CodeGenModule.cpp revision 005eedce54da6580de37bb115bf581008637e4b1
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/Diagnostic.h" 25#include "clang/Basic/SourceManager.h" 26#include "clang/Basic/TargetInfo.h" 27#include "clang/Basic/ConvertUTF.h" 28#include "llvm/CallingConv.h" 29#include "llvm/Module.h" 30#include "llvm/Intrinsics.h" 31#include "llvm/Target/TargetData.h" 32using namespace clang; 33using namespace CodeGen; 34 35 36CodeGenModule::CodeGenModule(ASTContext &C, const CompileOptions &compileOpts, 37 llvm::Module &M, const llvm::TargetData &TD, 38 Diagnostic &diags) 39 : BlockModule(C, M, TD, Types, *this), Context(C), 40 Features(C.getLangOptions()), CompileOpts(compileOpts), TheModule(M), 41 TheTargetData(TD), Diags(diags), Types(C, M, TD), Runtime(0), 42 MemCpyFn(0), MemMoveFn(0), MemSetFn(0), CFConstantStringClassRef(0) { 43 44 if (!Features.ObjC1) 45 Runtime = 0; 46 else if (!Features.NeXTRuntime) 47 Runtime = CreateGNUObjCRuntime(*this); 48 else if (Features.ObjCNonFragileABI) 49 Runtime = CreateMacNonFragileABIObjCRuntime(*this); 50 else 51 Runtime = CreateMacObjCRuntime(*this); 52 53 // If debug info generation is enabled, create the CGDebugInfo object. 54 DebugInfo = CompileOpts.DebugInfo ? new CGDebugInfo(this) : 0; 55} 56 57CodeGenModule::~CodeGenModule() { 58 delete Runtime; 59 delete DebugInfo; 60} 61 62void CodeGenModule::Release() { 63 EmitDeferred(); 64 if (Runtime) 65 if (llvm::Function *ObjCInitFunction = Runtime->ModuleInitFunction()) 66 AddGlobalCtor(ObjCInitFunction); 67 EmitCtorList(GlobalCtors, "llvm.global_ctors"); 68 EmitCtorList(GlobalDtors, "llvm.global_dtors"); 69 EmitAnnotations(); 70 EmitLLVMUsed(); 71} 72 73/// ErrorUnsupported - Print out an error that codegen doesn't support the 74/// specified stmt yet. 75void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type, 76 bool OmitOnError) { 77 if (OmitOnError && getDiags().hasErrorOccurred()) 78 return; 79 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 80 "cannot compile this %0 yet"); 81 std::string Msg = Type; 82 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID) 83 << Msg << S->getSourceRange(); 84} 85 86/// ErrorUnsupported - Print out an error that codegen doesn't support the 87/// specified decl yet. 88void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type, 89 bool OmitOnError) { 90 if (OmitOnError && getDiags().hasErrorOccurred()) 91 return; 92 unsigned DiagID = getDiags().getCustomDiagID(Diagnostic::Error, 93 "cannot compile this %0 yet"); 94 std::string Msg = Type; 95 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg; 96} 97 98LangOptions::VisibilityMode 99CodeGenModule::getDeclVisibilityMode(const Decl *D) const { 100 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 101 if (VD->getStorageClass() == VarDecl::PrivateExtern) 102 return LangOptions::Hidden; 103 104 if (const VisibilityAttr *attr = D->getAttr<VisibilityAttr>()) { 105 switch (attr->getVisibility()) { 106 default: assert(0 && "Unknown visibility!"); 107 case VisibilityAttr::DefaultVisibility: 108 return LangOptions::Default; 109 case VisibilityAttr::HiddenVisibility: 110 return LangOptions::Hidden; 111 case VisibilityAttr::ProtectedVisibility: 112 return LangOptions::Protected; 113 } 114 } 115 116 return getLangOptions().getVisibilityMode(); 117} 118 119void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV, 120 const Decl *D) const { 121 // Internal definitions always have default visibility. 122 if (GV->hasLocalLinkage()) { 123 GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 124 return; 125 } 126 127 switch (getDeclVisibilityMode(D)) { 128 default: assert(0 && "Unknown visibility!"); 129 case LangOptions::Default: 130 return GV->setVisibility(llvm::GlobalValue::DefaultVisibility); 131 case LangOptions::Hidden: 132 return GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 133 case LangOptions::Protected: 134 return GV->setVisibility(llvm::GlobalValue::ProtectedVisibility); 135 } 136} 137 138const char *CodeGenModule::getMangledName(const GlobalDecl &GD) { 139 const NamedDecl *ND = GD.getDecl(); 140 141 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND)) 142 return getMangledCXXCtorName(D, GD.getCtorType()); 143 if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND)) 144 return getMangledCXXDtorName(D, GD.getDtorType()); 145 146 return getMangledName(ND); 147} 148 149/// \brief Retrieves the mangled name for the given declaration. 150/// 151/// If the given declaration requires a mangled name, returns an 152/// const char* containing the mangled name. Otherwise, returns 153/// the unmangled name. 154/// 155const char *CodeGenModule::getMangledName(const NamedDecl *ND) { 156 // In C, functions with no attributes never need to be mangled. Fastpath them. 157 if (!getLangOptions().CPlusPlus && !ND->hasAttrs()) { 158 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl."); 159 return ND->getNameAsCString(); 160 } 161 162 llvm::SmallString<256> Name; 163 llvm::raw_svector_ostream Out(Name); 164 if (!mangleName(ND, Context, Out)) { 165 assert(ND->getIdentifier() && "Attempt to mangle unnamed decl."); 166 return ND->getNameAsCString(); 167 } 168 169 Name += '\0'; 170 return UniqueMangledName(Name.begin(), Name.end()); 171} 172 173const char *CodeGenModule::UniqueMangledName(const char *NameStart, 174 const char *NameEnd) { 175 assert(*(NameEnd - 1) == '\0' && "Mangled name must be null terminated!"); 176 177 return MangledNames.GetOrCreateValue(NameStart, NameEnd).getKeyData(); 178} 179 180/// AddGlobalCtor - Add a function to the list that will be called before 181/// main() runs. 182void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) { 183 // FIXME: Type coercion of void()* types. 184 GlobalCtors.push_back(std::make_pair(Ctor, Priority)); 185} 186 187/// AddGlobalDtor - Add a function to the list that will be called 188/// when the module is unloaded. 189void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) { 190 // FIXME: Type coercion of void()* types. 191 GlobalDtors.push_back(std::make_pair(Dtor, Priority)); 192} 193 194void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) { 195 // Ctor function type is void()*. 196 llvm::FunctionType* CtorFTy = 197 llvm::FunctionType::get(llvm::Type::VoidTy, 198 std::vector<const llvm::Type*>(), 199 false); 200 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy); 201 202 // Get the type of a ctor entry, { i32, void ()* }. 203 llvm::StructType* CtorStructTy = 204 llvm::StructType::get(llvm::Type::Int32Ty, 205 llvm::PointerType::getUnqual(CtorFTy), NULL); 206 207 // Construct the constructor and destructor arrays. 208 std::vector<llvm::Constant*> Ctors; 209 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 210 std::vector<llvm::Constant*> S; 211 S.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, I->second, false)); 212 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy)); 213 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S)); 214 } 215 216 if (!Ctors.empty()) { 217 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size()); 218 new llvm::GlobalVariable(AT, false, 219 llvm::GlobalValue::AppendingLinkage, 220 llvm::ConstantArray::get(AT, Ctors), 221 GlobalName, 222 &TheModule); 223 } 224} 225 226void CodeGenModule::EmitAnnotations() { 227 if (Annotations.empty()) 228 return; 229 230 // Create a new global variable for the ConstantStruct in the Module. 