CodeGenModule.cpp revision ec586e7b10394aeed25c8e5ee02d230951826136
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 VMContext(M.getContext()) { 45 46 if (!Features.ObjC1) 47 Runtime = 0; 48 else if (!Features.NeXTRuntime) 49 Runtime = CreateGNUObjCRuntime(*this); 50 else if (Features.ObjCNonFragileABI) 51 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 52 else 53 Runtime = CreateMacObjCRuntime(*this); 54 55 // If debug info generation is enabled, create the CGDebugInfo object. 56 DebugInfo = CompileOpts.DebugInfo ? new CGDebugInfo(this) : 0; 57} 58 59CodeGenModule::~CodeGenModule() { 60 delete Runtime; 61 delete DebugInfo; 62} 63 64void CodeGenModule::Release() { 65 EmitDeferred(); 66 if (Runtime) 67 if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction()) 68 AddGlobalCtor(ObjCInitFunction); 69 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 70 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 71 EmitAnnotations(); 72 EmitLLVMUsed(); 73} 74 75/// ErrorUnsupported - Print out an error that codegen doesn't support the 76/// specified stmt yet. 77void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 78 bool OmitOnError) { 79 if (OmitOnError && getDiags().hasErrorOccurred()) 80 return; 81 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 82 "cannot compile this %0 yet"); 83 std::string Msg = Type; 84 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 85 << Msg << S->getSourceRange(); 86} 87 88/// ErrorUnsupported - Print out an error that codegen doesn't support the 89/// specified decl yet. 90void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 91 bool OmitOnError) { 92 if (OmitOnError && getDiags().hasErrorOccurred()) 93 return; 94 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 95 "cannot compile this %0 yet"); 96 std::string Msg = Type; 97 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 98} 99 100LangOptions::VisibilityMode 101CodeGenModule::getDeclVisibilityMode(const Decl *D) const { 102 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 103 if (VD->getStorageClass() == VarDecl::PrivateExtern) 104 return LangOptions::Hidden; 105 106 if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>()) { 107 switch (attr->getVisibility()) { 108 default: assert(0 && "Unknown visibility!"); 109 case VisibilityAttr::DefaultVisibility: 110 return LangOptions::Default; 111 case VisibilityAttr::HiddenVisibility: 112 return LangOptions::Hidden; 113 case VisibilityAttr::ProtectedVisibility: 114 return LangOptions::Protected; 115 } 116 } 117 118 return getLangOptions().getVisibilityMode(); 119} 120 121void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 122 const Decl *D) const { 123 // Internal definitions always have default visibility. 124 if (GV->hasLocalLinkage()) { 125 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 126 return; 127 } 128 129 switch (getDeclVisibilityMode(D)) { 130 default: assert(0 && "Unknown visibility!"); 131 case LangOptions::Default: 132 return GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 133 case LangOptions::Hidden: 134 return GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 135 case LangOptions::Protected: 136 return GV->setVisibility(llvm::GlobalValue::ProtectedVisibility); 137 } 138} 139 140const char *CodeGenModule::getMangledName(const GlobalDecl &GD) { 141 const NamedDecl *ND = GD.getDecl(); 142 143 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 144 return getMangledCXXCtorName(D, GD.getCtorType()); 145 if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 146 return getMangledCXXDtorName(D, GD.getDtorType()); 147 148 return getMangledName(ND); 149} 150 151/// \brief Retrieves the mangled name for the given declaration. 152/// 153/// If the given declaration requires a mangled name, returns an 154/// const char* containing the mangled name. Otherwise, returns 155/// the unmangled name. 156/// 157const char *CodeGenModule::getMangledName(const NamedDecl *ND) { 158 // In C, functions with no attributes never need to be mangled. Fastpath them. 159 if (!getLangOptions().CPlusPlus && !ND->hasAttrs()) { 160 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl."); 161 return ND->getNameAsCString(); 162 } 163 164 llvm::SmallString<256> Name; 165 llvm::raw_svector_ostream Out(Name); 166 if (!mangleName(ND, Context, Out)) { 167 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl."); 168 return ND->getNameAsCString(); 169 } 170 171 Name += '\0'; 172 return UniqueMangledName(Name.begin(), Name.end()); 173} 174 175const char *CodeGenModule::UniqueMangledName(const char *NameStart, 176 const char *NameEnd) { 177 assert(*(NameEnd - 1) == '\0' && "Mangled name must be null terminated!"); 178 179 return MangledNames.GetOrCreateValue(NameStart, NameEnd).getKeyData(); 180} 181 182/// AddGlobalCtor - Add a function to the list that will be called before 183/// main() runs. 184void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 185 // FIXME: Type coercion of void()* types. 186 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 187} 188 189/// AddGlobalDtor - Add a function to the list that will be called 190/// when the module is unloaded. 191void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 192 // FIXME: Type coercion of void()* types. 193 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 194} 195 196void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 197 // Ctor function type is void()*. 198 llvm::FunctionType* CtorFTy = 199 VMContext.getFunctionType(llvm::Type::VoidTy, 200 std::vector<const llvm::Type*>(), 201 false); 202 llvm::Type *CtorPFTy = VMContext.getPointerTypeUnqual(CtorFTy); 203 204 // Get the type of a ctor entry, { i32, void ()* }. 205 llvm::StructType* CtorStructTy = 206 VMContext.getStructType(llvm::Type::Int32Ty, 207 VMContext.getPointerTypeUnqual(CtorFTy), NULL); 208 209 // Construct the constructor and destructor arrays. 210 std::vector<llvm::Constant*> Ctors; 211 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 212 std::vector<llvm::Constant*> S; 213 S.push_back( 214 VMContext.getConstantInt(llvm::Type::Int32Ty, I->second, false)); 215 S.push_back(VMContext.getConstantExprBitCast(I->first, CtorPFTy)); 216 Ctors.push_back(VMContext.getConstantStruct(CtorStructTy, S)); 217 } 218 219 if (!Ctors.empty()) { 220 llvm::ArrayType *AT = VMContext.getArrayType(CtorStructTy, Ctors.size()); 221 new llvm::GlobalVariable(TheModule, AT, false, 222 llvm::GlobalValue::AppendingLinkage, 223 VMContext.getConstantArray(AT, Ctors), 224 GlobalName); 225 } 226} 227 228void CodeGenModule::EmitAnnotations() { 229 if (Annotations.empty()) 230 return; 231 232 // Create a new global variable for the ConstantStruct in the Module. 233 llvm::Constant *Array = 234 VMContext.getConstantArray(VMContext.getArrayType(Annotations[0]->getType(), 235 Annotations.size()), 236 Annotations); 237 llvm::GlobalValue *gv = 238 new llvm::GlobalVariable(TheModule, Array->getType(), false, 239 llvm::GlobalValue::AppendingLinkage, Array, 240 "llvm.global.annotations"); 241 gv->setSection("llvm.metadata"); 242} 243 244static CodeGenModule::GVALinkage 245GetLinkageForFunction(ASTContext &Context, const FunctionDecl *FD, 246 const LangOptions &Features) { 247 // The kind of external linkage this function will have, if it is not 248 // inline or static. 