CodeGenModule.cpp revision 206275
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), VTables(*this), Runtime(0), CFConstantStringClassRef(0), 51 VMContext(M.getContext()) { 52 53 if (!Features.ObjC1) 54 Runtime = 0; 55 else if (!Features.NeXTRuntime) 56 Runtime = CreateGNUObjCRuntime(*this); 57 else if (Features.ObjCNonFragileABI) 58 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 59 else 60 Runtime = CreateMacObjCRuntime(*this); 61 62 // If debug info generation is enabled, create the CGDebugInfo object. 63 DebugInfo = CodeGenOpts.DebugInfo ? new CGDebugInfo(*this) : 0; 64} 65 66CodeGenModule::~CodeGenModule() { 67 delete Runtime; 68 delete DebugInfo; 69} 70 71void CodeGenModule::createObjCRuntime() { 72 if (!Features.NeXTRuntime) 73 Runtime = CreateGNUObjCRuntime(*this); 74 else if (Features.ObjCNonFragileABI) 75 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 76 else 77 Runtime = CreateMacObjCRuntime(*this); 78} 79 80void CodeGenModule::Release() { 81 EmitFundamentalRTTIDescriptors(); 82 EmitDeferred(); 83 EmitCXXGlobalInitFunc(); 84 EmitCXXGlobalDtorFunc(); 85 if (Runtime) 86 if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction()) 87 AddGlobalCtor(ObjCInitFunction); 88 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 89 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 90 EmitAnnotations(); 91 EmitLLVMUsed(); 92} 93 94bool CodeGenModule::isTargetDarwin() const { 95 return getContext().Target.getTriple().getOS() == llvm::Triple::Darwin; 96} 97 98/// ErrorUnsupported - Print out an error that codegen doesn't support the 99/// specified stmt yet. 100void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 101 bool OmitOnError) { 102 if (OmitOnError && getDiags().hasErrorOccurred()) 103 return; 104 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 105 "cannot compile this %0 yet"); 106 std::string Msg = Type; 107 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 108 << Msg << S->getSourceRange(); 109} 110 111/// ErrorUnsupported - Print out an error that codegen doesn't support the 112/// specified decl yet. 113void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 114 bool OmitOnError) { 115 if (OmitOnError && getDiags().hasErrorOccurred()) 116 return; 117 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 118 "cannot compile this %0 yet"); 119 std::string Msg = Type; 120 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 121} 122 123LangOptions::VisibilityMode 124CodeGenModule::getDeclVisibilityMode(const Decl *D) const { 125 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 126 if (VD->getStorageClass() == VarDecl::PrivateExtern) 127 return LangOptions::Hidden; 128 129 if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>()) { 130 switch (attr->getVisibility()) { 131 default: assert(0 && "Unknown visibility!"); 132 case VisibilityAttr::DefaultVisibility: 133 return LangOptions::Default; 134 case VisibilityAttr::HiddenVisibility: 135 return LangOptions::Hidden; 136 case VisibilityAttr::ProtectedVisibility: 137 return LangOptions::Protected; 138 } 139 } 140 141 // This decl should have the same visibility as its parent. 142 if (const DeclContext *DC = D->getDeclContext()) 143 return getDeclVisibilityMode(cast<Decl>(DC)); 144 145 return getLangOptions().getVisibilityMode(); 146} 147 148void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 149 const Decl *D) const { 150 // Internal definitions always have default visibility. 151 if (GV->hasLocalLinkage()) { 152 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 153 return; 154 } 155 156 switch (getDeclVisibilityMode(D)) { 157 default: assert(0 && "Unknown visibility!"); 158 case LangOptions::Default: 159 return GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 160 case LangOptions::Hidden: 161 return GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 162 case LangOptions::Protected: 163 return GV->setVisibility(llvm::GlobalValue::ProtectedVisibility); 164 } 165} 166 167void CodeGenModule::getMangledName(MangleBuffer &Buffer, GlobalDecl GD) { 168 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 169 170 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 171 return getMangledCXXCtorName(Buffer, D, GD.getCtorType()); 172 if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 173 return getMangledCXXDtorName(Buffer, D, GD.getDtorType()); 174 175 return getMangledName(Buffer, ND); 176} 177 178/// \brief Retrieves the mangled name for the given declaration. 179/// 180/// If the given declaration requires a mangled name, returns an 181/// const char* containing the mangled name. Otherwise, returns 182/// the unmangled name. 183/// 184void CodeGenModule::getMangledName(MangleBuffer &Buffer, 185 const NamedDecl *ND) { 186 if (!getMangleContext().shouldMangleDeclName(ND)) { 187 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl."); 188 Buffer.setString(ND->getNameAsCString()); 189 return; 190 } 191 192 getMangleContext().mangleName(ND, Buffer.getBuffer()); 193} 194 195llvm::GlobalValue *CodeGenModule::GetGlobalValue(llvm::StringRef Name) { 196 return getModule().getNamedValue(Name); 197} 198 199/// AddGlobalCtor - Add a function to the list that will be called before 200/// main() runs. 201void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 202 // FIXME: Type coercion of void()* types. 203 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 204} 205 206/// AddGlobalDtor - Add a function to the list that will be called 207/// when the module is unloaded. 208void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 209 // FIXME: Type coercion of void()* types. 210 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 211} 212 213void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 214 // Ctor function type is void()*. 215 llvm::FunctionType* CtorFTy = 216 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), 217 std::vector<const llvm::Type*>(), 218 false); 219 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 220 221 // Get the type of a ctor entry, { i32, void ()* }. 222 llvm::StructType* CtorStructTy = 223 llvm::StructType::get(VMContext, llvm::Type::getInt32Ty(VMContext), 224 llvm::PointerType::getUnqual(CtorFTy), NULL); 225 226 // Construct the constructor and destructor arrays. 227 std::vector<llvm::Constant*> Ctors; 228 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 229 std::vector<llvm::Constant*> S; 230 S.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 231 I->second, false)); 232 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy)); 233 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 234 } 235 236 if (!Ctors.empty()) { 237 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 238 new llvm::GlobalVariable(TheModule, AT, false, 239 llvm::GlobalValue::AppendingLinkage, 240 llvm::ConstantArray::get(AT, Ctors), 241 GlobalName); 242 } 243} 244 245void CodeGenModule::EmitAnnotations() { 246 if (Annotations.empty()) 247 return; 248 249 // Create a new global variable for the ConstantStruct in the Module. 250 llvm::Constant *Array = 251 llvm::ConstantArray::get(llvm::ArrayType::get(Annotations[0]->getType(), 252 Annotations.size()), 253 Annotations); 254 llvm::GlobalValue *gv = 255 new llvm::GlobalVariable(TheModule, Array->getType(), false, 256 llvm::GlobalValue::AppendingLinkage, Array, 257 "llvm.global.annotations"); 258 gv->setSection("llvm.metadata"); 259} 260 261static CodeGenModule::GVALinkage 262GetLinkageForFunction(ASTContext &Context, const FunctionDecl *FD, 263 const LangOptions &Features) { 264 CodeGenModule::GVALinkage External = CodeGenModule::GVA_StrongExternal; 265 266 Linkage L = FD->getLinkage(); 267 if (L == ExternalLinkage && Context.getLangOptions().CPlusPlus && 268 FD->getType()->getLinkage() == UniqueExternalLinkage) 269 L = UniqueExternalLinkage; 270 271 switch (L) { 272 case NoLinkage: 273 case InternalLinkage: 274 case UniqueExternalLinkage: 275 return CodeGenModule::GVA_Internal; 276 277 case ExternalLinkage: 278 switch (FD->getTemplateSpecializationKind()) { 279 case TSK_Undeclared: 280 case TSK_ExplicitSpecialization: 281 External = CodeGenModule::GVA_StrongExternal; 282 break; 283 284 case TSK_ExplicitInstantiationDefinition: 285 return CodeGenModule::GVA_ExplicitTemplateInstantiation; 286 287 case TSK_ExplicitInstantiationDeclaration: 288 case TSK_ImplicitInstantiation: 289 External = CodeGenModule::GVA_TemplateInstantiation; 290 break; 291 } 292 } 293 294 if (!FD->isInlined()) 295 return External; 296 297 if (!Features.CPlusPlus || FD->hasAttr<GNUInlineAttr>()) { 298 // GNU or C99 inline semantics. Determine whether this symbol should be 299 // externally visible. 