1 //===--- CodeGenModule.cpp - Emit LLVM Code from ASTs for a Module --------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This coordinates the per-module state used while generating code.
12 //===----------------------------------------------------------------------===//
14 #include "CodeGenModule.h"
15 #include "CGDebugInfo.h"
16 #include "CodeGenFunction.h"
17 #include "CodeGenTBAA.h"
19 #include "CGCUDARuntime.h"
21 #include "CGObjCRuntime.h"
22 #include "CGOpenCLRuntime.h"
23 #include "TargetInfo.h"
24 #include "clang/Frontend/CodeGenOptions.h"
25 #include "clang/AST/ASTContext.h"
26 #include "clang/AST/CharUnits.h"
27 #include "clang/AST/DeclObjC.h"
28 #include "clang/AST/DeclCXX.h"
29 #include "clang/AST/DeclTemplate.h"
30 #include "clang/AST/Mangle.h"
31 #include "clang/AST/RecordLayout.h"
32 #include "clang/AST/RecursiveASTVisitor.h"
33 #include "clang/Basic/Diagnostic.h"
34 #include "clang/Basic/SourceManager.h"
35 #include "clang/Basic/TargetInfo.h"
36 #include "clang/Basic/ConvertUTF.h"
37 #include "llvm/CallingConv.h"
38 #include "llvm/Module.h"
39 #include "llvm/Intrinsics.h"
40 #include "llvm/LLVMContext.h"
41 #include "llvm/ADT/Triple.h"
42 #include "llvm/Target/Mangler.h"
43 #include "llvm/Target/TargetData.h"
44 #include "llvm/Support/CallSite.h"
45 #include "llvm/Support/ErrorHandling.h"
46 using namespace clang;
47 using namespace CodeGen;
49 static const char AnnotationSection[] = "llvm.metadata";
51 static CGCXXABI &createCXXABI(CodeGenModule &CGM) {
52 switch (CGM.getContext().getTargetInfo().getCXXABI()) {
53 case CXXABI_ARM: return *CreateARMCXXABI(CGM);
54 case CXXABI_Itanium: return *CreateItaniumCXXABI(CGM);
55 case CXXABI_Microsoft: return *CreateMicrosoftCXXABI(CGM);
58 llvm_unreachable("invalid C++ ABI kind");
59 return *CreateItaniumCXXABI(CGM);
63 CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO,
64 llvm::Module &M, const llvm::TargetData &TD,
65 DiagnosticsEngine &diags)
66 : Context(C), Features(C.getLangOptions()), CodeGenOpts(CGO), TheModule(M),
67 TheTargetData(TD), TheTargetCodeGenInfo(0), Diags(diags),
68 ABI(createCXXABI(*this)),
69 Types(C, M, TD, getTargetCodeGenInfo().getABIInfo(), ABI, CGO),
71 VTables(*this), ObjCRuntime(0), OpenCLRuntime(0), CUDARuntime(0),
72 DebugInfo(0), ARCData(0), RRData(0), CFConstantStringClassRef(0),
73 ConstantStringClassRef(0), NSConstantStringType(0),
74 VMContext(M.getContext()),
75 NSConcreteGlobalBlock(0), NSConcreteStackBlock(0),
76 BlockObjectAssign(0), BlockObjectDispose(0),
77 BlockDescriptorType(0), GenericBlockLiteralType(0) {
81 createOpenCLRuntime();
85 // Enable TBAA unless it's suppressed.
86 if (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0)
87 TBAA = new CodeGenTBAA(Context, VMContext, getLangOptions(),
88 ABI.getMangleContext());
90 // If debug info or coverage generation is enabled, create the CGDebugInfo
92 if (CodeGenOpts.DebugInfo || CodeGenOpts.EmitGcovArcs ||
93 CodeGenOpts.EmitGcovNotes)
94 DebugInfo = new CGDebugInfo(*this);
96 Block.GlobalUniqueCount = 0;
98 if (C.getLangOptions().ObjCAutoRefCount)
99 ARCData = new ARCEntrypoints();
100 RRData = new RREntrypoints();
102 // Initialize the type cache.
103 llvm::LLVMContext &LLVMContext = M.getContext();
104 VoidTy = llvm::Type::getVoidTy(LLVMContext);
105 Int8Ty = llvm::Type::getInt8Ty(LLVMContext);
106 Int32Ty = llvm::Type::getInt32Ty(LLVMContext);
107 Int64Ty = llvm::Type::getInt64Ty(LLVMContext);
108 PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
109 PointerAlignInBytes =
110 C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
111 IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
112 IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits);
113 Int8PtrTy = Int8Ty->getPointerTo(0);
114 Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
117 CodeGenModule::~CodeGenModule() {
119 delete OpenCLRuntime;
121 delete TheTargetCodeGenInfo;
129 void CodeGenModule::createObjCRuntime() {
130 if (!Features.NeXTRuntime)
131 ObjCRuntime = CreateGNUObjCRuntime(*this);
133 ObjCRuntime = CreateMacObjCRuntime(*this);
136 void CodeGenModule::createOpenCLRuntime() {
137 OpenCLRuntime = new CGOpenCLRuntime(*this);
140 void CodeGenModule::createCUDARuntime() {
141 CUDARuntime = CreateNVCUDARuntime(*this);
144 void CodeGenModule::Release() {
146 EmitCXXGlobalInitFunc();
147 EmitCXXGlobalDtorFunc();
149 if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
150 AddGlobalCtor(ObjCInitFunction);
151 EmitCtorList(GlobalCtors, "llvm.global_ctors");
152 EmitCtorList(GlobalDtors, "llvm.global_dtors");
153 EmitGlobalAnnotations();
156 SimplifyPersonality();
158 if (getCodeGenOpts().EmitDeclMetadata)
161 if (getCodeGenOpts().EmitGcovArcs || getCodeGenOpts().EmitGcovNotes)
165 DebugInfo->finalize();
168 void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
169 // Make sure that this type is translated.
170 Types.UpdateCompletedType(TD);
172 DebugInfo->UpdateCompletedType(TD);
175 llvm::MDNode *CodeGenModule::getTBAAInfo(QualType QTy) {
178 return TBAA->getTBAAInfo(QTy);
181 void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
182 llvm::MDNode *TBAAInfo) {
183 Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo);
186 bool CodeGenModule::isTargetDarwin() const {
187 return getContext().getTargetInfo().getTriple().isOSDarwin();
190 void CodeGenModule::Error(SourceLocation loc, StringRef error) {
191 unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, error);
192 getDiags().Report(Context.getFullLoc(loc), diagID);
195 /// ErrorUnsupported - Print out an error that codegen doesn't support the
196 /// specified stmt yet.
197 void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type,
199 if (OmitOnError && getDiags().hasErrorOccurred())
201 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
202 "cannot compile this %0 yet");
203 std::string Msg = Type;
204 getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID)
205 << Msg << S->getSourceRange();
208 /// ErrorUnsupported - Print out an error that codegen doesn't support the
209 /// specified decl yet.
210 void CodeGenModule::ErrorUnsupported(const Decl *D, const char *Type,
212 if (OmitOnError && getDiags().hasErrorOccurred())
214 unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
215 "cannot compile this %0 yet");
216 std::string Msg = Type;
217 getDiags().Report(Context.getFullLoc(D->getLocation()), DiagID) << Msg;
220 llvm::ConstantInt *CodeGenModule::getSize(CharUnits size) {
221 return llvm::ConstantInt::get(SizeTy, size.getQuantity());
224 void CodeGenModule::setGlobalVisibility(llvm::GlobalValue *GV,
225 const NamedDecl *D) const {
226 // Internal definitions always have default visibility.
227 if (GV->hasLocalLinkage()) {
228 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
232 // Set visibility for definitions.
233 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility();
234 if (LV.visibilityExplicit() || !GV->hasAvailableExternallyLinkage())
235 GV->setVisibility(GetLLVMVisibility(LV.visibility()));
238 /// Set the symbol visibility of type information (vtable and RTTI)
239 /// associated with the given type.
240 void CodeGenModule::setTypeVisibility(llvm::GlobalValue *GV,
241 const CXXRecordDecl *RD,
242 TypeVisibilityKind TVK) const {
243 setGlobalVisibility(GV, RD);
245 if (!CodeGenOpts.HiddenWeakVTables)
248 // We never want to drop the visibility for RTTI names.
249 if (TVK == TVK_ForRTTIName)
252 // We want to drop the visibility to hidden for weak type symbols.
253 // This isn't possible if there might be unresolved references
254 // elsewhere that rely on this symbol being visible.
256 // This should be kept roughly in sync with setThunkVisibility
260 if (GV->getLinkage() != llvm::GlobalVariable::LinkOnceODRLinkage ||
261 GV->getVisibility() != llvm::GlobalVariable::DefaultVisibility)
264 // Don't override an explicit visibility attribute.
265 if (RD->getExplicitVisibility())
268 switch (RD->getTemplateSpecializationKind()) {
269 // We have to disable the optimization if this is an EI definition
270 // because there might be EI declarations in other shared objects.
271 case TSK_ExplicitInstantiationDefinition:
272 case TSK_ExplicitInstantiationDeclaration:
275 // Every use of a non-template class's type information has to emit it.
279 // In theory, implicit instantiations can ignore the possibility of
280 // an explicit instantiation declaration because there necessarily
281 // must be an EI definition somewhere with default visibility. In
282 // practice, it's possible to have an explicit instantiation for
283 // an arbitrary template class, and linkers aren't necessarily able
284 // to deal with mixed-visibility symbols.
285 case TSK_ExplicitSpecialization:
286 case TSK_ImplicitInstantiation:
287 if (!CodeGenOpts.HiddenWeakTemplateVTables)
292 // If there's a key function, there may be translation units
293 // that don't have the key function's definition. But ignore
294 // this if we're emitting RTTI under -fno-rtti.
295 if (!(TVK != TVK_ForRTTI) || Features.RTTI) {
296 if (Context.getKeyFunction(RD))
300 // Otherwise, drop the visibility to hidden.
301 GV->setVisibility(llvm::GlobalValue::HiddenVisibility);
302 GV->setUnnamedAddr(true);
305 StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
306 const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
308 StringRef &Str = MangledDeclNames[GD.getCanonicalDecl()];
312 if (!getCXXABI().getMangleContext().shouldMangleDeclName(ND)) {
313 IdentifierInfo *II = ND->getIdentifier();
314 assert(II && "Attempt to mangle unnamed decl.");
320 llvm::SmallString<256> Buffer;
321 llvm::raw_svector_ostream Out(Buffer);
322 if (const CXXConstructorDecl *D = dyn_cast<CXXConstructorDecl>(ND))
323 getCXXABI().getMangleContext().mangleCXXCtor(D, GD.getCtorType(), Out);
324 else if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(ND))
325 getCXXABI().getMangleContext().mangleCXXDtor(D, GD.getDtorType(), Out);
326 else if (const BlockDecl *BD = dyn_cast<BlockDecl>(ND))
327 getCXXABI().getMangleContext().mangleBlock(BD, Out);
329 getCXXABI().getMangleContext().mangleName(ND, Out);
331 // Allocate space for the mangled name.
