| //===--- CGVtable.cpp - Emit LLVM Code for C++ vtables --------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This contains code dealing with C++ code generation of virtual tables. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CodeGenModule.h" |
| #include "CodeGenFunction.h" |
| #include "clang/AST/CXXInheritance.h" |
| #include "clang/AST/RecordLayout.h" |
| #include "llvm/ADT/DenseSet.h" |
| #include <cstdio> |
| |
| using namespace clang; |
| using namespace CodeGen; |
| |
| namespace { |
| class VtableBuilder { |
| public: |
| /// Index_t - Vtable index type. |
| typedef uint64_t Index_t; |
| typedef std::vector<std::pair<GlobalDecl, |
| std::pair<GlobalDecl, ThunkAdjustment> > > |
| SavedAdjustmentsVectorTy; |
| private: |
| |
| // VtableComponents - The components of the vtable being built. |
| typedef llvm::SmallVector<llvm::Constant *, 64> VtableComponentsVectorTy; |
| VtableComponentsVectorTy VtableComponents; |
| |
| const bool BuildVtable; |
| |
| llvm::Type *Ptr8Ty; |
| |
| /// MostDerivedClass - The most derived class that this vtable is being |
| /// built for. |
| const CXXRecordDecl *MostDerivedClass; |
| |
| /// LayoutClass - The most derived class used for virtual base layout |
| /// information. |
| const CXXRecordDecl *LayoutClass; |
| /// LayoutOffset - The offset for Class in LayoutClass. |
| uint64_t LayoutOffset; |
| /// BLayout - Layout for the most derived class that this vtable is being |
| /// built for. |
| const ASTRecordLayout &BLayout; |
| llvm::SmallSet<const CXXRecordDecl *, 32> IndirectPrimary; |
| llvm::SmallSet<const CXXRecordDecl *, 32> SeenVBase; |
| llvm::Constant *rtti; |
| llvm::LLVMContext &VMContext; |
| CodeGenModule &CGM; // Per-module state. |
| |
| llvm::DenseMap<GlobalDecl, Index_t> VCall; |
| llvm::DenseMap<GlobalDecl, Index_t> VCallOffset; |
| // This is the offset to the nearest virtual base |
| llvm::DenseMap<GlobalDecl, Index_t> NonVirtualOffset; |
| llvm::DenseMap<const CXXRecordDecl *, Index_t> VBIndex; |
| |
| /// PureVirtualFunction - Points to __cxa_pure_virtual. |
| llvm::Constant *PureVirtualFn; |
| |
| /// VtableMethods - A data structure for keeping track of methods in a vtable. |
| /// Can add methods, override methods and iterate in vtable order. |
| class VtableMethods { |
| // MethodToIndexMap - Maps from a global decl to the index it has in the |
| // Methods vector. |
| llvm::DenseMap<GlobalDecl, uint64_t> MethodToIndexMap; |
| |
| /// Methods - The methods, in vtable order. |
| typedef llvm::SmallVector<GlobalDecl, 16> MethodsVectorTy; |
| MethodsVectorTy Methods; |
| MethodsVectorTy OrigMethods; |
| |
| public: |
| /// AddMethod - Add a method to the vtable methods. |
| void AddMethod(GlobalDecl GD) { |
| assert(!MethodToIndexMap.count(GD) && |
| "Method has already been added!"); |
| |
| MethodToIndexMap[GD] = Methods.size(); |
| Methods.push_back(GD); |
| OrigMethods.push_back(GD); |
| } |
| |
| /// OverrideMethod - Replace a method with another. |
| void OverrideMethod(GlobalDecl OverriddenGD, GlobalDecl GD) { |
| llvm::DenseMap<GlobalDecl, uint64_t>::iterator i |
| = MethodToIndexMap.find(OverriddenGD); |
| assert(i != MethodToIndexMap.end() && "Did not find entry!"); |
| |
| // Get the index of the old decl. |
| uint64_t Index = i->second; |
| |
| // Replace the old decl with the new decl. |
| Methods[Index] = GD; |
| |
| // And add the new. |
| MethodToIndexMap[GD] = Index; |
| } |
| |
| /// getIndex - Gives the index of a passed in GlobalDecl. Returns false if |
| /// the index couldn't be found. |
| bool getIndex(GlobalDecl GD, uint64_t &Index) const { |
| llvm::DenseMap<GlobalDecl, uint64_t>::const_iterator i |
| = MethodToIndexMap.find(GD); |
| |
| if (i == MethodToIndexMap.end()) |
| return false; |
| |
| Index = i->second; |
| return true; |
| } |
| |
| GlobalDecl getOrigMethod(uint64_t Index) const { |
| return OrigMethods[Index]; |
| } |
| |
| MethodsVectorTy::size_type size() const { |
| return Methods.size(); |
| } |
| |
| void clear() { |
| MethodToIndexMap.clear(); |
| Methods.clear(); |
| OrigMethods.clear(); |
| } |
| |
| GlobalDecl operator[](uint64_t Index) const { |
| return Methods[Index]; |
| } |
| }; |
| |
| /// Methods - The vtable methods we're currently building. |
| VtableMethods Methods; |
| |
| /// ThisAdjustments - For a given index in the vtable, contains the 'this' |
| /// pointer adjustment needed for a method. |
| typedef llvm::DenseMap<uint64_t, ThunkAdjustment> ThisAdjustmentsMapTy; |
| ThisAdjustmentsMapTy ThisAdjustments; |
| |
| SavedAdjustmentsVectorTy SavedAdjustments; |
| |
| /// BaseReturnTypes - Contains the base return types of methods who have been |
| /// overridden with methods whose return types require adjustment. Used for |
| /// generating covariant thunk information. |
| typedef llvm::DenseMap<uint64_t, CanQualType> BaseReturnTypesMapTy; |
| BaseReturnTypesMapTy BaseReturnTypes; |
| |
| std::vector<Index_t> VCalls; |
| |
| typedef std::pair<const CXXRecordDecl *, uint64_t> CtorVtable_t; |
| // subAddressPoints - Used to hold the AddressPoints (offsets) into the built |
| // vtable for use in computing the initializers for the VTT. |
| llvm::DenseMap<CtorVtable_t, int64_t> &subAddressPoints; |
| |
| typedef CXXRecordDecl::method_iterator method_iter; |
| const bool Extern; |
| const uint32_t LLVMPointerWidth; |
| Index_t extra; |
| typedef std::vector<std::pair<const CXXRecordDecl *, int64_t> > Path_t; |
| static llvm::DenseMap<CtorVtable_t, int64_t>& |
| AllocAddressPoint(CodeGenModule &cgm, const CXXRecordDecl *l, |
| const CXXRecordDecl *c) { |
| CodeGenModule::AddrMap_t *&oref = cgm.AddressPoints[l]; |
| if (oref == 0) |
| oref = new CodeGenModule::AddrMap_t; |
| |
| llvm::DenseMap<CtorVtable_t, int64_t> *&ref = (*oref)[c]; |
| if (ref == 0) |
| ref = new llvm::DenseMap<CtorVtable_t, int64_t>; |
| return *ref; |
| } |
| |
| /// getPureVirtualFn - Return the __cxa_pure_virtual function. |
