CodeGenModule.cpp revision 204962
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 "CGCall.h" 18#include "CGObjCRuntime.h" 19#include "Mangle.h" 20#include "TargetInfo.h" 21#include "clang/CodeGen/CodeGenOptions.h" 22#include "clang/AST/ASTContext.h" 23#include "clang/AST/CharUnits.h" 24#include "clang/AST/DeclObjC.h" 25#include "clang/AST/DeclCXX.h" 26#include "clang/AST/RecordLayout.h" 27#include "clang/Basic/Builtins.h" 28#include "clang/Basic/Diagnostic.h" 29#include "clang/Basic/SourceManager.h" 30#include "clang/Basic/TargetInfo.h" 31#include "clang/Basic/ConvertUTF.h" 32#include "llvm/CallingConv.h" 33#include "llvm/Module.h" 34#include "llvm/Intrinsics.h" 35#include "llvm/LLVMContext.h" 36#include "llvm/ADT/Triple.h" 37#include "llvm/Target/TargetData.h" 38#include "llvm/Support/ErrorHandling.h" 39using namespace clang; 40using namespace CodeGen; 41 42 43CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 44 llvm::Module &M, const llvm::TargetData &TD, 45 Diagnostic &diags) 46 : BlockModule(C, M, TD, Types, *this), Context(C), 47 Features(C.getLangOptions()), CodeGenOpts(CGO), TheModule(M), 48 TheTargetData(TD), TheTargetCodeGenInfo(0), Diags(diags), 49 Types(C, M, TD, getTargetCodeGenInfo().getABIInfo()), 50 MangleCtx(C), VtableInfo(*this), Runtime(0), 51 MemCpyFn(0), MemMoveFn(0), MemSetFn(0), CFConstantStringClassRef(0), 52 VMContext(M.getContext()) { 53 54 if (!Features.ObjC1) 55 Runtime = 0; 56 else if (!Features.NeXTRuntime) 57 Runtime = CreateGNUObjCRuntime(*this); 58 else if (Features.ObjCNonFragileABI) 59 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 60 else 61 Runtime = CreateMacObjCRuntime(*this); 62 63 // If debug info generation is enabled, create the CGDebugInfo object. 64 DebugInfo = CodeGenOpts.DebugInfo ? new CGDebugInfo(*this) : 0; 65} 66 67CodeGenModule::~CodeGenModule() { 68 delete Runtime; 69 delete DebugInfo; 70} 71 72void CodeGenModule::createObjCRuntime() { 73 if (!Features.NeXTRuntime) 74 Runtime = CreateGNUObjCRuntime(*this); 75 else if (Features.ObjCNonFragileABI) 76 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 77 else 78 Runtime = CreateMacObjCRuntime(*this); 79} 80 81void CodeGenModule::Release() { 82 EmitDeferred(); 83 EmitCXXGlobalInitFunc(); 84 if (Runtime) 85 if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction()) 86 AddGlobalCtor(ObjCInitFunction); 87 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 88 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 89 EmitAnnotations(); 90 EmitLLVMUsed(); 91} 92 93bool CodeGenModule::isTargetDarwin() const { 94 return getContext().Target.getTriple().getOS() == llvm::Triple::Darwin; 95} 96 97/// ErrorUnsupported - Print out an error that codegen doesn't support the 98/// specified stmt yet. 99void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 100 bool OmitOnError) { 101 if (OmitOnError && getDiags().hasErrorOccurred()) 102 return; 103 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 104 "cannot compile this %0 yet"); 105 std::string Msg = Type; 106 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 107 << Msg << S->getSourceRange(); 108} 109 110/// ErrorUnsupported - Print out an error that codegen doesn't support the 111/// specified decl yet. 112void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 113 bool OmitOnError) { 114 if (OmitOnError && getDiags().hasErrorOccurred()) 115 return; 116 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 117 "cannot compile this %0 yet"); 118 std::string Msg = Type; 119 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 120} 121 122LangOptions::VisibilityMode 123CodeGenModule::getDeclVisibilityMode(const Decl *D) const { 124 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 125 if (VD->getStorageClass() == VarDecl::PrivateExtern) 126 return LangOptions::Hidden; 127 128 if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>()) { 129 switch (attr->getVisibility()) { 130 default: assert(0 && "Unknown visibility!"); 131 case VisibilityAttr::DefaultVisibility: 132 return LangOptions::Default; 133 case VisibilityAttr::HiddenVisibility: 134 return LangOptions::Hidden; 135 case VisibilityAttr::ProtectedVisibility: 136 return LangOptions::Protected; 137 } 138 } 139 140 // This decl should have the same visibility as its parent. 141 if (const DeclContext *DC = D->getDeclContext()) 142 return getDeclVisibilityMode(cast<Decl>(DC)); 143 144 return getLangOptions().getVisibilityMode(); 145} 146 147void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 148 const Decl *D) const { 149 // Internal definitions always have default visibility. 150 if (GV->hasLocalLinkage()) { 151 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 152 return; 153 } 154 155 switch (getDeclVisibilityMode(D)) { 156 default: assert(0 && "Unknown visibility!"); 157 case LangOptions::Default: 158 return GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 159 case LangOptions::Hidden: 160 return GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 161 case LangOptions::Protected: 162 return GV->setVisibility(llvm::GlobalValue::ProtectedVisibility); 163 } 164} 165 166const char *CodeGenModule::getMangledName(const GlobalDecl &GD) { 167 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 168 169 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 170 return getMangledCXXCtorName(D, GD.getCtorType()); 171 if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 172 return getMangledCXXDtorName(D, GD.getDtorType()); 173 174 return getMangledName(ND); 175} 176 177/// \brief Retrieves the mangled name for the given declaration. 178/// 179/// If the given declaration requires a mangled name, returns an 180/// const char* containing the mangled name. Otherwise, returns 181/// the unmangled name. 182/// 183const char *CodeGenModule::getMangledName(const NamedDecl *ND) { 184 if (!getMangleContext().shouldMangleDeclName(ND)) { 185 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl."); 186 return ND->getNameAsCString(); 187 } 188 189 llvm::SmallString<256> Name; 190 getMangleContext().mangleName(ND, Name); 191 Name += '\0'; 192 return UniqueMangledName(Name.begin(), Name.end()); 193} 194 195const char *CodeGenModule::UniqueMangledName(const char *NameStart, 196 const char *NameEnd) { 197 assert(*(NameEnd - 1) == '\0' && "Mangled name must be null terminated!"); 198 199 return MangledNames.GetOrCreateValue(NameStart, NameEnd).getKeyData(); 200} 201 202/// AddGlobalCtor - Add a function to the list that will be called before 203/// main() runs. 204void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 205 // FIXME: Type coercion of void()* types. 206 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 207} 208 209/// AddGlobalDtor - Add a function to the list that will be called 210/// when the module is unloaded. 211void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 212 // FIXME: Type coercion of void()* types. 213 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 214} 215 216void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 217 // Ctor function type is void()*. 218 llvm::FunctionType* CtorFTy = 219 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), 220 std::vector<const llvm::Type*>(), 221 false); 222 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 223 224 // Get the type of a ctor entry, { i32, void ()* }. 225 llvm::StructType* CtorStructTy = 226 llvm::StructType::get(VMContext, llvm::Type::getInt32Ty(VMContext), 227 llvm::PointerType::getUnqual(CtorFTy), NULL); 228 229 // Construct the constructor and destructor arrays. 230 std::vector<llvm::Constant*> Ctors; 231 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 232 std::vector<llvm::Constant*> S; 233 S.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 234 I->second, false)); 235 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy)); 236 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 237 } 238 239 if (!Ctors.empty()) { 240 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 241 new llvm::GlobalVariable(TheModule, AT, false, 242 llvm::GlobalValue::AppendingLinkage, 243 llvm::ConstantArray::get(AT, Ctors), 244 GlobalName); 245 } 246} 247 248void CodeGenModule::EmitAnnotations() { 249 if (Annotations.empty()) 250 return; 251 252 // Create a new global variable for the ConstantStruct in the Module. 