333 size_t Length = Buffer.size();
334 char *Name = MangledNamesAllocator.Allocate<char>(Length);
335 std::copy(Buffer.begin(), Buffer.end(), Name);
337 Str = StringRef(Name, Length);
342 void CodeGenModule::getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer,
343 const BlockDecl *BD) {
344 MangleContext &MangleCtx = getCXXABI().getMangleContext();
345 const Decl *D = GD.getDecl();
346 llvm::raw_svector_ostream Out(Buffer.getBuffer());
348 MangleCtx.mangleGlobalBlock(BD, Out);
349 else if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D))
350 MangleCtx.mangleCtorBlock(CD, GD.getCtorType(), BD, Out);
351 else if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(D))
352 MangleCtx.mangleDtorBlock(DD, GD.getDtorType(), BD, Out);
354 MangleCtx.mangleBlock(cast<DeclContext>(D), BD, Out);
357 llvm::GlobalValue *CodeGenModule::GetGlobalValue(StringRef Name) {
358 return getModule().getNamedValue(Name);
361 /// AddGlobalCtor - Add a function to the list that will be called before
363 void CodeGenModule::AddGlobalCtor(llvm::Function * Ctor, int Priority) {
364 // FIXME: Type coercion of void()* types.
365 GlobalCtors.push_back(std::make_pair(Ctor, Priority));
368 /// AddGlobalDtor - Add a function to the list that will be called
369 /// when the module is unloaded.
370 void CodeGenModule::AddGlobalDtor(llvm::Function * Dtor, int Priority) {
371 // FIXME: Type coercion of void()* types.
372 GlobalDtors.push_back(std::make_pair(Dtor, Priority));
375 void CodeGenModule::EmitCtorList(const CtorList &Fns, const char *GlobalName) {
376 // Ctor function type is void()*.
377 llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
378 llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy);
380 // Get the type of a ctor entry, { i32, void ()* }.
381 llvm::StructType *CtorStructTy =
382 llvm::StructType::get(llvm::Type::getInt32Ty(VMContext),
383 llvm::PointerType::getUnqual(CtorFTy), NULL);
385 // Construct the constructor and destructor arrays.
386 std::vector<llvm::Constant*> Ctors;
387 for (CtorList::const_iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) {
388 std::vector<llvm::Constant*> S;
389 S.push_back(llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
391 S.push_back(llvm::ConstantExpr::getBitCast(I->first, CtorPFTy));
392 Ctors.push_back(llvm::ConstantStruct::get(CtorStructTy, S));
395 if (!Ctors.empty()) {
396 llvm::ArrayType *AT = llvm::ArrayType::get(CtorStructTy, Ctors.size());
397 new llvm::GlobalVariable(TheModule, AT, false,
398 llvm::GlobalValue::AppendingLinkage,
399 llvm::ConstantArray::get(AT, Ctors),
404 llvm::GlobalValue::LinkageTypes
405 CodeGenModule::getFunctionLinkage(const FunctionDecl *D) {
406 GVALinkage Linkage = getContext().GetGVALinkageForFunction(D);
408 if (Linkage == GVA_Internal)
409 return llvm::Function::InternalLinkage;
411 if (D->hasAttr<DLLExportAttr>())
412 return llvm::Function::DLLExportLinkage;
414 if (D->hasAttr<WeakAttr>())
415 return llvm::Function::WeakAnyLinkage;
417 // In C99 mode, 'inline' functions are guaranteed to have a strong
418 // definition somewhere else, so we can use available_externally linkage.
419 if (Linkage == GVA_C99Inline)
420 return llvm::Function::AvailableExternallyLinkage;
422 // Note that Apple's kernel linker doesn't support symbol
423 // coalescing, so we need to avoid linkonce and weak linkages there.
424 // Normally, this means we just map to internal, but for explicit
425 // instantiations we'll map to external.
427 // In C++, the compiler has to emit a definition in every translation unit
428 // that references the function. We should use linkonce_odr because
429 // a) if all references in this translation unit are optimized away, we
430 // don't need to codegen it. b) if the function persists, it needs to be
431 // merged with other definitions. c) C++ has the ODR, so we know the
432 // definition is dependable.
433 if (Linkage == GVA_CXXInline || Linkage == GVA_TemplateInstantiation)
434 return !Context.getLangOptions().AppleKext
435 ? llvm::Function::LinkOnceODRLinkage
436 : llvm::Function::InternalLinkage;
438 // An explicit instantiation of a template has weak linkage, since
439 // explicit instantiations can occur in multiple translation units
440 // and must all be equivalent. However, we are not allowed to
441 // throw away these explicit instantiations.
442 if (Linkage == GVA_ExplicitTemplateInstantiation)
443 return !Context.getLangOptions().AppleKext
444 ? llvm::Function::WeakODRLinkage
445 : llvm::Function::ExternalLinkage;
447 // Otherwise, we have strong external linkage.
448 assert(Linkage == GVA_StrongExternal);
449 return llvm::Function::ExternalLinkage;
453 /// SetFunctionDefinitionAttributes - Set attributes for a global.
455 /// FIXME: This is currently only done for aliases and functions, but not for
456 /// variables (these details are set in EmitGlobalVarDefinition for variables).
457 void CodeGenModule::SetFunctionDefinitionAttributes(const FunctionDecl *D,
458 llvm::GlobalValue *GV) {
459 SetCommonAttributes(D, GV);
462 void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
463 const CGFunctionInfo &Info,
465 unsigned CallingConv;
466 AttributeListType AttributeList;
467 ConstructAttributeList(Info, D, AttributeList, CallingConv);
468 F->setAttributes(llvm::AttrListPtr::get(AttributeList.begin(),
469 AttributeList.size()));
470 F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
473 /// Determines whether the language options require us to model
474 /// unwind exceptions. We treat -fexceptions as mandating this
475 /// except under the fragile ObjC ABI with only ObjC exceptions
476 /// enabled. This means, for example, that C with -fexceptions
478 static bool hasUnwindExceptions(const LangOptions &Features) {
479 // If exceptions are completely disabled, obviously this is false.
480 if (!Features.Exceptions) return false;
482 // If C++ exceptions are enabled, this is true.
483 if (Features.CXXExceptions) return true;
485 // If ObjC exceptions are enabled, this depends on the ABI.
486 if (Features.ObjCExceptions) {
487 if (!Features.ObjCNonFragileABI) return false;
493 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
495 if (CodeGenOpts.UnwindTables)
498 if (!hasUnwindExceptions(Features))
499 F->addFnAttr(llvm::Attribute::NoUnwind);
501 if (D->hasAttr<NakedAttr>()) {
502 // Naked implies noinline: we should not be inlining such functions.
503 F->addFnAttr(llvm::Attribute::Naked);
504 F->addFnAttr(llvm::Attribute::NoInline);
507 if (D->hasAttr<NoInlineAttr>())
508 F->addFnAttr(llvm::Attribute::NoInline);
510 // (noinline wins over always_inline, and we can't specify both in IR)
511 if (D->hasAttr<AlwaysInlineAttr>() &&
512 !F->hasFnAttr(llvm::Attribute::NoInline))
513 F->addFnAttr(llvm::Attribute::AlwaysInline);
515 if (isa<CXXConstructorDecl>(D) || isa<CXXDestructorDecl>(D))
516 F->setUnnamedAddr(true);
518 if (Features.getStackProtector() == LangOptions::SSPOn)
519 F->addFnAttr(llvm::Attribute::StackProtect);
520 else if (Features.getStackProtector() == LangOptions::SSPReq)
521 F->addFnAttr(llvm::Attribute::StackProtectReq);
523 unsigned alignment = D->getMaxAlignment() / Context.getCharWidth();
525 F->setAlignment(alignment);
527 // C++ ABI requires 2-byte alignment for member functions.
528 if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
532 void CodeGenModule::SetCommonAttributes(const Decl *D,
533 llvm::GlobalValue *GV) {
534 if (const NamedDecl *ND = dyn_cast<NamedDecl>(D))
535 setGlobalVisibility(GV, ND);
537 GV->setVisibility(llvm::GlobalValue::DefaultVisibility);
539 if (D->hasAttr<UsedAttr>())
542 if (const SectionAttr *SA = D->getAttr<SectionAttr>())
543 GV->setSection(SA->getName());
545 getTargetCodeGenInfo().SetTargetAttributes(D, GV, *this);
548 void CodeGenModule::SetInternalFunctionAttributes(const Decl *D,
550 const CGFunctionInfo &FI) {
551 SetLLVMFunctionAttributes(D, FI, F);
552 SetLLVMFunctionAttributesForDefinition(D, F);
554 F->setLinkage(llvm::Function::InternalLinkage);
556 SetCommonAttributes(D, F);
559 void CodeGenModule::SetFunctionAttributes(GlobalDecl GD,
561 bool IsIncompleteFunction) {
562 if (unsigned IID = F->getIntrinsicID()) {
563 // If this is an intrinsic function, set the function's attributes
564 // to the intrinsic's attributes.
565 F->setAttributes(llvm::Intrinsic::getAttributes((llvm::Intrinsic::ID)IID));
569 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
571 if (!IsIncompleteFunction)
572 SetLLVMFunctionAttributes(FD, getTypes().getFunctionInfo(GD), F);
574 // Only a few attributes are set on declarations; these may later be
575 // overridden by a definition.
577 if (FD->hasAttr<DLLImportAttr>()) {
578 F->setLinkage(llvm::Function::DLLImportLinkage);
579 } else if (FD->hasAttr<WeakAttr>() ||
580 FD->isWeakImported()) {
581 // "extern_weak" is overloaded in LLVM; we probably should have
582 // separate linkage types for this.
583 F->setLinkage(llvm::Function::ExternalWeakLinkage);
585 F->setLinkage(llvm::Function::ExternalLinkage);
587 NamedDecl::LinkageInfo LV = FD->getLinkageAndVisibility();
588 if (LV.linkage() == ExternalLinkage && LV.visibilityExplicit()) {
589 F->setVisibility(GetLLVMVisibility(LV.visibility()));
593 if (const SectionAttr *SA = FD->getAttr<SectionAttr>())
594 F->setSection(SA->getName());
597 void CodeGenModule::AddUsedGlobal(llvm::GlobalValue *GV) {
598 assert(!GV->isDeclaration() &&
599 "Only globals with definition can force usage.");
600 LLVMUsed.push_back(GV);
603 void CodeGenModule::EmitLLVMUsed() {
604 // Don't create llvm.used if there is no need.
605 if (LLVMUsed.empty())
608 llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
610 // Convert LLVMUsed to what ConstantArray needs.
611 std::vector<llvm::Constant*> UsedArray;
612 UsedArray.resize(LLVMUsed.size());
613 for (unsigned i = 0, e = LLVMUsed.size(); i != e; ++i) {
615 llvm::ConstantExpr::getBitCast(cast<llvm::Constant>(&*LLVMUsed[i]),
619 if (UsedArray.empty())
621 llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, UsedArray.size());
623 llvm::GlobalVariable *GV =
624 new llvm::GlobalVariable(getModule(), ATy, false,
625 llvm::GlobalValue::AppendingLinkage,
626 llvm::ConstantArray::get(ATy, UsedArray),
629 GV->setSection("llvm.metadata");
632 void CodeGenModule::EmitDeferred() {
633 // Emit code for any potentially referenced deferred decls. Since a
634 // previously unused static decl may become used during the generation of code
635 // for a static function, iterate until no changes are made.