| llvm::Constant* getPureVirtualFn() { |
| if (!PureVirtualFn) { |
| const llvm::FunctionType *Ty = |
| llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), |
| /*isVarArg=*/false); |
| PureVirtualFn = wrap(CGM.CreateRuntimeFunction(Ty, "__cxa_pure_virtual")); |
| } |
| |
| return PureVirtualFn; |
| } |
| |
| public: |
| VtableBuilder(const CXXRecordDecl *MostDerivedClass, |
| const CXXRecordDecl *l, uint64_t lo, CodeGenModule &cgm, |
| bool build) |
| : BuildVtable(build), MostDerivedClass(MostDerivedClass), LayoutClass(l), |
| LayoutOffset(lo), BLayout(cgm.getContext().getASTRecordLayout(l)), |
| rtti(0), VMContext(cgm.getModule().getContext()),CGM(cgm), |
| PureVirtualFn(0), |
| subAddressPoints(AllocAddressPoint(cgm, l, MostDerivedClass)), |
| Extern(!l->isInAnonymousNamespace()), |
| LLVMPointerWidth(cgm.getContext().Target.getPointerWidth(0)) { |
| Ptr8Ty = llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext), 0); |
| if (BuildVtable) { |
| QualType ClassType = CGM.getContext().getTagDeclType(MostDerivedClass); |
| rtti = CGM.GetAddrOfRTTIDescriptor(ClassType); |
| } |
| } |
| |
| // getVtableComponents - Returns a reference to the vtable components. |
| const VtableComponentsVectorTy &getVtableComponents() const { |
| return VtableComponents; |
| } |
| |
| llvm::DenseMap<const CXXRecordDecl *, Index_t> &getVBIndex() |
| { return VBIndex; } |
| |
| SavedAdjustmentsVectorTy &getSavedAdjustments() |
| { return SavedAdjustments; } |
| |
| llvm::Constant *wrap(Index_t i) { |
| llvm::Constant *m; |
| m = llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext), i); |
| return llvm::ConstantExpr::getIntToPtr(m, Ptr8Ty); |
| } |
| |
| llvm::Constant *wrap(llvm::Constant *m) { |
| return llvm::ConstantExpr::getBitCast(m, Ptr8Ty); |
| } |
| |
| #define D1(x) |
| //#define D1(X) do { if (getenv("DEBUG")) { X; } } while (0) |
| |
| void GenerateVBaseOffsets(const CXXRecordDecl *RD, uint64_t Offset, |
| bool updateVBIndex, Index_t current_vbindex) { |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); i != e; ++i) { |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| Index_t next_vbindex = current_vbindex; |
| if (i->isVirtual() && !SeenVBase.count(Base)) { |
| SeenVBase.insert(Base); |
| if (updateVBIndex) { |
| next_vbindex = (ssize_t)(-(VCalls.size()*LLVMPointerWidth/8) |
| - 3*LLVMPointerWidth/8); |
| VBIndex[Base] = next_vbindex; |
| } |
| int64_t BaseOffset = -(Offset/8) + BLayout.getVBaseClassOffset(Base)/8; |
| VCalls.push_back((0?700:0) + BaseOffset); |
| D1(printf(" vbase for %s at %d delta %d most derived %s\n", |
| Base->getNameAsCString(), |
| (int)-VCalls.size()-3, (int)BaseOffset, |
| Class->getNameAsCString())); |
| } |
| // We also record offsets for non-virtual bases to closest enclosing |
| // virtual base. We do this so that we don't have to search |
| // for the nearst virtual base class when generating thunks. |
| if (updateVBIndex && VBIndex.count(Base) == 0) |
| VBIndex[Base] = next_vbindex; |
| GenerateVBaseOffsets(Base, Offset, updateVBIndex, next_vbindex); |
| } |
| } |
| |
| void StartNewTable() { |
| SeenVBase.clear(); |
| } |
| |
| Index_t getNVOffset_1(const CXXRecordDecl *D, const CXXRecordDecl *B, |
| Index_t Offset = 0) { |
| |
| if (B == D) |
| return Offset; |
| |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(D); |
| for (CXXRecordDecl::base_class_const_iterator i = D->bases_begin(), |
| e = D->bases_end(); i != e; ++i) { |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| int64_t BaseOffset = 0; |
| if (!i->isVirtual()) |
| BaseOffset = Offset + Layout.getBaseClassOffset(Base); |
| int64_t o = getNVOffset_1(Base, B, BaseOffset); |
| if (o >= 0) |
| return o; |
| } |
| |
| return -1; |
| } |
| |
| /// getNVOffset - Returns the non-virtual offset for the given (B) base of the |
| /// derived class D. |
| Index_t getNVOffset(QualType qB, QualType qD) { |
| qD = qD->getPointeeType(); |
| qB = qB->getPointeeType(); |
| CXXRecordDecl *D = cast<CXXRecordDecl>(qD->getAs<RecordType>()->getDecl()); |
| CXXRecordDecl *B = cast<CXXRecordDecl>(qB->getAs<RecordType>()->getDecl()); |
| int64_t o = getNVOffset_1(D, B); |
| if (o >= 0) |
| return o; |
| |
| assert(false && "FIXME: non-virtual base not found"); |
| return 0; |
| } |
| |
| /// getVbaseOffset - Returns the index into the vtable for the virtual base |
| /// offset for the given (B) virtual base of the derived class D. |
| Index_t getVbaseOffset(QualType qB, QualType qD) { |
| qD = qD->getPointeeType(); |
| qB = qB->getPointeeType(); |
| CXXRecordDecl *D = cast<CXXRecordDecl>(qD->getAs<RecordType>()->getDecl()); |
| CXXRecordDecl *B = cast<CXXRecordDecl>(qB->getAs<RecordType>()->getDecl()); |
| if (D != MostDerivedClass) |
| return CGM.getVtableInfo().getVirtualBaseOffsetIndex(D, B); |
| llvm::DenseMap<const CXXRecordDecl *, Index_t>::iterator i; |
| i = VBIndex.find(B); |
| if (i != VBIndex.end()) |
| return i->second; |
| |
| assert(false && "FIXME: Base not found"); |
| return 0; |
| } |
| |
| bool OverrideMethod(GlobalDecl GD, bool MorallyVirtual, |
| Index_t OverrideOffset, Index_t Offset, |
| int64_t CurrentVBaseOffset); |
| |
| /// AppendMethods - Append the current methods to the vtable. |
| void AppendMethodsToVtable(); |
| |
| llvm::Constant *WrapAddrOf(GlobalDecl GD) { |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| |
| const llvm::Type *Ty = CGM.getTypes().GetFunctionTypeForVtable(MD); |
| |
| return wrap(CGM.GetAddrOfFunction(GD, Ty)); |
| } |
| |
| void OverrideMethods(Path_t *Path, bool MorallyVirtual, int64_t Offset, |
| int64_t CurrentVBaseOffset) { |
| for (Path_t::reverse_iterator i = Path->rbegin(), |
| e = Path->rend(); i != e; ++i) { |
| const CXXRecordDecl *RD = i->first; |
| int64_t OverrideOffset = i->second; |
| for (method_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; |
| ++mi) { |
| const CXXMethodDecl *MD = *mi; |
| |
| if (!MD->isVirtual()) |
| continue; |
| |
| if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) { |
