1 //===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This coordinates the per-module state used while generating code. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "CodeGenModule.h" 15 #include "CGDebugInfo.h" 16 #include "CodeGenFunction.h" 17 #include "CodeGenTBAA.h" 18 #include "CGCall.h" 19 #include "CGCUDARuntime.h" 20 #include "CGCXXABI.h" 21 #include "CGObjCRuntime.h" 22 #include "CGOpenCLRuntime.h" 23 #include "TargetInfo.h" 24 #include "clang/Frontend/CodeGenOptions.h" 25 #include "clang/AST/ASTContext.h" 26 #include "clang/AST/CharUnits.h" 27 #include "clang/AST/DeclObjC.h" 28 #include "clang/AST/DeclCXX.h" 29 #include "clang/AST/DeclTemplate.h" 30 #include "clang/AST/Mangle.h" 31 #include "clang/AST/RecordLayout.h" 32 #include "clang/AST/RecursiveASTVisitor.h" 33 #include "clang/Basic/Builtins.h" 34 #include "clang/Basic/Diagnostic.h" 35 #include "clang/Basic/SourceManager.h" 36 #include "clang/Basic/TargetInfo.h" 37 #include "clang/Basic/ConvertUTF.h" 38 #include "llvm/CallingConv.h" 39 #include "llvm/Module.h" 40 #include "llvm/Intrinsics.h" 41 #include "llvm/LLVMContext.h" 42 #include "llvm/ADT/Triple.h" 43 #include "llvm/Target/Mangler.h" 44 #include "llvm/Target/TargetData.h" 45 #include "llvm/Support/CallSite.h" 46 #include "llvm/Support/ErrorHandling.h" 47 using namespace clang; 48 using namespace CodeGen; 49 50 static const char AnnotationSection[] = "llvm.metadata"; 51 52 static CGCXXABI &createCXXABI(CodeGenModule &CGM) { 53 switch (CGM.getContext().getTargetInfo().getCXXABI()) { 54 case CXXABI_ARM: return *CreateARMCXXABI(CGM); 55 case CXXABI_Itanium: return *CreateItaniumCXXABI(CGM); 56 case CXXABI_Microsoft: return *CreateMicrosoftCXXABI(CGM); 57 } 58 59 llvm_unreachable("invalid C++ ABI kind"); 60 } 61 62 63 CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 64 llvm::Module &M, const llvm::TargetData &TD, 65 DiagnosticsEngine &diags) 66 : Context(C), Features(C.getLangOptions()), CodeGenOpts(CGO), TheModule(M), 67 TheTargetData(TD), TheTargetCodeGenInfo(0), Diags(diags), 68 ABI(createCXXABI(*this)), 69 Types(C, M, TD, getTargetCodeGenInfo().getABIInfo(), ABI, CGO), 70 TBAA(0), 71 VTables(*this), ObjCRuntime(0), OpenCLRuntime(0), CUDARuntime(0), 72 DebugInfo(0), ARCData(0), RRData(0), CFConstantStringClassRef(0), 73 ConstantStringClassRef(0), NSConstantStringType(0), 74 VMContext(M.getContext()), 75 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), 76 BlockObjectAssign(0), BlockObjectDispose(0), 77 BlockDescriptorType(0), GenericBlockLiteralType(0) { 78 if (Features.ObjC1) 79 createObjCRuntime(); 80 if (Features.OpenCL) 81 createOpenCLRuntime(); 82 if (Features.CUDA) 83 createCUDARuntime(); 84 85 // Enable TBAA unless it's suppressed. 86 if (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0) 87 TBAA = new CodeGenTBAA(Context, VMContext, getLangOptions(), 88 ABI.getMangleContext()); 89 90 // If debug info or coverage generation is enabled, create the CGDebugInfo 91 // object. 92 if (CodeGenOpts.DebugInfo || CodeGenOpts.EmitGcovArcs || 93 CodeGenOpts.EmitGcovNotes) 94 DebugInfo = new CGDebugInfo(*this); 95 96 Block.GlobalUniqueCount = 0; 97 98 if (C.getLangOptions().ObjCAutoRefCount) 99 ARCData = new ARCEntrypoints(); 100 RRData = new RREntrypoints(); 101 102 // Initialize the type cache. 103 llvm::LLVMContext &LLVMContext = M.getContext(); 104 VoidTy = llvm::Type::getVoidTy(LLVMContext); 105 Int8Ty = llvm::Type::getInt8Ty(LLVMContext); 106 Int32Ty = llvm::Type::getInt32Ty(LLVMContext); 107 Int64Ty = llvm::Type::getInt64Ty(LLVMContext); 108 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0); 109 PointerAlignInBytes = 110 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity(); 111 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth()); 112 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits); 113 Int8PtrTy = Int8Ty->getPointerTo(0); 114 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0); 115 } 116 117 CodeGenModule::~CodeGenModule() { 118 delete ObjCRuntime; 119 delete OpenCLRuntime; 120 delete CUDARuntime; 121 delete TheTargetCodeGenInfo; 122 delete &ABI; 123 delete TBAA; 124 delete DebugInfo; 125 delete ARCData; 126 delete RRData; 127 } 128 129 void CodeGenModule::createObjCRuntime() { 130 if (!Features.NeXTRuntime) 131 ObjCRuntime = CreateGNUObjCRuntime(*this); 132 else 133 ObjCRuntime = CreateMacObjCRuntime(*this); 134 } 135 136 void CodeGenModule::createOpenCLRuntime() { 137 OpenCLRuntime = new CGOpenCLRuntime(*this); 138 } 139 140 void CodeGenModule::createCUDARuntime() { 141 CUDARuntime = CreateNVCUDARuntime(*this); 142 } 143 144 void CodeGenModule::Release() { 145 EmitDeferred(); 146 EmitCXXGlobalInitFunc(); 147 EmitCXXGlobalDtorFunc(); 148 if (ObjCRuntime) 149 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction()) 150 AddGlobalCtor(ObjCInitFunction); 151 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 152 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 153 EmitGlobalAnnotations(); 154 EmitLLVMUsed(); 155 156 SimplifyPersonality(); 157 158 if (getCodeGenOpts().EmitDeclMetadata) 159 EmitDeclMetadata(); 160 161 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes) 162 EmitCoverageFile(); 163 164 if (DebugInfo) 165 DebugInfo->finalize(); 166 } 167 168 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) { 169 // Make sure that this type is translated. 170 Types.UpdateCompletedType(TD); 171 if (DebugInfo) 172 DebugInfo->UpdateCompletedType(TD); 173 } 174 175 llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 176 if (!TBAA) 177 return 0; 178 return TBAA->getTBAAInfo(QTy); 179 } 180 181 void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 182 llvm::MDNode *TBAAInfo) { 183 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 184 } 185 186 bool CodeGenModule::isTargetDarwin() const { 187 return getContext().getTargetInfo().getTriple().isOSDarwin(); 188 } 189 190 void CodeGenModule::Error(SourceLocation loc, StringRef error) { 191 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error); 192 getDiags().Report(Context.getFullLoc(loc), diagID); 193 } 194 195 /// ErrorUnsupported - Print out an error that codegen doesn't support the 196 /// specified stmt yet. 197 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 198 bool OmitOnError) { 199 if (OmitOnError && getDiags().hasErrorOccurred()) 200 return; 201 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 202 "cannot compile this %0 yet"); 203 std::string Msg = Type; 204 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 205 << Msg << S->getSourceRange(); 206 } 207 208 /// ErrorUnsupported - Print out an error that codegen doesn't support the 209 /// specified decl yet. 210 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 211 bool OmitOnError) { 212 if (OmitOnError && getDiags().hasErrorOccurred()) 213 return; 214 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, 215 "cannot compile this %0 yet"); 216 std::string Msg = Type; 217 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 218 } 219 220 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) { 221 return llvm::ConstantInt::get(SizeTy, size.getQuantity()); 222 } 223 224 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 225 const NamedDecl *D) const { 226 // Internal definitions always have default visibility. 227 if (GV->hasLocalLinkage()) { 228 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 229 return; 230 } 231 232 // Set visibility for definitions. 233 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 234 if (LV.visibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 235 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 236 } 237 238 /// Set the symbol visibility of type information (vtable and RTTI) 239 /// associated with the given type. 240 void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 241 const CXXRecordDecl *RD, 242 TypeVisibilityKind TVK) const { 243 setGlobalVisibility(GV, RD); 244 245 if (!CodeGenOpts.HiddenWeakVTables) 246 return; 247 248 // We never want to drop the visibility for RTTI names. 249 if (TVK == TVK_ForRTTIName) 250 return; 251 252 // We want to drop the visibility to hidden for weak type symbols. 253 // This isn't possible if there might be unresolved references 254 // elsewhere that rely on this symbol being visible. 255 256 // This should be kept roughly in sync with setThunkVisibility 257 // in CGVTables.cpp. 258 259 // Preconditions. 260 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 261 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 262 return; 263 264 // Don't override an explicit visibility attribute. 265 if (RD->getExplicitVisibility()) 266 return; 267 268 switch (RD->getTemplateSpecializationKind()) { 269 // We have to disable the optimization if this is an EI definition 270 // because there might be EI declarations in other shared objects. 271 case TSK_ExplicitInstantiationDefinition: 272 case TSK_ExplicitInstantiationDeclaration: 273 return; 274 275 // Every use of a non-template class's type information has to emit it. 276 case TSK_Undeclared: 277 break; 278 279 // In theory, implicit instantiations can ignore the possibility of 280 // an explicit instantiation declaration because there necessarily 281 // must be an EI definition somewhere with default visibility. In 282 // practice, it's possible to have an explicit instantiation for 283 // an arbitrary template class, and linkers aren't necessarily able 284 // to deal with mixed-visibility symbols. 285 case TSK_ExplicitSpecialization: 286 case TSK_ImplicitInstantiation: 287 if (!CodeGenOpts.HiddenWeakTemplateVTables) 288 return; 289 break; 290 } 291 292 // If there's a key function, there may be translation units 293 // that don't have the key function's definition. But ignore 294 // this if we're emitting RTTI under -fno-rtti. 295 if (!(TVK != TVK_ForRTTI) || Features.RTTI) { 296 if (Context.getKeyFunction(RD)) 297 return; 298 } 299 300 // Otherwise, drop the visibility to hidden. 301 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 302 GV->setUnnamedAddr(true); 303 } 304 305 StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 306 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 307 308 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 309 if (!Str.empty()) 310 return Str; 311 312 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 313 IdentifierInfo *II = ND->getIdentifier(); 314 assert(II && "Attempt to mangle unnamed decl."); 315 316 Str = II->getName(); 317 return Str; 318 } 319 320 SmallString<256> Buffer; 321 llvm::raw_svector_ostream Out(Buffer); 322 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 323 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 324 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 325 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 326 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND)) 327 getCXXABI().getMangleContext().mangleBlock(BD, Out); 328 else 329 getCXXABI().getMangleContext().mangleName(ND, Out); 330 331 // Allocate space for the mangled name. 332 Out.flush(); 333 size_t Length = Buffer.size(); 334 char *Name = MangledNamesAllocator.Allocate<char>(Length); 335 std::copy(Buffer.begin(), Buffer.end(), Name); 336 337 Str = StringRef(Name, Length); 338 339 return Str; 340 } 341 342 void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 343 const BlockDecl *BD) { 344 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 345 const Decl *D = GD.getDecl(); 346 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 347 if (D == 0) 348 MangleCtx.mangleGlobalBlock(BD, Out); 349 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 350 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 351 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 352 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 353 else 354 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 355 } 356 357 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) { 358 return getModule().getNamedValue(Name); 359 } 360 361 /// AddGlobalCtor - Add a function to the list that will be called before 362 /// main() runs. 363 void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 364 // FIXME: Type coercion of void()* types. 