637 while (!DeferredDeclsToEmit.empty() || !DeferredVTables.empty()) {
638 if (!DeferredVTables.empty()) {
639 const CXXRecordDecl *RD = DeferredVTables.back();
640 DeferredVTables.pop_back();
641 getVTables().GenerateClassData(getVTableLinkage(RD), RD);
645 GlobalDecl D = DeferredDeclsToEmit.back();
646 DeferredDeclsToEmit.pop_back();
648 // Check to see if we've already emitted this. This is necessary
649 // for a couple of reasons: first, decls can end up in the
650 // deferred-decls queue multiple times, and second, decls can end
651 // up with definitions in unusual ways (e.g. by an extern inline
652 // function acquiring a strong function redefinition). Just
653 // ignore these cases.
655 // TODO: That said, looking this up multiple times is very wasteful.
656 StringRef Name = getMangledName(D);
657 llvm::GlobalValue *CGRef = GetGlobalValue(Name);
658 assert(CGRef && "Deferred decl wasn't referenced?");
660 if (!CGRef->isDeclaration())
663 // GlobalAlias::isDeclaration() defers to the aliasee, but for our
664 // purposes an alias counts as a definition.
665 if (isa<llvm::GlobalAlias>(CGRef))
668 // Otherwise, emit the definition and move on to the next one.
669 EmitGlobalDefinition(D);
673 void CodeGenModule::EmitGlobalAnnotations() {
674 if (Annotations.empty())
677 // Create a new global variable for the ConstantStruct in the Module.
678 llvm::Constant *Array = llvm::ConstantArray::get(llvm::ArrayType::get(
679 Annotations[0]->getType(), Annotations.size()), Annotations);
680 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(),
681 Array->getType(), false, llvm::GlobalValue::AppendingLinkage, Array,
682 "llvm.global.annotations");
683 gv->setSection(AnnotationSection);
686 llvm::Constant *CodeGenModule::EmitAnnotationString(llvm::StringRef Str) {
687 llvm::StringMap<llvm::Constant*>::iterator i = AnnotationStrings.find(Str);
688 if (i != AnnotationStrings.end())
691 // Not found yet, create a new global.
692 llvm::Constant *s = llvm::ConstantArray::get(getLLVMContext(), Str, true);
693 llvm::GlobalValue *gv = new llvm::GlobalVariable(getModule(), s->getType(),
694 true, llvm::GlobalValue::PrivateLinkage, s, ".str");
695 gv->setSection(AnnotationSection);
696 gv->setUnnamedAddr(true);
697 AnnotationStrings[Str] = gv;
701 llvm::Constant *CodeGenModule::EmitAnnotationUnit(SourceLocation Loc) {
702 SourceManager &SM = getContext().getSourceManager();
703 PresumedLoc PLoc = SM.getPresumedLoc(Loc);
705 return EmitAnnotationString(PLoc.getFilename());
706 return EmitAnnotationString(SM.getBufferName(Loc));
709 llvm::Constant *CodeGenModule::EmitAnnotationLineNo(SourceLocation L) {
710 SourceManager &SM = getContext().getSourceManager();
711 PresumedLoc PLoc = SM.getPresumedLoc(L);
712 unsigned LineNo = PLoc.isValid() ? PLoc.getLine() :
713 SM.getExpansionLineNumber(L);
714 return llvm::ConstantInt::get(Int32Ty, LineNo);
717 llvm::Constant *CodeGenModule::EmitAnnotateAttr(llvm::GlobalValue *GV,
718 const AnnotateAttr *AA,
720 // Get the globals for file name, annotation, and the line number.
721 llvm::Constant *AnnoGV = EmitAnnotationString(AA->getAnnotation()),
722 *UnitGV = EmitAnnotationUnit(L),
723 *LineNoCst = EmitAnnotationLineNo(L);
725 // Create the ConstantStruct for the global annotation.
726 llvm::Constant *Fields[4] = {
727 llvm::ConstantExpr::getBitCast(GV, Int8PtrTy),
728 llvm::ConstantExpr::getBitCast(AnnoGV, Int8PtrTy),
729 llvm::ConstantExpr::getBitCast(UnitGV, Int8PtrTy),
732 return llvm::ConstantStruct::getAnon(Fields);
735 void CodeGenModule::AddGlobalAnnotations(const ValueDecl *D,
736 llvm::GlobalValue *GV) {
737 assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute");
738 // Get the struct elements for these annotations.
739 for (specific_attr_iterator<AnnotateAttr>
740 ai = D->specific_attr_begin<AnnotateAttr>(),
741 ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai)
742 Annotations.push_back(EmitAnnotateAttr(GV, *ai, D->getLocation()));
745 bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) {
746 // Never defer when EmitAllDecls is specified.
747 if (Features.EmitAllDecls)
750 return !getContext().DeclMustBeEmitted(Global);
753 llvm::Constant *CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
754 const AliasAttr *AA = VD->getAttr<AliasAttr>();
755 assert(AA && "No alias?");
757 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(VD->getType());
759 // See if there is already something with the target's name in the module.
760 llvm::GlobalValue *Entry = GetGlobalValue(AA->getAliasee());
762 llvm::Constant *Aliasee;
763 if (isa<llvm::FunctionType>(DeclTy))
764 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(),
765 /*ForVTable=*/false);
767 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
768 llvm::PointerType::getUnqual(DeclTy), 0);
770 llvm::GlobalValue* F = cast<llvm::GlobalValue>(Aliasee);
771 F->setLinkage(llvm::Function::ExternalWeakLinkage);
772 WeakRefReferences.insert(F);
778 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
779 const ValueDecl *Global = cast<ValueDecl>(GD.getDecl());
781 // Weak references don't produce any output by themselves.
782 if (Global->hasAttr<WeakRefAttr>())
785 // If this is an alias definition (which otherwise looks like a declaration)
787 if (Global->hasAttr<AliasAttr>())
788 return EmitAliasDefinition(GD);
790 // If this is CUDA, be selective about which declarations we emit.
792 if (CodeGenOpts.CUDAIsDevice) {
793 if (!Global->hasAttr<CUDADeviceAttr>() &&
794 !Global->hasAttr<CUDAGlobalAttr>() &&
795 !Global->hasAttr<CUDAConstantAttr>() &&
796 !Global->hasAttr<CUDASharedAttr>())
799 if (!Global->hasAttr<CUDAHostAttr>() && (
800 Global->hasAttr<CUDADeviceAttr>() ||
801 Global->hasAttr<CUDAConstantAttr>() ||
802 Global->hasAttr<CUDASharedAttr>()))
807 // Ignore declarations, they will be emitted on their first use.
808 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Global)) {
809 // Forward declarations are emitted lazily on first use.
810 if (!FD->doesThisDeclarationHaveABody()) {
811 if (!FD->doesDeclarationForceExternallyVisibleDefinition())
814 const FunctionDecl *InlineDefinition = 0;
815 FD->getBody(InlineDefinition);
817 StringRef MangledName = getMangledName(GD);
818 llvm::StringMap<GlobalDecl>::iterator DDI =
819 DeferredDecls.find(MangledName);
820 if (DDI != DeferredDecls.end())
821 DeferredDecls.erase(DDI);
822 EmitGlobalDefinition(InlineDefinition);
826 const VarDecl *VD = cast<VarDecl>(Global);
827 assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
829 if (VD->isThisDeclarationADefinition() != VarDecl::Definition)
833 // Defer code generation when possible if this is a static definition, inline
834 // function etc. These we only want to emit if they are used.
835 if (!MayDeferGeneration(Global)) {
836 // Emit the definition if it can't be deferred.
837 EmitGlobalDefinition(GD);
841 // If we're deferring emission of a C++ variable with an
842 // initializer, remember the order in which it appeared in the file.
843 if (getLangOptions().CPlusPlus && isa<VarDecl>(Global) &&
844 cast<VarDecl>(Global)->hasInit()) {
845 DelayedCXXInitPosition[Global] = CXXGlobalInits.size();
846 CXXGlobalInits.push_back(0);
849 // If the value has already been used, add it directly to the
850 // DeferredDeclsToEmit list.
851 StringRef MangledName = getMangledName(GD);
852 if (GetGlobalValue(MangledName))
853 DeferredDeclsToEmit.push_back(GD);
855 // Otherwise, remember that we saw a deferred decl with this name. The
856 // first use of the mangled name will cause it to move into
857 // DeferredDeclsToEmit.
858 DeferredDecls[MangledName] = GD;
863 struct FunctionIsDirectlyRecursive :
864 public RecursiveASTVisitor<FunctionIsDirectlyRecursive> {
865 const StringRef Name;
867 FunctionIsDirectlyRecursive(const FunctionDecl *F) :
868 Name(F->getName()), Result(false) {
870 typedef RecursiveASTVisitor<FunctionIsDirectlyRecursive> Base;
872 bool TraverseCallExpr(CallExpr *E) {
873 const Decl *D = E->getCalleeDecl();
876 AsmLabelAttr *Attr = D->getAttr<AsmLabelAttr>();
879 if (Name == Attr->getLabel()) {
888 // isTriviallyRecursiveViaAsm - Check if this function calls another
889 // decl that, because of the asm attribute, ends up pointing to itself.
891 CodeGenModule::isTriviallyRecursiveViaAsm(const FunctionDecl *F) {
892 if (getCXXABI().getMangleContext().shouldMangleDeclName(F))
895 FunctionIsDirectlyRecursive Walker(F);
896 Walker.TraverseFunctionDecl(const_cast<FunctionDecl*>(F));
897 return Walker.Result;
901 CodeGenModule::shouldEmitFunction(const FunctionDecl *F) {
902 if (getFunctionLinkage(F) != llvm::Function::AvailableExternallyLinkage)
904 if (CodeGenOpts.OptimizationLevel == 0 &&
905 !F->hasAttr<AlwaysInlineAttr>())
907 // PR9614. Avoid cases where the source code is lying to us. An available
908 // externally function should have an equivalent function somewhere else,
909 // but a function that calls itself is clearly not equivalent to the real
911 // This happens in glibc's btowc and in some configure checks.
912 return !isTriviallyRecursiveViaAsm(F);
915 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) {
916 const ValueDecl *D = cast<ValueDecl>(GD.getDecl());
918 PrettyStackTraceDecl CrashInfo(const_cast<ValueDecl *>(D), D->getLocation(),
919 Context.getSourceManager(),
920 "Generating code for declaration");
922 if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) {
923 // At -O0, don't generate IR for functions with available_externally
925 if (!shouldEmitFunction(Function))
928 if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
929 // Make sure to emit the definition(s) before we emit the thunks.
930 // This is necessary for the generation of certain thunks.
931 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method))
932 EmitCXXConstructor(CD, GD.getCtorType());
933 else if (const CXXDestructorDecl *DD =dyn_cast<CXXDestructorDecl>(Method))
934 EmitCXXDestructor(DD, GD.getDtorType());
936 EmitGlobalFunctionDefinition(GD);
938 if (Method->isVirtual())
939 getVTables().EmitThunks(GD);
944 return EmitGlobalFunctionDefinition(GD);
947 if (const VarDecl *VD = dyn_cast<VarDecl>(D))
948 return EmitGlobalVarDefinition(VD);
950 llvm_unreachable("Invalid argument to EmitGlobalDefinition()");
953 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
954 /// module, create and return an llvm Function with the specified type. If there
955 /// is something in the module with the specified name, return it potentially
956 /// bitcasted to the right type.
958 /// If D is non-null, it specifies a decl that correspond to this. This is used
959 /// to set the attributes on the function when it is first created.
961 CodeGenModule::GetOrCreateLLVMFunction(StringRef MangledName,
963 GlobalDecl D, bool ForVTable,
964 llvm::Attributes ExtraAttrs) {
965 // Lookup the entry, lazily creating it if necessary.
