CodeGenModule.cpp revision 219077
1//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This coordinates the per-module state used while generating code. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenModule.h" 15#include "CGDebugInfo.h" 16#include "CodeGenFunction.h" 17#include "CodeGenTBAA.h" 18#include "CGCall.h" 19#include "CGCXXABI.h" 20#include "CGObjCRuntime.h" 21#include "TargetInfo.h" 22#include "clang/Frontend/CodeGenOptions.h" 23#include "clang/AST/ASTContext.h" 24#include "clang/AST/CharUnits.h" 25#include "clang/AST/DeclObjC.h" 26#include "clang/AST/DeclCXX.h" 27#include "clang/AST/DeclTemplate.h" 28#include "clang/AST/Mangle.h" 29#include "clang/AST/RecordLayout.h" 30#include "clang/Basic/Builtins.h" 31#include "clang/Basic/Diagnostic.h" 32#include "clang/Basic/SourceManager.h" 33#include "clang/Basic/TargetInfo.h" 34#include "clang/Basic/ConvertUTF.h" 35#include "llvm/CallingConv.h" 36#include "llvm/Module.h" 37#include "llvm/Intrinsics.h" 38#include "llvm/LLVMContext.h" 39#include "llvm/ADT/Triple.h" 40#include "llvm/Target/Mangler.h" 41#include "llvm/Target/TargetData.h" 42#include "llvm/Support/CallSite.h" 43#include "llvm/Support/ErrorHandling.h" 44using namespace clang; 45using namespace CodeGen; 46 47static CGCXXABI &createCXXABI(CodeGenModule &CGM) { 48 switch (CGM.getContext().Target.getCXXABI()) { 49 case CXXABI_ARM: return *CreateARMCXXABI(CGM); 50 case CXXABI_Itanium: return *CreateItaniumCXXABI(CGM); 51 case CXXABI_Microsoft: return *CreateMicrosoftCXXABI(CGM); 52 } 53 54 llvm_unreachable("invalid C++ ABI kind"); 55 return *CreateItaniumCXXABI(CGM); 56} 57 58 59CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 60 llvm::Module &M, const llvm::TargetData &TD, 61 Diagnostic &diags) 62 : Context(C), Features(C.getLangOptions()), CodeGenOpts(CGO), TheModule(M), 63 TheTargetData(TD), TheTargetCodeGenInfo(0), Diags(diags), 64 ABI(createCXXABI(*this)), 65 Types(C, M, TD, getTargetCodeGenInfo().getABIInfo(), ABI), 66 TBAA(0), 67 VTables(*this), Runtime(0), 68 CFConstantStringClassRef(0), ConstantStringClassRef(0), 69 VMContext(M.getContext()), 70 NSConcreteGlobalBlockDecl(0), NSConcreteStackBlockDecl(0), 71 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0), 72 BlockObjectAssignDecl(0), BlockObjectDisposeDecl(0), 73 BlockObjectAssign(0), BlockObjectDispose(0), 74 BlockDescriptorType(0), GenericBlockLiteralType(0) { 75 if (!Features.ObjC1) 76 Runtime = 0; 77 else if (!Features.NeXTRuntime) 78 Runtime = CreateGNUObjCRuntime(*this); 79 else if (Features.ObjCNonFragileABI) 80 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 81 else 82 Runtime = CreateMacObjCRuntime(*this); 83 84 // Enable TBAA unless it's suppressed. 85 if (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0) 86 TBAA = new CodeGenTBAA(Context, VMContext, getLangOptions(), 87 ABI.getMangleContext()); 88 89 // If debug info generation is enabled, create the CGDebugInfo object. 90 DebugInfo = CodeGenOpts.DebugInfo ? new CGDebugInfo(*this) : 0; 91 92 Block.GlobalUniqueCount = 0; 93 94 // Initialize the type cache. 95 llvm::LLVMContext &LLVMContext = M.getContext(); 96 Int8Ty = llvm::Type::getInt8Ty(LLVMContext); 97 Int32Ty = llvm::Type::getInt32Ty(LLVMContext); 98 Int64Ty = llvm::Type::getInt64Ty(LLVMContext); 99 PointerWidthInBits = C.Target.getPointerWidth(0); 100 PointerAlignInBytes = 101 C.toCharUnitsFromBits(C.Target.getPointerAlign(0)).getQuantity(); 102 IntTy = llvm::IntegerType::get(LLVMContext, C.Target.getIntWidth()); 103 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits); 104 Int8PtrTy = Int8Ty->getPointerTo(0); 105 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0); 106} 107 108CodeGenModule::~CodeGenModule() { 109 delete Runtime; 110 delete &ABI; 111 delete TBAA; 112 delete DebugInfo; 113} 114 115void CodeGenModule::createObjCRuntime() { 116 if (!Features.NeXTRuntime) 117 Runtime = CreateGNUObjCRuntime(*this); 118 else if (Features.ObjCNonFragileABI) 119 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 120 else 121 Runtime = CreateMacObjCRuntime(*this); 122} 123 124void CodeGenModule::Release() { 125 EmitDeferred(); 126 EmitCXXGlobalInitFunc(); 127 EmitCXXGlobalDtorFunc(); 128 if (Runtime) 129 if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction()) 130 AddGlobalCtor(ObjCInitFunction); 131 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 132 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 133 EmitAnnotations(); 134 EmitLLVMUsed(); 135 136 SimplifyPersonality(); 137 138 if (getCodeGenOpts().EmitDeclMetadata) 139 EmitDeclMetadata(); 140} 141 142llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) { 143 if (!TBAA) 144 return 0; 145 return TBAA->getTBAAInfo(QTy); 146} 147 148void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst, 149 llvm::MDNode *TBAAInfo) { 150 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo); 151} 152 153bool CodeGenModule::isTargetDarwin() const { 154 return getContext().Target.getTriple().getOS() == llvm::Triple::Darwin; 155} 156 157/// ErrorUnsupported - Print out an error that codegen doesn't support the 158/// specified stmt yet. 159void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 160 bool OmitOnError) { 161 if (OmitOnError && getDiags().hasErrorOccurred()) 162 return; 163 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 164 "cannot compile this %0 yet"); 165 std::string Msg = Type; 166 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 167 << Msg << S->getSourceRange(); 168} 169 170/// ErrorUnsupported - Print out an error that codegen doesn't support the 171/// specified decl yet. 172void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 173 bool OmitOnError) { 174 if (OmitOnError && getDiags().hasErrorOccurred()) 175 return; 176 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 177 "cannot compile this %0 yet"); 178 std::string Msg = Type; 179 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 180} 181 182void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 183 const NamedDecl *D) const { 184 // Internal definitions always have default visibility. 185 if (GV->hasLocalLinkage()) { 186 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 187 return; 188 } 189 190 // Set visibility for definitions. 191 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 192 if (LV.visibilityExplicit() || !GV->hasAvailableExternallyLinkage()) 193 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 194} 195 196/// Set the symbol visibility of type information (vtable and RTTI) 197/// associated with the given type. 198void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV, 199 const CXXRecordDecl *RD, 200 TypeVisibilityKind TVK) const { 201 setGlobalVisibility(GV, RD); 202 203 if (!CodeGenOpts.HiddenWeakVTables) 204 return; 205 206 // We never want to drop the visibility for RTTI names. 207 if (TVK == TVK_ForRTTIName) 208 return; 209 210 // We want to drop the visibility to hidden for weak type symbols. 211 // This isn't possible if there might be unresolved references 212 // elsewhere that rely on this symbol being visible. 213 214 // This should be kept roughly in sync with setThunkVisibility 215 // in CGVTables.cpp. 216 217 // Preconditions. 218 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage || 219 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility) 220 return; 221 222 // Don't override an explicit visibility attribute. 223 if (RD->hasAttr<VisibilityAttr>()) 224 return; 225 226 switch (RD->getTemplateSpecializationKind()) { 227 // We have to disable the optimization if this is an EI definition 228 // because there might be EI declarations in other shared objects. 229 case TSK_ExplicitInstantiationDefinition: 230 case TSK_ExplicitInstantiationDeclaration: 231 return; 232 233 // Every use of a non-template class's type information has to emit it. 234 case TSK_Undeclared: 235 break; 236 237 // In theory, implicit instantiations can ignore the possibility of 238 // an explicit instantiation declaration because there necessarily 239 // must be an EI definition somewhere with default visibility. In 240 // practice, it's possible to have an explicit instantiation for 241 // an arbitrary template class, and linkers aren't necessarily able 242 // to deal with mixed-visibility symbols. 243 case TSK_ExplicitSpecialization: 244 case TSK_ImplicitInstantiation: 245 if (!CodeGenOpts.HiddenWeakTemplateVTables) 246 return; 247 break; 248 } 249 250 // If there's a key function, there may be translation units 251 // that don't have the key function's definition. But ignore 252 // this if we're emitting RTTI under -fno-rtti. 253 if (!(TVK != TVK_ForRTTI) || Features.RTTI) { 254 if (Context.getKeyFunction(RD)) 255 return; 256 } 257 258 // Otherwise, drop the visibility to hidden. 259 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 260 GV->setUnnamedAddr(true); 261} 262 263llvm::StringRef CodeGenModule::getMangledName(GlobalDecl GD) { 264 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 265 266 llvm::StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()]; 267 if (!Str.empty()) 268 return Str; 269 270 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) { 271 IdentifierInfo *II = ND->getIdentifier(); 272 assert(II && "Attempt to mangle unnamed decl."); 273 274 Str = II->getName(); 275 return Str; 276 } 277 278 llvm::SmallString<256> Buffer; 279 llvm::raw_svector_ostream Out(Buffer); 280 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 281 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out); 282 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 283 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out); 284 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND)) 285 getCXXABI().getMangleContext().mangleBlock(BD, Out); 286 else 287 getCXXABI().getMangleContext().mangleName(ND, Out); 288 289 // Allocate space for the mangled name. 290 Out.flush(); 291 size_t Length = Buffer.size(); 292 char *Name = MangledNamesAllocator.Allocate<char>(Length); 293 std::copy(Buffer.begin(), Buffer.end(), Name); 294 295 Str = llvm::StringRef(Name, Length); 296 297 return Str; 298} 299 300void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer, 301 const BlockDecl *BD) { 302 MangleContext &MangleCtx = getCXXABI().getMangleContext(); 303 const Decl *D = GD.getDecl(); 304 llvm::raw_svector_ostream Out(Buffer.getBuffer()); 305 if (D == 0) 306 MangleCtx.mangleGlobalBlock(BD, Out); 307 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 308 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out); 309 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 310 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out); 311 else 312 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out); 313} 314 315llvm::GlobalValue *CodeGenModule::GetGlobalValue(llvm::StringRef Name) { 316 return getModule().getNamedValue(Name); 317} 318 319/// AddGlobalCtor - Add a function to the list that will be called before 320/// main() runs. 321void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 322 // FIXME: Type coercion of void()* types. 