365 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 366 } 367 368 /// AddGlobalDtor - Add a function to the list that will be called 369 /// when the module is unloaded. 370 void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 371 // FIXME: Type coercion of void()* types. 372 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 373 } 374 375 void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 376 // Ctor function type is void()*. 377 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false); 378 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 379 380 // Get the type of a ctor entry, { i32, void ()* }. 381 llvm::StructType *CtorStructTy = 382 llvm::StructType::get(llvm::Type::getInt32Ty(VMContext), 383 llvm::PointerType::getUnqual(CtorFTy), NULL); 384 385 // Construct the constructor and destructor arrays. 386 SmallVector<llvm::Constant*, 8> Ctors; 387 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 388 llvm::Constant *S[] = { 389 llvm::ConstantInt::get(Int32Ty, I->second, false), 390 llvm::ConstantExpr::getBitCast(I->first, CtorPFTy) 391 }; 392 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 393 } 394 395 if (!Ctors.empty()) { 396 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 397 new llvm::GlobalVariable(TheModule, AT, false, 398 llvm::GlobalValue::AppendingLinkage, 399 llvm::ConstantArray::get(AT, Ctors), 400 GlobalName); 401 } 402 } 403 404 llvm::GlobalValue::LinkageTypes 405 CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 406 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 407 408 if (Linkage == GVA_Internal) 409 return llvm::Function::InternalLinkage; 410 411 if (D->hasAttr<DLLExportAttr>()) 412 return llvm::Function::DLLExportLinkage; 413 414 if (D->hasAttr<WeakAttr>()) 415 return llvm::Function::WeakAnyLinkage; 416 417 // In C99 mode, 'inline' functions are guaranteed to have a strong 418 // definition somewhere else, so we can use available_externally linkage. 419 if (Linkage == GVA_C99Inline) 420 return llvm::Function::AvailableExternallyLinkage; 421 422 // Note that Apple's kernel linker doesn't support symbol 423 // coalescing, so we need to avoid linkonce and weak linkages there. 424 // Normally, this means we just map to internal, but for explicit 425 // instantiations we'll map to external. 426 427 // In C++, the compiler has to emit a definition in every translation unit 428 // that references the function. We should use linkonce_odr because 429 // a) if all references in this translation unit are optimized away, we 430 // don't need to codegen it. b) if the function persists, it needs to be 431 // merged with other definitions. c) C++ has the ODR, so we know the 432 // definition is dependable. 433 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 434 return !Context.getLangOptions().AppleKext 435 ? llvm::Function::LinkOnceODRLinkage 436 : llvm::Function::InternalLinkage; 437 438 // An explicit instantiation of a template has weak linkage, since 439 // explicit instantiations can occur in multiple translation units 440 // and must all be equivalent. However, we are not allowed to 441 // throw away these explicit instantiations. 442 if (Linkage == GVA_ExplicitTemplateInstantiation) 443 return !Context.getLangOptions().AppleKext 444 ? llvm::Function::WeakODRLinkage 445 : llvm::Function::ExternalLinkage; 446 447 // Otherwise, we have strong external linkage. 448 assert(Linkage == GVA_StrongExternal); 449 return llvm::Function::ExternalLinkage; 450 } 451 452 453 /// SetFunctionDefinitionAttributes - Set attributes for a global. 454 /// 455 /// FIXME: This is currently only done for aliases and functions, but not for 456 /// variables (these details are set in EmitGlobalVarDefinition for variables). 457 void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 458 llvm::GlobalValue *GV) { 459 SetCommonAttributes(D, GV); 460 } 461 462 void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 463 const CGFunctionInfo &Info, 464 llvm::Function *F) { 465 unsigned CallingConv; 466 AttributeListType AttributeList; 467 ConstructAttributeList(Info, D, AttributeList, CallingConv); 468 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 469 AttributeList.size())); 470 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 471 } 472 473 /// Determines whether the language options require us to model 474 /// unwind exceptions. We treat -fexceptions as mandating this 475 /// except under the fragile ObjC ABI with only ObjC exceptions 476 /// enabled. This means, for example, that C with -fexceptions 477 /// enables this. 478 static bool hasUnwindExceptions(const LangOptions &Features) { 479 // If exceptions are completely disabled, obviously this is false. 480 if (!Features.Exceptions) return false; 481 482 // If C++ exceptions are enabled, this is true. 483 if (Features.CXXExceptions) return true; 484 485 // If ObjC exceptions are enabled, this depends on the ABI. 486 if (Features.ObjCExceptions) { 487 if (!Features.ObjCNonFragileABI) return false; 488 } 489 490 return true; 491 } 492 493 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 494 llvm::Function *F) { 495 if (CodeGenOpts.UnwindTables) 496 F->setHasUWTable(); 497 498 if (!hasUnwindExceptions(Features)) 499 F->addFnAttr(llvm::Attribute::NoUnwind); 500 501 if (D->hasAttr<NakedAttr>()) { 502 // Naked implies noinline: we should not be inlining such functions. 503 F->addFnAttr(llvm::Attribute::Naked); 504 F->addFnAttr(llvm::Attribute::NoInline); 505 } 506 507 if (D->hasAttr<NoInlineAttr>()) 508 F->addFnAttr(llvm::Attribute::NoInline); 509 510 // (noinline wins over always_inline, and we can't specify both in IR) 511 if (D->hasAttr<AlwaysInlineAttr>() && 512 !F->hasFnAttr(llvm::Attribute::NoInline)) 513 F->addFnAttr(llvm::Attribute::AlwaysInline); 514 515 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 516 F->setUnnamedAddr(true); 517 518 if (Features.getStackProtector() == LangOptions::SSPOn) 519 F->addFnAttr(llvm::Attribute::StackProtect); 520 else if (Features.getStackProtector() == LangOptions::SSPReq) 521 F->addFnAttr(llvm::Attribute::StackProtectReq); 522 523 if (Features.AddressSanitizer) { 524 // When AddressSanitizer is enabled, set AddressSafety attribute 525 // unless __attribute__((no_address_safety_analysis)) is used. 526 if (!D->hasAttr<NoAddressSafetyAnalysisAttr>()) 527 F->addFnAttr(llvm::Attribute::AddressSafety); 528 } 529 530 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 531 if (alignment) 532 F->setAlignment(alignment); 533 534 // C++ ABI requires 2-byte alignment for member functions. 535 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 536 F->setAlignment(2); 537 } 538 539 void CodeGenModule::SetCommonAttributes(const Decl *D, 540 llvm::GlobalValue *GV) { 541 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 542 setGlobalVisibility(GV, ND); 543 else 544 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 545 546 if (D->hasAttr<UsedAttr>()) 547 AddUsedGlobal(GV); 548 549 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 550 GV->setSection(SA->getName()); 551 552 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 553 } 554 555 void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 556 llvm::Function *F, 557 const CGFunctionInfo &FI) { 558 SetLLVMFunctionAttributes(D, FI, F); 559 SetLLVMFunctionAttributesForDefinition(D, F); 560 561 F->setLinkage(llvm::Function::InternalLinkage); 562 563 SetCommonAttributes(D, F); 564 } 565 566 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 567 llvm::Function *F, 568 bool IsIncompleteFunction) { 569 if (unsigned IID = F->getIntrinsicID()) { 570 // If this is an intrinsic function, set the function's attributes 571 // to the intrinsic's attributes. 572 F->setAttributes(llvm::Intrinsic::getAttributes((llvm::Intrinsic::ID)IID)); 573 return; 574 } 575 576 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 577 578 if (!IsIncompleteFunction) 579 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(GD), F); 580 581 // Only a few attributes are set on declarations; these may later be 582 // overridden by a definition. 583 584 if (FD->hasAttr<DLLImportAttr>()) { 585 F->setLinkage(llvm::Function::DLLImportLinkage); 586 } else if (FD->hasAttr<WeakAttr>() || 587 FD->isWeakImported()) { 588 // "extern_weak" is overloaded in LLVM; we probably should have 589 // separate linkage types for this. 590 F->setLinkage(llvm::Function::ExternalWeakLinkage); 591 } else { 592 F->setLinkage(llvm::Function::ExternalLinkage); 593 594 NamedDecl::LinkageInfo LV = FD->getLinkageAndVisibility(); 595 if (LV.linkage() == ExternalLinkage && LV.visibilityExplicit()) { 596 F->setVisibility(GetLLVMVisibility(LV.visibility())); 597 } 598 } 599 600 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 601 F->setSection(SA->getName()); 602 } 603 604 void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 605 assert(!GV->isDeclaration() && 606 "Only globals with definition can force usage."); 607 LLVMUsed.push_back(GV); 608 } 609 610 void CodeGenModule::EmitLLVMUsed() { 611 // Don't create llvm.used if there is no need. 612 if (LLVMUsed.empty()) 613 return; 614 615 // Convert LLVMUsed to what ConstantArray needs. 616 SmallVector<llvm::Constant*, 8> UsedArray; 617 UsedArray.resize(LLVMUsed.size()); 618 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 619 UsedArray[i] = 620 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 621 Int8PtrTy); 622 } 623 624 if (UsedArray.empty()) 625 return; 626 llvm::ArrayType *ATy = llvm::ArrayType::get(Int8PtrTy, UsedArray.size()); 627 628 llvm::GlobalVariable *GV = 629 new llvm::GlobalVariable(getModule(), ATy, false, 630 llvm::GlobalValue::AppendingLinkage, 631 llvm::ConstantArray::get(ATy, UsedArray), 632 "llvm.used"); 633 634 GV->setSection("llvm.metadata"); 635 } 636 637 void CodeGenModule::EmitDeferred() { 638 // Emit code for any potentially referenced deferred decls. Since a 639 // previously unused static decl may become used during the generation of code 640 // for a static function, iterate until no changes are made. 641 642 while (!DeferredDeclsToEmit.empty() || !DeferredVTables.empty()) { 643 if (!DeferredVTables.empty()) { 644 const CXXRecordDecl *RD = DeferredVTables.back(); 645 DeferredVTables.pop_back(); 646 getVTables().GenerateClassData(getVTableLinkage(RD), RD); 647 continue; 648 } 649 650 GlobalDecl D = DeferredDeclsToEmit.back(); 651 DeferredDeclsToEmit.pop_back(); 652 653 // Check to see if we've already emitted this. This is necessary 654 // for a couple of reasons: first, decls can end up in the 655 // deferred-decls queue multiple times, and second, decls can end 656 // up with definitions in unusual ways (e.g. by an extern inline 657 // function acquiring a strong function redefinition). Just 658 // ignore these cases. 