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 "clang/CodeGen/CodeGenOptions.h" 21 #include "clang/AST/ASTContext.h" 22 #include "clang/AST/DeclObjC.h" 23 #include "clang/AST/DeclCXX.h" 24 #include "clang/Basic/Builtins.h" 25 #include "clang/Basic/Diagnostic.h" 26 #include "clang/Basic/SourceManager.h" 27 #include "clang/Basic/TargetInfo.h" 28 #include "clang/Basic/ConvertUTF.h" 29 #include "llvm/CallingConv.h" 30 #include "llvm/Module.h" 31 #include "llvm/Intrinsics.h" 32 #include "llvm/Target/TargetData.h" 33 #include "llvm/Support/ErrorHandling.h" 34 using namespace clang; 35 using namespace CodeGen; 36 37 38 CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 39 llvm::Module &M, const llvm::TargetData &TD, 40 Diagnostic &diags) 41 : BlockModule(C, M, TD, Types, *this), Context(C), 42 Features(C.getLangOptions()), CodeGenOpts(CGO), TheModule(M), 43 TheTargetData(TD), Diags(diags), Types(C, M, TD), MangleCtx(C), 44 VtableInfo(*this), Runtime(0), 45 MemCpyFn(0), MemMoveFn(0), MemSetFn(0), CFConstantStringClassRef(0), 46 VMContext(M.getContext()) { 47 48 if (!Features.ObjC1) 49 Runtime = 0; 50 else if (!Features.NeXTRuntime) 51 Runtime = CreateGNUObjCRuntime(*this); 52 else if (Features.ObjCNonFragileABI) 53 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 54 else 55 Runtime = CreateMacObjCRuntime(*this); 56 57 // If debug info generation is enabled, create the CGDebugInfo object. 58 DebugInfo = CodeGenOpts.DebugInfo ? new CGDebugInfo(this) : 0; 59 } 60 61 CodeGenModule::~CodeGenModule() { 62 delete Runtime; 63 delete DebugInfo; 64 } 65 66 void CodeGenModule::Release() { 67 // We need to call this first because it can add deferred declarations. 68 EmitCXXGlobalInitFunc(); 69 70 EmitDeferred(); 71 if (Runtime) 72 if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction()) 73 AddGlobalCtor(ObjCInitFunction); 74 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 75 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 76 EmitAnnotations(); 77 EmitLLVMUsed(); 78 } 79 80 /// ErrorUnsupported - Print out an error that codegen doesn't support the 81 /// specified stmt yet. 82 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 83 bool OmitOnError) { 84 if (OmitOnError && getDiags().hasErrorOccurred()) 85 return; 86 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 87 "cannot compile this %0 yet"); 88 std::string Msg = Type; 89 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 90 << Msg << S->getSourceRange(); 91 } 92 93 /// ErrorUnsupported - Print out an error that codegen doesn't support the 94 /// specified decl yet. 95 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 96 bool OmitOnError) { 97 if (OmitOnError && getDiags().hasErrorOccurred()) 98 return; 99 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 100 "cannot compile this %0 yet"); 101 std::string Msg = Type; 102 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 103 } 104 105 LangOptions::VisibilityMode 106 CodeGenModule::getDeclVisibilityMode(const Decl *D) const { 107 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 108 if (VD->getStorageClass() == VarDecl::PrivateExtern) 109 return LangOptions::Hidden; 110 111 if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>()) { 112 switch (attr->getVisibility()) { 113 default: assert(0 && "Unknown visibility!"); 114 case VisibilityAttr::DefaultVisibility: 115 return LangOptions::Default; 116 case VisibilityAttr::HiddenVisibility: 117 return LangOptions::Hidden; 118 case VisibilityAttr::ProtectedVisibility: 119 return LangOptions::Protected; 120 } 121 } 122 123 return getLangOptions().getVisibilityMode(); 124 } 125 126 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 127 const Decl *D) const { 128 // Internal definitions always have default visibility. 129 if (GV->hasLocalLinkage()) { 130 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 131 return; 132 } 133 134 switch (getDeclVisibilityMode(D)) { 135 default: assert(0 && "Unknown visibility!"); 136 case LangOptions::Default: 137 return GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 138 case LangOptions::Hidden: 139 return GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 140 case LangOptions::Protected: 141 return GV->setVisibility(llvm::GlobalValue::ProtectedVisibility); 142 } 143 } 144 145 const char *CodeGenModule::getMangledName(const GlobalDecl &GD) { 146 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 147 148 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 149 return getMangledCXXCtorName(D, GD.getCtorType()); 150 if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 151 return getMangledCXXDtorName(D, GD.getDtorType()); 152 153 return getMangledName(ND); 154 } 155 156 /// \brief Retrieves the mangled name for the given declaration. 157 /// 158 /// If the given declaration requires a mangled name, returns an 159 /// const char* containing the mangled name. Otherwise, returns 160 /// the unmangled name. 161 /// 162 const char *CodeGenModule::getMangledName(const NamedDecl *ND) { 163 if (!getMangleContext().shouldMangleDeclName(ND)) { 164 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl."); 165 return ND->getNameAsCString(); 166 } 167 168 llvm::SmallString<256> Name; 169 getMangleContext().mangleName(ND, Name); 170 Name += '\0'; 171 return UniqueMangledName(Name.begin(), Name.end()); 172 } 173 174 const char *CodeGenModule::UniqueMangledName(const char *NameStart, 175 const char *NameEnd) { 176 assert(*(NameEnd - 1) == '\0' && "Mangled name must be null terminated!"); 177 178 return MangledNames.GetOrCreateValue(NameStart, NameEnd).getKeyData(); 179 } 180 181 /// AddGlobalCtor - Add a function to the list that will be called before 182 /// main() runs. 183 void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 184 // FIXME: Type coercion of void()* types. 185 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 186 } 187 188 /// AddGlobalDtor - Add a function to the list that will be called 189 /// when the module is unloaded. 190 void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 191 // FIXME: Type coercion of void()* types. 192 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 193 } 194 195 void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 196 // Ctor function type is void()*. 197 llvm::FunctionType* CtorFTy = 198 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), 199 std::vector<const llvm::Type*>(), 200 false); 201 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 202 203 // Get the type of a ctor entry, { i32, void ()* }. 204 llvm::StructType* CtorStructTy = 205 llvm::StructType::get(VMContext, llvm::Type::getInt32Ty(VMContext), 206 llvm::PointerType::getUnqual(CtorFTy), NULL); 207 208 // Construct the constructor and destructor arrays. 209 std::vector<llvm::Constant*> Ctors; 210 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 211 std::vector<llvm::Constant*> S; 212 S.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 213 I->second, false)); 214 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy)); 215 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 216 } 217 218 if (!Ctors.empty()) { 219 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 220 new llvm::GlobalVariable(TheModule, AT, false, 221 llvm::GlobalValue::AppendingLinkage, 222 llvm::ConstantArray::get(AT, Ctors), 223 GlobalName); 224 } 225 } 226 227 void CodeGenModule::EmitAnnotations() { 228 if (Annotations.empty()) 229 return; 230 231 // Create a new global variable for the ConstantStruct in the Module. 232 llvm::Constant *Array = 233 llvm::ConstantArray::get(llvm::ArrayType::get(Annotations[0]->getType(), 234 Annotations.size()), 235 Annotations); 236 llvm::GlobalValue *gv = 237 new llvm::GlobalVariable(TheModule, Array->getType(), false, 238 llvm::GlobalValue::AppendingLinkage, Array, 239 "llvm.global.annotations"); 240 gv->setSection("llvm.metadata"); 241 } 242 243 static CodeGenModule::GVALinkage 244 GetLinkageForFunction(ASTContext &Context, const FunctionDecl *FD, 245 const LangOptions &Features) { 246 // Everything located semantically within an anonymous namespace is 247 // always internal. 248 if (FD->isInAnonymousNamespace()) 249 return CodeGenModule::GVA_Internal; 250 251 // "static" functions get internal linkage. 252 if (FD->getStorageClass() == FunctionDecl::Static && !isa<CXXMethodDecl>(FD)) 253 return CodeGenModule::GVA_Internal; 254 255 // The kind of external linkage this function will have, if it is not 256 // inline or static. 