323 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 324} 325 326/// AddGlobalDtor - Add a function to the list that will be called 327/// when the module is unloaded. 328void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 329 // FIXME: Type coercion of void()* types. 330 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 331} 332 333void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 334 // Ctor function type is void()*. 335 llvm::FunctionType* CtorFTy = 336 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false); 337 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 338 339 // Get the type of a ctor entry, { i32, void ()* }. 340 llvm::StructType* CtorStructTy = 341 llvm::StructType::get(VMContext, llvm::Type::getInt32Ty(VMContext), 342 llvm::PointerType::getUnqual(CtorFTy), NULL); 343 344 // Construct the constructor and destructor arrays. 345 std::vector<llvm::Constant*> Ctors; 346 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 347 std::vector<llvm::Constant*> S; 348 S.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 349 I->second, false)); 350 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy)); 351 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 352 } 353 354 if (!Ctors.empty()) { 355 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 356 new llvm::GlobalVariable(TheModule, AT, false, 357 llvm::GlobalValue::AppendingLinkage, 358 llvm::ConstantArray::get(AT, Ctors), 359 GlobalName); 360 } 361} 362 363void CodeGenModule::EmitAnnotations() { 364 if (Annotations.empty()) 365 return; 366 367 // Create a new global variable for the ConstantStruct in the Module. 368 llvm::Constant *Array = 369 llvm::ConstantArray::get(llvm::ArrayType::get(Annotations[0]->getType(), 370 Annotations.size()), 371 Annotations); 372 llvm::GlobalValue *gv = 373 new llvm::GlobalVariable(TheModule, Array->getType(), false, 374 llvm::GlobalValue::AppendingLinkage, Array, 375 "llvm.global.annotations"); 376 gv->setSection("llvm.metadata"); 377} 378 379llvm::GlobalValue::LinkageTypes 380CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 381 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D); 382 383 if (Linkage == GVA_Internal) 384 return llvm::Function::InternalLinkage; 385 386 if (D->hasAttr<DLLExportAttr>()) 387 return llvm::Function::DLLExportLinkage; 388 389 if (D->hasAttr<WeakAttr>()) 390 return llvm::Function::WeakAnyLinkage; 391 392 // In C99 mode, 'inline' functions are guaranteed to have a strong 393 // definition somewhere else, so we can use available_externally linkage. 394 if (Linkage == GVA_C99Inline) 395 return llvm::Function::AvailableExternallyLinkage; 396 397 // In C++, the compiler has to emit a definition in every translation unit 398 // that references the function. We should use linkonce_odr because 399 // a) if all references in this translation unit are optimized away, we 400 // don't need to codegen it. b) if the function persists, it needs to be 401 // merged with other definitions. c) C++ has the ODR, so we know the 402 // definition is dependable. 403 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 404 return !Context.getLangOptions().AppleKext 405 ? llvm::Function::LinkOnceODRLinkage 406 : llvm::Function::InternalLinkage; 407 408 // An explicit instantiation of a template has weak linkage, since 409 // explicit instantiations can occur in multiple translation units 410 // and must all be equivalent. However, we are not allowed to 411 // throw away these explicit instantiations. 412 if (Linkage == GVA_ExplicitTemplateInstantiation) 413 return !Context.getLangOptions().AppleKext 414 ? llvm::Function::WeakODRLinkage 415 : llvm::Function::InternalLinkage; 416 417 // Otherwise, we have strong external linkage. 418 assert(Linkage == GVA_StrongExternal); 419 return llvm::Function::ExternalLinkage; 420} 421 422 423/// SetFunctionDefinitionAttributes - Set attributes for a global. 424/// 425/// FIXME: This is currently only done for aliases and functions, but not for 426/// variables (these details are set in EmitGlobalVarDefinition for variables). 427void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 428 llvm::GlobalValue *GV) { 429 SetCommonAttributes(D, GV); 430} 431 432void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 433 const CGFunctionInfo &Info, 434 llvm::Function *F) { 435 unsigned CallingConv; 436 AttributeListType AttributeList; 437 ConstructAttributeList(Info, D, AttributeList, CallingConv); 438 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 439 AttributeList.size())); 440 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 441} 442 443void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 444 llvm::Function *F) { 445 if (!Features.Exceptions && !Features.ObjCNonFragileABI) 446 F->addFnAttr(llvm::Attribute::NoUnwind); 447 448 if (D->hasAttr<AlwaysInlineAttr>()) 449 F->addFnAttr(llvm::Attribute::AlwaysInline); 450 451 if (D->hasAttr<NakedAttr>()) 452 F->addFnAttr(llvm::Attribute::Naked); 453 454 if (D->hasAttr<NoInlineAttr>()) 455 F->addFnAttr(llvm::Attribute::NoInline); 456 457 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D)) 458 F->setUnnamedAddr(true); 459 460 if (Features.getStackProtectorMode() == LangOptions::SSPOn) 461 F->addFnAttr(llvm::Attribute::StackProtect); 462 else if (Features.getStackProtectorMode() == LangOptions::SSPReq) 463 F->addFnAttr(llvm::Attribute::StackProtectReq); 464 465 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth(); 466 if (alignment) 467 F->setAlignment(alignment); 468 469 // C++ ABI requires 2-byte alignment for member functions. 470 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 471 F->setAlignment(2); 472} 473 474void CodeGenModule::SetCommonAttributes(const Decl *D, 475 llvm::GlobalValue *GV) { 476 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) 477 setGlobalVisibility(GV, ND); 478 else 479 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 480 481 if (D->hasAttr<UsedAttr>()) 482 AddUsedGlobal(GV); 483 484 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 485 GV->setSection(SA->getName()); 486 487 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 488} 489 490void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 491 llvm::Function *F, 492 const CGFunctionInfo &FI) { 493 SetLLVMFunctionAttributes(D, FI, F); 494 SetLLVMFunctionAttributesForDefinition(D, F); 495 496 F->setLinkage(llvm::Function::InternalLinkage); 497 498 SetCommonAttributes(D, F); 499} 500 501void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 502 llvm::Function *F, 503 bool IsIncompleteFunction) { 504 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 505 506 if (!IsIncompleteFunction) 507 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(GD), F); 508 509 // Only a few attributes are set on declarations; these may later be 510 // overridden by a definition. 511 512 if (FD->hasAttr<DLLImportAttr>()) { 513 F->setLinkage(llvm::Function::DLLImportLinkage); 514 } else if (FD->hasAttr<WeakAttr>() || 515 FD->hasAttr<WeakImportAttr>()) { 516 // "extern_weak" is overloaded in LLVM; we probably should have 517 // separate linkage types for this. 518 F->setLinkage(llvm::Function::ExternalWeakLinkage); 519 } else { 520 F->setLinkage(llvm::Function::ExternalLinkage); 521 522 NamedDecl::LinkageInfo LV = FD->getLinkageAndVisibility(); 523 if (LV.linkage() == ExternalLinkage && LV.visibilityExplicit()) { 524 F->setVisibility(GetLLVMVisibility(LV.visibility())); 525 } 526 } 527 528 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 529 F->setSection(SA->getName()); 530} 531 532void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 533 assert(!GV->isDeclaration() && 534 "Only globals with definition can force usage."); 535 LLVMUsed.push_back(GV); 536} 537 538void CodeGenModule::EmitLLVMUsed() { 539 // Don't create llvm.used if there is no need. 540 if (LLVMUsed.empty()) 541 return; 542 543 const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext); 544 545 // Convert LLVMUsed to what ConstantArray needs. 546 std::vector<llvm::Constant*> UsedArray; 547 UsedArray.resize(LLVMUsed.size()); 548 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 549 UsedArray[i] = 550 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 551 i8PTy); 552 } 553 554 if (UsedArray.empty()) 555 return; 556 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, UsedArray.size()); 557 558 llvm::GlobalVariable *GV = 559 new llvm::GlobalVariable(getModule(), ATy, false, 560 llvm::GlobalValue::AppendingLinkage, 561 llvm::ConstantArray::get(ATy, UsedArray), 562 "llvm.used"); 563 564 GV->setSection("llvm.metadata"); 565} 566 567void CodeGenModule::EmitDeferred() { 568 // Emit code for any potentially referenced deferred decls. Since a 569 // previously unused static decl may become used during the generation of code 570 // for a static function, iterate until no changes are made. 571 572 while (!DeferredDeclsToEmit.empty() || !DeferredVTables.empty()) { 573 if (!DeferredVTables.empty()) { 574 const CXXRecordDecl *RD = DeferredVTables.back(); 575 DeferredVTables.pop_back(); 576 getVTables().GenerateClassData(getVTableLinkage(RD), RD); 577 continue; 578 } 579 580 GlobalDecl D = DeferredDeclsToEmit.back(); 581 DeferredDeclsToEmit.pop_back(); 582 583 // Check to see if we've already emitted this. This is necessary 584 // for a couple of reasons: first, decls can end up in the 585 // deferred-decls queue multiple times, and second, decls can end 586 // up with definitions in unusual ways (e.g. by an extern inline 587 // function acquiring a strong function redefinition). Just 588 // ignore these cases. 