231 llvm::Constant *Array = 232 llvm::ConstantArray::get(llvm::ArrayType::get(Annotations[0]->getType(), 233 Annotations.size()), 234 Annotations); 235 llvm::GlobalValue *gv = 236 new llvm::GlobalVariable(Array->getType(), false, 237 llvm::GlobalValue::AppendingLinkage, Array, 238 "llvm.global.annotations", &TheModule); 239 gv->setSection("llvm.metadata"); 240} 241 242static CodeGenModule::GVALinkage 243GetLinkageForFunction(const FunctionDecl *FD, const LangOptions &Features) { 244 // "static" functions get internal linkage. 245 if (FD->getStorageClass() == FunctionDecl::Static) 246 return CodeGenModule::GVA_Internal; 247 248 if (!FD->isInline()) 249 return CodeGenModule::GVA_StrongExternal; 250 251 // If the inline function explicitly has the GNU inline attribute on it, or if 252 // this is C89 mode, we use to GNU semantics. 253 if (!Features.C99 && !Features.CPlusPlus) { 254 // extern inline in GNU mode is like C99 inline. 255 if (FD->getStorageClass() == FunctionDecl::Extern) 256 return CodeGenModule::GVA_C99Inline; 257 // Normal inline is a strong symbol. 258 return CodeGenModule::GVA_StrongExternal; 259 } else if (FD->hasActiveGNUInlineAttribute()) { 260 // GCC in C99 mode seems to use a different decision-making 261 // process for extern inline, which factors in previous 262 // declarations. 263 if (FD->isExternGNUInline()) 264 return CodeGenModule::GVA_C99Inline; 265 // Normal inline is a strong symbol. 266 return CodeGenModule::GVA_StrongExternal; 267 } 268 269 // The definition of inline changes based on the language. Note that we 270 // have already handled "static inline" above, with the GVA_Internal case. 271 if (Features.CPlusPlus) // inline and extern inline. 272 return CodeGenModule::GVA_CXXInline; 273 274 assert(Features.C99 && "Must be in C99 mode if not in C89 or C++ mode"); 275 if (FD->isC99InlineDefinition()) 276 return CodeGenModule::GVA_C99Inline; 277 278 return CodeGenModule::GVA_StrongExternal; 279} 280 281/// SetFunctionDefinitionAttributes - Set attributes for a global. 282/// 283/// FIXME: This is currently only done for aliases and functions, but 284/// not for variables (these details are set in 285/// EmitGlobalVarDefinition for variables). 286void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D, 287 llvm::GlobalValue *GV) { 288 GVALinkage Linkage = GetLinkageForFunction(D, Features); 289 290 if (Linkage == GVA_Internal) { 291 GV->setLinkage(llvm::Function::InternalLinkage); 292 } else if (D->hasAttr<DLLExportAttr>()) { 293 GV->setLinkage(llvm::Function::DLLExportLinkage); 294 } else if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakImportAttr>()) { 295 GV->setLinkage(llvm::Function::WeakAnyLinkage); 296 } else if (Linkage == GVA_C99Inline) { 297 // In C99 mode, 'inline' functions are guaranteed to have a strong 298 // definition somewhere else, so we can use available_externally linkage. 299 GV->setLinkage(llvm::Function::AvailableExternallyLinkage); 300 } else if (Linkage == GVA_CXXInline) { 301 // In C++, the compiler has to emit a definition in every translation unit 302 // that references the function. We should use linkonce_odr because 303 // a) if all references in this translation unit are optimized away, we 304 // don't need to codegen it. b) if the function persists, it needs to be 305 // merged with other definitions. c) C++ has the ODR, so we know the 306 // definition is dependable. 307 GV->setLinkage(llvm::Function::LinkOnceODRLinkage); 308 } else { 309 assert(Linkage == GVA_StrongExternal); 310 // Otherwise, we have strong external linkage. 311 GV->setLinkage(llvm::Function::ExternalLinkage); 312 } 313 314 SetCommonAttributes(D, GV); 315} 316 317void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D, 318 const CGFunctionInfo &Info, 319 llvm::Function *F) { 320 AttributeListType AttributeList; 321 ConstructAttributeList(Info, D, AttributeList); 322 323 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(), 324 AttributeList.size())); 325 326 // Set the appropriate calling convention for the Function. 327 if (D->hasAttr<FastCallAttr>()) 328 F->setCallingConv(llvm::CallingConv::X86_FastCall); 329 330 if (D->hasAttr<StdCallAttr>()) 331 F->setCallingConv(llvm::CallingConv::X86_StdCall); 332} 333 334void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, 335 llvm::Function *F) { 336 if (!Features.Exceptions && !Features.ObjCNonFragileABI) 337 F->addFnAttr(llvm::Attribute::NoUnwind); 338 339 if (D->hasAttr<AlwaysInlineAttr>()) 340 F->addFnAttr(llvm::Attribute::AlwaysInline); 341 342 if (D->hasAttr<NoinlineAttr>()) 343 F->addFnAttr(llvm::Attribute::NoInline); 344} 345 346void CodeGenModule::SetCommonAttributes(const Decl *D, 347 llvm::GlobalValue *GV) { 348 setGlobalVisibility(GV, D); 349 350 if (D->hasAttr<UsedAttr>()) 351 AddUsedGlobal(GV); 352 353 if (const SectionAttr *SA = D->getAttr<SectionAttr>()) 354 GV->setSection(SA->getName()); 355} 356 357void CodeGenModule::SetInternalFunctionAttributes(const Decl *D, 358 llvm::Function *F, 359 const CGFunctionInfo &FI) { 360 SetLLVMFunctionAttributes(D, FI, F); 361 SetLLVMFunctionAttributesForDefinition(D, F); 362 363 F->setLinkage(llvm::Function::InternalLinkage); 364 365 SetCommonAttributes(D, F); 366} 367 368void CodeGenModule::SetFunctionAttributes(const FunctionDecl *FD, 369 llvm::Function *F) { 370 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(FD), F); 371 372 // Only a few attributes are set on declarations; these may later be 373 // overridden by a definition. 374 375 if (FD->hasAttr<DLLImportAttr>()) { 376 F->setLinkage(llvm::Function::DLLImportLinkage); 377 } else if (FD->hasAttr<WeakAttr>() || FD->hasAttr<WeakImportAttr>()) { 378 // "extern_weak" is overloaded in LLVM; we probably should have 379 // separate linkage types for this. 380 F->setLinkage(llvm::Function::ExternalWeakLinkage); 381 } else { 382 F->setLinkage(llvm::Function::ExternalLinkage); 383 } 384 385 if (const SectionAttr *SA = FD->getAttr<SectionAttr>()) 386 F->setSection(SA->getName()); 387} 388 389void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) { 390 assert(!GV->isDeclaration() && 391 "Only globals with definition can force usage."); 392 LLVMUsed.push_back(GV); 393} 394 395void CodeGenModule::EmitLLVMUsed() { 396 // Don't create llvm.used if there is no need. 397 if (LLVMUsed.empty()) 398 return; 399 400 llvm::Type *i8PTy = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); 401 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, LLVMUsed.size()); 402 403 // Convert LLVMUsed to what ConstantArray needs. 