966 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
968 if (WeakRefReferences.count(Entry)) {
969 const FunctionDecl *FD = cast_or_null<FunctionDecl>(D.getDecl());
970 if (FD && !FD->hasAttr<WeakAttr>())
971 Entry->setLinkage(llvm::Function::ExternalLinkage);
973 WeakRefReferences.erase(Entry);
976 if (Entry->getType()->getElementType() == Ty)
979 // Make sure the result is of the correct type.
980 return llvm::ConstantExpr::getBitCast(Entry, Ty->getPointerTo());
983 // This function doesn't have a complete type (for example, the return
984 // type is an incomplete struct). Use a fake type instead, and make
985 // sure not to try to set attributes.
986 bool IsIncompleteFunction = false;
988 llvm::FunctionType *FTy;
989 if (isa<llvm::FunctionType>(Ty)) {
990 FTy = cast<llvm::FunctionType>(Ty);
992 FTy = llvm::FunctionType::get(VoidTy, false);
993 IsIncompleteFunction = true;
996 llvm::Function *F = llvm::Function::Create(FTy,
997 llvm::Function::ExternalLinkage,
998 MangledName, &getModule());
999 assert(F->getName() == MangledName && "name was uniqued!");
1001 SetFunctionAttributes(D, F, IsIncompleteFunction);
1002 if (ExtraAttrs != llvm::Attribute::None)
1003 F->addFnAttr(ExtraAttrs);
1005 // This is the first use or definition of a mangled name. If there is a
1006 // deferred decl with this name, remember that we need to emit it at the end
1008 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName);
1009 if (DDI != DeferredDecls.end()) {
1010 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
1011 // list, and remove it from DeferredDecls (since we don't need it anymore).
1012 DeferredDeclsToEmit.push_back(DDI->second);
1013 DeferredDecls.erase(DDI);
1015 // Otherwise, there are cases we have to worry about where we're
1016 // using a declaration for which we must emit a definition but where
1017 // we might not find a top-level definition:
1018 // - member functions defined inline in their classes
1019 // - friend functions defined inline in some class
1020 // - special member functions with implicit definitions
1021 // If we ever change our AST traversal to walk into class methods,
1022 // this will be unnecessary.
1024 // We also don't emit a definition for a function if it's going to be an entry
1025 // in a vtable, unless it's already marked as used.
1026 } else if (getLangOptions().CPlusPlus && D.getDecl()) {
1027 // Look for a declaration that's lexically in a record.
1028 const FunctionDecl *FD = cast<FunctionDecl>(D.getDecl());
1030 if (isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
1031 if (FD->isImplicit() && !ForVTable) {
1032 assert(FD->isUsed() && "Sema didn't mark implicit function as used!");
1033 DeferredDeclsToEmit.push_back(D.getWithDecl(FD));
1035 } else if (FD->doesThisDeclarationHaveABody()) {
1036 DeferredDeclsToEmit.push_back(D.getWithDecl(FD));
1040 FD = FD->getPreviousDeclaration();
1044 // Make sure the result is of the requested type.
1045 if (!IsIncompleteFunction) {
1046 assert(F->getType()->getElementType() == Ty);
1050 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
1051 return llvm::ConstantExpr::getBitCast(F, PTy);
1054 /// GetAddrOfFunction - Return the address of the given function. If Ty is
1055 /// non-null, then this function will use the specified type if it has to
1056 /// create it (this occurs when we see a definition of the function).
1057 llvm::Constant *CodeGenModule::GetAddrOfFunction(GlobalDecl GD,
1060 // If there was no specific requested type, just convert it now.
1062 Ty = getTypes().ConvertType(cast<ValueDecl>(GD.getDecl())->getType());
1064 StringRef MangledName = getMangledName(GD);
1065 return GetOrCreateLLVMFunction(MangledName, Ty, GD, ForVTable);
1068 /// CreateRuntimeFunction - Create a new runtime function with the specified
1071 CodeGenModule::CreateRuntimeFunction(llvm::FunctionType *FTy,
1073 llvm::Attributes ExtraAttrs) {
1074 return GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(), /*ForVTable=*/false,
1078 static bool DeclIsConstantGlobal(ASTContext &Context, const VarDecl *D,
1079 bool ConstantInit) {
1080 if (!D->getType().isConstant(Context) && !D->getType()->isReferenceType())
1083 if (Context.getLangOptions().CPlusPlus) {
1084 if (const RecordType *Record
1085 = Context.getBaseElementType(D->getType())->getAs<RecordType>())
1086 return ConstantInit &&
1087 cast<CXXRecordDecl>(Record->getDecl())->isPOD() &&
1088 !cast<CXXRecordDecl>(Record->getDecl())->hasMutableFields();
1094 /// GetOrCreateLLVMGlobal - If the specified mangled name is not in the module,
1095 /// create and return an llvm GlobalVariable with the specified type. If there
1096 /// is something in the module with the specified name, return it potentially
1097 /// bitcasted to the right type.
1099 /// If D is non-null, it specifies a decl that correspond to this. This is used
1100 /// to set the attributes on the global when it is first created.
1102 CodeGenModule::GetOrCreateLLVMGlobal(StringRef MangledName,
1103 llvm::PointerType *Ty,
1106 // Lookup the entry, lazily creating it if necessary.
1107 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
1109 if (WeakRefReferences.count(Entry)) {
1110 if (D && !D->hasAttr<WeakAttr>())
1111 Entry->setLinkage(llvm::Function::ExternalLinkage);
1113 WeakRefReferences.erase(Entry);
1117 Entry->setUnnamedAddr(true);
1119 if (Entry->getType() == Ty)
1122 // Make sure the result is of the correct type.
1123 return llvm::ConstantExpr::getBitCast(Entry, Ty);
1126 // This is the first use or definition of a mangled name. If there is a
1127 // deferred decl with this name, remember that we need to emit it at the end
1129 llvm::StringMap<GlobalDecl>::iterator DDI = DeferredDecls.find(MangledName);
1130 if (DDI != DeferredDecls.end()) {
1131 // Move the potentially referenced deferred decl to the DeferredDeclsToEmit
1132 // list, and remove it from DeferredDecls (since we don't need it anymore).
1133 DeferredDeclsToEmit.push_back(DDI->second);
1134 DeferredDecls.erase(DDI);
1137 llvm::GlobalVariable *GV =
1138 new llvm::GlobalVariable(getModule(), Ty->getElementType(), false,
1139 llvm::GlobalValue::ExternalLinkage,
1141 false, Ty->getAddressSpace());
1143 // Handle things which are present even on external declarations.
1145 // FIXME: This code is overly simple and should be merged with other global
1147 GV->setConstant(DeclIsConstantGlobal(Context, D, false));
1149 // Set linkage and visibility in case we never see a definition.
1150 NamedDecl::LinkageInfo LV = D->getLinkageAndVisibility();
1151 if (LV.linkage() != ExternalLinkage) {
1152 // Don't set internal linkage on declarations.
1154 if (D->hasAttr<DLLImportAttr>())
1155 GV->setLinkage(llvm::GlobalValue::DLLImportLinkage);
1156 else if (D->hasAttr<WeakAttr>() || D->isWeakImported())
1157 GV->setLinkage(llvm::GlobalValue::ExternalWeakLinkage);
1159 // Set visibility on a declaration only if it's explicit.
1160 if (LV.visibilityExplicit())
1161 GV->setVisibility(GetLLVMVisibility(LV.visibility()));
1164 GV->setThreadLocal(D->isThreadSpecified());
1171 llvm::GlobalVariable *
1172 CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name,
1174 llvm::GlobalValue::LinkageTypes Linkage) {
1175 llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
1176 llvm::GlobalVariable *OldGV = 0;
1180 // Check if the variable has the right type.
1181 if (GV->getType()->getElementType() == Ty)
1184 // Because C++ name mangling, the only way we can end up with an already
1185 // existing global with the same name is if it has been declared extern "C".
1186 assert(GV->isDeclaration() && "Declaration has wrong type!");
1190 // Create a new variable.
1191 GV = new llvm::GlobalVariable(getModule(), Ty, /*isConstant=*/true,
1195 // Replace occurrences of the old variable if needed.
1196 GV->takeName(OldGV);
1198 if (!OldGV->use_empty()) {
1199 llvm::Constant *NewPtrForOldDecl =
1200 llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
1201 OldGV->replaceAllUsesWith(NewPtrForOldDecl);
1204 OldGV->eraseFromParent();
1210 /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
1211 /// given global variable. If Ty is non-null and if the global doesn't exist,
1212 /// then it will be greated with the specified type instead of whatever the
1213 /// normal requested type would be.
1214 llvm::Constant *CodeGenModule::GetAddrOfGlobalVar(const VarDecl *D,
1216 assert(D->hasGlobalStorage() && "Not a global variable");
1217 QualType ASTTy = D->getType();
1219 Ty = getTypes().ConvertTypeForMem(ASTTy);
1221 llvm::PointerType *PTy =
1222 llvm::PointerType::get(Ty, getContext().getTargetAddressSpace(ASTTy));
1224 StringRef MangledName = getMangledName(D);
1225 return GetOrCreateLLVMGlobal(MangledName, PTy, D);
1228 /// CreateRuntimeVariable - Create a new runtime global variable with the
1229 /// specified type and name.
1231 CodeGenModule::CreateRuntimeVariable(llvm::Type *Ty,
1233 return GetOrCreateLLVMGlobal(Name, llvm::PointerType::getUnqual(Ty), 0,
1237 void CodeGenModule::EmitTentativeDefinition(const VarDecl *D) {
1238 assert(!D->getInit() && "Cannot emit definite definitions here!");
1240 if (MayDeferGeneration(D)) {
1241 // If we have not seen a reference to this variable yet, place it
1242 // into the deferred declarations table to be emitted if needed
1244 StringRef MangledName = getMangledName(D);
1245 if (!GetGlobalValue(MangledName)) {
1246 DeferredDecls[MangledName] = D;
1251 // The tentative definition is the only definition.
1252 EmitGlobalVarDefinition(D);
1255 void CodeGenModule::EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired) {
1256 if (DefinitionRequired)
1257 getVTables().GenerateClassData(getVTableLinkage(Class), Class);
1260 llvm::GlobalVariable::LinkageTypes
1261 CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) {
1262 if (RD->getLinkage() != ExternalLinkage)
1263 return llvm::GlobalVariable::InternalLinkage;
1265 if (const CXXMethodDecl *KeyFunction
1266 = RD->getASTContext().getKeyFunction(RD)) {
1267 // If this class has a key function, use that to determine the linkage of
1269 const FunctionDecl *Def = 0;
1270 if (KeyFunction->hasBody(Def))
1271 KeyFunction = cast<CXXMethodDecl>(Def);
1273 switch (KeyFunction->getTemplateSpecializationKind()) {
1274 case TSK_Undeclared:
1275 case TSK_ExplicitSpecialization:
1276 // When compiling with optimizations turned on, we emit all vtables,
1277 // even if the key function is not defined in the current translation
1278 // unit. If this is the case, use available_externally linkage.
1279 if (!Def && CodeGenOpts.OptimizationLevel)
1280 return llvm::GlobalVariable::AvailableExternallyLinkage;
1282 if (KeyFunction->isInlined())
1283 return !Context.getLangOptions().AppleKext ?