253 llvm::Constant *Array = 254 llvm::ConstantArray::get(llvm::ArrayType::get(Annotations[0]->getType(), 255 Annotations.size()), 256 Annotations); 257 llvm::GlobalValue *gv = 258 new llvm::GlobalVariable(TheModule, Array->getType(), false, 259 llvm::GlobalValue::AppendingLinkage, Array, 260 "llvm.global.annotations"); 261 gv->setSection("llvm.metadata"); 262} 263 264static CodeGenModule::GVALinkage 265GetLinkageForFunction(ASTContext &Context, const FunctionDecl *FD, 266 const LangOptions &Features) { 267 CodeGenModule::GVALinkage External = CodeGenModule::GVA_StrongExternal; 268 269 Linkage L = FD->getLinkage(); 270 if (L == ExternalLinkage && Context.getLangOptions().CPlusPlus && 271 FD->getType()->getLinkage() == UniqueExternalLinkage) 272 L = UniqueExternalLinkage; 273 274 switch (L) { 275 case NoLinkage: 276 case InternalLinkage: 277 case UniqueExternalLinkage: 278 return CodeGenModule::GVA_Internal; 279 280 case ExternalLinkage: 281 switch (FD->getTemplateSpecializationKind()) { 282 case TSK_Undeclared: 283 case TSK_ExplicitSpecialization: 284 External = CodeGenModule::GVA_StrongExternal; 285 break; 286 287 case TSK_ExplicitInstantiationDefinition: 288 // FIXME: explicit instantiation definitions should use weak linkage 289 return CodeGenModule::GVA_StrongExternal; 290 291 case TSK_ExplicitInstantiationDeclaration: 292 case TSK_ImplicitInstantiation: 293 External = CodeGenModule::GVA_TemplateInstantiation; 294 break; 295 } 296 } 297 298 if (!FD->isInlined()) 299 return External; 300 301 if (!Features.CPlusPlus || FD->hasAttr<GNUInlineAttr>()) { 302 // GNU or C99 inline semantics. Determine whether this symbol should be 303 // externally visible. 304 if (FD->isInlineDefinitionExternallyVisible()) 305 return External; 306 307 // C99 inline semantics, where the symbol is not externally visible. 308 return CodeGenModule::GVA_C99Inline; 309 } 310 311 // C++0x [temp.explicit]p9: 312 // [ Note: The intent is that an inline function that is the subject of 313 // an explicit instantiation declaration will still be implicitly 314 // instantiated when used so that the body can be considered for 315 // inlining, but that no out-of-line copy of the inline function would be 316 // generated in the translation unit. -- end note ] 317 if (FD->getTemplateSpecializationKind() 318 == TSK_ExplicitInstantiationDeclaration) 319 return CodeGenModule::GVA_C99Inline; 320 321 return CodeGenModule::GVA_CXXInline; 322} 323 324llvm::GlobalValue::LinkageTypes 325CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 326 GVALinkage Linkage = GetLinkageForFunction(getContext(), D, Features); 327 328 if (Linkage == GVA_Internal) { 329 return llvm::Function::InternalLinkage; 330 } else if (D->hasAttr<DLLExportAttr>()) { 331 return llvm::Function::DLLExportLinkage; 332 } else if (D->hasAttr<WeakAttr>()) { 333 return llvm::Function::WeakAnyLinkage; 334 } else if (Linkage == GVA_C99Inline) { 335 // In C99 mode, 'inline' functions are guaranteed to have a strong 336 // definition somewhere else, so we can use available_externally linkage. 337 return llvm::Function::AvailableExternallyLinkage; 338 } else if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) { 339 // In C++, the compiler has to emit a definition in every translation unit 340 // that references the function. We should use linkonce_odr because 341 // a) if all references in this translation unit are optimized away, we 342 // don't need to codegen it. b) if the function persists, it needs to be 343 // merged with other definitions. c) C++ has the ODR, so we know the 344 // definition is dependable. 345 return llvm::Function::LinkOnceODRLinkage; 346 } else { 347 assert(Linkage == GVA_StrongExternal); 348 // Otherwise, we have strong external linkage. 349 return llvm::Function::ExternalLinkage; 350 } 351} 352 353 354/// SetFunctionDefinitionAttributes - Set attributes for a global. 355/// 356/// FIXME: This is currently only done for aliases and functions, but not for 357/// variables (these details are set in EmitGlobalVarDefinition for variables). 358void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 359 llvm::GlobalValue *GV) { 360 GV->setLinkage(getFunctionLinkage(D)); 361 SetCommonAttributes(D, GV); 362} 363 364void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 365 const CGFunctionInfo &Info, 366 llvm::Function *F) { 367 unsigned CallingConv; 368 AttributeListType AttributeList; 369 ConstructAttributeList(Info, D, AttributeList, CallingConv); 370 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 371 AttributeList.size())); 372 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 373} 374 375void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 376 llvm::Function *F) { 377 if (!Features.Exceptions && !Features.ObjCNonFragileABI) 378 F->addFnAttr(llvm::Attribute::NoUnwind); 379 380 if (D->hasAttr<AlwaysInlineAttr>()) 381 F->addFnAttr(llvm::Attribute::AlwaysInline); 382 383 if (D->hasAttr<NoInlineAttr>()) 384 F->addFnAttr(llvm::Attribute::NoInline); 385 386 if (Features.getStackProtectorMode() == LangOptions::SSPOn) 387 F->addFnAttr(llvm::Attribute::StackProtect); 388 else if (Features.getStackProtectorMode() == LangOptions::SSPReq) 389 F->addFnAttr(llvm::Attribute::StackProtectReq); 390 391 if (const AlignedAttr *AA = D->getAttr<AlignedAttr>()) { 392 unsigned width = Context.Target.getCharWidth(); 393 F->setAlignment(AA->getAlignment() / width); 394 while ((AA = AA->getNext<AlignedAttr>())) 395 F->setAlignment(std::max(F->getAlignment(), AA->getAlignment() / width)); 396 } 397 // C++ ABI requires 2-byte alignment for member functions. 398 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 399 F->setAlignment(2); 400} 401 402void CodeGenModule::SetCommonAttributes(const Decl *D, 403 llvm::GlobalValue *GV) { 404 setGlobalVisibility(GV, D); 405 406 if (D->hasAttr<UsedAttr>()) 407 AddUsedGlobal(GV); 408 409 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 410 GV->setSection(SA->getName()); 411 412 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 413} 414 415void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 416 llvm::Function *F, 417 const CGFunctionInfo &FI) { 418 SetLLVMFunctionAttributes(D, FI, F); 419 SetLLVMFunctionAttributesForDefinition(D, F); 420 421 F->setLinkage(llvm::Function::InternalLinkage); 422 423 SetCommonAttributes(D, F); 424} 425 426void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 427 llvm::Function *F, 428 bool IsIncompleteFunction) { 429 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 430 431 if (!IsIncompleteFunction) 432 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(GD), F); 433 434 // Only a few attributes are set on declarations; these may later be 435 // overridden by a definition. 436 437 if (FD->hasAttr<DLLImportAttr>()) { 438 F->setLinkage(llvm::Function::DLLImportLinkage); 439 } else if (FD->hasAttr<WeakAttr>() || 440 FD->hasAttr<WeakImportAttr>()) { 441 // "extern_weak" is overloaded in LLVM; we probably should have 442 // separate linkage types for this. 443 F->setLinkage(llvm::Function::ExternalWeakLinkage); 444 } else { 445 F->setLinkage(llvm::Function::ExternalLinkage); 446 } 447 448 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 449 F->setSection(SA->getName()); 450} 451 452void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 453 assert(!GV->isDeclaration() && 454 "Only globals with definition can force usage."); 455 LLVMUsed.push_back(GV); 456} 457 458void CodeGenModule::EmitLLVMUsed() { 459 // Don't create llvm.used if there is no need. 460 if (LLVMUsed.empty()) 461 return; 462 463 const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext); 464 465 // Convert LLVMUsed to what ConstantArray needs. 466 std::vector<llvm::Constant*> UsedArray; 467 UsedArray.resize(LLVMUsed.size()); 468 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 469 UsedArray[i] = 470 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 471 i8PTy); 472 } 473 474 if (UsedArray.empty()) 475 return; 476 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, UsedArray.size()); 477 478 llvm::GlobalVariable *GV = 479 new llvm::GlobalVariable(getModule(), ATy, false, 480 llvm::GlobalValue::AppendingLinkage, 481 llvm::ConstantArray::get(ATy, UsedArray), 482 "llvm.used"); 483 484 GV->setSection("llvm.metadata"); 485} 486 487void CodeGenModule::EmitDeferred() { 488 // Emit code for any potentially referenced deferred decls. Since a 489 // previously unused static decl may become used during the generation of code 490 // for a static function, iterate until no changes are made. 491 492 while (!DeferredDeclsToEmit.empty() || !DeferredVtables.empty()) { 493 if (!DeferredVtables.empty()) { 494 const CXXRecordDecl *RD = DeferredVtables.back(); 495 DeferredVtables.pop_back(); 496 getVtableInfo().GenerateClassData(getVtableLinkage(RD), RD); 497 continue; 498 } 499 500 GlobalDecl D = DeferredDeclsToEmit.back(); 501 DeferredDeclsToEmit.pop_back(); 502 503 // The mangled name for the decl must have been emitted in GlobalDeclMap. 