257 CodeGenModule::GVALinkage External = CodeGenModule::GVA_StrongExternal; 258 if (Context.getLangOptions().CPlusPlus && 259 FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation) 260 External = CodeGenModule::GVA_TemplateInstantiation; 261 262 if (!FD->isInlined()) 263 return External; 264 265 if (!Features.CPlusPlus || FD->hasAttr<GNUInlineAttr>()) { 266 // GNU or C99 inline semantics. Determine whether this symbol should be 267 // externally visible. 268 if (FD->isInlineDefinitionExternallyVisible()) 269 return External; 270 271 // C99 inline semantics, where the symbol is not externally visible. 272 return CodeGenModule::GVA_C99Inline; 273 } 274 275 // C++0x [temp.explicit]p9: 276 // [ Note: The intent is that an inline function that is the subject of 277 // an explicit instantiation declaration will still be implicitly 278 // instantiated when used so that the body can be considered for 279 // inlining, but that no out-of-line copy of the inline function would be 280 // generated in the translation unit. -- end note ] 281 if (FD->getTemplateSpecializationKind() 282 == TSK_ExplicitInstantiationDeclaration) 283 return CodeGenModule::GVA_C99Inline; 284 285 return CodeGenModule::GVA_CXXInline; 286 } 287 288 /// SetFunctionDefinitionAttributes - Set attributes for a global. 289 /// 290 /// FIXME: This is currently only done for aliases and functions, but not for 291 /// variables (these details are set in EmitGlobalVarDefinition for variables). 292 void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 293 llvm::GlobalValue *GV) { 294 GVALinkage Linkage = GetLinkageForFunction(getContext(), D, Features); 295 296 if (Linkage == GVA_Internal) { 297 GV->setLinkage(llvm::Function::InternalLinkage); 298 } else if (D->hasAttr<DLLExportAttr>()) { 299 GV->setLinkage(llvm::Function::DLLExportLinkage); 300 } else if (D->hasAttr<WeakAttr>()) { 301 GV->setLinkage(llvm::Function::WeakAnyLinkage); 302 } else if (Linkage == GVA_C99Inline) { 303 // In C99 mode, 'inline' functions are guaranteed to have a strong 304 // definition somewhere else, so we can use available_externally linkage. 305 GV->setLinkage(llvm::Function::AvailableExternallyLinkage); 306 } else if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) { 307 // In C++, the compiler has to emit a definition in every translation unit 308 // that references the function. We should use linkonce_odr because 309 // a) if all references in this translation unit are optimized away, we 310 // don't need to codegen it. b) if the function persists, it needs to be 311 // merged with other definitions. c) C++ has the ODR, so we know the 312 // definition is dependable. 313 GV->setLinkage(llvm::Function::LinkOnceODRLinkage); 314 } else { 315 assert(Linkage == GVA_StrongExternal); 316 // Otherwise, we have strong external linkage. 317 GV->setLinkage(llvm::Function::ExternalLinkage); 318 } 319 320 SetCommonAttributes(D, GV); 321 } 322 323 void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 324 const CGFunctionInfo &Info, 325 llvm::Function *F) { 326 unsigned CallingConv; 327 AttributeListType AttributeList; 328 ConstructAttributeList(Info, D, AttributeList, CallingConv); 329 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 330 AttributeList.size())); 331 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 332 } 333 334 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 335 llvm::Function *F) { 336 if (!Features.Exceptions && !Features.ObjCNonFragileABI) 337 F->addFnAttr(llvm::Attribute::NoUnwind); 338 339 if (D->hasAttr<AlwaysInlineAttr>()) 340 F->addFnAttr(llvm::Attribute::AlwaysInline); 341 342 if (D->hasAttr<NoInlineAttr>()) 343 F->addFnAttr(llvm::Attribute::NoInline); 344 345 if (Features.getStackProtectorMode() == LangOptions::SSPOn) 346 F->addFnAttr(llvm::Attribute::StackProtect); 347 else if (Features.getStackProtectorMode() == LangOptions::SSPReq) 348 F->addFnAttr(llvm::Attribute::StackProtectReq); 349 350 if (const AlignedAttr *AA = D->getAttr<AlignedAttr>()) { 351 unsigned width = Context.Target.getCharWidth(); 352 F->setAlignment(AA->getAlignment() / width); 353 while ((AA = AA->getNext<AlignedAttr>())) 354 F->setAlignment(std::max(F->getAlignment(), AA->getAlignment() / width)); 355 } 356 // C++ ABI requires 2-byte alignment for member functions. 357 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 358 F->setAlignment(2); 359 } 360 361 void CodeGenModule::SetCommonAttributes(const Decl *D, 362 llvm::GlobalValue *GV) { 363 setGlobalVisibility(GV, D); 364 365 if (D->hasAttr<UsedAttr>()) 366 AddUsedGlobal(GV); 367 368 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 369 GV->setSection(SA->getName()); 370 } 371 372 void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 373 llvm::Function *F, 374 const CGFunctionInfo &FI) { 375 SetLLVMFunctionAttributes(D, FI, F); 376 SetLLVMFunctionAttributesForDefinition(D, F); 377 378 F->setLinkage(llvm::Function::InternalLinkage); 379 380 SetCommonAttributes(D, F); 381 } 382 383 void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD, 384 llvm::Function *F, 385 bool IsIncompleteFunction) { 386 if (!IsIncompleteFunction) 387 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(FD), F); 388 389 // Only a few attributes are set on declarations; these may later be 390 // overridden by a definition. 391 392 if (FD->hasAttr<DLLImportAttr>()) { 393 F->setLinkage(llvm::Function::DLLImportLinkage); 394 } else if (FD->hasAttr<WeakAttr>() || 395 FD->hasAttr<WeakImportAttr>()) { 396 // "extern_weak" is overloaded in LLVM; we probably should have 397 // separate linkage types for this. 398 F->setLinkage(llvm::Function::ExternalWeakLinkage); 399 } else { 400 F->setLinkage(llvm::Function::ExternalLinkage); 401 } 402 403 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 404 F->setSection(SA->getName()); 405 } 406 407 void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 408 assert(!GV->isDeclaration() && 409 "Only globals with definition can force usage."); 410 LLVMUsed.push_back(GV); 411 } 412 413 void CodeGenModule::EmitLLVMUsed() { 414 // Don't create llvm.used if there is no need. 415 if (LLVMUsed.empty()) 416 return; 417 418 const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext); 419 420 // Convert LLVMUsed to what ConstantArray needs. 421 std::vector<llvm::Constant*> UsedArray; 422 UsedArray.resize(LLVMUsed.size()); 423 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 424 UsedArray[i] = 425 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 426 i8PTy); 427 } 428 429 if (UsedArray.empty()) 430 return; 431 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, UsedArray.size()); 432 433 llvm::GlobalVariable *GV = 434 new llvm::GlobalVariable(getModule(), ATy, false, 435 llvm::GlobalValue::AppendingLinkage, 436 llvm::ConstantArray::get(ATy, UsedArray), 437 "llvm.used"); 438 439 GV->setSection("llvm.metadata"); 440 } 441 442 void CodeGenModule::EmitDeferred() { 443 // Emit code for any potentially referenced deferred decls. Since a 444 // previously unused static decl may become used during the generation of code 445 // for a static function, iterate until no changes are made. 446 while (!DeferredDeclsToEmit.empty()) { 447 GlobalDecl D = DeferredDeclsToEmit.back(); 448 DeferredDeclsToEmit.pop_back(); 449 450 // The mangled name for the decl must have been emitted in GlobalDeclMap. 451 // Look it up to see if it was defined with a stronger definition (e.g. an 452 // extern inline function with a strong function redefinition). If so, 453 // just ignore the deferred decl. 454 llvm::GlobalValue *CGRef = GlobalDeclMap[getMangledName(D)]; 455 assert(CGRef && "Deferred decl wasn't referenced?"); 456 457 if (!CGRef->isDeclaration()) 458 continue; 459 460 // Otherwise, emit the definition and move on to the next one. 461 EmitGlobalDefinition(D); 462 } 463 } 464 465 /// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the 466 /// annotation information for a given GlobalValue. The annotation struct is 467 /// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the 468 /// GlobalValue being annotated. The second field is the constant string 469 /// created from the AnnotateAttr's annotation. The third field is a constant 470 /// string containing the name of the translation unit. The fourth field is 471 /// the line number in the file of the annotated value declaration. 