659 // 660 // TODO: That said, looking this up multiple times is very wasteful. 661 StringRef Name = getMangledName(D); 662 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 663 assert(CGRef && "Deferred decl wasn't referenced?"); 664 665 if (!CGRef->isDeclaration()) 666 continue; 667 668 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 669 // purposes an alias counts as a definition. 670 if (isa<llvm::GlobalAlias>(CGRef)) 671 continue; 672 673 // Otherwise, emit the definition and move on to the next one. 674 EmitGlobalDefinition(D); 675 } 676 } 677 678 void CodeGenModule::EmitGlobalAnnotations() { 679 if (Annotations.empty()) 680 return; 681 682 // Create a new global variable for the ConstantStruct in the Module. 683 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get( 684 Annotations[0]->getType(), Annotations.size()), Annotations); 685 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), 686 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array, 687 "llvm.global.annotations"); 688 gv->setSection(AnnotationSection); 689 } 690 691 llvm::Constant *CodeGenModule::EmitAnnotationString(llvm::StringRef Str) { 692 llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str); 693 if (i != AnnotationStrings.end()) 694 return i->second; 695 696 // Not found yet, create a new global. 697 llvm::Constant *s = llvm::ConstantDataArray::getString(getLLVMContext(), Str); 698 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(), 699 true, llvm::GlobalValue::PrivateLinkage, s, ".str"); 700 gv->setSection(AnnotationSection); 701 gv->setUnnamedAddr(true); 702 AnnotationStrings[Str] = gv; 703 return gv; 704 } 705 706 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) { 707 SourceManager &SM = getContext().getSourceManager(); 708 PresumedLoc PLoc = SM.getPresumedLoc(Loc); 709 if (PLoc.isValid()) 710 return EmitAnnotationString(PLoc.getFilename()); 711 return EmitAnnotationString(SM.getBufferName(Loc)); 712 } 713 714 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) { 715 SourceManager &SM = getContext().getSourceManager(); 716 PresumedLoc PLoc = SM.getPresumedLoc(L); 717 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() : 718 SM.getExpansionLineNumber(L); 719 return llvm::ConstantInt::get(Int32Ty, LineNo); 720 } 721 722 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 723 const AnnotateAttr *AA, 724 SourceLocation L) { 725 // Get the globals for file name, annotation, and the line number. 726 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()), 727 *UnitGV = EmitAnnotationUnit(L), 728 *LineNoCst = EmitAnnotationLineNo(L); 729 730 // Create the ConstantStruct for the global annotation. 731 llvm::Constant *Fields[4] = { 732 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy), 733 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy), 734 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy), 735 LineNoCst 736 }; 737 return llvm::ConstantStruct::getAnon(Fields); 738 } 739 740 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D, 741 llvm::GlobalValue *GV) { 742 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); 743 // Get the struct elements for these annotations. 744 for (specific_attr_iterator<AnnotateAttr> 745 ai = D->specific_attr_begin<AnnotateAttr>(), 746 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) 747 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation())); 748 } 749 750 bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 751 // Never defer when EmitAllDecls is specified. 752 if (Features.EmitAllDecls) 753 return false; 754 755 return !getContext().DeclMustBeEmitted(Global); 756 } 757 758 llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 759 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 760 assert(AA && "No alias?"); 761 762 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 763 764 // See if there is already something with the target's name in the module. 765 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 766 767 llvm::Constant *Aliasee; 768 if (isa<llvm::FunctionType>(DeclTy)) 769 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 770 /*ForVTable=*/false); 771 else 772 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 773 llvm::PointerType::getUnqual(DeclTy), 0); 774 if (!Entry) { 775 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 776 F->setLinkage(llvm::Function::ExternalWeakLinkage); 777 WeakRefReferences.insert(F); 778 } 779 780 return Aliasee; 781 } 782 783 void CodeGenModule::EmitGlobal(GlobalDecl GD) { 784 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 785 786 // Weak references don't produce any output by themselves. 787 if (Global->hasAttr<WeakRefAttr>()) 788 return; 789 790 // If this is an alias definition (which otherwise looks like a declaration) 791 // emit it now. 792 if (Global->hasAttr<AliasAttr>()) 793 return EmitAliasDefinition(GD); 794 795 // If this is CUDA, be selective about which declarations we emit. 796 if (Features.CUDA) { 797 if (CodeGenOpts.CUDAIsDevice) { 798 if (!Global->hasAttr<CUDADeviceAttr>() && 799 !Global->hasAttr<CUDAGlobalAttr>() && 800 !Global->hasAttr<CUDAConstantAttr>() && 801 !Global->hasAttr<CUDASharedAttr>()) 802 return; 803 } else { 804 if (!Global->hasAttr<CUDAHostAttr>() && ( 805 Global->hasAttr<CUDADeviceAttr>() || 806 Global->hasAttr<CUDAConstantAttr>() || 807 Global->hasAttr<CUDASharedAttr>())) 808 return; 809 } 810 } 811 812 // Ignore declarations, they will be emitted on their first use. 813 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 814 // Forward declarations are emitted lazily on first use. 815 if (!FD->doesThisDeclarationHaveABody()) { 816 if (!FD->doesDeclarationForceExternallyVisibleDefinition()) 817 return; 818 819 const FunctionDecl *InlineDefinition = 0; 820 FD->getBody(InlineDefinition); 821 822 StringRef MangledName = getMangledName(GD); 823 llvm::StringMap<GlobalDecl>::iterator DDI = 824 DeferredDecls.find(MangledName); 825 if (DDI != DeferredDecls.end()) 826 DeferredDecls.erase(DDI); 827 EmitGlobalDefinition(InlineDefinition); 828 return; 829 } 830 } else { 831 const VarDecl *VD = cast<VarDecl>(Global); 832 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 833 834 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 835 return; 836 } 837 838 // Defer code generation when possible if this is a static definition, inline 839 // function etc. These we only want to emit if they are used. 840 if (!MayDeferGeneration(Global)) { 841 // Emit the definition if it can't be deferred. 842 EmitGlobalDefinition(GD); 843 return; 844 } 845 846 // If we're deferring emission of a C++ variable with an 847 // initializer, remember the order in which it appeared in the file. 848 if (getLangOptions().CPlusPlus && isa<VarDecl>(Global) && 849 cast<VarDecl>(Global)->hasInit()) { 850 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 851 CXXGlobalInits.push_back(0); 852 } 853 854 // If the value has already been used, add it directly to the 855 // DeferredDeclsToEmit list. 856 StringRef MangledName = getMangledName(GD); 857 if (GetGlobalValue(MangledName)) 858 DeferredDeclsToEmit.push_back(GD); 859 else { 860 // Otherwise, remember that we saw a deferred decl with this name. The 861 // first use of the mangled name will cause it to move into 862 // DeferredDeclsToEmit. 863 DeferredDecls[MangledName] = GD; 864 } 865 } 866 867 namespace { 868 struct FunctionIsDirectlyRecursive : 869 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> { 870 const StringRef Name; 871 const Builtin::Context &BI; 872 bool Result; 873 FunctionIsDirectlyRecursive(StringRef N, const Builtin::Context &C) : 874 Name(N), BI(C), Result(false) { 875 } 876 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base; 877 878 bool TraverseCallExpr(CallExpr *E) { 879 const FunctionDecl *FD = E->getDirectCallee(); 880 if (!FD) 881 return true; 882 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 883 if (Attr && Name == Attr->getLabel()) { 884 Result = true; 885 return false; 886 } 887 unsigned BuiltinID = FD->getBuiltinID(); 888 if (!BuiltinID) 889 return true; 890 StringRef BuiltinName = BI.GetName(BuiltinID); 891 if (BuiltinName.startswith("__builtin_") && 892 Name == BuiltinName.slice(strlen("__builtin_"), StringRef::npos)) { 893 Result = true; 894 return false; 895 } 896 return true; 897 } 898 }; 899 } 900 901 // isTriviallyRecursive - Check if this function calls another 902 // decl that, because of the asm attribute or the other decl being a builtin, 903 // ends up pointing to itself. 904 bool 905 CodeGenModule::isTriviallyRecursive(const FunctionDecl *FD) { 906 StringRef Name; 907 if (getCXXABI().getMangleContext().shouldMangleDeclName(FD)) { 908 // asm labels are a special kind of mangling we have to support. 909 AsmLabelAttr *Attr = FD->getAttr<AsmLabelAttr>(); 910 if (!Attr) 911 return false; 912 Name = Attr->getLabel(); 913 } else { 914 Name = FD->getName(); 915 } 916 917 FunctionIsDirectlyRecursive Walker(Name, Context.BuiltinInfo); 918 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(FD)); 919 return Walker.Result; 920 } 921 922 bool 923 CodeGenModule::shouldEmitFunction(const FunctionDecl *F) { 924 if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage) 925 return true; 926 if (CodeGenOpts.OptimizationLevel == 0 && 927 !F->hasAttr<AlwaysInlineAttr>()) 928 return false; 929 // PR9614. Avoid cases where the source code is lying to us. An available 930 // externally function should have an equivalent function somewhere else, 931 // but a function that calls itself is clearly not equivalent to the real 932 // implementation. 933 // This happens in glibc's btowc and in some configure checks. 934 return !isTriviallyRecursive(F); 935 } 936 937 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 938 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 939 940 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 941 Context.getSourceManager(), 942 "Generating code for declaration"); 943 944 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 945 // At -O0, don't generate IR for functions with available_externally 946 // linkage. 947 if (!shouldEmitFunction(Function)) 948 return; 949 950 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 951 // Make sure to emit the definition(s) before we emit the thunks. 952 // This is necessary for the generation of certain thunks. 953 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 954 EmitCXXConstructor(CD, GD.getCtorType()); 955 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method)) 956 EmitCXXDestructor(DD, GD.getDtorType()); 957 else 958 EmitGlobalFunctionDefinition(GD); 959 960 if (Method->isVirtual()) 961 getVTables().EmitThunks(GD); 962 963 return; 964 } 965 966 return EmitGlobalFunctionDefinition(GD); 967 } 968 969 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 970 return EmitGlobalVarDefinition(VD); 971 972 llvm_unreachable("Invalid argument to EmitGlobalDefinition()"); 973 } 974 975 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the 976 /// module, create and return an llvm Function with the specified type. If there 977 /// is something in the module with the specified name, return it potentially 978 /// bitcasted to the right type. 979 /// 980 /// If D is non-null, it specifies a decl that correspond to this. This is used 981 /// to set the attributes on the function when it is first created. 