504 // Look it up to see if it was defined with a stronger definition (e.g. an 505 // extern inline function with a strong function redefinition). If so, 506 // just ignore the deferred decl. 507 llvm::GlobalValue *CGRef = GlobalDeclMap[getMangledName(D)]; 508 assert(CGRef && "Deferred decl wasn't referenced?"); 509 510 if (!CGRef->isDeclaration()) 511 continue; 512 513 // Otherwise, emit the definition and move on to the next one. 514 EmitGlobalDefinition(D); 515 } 516} 517 518/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the 519/// annotation information for a given GlobalValue. The annotation struct is 520/// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the 521/// GlobalValue being annotated. The second field is the constant string 522/// created from the AnnotateAttr's annotation. The third field is a constant 523/// string containing the name of the translation unit. The fourth field is 524/// the line number in the file of the annotated value declaration. 525/// 526/// FIXME: this does not unique the annotation string constants, as llvm-gcc 527/// appears to. 528/// 529llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 530 const AnnotateAttr *AA, 531 unsigned LineNo) { 532 llvm::Module *M = &getModule(); 533 534 // get [N x i8] constants for the annotation string, and the filename string 535 // which are the 2nd and 3rd elements of the global annotation structure. 536 const llvm::Type *SBP = llvm::Type::getInt8PtrTy(VMContext); 537 llvm::Constant *anno = llvm::ConstantArray::get(VMContext, 538 AA->getAnnotation(), true); 539 llvm::Constant *unit = llvm::ConstantArray::get(VMContext, 540 M->getModuleIdentifier(), 541 true); 542 543 // Get the two global values corresponding to the ConstantArrays we just 544 // created to hold the bytes of the strings. 545 llvm::GlobalValue *annoGV = 546 new llvm::GlobalVariable(*M, anno->getType(), false, 547 llvm::GlobalValue::PrivateLinkage, anno, 548 GV->getName()); 549 // translation unit name string, emitted into the llvm.metadata section. 550 llvm::GlobalValue *unitGV = 551 new llvm::GlobalVariable(*M, unit->getType(), false, 552 llvm::GlobalValue::PrivateLinkage, unit, 553 ".str"); 554 555 // Create the ConstantStruct for the global annotation. 556 llvm::Constant *Fields[4] = { 557 llvm::ConstantExpr::getBitCast(GV, SBP), 558 llvm::ConstantExpr::getBitCast(annoGV, SBP), 559 llvm::ConstantExpr::getBitCast(unitGV, SBP), 560 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), LineNo) 561 }; 562 return llvm::ConstantStruct::get(VMContext, Fields, 4, false); 563} 564 565bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 566 // Never defer when EmitAllDecls is specified or the decl has 567 // attribute used. 568 if (Features.EmitAllDecls || Global->hasAttr<UsedAttr>()) 569 return false; 570 571 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 572 // Constructors and destructors should never be deferred. 573 if (FD->hasAttr<ConstructorAttr>() || 574 FD->hasAttr<DestructorAttr>()) 575 return false; 576 577 // The key function for a class must never be deferred. 578 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Global)) { 579 const CXXRecordDecl *RD = MD->getParent(); 580 if (MD->isOutOfLine() && RD->isDynamicClass()) { 581 const CXXMethodDecl *KeyFunction = getContext().getKeyFunction(RD); 582 if (KeyFunction && 583 KeyFunction->getCanonicalDecl() == MD->getCanonicalDecl()) 584 return false; 585 } 586 } 587 588 GVALinkage Linkage = GetLinkageForFunction(getContext(), FD, Features); 589 590 // static, static inline, always_inline, and extern inline functions can 591 // always be deferred. Normal inline functions can be deferred in C99/C++. 592 if (Linkage == GVA_Internal || Linkage == GVA_C99Inline || 593 Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 594 return true; 595 return false; 596 } 597 598 const VarDecl *VD = cast<VarDecl>(Global); 599 assert(VD->isFileVarDecl() && "Invalid decl"); 600 601 // We never want to defer structs that have non-trivial constructors or 602 // destructors. 603 604 // FIXME: Handle references. 605 if (const RecordType *RT = VD->getType()->getAs<RecordType>()) { 606 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 607 if (!RD->hasTrivialConstructor() || !RD->hasTrivialDestructor()) 608 return false; 609 } 610 } 611 612 // Static data may be deferred, but out-of-line static data members 613 // cannot be. 614 Linkage L = VD->getLinkage(); 615 if (L == ExternalLinkage && getContext().getLangOptions().CPlusPlus && 616 VD->getType()->getLinkage() == UniqueExternalLinkage) 617 L = UniqueExternalLinkage; 618 619 switch (L) { 620 case NoLinkage: 621 case InternalLinkage: 622 case UniqueExternalLinkage: 623 // Initializer has side effects? 624 if (VD->getInit() && VD->getInit()->HasSideEffects(Context)) 625 return false; 626 return !(VD->isStaticDataMember() && VD->isOutOfLine()); 627 628 case ExternalLinkage: 629 break; 630 } 631 632 return false; 633} 634 635llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 636 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 637 assert(AA && "No alias?"); 638 639 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 640 641 // Unique the name through the identifier table. 642 const char *AliaseeName = 643 getContext().Idents.get(AA->getAliasee()).getNameStart(); 644 645 // See if there is already something with the target's name in the module. 646 llvm::GlobalValue *Entry = GlobalDeclMap[AliaseeName]; 647 648 llvm::Constant *Aliasee; 649 if (isa<llvm::FunctionType>(DeclTy)) 650 Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, GlobalDecl()); 651 else 652 Aliasee = GetOrCreateLLVMGlobal(AliaseeName, 653 llvm::PointerType::getUnqual(DeclTy), 0); 654 if (!Entry) { 655 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee); 656 F->setLinkage(llvm::Function::ExternalWeakLinkage); 657 WeakRefReferences.insert(F); 658 } 659 660 return Aliasee; 661} 662 663void CodeGenModule::EmitGlobal(GlobalDecl GD) { 664 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 665 666 // Weak references don't produce any output by themselves. 667 if (Global->hasAttr<WeakRefAttr>()) 668 return; 669 670 // If this is an alias definition (which otherwise looks like a declaration) 671 // emit it now. 672 if (Global->hasAttr<AliasAttr>()) 673 return EmitAliasDefinition(Global); 674 675 // Ignore declarations, they will be emitted on their first use. 676 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 677 // Forward declarations are emitted lazily on first use. 678 if (!FD->isThisDeclarationADefinition()) 679 return; 680 } else { 681 const VarDecl *VD = cast<VarDecl>(Global); 682 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 683 684 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) 685 return; 686 } 687 688 // Defer code generation when possible if this is a static definition, inline 689 // function etc. These we only want to emit if they are used. 690 if (MayDeferGeneration(Global)) { 691 // If the value has already been used, add it directly to the 692 // DeferredDeclsToEmit list. 693 const char *MangledName = getMangledName(GD); 694 if (GlobalDeclMap.count(MangledName)) 695 DeferredDeclsToEmit.push_back(GD); 696 else { 697 // Otherwise, remember that we saw a deferred decl with this name. The 698 // first use of the mangled name will cause it to move into 699 // DeferredDeclsToEmit. 700 DeferredDecls[MangledName] = GD; 701 } 702 return; 703 } 704 705 // Otherwise emit the definition. 