvm::Constant * 994CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 995 StringRef Name, 996 llvm::Attributes ExtraAttrs) { 997 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 998 ExtraAttrs); 999} 1000 1001static bool DeclIsConstantGlobal(ASTContext &Context, const VarDecl *D, 1002 bool ConstantInit) { 1003 if (!D->getType().isConstant(Context) && !D->getType()->isReferenceType()) 1004 return false; 1005 1006 if (Context.getLangOptions().CPlusPlus) { 1007 if (const RecordType *Record 1008 = Context.getBaseElementType(D->getType())->getAs<RecordType>()) 1009 return ConstantInit && 1010 cast<CXXRecordDecl>(Record->getDecl())->isPOD() && 1011 !cast<CXXRecordDecl>(Record->getDecl())->hasMutableFields(); 1012 } 1013 1014 return true; 1015} 1016 1017/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1018/// create and return an llvm GlobalVariable with the specified type. If there 1019/// is something in the module with the specified name, return it potentially 1020/// bitcasted to the right type. 1021/// 1022/// If D is non-null, it specifies a decl that correspond to this. This is used 1023/// to set the attributes on the global when it is first created. 1024llvm::Constant * 1025CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1026 llvm::PointerType *Ty, 1027 const VarDecl *D, 1028 bool UnnamedAddr) { 1029 // Lookup the entry, lazily creating it if necessary. 1030 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1031 if (Entry) { 1032 if (WeakRefReferences.count(Entry)) { 1033 if (D && !D->hasAttr<WeakAttr>()) 1034 Entry->setLinkage(llvm::Function::ExternalLinkage); 1035 1036 WeakRefReferences.erase(Entry); 1037 } 1038 1039 if (UnnamedAddr) 1040 Entry->setUnnamedAddr(true); 1041 1042 if (Entry->getType() == Ty) 1043 return Entry; 1044 1045 // Make sure the result is of the correct type. 1046 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1047 } 1048 1049 // This is the first use or definition of a mangled name. If there is a 1050 // deferred decl with this name, remember that we need to emit it at the end 1051 // of the file. 1052 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1053 if (DDI != DeferredDecls.end()) { 1054 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1055 // list, and remove it from DeferredDecls (since we don't need it anymore). 1056 DeferredDeclsToEmit.push_back(DDI->second); 1057 DeferredDecls.erase(DDI); 1058 } 1059 1060 llvm::GlobalVariable *GV = 1061 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1062 llvm::GlobalValue::ExternalLinkage, 1063 0, MangledName, 0, 1064 false, Ty->getAddressSpace()); 1065 1066 // Handle things which are present even on external declarations. 1067 if (D) { 1068 // FIXME: This code is overly simple and should be merged with other global 1069 // handling. 1070 GV->setConstant(DeclIsConstantGlobal(Context, D, false)); 1071 1072 // Set linkage and visibility in case we never see a definition. 1073 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 1074 if (LV.linkage() != ExternalLinkage) { 1075 // Don't set internal linkage on declarations. 1076 } else { 1077 if (D->hasAttr<DLLImportAttr>()) 1078 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1079 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1080 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1081 1082 // Set visibility on a declaration only if it's explicit. 1083 if (LV.visibilityExplicit()) 1084 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 1085 } 1086 1087 GV->setThreadLocal(D->isThreadSpecified()); 1088 } 1089 1090 return GV; 1091} 1092 1093 1094llvm::GlobalVariable * 1095CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1096 llvm::Type *Ty, 1097 llvm::GlobalValue::LinkageTypes Linkage) { 1098 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1099 llvm::GlobalVariable *OldGV = 0; 1100 1101 1102 if (GV) { 1103 // Check if the variable has the right type. 1104 if (GV->getType()->getElementType() == Ty) 1105 return GV; 1106 1107 // Because C++ name mangling, the only way we can end up with an already 1108 // existing global with the same name is if it has been declared extern "C". 1109 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1110 OldGV = GV; 1111 } 1112 1113 // Create a new variable. 1114 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1115 Linkage, 0, Name); 1116 1117 if (OldGV) { 1118 // Replace occurrences of the old variable if needed. 1119 GV->takeName(OldGV); 1120 1121 if (!OldGV->use_empty()) { 1122 llvm::Constant *NewPtrForOldDecl = 1123 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1124 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1125 } 1126 1127 OldGV->eraseFromParent(); 1128 } 1129 1130 return GV; 1131} 1132 1133/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1134/// given global variable. If Ty is non-null and if the global doesn't exist, 1135/// then it will be greated with the specified type instead of whatever the 1136/// normal requested type would be. 1137llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1138 llvm::Type *Ty) { 1139 assert(D->hasGlobalStorage() && "Not a global variable"); 1140 QualType ASTTy = D->getType(); 1141 if (Ty == 0) 1142 Ty = getTypes().ConvertTypeForMem(ASTTy); 1143 1144 llvm::PointerType *PTy = 1145 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1146 1147 StringRef MangledName = getMangledName(D); 1148 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1149} 1150 1151/// CreateRuntimeVariable - Create a new runtime global variable with the 1152/// specified type and name. 1153llvm::Constant * 1154CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1155 StringRef Name) { 1156 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1157 true); 1158} 1159 1160void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1161 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1162 1163 if (MayDeferGeneration(D)) { 1164 // If we have not seen a reference to this variable yet, place it 1165 // into the deferred declarations table to be emitted if needed 1166 // later. 1167 StringRef MangledName = getMangledName(D); 1168 if (!GetGlobalValue(MangledName)) { 1169 DeferredDecls[MangledName] = D; 1170 return; 1171 } 1172 } 1173 1174 // The tentative definition is the only definition. 