404 std::vector<llvm::Constant*> UsedArray; 405 UsedArray.resize(LLVMUsed.size()); 406 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) { 407 UsedArray[i] = 408 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]), i8PTy); 409 } 410 411 llvm::GlobalVariable *GV = 412 new llvm::GlobalVariable(ATy, false, 413 llvm::GlobalValue::AppendingLinkage, 414 llvm::ConstantArray::get(ATy, UsedArray), 415 "llvm.used", &getModule()); 416 417 GV->setSection("llvm.metadata"); 418} 419 420void CodeGenModule::EmitDeferred() { 421 // Emit code for any potentially referenced deferred decls. Since a 422 // previously unused static decl may become used during the generation of code 423 // for a static function, iterate until no changes are made. 424 while (!DeferredDeclsToEmit.empty()) { 425 GlobalDecl D = DeferredDeclsToEmit.back(); 426 DeferredDeclsToEmit.pop_back(); 427 428 // The mangled name for the decl must have been emitted in GlobalDeclMap. 429 // Look it up to see if it was defined with a stronger definition (e.g. an 430 // extern inline function with a strong function redefinition). If so, 431 // just ignore the deferred decl. 432 llvm::GlobalValue *CGRef = GlobalDeclMap[getMangledName(D)]; 433 assert(CGRef && "Deferred decl wasn't referenced?"); 434 435 if (!CGRef->isDeclaration()) 436 continue; 437 438 // Otherwise, emit the definition and move on to the next one. 439 EmitGlobalDefinition(D); 440 } 441} 442 443/// EmitAnnotateAttr - Generate the llvm::ConstantStruct which contains the 444/// annotation information for a given GlobalValue. The annotation struct is 445/// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the 446/// GlobalValue being annotated. The second field is the constant string 447/// created from the AnnotateAttr's annotation. The third field is a constant 448/// string containing the name of the translation unit. The fourth field is 449/// the line number in the file of the annotated value declaration. 450/// 451/// FIXME: this does not unique the annotation string constants, as llvm-gcc 452/// appears to. 453/// 454llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV, 455 const AnnotateAttr *AA, 456 unsigned LineNo) { 457 llvm::Module *M = &getModule(); 458 459 // get [N x i8] constants for the annotation string, and the filename string 460 // which are the 2nd and 3rd elements of the global annotation structure. 461 const llvm::Type *SBP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); 462 llvm::Constant *anno = llvm::ConstantArray::get(AA->getAnnotation(), true); 463 llvm::Constant *unit = llvm::ConstantArray::get(M->getModuleIdentifier(), 464 true); 465 466 // Get the two global values corresponding to the ConstantArrays we just 467 // created to hold the bytes of the strings. 468 const char *StringPrefix = getContext().Target.getStringSymbolPrefix(true); 469 llvm::GlobalValue *annoGV = 470 new llvm::GlobalVariable(anno->getType(), false, 471 llvm::GlobalValue::InternalLinkage, anno, 472 GV->getName() + StringPrefix, M); 473 // translation unit name string, emitted into the llvm.metadata section. 474 llvm::GlobalValue *unitGV = 475 new llvm::GlobalVariable(unit->getType(), false, 476 llvm::GlobalValue::InternalLinkage, unit, 477 StringPrefix, M); 478 479 // Create the ConstantStruct for the global annotation. 480 llvm::Constant *Fields[4] = { 481 llvm::ConstantExpr::getBitCast(GV, SBP), 482 llvm::ConstantExpr::getBitCast(annoGV, SBP), 483 llvm::ConstantExpr::getBitCast(unitGV, SBP), 484 llvm::ConstantInt::get(llvm::Type::Int32Ty, LineNo) 485 }; 486 return llvm::ConstantStruct::get(Fields, 4, false); 487} 488 489bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { 490 // Never defer when EmitAllDecls is specified or the decl has 491 // attribute used. 492 if (Features.EmitAllDecls || Global->hasAttr<UsedAttr>()) 493 return false; 494 495 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 496 // Constructors and destructors should never be deferred. 497 if (FD->hasAttr<ConstructorAttr>() || FD->hasAttr<DestructorAttr>()) 498 return false; 499 500 GVALinkage Linkage = GetLinkageForFunction(FD, Features); 501 502 // static, static inline, always_inline, and extern inline functions can 503 // always be deferred. Normal inline functions can be deferred in C99/C++. 504 if (Linkage == GVA_Internal || Linkage == GVA_C99Inline || 505 Linkage == GVA_CXXInline) 506 return true; 507 return false; 508 } 509 510 const VarDecl *VD = cast<VarDecl>(Global); 511 assert(VD->isFileVarDecl() && "Invalid decl"); 512 513 return VD->getStorageClass() == VarDecl::Static; 514} 515 516void CodeGenModule::EmitGlobal(const GlobalDecl &GD) { 517 const ValueDecl *Global = GD.getDecl(); 518 519 // If this is an alias definition (which otherwise looks like a declaration) 520 // emit it now. 521 if (Global->hasAttr<AliasAttr>()) 522 return EmitAliasDefinition(Global); 523 524 // Ignore declarations, they will be emitted on their first use. 525 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) { 526 // Forward declarations are emitted lazily on first use. 527 if (!FD->isThisDeclarationADefinition()) 528 return; 529 } else { 530 const VarDecl *VD = cast<VarDecl>(Global); 531 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global."); 532 533 // In C++, if this is marked "extern", defer code generation. 534 if (getLangOptions().CPlusPlus && 535 VD->getStorageClass() == VarDecl::Extern && !VD->getInit()) 536 return; 537 538 // In C, if this isn't a definition, defer code generation. 539 if (!getLangOptions().CPlusPlus && !VD->getInit()) 540 return; 541 } 542 543 // Defer code generation when possible if this is a static definition, inline 544 // function etc. These we only want to emit if they are used. 545 if (MayDeferGeneration(Global)) { 546 // If the value has already been used, add it directly to the 547 // DeferredDeclsToEmit list. 548 const char *MangledName = getMangledName(GD); 549 if (GlobalDeclMap.count(MangledName)) 550 DeferredDeclsToEmit.push_back(GD); 551 else { 552 // Otherwise, remember that we saw a deferred decl with this name. The 553 // first use of the mangled name will cause it to move into 554 // DeferredDeclsToEmit. 555 DeferredDecls[MangledName] = GD; 556 } 557 return; 558 } 559 560 // Otherwise emit the definition. 561 EmitGlobalDefinition(GD); 562} 563 564void CodeGenModule::EmitGlobalDefinition(const GlobalDecl &GD) { 565 const ValueDecl *D = GD.getDecl(); 566 567 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D)) 568 EmitCXXConstructor(CD, GD.getCtorType()); 569 else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) 570 EmitGlobalFunctionDefinition(FD); 571 else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) 572 EmitGlobalVarDefinition(VD); 573 else { 574 assert(0 && "Invalid argument to EmitGlobalDefinition()"); 575 } 576} 577 578/// GetOrCreateLLVMFunction - If the specified mangled name is not in the 579/// module, create and return an llvm Function with the specified type. If there 580/// is something in the module with the specified name, return it potentially 581/// bitcasted to the right type. 582/// 583/// If D is non-null, it specifies a decl that correspond to this. This is used 584/// to set the attributes on the function when it is first created. 585llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(const char *MangledName, 586 const llvm::Type *Ty, 587 const FunctionDecl *D) { 588 // Lookup the entry, lazily creating it if necessary. 