706 EmitGlobalDefinition(GD); 707} 708 709void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 710 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 711 712 PrettyStackTraceDecl CrashInfo((ValueDecl *)D, D->getLocation(), 713 Context.getSourceManager(), 714 "Generating code for declaration"); 715 716 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { 717 getVtableInfo().MaybeEmitVtable(GD); 718 if (MD->isVirtual() && MD->isOutOfLine() && 719 (!isa<CXXDestructorDecl>(D) || GD.getDtorType() != Dtor_Base)) { 720 if (isa<CXXDestructorDecl>(D)) { 721 GlobalDecl CanonGD(cast<CXXDestructorDecl>(D->getCanonicalDecl()), 722 GD.getDtorType()); 723 BuildThunksForVirtual(CanonGD); 724 } else { 725 BuildThunksForVirtual(MD->getCanonicalDecl()); 726 } 727 } 728 } 729 730 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 731 EmitCXXConstructor(CD, GD.getCtorType()); 732 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 733 EmitCXXDestructor(DD, GD.getDtorType()); 734 else if (isa<FunctionDecl>(D)) 735 EmitGlobalFunctionDefinition(GD); 736 else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 737 EmitGlobalVarDefinition(VD); 738 else { 739 assert(0 && "Invalid argument to EmitGlobalDefinition()"); 740 } 741} 742 743/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 744/// module, create and return an llvm Function with the specified type. If there 745/// is something in the module with the specified name, return it potentially 746/// bitcasted to the right type. 747/// 748/// If D is non-null, it specifies a decl that correspond to this. This is used 749/// to set the attributes on the function when it is first created. 750llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(const char *MangledName, 751 const llvm::Type *Ty, 752 GlobalDecl D) { 753 // Lookup the entry, lazily creating it if necessary. 754 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 755 if (Entry) { 756 if (WeakRefReferences.count(Entry)) { 757 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 758 if (FD && !FD->hasAttr<WeakAttr>()) 759 Entry->setLinkage(llvm::Function::ExternalLinkage); 760 761 WeakRefReferences.erase(Entry); 762 } 763 764 if (Entry->getType()->getElementType() == Ty) 765 return Entry; 766 767 // Make sure the result is of the correct type. 768 const llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 769 return llvm::ConstantExpr::getBitCast(Entry, PTy); 770 } 771 772 // This function doesn't have a complete type (for example, the return 773 // type is an incomplete struct). Use a fake type instead, and make 774 // sure not to try to set attributes. 775 bool IsIncompleteFunction = false; 776 if (!isa<llvm::FunctionType>(Ty)) { 777 Ty = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), 778 std::vector<const llvm::Type*>(), false); 779 IsIncompleteFunction = true; 780 } 781 llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty), 782 llvm::Function::ExternalLinkage, 783 "", &getModule()); 784 F->setName(MangledName); 785 if (D.getDecl()) 786 SetFunctionAttributes(D, F, IsIncompleteFunction); 787 Entry = F; 788 789 // This is the first use or definition of a mangled name. If there is a 790 // deferred decl with this name, remember that we need to emit it at the end 791 // of the file. 792 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 793 DeferredDecls.find(MangledName); 794 if (DDI != DeferredDecls.end()) { 795 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 796 // list, and remove it from DeferredDecls (since we don't need it anymore). 797 DeferredDeclsToEmit.push_back(DDI->second); 798 DeferredDecls.erase(DDI); 799 } else if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl())) { 800 // If this the first reference to a C++ inline function in a class, queue up 801 // the deferred function body for emission. These are not seen as 802 // top-level declarations. 803 if (FD->isThisDeclarationADefinition() && MayDeferGeneration(FD)) 804 DeferredDeclsToEmit.push_back(D); 805 // A called constructor which has no definition or declaration need be 806 // synthesized. 807 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) { 808 if (CD->isImplicit()) { 809 assert(CD->isUsed() && "Sema doesn't consider constructor as used."); 810 DeferredDeclsToEmit.push_back(D); 811 } 812 } else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(FD)) { 813 if (DD->isImplicit()) { 814 assert(DD->isUsed() && "Sema doesn't consider destructor as used."); 815 DeferredDeclsToEmit.push_back(D); 816 } 817 } else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 818 if (MD->isCopyAssignment() && MD->isImplicit()) { 819 assert(MD->isUsed() && "Sema doesn't consider CopyAssignment as used."); 820 DeferredDeclsToEmit.push_back(D); 821 } 822 } 823 } 824 825 return F; 826} 827 828/// GetAddrOfFunction - Return the address of the given function. If Ty is 829/// non-null, then this function will use the specified type if it has to 830/// create it (this occurs when we see a definition of the function). 831llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 832 const llvm::Type *Ty) { 833 // If there was no specific requested type, just convert it now. 834 if (!Ty) 835 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 836 return GetOrCreateLLVMFunction(getMangledName(GD), Ty, GD); 837} 838 839/// CreateRuntimeFunction - Create a new runtime function with the specified 840/// type and name. 841llvm::Constant * 842CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy, 843 const char *Name) { 844 // Convert Name to be a uniqued string from the IdentifierInfo table. 845 Name = getContext().Idents.get(Name).getNameStart(); 846 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl()); 847} 848 849static bool DeclIsConstantGlobal(ASTContext &Context, const VarDecl *D) { 850 if (!D->getType().isConstant(Context) && !D->getType()->isReferenceType()) 851 return false; 852 if (Context.getLangOptions().CPlusPlus && 853 Context.getBaseElementType(D->getType())->getAs<RecordType>()) { 854 // FIXME: We should do something fancier here! 855 return false; 856 } 857 return true; 858} 859 860/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 861/// create and return an llvm GlobalVariable with the specified type. If there 862/// is something in the module with the specified name, return it potentially 863/// bitcasted to the right type. 864/// 865/// If D is non-null, it specifies a decl that correspond to this. This is used 866/// to set the attributes on the global when it is first created. 867llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName, 868 const llvm::PointerType*Ty, 869 const VarDecl *D) { 870 // Lookup the entry, lazily creating it if necessary. 871 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 872 if (Entry) { 873 if (WeakRefReferences.count(Entry)) { 874 if (D && !D->hasAttr<WeakAttr>()) 875 Entry->setLinkage(llvm::Function::ExternalLinkage); 876 877 WeakRefReferences.erase(Entry); 878 } 879 880 if (Entry->getType() == Ty) 881 return Entry; 882 883 // Make sure the result is of the correct type. 884 return llvm::ConstantExpr::getBitCast(Entry, Ty); 885 } 886 887 // This is the first use or definition of a mangled name. If there is a 888 // deferred decl with this name, remember that we need to emit it at the end 889 // of the file. 890 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 891 DeferredDecls.find(MangledName); 892 if (DDI != DeferredDecls.end()) { 893 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 894 // list, and remove it from DeferredDecls (since we don't need it anymore). 895 DeferredDeclsToEmit.push_back(DDI->second); 896 DeferredDecls.erase(DDI); 897 } 898 899 llvm::GlobalVariable *GV = 900 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 901 llvm::GlobalValue::ExternalLinkage, 902 0, "", 0, 903 false, Ty->getAddressSpace()); 904 GV->setName(MangledName); 905 906 // Handle things which are present even on external declarations. 907 if (D) { 908 // FIXME: This code is overly simple and should be merged with other global 909 // handling. 910 GV->setConstant(DeclIsConstantGlobal(Context, D)); 911 912 // FIXME: Merge with other attribute handling code. 913 if (D->getStorageClass() == VarDecl::PrivateExtern) 914 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 915 916 if (D->hasAttr<WeakAttr>() || 917 D->hasAttr<WeakImportAttr>()) 918 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 919 920 GV->setThreadLocal(D->isThreadSpecified()); 921 } 922 923 return Entry = GV; 924} 925 926 927/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 928/// given global variable. If Ty is non-null and if the global doesn't exist, 929/// then it will be greated with the specified type instead of whatever the 930/// normal requested type would be. 931llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 932 const llvm::Type *Ty) { 933 assert(D->hasGlobalStorage() && "Not a global variable"); 934 QualType ASTTy = D->getType(); 935 if (Ty == 0) 936 Ty = getTypes().ConvertTypeForMem(ASTTy); 937 938 const llvm::PointerType *PTy = 939 llvm::PointerType::get(Ty, ASTTy.getAddressSpace()); 940 return GetOrCreateLLVMGlobal(getMangledName(D), PTy, D); 941} 942 943/// CreateRuntimeVariable - Create a new runtime global variable with the 944/// specified type and name. 945llvm::Constant * 946CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty, 947 const char *Name) { 948 // Convert Name to be a uniqued string from the IdentifierInfo table. 