| // Override both the complete and the deleting destructor. |
| GlobalDecl CompDtor(DD, Dtor_Complete); |
| OverrideMethod(CompDtor, MorallyVirtual, OverrideOffset, Offset, |
| CurrentVBaseOffset); |
| |
| GlobalDecl DeletingDtor(DD, Dtor_Deleting); |
| OverrideMethod(DeletingDtor, MorallyVirtual, OverrideOffset, Offset, |
| CurrentVBaseOffset); |
| } else { |
| OverrideMethod(MD, MorallyVirtual, OverrideOffset, Offset, |
| CurrentVBaseOffset); |
| } |
| } |
| } |
| } |
| |
| void AddMethod(const GlobalDecl GD, bool MorallyVirtual, Index_t Offset, |
| int64_t CurrentVBaseOffset) { |
| // If we can find a previously allocated slot for this, reuse it. |
| if (OverrideMethod(GD, MorallyVirtual, Offset, Offset, |
| CurrentVBaseOffset)) |
| return; |
| |
| // We didn't find an entry in the vtable that we could use, add a new |
| // entry. |
| Methods.AddMethod(GD); |
| |
| D1(printf(" vfn for %s at %d\n", MD->getNameAsString().c_str(), |
| (int)Index[GD])); |
| |
| VCallOffset[GD] = Offset/8; |
| if (MorallyVirtual) { |
| Index_t &idx = VCall[GD]; |
| // Allocate the first one, after that, we reuse the previous one. |
| if (idx == 0) { |
| NonVirtualOffset[GD] = CurrentVBaseOffset/8 - Offset/8; |
| idx = VCalls.size()+1; |
| VCalls.push_back(0); |
| D1(printf(" vcall for %s at %d with delta %d\n", |
| MD->getNameAsString().c_str(), (int)-VCalls.size()-3, 0)); |
| } |
| } |
| } |
| |
| void AddMethods(const CXXRecordDecl *RD, bool MorallyVirtual, |
| Index_t Offset, int64_t CurrentVBaseOffset) { |
| for (method_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; |
| ++mi) { |
| const CXXMethodDecl *MD = *mi; |
| if (!MD->isVirtual()) |
| continue; |
| |
| if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) { |
| // For destructors, add both the complete and the deleting destructor |
| // to the vtable. |
| AddMethod(GlobalDecl(DD, Dtor_Complete), MorallyVirtual, Offset, |
| CurrentVBaseOffset); |
| AddMethod(GlobalDecl(DD, Dtor_Deleting), MorallyVirtual, Offset, |
| CurrentVBaseOffset); |
| } else |
| AddMethod(MD, MorallyVirtual, Offset, CurrentVBaseOffset); |
| } |
| } |
| |
| void NonVirtualBases(const CXXRecordDecl *RD, const ASTRecordLayout &Layout, |
| const CXXRecordDecl *PrimaryBase, |
| bool PrimaryBaseWasVirtual, bool MorallyVirtual, |
| int64_t Offset, int64_t CurrentVBaseOffset, |
| Path_t *Path) { |
| Path->push_back(std::make_pair(RD, Offset)); |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); i != e; ++i) { |
| if (i->isVirtual()) |
| continue; |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| if (Base != PrimaryBase || PrimaryBaseWasVirtual) { |
| uint64_t o = Offset + Layout.getBaseClassOffset(Base); |
| StartNewTable(); |
| GenerateVtableForBase(Base, o, MorallyVirtual, false, |
| CurrentVBaseOffset, Path); |
| } |
| } |
| Path->pop_back(); |
| } |
| |
| // #define D(X) do { X; } while (0) |
| #define D(X) |
| |
| void insertVCalls(int InsertionPoint) { |
| D1(printf("============= combining vbase/vcall\n")); |
| D(VCalls.insert(VCalls.begin(), 673)); |
| D(VCalls.push_back(672)); |
| |
| VtableComponents.insert(VtableComponents.begin() + InsertionPoint, |
| VCalls.size(), 0); |
| if (BuildVtable) { |
| // The vcalls come first... |
| for (std::vector<Index_t>::reverse_iterator i = VCalls.rbegin(), |
| e = VCalls.rend(); |
| i != e; ++i) |
| VtableComponents[InsertionPoint++] = wrap((0?600:0) + *i); |
| } |
| VCalls.clear(); |
| VCall.clear(); |
| } |
| |
| void AddAddressPoints(const CXXRecordDecl *RD, uint64_t Offset, |
| Index_t AddressPoint) { |
| D1(printf("XXX address point for %s in %s layout %s at offset %d is %d\n", |
| RD->getNameAsCString(), Class->getNameAsCString(), |
| LayoutClass->getNameAsCString(), (int)Offset, (int)AddressPoint)); |
| subAddressPoints[std::make_pair(RD, Offset)] = AddressPoint; |
| |
| // Now also add the address point for all our primary bases. |
| while (1) { |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| RD = Layout.getPrimaryBase(); |
| const bool PrimaryBaseWasVirtual = Layout.getPrimaryBaseWasVirtual(); |
| // FIXME: Double check this. |
| if (RD == 0) |
| break; |
| if (PrimaryBaseWasVirtual && |
| BLayout.getVBaseClassOffset(RD) != Offset) |
| break; |
| D1(printf("XXX address point for %s in %s layout %s at offset %d is %d\n", |
| RD->getNameAsCString(), Class->getNameAsCString(), |
| LayoutClass->getNameAsCString(), (int)Offset, (int)AddressPoint)); |
| subAddressPoints[std::make_pair(RD, Offset)] = AddressPoint; |
| } |
| } |
| |
| |
| Index_t FinishGenerateVtable(const CXXRecordDecl *RD, |
| const ASTRecordLayout &Layout, |
| const CXXRecordDecl *PrimaryBase, |
| bool PrimaryBaseWasVirtual, |
| bool MorallyVirtual, int64_t Offset, |
| bool ForVirtualBase, int64_t CurrentVBaseOffset, |
| Path_t *Path) { |
| bool alloc = false; |
| if (Path == 0) { |
| alloc = true; |
| Path = new Path_t; |
| } |
| |
| StartNewTable(); |
| extra = 0; |
| bool DeferVCalls = MorallyVirtual || ForVirtualBase; |
| int VCallInsertionPoint = VtableComponents.size(); |
| if (!DeferVCalls) { |
| insertVCalls(VCallInsertionPoint); |
| } else |
| // FIXME: just for extra, or for all uses of VCalls.size post this? |
| extra = -VCalls.size(); |
| |
| // Add the offset to top. |
| VtableComponents.push_back(BuildVtable ? wrap(-((Offset-LayoutOffset)/8)) : 0); |
| |
| // Add the RTTI information. |
| VtableComponents.push_back(rtti); |
| |
| Index_t AddressPoint = VtableComponents.size(); |
| |
| AppendMethodsToVtable(); |
| |
| // and then the non-virtual bases. |
| NonVirtualBases(RD, Layout, PrimaryBase, PrimaryBaseWasVirtual, |
| MorallyVirtual, Offset, CurrentVBaseOffset, Path); |
| |
| if (ForVirtualBase) { |
| // FIXME: We're adding to VCalls in callers, we need to do the overrides |
| // in the inner part, so that we know the complete set of vcalls during |
| // the build and don't have to insert into methods. Saving out the |