589 // 590 // TODO: That said, looking this up multiple times is very wasteful. 591 llvm::StringRef Name = getMangledName(D); 592 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 593 assert(CGRef && "Deferred decl wasn't referenced?"); 594 595 if (!CGRef->isDeclaration()) 596 continue; 597 598 // GlobalAlias::isDeclaration() defers to the aliasee, but for our 599 // purposes an alias counts as a definition. 600 if (isa<llvm::GlobalAlias>(CGRef)) 601 continue; 602 603 // Otherwise, emit the definition and move on to the next one. 604 EmitGlobalDefinition(D); 605 } 606} 607 608/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the 609/// annotation information for a given GlobalValue. The annotation struct is 610/// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the 611/// GlobalValue being annotated. The second field is the constant string 612/// created from the AnnotateAttr's annotation. The third field is a constant 613/// string containing the name of the translation unit. The fourth field is 614/// the line number in the file of the annotated value declaration. 615/// 616/// FIXME: this does not unique the annotation string constants, as llvm-gcc 617/// appears to. 618/// 619llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 620 const AnnotateAttr *AA, 621 unsigned LineNo) { 622 llvm::Module *M = &getModule(); 623 624 // get [N x i8] constants for the annotation string, and the filename string 625 // which are the 2nd and 3rd elements of the global annotation structure. 626 const llvm::Type *SBP = llvm::Type::getInt8PtrTy(VMContext); 627 llvm::Constant *anno = llvm::ConstantArray::get(VMContext, 628 AA->getAnnotation(), true); 629 llvm::Constant *unit = llvm::ConstantArray::get(VMContext, 630 M->getModuleIdentifier(), 631 true); 632 633 // Get the two global values corresponding to the ConstantArrays we just 634 // created to hold the bytes of the strings. 635 llvm::GlobalValue *annoGV = 636 new llvm::GlobalVariable(*M, anno->getType(), false, 637 llvm::GlobalValue::PrivateLinkage, anno, 638 GV->getName()); 639 // translation unit name string, emitted into the llvm.metadata section. 640 llvm::GlobalValue *unitGV = 641 new llvm::GlobalVariable(*M, unit->getType(), false, 642 llvm::GlobalValue::PrivateLinkage, unit, 643 ".str"); 644 unitGV->setUnnamedAddr(true); 645 646 // Create the ConstantStruct for the global annotation. 647 llvm::Constant *Fields[4] = { 648 llvm::ConstantExpr::getBitCast(GV, SBP), 649 llvm::ConstantExpr::getBitCast(annoGV, SBP), 650 llvm::ConstantExpr::getBitCast(unitGV, SBP), 651 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), LineNo) 652 }; 653 return llvm::ConstantStruct::get(VMContext, Fields, 4, false); 654} 655 656bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 657 // Never defer when EmitAllDecls is specified. 658 if (Features.EmitAllDecls) 659 return false; 660 661 return !getContext().DeclMustBeEmitted(Global); 662} 663 664llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 665 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 666 assert(AA && "No alias?"); 667 668 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 669 670 // See if there is already something with the target's name in the module. 671 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 672 673 llvm::Constant *Aliasee; 674 if (isa<llvm::FunctionType>(DeclTy)) 675 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 676 /*ForVTable=*/false); 677 else 678 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 679 llvm::PointerType::getUnqual(DeclTy), 0); 680 if (!Entry) { 681 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 682 F->setLinkage(llvm::Function::ExternalWeakLinkage); 683 WeakRefReferences.insert(F); 684 } 685 686 return Aliasee; 687} 688 689void CodeGenModule::EmitGlobal(GlobalDecl GD) { 690 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 691 692 // Weak references don't produce any output by themselves. 693 if (Global->hasAttr<WeakRefAttr>()) 694 return; 695 696 // If this is an alias definition (which otherwise looks like a declaration) 697 // emit it now. 698 if (Global->hasAttr<AliasAttr>()) 699 return EmitAliasDefinition(GD); 700 701 // Ignore declarations, they will be emitted on their first use. 702 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 703 if (FD->getIdentifier()) { 704 llvm::StringRef Name = FD->getName(); 705 if (Name == "_Block_object_assign") { 706 BlockObjectAssignDecl = FD; 707 } else if (Name == "_Block_object_dispose") { 708 BlockObjectDisposeDecl = FD; 709 } 710 } 711 712 // Forward declarations are emitted lazily on first use. 713 if (!FD->isThisDeclarationADefinition()) 714 return; 715 } else { 716 const VarDecl *VD = cast<VarDecl>(Global); 717 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 718 719 if (VD->getIdentifier()) { 720 llvm::StringRef Name = VD->getName(); 721 if (Name == "_NSConcreteGlobalBlock") { 722 NSConcreteGlobalBlockDecl = VD; 723 } else if (Name == "_NSConcreteStackBlock") { 724 NSConcreteStackBlockDecl = VD; 725 } 726 } 727 728 729 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 730 return; 731 } 732 733 // Defer code generation when possible if this is a static definition, inline 734 // function etc. These we only want to emit if they are used. 735 if (!MayDeferGeneration(Global)) { 736 // Emit the definition if it can't be deferred. 737 EmitGlobalDefinition(GD); 738 return; 739 } 740 741 // If we're deferring emission of a C++ variable with an 742 // initializer, remember the order in which it appeared in the file. 743 if (getLangOptions().CPlusPlus && isa<VarDecl>(Global) && 744 cast<VarDecl>(Global)->hasInit()) { 745 DelayedCXXInitPosition[Global] = CXXGlobalInits.size(); 746 CXXGlobalInits.push_back(0); 747 } 748 749 // If the value has already been used, add it directly to the 750 // DeferredDeclsToEmit list. 751 llvm::StringRef MangledName = getMangledName(GD); 752 if (GetGlobalValue(MangledName)) 753 DeferredDeclsToEmit.push_back(GD); 754 else { 755 // Otherwise, remember that we saw a deferred decl with this name. The 756 // first use of the mangled name will cause it to move into 757 // DeferredDeclsToEmit. 758 DeferredDecls[MangledName] = GD; 759 } 760} 761 762void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 763 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 764 765 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(), 766 Context.getSourceManager(), 767 "Generating code for declaration"); 768 769 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { 770 // At -O0, don't generate IR for functions with available_externally 771 // linkage. 772 if (CodeGenOpts.OptimizationLevel == 0 && 773 !Function->hasAttr<AlwaysInlineAttr>() && 774 getFunctionLinkage(Function) 775 == llvm::Function::AvailableExternallyLinkage) 776 return; 777 778 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) { 779 if (Method->isVirtual()) 780 getVTables().EmitThunks(GD); 781 782 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method)) 783 return EmitCXXConstructor(CD, GD.getCtorType()); 784 785 if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(Method)) 786 return EmitCXXDestructor(DD, GD.getDtorType()); 787 } 788 789 return EmitGlobalFunctionDefinition(GD); 790 } 791 792 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 793 return EmitGlobalVarDefinition(VD); 794 795 assert(0 && "Invalid argument to EmitGlobalDefinition()"); 796} 797 798/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 799/// module, create and return an llvm Function with the specified type. If there 800/// is something in the module with the specified name, return it potentially 801/// bitcasted to the right type. 802/// 803/// If D is non-null, it specifies a decl that correspond to this. This is used 804/// to set the attributes on the function when it is first created. 805llvm::Constant * 806CodeGenModule::GetOrCreateLLVMFunction(llvm::StringRef MangledName, 807 const llvm::Type *Ty, 808 GlobalDecl D, bool ForVTable) { 809 // Lookup the entry, lazily creating it if necessary. 810 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 811 if (Entry) { 812 if (WeakRefReferences.count(Entry)) { 813 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 814 if (FD && !FD->hasAttr<WeakAttr>()) 815 Entry->setLinkage(llvm::Function::ExternalLinkage); 816 817 WeakRefReferences.erase(Entry); 818 } 819 820 if (Entry->getType()->getElementType() == Ty) 821 return Entry; 822 823 // Make sure the result is of the correct type. 824 const llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 825 return llvm::ConstantExpr::getBitCast(Entry, PTy); 826 } 827 828 // This function doesn't have a complete type (for example, the return 829 // type is an incomplete struct). Use a fake type instead, and make 830 // sure not to try to set attributes. 831 bool IsIncompleteFunction = false; 832 833 const llvm::FunctionType *FTy; 834 if (isa<llvm::FunctionType>(Ty)) { 835 FTy = cast<llvm::FunctionType>(Ty); 836 } else { 837 FTy = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), false); 838 IsIncompleteFunction = true; 839 } 840 841 llvm::Function *F = llvm::Function::Create(FTy, 842 llvm::Function::ExternalLinkage, 843 MangledName, &getModule()); 844 assert(F->getName() == MangledName && "name was uniqued!"); 845 if (D.getDecl()) 846 SetFunctionAttributes(D, F, IsIncompleteFunction); 847 848 // This is the first use or definition of a mangled name. If there is a 849 // deferred decl with this name, remember that we need to emit it at the end 850 // of the file. 851 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 852 if (DDI != DeferredDecls.end()) { 853 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 854 // list, and remove it from DeferredDecls (since we don't need it anymore). 