982 llvm::Constant * 983 CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName, 984 llvm::Type *Ty, 985 GlobalDecl D, bool ForVTable, 986 llvm::Attributes ExtraAttrs) { 987 // Lookup the entry, lazily creating it if necessary. 988 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 989 if (Entry) { 990 if (WeakRefReferences.count(Entry)) { 991 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 992 if (FD && !FD->hasAttr<WeakAttr>()) 993 Entry->setLinkage(llvm::Function::ExternalLinkage); 994 995 WeakRefReferences.erase(Entry); 996 } 997 998 if (Entry->getType()->getElementType() == Ty) 999 return Entry; 1000 1001 // Make sure the result is of the correct type. 1002 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo()); 1003 } 1004 1005 // This function doesn't have a complete type (for example, the return 1006 // type is an incomplete struct). Use a fake type instead, and make 1007 // sure not to try to set attributes. 1008 bool IsIncompleteFunction = false; 1009 1010 llvm::FunctionType *FTy; 1011 if (isa<llvm::FunctionType>(Ty)) { 1012 FTy = cast<llvm::FunctionType>(Ty); 1013 } else { 1014 FTy = llvm::FunctionType::get(VoidTy, false); 1015 IsIncompleteFunction = true; 1016 } 1017 1018 llvm::Function *F = llvm::Function::Create(FTy, 1019 llvm::Function::ExternalLinkage, 1020 MangledName, &getModule()); 1021 assert(F->getName() == MangledName && "name was uniqued!"); 1022 if (D.getDecl()) 1023 SetFunctionAttributes(D, F, IsIncompleteFunction); 1024 if (ExtraAttrs != llvm::Attribute::None) 1025 F->addFnAttr(ExtraAttrs); 1026 1027 // This is the first use or definition of a mangled name. If there is a 1028 // deferred decl with this name, remember that we need to emit it at the end 1029 // of the file. 1030 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1031 if (DDI != DeferredDecls.end()) { 1032 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1033 // list, and remove it from DeferredDecls (since we don't need it anymore). 1034 DeferredDeclsToEmit.push_back(DDI->second); 1035 DeferredDecls.erase(DDI); 1036 1037 // Otherwise, there are cases we have to worry about where we're 1038 // using a declaration for which we must emit a definition but where 1039 // we might not find a top-level definition: 1040 // - member functions defined inline in their classes 1041 // - friend functions defined inline in some class 1042 // - special member functions with implicit definitions 1043 // If we ever change our AST traversal to walk into class methods, 1044 // this will be unnecessary. 1045 // 1046 // We also don't emit a definition for a function if it's going to be an entry 1047 // in a vtable, unless it's already marked as used. 1048 } else if (getLangOptions().CPlusPlus && D.getDecl()) { 1049 // Look for a declaration that's lexically in a record. 1050 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); 1051 do { 1052 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 1053 if (FD->isImplicit() && !ForVTable) { 1054 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 1055 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1056 break; 1057 } else if (FD->doesThisDeclarationHaveABody()) { 1058 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 1059 break; 1060 } 1061 } 1062 FD = FD->getPreviousDecl(); 1063 } while (FD); 1064 } 1065 1066 // Make sure the result is of the requested type. 1067 if (!IsIncompleteFunction) { 1068 assert(F->getType()->getElementType() == Ty); 1069 return F; 1070 } 1071 1072 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1073 return llvm::ConstantExpr::getBitCast(F, PTy); 1074 } 1075 1076 /// GetAddrOfFunction - Return the address of the given function. If Ty is 1077 /// non-null, then this function will use the specified type if it has to 1078 /// create it (this occurs when we see a definition of the function). 1079 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 1080 llvm::Type *Ty, 1081 bool ForVTable) { 1082 // If there was no specific requested type, just convert it now. 1083 if (!Ty) 1084 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 1085 1086 StringRef MangledName = getMangledName(GD); 1087 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 1088 } 1089 1090 /// CreateRuntimeFunction - Create a new runtime function with the specified 1091 /// type and name. 1092 llvm::Constant * 1093 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy, 1094 StringRef Name, 1095 llvm::Attributes ExtraAttrs) { 1096 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false, 1097 ExtraAttrs); 1098 } 1099 1100 static bool DeclIsConstantGlobal(ASTContext &Context, const VarDecl *D, 1101 bool ConstantInit) { 1102 if (!D->getType().isConstant(Context) && !D->getType()->isReferenceType()) 1103 return false; 1104 1105 if (Context.getLangOptions().CPlusPlus) { 1106 if (const RecordType *Record 1107 = Context.getBaseElementType(D->getType())->getAs<RecordType>()) 1108 return ConstantInit && 1109 cast<CXXRecordDecl>(Record->getDecl())->isPOD() && 1110 !cast<CXXRecordDecl>(Record->getDecl())->hasMutableFields(); 1111 } 1112 1113 return true; 1114 } 1115 1116 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 1117 /// create and return an llvm GlobalVariable with the specified type. If there 1118 /// is something in the module with the specified name, return it potentially 1119 /// bitcasted to the right type. 1120 /// 1121 /// If D is non-null, it specifies a decl that correspond to this. This is used 1122 /// to set the attributes on the global when it is first created. 1123 llvm::Constant * 1124 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName, 1125 llvm::PointerType *Ty, 1126 const VarDecl *D, 1127 bool UnnamedAddr) { 1128 // Lookup the entry, lazily creating it if necessary. 1129 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1130 if (Entry) { 1131 if (WeakRefReferences.count(Entry)) { 1132 if (D && !D->hasAttr<WeakAttr>()) 1133 Entry->setLinkage(llvm::Function::ExternalLinkage); 1134 1135 WeakRefReferences.erase(Entry); 1136 } 1137 1138 if (UnnamedAddr) 1139 Entry->setUnnamedAddr(true); 1140 1141 if (Entry->getType() == Ty) 1142 return Entry; 1143 1144 // Make sure the result is of the correct type. 1145 return llvm::ConstantExpr::getBitCast(Entry, Ty); 1146 } 1147 1148 // This is the first use or definition of a mangled name. If there is a 1149 // deferred decl with this name, remember that we need to emit it at the end 1150 // of the file. 1151 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 1152 if (DDI != DeferredDecls.end()) { 1153 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 1154 // list, and remove it from DeferredDecls (since we don't need it anymore). 1155 DeferredDeclsToEmit.push_back(DDI->second); 1156 DeferredDecls.erase(DDI); 1157 } 1158 1159 llvm::GlobalVariable *GV = 1160 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 1161 llvm::GlobalValue::ExternalLinkage, 1162 0, MangledName, 0, 1163 false, Ty->getAddressSpace()); 1164 1165 // Handle things which are present even on external declarations. 1166 if (D) { 1167 // FIXME: This code is overly simple and should be merged with other global 1168 // handling. 1169 GV->setConstant(DeclIsConstantGlobal(Context, D, false)); 1170 1171 // Set linkage and visibility in case we never see a definition. 1172 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 1173 if (LV.linkage() != ExternalLinkage) { 1174 // Don't set internal linkage on declarations. 1175 } else { 1176 if (D->hasAttr<DLLImportAttr>()) 1177 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 1178 else if (D->hasAttr<WeakAttr>() || D->isWeakImported()) 1179 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 1180 1181 // Set visibility on a declaration only if it's explicit. 1182 if (LV.visibilityExplicit()) 1183 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 1184 } 1185 1186 GV->setThreadLocal(D->isThreadSpecified()); 1187 } 1188 1189 return GV; 1190 } 1191 1192 1193 llvm::GlobalVariable * 1194 CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name, 1195 llvm::Type *Ty, 1196 llvm::GlobalValue::LinkageTypes Linkage) { 1197 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1198 llvm::GlobalVariable *OldGV = 0; 1199 1200 1201 if (GV) { 1202 // Check if the variable has the right type. 1203 if (GV->getType()->getElementType() == Ty) 1204 return GV; 1205 1206 // Because C++ name mangling, the only way we can end up with an already 1207 // existing global with the same name is if it has been declared extern "C". 1208 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1209 OldGV = GV; 1210 } 1211 1212 // Create a new variable. 1213 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1214 Linkage, 0, Name); 1215 1216 if (OldGV) { 1217 // Replace occurrences of the old variable if needed. 1218 GV->takeName(OldGV); 1219 1220 if (!OldGV->use_empty()) { 1221 llvm::Constant *NewPtrForOldDecl = 1222 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1223 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1224 } 1225 1226 OldGV->eraseFromParent(); 1227 } 1228 1229 return GV; 1230 } 1231 1232 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1233 /// given global variable. If Ty is non-null and if the global doesn't exist, 1234 /// then it will be greated with the specified type instead of whatever the 1235 /// normal requested type would be. 1236 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1237 llvm::Type *Ty) { 1238 assert(D->hasGlobalStorage() && "Not a global variable"); 1239 QualType ASTTy = D->getType(); 1240 if (Ty == 0) 1241 Ty = getTypes().ConvertTypeForMem(ASTTy); 1242 1243 llvm::PointerType *PTy = 1244 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy)); 1245 1246 StringRef MangledName = getMangledName(D); 1247 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1248 } 1249 1250 /// CreateRuntimeVariable - Create a new runtime global variable with the 1251 /// specified type and name. 1252 llvm::Constant * 1253 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty, 1254 StringRef Name) { 1255 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1256 true); 1257 } 1258 1259 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1260 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1261 1262 if (MayDeferGeneration(D)) { 1263 // If we have not seen a reference to this variable yet, place it 1264 // into the deferred declarations table to be emitted if needed 1265 // later. 1266 StringRef MangledName = getMangledName(D); 1267 if (!GetGlobalValue(MangledName)) { 1268 DeferredDecls[MangledName] = D; 1269 return; 1270 } 1271 } 1272 1273 // The tentative definition is the only definition. 