249 CodeGenModule::GVALinkage External = CodeGenModule::GVA_StrongExternal; 250 if (Context.getLangOptions().CPlusPlus && 251 (FD->getPrimaryTemplate() || FD->getInstantiatedFromMemberFunction()) && 252 !FD->isExplicitSpecialization()) 253 External = CodeGenModule::GVA_TemplateInstantiation; 254 255 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) { 256 // C++ member functions defined inside the class are always inline. 257 if (MD->isInline() || !MD->isOutOfLine()) 258 return CodeGenModule::GVA_CXXInline; 259 260 return External; 261 } 262 263 // "static" functions get internal linkage. 264 if (FD->getStorageClass() == FunctionDecl::Static) 265 return CodeGenModule::GVA_Internal; 266 267 if (!FD->isInline()) 268 return External; 269 270 // If the inline function explicitly has the GNU inline attribute on it, or if 271 // this is C89 mode, we use to GNU semantics. 272 if (!Features.C99 && !Features.CPlusPlus) { 273 // extern inline in GNU mode is like C99 inline. 274 if (FD->getStorageClass() == FunctionDecl::Extern) 275 return CodeGenModule::GVA_C99Inline; 276 // Normal inline is a strong symbol. 277 return CodeGenModule::GVA_StrongExternal; 278 } else if (FD->hasActiveGNUInlineAttribute(Context)) { 279 // GCC in C99 mode seems to use a different decision-making 280 // process for extern inline, which factors in previous 281 // declarations. 282 if (FD->isExternGNUInline(Context)) 283 return CodeGenModule::GVA_C99Inline; 284 // Normal inline is a strong symbol. 285 return External; 286 } 287 288 // The definition of inline changes based on the language. Note that we 289 // have already handled "static inline" above, with the GVA_Internal case. 290 if (Features.CPlusPlus) // inline and extern inline. 291 return CodeGenModule::GVA_CXXInline; 292 293 assert(Features.C99 && "Must be in C99 mode if not in C89 or C++ mode"); 294 if (FD->isC99InlineDefinition()) 295 return CodeGenModule::GVA_C99Inline; 296 297 return CodeGenModule::GVA_StrongExternal; 298} 299 300/// SetFunctionDefinitionAttributes - Set attributes for a global. 301/// 302/// FIXME: This is currently only done for aliases and functions, but not for 303/// variables (these details are set in EmitGlobalVarDefinition for variables). 304void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 305 llvm::GlobalValue *GV) { 306 GVALinkage Linkage = GetLinkageForFunction(getContext(), D, Features); 307 308 if (Linkage == GVA_Internal) { 309 GV->setLinkage(llvm::Function::InternalLinkage); 310 } else if (D->hasAttr<DLLExportAttr>()) { 311 GV->setLinkage(llvm::Function::DLLExportLinkage); 312 } else if (D->hasAttr<WeakAttr>()) { 313 GV->setLinkage(llvm::Function::WeakAnyLinkage); 314 } else if (Linkage == GVA_C99Inline) { 315 // In C99 mode, 'inline' functions are guaranteed to have a strong 316 // definition somewhere else, so we can use available_externally linkage. 317 GV->setLinkage(llvm::Function::AvailableExternallyLinkage); 318 } else if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation) { 319 // In C++, the compiler has to emit a definition in every translation unit 320 // that references the function. We should use linkonce_odr because 321 // a) if all references in this translation unit are optimized away, we 322 // don't need to codegen it. b) if the function persists, it needs to be 323 // merged with other definitions. c) C++ has the ODR, so we know the 324 // definition is dependable. 325 GV->setLinkage(llvm::Function::LinkOnceODRLinkage); 326 } else { 327 assert(Linkage == GVA_StrongExternal); 328 // Otherwise, we have strong external linkage. 329 GV->setLinkage(llvm::Function::ExternalLinkage); 330 } 331 332 SetCommonAttributes(D, GV); 333} 334 335void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 336 const CGFunctionInfo &Info, 337 llvm::Function *F) { 338 AttributeListType AttributeList; 339 ConstructAttributeList(Info, D, AttributeList); 340 341 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 342 AttributeList.size())); 343 344 // Set the appropriate calling convention for the Function. 345 if (D->hasAttr<FastCallAttr>()) 346 F->setCallingConv(llvm::CallingConv::X86_FastCall); 347 348 if (D->hasAttr<StdCallAttr>()) 349 F->setCallingConv(llvm::CallingConv::X86_StdCall); 350} 351 352void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 353 llvm::Function *F) { 354 if (!Features.Exceptions && !Features.ObjCNonFragileABI) 355 F->addFnAttr(llvm::Attribute::NoUnwind); 356 357 if (D->hasAttr<AlwaysInlineAttr>()) 358 F->addFnAttr(llvm::Attribute::AlwaysInline); 359 360 if (D->hasAttr<NoinlineAttr>()) 361 F->addFnAttr(llvm::Attribute::NoInline); 362} 363 364void CodeGenModule::SetCommonAttributes(const Decl *D, 365 llvm::GlobalValue *GV) { 366 setGlobalVisibility(GV, D); 367 368 if (D->hasAttr<UsedAttr>()) 369 AddUsedGlobal(GV); 370 371 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 372 GV->setSection(SA->getName()); 373} 374 375void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 376 llvm::Function *F, 377 const CGFunctionInfo &FI) { 378 SetLLVMFunctionAttributes(D, FI, F); 379 SetLLVMFunctionAttributesForDefinition(D, F); 380 381 F->setLinkage(llvm::Function::InternalLinkage); 382 383 SetCommonAttributes(D, F); 384} 385 386void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD, 387 llvm::Function *F, 388 bool IsIncompleteFunction) { 389 if (!IsIncompleteFunction) 390 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(FD), F); 391 392 // Only a few attributes are set on declarations; these may later be 393 // overridden by a definition. 394 395 if (FD->hasAttr<DLLImportAttr>()) { 396 F->setLinkage(llvm::Function::DLLImportLinkage); 397 } else if (FD->hasAttr<WeakAttr>() || 398 FD->hasAttr<WeakImportAttr>()) { 399 // "extern_weak" is overloaded in LLVM; we probably should have 400 // separate linkage types for this. 401 F->setLinkage(llvm::Function::ExternalWeakLinkage); 402 } else { 403 F->setLinkage(llvm::Function::ExternalLinkage); 404 } 405 406 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 407 F->setSection(SA->getName()); 408} 409 410void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 411 assert(!GV->isDeclaration() && 412 "Only globals with definition can force usage."); 413 LLVMUsed.push_back(GV); 414} 415 416void CodeGenModule::EmitLLVMUsed() { 417 // Don't create llvm.used if there is no need. 418 if (LLVMUsed.empty()) 419 return; 420 421 llvm::Type *i8PTy = VMContext.getPointerTypeUnqual(llvm::Type::Int8Ty); 422 423 // Convert LLVMUsed to what ConstantArray needs. 