| // AddressPoint here, would need to be fixed, if we didn't do that. Also |
| // retroactively adding vcalls for overrides later wind up in the wrong |
| // place, the vcall slot has to be alloted during the walk of the base |
| // when the function is first introduces. |
| AddressPoint += VCalls.size(); |
| insertVCalls(VCallInsertionPoint); |
| } |
| |
| AddAddressPoints(RD, Offset, AddressPoint); |
| |
| if (alloc) { |
| delete Path; |
| } |
| return AddressPoint; |
| } |
| |
| void Primaries(const CXXRecordDecl *RD, bool MorallyVirtual, int64_t Offset, |
| bool updateVBIndex, Index_t current_vbindex, |
| int64_t CurrentVBaseOffset) { |
| if (!RD->isDynamicClass()) |
| return; |
| |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); |
| const bool PrimaryBaseWasVirtual = Layout.getPrimaryBaseWasVirtual(); |
| |
| // vtables are composed from the chain of primaries. |
| if (PrimaryBase && !PrimaryBaseWasVirtual) { |
| D1(printf(" doing primaries for %s most derived %s\n", |
| RD->getNameAsCString(), Class->getNameAsCString())); |
| Primaries(PrimaryBase, PrimaryBaseWasVirtual|MorallyVirtual, Offset, |
| updateVBIndex, current_vbindex, CurrentVBaseOffset); |
| } |
| |
| D1(printf(" doing vcall entries for %s most derived %s\n", |
| RD->getNameAsCString(), Class->getNameAsCString())); |
| |
| // And add the virtuals for the class to the primary vtable. |
| AddMethods(RD, MorallyVirtual, Offset, CurrentVBaseOffset); |
| } |
| |
| void VBPrimaries(const CXXRecordDecl *RD, bool MorallyVirtual, int64_t Offset, |
| bool updateVBIndex, Index_t current_vbindex, |
| bool RDisVirtualBase, int64_t CurrentVBaseOffset, |
| bool bottom) { |
| if (!RD->isDynamicClass()) |
| return; |
| |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); |
| const bool PrimaryBaseWasVirtual = Layout.getPrimaryBaseWasVirtual(); |
| |
| // vtables are composed from the chain of primaries. |
| if (PrimaryBase) { |
| int BaseCurrentVBaseOffset = CurrentVBaseOffset; |
| if (PrimaryBaseWasVirtual) { |
| IndirectPrimary.insert(PrimaryBase); |
| BaseCurrentVBaseOffset = BLayout.getVBaseClassOffset(PrimaryBase); |
| } |
| |
| D1(printf(" doing primaries for %s most derived %s\n", |
| RD->getNameAsCString(), Class->getNameAsCString())); |
| |
| VBPrimaries(PrimaryBase, PrimaryBaseWasVirtual|MorallyVirtual, Offset, |
| updateVBIndex, current_vbindex, PrimaryBaseWasVirtual, |
| BaseCurrentVBaseOffset, false); |
| } |
| |
| D1(printf(" doing vbase entries for %s most derived %s\n", |
| RD->getNameAsCString(), Class->getNameAsCString())); |
| GenerateVBaseOffsets(RD, Offset, updateVBIndex, current_vbindex); |
| |
| if (RDisVirtualBase || bottom) { |
| Primaries(RD, MorallyVirtual, Offset, updateVBIndex, current_vbindex, |
| CurrentVBaseOffset); |
| } |
| } |
| |
| int64_t GenerateVtableForBase(const CXXRecordDecl *RD, int64_t Offset = 0, |
| bool MorallyVirtual = false, |
| bool ForVirtualBase = false, |
| int CurrentVBaseOffset = 0, |
| Path_t *Path = 0) { |
| if (!RD->isDynamicClass()) |
| return 0; |
| |
| // Construction vtable don't need parts that have no virtual bases and |
| // aren't morally virtual. |
| if ((LayoutClass != MostDerivedClass) && |
| RD->getNumVBases() == 0 && !MorallyVirtual) |
| return 0; |
| |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); |
| const bool PrimaryBaseWasVirtual = Layout.getPrimaryBaseWasVirtual(); |
| |
| extra = 0; |
| D1(printf("building entries for base %s most derived %s\n", |
| RD->getNameAsCString(), Class->getNameAsCString())); |
| |
| if (ForVirtualBase) |
| extra = VCalls.size(); |
| |
| VBPrimaries(RD, MorallyVirtual, Offset, !ForVirtualBase, 0, ForVirtualBase, |
| CurrentVBaseOffset, true); |
| |
| if (Path) |
| OverrideMethods(Path, MorallyVirtual, Offset, CurrentVBaseOffset); |
| |
| return FinishGenerateVtable(RD, Layout, PrimaryBase, PrimaryBaseWasVirtual, |
| MorallyVirtual, Offset, ForVirtualBase, |
| CurrentVBaseOffset, Path); |
| } |
| |
| void GenerateVtableForVBases(const CXXRecordDecl *RD, |
| int64_t Offset = 0, |
| Path_t *Path = 0) { |
| bool alloc = false; |
| if (Path == 0) { |
| alloc = true; |
| Path = new Path_t; |
| } |
| // FIXME: We also need to override using all paths to a virtual base, |
| // right now, we just process the first path |
| Path->push_back(std::make_pair(RD, Offset)); |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); i != e; ++i) { |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| if (i->isVirtual() && !IndirectPrimary.count(Base)) { |
| // Mark it so we don't output it twice. |
| IndirectPrimary.insert(Base); |
| StartNewTable(); |
| VCall.clear(); |
| int64_t BaseOffset = BLayout.getVBaseClassOffset(Base); |
| int64_t CurrentVBaseOffset = BaseOffset; |
| D1(printf("vtable %s virtual base %s\n", |
| Class->getNameAsCString(), Base->getNameAsCString())); |
| GenerateVtableForBase(Base, BaseOffset, true, true, CurrentVBaseOffset, |
| Path); |
| } |
| int64_t BaseOffset; |
| if (i->isVirtual()) |
| BaseOffset = BLayout.getVBaseClassOffset(Base); |
| else { |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| BaseOffset = Offset + Layout.getBaseClassOffset(Base); |
| } |
| |
| if (Base->getNumVBases()) { |
| GenerateVtableForVBases(Base, BaseOffset, Path); |
| } |
| } |
| Path->pop_back(); |
| if (alloc) |
| delete Path; |
| } |
| }; |
| } // end anonymous namespace |
| |
| /// TypeConversionRequiresAdjustment - Returns whether conversion from a |
| /// derived type to a base type requires adjustment. |
| static bool |
| TypeConversionRequiresAdjustment(ASTContext &Ctx, |
| const CXXRecordDecl *DerivedDecl, |
| const CXXRecordDecl *BaseDecl) { |
| CXXBasePaths Paths(/*FindAmbiguities=*/false, |
| /*RecordPaths=*/true, /*DetectVirtual=*/true); |
| if (!const_cast<CXXRecordDecl *>(DerivedDecl)-> |
| isDerivedFrom(const_cast<CXXRecordDecl *>(BaseDecl), Paths)) { |
| assert(false && "Class must be derived from the passed in base class!"); |
| return false; |
| } |
| |