1284 llvm::GlobalVariable::LinkOnceODRLinkage :
1285 llvm::Function::InternalLinkage;
1287 return llvm::GlobalVariable::ExternalLinkage;
1289 case TSK_ImplicitInstantiation:
1290 return !Context.getLangOptions().AppleKext ?
1291 llvm::GlobalVariable::LinkOnceODRLinkage :
1292 llvm::Function::InternalLinkage;
1294 case TSK_ExplicitInstantiationDefinition:
1295 return !Context.getLangOptions().AppleKext ?
1296 llvm::GlobalVariable::WeakODRLinkage :
1297 llvm::Function::InternalLinkage;
1299 case TSK_ExplicitInstantiationDeclaration:
1300 // FIXME: Use available_externally linkage. However, this currently
1301 // breaks LLVM's build due to undefined symbols.
1302 // return llvm::GlobalVariable::AvailableExternallyLinkage;
1303 return !Context.getLangOptions().AppleKext ?
1304 llvm::GlobalVariable::LinkOnceODRLinkage :
1305 llvm::Function::InternalLinkage;
1309 if (Context.getLangOptions().AppleKext)
1310 return llvm::Function::InternalLinkage;
1312 switch (RD->getTemplateSpecializationKind()) {
1313 case TSK_Undeclared:
1314 case TSK_ExplicitSpecialization:
1315 case TSK_ImplicitInstantiation:
1316 // FIXME: Use available_externally linkage. However, this currently
1317 // breaks LLVM's build due to undefined symbols.
1318 // return llvm::GlobalVariable::AvailableExternallyLinkage;
1319 case TSK_ExplicitInstantiationDeclaration:
1320 return llvm::GlobalVariable::LinkOnceODRLinkage;
1322 case TSK_ExplicitInstantiationDefinition:
1323 return llvm::GlobalVariable::WeakODRLinkage;
1326 // Silence GCC warning.
1327 return llvm::GlobalVariable::LinkOnceODRLinkage;
1330 CharUnits CodeGenModule::GetTargetTypeStoreSize(llvm::Type *Ty) const {
1331 return Context.toCharUnitsFromBits(
1332 TheTargetData.getTypeStoreSizeInBits(Ty));
1335 void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) {
1336 llvm::Constant *Init = 0;
1337 QualType ASTTy = D->getType();
1338 bool NonConstInit = false;
1340 const Expr *InitExpr = D->getAnyInitializer();
1343 // This is a tentative definition; tentative definitions are
1344 // implicitly initialized with { 0 }.
1346 // Note that tentative definitions are only emitted at the end of
1347 // a translation unit, so they should never have incomplete
1348 // type. In addition, EmitTentativeDefinition makes sure that we
1349 // never attempt to emit a tentative definition if a real one
1350 // exists. A use may still exists, however, so we still may need
1352 assert(!ASTTy->isIncompleteType() && "Unexpected incomplete type");
1353 Init = EmitNullConstant(D->getType());
1355 Init = EmitConstantExpr(InitExpr, D->getType());
1357 QualType T = InitExpr->getType();
1358 if (D->getType()->isReferenceType())
1361 if (getLangOptions().CPlusPlus) {
1362 Init = EmitNullConstant(T);
1363 NonConstInit = true;
1365 ErrorUnsupported(D, "static initializer");
1366 Init = llvm::UndefValue::get(getTypes().ConvertType(T));
1369 // We don't need an initializer, so remove the entry for the delayed
1370 // initializer position (just in case this entry was delayed).
1371 if (getLangOptions().CPlusPlus)
1372 DelayedCXXInitPosition.erase(D);
1376 llvm::Type* InitType = Init->getType();
1377 llvm::Constant *Entry = GetAddrOfGlobalVar(D, InitType);
1379 // Strip off a bitcast if we got one back.
1380 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
1381 assert(CE->getOpcode() == llvm::Instruction::BitCast ||
1382 // all zero index gep.
1383 CE->getOpcode() == llvm::Instruction::GetElementPtr);
1384 Entry = CE->getOperand(0);
1387 // Entry is now either a Function or GlobalVariable.
1388 llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Entry);
1390 // We have a definition after a declaration with the wrong type.
1391 // We must make a new GlobalVariable* and update everything that used OldGV
1392 // (a declaration or tentative definition) with the new GlobalVariable*
1393 // (which will be a definition).
1395 // This happens if there is a prototype for a global (e.g.
1396 // "extern int x[];") and then a definition of a different type (e.g.
1397 // "int x[10];"). This also happens when an initializer has a different type
1398 // from the type of the global (this happens with unions).
1400 GV->getType()->getElementType() != InitType ||
1401 GV->getType()->getAddressSpace() !=
1402 getContext().getTargetAddressSpace(ASTTy)) {
1404 // Move the old entry aside so that we'll create a new one.
1405 Entry->setName(StringRef());
1407 // Make a new global with the correct type, this is now guaranteed to work.
1408 GV = cast<llvm::GlobalVariable>(GetAddrOfGlobalVar(D, InitType));
1410 // Replace all uses of the old global with the new global
1411 llvm::Constant *NewPtrForOldDecl =
1412 llvm::ConstantExpr::getBitCast(GV, Entry->getType());
1413 Entry->replaceAllUsesWith(NewPtrForOldDecl);
1415 // Erase the old global, since it is no longer used.
1416 cast<llvm::GlobalValue>(Entry)->eraseFromParent();
1419 if (D->hasAttr<AnnotateAttr>())
1420 AddGlobalAnnotations(D, GV);
1422 GV->setInitializer(Init);
1424 // If it is safe to mark the global 'constant', do so now.
1425 GV->setConstant(false);
1426 if (!NonConstInit && DeclIsConstantGlobal(Context, D, true))
1427 GV->setConstant(true);
1429 GV->setAlignment(getContext().getDeclAlign(D).getQuantity());
1431 // Set the llvm linkage type as appropriate.
1432 llvm::GlobalValue::LinkageTypes Linkage =
1433 GetLLVMLinkageVarDefinition(D, GV);
1434 GV->setLinkage(Linkage);
1435 if (Linkage == llvm::GlobalVariable::CommonLinkage)
1436 // common vars aren't constant even if declared const.
1437 GV->setConstant(false);
1439 SetCommonAttributes(D, GV);
1441 // Emit the initializer function if necessary.
1443 EmitCXXGlobalVarDeclInitFunc(D, GV);
1445 // Emit global variable debug information.
1446 if (CGDebugInfo *DI = getModuleDebugInfo())
1447 DI->EmitGlobalVariable(GV, D);
1450 llvm::GlobalValue::LinkageTypes
1451 CodeGenModule::GetLLVMLinkageVarDefinition(const VarDecl *D,
1452 llvm::GlobalVariable *GV) {
1453 GVALinkage Linkage = getContext().GetGVALinkageForVariable(D);
1454 if (Linkage == GVA_Internal)
1455 return llvm::Function::InternalLinkage;
1456 else if (D->hasAttr<DLLImportAttr>())
1457 return llvm::Function::DLLImportLinkage;
1458 else if (D->hasAttr<DLLExportAttr>())
1459 return llvm::Function::DLLExportLinkage;
1460 else if (D->hasAttr<WeakAttr>()) {
1461 if (GV->isConstant())
1462 return llvm::GlobalVariable::WeakODRLinkage;
1464 return llvm::GlobalVariable::WeakAnyLinkage;
1465 } else if (Linkage == GVA_TemplateInstantiation ||
1466 Linkage == GVA_ExplicitTemplateInstantiation)
1467 return llvm::GlobalVariable::WeakODRLinkage;
1468 else if (!getLangOptions().CPlusPlus &&
1469 ((!CodeGenOpts.NoCommon && !D->getAttr<NoCommonAttr>()) ||
1470 D->getAttr<CommonAttr>()) &&
1471 !D->hasExternalStorage() && !D->getInit() &&
1472 !D->getAttr<SectionAttr>() && !D->isThreadSpecified() &&
1473 !D->getAttr<WeakImportAttr>()) {
1474 // Thread local vars aren't considered common linkage.
1475 return llvm::GlobalVariable::CommonLinkage;
1477 return llvm::GlobalVariable::ExternalLinkage;
1480 /// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
1481 /// implement a function with no prototype, e.g. "int foo() {}". If there are
1482 /// existing call uses of the old function in the module, this adjusts them to
1483 /// call the new function directly.
1485 /// This is not just a cleanup: the always_inline pass requires direct calls to
1486 /// functions to be able to inline them. If there is a bitcast in the way, it
1487 /// won't inline them. Instcombine normally deletes these calls, but it isn't
1489 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
1490 llvm::Function *NewFn) {
1491 // If we're redefining a global as a function, don't transform it.
1492 llvm::Function *OldFn = dyn_cast<llvm::Function>(Old);
1493 if (OldFn == 0) return;
1495 llvm::Type *NewRetTy = NewFn->getReturnType();
1496 SmallVector<llvm::Value*, 4> ArgList;
1498 for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end();
1500 // TODO: Do invokes ever occur in C code? If so, we should handle them too.
1501 llvm::Value::use_iterator I = UI++; // Increment before the CI is erased.
1502 llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*I);
1503 if (!CI) continue; // FIXME: when we allow Invoke, just do CallSite CS(*I)
1504 llvm::CallSite CS(CI);
1505 if (!CI || !CS.isCallee(I)) continue;
1507 // If the return types don't match exactly, and if the call isn't dead, then
1508 // we can't transform this call.
1509 if (CI->getType() != NewRetTy && !CI->use_empty())
1512 // Get the attribute list.
1513 llvm::SmallVector<llvm::AttributeWithIndex, 8> AttrVec;
1514 llvm::AttrListPtr AttrList = CI->getAttributes();
1516 // Get any return attributes.
1517 llvm::Attributes RAttrs = AttrList.getRetAttributes();
1519 // Add the return attributes.
1521 AttrVec.push_back(llvm::AttributeWithIndex::get(0, RAttrs));
1523 // If the function was passed too few arguments, don't transform. If extra
1524 // arguments were passed, we silently drop them. If any of the types
1525 // mismatch, we don't transform.
1527 bool DontTransform = false;
1528 for (llvm::Function::arg_iterator AI = NewFn->arg_begin(),
1529 E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) {
1530 if (CS.arg_size() == ArgNo ||
1531 CS.getArgument(ArgNo)->getType() != AI->getType()) {
1532 DontTransform = true;
1536 // Add any parameter attributes.
1537 if (llvm::Attributes PAttrs = AttrList.getParamAttributes(ArgNo + 1))
1538 AttrVec.push_back(llvm::AttributeWithIndex::get(ArgNo + 1, PAttrs));
1543 if (llvm::Attributes FnAttrs = AttrList.getFnAttributes())
1544 AttrVec.push_back(llvm::AttributeWithIndex::get(~0, FnAttrs));
1546 // Okay, we can transform this. Create the new call instruction and copy
1547 // over the required information.
1548 ArgList.append(CS.arg_begin(), CS.arg_begin() + ArgNo);
1549 llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList, "", CI);
1551 if (!NewCall->getType()->isVoidTy())
1552 NewCall->takeName(CI);
1553 NewCall->setAttributes(llvm::AttrListPtr::get(AttrVec.begin(),
1555 NewCall->setCallingConv(CI->getCallingConv());
1557 // Finally, remove the old call, replacing any uses with the new one.
1558 if (!CI->use_empty())
1559 CI->replaceAllUsesWith(NewCall);
1561 // Copy debug location attached to CI.