1175 EmitGlobalVarDefinition(D); 1176} 1177 1178void CodeGenModule::EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired) { 1179 if (DefinitionRequired) 1180 getVTables().GenerateClassData(getVTableLinkage(Class), Class); 1181} 1182 1183llvm::GlobalVariable::LinkageTypes 1184CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) { 1185 if (RD->getLinkage() != ExternalLinkage) 1186 return llvm::GlobalVariable::InternalLinkage; 1187 1188 if (const CXXMethodDecl *KeyFunction 1189 = RD->getASTContext().getKeyFunction(RD)) { 1190 // If this class has a key function, use that to determine the linkage of 1191 // the vtable. 1192 const FunctionDecl *Def = 0; 1193 if (KeyFunction->hasBody(Def)) 1194 KeyFunction = cast<CXXMethodDecl>(Def); 1195 1196 switch (KeyFunction->getTemplateSpecializationKind()) { 1197 case TSK_Undeclared: 1198 case TSK_ExplicitSpecialization: 1199 // When compiling with optimizations turned on, we emit all vtables, 1200 // even if the key function is not defined in the current translation 1201 // unit. If this is the case, use available_externally linkage. 1202 if (!Def && CodeGenOpts.OptimizationLevel) 1203 return llvm::GlobalVariable::AvailableExternallyLinkage; 1204 1205 if (KeyFunction->isInlined()) 1206 return !Context.getLangOptions().AppleKext ? 1207 llvm::GlobalVariable::LinkOnceODRLinkage : 1208 llvm::Function::InternalLinkage; 1209 1210 return llvm::GlobalVariable::ExternalLinkage; 1211 1212 case TSK_ImplicitInstantiation: 1213 return !Context.getLangOptions().AppleKext ? 1214 llvm::GlobalVariable::LinkOnceODRLinkage : 1215 llvm::Function::InternalLinkage; 1216 1217 case TSK_ExplicitInstantiationDefinition: 1218 return !Context.getLangOptions().AppleKext ? 1219 llvm::GlobalVariable::WeakODRLinkage : 1220 llvm::Function::InternalLinkage; 1221 1222 case TSK_ExplicitInstantiationDeclaration: 1223 // FIXME: Use available_externally linkage. However, this currently 1224 // breaks LLVM's build due to undefined symbols. 1225 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1226 return !Context.getLangOptions().AppleKext ? 1227 llvm::GlobalVariable::LinkOnceODRLinkage : 1228 llvm::Function::InternalLinkage; 1229 } 1230 } 1231 1232 if (Context.getLangOptions().AppleKext) 1233 return llvm::Function::InternalLinkage; 1234 1235 switch (RD->getTemplateSpecializationKind()) { 1236 case TSK_Undeclared: 1237 case TSK_ExplicitSpecialization: 1238 case TSK_ImplicitInstantiation: 1239 // FIXME: Use available_externally linkage. However, this currently 1240 // breaks LLVM's build due to undefined symbols. 1241 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1242 case TSK_ExplicitInstantiationDeclaration: 1243 return llvm::GlobalVariable::LinkOnceODRLinkage; 1244 1245 case TSK_ExplicitInstantiationDefinition: 1246 return llvm::GlobalVariable::WeakODRLinkage; 1247 } 1248 1249 // Silence GCC warning. 1250 return llvm::GlobalVariable::LinkOnceODRLinkage; 1251} 1252 1253CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1254 return Context.toCharUnitsFromBits( 1255 TheTargetData.getTypeStoreSizeInBits(Ty)); 1256} 1257 1258void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1259 llvm::Constant *Init = 0; 1260 QualType ASTTy = D->getType(); 1261 bool NonConstInit = false; 1262 1263 const Expr *InitExpr = D->getAnyInitializer(); 1264 1265 if (!InitExpr) { 1266 // This is a tentative definition; tentative definitions are 1267 // implicitly initialized with { 0 }. 1268 // 1269 // Note that tentative definitions are only emitted at the end of 1270 // a translation unit, so they should never have incomplete 1271 // type. In addition, EmitTentativeDefinition makes sure that we 1272 // never attempt to emit a tentative definition if a real one 1273 // exists. A use may still exists, however, so we still may need 1274 // to do a RAUW. 1275 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1276 Init = EmitNullConstant(D->getType()); 1277 } else { 1278 Init = EmitConstantExpr(InitExpr, D->getType()); 1279 if (!Init) { 1280 QualType T = InitExpr->getType(); 1281 if (D->getType()->isReferenceType()) 1282 T = D->getType(); 1283 1284 if (getLangOptions().CPlusPlus) { 1285 Init = EmitNullConstant(T); 1286 NonConstInit = true; 1287 } else { 1288 ErrorUnsupported(D, "static initializer"); 1289 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1290 } 1291 } else { 1292 // We don't need an initializer, so remove the entry for the delayed 1293 // initializer position (just in case this entry was delayed). 1294 if (getLangOptions().CPlusPlus) 1295 DelayedCXXInitPosition.erase(D); 1296 } 1297 } 1298 1299 llvm::Type* InitType = Init->getType(); 1300 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1301 1302 // Strip off a bitcast if we got one back. 1303 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1304 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1305 // all zero index gep. 1306 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1307 Entry = CE->getOperand(0); 1308 } 1309 1310 // Entry is now either a Function or GlobalVariable. 1311 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1312 1313 // We have a definition after a declaration with the wrong type. 1314 // We must make a new GlobalVariable* and update everything that used OldGV 1315 // (a declaration or tentative definition) with the new GlobalVariable* 1316 // (which will be a definition). 1317 // 1318 // This happens if there is a prototype for a global (e.g. 1319 // "extern int x[];") and then a definition of a different type (e.g. 1320 // "int x[10];"). This also happens when an initializer has a different type 1321 // from the type of the global (this happens with unions). 1322 if (GV == 0 || 1323 GV->getType()->getElementType() != InitType || 1324 GV->getType()->getAddressSpace() != 1325 getContext().getTargetAddressSpace(ASTTy)) { 1326 1327 // Move the old entry aside so that we'll create a new one. 1328 Entry->setName(StringRef()); 1329 1330 // Make a new global with the correct type, this is now guaranteed to work. 1331 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1332 1333 // Replace all uses of the old global with the new global 1334 llvm::Constant *NewPtrForOldDecl = 1335 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1336 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1337 1338 // Erase the old global, since it is no longer used. 1339 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1340 } 1341 1342 if (D->hasAttr<AnnotateAttr>()) 1343 AddGlobalAnnotations(D, GV); 1344 1345 GV->setInitializer(Init); 1346 1347 // If it is safe to mark the global 'constant', do so now. 1348 GV->setConstant(false); 1349 if (!NonConstInit && DeclIsConstantGlobal(Context, D, true)) 1350 GV->setConstant(true); 1351 1352 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1353 1354 // Set the llvm linkage type as appropriate. 