CodeGenModule.cpp revision 0d13f6fdbdd6f06e2449b8834dda53334abd399a
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/DeclObjC.h" 24#include "clang/AST/DeclCXX.h" 25#include "clang/AST/RecordLayout.h" 26#include "clang/Basic/Builtins.h" 27#include "clang/Basic/Diagnostic.h" 28#include "clang/Basic/SourceManager.h" 29#include "clang/Basic/TargetInfo.h" 30#include "clang/Basic/ConvertUTF.h" 31#include "llvm/CallingConv.h" 32#include "llvm/Module.h" 33#include "llvm/Intrinsics.h" 34#include "llvm/LLVMContext.h" 35#include "llvm/Target/TargetData.h" 36#include "llvm/Support/ErrorHandling.h" 37using namespace clang; 38using namespace CodeGen; 39 40 41CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO, 42 llvm::Module &M, const llvm::TargetData &TD, 43 Diagnostic &diags) 44 : BlockModule(C, M, TD, Types, *this), Context(C), 45 Features(C.getLangOptions()), CodeGenOpts(CGO), TheModule(M), 46 TheTargetData(TD), TheTargetCodeGenInfo(0), Diags(diags), 47 Types(C, M, TD, getTargetCodeGenInfo().getABIInfo()), 48 MangleCtx(C), VtableInfo(*this), Runtime(0), 49 MemCpyFn(0), MemMoveFn(0), MemSetFn(0), CFConstantStringClassRef(0), 50 VMContext(M.getContext()) { 51 52 if (!Features.ObjC1) 53 Runtime = 0; 54 else if (!Features.NeXTRuntime) 55 Runtime = CreateGNUObjCRuntime(*this); 56 else if (Features.ObjCNonFragileABI) 57 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 58 else 59 Runtime = CreateMacObjCRuntime(*this); 60 61 // If debug info generation is enabled, create the CGDebugInfo object. 62 DebugInfo = CodeGenOpts.DebugInfo ? new CGDebugInfo(*this) : 0; 63} 64 65CodeGenModule::~CodeGenModule() { 66 delete Runtime; 67 delete DebugInfo; 68} 69 70void CodeGenModule::createObjCRuntime() { 71 if (!Features.NeXTRuntime) 72 Runtime = CreateGNUObjCRuntime(*this); 73 else if (Features.ObjCNonFragileABI) 74 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 75 else 76 Runtime = CreateMacObjCRuntime(*this); 77} 78 79void CodeGenModule::Release() { 80 EmitDeferred(); 81 EmitCXXGlobalInitFunc(); 82 if (Runtime) 83 if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction()) 84 AddGlobalCtor(ObjCInitFunction); 85 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 86 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 87 EmitAnnotations(); 88 EmitLLVMUsed(); 89} 90 91/// ErrorUnsupported - Print out an error that codegen doesn't support the 92/// specified stmt yet. 93void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 94 bool OmitOnError) { 95 if (OmitOnError && getDiags().hasErrorOccurred()) 96 return; 97 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 98 "cannot compile this %0 yet"); 99 std::string Msg = Type; 100 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 101 << Msg << S->getSourceRange(); 102} 103 104/// ErrorUnsupported - Print out an error that codegen doesn't support the 105/// specified decl yet. 106void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 107 bool OmitOnError) { 108 if (OmitOnError && getDiags().hasErrorOccurred()) 109 return; 110 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 111 "cannot compile this %0 yet"); 112 std::string Msg = Type; 113 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 114} 115 116LangOptions::VisibilityMode 117CodeGenModule::getDeclVisibilityMode(const Decl *D) const { 118 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 119 if (VD->getStorageClass() == VarDecl::PrivateExtern) 120 return LangOptions::Hidden; 121 122 if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>()) { 123 switch (attr->getVisibility()) { 124 default: assert(0 && "Unknown visibility!"); 125 case VisibilityAttr::DefaultVisibility: 126 return LangOptions::Default; 127 case VisibilityAttr::HiddenVisibility: 128 return LangOptions::Hidden; 129 case VisibilityAttr::ProtectedVisibility: 130 return LangOptions::Protected; 131 } 132 } 133 134 return getLangOptions().getVisibilityMode(); 135} 136 137void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 138 const Decl *D) const { 139 // Internal definitions always have default visibility. 140 if (GV->hasLocalLinkage()) { 141 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 142 return; 143 } 144 145 switch (getDeclVisibilityMode(D)) { 146 default: assert(0 && "Unknown visibility!"); 147 case LangOptions::Default: 148 return GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 149 case LangOptions::Hidden: 150 return GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 151 case LangOptions::Protected: 152 return GV->setVisibility(llvm::GlobalValue::ProtectedVisibility); 153 } 154} 155 156const char *CodeGenModule::getMangledName(const GlobalDecl &GD) { 157 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl()); 158 159 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 160 return getMangledCXXCtorName(D, GD.getCtorType()); 161 if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 162 return getMangledCXXDtorName(D, GD.getDtorType()); 163 164 return getMangledName(ND); 165} 166 167/// \brief Retrieves the mangled name for the given declaration. 168/// 169/// If the given declaration requires a mangled name, returns an 170/// const char* containing the mangled name. Otherwise, returns 171/// the unmangled name. 172/// 173const char *CodeGenModule::getMangledName(const NamedDecl *ND) { 174 if (!getMangleContext().shouldMangleDeclName(ND)) { 175 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl."); 176 return ND->getNameAsCString(); 177 } 178 179 llvm::SmallString<256> Name; 180 getMangleContext().mangleName(ND, Name); 181 Name += '\0'; 182 return UniqueMangledName(Name.begin(), Name.end()); 183} 184 185const char *CodeGenModule::UniqueMangledName(const char *NameStart, 186 const char *NameEnd) { 187 assert(*(NameEnd - 1) == '\0' && "Mangled name must be null terminated!"); 188 189 return MangledNames.GetOrCreateValue(NameStart, NameEnd).getKeyData(); 190} 191 192/// AddGlobalCtor - Add a function to the list that will be called before 193/// main() runs. 194void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 195 // FIXME: Type coercion of void()* types. 196 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 197} 198 199/// AddGlobalDtor - Add a function to the list that will be called 200/// when the module is unloaded. 201void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 202 // FIXME: Type coercion of void()* types. 203 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 204} 205 206void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 207 // Ctor function type is void()*. 208 llvm::FunctionType* CtorFTy = 209 llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), 210 std::vector<const llvm::Type*>(), 211 false); 212 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 213 214 // Get the type of a ctor entry, { i32, void ()* }. 215 llvm::StructType* CtorStructTy = 216 llvm::StructType::get(VMContext, llvm::Type::getInt32Ty(VMContext), 217 llvm::PointerType::getUnqual(CtorFTy), NULL); 218 219 // Construct the constructor and destructor arrays. 220 std::vector<llvm::Constant*> Ctors; 221 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 222 std::vector<llvm::Constant*> S; 223 S.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 224 I->second, false)); 225 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy)); 226 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 227 } 228 229 if (!Ctors.empty()) { 230 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 231 new llvm::GlobalVariable(TheModule, AT, false, 232 llvm::GlobalValue::AppendingLinkage, 233 llvm::ConstantArray::get(AT, Ctors), 234 GlobalName); 235 } 236} 237 238void CodeGenModule::EmitAnnotations() { 239 if (Annotations.empty()) 240 return; 241 242 // Create a new global variable for the ConstantStruct in the Module. 243 llvm::Constant *Array = 244 llvm::ConstantArray::get(llvm::ArrayType::get(Annotations[0]->getType(), 245 Annotations.size()), 246 Annotations); 247 llvm::GlobalValue *gv = 248 new llvm::GlobalVariable(TheModule, Array->getType(), false, 249 llvm::GlobalValue::AppendingLinkage, Array, 250 "llvm.global.annotations"); 251 gv->setSection("llvm.metadata"); 252} 253 254static CodeGenModule::GVALinkage 255GetLinkageForFunction(ASTContext &Context, const FunctionDecl *FD, 256 const LangOptions &Features) { 257 // Everything located semantically within an anonymous namespace is 258 // always internal. 