855 DeferredDeclsToEmit.push_back(DDI->second); 856 DeferredDecls.erase(DDI); 857 858 // Otherwise, there are cases we have to worry about where we're 859 // using a declaration for which we must emit a definition but where 860 // we might not find a top-level definition: 861 // - member functions defined inline in their classes 862 // - friend functions defined inline in some class 863 // - special member functions with implicit definitions 864 // If we ever change our AST traversal to walk into class methods, 865 // this will be unnecessary. 866 // 867 // We also don't emit a definition for a function if it's going to be an entry 868 // in a vtable, unless it's already marked as used. 869 } else if (getLangOptions().CPlusPlus && D.getDecl()) { 870 // Look for a declaration that's lexically in a record. 871 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl()); 872 do { 873 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 874 if (FD->isImplicit() && !ForVTable) { 875 assert(FD->isUsed() && "Sema didn't mark implicit function as used!"); 876 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 877 break; 878 } else if (FD->isThisDeclarationADefinition()) { 879 DeferredDeclsToEmit.push_back(D.getWithDecl(FD)); 880 break; 881 } 882 } 883 FD = FD->getPreviousDeclaration(); 884 } while (FD); 885 } 886 887 // Make sure the result is of the requested type. 888 if (!IsIncompleteFunction) { 889 assert(F->getType()->getElementType() == Ty); 890 return F; 891 } 892 893 const llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 894 return llvm::ConstantExpr::getBitCast(F, PTy); 895} 896 897/// GetAddrOfFunction - Return the address of the given function. If Ty is 898/// non-null, then this function will use the specified type if it has to 899/// create it (this occurs when we see a definition of the function). 900llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 901 const llvm::Type *Ty, 902 bool ForVTable) { 903 // If there was no specific requested type, just convert it now. 904 if (!Ty) 905 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 906 907 llvm::StringRef MangledName = getMangledName(GD); 908 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable); 909} 910 911/// CreateRuntimeFunction - Create a new runtime function with the specified 912/// type and name. 913llvm::Constant * 914CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy, 915 llvm::StringRef Name) { 916 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false); 917} 918 919static bool DeclIsConstantGlobal(ASTContext &Context, const VarDecl *D) { 920 if (!D->getType().isConstant(Context) && !D->getType()->isReferenceType()) 921 return false; 922 if (Context.getLangOptions().CPlusPlus && 923 Context.getBaseElementType(D->getType())->getAs<RecordType>()) { 924 // FIXME: We should do something fancier here! 925 return false; 926 } 927 return true; 928} 929 930/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 931/// create and return an llvm GlobalVariable with the specified type. If there 932/// is something in the module with the specified name, return it potentially 933/// bitcasted to the right type. 934/// 935/// If D is non-null, it specifies a decl that correspond to this. This is used 936/// to set the attributes on the global when it is first created. 937llvm::Constant * 938CodeGenModule::GetOrCreateLLVMGlobal(llvm::StringRef MangledName, 939 const llvm::PointerType *Ty, 940 const VarDecl *D, 941 bool UnnamedAddr) { 942 // Lookup the entry, lazily creating it if necessary. 943 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 944 if (Entry) { 945 if (WeakRefReferences.count(Entry)) { 946 if (D && !D->hasAttr<WeakAttr>()) 947 Entry->setLinkage(llvm::Function::ExternalLinkage); 948 949 WeakRefReferences.erase(Entry); 950 } 951 952 if (UnnamedAddr) 953 Entry->setUnnamedAddr(true); 954 955 if (Entry->getType() == Ty) 956 return Entry; 957 958 // Make sure the result is of the correct type. 959 return llvm::ConstantExpr::getBitCast(Entry, Ty); 960 } 961 962 // This is the first use or definition of a mangled name. If there is a 963 // deferred decl with this name, remember that we need to emit it at the end 964 // of the file. 965 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 966 if (DDI != DeferredDecls.end()) { 967 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 968 // list, and remove it from DeferredDecls (since we don't need it anymore). 969 DeferredDeclsToEmit.push_back(DDI->second); 970 DeferredDecls.erase(DDI); 971 } 972 973 llvm::GlobalVariable *GV = 974 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 975 llvm::GlobalValue::ExternalLinkage, 976 0, MangledName, 0, 977 false, Ty->getAddressSpace()); 978 979 // Handle things which are present even on external declarations. 980 if (D) { 981 // FIXME: This code is overly simple and should be merged with other global 982 // handling. 983 GV->setConstant(DeclIsConstantGlobal(Context, D)); 984 985 // Set linkage and visibility in case we never see a definition. 986 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility(); 987 if (LV.linkage() != ExternalLinkage) { 988 // Don't set internal linkage on declarations. 989 } else { 990 if (D->hasAttr<DLLImportAttr>()) 991 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage); 992 else if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakImportAttr>()) 993 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 994 995 // Set visibility on a declaration only if it's explicit. 996 if (LV.visibilityExplicit()) 997 GV->setVisibility(GetLLVMVisibility(LV.visibility())); 998 } 999 1000 GV->setThreadLocal(D->isThreadSpecified()); 1001 } 1002 1003 return GV; 1004} 1005 1006 1007llvm::GlobalVariable * 1008CodeGenModule::CreateOrReplaceCXXRuntimeVariable(llvm::StringRef Name, 1009 const llvm::Type *Ty, 1010 llvm::GlobalValue::LinkageTypes Linkage) { 1011 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name); 1012 llvm::GlobalVariable *OldGV = 0; 1013 1014 1015 if (GV) { 1016 // Check if the variable has the right type. 1017 if (GV->getType()->getElementType() == Ty) 1018 return GV; 1019 1020 // Because C++ name mangling, the only way we can end up with an already 1021 // existing global with the same name is if it has been declared extern "C". 1022 assert(GV->isDeclaration() && "Declaration has wrong type!"); 1023 OldGV = GV; 1024 } 1025 1026 // Create a new variable. 1027 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true, 1028 Linkage, 0, Name); 1029 1030 if (OldGV) { 1031 // Replace occurrences of the old variable if needed. 1032 GV->takeName(OldGV); 1033 1034 if (!OldGV->use_empty()) { 1035 llvm::Constant *NewPtrForOldDecl = 1036 llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 1037 OldGV->replaceAllUsesWith(NewPtrForOldDecl); 1038 } 1039 1040 OldGV->eraseFromParent(); 1041 } 1042 1043 return GV; 1044} 1045 1046/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 1047/// given global variable. If Ty is non-null and if the global doesn't exist, 1048/// then it will be greated with the specified type instead of whatever the 1049/// normal requested type would be. 1050llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 1051 const llvm::Type *Ty) { 1052 assert(D->hasGlobalStorage() && "Not a global variable"); 1053 QualType ASTTy = D->getType(); 1054 if (Ty == 0) 1055 Ty = getTypes().ConvertTypeForMem(ASTTy); 1056 1057 const llvm::PointerType *PTy = 1058 llvm::PointerType::get(Ty, ASTTy.getAddressSpace()); 1059 1060 llvm::StringRef MangledName = getMangledName(D); 1061 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 1062} 1063 1064/// CreateRuntimeVariable - Create a new runtime global variable with the 1065/// specified type and name. 1066llvm::Constant * 1067CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty, 1068 llvm::StringRef Name) { 1069 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0, 1070 true); 1071} 1072 1073void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 1074 assert(!D->getInit() && "Cannot emit definite definitions here!"); 1075 1076 if (MayDeferGeneration(D)) { 1077 // If we have not seen a reference to this variable yet, place it 1078 // into the deferred declarations table to be emitted if needed 1079 // later. 1080 llvm::StringRef MangledName = getMangledName(D); 1081 if (!GetGlobalValue(MangledName)) { 1082 DeferredDecls[MangledName] = D; 1083 return; 1084 } 1085 } 1086 1087 // The tentative definition is the only definition. 1088 EmitGlobalVarDefinition(D); 1089} 1090 1091void CodeGenModule::EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired) { 1092 if (DefinitionRequired) 1093 getVTables().GenerateClassData(getVTableLinkage(Class), Class); 1094} 1095 1096llvm::GlobalVariable::LinkageTypes 1097CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) { 1098 if (RD->isInAnonymousNamespace() || !RD->hasLinkage()) 1099 return llvm::GlobalVariable::InternalLinkage; 1100 1101 if (const CXXMethodDecl *KeyFunction 1102 = RD->getASTContext().getKeyFunction(RD)) { 1103 // If this class has a key function, use that to determine the linkage of 1104 // the vtable. 1105 const FunctionDecl *Def = 0; 1106 if (KeyFunction->hasBody(Def)) 1107 KeyFunction = cast<CXXMethodDecl>(Def); 1108 1109 switch (KeyFunction->getTemplateSpecializationKind()) { 1110 case TSK_Undeclared: 1111 case TSK_ExplicitSpecialization: 1112 // When compiling with optimizations turned on, we emit all vtables, 1113 // even if the key function is not defined in the current translation 1114 // unit. If this is the case, use available_externally linkage. 1115 if (!Def && CodeGenOpts.OptimizationLevel) 1116 return llvm::GlobalVariable::AvailableExternallyLinkage; 1117 1118 if (KeyFunction->isInlined()) 1119 return !Context.getLangOptions().AppleKext ? 1120 llvm::GlobalVariable::LinkOnceODRLinkage : 1121 llvm::Function::InternalLinkage; 1122 1123 return llvm::GlobalVariable::ExternalLinkage; 1124 1125 case TSK_ImplicitInstantiation: 1126 return !Context.getLangOptions().AppleKext ? 1127 llvm::GlobalVariable::LinkOnceODRLinkage : 1128 llvm::Function::InternalLinkage; 1129 1130 case TSK_ExplicitInstantiationDefinition: 1131 return !Context.getLangOptions().AppleKext ? 