1355 llvm::GlobalValue::LinkageTypes Linkage = 1356 GetLLVMLinkageVarDefinition(D, GV); 1357 GV->setLinkage(Linkage); 1358 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1359 // common vars aren't constant even if declared const. 1360 GV->setConstant(false); 1361 1362 SetCommonAttributes(D, GV); 1363 1364 // Emit the initializer function if necessary. 1365 if (NonConstInit) 1366 EmitCXXGlobalVarDeclInitFunc(D, GV); 1367 1368 // Emit global variable debug information. 1369 if (CGDebugInfo *DI = getModuleDebugInfo()) { 1370 DI->setLocation(D->getLocation()); 1371 DI->EmitGlobalVariable(GV, D); 1372 } 1373} 1374 1375llvm::GlobalValue::LinkageTypes 1376CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, 1377 llvm::GlobalVariable *GV) { 1378 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1379 if (Linkage == GVA_Internal) 1380 return llvm::Function::InternalLinkage; 1381 else if (D->hasAttr<DLLImportAttr>()) 1382 return llvm::Function::DLLImportLinkage; 1383 else if (D->hasAttr<DLLExportAttr>()) 1384 return llvm::Function::DLLExportLinkage; 1385 else if (D->hasAttr<WeakAttr>()) { 1386 if (GV->isConstant()) 1387 return llvm::GlobalVariable::WeakODRLinkage; 1388 else 1389 return llvm::GlobalVariable::WeakAnyLinkage; 1390 } else if (Linkage == GVA_TemplateInstantiation || 1391 Linkage == GVA_ExplicitTemplateInstantiation) 1392 return llvm::GlobalVariable::WeakODRLinkage; 1393 else if (!getLangOptions().CPlusPlus && 1394 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1395 D->getAttr<CommonAttr>()) && 1396 !D->hasExternalStorage() && !D->getInit() && 1397 !D->getAttr<SectionAttr>() && !D->isThreadSpecified() && 1398 !D->getAttr<WeakImportAttr>()) { 1399 // Thread local vars aren't considered common linkage. 1400 return llvm::GlobalVariable::CommonLinkage; 1401 } 1402 return llvm::GlobalVariable::ExternalLinkage; 1403} 1404 1405/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1406/// implement a function with no prototype, e.g. "int foo() {}". If there are 1407/// existing call uses of the old function in the module, this adjusts them to 1408/// call the new function directly. 1409/// 1410/// This is not just a cleanup: the always_inline pass requires direct calls to 1411/// functions to be able to inline them. If there is a bitcast in the way, it 1412/// won't inline them. Instcombine normally deletes these calls, but it isn't 1413/// run at -O0. 1414static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1415 llvm::Function *NewFn) { 1416 // If we're redefining a global as a function, don't transform it. 1417 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1418 if (OldFn == 0) return; 1419 1420 llvm::Type *NewRetTy = NewFn->getReturnType(); 1421 SmallVector<llvm::Value*, 4> ArgList; 1422 1423 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1424 UI != E; ) { 1425 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1426 llvm::Value::use_iterator I = UI++; // Increment before the CI is erased. 1427 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*I); 1428 if (!CI) continue; // FIXME: when we allow Invoke, just do CallSite CS(*I) 1429 llvm::CallSite CS(CI); 1430 if (!CI || !CS.isCallee(I)) continue; 1431 1432 // If the return types don't match exactly, and if the call isn't dead, then 1433 // we can't transform this call. 1434 if (CI->getType() != NewRetTy && !CI->use_empty()) 1435 continue; 1436 1437 // Get the attribute list. 1438 llvm::SmallVector<llvm::AttributeWithIndex, 8> AttrVec; 1439 llvm::AttrListPtr AttrList = CI->getAttributes(); 1440 1441 // Get any return attributes. 1442 llvm::Attributes RAttrs = AttrList.getRetAttributes(); 1443 1444 // Add the return attributes. 1445 if (RAttrs) 1446 AttrVec.push_back(llvm::AttributeWithIndex::get(0, RAttrs)); 1447 1448 // If the function was passed too few arguments, don't transform. If extra 1449 // arguments were passed, we silently drop them. If any of the types 1450 // mismatch, we don't transform. 1451 unsigned ArgNo = 0; 1452 bool DontTransform = false; 1453 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1454 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1455 if (CS.arg_size() == ArgNo || 1456 CS.getArgument(ArgNo)->getType() != AI->getType()) { 1457 DontTransform = true; 1458 break; 1459 } 1460 1461 // Add any parameter attributes. 1462 if (llvm::Attributes PAttrs = AttrList.getParamAttributes(ArgNo + 1)) 1463 AttrVec.push_back(llvm::AttributeWithIndex::get(ArgNo + 1, PAttrs)); 1464 } 1465 if (DontTransform) 1466 continue; 1467 1468 if (llvm::Attributes FnAttrs = AttrList.getFnAttributes()) 1469 AttrVec.push_back(llvm::AttributeWithIndex::get(~0, FnAttrs)); 1470 1471 // Okay, we can transform this. Create the new call instruction and copy 1472 // over the required information. 1473 ArgList.append(CS.arg_begin(), CS.arg_begin() + ArgNo); 1474 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList, "", CI); 1475 ArgList.clear(); 1476 if (!NewCall->getType()->isVoidTy()) 1477 NewCall->takeName(CI); 1478 NewCall->setAttributes(llvm::AttrListPtr::get(AttrVec.begin(), 1479 AttrVec.end())); 1480 NewCall->setCallingConv(CI->getCallingConv()); 1481 1482 // Finally, remove the old call, replacing any uses with the new one. 1483 if (!CI->use_empty()) 1484 CI->replaceAllUsesWith(NewCall); 1485 1486 // Copy debug location attached to CI. 1487 if (!CI->getDebugLoc().isUnknown()) 1488 NewCall->setDebugLoc(CI->getDebugLoc()); 1489 CI->eraseFromParent(); 1490 } 1491} 1492 1493 1494void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1495 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1496 1497 // Compute the function info and LLVM type. 1498 const CGFunctionInfo &FI = getTypes().getFunctionInfo(GD); 1499 bool variadic = false; 1500 if (const FunctionProtoType *fpt = D->getType()->getAs<FunctionProtoType>()) 1501 variadic = fpt->isVariadic(); 1502 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI, variadic); 1503 1504 // Get or create the prototype for the function. 