259 if (FD->isInAnonymousNamespace()) 260 return CodeGenModule::GVA_Internal; 261 262 // "static" functions get internal linkage. 263 if (FD->getStorageClass() == FunctionDecl::Static && !isa<CXXMethodDecl>(FD)) 264 return CodeGenModule::GVA_Internal; 265 266 // The kind of external linkage this function will have, if it is not 267 // inline or static. 268 CodeGenModule::GVALinkage External = CodeGenModule::GVA_StrongExternal; 269 if (Context.getLangOptions().CPlusPlus) { 270 TemplateSpecializationKind TSK = FD->getTemplateSpecializationKind(); 271 272 if (TSK == TSK_ExplicitInstantiationDefinition) { 273 // If a function has been explicitly instantiated, then it should 274 // always have strong external linkage. 275 return CodeGenModule::GVA_StrongExternal; 276 } 277 278 if (TSK == TSK_ImplicitInstantiation) 279 External = CodeGenModule::GVA_TemplateInstantiation; 280 } 281 282 if (!FD->isInlined()) 283 return External; 284 285 if (!Features.CPlusPlus || FD->hasAttr<GNUInlineAttr>()) { 286 // GNU or C99 inline semantics. Determine whether this symbol should be 287 // externally visible. 288 if (FD->isInlineDefinitionExternallyVisible()) 289 return External; 290 291 // C99 inline semantics, where the symbol is not externally visible. 292 return CodeGenModule::GVA_C99Inline; 293 } 294 295 // C++0x [temp.explicit]p9: 296 // [ Note: The intent is that an inline function that is the subject of 297 // an explicit instantiation declaration will still be implicitly 298 // instantiated when used so that the body can be considered for 299 // inlining, but that no out-of-line copy of the inline function would be 300 // generated in the translation unit. -- end note ] 301 if (FD->getTemplateSpecializationKind() 302 == TSK_ExplicitInstantiationDeclaration) 303 return CodeGenModule::GVA_C99Inline; 304 305 return CodeGenModule::GVA_CXXInline; 306} 307 308/// SetFunctionDefinitionAttributes - Set attributes for a global. 309/// 310/// FIXME: This is currently only done for aliases and functions, but not for 311/// variables (these details are set in EmitGlobalVarDefinition for variables). 312void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 313 llvm::GlobalValue *GV) { 314 GVALinkage Linkage = GetLinkageForFunction(getContext(), D, Features); 315 316 if (Linkage == GVA_Internal) { 317 GV->setLinkage(llvm::Function::InternalLinkage); 318 } else if (D->hasAttr<DLLExportAttr>()) { 319 GV->setLinkage(llvm::Function::DLLExportLinkage); 320 } else if (D->hasAttr<WeakAttr>()) { 321 GV->setLinkage(llvm::Function::WeakAnyLinkage); 322 } else if (Linkage == GVA_C99Inline) { 323 // In C99 mode, 'inline' functions are guaranteed to have a strong 324 // definition somewhere else, so we can use available_externally linkage. 325 GV->setLinkage(llvm::Function::AvailableExternallyLinkage); 326 } else if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) { 327 // In C++, the compiler has to emit a definition in every translation unit 328 // that references the function. We should use linkonce_odr because 329 // a) if all references in this translation unit are optimized away, we 330 // don't need to codegen it. b) if the function persists, it needs to be 331 // merged with other definitions. c) C++ has the ODR, so we know the 332 // definition is dependable. 333 GV->setLinkage(llvm::Function::LinkOnceODRLinkage); 334 } else { 335 assert(Linkage == GVA_StrongExternal); 336 // Otherwise, we have strong external linkage. 337 GV->setLinkage(llvm::Function::ExternalLinkage); 338 } 339 340 SetCommonAttributes(D, GV); 341} 342 343void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 344 const CGFunctionInfo &Info, 345 llvm::Function *F) { 346 unsigned CallingConv; 347 AttributeListType AttributeList; 348 ConstructAttributeList(Info, D, AttributeList, CallingConv); 349 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 350 AttributeList.size())); 351 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); 352} 353 354void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 355 llvm::Function *F) { 356 if (!Features.Exceptions && !Features.ObjCNonFragileABI) 357 F->addFnAttr(llvm::Attribute::NoUnwind); 358 359 if (D->hasAttr<AlwaysInlineAttr>()) 360 F->addFnAttr(llvm::Attribute::AlwaysInline); 361 362 if (D->hasAttr<NoInlineAttr>()) 363 F->addFnAttr(llvm::Attribute::NoInline); 364 365 if (Features.getStackProtectorMode() == LangOptions::SSPOn) 366 F->addFnAttr(llvm::Attribute::StackProtect); 367 else if (Features.getStackProtectorMode() == LangOptions::SSPReq) 368 F->addFnAttr(llvm::Attribute::StackProtectReq); 369 370 if (const AlignedAttr *AA = D->getAttr<AlignedAttr>()) { 371 unsigned width = Context.Target.getCharWidth(); 372 F->setAlignment(AA->getAlignment() / width); 373 while ((AA = AA->getNext<AlignedAttr>())) 374 F->setAlignment(std::max(F->getAlignment(), AA->getAlignment() / width)); 375 } 376 // C++ ABI requires 2-byte alignment for member functions. 377 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D)) 378 F->setAlignment(2); 379} 380 381void CodeGenModule::SetCommonAttributes(const Decl *D, 382 llvm::GlobalValue *GV) { 383 setGlobalVisibility(GV, D); 384 385 if (D->hasAttr<UsedAttr>()) 386 AddUsedGlobal(GV); 387 388 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 389 GV->setSection(SA->getName()); 390 391 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this); 392} 393 394void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 395 llvm::Function *F, 396 const CGFunctionInfo &FI) { 397 SetLLVMFunctionAttributes(D, FI, F); 398 SetLLVMFunctionAttributesForDefinition(D, F); 399 400 F->setLinkage(llvm::Function::InternalLinkage); 401 402 SetCommonAttributes(D, F); 403} 404 405void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD, 406 llvm::Function *F, 407 bool IsIncompleteFunction) { 408 if (!IsIncompleteFunction) 409 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(FD), F); 410 411 // Only a few attributes are set on declarations; these may later be 412 // overridden by a definition. 413 414 if (FD->hasAttr<DLLImportAttr>()) { 415 F->setLinkage(llvm::Function::DLLImportLinkage); 416 } else if (FD->hasAttr<WeakAttr>() || 417 FD->hasAttr<WeakImportAttr>()) { 418 // "extern_weak" is overloaded in LLVM; we probably should have 419 // separate linkage types for this. 420 F->setLinkage(llvm::Function::ExternalWeakLinkage); 421 } else { 422 F->setLinkage(llvm::Function::ExternalLinkage); 423 } 424 425 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 426 F->setSection(SA->getName()); 427} 428 429void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 430 assert(!GV->isDeclaration() && 431 "Only globals with definition can force usage."); 432 LLVMUsed.push_back(GV); 433} 434 435void CodeGenModule::EmitLLVMUsed() { 436 // Don't create llvm.used if there is no need. 437 if (LLVMUsed.empty()) 438 return; 439 440 const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext); 441 442 // Convert LLVMUsed to what ConstantArray needs. 443 std::vector<llvm::Constant*> UsedArray; 444 UsedArray.resize(LLVMUsed.size()); 445 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 446 UsedArray[i] = 447 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 448 i8PTy); 449 } 450 451 if (UsedArray.empty()) 452 return; 453 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, UsedArray.size()); 454 455 llvm::GlobalVariable *GV = 456 new llvm::GlobalVariable(getModule(), ATy, false, 457 llvm::GlobalValue::AppendingLinkage, 458 llvm::ConstantArray::get(ATy, UsedArray), 459 "llvm.used"); 460 461 GV->setSection("llvm.metadata"); 462} 463 464void CodeGenModule::EmitDeferred() { 465 // Emit code for any potentially referenced deferred decls. Since a 466 // previously unused static decl may become used during the generation of code 467 // for a static function, iterate until no changes are made. 468 while (!DeferredDeclsToEmit.empty()) { 469 GlobalDecl D = DeferredDeclsToEmit.back(); 470 DeferredDeclsToEmit.pop_back(); 471 472 // The mangled name for the decl must have been emitted in GlobalDeclMap. 