1274 EmitGlobalVarDefinition(D); 1275 } 1276 1277 void CodeGenModule::EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired) { 1278 if (DefinitionRequired) 1279 getVTables().GenerateClassData(getVTableLinkage(Class), Class); 1280 } 1281 1282 llvm::GlobalVariable::LinkageTypes 1283 CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) { 1284 if (RD->getLinkage() != ExternalLinkage) 1285 return llvm::GlobalVariable::InternalLinkage; 1286 1287 if (const CXXMethodDecl *KeyFunction 1288 = RD->getASTContext().getKeyFunction(RD)) { 1289 // If this class has a key function, use that to determine the linkage of 1290 // the vtable. 1291 const FunctionDecl *Def = 0; 1292 if (KeyFunction->hasBody(Def)) 1293 KeyFunction = cast<CXXMethodDecl>(Def); 1294 1295 switch (KeyFunction->getTemplateSpecializationKind()) { 1296 case TSK_Undeclared: 1297 case TSK_ExplicitSpecialization: 1298 // When compiling with optimizations turned on, we emit all vtables, 1299 // even if the key function is not defined in the current translation 1300 // unit. If this is the case, use available_externally linkage. 1301 if (!Def && CodeGenOpts.OptimizationLevel) 1302 return llvm::GlobalVariable::AvailableExternallyLinkage; 1303 1304 if (KeyFunction->isInlined()) 1305 return !Context.getLangOptions().AppleKext ? 1306 llvm::GlobalVariable::LinkOnceODRLinkage : 1307 llvm::Function::InternalLinkage; 1308 1309 return llvm::GlobalVariable::ExternalLinkage; 1310 1311 case TSK_ImplicitInstantiation: 1312 return !Context.getLangOptions().AppleKext ? 1313 llvm::GlobalVariable::LinkOnceODRLinkage : 1314 llvm::Function::InternalLinkage; 1315 1316 case TSK_ExplicitInstantiationDefinition: 1317 return !Context.getLangOptions().AppleKext ? 1318 llvm::GlobalVariable::WeakODRLinkage : 1319 llvm::Function::InternalLinkage; 1320 1321 case TSK_ExplicitInstantiationDeclaration: 1322 // FIXME: Use available_externally linkage. However, this currently 1323 // breaks LLVM's build due to undefined symbols. 1324 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1325 return !Context.getLangOptions().AppleKext ? 1326 llvm::GlobalVariable::LinkOnceODRLinkage : 1327 llvm::Function::InternalLinkage; 1328 } 1329 } 1330 1331 if (Context.getLangOptions().AppleKext) 1332 return llvm::Function::InternalLinkage; 1333 1334 switch (RD->getTemplateSpecializationKind()) { 1335 case TSK_Undeclared: 1336 case TSK_ExplicitSpecialization: 1337 case TSK_ImplicitInstantiation: 1338 // FIXME: Use available_externally linkage. However, this currently 1339 // breaks LLVM's build due to undefined symbols. 1340 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1341 case TSK_ExplicitInstantiationDeclaration: 1342 return llvm::GlobalVariable::LinkOnceODRLinkage; 1343 1344 case TSK_ExplicitInstantiationDefinition: 1345 return llvm::GlobalVariable::WeakODRLinkage; 1346 } 1347 1348 llvm_unreachable("Invalid TemplateSpecializationKind!"); 1349 } 1350 1351 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const { 1352 return Context.toCharUnitsFromBits( 1353 TheTargetData.getTypeStoreSizeInBits(Ty)); 1354 } 1355 1356 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1357 llvm::Constant *Init = 0; 1358 QualType ASTTy = D->getType(); 1359 bool NonConstInit = false; 1360 1361 const VarDecl *InitDecl; 1362 const Expr *InitExpr = D->getAnyInitializer(InitDecl); 1363 1364 if (!InitExpr) { 1365 // This is a tentative definition; tentative definitions are 1366 // implicitly initialized with { 0 }. 1367 // 1368 // Note that tentative definitions are only emitted at the end of 1369 // a translation unit, so they should never have incomplete 1370 // type. In addition, EmitTentativeDefinition makes sure that we 1371 // never attempt to emit a tentative definition if a real one 1372 // exists. A use may still exists, however, so we still may need 1373 // to do a RAUW. 1374 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1375 Init = EmitNullConstant(D->getType()); 1376 } else { 1377 Init = EmitConstantInit(*InitDecl); 1378 if (!Init) { 1379 QualType T = InitExpr->getType(); 1380 if (D->getType()->isReferenceType()) 1381 T = D->getType(); 1382 1383 if (getLangOptions().CPlusPlus) { 1384 Init = EmitNullConstant(T); 1385 NonConstInit = true; 1386 } else { 1387 ErrorUnsupported(D, "static initializer"); 1388 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1389 } 1390 } else { 1391 // We don't need an initializer, so remove the entry for the delayed 1392 // initializer position (just in case this entry was delayed). 1393 if (getLangOptions().CPlusPlus) 1394 DelayedCXXInitPosition.erase(D); 1395 } 1396 } 1397 1398 llvm::Type* InitType = Init->getType(); 1399 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1400 1401 // Strip off a bitcast if we got one back. 1402 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1403 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1404 // all zero index gep. 1405 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1406 Entry = CE->getOperand(0); 1407 } 1408 1409 // Entry is now either a Function or GlobalVariable. 1410 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1411 1412 // We have a definition after a declaration with the wrong type. 1413 // We must make a new GlobalVariable* and update everything that used OldGV 1414 // (a declaration or tentative definition) with the new GlobalVariable* 1415 // (which will be a definition). 1416 // 1417 // This happens if there is a prototype for a global (e.g. 1418 // "extern int x[];") and then a definition of a different type (e.g. 1419 // "int x[10];"). This also happens when an initializer has a different type 1420 // from the type of the global (this happens with unions). 1421 if (GV == 0 || 1422 GV->getType()->getElementType() != InitType || 1423 GV->getType()->getAddressSpace() != 1424 getContext().getTargetAddressSpace(ASTTy)) { 1425 1426 // Move the old entry aside so that we'll create a new one. 1427 Entry->setName(StringRef()); 1428 1429 // Make a new global with the correct type, this is now guaranteed to work. 1430 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1431 1432 // Replace all uses of the old global with the new global 1433 llvm::Constant *NewPtrForOldDecl = 1434 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1435 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1436 1437 // Erase the old global, since it is no longer used. 1438 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1439 } 1440 1441 if (D->hasAttr<AnnotateAttr>()) 1442 AddGlobalAnnotations(D, GV); 1443 1444 GV->setInitializer(Init); 1445 1446 // If it is safe to mark the global 'constant', do so now. 1447 GV->setConstant(false); 1448 if (!NonConstInit && DeclIsConstantGlobal(Context, D, true)) 1449 GV->setConstant(true); 1450 1451 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1452 1453 // Set the llvm linkage type as appropriate. 1454 llvm::GlobalValue::LinkageTypes Linkage = 1455 GetLLVMLinkageVarDefinition(D, GV); 1456 GV->setLinkage(Linkage); 1457 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1458 // common vars aren't constant even if declared const. 1459 GV->setConstant(false); 1460 1461 SetCommonAttributes(D, GV); 1462 1463 // Emit the initializer function if necessary. 1464 if (NonConstInit) 1465 EmitCXXGlobalVarDeclInitFunc(D, GV); 1466 1467 // Emit global variable debug information. 1468 if (CGDebugInfo *DI = getModuleDebugInfo()) 1469 DI->EmitGlobalVariable(GV, D); 1470 } 1471 1472 llvm::GlobalValue::LinkageTypes 1473 CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, 1474 llvm::GlobalVariable *GV) { 1475 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1476 if (Linkage == GVA_Internal) 1477 return llvm::Function::InternalLinkage; 1478 else if (D->hasAttr<DLLImportAttr>()) 1479 return llvm::Function::DLLImportLinkage; 1480 else if (D->hasAttr<DLLExportAttr>()) 1481 return llvm::Function::DLLExportLinkage; 1482 else if (D->hasAttr<WeakAttr>()) { 1483 if (GV->isConstant()) 1484 return llvm::GlobalVariable::WeakODRLinkage; 1485 else 1486 return llvm::GlobalVariable::WeakAnyLinkage; 1487 } else if (Linkage == GVA_TemplateInstantiation || 1488 Linkage == GVA_ExplicitTemplateInstantiation) 1489 return llvm::GlobalVariable::WeakODRLinkage; 1490 else if (!getLangOptions().CPlusPlus && 1491 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1492 D->getAttr<CommonAttr>()) && 1493 !D->hasExternalStorage() && !D->getInit() && 1494 !D->getAttr<SectionAttr>() && !D->isThreadSpecified() && 1495 !D->getAttr<WeakImportAttr>()) { 1496 // Thread local vars aren't considered common linkage. 1497 return llvm::GlobalVariable::CommonLinkage; 1498 } 1499 return llvm::GlobalVariable::ExternalLinkage; 1500 } 1501 1502 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1503 /// implement a function with no prototype, e.g. "int foo() {}". If there are 1504 /// existing call uses of the old function in the module, this adjusts them to 1505 /// call the new function directly. 1506 /// 1507 /// This is not just a cleanup: the always_inline pass requires direct calls to 1508 /// functions to be able to inline them. If there is a bitcast in the way, it 1509 /// won't inline them. Instcombine normally deletes these calls, but it isn't 1510 /// run at -O0. 1511 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1512 llvm::Function *NewFn) { 1513 // If we're redefining a global as a function, don't transform it. 1514 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1515 if (OldFn == 0) return; 1516 1517 llvm::Type *NewRetTy = NewFn->getReturnType(); 1518 SmallVector<llvm::Value*, 4> ArgList; 1519 1520 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1521 UI != E; ) { 1522 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1523 llvm::Value::use_iterator I = UI++; // Increment before the CI is erased. 1524 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*I); 1525 if (!CI) continue; // FIXME: when we allow Invoke, just do CallSite CS(*I) 1526 llvm::CallSite CS(CI); 1527 if (!CI || !CS.isCallee(I)) continue; 1528 1529 // If the return types don't match exactly, and if the call isn't dead, then 1530 // we can't transform this call. 1531 if (CI->getType() != NewRetTy && !CI->use_empty()) 1532 continue; 1533 1534 // Get the attribute list. 1535 llvm::SmallVector<llvm::AttributeWithIndex, 8> AttrVec; 1536 llvm::AttrListPtr AttrList = CI->getAttributes(); 1537 1538 // Get any return attributes. 1539 llvm::Attributes RAttrs = AttrList.getRetAttributes(); 1540 1541 // Add the return attributes. 1542 if (RAttrs) 1543 AttrVec.push_back(llvm::AttributeWithIndex::get(0, RAttrs)); 1544 1545 // If the function was passed too few arguments, don't transform. If extra 1546 // arguments were passed, we silently drop them. If any of the types 1547 // mismatch, we don't transform. 1548 unsigned ArgNo = 0; 1549 bool DontTransform = false; 1550 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1551 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1552 if (CS.arg_size() == ArgNo || 1553 CS.getArgument(ArgNo)->getType() != AI->getType()) { 1554 DontTransform = true; 1555 break; 1556 } 1557 1558 // Add any parameter attributes. 1559 if (llvm::Attributes PAttrs = AttrList.getParamAttributes(ArgNo + 1)) 1560 AttrVec.push_back(llvm::AttributeWithIndex::get(ArgNo + 1, PAttrs)); 1561 } 1562 if (DontTransform) 1563 continue; 1564 1565 if (llvm::Attributes FnAttrs = AttrList.getFnAttributes()) 1566 AttrVec.push_back(llvm::AttributeWithIndex::get(~0, FnAttrs)); 1567 1568 // Okay, we can transform this. Create the new call instruction and copy 1569 // over the required information. 