472 /// 473 /// FIXME: this does not unique the annotation string constants, as llvm-gcc 474 /// appears to. 475 /// 476 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 477 const AnnotateAttr *AA, 478 unsigned LineNo) { 479 llvm::Module *M = &getModule(); 480 481 // get [N x i8] constants for the annotation string, and the filename string 482 // which are the 2nd and 3rd elements of the global annotation structure. 483 const llvm::Type *SBP = llvm::Type::getInt8PtrTy(VMContext); 484 llvm::Constant *anno = llvm::ConstantArray::get(VMContext, 485 AA->getAnnotation(), true); 486 llvm::Constant *unit = llvm::ConstantArray::get(VMContext, 487 M->getModuleIdentifier(), 488 true); 489 490 // Get the two global values corresponding to the ConstantArrays we just 491 // created to hold the bytes of the strings. 492 llvm::GlobalValue *annoGV = 493 new llvm::GlobalVariable(*M, anno->getType(), false, 494 llvm::GlobalValue::PrivateLinkage, anno, 495 GV->getName()); 496 // translation unit name string, emitted into the llvm.metadata section. 497 llvm::GlobalValue *unitGV = 498 new llvm::GlobalVariable(*M, unit->getType(), false, 499 llvm::GlobalValue::PrivateLinkage, unit, 500 ".str"); 501 502 // Create the ConstantStruct for the global annotation. 503 llvm::Constant *Fields[4] = { 504 llvm::ConstantExpr::getBitCast(GV, SBP), 505 llvm::ConstantExpr::getBitCast(annoGV, SBP), 506 llvm::ConstantExpr::getBitCast(unitGV, SBP), 507 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), LineNo) 508 }; 509 return llvm::ConstantStruct::get(VMContext, Fields, 4, false); 510 } 511 512 bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 513 // Never defer when EmitAllDecls is specified or the decl has 514 // attribute used. 515 if (Features.EmitAllDecls || Global->hasAttr<UsedAttr>()) 516 return false; 517 518 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 519 // Constructors and destructors should never be deferred. 520 if (FD->hasAttr<ConstructorAttr>() || 521 FD->hasAttr<DestructorAttr>()) 522 return false; 523 524 GVALinkage Linkage = GetLinkageForFunction(getContext(), FD, Features); 525 526 // static, static inline, always_inline, and extern inline functions can 527 // always be deferred. Normal inline functions can be deferred in C99/C++. 528 if (Linkage == GVA_Internal || Linkage == GVA_C99Inline || 529 Linkage == GVA_CXXInline) 530 return true; 531 return false; 532 } 533 534 const VarDecl *VD = cast<VarDecl>(Global); 535 assert(VD->isFileVarDecl() && "Invalid decl"); 536 537 // We never want to defer structs that have non-trivial constructors or 538 // destructors. 539 540 // FIXME: Handle references. 541 if (const RecordType *RT = VD->getType()->getAs<RecordType>()) { 542 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 543 if (!RD->hasTrivialConstructor() || !RD->hasTrivialDestructor()) 544 return false; 545 } 546 } 547 548 // Static data may be deferred, but out-of-line static data members 549 // cannot be. 550 if (VD->isInAnonymousNamespace()) 551 return true; 552 if (VD->getLinkage() == VarDecl::InternalLinkage) { 553 // Initializer has side effects? 554 if (VD->getInit() && VD->getInit()->HasSideEffects(Context)) 555 return false; 556 return !(VD->isStaticDataMember() && VD->isOutOfLine()); 557 } 558 return false; 559 } 560 561 void CodeGenModule::EmitGlobal(GlobalDecl GD) { 562 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 563 564 // If this is an alias definition (which otherwise looks like a declaration) 565 // emit it now. 566 if (Global->hasAttr<AliasAttr>()) 567 return EmitAliasDefinition(Global); 568 569 // Ignore declarations, they will be emitted on their first use. 570 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 571 // Forward declarations are emitted lazily on first use. 572 if (!FD->isThisDeclarationADefinition()) 573 return; 574 } else { 575 const VarDecl *VD = cast<VarDecl>(Global); 576 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 577 578 // In C++, if this is marked "extern", defer code generation. 579 if (getLangOptions().CPlusPlus && !VD->getInit() && 580 (VD->getStorageClass() == VarDecl::Extern || 581 VD->isExternC())) 582 return; 583 584 // In C, if this isn't a definition, defer code generation. 585 if (!getLangOptions().CPlusPlus && !VD->getInit()) 586 return; 587 } 588 589 // Defer code generation when possible if this is a static definition, inline 590 // function etc. These we only want to emit if they are used. 591 if (MayDeferGeneration(Global)) { 592 // If the value has already been used, add it directly to the 593 // DeferredDeclsToEmit list. 594 const char *MangledName = getMangledName(GD); 595 if (GlobalDeclMap.count(MangledName)) 596 DeferredDeclsToEmit.push_back(GD); 597 else { 598 // Otherwise, remember that we saw a deferred decl with this name. The 599 // first use of the mangled name will cause it to move into 600 // DeferredDeclsToEmit. 601 DeferredDecls[MangledName] = GD; 602 } 603 return; 604 } 605 606 // Otherwise emit the definition. 607 EmitGlobalDefinition(GD); 608 } 609 610 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 611 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 612 613 PrettyStackTraceDecl CrashInfo((ValueDecl *)D, D->getLocation(), 614 Context.getSourceManager(), 615 "Generating code for declaration"); 616 617 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { 618 const CXXRecordDecl *RD = MD->getParent(); 619 // We have to convert it to have a record layout. 620 Types.ConvertTagDeclType(RD); 621 const CGRecordLayout &CGLayout = Types.getCGRecordLayout(RD); 622 // A definition of a KeyFunction, generates all the class data, such 623 // as vtable, rtti and the VTT. 624 if (CGLayout.getKeyFunction() 625 && (CGLayout.getKeyFunction()->getCanonicalDecl() 626 == MD->getCanonicalDecl())) 627 getVtableInfo().GenerateClassData(RD); 628 } 629 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 630 EmitCXXConstructor(CD, GD.getCtorType()); 631 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 632 EmitCXXDestructor(DD, GD.getDtorType()); 633 else if (isa<FunctionDecl>(D)) 634 EmitGlobalFunctionDefinition(GD); 635 else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 636 EmitGlobalVarDefinition(VD); 637 else { 638 assert(0 && "Invalid argument to EmitGlobalDefinition()"); 639 } 640 } 641 642 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the 643 /// module, create and return an llvm Function with the specified type. If there 644 /// is something in the module with the specified name, return it potentially 645 /// bitcasted to the right type. 646 /// 647 /// If D is non-null, it specifies a decl that correspond to this. This is used 648 /// to set the attributes on the function when it is first created. 649 llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(const char *MangledName, 650 const llvm::Type *Ty, 651 GlobalDecl D) { 652 // Lookup the entry, lazily creating it if necessary. 653 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 654 if (Entry) { 655 if (Entry->getType()->getElementType() == Ty) 656 return Entry; 657 658 // Make sure the result is of the correct type. 659 const llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 660 return llvm::ConstantExpr::getBitCast(Entry, PTy); 661 } 662 663 // This function doesn't have a complete type (for example, the return 664 // type is an incomplete struct). Use a fake type instead, and make 665 // sure not to try to set attributes. 666 bool IsIncompleteFunction = false; 667 if (!isa<llvm::FunctionType>(Ty)) { 668 Ty = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), 669 std::vector<const llvm::Type*>(), false); 670 IsIncompleteFunction = true; 671 } 672 llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty), 673 llvm::Function::ExternalLinkage, 674 "", &getModule()); 675 F->setName(MangledName); 676 if (D.getDecl()) 677 SetFunctionAttributes(cast<FunctionDecl>(D.getDecl()), F, 678 IsIncompleteFunction); 679 Entry = F; 680 681 // This is the first use or definition of a mangled name. If there is a 682 // deferred decl with this name, remember that we need to emit it at the end 683 // of the file. 684 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 685 DeferredDecls.find(MangledName); 686 if (DDI != DeferredDecls.end()) { 687 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 688 // list, and remove it from DeferredDecls (since we don't need it anymore). 