300 if (FD->isInlineDefinitionExternallyVisible()) 301 return External; 302 303 // C99 inline semantics, where the symbol is not externally visible. 304 return CodeGenModule::GVA_C99Inline; 305 } 306 307 // C++0x [temp.explicit]p9: 308 // [ Note: The intent is that an inline function that is the subject of 309 // an explicit instantiation declaration will still be implicitly 310 // instantiated when used so that the body can be considered for 311 // inlining, but that no out-of-line copy of the inline function would be 312 // generated in the translation unit. -- end note ] 313 if (FD->getTemplateSpecializationKind() 314 == TSK_ExplicitInstantiationDeclaration) 315 return CodeGenModule::GVA_C99Inline; 316 317 return CodeGenModule::GVA_CXXInline; 318} 319 320llvm::GlobalValue::LinkageTypes 321CodeGenModule::getFunctionLinkage(const FunctionDecl *D) { 322 GVALinkage Linkage = GetLinkageForFunction(getContext(), D, Features); 323 324 if (Linkage == GVA_Internal) { 325 return llvm::Function::InternalLinkage; 326 } else if (D->hasAttr<DLLExportAttr>()) { 327 return llvm::Function::DLLExportLinkage; 328 } else if (D->hasAttr<WeakAttr>()) { 329 return llvm::Function::WeakAnyLinkage; 330 } else if (Linkage == GVA_C99Inline) { 331 // In C99 mode, 'inline' functions are guaranteed to have a strong 332 // definition somewhere else, so we can use available_externally linkage. 333 return llvm::Function::AvailableExternallyLinkage; 334 } else if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) { 335 // In C++, the compiler has to emit a definition in every translation unit 336 // that references the function. We should use linkonce_odr because 337 // a) if all references in this translation unit are optimized away, we 338 // don't need to codegen it. b) if the function persists, it needs to be 339 // merged with other definitions. c) C++ has the ODR, so we know the 340 // definition is dependable. 341 return llvm::Function::LinkOnceODRLinkage; 342 } else if (Linkage == GVA_ExplicitTemplateInstantiation) { 343 // An explicit instantiation of a template has weak linkage, since 344 // explicit instantiations can occur in multiple translation units 345 // and must all be equivalent. However, we are not allowed to 346 // throw away these explicit instantiations. 347 return llvm::Function::WeakODRLinkage; 348 } else { 349 assert(Linkage == GVA_StrongExternal); 350 // Otherwise, we have strong external linkage. 351 return llvm::Function::ExternalLinkage; 352 } 353} 354 355 356/// SetFunctionDefinitionAttributes - Set attributes for a global. 357/// 358/// FIXME: This is currently only done for aliases and functions, but not for 359/// variables (these details are set in EmitGlobalVarDefinition for variables). 360void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 361 llvm::GlobalValue *GV) { 362 GV->setLinkage(getFunctionLinkage(D)); 363 SetCommonAttributes(D, GV); 364} 365 366void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 367 const CGFunctionInfo &Info, 368 llvm::Function *F) { 369 unsigned CallingConv; 370 AttributeListType AttributeList; 371 ConstructAttributeList(Info, D, AttributeList, CallingConv); 372 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 373 AttributeList.size())); 374 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 375} 376 377void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 378 llvm::Function *F) { 379 if (!Features.Exceptions && !Features.ObjCNonFragileABI) 380 F->addFnAttr(llvm::Attribute::NoUnwind); 381 382 if (D->hasAttr<AlwaysInlineAttr>()) 383 F->addFnAttr(llvm::Attribute::AlwaysInline); 384 385 if (D->hasAttr<NoInlineAttr>()) 386 F->addFnAttr(llvm::Attribute::NoInline); 387 388 if (Features.getStackProtectorMode() == LangOptions::SSPOn) 389 F->addFnAttr(llvm::Attribute::StackProtect); 390 else if (Features.getStackProtectorMode() == LangOptions::SSPReq) 391 F->addFnAttr(llvm::Attribute::StackProtectReq); 392 393 if (const AlignedAttr *AA = D->getAttr<AlignedAttr>()) { 394 unsigned width = Context.Target.getCharWidth(); 395 F->setAlignment(AA->getAlignment() / width); 396 while ((AA = AA->getNext<AlignedAttr>())) 397 F->setAlignment(std::max(F->getAlignment(), AA->getAlignment() / width)); 398 } 399 // C++ ABI requires 2-byte alignment for member functions. 400 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 401 F->setAlignment(2); 402} 403 404void CodeGenModule::SetCommonAttributes(const Decl *D, 405 llvm::GlobalValue *GV) { 406 setGlobalVisibility(GV, D); 407 408 if (D->hasAttr<UsedAttr>()) 409 AddUsedGlobal(GV); 410 411 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 412 GV->setSection(SA->getName()); 413 414 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 415} 416 417void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 418 llvm::Function *F, 419 const CGFunctionInfo &FI) { 420 SetLLVMFunctionAttributes(D, FI, F); 421 SetLLVMFunctionAttributesForDefinition(D, F); 422 423 F->setLinkage(llvm::Function::InternalLinkage); 424 425 SetCommonAttributes(D, F); 426} 427 428void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, 429 llvm::Function *F, 430 bool IsIncompleteFunction) { 431 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 432 433 if (!IsIncompleteFunction) 434 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(GD), F); 435 436 // Only a few attributes are set on declarations; these may later be 437 // overridden by a definition. 438 439 if (FD->hasAttr<DLLImportAttr>()) { 440 F->setLinkage(llvm::Function::DLLImportLinkage); 441 } else if (FD->hasAttr<WeakAttr>() || 442 FD->hasAttr<WeakImportAttr>()) { 443 // "extern_weak" is overloaded in LLVM; we probably should have 444 // separate linkage types for this. 445 F->setLinkage(llvm::Function::ExternalWeakLinkage); 446 } else { 447 F->setLinkage(llvm::Function::ExternalLinkage); 448 } 449 450 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 451 F->setSection(SA->getName()); 452} 453 454void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 455 assert(!GV->isDeclaration() && 456 "Only globals with definition can force usage."); 457 LLVMUsed.push_back(GV); 458} 459 460void CodeGenModule::EmitLLVMUsed() { 461 // Don't create llvm.used if there is no need. 462 if (LLVMUsed.empty()) 463 return; 464 465 const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext); 466 467 // Convert LLVMUsed to what ConstantArray needs. 