1562 if (!CI->getDebugLoc().isUnknown())
1563 NewCall->setDebugLoc(CI->getDebugLoc());
1564 CI->eraseFromParent();
1569 void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD) {
1570 const FunctionDecl *D = cast<FunctionDecl>(GD.getDecl());
1572 // Compute the function info and LLVM type.
1573 const CGFunctionInfo &FI = getTypes().getFunctionInfo(GD);
1574 bool variadic = false;
1575 if (const FunctionProtoType *fpt = D->getType()->getAs<FunctionProtoType>())
1576 variadic = fpt->isVariadic();
1577 llvm::FunctionType *Ty = getTypes().GetFunctionType(FI, variadic);
1579 // Get or create the prototype for the function.
1580 llvm::Constant *Entry = GetAddrOfFunction(GD, Ty);
1582 // Strip off a bitcast if we got one back.
1583 if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) {
1584 assert(CE->getOpcode() == llvm::Instruction::BitCast);
1585 Entry = CE->getOperand(0);
1589 if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) {
1590 llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry);
1592 // If the types mismatch then we have to rewrite the definition.
1593 assert(OldFn->isDeclaration() &&
1594 "Shouldn't replace non-declaration");
1596 // F is the Function* for the one with the wrong type, we must make a new
1597 // Function* and update everything that used F (a declaration) with the new
1598 // Function* (which will be a definition).
1600 // This happens if there is a prototype for a function
1601 // (e.g. "int f()") and then a definition of a different type
1602 // (e.g. "int f(int x)"). Move the old function aside so that it
1603 // doesn't interfere with GetAddrOfFunction.
1604 OldFn->setName(StringRef());
1605 llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(GD, Ty));
1607 // If this is an implementation of a function without a prototype, try to
1608 // replace any existing uses of the function (which may be calls) with uses
1609 // of the new function
1610 if (D->getType()->isFunctionNoProtoType()) {
1611 ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn);
1612 OldFn->removeDeadConstantUsers();
1615 // Replace uses of F with the Function we will endow with a body.
1616 if (!Entry->use_empty()) {
1617 llvm::Constant *NewPtrForOldDecl =
1618 llvm::ConstantExpr::getBitCast(NewFn, Entry->getType());
1619 Entry->replaceAllUsesWith(NewPtrForOldDecl);
1622 // Ok, delete the old function now, which is dead.
1623 OldFn->eraseFromParent();
1628 // We need to set linkage and visibility on the function before
1629 // generating code for it because various parts of IR generation
1630 // want to propagate this information down (e.g. to local static
1632 llvm::Function *Fn = cast<llvm::Function>(Entry);
1633 setFunctionLinkage(D, Fn);
1635 // FIXME: this is redundant with part of SetFunctionDefinitionAttributes
1636 setGlobalVisibility(Fn, D);
1638 CodeGenFunction(*this).GenerateCode(D, Fn, FI);
1640 SetFunctionDefinitionAttributes(D, Fn);
1641 SetLLVMFunctionAttributesForDefinition(D, Fn);
1643 if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
1644 AddGlobalCtor(Fn, CA->getPriority());
1645 if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
1646 AddGlobalDtor(Fn, DA->getPriority());
1647 if (D->hasAttr<AnnotateAttr>())
1648 AddGlobalAnnotations(D, Fn);
1651 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
1652 const ValueDecl *D = cast<ValueDecl>(GD.getDecl());
1653 const AliasAttr *AA = D->getAttr<AliasAttr>();
1654 assert(AA && "Not an alias?");
1656 StringRef MangledName = getMangledName(GD);
1658 // If there is a definition in the module, then it wins over the alias.
1659 // This is dubious, but allow it to be safe. Just ignore the alias.
1660 llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
1661 if (Entry && !Entry->isDeclaration())
1664 llvm::Type *DeclTy = getTypes().ConvertTypeForMem(D->getType());
1666 // Create a reference to the named value. This ensures that it is emitted
1667 // if a deferred decl.
1668 llvm::Constant *Aliasee;
1669 if (isa<llvm::FunctionType>(DeclTy))
1670 Aliasee = GetOrCreateLLVMFunction(AA->getAliasee(), DeclTy, GlobalDecl(),
1671 /*ForVTable=*/false);
1673 Aliasee = GetOrCreateLLVMGlobal(AA->getAliasee(),
1674 llvm::PointerType::getUnqual(DeclTy), 0);
1676 // Create the new alias itself, but don't set a name yet.
1677 llvm::GlobalValue *GA =
1678 new llvm::GlobalAlias(Aliasee->getType(),
1679 llvm::Function::ExternalLinkage,
1680 "", Aliasee, &getModule());
1683 assert(Entry->isDeclaration());
1685 // If there is a declaration in the module, then we had an extern followed
1686 // by the alias, as in:
1687 // extern int test6();
1689 // int test6() __attribute__((alias("test7")));
1691 // Remove it and replace uses of it with the alias.
1692 GA->takeName(Entry);
1694 Entry->replaceAllUsesWith(llvm::ConstantExpr::getBitCast(GA,
1696 Entry->eraseFromParent();
1698 GA->setName(MangledName);
1701 // Set attributes which are particular to an alias; this is a
1702 // specialization of the attributes which may be set on a global
1703 // variable/function.
1704 if (D->hasAttr<DLLExportAttr>()) {
1705 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
1706 // The dllexport attribute is ignored for undefined symbols.
1708 GA->setLinkage(llvm::Function::DLLExportLinkage);
1710 GA->setLinkage(llvm::Function::DLLExportLinkage);
1712 } else if (D->hasAttr<WeakAttr>() ||
1713 D->hasAttr<WeakRefAttr>() ||
1714 D->isWeakImported()) {
1715 GA->setLinkage(llvm::Function::WeakAnyLinkage);
1718 SetCommonAttributes(D, GA);
1721 llvm::Function *CodeGenModule::getIntrinsic(unsigned IID,
1722 ArrayRef<llvm::Type*> Tys) {
1723 return llvm::Intrinsic::getDeclaration(&getModule(), (llvm::Intrinsic::ID)IID,
1727 static llvm::StringMapEntry<llvm::Constant*> &
1728 GetConstantCFStringEntry(llvm::StringMap<llvm::Constant*> &Map,
1729 const StringLiteral *Literal,
1732 unsigned &StringLength) {
1733 StringRef String = Literal->getString();
1734 unsigned NumBytes = String.size();
1736 // Check for simple case.
1737 if (!Literal->containsNonAsciiOrNull()) {
1738 StringLength = NumBytes;
1739 return Map.GetOrCreateValue(String);
1742 // Otherwise, convert the UTF8 literals into a byte string.
1743 SmallVector<UTF16, 128> ToBuf(NumBytes);
1744 const UTF8 *FromPtr = (UTF8 *)String.data();
1745 UTF16 *ToPtr = &ToBuf[0];
1747 (void)ConvertUTF8toUTF16(&FromPtr, FromPtr + NumBytes,
1748 &ToPtr, ToPtr + NumBytes,
1751 // ConvertUTF8toUTF16 returns the length in ToPtr.
1752 StringLength = ToPtr - &ToBuf[0];
1754 // Render the UTF-16 string into a byte array and convert to the target byte
1757 // FIXME: This isn't something we should need to do here.
1758 llvm::SmallString<128> AsBytes;
1759 AsBytes.reserve(StringLength * 2);
1760 for (unsigned i = 0; i != StringLength; ++i) {
1761 unsigned short Val = ToBuf[i];
1763 AsBytes.push_back(Val & 0xFF);
1764 AsBytes.push_back(Val >> 8);
1766 AsBytes.push_back(Val >> 8);
1767 AsBytes.push_back(Val & 0xFF);
1770 // Append one extra null character, the second is automatically added by our
1772 AsBytes.push_back(0);
1775 return Map.GetOrCreateValue(StringRef(AsBytes.data(), AsBytes.size()));
1778 static llvm::StringMapEntry<llvm::Constant*> &
1779 GetConstantStringEntry(llvm::StringMap<llvm::Constant*> &Map,
1780 const StringLiteral *Literal,
1781 unsigned &StringLength)
1783 StringRef String = Literal->getString();
1784 StringLength = String.size();
1785 return Map.GetOrCreateValue(String);
1789 CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
1790 unsigned StringLength = 0;
1791 bool isUTF16 = false;
1792 llvm::StringMapEntry<llvm::Constant*> &Entry =
1793 GetConstantCFStringEntry(CFConstantStringMap, Literal,
1794 getTargetData().isLittleEndian(),
1795 isUTF16, StringLength);
1797 if (llvm::Constant *C = Entry.getValue())
1800 llvm::Constant *Zero =
1801 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext));
1802 llvm::Constant *Zeros[] = { Zero, Zero };
1804 // If we don't already have it, get __CFConstantStringClassReference.
1805 if (!CFConstantStringClassRef) {
1806 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
1807 Ty = llvm::ArrayType::get(Ty, 0);
1808 llvm::Constant *GV = CreateRuntimeVariable(Ty,
1809 "__CFConstantStringClassReference");
1810 // Decay array -> ptr
1811 CFConstantStringClassRef =
1812 llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
1815 QualType CFTy = getContext().getCFConstantStringType();
1817 llvm::StructType *STy =
1818 cast<llvm::StructType>(getTypes().ConvertType(CFTy));
1820 std::vector<llvm::Constant*> Fields(4);
1823 Fields[0] = CFConstantStringClassRef;
1826 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy);
1827 Fields[1] = isUTF16 ? llvm::ConstantInt::get(Ty, 0x07d0) :
1828 llvm::ConstantInt::get(Ty, 0x07C8);
1831 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str());
1833 llvm::GlobalValue::LinkageTypes Linkage;
1836 // FIXME: why do utf strings get "_" labels instead of "L" labels?
1837 Linkage = llvm::GlobalValue::InternalLinkage;
1838 // Note: -fwritable-strings doesn't make unicode CFStrings writable, but
1839 // does make plain ascii ones writable.
1842 // FIXME: With OS X ld 123.2 (xcode 4) and LTO we would get a linker error
1843 // when using private linkage. It is not clear if this is a bug in ld
1844 // or a reasonable new restriction.
1845 Linkage = llvm::GlobalValue::LinkerPrivateLinkage;
1846 isConstant = !Features.WritableStrings;
1849 llvm::GlobalVariable *GV =
1850 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C,
1852 GV->setUnnamedAddr(true);
1854 CharUnits Align = getContext().getTypeAlignInChars(getContext().ShortTy);
1855 GV->setAlignment(Align.getQuantity());
1857 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy);
1858 GV->setAlignment(Align.getQuantity());
1860 Fields[2] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
1863 Ty = getTypes().ConvertType(getContext().LongTy);
1864 Fields[3] = llvm::ConstantInt::get(Ty, StringLength);
1867 C = llvm::ConstantStruct::get(STy, Fields);
1868 GV = new llvm::GlobalVariable(getModule(), C->getType(), true,
1869 llvm::GlobalVariable::PrivateLinkage, C,
1870 "_unnamed_cfstring_");
1871 if (const char *Sect = getContext().getTargetInfo().getCFStringSection())
1872 GV->setSection(Sect);
1879 CreateRecordDecl(const ASTContext &Ctx, RecordDecl::TagKind TK,
1880 DeclContext *DC, IdentifierInfo *Id) {
1882 if (Ctx.getLangOptions().CPlusPlus)
1883 return CXXRecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id);
1885 return RecordDecl::Create(Ctx, TK, DC, Loc, Loc, Id);
1889 CodeGenModule::GetAddrOfConstantString(const StringLiteral *Literal) {
1890 unsigned StringLength = 0;
1891 llvm::StringMapEntry<llvm::Constant*> &Entry =
1892 GetConstantStringEntry(CFConstantStringMap, Literal, StringLength);
1894 if (llvm::Constant *C = Entry.getValue())
1897 llvm::Constant *Zero =
1898 llvm::Constant::getNullValue(llvm::Type::getInt32Ty(VMContext));
1899 llvm::Constant *Zeros[] = { Zero, Zero };
1901 // If we don't already have it, get _NSConstantStringClassReference.
