CodeGenModule.cpp revision 194613
1//===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This coordinates the per-module state used while generating code. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenModule.h" 15#include "CGDebugInfo.h" 16#include "CodeGenFunction.h" 17#include "CGCall.h" 18#include "CGObjCRuntime.h" 19#include "Mangle.h" 20#include "clang/Frontend/CompileOptions.h" 21#include "clang/AST/ASTContext.h" 22#include "clang/AST/DeclObjC.h" 23#include "clang/AST/DeclCXX.h" 24#include "clang/Basic/Builtins.h" 25#include "clang/Basic/Diagnostic.h" 26#include "clang/Basic/SourceManager.h" 27#include "clang/Basic/TargetInfo.h" 28#include "clang/Basic/ConvertUTF.h" 29#include "llvm/CallingConv.h" 30#include "llvm/Module.h" 31#include "llvm/Intrinsics.h" 32#include "llvm/Target/TargetData.h" 33using namespace clang; 34using namespace CodeGen; 35 36 37CodeGenModule::CodeGenModule(ASTContext &C, const CompileOptions &compileOpts, 38 llvm::Module &M, const llvm::TargetData &TD, 39 Diagnostic &diags) 40 : BlockModule(C, M, TD, Types, *this), Context(C), 41 Features(C.getLangOptions()), CompileOpts(compileOpts), TheModule(M), 42 TheTargetData(TD), Diags(diags), Types(C, M, TD), Runtime(0), 43 MemCpyFn(0), MemMoveFn(0), MemSetFn(0), CFConstantStringClassRef(0) { 44 45 if (!Features.ObjC1) 46 Runtime = 0; 47 else if (!Features.NeXTRuntime) 48 Runtime = CreateGNUObjCRuntime(*this); 49 else if (Features.ObjCNonFragileABI) 50 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 51 else 52 Runtime = CreateMacObjCRuntime(*this); 53 54 // If debug info generation is enabled, create the CGDebugInfo object. 55 DebugInfo = CompileOpts.DebugInfo ? new CGDebugInfo(this) : 0; 56} 57 58CodeGenModule::~CodeGenModule() { 59 delete Runtime; 60 delete DebugInfo; 61} 62 63void CodeGenModule::Release() { 64 EmitDeferred(); 65 if (Runtime) 66 if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction()) 67 AddGlobalCtor(ObjCInitFunction); 68 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 69 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 70 EmitAnnotations(); 71 EmitLLVMUsed(); 72} 73 74/// ErrorUnsupported - Print out an error that codegen doesn't support the 75/// specified stmt yet. 76void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 77 bool OmitOnError) { 78 if (OmitOnError && getDiags().hasErrorOccurred()) 79 return; 80 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 81 "cannot compile this %0 yet"); 82 std::string Msg = Type; 83 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 84 << Msg << S->getSourceRange(); 85} 86 87/// ErrorUnsupported - Print out an error that codegen doesn't support the 88/// specified decl yet. 89void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 90 bool OmitOnError) { 91 if (OmitOnError && getDiags().hasErrorOccurred()) 92 return; 93 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 94 "cannot compile this %0 yet"); 95 std::string Msg = Type; 96 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 97} 98 99LangOptions::VisibilityMode 100CodeGenModule::getDeclVisibilityMode(const Decl *D) const { 101 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 102 if (VD->getStorageClass() == VarDecl::PrivateExtern) 103 return LangOptions::Hidden; 104 105 if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>(getContext())) { 106 switch (attr->getVisibility()) { 107 default: assert(0 && "Unknown visibility!"); 108 case VisibilityAttr::DefaultVisibility: 109 return LangOptions::Default; 110 case VisibilityAttr::HiddenVisibility: 111 return LangOptions::Hidden; 112 case VisibilityAttr::ProtectedVisibility: 113 return LangOptions::Protected; 114 } 115 } 116 117 return getLangOptions().getVisibilityMode(); 118} 119 120void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 121 const Decl *D) const { 122 // Internal definitions always have default visibility. 123 if (GV->hasLocalLinkage()) { 124 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 125 return; 126 } 127 128 switch (getDeclVisibilityMode(D)) { 129 default: assert(0 && "Unknown visibility!"); 130 case LangOptions::Default: 131 return GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 132 case LangOptions::Hidden: 133 return GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 134 case LangOptions::Protected: 135 return GV->setVisibility(llvm::GlobalValue::ProtectedVisibility); 136 } 137} 138 139const char *CodeGenModule::getMangledName(const GlobalDecl &GD) { 140 const NamedDecl *ND = GD.getDecl(); 141 142 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 143 return getMangledCXXCtorName(D, GD.getCtorType()); 144 if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 145 return getMangledCXXDtorName(D, GD.getDtorType()); 146 147 return getMangledName(ND); 148} 149 150/// \brief Retrieves the mangled name for the given declaration. 151/// 152/// If the given declaration requires a mangled name, returns an 153/// const char* containing the mangled name. Otherwise, returns 154/// the unmangled name. 155/// 156const char *CodeGenModule::getMangledName(const NamedDecl *ND) { 157 // In C, functions with no attributes never need to be mangled. Fastpath them. 158 if (!getLangOptions().CPlusPlus && !ND->hasAttrs()) { 159 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl."); 160 return ND->getNameAsCString(); 161 } 162 163 llvm::SmallString<256> Name; 164 llvm::raw_svector_ostream Out(Name); 165 if (!mangleName(ND, Context, Out)) { 166 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl."); 167 return ND->getNameAsCString(); 168 } 169 170 Name += '\0'; 171 return UniqueMangledName(Name.begin(), Name.end()); 172} 173 174const char *CodeGenModule::UniqueMangledName(const char *NameStart, 175 const char *NameEnd) { 176 assert(*(NameEnd - 1) == '\0' && "Mangled name must be null terminated!"); 177 178 return MangledNames.GetOrCreateValue(NameStart, NameEnd).getKeyData(); 179} 180 181/// AddGlobalCtor - Add a function to the list that will be called before 182/// main() runs. 183void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 184 // FIXME: Type coercion of void()* types. 185 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 186} 187 188/// AddGlobalDtor - Add a function to the list that will be called 189/// when the module is unloaded. 190void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 191 // FIXME: Type coercion of void()* types. 192 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 193} 194 195void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 196 // Ctor function type is void()*. 197 llvm::FunctionType* CtorFTy = 198 llvm::FunctionType::get(llvm::Type::VoidTy, 199 std::vector<const llvm::Type*>(), 200 false); 201 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 202 203 // Get the type of a ctor entry, { i32, void ()* }. 204 llvm::StructType* CtorStructTy = 205 llvm::StructType::get(llvm::Type::Int32Ty, 206 llvm::PointerType::getUnqual(CtorFTy), NULL); 207 208 // Construct the constructor and destructor arrays. 209 std::vector<llvm::Constant*> Ctors; 210 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 211 std::vector<llvm::Constant*> S; 212 S.