589 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 590 if (Entry) { 591 if (Entry->getType()->getElementType() == Ty) 592 return Entry; 593 594 // Make sure the result is of the correct type. 595 const llvm::Type *PTy = llvm::PointerType::getUnqual(Ty); 596 return llvm::ConstantExpr::getBitCast(Entry, PTy); 597 } 598 599 // This is the first use or definition of a mangled name. If there is a 600 // deferred decl with this name, remember that we need to emit it at the end 601 // of the file. 602 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 603 DeferredDecls.find(MangledName); 604 if (DDI != DeferredDecls.end()) { 605 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 606 // list, and remove it from DeferredDecls (since we don't need it anymore). 607 DeferredDeclsToEmit.push_back(DDI->second); 608 DeferredDecls.erase(DDI); 609 } 610 611 // This function doesn't have a complete type (for example, the return 612 // type is an incomplete struct). Use a fake type instead, and make 613 // sure not to try to set attributes. 614 bool ShouldSetAttributes = true; 615 if (!isa<llvm::FunctionType>(Ty)) { 616 Ty = llvm::FunctionType::get(llvm::Type::VoidTy, 617 std::vector<const llvm::Type*>(), false); 618 ShouldSetAttributes = false; 619 } 620 llvm::Function *F = llvm::Function::Create(cast<llvm::FunctionType>(Ty), 621 llvm::Function::ExternalLinkage, 622 "", &getModule()); 623 F->setName(MangledName); 624 if (D && ShouldSetAttributes) 625 SetFunctionAttributes(D, F); 626 Entry = F; 627 return F; 628} 629 630/// GetAddrOfFunction - Return the address of the given function. If Ty is 631/// non-null, then this function will use the specified type if it has to 632/// create it (this occurs when we see a definition of the function). 633llvm::Constant *CodeGenModule::GetAddrOfFunction(const FunctionDecl *D, 634 const llvm::Type *Ty) { 635 // If there was no specific requested type, just convert it now. 636 if (!Ty) 637 Ty = getTypes().ConvertType(D->getType()); 638 return GetOrCreateLLVMFunction(getMangledName(D), Ty, D); 639} 640 641/// CreateRuntimeFunction - Create a new runtime function with the specified 642/// type and name. 643llvm::Constant * 644CodeGenModule::CreateRuntimeFunction(const llvm::FunctionType *FTy, 645 const char *Name) { 646 // Convert Name to be a uniqued string from the IdentifierInfo table. 647 Name = getContext().Idents.get(Name).getName(); 648 return GetOrCreateLLVMFunction(Name, FTy, 0); 649} 650 651/// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module, 652/// create and return an llvm GlobalVariable with the specified type. If there 653/// is something in the module with the specified name, return it potentially 654/// bitcasted to the right type. 655/// 656/// If D is non-null, it specifies a decl that correspond to this. This is used 657/// to set the attributes on the global when it is first created. 658llvm::Constant *CodeGenModule::GetOrCreateLLVMGlobal(const char *MangledName, 659 const llvm::PointerType*Ty, 660 const VarDecl *D) { 661 // Lookup the entry, lazily creating it if necessary. 662 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 663 if (Entry) { 664 if (Entry->getType() == Ty) 665 return Entry; 666 667 // Make sure the result is of the correct type. 668 return llvm::ConstantExpr::getBitCast(Entry, Ty); 669 } 670 671 // This is the first use or definition of a mangled name. If there is a 672 // deferred decl with this name, remember that we need to emit it at the end 673 // of the file. 674 llvm::DenseMap<const char*, GlobalDecl>::iterator DDI = 675 DeferredDecls.find(MangledName); 676 if (DDI != DeferredDecls.end()) { 677 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit 678 // list, and remove it from DeferredDecls (since we don't need it anymore). 679 DeferredDeclsToEmit.push_back(DDI->second); 680 DeferredDecls.erase(DDI); 681 } 682 683 llvm::GlobalVariable *GV = 684 new llvm::GlobalVariable(Ty->getElementType(), false, 685 llvm::GlobalValue::ExternalLinkage, 686 0, "", &getModule(), 687 false, Ty->getAddressSpace()); 688 GV->setName(MangledName); 689 690 // Handle things which are present even on external declarations. 691 if (D) { 692 // FIXME: This code is overly simple and should be merged with 693 // other global handling. 694 GV->setConstant(D->getType().isConstant(Context)); 695 696 // FIXME: Merge with other attribute handling code. 697 if (D->getStorageClass() == VarDecl::PrivateExtern) 698 GV->setVisibility(llvm::GlobalValue::HiddenVisibility); 699 700 if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakImportAttr>()) 701 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage); 702 703 GV->setThreadLocal(D->isThreadSpecified()); 704 } 705 706 return Entry = GV; 707} 708 709 710/// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the 711/// given global variable. If Ty is non-null and if the global doesn't exist, 712/// then it will be greated with the specified type instead of whatever the 713/// normal requested type would be. 714llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D, 715 const llvm::Type *Ty) { 716 assert(D->hasGlobalStorage() && "Not a global variable"); 717 QualType ASTTy = D->getType(); 718 if (Ty == 0) 719 Ty = getTypes().ConvertTypeForMem(ASTTy); 720 721 const llvm::PointerType *PTy = 722 llvm::PointerType::get(Ty, ASTTy.getAddressSpace()); 723 return GetOrCreateLLVMGlobal(getMangledName(D), PTy, D); 724} 725 726/// CreateRuntimeVariable - Create a new runtime global variable with the 727/// specified type and name. 728llvm::Constant * 729CodeGenModule::CreateRuntimeVariable(const llvm::Type *Ty, 730 const char *Name) { 731 // Convert Name to be a uniqued string from the IdentifierInfo table. 732 Name = getContext().Idents.get(Name).getName(); 733 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0); 734} 735 736void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) { 737 assert(!D->getInit() && "Cannot emit definite definitions here!"); 738 739 if (MayDeferGeneration(D)) { 740 // If we have not seen a reference to this variable yet, place it 741 // into the deferred declarations table to be emitted if needed 742 // later. 743 const char *MangledName = getMangledName(D); 744 if (GlobalDeclMap.count(MangledName) == 0) { 745 DeferredDecls[MangledName] = GlobalDecl(D); 746 return; 747 } 748 } 749 750 // The tentative definition is the only definition. 751 EmitGlobalVarDefinition(D); 752} 753 754void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { 755 llvm::Constant *Init = 0; 756 QualType ASTTy = D->getType(); 757 758 if (D->getInit() == 0) { 759 // This is a tentative definition; tentative definitions are 760 // implicitly initialized with { 0 }. 