689 DeferredDeclsToEmit.push_back(DDI->second); 690 DeferredDecls.erase(DDI); 691 } else if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl())) { 692 // If this the first reference to a C++ inline function in a class, queue up 693 // the deferred function body for emission. These are not seen as 694 // top-level declarations. 695 if (FD->isThisDeclarationADefinition() && MayDeferGeneration(FD)) 696 DeferredDeclsToEmit.push_back(D); 697 // A called constructor which has no definition or declaration need be 698 // synthesized. 699 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) { 700 const CXXRecordDecl *ClassDecl = 701 cast<CXXRecordDecl>(CD->getDeclContext()); 702 if (CD->isCopyConstructor(getContext())) 703 DeferredCopyConstructorToEmit(D); 704 else if (!ClassDecl->hasUserDeclaredConstructor()) 705 DeferredDeclsToEmit.push_back(D); 706 } 707 else if (isa<CXXDestructorDecl>(FD)) 708 DeferredDestructorToEmit(D); 709 else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) 710 if (MD->isCopyAssignment()) 711 DeferredCopyAssignmentToEmit(D); 712 } 713 714 return F; 715 } 716 717 /// Defer definition of copy constructor(s) which need be implicitly defined. 718 void CodeGenModule::DeferredCopyConstructorToEmit(GlobalDecl CopyCtorDecl) { 719 const CXXConstructorDecl *CD = 720 cast<CXXConstructorDecl>(CopyCtorDecl.getDecl()); 721 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(CD->getDeclContext()); 722 if (ClassDecl->hasTrivialCopyConstructor() || 723 ClassDecl->hasUserDeclaredCopyConstructor()) 724 return; 725 726 // First make sure all direct base classes and virtual bases and non-static 727 // data mebers which need to have their copy constructors implicitly defined 728 // are defined. 12.8.p7 729 for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin(); 730 Base != ClassDecl->bases_end(); ++Base) { 731 CXXRecordDecl *BaseClassDecl 732 = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl()); 733 if (CXXConstructorDecl *BaseCopyCtor = 734 BaseClassDecl->getCopyConstructor(Context, 0)) 735 GetAddrOfCXXConstructor(BaseCopyCtor, Ctor_Complete); 736 } 737 738 for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(), 739 FieldEnd = ClassDecl->field_end(); 740 Field != FieldEnd; ++Field) { 741 QualType FieldType = Context.getCanonicalType((*Field)->getType()); 742 if (const ArrayType *Array = Context.getAsArrayType(FieldType)) 743 FieldType = Array->getElementType(); 744 if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) { 745 if ((*Field)->isAnonymousStructOrUnion()) 746 continue; 747 CXXRecordDecl *FieldClassDecl 748 = cast<CXXRecordDecl>(FieldClassType->getDecl()); 749 if (CXXConstructorDecl *FieldCopyCtor = 750 FieldClassDecl->getCopyConstructor(Context, 0)) 751 GetAddrOfCXXConstructor(FieldCopyCtor, Ctor_Complete); 752 } 753 } 754 DeferredDeclsToEmit.push_back(CopyCtorDecl); 755 } 756 757 /// Defer definition of copy assignments which need be implicitly defined. 758 void CodeGenModule::DeferredCopyAssignmentToEmit(GlobalDecl CopyAssignDecl) { 759 const CXXMethodDecl *CD = cast<CXXMethodDecl>(CopyAssignDecl.getDecl()); 760 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(CD->getDeclContext()); 761 762 if (ClassDecl->hasTrivialCopyAssignment() || 763 ClassDecl->hasUserDeclaredCopyAssignment()) 764 return; 765 766 // First make sure all direct base classes and virtual bases and non-static 767 // data mebers which need to have their copy assignments implicitly defined 768 // are defined. 12.8.p12 769 for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin(); 770 Base != ClassDecl->bases_end(); ++Base) { 771 CXXRecordDecl *BaseClassDecl 772 = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl()); 773 const CXXMethodDecl *MD = 0; 774 if (!BaseClassDecl->hasTrivialCopyAssignment() && 775 !BaseClassDecl->hasUserDeclaredCopyAssignment() && 776 BaseClassDecl->hasConstCopyAssignment(getContext(), MD)) 777 GetAddrOfFunction(MD, 0); 778 } 779 780 for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(), 781 FieldEnd = ClassDecl->field_end(); 782 Field != FieldEnd; ++Field) { 783 QualType FieldType = Context.getCanonicalType((*Field)->getType()); 784 if (const ArrayType *Array = Context.getAsArrayType(FieldType)) 785 FieldType = Array->getElementType(); 786 if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) { 787 if ((*Field)->isAnonymousStructOrUnion()) 788 continue; 789 CXXRecordDecl *FieldClassDecl 790 = cast<CXXRecordDecl>(FieldClassType->getDecl()); 791 const CXXMethodDecl *MD = 0; 792 if (!FieldClassDecl->hasTrivialCopyAssignment() && 793 !FieldClassDecl->hasUserDeclaredCopyAssignment() && 794 FieldClassDecl->hasConstCopyAssignment(getContext(), MD)) 795 GetAddrOfFunction(MD, 0); 796 } 797 } 798 DeferredDeclsToEmit.push_back(CopyAssignDecl); 799 } 800 801 void CodeGenModule::DeferredDestructorToEmit(GlobalDecl DtorDecl) { 802 const CXXDestructorDecl *DD = cast<CXXDestructorDecl>(DtorDecl.getDecl()); 803 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(DD->getDeclContext()); 804 if (ClassDecl->hasTrivialDestructor() || 805 ClassDecl->hasUserDeclaredDestructor()) 806 return; 807 808 for (CXXRecordDecl::base_class_const_iterator Base = ClassDecl->bases_begin(); 809 Base != ClassDecl->bases_end(); ++Base) { 810 CXXRecordDecl *BaseClassDecl 811 = cast<CXXRecordDecl>(Base->getType()->getAs<RecordType>()->getDecl()); 812 if (const CXXDestructorDecl *BaseDtor = 813 BaseClassDecl->getDestructor(Context)) 814 GetAddrOfCXXDestructor(BaseDtor, Dtor_Complete); 815 } 816 817 for (CXXRecordDecl::field_iterator Field = ClassDecl->field_begin(), 818 FieldEnd = ClassDecl->field_end(); 819 Field != FieldEnd; ++Field) { 820 QualType FieldType = Context.getCanonicalType((*Field)->getType()); 821 if (const ArrayType *Array = Context.getAsArrayType(FieldType)) 822 FieldType = Array->getElementType(); 823 if (const RecordType *FieldClassType = FieldType->getAs<RecordType>()) { 824 if ((*Field)->isAnonymousStructOrUnion()) 825 continue; 826 CXXRecordDecl *FieldClassDecl 827 = cast<CXXRecordDecl>(FieldClassType->getDecl()); 828 if (const CXXDestructorDecl *FieldDtor = 829 FieldClassDecl->getDestructor(Context)) 830 GetAddrOfCXXDestructor(FieldDtor, Dtor_Complete); 831 } 832 } 833 DeferredDeclsToEmit.push_back(DtorDecl); 834 } 835 836 837 /// GetAddrOfFunction - Return the address of the given function. If Ty is 838 /// non-null, then this function will use the specified type if it has to 839 /// create it (this occurs when we see a definition of the function). 840 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 841 const llvm::Type *Ty) { 842 // If there was no specific requested type, just convert it now. 843 if (!Ty) 844 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 845 return GetOrCreateLLVMFunction(getMangledName(GD), Ty, GD); 846 } 847 848 /// CreateRuntimeFunction - Create a new runtime function with the specified 849 /// type and name. 850 llvm::Constant * 851 CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy, 852 const char *Name) { 853 // Convert Name to be a uniqued string from the IdentifierInfo table. 854 Name = getContext().Idents.get(Name).getNameStart(); 855 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl()); 856 } 857 858 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 859 /// create and return an llvm GlobalVariable with the specified type. If there 860 /// is something in the module with the specified name, return it potentially 861 /// bitcasted to the right type. 862 /// 863 /// If D is non-null, it specifies a decl that correspond to this. This is used 864 /// to set the attributes on the global when it is first created. 865 llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName, 866 const llvm::PointerType*Ty, 867 const VarDecl *D) { 868 // Lookup the entry, lazily creating it if necessary. 869 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 870 if (Entry) { 871 if (Entry->getType() == Ty) 872 return Entry; 873 874 // Make sure the result is of the correct type. 875 return llvm::ConstantExpr::getBitCast(Entry, Ty); 876 } 877 878 // This is the first use or definition of a mangled name. If there is a 879 // deferred decl with this name, remember that we need to emit it at the end 880 // of the file. 881 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 882 DeferredDecls.find(MangledName); 883 if (DDI != DeferredDecls.end()) { 884 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 885 // list, and remove it from DeferredDecls (since we don't need it anymore). 