424 std::vector<llvm::Constant*> UsedArray; 425 UsedArray.resize(LLVMUsed.size()); 426 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 427 UsedArray[i] = 428 VMContext.getConstantExprBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), 429 i8PTy); 430 } 431 432 if (UsedArray.empty()) 433 return; 434 llvm::ArrayType *ATy = VMContext.getArrayType(i8PTy, UsedArray.size()); 435 436 llvm::GlobalVariable *GV = 437 new llvm::GlobalVariable(getModule(), ATy, false, 438 llvm::GlobalValue::AppendingLinkage, 439 VMContext.getConstantArray(ATy, UsedArray), 440 "llvm.used"); 441 442 GV->setSection("llvm.metadata"); 443} 444 445void CodeGenModule::EmitDeferred() { 446 // Emit code for any potentially referenced deferred decls. Since a 447 // previously unused static decl may become used during the generation of code 448 // for a static function, iterate until no changes are made. 449 while (!DeferredDeclsToEmit.empty()) { 450 GlobalDecl D = DeferredDeclsToEmit.back(); 451 DeferredDeclsToEmit.pop_back(); 452 453 // The mangled name for the decl must have been emitted in GlobalDeclMap. 454 // Look it up to see if it was defined with a stronger definition (e.g. an 455 // extern inline function with a strong function redefinition). If so, 456 // just ignore the deferred decl. 457 llvm::GlobalValue *CGRef = GlobalDeclMap[getMangledName(D)]; 458 assert(CGRef && "Deferred decl wasn't referenced?"); 459 460 if (!CGRef->isDeclaration()) 461 continue; 462 463 // Otherwise, emit the definition and move on to the next one. 464 EmitGlobalDefinition(D); 465 } 466} 467 468/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the 469/// annotation information for a given GlobalValue. The annotation struct is 470/// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the 471/// GlobalValue being annotated. The second field is the constant string 472/// created from the AnnotateAttr's annotation. The third field is a constant 473/// string containing the name of the translation unit. The fourth field is 474/// the line number in the file of the annotated value declaration. 475/// 476/// FIXME: this does not unique the annotation string constants, as llvm-gcc 477/// appears to. 478/// 479llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 480 const AnnotateAttr *AA, 481 unsigned LineNo) { 482 llvm::Module *M = &getModule(); 483 484 // get [N x i8] constants for the annotation string, and the filename string 485 // which are the 2nd and 3rd elements of the global annotation structure. 486 const llvm::Type *SBP = VMContext.getPointerTypeUnqual(llvm::Type::Int8Ty); 487 llvm::Constant *anno = VMContext.getConstantArray(AA->getAnnotation(), true); 488 llvm::Constant *unit = VMContext.getConstantArray(M->getModuleIdentifier(), 489 true); 490 491 // Get the two global values corresponding to the ConstantArrays we just 492 // created to hold the bytes of the strings. 493 llvm::GlobalValue *annoGV = 494 new llvm::GlobalVariable(*M, anno->getType(), false, 495 llvm::GlobalValue::PrivateLinkage, anno, 496 GV->getName()); 497 // translation unit name string, emitted into the llvm.metadata section. 498 llvm::GlobalValue *unitGV = 499 new llvm::GlobalVariable(*M, unit->getType(), false, 500 llvm::GlobalValue::PrivateLinkage, unit, 501 ".str"); 502 503 // Create the ConstantStruct for the global annotation. 504 llvm::Constant *Fields[4] = { 505 VMContext.getConstantExprBitCast(GV, SBP), 506 VMContext.getConstantExprBitCast(annoGV, SBP), 507 VMContext.getConstantExprBitCast(unitGV, SBP), 508 VMContext.getConstantInt(llvm::Type::Int32Ty, LineNo) 509 }; 510 return VMContext.getConstantStruct(Fields, 4, false); 511} 512 513bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 514 // Never defer when EmitAllDecls is specified or the decl has 515 // attribute used. 516 if (Features.EmitAllDecls || Global->hasAttr<UsedAttr>()) 517 return false; 518 519 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 520 // Constructors and destructors should never be deferred. 521 if (FD->hasAttr<ConstructorAttr>() || 522 FD->hasAttr<DestructorAttr>()) 523 return false; 524 525 GVALinkage Linkage = GetLinkageForFunction(getContext(), FD, Features); 526 527 // static, static inline, always_inline, and extern inline functions can 528 // always be deferred. Normal inline functions can be deferred in C99/C++. 529 if (Linkage == GVA_Internal || Linkage == GVA_C99Inline || 530 Linkage == GVA_CXXInline) 531 return true; 532 return false; 533 } 534 535 const VarDecl *VD = cast<VarDecl>(Global); 536 assert(VD->isFileVarDecl() && "Invalid decl"); 537 538 return VD->getStorageClass() == VarDecl::Static; 539} 540 541void CodeGenModule::EmitGlobal(GlobalDecl GD) { 542 const ValueDecl *Global = GD.getDecl(); 543 544 // If this is an alias definition (which otherwise looks like a declaration) 545 // emit it now. 546 if (Global->hasAttr<AliasAttr>()) 547 return EmitAliasDefinition(Global); 548 549 // Ignore declarations, they will be emitted on their first use. 550 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 551 // Forward declarations are emitted lazily on first use. 552 if (!FD->isThisDeclarationADefinition()) 553 return; 554 } else { 555 const VarDecl *VD = cast<VarDecl>(Global); 556 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 557 558 // In C++, if this is marked "extern", defer code generation. 559 if (getLangOptions().CPlusPlus && !VD->getInit() && 560 (VD->getStorageClass() == VarDecl::Extern || 561 VD->isExternC(getContext()))) 562 return; 563 564 // In C, if this isn't a definition, defer code generation. 565 if (!getLangOptions().CPlusPlus && !VD->getInit()) 566 return; 567 } 568 569 // Defer code generation when possible if this is a static definition, inline 570 // function etc. These we only want to emit if they are used. 571 if (MayDeferGeneration(Global)) { 572 // If the value has already been used, add it directly to the 573 // DeferredDeclsToEmit list. 574 const char *MangledName = getMangledName(GD); 575 if (GlobalDeclMap.count(MangledName)) 576 DeferredDeclsToEmit.push_back(GD); 577 else { 578 // Otherwise, remember that we saw a deferred decl with this name. The 579 // first use of the mangled name will cause it to move into 580 // DeferredDeclsToEmit. 581 DeferredDecls[MangledName] = GD; 582 } 583 return; 584 } 585 586 // Otherwise emit the definition. 587 EmitGlobalDefinition(GD); 588} 589 590void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) { 591 const ValueDecl *D = GD.getDecl(); 592 593 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 594 EmitCXXConstructor(CD, GD.getCtorType()); 595 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D)) 596 EmitCXXDestructor(DD, GD.getDtorType()); 597 else if (isa<FunctionDecl>(D)) 598 EmitGlobalFunctionDefinition(GD); 599 else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 600 EmitGlobalVarDefinition(VD); 601 else { 602 assert(0 && "Invalid argument to EmitGlobalDefinition()"); 603 } 604} 605 606/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 607/// module, create and return an llvm Function with the specified type. If there 608/// is something in the module with the specified name, return it potentially 609/// bitcasted to the right type. 610/// 611/// If D is non-null, it specifies a decl that correspond to this. This is used 612/// to set the attributes on the function when it is first created. 613llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(const char *MangledName, 614 const llvm::Type *Ty, 615 GlobalDecl D) { 616 // Lookup the entry, lazily creating it if necessary. 