473 // Look it up to see if it was defined with a stronger definition (e.g. an 474 // extern inline function with a strong function redefinition). If so, 475 // just ignore the deferred decl. 476 llvm::GlobalValue *CGRef = GlobalDeclMap[getMangledName(D)]; 477 assert(CGRef && "Deferred decl wasn't referenced?"); 478 479 if (!CGRef->isDeclaration()) 480 continue; 481 482 // Otherwise, emit the definition and move on to the next one. 483 EmitGlobalDefinition(D); 484 } 485} 486 487/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the 488/// annotation information for a given GlobalValue. The annotation struct is 489/// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the 490/// GlobalValue being annotated. The second field is the constant string 491/// created from the AnnotateAttr's annotation. The third field is a constant 492/// string containing the name of the translation unit. The fourth field is 493/// the line number in the file of the annotated value declaration. 494/// 495/// FIXME: this does not unique the annotation string constants, as llvm-gcc 496/// appears to. 497/// 498llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 499 const AnnotateAttr *AA, 500 unsigned LineNo) { 501 llvm::Module *M = &getModule(); 502 503 // get [N x i8] constants for the annotation string, and the filename string 504 // which are the 2nd and 3rd elements of the global annotation structure. 505 const llvm::Type *SBP = llvm::Type::getInt8PtrTy(VMContext); 506 llvm::Constant *anno = llvm::ConstantArray::get(VMContext, 507 AA->getAnnotation(), true); 508 llvm::Constant *unit = llvm::ConstantArray::get(VMContext, 509 M->getModuleIdentifier(), 510 true); 511 512 // Get the two global values corresponding to the ConstantArrays we just 513 // created to hold the bytes of the strings. 514 llvm::GlobalValue *annoGV = 515 new llvm::GlobalVariable(*M, anno->getType(), false, 516 llvm::GlobalValue::PrivateLinkage, anno, 517 GV->getName()); 518 // translation unit name string, emitted into the llvm.metadata section. 519 llvm::GlobalValue *unitGV = 520 new llvm::GlobalVariable(*M, unit->getType(), false, 521 llvm::GlobalValue::PrivateLinkage, unit, 522 ".str"); 523 524 // Create the ConstantStruct for the global annotation. 525 llvm::Constant *Fields[4] = { 526 llvm::ConstantExpr::getBitCast(GV, SBP), 527 llvm::ConstantExpr::getBitCast(annoGV, SBP), 528 llvm::ConstantExpr::getBitCast(unitGV, SBP), 529 llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), LineNo) 530 }; 531 return llvm::ConstantStruct::get(VMContext, Fields, 4, false); 532} 533 534bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 535 // Never defer when EmitAllDecls is specified or the decl has 536 // attribute used. 537 if (Features.EmitAllDecls || Global->hasAttr<UsedAttr>()) 538 return false; 539 540 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 541 // Constructors and destructors should never be deferred. 542 if (FD->hasAttr<ConstructorAttr>() || 543 FD->hasAttr<DestructorAttr>()) 544 return false; 545 546 // The key function for a class must never be deferred. 547 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Global)) { 548 const CXXRecordDecl *RD = MD->getParent(); 549 if (MD->isOutOfLine() && RD->isDynamicClass()) { 550 const CXXMethodDecl *KeyFunction = getContext().getKeyFunction(RD); 551 if (KeyFunction && 552 KeyFunction->getCanonicalDecl() == MD->getCanonicalDecl()) 553 return false; 554 } 555 } 556 557 GVALinkage Linkage = GetLinkageForFunction(getContext(), FD, Features); 558 559 // static, static inline, always_inline, and extern inline functions can 560 // always be deferred. Normal inline functions can be deferred in C99/C++. 561 if (Linkage == GVA_Internal || Linkage == GVA_C99Inline || 562 Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) 563 return true; 564 return false; 565 } 566 567 const VarDecl *VD = cast<VarDecl>(Global); 568 assert(VD->isFileVarDecl() && "Invalid decl"); 569 570 // We never want to defer structs that have non-trivial constructors or 571 // destructors. 572 573 // FIXME: Handle references. 574 if (const RecordType *RT = VD->getType()->getAs<RecordType>()) { 575 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 576 if (!RD->hasTrivialConstructor() || !RD->hasTrivialDestructor()) 577 return false; 578 } 579 } 580 581 // Static data may be deferred, but out-of-line static data members 582 // cannot be. 583 if (VD->isInAnonymousNamespace()) 584 return true; 585 if (VD->getLinkage() == VarDecl::InternalLinkage) { 586 // Initializer has side effects? 587 if (VD->getInit() && VD->getInit()->HasSideEffects(Context)) 588 return false; 589 return !(VD->isStaticDataMember() && VD->isOutOfLine()); 590 } 591 return false; 592} 593 594void CodeGenModule::EmitGlobal(GlobalDecl GD) { 595 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl()); 596 597 // If this is an alias definition (which otherwise looks like a declaration) 598 // emit it now. 599 if (Global->hasAttr<AliasAttr>()) 600 return EmitAliasDefinition(Global); 601 602 // Ignore declarations, they will be emitted on their first use. 603 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 604 // Forward declarations are emitted lazily on first use. 605 if (!FD->isThisDeclarationADefinition()) 606 return; 607 } else { 608 const VarDecl *VD = cast<VarDecl>(Global); 609 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 610 611 if (getLangOptions().CPlusPlus && !VD->getInit()) { 612 // In C++, if this is marked "extern", defer code generation. 613 if (VD->getStorageClass() == VarDecl::Extern || VD->isExternC()) 614 return; 615 616 // If this is a declaration of an explicit specialization of a static 617 // data member in a class template, don't emit it. 618 if (VD->isStaticDataMember() && 619 VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) 620 return; 621 } 622 623 // In C, if this isn't a definition, defer code generation. 624 if (!getLangOptions().CPlusPlus && !VD->getInit()) 625 return; 626 } 627 628 // Defer code generation when possible if this is a static definition, inline 629 // function etc. These we only want to emit if they are used. 630 if (MayDeferGeneration(Global)) { 631 // If the value has already been used, add it directly to the 632 // DeferredDeclsToEmit list. 633 const char *MangledName = getMangledName(GD); 634 if (GlobalDeclMap.count(MangledName)) 635 DeferredDeclsToEmit.push_back(GD); 636 else { 637 // Otherwise, remember that we saw a deferred decl with this name. The 638 // first use of the mangled name will cause it to move into 639 // DeferredDeclsToEmit. 640 DeferredDecls[MangledName] = GD; 641 } 642 return; 643 } 644 645 // Otherwise emit the definition. 646 EmitGlobalDefinition(GD); 647} 648 649void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 650 const ValueDecl *D = cast<ValueDecl>(GD.getDecl()); 651 652 PrettyStackTraceDecl CrashInfo((ValueDecl *)D, D->getLocation(), 653 Context.getSourceManager(), 654 "Generating code for declaration"); 655 656 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { 657 getVtableInfo().MaybeEmitVtable(GD); 658 if (MD->isVirtual() && MD->isOutOfLine() && 659 (!isa<CXXDestructorDecl>(D) || GD.getDtorType() != Dtor_Base)) { 660 if (isa<CXXDestructorDecl>(D)) { 661 GlobalDecl CanonGD(cast<CXXDestructorDecl>(D->getCanonicalDecl()), 662 GD.getDtorType()); 663 BuildThunksForVirtual(CanonGD); 664 } else { 665 BuildThunksForVirtual(MD->getCanonicalDecl()); 666 } 667 } 668 } 669 670 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 671 EmitCXXConstructor(CD, GD.getCtorType()); 672 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 673 EmitCXXDestructor(DD, GD.getDtorType()); 674 else if (isa<FunctionDecl>(D)) 675 EmitGlobalFunctionDefinition(GD); 676 else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 677 EmitGlobalVarDefinition(VD); 678 else { 679 assert(0 && "Invalid argument to EmitGlobalDefinition()"); 680 } 681} 682 683/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 684/// module, create and return an llvm Function with the specified type. If there 685/// is something in the module with the specified name, return it potentially 686/// bitcasted to the right type. 687/// 688/// If D is non-null, it specifies a decl that correspond to this. This is used 689/// to set the attributes on the function when it is first created. 690llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(const char *MangledName, 691 const llvm::Type *Ty, 692 GlobalDecl D) { 693 // Lookup the entry, lazily creating it if necessary. 694 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 695 if (Entry) { 696 if (Entry->getType()->getElementType() == Ty) 697 return Entry; 698 699 // Make sure the result is of the correct type. 700 const llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 701 return llvm::ConstantExpr::getBitCast(Entry, PTy); 702 } 703 704 // This function doesn't have a complete type (for example, the return 705 // type is an incomplete struct). Use a fake type instead, and make 706 // sure not to try to set attributes. 707 bool IsIncompleteFunction = false; 708 if (!isa<llvm::FunctionType>(Ty)) { 709 Ty = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), 710 std::vector<const llvm::Type*>(), false); 711 IsIncompleteFunction = true; 712 } 713 llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty), 714 llvm::Function::ExternalLinkage, 715 "", &getModule()); 716 F->setName(MangledName); 717 if (D.getDecl()) 718 SetFunctionAttributes(cast<FunctionDecl>(D.getDecl()), F, 719 IsIncompleteFunction); 720 Entry = F; 721 722 // This is the first use or definition of a mangled name. If there is a 723 // deferred decl with this name, remember that we need to emit it at the end 724 // of the file. 725 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 726 DeferredDecls.find(MangledName); 727 if (DDI != DeferredDecls.end()) { 728 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 729 // list, and remove it from DeferredDecls (since we don't need it anymore). 730 DeferredDeclsToEmit.push_back(DDI->second); 731 DeferredDecls.erase(DDI); 732 } else if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl())) { 733 // If this the first reference to a C++ inline function in a class, queue up 734 // the deferred function body for emission. These are not seen as 735 // top-level declarations. 736 if (FD->isThisDeclarationADefinition() && MayDeferGeneration(FD)) 737 DeferredDeclsToEmit.push_back(D); 738 // A called constructor which has no definition or declaration need be 739 // synthesized. 740 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) { 741 if (CD->isImplicit()) 742 DeferredDeclsToEmit.push_back(D); 743 } else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(FD)) { 744 if (DD->isImplicit()) 745 DeferredDeclsToEmit.push_back(D); 746 } else if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 747 if (MD->isCopyAssignment() && MD->isImplicit()) 748 DeferredDeclsToEmit.push_back(D); 749 } 750 } 751 752 return F; 753} 754 755/// GetAddrOfFunction - Return the address of the given function. If Ty is 756/// non-null, then this function will use the specified type if it has to 757/// create it (this occurs when we see a definition of the function). 758llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 759 const llvm::Type *Ty) { 760 // If there was no specific requested type, just convert it now. 761 if (!Ty) 762 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType()); 763 return GetOrCreateLLVMFunction(getMangledName(GD), Ty, GD); 764} 765 766/// CreateRuntimeFunction - Create a new runtime function with the specified 767/// type and name. 768llvm::Constant * 769CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy, 770 const char *Name) { 771 // Convert Name to be a uniqued string from the IdentifierInfo table. 772 Name = getContext().Idents.get(Name).getNameStart(); 773 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl()); 774} 775 776static bool DeclIsConstantGlobal(ASTContext &Context, const VarDecl *D) { 777 if (!D->getType().isConstant(Context)) 778 return false; 779 if (Context.getLangOptions().CPlusPlus && 780 Context.getBaseElementType(D->getType())->getAs<RecordType>()) { 781 // FIXME: We should do something fancier here! 782 return false; 783 } 784 return true; 785} 786 787/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 788/// create and return an llvm GlobalVariable with the specified type. If there 789/// is something in the module with the specified name, return it potentially 790/// bitcasted to the right type. 791/// 792/// If D is non-null, it specifies a decl that correspond to this. This is used 793/// to set the attributes on the global when it is first created. 794llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName, 795 const llvm::PointerType*Ty, 796 const VarDecl *D) { 797 // Lookup the entry, lazily creating it if necessary. 798 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 799 if (Entry) { 800 if (Entry->getType() == Ty) 801 return Entry; 802 803 // Make sure the result is of the correct type. 804 return llvm::ConstantExpr::getBitCast(Entry, Ty); 805 } 806 807 // This is the first use or definition of a mangled name. If there is a 808 // deferred decl with this name, remember that we need to emit it at the end 809 // of the file. 810 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 811 DeferredDecls.find(MangledName); 812 if (DDI != DeferredDecls.end()) { 813 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 814 // list, and remove it from DeferredDecls (since we don't need it anymore). 815 DeferredDeclsToEmit.push_back(DDI->second); 816 DeferredDecls.erase(DDI); 817 } 818 819 llvm::GlobalVariable *GV = 820 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 821 llvm::GlobalValue::ExternalLinkage, 822 0, "", 0, 823 false, Ty->getAddressSpace()); 824 GV->setName(MangledName); 825 826 // Handle things which are present even on external declarations. 827 if (D) { 828 // FIXME: This code is overly simple and should be merged with other global 829 // handling. 830 GV->setConstant(DeclIsConstantGlobal(Context, D)); 831 832 // FIXME: Merge with other attribute handling code. 833 if (D->getStorageClass() == VarDecl::PrivateExtern) 834 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 835 836 if (D->hasAttr<WeakAttr>() || 837 D->hasAttr<WeakImportAttr>()) 838 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 839 840 GV->setThreadLocal(D->isThreadSpecified()); 841 } 842 843 return Entry = GV; 844} 845 846 847/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 848/// given global variable. If Ty is non-null and if the global doesn't exist, 849/// then it will be greated with the specified type instead of whatever the 850/// normal requested type would be. 851llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 852 const llvm::Type *Ty) { 853 assert(D->hasGlobalStorage() && "Not a global variable"); 854 QualType ASTTy = D->getType(); 855 if (Ty == 0) 856 Ty = getTypes().ConvertTypeForMem(ASTTy); 857 858 const llvm::PointerType *PTy = 859 llvm::PointerType::get(Ty, ASTTy.getAddressSpace()); 860 return GetOrCreateLLVMGlobal(getMangledName(D), PTy, D); 861} 862 863/// CreateRuntimeVariable - Create a new runtime global variable with the 864/// specified type and name. 865llvm::Constant * 866CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty, 867 const char *Name) { 868 // Convert Name to be a uniqued string from the IdentifierInfo table. 869 Name = getContext().Idents.get(Name).getNameStart(); 870 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0); 871} 872 873void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 874 assert(!D->getInit() && "Cannot emit definite definitions here!"); 875 876 if (MayDeferGeneration(D)) { 877 // If we have not seen a reference to this variable yet, place it 878 // into the deferred declarations table to be emitted if needed 879 // later. 880 const char *MangledName = getMangledName(D); 881 if (GlobalDeclMap.count(MangledName) == 0) { 882 DeferredDecls[MangledName] = D; 883 return; 884 } 885 } 886 887 // The tentative definition is the only definition. 