1132 llvm::GlobalVariable::WeakODRLinkage : 1133 llvm::Function::InternalLinkage; 1134 1135 case TSK_ExplicitInstantiationDeclaration: 1136 // FIXME: Use available_externally linkage. However, this currently 1137 // breaks LLVM's build due to undefined symbols. 1138 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1139 return !Context.getLangOptions().AppleKext ? 1140 llvm::GlobalVariable::LinkOnceODRLinkage : 1141 llvm::Function::InternalLinkage; 1142 } 1143 } 1144 1145 if (Context.getLangOptions().AppleKext) 1146 return llvm::Function::InternalLinkage; 1147 1148 switch (RD->getTemplateSpecializationKind()) { 1149 case TSK_Undeclared: 1150 case TSK_ExplicitSpecialization: 1151 case TSK_ImplicitInstantiation: 1152 // FIXME: Use available_externally linkage. However, this currently 1153 // breaks LLVM's build due to undefined symbols. 1154 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1155 case TSK_ExplicitInstantiationDeclaration: 1156 return llvm::GlobalVariable::LinkOnceODRLinkage; 1157 1158 case TSK_ExplicitInstantiationDefinition: 1159 return llvm::GlobalVariable::WeakODRLinkage; 1160 } 1161 1162 // Silence GCC warning. 1163 return llvm::GlobalVariable::LinkOnceODRLinkage; 1164} 1165 1166CharUnits CodeGenModule::GetTargetTypeStoreSize(const llvm::Type *Ty) const { 1167 return Context.toCharUnitsFromBits( 1168 TheTargetData.getTypeStoreSizeInBits(Ty)); 1169} 1170 1171void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1172 llvm::Constant *Init = 0; 1173 QualType ASTTy = D->getType(); 1174 bool NonConstInit = false; 1175 1176 const Expr *InitExpr = D->getAnyInitializer(); 1177 1178 if (!InitExpr) { 1179 // This is a tentative definition; tentative definitions are 1180 // implicitly initialized with { 0 }. 1181 // 1182 // Note that tentative definitions are only emitted at the end of 1183 // a translation unit, so they should never have incomplete 1184 // type. In addition, EmitTentativeDefinition makes sure that we 1185 // never attempt to emit a tentative definition if a real one 1186 // exists. A use may still exists, however, so we still may need 1187 // to do a RAUW. 1188 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1189 Init = EmitNullConstant(D->getType()); 1190 } else { 1191 Init = EmitConstantExpr(InitExpr, D->getType()); 1192 if (!Init) { 1193 QualType T = InitExpr->getType(); 1194 if (D->getType()->isReferenceType()) 1195 T = D->getType(); 1196 1197 if (getLangOptions().CPlusPlus) { 1198 Init = EmitNullConstant(T); 1199 NonConstInit = true; 1200 } else { 1201 ErrorUnsupported(D, "static initializer"); 1202 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1203 } 1204 } else { 1205 // We don't need an initializer, so remove the entry for the delayed 1206 // initializer position (just in case this entry was delayed). 1207 if (getLangOptions().CPlusPlus) 1208 DelayedCXXInitPosition.erase(D); 1209 } 1210 } 1211 1212 const llvm::Type* InitType = Init->getType(); 1213 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1214 1215 // Strip off a bitcast if we got one back. 1216 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1217 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1218 // all zero index gep. 1219 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1220 Entry = CE->getOperand(0); 1221 } 1222 1223 // Entry is now either a Function or GlobalVariable. 1224 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1225 1226 // We have a definition after a declaration with the wrong type. 1227 // We must make a new GlobalVariable* and update everything that used OldGV 1228 // (a declaration or tentative definition) with the new GlobalVariable* 1229 // (which will be a definition). 1230 // 1231 // This happens if there is a prototype for a global (e.g. 1232 // "extern int x[];") and then a definition of a different type (e.g. 1233 // "int x[10];"). This also happens when an initializer has a different type 1234 // from the type of the global (this happens with unions). 1235 if (GV == 0 || 1236 GV->getType()->getElementType() != InitType || 1237 GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) { 1238 1239 // Move the old entry aside so that we'll create a new one. 1240 Entry->setName(llvm::StringRef()); 1241 1242 // Make a new global with the correct type, this is now guaranteed to work. 1243 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1244 1245 // Replace all uses of the old global with the new global 1246 llvm::Constant *NewPtrForOldDecl = 1247 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1248 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1249 1250 // Erase the old global, since it is no longer used. 1251 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1252 } 1253 1254 if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>()) { 1255 SourceManager &SM = Context.getSourceManager(); 1256 AddAnnotation(EmitAnnotateAttr(GV, AA, 1257 SM.getInstantiationLineNumber(D->getLocation()))); 1258 } 1259 1260 GV->setInitializer(Init); 1261 1262 // If it is safe to mark the global 'constant', do so now. 1263 GV->setConstant(false); 1264 if (!NonConstInit && DeclIsConstantGlobal(Context, D)) 1265 GV->setConstant(true); 1266 1267 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1268 1269 // Set the llvm linkage type as appropriate. 1270 llvm::GlobalValue::LinkageTypes Linkage = 1271 GetLLVMLinkageVarDefinition(D, GV); 1272 GV->setLinkage(Linkage); 1273 if (Linkage == llvm::GlobalVariable::CommonLinkage) 1274 // common vars aren't constant even if declared const. 1275 GV->setConstant(false); 1276 1277 SetCommonAttributes(D, GV); 1278 1279 // Emit the initializer function if necessary. 1280 if (NonConstInit) 1281 EmitCXXGlobalVarDeclInitFunc(D, GV); 1282 1283 // Emit global variable debug information. 1284 if (CGDebugInfo *DI = getDebugInfo()) { 1285 DI->setLocation(D->getLocation()); 1286 DI->EmitGlobalVariable(GV, D); 1287 } 1288} 1289 1290llvm::GlobalValue::LinkageTypes 1291CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D, 1292 llvm::GlobalVariable *GV) { 1293 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D); 1294 if (Linkage == GVA_Internal) 1295 return llvm::Function::InternalLinkage; 1296 else if (D->hasAttr<DLLImportAttr>()) 1297 return llvm::Function::DLLImportLinkage; 1298 else if (D->hasAttr<DLLExportAttr>()) 1299 return llvm::Function::DLLExportLinkage; 1300 else if (D->hasAttr<WeakAttr>()) { 1301 if (GV->isConstant()) 1302 return llvm::GlobalVariable::WeakODRLinkage; 1303 else 1304 return llvm::GlobalVariable::WeakAnyLinkage; 1305 } else if (Linkage == GVA_TemplateInstantiation || 1306 Linkage == GVA_ExplicitTemplateInstantiation) 1307 // FIXME: It seems like we can provide more specific linkage here 1308 // (LinkOnceODR, WeakODR). 1309 return llvm::GlobalVariable::WeakAnyLinkage; 1310 else if (!getLangOptions().CPlusPlus && 1311 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) || 1312 D->getAttr<CommonAttr>()) && 1313 !D->hasExternalStorage() && !D->getInit() && 1314 !D->getAttr<SectionAttr>() && !D->isThreadSpecified()) { 1315 // Thread local vars aren't considered common linkage. 1316 return llvm::GlobalVariable::CommonLinkage; 1317 } 1318 return llvm::GlobalVariable::ExternalLinkage; 1319} 1320 1321/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1322/// implement a function with no prototype, e.g. "int foo() {}". If there are 1323/// existing call uses of the old function in the module, this adjusts them to 1324/// call the new function directly. 1325/// 1326/// This is not just a cleanup: the always_inline pass requires direct calls to 1327/// functions to be able to inline them. If there is a bitcast in the way, it 1328/// won't inline them. Instcombine normally deletes these calls, but it isn't 1329/// run at -O0. 1330static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1331 llvm::Function *NewFn) { 1332 // If we're redefining a global as a function, don't transform it. 1333 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1334 if (OldFn == 0) return; 1335 1336 const llvm::Type *NewRetTy = NewFn->getReturnType(); 1337 llvm::SmallVector<llvm::Value*, 4> ArgList; 1338 1339 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1340 UI != E; ) { 1341 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1342 llvm::Value::use_iterator I = UI++; // Increment before the CI is erased. 1343 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*I); 1344 if (!CI) continue; // FIXME: when we allow Invoke, just do CallSite CS(*I) 1345 llvm::CallSite CS(CI); 1346 if (!CI || !CS.isCallee(I)) continue; 1347 1348 // If the return types don't match exactly, and if the call isn't dead, then 1349 // we can't transform this call. 1350 if (CI->getType() != NewRetTy && !CI->use_empty()) 1351 continue; 1352 1353 // If the function was passed too few arguments, don't transform. If extra 1354 // arguments were passed, we silently drop them. If any of the types 1355 // mismatch, we don't transform. 1356 unsigned ArgNo = 0; 1357 bool DontTransform = false; 1358 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1359 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1360 if (CS.arg_size() == ArgNo || 1361 CS.getArgument(ArgNo)->getType() != AI->getType()) { 1362 DontTransform = true; 1363 break; 1364 } 1365 } 1366 if (DontTransform) 1367 continue; 1368 1369 // Okay, we can transform this. Create the new call instruction and copy 1370 // over the required information. 1371 ArgList.append(CS.arg_begin(), CS.arg_begin() + ArgNo); 1372 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(), 1373 ArgList.end(), "", CI); 1374 ArgList.clear(); 1375 if (!NewCall->getType()->isVoidTy()) 1376 NewCall->takeName(CI); 1377 NewCall->setAttributes(CI->getAttributes()); 1378 NewCall->setCallingConv(CI->getCallingConv()); 1379 1380 // Finally, remove the old call, replacing any uses with the new one. 1381 if (!CI->use_empty()) 1382 CI->replaceAllUsesWith(NewCall); 1383 1384 // Copy debug location attached to CI. 1385 if (!CI->getDebugLoc().isUnknown()) 1386 NewCall->setDebugLoc(CI->getDebugLoc()); 1387 CI->eraseFromParent(); 1388 } 1389} 1390 1391 1392void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1393 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1394 const llvm::FunctionType *Ty = getTypes().GetFunctionType(GD); 1395 // Get or create the prototype for the function. 