761 // 762 // Note that tentative definitions are only emitted at the end of 763 // a translation unit, so they should never have incomplete 764 // type. In addition, EmitTentativeDefinition makes sure that we 765 // never attempt to emit a tentative definition if a real one 766 // exists. A use may still exists, however, so we still may need 767 // to do a RAUW. 768 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type"); 769 Init = llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(ASTTy)); 770 } else { 771 Init = EmitConstantExpr(D->getInit(), D->getType()); 772 if (!Init) { 773 ErrorUnsupported(D, "static initializer"); 774 QualType T = D->getInit()->getType(); 775 Init = llvm::UndefValue::get(getTypes().ConvertType(T)); 776 } 777 } 778 779 const llvm::Type* InitType = Init->getType(); 780 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType); 781 782 // Strip off a bitcast if we got one back. 783 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 784 assert(CE->getOpcode() == llvm::Instruction::BitCast); 785 Entry = CE->getOperand(0); 786 } 787 788 // Entry is now either a Function or GlobalVariable. 789 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry); 790 791 // We have a definition after a declaration with the wrong type. 792 // We must make a new GlobalVariable* and update everything that used OldGV 793 // (a declaration or tentative definition) with the new GlobalVariable* 794 // (which will be a definition). 795 // 796 // This happens if there is a prototype for a global (e.g. 797 // "extern int x[];") and then a definition of a different type (e.g. 798 // "int x[10];"). This also happens when an initializer has a different type 799 // from the type of the global (this happens with unions). 800 if (GV == 0 || 801 GV->getType()->getElementType() != InitType || 802 GV->getType()->getAddressSpace() != ASTTy.getAddressSpace()) { 803 804 // Remove the old entry from GlobalDeclMap so that we'll create a new one. 805 GlobalDeclMap.erase(getMangledName(D)); 806 807 // Make a new global with the correct type, this is now guaranteed to work. 808 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType)); 809 GV->takeName(cast<llvm::GlobalValue>(Entry)); 810 811 // Replace all uses of the old global with the new global 812 llvm::Constant *NewPtrForOldDecl = 813 llvm::ConstantExpr::getBitCast(GV, Entry->getType()); 814 Entry->replaceAllUsesWith(NewPtrForOldDecl); 815 816 // Erase the old global, since it is no longer used. 817 cast<llvm::GlobalValue>(Entry)->eraseFromParent(); 818 } 819 820 if (const AnnotateAttr *AA = D->getAttr<AnnotateAttr>()) { 821 SourceManager &SM = Context.getSourceManager(); 822 AddAnnotation(EmitAnnotateAttr(GV, AA, 823 SM.getInstantiationLineNumber(D->getLocation()))); 824 } 825 826 GV->setInitializer(Init); 827 GV->setConstant(D->getType().isConstant(Context)); 828 GV->setAlignment(getContext().getDeclAlignInBytes(D)); 829 830 // Set the llvm linkage type as appropriate. 831 if (D->getStorageClass() == VarDecl::Static) 832 GV->setLinkage(llvm::Function::InternalLinkage); 833 else if (D->hasAttr<DLLImportAttr>()) 834 GV->setLinkage(llvm::Function::DLLImportLinkage); 835 else if (D->hasAttr<DLLExportAttr>()) 836 GV->setLinkage(llvm::Function::DLLExportLinkage); 837 else if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakImportAttr>()) 838 GV->setLinkage(llvm::GlobalVariable::WeakAnyLinkage); 839 else if (!CompileOpts.NoCommon && 840 (!D->hasExternalStorage() && !D->getInit())) 841 GV->setLinkage(llvm::GlobalVariable::CommonLinkage); 842 else 843 GV->setLinkage(llvm::GlobalVariable::ExternalLinkage); 844 845 SetCommonAttributes(D, GV); 846 847 // Emit global variable debug information. 848 if (CGDebugInfo *DI = getDebugInfo()) { 849 DI->setLocation(D->getLocation()); 850 DI->EmitGlobalVariable(GV, D); 851 } 852} 853 854/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we 855/// implement a function with no prototype, e.g. "int foo() {}". If there are 856/// existing call uses of the old function in the module, this adjusts them to 857/// call the new function directly. 858/// 859/// This is not just a cleanup: the always_inline pass requires direct calls to 860/// functions to be able to inline them. If there is a bitcast in the way, it 861/// won't inline them. Instcombine normally deletes these calls, but it isn't 862/// run at -O0. 863static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old, 864 llvm::Function *NewFn) { 865 // If we're redefining a global as a function, don't transform it. 866 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old); 867 if (OldFn == 0) return; 868 869 const llvm::Type *NewRetTy = NewFn->getReturnType(); 870 llvm::SmallVector<llvm::Value*, 4> ArgList; 871 872 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end(); 873 UI != E; ) { 874 // TODO: Do invokes ever occur in C code? If so, we should handle them too. 875 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*UI++); 876 if (!CI) continue; 877 878 // If the return types don't match exactly, and if the call isn't dead, then 879 // we can't transform this call. 880 if (CI->getType() != NewRetTy && !CI->use_empty()) 881 continue; 882 883 // If the function was passed too few arguments, don't transform. If extra 884 // arguments were passed, we silently drop them. If any of the types 885 // mismatch, we don't transform. 886 unsigned ArgNo = 0; 887 bool DontTransform = false; 888 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(), 889 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) { 890 if (CI->getNumOperands()-1 == ArgNo || 891 CI->getOperand(ArgNo+1)->getType() != AI->getType()) { 892 DontTransform = true; 893 break; 894 } 895 } 896 if (DontTransform) 897 continue; 898 899 // Okay, we can transform this. Create the new call instruction and copy 900 // over the required information. 901 ArgList.append(CI->op_begin()+1, CI->op_begin()+1+ArgNo); 902 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(), 903 ArgList.end(), "", CI); 904 ArgList.clear(); 905 if (NewCall->getType() != llvm::Type::VoidTy) 906 NewCall->takeName(CI); 907 NewCall->setCallingConv(CI->getCallingConv()); 908 NewCall->setAttributes(CI->getAttributes()); 909 910 // Finally, remove the old call, replacing any uses with the new one. 911 if (!CI->use_empty()) 912 CI->replaceAllUsesWith(NewCall); 913 CI->eraseFromParent(); 914 } 915} 916 917 918void CodeGenModule::EmitGlobalFunctionDefinition(const FunctionDecl *D) { 919 const llvm::FunctionType *Ty; 920 921 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { 922 bool isVariadic = D->getType()->getAsFunctionProtoType()->isVariadic(); 923 924 Ty = getTypes().GetFunctionType(getTypes().getFunctionInfo(MD), isVariadic); 925 } else { 926 Ty = cast<llvm::FunctionType>(getTypes().ConvertType(D->getType())); 927 928 // As a special case, make sure that definitions of K&R function 929 // "type foo()" aren't declared as varargs (which forces the backend 930 // to do unnecessary work). 931 if (D->getType()->isFunctionNoProtoType()) { 932 assert(Ty->isVarArg() && "Didn't lower type as expected"); 933 // Due to stret, the lowered function could have arguments. 934 // Just create the same type as was lowered by ConvertType 935 // but strip off the varargs bit. 936 std::vector<const llvm::Type*> Args(Ty->param_begin(), Ty->param_end()); 937 Ty = llvm::FunctionType::get(Ty->getReturnType(), Args, false); 938 } 939 } 940 941 // Get or create the prototype for teh function. 