888 EmitGlobalVarDefinition(D); 889} 890 891llvm::GlobalVariable::LinkageTypes 892CodeGenModule::getVtableLinkage(const CXXRecordDecl *RD) { 893 if (RD->isInAnonymousNamespace() || !RD->hasLinkage()) 894 return llvm::GlobalVariable::InternalLinkage; 895 896 if (const CXXMethodDecl *KeyFunction 897 = RD->getASTContext().getKeyFunction(RD)) { 898 // If this class has a key function, use that to determine the linkage of 899 // the vtable. 900 const FunctionDecl *Def = 0; 901 if (KeyFunction->getBody(Def)) 902 KeyFunction = cast<CXXMethodDecl>(Def); 903 904 switch (KeyFunction->getTemplateSpecializationKind()) { 905 case TSK_Undeclared: 906 case TSK_ExplicitSpecialization: 907 if (KeyFunction->isInlined()) 908 return llvm::GlobalVariable::WeakODRLinkage; 909 910 return llvm::GlobalVariable::ExternalLinkage; 911 912 case TSK_ImplicitInstantiation: 913 case TSK_ExplicitInstantiationDefinition: 914 return llvm::GlobalVariable::WeakODRLinkage; 915 916 case TSK_ExplicitInstantiationDeclaration: 917 // FIXME: Use available_externally linkage. However, this currently 918 // breaks LLVM's build due to undefined symbols. 919 // return llvm::GlobalVariable::AvailableExternallyLinkage; 920 return llvm::GlobalVariable::WeakODRLinkage; 921 } 922 } 923 924 switch (RD->getTemplateSpecializationKind()) { 925 case TSK_Undeclared: 926 case TSK_ExplicitSpecialization: 927 case TSK_ImplicitInstantiation: 928 case TSK_ExplicitInstantiationDefinition: 929 return llvm::GlobalVariable::WeakODRLinkage; 930 931 case TSK_ExplicitInstantiationDeclaration: 932 // FIXME: Use available_externally linkage. However, this currently 933 // breaks LLVM's build due to undefined symbols. 934 // return llvm::GlobalVariable::AvailableExternallyLinkage; 935 return llvm::GlobalVariable::WeakODRLinkage; 936 } 937 938 // Silence GCC warning. 939 return llvm::GlobalVariable::WeakODRLinkage; 940} 941 942static CodeGenModule::GVALinkage 943GetLinkageForVariable(ASTContext &Context, const VarDecl *VD) { 944 // Everything located semantically within an anonymous namespace is 945 // always internal. 946 if (VD->isInAnonymousNamespace()) 947 return CodeGenModule::GVA_Internal; 948 949 // Handle linkage for static data members. 950 if (VD->isStaticDataMember()) { 951 switch (VD->getTemplateSpecializationKind()) { 952 case TSK_Undeclared: 953 case TSK_ExplicitSpecialization: 954 case TSK_ExplicitInstantiationDefinition: 955 return CodeGenModule::GVA_StrongExternal; 956 957 case TSK_ExplicitInstantiationDeclaration: 958 llvm_unreachable("Variable should not be instantiated"); 959 // Fall through to treat this like any other instantiation. 960 961 case TSK_ImplicitInstantiation: 962 return CodeGenModule::GVA_TemplateInstantiation; 963 } 964 } 965 966 if (VD->getLinkage() == VarDecl::InternalLinkage) 967 return CodeGenModule::GVA_Internal; 968 969 return CodeGenModule::GVA_StrongExternal; 970} 971 972void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 973 llvm::Constant *Init = 0; 974 QualType ASTTy = D->getType(); 975 bool NonConstInit = false; 976 977 if (D->getInit() == 0) { 978 // This is a tentative definition; tentative definitions are 979 // implicitly initialized with { 0 }. 980 // 981 // Note that tentative definitions are only emitted at the end of 982 // a translation unit, so they should never have incomplete 983 // type. In addition, EmitTentativeDefinition makes sure that we 984 // never attempt to emit a tentative definition if a real one 985 // exists. A use may still exists, however, so we still may need 986 // to do a RAUW. 987 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 988 Init = EmitNullConstant(D->getType()); 989 } else { 990 Init = EmitConstantExpr(D->getInit(), D->getType()); 991 992 if (!Init) { 993 QualType T = D->getInit()->getType(); 994 if (getLangOptions().CPlusPlus) { 995 EmitCXXGlobalVarDeclInitFunc(D); 996 Init = EmitNullConstant(T); 997 NonConstInit = true; 998 } else { 999 ErrorUnsupported(D, "static initializer"); 1000 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 1001 } 1002 } 1003 } 1004 1005 const llvm::Type* InitType = Init->getType(); 1006 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 1007 1008 // Strip off a bitcast if we got one back. 1009 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1010 assert(CE->getOpcode() == llvm::Instruction::BitCast || 1011 // all zero index gep. 1012 CE->getOpcode() == llvm::Instruction::GetElementPtr); 1013 Entry = CE->getOperand(0); 1014 } 1015 1016 // Entry is now either a Function or GlobalVariable. 1017 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 1018 1019 // We have a definition after a declaration with the wrong type. 1020 // We must make a new GlobalVariable* and update everything that used OldGV 1021 // (a declaration or tentative definition) with the new GlobalVariable* 1022 // (which will be a definition). 1023 // 1024 // This happens if there is a prototype for a global (e.g. 1025 // "extern int x[];") and then a definition of a different type (e.g. 1026 // "int x[10];"). This also happens when an initializer has a different type 1027 // from the type of the global (this happens with unions). 1028 if (GV == 0 || 1029 GV->getType()->getElementType() != InitType || 1030 GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) { 1031 1032 // Remove the old entry from GlobalDeclMap so that we'll create a new one. 1033 GlobalDeclMap.erase(getMangledName(D)); 1034 1035 // Make a new global with the correct type, this is now guaranteed to work. 1036 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 1037 GV->takeName(cast<llvm::GlobalValue>(Entry)); 1038 1039 // Replace all uses of the old global with the new global 1040 llvm::Constant *NewPtrForOldDecl = 1041 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 1042 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1043 1044 // Erase the old global, since it is no longer used. 1045 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 1046 } 1047 1048 if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>()) { 1049 SourceManager &SM = Context.getSourceManager(); 1050 AddAnnotation(EmitAnnotateAttr(GV, AA, 1051 SM.getInstantiationLineNumber(D->getLocation()))); 1052 } 1053 1054 GV->setInitializer(Init); 1055 1056 // If it is safe to mark the global 'constant', do so now. 1057 GV->setConstant(false); 1058 if (!NonConstInit && DeclIsConstantGlobal(Context, D)) 1059 GV->setConstant(true); 1060 1061 GV->setAlignment(getContext().getDeclAlignInBytes(D)); 1062 1063 // Set the llvm linkage type as appropriate. 1064 GVALinkage Linkage = GetLinkageForVariable(getContext(), D); 1065 if (Linkage == GVA_Internal) 1066 GV->setLinkage(llvm::Function::InternalLinkage); 1067 else if (D->hasAttr<DLLImportAttr>()) 1068 GV->setLinkage(llvm::Function::DLLImportLinkage); 1069 else if (D->hasAttr<DLLExportAttr>()) 1070 GV->setLinkage(llvm::Function::DLLExportLinkage); 1071 else if (D->hasAttr<WeakAttr>()) { 1072 if (GV->isConstant()) 1073 GV->setLinkage(llvm::GlobalVariable::WeakODRLinkage); 1074 else 1075 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 1076 } else if (Linkage == GVA_TemplateInstantiation) 1077 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 1078 else if (!getLangOptions().CPlusPlus && !CodeGenOpts.NoCommon && 1079 !D->hasExternalStorage() && !D->getInit() && 1080 !D->getAttr<SectionAttr>()) { 1081 GV->setLinkage(llvm::GlobalVariable::CommonLinkage); 1082 // common vars aren't constant even if declared const. 1083 GV->setConstant(false); 1084 } else 1085 GV->setLinkage(llvm::GlobalVariable::ExternalLinkage); 1086 1087 SetCommonAttributes(D, GV); 1088 1089 // Emit global variable debug information. 1090 if (CGDebugInfo *DI = getDebugInfo()) { 1091 DI->setLocation(D->getLocation()); 1092 DI->EmitGlobalVariable(GV, D); 1093 } 1094} 1095 1096/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 1097/// implement a function with no prototype, e.g. "int foo() {}". If there are 1098/// existing call uses of the old function in the module, this adjusts them to 1099/// call the new function directly. 1100/// 1101/// This is not just a cleanup: the always_inline pass requires direct calls to 1102/// functions to be able to inline them. If there is a bitcast in the way, it 1103/// won't inline them. Instcombine normally deletes these calls, but it isn't 1104/// run at -O0. 