1396 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1397 1398 // Strip off a bitcast if we got one back. 1399 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1400 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1401 Entry = CE->getOperand(0); 1402 } 1403 1404 1405 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1406 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1407 1408 // If the types mismatch then we have to rewrite the definition. 1409 assert(OldFn->isDeclaration() && 1410 "Shouldn't replace non-declaration"); 1411 1412 // F is the Function* for the one with the wrong type, we must make a new 1413 // Function* and update everything that used F (a declaration) with the new 1414 // Function* (which will be a definition). 1415 // 1416 // This happens if there is a prototype for a function 1417 // (e.g. "int f()") and then a definition of a different type 1418 // (e.g. "int f(int x)"). Move the old function aside so that it 1419 // doesn't interfere with GetAddrOfFunction. 1420 OldFn->setName(llvm::StringRef()); 1421 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1422 1423 // If this is an implementation of a function without a prototype, try to 1424 // replace any existing uses of the function (which may be calls) with uses 1425 // of the new function 1426 if (D->getType()->isFunctionNoProtoType()) { 1427 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1428 OldFn->removeDeadConstantUsers(); 1429 } 1430 1431 // Replace uses of F with the Function we will endow with a body. 1432 if (!Entry->use_empty()) { 1433 llvm::Constant *NewPtrForOldDecl = 1434 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1435 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1436 } 1437 1438 // Ok, delete the old function now, which is dead. 1439 OldFn->eraseFromParent(); 1440 1441 Entry = NewFn; 1442 } 1443 1444 // We need to set linkage and visibility on the function before 1445 // generating code for it because various parts of IR generation 1446 // want to propagate this information down (e.g. to local static 1447 // declarations). 1448 llvm::Function *Fn = cast<llvm::Function>(Entry); 1449 setFunctionLinkage(D, Fn); 1450 1451 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes 1452 setGlobalVisibility(Fn, D); 1453 1454 CodeGenFunction(*this).GenerateCode(D, Fn); 1455 1456 SetFunctionDefinitionAttributes(D, Fn); 1457 SetLLVMFunctionAttributesForDefinition(D, Fn); 1458 1459 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1460 AddGlobalCtor(Fn, CA->getPriority()); 1461 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1462 AddGlobalDtor(Fn, DA->getPriority()); 1463} 1464 1465void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 1466 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1467 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1468 assert(AA && "Not an alias?"); 1469 1470 llvm::StringRef MangledName = getMangledName(GD); 1471 1472 // If there is a definition in the module, then it wins over the alias. 1473 // This is dubious, but allow it to be safe. Just ignore the alias. 1474 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1475 if (Entry && !Entry->isDeclaration()) 1476 return; 1477 1478 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1479 1480 // Create a reference to the named value. This ensures that it is emitted 1481 // if a deferred decl. 1482 llvm::Constant *Aliasee; 1483 if (isa<llvm::FunctionType>(DeclTy)) 1484 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(), 1485 /*ForVTable=*/false); 1486 else 1487 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1488 llvm::PointerType::getUnqual(DeclTy), 0); 1489 1490 // Create the new alias itself, but don't set a name yet. 1491 llvm::GlobalValue *GA = 1492 new llvm::GlobalAlias(Aliasee->getType(), 1493 llvm::Function::ExternalLinkage, 1494 "", Aliasee, &getModule()); 1495 1496 if (Entry) { 1497 assert(Entry->isDeclaration()); 1498 1499 // If there is a declaration in the module, then we had an extern followed 1500 // by the alias, as in: 1501 // extern int test6(); 1502 // ... 1503 // int test6() __attribute__((alias("test7"))); 1504 // 1505 // Remove it and replace uses of it with the alias. 1506 GA->takeName(Entry); 1507 1508 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1509 Entry->getType())); 1510 Entry->eraseFromParent(); 1511 } else { 1512 GA->setName(MangledName); 1513 } 1514 1515 // Set attributes which are particular to an alias; this is a 1516 // specialization of the attributes which may be set on a global 1517 // variable/function. 1518 if (D->hasAttr<DLLExportAttr>()) { 1519 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1520 // The dllexport attribute is ignored for undefined symbols. 1521 if (FD->hasBody()) 1522 GA->setLinkage(llvm::Function::DLLExportLinkage); 1523 } else { 1524 GA->setLinkage(llvm::Function::DLLExportLinkage); 1525 } 1526 } else if (D->hasAttr<WeakAttr>() || 1527 D->hasAttr<WeakRefAttr>() || 1528 D->hasAttr<WeakImportAttr>()) { 1529 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1530 } 1531 1532 SetCommonAttributes(D, GA); 1533} 1534 1535/// getBuiltinLibFunction - Given a builtin id for a function like 1536/// "__builtin_fabsf", return a Function* for "fabsf". 1537llvm::Value *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD, 1538 unsigned BuiltinID) { 1539 assert((Context.BuiltinInfo.isLibFunction(BuiltinID) || 1540 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) && 1541 "isn't a lib fn"); 1542 1543 // Get the name, skip over the __builtin_ prefix (if necessary). 1544 const char *Name = Context.BuiltinInfo.GetName(BuiltinID); 1545 if (Context.BuiltinInfo.isLibFunction(BuiltinID)) 1546 Name += 10; 1547 1548 const llvm::FunctionType *Ty = 1549 cast<llvm::FunctionType>(getTypes().ConvertType(FD->getType())); 1550 1551 return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl(FD), /*ForVTable=*/false); 1552} 1553 1554llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys, 1555 unsigned NumTys) { 1556 return llvm::Intrinsic::getDeclaration(&getModule(), 1557 (llvm::Intrinsic::ID)IID, Tys, NumTys); 1558} 1559 1560static llvm::StringMapEntry<llvm::Constant*> & 1561GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1562 const StringLiteral *Literal, 1563 bool TargetIsLSB, 1564 bool &IsUTF16, 1565 unsigned &StringLength) { 1566 llvm::StringRef String = Literal->getString(); 1567 unsigned NumBytes = String.size(); 1568 1569 // Check for simple case. 1570 if (!Literal->containsNonAsciiOrNull()) { 1571 StringLength = NumBytes; 1572 return Map.GetOrCreateValue(String); 1573 } 1574 1575 // Otherwise, convert the UTF8 literals into a byte string. 1576 llvm::SmallVector<UTF16, 128> ToBuf(NumBytes); 1577 const UTF8 *FromPtr = (UTF8 *)String.data(); 1578 UTF16 *ToPtr = &ToBuf[0]; 1579 1580 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 1581 &ToPtr, ToPtr + NumBytes, 1582 strictConversion); 1583 1584 // ConvertUTF8toUTF16 returns the length in ToPtr. 1585 StringLength = ToPtr - &ToBuf[0]; 1586 1587 // Render the UTF-16 string into a byte array and convert to the target byte 1588 // order. 1589 // 1590 // FIXME: This isn't something we should need to do here. 1591 llvm::SmallString<128> AsBytes; 1592 AsBytes.reserve(StringLength * 2); 1593 for (unsigned i = 0; i != StringLength; ++i) { 1594 unsigned short Val = ToBuf[i]; 1595 if (TargetIsLSB) { 1596 AsBytes.push_back(Val & 0xFF); 1597 AsBytes.push_back(Val >> 8); 1598 } else { 1599 AsBytes.push_back(Val >> 8); 1600 AsBytes.push_back(Val & 0xFF); 1601 } 1602 } 1603 // Append one extra null character, the second is automatically added by our 1604 // caller. 1605 AsBytes.push_back(0); 1606 1607 IsUTF16 = true; 1608 return Map.GetOrCreateValue(llvm::StringRef(AsBytes.data(), AsBytes.size())); 1609} 1610 1611llvm::Constant * 1612CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 1613 unsigned StringLength = 0; 1614 bool isUTF16 = false; 1615 llvm::StringMapEntry<llvm::Constant*> &Entry = 1616 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1617 getTargetData().isLittleEndian(), 1618 isUTF16, StringLength); 1619 1620 if (llvm::Constant *C = Entry.getValue()) 1621 return C; 1622 1623 llvm::Constant *Zero = 1624 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1625 llvm::Constant *Zeros[] = { Zero, Zero }; 1626 1627 // If we don't already have it, get __CFConstantStringClassReference. 1628 if (!CFConstantStringClassRef) { 1629 const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1630 Ty = llvm::ArrayType::get(Ty, 0); 1631 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1632 "__CFConstantStringClassReference"); 1633 // Decay array -> ptr 1634 CFConstantStringClassRef = 1635 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1636 } 1637 1638 QualType CFTy = getContext().getCFConstantStringType(); 1639 1640 const llvm::StructType *STy = 1641 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1642 1643 std::vector<llvm::Constant*> Fields(4); 1644 1645 // Class pointer. 1646 Fields[0] = CFConstantStringClassRef; 1647 1648 // Flags. 1649 const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1650 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 1651 llvm::ConstantInt::get(Ty, 0x07C8); 1652 1653 // String pointer. 1654 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1655 1656 llvm::GlobalValue::LinkageTypes Linkage; 1657 bool isConstant; 1658 if (isUTF16) { 1659 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1660 Linkage = llvm::GlobalValue::InternalLinkage; 1661 // Note: -fwritable-strings doesn't make unicode CFStrings writable, but 1662 // does make plain ascii ones writable. 1663 isConstant = true; 1664 } else { 1665 Linkage = llvm::GlobalValue::PrivateLinkage; 1666 isConstant = !Features.WritableStrings; 1667 } 1668 1669 llvm::GlobalVariable *GV = 1670 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1671 ".str"); 1672 GV->setUnnamedAddr(true); 1673 if (isUTF16) { 1674 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 1675 GV->setAlignment(Align.getQuantity()); 1676 } 1677 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1678 1679 // String length. 