1902 if (!ConstantStringClassRef) {
1903 std::string StringClass(getLangOptions().ObjCConstantStringClass);
1904 llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
1906 if (Features.ObjCNonFragileABI) {
1908 StringClass.empty() ? "OBJC_CLASS_$_NSConstantString"
1909 : "OBJC_CLASS_$_" + StringClass;
1910 GV = getObjCRuntime().GetClassGlobal(str);
1911 // Make sure the result is of the correct type.
1912 llvm::Type *PTy = llvm::PointerType::getUnqual(Ty);
1913 ConstantStringClassRef =
1914 llvm::ConstantExpr::getBitCast(GV, PTy);
1917 StringClass.empty() ? "_NSConstantStringClassReference"
1918 : "_" + StringClass + "ClassReference";
1919 llvm::Type *PTy = llvm::ArrayType::get(Ty, 0);
1920 GV = CreateRuntimeVariable(PTy, str);
1921 // Decay array -> ptr
1922 ConstantStringClassRef =
1923 llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
1927 if (!NSConstantStringType) {
1928 // Construct the type for a constant NSString.
1929 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct,
1930 Context.getTranslationUnitDecl(),
1931 &Context.Idents.get("__builtin_NSString"));
1932 D->startDefinition();
1934 QualType FieldTypes[3];
1937 FieldTypes[0] = Context.getPointerType(Context.IntTy.withConst());
1939 FieldTypes[1] = Context.getPointerType(Context.CharTy.withConst());
1940 // unsigned int length;
1941 FieldTypes[2] = Context.UnsignedIntTy;
1944 for (unsigned i = 0; i < 3; ++i) {
1945 FieldDecl *Field = FieldDecl::Create(Context, D,
1947 SourceLocation(), 0,
1948 FieldTypes[i], /*TInfo=*/0,
1952 Field->setAccess(AS_public);
1956 D->completeDefinition();
1957 QualType NSTy = Context.getTagDeclType(D);
1958 NSConstantStringType = cast<llvm::StructType>(getTypes().ConvertType(NSTy));
1961 std::vector<llvm::Constant*> Fields(3);
1964 Fields[0] = ConstantStringClassRef;
1967 llvm::Constant *C = llvm::ConstantArray::get(VMContext, Entry.getKey().str());
1969 llvm::GlobalValue::LinkageTypes Linkage;
1971 Linkage = llvm::GlobalValue::PrivateLinkage;
1972 isConstant = !Features.WritableStrings;
1974 llvm::GlobalVariable *GV =
1975 new llvm::GlobalVariable(getModule(), C->getType(), isConstant, Linkage, C,
1977 GV->setUnnamedAddr(true);
1978 CharUnits Align = getContext().getTypeAlignInChars(getContext().CharTy);
1979 GV->setAlignment(Align.getQuantity());
1980 Fields[1] = llvm::ConstantExpr::getGetElementPtr(GV, Zeros);
1983 llvm::Type *Ty = getTypes().ConvertType(getContext().UnsignedIntTy);
1984 Fields[2] = llvm::ConstantInt::get(Ty, StringLength);
1987 C = llvm::ConstantStruct::get(NSConstantStringType, Fields);
1988 GV = new llvm::GlobalVariable(getModule(), C->getType(), true,
1989 llvm::GlobalVariable::PrivateLinkage, C,
1990 "_unnamed_nsstring_");
1991 // FIXME. Fix section.
1992 if (const char *Sect =
1993 Features.ObjCNonFragileABI
1994 ? getContext().getTargetInfo().getNSStringNonFragileABISection()
1995 : getContext().getTargetInfo().getNSStringSection())
1996 GV->setSection(Sect);
2002 QualType CodeGenModule::getObjCFastEnumerationStateType() {
2003 if (ObjCFastEnumerationStateType.isNull()) {
2004 RecordDecl *D = CreateRecordDecl(Context, TTK_Struct,
2005 Context.getTranslationUnitDecl(),
2006 &Context.Idents.get("__objcFastEnumerationState"));
2007 D->startDefinition();
2009 QualType FieldTypes[] = {
2010 Context.UnsignedLongTy,
2011 Context.getPointerType(Context.getObjCIdType()),
2012 Context.getPointerType(Context.UnsignedLongTy),
2013 Context.getConstantArrayType(Context.UnsignedLongTy,
2014 llvm::APInt(32, 5), ArrayType::Normal, 0)
2017 for (size_t i = 0; i < 4; ++i) {
2018 FieldDecl *Field = FieldDecl::Create(Context,
2021 SourceLocation(), 0,
2022 FieldTypes[i], /*TInfo=*/0,
2026 Field->setAccess(AS_public);
2030 D->completeDefinition();
2031 ObjCFastEnumerationStateType = Context.getTagDeclType(D);
2034 return ObjCFastEnumerationStateType;
2037 /// GetStringForStringLiteral - Return the appropriate bytes for a
2038 /// string literal, properly padded to match the literal type.
2039 std::string CodeGenModule::GetStringForStringLiteral(const StringLiteral *E) {
2040 const ASTContext &Context = getContext();
2041 const ConstantArrayType *CAT =
2042 Context.getAsConstantArrayType(E->getType());
2043 assert(CAT && "String isn't pointer or array!");
2045 // Resize the string to the right size.
2046 uint64_t RealLen = CAT->getSize().getZExtValue();
2048 switch (E->getKind()) {
2049 case StringLiteral::Ascii:
2050 case StringLiteral::UTF8:
2052 case StringLiteral::Wide:
2053 RealLen *= Context.getTargetInfo().getWCharWidth() / Context.getCharWidth();
2055 case StringLiteral::UTF16:
2056 RealLen *= Context.getTargetInfo().getChar16Width() / Context.getCharWidth();
2058 case StringLiteral::UTF32:
2059 RealLen *= Context.getTargetInfo().getChar32Width() / Context.getCharWidth();
2063 std::string Str = E->getString().str();
2064 Str.resize(RealLen, '\0');
2069 /// GetAddrOfConstantStringFromLiteral - Return a pointer to a
2070 /// constant array for the given string literal.
2072 CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) {
2073 // FIXME: This can be more efficient.
2074 // FIXME: We shouldn't need to bitcast the constant in the wide string case.
2075 CharUnits Align = getContext().getTypeAlignInChars(S->getType());
2076 llvm::Constant *C = GetAddrOfConstantString(GetStringForStringLiteral(S),
2078 Align.getQuantity());
2079 if (S->isWide() || S->isUTF16() || S->isUTF32()) {
2080 llvm::Type *DestTy =
2081 llvm::PointerType::getUnqual(getTypes().ConvertType(S->getType()));
2082 C = llvm::ConstantExpr::getBitCast(C, DestTy);
2087 /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
2088 /// array for the given ObjCEncodeExpr node.
2090 CodeGenModule::GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *E) {
2092 getContext().getObjCEncodingForType(E->getEncodedType(), Str);
2094 return GetAddrOfConstantCString(Str);
2098 /// GenerateWritableString -- Creates storage for a string literal.
2099 static llvm::GlobalVariable *GenerateStringLiteral(StringRef str,
2102 const char *GlobalName,
2103 unsigned Alignment) {
2104 // Create Constant for this string literal. Don't add a '\0'.
2106 llvm::ConstantArray::get(CGM.getLLVMContext(), str, false);
2108 // Create a global variable for this string
2109 llvm::GlobalVariable *GV =
2110 new llvm::GlobalVariable(CGM.getModule(), C->getType(), constant,
2111 llvm::GlobalValue::PrivateLinkage,
2113 GV->setAlignment(Alignment);
2114 GV->setUnnamedAddr(true);
2118 /// GetAddrOfConstantString - Returns a pointer to a character array
2119 /// containing the literal. This contents are exactly that of the
2120 /// given string, i.e. it will not be null terminated automatically;
2121 /// see GetAddrOfConstantCString. Note that whether the result is
2122 /// actually a pointer to an LLVM constant depends on
2123 /// Feature.WriteableStrings.
2125 /// The result has pointer to array type.
2126 llvm::Constant *CodeGenModule::GetAddrOfConstantString(StringRef Str,
2127 const char *GlobalName,
2128 unsigned Alignment) {
2129 bool IsConstant = !Features.WritableStrings;
2131 // Get the default prefix if a name wasn't specified.
2133 GlobalName = ".str";
2135 // Don't share any string literals if strings aren't constant.
2137 return GenerateStringLiteral(Str, false, *this, GlobalName, Alignment);
2139 llvm::StringMapEntry<llvm::GlobalVariable *> &Entry =
2140 ConstantStringMap.GetOrCreateValue(Str);
2142 if (llvm::GlobalVariable *GV = Entry.getValue()) {
2143 if (Alignment > GV->getAlignment()) {
2144 GV->setAlignment(Alignment);
2149 // Create a global variable for this.
2150 llvm::GlobalVariable *GV = GenerateStringLiteral(Str, true, *this, GlobalName, Alignment);
2155 /// GetAddrOfConstantCString - Returns a pointer to a character
2156 /// array containing the literal and a terminating '\0'
2157 /// character. The result has pointer to array type.
2158 llvm::Constant *CodeGenModule::GetAddrOfConstantCString(const std::string &Str,
2159 const char *GlobalName,
2160 unsigned Alignment) {
2161 StringRef StrWithNull(Str.c_str(), Str.size() + 1);
2162 return GetAddrOfConstantString(StrWithNull, GlobalName, Alignment);
2165 /// EmitObjCPropertyImplementations - Emit information for synthesized
2166 /// properties for an implementation.
2167 void CodeGenModule::EmitObjCPropertyImplementations(const
2168 ObjCImplementationDecl *D) {
2169 for (ObjCImplementationDecl::propimpl_iterator
2170 i = D->propimpl_begin(), e = D->propimpl_end(); i != e; ++i) {
2171 ObjCPropertyImplDecl *PID = *i;
2173 // Dynamic is just for type-checking.
2174 if (PID->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize) {
2175 ObjCPropertyDecl *PD = PID->getPropertyDecl();
2177 // Determine which methods need to be implemented, some may have
2178 // been overridden. Note that ::isSynthesized is not the method
2179 // we want, that just indicates if the decl came from a
2180 // property. What we want to know is if the method is defined in
2181 // this implementation.
2182 if (!D->getInstanceMethod(PD->getGetterName()))
2183 CodeGenFunction(*this).GenerateObjCGetter(
2184 const_cast<ObjCImplementationDecl *>(D), PID);
2185 if (!PD->isReadOnly() &&
2186 !D->getInstanceMethod(PD->getSetterName()))
2187 CodeGenFunction(*this).GenerateObjCSetter(
2188 const_cast<ObjCImplementationDecl *>(D), PID);
2193 static bool needsDestructMethod(ObjCImplementationDecl *impl) {
2194 const ObjCInterfaceDecl *iface = impl->getClassInterface();
2195 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
2196 ivar; ivar = ivar->getNextIvar())
2197 if (ivar->getType().isDestructedType())
2203 /// EmitObjCIvarInitializations - Emit information for ivar initialization
2204 /// for an implementation.