| // If we found a virtual base we always want to require adjustment. |
| if (Paths.getDetectedVirtual()) |
| return true; |
| |
| const CXXBasePath &Path = Paths.front(); |
| |
| for (size_t Start = 0, End = Path.size(); Start != End; ++Start) { |
| const CXXBasePathElement &Element = Path[Start]; |
| |
| // Check the base class offset. |
| const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(Element.Class); |
| |
| const RecordType *BaseType = Element.Base->getType()->getAs<RecordType>(); |
| const CXXRecordDecl *Base = cast<CXXRecordDecl>(BaseType->getDecl()); |
| |
| if (Layout.getBaseClassOffset(Base) != 0) { |
| // This requires an adjustment. |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| static bool |
| TypeConversionRequiresAdjustment(ASTContext &Ctx, |
| QualType DerivedType, QualType BaseType) { |
| // Canonicalize the types. |
| QualType CanDerivedType = Ctx.getCanonicalType(DerivedType); |
| QualType CanBaseType = Ctx.getCanonicalType(BaseType); |
| |
| assert(CanDerivedType->getTypeClass() == CanBaseType->getTypeClass() && |
| "Types must have same type class!"); |
| |
| if (CanDerivedType == CanBaseType) { |
| // No adjustment needed. |
| return false; |
| } |
| |
| if (const ReferenceType *RT = dyn_cast<ReferenceType>(CanDerivedType)) { |
| CanDerivedType = RT->getPointeeType(); |
| CanBaseType = cast<ReferenceType>(CanBaseType)->getPointeeType(); |
| } else if (const PointerType *PT = dyn_cast<PointerType>(CanDerivedType)) { |
| CanDerivedType = PT->getPointeeType(); |
| CanBaseType = cast<PointerType>(CanBaseType)->getPointeeType(); |
| } else { |
| assert(false && "Unexpected return type!"); |
| } |
| |
| if (CanDerivedType == CanBaseType) { |
| // No adjustment needed. |
| return false; |
| } |
| |
| const CXXRecordDecl *DerivedDecl = |
| cast<CXXRecordDecl>(cast<RecordType>(CanDerivedType)->getDecl()); |
| |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(cast<RecordType>(CanBaseType)->getDecl()); |
| |
| return TypeConversionRequiresAdjustment(Ctx, DerivedDecl, BaseDecl); |
| } |
| |
| bool VtableBuilder::OverrideMethod(GlobalDecl GD, bool MorallyVirtual, |
| Index_t OverrideOffset, Index_t Offset, |
| int64_t CurrentVBaseOffset) { |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| |
| const bool isPure = MD->isPure(); |
| |
| // FIXME: Should OverrideOffset's be Offset? |
| |
| for (CXXMethodDecl::method_iterator mi = MD->begin_overridden_methods(), |
| e = MD->end_overridden_methods(); mi != e; ++mi) { |
| GlobalDecl OGD; |
| |
| const CXXMethodDecl *OMD = *mi; |
| if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(OMD)) |
| OGD = GlobalDecl(DD, GD.getDtorType()); |
| else |
| OGD = OMD; |
| |
| // Check whether this is the method being overridden in this section of |
| // the vtable. |
| uint64_t Index; |
| if (!Methods.getIndex(OGD, Index)) |
| continue; |
| |
| // Get the original method, which we should be computing thunks, etc, |
| // against. |
| OGD = Methods.getOrigMethod(Index); |
| OMD = cast<CXXMethodDecl>(OGD.getDecl()); |
| |
| QualType ReturnType = |
| MD->getType()->getAs<FunctionType>()->getResultType(); |
| QualType OverriddenReturnType = |
| OMD->getType()->getAs<FunctionType>()->getResultType(); |
| |
| // Check if we need a return type adjustment. |
| if (TypeConversionRequiresAdjustment(CGM.getContext(), ReturnType, |
| OverriddenReturnType)) { |
| CanQualType &BaseReturnType = BaseReturnTypes[Index]; |
| |
| // Insert the base return type. |
| if (BaseReturnType.isNull()) |
| BaseReturnType = |
| CGM.getContext().getCanonicalType(OverriddenReturnType); |
| } |
| |
| Methods.OverrideMethod(OGD, GD); |
| |
| ThisAdjustments.erase(Index); |
| if (MorallyVirtual || VCall.count(OGD)) { |
| Index_t &idx = VCall[OGD]; |
| if (idx == 0) { |
| NonVirtualOffset[GD] = -OverrideOffset/8 + CurrentVBaseOffset/8; |
| VCallOffset[GD] = OverrideOffset/8; |
| idx = VCalls.size()+1; |
| VCalls.push_back(0); |
| D1(printf(" vcall for %s at %d with delta %d most derived %s\n", |
| MD->getNameAsString().c_str(), (int)-idx-3, |
| (int)VCalls[idx-1], Class->getNameAsCString())); |
| } else { |
| NonVirtualOffset[GD] = NonVirtualOffset[OGD]; |
| VCallOffset[GD] = VCallOffset[OGD]; |
| VCalls[idx-1] = -VCallOffset[OGD] + OverrideOffset/8; |
| D1(printf(" vcall patch for %s at %d with delta %d most derived %s\n", |
| MD->getNameAsString().c_str(), (int)-idx-3, |
| (int)VCalls[idx-1], Class->getNameAsCString())); |
| } |
| VCall[GD] = idx; |
| int64_t NonVirtualAdjustment = NonVirtualOffset[GD]; |
| int64_t VirtualAdjustment = |
| -((idx + extra + 2) * LLVMPointerWidth / 8); |
| |
| // Optimize out virtual adjustments of 0. |
| if (VCalls[idx-1] == 0) |
| VirtualAdjustment = 0; |
| |
| ThunkAdjustment ThisAdjustment(NonVirtualAdjustment, |
| VirtualAdjustment); |
| |
| if (!isPure && !ThisAdjustment.isEmpty()) { |
| ThisAdjustments[Index] = ThisAdjustment; |
| SavedAdjustments.push_back( |
| std::make_pair(GD, std::make_pair(OGD, ThisAdjustment))); |
| } |
| return true; |
| } |
| |
| int64_t NonVirtualAdjustment = -VCallOffset[OGD] + OverrideOffset/8; |
| |
| if (NonVirtualAdjustment) { |
| ThunkAdjustment ThisAdjustment(NonVirtualAdjustment, 0); |
| |
| if (!isPure) { |
| ThisAdjustments[Index] = ThisAdjustment; |
| SavedAdjustments.push_back( |
| std::make_pair(GD, std::make_pair(OGD, ThisAdjustment))); |
| } |
| } |
| return true; |
| } |
| |
| return false; |
| } |
| |
| void VtableBuilder::AppendMethodsToVtable() { |
| if (!BuildVtable) { |
| VtableComponents.insert(VtableComponents.end(), Methods.size(), |
| (llvm::Constant *)0); |
| ThisAdjustments.clear(); |
| BaseReturnTypes.clear(); |
| Methods.clear(); |
| return; |
| } |
| |
| // Reserve room in the vtable for our new methods. |
| VtableComponents.reserve(VtableComponents.size() + Methods.size()); |
| |
| for (unsigned i = 0, e = Methods.size(); i != e; ++i) { |
| GlobalDecl GD = Methods[i]; |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| |