468 std::vector<llvm::Constant*> UsedArray; 469 UsedArray.resize(LLVMUsed.size()); 470 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 471 UsedArray[i] = 472 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 473 i8PTy); 474 } 475 476 if (UsedArray.empty()) 477 return; 478 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, UsedArray.size()); 479 480 llvm::GlobalVariable *GV = 481 new llvm::GlobalVariable(getModule(), ATy, false, 482 llvm::GlobalValue::AppendingLinkage, 483 llvm::ConstantArray::get(ATy, UsedArray), 484 "llvm.used"); 485 486 GV->setSection("llvm.metadata"); 487} 488 489void CodeGenModule::EmitDeferred() { 490 // Emit code for any potentially referenced deferred decls. Since a 491 // previously unused static decl may become used during the generation of code 492 // for a static function, iterate until no changes are made. 493 494 while (!DeferredDeclsToEmit.empty() || !DeferredVtables.empty()) { 495 if (!DeferredVtables.empty()) { 496 const CXXRecordDecl *RD = DeferredVtables.back(); 497 DeferredVtables.pop_back(); 498 getVTables().GenerateClassData(getVtableLinkage(RD), RD); 499 continue; 500 } 501 502 GlobalDecl D = DeferredDeclsToEmit.back(); 503 DeferredDeclsToEmit.pop_back(); 504 505 // Look it up to see if it was defined with a stronger definition (e.g. an 506 // extern inline function with a strong function redefinition). If so, 507 // just ignore the deferred decl. 508 MangleBuffer Name; 509 getMangledName(Name, D); 510 llvm::GlobalValue *CGRef = GetGlobalValue(Name); 511 assert(CGRef && "Deferred decl wasn't referenced?"); 512 513 if (!CGRef->isDeclaration()) 514 continue; 515 516 // Otherwise, emit the definition and move on to the next one. 517 EmitGlobalDefinition(D); 518 } 519} 520 521/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the 522/// annotation information for a given GlobalValue. The annotation struct is 523/// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the 524/// GlobalValue being annotated. The second field is the constant string 525/// created from the AnnotateAttr's annotation. The third field is a constant 526/// string containing the name of the translation unit. The fourth field is 527/// the line number in the file of the annotated value declaration. 528/// 529/// FIXME: this does not unique the annotation string constants, as llvm-gcc 530/// appears to. 531/// 532llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 533 const AnnotateAttr *AA, 534 unsigned LineNo) { 535 llvm::Module *M = &getModule(); 536 537 // get [N x i8] constants for the annotation string, and the filename string 538 // which are the 2nd and 3rd elements of the global annotation structure. 539 const llvm::Type *SBP = llvm::Type::getInt8PtrTy(VMContext); 540 llvm::Constant *anno = llvm::ConstantArray::get(VMContext, 541 AA->getAnnotation(), true); 542 llvm::Constant *unit = llvm::ConstantArray::get(VMContext, 543 M->getModuleIdentifier(), 544 true); 545 546 // Get the two global values corresponding to the ConstantArrays we just 547 // created to hold the bytes of the strings. 548 llvm::GlobalValue *annoGV = 549 new llvm::GlobalVariable(*M, anno->getType(), false, 550 llvm::GlobalValue::PrivateLinkage, anno, 551 GV->getName()); 552 // translation unit name string, emitted into the llvm.metadata section. 553 llvm::GlobalValue *unitGV = 554 new llvm::GlobalVariable(*M, unit->getType(), false, 555 llvm::GlobalValue::PrivateLinkage, unit, 556 ".str"); 557 558 // Create the ConstantStruct for the global annotation. 559 llvm::Constant *Fields[4] = { 560 llvm::ConstantExpr::getBitCast(GV, SBP), 561 llvm::ConstantExpr::getBitCast(annoGV, SBP), 562 llvm::ConstantExpr::getBitCast(unitGV, SBP), 563 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), LineNo) 564 }; 565 return llvm::ConstantStruct::get(VMContext, Fields, 4, false); 566} 567 568bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 569 // Never defer when EmitAllDecls is specified or the decl has 570 // attribute used. 571 if (Features.EmitAllDecls || Global->hasAttr<UsedAttr>()) 572 return false; 573 574 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 575 // Constructors and destructors should never be deferred. 576 if (FD->hasAttr<ConstructorAttr>() || 577 FD->hasAttr<DestructorAttr>()) 578 return false; 579 580 // The key function for a class must never be deferred. 581 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Global)) { 582 const CXXRecordDecl *RD = MD->getParent(); 583 if (MD->isOutOfLine() && RD->isDynamicClass()) { 584 const CXXMethodDecl *KeyFunction = getContext().getKeyFunction(RD); 585 if (KeyFunction && 586 KeyFunction->getCanonicalDecl() == MD->getCanonicalDecl()) 587 return false; 588 } 589 } 590 591 GVALinkage Linkage = GetLinkageForFunction(getContext(), FD, Features); 592 593 // static, static inline, always_inline, and extern inline functions can 594 // always be deferred. Normal inline functions can be deferred in C99/C++. 595 // Implicit template instantiations can also be deferred in C++. 596 if (Linkage == GVA_Internal || Linkage == GVA_C99Inline || 597 Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 598 return true; 599 return false; 600 } 601 602 const VarDecl *VD = cast<VarDecl>(Global); 603 assert(VD->isFileVarDecl() && "Invalid decl"); 604 605 // We never want to defer structs that have non-trivial constructors or 606 // destructors. 607 608 // FIXME: Handle references. 609 if (const RecordType *RT = VD->getType()->getAs<RecordType>()) { 610 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 611 if (!RD->hasTrivialConstructor() || !RD->hasTrivialDestructor()) 612 return false; 613 } 614 } 615 616 // Static data may be deferred, but out-of-line static data members 617 // cannot be. 618 Linkage L = VD->getLinkage(); 619 if (L == ExternalLinkage && getContext().getLangOptions().CPlusPlus && 620 VD->getType()->getLinkage() == UniqueExternalLinkage) 621 L = UniqueExternalLinkage; 622 623 switch (L) { 624 case NoLinkage: 625 case InternalLinkage: 626 case UniqueExternalLinkage: 627 // Initializer has side effects? 628 if (VD->getInit() && VD->getInit()->HasSideEffects(Context)) 629 return false; 630 return !(VD->isStaticDataMember() && VD->isOutOfLine()); 631 632 case ExternalLinkage: 633 break; 634 } 635 636 return false; 637} 638 639llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) { 640 const AliasAttr *AA = VD->getAttr<AliasAttr>(); 641 assert(AA && "No alias?"); 642 643 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType()); 644 645 // See if there is already something with the target's name in the module. 646 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee()); 647 648 llvm::Constant *Aliasee; 649 if (isa<llvm::FunctionType>(DeclTy)) 650 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl()); 651 else 652 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 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(GD); 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 MangleBuffer MangledName; 694 getMangledName(MangledName, GD); 695 if (GetGlobalValue(MangledName)) 696 DeferredDeclsToEmit.push_back(GD); 697 else { 698 // Otherwise, remember that we saw a deferred decl with this name. The 699 // first use of the mangled name will cause it to move into 700 // DeferredDeclsToEmit. 701 DeferredDecls[MangledName] = GD; 702 } 703 return; 704 } 705 706 // Otherwise emit the definition. 707 EmitGlobalDefinition(GD); 708} 709 710void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 711 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 712 713 PrettyStackTraceDecl CrashInfo((ValueDecl *)D, D->getLocation(), 714 Context.getSourceManager(), 715 "Generating code for declaration"); 716 717 if (isa<CXXMethodDecl>(D)) 718 getVTables().EmitVTableRelatedData(GD); 719 720 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 721 EmitCXXConstructor(CD, GD.getCtorType()); 722 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 723 EmitCXXDestructor(DD, GD.getDtorType()); 724 else if (isa<FunctionDecl>(D)) 725 EmitGlobalFunctionDefinition(GD); 726 else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 727 EmitGlobalVarDefinition(VD); 728 else { 729 assert(0 && "Invalid argument to EmitGlobalDefinition()"); 730 } 731} 732 733/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 734/// module, create and return an llvm Function with the specified type. If there 735/// is something in the module with the specified name, return it potentially 736/// bitcasted to the right type. 737/// 738/// If D is non-null, it specifies a decl that correspond to this. This is used 739/// to set the attributes on the function when it is first created. 740llvm::Constant * 741CodeGenModule::GetOrCreateLLVMFunction(llvm::StringRef MangledName, 742 const llvm::Type *Ty, 743 GlobalDecl D) { 744 // Lookup the entry, lazily creating it if necessary. 