2205 void CodeGenModule::EmitObjCIvarInitializations(ObjCImplementationDecl *D) {
2206 // We might need a .cxx_destruct even if we don't have any ivar initializers.
2207 if (needsDestructMethod(D)) {
2208 IdentifierInfo *II = &getContext().Idents.get(".cxx_destruct");
2209 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
2210 ObjCMethodDecl *DTORMethod =
2211 ObjCMethodDecl::Create(getContext(), D->getLocation(), D->getLocation(),
2212 cxxSelector, getContext().VoidTy, 0, D,
2213 /*isInstance=*/true, /*isVariadic=*/false,
2214 /*isSynthesized=*/true, /*isImplicitlyDeclared=*/true,
2215 /*isDefined=*/false, ObjCMethodDecl::Required);
2216 D->addInstanceMethod(DTORMethod);
2217 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, DTORMethod, false);
2218 D->setHasCXXStructors(true);
2221 // If the implementation doesn't have any ivar initializers, we don't need
2222 // a .cxx_construct.
2223 if (D->getNumIvarInitializers() == 0)
2226 IdentifierInfo *II = &getContext().Idents.get(".cxx_construct");
2227 Selector cxxSelector = getContext().Selectors.getSelector(0, &II);
2228 // The constructor returns 'self'.
2229 ObjCMethodDecl *CTORMethod = ObjCMethodDecl::Create(getContext(),
2233 getContext().getObjCIdType(), 0,
2234 D, /*isInstance=*/true,
2235 /*isVariadic=*/false,
2236 /*isSynthesized=*/true,
2237 /*isImplicitlyDeclared=*/true,
2238 /*isDefined=*/false,
2239 ObjCMethodDecl::Required);
2240 D->addInstanceMethod(CTORMethod);
2241 CodeGenFunction(*this).GenerateObjCCtorDtorMethod(D, CTORMethod, true);
2242 D->setHasCXXStructors(true);
2245 /// EmitNamespace - Emit all declarations in a namespace.
2246 void CodeGenModule::EmitNamespace(const NamespaceDecl *ND) {
2247 for (RecordDecl::decl_iterator I = ND->decls_begin(), E = ND->decls_end();
2249 EmitTopLevelDecl(*I);
2252 // EmitLinkageSpec - Emit all declarations in a linkage spec.
2253 void CodeGenModule::EmitLinkageSpec(const LinkageSpecDecl *LSD) {
2254 if (LSD->getLanguage() != LinkageSpecDecl::lang_c &&
2255 LSD->getLanguage() != LinkageSpecDecl::lang_cxx) {
2256 ErrorUnsupported(LSD, "linkage spec");
2260 for (RecordDecl::decl_iterator I = LSD->decls_begin(), E = LSD->decls_end();
2262 EmitTopLevelDecl(*I);
2265 /// EmitTopLevelDecl - Emit code for a single top level declaration.
2266 void CodeGenModule::EmitTopLevelDecl(Decl *D) {
2267 // If an error has occurred, stop code generation, but continue
2268 // parsing and semantic analysis (to ensure all warnings and errors
2270 if (Diags.hasErrorOccurred())
2273 // Ignore dependent declarations.
2274 if (D->getDeclContext() && D->getDeclContext()->isDependentContext())
2277 switch (D->getKind()) {
2278 case Decl::CXXConversion:
2279 case Decl::CXXMethod:
2280 case Decl::Function:
2281 // Skip function templates
2282 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
2283 cast<FunctionDecl>(D)->isLateTemplateParsed())
2286 EmitGlobal(cast<FunctionDecl>(D));
2290 EmitGlobal(cast<VarDecl>(D));
2293 // Indirect fields from global anonymous structs and unions can be
2294 // ignored; only the actual variable requires IR gen support.
2295 case Decl::IndirectField:
2299 case Decl::Namespace:
2300 EmitNamespace(cast<NamespaceDecl>(D));
2302 // No code generation needed.
2303 case Decl::UsingShadow:
2305 case Decl::UsingDirective:
2306 case Decl::ClassTemplate:
2307 case Decl::FunctionTemplate:
2308 case Decl::TypeAliasTemplate:
2309 case Decl::NamespaceAlias:
2312 case Decl::CXXConstructor:
2313 // Skip function templates
2314 if (cast<FunctionDecl>(D)->getDescribedFunctionTemplate() ||
2315 cast<FunctionDecl>(D)->isLateTemplateParsed())
2318 EmitCXXConstructors(cast<CXXConstructorDecl>(D));
2320 case Decl::CXXDestructor:
2321 if (cast<FunctionDecl>(D)->isLateTemplateParsed())
2323 EmitCXXDestructors(cast<CXXDestructorDecl>(D));
2326 case Decl::StaticAssert:
2330 // Objective-C Decls
2332 // Forward declarations, no (immediate) code generation.
2333 case Decl::ObjCClass:
2334 case Decl::ObjCForwardProtocol:
2335 case Decl::ObjCInterface:
2338 case Decl::ObjCCategory: {
2339 ObjCCategoryDecl *CD = cast<ObjCCategoryDecl>(D);
2340 if (CD->IsClassExtension() && CD->hasSynthBitfield())
2341 Context.ResetObjCLayout(CD->getClassInterface());
2345 case Decl::ObjCProtocol:
2346 ObjCRuntime->GenerateProtocol(cast<ObjCProtocolDecl>(D));
2349 case Decl::ObjCCategoryImpl:
2350 // Categories have properties but don't support synthesize so we
2351 // can ignore them here.
2352 ObjCRuntime->GenerateCategory(cast<ObjCCategoryImplDecl>(D));
2355 case Decl::ObjCImplementation: {
2356 ObjCImplementationDecl *OMD = cast<ObjCImplementationDecl>(D);
2357 if (Features.ObjCNonFragileABI2 && OMD->hasSynthBitfield())
2358 Context.ResetObjCLayout(OMD->getClassInterface());
2359 EmitObjCPropertyImplementations(OMD);
2360 EmitObjCIvarInitializations(OMD);
2361 ObjCRuntime->GenerateClass(OMD);
2364 case Decl::ObjCMethod: {
2365 ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(D);
2366 // If this is not a prototype, emit the body.
2368 CodeGenFunction(*this).GenerateObjCMethod(OMD);
2371 case Decl::ObjCCompatibleAlias:
2372 // compatibility-alias is a directive and has no code gen.
2375 case Decl::LinkageSpec:
2376 EmitLinkageSpec(cast<LinkageSpecDecl>(D));
2379 case Decl::FileScopeAsm: {
2380 FileScopeAsmDecl *AD = cast<FileScopeAsmDecl>(D);
2381 StringRef AsmString = AD->getAsmString()->getString();
2383 const std::string &S = getModule().getModuleInlineAsm();
2385 getModule().setModuleInlineAsm(AsmString);
2386 else if (*--S.end() == '\n')
2387 getModule().setModuleInlineAsm(S + AsmString.str());
2389 getModule().setModuleInlineAsm(S + '\n' + AsmString.str());
2394 // Make sure we handled everything we should, every other kind is a
2395 // non-top-level decl. FIXME: Would be nice to have an isTopLevelDeclKind
2396 // function. Need to recode Decl::Kind to do that easily.
2397 assert(isa<TypeDecl>(D) && "Unsupported decl kind");
2401 /// Turns the given pointer into a constant.
2402 static llvm::Constant *GetPointerConstant(llvm::LLVMContext &Context,
2404 uintptr_t PtrInt = reinterpret_cast<uintptr_t>(Ptr);
2405 llvm::Type *i64 = llvm::Type::getInt64Ty(Context);
2406 return llvm::ConstantInt::get(i64, PtrInt);
2409 static void EmitGlobalDeclMetadata(CodeGenModule &CGM,
2410 llvm::NamedMDNode *&GlobalMetadata,
2412 llvm::GlobalValue *Addr) {
2413 if (!GlobalMetadata)
2415 CGM.getModule().getOrInsertNamedMetadata("clang.global.decl.ptrs");
2417 // TODO: should we report variant information for ctors/dtors?
2418 llvm::Value *Ops[] = {
2420 GetPointerConstant(CGM.getLLVMContext(), D.getDecl())
2422 GlobalMetadata->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2425 /// Emits metadata nodes associating all the global values in the
2426 /// current module with the Decls they came from. This is useful for
2427 /// projects using IR gen as a subroutine.
2429 /// Since there's currently no way to associate an MDNode directly
2430 /// with an llvm::GlobalValue, we create a global named metadata
2431 /// with the name 'clang.global.decl.ptrs'.
2432 void CodeGenModule::EmitDeclMetadata() {
2433 llvm::NamedMDNode *GlobalMetadata = 0;
2435 // StaticLocalDeclMap
2436 for (llvm::DenseMap<GlobalDecl,StringRef>::iterator
2437 I = MangledDeclNames.begin(), E = MangledDeclNames.end();
2439 llvm::GlobalValue *Addr = getModule().getNamedValue(I->second);
2440 EmitGlobalDeclMetadata(*this, GlobalMetadata, I->first, Addr);
2444 /// Emits metadata nodes for all the local variables in the current
2446 void CodeGenFunction::EmitDeclMetadata() {
2447 if (LocalDeclMap.empty()) return;
2449 llvm::LLVMContext &Context = getLLVMContext();
2451 // Find the unique metadata ID for this name.
2452 unsigned DeclPtrKind = Context.getMDKindID("clang.decl.ptr");
2454 llvm::NamedMDNode *GlobalMetadata = 0;
2456 for (llvm::DenseMap<const Decl*, llvm::Value*>::iterator
2457 I = LocalDeclMap.begin(), E = LocalDeclMap.end(); I != E; ++I) {
2458 const Decl *D = I->first;
2459 llvm::Value *Addr = I->second;
2461 if (llvm::AllocaInst *Alloca = dyn_cast<llvm::AllocaInst>(Addr)) {
2462 llvm::Value *DAddr = GetPointerConstant(getLLVMContext(), D);
2463 Alloca->setMetadata(DeclPtrKind, llvm::MDNode::get(Context, DAddr));
2464 } else if (llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(Addr)) {
2465 GlobalDecl GD = GlobalDecl(cast<VarDecl>(D));
2466 EmitGlobalDeclMetadata(CGM, GlobalMetadata, GD, GV);
2471 void CodeGenModule::EmitCoverageFile() {
2472 if (!getCodeGenOpts().CoverageFile.empty()) {
2473 if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu")) {
2474 llvm::NamedMDNode *GCov = TheModule.getOrInsertNamedMetadata("llvm.gcov");
2475 llvm::LLVMContext &Ctx = TheModule.getContext();
2476 llvm::MDString *CoverageFile =
2477 llvm::MDString::get(Ctx, getCodeGenOpts().CoverageFile);
2478 for (int i = 0, e = CUNode->getNumOperands(); i != e; ++i) {
2479 llvm::MDNode *CU = CUNode->getOperand(i);
2480 llvm::Value *node[] = { CoverageFile, CU };
2481 llvm::MDNode *N = llvm::MDNode::get(Ctx, node);
2482 GCov->addOperand(N);