| // Get the 'this' pointer adjustment. |
| ThunkAdjustment ThisAdjustment = ThisAdjustments.lookup(i); |
| |
| // Construct the return type adjustment. |
| ThunkAdjustment ReturnAdjustment; |
| |
| QualType BaseReturnType = BaseReturnTypes.lookup(i); |
| if (!BaseReturnType.isNull() && !MD->isPure()) { |
| QualType DerivedType = |
| MD->getType()->getAs<FunctionType>()->getResultType(); |
| |
| int64_t NonVirtualAdjustment = |
| getNVOffset(BaseReturnType, DerivedType) / 8; |
| |
| int64_t VirtualAdjustment = |
| getVbaseOffset(BaseReturnType, DerivedType); |
| |
| ReturnAdjustment = ThunkAdjustment(NonVirtualAdjustment, |
| VirtualAdjustment); |
| } |
| |
| llvm::Constant *Method = 0; |
| if (!ReturnAdjustment.isEmpty()) { |
| // Build a covariant thunk. |
| CovariantThunkAdjustment Adjustment(ThisAdjustment, ReturnAdjustment); |
| Method = wrap(CGM.GetAddrOfCovariantThunk(GD, Adjustment)); |
| } else if (!ThisAdjustment.isEmpty()) { |
| // Build a "regular" thunk. |
| Method = wrap(CGM.GetAddrOfThunk(GD, ThisAdjustment)); |
| } else if (MD->isPure()) { |
| // We have a pure virtual method. |
| Method = getPureVirtualFn(); |
| } else { |
| // We have a good old regular method. |
| Method = WrapAddrOf(GD); |
| } |
| |
| // Add the method to the vtable. |
| VtableComponents.push_back(Method); |
| } |
| |
| |
| ThisAdjustments.clear(); |
| BaseReturnTypes.clear(); |
| |
| Methods.clear(); |
| } |
| |
| void CGVtableInfo::ComputeMethodVtableIndices(const CXXRecordDecl *RD) { |
| |
| // Itanium C++ ABI 2.5.2: |
| // The order of the virtual function pointers in a virtual table is the |
| // order of declaration of the corresponding member functions in the class. |
| // |
| // There is an entry for any virtual function declared in a class, |
| // whether it is a new function or overrides a base class function, |
| // unless it overrides a function from the primary base, and conversion |
| // between their return types does not require an adjustment. |
| |
| int64_t CurrentIndex = 0; |
| |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); |
| |
| if (PrimaryBase) { |
| assert(PrimaryBase->isDefinition() && |
| "Should have the definition decl of the primary base!"); |
| |
| // Since the record decl shares its vtable pointer with the primary base |
| // we need to start counting at the end of the primary base's vtable. |
| CurrentIndex = getNumVirtualFunctionPointers(PrimaryBase); |
| } |
| |
| // Collect all the primary bases, so we can check whether methods override |
| // a method from the base. |
| llvm::SmallPtrSet<const CXXRecordDecl *, 5> PrimaryBases; |
| for (ASTRecordLayout::primary_base_info_iterator |
| I = Layout.primary_base_begin(), E = Layout.primary_base_end(); |
| I != E; ++I) |
| PrimaryBases.insert((*I).getBase()); |
| |
| const CXXDestructorDecl *ImplicitVirtualDtor = 0; |
| |
| for (CXXRecordDecl::method_iterator i = RD->method_begin(), |
| e = RD->method_end(); i != e; ++i) { |
| const CXXMethodDecl *MD = *i; |
| |
| // We only want virtual methods. |
| if (!MD->isVirtual()) |
| continue; |
| |
| bool ShouldAddEntryForMethod = true; |
| |
| // Check if this method overrides a method in the primary base. |
| for (CXXMethodDecl::method_iterator i = MD->begin_overridden_methods(), |
| e = MD->end_overridden_methods(); i != e; ++i) { |
| const CXXMethodDecl *OverriddenMD = *i; |
| const CXXRecordDecl *OverriddenRD = OverriddenMD->getParent(); |
| assert(OverriddenMD->isCanonicalDecl() && |
| "Should have the canonical decl of the overridden RD!"); |
| |
| if (PrimaryBases.count(OverriddenRD)) { |
| // Check if converting from the return type of the method to the |
| // return type of the overridden method requires conversion. |
| QualType ReturnType = |
| MD->getType()->getAs<FunctionType>()->getResultType(); |
| QualType OverriddenReturnType = |
| OverriddenMD->getType()->getAs<FunctionType>()->getResultType(); |
| |
| if (!TypeConversionRequiresAdjustment(CGM.getContext(), |
| ReturnType, OverriddenReturnType)) { |
| // This index is shared between the index in the vtable of the primary |
| // base class. |
| if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) { |
| const CXXDestructorDecl *OverriddenDD = |
| cast<CXXDestructorDecl>(OverriddenMD); |
| |
| // Add both the complete and deleting entries. |
| MethodVtableIndices[GlobalDecl(DD, Dtor_Complete)] = |
| getMethodVtableIndex(GlobalDecl(OverriddenDD, Dtor_Complete)); |
| MethodVtableIndices[GlobalDecl(DD, Dtor_Deleting)] = |
| getMethodVtableIndex(GlobalDecl(OverriddenDD, Dtor_Deleting)); |
| } else { |
| MethodVtableIndices[MD] = getMethodVtableIndex(OverriddenMD); |
| } |
| |
| // We don't need to add an entry for this method. |
| ShouldAddEntryForMethod = false; |
| break; |
| } |
| } |
| } |
| |
| if (!ShouldAddEntryForMethod) |
| continue; |
| |
| if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) { |
| if (MD->isImplicit()) { |
| assert(!ImplicitVirtualDtor && |
| "Did already see an implicit virtual dtor!"); |
| ImplicitVirtualDtor = DD; |
| continue; |
| } |
| |
| // Add the complete dtor. |
| MethodVtableIndices[GlobalDecl(DD, Dtor_Complete)] = CurrentIndex++; |
| |
| // Add the deleting dtor. |
| MethodVtableIndices[GlobalDecl(DD, Dtor_Deleting)] = CurrentIndex++; |
| } else { |
| // Add the entry. |
| MethodVtableIndices[MD] = CurrentIndex++; |
| } |
| } |
| |
| if (ImplicitVirtualDtor) { |
| // Itanium C++ ABI 2.5.2: |
| // If a class has an implicitly-defined virtual destructor, |
| // its entries come after the declared virtual function pointers. |
| |
| // Add the complete dtor. |
| MethodVtableIndices[GlobalDecl(ImplicitVirtualDtor, Dtor_Complete)] = |
| CurrentIndex++; |
| |
| // Add the deleting dtor. |
| MethodVtableIndices[GlobalDecl(ImplicitVirtualDtor, Dtor_Deleting)] = |
| CurrentIndex++; |
| } |
| |
| NumVirtualFunctionPointers[RD] = CurrentIndex; |
| } |
| |
| uint64_t CGVtableInfo::getNumVirtualFunctionPointers(const CXXRecordDecl *RD) { |