1505 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1506 1507 // Strip off a bitcast if we got one back. 1508 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1509 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1510 Entry = CE->getOperand(0); 1511 } 1512 1513 1514 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1515 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1516 1517 // If the types mismatch then we have to rewrite the definition. 1518 assert(OldFn->isDeclaration() && 1519 "Shouldn't replace non-declaration"); 1520 1521 // F is the Function* for the one with the wrong type, we must make a new 1522 // Function* and update everything that used F (a declaration) with the new 1523 // Function* (which will be a definition). 1524 // 1525 // This happens if there is a prototype for a function 1526 // (e.g. "int f()") and then a definition of a different type 1527 // (e.g. "int f(int x)"). Move the old function aside so that it 1528 // doesn't interfere with GetAddrOfFunction. 1529 OldFn->setName(StringRef()); 1530 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1531 1532 // If this is an implementation of a function without a prototype, try to 1533 // replace any existing uses of the function (which may be calls) with uses 1534 // of the new function 1535 if (D->getType()->isFunctionNoProtoType()) { 1536 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1537 OldFn->removeDeadConstantUsers(); 1538 } 1539 1540 // Replace uses of F with the Function we will endow with a body. 1541 if (!Entry->use_empty()) { 1542 llvm::Constant *NewPtrForOldDecl = 1543 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1544 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1545 } 1546 1547 // Ok, delete the old function now, which is dead. 1548 OldFn->eraseFromParent(); 1549 1550 Entry = NewFn; 1551 } 1552 1553 // We need to set linkage and visibility on the function before 1554 // generating code for it because various parts of IR generation 1555 // want to propagate this information down (e.g. to local static 1556 // declarations). 1557 llvm::Function *Fn = cast<llvm::Function>(Entry); 1558 setFunctionLinkage(D, Fn); 1559 1560 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 1561 setGlobalVisibility(Fn, D); 1562 1563 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 1564 1565 SetFunctionDefinitionAttributes(D, Fn); 1566 SetLLVMFunctionAttributesForDefinition(D, Fn); 1567 1568 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1569 AddGlobalCtor(Fn, CA->getPriority()); 1570 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1571 AddGlobalDtor(Fn, DA->getPriority()); 1572 if (D->hasAttr<AnnotateAttr>()) 1573 AddGlobalAnnotations(D, Fn); 1574} 1575 1576void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 1577 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1578 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1579 assert(AA && "Not an alias?"); 1580 1581 StringRef MangledName = getMangledName(GD); 1582 1583 // If there is a definition in the module, then it wins over the alias. 1584 // This is dubious, but allow it to be safe. Just ignore the alias. 1585 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1586 if (Entry && !Entry->isDeclaration()) 1587 return; 1588 1589 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1590 1591 // Create a reference to the named value. This ensures that it is emitted 1592 // if a deferred decl. 1593 llvm::Constant *Aliasee; 1594 if (isa<llvm::FunctionType>(DeclTy)) 1595 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 1596 /*ForVTable=*/false); 1597 else 1598 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1599 llvm::PointerType::getUnqual(DeclTy), 0); 1600 1601 // Create the new alias itself, but don't set a name yet. 1602 llvm::GlobalValue *GA = 1603 new llvm::GlobalAlias(Aliasee->getType(), 1604 llvm::Function::ExternalLinkage, 1605 "", Aliasee, &getModule()); 1606 1607 if (Entry) { 1608 assert(Entry->isDeclaration()); 1609 1610 // If there is a declaration in the module, then we had an extern followed 1611 // by the alias, as in: 1612 // extern int test6(); 1613 // ... 1614 // int test6() __attribute__((alias("test7"))); 1615 // 1616 // Remove it and replace uses of it with the alias. 1617 GA->takeName(Entry); 1618 1619 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1620 Entry->getType())); 1621 Entry->eraseFromParent(); 1622 } else { 1623 GA->setName(MangledName); 1624 } 1625 1626 // Set attributes which are particular to an alias; this is a 1627 // specialization of the attributes which may be set on a global 1628 // variable/function. 1629 if (D->hasAttr<DLLExportAttr>()) { 1630 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1631 // The dllexport attribute is ignored for undefined symbols. 1632 if (FD->hasBody()) 1633 GA->setLinkage(llvm::Function::DLLExportLinkage); 1634 } else { 1635 GA->setLinkage(llvm::Function::DLLExportLinkage); 1636 } 1637 } else if (D->hasAttr<WeakAttr>() || 1638 D->hasAttr<WeakRefAttr>() || 1639 D->isWeakImported()) { 1640 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1641 } 1642 1643 SetCommonAttributes(D, GA); 1644} 1645 1646llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 1647 ArrayRef<llvm::Type*> Tys) { 1648 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 1649 Tys); 1650} 1651 1652static llvm::StringMapEntry<llvm::Constant*> & 1653GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1654 const StringLiteral *Literal, 1655 bool TargetIsLSB, 1656 bool &IsUTF16, 1657 unsigned &StringLength) { 1658 StringRef String = Literal->getString(); 1659 unsigned NumBytes = String.size(); 1660 1661 // Check for simple case. 1662 if (!Literal->containsNonAsciiOrNull()) { 1663 StringLength = NumBytes; 1664 return Map.GetOrCreateValue(String); 1665 } 1666 1667 // Otherwise, convert the UTF8 literals into a byte string. 1668 SmallVector<UTF16, 128> ToBuf(NumBytes); 1669 const UTF8 *FromPtr = (UTF8 *)String.data(); 1670 UTF16 *ToPtr = &ToBuf[0]; 1671 1672 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 1673 &ToPtr, ToPtr + NumBytes, 1674 strictConversion); 1675 1676 // ConvertUTF8toUTF16 returns the length in ToPtr. 