617 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 618 if (Entry) { 619 if (Entry->getType()->getElementType() == Ty) 620 return Entry; 621 622 // Make sure the result is of the correct type. 623 const llvm::Type *PTy = VMContext.getPointerTypeUnqual(Ty); 624 return VMContext.getConstantExprBitCast(Entry, PTy); 625 } 626 627 // This is the first use or definition of a mangled name. If there is a 628 // deferred decl with this name, remember that we need to emit it at the end 629 // of the file. 630 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 631 DeferredDecls.find(MangledName); 632 if (DDI != DeferredDecls.end()) { 633 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 634 // list, and remove it from DeferredDecls (since we don't need it anymore). 635 DeferredDeclsToEmit.push_back(DDI->second); 636 DeferredDecls.erase(DDI); 637 } else if (const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl())) { 638 // If this the first reference to a C++ inline function in a class, queue up 639 // the deferred function body for emission. These are not seen as 640 // top-level declarations. 641 if (FD->isThisDeclarationADefinition() && MayDeferGeneration(FD)) 642 DeferredDeclsToEmit.push_back(D); 643 } 644 645 // This function doesn't have a complete type (for example, the return 646 // type is an incomplete struct). Use a fake type instead, and make 647 // sure not to try to set attributes. 648 bool IsIncompleteFunction = false; 649 if (!isa<llvm::FunctionType>(Ty)) { 650 Ty = VMContext.getFunctionType(llvm::Type::VoidTy, 651 std::vector<const llvm::Type*>(), false); 652 IsIncompleteFunction = true; 653 } 654 llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty), 655 llvm::Function::ExternalLinkage, 656 "", &getModule()); 657 F->setName(MangledName); 658 if (D.getDecl()) 659 SetFunctionAttributes(cast<FunctionDecl>(D.getDecl()), F, 660 IsIncompleteFunction); 661 Entry = F; 662 return F; 663} 664 665/// GetAddrOfFunction - Return the address of the given function. If Ty is 666/// non-null, then this function will use the specified type if it has to 667/// create it (this occurs when we see a definition of the function). 668llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD, 669 const llvm::Type *Ty) { 670 // If there was no specific requested type, just convert it now. 671 if (!Ty) 672 Ty = getTypes().ConvertType(GD.getDecl()->getType()); 673 return GetOrCreateLLVMFunction(getMangledName(GD.getDecl()), Ty, GD); 674} 675 676/// CreateRuntimeFunction - Create a new runtime function with the specified 677/// type and name. 678llvm::Constant * 679CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy, 680 const char *Name) { 681 // Convert Name to be a uniqued string from the IdentifierInfo table. 682 Name = getContext().Idents.get(Name).getName(); 683 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl()); 684} 685 686/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 687/// create and return an llvm GlobalVariable with the specified type. If there 688/// is something in the module with the specified name, return it potentially 689/// bitcasted to the right type. 690/// 691/// If D is non-null, it specifies a decl that correspond to this. This is used 692/// to set the attributes on the global when it is first created. 693llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName, 694 const llvm::PointerType*Ty, 695 const VarDecl *D) { 696 // Lookup the entry, lazily creating it if necessary. 697 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 698 if (Entry) { 699 if (Entry->getType() == Ty) 700 return Entry; 701 702 // Make sure the result is of the correct type. 703 return VMContext.getConstantExprBitCast(Entry, Ty); 704 } 705 706 // This is the first use or definition of a mangled name. If there is a 707 // deferred decl with this name, remember that we need to emit it at the end 708 // of the file. 709 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 710 DeferredDecls.find(MangledName); 711 if (DDI != DeferredDecls.end()) { 712 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 713 // list, and remove it from DeferredDecls (since we don't need it anymore). 714 DeferredDeclsToEmit.push_back(DDI->second); 715 DeferredDecls.erase(DDI); 716 } 717 718 llvm::GlobalVariable *GV = 719 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false, 720 llvm::GlobalValue::ExternalLinkage, 721 0, "", 0, 722 false, Ty->getAddressSpace()); 723 GV->setName(MangledName); 724 725 // Handle things which are present even on external declarations. 726 if (D) { 727 // FIXME: This code is overly simple and should be merged with other global 728 // handling. 729 GV->setConstant(D->getType().isConstant(Context)); 730 731 // FIXME: Merge with other attribute handling code. 732 if (D->getStorageClass() == VarDecl::PrivateExtern) 733 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 734 735 if (D->hasAttr<WeakAttr>() || 736 D->hasAttr<WeakImportAttr>()) 737 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 738 739 GV->setThreadLocal(D->isThreadSpecified()); 740 } 741 742 return Entry = GV; 743} 744 745 746/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 747/// given global variable. If Ty is non-null and if the global doesn't exist, 748/// then it will be greated with the specified type instead of whatever the 749/// normal requested type would be. 750llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 751 const llvm::Type *Ty) { 752 assert(D->hasGlobalStorage() && "Not a global variable"); 753 QualType ASTTy = D->getType(); 754 if (Ty == 0) 755 Ty = getTypes().ConvertTypeForMem(ASTTy); 756 757 const llvm::PointerType *PTy = 758 VMContext.getPointerType(Ty, ASTTy.getAddressSpace()); 759 return GetOrCreateLLVMGlobal(getMangledName(D), PTy, D); 760} 761 762/// CreateRuntimeVariable - Create a new runtime global variable with the 763/// specified type and name. 764llvm::Constant * 765CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty, 766 const char *Name) { 767 // Convert Name to be a uniqued string from the IdentifierInfo table. 768 Name = getContext().Idents.get(Name).getName(); 769 return GetOrCreateLLVMGlobal(Name, VMContext.getPointerTypeUnqual(Ty), 0); 770} 771 772void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 773 assert(!D->getInit() && "Cannot emit definite definitions here!"); 774 775 if (MayDeferGeneration(D)) { 776 // If we have not seen a reference to this variable yet, place it 777 // into the deferred declarations table to be emitted if needed 778 // later. 779 const char *MangledName = getMangledName(D); 780 if (GlobalDeclMap.count(MangledName) == 0) { 781 DeferredDecls[MangledName] = GlobalDecl(D); 782 return; 783 } 784 } 785 786 // The tentative definition is the only definition. 787 EmitGlobalVarDefinition(D); 788} 789 790void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 791 llvm::Constant *Init = 0; 792 QualType ASTTy = D->getType(); 793 794 if (D->getInit() == 0) { 795 // This is a tentative definition; tentative definitions are 796 // implicitly initialized with { 0 }. 