886 DeferredDeclsToEmit.push_back(DDI->second); 887 DeferredDecls.erase(DDI); 888 } 889 890 llvm::GlobalVariable *GV = 891 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 892 llvm::GlobalValue::ExternalLinkage, 893 0, "", 0, 894 false, Ty->getAddressSpace()); 895 GV->setName(MangledName); 896 897 // Handle things which are present even on external declarations. 898 if (D) { 899 // FIXME: This code is overly simple and should be merged with other global 900 // handling. 901 GV->setConstant(D->getType().isConstant(Context)); 902 903 // FIXME: Merge with other attribute handling code. 904 if (D->getStorageClass() == VarDecl::PrivateExtern) 905 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 906 907 if (D->hasAttr<WeakAttr>() || 908 D->hasAttr<WeakImportAttr>()) 909 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 910 911 GV->setThreadLocal(D->isThreadSpecified()); 912 } 913 914 return Entry = GV; 915 } 916 917 918 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 919 /// given global variable. If Ty is non-null and if the global doesn't exist, 920 /// then it will be greated with the specified type instead of whatever the 921 /// normal requested type would be. 922 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 923 const llvm::Type *Ty) { 924 assert(D->hasGlobalStorage() && "Not a global variable"); 925 QualType ASTTy = D->getType(); 926 if (Ty == 0) 927 Ty = getTypes().ConvertTypeForMem(ASTTy); 928 929 const llvm::PointerType *PTy = 930 llvm::PointerType::get(Ty, ASTTy.getAddressSpace()); 931 return GetOrCreateLLVMGlobal(getMangledName(D), PTy, D); 932 } 933 934 /// CreateRuntimeVariable - Create a new runtime global variable with the 935 /// specified type and name. 936 llvm::Constant * 937 CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty, 938 const char *Name) { 939 // Convert Name to be a uniqued string from the IdentifierInfo table. 940 Name = getContext().Idents.get(Name).getNameStart(); 941 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0); 942 } 943 944 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 945 assert(!D->getInit() && "Cannot emit definite definitions here!"); 946 947 if (MayDeferGeneration(D)) { 948 // If we have not seen a reference to this variable yet, place it 949 // into the deferred declarations table to be emitted if needed 950 // later. 951 const char *MangledName = getMangledName(D); 952 if (GlobalDeclMap.count(MangledName) == 0) { 953 DeferredDecls[MangledName] = D; 954 return; 955 } 956 } 957 958 // The tentative definition is the only definition. 959 EmitGlobalVarDefinition(D); 960 } 961 962 static CodeGenModule::GVALinkage 963 GetLinkageForVariable(ASTContext &Context, const VarDecl *VD) { 964 // Everything located semantically within an anonymous namespace is 965 // always internal. 966 if (VD->isInAnonymousNamespace()) 967 return CodeGenModule::GVA_Internal; 968 969 // Handle linkage for static data members. 970 if (VD->isStaticDataMember()) { 971 switch (VD->getTemplateSpecializationKind()) { 972 case TSK_Undeclared: 973 case TSK_ExplicitSpecialization: 974 case TSK_ExplicitInstantiationDefinition: 975 return CodeGenModule::GVA_StrongExternal; 976 977 case TSK_ExplicitInstantiationDeclaration: 978 llvm::llvm_unreachable("Variable should not be instantiated"); 979 // Fall through to treat this like any other instantiation. 980 981 case TSK_ImplicitInstantiation: 982 return CodeGenModule::GVA_TemplateInstantiation; 983 } 984 } 985 986 if (VD->getLinkage() == VarDecl::InternalLinkage) 987 return CodeGenModule::GVA_Internal; 988 989 return CodeGenModule::GVA_StrongExternal; 990 } 991 992 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 993 llvm::Constant *Init = 0; 994 QualType ASTTy = D->getType(); 995 996 if (D->getInit() == 0) { 997 // This is a tentative definition; tentative definitions are 998 // implicitly initialized with { 0 }. 999 // 1000 // Note that tentative definitions are only emitted at the end of 1001 // a translation unit, so they should never have incomplete 1002 // type. In addition, EmitTentativeDefinition makes sure that we 1003 // never attempt to emit a tentative definition if a real one 1004 // exists. A use may still exists, however, so we still may need 1005 // to do a RAUW. 1006 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1007 Init = EmitNullConstant(D->getType()); 1008 } else { 1009 Init = EmitConstantExpr(D->getInit(), D->getType()); 1010 1011 if (!Init) { 1012 QualType T = D->getInit()->getType(); 1013 if (getLangOptions().CPlusPlus) { 1014 CXXGlobalInits.push_back(D); 1015 Init = EmitNullConstant(T); 1016 } else { 1017 ErrorUnsupported(D, "static initializer"); 1018 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1019 } 1020 } 1021 } 1022 1023 const llvm::Type* InitType = Init->getType(); 1024 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1025 1026 // Strip off a bitcast if we got one back. 1027 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1028 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1029 // all zero index gep. 1030 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1031 Entry = CE->getOperand(0); 1032 } 1033 1034 // Entry is now either a Function or GlobalVariable. 1035 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1036 1037 // We have a definition after a declaration with the wrong type. 1038 // We must make a new GlobalVariable* and update everything that used OldGV 1039 // (a declaration or tentative definition) with the new GlobalVariable* 1040 // (which will be a definition). 1041 // 1042 // This happens if there is a prototype for a global (e.g. 1043 // "extern int x[];") and then a definition of a different type (e.g. 1044 // "int x[10];"). This also happens when an initializer has a different type 1045 // from the type of the global (this happens with unions). 1046 if (GV == 0 || 1047 GV->getType()->getElementType() != InitType || 1048 GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) { 1049 1050 // Remove the old entry from GlobalDeclMap so that we'll create a new one. 1051 GlobalDeclMap.erase(getMangledName(D)); 1052 1053 // Make a new global with the correct type, this is now guaranteed to work. 1054 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1055 GV->takeName(cast<llvm::GlobalValue>(Entry)); 1056 1057 // Replace all uses of the old global with the new global 1058 llvm::Constant *NewPtrForOldDecl = 1059 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1060 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1061 1062 // Erase the old global, since it is no longer used. 1063 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1064 } 1065 1066 if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>()) { 1067 SourceManager &SM = Context.getSourceManager(); 1068 AddAnnotation(EmitAnnotateAttr(GV, AA, 1069 SM.getInstantiationLineNumber(D->getLocation()))); 1070 } 1071 1072 GV->setInitializer(Init); 1073 1074 // If it is safe to mark the global 'constant', do so now. 1075 GV->setConstant(false); 1076 if (D->getType().isConstant(Context)) { 1077 // FIXME: In C++, if the variable has a non-trivial ctor/dtor or any mutable 1078 // members, it cannot be declared "LLVM const". 1079 GV->setConstant(true); 1080 } 1081 1082 GV->setAlignment(getContext().getDeclAlignInBytes(D)); 1083 1084 // Set the llvm linkage type as appropriate. 1085 GVALinkage Linkage = GetLinkageForVariable(getContext(), D); 1086 if (Linkage == GVA_Internal) 1087 GV->setLinkage(llvm::Function::InternalLinkage); 1088 else if (D->hasAttr<DLLImportAttr>()) 1089 GV->setLinkage(llvm::Function::DLLImportLinkage); 1090 else if (D->hasAttr<DLLExportAttr>()) 1091 GV->setLinkage(llvm::Function::DLLExportLinkage); 1092 else if (D->hasAttr<WeakAttr>()) { 1093 if (GV->isConstant()) 1094 GV->setLinkage(llvm::GlobalVariable::WeakODRLinkage); 1095 else 1096 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 1097 } else if (Linkage == GVA_TemplateInstantiation) 1098 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 1099 else if (!CodeGenOpts.NoCommon && 1100 !D->hasExternalStorage() && !D->getInit() && 1101 !D->getAttr<SectionAttr>()) { 1102 GV->setLinkage(llvm::GlobalVariable::CommonLinkage); 1103 // common vars aren't constant even if declared const. 1104 GV->setConstant(false); 1105 } else 1106 GV->setLinkage(llvm::GlobalVariable::ExternalLinkage); 1107 1108 SetCommonAttributes(D, GV); 1109 1110 // Emit global variable debug information. 