949 Name = getContext().Idents.get(Name).getNameStart(); 950 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0); 951} 952 953void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 954 assert(!D->getInit() && "Cannot emit definite definitions here!"); 955 956 if (MayDeferGeneration(D)) { 957 // If we have not seen a reference to this variable yet, place it 958 // into the deferred declarations table to be emitted if needed 959 // later. 960 const char *MangledName = getMangledName(D); 961 if (GlobalDeclMap.count(MangledName) == 0) { 962 DeferredDecls[MangledName] = D; 963 return; 964 } 965 } 966 967 // The tentative definition is the only definition. 968 EmitGlobalVarDefinition(D); 969} 970 971llvm::GlobalVariable::LinkageTypes 972CodeGenModule::getVtableLinkage(const CXXRecordDecl *RD) { 973 if (RD->isInAnonymousNamespace() || !RD->hasLinkage()) 974 return llvm::GlobalVariable::InternalLinkage; 975 976 if (const CXXMethodDecl *KeyFunction 977 = RD->getASTContext().getKeyFunction(RD)) { 978 // If this class has a key function, use that to determine the linkage of 979 // the vtable. 980 const FunctionDecl *Def = 0; 981 if (KeyFunction->getBody(Def)) 982 KeyFunction = cast<CXXMethodDecl>(Def); 983 984 switch (KeyFunction->getTemplateSpecializationKind()) { 985 case TSK_Undeclared: 986 case TSK_ExplicitSpecialization: 987 if (KeyFunction->isInlined()) 988 return llvm::GlobalVariable::WeakODRLinkage; 989 990 return llvm::GlobalVariable::ExternalLinkage; 991 992 case TSK_ImplicitInstantiation: 993 case TSK_ExplicitInstantiationDefinition: 994 return llvm::GlobalVariable::WeakODRLinkage; 995 996 case TSK_ExplicitInstantiationDeclaration: 997 // FIXME: Use available_externally linkage. However, this currently 998 // breaks LLVM's build due to undefined symbols. 999 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1000 return llvm::GlobalVariable::WeakODRLinkage; 1001 } 1002 } 1003 1004 switch (RD->getTemplateSpecializationKind()) { 1005 case TSK_Undeclared: 1006 case TSK_ExplicitSpecialization: 1007 case TSK_ImplicitInstantiation: 1008 case TSK_ExplicitInstantiationDefinition: 1009 return llvm::GlobalVariable::WeakODRLinkage; 1010 1011 case TSK_ExplicitInstantiationDeclaration: 1012 // FIXME: Use available_externally linkage. However, this currently 1013 // breaks LLVM's build due to undefined symbols. 1014 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1015 return llvm::GlobalVariable::WeakODRLinkage; 1016 } 1017 1018 // Silence GCC warning. 1019 return llvm::GlobalVariable::WeakODRLinkage; 1020} 1021 1022static CodeGenModule::GVALinkage 1023GetLinkageForVariable(ASTContext &Context, const VarDecl *VD) { 1024 // If this is a static data member, compute the kind of template 1025 // specialization. Otherwise, this variable is not part of a 1026 // template. 1027 TemplateSpecializationKind TSK = TSK_Undeclared; 1028 if (VD->isStaticDataMember()) 1029 TSK = VD->getTemplateSpecializationKind(); 1030 1031 Linkage L = VD->getLinkage(); 1032 if (L == ExternalLinkage && Context.getLangOptions().CPlusPlus && 1033 VD->getType()->getLinkage() == UniqueExternalLinkage) 1034 L = UniqueExternalLinkage; 1035 1036 switch (L) { 1037 case NoLinkage: 1038 case InternalLinkage: 1039 case UniqueExternalLinkage: 1040 return CodeGenModule::GVA_Internal; 1041 1042 case ExternalLinkage: 1043 switch (TSK) { 1044 case TSK_Undeclared: 1045 case TSK_ExplicitSpecialization: 1046 1047 // FIXME: ExplicitInstantiationDefinition should be weak! 1048 case TSK_ExplicitInstantiationDefinition: 1049 return CodeGenModule::GVA_StrongExternal; 1050 1051 case TSK_ExplicitInstantiationDeclaration: 1052 llvm_unreachable("Variable should not be instantiated"); 1053 // Fall through to treat this like any other instantiation. 1054 1055 case TSK_ImplicitInstantiation: 1056 return CodeGenModule::GVA_TemplateInstantiation; 1057 } 1058 } 1059 1060 return CodeGenModule::GVA_StrongExternal; 1061} 1062 1063CharUnits CodeGenModule::GetTargetTypeStoreSize(const llvm::Type *Ty) const { 1064 return CharUnits::fromQuantity( 1065 TheTargetData.getTypeStoreSizeInBits(Ty) / Context.getCharWidth()); 1066} 1067 1068void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1069 llvm::Constant *Init = 0; 1070 QualType ASTTy = D->getType(); 1071 bool NonConstInit = false; 1072 1073 const Expr *InitExpr = D->getAnyInitializer(); 1074 1075 if (!InitExpr) { 1076 // This is a tentative definition; tentative definitions are 1077 // implicitly initialized with { 0 }. 1078 // 1079 // Note that tentative definitions are only emitted at the end of 1080 // a translation unit, so they should never have incomplete 1081 // type. In addition, EmitTentativeDefinition makes sure that we 1082 // never attempt to emit a tentative definition if a real one 1083 // exists. A use may still exists, however, so we still may need 1084 // to do a RAUW. 1085 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1086 Init = EmitNullConstant(D->getType()); 1087 } else { 1088 Init = EmitConstantExpr(InitExpr, D->getType()); 1089 1090 if (!Init) { 1091 QualType T = InitExpr->getType(); 1092 if (getLangOptions().CPlusPlus) { 1093 EmitCXXGlobalVarDeclInitFunc(D); 1094 Init = EmitNullConstant(T); 1095 NonConstInit = true; 1096 } else { 1097 ErrorUnsupported(D, "static initializer"); 1098 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1099 } 1100 } 1101 } 1102 1103 const llvm::Type* InitType = Init->getType(); 1104 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1105 1106 // Strip off a bitcast if we got one back. 1107 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1108 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1109 // all zero index gep. 1110 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1111 Entry = CE->getOperand(0); 1112 } 1113 1114 // Entry is now either a Function or GlobalVariable. 1115 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1116 1117 // We have a definition after a declaration with the wrong type. 1118 // We must make a new GlobalVariable* and update everything that used OldGV 1119 // (a declaration or tentative definition) with the new GlobalVariable* 1120 // (which will be a definition). 1121 // 1122 // This happens if there is a prototype for a global (e.g. 1123 // "extern int x[];") and then a definition of a different type (e.g. 1124 // "int x[10];"). This also happens when an initializer has a different type 1125 // from the type of the global (this happens with unions). 1126 if (GV == 0 || 1127 GV->getType()->getElementType() != InitType || 1128 GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) { 1129 1130 // Remove the old entry from GlobalDeclMap so that we'll create a new one. 1131 GlobalDeclMap.erase(getMangledName(D)); 1132 1133 // Make a new global with the correct type, this is now guaranteed to work. 1134 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1135 GV->takeName(cast<llvm::GlobalValue>(Entry)); 1136 1137 // Replace all uses of the old global with the new global 1138 llvm::Constant *NewPtrForOldDecl = 1139 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1140 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1141 1142 // Erase the old global, since it is no longer used. 1143 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1144 } 1145 1146 if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>()) { 1147 SourceManager &SM = Context.getSourceManager(); 1148 AddAnnotation(EmitAnnotateAttr(GV, AA, 1149 SM.getInstantiationLineNumber(D->getLocation()))); 1150 } 1151 1152 GV->setInitializer(Init); 1153 1154 // If it is safe to mark the global 'constant', do so now. 1155 GV->setConstant(false); 1156 if (!NonConstInit && DeclIsConstantGlobal(Context, D)) 1157 GV->setConstant(true); 1158 1159 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1160 1161 // Set the llvm linkage type as appropriate. 