797 // 798 // Note that tentative definitions are only emitted at the end of 799 // a translation unit, so they should never have incomplete 800 // type. In addition, EmitTentativeDefinition makes sure that we 801 // never attempt to emit a tentative definition if a real one 802 // exists. A use may still exists, however, so we still may need 803 // to do a RAUW. 804 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 805 Init = getLLVMContext().getNullValue(getTypes().ConvertTypeForMem(ASTTy)); 806 } else { 807 Init = EmitConstantExpr(D->getInit(), D->getType()); 808 if (!Init) { 809 ErrorUnsupported(D, "static initializer"); 810 QualType T = D->getInit()->getType(); 811 Init = VMContext.getUndef(getTypes().ConvertType(T)); 812 } 813 } 814 815 const llvm::Type* InitType = Init->getType(); 816 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 817 818 // Strip off a bitcast if we got one back. 819 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 820 assert(CE->getOpcode() == llvm::Instruction::BitCast || 821 // all zero index gep. 822 CE->getOpcode() == llvm::Instruction::GetElementPtr); 823 Entry = CE->getOperand(0); 824 } 825 826 // Entry is now either a Function or GlobalVariable. 827 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 828 829 // We have a definition after a declaration with the wrong type. 830 // We must make a new GlobalVariable* and update everything that used OldGV 831 // (a declaration or tentative definition) with the new GlobalVariable* 832 // (which will be a definition). 833 // 834 // This happens if there is a prototype for a global (e.g. 835 // "extern int x[];") and then a definition of a different type (e.g. 836 // "int x[10];"). This also happens when an initializer has a different type 837 // from the type of the global (this happens with unions). 838 if (GV == 0 || 839 GV->getType()->getElementType() != InitType || 840 GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) { 841 842 // Remove the old entry from GlobalDeclMap so that we'll create a new one. 843 GlobalDeclMap.erase(getMangledName(D)); 844 845 // Make a new global with the correct type, this is now guaranteed to work. 846 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 847 GV->takeName(cast<llvm::GlobalValue>(Entry)); 848 849 // Replace all uses of the old global with the new global 850 llvm::Constant *NewPtrForOldDecl = 851 VMContext.getConstantExprBitCast(GV, Entry->getType()); 852 Entry->replaceAllUsesWith(NewPtrForOldDecl); 853 854 // Erase the old global, since it is no longer used. 855 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 856 } 857 858 if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>()) { 859 SourceManager &SM = Context.getSourceManager(); 860 AddAnnotation(EmitAnnotateAttr(GV, AA, 861 SM.getInstantiationLineNumber(D->getLocation()))); 862 } 863 864 GV->setInitializer(Init); 865 GV->setConstant(D->getType().isConstant(Context)); 866 GV->setAlignment(getContext().getDeclAlignInBytes(D)); 867 868 // Set the llvm linkage type as appropriate. 869 if (D->getStorageClass() == VarDecl::Static) 870 GV->setLinkage(llvm::Function::InternalLinkage); 871 else if (D->hasAttr<DLLImportAttr>()) 872 GV->setLinkage(llvm::Function::DLLImportLinkage); 873 else if (D->hasAttr<DLLExportAttr>()) 874 GV->setLinkage(llvm::Function::DLLExportLinkage); 875 else if (D->hasAttr<WeakAttr>()) 876 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 877 else if (!CompileOpts.NoCommon && 878 (!D->hasExternalStorage() && !D->getInit())) 879 GV->setLinkage(llvm::GlobalVariable::CommonLinkage); 880 else 881 GV->setLinkage(llvm::GlobalVariable::ExternalLinkage); 882 883 SetCommonAttributes(D, GV); 884 885 // Emit global variable debug information. 886 if (CGDebugInfo *DI = getDebugInfo()) { 887 DI->setLocation(D->getLocation()); 888 DI->EmitGlobalVariable(GV, D); 889 } 890} 891 892/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 893/// implement a function with no prototype, e.g. "int foo() {}". If there are 894/// existing call uses of the old function in the module, this adjusts them to 895/// call the new function directly. 896/// 897/// This is not just a cleanup: the always_inline pass requires direct calls to 898/// functions to be able to inline them. If there is a bitcast in the way, it 899/// won't inline them. Instcombine normally deletes these calls, but it isn't 900/// run at -O0. 901static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 902 llvm::Function *NewFn) { 903 // If we're redefining a global as a function, don't transform it. 904 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 905 if (OldFn == 0) return; 906 907 const llvm::Type *NewRetTy = NewFn->getReturnType(); 908 llvm::SmallVector<llvm::Value*, 4> ArgList; 909 910 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 911 UI != E; ) { 912 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 913 unsigned OpNo = UI.getOperandNo(); 914 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*UI++); 915 if (!CI || OpNo != 0) continue; 916 917 // If the return types don't match exactly, and if the call isn't dead, then 918 // we can't transform this call. 919 if (CI->getType() != NewRetTy && !CI->use_empty()) 920 continue; 921 922 // If the function was passed too few arguments, don't transform. If extra 923 // arguments were passed, we silently drop them. If any of the types 924 // mismatch, we don't transform. 925 unsigned ArgNo = 0; 926 bool DontTransform = false; 927 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 928 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 929 if (CI->getNumOperands()-1 == ArgNo || 930 CI->getOperand(ArgNo+1)->getType() != AI->getType()) { 931 DontTransform = true; 932 break; 933 } 934 } 935 if (DontTransform) 936 continue; 937 938 // Okay, we can transform this. Create the new call instruction and copy 939 // over the required information. 940 ArgList.append(CI->op_begin()+1, CI->op_begin()+1+ArgNo); 941 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(), 942 ArgList.end(), "", CI); 943 ArgList.clear(); 944 if (NewCall->getType() != llvm::Type::VoidTy) 945 NewCall->takeName(CI); 946 NewCall->setCallingConv(CI->getCallingConv()); 947 NewCall->setAttributes(CI->getAttributes()); 948 949 // Finally, remove the old call, replacing any uses with the new one. 950 if (!CI->use_empty()) 951 CI->replaceAllUsesWith(NewCall); 952 CI->eraseFromParent(); 953 } 954} 955 956 957void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) { 958 const llvm::FunctionType *Ty; 959 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl()); 960 961 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { 962 bool isVariadic = D->getType()->getAsFunctionProtoType()->isVariadic(); 963 964 Ty = getTypes().GetFunctionType(getTypes().getFunctionInfo(MD), isVariadic); 965 } else { 966 Ty = cast<llvm::FunctionType>(getTypes().ConvertType(D->getType())); 967 968 // As a special case, make sure that definitions of K&R function 969 // "type foo()" aren't declared as varargs (which forces the backend 970 // to do unnecessary work). 971 if (D->getType()->isFunctionNoProtoType()) { 972 assert(Ty->isVarArg() && "Didn't lower type as expected"); 973 // Due to stret, the lowered function could have arguments. 