745 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 746 if (Entry) { 747 if (WeakRefReferences.count(Entry)) { 748 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl()); 749 if (FD && !FD->hasAttr<WeakAttr>()) 750 Entry->setLinkage(llvm::Function::ExternalLinkage); 751 752 WeakRefReferences.erase(Entry); 753 } 754 755 if (Entry->getType()->getElementType() == Ty) 756 return Entry; 757 758 // Make sure the result is of the correct type. 759 const llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 760 return llvm::ConstantExpr::getBitCast(Entry, PTy); 761 } 762 763 // This function doesn't have a complete type (for example, the return 764 // type is an incomplete struct). Use a fake type instead, and make 765 // sure not to try to set attributes. 766 bool IsIncompleteFunction = false; 767 if (!isa<llvm::FunctionType>(Ty)) { 768 Ty = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), 769 std::vector<const llvm::Type*>(), false); 770 IsIncompleteFunction = true; 771 } 772 llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty), 773 llvm::Function::ExternalLinkage, 774 MangledName, &getModule()); 775 assert(F->getName() == MangledName && "name was uniqued!"); 776 if (D.getDecl()) 777 SetFunctionAttributes(D, F, IsIncompleteFunction); 778 779 // This is the first use or definition of a mangled name. If there is a 780 // deferred decl with this name, remember that we need to emit it at the end 781 // of the file. 782 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 783 if (DDI != DeferredDecls.end()) { 784 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 785 // list, and remove it from DeferredDecls (since we don't need it anymore). 786 DeferredDeclsToEmit.push_back(DDI->second); 787 DeferredDecls.erase(DDI); 788 } else if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl())) { 789 // If this the first reference to a C++ inline function in a class, queue up 790 // the deferred function body for emission. These are not seen as 791 // top-level declarations. 792 if (FD->isThisDeclarationADefinition() && MayDeferGeneration(FD)) 793 DeferredDeclsToEmit.push_back(D); 794 // A called constructor which has no definition or declaration need be 795 // synthesized. 796 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) { 797 if (CD->isImplicit()) { 798 assert(CD->isUsed() && "Sema doesn't consider constructor as used."); 799 DeferredDeclsToEmit.push_back(D); 800 } 801 } else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(FD)) { 802 if (DD->isImplicit()) { 803 assert(DD->isUsed() && "Sema doesn't consider destructor as used."); 804 DeferredDeclsToEmit.push_back(D); 805 } 806 } else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 807 if (MD->isCopyAssignment() && MD->isImplicit()) { 808 assert(MD->isUsed() && "Sema doesn't consider CopyAssignment as used."); 809 DeferredDeclsToEmit.push_back(D); 810 } 811 } 812 } 813 814 return F; 815} 816 817/// GetAddrOfFunction - Return the address of the given function. If Ty is 818/// non-null, then this function will use the specified type if it has to 819/// create it (this occurs when we see a definition of the function). 820llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 821 const llvm::Type *Ty) { 822 // If there was no specific requested type, just convert it now. 823 if (!Ty) 824 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 825 MangleBuffer MangledName; 826 getMangledName(MangledName, GD); 827 return GetOrCreateLLVMFunction(MangledName, Ty, GD); 828} 829 830/// CreateRuntimeFunction - Create a new runtime function with the specified 831/// type and name. 832llvm::Constant * 833CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy, 834 llvm::StringRef Name) { 835 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl()); 836} 837 838static bool DeclIsConstantGlobal(ASTContext &Context, const VarDecl *D) { 839 if (!D->getType().isConstant(Context) && !D->getType()->isReferenceType()) 840 return false; 841 if (Context.getLangOptions().CPlusPlus && 842 Context.getBaseElementType(D->getType())->getAs<RecordType>()) { 843 // FIXME: We should do something fancier here! 844 return false; 845 } 846 return true; 847} 848 849/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 850/// create and return an llvm GlobalVariable with the specified type. If there 851/// is something in the module with the specified name, return it potentially 852/// bitcasted to the right type. 853/// 854/// If D is non-null, it specifies a decl that correspond to this. This is used 855/// to set the attributes on the global when it is first created. 856llvm::Constant * 857CodeGenModule::GetOrCreateLLVMGlobal(llvm::StringRef MangledName, 858 const llvm::PointerType *Ty, 859 const VarDecl *D) { 860 // Lookup the entry, lazily creating it if necessary. 861 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 862 if (Entry) { 863 if (WeakRefReferences.count(Entry)) { 864 if (D && !D->hasAttr<WeakAttr>()) 865 Entry->setLinkage(llvm::Function::ExternalLinkage); 866 867 WeakRefReferences.erase(Entry); 868 } 869 870 if (Entry->getType() == Ty) 871 return Entry; 872 873 // Make sure the result is of the correct type. 874 return llvm::ConstantExpr::getBitCast(Entry, Ty); 875 } 876 877 // This is the first use or definition of a mangled name. If there is a 878 // deferred decl with this name, remember that we need to emit it at the end 879 // of the file. 880 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName); 881 if (DDI != DeferredDecls.end()) { 882 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 883 // list, and remove it from DeferredDecls (since we don't need it anymore). 884 DeferredDeclsToEmit.push_back(DDI->second); 885 DeferredDecls.erase(DDI); 886 } 887 888 llvm::GlobalVariable *GV = 889 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 890 llvm::GlobalValue::ExternalLinkage, 891 0, MangledName, 0, 892 false, Ty->getAddressSpace()); 893 894 // Handle things which are present even on external declarations. 895 if (D) { 896 // FIXME: This code is overly simple and should be merged with other global 897 // handling. 898 GV->setConstant(DeclIsConstantGlobal(Context, D)); 899 900 // FIXME: Merge with other attribute handling code. 901 if (D->getStorageClass() == VarDecl::PrivateExtern) 902 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 903 904 if (D->hasAttr<WeakAttr>() || 905 D->hasAttr<WeakImportAttr>()) 906 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 907 908 GV->setThreadLocal(D->isThreadSpecified()); 909 } 910 911 return GV; 912} 913 914 915/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 916/// given global variable. If Ty is non-null and if the global doesn't exist, 917/// then it will be greated with the specified type instead of whatever the 918/// normal requested type would be. 919llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 920 const llvm::Type *Ty) { 921 assert(D->hasGlobalStorage() && "Not a global variable"); 922 QualType ASTTy = D->getType(); 923 if (Ty == 0) 924 Ty = getTypes().ConvertTypeForMem(ASTTy); 925 926 const llvm::PointerType *PTy = 927 llvm::PointerType::get(Ty, ASTTy.getAddressSpace()); 928 929 MangleBuffer MangledName; 930 getMangledName(MangledName, D); 931 return GetOrCreateLLVMGlobal(MangledName, PTy, D); 932} 933 934/// CreateRuntimeVariable - Create a new runtime global variable with the 935/// specified type and name. 936llvm::Constant * 937CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty, 938 llvm::StringRef Name) { 939 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0); 940} 941 942void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 943 assert(!D->getInit() && "Cannot emit definite definitions here!"); 944 945 if (MayDeferGeneration(D)) { 946 // If we have not seen a reference to this variable yet, place it 947 // into the deferred declarations table to be emitted if needed 948 // later. 949 MangleBuffer MangledName; 950 getMangledName(MangledName, D); 951 if (!GetGlobalValue(MangledName)) { 952 DeferredDecls[MangledName] = D; 953 return; 954 } 955 } 956 957 // The tentative definition is the only definition. 