942 llvm::Constant *Entry = GetAddrOfFunction(D, Ty); 943 944 // Strip off a bitcast if we got one back. 945 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { 946 assert(CE->getOpcode() == llvm::Instruction::BitCast); 947 Entry = CE->getOperand(0); 948 } 949 950 951 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) { 952 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry); 953 954 // If the types mismatch then we have to rewrite the definition. 955 assert(OldFn->isDeclaration() && 956 "Shouldn't replace non-declaration"); 957 958 // F is the Function* for the one with the wrong type, we must make a new 959 // Function* and update everything that used F (a declaration) with the new 960 // Function* (which will be a definition). 961 // 962 // This happens if there is a prototype for a function 963 // (e.g. "int f()") and then a definition of a different type 964 // (e.g. "int f(int x)"). Start by making a new function of the 965 // correct type, RAUW, then steal the name. 966 GlobalDeclMap.erase(getMangledName(D)); 967 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(D, Ty)); 968 NewFn->takeName(OldFn); 969 970 // If this is an implementation of a function without a prototype, try to 971 // replace any existing uses of the function (which may be calls) with uses 972 // of the new function 973 if (D->getType()->isFunctionNoProtoType()) 974 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn); 975 976 // Replace uses of F with the Function we will endow with a body. 977 if (!Entry->use_empty()) { 978 llvm::Constant *NewPtrForOldDecl = 979 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType()); 980 Entry->replaceAllUsesWith(NewPtrForOldDecl); 981 } 982 983 // Ok, delete the old function now, which is dead. 984 OldFn->eraseFromParent(); 985 986 Entry = NewFn; 987 } 988 989 llvm::Function *Fn = cast<llvm::Function>(Entry); 990 991 CodeGenFunction(*this).GenerateCode(D, Fn); 992 993 SetFunctionDefinitionAttributes(D, Fn); 994 SetLLVMFunctionAttributesForDefinition(D, Fn); 995 996 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>()) 997 AddGlobalCtor(Fn, CA->getPriority()); 998 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>()) 999 AddGlobalDtor(Fn, DA->getPriority()); 1000} 1001 1002void CodeGenModule::EmitAliasDefinition(const ValueDecl *D) { 1003 const AliasAttr *AA = D->getAttr<AliasAttr>(); 1004 assert(AA && "Not an alias?"); 1005 1006 const llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType()); 1007 1008 // Unique the name through the identifier table. 1009 const char *AliaseeName = AA->getAliasee().c_str(); 1010 AliaseeName = getContext().Idents.get(AliaseeName).getName(); 1011 1012 // Create a reference to the named value. This ensures that it is emitted 1013 // if a deferred decl. 1014 llvm::Constant *Aliasee; 1015 if (isa<llvm::FunctionType>(DeclTy)) 1016 Aliasee = GetOrCreateLLVMFunction(AliaseeName, DeclTy, 0); 1017 else 1018 Aliasee = GetOrCreateLLVMGlobal(AliaseeName, 1019 llvm::PointerType::getUnqual(DeclTy), 0); 1020 1021 // Create the new alias itself, but don't set a name yet. 1022 llvm::GlobalValue *GA = 1023 new llvm::GlobalAlias(Aliasee->getType(), 1024 llvm::Function::ExternalLinkage, 1025 "", Aliasee, &getModule()); 1026 1027 // See if there is already something with the alias' name in the module. 1028 const char *MangledName = getMangledName(D); 1029 llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName]; 1030 1031 if (Entry && !Entry->isDeclaration()) { 1032 // If there is a definition in the module, then it wins over the alias. 1033 // This is dubious, but allow it to be safe. Just ignore the alias. 1034 GA->eraseFromParent(); 1035 return; 1036 } 1037 1038 if (Entry) { 1039 // If there is a declaration in the module, then we had an extern followed 1040 // by the alias, as in: 1041 // extern int test6(); 1042 // ... 1043 // int test6() __attribute__((alias("test7"))); 1044 // 1045 // Remove it and replace uses of it with the alias. 1046 1047 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA, 1048 Entry->getType())); 1049 Entry->eraseFromParent(); 1050 } 1051 1052 // Now we know that there is no conflict, set the name. 1053 Entry = GA; 1054 GA->setName(MangledName); 1055 1056 // Set attributes which are particular to an alias; this is a 1057 // specialization of the attributes which may be set on a global 1058 // variable/function. 1059 if (D->hasAttr<DLLExportAttr>()) { 1060 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 1061 // The dllexport attribute is ignored for undefined symbols. 1062 if (FD->getBody(getContext())) 1063 GA->setLinkage(llvm::Function::DLLExportLinkage); 1064 } else { 1065 GA->setLinkage(llvm::Function::DLLExportLinkage); 1066 } 1067 } else if (D->hasAttr<WeakAttr>() || D->hasAttr<WeakImportAttr>()) { 1068 GA->setLinkage(llvm::Function::WeakAnyLinkage); 1069 } 1070 1071 SetCommonAttributes(D, GA); 1072} 1073 1074/// getBuiltinLibFunction - Given a builtin id for a function like 1075/// "__builtin_fabsf", return a Function* for "fabsf". 1076llvm::Value *CodeGenModule::getBuiltinLibFunction(unsigned BuiltinID) { 1077 assert((Context.BuiltinInfo.isLibFunction(BuiltinID) || 1078 Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) && 1079 "isn't a lib fn"); 1080 1081 // Get the name, skip over the __builtin_ prefix (if necessary). 1082 const char *Name = Context.BuiltinInfo.GetName(BuiltinID); 1083 if (Context.BuiltinInfo.isLibFunction(BuiltinID)) 1084 Name += 10; 1085 1086 // Get the type for the builtin. 1087 Builtin::Context::GetBuiltinTypeError Error; 1088 QualType Type = Context.BuiltinInfo.GetBuiltinType(BuiltinID, Context, Error); 1089 assert(Error == Builtin::Context::GE_None && "Can't get builtin type"); 1090 1091 const llvm::FunctionType *Ty = 1092 cast<llvm::FunctionType>(getTypes().ConvertType(Type)); 1093 1094 // Unique the name through the identifier table. 1095 Name = getContext().Idents.get(Name).getName(); 1096 // FIXME: param attributes for sext/zext etc. 1097 return GetOrCreateLLVMFunction(Name, Ty, 0); 1098} 1099 1100llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,const llvm::Type **Tys, 1101 unsigned NumTys) { 1102 return llvm::Intrinsic::getDeclaration(&getModule(), 1103 (llvm::Intrinsic::ID)IID, Tys, NumTys); 1104} 1105 1106llvm::Function *CodeGenModule::getMemCpyFn() { 1107 if (MemCpyFn) return MemCpyFn; 1108 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(); 1109 return MemCpyFn = getIntrinsic(llvm::Intrinsic::memcpy, &IntPtr, 1); 1110} 1111 1112llvm::Function *CodeGenModule::getMemMoveFn() { 1113 if (MemMoveFn) return MemMoveFn; 1114 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(); 1115 return MemMoveFn = getIntrinsic(llvm::Intrinsic::memmove, &IntPtr, 1); 1116} 1117 1118llvm::Function *CodeGenModule::getMemSetFn() { 1119 if (MemSetFn) return MemSetFn; 1120 const llvm::Type *IntPtr = TheTargetData.getIntPtrType(); 1121 return MemSetFn = getIntrinsic(llvm::Intrinsic::memset, &IntPtr, 1); 1122} 1123 1124static void appendFieldAndPadding(CodeGenModule &CGM, 1125 std::vector<llvm::Constant*>& Fields, 1126 FieldDecl *FieldD, FieldDecl *NextFieldD, 1127 llvm::Constant* Field, 1128 RecordDecl* RD, const llvm::StructType *STy) { 1129 // Append the field. 