974 // Just create the same type as was lowered by ConvertType 975 // but strip off the varargs bit. 976 std::vector<const llvm::Type*> Args(Ty->param_begin(), Ty->param_end()); 977 Ty = VMContext.getFunctionType(Ty->getReturnType(), Args, false); 978 } 979 } 980 981 // Get or create the prototype for the function. 982 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty); 983 984 // Strip off a bitcast if we got one back. 985 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 986 assert(CE->getOpcode() == llvm::Instruction::BitCast); 987 Entry = CE->getOperand(0); 988 } 989 990 991 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 992 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 993 994 // If the types mismatch then we have to rewrite the definition. 995 assert(OldFn->isDeclaration() && 996 "Shouldn't replace non-declaration"); 997 998 // F is the Function* for the one with the wrong type, we must make a new 999 // Function* and update everything that used F (a declaration) with the new 1000 // Function* (which will be a definition). 1001 // 1002 // This happens if there is a prototype for a function 1003 // (e.g. "int f()") and then a definition of a different type 1004 // (e.g. "int f(int x)"). Start by making a new function of the 1005 // correct type, RAUW, then steal the name. 1006 GlobalDeclMap.erase(getMangledName(D)); 1007 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty)); 1008 NewFn->takeName(OldFn); 1009 1010 // If this is an implementation of a function without a prototype, try to 1011 // replace any existing uses of the function (which may be calls) with uses 1012 // of the new function 1013 if (D->getType()->isFunctionNoProtoType()) { 1014 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 1015 OldFn->removeDeadConstantUsers(); 1016 } 1017 1018 // Replace uses of F with the Function we will endow with a body. 1019 if (!Entry->use_empty()) { 1020 llvm::Constant *NewPtrForOldDecl = 1021 VMContext.getConstantExprBitCast(NewFn, Entry->getType()); 1022 Entry->replaceAllUsesWith(NewPtrForOldDecl); 1023 } 1024 1025 // Ok, delete the old function now, which is dead. 1026 OldFn->eraseFromParent(); 1027 1028 Entry = NewFn; 1029 } 1030 1031 llvm::Function *Fn = cast<llvm::Function>(Entry); 1032 1033 CodeGenFunction(*this).GenerateCode(D, Fn); 1034 1035 SetFunctionDefinitionAttributes(D, Fn); 1036 SetLLVMFunctionAttributesForDefinition(D, Fn); 1037 1038 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 1039 AddGlobalCtor(Fn, CA->getPriority()); 1040 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 1041 AddGlobalDtor(Fn, DA->getPriority()); 1042} 1043 1044void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) { 1045 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1046 assert(AA && "Not an alias?"); 1047 1048 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1049 1050 // Unique the name through the identifier table. 1051 const char *AliaseeName = AA->getAliasee().c_str(); 1052 AliaseeName = getContext().Idents.get(AliaseeName).getName(); 1053 1054 // Create a reference to the named value. This ensures that it is emitted 1055 // if a deferred decl. 1056 llvm::Constant *Aliasee; 1057 if (isa<llvm::FunctionType>(DeclTy)) 1058 Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, GlobalDecl()); 1059 else 1060 Aliasee = GetOrCreateLLVMGlobal(AliaseeName, 1061 VMContext.getPointerTypeUnqual(DeclTy), 0); 1062 1063 // Create the new alias itself, but don't set a name yet. 1064 llvm::GlobalValue *GA = 1065 new llvm::GlobalAlias(Aliasee->getType(), 1066 llvm::Function::ExternalLinkage, 1067 "", Aliasee, &getModule()); 1068 1069 // See if there is already something with the alias' name in the module. 1070 const char *MangledName = getMangledName(D); 1071 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 1072 1073 if (Entry && !Entry->isDeclaration()) { 1074 // If there is a definition in the module, then it wins over the alias. 1075 // This is dubious, but allow it to be safe. Just ignore the alias. 1076 GA->eraseFromParent(); 1077 return; 1078 } 1079 1080 if (Entry) { 1081 // If there is a declaration in the module, then we had an extern followed 1082 // by the alias, as in: 1083 // extern int test6(); 1084 // ... 1085 // int test6() __attribute__((alias("test7"))); 1086 // 1087 // Remove it and replace uses of it with the alias. 1088 1089 Entry->replaceAllUsesWith(VMContext.getConstantExprBitCast(GA, 1090 Entry->getType())); 1091 Entry->eraseFromParent(); 1092 } 1093 1094 // Now we know that there is no conflict, set the name. 1095 Entry = GA; 1096 GA->setName(MangledName); 1097 1098 // Set attributes which are particular to an alias; this is a 1099 // specialization of the attributes which may be set on a global 1100 // variable/function. 1101 if (D->hasAttr<DLLExportAttr>()) { 1102 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1103 // The dllexport attribute is ignored for undefined symbols. 1104 if (FD->getBody()) 1105 GA->setLinkage(llvm::Function::DLLExportLinkage); 1106 } else { 1107 GA->setLinkage(llvm::Function::DLLExportLinkage); 1108 } 1109 } else if (D->hasAttr<WeakAttr>() || 1110 D->hasAttr<WeakImportAttr>()) { 1111 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1112 } 1113 1114 SetCommonAttributes(D, GA); 1115} 1116 1117/// getBuiltinLibFunction - Given a builtin id for a function like 1118/// "__builtin_fabsf", return a Function* for "fabsf". 1119llvm::Value *CodeGenModule::getBuiltinLibFunction(unsigned BuiltinID) { 1120 assert((Context.BuiltinInfo.isLibFunction(BuiltinID) || 1121 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) && 1122 "isn't a lib fn"); 1123 1124 // Get the name, skip over the __builtin_ prefix (if necessary). 1125 const char *Name = Context.BuiltinInfo.GetName(BuiltinID); 1126 if (Context.BuiltinInfo.isLibFunction(BuiltinID)) 1127 Name += 10; 1128 1129 // Get the type for the builtin. 1130 ASTContext::GetBuiltinTypeError Error; 1131 QualType Type = Context.GetBuiltinType(BuiltinID, Error); 1132 assert(Error == ASTContext::GE_None && "Can't get builtin type"); 1133 1134 const llvm::FunctionType *Ty = 1135 cast<llvm::FunctionType>(getTypes().ConvertType(Type)); 1136 1137 // Unique the name through the identifier table. 1138 Name = getContext().Idents.get(Name).getName(); 1139 // FIXME: param attributes for sext/zext etc. 1140 return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl()); 1141} 1142 1143llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys, 1144 unsigned NumTys) { 1145 return llvm::Intrinsic::getDeclaration(&getModule(), 1146 (llvm::Intrinsic::ID)IID, Tys, NumTys); 1147} 1148 1149llvm::Function *CodeGenModule::getMemCpyFn() { 1150 if (MemCpyFn) return MemCpyFn; 1151 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(); 1152 return MemCpyFn = getIntrinsic(llvm::Intrinsic::memcpy, &IntPtr, 1); 1153} 1154 1155llvm::Function *CodeGenModule::getMemMoveFn() { 1156 if (MemMoveFn) return MemMoveFn; 1157 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(); 1158 return MemMoveFn = getIntrinsic(llvm::Intrinsic::memmove, &IntPtr, 1); 1159} 1160 1161llvm::Function *CodeGenModule::getMemSetFn() { 1162 if (MemSetFn) return MemSetFn; 1163 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(); 1164 return MemSetFn = getIntrinsic(llvm::Intrinsic::memset, &IntPtr, 1); 1165} 1166 1167static void appendFieldAndPadding(CodeGenModule &CGM, 1168 std::vector<llvm::Constant*>& Fields, 1169 FieldDecl *FieldD, FieldDecl *NextFieldD, 1170 llvm::Constant* Field, 1171 RecordDecl* RD, const llvm::StructType *STy) { 1172 // Append the field. 