1570 ArgList.append(CS.arg_begin(), CS.arg_begin() + ArgNo); 1571 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList, "", CI); 1572 ArgList.clear(); 1573 if (!NewCall->getType()->isVoidTy()) 1574 NewCall->takeName(CI); 1575 NewCall->setAttributes(llvm::AttrListPtr::get(AttrVec.begin(), 1576 AttrVec.end())); 1577 NewCall->setCallingConv(CI->getCallingConv()); 1578 1579 // Finally, remove the old call, replacing any uses with the new one. 1580 if (!CI->use_empty()) 1581 CI->replaceAllUsesWith(NewCall); 1582 1583 // Copy debug location attached to CI. 1584 if (!CI->getDebugLoc().isUnknown()) 1585 NewCall->setDebugLoc(CI->getDebugLoc()); 1586 CI->eraseFromParent(); 1587 } 1588 } 1589 1590 1591 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1592 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1593 1594 // Compute the function info and LLVM type. 1595 const CGFunctionInfo &FI = getTypes().getFunctionInfo(GD); 1596 bool variadic = false; 1597 if (const FunctionProtoType *fpt = D->getType()->getAs<FunctionProtoType>()) 1598 variadic = fpt->isVariadic(); 1599 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI, variadic); 1600 1601 // Get or create the prototype for the function. 1602 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1603 1604 // Strip off a bitcast if we got one back. 1605 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1606 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1607 Entry = CE->getOperand(0); 1608 } 1609 1610 1611 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1612 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1613 1614 // If the types mismatch then we have to rewrite the definition. 1615 assert(OldFn->isDeclaration() && 1616 "Shouldn't replace non-declaration"); 1617 1618 // F is the Function* for the one with the wrong type, we must make a new 1619 // Function* and update everything that used F (a declaration) with the new 1620 // Function* (which will be a definition). 1621 // 1622 // This happens if there is a prototype for a function 1623 // (e.g. "int f()") and then a definition of a different type 1624 // (e.g. "int f(int x)"). Move the old function aside so that it 1625 // doesn't interfere with GetAddrOfFunction. 1626 OldFn->setName(StringRef()); 1627 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1628 1629 // If this is an implementation of a function without a prototype, try to 1630 // replace any existing uses of the function (which may be calls) with uses 1631 // of the new function 1632 if (D->getType()->isFunctionNoProtoType()) { 1633 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1634 OldFn->removeDeadConstantUsers(); 1635 } 1636 1637 // Replace uses of F with the Function we will endow with a body. 1638 if (!Entry->use_empty()) { 1639 llvm::Constant *NewPtrForOldDecl = 1640 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1641 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1642 } 1643 1644 // Ok, delete the old function now, which is dead. 1645 OldFn->eraseFromParent(); 1646 1647 Entry = NewFn; 1648 } 1649 1650 // We need to set linkage and visibility on the function before 1651 // generating code for it because various parts of IR generation 1652 // want to propagate this information down (e.g. to local static 1653 // declarations). 1654 llvm::Function *Fn = cast<llvm::Function>(Entry); 1655 setFunctionLinkage(D, Fn); 1656 1657 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 1658 setGlobalVisibility(Fn, D); 1659 1660 CodeGenFunction(*this).GenerateCode(D, Fn, FI); 1661 1662 SetFunctionDefinitionAttributes(D, Fn); 1663 SetLLVMFunctionAttributesForDefinition(D, Fn); 1664 1665 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1666 AddGlobalCtor(Fn, CA->getPriority()); 1667 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1668 AddGlobalDtor(Fn, DA->getPriority()); 1669 if (D->hasAttr<AnnotateAttr>()) 1670 AddGlobalAnnotations(D, Fn); 1671 } 1672 1673 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 1674 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1675 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1676 assert(AA && "Not an alias?"); 1677 1678 StringRef MangledName = getMangledName(GD); 1679 1680 // If there is a definition in the module, then it wins over the alias. 1681 // This is dubious, but allow it to be safe. Just ignore the alias. 1682 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1683 if (Entry && !Entry->isDeclaration()) 1684 return; 1685 1686 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1687 1688 // Create a reference to the named value. This ensures that it is emitted 1689 // if a deferred decl. 1690 llvm::Constant *Aliasee; 1691 if (isa<llvm::FunctionType>(DeclTy)) 1692 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 1693 /*ForVTable=*/false); 1694 else 1695 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1696 llvm::PointerType::getUnqual(DeclTy), 0); 1697 1698 // Create the new alias itself, but don't set a name yet. 1699 llvm::GlobalValue *GA = 1700 new llvm::GlobalAlias(Aliasee->getType(), 1701 llvm::Function::ExternalLinkage, 1702 "", Aliasee, &getModule()); 1703 1704 if (Entry) { 1705 assert(Entry->isDeclaration()); 1706 1707 // If there is a declaration in the module, then we had an extern followed 1708 // by the alias, as in: 1709 // extern int test6(); 1710 // ... 1711 // int test6() __attribute__((alias("test7"))); 1712 // 1713 // Remove it and replace uses of it with the alias. 1714 GA->takeName(Entry); 1715 1716 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1717 Entry->getType())); 1718 Entry->eraseFromParent(); 1719 } else { 1720 GA->setName(MangledName); 1721 } 1722 1723 // Set attributes which are particular to an alias; this is a 1724 // specialization of the attributes which may be set on a global 1725 // variable/function. 1726 if (D->hasAttr<DLLExportAttr>()) { 1727 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1728 // The dllexport attribute is ignored for undefined symbols. 1729 if (FD->hasBody()) 1730 GA->setLinkage(llvm::Function::DLLExportLinkage); 1731 } else { 1732 GA->setLinkage(llvm::Function::DLLExportLinkage); 1733 } 1734 } else if (D->hasAttr<WeakAttr>() || 1735 D->hasAttr<WeakRefAttr>() || 1736 D->isWeakImported()) { 1737 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1738 } 1739 1740 SetCommonAttributes(D, GA); 1741 } 1742 1743 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID, 1744 ArrayRef<llvm::Type*> Tys) { 1745 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID, 1746 Tys); 1747 } 1748 1749 static llvm::StringMapEntry<llvm::Constant*> & 1750 GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1751 const StringLiteral *Literal, 1752 bool TargetIsLSB, 1753 bool &IsUTF16, 1754 unsigned &StringLength) { 1755 StringRef String = Literal->getString(); 1756 unsigned NumBytes = String.size(); 1757 1758 // Check for simple case. 1759 if (!Literal->containsNonAsciiOrNull()) { 1760 StringLength = NumBytes; 1761 return Map.GetOrCreateValue(String); 1762 } 1763 1764 // Otherwise, convert the UTF8 literals into a byte string. 1765 SmallVector<UTF16, 128> ToBuf(NumBytes); 1766 const UTF8 *FromPtr = (UTF8 *)String.data(); 1767 UTF16 *ToPtr = &ToBuf[0]; 1768 1769 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 1770 &ToPtr, ToPtr + NumBytes, 1771 strictConversion); 1772 1773 // ConvertUTF8toUTF16 returns the length in ToPtr. 1774 StringLength = ToPtr - &ToBuf[0]; 1775 1776 // Render the UTF-16 string into a byte array and convert to the target byte 1777 // order. 1778 // 1779 // FIXME: This isn't something we should need to do here. 1780 SmallString<128> AsBytes; 1781 AsBytes.reserve(StringLength * 2); 1782 for (unsigned i = 0; i != StringLength; ++i) { 1783 unsigned short Val = ToBuf[i]; 1784 if (TargetIsLSB) { 1785 AsBytes.push_back(Val & 0xFF); 1786 AsBytes.push_back(Val >> 8); 1787 } else { 1788 AsBytes.push_back(Val >> 8); 1789 AsBytes.push_back(Val & 0xFF); 1790 } 1791 } 1792 // Append one extra null character, the second is automatically added by our 1793 // caller. 1794 AsBytes.push_back(0); 1795 1796 IsUTF16 = true; 1797 return Map.GetOrCreateValue(StringRef(AsBytes.data(), AsBytes.size())); 1798 } 1799 1800 static llvm::StringMapEntry<llvm::Constant*> & 1801 GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1802 const StringLiteral *Literal, 1803 unsigned &StringLength) 1804 { 1805 StringRef String = Literal->getString(); 1806 StringLength = String.size(); 1807 return Map.GetOrCreateValue(String); 1808 } 1809 1810 llvm::Constant * 1811 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 1812 unsigned StringLength = 0; 1813 bool isUTF16 = false; 1814 llvm::StringMapEntry<llvm::Constant*> &Entry = 1815 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1816 getTargetData().isLittleEndian(), 1817 isUTF16, 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 __CFConstantStringClassReference. 1827 if (!CFConstantStringClassRef) { 1828 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1829 Ty = llvm::ArrayType::get(Ty, 0); 1830 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1831 "__CFConstantStringClassReference"); 1832 // Decay array -> ptr 1833 CFConstantStringClassRef = 1834 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1835 } 1836 1837 QualType CFTy = getContext().getCFConstantStringType(); 1838 1839 llvm::StructType *STy = 1840 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1841 1842 llvm::Constant *Fields[4]; 1843 1844 // Class pointer. 1845 Fields[0] = CFConstantStringClassRef; 1846 1847 // Flags. 1848 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1849 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 1850 llvm::ConstantInt::get(Ty, 0x07C8); 1851 1852 // String pointer. 1853 llvm::Constant *C = llvm::ConstantDataArray::getString(VMContext, 1854 Entry.getKey()); 1855 1856 llvm::GlobalValue::LinkageTypes Linkage; 1857 if (isUTF16) 1858 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1859 Linkage = llvm::GlobalValue::InternalLinkage; 1860 else 1861 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error 1862 // when using private linkage. It is not clear if this is a bug in ld 1863 // or a reasonable new restriction. 1864 Linkage = llvm::GlobalValue::LinkerPrivateLinkage; 1865 1866 // Note: -fwritable-strings doesn't make the backing store strings of 1867 // CFStrings writable. (See <rdar://problem/10657500>) 1868 llvm::GlobalVariable *GV = 1869 new llvm::GlobalVariable(getModule(), C->getType(), /*isConstant=*/true, 1870 Linkage, C, ".str"); 1871 GV->setUnnamedAddr(true); 1872 if (isUTF16) { 1873 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 1874 GV->setAlignment(Align.getQuantity()); 1875 } else { 1876 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 1877 GV->setAlignment(Align.getQuantity()); 1878 } 1879 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1880 1881 // String length. 1882 Ty = getTypes().ConvertType(getContext().LongTy); 1883 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 1884 1885 // The struct. 