1105static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 1106 llvm::Function *NewFn) { 1107 // If we're redefining a global as a function, don't transform it. 1108 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 1109 if (OldFn == 0) return; 1110 1111 const llvm::Type *NewRetTy = NewFn->getReturnType(); 1112 llvm::SmallVector<llvm::Value*, 4> ArgList; 1113 1114 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 1115 UI != E; ) { 1116 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 1117 unsigned OpNo = UI.getOperandNo(); 1118 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*UI++); 1119 if (!CI || OpNo != 0) continue; 1120 1121 // If the return types don't match exactly, and if the call isn't dead, then 1122 // we can't transform this call. 1123 if (CI->getType() != NewRetTy && !CI->use_empty()) 1124 continue; 1125 1126 // If the function was passed too few arguments, don't transform. If extra 1127 // arguments were passed, we silently drop them. If any of the types 1128 // mismatch, we don't transform. 1129 unsigned ArgNo = 0; 1130 bool DontTransform = false; 1131 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 1132 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 1133 if (CI->getNumOperands()-1 == ArgNo || 1134 CI->getOperand(ArgNo+1)->getType() != AI->getType()) { 1135 DontTransform = true; 1136 break; 1137 } 1138 } 1139 if (DontTransform) 1140 continue; 1141 1142 // Okay, we can transform this. Create the new call instruction and copy 1143 // over the required information. 1144 ArgList.append(CI->op_begin()+1, CI->op_begin()+1+ArgNo); 1145 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(), 1146 ArgList.end(), "", CI); 1147 ArgList.clear(); 1148 if (!NewCall->getType()->isVoidTy()) 1149 NewCall->takeName(CI); 1150 NewCall->setAttributes(CI->getAttributes()); 1151 NewCall->setCallingConv(CI->getCallingConv()); 1152 1153 // Finally, remove the old call, replacing any uses with the new one. 1154 if (!CI->use_empty()) 1155 CI->replaceAllUsesWith(NewCall); 1156 1157 // Copy any custom metadata attached with CI. 1158 if (llvm::MDNode *DbgNode = CI->getMetadata("dbg")) 1159 NewCall->setMetadata("dbg", DbgNode); 1160 CI->eraseFromParent(); 1161 } 1162} 1163 1164 1165void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 1166 const llvm::FunctionType *Ty; 1167 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 1168 1169 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { 1170 bool isVariadic = D->getType()->getAs<FunctionProtoType>()->isVariadic(); 1171 1172 Ty = getTypes().GetFunctionType(getTypes().getFunctionInfo(MD), isVariadic); 1173 } else { 1174 Ty = cast<llvm::FunctionType>(getTypes().ConvertType(D->getType())); 1175 1176 // As a special case, make sure that definitions of K&R function 1177 // "type foo()" aren't declared as varargs (which forces the backend 1178 // to do unnecessary work). 1179 if (D->getType()->isFunctionNoProtoType()) { 1180 assert(Ty->isVarArg() && "Didn't lower type as expected"); 1181 // Due to stret, the lowered function could have arguments. 1182 // Just create the same type as was lowered by ConvertType 1183 // but strip off the varargs bit. 1184 std::vector<const llvm::Type*> Args(Ty->param_begin(), Ty->param_end()); 1185 Ty = llvm::FunctionType::get(Ty->getReturnType(), Args, false); 1186 } 1187 } 1188 1189 // Get or create the prototype for the function. 1190 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 1191 1192 // Strip off a bitcast if we got one back. 1193 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 1194 assert(CE->getOpcode() == llvm::Instruction::BitCast); 1195 Entry = CE->getOperand(0); 1196 } 1197 1198 1199 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 1200 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 1201 1202 // If the types mismatch then we have to rewrite the definition. 1203 assert(OldFn->isDeclaration() && 1204 "Shouldn't replace non-declaration"); 1205 1206 // F is the Function* for the one with the wrong type, we must make a new 1207 // Function* and update everything that used F (a declaration) with the new 1208 // Function* (which will be a definition). 1209 // 1210 // This happens if there is a prototype for a function 1211 // (e.g. "int f()") and then a definition of a different type 1212 // (e.g. "int f(int x)"). Start by making a new function of the 1213 // correct type, RAUW, then steal the name. 1214 GlobalDeclMap.erase(getMangledName(D)); 1215 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1216 NewFn->takeName(OldFn); 1217 1218 // If this is an implementation of a function without a prototype, try to 1219 // replace any existing uses of the function (which may be calls) with uses 1220 // of the new function 1221 if (D->getType()->isFunctionNoProtoType()) { 1222 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1223 OldFn->removeDeadConstantUsers(); 1224 } 1225 1226 // Replace uses of F with the Function we will endow with a body. 1227 if (!Entry->use_empty()) { 1228 llvm::Constant *NewPtrForOldDecl = 1229 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1230 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1231 } 1232 1233 // Ok, delete the old function now, which is dead. 1234 OldFn->eraseFromParent(); 1235 1236 Entry = NewFn; 1237 } 1238 1239 llvm::Function *Fn = cast<llvm::Function>(Entry); 1240 1241 CodeGenFunction(*this).GenerateCode(D, Fn); 1242 1243 SetFunctionDefinitionAttributes(D, Fn); 1244 SetLLVMFunctionAttributesForDefinition(D, Fn); 1245 1246 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1247 AddGlobalCtor(Fn, CA->getPriority()); 1248 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1249 AddGlobalDtor(Fn, DA->getPriority()); 1250} 1251 1252void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) { 1253 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1254 assert(AA && "Not an alias?"); 1255 1256 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1257 1258 // Unique the name through the identifier table. 1259 const char *AliaseeName = AA->getAliasee().c_str(); 1260 AliaseeName = getContext().Idents.get(AliaseeName).getNameStart(); 1261 1262 // Create a reference to the named value. This ensures that it is emitted 1263 // if a deferred decl. 1264 llvm::Constant *Aliasee; 1265 if (isa<llvm::FunctionType>(DeclTy)) 1266 Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, GlobalDecl()); 1267 else 1268 Aliasee = GetOrCreateLLVMGlobal(AliaseeName, 1269 llvm::PointerType::getUnqual(DeclTy), 0); 1270 1271 // Create the new alias itself, but don't set a name yet. 1272 llvm::GlobalValue *GA = 1273 new llvm::GlobalAlias(Aliasee->getType(), 1274 llvm::Function::ExternalLinkage, 1275 "", Aliasee, &getModule()); 1276 1277 // See if there is already something with the alias' name in the module. 1278 const char *MangledName = getMangledName(D); 1279 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 1280 1281 if (Entry && !Entry->isDeclaration()) { 1282 // If there is a definition in the module, then it wins over the alias. 1283 // This is dubious, but allow it to be safe. Just ignore the alias. 1284 GA->eraseFromParent(); 1285 return; 1286 } 1287 1288 if (Entry) { 1289 // If there is a declaration in the module, then we had an extern followed 1290 // by the alias, as in: 1291 // extern int test6(); 1292 // ... 1293 // int test6() __attribute__((alias("test7"))); 1294 // 1295 // Remove it and replace uses of it with the alias. 1296 1297 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1298 Entry->getType())); 1299 Entry->eraseFromParent(); 1300 } 1301 1302 // Now we know that there is no conflict, set the name. 1303 Entry = GA; 1304 GA->setName(MangledName); 1305 1306 // Set attributes which are particular to an alias; this is a 1307 // specialization of the attributes which may be set on a global 1308 // variable/function. 1309 if (D->hasAttr<DLLExportAttr>()) { 1310 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1311 // The dllexport attribute is ignored for undefined symbols. 