1130 Fields.push_back(Field); 1131 1132 int StructFieldNo = CGM.getTypes().getLLVMFieldNo(FieldD); 1133 1134 int NextStructFieldNo; 1135 if (!NextFieldD) { 1136 NextStructFieldNo = STy->getNumElements(); 1137 } else { 1138 NextStructFieldNo = CGM.getTypes().getLLVMFieldNo(NextFieldD); 1139 } 1140 1141 // Append padding 1142 for (int i = StructFieldNo + 1; i < NextStructFieldNo; i++) { 1143 llvm::Constant *C = 1144 llvm::Constant::getNullValue(STy->getElementType(StructFieldNo + 1)); 1145 1146 Fields.push_back(C); 1147 } 1148} 1149 1150llvm::Constant *CodeGenModule:: 1151GetAddrOfConstantCFString(const StringLiteral *Literal) { 1152 std::string str; 1153 unsigned StringLength = 0; 1154 1155 bool isUTF16 = false; 1156 if (Literal->containsNonAsciiOrNull()) { 1157 // Convert from UTF-8 to UTF-16. 1158 llvm::SmallVector<UTF16, 128> ToBuf(Literal->getByteLength()); 1159 const UTF8 *FromPtr = (UTF8 *)Literal->getStrData(); 1160 UTF16 *ToPtr = &ToBuf[0]; 1161 1162 ConversionResult Result; 1163 Result = ConvertUTF8toUTF16(&FromPtr, FromPtr+Literal->getByteLength(), 1164 &ToPtr, ToPtr+Literal->getByteLength(), 1165 strictConversion); 1166 if (Result == conversionOK) { 1167 // FIXME: Storing UTF-16 in a C string is a hack to test Unicode strings 1168 // without doing more surgery to this routine. Since we aren't explicitly 1169 // checking for endianness here, it's also a bug (when generating code for 1170 // a target that doesn't match the host endianness). Modeling this as an 1171 // i16 array is likely the cleanest solution. 1172 StringLength = ToPtr-&ToBuf[0]; 1173 str.assign((char *)&ToBuf[0], StringLength*2);// Twice as many UTF8 chars. 1174 isUTF16 = true; 1175 } else if (Result == sourceIllegal) { 1176 // FIXME: Have Sema::CheckObjCString() validate the UTF-8 string. 1177 str.assign(Literal->getStrData(), Literal->getByteLength()); 1178 StringLength = str.length(); 1179 } else 1180 assert(Result == conversionOK && "UTF-8 to UTF-16 conversion failed"); 1181 1182 } else { 1183 str.assign(Literal->getStrData(), Literal->getByteLength()); 1184 StringLength = str.length(); 1185 } 1186 llvm::StringMapEntry<llvm::Constant *> &Entry = 1187 CFConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]); 1188 1189 if (llvm::Constant *C = Entry.getValue()) 1190 return C; 1191 1192 llvm::Constant *Zero = llvm::Constant::getNullValue(llvm::Type::Int32Ty); 1193 llvm::Constant *Zeros[] = { Zero, Zero }; 1194 1195 if (!CFConstantStringClassRef) { 1196 const llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy); 1197 Ty = llvm::ArrayType::get(Ty, 0); 1198 1199 // FIXME: This is fairly broken if 1200 // __CFConstantStringClassReference is already defined, in that it 1201 // will get renamed and the user will most likely see an opaque 1202 // error message. This is a general issue with relying on 1203 // particular names. 1204 llvm::GlobalVariable *GV = 1205 new llvm::GlobalVariable(Ty, false, 1206 llvm::GlobalVariable::ExternalLinkage, 0, 1207 "__CFConstantStringClassReference", 1208 &getModule()); 1209 1210 // Decay array -> ptr 1211 CFConstantStringClassRef = 1212 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2); 1213 } 1214 1215 QualType CFTy = getContext().getCFConstantStringType(); 1216 RecordDecl *CFRD = CFTy->getAsRecordType()->getDecl(); 1217 1218 const llvm::StructType *STy = 1219 cast<llvm::StructType>(getTypes().ConvertType(CFTy)); 1220 1221 std::vector<llvm::Constant*> Fields; 1222 RecordDecl::field_iterator Field = CFRD->field_begin(getContext()); 1223 1224 // Class pointer. 1225 FieldDecl *CurField = *Field++; 1226 FieldDecl *NextField = *Field++; 1227 appendFieldAndPadding(*this, Fields, CurField, NextField, 1228 CFConstantStringClassRef, CFRD, STy); 1229 1230 // Flags. 1231 CurField = NextField; 1232 NextField = *Field++; 1233 const llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy); 1234 appendFieldAndPadding(*this, Fields, CurField, NextField, 1235 isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) 1236 : llvm::ConstantInt::get(Ty, 0x07C8), 1237 CFRD, STy); 1238 1239 // String pointer. 1240 CurField = NextField; 1241 NextField = *Field++; 1242 llvm::Constant *C = llvm::ConstantArray::get(str); 1243 1244 const char *Sect, *Prefix; 1245 bool isConstant; 1246 if (isUTF16) { 1247 Prefix = getContext().Target.getUnicodeStringSymbolPrefix(); 1248 Sect = getContext().Target.getUnicodeStringSection(); 1249 // FIXME: Why does GCC not set constant here? 1250 isConstant = false; 1251 } else { 1252 Prefix = getContext().Target.getStringSymbolPrefix(true); 1253 Sect = getContext().Target.getCFStringDataSection(); 1254 // FIXME: -fwritable-strings should probably affect this, but we 1255 // are following gcc here. 1256 isConstant = true; 1257 } 1258 llvm::GlobalVariable *GV = 1259 new llvm::GlobalVariable(C->getType(), isConstant, 1260 llvm::GlobalValue::InternalLinkage, 1261 C, Prefix, &getModule()); 1262 if (Sect) 1263 GV->setSection(Sect); 1264 if (isUTF16) { 1265 unsigned Align = getContext().getTypeAlign(getContext().ShortTy)/8; 1266 GV->setAlignment(Align); 1267 } 1268 appendFieldAndPadding(*this, Fields, CurField, NextField, 1269 llvm::ConstantExpr::getGetElementPtr(GV, Zeros, 2), 1270 CFRD, STy); 1271 1272 // String length. 1273 CurField = NextField; 1274 NextField = 0; 1275 Ty = getTypes().ConvertType(getContext().LongTy); 1276 appendFieldAndPadding(*this, Fields, CurField, NextField, 1277 llvm::ConstantInt::get(Ty, StringLength), CFRD, STy); 1278 1279 // The struct. 1280 C = llvm::ConstantStruct::get(STy, Fields); 1281 GV = new llvm::GlobalVariable(C->getType(), true, 1282 llvm::GlobalVariable::InternalLinkage, C, 1283 getContext().Target.getCFStringSymbolPrefix(), 1284 &getModule()); 1285 if (const char *Sect = getContext().Target.getCFStringSection()) 1286 GV->setSection(Sect); 1287 Entry.setValue(GV); 1288 1289 return GV; 1290} 1291 1292/// GetStringForStringLiteral - Return the appropriate bytes for a 1293/// string literal, properly padded to match the literal type. 1294std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) { 1295 const char *StrData = E->getStrData(); 1296 unsigned Len = E->getByteLength(); 1297 1298 const ConstantArrayType *CAT = 1299 getContext().getAsConstantArrayType(E->getType()); 1300 assert(CAT && "String isn't pointer or array!"); 1301 1302 // Resize the string to the right size. 1303 std::string Str(StrData, StrData+Len); 1304 uint64_t RealLen = CAT->getSize().getZExtValue(); 1305 1306 if (E->isWide()) 1307 RealLen *= getContext().Target.getWCharWidth()/8; 1308 1309 Str.resize(RealLen, '\0'); 1310 1311 return Str; 1312} 1313 1314/// GetAddrOfConstantStringFromLiteral - Return a pointer to a 1315/// constant array for the given string literal. 1316llvm::Constant * 1317CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { 1318 // FIXME: This can be more efficient. 