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, I->second, false)); 213 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy)); 214 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 215 } 216 217 if (!Ctors.empty()) { 218 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 219 new llvm::GlobalVariable(AT, false, 220 llvm::GlobalValue::AppendingLinkage, 221 llvm::ConstantArray::get(AT, Ctors), 222 GlobalName, 223 &TheModule); 224 } 225} 226 227void CodeGenModule::EmitAnnotations() { 228 if (Annotations.empty()) 229 return; 230 231 // Create a new global variable for the ConstantStruct in the Module. 232 llvm::Constant *Array = 233 llvm::ConstantArray::get(llvm::ArrayType::get(Annotations[0]->getType(), 234 Annotations.size()), 235 Annotations); 236 llvm::GlobalValue *gv = 237 new llvm::GlobalVariable(Array->getType(), false, 238 llvm::GlobalValue::AppendingLinkage, Array, 239 "llvm.global.annotations", &TheModule); 240 gv->setSection("llvm.metadata"); 241} 242 243static CodeGenModule::GVALinkage 244GetLinkageForFunction(ASTContext &Context, const FunctionDecl *FD, 245 const LangOptions &Features) { 246 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 247 // C++ member functions defined inside the class are always inline. 248 if (MD->isInline() || !MD->isOutOfLine()) 249 return CodeGenModule::GVA_CXXInline; 250 251 return CodeGenModule::GVA_StrongExternal; 252 } 253 254 // "static" functions get internal linkage. 255 if (FD->getStorageClass() == FunctionDecl::Static) 256 return CodeGenModule::GVA_Internal; 257 258 if (!FD->isInline()) 259 return CodeGenModule::GVA_StrongExternal; 260 261 // If the inline function explicitly has the GNU inline attribute on it, or if 262 // this is C89 mode, we use to GNU semantics. 263 if (!Features.C99 && !Features.CPlusPlus) { 264 // extern inline in GNU mode is like C99 inline. 265 if (FD->getStorageClass() == FunctionDecl::Extern) 266 return CodeGenModule::GVA_C99Inline; 267 // Normal inline is a strong symbol. 268 return CodeGenModule::GVA_StrongExternal; 269 } else if (FD->hasActiveGNUInlineAttribute(Context)) { 270 // GCC in C99 mode seems to use a different decision-making 271 // process for extern inline, which factors in previous 272 // declarations. 273 if (FD->isExternGNUInline(Context)) 274 return CodeGenModule::GVA_C99Inline; 275 // Normal inline is a strong symbol. 276 return CodeGenModule::GVA_StrongExternal; 277 } 278 279 // The definition of inline changes based on the language. Note that we 280 // have already handled "static inline" above, with the GVA_Internal case. 281 if (Features.CPlusPlus) // inline and extern inline. 282 return CodeGenModule::GVA_CXXInline; 283 284 assert(Features.C99 && "Must be in C99 mode if not in C89 or C++ mode"); 285 if (FD->isC99InlineDefinition()) 286 return CodeGenModule::GVA_C99Inline; 287 288 return CodeGenModule::GVA_StrongExternal; 289} 290 291/// SetFunctionDefinitionAttributes - Set attributes for a global. 292/// 293/// FIXME: This is currently only done for aliases and functions, but not for 294/// variables (these details are set in EmitGlobalVarDefinition for variables). 295void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 296 llvm::GlobalValue *GV) { 297 GVALinkage Linkage = GetLinkageForFunction(getContext(), D, Features); 298 299 if (Linkage == GVA_Internal) { 300 GV->setLinkage(llvm::Function::InternalLinkage); 301 } else if (D->hasAttr<DLLExportAttr>(getContext())) { 302 GV->setLinkage(llvm::Function::DLLExportLinkage); 303 } else if (D->hasAttr<WeakAttr>(getContext())) { 304 GV->setLinkage(llvm::Function::WeakAnyLinkage); 305 } else if (Linkage == GVA_C99Inline) { 306 // In C99 mode, 'inline' functions are guaranteed to have a strong 307 // definition somewhere else, so we can use available_externally linkage. 308 GV->setLinkage(llvm::Function::AvailableExternallyLinkage); 309 } else if (Linkage == GVA_CXXInline) { 310 // In C++, the compiler has to emit a definition in every translation unit 311 // that references the function. We should use linkonce_odr because 312 // a) if all references in this translation unit are optimized away, we 313 // don't need to codegen it. b) if the function persists, it needs to be 314 // merged with other definitions. c) C++ has the ODR, so we know the 315 // definition is dependable. 316 GV->setLinkage(llvm::Function::LinkOnceODRLinkage); 317 } else { 318 assert(Linkage == GVA_StrongExternal); 319 // Otherwise, we have strong external linkage. 320 GV->setLinkage(llvm::Function::ExternalLinkage); 321 } 322 323 SetCommonAttributes(D, GV); 324} 325 326void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 327 const CGFunctionInfo &Info, 328 llvm::Function *F) { 329 AttributeListType AttributeList; 330 ConstructAttributeList(Info, D, AttributeList); 331 332 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 333 AttributeList.size())); 334 335 // Set the appropriate calling convention for the Function. 336 if (D->hasAttr<FastCallAttr>(getContext())) 337 F->setCallingConv(llvm::CallingConv::X86_FastCall); 338 339 if (D->hasAttr<StdCallAttr>(getContext())) 340 F->setCallingConv(llvm::CallingConv::X86_StdCall); 341} 342 343void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 344 llvm::Function *F) { 345 if (!Features.Exceptions && !Features.ObjCNonFragileABI) 346 F->addFnAttr(llvm::Attribute::NoUnwind); 347 348 if (D->hasAttr<AlwaysInlineAttr>(getContext())) 349 F->addFnAttr(llvm::Attribute::AlwaysInline); 350 351 if (D->hasAttr<NoinlineAttr>(getContext())) 352 F->addFnAttr(llvm::Attribute::NoInline); 353} 354 355void CodeGenModule::SetCommonAttributes(const Decl *D, 356 llvm::GlobalValue *GV) { 357 setGlobalVisibility(GV, D); 358 359 if (D->hasAttr<UsedAttr>(getContext())) 360 AddUsedGlobal(GV); 361 362 if (const SectionAttr *SA = D->getAttr<SectionAttr>(getContext())) 363 GV->setSection(SA->getName()); 364} 365 366void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 367 llvm::Function *F, 368 const CGFunctionInfo &FI) { 369 SetLLVMFunctionAttributes(D, FI, F); 370 SetLLVMFunctionAttributesForDefinition(D, F); 371 372 F->setLinkage(llvm::Function::InternalLinkage); 373 374 SetCommonAttributes(D, F); 375} 376 377void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD, 378 llvm::Function *F, 379 bool IsIncompleteFunction) { 380 if (!IsIncompleteFunction) 381 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(FD), F); 382 383 // Only a few attributes are set on declarations; these may later be 384 // overridden by a definition. 385 386 if (FD->hasAttr<DLLImportAttr>(getContext())) { 387 F->setLinkage(llvm::Function::DLLImportLinkage); 388 } else if (FD->hasAttr<WeakAttr>(getContext()) || 389 FD->hasAttr<WeakImportAttr>(getContext())) { 390 // "extern_weak" is overloaded in LLVM; we probably should have 391 // separate linkage types for this. 392 F->setLinkage(llvm::Function::ExternalWeakLinkage); 393 } else { 394 F->setLinkage(llvm::Function::ExternalLinkage); 395 } 396 397 if (const SectionAttr *SA = FD->getAttr<SectionAttr>(getContext())) 398 F->setSection(SA->getName()); 399} 400 401void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 402 assert(!GV->isDeclaration() && 403 "Only globals with definition can force usage."); 404 LLVMUsed.push_back(GV); 405} 406 407void CodeGenModule::EmitLLVMUsed() { 408 // Don't create llvm.used if there is no need. 409 if (LLVMUsed.empty()) 410 return; 411 412 llvm::Type *i8PTy = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); 413 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, LLVMUsed.size()); 414 415 // Convert LLVMUsed to what ConstantArray needs. 