1677 StringLength = ToPtr - &ToBuf[0]; 1678 1679 // Render the UTF-16 string into a byte array and convert to the target byte 1680 // order. 1681 // 1682 // FIXME: This isn't something we should need to do here. 1683 llvm::SmallString<128> AsBytes; 1684 AsBytes.reserve(StringLength * 2); 1685 for (unsigned i = 0; i != StringLength; ++i) { 1686 unsigned short Val = ToBuf[i]; 1687 if (TargetIsLSB) { 1688 AsBytes.push_back(Val & 0xFF); 1689 AsBytes.push_back(Val >> 8); 1690 } else { 1691 AsBytes.push_back(Val >> 8); 1692 AsBytes.push_back(Val & 0xFF); 1693 } 1694 } 1695 // Append one extra null character, the second is automatically added by our 1696 // caller. 1697 AsBytes.push_back(0); 1698 1699 IsUTF16 = true; 1700 return Map.GetOrCreateValue(StringRef(AsBytes.data(), AsBytes.size())); 1701} 1702 1703static llvm::StringMapEntry<llvm::Constant*> & 1704GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1705 const StringLiteral *Literal, 1706 unsigned &StringLength) 1707{ 1708 StringRef String = Literal->getString(); 1709 StringLength = String.size(); 1710 return Map.GetOrCreateValue(String); 1711} 1712 1713llvm::Constant * 1714CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 1715 unsigned StringLength = 0; 1716 bool isUTF16 = false; 1717 llvm::StringMapEntry<llvm::Constant*> &Entry = 1718 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1719 getTargetData().isLittleEndian(), 1720 isUTF16, StringLength); 1721 1722 if (llvm::Constant *C = Entry.getValue()) 1723 return C; 1724 1725 llvm::Constant *Zero = 1726 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1727 llvm::Constant *Zeros[] = { Zero, Zero }; 1728 1729 // If we don't already have it, get __CFConstantStringClassReference. 1730 if (!CFConstantStringClassRef) { 1731 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1732 Ty = llvm::ArrayType::get(Ty, 0); 1733 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1734 "__CFConstantStringClassReference"); 1735 // Decay array -> ptr 1736 CFConstantStringClassRef = 1737 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1738 } 1739 1740 QualType CFTy = getContext().getCFConstantStringType(); 1741 1742 llvm::StructType *STy = 1743 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1744 1745 std::vector<llvm::Constant*> Fields(4); 1746 1747 // Class pointer. 1748 Fields[0] = CFConstantStringClassRef; 1749 1750 // Flags. 1751 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1752 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 1753 llvm::ConstantInt::get(Ty, 0x07C8); 1754 1755 // String pointer. 1756 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1757 1758 llvm::GlobalValue::LinkageTypes Linkage; 1759 bool isConstant; 1760 if (isUTF16) { 1761 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1762 Linkage = llvm::GlobalValue::InternalLinkage; 1763 // Note: -fwritable-strings doesn't make unicode CFStrings writable, but 1764 // does make plain ascii ones writable. 1765 isConstant = true; 1766 } else { 1767 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 1768 // when using private linkage. It is not clear if this is a bug in ld 1769 // or a reasonable new restriction. 1770 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 1771 isConstant = !Features.WritableStrings; 1772 } 1773 1774 llvm::GlobalVariable *GV = 1775 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1776 ".str"); 1777 GV->setUnnamedAddr(true); 1778 if (isUTF16) { 1779 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 1780 GV->setAlignment(Align.getQuantity()); 1781 } else { 1782 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 1783 GV->setAlignment(Align.getQuantity()); 1784 } 1785 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1786 1787 // String length. 1788 Ty = getTypes().ConvertType(getContext().LongTy); 1789 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 1790 1791 // The struct. 1792 C = llvm::ConstantStruct::get(STy, Fields); 1793 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1794 llvm::GlobalVariable::PrivateLinkage, C, 1795 "_unnamed_cfstring_"); 1796 if (const char *Sect = getContext().getTargetInfo().getCFStringSection()) 1797 GV->setSection(Sect); 1798 Entry.setValue(GV); 1799 1800 return GV; 1801} 1802 1803static RecordDecl * 1804CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 1805 DeclContext *DC, IdentifierInfo *Id) { 1806 SourceLocation Loc; 1807 if (Ctx.getLangOptions().CPlusPlus) 1808 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 1809 else 1810 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 1811} 1812 1813llvm::Constant * 1814CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 1815 unsigned StringLength = 0; 1816 llvm::StringMapEntry<llvm::Constant*> &Entry = 1817 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 1818 1819 if (llvm::Constant *C = Entry.getValue()) 1820 return C; 1821 1822 llvm::Constant *Zero = 1823 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1824 llvm::Constant *Zeros[] = { Zero, Zero }; 1825 1826 // If we don't already have it, get _NSConstantStringClassReference. 1827 if (!ConstantStringClassRef) { 1828 std::string StringClass(getLangOptions().ObjCConstantStringClass); 1829 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1830 llvm::Constant *GV; 1831 if (Features.ObjCNonFragileABI) { 1832 std::string str = 1833 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 1834 : "OBJC_CLASS_$_" + StringClass; 1835 GV = getObjCRuntime().GetClassGlobal(str); 1836 // Make sure the result is of the correct type. 1837 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1838 ConstantStringClassRef = 1839 llvm::ConstantExpr::getBitCast(GV, PTy); 1840 } else { 1841 std::string str = 1842 StringClass.empty() ? "_NSConstantStringClassReference" 1843 : "_" + StringClass + "ClassReference"; 1844 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 1845 GV = CreateRuntimeVariable(PTy, str); 1846 // Decay array -> ptr 1847 ConstantStringClassRef = 1848 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1849 } 1850 } 1851 1852 if (!NSConstantStringType) { 1853 // Construct the type for a constant NSString. 