1173 Fields.push_back(Field); 1174 1175 int StructFieldNo = CGM.getTypes().getLLVMFieldNo(FieldD); 1176 1177 int NextStructFieldNo; 1178 if (!NextFieldD) { 1179 NextStructFieldNo = STy->getNumElements(); 1180 } else { 1181 NextStructFieldNo = CGM.getTypes().getLLVMFieldNo(NextFieldD); 1182 } 1183 1184 // Append padding 1185 for (int i = StructFieldNo + 1; i < NextStructFieldNo; i++) { 1186 llvm::Constant *C = 1187 CGM.getLLVMContext().getNullValue(STy->getElementType(StructFieldNo + 1)); 1188 1189 Fields.push_back(C); 1190 } 1191} 1192 1193llvm::Constant *CodeGenModule:: 1194GetAddrOfConstantCFString(const StringLiteral *Literal) { 1195 std::string str; 1196 unsigned StringLength = 0; 1197 1198 bool isUTF16 = false; 1199 if (Literal->containsNonAsciiOrNull()) { 1200 // Convert from UTF-8 to UTF-16. 1201 llvm::SmallVector<UTF16, 128> ToBuf(Literal->getByteLength()); 1202 const UTF8 *FromPtr = (UTF8 *)Literal->getStrData(); 1203 UTF16 *ToPtr = &ToBuf[0]; 1204 1205 ConversionResult Result; 1206 Result = ConvertUTF8toUTF16(&FromPtr, FromPtr+Literal->getByteLength(), 1207 &ToPtr, ToPtr+Literal->getByteLength(), 1208 strictConversion); 1209 if (Result == conversionOK) { 1210 // FIXME: Storing UTF-16 in a C string is a hack to test Unicode strings 1211 // without doing more surgery to this routine. Since we aren't explicitly 1212 // checking for endianness here, it's also a bug (when generating code for 1213 // a target that doesn't match the host endianness). Modeling this as an 1214 // i16 array is likely the cleanest solution. 1215 StringLength = ToPtr-&ToBuf[0]; 1216 str.assign((char *)&ToBuf[0], StringLength*2);// Twice as many UTF8 chars. 1217 isUTF16 = true; 1218 } else { 1219 assert(Result == sourceIllegal && "UTF-8 to UTF-16 conversion failed"); 1220 // FIXME: Have Sema::CheckObjCString() validate the UTF-8 string. 1221 StringLength = Literal->getByteLength(); 1222 str.assign(Literal->getStrData(), StringLength); 1223 } 1224 } else { 1225 StringLength = Literal->getByteLength(); 1226 str.assign(Literal->getStrData(), StringLength); 1227 } 1228 llvm::Constant *&Entry = CFConstantStringMap[str]; 1229 1230 if (Entry) 1231 return Entry; 1232 1233 llvm::Constant *Zero = getLLVMContext().getNullValue(llvm::Type::Int32Ty); 1234 llvm::Constant *Zeros[] = { Zero, Zero }; 1235 1236 // If we don't already have it, get __CFConstantStringClassReference. 1237 if (!CFConstantStringClassRef) { 1238 const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1239 Ty = VMContext.getArrayType(Ty, 0); 1240 llvm::Constant *GV = CreateRuntimeVariable(Ty, 1241 "__CFConstantStringClassReference"); 1242 // Decay array -> ptr 1243 CFConstantStringClassRef = 1244 VMContext.getConstantExprGetElementPtr(GV, Zeros, 2); 1245 } 1246 1247 QualType CFTy = getContext().getCFConstantStringType(); 1248 RecordDecl *CFRD = CFTy->getAsRecordType()->getDecl(); 1249 1250 const llvm::StructType *STy = 1251 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1252 1253 std::vector<llvm::Constant*> Fields; 1254 RecordDecl::field_iterator Field = CFRD->field_begin(); 1255 1256 // Class pointer. 1257 FieldDecl *CurField = *Field++; 1258 FieldDecl *NextField = *Field++; 1259 appendFieldAndPadding(*this, Fields, CurField, NextField, 1260 CFConstantStringClassRef, CFRD, STy); 1261 1262 // Flags. 1263 CurField = NextField; 1264 NextField = *Field++; 1265 const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1266 appendFieldAndPadding(*this, Fields, CurField, NextField, 1267 isUTF16 ? VMContext.getConstantInt(Ty, 0x07d0) 1268 : VMContext.getConstantInt(Ty, 0x07C8), 1269 CFRD, STy); 1270 1271 // String pointer. 1272 CurField = NextField; 1273 NextField = *Field++; 1274 llvm::Constant *C = VMContext.getConstantArray(str); 1275 1276 const char *Sect, *Prefix; 1277 bool isConstant; 1278 llvm::GlobalValue::LinkageTypes Linkage; 1279 if (isUTF16) { 1280 Prefix = getContext().Target.getUnicodeStringSymbolPrefix(); 1281 Sect = getContext().Target.getUnicodeStringSection(); 1282 // FIXME: why do utf strings get "l" labels instead of "L" labels? 1283 Linkage = llvm::GlobalValue::InternalLinkage; 1284 // FIXME: Why does GCC not set constant here? 1285 isConstant = false; 1286 } else { 1287 Prefix = ".str"; 1288 Sect = getContext().Target.getCFStringDataSection(); 1289 Linkage = llvm::GlobalValue::PrivateLinkage; 1290 // FIXME: -fwritable-strings should probably affect this, but we 1291 // are following gcc here. 1292 isConstant = true; 1293 } 1294 llvm::GlobalVariable *GV = 1295 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, 1296 Linkage, C, Prefix); 1297 if (Sect) 1298 GV->setSection(Sect); 1299 if (isUTF16) { 1300 unsigned Align = getContext().getTypeAlign(getContext().ShortTy)/8; 1301 GV->setAlignment(Align); 1302 } 1303 appendFieldAndPadding(*this, Fields, CurField, NextField, 1304 VMContext.getConstantExprGetElementPtr(GV, Zeros, 2), 1305 CFRD, STy); 1306 1307 // String length. 1308 CurField = NextField; 1309 NextField = 0; 1310 Ty = getTypes().ConvertType(getContext().LongTy); 1311 appendFieldAndPadding(*this, Fields, CurField, NextField, 1312 VMContext.getConstantInt(Ty, StringLength), CFRD, STy); 1313 1314 // The struct. 1315 C = VMContext.getConstantStruct(STy, Fields); 1316 GV = new llvm::GlobalVariable(getModule(), C->getType(), true, 1317 llvm::GlobalVariable::PrivateLinkage, C, 1318 "_unnamed_cfstring_"); 1319 if (const char *Sect = getContext().Target.getCFStringSection()) 1320 GV->setSection(Sect); 1321 Entry = GV; 1322 1323 return GV; 1324} 1325 1326/// GetStringForStringLiteral - Return the appropriate bytes for a 1327/// string literal, properly padded to match the literal type. 1328std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 1329 const char *StrData = E->getStrData(); 1330 unsigned Len = E->getByteLength(); 1331 1332 const ConstantArrayType *CAT = 1333 getContext().getAsConstantArrayType(E->getType()); 1334 assert(CAT && "String isn't pointer or array!"); 1335 1336 // Resize the string to the right size. 1337 std::string Str(StrData, StrData+Len); 1338 uint64_t RealLen = CAT->getSize().getZExtValue(); 1339 1340 if (E->isWide()) 1341 RealLen *= getContext().Target.getWCharWidth()/8; 1342 1343 Str.resize(RealLen, '\0'); 1344 1345 return Str; 1346} 1347 1348/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 1349/// constant array for the given string literal. 1350llvm::Constant * 1351CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 1352 // FIXME: This can be more efficient. 1353 return GetAddrOfConstantString(GetStringForStringLiteral(S)); 1354} 1355 1356/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 1357/// array for the given ObjCEncodeExpr node. 1358llvm::Constant * 1359CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 1360 std::string Str; 1361 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 1362 1363 return GetAddrOfConstantCString(Str); 1364} 1365 1366 1367/// GenerateWritableString -- Creates storage for a string literal. 