416 std::vector<llvm::Constant*> UsedArray; 417 UsedArray.resize(LLVMUsed.size()); 418 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 419 UsedArray[i] = 420 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), i8PTy); 421 } 422 423 llvm::GlobalVariable *GV = 424 new llvm::GlobalVariable(ATy, false, 425 llvm::GlobalValue::AppendingLinkage, 426 llvm::ConstantArray::get(ATy, UsedArray), 427 "llvm.used", &getModule()); 428 429 GV->setSection("llvm.metadata"); 430} 431 432void CodeGenModule::EmitDeferred() { 433 // Emit code for any potentially referenced deferred decls. Since a 434 // previously unused static decl may become used during the generation of code 435 // for a static function, iterate until no changes are made. 436 while (!DeferredDeclsToEmit.empty()) { 437 GlobalDecl D = DeferredDeclsToEmit.back(); 438 DeferredDeclsToEmit.pop_back(); 439 440 // The mangled name for the decl must have been emitted in GlobalDeclMap. 441 // Look it up to see if it was defined with a stronger definition (e.g. an 442 // extern inline function with a strong function redefinition). If so, 443 // just ignore the deferred decl. 444 llvm::GlobalValue *CGRef = GlobalDeclMap[getMangledName(D)]; 445 assert(CGRef && "Deferred decl wasn't referenced?"); 446 447 if (!CGRef->isDeclaration()) 448 continue; 449 450 // Otherwise, emit the definition and move on to the next one. 451 EmitGlobalDefinition(D); 452 } 453} 454 455/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the 456/// annotation information for a given GlobalValue. The annotation struct is 457/// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the 458/// GlobalValue being annotated. The second field is the constant string 459/// created from the AnnotateAttr's annotation. The third field is a constant 460/// string containing the name of the translation unit. The fourth field is 461/// the line number in the file of the annotated value declaration. 462/// 463/// FIXME: this does not unique the annotation string constants, as llvm-gcc 464/// appears to. 465/// 466llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 467 const AnnotateAttr *AA, 468 unsigned LineNo) { 469 llvm::Module *M = &getModule(); 470 471 // get [N x i8] constants for the annotation string, and the filename string 472 // which are the 2nd and 3rd elements of the global annotation structure. 473 const llvm::Type *SBP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); 474 llvm::Constant *anno = llvm::ConstantArray::get(AA->getAnnotation(), true); 475 llvm::Constant *unit = llvm::ConstantArray::get(M->getModuleIdentifier(), 476 true); 477 478 // Get the two global values corresponding to the ConstantArrays we just 479 // created to hold the bytes of the strings. 480 const char *StringPrefix = getContext().Target.getStringSymbolPrefix(true); 481 llvm::GlobalValue *annoGV = 482 new llvm::GlobalVariable(anno->getType(), false, 483 llvm::GlobalValue::InternalLinkage, anno, 484 GV->getName() + StringPrefix, M); 485 // translation unit name string, emitted into the llvm.metadata section. 486 llvm::GlobalValue *unitGV = 487 new llvm::GlobalVariable(unit->getType(), false, 488 llvm::GlobalValue::InternalLinkage, unit, 489 StringPrefix, M); 490 491 // Create the ConstantStruct for the global annotation. 492 llvm::Constant *Fields[4] = { 493 llvm::ConstantExpr::getBitCast(GV, SBP), 494 llvm::ConstantExpr::getBitCast(annoGV, SBP), 495 llvm::ConstantExpr::getBitCast(unitGV, SBP), 496 llvm::ConstantInt::get(llvm::Type::Int32Ty, LineNo) 497 }; 498 return llvm::ConstantStruct::get(Fields, 4, false); 499} 500 501bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 502 // Never defer when EmitAllDecls is specified or the decl has 503 // attribute used. 504 if (Features.EmitAllDecls || Global->hasAttr<UsedAttr>(getContext())) 505 return false; 506 507 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 508 // Constructors and destructors should never be deferred. 509 if (FD->hasAttr<ConstructorAttr>(getContext()) || 510 FD->hasAttr<DestructorAttr>(getContext())) 511 return false; 512 513 GVALinkage Linkage = GetLinkageForFunction(getContext(), FD, Features); 514 515 // static, static inline, always_inline, and extern inline functions can 516 // always be deferred. Normal inline functions can be deferred in C99/C++. 517 if (Linkage == GVA_Internal || Linkage == GVA_C99Inline || 518 Linkage == GVA_CXXInline) 519 return true; 520 return false; 521 } 522 523 const VarDecl *VD = cast<VarDecl>(Global); 524 assert(VD->isFileVarDecl() && "Invalid decl"); 525 526 return VD->getStorageClass() == VarDecl::Static; 527} 528 529void CodeGenModule::EmitGlobal(GlobalDecl GD) { 530 const ValueDecl *Global = GD.getDecl(); 531 532 // If this is an alias definition (which otherwise looks like a declaration) 533 // emit it now. 534 if (Global->hasAttr<AliasAttr>(getContext())) 535 return EmitAliasDefinition(Global); 536 537 // Ignore declarations, they will be emitted on their first use. 538 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 539 // Forward declarations are emitted lazily on first use. 540 if (!FD->isThisDeclarationADefinition()) 541 return; 542 } else { 543 const VarDecl *VD = cast<VarDecl>(Global); 544 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 545 546 // In C++, if this is marked "extern", defer code generation. 547 if (getLangOptions().CPlusPlus && !VD->getInit() && 548 (VD->getStorageClass() == VarDecl::Extern || 549 VD->isExternC(getContext()))) 550 return; 551 552 // In C, if this isn't a definition, defer code generation. 553 if (!getLangOptions().CPlusPlus && !VD->getInit()) 554 return; 555 } 556 557 // Defer code generation when possible if this is a static definition, inline 558 // function etc. These we only want to emit if they are used. 559 if (MayDeferGeneration(Global)) { 560 // If the value has already been used, add it directly to the 561 // DeferredDeclsToEmit list. 562 const char *MangledName = getMangledName(GD); 563 if (GlobalDeclMap.count(MangledName)) 564 DeferredDeclsToEmit.push_back(GD); 565 else { 566 // Otherwise, remember that we saw a deferred decl with this name. The 567 // first use of the mangled name will cause it to move into 568 // DeferredDeclsToEmit. 569 DeferredDecls[MangledName] = GD; 570 } 571 return; 572 } 573 574 // Otherwise emit the definition. 575 EmitGlobalDefinition(GD); 576} 577 578void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 579 const ValueDecl *D = GD.getDecl(); 580 581 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 582 EmitCXXConstructor(CD, GD.getCtorType()); 583 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 584 EmitCXXDestructor(DD, GD.getDtorType()); 585 else if (isa<FunctionDecl>(D)) 586 EmitGlobalFunctionDefinition(GD); 587 else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 588 EmitGlobalVarDefinition(VD); 589 else { 590 assert(0 && "Invalid argument to EmitGlobalDefinition()"); 591 } 592} 593 594/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 595/// module, create and return an llvm Function with the specified type. If there 596/// is something in the module with the specified name, return it potentially 597/// bitcasted to the right type. 598/// 599/// If D is non-null, it specifies a decl that correspond to this. This is used 600/// to set the attributes on the function when it is first created. 601llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(const char *MangledName, 602 const llvm::Type *Ty, 603 GlobalDecl D) { 604 // Lookup the entry, lazily creating it if necessary. 605 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 606 if (Entry) { 607 if (Entry->getType()->getElementType() == Ty) 608 return Entry; 609 610 // Make sure the result is of the correct type. 611 const llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 612 return llvm::ConstantExpr::getBitCast(Entry, PTy); 613 } 614 615 // This is the first use or definition of a mangled name. If there is a 616 // deferred decl with this name, remember that we need to emit it at the end 617 // of the file. 618 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 619 DeferredDecls.find(MangledName); 620 if (DDI != DeferredDecls.end()) { 621 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 622 // list, and remove it from DeferredDecls (since we don't need it anymore). 623 DeferredDeclsToEmit.push_back(DDI->second); 624 DeferredDecls.erase(DDI); 625 } else if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl())) { 626 // If this the first reference to a C++ inline function in a class, queue up 627 // the deferred function body for emission. These are not seen as 628 // top-level declarations. 629 if (FD->isThisDeclarationADefinition() && MayDeferGeneration(FD)) 630 DeferredDeclsToEmit.push_back(D); 631 } 632 633 // This function doesn't have a complete type (for example, the return 634 // type is an incomplete struct). Use a fake type instead, and make 635 // sure not to try to set attributes. 636 bool IsIncompleteFunction = false; 637 if (!isa<llvm::FunctionType>(Ty)) { 638 Ty = llvm::FunctionType::get(llvm::Type::VoidTy, 639 std::vector<const llvm::Type*>(), false); 640 IsIncompleteFunction = true; 641 } 642 llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty), 643 llvm::Function::ExternalLinkage, 644 "", &getModule()); 645 F->setName(MangledName); 646 if (D.getDecl()) 647 SetFunctionAttributes(cast<FunctionDecl>(D.getDecl()), F, 648 IsIncompleteFunction); 649 Entry = F; 650 return F; 651} 652 653/// GetAddrOfFunction - Return the address of the given function. If Ty is 654/// non-null, then this function will use the specified type if it has to 655/// create it (this occurs when we see a definition of the function). 656llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 657 const llvm::Type *Ty) { 658 // If there was no specific requested type, just convert it now. 659 if (!Ty) 660 Ty = getTypes().ConvertType(GD.getDecl()->getType()); 661 return GetOrCreateLLVMFunction(getMangledName(GD.getDecl()), Ty, GD); 662} 663 664/// CreateRuntimeFunction - Create a new runtime function with the specified 665/// type and name. 666llvm::Constant * 667CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy, 668 const char *Name) { 669 // Convert Name to be a uniqued string from the IdentifierInfo table. 670 Name = getContext().Idents.get(Name).getName(); 671 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl()); 672} 673 674/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 675/// create and return an llvm GlobalVariable with the specified type. If there 676/// is something in the module with the specified name, return it potentially 677/// bitcasted to the right type. 678/// 679/// If D is non-null, it specifies a decl that correspond to this. This is used 680/// to set the attributes on the global when it is first created. 681llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName, 682 const llvm::PointerType*Ty, 683 const VarDecl *D) { 684 // Lookup the entry, lazily creating it if necessary. 685 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 686 if (Entry) { 687 if (Entry->getType() == Ty) 688 return Entry; 689 690 // Make sure the result is of the correct type. 691 return llvm::ConstantExpr::getBitCast(Entry, Ty); 692 } 693 694 // This is the first use or definition of a mangled name. If there is a 695 // deferred decl with this name, remember that we need to emit it at the end 696 // of the file. 697 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 698 DeferredDecls.find(MangledName); 699 if (DDI != DeferredDecls.end()) { 700 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 701 // list, and remove it from DeferredDecls (since we don't need it anymore). 702 DeferredDeclsToEmit.push_back(DDI->second); 703 DeferredDecls.erase(DDI); 704 } 705 706 llvm::GlobalVariable *GV = 707 new llvm::GlobalVariable(Ty->getElementType(), false, 708 llvm::GlobalValue::ExternalLinkage, 709 0, "", &getModule(), 710 false, Ty->getAddressSpace()); 711 GV->setName(MangledName); 712 713 // Handle things which are present even on external declarations. 714 if (D) { 715 // FIXME: This code is overly simple and should be merged with other global 716 // handling. 717 GV->setConstant(D->getType().isConstant(Context)); 718 719 // FIXME: Merge with other attribute handling code. 720 if (D->getStorageClass() == VarDecl::PrivateExtern) 721 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 722 723 if (D->hasAttr<WeakAttr>(getContext()) || 724 D->hasAttr<WeakImportAttr>(getContext())) 725 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 726 727 GV->setThreadLocal(D->isThreadSpecified()); 728 } 729 730 return Entry = GV; 731} 732 733 734/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 735/// given global variable. If Ty is non-null and if the global doesn't exist, 736/// then it will be greated with the specified type instead of whatever the 737/// normal requested type would be. 738llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 739 const llvm::Type *Ty) { 740 assert(D->hasGlobalStorage() && "Not a global variable"); 741 QualType ASTTy = D->getType(); 742 if (Ty == 0) 743 Ty = getTypes().ConvertTypeForMem(ASTTy); 744 745 const llvm::PointerType *PTy = 746 llvm::PointerType::get(Ty, ASTTy.getAddressSpace()); 747 return GetOrCreateLLVMGlobal(getMangledName(D), PTy, D); 748} 749 750/// CreateRuntimeVariable - Create a new runtime global variable with the 751/// specified type and name. 752llvm::Constant * 753CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty, 754 const char *Name) { 755 // Convert Name to be a uniqued string from the IdentifierInfo table. 756 Name = getContext().Idents.get(Name).getName(); 757 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0); 758} 759 760void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 761 assert(!D->getInit() && "Cannot emit definite definitions here!"); 762 763 if (MayDeferGeneration(D)) { 764 // If we have not seen a reference to this variable yet, place it 765 // into the deferred declarations table to be emitted if needed 766 // later. 767 const char *MangledName = getMangledName(D); 768 if (GlobalDeclMap.count(MangledName) == 0) { 769 DeferredDecls[MangledName] = GlobalDecl(D); 770 return; 771 } 772 } 773 774 // The tentative definition is the only definition. 