| llvm::DenseMap<const CXXRecordDecl *, uint64_t>::iterator I = |
| NumVirtualFunctionPointers.find(RD); |
| if (I != NumVirtualFunctionPointers.end()) |
| return I->second; |
| |
| ComputeMethodVtableIndices(RD); |
| |
| I = NumVirtualFunctionPointers.find(RD); |
| assert(I != NumVirtualFunctionPointers.end() && "Did not find entry!"); |
| return I->second; |
| } |
| |
| uint64_t CGVtableInfo::getMethodVtableIndex(GlobalDecl GD) { |
| MethodVtableIndicesTy::iterator I = MethodVtableIndices.find(GD); |
| if (I != MethodVtableIndices.end()) |
| return I->second; |
| |
| const CXXRecordDecl *RD = cast<CXXMethodDecl>(GD.getDecl())->getParent(); |
| |
| ComputeMethodVtableIndices(RD); |
| |
| I = MethodVtableIndices.find(GD); |
| assert(I != MethodVtableIndices.end() && "Did not find index!"); |
| return I->second; |
| } |
| |
| CGVtableInfo::AdjustmentVectorTy* |
| CGVtableInfo::getAdjustments(GlobalDecl GD) { |
| SavedAdjustmentsTy::iterator I = SavedAdjustments.find(GD); |
| if (I != SavedAdjustments.end()) |
| return &I->second; |
| |
| const CXXRecordDecl *RD = cast<CXXRecordDecl>(GD.getDecl()->getDeclContext()); |
| if (!SavedAdjustmentRecords.insert(RD).second) |
| return 0; |
| |
| VtableBuilder b(RD, RD, 0, CGM, false); |
| D1(printf("vtable %s\n", RD->getNameAsCString())); |
| b.GenerateVtableForBase(RD); |
| b.GenerateVtableForVBases(RD); |
| |
| for (VtableBuilder::SavedAdjustmentsVectorTy::iterator |
| i = b.getSavedAdjustments().begin(), |
| e = b.getSavedAdjustments().end(); i != e; i++) |
| SavedAdjustments[i->first].push_back(i->second); |
| |
| I = SavedAdjustments.find(GD); |
| if (I != SavedAdjustments.end()) |
| return &I->second; |
| |
| return 0; |
| } |
| |
| int64_t CGVtableInfo::getVirtualBaseOffsetIndex(const CXXRecordDecl *RD, |
| const CXXRecordDecl *VBase) { |
| ClassPairTy ClassPair(RD, VBase); |
| |
| VirtualBaseClassIndiciesTy::iterator I = |
| VirtualBaseClassIndicies.find(ClassPair); |
| if (I != VirtualBaseClassIndicies.end()) |
| return I->second; |
| |
| // FIXME: This seems expensive. Can we do a partial job to get |
| // just this data. |
| VtableBuilder b(RD, RD, 0, CGM, false); |
| D1(printf("vtable %s\n", RD->getNameAsCString())); |
| b.GenerateVtableForBase(RD); |
| b.GenerateVtableForVBases(RD); |
| |
| for (llvm::DenseMap<const CXXRecordDecl *, uint64_t>::iterator I = |
| b.getVBIndex().begin(), E = b.getVBIndex().end(); I != E; ++I) { |
| // Insert all types. |
| ClassPairTy ClassPair(RD, I->first); |
| |
| VirtualBaseClassIndicies.insert(std::make_pair(ClassPair, I->second)); |
| } |
| |
| I = VirtualBaseClassIndicies.find(ClassPair); |
| assert(I != VirtualBaseClassIndicies.end() && "Did not find index!"); |
| |
| return I->second; |
| } |
| |
| uint64_t CGVtableInfo::getVtableAddressPoint(const CXXRecordDecl *RD) { |
| uint64_t AddressPoint = |
| (*(*(CGM.AddressPoints[RD]))[RD])[std::make_pair(RD, 0)]; |
| |
| return AddressPoint; |
| } |
| |
| llvm::GlobalVariable * |
| CGVtableInfo::GenerateVtable(llvm::GlobalVariable::LinkageTypes Linkage, |
| bool GenerateDefinition, |
| const CXXRecordDecl *LayoutClass, |
| const CXXRecordDecl *RD, uint64_t Offset) { |
| llvm::SmallString<256> OutName; |
| if (LayoutClass != RD) |
| CGM.getMangleContext().mangleCXXCtorVtable(LayoutClass, Offset / 8, |
| RD, OutName); |
| else |
| CGM.getMangleContext().mangleCXXVtable(RD, OutName); |
| llvm::StringRef Name = OutName.str(); |
| |
| int64_t AddressPoint; |
| |
| llvm::GlobalVariable *GV = CGM.getModule().getGlobalVariable(Name); |
| if (GV && CGM.AddressPoints[LayoutClass] && !GV->isDeclaration()) { |
| AddressPoint=(*(*(CGM.AddressPoints[LayoutClass]))[RD])[std::make_pair(RD, |
| Offset)]; |
| // FIXME: We can never have 0 address point. Do this for now so gepping |
| // retains the same structure. Later, we'll just assert. |
| if (AddressPoint == 0) |
| AddressPoint = 1; |
| } else { |
| VtableBuilder b(RD, LayoutClass, Offset, CGM, GenerateDefinition); |
| |
| D1(printf("vtable %s\n", RD->getNameAsCString())); |
| // First comes the vtables for all the non-virtual bases... |
| AddressPoint = b.GenerateVtableForBase(RD, Offset); |
| |
| // then the vtables for all the virtual bases. |
| b.GenerateVtableForVBases(RD, Offset); |
| |
| llvm::Constant *Init = 0; |
| const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGM.getLLVMContext()); |
| llvm::ArrayType *ArrayType = |
| llvm::ArrayType::get(Int8PtrTy, b.getVtableComponents().size()); |
| |
| if (GenerateDefinition) |
| Init = llvm::ConstantArray::get(ArrayType, &b.getVtableComponents()[0], |
| b.getVtableComponents().size()); |
| |
| llvm::GlobalVariable *OGV = GV; |
| |
| GV = new llvm::GlobalVariable(CGM.getModule(), ArrayType, |
| /*isConstant=*/true, Linkage, Init, Name); |
| CGM.setGlobalVisibility(GV, RD); |
| |
| if (OGV) { |
| GV->takeName(OGV); |
| llvm::Constant *NewPtr = |
| llvm::ConstantExpr::getBitCast(GV, OGV->getType()); |
| OGV->replaceAllUsesWith(NewPtr); |
| OGV->eraseFromParent(); |
| } |
| } |
| |
| return GV; |
| } |
| |
| namespace { |
| class VTTBuilder { |
| /// Inits - The list of values built for the VTT. |
| std::vector<llvm::Constant *> &Inits; |
| /// Class - The most derived class that this vtable is being built for. |
| const CXXRecordDecl *Class; |
| CodeGenModule &CGM; // Per-module state. |
| llvm::SmallSet<const CXXRecordDecl *, 32> SeenVBase; |
| /// BLayout - Layout for the most derived class that this vtable is being |
| /// built for. |
| const ASTRecordLayout &BLayout; |
| CodeGenModule::AddrMap_t &AddressPoints; |
| // vtbl - A pointer to the vtable for Class. |
| llvm::Constant *ClassVtbl; |
| llvm::LLVMContext &VMContext; |
| |
| /// BuildVtablePtr - Build up a referene to the given secondary vtable |
| llvm::Constant *BuildVtablePtr(llvm::Constant *Vtable, |
| const CXXRecordDecl *VtableClass, |
| const CXXRecordDecl *RD, |
| uint64_t Offset) { |
| int64_t AddressPoint = |