1312 if (FD->getBody()) 1313 GA->setLinkage(llvm::Function::DLLExportLinkage); 1314 } else { 1315 GA->setLinkage(llvm::Function::DLLExportLinkage); 1316 } 1317 } else if (D->hasAttr<WeakAttr>() || 1318 D->hasAttr<WeakImportAttr>()) { 1319 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1320 } 1321 1322 SetCommonAttributes(D, GA); 1323} 1324 1325/// getBuiltinLibFunction - Given a builtin id for a function like 1326/// "__builtin_fabsf", return a Function* for "fabsf". 1327llvm::Value *CodeGenModule::getBuiltinLibFunction(const FunctionDecl *FD, 1328 unsigned BuiltinID) { 1329 assert((Context.BuiltinInfo.isLibFunction(BuiltinID) || 1330 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) && 1331 "isn't a lib fn"); 1332 1333 // Get the name, skip over the __builtin_ prefix (if necessary). 1334 const char *Name = Context.BuiltinInfo.GetName(BuiltinID); 1335 if (Context.BuiltinInfo.isLibFunction(BuiltinID)) 1336 Name += 10; 1337 1338 const llvm::FunctionType *Ty = 1339 cast<llvm::FunctionType>(getTypes().ConvertType(FD->getType())); 1340 1341 // Unique the name through the identifier table. 1342 Name = getContext().Idents.get(Name).getNameStart(); 1343 return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl(FD)); 1344} 1345 1346llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys, 1347 unsigned NumTys) { 1348 return llvm::Intrinsic::getDeclaration(&getModule(), 1349 (llvm::Intrinsic::ID)IID, Tys, NumTys); 1350} 1351 1352llvm::Function *CodeGenModule::getMemCpyFn() { 1353 if (MemCpyFn) return MemCpyFn; 1354 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(VMContext); 1355 return MemCpyFn = getIntrinsic(llvm::Intrinsic::memcpy, &IntPtr, 1); 1356} 1357 1358llvm::Function *CodeGenModule::getMemMoveFn() { 1359 if (MemMoveFn) return MemMoveFn; 1360 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(VMContext); 1361 return MemMoveFn = getIntrinsic(llvm::Intrinsic::memmove, &IntPtr, 1); 1362} 1363 1364llvm::Function *CodeGenModule::getMemSetFn() { 1365 if (MemSetFn) return MemSetFn; 1366 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(VMContext); 1367 return MemSetFn = getIntrinsic(llvm::Intrinsic::memset, &IntPtr, 1); 1368} 1369 1370static llvm::StringMapEntry<llvm::Constant*> & 1371GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map, 1372 const StringLiteral *Literal, 1373 bool TargetIsLSB, 1374 bool &IsUTF16, 1375 unsigned &StringLength) { 1376 unsigned NumBytes = Literal->getByteLength(); 1377 1378 // Check for simple case. 1379 if (!Literal->containsNonAsciiOrNull()) { 1380 StringLength = NumBytes; 1381 return Map.GetOrCreateValue(llvm::StringRef(Literal->getStrData(), 1382 StringLength)); 1383 } 1384 1385 // Otherwise, convert the UTF8 literals into a byte string. 1386 llvm::SmallVector<UTF16, 128> ToBuf(NumBytes); 1387 const UTF8 *FromPtr = (UTF8 *)Literal->getStrData(); 1388 UTF16 *ToPtr = &ToBuf[0]; 1389 1390 ConversionResult Result = ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes, 1391 &ToPtr, ToPtr + NumBytes, 1392 strictConversion); 1393 1394 // Check for conversion failure. 1395 if (Result != conversionOK) { 1396 // FIXME: Have Sema::CheckObjCString() validate the UTF-8 string and remove 1397 // this duplicate code. 1398 assert(Result == sourceIllegal && "UTF-8 to UTF-16 conversion failed"); 1399 StringLength = NumBytes; 1400 return Map.GetOrCreateValue(llvm::StringRef(Literal->getStrData(), 1401 StringLength)); 1402 } 1403 1404 // ConvertUTF8toUTF16 returns the length in ToPtr. 1405 StringLength = ToPtr - &ToBuf[0]; 1406 1407 // Render the UTF-16 string into a byte array and convert to the target byte 1408 // order. 1409 // 1410 // FIXME: This isn't something we should need to do here. 1411 llvm::SmallString<128> AsBytes; 1412 AsBytes.reserve(StringLength * 2); 1413 for (unsigned i = 0; i != StringLength; ++i) { 1414 unsigned short Val = ToBuf[i]; 1415 if (TargetIsLSB) { 1416 AsBytes.push_back(Val & 0xFF); 1417 AsBytes.push_back(Val >> 8); 1418 } else { 1419 AsBytes.push_back(Val >> 8); 1420 AsBytes.push_back(Val & 0xFF); 1421 } 1422 } 1423 // Append one extra null character, the second is automatically added by our 1424 // caller. 1425 AsBytes.push_back(0); 1426 1427 IsUTF16 = true; 1428 return Map.GetOrCreateValue(llvm::StringRef(AsBytes.data(), AsBytes.size())); 1429} 1430 1431llvm::Constant * 1432CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) { 1433 unsigned StringLength = 0; 1434 bool isUTF16 = false; 1435 llvm::StringMapEntry<llvm::Constant*> &Entry = 1436 GetConstantCFStringEntry(CFConstantStringMap, Literal, 1437 getTargetData().isLittleEndian(), 1438 isUTF16, StringLength); 1439 1440 if (llvm::Constant *C = Entry.getValue()) 1441 return C; 1442 1443 llvm::Constant *Zero = 1444 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext)); 1445 llvm::Constant *Zeros[] = { Zero, Zero }; 1446 1447 // If we don't already have it, get __CFConstantStringClassReference. 1448 if (!CFConstantStringClassRef) { 1449 const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1450 Ty = llvm::ArrayType::get(Ty, 0); 1451 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1452 "__CFConstantStringClassReference"); 1453 // Decay array -> ptr 1454 CFConstantStringClassRef = 1455 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1456 } 1457 1458 QualType CFTy = getContext().getCFConstantStringType(); 1459 1460 const llvm::StructType *STy = 1461 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1462 1463 std::vector<llvm::Constant*> Fields(4); 1464 1465 // Class pointer. 1466 Fields[0] = CFConstantStringClassRef; 1467 1468 // Flags. 1469 const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1470 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) : 1471 llvm::ConstantInt::get(Ty, 0x07C8); 1472 1473 // String pointer. 1474 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str()); 1475 1476 const char *Sect = 0; 1477 llvm::GlobalValue::LinkageTypes Linkage; 1478 bool isConstant; 1479 if (isUTF16) { 1480 Sect = getContext().Target.getUnicodeStringSection(); 1481 // FIXME: why do utf strings get "_" labels instead of "L" labels? 1482 Linkage = llvm::GlobalValue::InternalLinkage; 1483 // Note: -fwritable-strings doesn't make unicode CFStrings writable, but 1484 // does make plain ascii ones writable. 1485 isConstant = true; 1486 } else { 1487 Linkage = llvm::GlobalValue::PrivateLinkage; 1488 isConstant = !Features.WritableStrings; 1489 } 1490 1491 llvm::GlobalVariable *GV = 1492 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C, 1493 ".str"); 1494 if (Sect) 1495 GV->setSection(Sect); 1496 if (isUTF16) { 1497 unsigned Align = getContext().getTypeAlign(getContext().ShortTy)/8; 1498 GV->setAlignment(Align); 1499 } 1500 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1501 1502 // String length. 1503 Ty = getTypes().ConvertType(getContext().LongTy); 1504 Fields[3] = llvm::ConstantInt::get(Ty, StringLength); 1505 1506 // The struct. 1507 C = llvm::ConstantStruct::get(STy, Fields); 1508 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1509 llvm::GlobalVariable::PrivateLinkage, C, 1510 "_unnamed_cfstring_"); 1511 if (const char *Sect = getContext().Target.getCFStringSection()) 1512 GV->setSection(Sect); 1513 Entry.setValue(GV); 1514 1515 return GV; 1516} 1517 1518/// GetStringForStringLiteral - Return the appropriate bytes for a 1519/// string literal, properly padded to match the literal type. 1520std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 1521 const char *StrData = E->getStrData(); 1522 unsigned Len = E->getByteLength(); 1523 1524 const ConstantArrayType *CAT = 1525 getContext().getAsConstantArrayType(E->getType()); 1526 assert(CAT && "String isn't pointer or array!"); 1527 1528 // Resize the string to the right size. 1529 std::string Str(StrData, StrData+Len); 1530 uint64_t RealLen = CAT->getSize().getZExtValue(); 1531 1532 if (E->isWide()) 1533 RealLen *= getContext().Target.getWCharWidth()/8; 1534 1535 Str.resize(RealLen, '\0'); 1536 1537 return Str; 1538} 1539 1540/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 1541/// constant array for the given string literal. 1542llvm::Constant * 1543CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 1544 // FIXME: This can be more efficient. 