1854 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 1855 Context.getTranslationUnitDecl(), 1856 &Context.Idents.get("__builtin_NSString")); 1857 D->startDefinition(); 1858 1859 QualType FieldTypes[3]; 1860 1861 // const int *isa; 1862 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 1863 // const char *str; 1864 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 1865 // unsigned int length; 1866 FieldTypes[2] = Context.UnsignedIntTy; 1867 1868 // Create fields 1869 for (unsigned i = 0; i < 3; ++i) { 1870 FieldDecl *Field = FieldDecl::Create(Context, D, 1871 SourceLocation(), 1872 SourceLocation(), 0, 1873 FieldTypes[i], /*TInfo=*/0, 1874 /*BitWidth=*/0, 1875 /*Mutable=*/false, 1876 /*HasInit=*/false); 1877 Field->setAccess(AS_public); 1878 D->addDecl(Field); 1879 } 1880 1881 D->completeDefinition(); 1882 QualType NSTy = Context.getTagDeclType(D); 1883 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 1884 } 1885 1886 std::vector<llvm::Constant*> Fields(3); 1887 1888 // Class pointer. 1889 Fields[0] = ConstantStringClassRef; 1890 1891 // String pointer. 1892 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1893 1894 llvm::GlobalValue::LinkageTypes Linkage; 1895 bool isConstant; 1896 Linkage = llvm::GlobalValue::PrivateLinkage; 1897 isConstant = !Features.WritableStrings; 1898 1899 llvm::GlobalVariable *GV = 1900 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1901 ".str"); 1902 GV->setUnnamedAddr(true); 1903 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 1904 GV->setAlignment(Align.getQuantity()); 1905 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1906 1907 // String length. 1908 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1909 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 1910 1911 // The struct. 1912 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 1913 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1914 llvm::GlobalVariable::PrivateLinkage, C, 1915 "_unnamed_nsstring_"); 1916 // FIXME. Fix section. 1917 if (const char *Sect = 1918 Features.ObjCNonFragileABI 1919 ? getContext().getTargetInfo().getNSStringNonFragileABISection() 1920 : getContext().getTargetInfo().getNSStringSection()) 1921 GV->setSection(Sect); 1922 Entry.setValue(GV); 1923 1924 return GV; 1925} 1926 1927QualType CodeGenModule::getObjCFastEnumerationStateType() { 1928 if (ObjCFastEnumerationStateType.isNull()) { 1929 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 1930 Context.getTranslationUnitDecl(), 1931 &Context.Idents.get("__objcFastEnumerationState")); 1932 D->startDefinition(); 1933 1934 QualType FieldTypes[] = { 1935 Context.UnsignedLongTy, 1936 Context.getPointerType(Context.getObjCIdType()), 1937 Context.getPointerType(Context.UnsignedLongTy), 1938 Context.getConstantArrayType(Context.UnsignedLongTy, 1939 llvm::APInt(32, 5), ArrayType::Normal, 0) 1940 }; 1941 1942 for (size_t i = 0; i < 4; ++i) { 1943 FieldDecl *Field = FieldDecl::Create(Context, 1944 D, 1945 SourceLocation(), 1946 SourceLocation(), 0, 1947 FieldTypes[i], /*TInfo=*/0, 1948 /*BitWidth=*/0, 1949 /*Mutable=*/false, 1950 /*HasInit=*/false); 1951 Field->setAccess(AS_public); 1952 D->addDecl(Field); 1953 } 1954 1955 D->completeDefinition(); 1956 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 1957 } 1958 1959 return ObjCFastEnumerationStateType; 1960} 1961 1962/// GetStringForStringLiteral - Return the appropriate bytes for a 1963/// string literal, properly padded to match the literal type. 1964std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 1965 const ASTContext &Context = getContext(); 1966 const ConstantArrayType *CAT = 1967 Context.getAsConstantArrayType(E->getType()); 1968 assert(CAT && "String isn't pointer or array!"); 1969 1970 // Resize the string to the right size. 1971 uint64_t RealLen = CAT->getSize().getZExtValue(); 1972 1973 switch (E->getKind()) { 1974 case StringLiteral::Ascii: 1975 case StringLiteral::UTF8: 1976 break; 1977 case StringLiteral::Wide: 1978 RealLen *= Context.getTargetInfo().getWCharWidth() / Context.getCharWidth(); 1979 break; 1980 case StringLiteral::UTF16: 1981 RealLen *= Context.getTargetInfo().getChar16Width() / Context.getCharWidth(); 1982 break; 1983 case StringLiteral::UTF32: 1984 RealLen *= Context.getTargetInfo().getChar32Width() / Context.getCharWidth(); 1985 break; 1986 } 1987 1988 std::string Str = E->getString().str(); 1989 Str.resize(RealLen, '\0'); 1990 1991 return Str; 1992} 1993 1994/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 1995/// constant array for the given string literal. 1996llvm::Constant * 1997CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 1998 // FIXME: This can be more efficient. 1999 // FIXME: We shouldn't need to bitcast the constant in the wide string case. 2000 CharUnits Align = getContext().getTypeAlignInChars(S->getType()); 2001 llvm::Constant *C = GetAddrOfConstantString(GetStringForStringLiteral(S), 2002 /* GlobalName */ 0, 2003 Align.getQuantity()); 2004 if (S->isWide() || S->isUTF16() || S->isUTF32()) { 2005 llvm::Type *DestTy = 2006 llvm::PointerType::getUnqual(getTypes().ConvertType(S->getType())); 2007 C = llvm::ConstantExpr::getBitCast(C, DestTy); 2008 } 2009 return C; 2010} 2011 2012/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2013/// array for the given ObjCEncodeExpr node. 2014llvm::Constant * 2015CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2016 std::string Str; 2017 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2018 2019 return GetAddrOfConstantCString(Str); 2020} 2021 2022 2023/// GenerateWritableString -- Creates storage for a string literal. 2024static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2025 bool constant, 2026 CodeGenModule &CGM, 2027 const char *GlobalName, 2028 unsigned Alignment) { 2029 // Create Constant for this string literal. Don't add a '\0'. 2030 llvm::Constant *C = 2031 llvm::ConstantArray::get(CGM.getLLVMContext(), str, false); 2032 2033 // Create a global variable for this string 2034 llvm::GlobalVariable *GV = 2035 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 2036 llvm::GlobalValue::PrivateLinkage, 2037 C, GlobalName); 2038 GV->setAlignment(Alignment); 2039 GV->setUnnamedAddr(true); 2040 return GV; 2041} 2042 2043/// GetAddrOfConstantString - Returns a pointer to a character array 2044/// containing the literal. This contents are exactly that of the 2045/// given string, i.e. it will not be null terminated automatically; 2046/// see GetAddrOfConstantCString. Note that whether the result is 2047/// actually a pointer to an LLVM constant depends on 2048/// Feature.WriteableStrings. 