958 EmitGlobalVarDefinition(D); 959} 960 961llvm::GlobalVariable::LinkageTypes 962CodeGenModule::getVtableLinkage(const CXXRecordDecl *RD) { 963 if (RD->isInAnonymousNamespace() || !RD->hasLinkage()) 964 return llvm::GlobalVariable::InternalLinkage; 965 966 if (const CXXMethodDecl *KeyFunction 967 = RD->getASTContext().getKeyFunction(RD)) { 968 // If this class has a key function, use that to determine the linkage of 969 // the vtable. 970 const FunctionDecl *Def = 0; 971 if (KeyFunction->getBody(Def)) 972 KeyFunction = cast<CXXMethodDecl>(Def); 973 974 switch (KeyFunction->getTemplateSpecializationKind()) { 975 case TSK_Undeclared: 976 case TSK_ExplicitSpecialization: 977 if (KeyFunction->isInlined()) 978 return llvm::GlobalVariable::WeakODRLinkage; 979 980 return llvm::GlobalVariable::ExternalLinkage; 981 982 case TSK_ImplicitInstantiation: 983 case TSK_ExplicitInstantiationDefinition: 984 return llvm::GlobalVariable::WeakODRLinkage; 985 986 case TSK_ExplicitInstantiationDeclaration: 987 // FIXME: Use available_externally linkage. However, this currently 988 // breaks LLVM's build due to undefined symbols. 989 // return llvm::GlobalVariable::AvailableExternallyLinkage; 990 return llvm::GlobalVariable::WeakODRLinkage; 991 } 992 } 993 994 switch (RD->getTemplateSpecializationKind()) { 995 case TSK_Undeclared: 996 case TSK_ExplicitSpecialization: 997 case TSK_ImplicitInstantiation: 998 case TSK_ExplicitInstantiationDefinition: 999 return llvm::GlobalVariable::WeakODRLinkage; 1000 1001 case TSK_ExplicitInstantiationDeclaration: 1002 // FIXME: Use available_externally linkage. However, this currently 1003 // breaks LLVM's build due to undefined symbols. 1004 // return llvm::GlobalVariable::AvailableExternallyLinkage; 1005 return llvm::GlobalVariable::WeakODRLinkage; 1006 } 1007 1008 // Silence GCC warning. 1009 return llvm::GlobalVariable::WeakODRLinkage; 1010} 1011 1012static CodeGenModule::GVALinkage 1013GetLinkageForVariable(ASTContext &Context, const VarDecl *VD) { 1014 // If this is a static data member, compute the kind of template 1015 // specialization. Otherwise, this variable is not part of a 1016 // template. 1017 TemplateSpecializationKind TSK = TSK_Undeclared; 1018 if (VD->isStaticDataMember()) 1019 TSK = VD->getTemplateSpecializationKind(); 1020 1021 Linkage L = VD->getLinkage(); 1022 if (L == ExternalLinkage && Context.getLangOptions().CPlusPlus && 1023 VD->getType()->getLinkage() == UniqueExternalLinkage) 1024 L = UniqueExternalLinkage; 1025 1026 switch (L) { 1027 case NoLinkage: 1028 case InternalLinkage: 1029 case UniqueExternalLinkage: 1030 return CodeGenModule::GVA_Internal; 1031 1032 case ExternalLinkage: 1033 switch (TSK) { 1034 case TSK_Undeclared: 1035 case TSK_ExplicitSpecialization: 1036 return CodeGenModule::GVA_StrongExternal; 1037 1038 case TSK_ExplicitInstantiationDeclaration: 1039 llvm_unreachable("Variable should not be instantiated"); 1040 // Fall through to treat this like any other instantiation. 1041 1042 case TSK_ExplicitInstantiationDefinition: 1043 return CodeGenModule::GVA_ExplicitTemplateInstantiation; 1044 1045 case TSK_ImplicitInstantiation: 1046 return CodeGenModule::GVA_TemplateInstantiation; 1047 } 1048 } 1049 1050 return CodeGenModule::GVA_StrongExternal; 1051} 1052 1053CharUnits CodeGenModule::GetTargetTypeStoreSize(const llvm::Type *Ty) const { 1054 return CharUnits::fromQuantity( 1055 TheTargetData.getTypeStoreSizeInBits(Ty) / Context.getCharWidth()); 1056} 1057 1058void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 1059 llvm::Constant *Init = 0; 1060 QualType ASTTy = D->getType(); 1061 bool NonConstInit = false; 1062 1063 const Expr *InitExpr = D->getAnyInitializer(); 1064 1065 if (!InitExpr) { 1066 // This is a tentative definition; tentative definitions are 1067 // implicitly initialized with { 0 }. 1068 // 1069 // Note that tentative definitions are only emitted at the end of 1070 // a translation unit, so they should never have incomplete 1071 // type. In addition, EmitTentativeDefinition makes sure that we 1072 // never attempt to emit a tentative definition if a real one 1073 // exists. A use may still exists, however, so we still may need 1074 // to do a RAUW. 1075 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 1076 Init = EmitNullConstant(D->getType()); 1077 } else { 1078 Init = EmitConstantExpr(InitExpr, D->getType()); 1079 1080 if (!Init) { 1081 QualType T = InitExpr->getType(); 1082 if (getLangOptions().CPlusPlus) { 1083 EmitCXXGlobalVarDeclInitFunc(D); 1084 Init = EmitNullConstant(T); 1085 NonConstInit = true; 1086 } else { 1087 ErrorUnsupported(D, "static initializer"); 1088 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1089 } 1090 } 1091 } 1092 1093 const llvm::Type* InitType = Init->getType(); 1094 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1095 1096 // Strip off a bitcast if we got one back. 1097 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1098 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1099 // all zero index gep. 1100 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1101 Entry = CE->getOperand(0); 1102 } 1103 1104 // Entry is now either a Function or GlobalVariable. 1105 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1106 1107 // We have a definition after a declaration with the wrong type. 1108 // We must make a new GlobalVariable* and update everything that used OldGV 1109 // (a declaration or tentative definition) with the new GlobalVariable* 1110 // (which will be a definition). 1111 // 1112 // This happens if there is a prototype for a global (e.g. 1113 // "extern int x[];") and then a definition of a different type (e.g. 1114 // "int x[10];"). This also happens when an initializer has a different type 1115 // from the type of the global (this happens with unions). 1116 if (GV == 0 || 1117 GV->getType()->getElementType() != InitType || 1118 GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) { 1119 1120 // Move the old entry aside so that we'll create a new one. 1121 Entry->setName(llvm::StringRef()); 1122 1123 // Make a new global with the correct type, this is now guaranteed to work. 1124 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1125 1126 // Replace all uses of the old global with the new global 1127 llvm::Constant *NewPtrForOldDecl = 1128 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1129 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1130 1131 // Erase the old global, since it is no longer used. 1132 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1133 } 1134 1135 if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>()) { 1136 SourceManager &SM = Context.getSourceManager(); 1137 AddAnnotation(EmitAnnotateAttr(GV, AA, 1138 SM.getInstantiationLineNumber(D->getLocation()))); 1139 } 1140 1141 GV->setInitializer(Init); 1142 1143 // If it is safe to mark the global 'constant', do so now. 1144 GV->setConstant(false); 1145 if (!NonConstInit && DeclIsConstantGlobal(Context, D)) 1146 GV->setConstant(true); 1147 1148 GV->setAlignment(getContext().getDeclAlign(D).getQuantity()); 1149 1150 // Set the llvm linkage type as appropriate. 1151 GVALinkage Linkage = GetLinkageForVariable(getContext(), D); 1152 if (Linkage == GVA_Internal) 1153 GV->setLinkage(llvm::Function::InternalLinkage); 1154 else if (D->hasAttr<DLLImportAttr>()) 1155 GV->setLinkage(llvm::Function::DLLImportLinkage); 1156 else if (D->hasAttr<DLLExportAttr>()) 1157 GV->setLinkage(llvm::Function::DLLExportLinkage); 1158 else if (D->hasAttr<WeakAttr>()) { 1159 if (GV->isConstant()) 1160 GV->setLinkage(llvm::GlobalVariable::WeakODRLinkage); 1161 else 1162 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 1163 } else if (Linkage == GVA_TemplateInstantiation || 1164 Linkage == GVA_ExplicitTemplateInstantiation) 1165 // FIXME: It seems like we can provide more specific linkage here 1166 // (LinkOnceODR, WeakODR). 1167 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 1168 else if (!getLangOptions().CPlusPlus && !CodeGenOpts.NoCommon && 1169 !D->hasExternalStorage() && !D->getInit() && 1170 !D->getAttr<SectionAttr>()) { 1171 GV->setLinkage(llvm::GlobalVariable::CommonLinkage); 1172 // common vars aren't constant even if declared const. 