1545 // FIXME: We shouldn't need to bitcast the constant in the wide string case. 1546 llvm::Constant *C = GetAddrOfConstantString(GetStringForStringLiteral(S)); 1547 if (S->isWide()) { 1548 llvm::Type *DestTy = 1549 llvm::PointerType::getUnqual(getTypes().ConvertType(S->getType())); 1550 C = llvm::ConstantExpr::getBitCast(C, DestTy); 1551 } 1552 return C; 1553} 1554 1555/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 1556/// array for the given ObjCEncodeExpr node. 1557llvm::Constant * 1558CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 1559 std::string Str; 1560 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 1561 1562 return GetAddrOfConstantCString(Str); 1563} 1564 1565 1566/// GenerateWritableString -- Creates storage for a string literal. 1567static llvm::Constant *GenerateStringLiteral(const std::string &str, 1568 bool constant, 1569 CodeGenModule &CGM, 1570 const char *GlobalName) { 1571 // Create Constant for this string literal. Don't add a '\0'. 1572 llvm::Constant *C = 1573 llvm::ConstantArray::get(CGM.getLLVMContext(), str, false); 1574 1575 // Create a global variable for this string 1576 return new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 1577 llvm::GlobalValue::PrivateLinkage, 1578 C, GlobalName); 1579} 1580 1581/// GetAddrOfConstantString - Returns a pointer to a character array 1582/// containing the literal. This contents are exactly that of the 1583/// given string, i.e. it will not be null terminated automatically; 1584/// see GetAddrOfConstantCString. Note that whether the result is 1585/// actually a pointer to an LLVM constant depends on 1586/// Feature.WriteableStrings. 1587/// 1588/// The result has pointer to array type. 1589llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str, 1590 const char *GlobalName) { 1591 bool IsConstant = !Features.WritableStrings; 1592 1593 // Get the default prefix if a name wasn't specified. 1594 if (!GlobalName) 1595 GlobalName = ".str"; 1596 1597 // Don't share any string literals if strings aren't constant. 1598 if (!IsConstant) 1599 return GenerateStringLiteral(str, false, *this, GlobalName); 1600 1601 llvm::StringMapEntry<llvm::Constant *> &Entry = 1602 ConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]); 1603 1604 if (Entry.getValue()) 1605 return Entry.getValue(); 1606 1607 // Create a global variable for this. 1608 llvm::Constant *C = GenerateStringLiteral(str, true, *this, GlobalName); 1609 Entry.setValue(C); 1610 return C; 1611} 1612 1613/// GetAddrOfConstantCString - Returns a pointer to a character 1614/// array containing the literal and a terminating '\-' 1615/// character. The result has pointer to array type. 1616llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &str, 1617 const char *GlobalName){ 1618 return GetAddrOfConstantString(str + '\0', GlobalName); 1619} 1620 1621/// EmitObjCPropertyImplementations - Emit information for synthesized 1622/// properties for an implementation. 1623void CodeGenModule::EmitObjCPropertyImplementations(const 1624 ObjCImplementationDecl *D) { 1625 for (ObjCImplementationDecl::propimpl_iterator 1626 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 1627 ObjCPropertyImplDecl *PID = *i; 1628 1629 // Dynamic is just for type-checking. 1630 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 1631 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 1632 1633 // Determine which methods need to be implemented, some may have 1634 // been overridden. Note that ::isSynthesized is not the method 1635 // we want, that just indicates if the decl came from a 1636 // property. What we want to know is if the method is defined in 1637 // this implementation. 1638 if (!D->getInstanceMethod(PD->getGetterName())) 1639 CodeGenFunction(*this).GenerateObjCGetter( 1640 const_cast<ObjCImplementationDecl *>(D), PID); 1641 if (!PD->isReadOnly() && 1642 !D->getInstanceMethod(PD->getSetterName())) 1643 CodeGenFunction(*this).GenerateObjCSetter( 1644 const_cast<ObjCImplementationDecl *>(D), PID); 1645 } 1646 } 1647} 1648 1649/// EmitNamespace - Emit all declarations in a namespace. 1650void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 1651 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 1652 I != E; ++I) 1653 EmitTopLevelDecl(*I); 1654} 1655 1656// EmitLinkageSpec - Emit all declarations in a linkage spec. 1657void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 1658 if (LSD->getLanguage() != LinkageSpecDecl::lang_c && 1659 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) { 1660 ErrorUnsupported(LSD, "linkage spec"); 1661 return; 1662 } 1663 1664 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 1665 I != E; ++I) 1666 EmitTopLevelDecl(*I); 1667} 1668 1669/// EmitTopLevelDecl - Emit code for a single top level declaration. 1670void CodeGenModule::EmitTopLevelDecl(Decl *D) { 1671 // If an error has occurred, stop code generation, but continue 1672 // parsing and semantic analysis (to ensure all warnings and errors 1673 // are emitted). 1674 if (Diags.hasErrorOccurred()) 1675 return; 1676 1677 // Ignore dependent declarations. 1678 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 1679 return; 1680 1681 switch (D->getKind()) { 1682 case Decl::CXXConversion: 1683 case Decl::CXXMethod: 1684 case Decl::Function: 1685 // Skip function templates 1686 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 1687 return; 1688 1689 EmitGlobal(cast<FunctionDecl>(D)); 1690 break; 1691 1692 case Decl::Var: 1693 EmitGlobal(cast<VarDecl>(D)); 1694 break; 1695 1696 // C++ Decls 1697 case Decl::Namespace: 1698 EmitNamespace(cast<NamespaceDecl>(D)); 1699 break; 1700 // No code generation needed. 1701 case Decl::UsingShadow: 1702 case Decl::Using: 1703 case Decl::UsingDirective: 1704 case Decl::ClassTemplate: 1705 case Decl::FunctionTemplate: 1706 case Decl::NamespaceAlias: 1707 break; 1708 case Decl::CXXConstructor: 1709 // Skip function templates 1710 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 1711 return; 1712 1713 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 1714 break; 1715 case Decl::CXXDestructor: 1716 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 1717 break; 1718 1719 case Decl::StaticAssert: 1720 // Nothing to do. 1721 break; 1722 1723 // Objective-C Decls 1724 1725 // Forward declarations, no (immediate) code generation. 1726 case Decl::ObjCClass: 1727 case Decl::ObjCForwardProtocol: 1728 case Decl::ObjCCategory: 1729 case Decl::ObjCInterface: 1730 break; 1731 1732 case Decl::ObjCProtocol: 1733 Runtime->GenerateProtocol(cast<ObjCProtocolDecl>(D)); 1734 break; 1735 1736 case Decl::ObjCCategoryImpl: 1737 // Categories have properties but don't support synthesize so we 1738 // can ignore them here. 1739 Runtime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 1740 break; 1741 1742 case Decl::ObjCImplementation: { 1743 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 1744 EmitObjCPropertyImplementations(OMD); 1745 Runtime->GenerateClass(OMD); 1746 break; 1747 } 1748 case Decl::ObjCMethod: { 1749 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 1750 // If this is not a prototype, emit the body. 1751 if (OMD->getBody()) 1752 CodeGenFunction(*this).GenerateObjCMethod(OMD); 1753 break; 1754 } 1755 case Decl::ObjCCompatibleAlias: 1756 // compatibility-alias is a directive and has no code gen. 1757 break; 1758 1759 case Decl::LinkageSpec: 1760 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 1761 break; 1762 1763 case Decl::FileScopeAsm: { 1764 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 1765 llvm::StringRef AsmString = AD->getAsmString()->getString(); 1766 1767 const std::string &S = getModule().getModuleInlineAsm(); 1768 if (S.empty()) 1769 getModule().setModuleInlineAsm(AsmString); 1770 else 1771 getModule().setModuleInlineAsm(S + '\n' + AsmString.str()); 1772 break; 1773 } 1774 1775 default: 1776 // Make sure we handled everything we should, every other kind is a 1777 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 1778 // function. Need to recode Decl::Kind to do that easily. 1779 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 1780 } 1781} 1782