775 EmitGlobalVarDefinition(D); 776} 777 778void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 779 llvm::Constant *Init = 0; 780 QualType ASTTy = D->getType(); 781 782 if (D->getInit() == 0) { 783 // This is a tentative definition; tentative definitions are 784 // implicitly initialized with { 0 }. 785 // 786 // Note that tentative definitions are only emitted at the end of 787 // a translation unit, so they should never have incomplete 788 // type. In addition, EmitTentativeDefinition makes sure that we 789 // never attempt to emit a tentative definition if a real one 790 // exists. A use may still exists, however, so we still may need 791 // to do a RAUW. 792 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 793 Init = llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(ASTTy)); 794 } else { 795 Init = EmitConstantExpr(D->getInit(), D->getType()); 796 if (!Init) { 797 ErrorUnsupported(D, "static initializer"); 798 QualType T = D->getInit()->getType(); 799 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 800 } 801 } 802 803 const llvm::Type* InitType = Init->getType(); 804 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 805 806 // Strip off a bitcast if we got one back. 807 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 808 assert(CE->getOpcode() == llvm::Instruction::BitCast); 809 Entry = CE->getOperand(0); 810 } 811 812 // Entry is now either a Function or GlobalVariable. 813 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 814 815 // We have a definition after a declaration with the wrong type. 816 // We must make a new GlobalVariable* and update everything that used OldGV 817 // (a declaration or tentative definition) with the new GlobalVariable* 818 // (which will be a definition). 819 // 820 // This happens if there is a prototype for a global (e.g. 821 // "extern int x[];") and then a definition of a different type (e.g. 822 // "int x[10];"). This also happens when an initializer has a different type 823 // from the type of the global (this happens with unions). 824 if (GV == 0 || 825 GV->getType()->getElementType() != InitType || 826 GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) { 827 828 // Remove the old entry from GlobalDeclMap so that we'll create a new one. 829 GlobalDeclMap.erase(getMangledName(D)); 830 831 // Make a new global with the correct type, this is now guaranteed to work. 832 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 833 GV->takeName(cast<llvm::GlobalValue>(Entry)); 834 835 // Replace all uses of the old global with the new global 836 llvm::Constant *NewPtrForOldDecl = 837 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 838 Entry->replaceAllUsesWith(NewPtrForOldDecl); 839 840 // Erase the old global, since it is no longer used. 841 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 842 } 843 844 if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>(getContext())) { 845 SourceManager &SM = Context.getSourceManager(); 846 AddAnnotation(EmitAnnotateAttr(GV, AA, 847 SM.getInstantiationLineNumber(D->getLocation()))); 848 } 849 850 GV->setInitializer(Init); 851 GV->setConstant(D->getType().isConstant(Context)); 852 GV->setAlignment(getContext().getDeclAlignInBytes(D)); 853 854 // Set the llvm linkage type as appropriate. 855 if (D->getStorageClass() == VarDecl::Static) 856 GV->setLinkage(llvm::Function::InternalLinkage); 857 else if (D->hasAttr<DLLImportAttr>(getContext())) 858 GV->setLinkage(llvm::Function::DLLImportLinkage); 859 else if (D->hasAttr<DLLExportAttr>(getContext())) 860 GV->setLinkage(llvm::Function::DLLExportLinkage); 861 else if (D->hasAttr<WeakAttr>(getContext())) 862 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 863 else if (!CompileOpts.NoCommon && 864 (!D->hasExternalStorage() && !D->getInit())) 865 GV->setLinkage(llvm::GlobalVariable::CommonLinkage); 866 else 867 GV->setLinkage(llvm::GlobalVariable::ExternalLinkage); 868 869 SetCommonAttributes(D, GV); 870 871 // Emit global variable debug information. 872 if (CGDebugInfo *DI = getDebugInfo()) { 873 DI->setLocation(D->getLocation()); 874 DI->EmitGlobalVariable(GV, D); 875 } 876} 877 878/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 879/// implement a function with no prototype, e.g. "int foo() {}". If there are 880/// existing call uses of the old function in the module, this adjusts them to 881/// call the new function directly. 882/// 883/// This is not just a cleanup: the always_inline pass requires direct calls to 884/// functions to be able to inline them. If there is a bitcast in the way, it 885/// won't inline them. Instcombine normally deletes these calls, but it isn't 886/// run at -O0. 887static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 888 llvm::Function *NewFn) { 889 // If we're redefining a global as a function, don't transform it. 890 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 891 if (OldFn == 0) return; 892 893 const llvm::Type *NewRetTy = NewFn->getReturnType(); 894 llvm::SmallVector<llvm::Value*, 4> ArgList; 895 896 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 897 UI != E; ) { 898 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 899 unsigned OpNo = UI.getOperandNo(); 900 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*UI++); 901 if (!CI || OpNo != 0) continue; 902 903 // If the return types don't match exactly, and if the call isn't dead, then 904 // we can't transform this call. 905 if (CI->getType() != NewRetTy && !CI->use_empty()) 906 continue; 907 908 // If the function was passed too few arguments, don't transform. If extra 909 // arguments were passed, we silently drop them. If any of the types 910 // mismatch, we don't transform. 911 unsigned ArgNo = 0; 912 bool DontTransform = false; 913 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 914 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 915 if (CI->getNumOperands()-1 == ArgNo || 916 CI->getOperand(ArgNo+1)->getType() != AI->getType()) { 917 DontTransform = true; 918 break; 919 } 920 } 921 if (DontTransform) 922 continue; 923 924 // Okay, we can transform this. Create the new call instruction and copy 925 // over the required information. 926 ArgList.append(CI->op_begin()+1, CI->op_begin()+1+ArgNo); 927 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(), 928 ArgList.end(), "", CI); 929 ArgList.clear(); 930 if (NewCall->getType() != llvm::Type::VoidTy) 931 NewCall->takeName(CI); 932 NewCall->setCallingConv(CI->getCallingConv()); 933 NewCall->setAttributes(CI->getAttributes()); 934 935 // Finally, remove the old call, replacing any uses with the new one. 936 if (!CI->use_empty()) 937 CI->replaceAllUsesWith(NewCall); 938 CI->eraseFromParent(); 939 } 940} 941 942 943void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 944 const llvm::FunctionType *Ty; 945 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 946 947 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { 948 bool isVariadic = D->getType()->getAsFunctionProtoType()->isVariadic(); 949 950 Ty = getTypes().GetFunctionType(getTypes().getFunctionInfo(MD), isVariadic); 951 } else { 952 Ty = cast<llvm::FunctionType>(getTypes().ConvertType(D->getType())); 953 954 // As a special case, make sure that definitions of K&R function 955 // "type foo()" aren't declared as varargs (which forces the backend 956 // to do unnecessary work). 957 if (D->getType()->isFunctionNoProtoType()) { 958 assert(Ty->isVarArg() && "Didn't lower type as expected"); 959 // Due to stret, the lowered function could have arguments. 