1111 if (CGDebugInfo *DI = getDebugInfo()) { 1112 DI->setLocation(D->getLocation()); 1113 DI->EmitGlobalVariable(GV, D); 1114 } 1115 } 1116 1117 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1118 /// implement a function with no prototype, e.g. "int foo() {}". If there are 1119 /// existing call uses of the old function in the module, this adjusts them to 1120 /// call the new function directly. 1121 /// 1122 /// This is not just a cleanup: the always_inline pass requires direct calls to 1123 /// functions to be able to inline them. If there is a bitcast in the way, it 1124 /// won't inline them. Instcombine normally deletes these calls, but it isn't 1125 /// run at -O0. 1126 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1127 llvm::Function *NewFn) { 1128 // If we're redefining a global as a function, don't transform it. 1129 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1130 if (OldFn == 0) return; 1131 1132 const llvm::Type *NewRetTy = NewFn->getReturnType(); 1133 llvm::SmallVector<llvm::Value*, 4> ArgList; 1134 1135 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1136 UI != E; ) { 1137 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1138 unsigned OpNo = UI.getOperandNo(); 1139 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*UI++); 1140 if (!CI || OpNo != 0) continue; 1141 1142 // If the return types don't match exactly, and if the call isn't dead, then 1143 // we can't transform this call. 1144 if (CI->getType() != NewRetTy && !CI->use_empty()) 1145 continue; 1146 1147 // If the function was passed too few arguments, don't transform. If extra 1148 // arguments were passed, we silently drop them. If any of the types 1149 // mismatch, we don't transform. 1150 unsigned ArgNo = 0; 1151 bool DontTransform = false; 1152 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1153 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1154 if (CI->getNumOperands()-1 == ArgNo || 1155 CI->getOperand(ArgNo+1)->getType() != AI->getType()) { 1156 DontTransform = true; 1157 break; 1158 } 1159 } 1160 if (DontTransform) 1161 continue; 1162 1163 // Okay, we can transform this. Create the new call instruction and copy 1164 // over the required information. 1165 ArgList.append(CI->op_begin()+1, CI->op_begin()+1+ArgNo); 1166 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(), 1167 ArgList.end(), "", CI); 1168 ArgList.clear(); 1169 if (!NewCall->getType()->isVoidTy()) 1170 NewCall->takeName(CI); 1171 NewCall->setAttributes(CI->getAttributes()); 1172 NewCall->setCallingConv(CI->getCallingConv()); 1173 1174 // Finally, remove the old call, replacing any uses with the new one. 1175 if (!CI->use_empty()) 1176 CI->replaceAllUsesWith(NewCall); 1177 1178 // Copy any custom metadata attached with CI. 1179 llvm::MetadataContext &TheMetadata = CI->getContext().getMetadata(); 1180 TheMetadata.copyMD(CI, NewCall); 1181 1182 CI->eraseFromParent(); 1183 } 1184 } 1185 1186 1187 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1188 const llvm::FunctionType *Ty; 1189 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1190 1191 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { 1192 bool isVariadic = D->getType()->getAs<FunctionProtoType>()->isVariadic(); 1193 1194 Ty = getTypes().GetFunctionType(getTypes().getFunctionInfo(MD), isVariadic); 1195 } else { 1196 Ty = cast<llvm::FunctionType>(getTypes().ConvertType(D->getType())); 1197 1198 // As a special case, make sure that definitions of K&R function 1199 // "type foo()" aren't declared as varargs (which forces the backend 1200 // to do unnecessary work). 1201 if (D->getType()->isFunctionNoProtoType()) { 1202 assert(Ty->isVarArg() && "Didn't lower type as expected"); 1203 // Due to stret, the lowered function could have arguments. 1204 // Just create the same type as was lowered by ConvertType 1205 // but strip off the varargs bit. 1206 std::vector<const llvm::Type*> Args(Ty->param_begin(), Ty->param_end()); 1207 Ty = llvm::FunctionType::get(Ty->getReturnType(), Args, false); 1208 } 1209 } 1210 1211 // Get or create the prototype for the function. 1212 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1213 1214 // Strip off a bitcast if we got one back. 1215 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1216 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1217 Entry = CE->getOperand(0); 1218 } 1219 1220 1221 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1222 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1223 1224 // If the types mismatch then we have to rewrite the definition. 1225 assert(OldFn->isDeclaration() && 1226 "Shouldn't replace non-declaration"); 1227 1228 // F is the Function* for the one with the wrong type, we must make a new 1229 // Function* and update everything that used F (a declaration) with the new 1230 // Function* (which will be a definition). 1231 // 1232 // This happens if there is a prototype for a function 1233 // (e.g. "int f()") and then a definition of a different type 1234 // (e.g. "int f(int x)"). Start by making a new function of the 1235 // correct type, RAUW, then steal the name. 1236 GlobalDeclMap.erase(getMangledName(D)); 1237 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1238 NewFn->takeName(OldFn); 1239 1240 // If this is an implementation of a function without a prototype, try to 1241 // replace any existing uses of the function (which may be calls) with uses 1242 // of the new function 1243 if (D->getType()->isFunctionNoProtoType()) { 1244 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1245 OldFn->removeDeadConstantUsers(); 1246 } 1247 1248 // Replace uses of F with the Function we will endow with a body. 1249 if (!Entry->use_empty()) { 1250 llvm::Constant *NewPtrForOldDecl = 1251 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1252 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1253 } 1254 1255 // Ok, delete the old function now, which is dead. 1256 OldFn->eraseFromParent(); 1257 1258 Entry = NewFn; 1259 } 1260 1261 llvm::Function *Fn = cast<llvm::Function>(Entry); 1262 1263 CodeGenFunction(*this).GenerateCode(D, Fn); 1264 1265 SetFunctionDefinitionAttributes(D, Fn); 1266 SetLLVMFunctionAttributesForDefinition(D, Fn); 1267 1268 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1269 AddGlobalCtor(Fn, CA->getPriority()); 1270 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1271 AddGlobalDtor(Fn, DA->getPriority()); 1272 } 1273 1274 void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) { 1275 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1276 assert(AA && "Not an alias?"); 1277 1278 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1279 1280 // Unique the name through the identifier table. 1281 const char *AliaseeName = AA->getAliasee().c_str(); 1282 AliaseeName = getContext().Idents.get(AliaseeName).getNameStart(); 1283 1284 // Create a reference to the named value. This ensures that it is emitted 1285 // if a deferred decl. 1286 llvm::Constant *Aliasee; 1287 if (isa<llvm::FunctionType>(DeclTy)) 1288 Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, GlobalDecl()); 1289 else 1290 Aliasee = GetOrCreateLLVMGlobal(AliaseeName, 1291 llvm::PointerType::getUnqual(DeclTy), 0); 1292 1293 // Create the new alias itself, but don't set a name yet. 1294 llvm::GlobalValue *GA = 1295 new llvm::GlobalAlias(Aliasee->getType(), 1296 llvm::Function::ExternalLinkage, 1297 "", Aliasee, &getModule()); 1298 1299 // See if there is already something with the alias' name in the module. 1300 const char *MangledName = getMangledName(D); 1301 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 1302 1303 if (Entry && !Entry->isDeclaration()) { 1304 // If there is a definition in the module, then it wins over the alias. 1305 // This is dubious, but allow it to be safe. Just ignore the alias. 1306 GA->eraseFromParent(); 1307 return; 1308 } 1309 1310 if (Entry) { 1311 // If there is a declaration in the module, then we had an extern followed 1312 // by the alias, as in: 1313 // extern int test6(); 1314 // ... 1315 // int test6() __attribute__((alias("test7"))); 1316 // 1317 // Remove it and replace uses of it with the alias. 1318 1319 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1320 Entry->getType())); 1321 Entry->eraseFromParent(); 1322 } 1323 1324 // Now we know that there is no conflict, set the name. 1325 Entry = GA; 1326 GA->setName(MangledName); 1327 1328 // Set attributes which are particular to an alias; this is a 1329 // specialization of the attributes which may be set on a global 1330 // variable/function. 