1886 C = llvm::ConstantStruct::get(STy, Fields); 1887 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1888 llvm::GlobalVariable::PrivateLinkage, C, 1889 "_unnamed_cfstring_"); 1890 if (const char *Sect = getContext().getTargetInfo().getCFStringSection()) 1891 GV->setSection(Sect); 1892 Entry.setValue(GV); 1893 1894 return GV; 1895 } 1896 1897 static RecordDecl * 1898 CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK, 1899 DeclContext *DC, IdentifierInfo *Id) { 1900 SourceLocation Loc; 1901 if (Ctx.getLangOptions().CPlusPlus) 1902 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 1903 else 1904 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id); 1905 } 1906 1907 llvm::Constant * 1908 CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 1909 unsigned StringLength = 0; 1910 llvm::StringMapEntry<llvm::Constant*> &Entry = 1911 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength); 1912 1913 if (llvm::Constant *C = Entry.getValue()) 1914 return C; 1915 1916 llvm::Constant *Zero = 1917 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1918 llvm::Constant *Zeros[] = { Zero, Zero }; 1919 1920 // If we don't already have it, get _NSConstantStringClassReference. 1921 if (!ConstantStringClassRef) { 1922 std::string StringClass(getLangOptions().ObjCConstantStringClass); 1923 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1924 llvm::Constant *GV; 1925 if (Features.ObjCNonFragileABI) { 1926 std::string str = 1927 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString" 1928 : "OBJC_CLASS_$_" + StringClass; 1929 GV = getObjCRuntime().GetClassGlobal(str); 1930 // Make sure the result is of the correct type. 1931 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 1932 ConstantStringClassRef = 1933 llvm::ConstantExpr::getBitCast(GV, PTy); 1934 } else { 1935 std::string str = 1936 StringClass.empty() ? "_NSConstantStringClassReference" 1937 : "_" + StringClass + "ClassReference"; 1938 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0); 1939 GV = CreateRuntimeVariable(PTy, str); 1940 // Decay array -> ptr 1941 ConstantStringClassRef = 1942 llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 1943 } 1944 } 1945 1946 if (!NSConstantStringType) { 1947 // Construct the type for a constant NSString. 1948 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 1949 Context.getTranslationUnitDecl(), 1950 &Context.Idents.get("__builtin_NSString")); 1951 D->startDefinition(); 1952 1953 QualType FieldTypes[3]; 1954 1955 // const int *isa; 1956 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst()); 1957 // const char *str; 1958 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst()); 1959 // unsigned int length; 1960 FieldTypes[2] = Context.UnsignedIntTy; 1961 1962 // Create fields 1963 for (unsigned i = 0; i < 3; ++i) { 1964 FieldDecl *Field = FieldDecl::Create(Context, D, 1965 SourceLocation(), 1966 SourceLocation(), 0, 1967 FieldTypes[i], /*TInfo=*/0, 1968 /*BitWidth=*/0, 1969 /*Mutable=*/false, 1970 /*HasInit=*/false); 1971 Field->setAccess(AS_public); 1972 D->addDecl(Field); 1973 } 1974 1975 D->completeDefinition(); 1976 QualType NSTy = Context.getTagDeclType(D); 1977 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 1978 } 1979 1980 llvm::Constant *Fields[3]; 1981 1982 // Class pointer. 1983 Fields[0] = ConstantStringClassRef; 1984 1985 // String pointer. 1986 llvm::Constant *C = 1987 llvm::ConstantDataArray::getString(VMContext, Entry.getKey()); 1988 1989 llvm::GlobalValue::LinkageTypes Linkage; 1990 bool isConstant; 1991 Linkage = llvm::GlobalValue::PrivateLinkage; 1992 isConstant = !Features.WritableStrings; 1993 1994 llvm::GlobalVariable *GV = 1995 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1996 ".str"); 1997 GV->setUnnamedAddr(true); 1998 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy); 1999 GV->setAlignment(Align.getQuantity()); 2000 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros); 2001 2002 // String length. 2003 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 2004 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 2005 2006 // The struct. 2007 C = llvm::ConstantStruct::get(NSConstantStringType, Fields); 2008 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 2009 llvm::GlobalVariable::PrivateLinkage, C, 2010 "_unnamed_nsstring_"); 2011 // FIXME. Fix section. 2012 if (const char *Sect = 2013 Features.ObjCNonFragileABI 2014 ? getContext().getTargetInfo().getNSStringNonFragileABISection() 2015 : getContext().getTargetInfo().getNSStringSection()) 2016 GV->setSection(Sect); 2017 Entry.setValue(GV); 2018 2019 return GV; 2020 } 2021 2022 QualType CodeGenModule::getObjCFastEnumerationStateType() { 2023 if (ObjCFastEnumerationStateType.isNull()) { 2024 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct, 2025 Context.getTranslationUnitDecl(), 2026 &Context.Idents.get("__objcFastEnumerationState")); 2027 D->startDefinition(); 2028 2029 QualType FieldTypes[] = { 2030 Context.UnsignedLongTy, 2031 Context.getPointerType(Context.getObjCIdType()), 2032 Context.getPointerType(Context.UnsignedLongTy), 2033 Context.getConstantArrayType(Context.UnsignedLongTy, 2034 llvm::APInt(32, 5), ArrayType::Normal, 0) 2035 }; 2036 2037 for (size_t i = 0; i < 4; ++i) { 2038 FieldDecl *Field = FieldDecl::Create(Context, 2039 D, 2040 SourceLocation(), 2041 SourceLocation(), 0, 2042 FieldTypes[i], /*TInfo=*/0, 2043 /*BitWidth=*/0, 2044 /*Mutable=*/false, 2045 /*HasInit=*/false); 2046 Field->setAccess(AS_public); 2047 D->addDecl(Field); 2048 } 2049 2050 D->completeDefinition(); 2051 ObjCFastEnumerationStateType = Context.getTagDeclType(D); 2052 } 2053 2054 return ObjCFastEnumerationStateType; 2055 } 2056 2057 /// GetStringForStringLiteral - Return the appropriate bytes for a 2058 /// string literal, properly padded to match the literal type. 2059 static std::string GetStringForStringLiteral(const StringLiteral *E, 2060 const ASTContext &Context) { 2061 assert((E->isAscii() || E->isUTF8()) 2062 && "Use GetConstantArrayFromStringLiteral for wide strings"); 2063 const ConstantArrayType *CAT = 2064 Context.getAsConstantArrayType(E->getType()); 2065 assert(CAT && "String isn't pointer or array!"); 2066 2067 // Resize the string to the right size. 2068 uint64_t RealLen = CAT->getSize().getZExtValue(); 2069 2070 std::string Str = E->getString().str(); 2071 Str.resize(RealLen, '\0'); 2072 return Str; 2073 } 2074 2075 llvm::Constant * 2076 CodeGenModule::GetConstantArrayFromStringLiteral(const StringLiteral *E) { 2077 assert(!E->getType()->isPointerType() && "Strings are always arrays"); 2078 2079 // Don't emit it as the address of the string, emit the string data itself 2080 // as an inline array. 2081 if (E->getCharByteWidth() == 1) 2082 return llvm::ConstantDataArray::getString(VMContext, 2083 GetStringForStringLiteral(E, getContext()), 2084 false); 2085 2086 llvm::ArrayType *AType = 2087 cast<llvm::ArrayType>(getTypes().ConvertType(E->getType())); 2088 llvm::Type *ElemTy = AType->getElementType(); 2089 unsigned NumElements = AType->getNumElements(); 2090 std::vector<llvm::Constant*> Elts; 2091 Elts.reserve(NumElements); 2092 2093 for(unsigned i=0;i<E->getLength();++i) { 2094 unsigned value = E->getCodeUnit(i); 2095 llvm::Constant *C = llvm::ConstantInt::get(ElemTy,value,false); 2096 Elts.push_back(C); 2097 } 2098 for(unsigned i=E->getLength();i<NumElements;++i) { 2099 llvm::Constant *C = llvm::ConstantInt::get(ElemTy,0,false); 2100 Elts.push_back(C); 2101 } 2102 2103 return llvm::ConstantArray::get(AType, Elts); 2104 } 2105 2106 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a 2107 /// constant array for the given string literal. 2108 llvm::Constant * 2109 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 2110 // FIXME: This can be more efficient. 2111 // FIXME: We shouldn't need to bitcast the constant in the wide string case. 2112 CharUnits Align = getContext().getTypeAlignInChars(S->getType()); 2113 if (S->isAscii() || S->isUTF8()) { 2114 return GetAddrOfConstantString(GetStringForStringLiteral(S, getContext()), 2115 /* GlobalName */ 0, 2116 Align.getQuantity()); 2117 } 2118 2119 // FIXME: the following does not memoize wide strings 2120 llvm::Constant *C = GetConstantArrayFromStringLiteral(S); 2121 llvm::GlobalVariable *GV = 2122 new llvm::GlobalVariable(getModule(),C->getType(), 2123 !Features.WritableStrings, 2124 llvm::GlobalValue::PrivateLinkage, 2125 C,".str"); 2126 2127 GV->setAlignment(Align.getQuantity()); 2128 GV->setUnnamedAddr(true); 2129 2130 return GV; 2131 } 2132 2133 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 2134 /// array for the given ObjCEncodeExpr node. 2135 llvm::Constant * 2136 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 2137 std::string Str; 2138 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 2139 2140 return GetAddrOfConstantCString(Str); 2141 } 2142 2143 2144 /// GenerateWritableString -- Creates storage for a string literal. 2145 static llvm::GlobalVariable *GenerateStringLiteral(StringRef str, 2146 bool constant, 2147 CodeGenModule &CGM, 2148 const char *GlobalName, 2149 unsigned Alignment) { 2150 // Create Constant for this string literal. Don't add a '\0'. 2151 llvm::Constant *C = 2152 llvm::ConstantDataArray::getString(CGM.getLLVMContext(), str, false); 2153 2154 // Create a global variable for this string 2155 llvm::GlobalVariable *GV = 2156 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 2157 llvm::GlobalValue::PrivateLinkage, 2158 C, GlobalName); 2159 GV->setAlignment(Alignment); 2160 GV->setUnnamedAddr(true); 2161 return GV; 2162 } 2163 2164 /// GetAddrOfConstantString - Returns a pointer to a character array 2165 /// containing the literal. This contents are exactly that of the 2166 /// given string, i.e. it will not be null terminated automatically; 2167 /// see GetAddrOfConstantCString. Note that whether the result is 2168 /// actually a pointer to an LLVM constant depends on 2169 /// Feature.WriteableStrings. 2170 /// 2171 /// The result has pointer to array type. 2172 llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str, 2173 const char *GlobalName, 2174 unsigned Alignment) { 2175 bool IsConstant = !Features.WritableStrings; 2176 2177 // Get the default prefix if a name wasn't specified. 2178 if (!GlobalName) 2179 GlobalName = ".str"; 2180 2181 // Don't share any string literals if strings aren't constant. 2182 if (!IsConstant) 2183 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment); 2184 2185 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry = 2186 ConstantStringMap.GetOrCreateValue(Str); 2187 2188 if (llvm::GlobalVariable *GV = Entry.getValue()) { 2189 if (Alignment > GV->getAlignment()) { 2190 GV->setAlignment(Alignment); 2191 } 2192 return GV; 2193 } 2194 2195 // Create a global variable for this. 2196 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, Alignment); 2197 Entry.setValue(GV); 2198 return GV; 2199 } 2200 2201 /// GetAddrOfConstantCString - Returns a pointer to a character 2202 /// array containing the literal and a terminating '\0' 2203 /// character. The result has pointer to array type. 2204 llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str, 2205 const char *GlobalName, 2206 unsigned Alignment) { 2207 StringRef StrWithNull(Str.c_str(), Str.size() + 1); 2208 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment); 2209 } 2210 2211 /// EmitObjCPropertyImplementations - Emit information for synthesized 2212 /// properties for an implementation. 