1162 GVALinkage Linkage = GetLinkageForVariable(getContext(), D); 1163 if (Linkage == GVA_Internal) 1164 GV->setLinkage(llvm::Function::InternalLinkage); 1165 else if (D->hasAttr<DLLImportAttr>()) 1166 GV->setLinkage(llvm::Function::DLLImportLinkage); 1167 else if (D->hasAttr<DLLExportAttr>()) 1168 GV->setLinkage(llvm::Function::DLLExportLinkage); 1169 else if (D->hasAttr<WeakAttr>()) { 1170 if (GV->isConstant()) 1171 GV->setLinkage(llvm::GlobalVariable::WeakODRLinkage); 1172 else 1173 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 1174 } else if (Linkage == GVA_TemplateInstantiation) 1175 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 1176 else if (!getLangOptions().CPlusPlus && !CodeGenOpts.NoCommon && 1177 !D->hasExternalStorage() && !D->getInit() && 1178 !D->getAttr<SectionAttr>()) { 1179 GV->setLinkage(llvm::GlobalVariable::CommonLinkage); 1180 // common vars aren't constant even if declared const. 1181 GV->setConstant(false); 1182 } else 1183 GV->setLinkage(llvm::GlobalVariable::ExternalLinkage); 1184 1185 SetCommonAttributes(D, GV); 1186 1187 // Emit global variable debug information. 1188 if (CGDebugInfo *DI = getDebugInfo()) { 1189 DI->setLocation(D->getLocation()); 1190 DI->EmitGlobalVariable(GV, D); 1191 } 1192} 1193 1194/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1195/// implement a function with no prototype, e.g. "int foo() {}". If there are 1196/// existing call uses of the old function in the module, this adjusts them to 1197/// call the new function directly. 1198/// 1199/// This is not just a cleanup: the always_inline pass requires direct calls to 1200/// functions to be able to inline them. If there is a bitcast in the way, it 1201/// won't inline them. Instcombine normally deletes these calls, but it isn't 1202/// run at -O0. 1203static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1204 llvm::Function *NewFn) { 1205 // If we're redefining a global as a function, don't transform it. 1206 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1207 if (OldFn == 0) return; 1208 1209 const llvm::Type *NewRetTy = NewFn->getReturnType(); 1210 llvm::SmallVector<llvm::Value*, 4> ArgList; 1211 1212 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1213 UI != E; ) { 1214 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1215 unsigned OpNo = UI.getOperandNo(); 1216 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*UI++); 1217 if (!CI || OpNo != 0) continue; 1218 1219 // If the return types don't match exactly, and if the call isn't dead, then 1220 // we can't transform this call. 1221 if (CI->getType() != NewRetTy && !CI->use_empty()) 1222 continue; 1223 1224 // If the function was passed too few arguments, don't transform. If extra 1225 // arguments were passed, we silently drop them. If any of the types 1226 // mismatch, we don't transform. 1227 unsigned ArgNo = 0; 1228 bool DontTransform = false; 1229 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1230 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1231 if (CI->getNumOperands()-1 == ArgNo || 1232 CI->getOperand(ArgNo+1)->getType() != AI->getType()) { 1233 DontTransform = true; 1234 break; 1235 } 1236 } 1237 if (DontTransform) 1238 continue; 1239 1240 // Okay, we can transform this. Create the new call instruction and copy 1241 // over the required information. 1242 ArgList.append(CI->op_begin()+1, CI->op_begin()+1+ArgNo); 1243 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(), 1244 ArgList.end(), "", CI); 1245 ArgList.clear(); 1246 if (!NewCall->getType()->isVoidTy()) 1247 NewCall->takeName(CI); 1248 NewCall->setAttributes(CI->getAttributes()); 1249 NewCall->setCallingConv(CI->getCallingConv()); 1250 1251 // Finally, remove the old call, replacing any uses with the new one. 1252 if (!CI->use_empty()) 1253 CI->replaceAllUsesWith(NewCall); 1254 1255 // Copy any custom metadata attached with CI. 1256 if (llvm::MDNode *DbgNode = CI->getMetadata("dbg")) 1257 NewCall->setMetadata("dbg", DbgNode); 1258 CI->eraseFromParent(); 1259 } 1260} 1261 1262 1263void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1264 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1265 const llvm::FunctionType *Ty = getTypes().GetFunctionType(GD); 1266 getMangleContext().mangleInitDiscriminator(); 1267 // Get or create the prototype for the function. 1268 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1269 1270 // Strip off a bitcast if we got one back. 1271 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1272 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1273 Entry = CE->getOperand(0); 1274 } 1275 1276 1277 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1278 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1279 1280 // If the types mismatch then we have to rewrite the definition. 1281 assert(OldFn->isDeclaration() && 1282 "Shouldn't replace non-declaration"); 1283 1284 // F is the Function* for the one with the wrong type, we must make a new 1285 // Function* and update everything that used F (a declaration) with the new 1286 // Function* (which will be a definition). 1287 // 1288 // This happens if there is a prototype for a function 1289 // (e.g. "int f()") and then a definition of a different type 1290 // (e.g. "int f(int x)"). Start by making a new function of the 1291 // correct type, RAUW, then steal the name. 1292 GlobalDeclMap.erase(getMangledName(D)); 1293 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1294 NewFn->takeName(OldFn); 1295 1296 // If this is an implementation of a function without a prototype, try to 1297 // replace any existing uses of the function (which may be calls) with uses 1298 // of the new function 1299 if (D->getType()->isFunctionNoProtoType()) { 1300 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1301 OldFn->removeDeadConstantUsers(); 1302 } 1303 1304 // Replace uses of F with the Function we will endow with a body. 1305 if (!Entry->use_empty()) { 1306 llvm::Constant *NewPtrForOldDecl = 1307 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1308 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1309 } 1310 1311 // Ok, delete the old function now, which is dead. 1312 OldFn->eraseFromParent(); 1313 1314 Entry = NewFn; 1315 } 1316 1317 llvm::Function *Fn = cast<llvm::Function>(Entry); 1318 1319 CodeGenFunction(*this).GenerateCode(D, Fn); 1320 1321 SetFunctionDefinitionAttributes(D, Fn); 1322 SetLLVMFunctionAttributesForDefinition(D, Fn); 1323 1324 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1325 AddGlobalCtor(Fn, CA->getPriority()); 1326 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1327 AddGlobalDtor(Fn, DA->getPriority()); 1328} 1329 1330void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) { 1331 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1332 assert(AA && "Not an alias?"); 1333 1334 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1335 1336 // Unique the name through the identifier table. 1337 const char *AliaseeName = 1338 getContext().Idents.get(AA->getAliasee()).getNameStart(); 1339 1340 // Create a reference to the named value. This ensures that it is emitted 1341 // if a deferred decl. 1342 llvm::Constant *Aliasee; 1343 if (isa<llvm::FunctionType>(DeclTy)) 1344 Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, GlobalDecl()); 1345 else 1346 Aliasee = GetOrCreateLLVMGlobal(AliaseeName, 1347 llvm::PointerType::getUnqual(DeclTy), 0); 1348 1349 // Create the new alias itself, but don't set a name yet. 1350 llvm::GlobalValue *GA = 1351 new llvm::GlobalAlias(Aliasee->getType(), 1352 llvm::Function::ExternalLinkage, 1353 "", Aliasee, &getModule()); 1354 1355 // See if there is already something with the alias' name in the module. 1356 const char *MangledName = getMangledName(D); 1357 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 1358 1359 if (Entry && !Entry->isDeclaration()) { 1360 // If there is a definition in the module, then it wins over the alias. 1361 // This is dubious, but allow it to be safe. Just ignore the alias. 1362 GA->eraseFromParent(); 1363 return; 1364 } 1365 1366 if (Entry) { 1367 // If there is a declaration in the module, then we had an extern followed 1368 // by the alias, as in: 1369 // extern int test6(); 1370 // ... 