1173 GV->setConstant(false); 1174 } else 1175 GV->setLinkage(llvm::GlobalVariable::ExternalLinkage); 1176 1177 SetCommonAttributes(D, GV); 1178 1179 // Emit global variable debug information. 1180 if (CGDebugInfo *DI = getDebugInfo()) { 1181 DI->setLocation(D->getLocation()); 1182 DI->EmitGlobalVariable(GV, D); 1183 } 1184} 1185 1186/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1187/// implement a function with no prototype, e.g. "int foo() {}". If there are 1188/// existing call uses of the old function in the module, this adjusts them to 1189/// call the new function directly. 1190/// 1191/// This is not just a cleanup: the always_inline pass requires direct calls to 1192/// functions to be able to inline them. If there is a bitcast in the way, it 1193/// won't inline them. Instcombine normally deletes these calls, but it isn't 1194/// run at -O0. 1195static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1196 llvm::Function *NewFn) { 1197 // If we're redefining a global as a function, don't transform it. 1198 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1199 if (OldFn == 0) return; 1200 1201 const llvm::Type *NewRetTy = NewFn->getReturnType(); 1202 llvm::SmallVector<llvm::Value*, 4> ArgList; 1203 1204 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1205 UI != E; ) { 1206 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1207 unsigned OpNo = UI.getOperandNo(); 1208 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*UI++); 1209 if (!CI || OpNo != 0) continue; 1210 1211 // If the return types don't match exactly, and if the call isn't dead, then 1212 // we can't transform this call. 1213 if (CI->getType() != NewRetTy && !CI->use_empty()) 1214 continue; 1215 1216 // If the function was passed too few arguments, don't transform. If extra 1217 // arguments were passed, we silently drop them. If any of the types 1218 // mismatch, we don't transform. 1219 unsigned ArgNo = 0; 1220 bool DontTransform = false; 1221 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1222 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1223 if (CI->getNumOperands()-1 == ArgNo || 1224 CI->getOperand(ArgNo+1)->getType() != AI->getType()) { 1225 DontTransform = true; 1226 break; 1227 } 1228 } 1229 if (DontTransform) 1230 continue; 1231 1232 // Okay, we can transform this. Create the new call instruction and copy 1233 // over the required information. 1234 ArgList.append(CI->op_begin()+1, CI->op_begin()+1+ArgNo); 1235 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(), 1236 ArgList.end(), "", CI); 1237 ArgList.clear(); 1238 if (!NewCall->getType()->isVoidTy()) 1239 NewCall->takeName(CI); 1240 NewCall->setAttributes(CI->getAttributes()); 1241 NewCall->setCallingConv(CI->getCallingConv()); 1242 1243 // Finally, remove the old call, replacing any uses with the new one. 1244 if (!CI->use_empty()) 1245 CI->replaceAllUsesWith(NewCall); 1246 1247 // Copy debug location attached to CI. 1248 if (!CI->getDebugLoc().isUnknown()) 1249 NewCall->setDebugLoc(CI->getDebugLoc()); 1250 CI->eraseFromParent(); 1251 } 1252} 1253 1254 1255void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1256 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1257 const llvm::FunctionType *Ty = getTypes().GetFunctionType(GD); 1258 getMangleContext().mangleInitDiscriminator(); 1259 // Get or create the prototype for the function. 1260 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1261 1262 // Strip off a bitcast if we got one back. 1263 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1264 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1265 Entry = CE->getOperand(0); 1266 } 1267 1268 1269 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1270 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1271 1272 // If the types mismatch then we have to rewrite the definition. 1273 assert(OldFn->isDeclaration() && 1274 "Shouldn't replace non-declaration"); 1275 1276 // F is the Function* for the one with the wrong type, we must make a new 1277 // Function* and update everything that used F (a declaration) with the new 1278 // Function* (which will be a definition). 1279 // 1280 // This happens if there is a prototype for a function 1281 // (e.g. "int f()") and then a definition of a different type 1282 // (e.g. "int f(int x)"). Move the old function aside so that it 1283 // doesn't interfere with GetAddrOfFunction. 1284 OldFn->setName(llvm::StringRef()); 1285 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1286 1287 // If this is an implementation of a function without a prototype, try to 1288 // replace any existing uses of the function (which may be calls) with uses 1289 // of the new function 1290 if (D->getType()->isFunctionNoProtoType()) { 1291 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1292 OldFn->removeDeadConstantUsers(); 1293 } 1294 1295 // Replace uses of F with the Function we will endow with a body. 1296 if (!Entry->use_empty()) { 1297 llvm::Constant *NewPtrForOldDecl = 1298 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1299 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1300 } 1301 1302 // Ok, delete the old function now, which is dead. 1303 OldFn->eraseFromParent(); 1304 1305 Entry = NewFn; 1306 } 1307 1308 llvm::Function *Fn = cast<llvm::Function>(Entry); 1309 1310 CodeGenFunction(*this).GenerateCode(D, Fn); 1311 1312 SetFunctionDefinitionAttributes(D, Fn); 1313 SetLLVMFunctionAttributesForDefinition(D, Fn); 1314 1315 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1316 AddGlobalCtor(Fn, CA->getPriority()); 1317 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1318 AddGlobalDtor(Fn, DA->getPriority()); 1319} 1320 1321void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) { 1322 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 1323 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1324 assert(AA && "Not an alias?"); 1325 1326 MangleBuffer MangledName; 1327 getMangledName(MangledName, GD); 1328 1329 // If there is a definition in the module, then it wins over the alias. 1330 // This is dubious, but allow it to be safe. Just ignore the alias. 1331 llvm::GlobalValue *Entry = GetGlobalValue(MangledName); 1332 if (Entry && !Entry->isDeclaration()) 1333 return; 1334 1335 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1336 1337 // Create a reference to the named value. This ensures that it is emitted 1338 // if a deferred decl. 1339 llvm::Constant *Aliasee; 1340 if (isa<llvm::FunctionType>(DeclTy)) 1341 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl()); 1342 else 1343 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(), 1344 llvm::PointerType::getUnqual(DeclTy), 0); 1345 1346 // Create the new alias itself, but don't set a name yet. 1347 llvm::GlobalValue *GA = 1348 new llvm::GlobalAlias(Aliasee->getType(), 1349 llvm::Function::ExternalLinkage, 1350 "", Aliasee, &getModule()); 1351 1352 if (Entry) { 1353 assert(Entry->isDeclaration()); 1354 1355 // If there is a declaration in the module, then we had an extern followed 1356 // by the alias, as in: 1357 // extern int test6(); 1358 // ... 1359 // int test6() __attribute__((alias("test7"))); 1360 // 1361 // Remove it and replace uses of it with the alias. 1362 GA->takeName(Entry); 1363 1364 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1365 Entry->getType())); 1366 Entry->eraseFromParent(); 1367 } else { 1368 GA->setName(MangledName.getString()); 1369 } 1370 1371 // Set attributes which are particular to an alias; this is a 1372 // specialization of the attributes which may be set on a global 1373 // variable/function. 1374 if (D->hasAttr<DLLExportAttr>()) { 1375 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1376 // The dllexport attribute is ignored for undefined symbols. 