1368static llvm::Constant *GenerateStringLiteral(const std::string &str, 1369 bool constant, 1370 CodeGenModule &CGM, 1371 const char *GlobalName) { 1372 // Create Constant for this string literal. Don't add a '\0'. 1373 llvm::Constant *C = CGM.getLLVMContext().getConstantArray(str, false); 1374 1375 // Create a global variable for this string 1376 return new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant, 1377 llvm::GlobalValue::PrivateLinkage, 1378 C, GlobalName); 1379} 1380 1381/// GetAddrOfConstantString - Returns a pointer to a character array 1382/// containing the literal. This contents are exactly that of the 1383/// given string, i.e. it will not be null terminated automatically; 1384/// see GetAddrOfConstantCString. Note that whether the result is 1385/// actually a pointer to an LLVM constant depends on 1386/// Feature.WriteableStrings. 1387/// 1388/// The result has pointer to array type. 1389llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str, 1390 const char *GlobalName) { 1391 bool IsConstant = !Features.WritableStrings; 1392 1393 // Get the default prefix if a name wasn't specified. 1394 if (!GlobalName) 1395 GlobalName = ".str"; 1396 1397 // Don't share any string literals if strings aren't constant. 1398 if (!IsConstant) 1399 return GenerateStringLiteral(str, false, *this, GlobalName); 1400 1401 llvm::StringMapEntry<llvm::Constant *> &Entry = 1402 ConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]); 1403 1404 if (Entry.getValue()) 1405 return Entry.getValue(); 1406 1407 // Create a global variable for this. 1408 llvm::Constant *C = GenerateStringLiteral(str, true, *this, GlobalName); 1409 Entry.setValue(C); 1410 return C; 1411} 1412 1413/// GetAddrOfConstantCString - Returns a pointer to a character 1414/// array containing the literal and a terminating '\-' 1415/// character. The result has pointer to array type. 1416llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &str, 1417 const char *GlobalName){ 1418 return GetAddrOfConstantString(str + '\0', GlobalName); 1419} 1420 1421/// EmitObjCPropertyImplementations - Emit information for synthesized 1422/// properties for an implementation. 1423void CodeGenModule::EmitObjCPropertyImplementations(const 1424 ObjCImplementationDecl *D) { 1425 for (ObjCImplementationDecl::propimpl_iterator 1426 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) { 1427 ObjCPropertyImplDecl *PID = *i; 1428 1429 // Dynamic is just for type-checking. 1430 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 1431 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 1432 1433 // Determine which methods need to be implemented, some may have 1434 // been overridden. Note that ::isSynthesized is not the method 1435 // we want, that just indicates if the decl came from a 1436 // property. What we want to know is if the method is defined in 1437 // this implementation. 1438 if (!D->getInstanceMethod(PD->getGetterName())) 1439 CodeGenFunction(*this).GenerateObjCGetter( 1440 const_cast<ObjCImplementationDecl *>(D), PID); 1441 if (!PD->isReadOnly() && 1442 !D->getInstanceMethod(PD->getSetterName())) 1443 CodeGenFunction(*this).GenerateObjCSetter( 1444 const_cast<ObjCImplementationDecl *>(D), PID); 1445 } 1446 } 1447} 1448 1449/// EmitNamespace - Emit all declarations in a namespace. 1450void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 1451 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end(); 1452 I != E; ++I) 1453 EmitTopLevelDecl(*I); 1454} 1455 1456// EmitLinkageSpec - Emit all declarations in a linkage spec. 1457void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 1458 if (LSD->getLanguage() != LinkageSpecDecl::lang_c) { 1459 ErrorUnsupported(LSD, "linkage spec"); 1460 return; 1461 } 1462 1463 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end(); 1464 I != E; ++I) 1465 EmitTopLevelDecl(*I); 1466} 1467 1468/// EmitTopLevelDecl - Emit code for a single top level declaration. 1469void CodeGenModule::EmitTopLevelDecl(Decl *D) { 1470 // If an error has occurred, stop code generation, but continue 1471 // parsing and semantic analysis (to ensure all warnings and errors 1472 // are emitted). 1473 if (Diags.hasErrorOccurred()) 1474 return; 1475 1476 // Ignore dependent declarations. 1477 if (D->getDeclContext() && D->getDeclContext()->isDependentContext()) 1478 return; 1479 1480 switch (D->getKind()) { 1481 case Decl::CXXMethod: 1482 case Decl::Function: 1483 // Skip function templates 1484 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate()) 1485 return; 1486 1487 // Fall through 1488 1489 case Decl::Var: 1490 EmitGlobal(GlobalDecl(cast<ValueDecl>(D))); 1491 break; 1492 1493 // C++ Decls 1494 case Decl::Namespace: 1495 EmitNamespace(cast<NamespaceDecl>(D)); 1496 break; 1497 // No code generation needed. 1498 case Decl::Using: 1499 case Decl::ClassTemplate: 1500 case Decl::FunctionTemplate: 1501 break; 1502 case Decl::CXXConstructor: 1503 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 1504 break; 1505 case Decl::CXXDestructor: 1506 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 1507 break; 1508 1509 case Decl::StaticAssert: 1510 // Nothing to do. 1511 break; 1512 1513 // Objective-C Decls 1514 1515 // Forward declarations, no (immediate) code generation. 1516 case Decl::ObjCClass: 1517 case Decl::ObjCForwardProtocol: 1518 case Decl::ObjCCategory: 1519 case Decl::ObjCInterface: 1520 break; 1521 1522 case Decl::ObjCProtocol: 1523 Runtime->GenerateProtocol(cast<ObjCProtocolDecl>(D)); 1524 break; 1525 1526 case Decl::ObjCCategoryImpl: 1527 // Categories have properties but don't support synthesize so we 1528 // can ignore them here. 1529 Runtime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 1530 break; 1531 1532 case Decl::ObjCImplementation: { 1533 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 1534 EmitObjCPropertyImplementations(OMD); 1535 Runtime->GenerateClass(OMD); 1536 break; 1537 } 1538 case Decl::ObjCMethod: { 1539 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 1540 // If this is not a prototype, emit the body. 1541 if (OMD->getBody()) 1542 CodeGenFunction(*this).GenerateObjCMethod(OMD); 1543 break; 1544 } 1545 case Decl::ObjCCompatibleAlias: 1546 // compatibility-alias is a directive and has no code gen. 1547 break; 1548 1549 case Decl::LinkageSpec: 1550 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 1551 break; 1552 1553 case Decl::FileScopeAsm: { 1554 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 1555 std::string AsmString(AD->getAsmString()->getStrData(), 1556 AD->getAsmString()->getByteLength()); 1557 1558 const std::string &S = getModule().getModuleInlineAsm(); 1559 if (S.empty()) 1560 getModule().setModuleInlineAsm(AsmString); 1561 else 1562 getModule().setModuleInlineAsm(S + '\n' + AsmString); 1563 break; 1564 } 1565 1566 default: 1567 // Make sure we handled everything we should, every other kind is a 1568 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind 1569 // function. Need to recode Decl::Kind to do that easily. 1570 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 1571 } 1572} 1573