2049/// 2050/// The result has pointer to array type. 2051llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2052 const char *GlobalName, 2053 unsigned Alignment) { 2054 bool IsConstant = !Features.WritableStrings; 2055 2056 // Get the default prefix if a name wasn't specified. 2057 if (!GlobalName) 2058 GlobalName = ".str"; 2059 2060 // Don't share any string literals if strings aren't constant. 2061 if (!IsConstant) 2062 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2063 2064 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2065 ConstantStringMap.GetOrCreateValue(Str); 2066 2067 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2068 if (Alignment > GV->getAlignment()) { 2069 GV->setAlignment(Alignment); 2070 } 2071 return GV; 2072 } 2073 2074 // Create a global variable for this. 2075 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, Alignment); 2076 Entry.setValue(GV); 2077 return GV; 2078} 2079 2080/// GetAddrOfConstantCString - Returns a pointer to a character 2081/// array containing the literal and a terminating '\0' 2082/// character. The result has pointer to array type. 2083llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2084 const char *GlobalName, 2085 unsigned Alignment) { 2086 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2087 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2088} 2089 2090/// EmitObjCPropertyImplementations - Emit information for synthesized 2091/// properties for an implementation. 2092void CodeGenModule::EmitObjCPropertyImplementations(const 2093 ObjCImplementationDecl *D) { 2094 for (ObjCImplementationDecl::propimpl_iterator 2095 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2096 ObjCPropertyImplDecl *PID = *i; 2097 2098 // Dynamic is just for type-checking. 2099 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2100 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2101 2102 // Determine which methods need to be implemented, some may have 2103 // been overridden. Note that ::isSynthesized is not the method 2104 // we want, that just indicates if the decl came from a 2105 // property. What we want to know is if the method is defined in 2106 // this implementation. 2107 if (!D->getInstanceMethod(PD->getGetterName())) 2108 CodeGenFunction(*this).GenerateObjCGetter( 2109 const_cast<ObjCImplementationDecl *>(D), PID); 2110 if (!PD->isReadOnly() && 2111 !D->getInstanceMethod(PD->getSetterName())) 2112 CodeGenFunction(*this).GenerateObjCSetter( 2113 const_cast<ObjCImplementationDecl *>(D), PID); 2114 } 2115 } 2116} 2117 2118static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2119 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2120 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2121 ivar; ivar = ivar->getNextIvar()) 2122 if (ivar->getType().isDestructedType()) 2123 return true; 2124 2125 return false; 2126} 2127 2128/// EmitObjCIvarInitializations - Emit information for ivar initialization 2129/// for an implementation. 2130void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2131 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2132 if (needsDestructMethod(D)) { 2133 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2134 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2135 ObjCMethodDecl *DTORMethod = 2136 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2137 cxxSelector, getContext().VoidTy, 0, D, 2138 /*isInstance=*/true, /*isVariadic=*/false, 2139 /*isSynthesized=*/true, /*isImplicitlyDeclared=*/true, 2140 /*isDefined=*/false, ObjCMethodDecl::Required); 2141 D->addInstanceMethod(DTORMethod); 2142 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2143 D->setHasCXXStructors(true); 2144 } 2145 2146 // If the implementation doesn't have any ivar initializers, we don't need 2147 // a .cxx_construct. 2148 if (D->getNumIvarInitializers() == 0) 2149 return; 2150 2151 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2152 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2153 // The constructor returns 'self'. 2154 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2155 D->getLocation(), 2156 D->getLocation(), 2157 cxxSelector, 2158 getContext().getObjCIdType(), 0, 2159 D, /*isInstance=*/true, 2160 /*isVariadic=*/false, 2161 /*isSynthesized=*/true, 2162 /*isImplicitlyDeclared=*/true, 2163 /*isDefined=*/false, 2164 ObjCMethodDecl::Required); 2165 D->addInstanceMethod(CTORMethod); 2166 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2167 D->setHasCXXStructors(true); 2168} 2169 2170/// EmitNamespace - Emit all declarations in a namespace. 2171void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2172 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2173 I != E; ++I) 2174 EmitTopLevelDecl(*I); 2175} 2176 2177// EmitLinkageSpec - Emit all declarations in a linkage spec. 2178void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2179 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2180 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2181 ErrorUnsupported(LSD, "linkage spec"); 2182 return; 2183 } 2184 2185 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2186 I != E; ++I) 2187 EmitTopLevelDecl(*I); 2188} 2189 2190/// EmitTopLevelDecl - Emit code for a single top level declaration. 2191void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2192 // If an error has occurred, stop code generation, but continue 2193 // parsing and semantic analysis (to ensure all warnings and errors 2194 // are emitted). 2195 if (Diags.hasErrorOccurred()) 2196 return; 2197 2198 // Ignore dependent declarations. 2199 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2200 return; 2201 2202 switch (D->getKind()) { 2203 case Decl::CXXConversion: 2204 case Decl::CXXMethod: 2205 case Decl::Function: 2206 // Skip function templates 2207 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2208 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2209 return; 2210 2211 EmitGlobal(cast<FunctionDecl>(D)); 2212 break; 2213 2214 case Decl::Var: 2215 EmitGlobal(cast<VarDecl>(D)); 2216 break; 2217 2218 // Indirect fields from global anonymous structs and unions can be 2219 // ignored; only the actual variable requires IR gen support. 2220 case Decl::IndirectField: 2221 break; 2222 2223 // C++ Decls 2224 case Decl::Namespace: 2225 EmitNamespace(cast<NamespaceDecl>(D)); 2226 break; 2227 // No code generation needed. 