1371 // int test6() __attribute__((alias("test7"))); 1372 // 1373 // Remove it and replace uses of it with the alias. 1374 1375 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1376 Entry->getType())); 1377 Entry->eraseFromParent(); 1378 } 1379 1380 // Now we know that there is no conflict, set the name. 1381 Entry = GA; 1382 GA->setName(MangledName); 1383 1384 // Set attributes which are particular to an alias; this is a 1385 // specialization of the attributes which may be set on a global 1386 // variable/function. 1387 if (D->hasAttr<DLLExportAttr>()) { 1388 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1389 // The dllexport attribute is ignored for undefined symbols. 1390 if (FD->getBody()) 1391 GA->setLinkage(llvm::Function::DLLExportLinkage); 1392 } else { 1393 GA->setLinkage(llvm::Function::DLLExportLinkage); 1394 } 1395 } else if (D->hasAttr<WeakAttr>() || 1396 D->hasAttr<WeakRefAttr>() || 1397 D->hasAttr<WeakImportAttr>()) { 1398 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1399 } 1400 1401 SetCommonAttributes(D, GA); 1402} 1403 1404/// getBuiltinLibFunction - Given a builtin id for a function like 1405/// "__builtin_fabsf", return a Function* for "fabsf". 1406llvm::Value *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD, 1407 unsigned BuiltinID) { 1408 assert((Context.BuiltinInfo.isLibFunction(BuiltinID) || 1409 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) && 1410 "isn't a lib fn"); 1411 1412 // Get the name, skip over the __builtin_ prefix (if necessary). 1413 const char *Name = Context.BuiltinInfo.GetName(BuiltinID); 1414 if (Context.BuiltinInfo.isLibFunction(BuiltinID)) 1415 Name += 10; 1416 1417 const llvm::FunctionType *Ty = 1418 cast<llvm::FunctionType>(getTypes().ConvertType(FD->getType())); 1419 1420 // Unique the name through the identifier table. 1421 Name = getContext().Idents.get(Name).getNameStart(); 1422 return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl(FD)); 1423} 1424 1425llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys, 1426 unsigned NumTys) { 1427 return llvm::Intrinsic::getDeclaration(&getModule(), 1428 (llvm::Intrinsic::ID)IID, Tys, NumTys); 1429} 1430 1431llvm::Function *CodeGenModule::getMemCpyFn() { 1432 if (MemCpyFn) return MemCpyFn; 1433 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(VMContext); 1434 return MemCpyFn = getIntrinsic(llvm::Intrinsic::memcpy, &IntPtr, 1); 1435} 1436 1437llvm::Function *CodeGenModule::getMemMoveFn() { 1438 if (MemMoveFn) return MemMoveFn; 1439 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(VMContext); 1440 return MemMoveFn = getIntrinsic(llvm::Intrinsic::memmove, &IntPtr, 1); 1441} 1442 1443llvm::Function *CodeGenModule::getMemSetFn() { 1444 if (MemSetFn) return MemSetFn; 1445 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(VMContext); 1446 return MemSetFn = getIntrinsic(llvm::Intrinsic::memset, &IntPtr, 1); 1447} 1448 1449static llvm::StringMapEntry<llvm::Constant*> & 1450GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1451 const StringLiteral *Literal, 1452 bool TargetIsLSB, 1453 bool &IsUTF16, 1454 unsigned &StringLength) { 1455 unsigned NumBytes = Literal->getByteLength(); 1456 1457 // Check for simple case. 1458 if (!Literal->containsNonAsciiOrNull()) { 1459 StringLength = NumBytes; 1460 return Map.GetOrCreateValue(llvm::StringRef(Literal->getStrData(), 1461 StringLength)); 1462 } 1463 1464 // Otherwise, convert the UTF8 literals into a byte string. 1465 llvm::SmallVector<UTF16, 128> ToBuf(NumBytes); 1466 const UTF8 *FromPtr = (UTF8 *)Literal->getStrData(); 1467 UTF16 *ToPtr = &ToBuf[0]; 1468 1469 ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 1470 &ToPtr, ToPtr + NumBytes, 1471 strictConversion); 1472 1473 // Check for conversion failure. 1474 if (Result != conversionOK) { 1475 // FIXME: Have Sema::CheckObjCString() validate the UTF-8 string and remove 1476 // this duplicate code. 1477 assert(Result == sourceIllegal && "UTF-8 to UTF-16 conversion failed"); 1478 StringLength = NumBytes; 1479 return Map.GetOrCreateValue(llvm::StringRef(Literal->getStrData(), 1480 StringLength)); 1481 } 1482 1483 // ConvertUTF8toUTF16 returns the length in ToPtr. 1484 StringLength = ToPtr - &ToBuf[0]; 1485 1486 // Render the UTF-16 string into a byte array and convert to the target byte 1487 // order. 1488 // 1489 // FIXME: This isn't something we should need to do here. 1490 llvm::SmallString<128> AsBytes; 1491 AsBytes.reserve(StringLength * 2); 1492 for (unsigned i = 0; i != StringLength; ++i) { 1493 unsigned short Val = ToBuf[i]; 1494 if (TargetIsLSB) { 1495 AsBytes.push_back(Val & 0xFF); 1496 AsBytes.push_back(Val >> 8); 1497 } else { 1498 AsBytes.push_back(Val >> 8); 1499 AsBytes.push_back(Val & 0xFF); 1500 } 1501 } 1502 // Append one extra null character, the second is automatically added by our 1503 // caller. 1504 AsBytes.push_back(0); 1505 1506 IsUTF16 = true; 1507 return Map.GetOrCreateValue(llvm::StringRef(AsBytes.data(), AsBytes.size())); 1508} 1509 1510llvm::Constant * 1511CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 1512 unsigned StringLength = 0; 1513 bool isUTF16 = false; 1514 llvm::StringMapEntry<llvm::Constant*> &Entry = 1515 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1516 getTargetData().isLittleEndian(), 1517 isUTF16, StringLength); 1518 1519 if (llvm::Constant *C = Entry.getValue()) 1520 return C; 1521 1522 llvm::Constant *Zero = 1523 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1524 llvm::Constant *Zeros[] = { Zero, Zero }; 1525 1526 // If we don't already have it, get __CFConstantStringClassReference. 1527 if (!CFConstantStringClassRef) { 1528 const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1529 Ty = llvm::ArrayType::get(Ty, 0); 1530 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1531 "__CFConstantStringClassReference"); 1532 // Decay array -> ptr 1533 CFConstantStringClassRef = 1534 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1535 } 1536 1537 QualType CFTy = getContext().getCFConstantStringType(); 1538 1539 const llvm::StructType *STy = 1540 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1541 1542 std::vector<llvm::Constant*> Fields(4); 1543 1544 // Class pointer. 1545 Fields[0] = CFConstantStringClassRef; 1546 1547 // Flags. 1548 const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1549 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 1550 llvm::ConstantInt::get(Ty, 0x07C8); 1551 1552 // String pointer. 1553 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1554 1555 llvm::GlobalValue::LinkageTypes Linkage; 1556 bool isConstant; 1557 if (isUTF16) { 1558 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1559 Linkage = llvm::GlobalValue::InternalLinkage; 1560 // Note: -fwritable-strings doesn't make unicode CFStrings writable, but 1561 // does make plain ascii ones writable. 1562 isConstant = true; 1563 } else { 1564 Linkage = llvm::GlobalValue::PrivateLinkage; 1565 isConstant = !Features.WritableStrings; 1566 } 1567 1568 llvm::GlobalVariable *GV = 1569 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1570 ".str"); 1571 if (isUTF16) { 1572 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 1573 GV->setAlignment(Align.getQuantity()); 1574 } 1575 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1576 1577 // String length. 1578 Ty = getTypes().ConvertType(getContext().LongTy); 1579 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 1580 1581 // The struct. 1582 C = llvm::ConstantStruct::get(STy, Fields); 1583 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1584 llvm::GlobalVariable::PrivateLinkage, C, 1585 "_unnamed_cfstring_"); 1586 if (const char *Sect = getContext().Target.getCFStringSection()) 1587 GV->setSection(Sect); 1588 Entry.setValue(GV); 1589 1590 return GV; 1591} 1592 1593/// GetStringForStringLiteral - Return the appropriate bytes for a 1594/// string literal, properly padded to match the literal type. 1595std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 1596 const char *StrData = E->getStrData(); 1597 unsigned Len = E->getByteLength(); 1598 1599 const ConstantArrayType *CAT = 1600 getContext().getAsConstantArrayType(E->getType()); 1601 assert(CAT && "String isn't pointer or array!"); 1602 1603 // Resize the string to the right size. 1604 std::string Str(StrData, StrData+Len); 1605 uint64_t RealLen = CAT->getSize().getZExtValue(); 1606 1607 if (E->isWide()) 1608 RealLen *= getContext().Target.getWCharWidth()/8; 1609 1610 Str.resize(RealLen, '\0'); 1611 1612 return Str; 1613} 1614 1615/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 1616/// constant array for the given string literal. 