2213 void CodeGenModule::EmitObjCPropertyImplementations(const 2214 ObjCImplementationDecl *D) { 2215 for (ObjCImplementationDecl::propimpl_iterator 2216 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 2217 ObjCPropertyImplDecl *PID = *i; 2218 2219 // Dynamic is just for type-checking. 2220 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 2221 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2222 2223 // Determine which methods need to be implemented, some may have 2224 // been overridden. Note that ::isSynthesized is not the method 2225 // we want, that just indicates if the decl came from a 2226 // property. What we want to know is if the method is defined in 2227 // this implementation. 2228 if (!D->getInstanceMethod(PD->getGetterName())) 2229 CodeGenFunction(*this).GenerateObjCGetter( 2230 const_cast<ObjCImplementationDecl *>(D), PID); 2231 if (!PD->isReadOnly() && 2232 !D->getInstanceMethod(PD->getSetterName())) 2233 CodeGenFunction(*this).GenerateObjCSetter( 2234 const_cast<ObjCImplementationDecl *>(D), PID); 2235 } 2236 } 2237 } 2238 2239 static bool needsDestructMethod(ObjCImplementationDecl *impl) { 2240 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 2241 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 2242 ivar; ivar = ivar->getNextIvar()) 2243 if (ivar->getType().isDestructedType()) 2244 return true; 2245 2246 return false; 2247 } 2248 2249 /// EmitObjCIvarInitializations - Emit information for ivar initialization 2250 /// for an implementation. 2251 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 2252 // We might need a .cxx_destruct even if we don't have any ivar initializers. 2253 if (needsDestructMethod(D)) { 2254 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 2255 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2256 ObjCMethodDecl *DTORMethod = 2257 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(), 2258 cxxSelector, getContext().VoidTy, 0, D, 2259 /*isInstance=*/true, /*isVariadic=*/false, 2260 /*isSynthesized=*/true, /*isImplicitlyDeclared=*/true, 2261 /*isDefined=*/false, ObjCMethodDecl::Required); 2262 D->addInstanceMethod(DTORMethod); 2263 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 2264 D->setHasCXXStructors(true); 2265 } 2266 2267 // If the implementation doesn't have any ivar initializers, we don't need 2268 // a .cxx_construct. 2269 if (D->getNumIvarInitializers() == 0) 2270 return; 2271 2272 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct"); 2273 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 2274 // The constructor returns 'self'. 2275 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 2276 D->getLocation(), 2277 D->getLocation(), 2278 cxxSelector, 2279 getContext().getObjCIdType(), 0, 2280 D, /*isInstance=*/true, 2281 /*isVariadic=*/false, 2282 /*isSynthesized=*/true, 2283 /*isImplicitlyDeclared=*/true, 2284 /*isDefined=*/false, 2285 ObjCMethodDecl::Required); 2286 D->addInstanceMethod(CTORMethod); 2287 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 2288 D->setHasCXXStructors(true); 2289 } 2290 2291 /// EmitNamespace - Emit all declarations in a namespace. 2292 void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 2293 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 2294 I != E; ++I) 2295 EmitTopLevelDecl(*I); 2296 } 2297 2298 // EmitLinkageSpec - Emit all declarations in a linkage spec. 2299 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 2300 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 2301 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 2302 ErrorUnsupported(LSD, "linkage spec"); 2303 return; 2304 } 2305 2306 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 2307 I != E; ++I) 2308 EmitTopLevelDecl(*I); 2309 } 2310 2311 /// EmitTopLevelDecl - Emit code for a single top level declaration. 2312 void CodeGenModule::EmitTopLevelDecl(Decl *D) { 2313 // If an error has occurred, stop code generation, but continue 2314 // parsing and semantic analysis (to ensure all warnings and errors 2315 // are emitted). 2316 if (Diags.hasErrorOccurred()) 2317 return; 2318 2319 // Ignore dependent declarations. 2320 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 2321 return; 2322 2323 switch (D->getKind()) { 2324 case Decl::CXXConversion: 2325 case Decl::CXXMethod: 2326 case Decl::Function: 2327 // Skip function templates 2328 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2329 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2330 return; 2331 2332 EmitGlobal(cast<FunctionDecl>(D)); 2333 break; 2334 2335 case Decl::Var: 2336 EmitGlobal(cast<VarDecl>(D)); 2337 break; 2338 2339 // Indirect fields from global anonymous structs and unions can be 2340 // ignored; only the actual variable requires IR gen support. 2341 case Decl::IndirectField: 2342 break; 2343 2344 // C++ Decls 2345 case Decl::Namespace: 2346 EmitNamespace(cast<NamespaceDecl>(D)); 2347 break; 2348 // No code generation needed. 2349 case Decl::UsingShadow: 2350 case Decl::Using: 2351 case Decl::UsingDirective: 2352 case Decl::ClassTemplate: 2353 case Decl::FunctionTemplate: 2354 case Decl::TypeAliasTemplate: 2355 case Decl::NamespaceAlias: 2356 case Decl::Block: 2357 case Decl::Import: 2358 break; 2359 case Decl::CXXConstructor: 2360 // Skip function templates 2361 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() || 2362 cast<FunctionDecl>(D)->isLateTemplateParsed()) 2363 return; 2364 2365 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2366 break; 2367 case Decl::CXXDestructor: 2368 if (cast<FunctionDecl>(D)->isLateTemplateParsed()) 2369 return; 2370 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2371 break; 2372 2373 case Decl::StaticAssert: 2374 // Nothing to do. 2375 break; 2376 2377 // Objective-C Decls 2378 2379 // Forward declarations, no (immediate) code generation. 2380 case Decl::ObjCInterface: 2381 break; 2382 2383 case Decl::ObjCCategory: { 2384 ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D); 2385 if (CD->IsClassExtension() && CD->hasSynthBitfield()) 2386 Context.ResetObjCLayout(CD->getClassInterface()); 2387 break; 2388 } 2389 2390 case Decl::ObjCProtocol: { 2391 ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(D); 2392 if (Proto->isThisDeclarationADefinition()) 2393 ObjCRuntime->GenerateProtocol(Proto); 2394 break; 2395 } 2396 2397 case Decl::ObjCCategoryImpl: 2398 // Categories have properties but don't support synthesize so we 2399 // can ignore them here. 2400 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2401 break; 2402 2403 case Decl::ObjCImplementation: { 2404 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2405 if (Features.ObjCNonFragileABI2 && OMD->hasSynthBitfield()) 2406 Context.ResetObjCLayout(OMD->getClassInterface()); 2407 EmitObjCPropertyImplementations(OMD); 2408 EmitObjCIvarInitializations(OMD); 2409 ObjCRuntime->GenerateClass(OMD); 2410 break; 2411 } 2412 case Decl::ObjCMethod: { 2413 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 2414 // If this is not a prototype, emit the body. 2415 if (OMD->getBody()) 2416 CodeGenFunction(*this).GenerateObjCMethod(OMD); 2417 break; 2418 } 2419 case Decl::ObjCCompatibleAlias: 2420 ObjCRuntime->RegisterAlias(cast<ObjCCompatibleAliasDecl>(D)); 2421 break; 2422 2423 case Decl::LinkageSpec: 2424 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 2425 break; 2426 2427 case Decl::FileScopeAsm: { 2428 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 2429 StringRef AsmString = AD->getAsmString()->getString(); 2430 2431 const std::string &S = getModule().getModuleInlineAsm(); 2432 if (S.empty()) 2433 getModule().setModuleInlineAsm(AsmString); 2434 else if (*--S.end() == '\n') 2435 getModule().setModuleInlineAsm(S + AsmString.str()); 2436 else 2437 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 2438 break; 2439 } 2440 2441 default: 2442 // Make sure we handled everything we should, every other kind is a 2443 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 2444 // function. Need to recode Decl::Kind to do that easily. 2445 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 2446 } 2447 } 2448 2449 /// Turns the given pointer into a constant. 2450 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 2451 const void *Ptr) { 2452 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 2453 llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 2454 return llvm::ConstantInt::get(i64, PtrInt); 2455 } 2456 2457 static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 2458 llvm::NamedMDNode *&GlobalMetadata, 2459 GlobalDecl D, 2460 llvm::GlobalValue *Addr) { 2461 if (!GlobalMetadata) 2462 GlobalMetadata = 2463 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 2464 2465 // TODO: should we report variant information for ctors/dtors? 2466 llvm::Value *Ops[] = { 2467 Addr, 2468 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 2469 }; 2470 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 2471 } 2472 2473 /// Emits metadata nodes associating all the global values in the 2474 /// current module with the Decls they came from. This is useful for 2475 /// projects using IR gen as a subroutine. 2476 /// 2477 /// Since there's currently no way to associate an MDNode directly 2478 /// with an llvm::GlobalValue, we create a global named metadata 2479 /// with the name 'clang.global.decl.ptrs'. 2480 void CodeGenModule::EmitDeclMetadata() { 2481 llvm::NamedMDNode *GlobalMetadata = 0; 2482 2483 // StaticLocalDeclMap 2484 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator 2485 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 2486 I != E; ++I) { 2487 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 2488 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 2489 } 2490 } 2491 2492 /// Emits metadata nodes for all the local variables in the current 2493 /// function. 2494 void CodeGenFunction::EmitDeclMetadata() { 2495 if (LocalDeclMap.empty()) return; 2496 2497 llvm::LLVMContext &Context = getLLVMContext(); 2498 2499 // Find the unique metadata ID for this name. 2500 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 2501 2502 llvm::NamedMDNode *GlobalMetadata = 0; 2503 2504 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 2505 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 2506 const Decl *D = I->first; 2507 llvm::Value *Addr = I->second; 2508 2509 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 2510 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 2511 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr)); 2512 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 2513 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 2514 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 2515 } 2516 } 2517 } 2518 2519 void CodeGenModule::EmitCoverageFile() { 2520 if (!getCodeGenOpts().CoverageFile.empty()) { 2521 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) { 2522 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov"); 2523 llvm::LLVMContext &Ctx = TheModule.getContext(); 2524 llvm::MDString *CoverageFile = 2525 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile); 2526 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) { 2527 llvm::MDNode *CU = CUNode->getOperand(i); 2528 llvm::Value *node[] = { CoverageFile, CU }; 2529 llvm::MDNode *N = llvm::MDNode::get(Ctx, node); 2530 GCov->addOperand(N); 2531 } 2532 } 2533 } 2534 } 2535