2228 case Decl::UsingShadow: 2229 case Decl::Using: 2230 case Decl::UsingDirective: 2231 case Decl::ClassTemplate: 2232 case Decl::FunctionTemplate: 2233 case Decl::TypeAliasTemplate: 2234 case Decl::NamespaceAlias: 2235 case Decl::Block: 2236 break; 2237 case Decl::CXXConstructor: 2238 // Skip function templates 2239 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2240 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2241 return; 2242 2243 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2244 break; 2245 case Decl::CXXDestructor: 2246 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2247 return; 2248 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2249 break; 2250 2251 case Decl::StaticAssert: 2252 // Nothing to do. 2253 break; 2254 2255 // Objective-C Decls 2256 2257 // Forward declarations, no (immediate) code generation. 2258 case Decl::ObjCClass: 2259 case Decl::ObjCForwardProtocol: 2260 case Decl::ObjCInterface: 2261 break; 2262 2263 case Decl::ObjCCategory: { 2264 ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D); 2265 if (CD->IsClassExtension() && CD->hasSynthBitfield()) 2266 Context.ResetObjCLayout(CD->getClassInterface()); 2267 break; 2268 } 2269 2270 case Decl::ObjCProtocol: 2271 ObjCRuntime->GenerateProtocol(cast<ObjCProtocolDecl>(D)); 2272 break; 2273 2274 case Decl::ObjCCategoryImpl: 2275 // Categories have properties but don't support synthesize so we 2276 // can ignore them here. 2277 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2278 break; 2279 2280 case Decl::ObjCImplementation: { 2281 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2282 if (Features.ObjCNonFragileABI2 && OMD->hasSynthBitfield()) 2283 Context.ResetObjCLayout(OMD->getClassInterface()); 2284 EmitObjCPropertyImplementations(OMD); 2285 EmitObjCIvarInitializations(OMD); 2286 ObjCRuntime->GenerateClass(OMD); 2287 break; 2288 } 2289 case Decl::ObjCMethod: { 2290 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 2291 // If this is not a prototype, emit the body. 2292 if (OMD->getBody()) 2293 CodeGenFunction(*this).GenerateObjCMethod(OMD); 2294 break; 2295 } 2296 case Decl::ObjCCompatibleAlias: 2297 // compatibility-alias is a directive and has no code gen. 2298 break; 2299 2300 case Decl::LinkageSpec: 2301 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 2302 break; 2303 2304 case Decl::FileScopeAsm: { 2305 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 2306 StringRef AsmString = AD->getAsmString()->getString(); 2307 2308 const std::string &S = getModule().getModuleInlineAsm(); 2309 if (S.empty()) 2310 getModule().setModuleInlineAsm(AsmString); 2311 else if (*--S.end() == '\n') 2312 getModule().setModuleInlineAsm(S + AsmString.str()); 2313 else 2314 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 2315 break; 2316 } 2317 2318 default: 2319 // Make sure we handled everything we should, every other kind is a 2320 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 2321 // function. Need to recode Decl::Kind to do that easily. 2322 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 2323 } 2324} 2325 2326/// Turns the given pointer into a constant. 2327static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 2328 const void *Ptr) { 2329 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 2330 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 2331 return llvm::ConstantInt::get(i64, PtrInt); 2332} 2333 2334static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 2335 llvm::NamedMDNode *&GlobalMetadata, 2336 GlobalDecl D, 2337 llvm::GlobalValue *Addr) { 2338 if (!GlobalMetadata) 2339 GlobalMetadata = 2340 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 2341 2342 // TODO: should we report variant information for ctors/dtors? 2343 llvm::Value *Ops[] = { 2344 Addr, 2345 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 2346 }; 2347 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 2348} 2349 2350/// Emits metadata nodes associating all the global values in the 2351/// current module with the Decls they came from. This is useful for 2352/// projects using IR gen as a subroutine. 2353/// 2354/// Since there's currently no way to associate an MDNode directly 2355/// with an llvm::GlobalValue, we create a global named metadata 2356/// with the name 'clang.global.decl.ptrs'. 2357void CodeGenModule::EmitDeclMetadata() { 2358 llvm::NamedMDNode *GlobalMetadata = 0; 2359 2360 // StaticLocalDeclMap 2361 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 2362 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 2363 I != E; ++I) { 2364 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 2365 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 2366 } 2367} 2368 2369/// Emits metadata nodes for all the local variables in the current 2370/// function. 2371void CodeGenFunction::EmitDeclMetadata() { 2372 if (LocalDeclMap.empty()) return; 2373 2374 llvm::LLVMContext &Context = getLLVMContext(); 2375 2376 // Find the unique metadata ID for this name. 2377 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 2378 2379 llvm::NamedMDNode *GlobalMetadata = 0; 2380 2381 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 2382 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 2383 const Decl *D = I->first; 2384 llvm::Value *Addr = I->second; 2385 2386 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 2387 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 2388 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 2389 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 2390 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 2391 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 2392 } 2393 } 2394} 2395 2396void CodeGenModule::EmitCoverageFile() { 2397 if (!getCodeGenOpts().CoverageFile.empty()) { 2398 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 2399 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 2400 llvm::LLVMContext &Ctx = TheModule.getContext(); 2401 llvm::MDString *CoverageFile = 2402 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 2403 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 2404 llvm::MDNode *CU = CUNode->getOperand(i); 2405 llvm::Value *node[] = { CoverageFile, CU }; 2406 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 2407 GCov->addOperand(N); 2408 } 2409 } 2410 } 2411} 2412