1331 if (D->hasAttr<DLLExportAttr>()) { 1332 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1333 // The dllexport attribute is ignored for undefined symbols. 1334 if (FD->getBody()) 1335 GA->setLinkage(llvm::Function::DLLExportLinkage); 1336 } else { 1337 GA->setLinkage(llvm::Function::DLLExportLinkage); 1338 } 1339 } else if (D->hasAttr<WeakAttr>() || 1340 D->hasAttr<WeakImportAttr>()) { 1341 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1342 } 1343 1344 SetCommonAttributes(D, GA); 1345 } 1346 1347 /// getBuiltinLibFunction - Given a builtin id for a function like 1348 /// "__builtin_fabsf", return a Function* for "fabsf". 1349 llvm::Value *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD, 1350 unsigned BuiltinID) { 1351 assert((Context.BuiltinInfo.isLibFunction(BuiltinID) || 1352 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) && 1353 "isn't a lib fn"); 1354 1355 // Get the name, skip over the __builtin_ prefix (if necessary). 1356 const char *Name = Context.BuiltinInfo.GetName(BuiltinID); 1357 if (Context.BuiltinInfo.isLibFunction(BuiltinID)) 1358 Name += 10; 1359 1360 // Get the type for the builtin. 1361 ASTContext::GetBuiltinTypeError Error; 1362 QualType Type = Context.GetBuiltinType(BuiltinID, Error); 1363 assert(Error == ASTContext::GE_None && "Can't get builtin type"); 1364 1365 const llvm::FunctionType *Ty = 1366 cast<llvm::FunctionType>(getTypes().ConvertType(Type)); 1367 1368 // Unique the name through the identifier table. 1369 Name = getContext().Idents.get(Name).getNameStart(); 1370 return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl(FD)); 1371 } 1372 1373 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys, 1374 unsigned NumTys) { 1375 return llvm::Intrinsic::getDeclaration(&getModule(), 1376 (llvm::Intrinsic::ID)IID, Tys, NumTys); 1377 } 1378 1379 llvm::Function *CodeGenModule::getMemCpyFn() { 1380 if (MemCpyFn) return MemCpyFn; 1381 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(VMContext); 1382 return MemCpyFn = getIntrinsic(llvm::Intrinsic::memcpy, &IntPtr, 1); 1383 } 1384 1385 llvm::Function *CodeGenModule::getMemMoveFn() { 1386 if (MemMoveFn) return MemMoveFn; 1387 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(VMContext); 1388 return MemMoveFn = getIntrinsic(llvm::Intrinsic::memmove, &IntPtr, 1); 1389 } 1390 1391 llvm::Function *CodeGenModule::getMemSetFn() { 1392 if (MemSetFn) return MemSetFn; 1393 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(VMContext); 1394 return MemSetFn = getIntrinsic(llvm::Intrinsic::memset, &IntPtr, 1); 1395 } 1396 1397 static llvm::StringMapEntry<llvm::Constant*> & 1398 GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1399 const StringLiteral *Literal, 1400 bool TargetIsLSB, 1401 bool &IsUTF16, 1402 unsigned &StringLength) { 1403 unsigned NumBytes = Literal->getByteLength(); 1404 1405 // Check for simple case. 1406 if (!Literal->containsNonAsciiOrNull()) { 1407 StringLength = NumBytes; 1408 return Map.GetOrCreateValue(llvm::StringRef(Literal->getStrData(), 1409 StringLength)); 1410 } 1411 1412 // Otherwise, convert the UTF8 literals into a byte string. 1413 llvm::SmallVector<UTF16, 128> ToBuf(NumBytes); 1414 const UTF8 *FromPtr = (UTF8 *)Literal->getStrData(); 1415 UTF16 *ToPtr = &ToBuf[0]; 1416 1417 ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 1418 &ToPtr, ToPtr + NumBytes, 1419 strictConversion); 1420 1421 // Check for conversion failure. 1422 if (Result != conversionOK) { 1423 // FIXME: Have Sema::CheckObjCString() validate the UTF-8 string and remove 1424 // this duplicate code. 1425 assert(Result == sourceIllegal && "UTF-8 to UTF-16 conversion failed"); 1426 StringLength = NumBytes; 1427 return Map.GetOrCreateValue(llvm::StringRef(Literal->getStrData(), 1428 StringLength)); 1429 } 1430 1431 // ConvertUTF8toUTF16 returns the length in ToPtr. 1432 StringLength = ToPtr - &ToBuf[0]; 1433 1434 // Render the UTF-16 string into a byte array and convert to the target byte 1435 // order. 1436 // 1437 // FIXME: This isn't something we should need to do here. 1438 llvm::SmallString<128> AsBytes; 1439 AsBytes.reserve(StringLength * 2); 1440 for (unsigned i = 0; i != StringLength; ++i) { 1441 unsigned short Val = ToBuf[i]; 1442 if (TargetIsLSB) { 1443 AsBytes.push_back(Val & 0xFF); 1444 AsBytes.push_back(Val >> 8); 1445 } else { 1446 AsBytes.push_back(Val >> 8); 1447 AsBytes.push_back(Val & 0xFF); 1448 } 1449 } 1450 // Append one extra null character, the second is automatically added by our 1451 // caller. 1452 AsBytes.push_back(0); 1453 1454 IsUTF16 = true; 1455 return Map.GetOrCreateValue(llvm::StringRef(AsBytes.data(), AsBytes.size())); 1456 } 1457 1458 llvm::Constant * 1459 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 1460 unsigned StringLength = 0; 1461 bool isUTF16 = false; 1462 llvm::StringMapEntry<llvm::Constant*> &Entry = 1463 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1464 getTargetData().isLittleEndian(), 1465 isUTF16, StringLength); 1466 1467 if (llvm::Constant *C = Entry.getValue()) 1468 return C; 1469 1470 llvm::Constant *Zero = 1471 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1472 llvm::Constant *Zeros[] = { Zero, Zero }; 1473 1474 // If we don't already have it, get __CFConstantStringClassReference. 1475 if (!CFConstantStringClassRef) { 1476 const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1477 Ty = llvm::ArrayType::get(Ty, 0); 1478 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1479 "__CFConstantStringClassReference"); 1480 // Decay array -> ptr 1481 CFConstantStringClassRef = 1482 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1483 } 1484 1485 QualType CFTy = getContext().getCFConstantStringType(); 1486 1487 const llvm::StructType *STy = 1488 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1489 1490 std::vector<llvm::Constant*> Fields(4); 1491 1492 // Class pointer. 1493 Fields[0] = CFConstantStringClassRef; 1494 1495 // Flags. 1496 const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1497 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 1498 llvm::ConstantInt::get(Ty, 0x07C8); 1499 1500 // String pointer. 1501 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1502 1503 const char *Sect = 0; 1504 llvm::GlobalValue::LinkageTypes Linkage; 1505 bool isConstant; 1506 if (isUTF16) { 1507 Sect = getContext().Target.getUnicodeStringSection(); 1508 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1509 Linkage = llvm::GlobalValue::InternalLinkage; 1510 // Note: -fwritable-strings doesn't make unicode CFStrings writable, but 1511 // does make plain ascii ones writable. 1512 isConstant = true; 1513 } else { 1514 Linkage = llvm::GlobalValue::PrivateLinkage; 1515 isConstant = !Features.WritableStrings; 1516 } 1517 1518 llvm::GlobalVariable *GV = 1519 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1520 ".str"); 1521 if (Sect) 1522 GV->setSection(Sect); 1523 if (isUTF16) { 1524 unsigned Align = getContext().getTypeAlign(getContext().ShortTy)/8; 1525 GV->setAlignment(Align); 1526 } 1527 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1528 1529 // String length. 1530 Ty = getTypes().ConvertType(getContext().LongTy); 1531 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 1532 1533 // The struct. 1534 C = llvm::ConstantStruct::get(STy, Fields); 1535 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1536 llvm::GlobalVariable::PrivateLinkage, C, 1537 "_unnamed_cfstring_"); 1538 if (const char *Sect = getContext().Target.getCFStringSection()) 1539 GV->setSection(Sect); 1540 Entry.setValue(GV); 1541 1542 return GV; 1543 } 1544 1545 /// GetStringForStringLiteral - Return the appropriate bytes for a 1546 /// string literal, properly padded to match the literal type. 1547 std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 1548 const char *StrData = E->getStrData(); 1549 unsigned Len = E->getByteLength(); 1550 1551 const ConstantArrayType *CAT = 1552 getContext().getAsConstantArrayType(E->getType()); 1553 assert(CAT && "String isn't pointer or array!"); 1554 1555 // Resize the string to the right size. 1556 std::string Str(StrData, StrData+Len); 1557 uint64_t RealLen = CAT->getSize().getZExtValue(); 1558 1559 if (E->isWide()) 1560 RealLen *= getContext().Target.getWCharWidth()/8; 1561 1562 Str.resize(RealLen, '\0'); 1563 1564 return Str; 1565 } 1566 1567 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a 1568 /// constant array for the given string literal. 