960 // Just create the same type as was lowered by ConvertType 961 // but strip off the varargs bit. 962 std::vector<const llvm::Type*> Args(Ty->param_begin(), Ty->param_end()); 963 Ty = llvm::FunctionType::get(Ty->getReturnType(), Args, false); 964 } 965 } 966 967 // Get or create the prototype for the function. 968 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 969 970 // Strip off a bitcast if we got one back. 971 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 972 assert(CE->getOpcode() == llvm::Instruction::BitCast); 973 Entry = CE->getOperand(0); 974 } 975 976 977 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 978 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 979 980 // If the types mismatch then we have to rewrite the definition. 981 assert(OldFn->isDeclaration() && 982 "Shouldn't replace non-declaration"); 983 984 // F is the Function* for the one with the wrong type, we must make a new 985 // Function* and update everything that used F (a declaration) with the new 986 // Function* (which will be a definition). 987 // 988 // This happens if there is a prototype for a function 989 // (e.g. "int f()") and then a definition of a different type 990 // (e.g. "int f(int x)"). Start by making a new function of the 991 // correct type, RAUW, then steal the name. 992 GlobalDeclMap.erase(getMangledName(D)); 993 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 994 NewFn->takeName(OldFn); 995 996 // If this is an implementation of a function without a prototype, try to 997 // replace any existing uses of the function (which may be calls) with uses 998 // of the new function 999 if (D->getType()->isFunctionNoProtoType()) { 1000 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1001 OldFn->removeDeadConstantUsers(); 1002 } 1003 1004 // Replace uses of F with the Function we will endow with a body. 1005 if (!Entry->use_empty()) { 1006 llvm::Constant *NewPtrForOldDecl = 1007 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 1008 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1009 } 1010 1011 // Ok, delete the old function now, which is dead. 1012 OldFn->eraseFromParent(); 1013 1014 Entry = NewFn; 1015 } 1016 1017 llvm::Function *Fn = cast<llvm::Function>(Entry); 1018 1019 CodeGenFunction(*this).GenerateCode(D, Fn); 1020 1021 SetFunctionDefinitionAttributes(D, Fn); 1022 SetLLVMFunctionAttributesForDefinition(D, Fn); 1023 1024 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>(getContext())) 1025 AddGlobalCtor(Fn, CA->getPriority()); 1026 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>(getContext())) 1027 AddGlobalDtor(Fn, DA->getPriority()); 1028} 1029 1030void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) { 1031 const AliasAttr *AA = D->getAttr<AliasAttr>(getContext()); 1032 assert(AA && "Not an alias?"); 1033 1034 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1035 1036 // Unique the name through the identifier table. 1037 const char *AliaseeName = AA->getAliasee().c_str(); 1038 AliaseeName = getContext().Idents.get(AliaseeName).getName(); 1039 1040 // Create a reference to the named value. This ensures that it is emitted 1041 // if a deferred decl. 1042 llvm::Constant *Aliasee; 1043 if (isa<llvm::FunctionType>(DeclTy)) 1044 Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, GlobalDecl()); 1045 else 1046 Aliasee = GetOrCreateLLVMGlobal(AliaseeName, 1047 llvm::PointerType::getUnqual(DeclTy), 0); 1048 1049 // Create the new alias itself, but don't set a name yet. 1050 llvm::GlobalValue *GA = 1051 new llvm::GlobalAlias(Aliasee->getType(), 1052 llvm::Function::ExternalLinkage, 1053 "", Aliasee, &getModule()); 1054 1055 // See if there is already something with the alias' name in the module. 1056 const char *MangledName = getMangledName(D); 1057 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 1058 1059 if (Entry && !Entry->isDeclaration()) { 1060 // If there is a definition in the module, then it wins over the alias. 1061 // This is dubious, but allow it to be safe. Just ignore the alias. 1062 GA->eraseFromParent(); 1063 return; 1064 } 1065 1066 if (Entry) { 1067 // If there is a declaration in the module, then we had an extern followed 1068 // by the alias, as in: 1069 // extern int test6(); 1070 // ... 1071 // int test6() __attribute__((alias("test7"))); 1072 // 1073 // Remove it and replace uses of it with the alias. 1074 1075 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1076 Entry->getType())); 1077 Entry->eraseFromParent(); 1078 } 1079 1080 // Now we know that there is no conflict, set the name. 1081 Entry = GA; 1082 GA->setName(MangledName); 1083 1084 // Set attributes which are particular to an alias; this is a 1085 // specialization of the attributes which may be set on a global 1086 // variable/function. 1087 if (D->hasAttr<DLLExportAttr>(getContext())) { 1088 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1089 // The dllexport attribute is ignored for undefined symbols. 1090 if (FD->getBody(getContext())) 1091 GA->setLinkage(llvm::Function::DLLExportLinkage); 1092 } else { 1093 GA->setLinkage(llvm::Function::DLLExportLinkage); 1094 } 1095 } else if (D->hasAttr<WeakAttr>(getContext()) || 1096 D->hasAttr<WeakImportAttr>(getContext())) { 1097 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1098 } 1099 1100 SetCommonAttributes(D, GA); 1101} 1102 1103/// getBuiltinLibFunction - Given a builtin id for a function like 1104/// "__builtin_fabsf", return a Function* for "fabsf". 1105llvm::Value *CodeGenModule::getBuiltinLibFunction(unsigned BuiltinID) { 1106 assert((Context.BuiltinInfo.isLibFunction(BuiltinID) || 1107 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) && 1108 "isn't a lib fn"); 1109 1110 // Get the name, skip over the __builtin_ prefix (if necessary). 1111 const char *Name = Context.BuiltinInfo.GetName(BuiltinID); 1112 if (Context.BuiltinInfo.isLibFunction(BuiltinID)) 1113 Name += 10; 1114 1115 // Get the type for the builtin. 1116 ASTContext::GetBuiltinTypeError Error; 1117 QualType Type = Context.GetBuiltinType(BuiltinID, Error); 1118 assert(Error == ASTContext::GE_None && "Can't get builtin type"); 1119 1120 const llvm::FunctionType *Ty = 1121 cast<llvm::FunctionType>(getTypes().ConvertType(Type)); 1122 1123 // Unique the name through the identifier table. 1124 Name = getContext().Idents.get(Name).getName(); 1125 // FIXME: param attributes for sext/zext etc. 1126 return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl()); 1127} 1128 1129llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys, 1130 unsigned NumTys) { 1131 return llvm::Intrinsic::getDeclaration(&getModule(), 1132 (llvm::Intrinsic::ID)IID, Tys, NumTys); 1133} 1134 1135llvm::Function *CodeGenModule::getMemCpyFn() { 1136 if (MemCpyFn) return MemCpyFn; 1137 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(); 1138 return MemCpyFn = getIntrinsic(llvm::Intrinsic::memcpy, &IntPtr, 1); 1139} 1140 1141llvm::Function *CodeGenModule::getMemMoveFn() { 1142 if (MemMoveFn) return MemMoveFn; 1143 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(); 1144 return MemMoveFn = getIntrinsic(llvm::Intrinsic::memmove, &IntPtr, 1); 1145} 1146 1147llvm::Function *CodeGenModule::getMemSetFn() { 1148 if (MemSetFn) return MemSetFn; 1149 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(); 1150 return MemSetFn = getIntrinsic(llvm::Intrinsic::memset, &IntPtr, 1); 1151} 1152 1153static void appendFieldAndPadding(CodeGenModule &CGM, 1154 std::vector<llvm::Constant*>& Fields, 1155 FieldDecl *FieldD, FieldDecl *NextFieldD, 1156 llvm::Constant* Field, 1157 RecordDecl* RD, const llvm::StructType *STy) { 1158 // Append the field. 