1319 return GetAddrOfConstantString(GetStringForStringLiteral(S)); 1320} 1321 1322/// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant 1323/// array for the given ObjCEncodeExpr node. 1324llvm::Constant * 1325CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) { 1326 std::string Str; 1327 getContext().getObjCEncodingForType(E->getEncodedType(), Str); 1328 1329 return GetAddrOfConstantCString(Str); 1330} 1331 1332 1333/// GenerateWritableString -- Creates storage for a string literal. 1334static llvm::Constant *GenerateStringLiteral(const std::string &str, 1335 bool constant, 1336 CodeGenModule &CGM, 1337 const char *GlobalName) { 1338 // Create Constant for this string literal. Don't add a '\0'. 1339 llvm::Constant *C = llvm::ConstantArray::get(str, false); 1340 1341 // Create a global variable for this string 1342 return new llvm::GlobalVariable(C->getType(), constant, 1343 llvm::GlobalValue::InternalLinkage, 1344 C, GlobalName, &CGM.getModule()); 1345} 1346 1347/// GetAddrOfConstantString - Returns a pointer to a character array 1348/// containing the literal. This contents are exactly that of the 1349/// given string, i.e. it will not be null terminated automatically; 1350/// see GetAddrOfConstantCString. Note that whether the result is 1351/// actually a pointer to an LLVM constant depends on 1352/// Feature.WriteableStrings. 1353/// 1354/// The result has pointer to array type. 1355llvm::Constant *CodeGenModule::GetAddrOfConstantString(const std::string &str, 1356 const char *GlobalName) { 1357 bool IsConstant = !Features.WritableStrings; 1358 1359 // Get the default prefix if a name wasn't specified. 1360 if (!GlobalName) 1361 GlobalName = getContext().Target.getStringSymbolPrefix(IsConstant); 1362 1363 // Don't share any string literals if strings aren't constant. 1364 if (!IsConstant) 1365 return GenerateStringLiteral(str, false, *this, GlobalName); 1366 1367 llvm::StringMapEntry<llvm::Constant *> &Entry = 1368 ConstantStringMap.GetOrCreateValue(&str[0], &str[str.length()]); 1369 1370 if (Entry.getValue()) 1371 return Entry.getValue(); 1372 1373 // Create a global variable for this. 1374 llvm::Constant *C = GenerateStringLiteral(str, true, *this, GlobalName); 1375 Entry.setValue(C); 1376 return C; 1377} 1378 1379/// GetAddrOfConstantCString - Returns a pointer to a character 1380/// array containing the literal and a terminating '\-' 1381/// character. The result has pointer to array type. 1382llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &str, 1383 const char *GlobalName){ 1384 return GetAddrOfConstantString(str + '\0', GlobalName); 1385} 1386 1387/// EmitObjCPropertyImplementations - Emit information for synthesized 1388/// properties for an implementation. 1389void CodeGenModule::EmitObjCPropertyImplementations(const 1390 ObjCImplementationDecl *D) { 1391 for (ObjCImplementationDecl::propimpl_iterator 1392 i = D->propimpl_begin(getContext()), 1393 e = D->propimpl_end(getContext()); i != e; ++i) { 1394 ObjCPropertyImplDecl *PID = *i; 1395 1396 // Dynamic is just for type-checking. 1397 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) { 1398 ObjCPropertyDecl *PD = PID->getPropertyDecl(); 1399 1400 // Determine which methods need to be implemented, some may have 1401 // been overridden. Note that ::isSynthesized is not the method 1402 // we want, that just indicates if the decl came from a 1403 // property. What we want to know is if the method is defined in 1404 // this implementation. 1405 if (!D->getInstanceMethod(getContext(), PD->getGetterName())) 1406 CodeGenFunction(*this).GenerateObjCGetter( 1407 const_cast<ObjCImplementationDecl *>(D), PID); 1408 if (!PD->isReadOnly() && 1409 !D->getInstanceMethod(getContext(), PD->getSetterName())) 1410 CodeGenFunction(*this).GenerateObjCSetter( 1411 const_cast<ObjCImplementationDecl *>(D), PID); 1412 } 1413 } 1414} 1415 1416/// EmitNamespace - Emit all declarations in a namespace. 1417void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) { 1418 for (RecordDecl::decl_iterator I = ND->decls_begin(getContext()), 1419 E = ND->decls_end(getContext()); 1420 I != E; ++I) 1421 EmitTopLevelDecl(*I); 1422} 1423 1424// EmitLinkageSpec - Emit all declarations in a linkage spec. 1425void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) { 1426 if (LSD->getLanguage() != LinkageSpecDecl::lang_c) { 1427 ErrorUnsupported(LSD, "linkage spec"); 1428 return; 1429 } 1430 1431 for (RecordDecl::decl_iterator I = LSD->decls_begin(getContext()), 1432 E = LSD->decls_end(getContext()); 1433 I != E; ++I) 1434 EmitTopLevelDecl(*I); 1435} 1436 1437/// EmitTopLevelDecl - Emit code for a single top level declaration. 1438void CodeGenModule::EmitTopLevelDecl(Decl *D) { 1439 // If an error has occurred, stop code generation, but continue 1440 // parsing and semantic analysis (to ensure all warnings and errors 1441 // are emitted). 1442 if (Diags.hasErrorOccurred()) 1443 return; 1444 1445 switch (D->getKind()) { 1446 case Decl::CXXMethod: 1447 case Decl::Function: 1448 case Decl::Var: 1449 EmitGlobal(GlobalDecl(cast<ValueDecl>(D))); 1450 break; 1451 1452 // C++ Decls 1453 case Decl::Namespace: 1454 EmitNamespace(cast<NamespaceDecl>(D)); 1455 break; 1456 case Decl::CXXConstructor: 1457 EmitCXXConstructors(cast<CXXConstructorDecl>(D)); 1458 break; 1459 case Decl::CXXDestructor: 1460 EmitCXXDestructors(cast<CXXDestructorDecl>(D)); 1461 break; 1462 1463 // Objective-C Decls 1464 1465 // Forward declarations, no (immediate) code generation. 1466 case Decl::ObjCClass: 1467 case Decl::ObjCForwardProtocol: 1468 case Decl::ObjCCategory: 1469 case Decl::ObjCInterface: 1470 break; 1471 1472 case Decl::ObjCProtocol: 1473 Runtime->GenerateProtocol(cast<ObjCProtocolDecl>(D)); 1474 break; 1475 1476 case Decl::ObjCCategoryImpl: 1477 // Categories have properties but don't support synthesize so we 1478 // can ignore them here. 1479 Runtime->GenerateCategory(cast<ObjCCategoryImplDecl>(D)); 1480 break; 1481 1482 case Decl::ObjCImplementation: { 1483 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D); 1484 EmitObjCPropertyImplementations(OMD); 1485 Runtime->GenerateClass(OMD); 1486 break; 1487 } 1488 case Decl::ObjCMethod: { 1489 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D); 1490 // If this is not a prototype, emit the body. 1491 if (OMD->getBody(getContext())) 1492 CodeGenFunction(*this).GenerateObjCMethod(OMD); 1493 break; 1494 } 1495 case Decl::ObjCCompatibleAlias: 1496 // compatibility-alias is a directive and has no code gen. 1497 break; 1498 1499 case Decl::LinkageSpec: 1500 EmitLinkageSpec(cast<LinkageSpecDecl>(D)); 1501 break; 1502 1503 case Decl::FileScopeAsm: { 1504 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D); 1505 std::string AsmString(AD->getAsmString()->getStrData(), 1506 AD->getAsmString()->getByteLength()); 1507 1508 const std::string &S = getModule().getModuleInlineAsm(); 1509 if (S.empty()) 1510 getModule().setModuleInlineAsm(AsmString); 1511 else 1512 getModule().setModuleInlineAsm(S + '\n' + AsmString); 1513 break; 1514 } 1515 1516 default: 1517 // Make sure we handled everything we should, every other kind is 1518 // a non-top-level decl. FIXME: Would be nice to have an 1519 // isTopLevelDeclKind function. Need to recode Decl::Kind to do 1520 // that easily. 1521 assert(isa<TypeDecl>(D) && "Unsupported decl kind"); 1522 } 1523} 1524