1617llvm::Constant * 1618CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 1619 // FIXME: This can be more efficient. 1620 // FIXME: We shouldn't need to bitcast the constant in the wide string case. 1621 llvm::Constant *C = GetAddrOfConstantString(GetStringForStringLiteral(S)); 1622 if (S->isWide()) { 1623 llvm::Type *DestTy = 1624 llvm::PointerType::getUnqual(getTypes().ConvertType(S->getType())); 1625 C = llvm::ConstantExpr::getBitCast(C, DestTy); 1626 } 1627 return C; 1628} 1629 1630/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 1631/// array for the given ObjCEncodeExpr node. 1632llvm::Constant * 1633CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 1634 std::string Str; 1635 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 1636 1637 return GetAddrOfConstantCString(Str); 1638} 1639 1640 1641/// GenerateWritableString -- Creates storage for a string literal. 1642static llvm::Constant *GenerateStringLiteral(const std::string &str, 1643 bool constant, 1644 CodeGenModule &CGM, 1645 const char *GlobalName) { 1646 // Create Constant for this string literal. Don't add a '\0'. 1647 llvm::Constant *C = 1648 llvm::ConstantArray::get(CGM.getLLVMContext(), str, false); 1649 1650 // Create a global variable for this string 1651 return new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 1652 llvm::GlobalValue::PrivateLinkage, 1653 C, GlobalName); 1654} 1655 1656/// GetAddrOfConstantString - Returns a pointer to a character array 1657/// containing the literal. This contents are exactly that of the 1658/// given string, i.e. it will not be null terminated automatically; 1659/// see GetAddrOfConstantCString. Note that whether the result is 1660/// actually a pointer to an LLVM constant depends on 1661/// Feature.WriteableStrings. 1662/// 1663/// The result has pointer to array type. 1664llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str, 1665 const char *GlobalName) { 1666 bool IsConstant = !Features.WritableStrings; 1667 1668 // Get the default prefix if a name wasn't specified. 1669 if (!GlobalName) 1670 GlobalName = ".str"; 1671 1672 // Don't share any string literals if strings aren't constant. 1673 if (!IsConstant) 1674 return GenerateStringLiteral(str, false, *this, GlobalName); 1675 1676 llvm::StringMapEntry<llvm::Constant *> &Entry = 1677 ConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]); 1678 1679 if (Entry.getValue()) 1680 return Entry.getValue(); 1681 1682 // Create a global variable for this. 1683 llvm::Constant *C = GenerateStringLiteral(str, true, *this, GlobalName); 1684 Entry.setValue(C); 1685 return C; 1686} 1687 1688/// GetAddrOfConstantCString - Returns a pointer to a character 1689/// array containing the literal and a terminating '\-' 1690/// character. The result has pointer to array type. 1691llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &str, 1692 const char *GlobalName){ 1693 return GetAddrOfConstantString(str + '\0', GlobalName); 1694} 1695 1696/// EmitObjCPropertyImplementations - Emit information for synthesized 1697/// properties for an implementation. 1698void CodeGenModule::EmitObjCPropertyImplementations(const 1699 ObjCImplementationDecl *D) { 1700 for (ObjCImplementationDecl::propimpl_iterator 1701 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 1702 ObjCPropertyImplDecl *PID = *i; 1703 1704 // Dynamic is just for type-checking. 1705 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 1706 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 1707 1708 // Determine which methods need to be implemented, some may have 1709 // been overridden. Note that ::isSynthesized is not the method 1710 // we want, that just indicates if the decl came from a 1711 // property. What we want to know is if the method is defined in 1712 // this implementation. 1713 if (!D->getInstanceMethod(PD->getGetterName())) 1714 CodeGenFunction(*this).GenerateObjCGetter( 1715 const_cast<ObjCImplementationDecl *>(D), PID); 1716 if (!PD->isReadOnly() && 1717 !D->getInstanceMethod(PD->getSetterName())) 1718 CodeGenFunction(*this).GenerateObjCSetter( 1719 const_cast<ObjCImplementationDecl *>(D), PID); 1720 } 1721 } 1722} 1723 1724/// EmitNamespace - Emit all declarations in a namespace. 1725void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 1726 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 1727 I != E; ++I) 1728 EmitTopLevelDecl(*I); 1729} 1730 1731// EmitLinkageSpec - Emit all declarations in a linkage spec. 1732void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 1733 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 1734 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 1735 ErrorUnsupported(LSD, "linkage spec"); 1736 return; 1737 } 1738 1739 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 1740 I != E; ++I) 1741 EmitTopLevelDecl(*I); 1742} 1743 1744/// EmitTopLevelDecl - Emit code for a single top level declaration. 1745void CodeGenModule::EmitTopLevelDecl(Decl *D) { 1746 // If an error has occurred, stop code generation, but continue 1747 // parsing and semantic analysis (to ensure all warnings and errors 1748 // are emitted). 1749 if (Diags.hasErrorOccurred()) 1750 return; 1751 1752 // Ignore dependent declarations. 1753 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 1754 return; 1755 1756 switch (D->getKind()) { 1757 case Decl::CXXConversion: 1758 case Decl::CXXMethod: 1759 case Decl::Function: 1760 // Skip function templates 1761 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 1762 return; 1763 1764 EmitGlobal(cast<FunctionDecl>(D)); 1765 break; 1766 1767 case Decl::Var: 1768 EmitGlobal(cast<VarDecl>(D)); 1769 break; 1770 1771 // C++ Decls 1772 case Decl::Namespace: 1773 EmitNamespace(cast<NamespaceDecl>(D)); 1774 break; 1775 // No code generation needed. 1776 case Decl::UsingShadow: 1777 case Decl::Using: 1778 case Decl::UsingDirective: 1779 case Decl::ClassTemplate: 1780 case Decl::FunctionTemplate: 1781 case Decl::NamespaceAlias: 1782 break; 1783 case Decl::CXXConstructor: 1784 // Skip function templates 1785 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 1786 return; 1787 1788 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 1789 break; 1790 case Decl::CXXDestructor: 1791 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 1792 break; 1793 1794 case Decl::StaticAssert: 1795 // Nothing to do. 1796 break; 1797 1798 // Objective-C Decls 1799 1800 // Forward declarations, no (immediate) code generation. 1801 case Decl::ObjCClass: 1802 case Decl::ObjCForwardProtocol: 1803 case Decl::ObjCCategory: 1804 case Decl::ObjCInterface: 1805 break; 1806 1807 case Decl::ObjCProtocol: 1808 Runtime->GenerateProtocol(cast<ObjCProtocolDecl>(D)); 1809 break; 1810 1811 case Decl::ObjCCategoryImpl: 1812 // Categories have properties but don't support synthesize so we 1813 // can ignore them here. 1814 Runtime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 1815 break; 1816 1817 case Decl::ObjCImplementation: { 1818 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 1819 EmitObjCPropertyImplementations(OMD); 1820 Runtime->GenerateClass(OMD); 1821 break; 1822 } 1823 case Decl::ObjCMethod: { 1824 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 1825 // If this is not a prototype, emit the body. 1826 if (OMD->getBody()) 1827 CodeGenFunction(*this).GenerateObjCMethod(OMD); 1828 break; 1829 } 1830 case Decl::ObjCCompatibleAlias: 1831 // compatibility-alias is a directive and has no code gen. 1832 break; 1833 1834 case Decl::LinkageSpec: 1835 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 1836 break; 1837 1838 case Decl::FileScopeAsm: { 1839 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 1840 llvm::StringRef AsmString = AD->getAsmString()->getString(); 1841 1842 const std::string &S = getModule().getModuleInlineAsm(); 1843 if (S.empty()) 1844 getModule().setModuleInlineAsm(AsmString); 1845 else 1846 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 1847 break; 1848 } 1849 1850 default: 1851 // Make sure we handled everything we should, every other kind is a 1852 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 1853 // function. Need to recode Decl::Kind to do that easily. 1854 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 1855 } 1856} 1857