1377 if (FD->getBody()) 1378 GA->setLinkage(llvm::Function::DLLExportLinkage); 1379 } else { 1380 GA->setLinkage(llvm::Function::DLLExportLinkage); 1381 } 1382 } else if (D->hasAttr<WeakAttr>() || 1383 D->hasAttr<WeakRefAttr>() || 1384 D->hasAttr<WeakImportAttr>()) { 1385 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1386 } 1387 1388 SetCommonAttributes(D, GA); 1389} 1390 1391/// getBuiltinLibFunction - Given a builtin id for a function like 1392/// "__builtin_fabsf", return a Function* for "fabsf". 1393llvm::Value *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD, 1394 unsigned BuiltinID) { 1395 assert((Context.BuiltinInfo.isLibFunction(BuiltinID) || 1396 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) && 1397 "isn't a lib fn"); 1398 1399 // Get the name, skip over the __builtin_ prefix (if necessary). 1400 const char *Name = Context.BuiltinInfo.GetName(BuiltinID); 1401 if (Context.BuiltinInfo.isLibFunction(BuiltinID)) 1402 Name += 10; 1403 1404 const llvm::FunctionType *Ty = 1405 cast<llvm::FunctionType>(getTypes().ConvertType(FD->getType())); 1406 1407 return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl(FD)); 1408} 1409 1410llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys, 1411 unsigned NumTys) { 1412 return llvm::Intrinsic::getDeclaration(&getModule(), 1413 (llvm::Intrinsic::ID)IID, Tys, NumTys); 1414} 1415 1416 1417llvm::Function *CodeGenModule::getMemCpyFn(const llvm::Type *DestType, 1418 const llvm::Type *SrcType, 1419 const llvm::Type *SizeType) { 1420 const llvm::Type *ArgTypes[3] = {DestType, SrcType, SizeType }; 1421 return getIntrinsic(llvm::Intrinsic::memcpy, ArgTypes, 3); 1422} 1423 1424llvm::Function *CodeGenModule::getMemMoveFn(const llvm::Type *DestType, 1425 const llvm::Type *SrcType, 1426 const llvm::Type *SizeType) { 1427 const llvm::Type *ArgTypes[3] = {DestType, SrcType, SizeType }; 1428 return getIntrinsic(llvm::Intrinsic::memmove, ArgTypes, 3); 1429} 1430 1431llvm::Function *CodeGenModule::getMemSetFn(const llvm::Type *DestType, 1432 const llvm::Type *SizeType) { 1433 const llvm::Type *ArgTypes[2] = { DestType, SizeType }; 1434 return getIntrinsic(llvm::Intrinsic::memset, ArgTypes, 2); 1435} 1436 1437static llvm::StringMapEntry<llvm::Constant*> & 1438GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1439 const StringLiteral *Literal, 1440 bool TargetIsLSB, 1441 bool &IsUTF16, 1442 unsigned &StringLength) { 1443 unsigned NumBytes = Literal->getByteLength(); 1444 1445 // Check for simple case. 1446 if (!Literal->containsNonAsciiOrNull()) { 1447 StringLength = NumBytes; 1448 return Map.GetOrCreateValue(llvm::StringRef(Literal->getStrData(), 1449 StringLength)); 1450 } 1451 1452 // Otherwise, convert the UTF8 literals into a byte string. 1453 llvm::SmallVector<UTF16, 128> ToBuf(NumBytes); 1454 const UTF8 *FromPtr = (UTF8 *)Literal->getStrData(); 1455 UTF16 *ToPtr = &ToBuf[0]; 1456 1457 ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 1458 &ToPtr, ToPtr + NumBytes, 1459 strictConversion); 1460 1461 // Check for conversion failure. 1462 if (Result != conversionOK) { 1463 // FIXME: Have Sema::CheckObjCString() validate the UTF-8 string and remove 1464 // this duplicate code. 1465 assert(Result == sourceIllegal && "UTF-8 to UTF-16 conversion failed"); 1466 StringLength = NumBytes; 1467 return Map.GetOrCreateValue(llvm::StringRef(Literal->getStrData(), 1468 StringLength)); 1469 } 1470 1471 // ConvertUTF8toUTF16 returns the length in ToPtr. 1472 StringLength = ToPtr - &ToBuf[0]; 1473 1474 // Render the UTF-16 string into a byte array and convert to the target byte 1475 // order. 1476 // 1477 // FIXME: This isn't something we should need to do here. 1478 llvm::SmallString<128> AsBytes; 1479 AsBytes.reserve(StringLength * 2); 1480 for (unsigned i = 0; i != StringLength; ++i) { 1481 unsigned short Val = ToBuf[i]; 1482 if (TargetIsLSB) { 1483 AsBytes.push_back(Val & 0xFF); 1484 AsBytes.push_back(Val >> 8); 1485 } else { 1486 AsBytes.push_back(Val >> 8); 1487 AsBytes.push_back(Val & 0xFF); 1488 } 1489 } 1490 // Append one extra null character, the second is automatically added by our 1491 // caller. 1492 AsBytes.push_back(0); 1493 1494 IsUTF16 = true; 1495 return Map.GetOrCreateValue(llvm::StringRef(AsBytes.data(), AsBytes.size())); 1496} 1497 1498llvm::Constant * 1499CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 1500 unsigned StringLength = 0; 1501 bool isUTF16 = false; 1502 llvm::StringMapEntry<llvm::Constant*> &Entry = 1503 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1504 getTargetData().isLittleEndian(), 1505 isUTF16, StringLength); 1506 1507 if (llvm::Constant *C = Entry.getValue()) 1508 return C; 1509 1510 llvm::Constant *Zero = 1511 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1512 llvm::Constant *Zeros[] = { Zero, Zero }; 1513 1514 // If we don't already have it, get __CFConstantStringClassReference. 1515 if (!CFConstantStringClassRef) { 1516 const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1517 Ty = llvm::ArrayType::get(Ty, 0); 1518 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1519 "__CFConstantStringClassReference"); 1520 // Decay array -> ptr 1521 CFConstantStringClassRef = 1522 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1523 } 1524 1525 QualType CFTy = getContext().getCFConstantStringType(); 1526 1527 const llvm::StructType *STy = 1528 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1529 1530 std::vector<llvm::Constant*> Fields(4); 1531 1532 // Class pointer. 1533 Fields[0] = CFConstantStringClassRef; 1534 1535 // Flags. 1536 const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1537 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 1538 llvm::ConstantInt::get(Ty, 0x07C8); 1539 1540 // String pointer. 1541 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1542 1543 llvm::GlobalValue::LinkageTypes Linkage; 1544 bool isConstant; 1545 if (isUTF16) { 1546 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1547 Linkage = llvm::GlobalValue::InternalLinkage; 1548 // Note: -fwritable-strings doesn't make unicode CFStrings writable, but 1549 // does make plain ascii ones writable. 1550 isConstant = true; 1551 } else { 1552 Linkage = llvm::GlobalValue::PrivateLinkage; 1553 isConstant = !Features.WritableStrings; 1554 } 1555 1556 llvm::GlobalVariable *GV = 1557 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1558 ".str"); 1559 if (isUTF16) { 1560 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy); 1561 GV->setAlignment(Align.getQuantity()); 1562 } 1563 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1564 1565 // String length. 1566 Ty = getTypes().ConvertType(getContext().LongTy); 1567 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 1568 1569 // The struct. 1570 C = llvm::ConstantStruct::get(STy, Fields); 1571 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1572 llvm::GlobalVariable::PrivateLinkage, C, 1573 "_unnamed_cfstring_"); 1574 if (const char *Sect = getContext().Target.getCFStringSection()) 1575 GV->setSection(Sect); 1576 Entry.setValue(GV); 1577 1578 return GV; 1579} 1580 1581/// GetStringForStringLiteral - Return the appropriate bytes for a 1582/// string literal, properly padded to match the literal type. 1583std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 1584 const char *StrData = E->getStrData(); 1585 unsigned Len = E->getByteLength(); 1586 1587 const ConstantArrayType *CAT = 1588 getContext().getAsConstantArrayType(E->getType()); 1589 assert(CAT && "String isn't pointer or array!"); 1590 1591 // Resize the string to the right size. 1592 std::string Str(StrData, StrData+Len); 1593 uint64_t RealLen = CAT->getSize().getZExtValue(); 1594 1595 if (E->isWide()) 1596 RealLen *= getContext().Target.getWCharWidth()/8; 1597 1598 Str.resize(RealLen, '\0'); 1599 1600 return Str; 1601} 1602 1603/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 1604/// constant array for the given string literal. 1605llvm::Constant * 1606CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 1607 // FIXME: This can be more efficient. 