1680 Ty = getTypes().ConvertType(getContext().LongTy); 1681 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 1682 1683 // The struct. 1684 C = llvm::ConstantStruct::get(STy, Fields); 1685 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1686 llvm::GlobalVariable::PrivateLinkage, C, 1687 "_unnamed_cfstring_"); 1688 if (const char *Sect = getContext().Target.getCFStringSection()) 1689 GV->setSection(Sect); 1690 Entry.setValue(GV); 1691 1692 return GV; 1693} 1694 1695llvm::Constant * 1696CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) { 1697 unsigned StringLength = 0; 1698 bool isUTF16 = false; 1699 llvm::StringMapEntry<llvm::Constant*> &Entry = 1700 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1701 getTargetData().isLittleEndian(), 1702 isUTF16, StringLength); 1703 1704 if (llvm::Constant *C = Entry.getValue()) 1705 return C; 1706 1707 llvm::Constant *Zero = 1708 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1709 llvm::Constant *Zeros[] = { Zero, Zero }; 1710 1711 // If we don't already have it, get _NSConstantStringClassReference. 1712 if (!ConstantStringClassRef) { 1713 std::string StringClass(getLangOptions().ObjCConstantStringClass); 1714 const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1715 Ty = llvm::ArrayType::get(Ty, 0); 1716 llvm::Constant *GV; 1717 if (StringClass.empty()) 1718 GV = CreateRuntimeVariable(Ty, 1719 Features.ObjCNonFragileABI ? 1720 "OBJC_CLASS_$_NSConstantString" : 1721 "_NSConstantStringClassReference"); 1722 else { 1723 std::string str; 1724 if (Features.ObjCNonFragileABI) 1725 str = "OBJC_CLASS_$_" + StringClass; 1726 else 1727 str = "_" + StringClass + "ClassReference"; 1728 GV = CreateRuntimeVariable(Ty, str); 1729 } 1730 // Decay array -> ptr 1731 ConstantStringClassRef = 1732 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1733 } 1734 1735 QualType NSTy = getContext().getNSConstantStringType(); 1736 1737 const llvm::StructType *STy = 1738 cast<llvm::StructType>(getTypes().ConvertType(NSTy)); 1739 1740 std::vector<llvm::Constant*> Fields(3); 1741 1742 // Class pointer. 1743 Fields[0] = ConstantStringClassRef; 1744 1745 // String pointer. 1746 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1747 1748 llvm::GlobalValue::LinkageTypes Linkage; 1749 bool isConstant; 1750 if (isUTF16) { 1751 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1752 Linkage = llvm::GlobalValue::InternalLinkage; 1753 // Note: -fwritable-strings doesn't make unicode NSStrings writable, but 1754 // does make plain ascii ones writable. 1755 isConstant = true; 1756 } else { 1757 Linkage = llvm::GlobalValue::PrivateLinkage; 1758 isConstant = !Features.WritableStrings; 1759 } 1760 1761 llvm::GlobalVariable *GV = 1762 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1763 ".str"); 1764 GV->setUnnamedAddr(true); 1765 if (isUTF16) { 1766 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 1767 GV->setAlignment(Align.getQuantity()); 1768 } 1769 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1770 1771 // String length. 1772 const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1773 Fields[2] = llvm::ConstantInt::get(Ty, StringLength); 1774 1775 // The struct. 1776 C = llvm::ConstantStruct::get(STy, Fields); 1777 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1778 llvm::GlobalVariable::PrivateLinkage, C, 1779 "_unnamed_nsstring_"); 1780 // FIXME. Fix section. 1781 if (const char *Sect = 1782 Features.ObjCNonFragileABI 1783 ? getContext().Target.getNSStringNonFragileABISection() 1784 : getContext().Target.getNSStringSection()) 1785 GV->setSection(Sect); 1786 Entry.setValue(GV); 1787 1788 return GV; 1789} 1790 1791/// GetStringForStringLiteral - Return the appropriate bytes for a 1792/// string literal, properly padded to match the literal type. 1793std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 1794 const ASTContext &Context = getContext(); 1795 const ConstantArrayType *CAT = 1796 Context.getAsConstantArrayType(E->getType()); 1797 assert(CAT && "String isn't pointer or array!"); 1798 1799 // Resize the string to the right size. 1800 uint64_t RealLen = CAT->getSize().getZExtValue(); 1801 1802 if (E->isWide()) 1803 RealLen *= Context.Target.getWCharWidth() / Context.getCharWidth(); 1804 1805 std::string Str = E->getString().str(); 1806 Str.resize(RealLen, '\0'); 1807 1808 return Str; 1809} 1810 1811/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 1812/// constant array for the given string literal. 1813llvm::Constant * 1814CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 1815 // FIXME: This can be more efficient. 1816 // FIXME: We shouldn't need to bitcast the constant in the wide string case. 1817 llvm::Constant *C = GetAddrOfConstantString(GetStringForStringLiteral(S)); 1818 if (S->isWide()) { 1819 llvm::Type *DestTy = 1820 llvm::PointerType::getUnqual(getTypes().ConvertType(S->getType())); 1821 C = llvm::ConstantExpr::getBitCast(C, DestTy); 1822 } 1823 return C; 1824} 1825 1826/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 1827/// array for the given ObjCEncodeExpr node. 1828llvm::Constant * 1829CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 1830 std::string Str; 1831 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 1832 1833 return GetAddrOfConstantCString(Str); 1834} 1835 1836 1837/// GenerateWritableString -- Creates storage for a string literal. 1838static llvm::Constant *GenerateStringLiteral(const std::string &str, 1839 bool constant, 1840 CodeGenModule &CGM, 1841 const char *GlobalName) { 1842 // Create Constant for this string literal. Don't add a '\0'. 1843 llvm::Constant *C = 1844 llvm::ConstantArray::get(CGM.getLLVMContext(), str, false); 1845 1846 // Create a global variable for this string 1847 llvm::GlobalVariable *GV = 1848 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 1849 llvm::GlobalValue::PrivateLinkage, 1850 C, GlobalName); 1851 GV->setUnnamedAddr(true); 1852 return GV; 1853} 1854 1855/// GetAddrOfConstantString - Returns a pointer to a character array 1856/// containing the literal. This contents are exactly that of the 1857/// given string, i.e. it will not be null terminated automatically; 1858/// see GetAddrOfConstantCString. Note that whether the result is 1859/// actually a pointer to an LLVM constant depends on 1860/// Feature.WriteableStrings. 1861/// 1862/// The result has pointer to array type. 1863llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str, 1864 const char *GlobalName) { 1865 bool IsConstant = !Features.WritableStrings; 1866 1867 // Get the default prefix if a name wasn't specified. 1868 if (!GlobalName) 1869 GlobalName = ".str"; 1870 1871 // Don't share any string literals if strings aren't constant. 1872 if (!IsConstant) 1873 return GenerateStringLiteral(str, false, *this, GlobalName); 1874 1875 llvm::StringMapEntry<llvm::Constant *> &Entry = 1876 ConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]); 1877 1878 if (Entry.getValue()) 1879 return Entry.getValue(); 1880 1881 // Create a global variable for this. 1882 llvm::Constant *C = GenerateStringLiteral(str, true, *this, GlobalName); 1883 Entry.setValue(C); 1884 return C; 1885} 1886 1887/// GetAddrOfConstantCString - Returns a pointer to a character 1888/// array containing the literal and a terminating '\-' 1889/// character. The result has pointer to array type. 1890llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &str, 1891 const char *GlobalName){ 1892 return GetAddrOfConstantString(str + '\0', GlobalName); 1893} 1894 1895/// EmitObjCPropertyImplementations - Emit information for synthesized 1896/// properties for an implementation. 1897void CodeGenModule::EmitObjCPropertyImplementations(const 1898 ObjCImplementationDecl *D) { 1899 for (ObjCImplementationDecl::propimpl_iterator 1900 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 1901 ObjCPropertyImplDecl *PID = *i; 1902 1903 // Dynamic is just for type-checking. 1904 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 1905 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 1906 1907 // Determine which methods need to be implemented, some may have 1908 // been overridden. Note that ::isSynthesized is not the method 1909 // we want, that just indicates if the decl came from a 1910 // property. What we want to know is if the method is defined in 1911 // this implementation. 1912 if (!D->getInstanceMethod(PD->getGetterName())) 1913 CodeGenFunction(*this).GenerateObjCGetter( 1914 const_cast<ObjCImplementationDecl *>(D), PID); 1915 if (!PD->isReadOnly() && 1916 !D->getInstanceMethod(PD->getSetterName())) 1917 CodeGenFunction(*this).GenerateObjCSetter( 1918 const_cast<ObjCImplementationDecl *>(D), PID); 1919 } 1920 } 1921} 1922 1923/// EmitObjCIvarInitializations - Emit information for ivar initialization 1924/// for an implementation. 1925void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) { 1926 if (!Features.NeXTRuntime || D->getNumIvarInitializers() == 0) 1927 return; 1928 DeclContext* DC = const_cast<DeclContext*>(dyn_cast<DeclContext>(D)); 1929 assert(DC && "EmitObjCIvarInitializations - null DeclContext"); 1930 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct"); 1931 Selector cxxSelector = getContext().Selectors.getSelector(0, &II); 1932 ObjCMethodDecl *DTORMethod = ObjCMethodDecl::Create(getContext(), 1933 D->getLocation(), 1934 D->getLocation(), cxxSelector, 1935 getContext().VoidTy, 0, 1936 DC, true, false, true, false, 1937 ObjCMethodDecl::Required); 1938 D->addInstanceMethod(DTORMethod); 1939 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false); 1940 1941 II = &getContext().Idents.get(".cxx_construct"); 1942 cxxSelector = getContext().Selectors.getSelector(0, &II); 1943 // The constructor returns 'self'. 1944 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(), 1945 D->getLocation(), 1946 D->getLocation(), cxxSelector, 1947 getContext().getObjCIdType(), 0, 1948 DC, true, false, true, false, 1949 ObjCMethodDecl::Required); 1950 D->addInstanceMethod(CTORMethod); 1951 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true); 1952 1953 1954} 1955 1956/// EmitNamespace - Emit all declarations in a namespace. 