1159 Fields.push_back(Field); 1160 1161 int StructFieldNo = CGM.getTypes().getLLVMFieldNo(FieldD); 1162 1163 int NextStructFieldNo; 1164 if (!NextFieldD) { 1165 NextStructFieldNo = STy->getNumElements(); 1166 } else { 1167 NextStructFieldNo = CGM.getTypes().getLLVMFieldNo(NextFieldD); 1168 } 1169 1170 // Append padding 1171 for (int i = StructFieldNo + 1; i < NextStructFieldNo; i++) { 1172 llvm::Constant *C = 1173 llvm::Constant::getNullValue(STy->getElementType(StructFieldNo + 1)); 1174 1175 Fields.push_back(C); 1176 } 1177} 1178 1179llvm::Constant *CodeGenModule:: 1180GetAddrOfConstantCFString(const StringLiteral *Literal) { 1181 std::string str; 1182 unsigned StringLength = 0; 1183 1184 bool isUTF16 = false; 1185 if (Literal->containsNonAsciiOrNull()) { 1186 // Convert from UTF-8 to UTF-16. 1187 llvm::SmallVector<UTF16, 128> ToBuf(Literal->getByteLength()); 1188 const UTF8 *FromPtr = (UTF8 *)Literal->getStrData(); 1189 UTF16 *ToPtr = &ToBuf[0]; 1190 1191 ConversionResult Result; 1192 Result = ConvertUTF8toUTF16(&FromPtr, FromPtr+Literal->getByteLength(), 1193 &ToPtr, ToPtr+Literal->getByteLength(), 1194 strictConversion); 1195 if (Result == conversionOK) { 1196 // FIXME: Storing UTF-16 in a C string is a hack to test Unicode strings 1197 // without doing more surgery to this routine. Since we aren't explicitly 1198 // checking for endianness here, it's also a bug (when generating code for 1199 // a target that doesn't match the host endianness). Modeling this as an 1200 // i16 array is likely the cleanest solution. 1201 StringLength = ToPtr-&ToBuf[0]; 1202 str.assign((char *)&ToBuf[0], StringLength*2);// Twice as many UTF8 chars. 1203 isUTF16 = true; 1204 } else if (Result == sourceIllegal) { 1205 // FIXME: Have Sema::CheckObjCString() validate the UTF-8 string. 1206 str.assign(Literal->getStrData(), Literal->getByteLength()); 1207 StringLength = str.length(); 1208 } else 1209 assert(Result == conversionOK && "UTF-8 to UTF-16 conversion failed"); 1210 1211 } else { 1212 str.assign(Literal->getStrData(), Literal->getByteLength()); 1213 StringLength = str.length(); 1214 } 1215 llvm::StringMapEntry<llvm::Constant *> &Entry = 1216 CFConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]); 1217 1218 if (llvm::Constant *C = Entry.getValue()) 1219 return C; 1220 1221 llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty); 1222 llvm::Constant *Zeros[] = { Zero, Zero }; 1223 1224 if (!CFConstantStringClassRef) { 1225 const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1226 Ty = llvm::ArrayType::get(Ty, 0); 1227 1228 // FIXME: This is fairly broken if __CFConstantStringClassReference is 1229 // already defined, in that it will get renamed and the user will most 1230 // likely see an opaque error message. This is a general issue with relying 1231 // on particular names. 1232 llvm::GlobalVariable *GV = 1233 new llvm::GlobalVariable(Ty, false, 1234 llvm::GlobalVariable::ExternalLinkage, 0, 1235 "__CFConstantStringClassReference", 1236 &getModule()); 1237 1238 // Decay array -> ptr 1239 CFConstantStringClassRef = 1240 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1241 } 1242 1243 QualType CFTy = getContext().getCFConstantStringType(); 1244 RecordDecl *CFRD = CFTy->getAsRecordType()->getDecl(); 1245 1246 const llvm::StructType *STy = 1247 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1248 1249 std::vector<llvm::Constant*> Fields; 1250 RecordDecl::field_iterator Field = CFRD->field_begin(getContext()); 1251 1252 // Class pointer. 1253 FieldDecl *CurField = *Field++; 1254 FieldDecl *NextField = *Field++; 1255 appendFieldAndPadding(*this, Fields, CurField, NextField, 1256 CFConstantStringClassRef, CFRD, STy); 1257 1258 // Flags. 1259 CurField = NextField; 1260 NextField = *Field++; 1261 const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1262 appendFieldAndPadding(*this, Fields, CurField, NextField, 1263 isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) 1264 : llvm::ConstantInt::get(Ty, 0x07C8), 1265 CFRD, STy); 1266 1267 // String pointer. 1268 CurField = NextField; 1269 NextField = *Field++; 1270 llvm::Constant *C = llvm::ConstantArray::get(str); 1271 1272 const char *Sect, *Prefix; 1273 bool isConstant; 1274 if (isUTF16) { 1275 Prefix = getContext().Target.getUnicodeStringSymbolPrefix(); 1276 Sect = getContext().Target.getUnicodeStringSection(); 1277 // FIXME: Why does GCC not set constant here? 1278 isConstant = false; 1279 } else { 1280 Prefix = getContext().Target.getStringSymbolPrefix(true); 1281 Sect = getContext().Target.getCFStringDataSection(); 1282 // FIXME: -fwritable-strings should probably affect this, but we 1283 // are following gcc here. 1284 isConstant = true; 1285 } 1286 llvm::GlobalVariable *GV = 1287 new llvm::GlobalVariable(C->getType(), isConstant, 1288 llvm::GlobalValue::InternalLinkage, 1289 C, Prefix, &getModule()); 1290 if (Sect) 1291 GV->setSection(Sect); 1292 if (isUTF16) { 1293 unsigned Align = getContext().getTypeAlign(getContext().ShortTy)/8; 1294 GV->setAlignment(Align); 1295 } 1296 appendFieldAndPadding(*this, Fields, CurField, NextField, 1297 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2), 1298 CFRD, STy); 1299 1300 // String length. 1301 CurField = NextField; 1302 NextField = 0; 1303 Ty = getTypes().ConvertType(getContext().LongTy); 1304 appendFieldAndPadding(*this, Fields, CurField, NextField, 1305 llvm::ConstantInt::get(Ty, StringLength), CFRD, STy); 1306 1307 // The struct. 1308 C = llvm::ConstantStruct::get(STy, Fields); 1309 GV = new llvm::GlobalVariable(C->getType(), true, 1310 llvm::GlobalVariable::InternalLinkage, C, 1311 getContext().Target.getCFStringSymbolPrefix(), 1312 &getModule()); 1313 if (const char *Sect = getContext().Target.getCFStringSection()) 1314 GV->setSection(Sect); 1315 Entry.setValue(GV); 1316 1317 return GV; 1318} 1319 1320/// GetStringForStringLiteral - Return the appropriate bytes for a 1321/// string literal, properly padded to match the literal type. 1322std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 1323 const char *StrData = E->getStrData(); 1324 unsigned Len = E->getByteLength(); 1325 1326 const ConstantArrayType *CAT = 1327 getContext().getAsConstantArrayType(E->getType()); 1328 assert(CAT && "String isn't pointer or array!"); 1329 1330 // Resize the string to the right size. 1331 std::string Str(StrData, StrData+Len); 1332 uint64_t RealLen = CAT->getSize().getZExtValue(); 1333 1334 if (E->isWide()) 1335 RealLen *= getContext().Target.getWCharWidth()/8; 1336 1337 Str.resize(RealLen, '\0'); 1338 1339 return Str; 1340} 1341 1342/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 1343/// constant array for the given string literal. 1344llvm::Constant * 1345CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 1346 // FIXME: This can be more efficient. 