1608 // FIXME: We shouldn't need to bitcast the constant in the wide string case. 1609 llvm::Constant *C = GetAddrOfConstantString(GetStringForStringLiteral(S)); 1610 if (S->isWide()) { 1611 llvm::Type *DestTy = 1612 llvm::PointerType::getUnqual(getTypes().ConvertType(S->getType())); 1613 C = llvm::ConstantExpr::getBitCast(C, DestTy); 1614 } 1615 return C; 1616} 1617 1618/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 1619/// array for the given ObjCEncodeExpr node. 1620llvm::Constant * 1621CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 1622 std::string Str; 1623 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 1624 1625 return GetAddrOfConstantCString(Str); 1626} 1627 1628 1629/// GenerateWritableString -- Creates storage for a string literal. 1630static llvm::Constant *GenerateStringLiteral(const std::string &str, 1631 bool constant, 1632 CodeGenModule &CGM, 1633 const char *GlobalName) { 1634 // Create Constant for this string literal. Don't add a '\0'. 1635 llvm::Constant *C = 1636 llvm::ConstantArray::get(CGM.getLLVMContext(), str, false); 1637 1638 // Create a global variable for this string 1639 return new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 1640 llvm::GlobalValue::PrivateLinkage, 1641 C, GlobalName); 1642} 1643 1644/// GetAddrOfConstantString - Returns a pointer to a character array 1645/// containing the literal. This contents are exactly that of the 1646/// given string, i.e. it will not be null terminated automatically; 1647/// see GetAddrOfConstantCString. Note that whether the result is 1648/// actually a pointer to an LLVM constant depends on 1649/// Feature.WriteableStrings. 1650/// 1651/// The result has pointer to array type. 1652llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str, 1653 const char *GlobalName) { 1654 bool IsConstant = !Features.WritableStrings; 1655 1656 // Get the default prefix if a name wasn't specified. 1657 if (!GlobalName) 1658 GlobalName = ".str"; 1659 1660 // Don't share any string literals if strings aren't constant. 1661 if (!IsConstant) 1662 return GenerateStringLiteral(str, false, *this, GlobalName); 1663 1664 llvm::StringMapEntry<llvm::Constant *> &Entry = 1665 ConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]); 1666 1667 if (Entry.getValue()) 1668 return Entry.getValue(); 1669 1670 // Create a global variable for this. 1671 llvm::Constant *C = GenerateStringLiteral(str, true, *this, GlobalName); 1672 Entry.setValue(C); 1673 return C; 1674} 1675 1676/// GetAddrOfConstantCString - Returns a pointer to a character 1677/// array containing the literal and a terminating '\-' 1678/// character. The result has pointer to array type. 1679llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &str, 1680 const char *GlobalName){ 1681 return GetAddrOfConstantString(str + '\0', GlobalName); 1682} 1683 1684/// EmitObjCPropertyImplementations - Emit information for synthesized 1685/// properties for an implementation. 1686void CodeGenModule::EmitObjCPropertyImplementations(const 1687 ObjCImplementationDecl *D) { 1688 for (ObjCImplementationDecl::propimpl_iterator 1689 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 1690 ObjCPropertyImplDecl *PID = *i; 1691 1692 // Dynamic is just for type-checking. 1693 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 1694 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 1695 1696 // Determine which methods need to be implemented, some may have 1697 // been overridden. Note that ::isSynthesized is not the method 1698 // we want, that just indicates if the decl came from a 1699 // property. What we want to know is if the method is defined in 1700 // this implementation. 1701 if (!D->getInstanceMethod(PD->getGetterName())) 1702 CodeGenFunction(*this).GenerateObjCGetter( 1703 const_cast<ObjCImplementationDecl *>(D), PID); 1704 if (!PD->isReadOnly() && 1705 !D->getInstanceMethod(PD->getSetterName())) 1706 CodeGenFunction(*this).GenerateObjCSetter( 1707 const_cast<ObjCImplementationDecl *>(D), PID); 1708 } 1709 } 1710} 1711 1712/// EmitNamespace - Emit all declarations in a namespace. 1713void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 1714 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 1715 I != E; ++I) 1716 EmitTopLevelDecl(*I); 1717} 1718 1719// EmitLinkageSpec - Emit all declarations in a linkage spec. 1720void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 1721 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 1722 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 1723 ErrorUnsupported(LSD, "linkage spec"); 1724 return; 1725 } 1726 1727 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 1728 I != E; ++I) 1729 EmitTopLevelDecl(*I); 1730} 1731 1732/// EmitTopLevelDecl - Emit code for a single top level declaration. 1733void CodeGenModule::EmitTopLevelDecl(Decl *D) { 1734 // If an error has occurred, stop code generation, but continue 1735 // parsing and semantic analysis (to ensure all warnings and errors 1736 // are emitted). 1737 if (Diags.hasErrorOccurred()) 1738 return; 1739 1740 // Ignore dependent declarations. 1741 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 1742 return; 1743 1744 switch (D->getKind()) { 1745 case Decl::CXXConversion: 1746 case Decl::CXXMethod: 1747 case Decl::Function: 1748 // Skip function templates 1749 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 1750 return; 1751 1752 EmitGlobal(cast<FunctionDecl>(D)); 1753 break; 1754 1755 case Decl::Var: 1756 EmitGlobal(cast<VarDecl>(D)); 1757 break; 1758 1759 // C++ Decls 1760 case Decl::Namespace: 1761 EmitNamespace(cast<NamespaceDecl>(D)); 1762 break; 1763 // No code generation needed. 1764 case Decl::UsingShadow: 1765 case Decl::Using: 1766 case Decl::UsingDirective: 1767 case Decl::ClassTemplate: 1768 case Decl::FunctionTemplate: 1769 case Decl::NamespaceAlias: 1770 break; 1771 case Decl::CXXConstructor: 1772 // Skip function templates 1773 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 1774 return; 1775 1776 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 1777 break; 1778 case Decl::CXXDestructor: 1779 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 1780 break; 1781 1782 case Decl::StaticAssert: 1783 // Nothing to do. 1784 break; 1785 1786 // Objective-C Decls 1787 1788 // Forward declarations, no (immediate) code generation. 1789 case Decl::ObjCClass: 1790 case Decl::ObjCForwardProtocol: 1791 case Decl::ObjCCategory: 1792 case Decl::ObjCInterface: 1793 break; 1794 1795 case Decl::ObjCProtocol: 1796 Runtime->GenerateProtocol(cast<ObjCProtocolDecl>(D)); 1797 break; 1798 1799 case Decl::ObjCCategoryImpl: 1800 // Categories have properties but don't support synthesize so we 1801 // can ignore them here. 1802 Runtime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 1803 break; 1804 1805 case Decl::ObjCImplementation: { 1806 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 1807 EmitObjCPropertyImplementations(OMD); 1808 Runtime->GenerateClass(OMD); 1809 break; 1810 } 1811 case Decl::ObjCMethod: { 1812 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 1813 // If this is not a prototype, emit the body. 1814 if (OMD->getBody()) 1815 CodeGenFunction(*this).GenerateObjCMethod(OMD); 1816 break; 1817 } 1818 case Decl::ObjCCompatibleAlias: 1819 // compatibility-alias is a directive and has no code gen. 1820 break; 1821 1822 case Decl::LinkageSpec: 1823 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 1824 break; 1825 1826 case Decl::FileScopeAsm: { 1827 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 1828 llvm::StringRef AsmString = AD->getAsmString()->getString(); 1829 1830 const std::string &S = getModule().getModuleInlineAsm(); 1831 if (S.empty()) 1832 getModule().setModuleInlineAsm(AsmString); 1833 else 1834 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 1835 break; 1836 } 1837 1838 default: 1839 // Make sure we handled everything we should, every other kind is a 1840 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 1841 // function. Need to recode Decl::Kind to do that easily. 1842 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 1843 } 1844} 1845