1957void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 1958 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 1959 I != E; ++I) 1960 EmitTopLevelDecl(*I); 1961} 1962 1963// EmitLinkageSpec - Emit all declarations in a linkage spec. 1964void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 1965 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 1966 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 1967 ErrorUnsupported(LSD, "linkage spec"); 1968 return; 1969 } 1970 1971 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 1972 I != E; ++I) 1973 EmitTopLevelDecl(*I); 1974} 1975 1976/// EmitTopLevelDecl - Emit code for a single top level declaration. 1977void CodeGenModule::EmitTopLevelDecl(Decl *D) { 1978 // If an error has occurred, stop code generation, but continue 1979 // parsing and semantic analysis (to ensure all warnings and errors 1980 // are emitted). 1981 if (Diags.hasErrorOccurred()) 1982 return; 1983 1984 // Ignore dependent declarations. 1985 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 1986 return; 1987 1988 switch (D->getKind()) { 1989 case Decl::CXXConversion: 1990 case Decl::CXXMethod: 1991 case Decl::Function: 1992 // Skip function templates 1993 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 1994 return; 1995 1996 EmitGlobal(cast<FunctionDecl>(D)); 1997 break; 1998 1999 case Decl::Var: 2000 EmitGlobal(cast<VarDecl>(D)); 2001 break; 2002 2003 // C++ Decls 2004 case Decl::Namespace: 2005 EmitNamespace(cast<NamespaceDecl>(D)); 2006 break; 2007 // No code generation needed. 2008 case Decl::UsingShadow: 2009 case Decl::Using: 2010 case Decl::UsingDirective: 2011 case Decl::ClassTemplate: 2012 case Decl::FunctionTemplate: 2013 case Decl::NamespaceAlias: 2014 break; 2015 case Decl::CXXConstructor: 2016 // Skip function templates 2017 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 2018 return; 2019 2020 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 2021 break; 2022 case Decl::CXXDestructor: 2023 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 2024 break; 2025 2026 case Decl::StaticAssert: 2027 // Nothing to do. 2028 break; 2029 2030 // Objective-C Decls 2031 2032 // Forward declarations, no (immediate) code generation. 2033 case Decl::ObjCClass: 2034 case Decl::ObjCForwardProtocol: 2035 case Decl::ObjCInterface: 2036 break; 2037 2038 case Decl::ObjCCategory: { 2039 ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D); 2040 if (CD->IsClassExtension() && CD->hasSynthBitfield()) 2041 Context.ResetObjCLayout(CD->getClassInterface()); 2042 break; 2043 } 2044 2045 2046 case Decl::ObjCProtocol: 2047 Runtime->GenerateProtocol(cast<ObjCProtocolDecl>(D)); 2048 break; 2049 2050 case Decl::ObjCCategoryImpl: 2051 // Categories have properties but don't support synthesize so we 2052 // can ignore them here. 2053 Runtime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 2054 break; 2055 2056 case Decl::ObjCImplementation: { 2057 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 2058 if (Features.ObjCNonFragileABI2 && OMD->hasSynthBitfield()) 2059 Context.ResetObjCLayout(OMD->getClassInterface()); 2060 EmitObjCPropertyImplementations(OMD); 2061 EmitObjCIvarInitializations(OMD); 2062 Runtime->GenerateClass(OMD); 2063 break; 2064 } 2065 case Decl::ObjCMethod: { 2066 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 2067 // If this is not a prototype, emit the body. 2068 if (OMD->getBody()) 2069 CodeGenFunction(*this).GenerateObjCMethod(OMD); 2070 break; 2071 } 2072 case Decl::ObjCCompatibleAlias: 2073 // compatibility-alias is a directive and has no code gen. 2074 break; 2075 2076 case Decl::LinkageSpec: 2077 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 2078 break; 2079 2080 case Decl::FileScopeAsm: { 2081 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 2082 llvm::StringRef AsmString = AD->getAsmString()->getString(); 2083 2084 const std::string &S = getModule().getModuleInlineAsm(); 2085 if (S.empty()) 2086 getModule().setModuleInlineAsm(AsmString); 2087 else 2088 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 2089 break; 2090 } 2091 2092 default: 2093 // Make sure we handled everything we should, every other kind is a 2094 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 2095 // function. Need to recode Decl::Kind to do that easily. 2096 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 2097 } 2098} 2099 2100/// Turns the given pointer into a constant. 2101static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context, 2102 const void *Ptr) { 2103 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr); 2104 const llvm::Type *i64 = llvm::Type::getInt64Ty(Context); 2105 return llvm::ConstantInt::get(i64, PtrInt); 2106} 2107 2108static void EmitGlobalDeclMetadata(CodeGenModule &CGM, 2109 llvm::NamedMDNode *&GlobalMetadata, 2110 GlobalDecl D, 2111 llvm::GlobalValue *Addr) { 2112 if (!GlobalMetadata) 2113 GlobalMetadata = 2114 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs"); 2115 2116 // TODO: should we report variant information for ctors/dtors? 2117 llvm::Value *Ops[] = { 2118 Addr, 2119 GetPointerConstant(CGM.getLLVMContext(), D.getDecl()) 2120 }; 2121 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops, 2)); 2122} 2123 2124/// Emits metadata nodes associating all the global values in the 2125/// current module with the Decls they came from. This is useful for 2126/// projects using IR gen as a subroutine. 2127/// 2128/// Since there's currently no way to associate an MDNode directly 2129/// with an llvm::GlobalValue, we create a global named metadata 2130/// with the name 'clang.global.decl.ptrs'. 2131void CodeGenModule::EmitDeclMetadata() { 2132 llvm::NamedMDNode *GlobalMetadata = 0; 2133 2134 // StaticLocalDeclMap 2135 for (llvm::DenseMap<GlobalDecl,llvm::StringRef>::iterator 2136 I = MangledDeclNames.begin(), E = MangledDeclNames.end(); 2137 I != E; ++I) { 2138 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second); 2139 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr); 2140 } 2141} 2142 2143/// Emits metadata nodes for all the local variables in the current 2144/// function. 2145void CodeGenFunction::EmitDeclMetadata() { 2146 if (LocalDeclMap.empty()) return; 2147 2148 llvm::LLVMContext &Context = getLLVMContext(); 2149 2150 // Find the unique metadata ID for this name. 2151 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr"); 2152 2153 llvm::NamedMDNode *GlobalMetadata = 0; 2154 2155 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator 2156 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) { 2157 const Decl *D = I->first; 2158 llvm::Value *Addr = I->second; 2159 2160 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) { 2161 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D); 2162 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, &DAddr, 1)); 2163 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) { 2164 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D)); 2165 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV); 2166 } 2167 } 2168} 2169 2170///@name Custom Runtime Function Interfaces 2171///@{ 2172// 2173// FIXME: These can be eliminated once we can have clients just get the required 2174// AST nodes from the builtin tables. 2175 2176llvm::Constant *CodeGenModule::getBlockObjectDispose() { 2177 if (BlockObjectDispose) 2178 return BlockObjectDispose; 2179 2180 // If we saw an explicit decl, use that. 2181 if (BlockObjectDisposeDecl) { 2182 return BlockObjectDispose = GetAddrOfFunction( 2183 BlockObjectDisposeDecl, 2184 getTypes().GetFunctionType(BlockObjectDisposeDecl)); 2185 } 2186 2187 // Otherwise construct the function by hand. 2188 const llvm::FunctionType *FTy; 2189 std::vector<const llvm::Type*> ArgTys; 2190 const llvm::Type *ResultType = llvm::Type::getVoidTy(VMContext); 2191 ArgTys.push_back(Int8PtrTy); 2192 ArgTys.push_back(llvm::Type::getInt32Ty(VMContext)); 2193 FTy = llvm::FunctionType::get(ResultType, ArgTys, false); 2194 return BlockObjectDispose = 2195 CreateRuntimeFunction(FTy, "_Block_object_dispose"); 2196} 2197 2198llvm::Constant *CodeGenModule::getBlockObjectAssign() { 2199 if (BlockObjectAssign) 2200 return BlockObjectAssign; 2201 2202 // If we saw an explicit decl, use that. 2203 if (BlockObjectAssignDecl) { 2204 return BlockObjectAssign = GetAddrOfFunction( 2205 BlockObjectAssignDecl, 2206 getTypes().GetFunctionType(BlockObjectAssignDecl)); 2207 } 2208 2209 // Otherwise construct the function by hand. 2210 const llvm::FunctionType *FTy; 2211 std::vector<const llvm::Type*> ArgTys; 2212 const llvm::Type *ResultType = llvm::Type::getVoidTy(VMContext); 2213 ArgTys.push_back(Int8PtrTy); 2214 ArgTys.push_back(Int8PtrTy); 2215 ArgTys.push_back(llvm::Type::getInt32Ty(VMContext)); 2216 FTy = llvm::FunctionType::get(ResultType, ArgTys, false); 2217 return BlockObjectAssign = 2218 CreateRuntimeFunction(FTy, "_Block_object_assign"); 2219} 2220 2221llvm::Constant *CodeGenModule::getNSConcreteGlobalBlock() { 2222 if (NSConcreteGlobalBlock) 2223 return NSConcreteGlobalBlock; 2224 2225 // If we saw an explicit decl, use that. 2226 if (NSConcreteGlobalBlockDecl) { 2227 return NSConcreteGlobalBlock = GetAddrOfGlobalVar( 2228 NSConcreteGlobalBlockDecl, 2229 getTypes().ConvertType(NSConcreteGlobalBlockDecl->getType())); 2230 } 2231 2232 // Otherwise construct the variable by hand. 2233 return NSConcreteGlobalBlock = 2234 CreateRuntimeVariable(Int8PtrTy, "_NSConcreteGlobalBlock"); 2235} 2236 2237llvm::Constant *CodeGenModule::getNSConcreteStackBlock() { 2238 if (NSConcreteStackBlock) 2239 return NSConcreteStackBlock; 2240 2241 // If we saw an explicit decl, use that. 2242 if (NSConcreteStackBlockDecl) { 2243 return NSConcreteStackBlock = GetAddrOfGlobalVar( 2244 NSConcreteStackBlockDecl, 2245 getTypes().ConvertType(NSConcreteStackBlockDecl->getType())); 2246 } 2247 2248 // Otherwise construct the variable by hand. 2249 return NSConcreteStackBlock = 2250 CreateRuntimeVariable(Int8PtrTy, "_NSConcreteStackBlock"); 2251} 2252 2253///@} 2254