1569 llvm::Constant * 1570 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 1571 // FIXME: This can be more efficient. 1572 // FIXME: We shouldn't need to bitcast the constant in the wide string case. 1573 llvm::Constant *C = GetAddrOfConstantString(GetStringForStringLiteral(S)); 1574 if (S->isWide()) { 1575 llvm::Type *DestTy = 1576 llvm::PointerType::getUnqual(getTypes().ConvertType(S->getType())); 1577 C = llvm::ConstantExpr::getBitCast(C, DestTy); 1578 } 1579 return C; 1580 } 1581 1582 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 1583 /// array for the given ObjCEncodeExpr node. 1584 llvm::Constant * 1585 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 1586 std::string Str; 1587 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 1588 1589 return GetAddrOfConstantCString(Str); 1590 } 1591 1592 1593 /// GenerateWritableString -- Creates storage for a string literal. 1594 static llvm::Constant *GenerateStringLiteral(const std::string &str, 1595 bool constant, 1596 CodeGenModule &CGM, 1597 const char *GlobalName) { 1598 // Create Constant for this string literal. Don't add a '\0'. 1599 llvm::Constant *C = 1600 llvm::ConstantArray::get(CGM.getLLVMContext(), str, false); 1601 1602 // Create a global variable for this string 1603 return new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 1604 llvm::GlobalValue::PrivateLinkage, 1605 C, GlobalName); 1606 } 1607 1608 /// GetAddrOfConstantString - Returns a pointer to a character array 1609 /// containing the literal. This contents are exactly that of the 1610 /// given string, i.e. it will not be null terminated automatically; 1611 /// see GetAddrOfConstantCString. Note that whether the result is 1612 /// actually a pointer to an LLVM constant depends on 1613 /// Feature.WriteableStrings. 1614 /// 1615 /// The result has pointer to array type. 1616 llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str, 1617 const char *GlobalName) { 1618 bool IsConstant = !Features.WritableStrings; 1619 1620 // Get the default prefix if a name wasn't specified. 1621 if (!GlobalName) 1622 GlobalName = ".str"; 1623 1624 // Don't share any string literals if strings aren't constant. 1625 if (!IsConstant) 1626 return GenerateStringLiteral(str, false, *this, GlobalName); 1627 1628 llvm::StringMapEntry<llvm::Constant *> &Entry = 1629 ConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]); 1630 1631 if (Entry.getValue()) 1632 return Entry.getValue(); 1633 1634 // Create a global variable for this. 1635 llvm::Constant *C = GenerateStringLiteral(str, true, *this, GlobalName); 1636 Entry.setValue(C); 1637 return C; 1638 } 1639 1640 /// GetAddrOfConstantCString - Returns a pointer to a character 1641 /// array containing the literal and a terminating '\-' 1642 /// character. The result has pointer to array type. 1643 llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &str, 1644 const char *GlobalName){ 1645 return GetAddrOfConstantString(str + '\0', GlobalName); 1646 } 1647 1648 /// EmitObjCPropertyImplementations - Emit information for synthesized 1649 /// properties for an implementation. 1650 void CodeGenModule::EmitObjCPropertyImplementations(const 1651 ObjCImplementationDecl *D) { 1652 for (ObjCImplementationDecl::propimpl_iterator 1653 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 1654 ObjCPropertyImplDecl *PID = *i; 1655 1656 // Dynamic is just for type-checking. 1657 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 1658 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 1659 1660 // Determine which methods need to be implemented, some may have 1661 // been overridden. Note that ::isSynthesized is not the method 1662 // we want, that just indicates if the decl came from a 1663 // property. What we want to know is if the method is defined in 1664 // this implementation. 1665 if (!D->getInstanceMethod(PD->getGetterName())) 1666 CodeGenFunction(*this).GenerateObjCGetter( 1667 const_cast<ObjCImplementationDecl *>(D), PID); 1668 if (!PD->isReadOnly() && 1669 !D->getInstanceMethod(PD->getSetterName())) 1670 CodeGenFunction(*this).GenerateObjCSetter( 1671 const_cast<ObjCImplementationDecl *>(D), PID); 1672 } 1673 } 1674 } 1675 1676 /// EmitNamespace - Emit all declarations in a namespace. 1677 void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 1678 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 1679 I != E; ++I) 1680 EmitTopLevelDecl(*I); 1681 } 1682 1683 // EmitLinkageSpec - Emit all declarations in a linkage spec. 1684 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 1685 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 1686 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 1687 ErrorUnsupported(LSD, "linkage spec"); 1688 return; 1689 } 1690 1691 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 1692 I != E; ++I) 1693 EmitTopLevelDecl(*I); 1694 } 1695 1696 /// EmitTopLevelDecl - Emit code for a single top level declaration. 1697 void CodeGenModule::EmitTopLevelDecl(Decl *D) { 1698 // If an error has occurred, stop code generation, but continue 1699 // parsing and semantic analysis (to ensure all warnings and errors 1700 // are emitted). 1701 if (Diags.hasErrorOccurred()) 1702 return; 1703 1704 // Ignore dependent declarations. 1705 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 1706 return; 1707 1708 switch (D->getKind()) { 1709 case Decl::CXXConversion: 1710 case Decl::CXXMethod: 1711 case Decl::Function: 1712 // Skip function templates 1713 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 1714 return; 1715 1716 EmitGlobal(cast<FunctionDecl>(D)); 1717 break; 1718 1719 case Decl::Var: 1720 EmitGlobal(cast<VarDecl>(D)); 1721 break; 1722 1723 // C++ Decls 1724 case Decl::Namespace: 1725 EmitNamespace(cast<NamespaceDecl>(D)); 1726 break; 1727 // No code generation needed. 1728 case Decl::UsingShadow: 1729 case Decl::Using: 1730 case Decl::UsingDirective: 1731 case Decl::ClassTemplate: 1732 case Decl::FunctionTemplate: 1733 case Decl::NamespaceAlias: 1734 break; 1735 case Decl::CXXConstructor: 1736 // Skip function templates 1737 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 1738 return; 1739 1740 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 1741 break; 1742 case Decl::CXXDestructor: 1743 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 1744 break; 1745 1746 case Decl::StaticAssert: 1747 // Nothing to do. 1748 break; 1749 1750 // Objective-C Decls 1751 1752 // Forward declarations, no (immediate) code generation. 1753 case Decl::ObjCClass: 1754 case Decl::ObjCForwardProtocol: 1755 case Decl::ObjCCategory: 1756 case Decl::ObjCInterface: 1757 break; 1758 1759 case Decl::ObjCProtocol: 1760 Runtime->GenerateProtocol(cast<ObjCProtocolDecl>(D)); 1761 break; 1762 1763 case Decl::ObjCCategoryImpl: 1764 // Categories have properties but don't support synthesize so we 1765 // can ignore them here. 1766 Runtime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 1767 break; 1768 1769 case Decl::ObjCImplementation: { 1770 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 1771 EmitObjCPropertyImplementations(OMD); 1772 Runtime->GenerateClass(OMD); 1773 break; 1774 } 1775 case Decl::ObjCMethod: { 1776 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 1777 // If this is not a prototype, emit the body. 1778 if (OMD->getBody()) 1779 CodeGenFunction(*this).GenerateObjCMethod(OMD); 1780 break; 1781 } 1782 case Decl::ObjCCompatibleAlias: 1783 // compatibility-alias is a directive and has no code gen. 1784 break; 1785 1786 case Decl::LinkageSpec: 1787 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 1788 break; 1789 1790 case Decl::FileScopeAsm: { 1791 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 1792 std::string AsmString(AD->getAsmString()->getStrData(), 1793 AD->getAsmString()->getByteLength()); 1794 1795 const std::string &S = getModule().getModuleInlineAsm(); 1796 if (S.empty()) 1797 getModule().setModuleInlineAsm(AsmString); 1798 else 1799 getModule().setModuleInlineAsm(S + '\n' + AsmString); 1800 break; 1801 } 1802 1803 default: 1804 // Make sure we handled everything we should, every other kind is a 1805 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 1806 // function. Need to recode Decl::Kind to do that easily. 1807 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 1808 } 1809 } 1810