1347 return GetAddrOfConstantString(GetStringForStringLiteral(S)); 1348} 1349 1350/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 1351/// array for the given ObjCEncodeExpr node. 1352llvm::Constant * 1353CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 1354 std::string Str; 1355 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 1356 1357 return GetAddrOfConstantCString(Str); 1358} 1359 1360 1361/// GenerateWritableString -- Creates storage for a string literal. 1362static llvm::Constant *GenerateStringLiteral(const std::string &str, 1363 bool constant, 1364 CodeGenModule &CGM, 1365 const char *GlobalName) { 1366 // Create Constant for this string literal. Don't add a '\0'. 1367 llvm::Constant *C = llvm::ConstantArray::get(str, false); 1368 1369 // Create a global variable for this string 1370 return new llvm::GlobalVariable(C->getType(), constant, 1371 llvm::GlobalValue::InternalLinkage, 1372 C, GlobalName, &CGM.getModule()); 1373} 1374 1375/// GetAddrOfConstantString - Returns a pointer to a character array 1376/// containing the literal. This contents are exactly that of the 1377/// given string, i.e. it will not be null terminated automatically; 1378/// see GetAddrOfConstantCString. Note that whether the result is 1379/// actually a pointer to an LLVM constant depends on 1380/// Feature.WriteableStrings. 1381/// 1382/// The result has pointer to array type. 1383llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str, 1384 const char *GlobalName) { 1385 bool IsConstant = !Features.WritableStrings; 1386 1387 // Get the default prefix if a name wasn't specified. 1388 if (!GlobalName) 1389 GlobalName = getContext().Target.getStringSymbolPrefix(IsConstant); 1390 1391 // Don't share any string literals if strings aren't constant. 1392 if (!IsConstant) 1393 return GenerateStringLiteral(str, false, *this, GlobalName); 1394 1395 llvm::StringMapEntry<llvm::Constant *> &Entry = 1396 ConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]); 1397 1398 if (Entry.getValue()) 1399 return Entry.getValue(); 1400 1401 // Create a global variable for this. 1402 llvm::Constant *C = GenerateStringLiteral(str, true, *this, GlobalName); 1403 Entry.setValue(C); 1404 return C; 1405} 1406 1407/// GetAddrOfConstantCString - Returns a pointer to a character 1408/// array containing the literal and a terminating '\-' 1409/// character. The result has pointer to array type. 1410llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &str, 1411 const char *GlobalName){ 1412 return GetAddrOfConstantString(str + '\0', GlobalName); 1413} 1414 1415/// EmitObjCPropertyImplementations - Emit information for synthesized 1416/// properties for an implementation. 1417void CodeGenModule::EmitObjCPropertyImplementations(const 1418 ObjCImplementationDecl *D) { 1419 for (ObjCImplementationDecl::propimpl_iterator 1420 i = D->propimpl_begin(getContext()), 1421 e = D->propimpl_end(getContext()); i != e; ++i) { 1422 ObjCPropertyImplDecl *PID = *i; 1423 1424 // Dynamic is just for type-checking. 1425 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 1426 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 1427 1428 // Determine which methods need to be implemented, some may have 1429 // been overridden. Note that ::isSynthesized is not the method 1430 // we want, that just indicates if the decl came from a 1431 // property. What we want to know is if the method is defined in 1432 // this implementation. 1433 if (!D->getInstanceMethod(getContext(), PD->getGetterName())) 1434 CodeGenFunction(*this).GenerateObjCGetter( 1435 const_cast<ObjCImplementationDecl *>(D), PID); 1436 if (!PD->isReadOnly() && 1437 !D->getInstanceMethod(getContext(), PD->getSetterName())) 1438 CodeGenFunction(*this).GenerateObjCSetter( 1439 const_cast<ObjCImplementationDecl *>(D), PID); 1440 } 1441 } 1442} 1443 1444/// EmitNamespace - Emit all declarations in a namespace. 1445void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 1446 for (RecordDecl::decl_iterator I = ND->decls_begin(getContext()), 1447 E = ND->decls_end(getContext()); 1448 I != E; ++I) 1449 EmitTopLevelDecl(*I); 1450} 1451 1452// EmitLinkageSpec - Emit all declarations in a linkage spec. 1453void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 1454 if (LSD->getLanguage() != LinkageSpecDecl::lang_c) { 1455 ErrorUnsupported(LSD, "linkage spec"); 1456 return; 1457 } 1458 1459 for (RecordDecl::decl_iterator I = LSD->decls_begin(getContext()), 1460 E = LSD->decls_end(getContext()); 1461 I != E; ++I) 1462 EmitTopLevelDecl(*I); 1463} 1464 1465/// EmitTopLevelDecl - Emit code for a single top level declaration. 1466void CodeGenModule::EmitTopLevelDecl(Decl *D) { 1467 // If an error has occurred, stop code generation, but continue 1468 // parsing and semantic analysis (to ensure all warnings and errors 1469 // are emitted). 1470 if (Diags.hasErrorOccurred()) 1471 return; 1472 1473 switch (D->getKind()) { 1474 case Decl::CXXMethod: 1475 case Decl::Function: 1476 case Decl::Var: 1477 EmitGlobal(GlobalDecl(cast<ValueDecl>(D))); 1478 break; 1479 1480 // C++ Decls 1481 case Decl::Namespace: 1482 EmitNamespace(cast<NamespaceDecl>(D)); 1483 break; 1484 // No code generation needed. 1485 case Decl::Using: 1486 break; 1487 case Decl::CXXConstructor: 1488 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 1489 break; 1490 case Decl::CXXDestructor: 1491 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 1492 break; 1493 1494 case Decl::StaticAssert: 1495 // Nothing to do. 1496 break; 1497 1498 // Objective-C Decls 1499 1500 // Forward declarations, no (immediate) code generation. 1501 case Decl::ObjCClass: 1502 case Decl::ObjCForwardProtocol: 1503 case Decl::ObjCCategory: 1504 case Decl::ObjCInterface: 1505 break; 1506 1507 case Decl::ObjCProtocol: 1508 Runtime->GenerateProtocol(cast<ObjCProtocolDecl>(D)); 1509 break; 1510 1511 case Decl::ObjCCategoryImpl: 1512 // Categories have properties but don't support synthesize so we 1513 // can ignore them here. 1514 Runtime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 1515 break; 1516 1517 case Decl::ObjCImplementation: { 1518 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 1519 EmitObjCPropertyImplementations(OMD); 1520 Runtime->GenerateClass(OMD); 1521 break; 1522 } 1523 case Decl::ObjCMethod: { 1524 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 1525 // If this is not a prototype, emit the body. 1526 if (OMD->getBody(getContext())) 1527 CodeGenFunction(*this).GenerateObjCMethod(OMD); 1528 break; 1529 } 1530 case Decl::ObjCCompatibleAlias: 1531 // compatibility-alias is a directive and has no code gen. 1532 break; 1533 1534 case Decl::LinkageSpec: 1535 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 1536 break; 1537 1538 case Decl::FileScopeAsm: { 1539 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 1540 std::string AsmString(AD->getAsmString()->getStrData(), 1541 AD->getAsmString()->getByteLength()); 1542 1543 const std::string &S = getModule().getModuleInlineAsm(); 1544 if (S.empty()) 1545 getModule().setModuleInlineAsm(AsmString); 1546 else 1547 getModule().setModuleInlineAsm(S + '\n' + AsmString); 1548 break; 1549 } 1550 1551 default: 1552 // Make sure we handled everything we should, every other kind is a 1553 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 1554 // function. Need to recode Decl::Kind to do that easily. 1555 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 1556 } 1557} 1558