| (*AddressPoints[VtableClass])[std::make_pair(RD, Offset)]; |
| |
| // FIXME: We can never have 0 address point. Do this for now so gepping |
| // retains the same structure. Later we'll just assert. |
| if (AddressPoint == 0) |
| AddressPoint = 1; |
| D1(printf("XXX address point for %s in %s layout %s at offset %d was %d\n", |
| RD->getNameAsCString(), VtblClass->getNameAsCString(), |
| Class->getNameAsCString(), (int)Offset, (int)AddressPoint)); |
| |
| llvm::Value *Idxs[] = { |
| llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext), 0), |
| llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext), AddressPoint) |
| }; |
| |
| llvm::Constant *Init = |
| llvm::ConstantExpr::getInBoundsGetElementPtr(Vtable, Idxs, 2); |
| |
| const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext); |
| return llvm::ConstantExpr::getBitCast(Init, Int8PtrTy); |
| } |
| |
| /// Secondary - Add the secondary vtable pointers to Inits. Offset is the |
| /// current offset in bits to the object we're working on. |
| void Secondary(const CXXRecordDecl *RD, llvm::Constant *vtbl, |
| const CXXRecordDecl *VtblClass, uint64_t Offset=0, |
| bool MorallyVirtual=false) { |
| if (RD->getNumVBases() == 0 && ! MorallyVirtual) |
| return; |
| |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); i != e; ++i) { |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); |
| const bool PrimaryBaseWasVirtual = Layout.getPrimaryBaseWasVirtual(); |
| bool NonVirtualPrimaryBase; |
| NonVirtualPrimaryBase = !PrimaryBaseWasVirtual && Base == PrimaryBase; |
| bool BaseMorallyVirtual = MorallyVirtual | i->isVirtual(); |
| uint64_t BaseOffset; |
| if (!i->isVirtual()) { |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| BaseOffset = Offset + Layout.getBaseClassOffset(Base); |
| } else |
| BaseOffset = BLayout.getVBaseClassOffset(Base); |
| llvm::Constant *subvtbl = vtbl; |
| const CXXRecordDecl *subVtblClass = VtblClass; |
| if ((Base->getNumVBases() || BaseMorallyVirtual) |
| && !NonVirtualPrimaryBase) { |
| // FIXME: Slightly too many of these for __ZTT8test8_B2 |
| llvm::Constant *init; |
| if (BaseMorallyVirtual) |
| init = BuildVtablePtr(vtbl, VtblClass, RD, Offset); |
| else { |
| init = CGM.getVtableInfo().getCtorVtable(Class, Base, BaseOffset); |
| |
| subvtbl = init; |
| subVtblClass = Base; |
| |
| init = BuildVtablePtr(init, Class, Base, BaseOffset); |
| } |
| Inits.push_back(init); |
| } |
| Secondary(Base, subvtbl, subVtblClass, BaseOffset, BaseMorallyVirtual); |
| } |
| } |
| |
| /// BuiltVTT - Add the VTT to Inits. Offset is the offset in bits to the |
| /// currnet object we're working on. |
| void BuildVTT(const CXXRecordDecl *RD, uint64_t Offset, bool MorallyVirtual) { |
| if (RD->getNumVBases() == 0 && !MorallyVirtual) |
| return; |
| |
| llvm::Constant *Vtable; |
| const CXXRecordDecl *VtableClass; |
| |
| // First comes the primary virtual table pointer... |
| if (MorallyVirtual) { |
| Vtable = ClassVtbl; |
| VtableClass = Class; |
| } else { |
| Vtable = CGM.getVtableInfo().getCtorVtable(Class, RD, Offset); |
| VtableClass = RD; |
| } |
| |
| llvm::Constant *Init = BuildVtablePtr(Vtable, VtableClass, RD, Offset); |
| Inits.push_back(Init); |
| |
| // then the secondary VTTs.... |
| SecondaryVTTs(RD, Offset, MorallyVirtual); |
| |
| // and last the secondary vtable pointers. |
| Secondary(RD, Vtable, VtableClass, Offset, MorallyVirtual); |
| } |
| |
| /// SecondaryVTTs - Add the secondary VTTs to Inits. The secondary VTTs are |
| /// built from each direct non-virtual proper base that requires a VTT in |
| /// declaration order. |
| void SecondaryVTTs(const CXXRecordDecl *RD, uint64_t Offset=0, |
| bool MorallyVirtual=false) { |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); i != e; ++i) { |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| if (i->isVirtual()) |
| continue; |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| uint64_t BaseOffset = Offset + Layout.getBaseClassOffset(Base); |
| BuildVTT(Base, BaseOffset, MorallyVirtual); |
| } |
| } |
| |
| /// VirtualVTTs - Add the VTT for each proper virtual base in inheritance |
| /// graph preorder. |
| void VirtualVTTs(const CXXRecordDecl *RD) { |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); i != e; ++i) { |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| if (i->isVirtual() && !SeenVBase.count(Base)) { |
| SeenVBase.insert(Base); |
| uint64_t BaseOffset = BLayout.getVBaseClassOffset(Base); |
| BuildVTT(Base, BaseOffset, true); |
| } |
| VirtualVTTs(Base); |
| } |
| } |
| |
| public: |
| VTTBuilder(std::vector<llvm::Constant *> &inits, const CXXRecordDecl *c, |
| CodeGenModule &cgm) |
| : Inits(inits), Class(c), CGM(cgm), |
| BLayout(cgm.getContext().getASTRecordLayout(c)), |
| AddressPoints(*cgm.AddressPoints[c]), |
| VMContext(cgm.getModule().getContext()) { |
| |
| // First comes the primary virtual table pointer for the complete class... |
| ClassVtbl = CGM.getVtableInfo().getVtable(Class); |
| Inits.push_back(BuildVtablePtr(ClassVtbl, Class, Class, 0)); |
| |
| // then the secondary VTTs... |
| SecondaryVTTs(Class); |
| |
| // then the secondary vtable pointers... |
| Secondary(Class, ClassVtbl, Class); |
| |
| // and last, the virtual VTTs. |
| VirtualVTTs(Class); |
| } |
| }; |
| } |
| |
| llvm::GlobalVariable * |
| CGVtableInfo::GenerateVTT(llvm::GlobalVariable::LinkageTypes Linkage, |
| const CXXRecordDecl *RD) { |
| // Only classes that have virtual bases need a VTT. |
| if (RD->getNumVBases() == 0) |
| return 0; |
| |
| llvm::SmallString<256> OutName; |
| CGM.getMangleContext().mangleCXXVTT(RD, OutName); |
| llvm::StringRef Name = OutName.str(); |
| |
| |
| D1(printf("vtt %s\n", RD->getNameAsCString())); |
| |
| std::vector<llvm::Constant *> inits; |
| VTTBuilder b(inits, RD, CGM); |
| |
| const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGM.getLLVMContext()); |
| const llvm::ArrayType *Type = llvm::ArrayType::get(Int8PtrTy, inits.size()); |
| |
| llvm::Constant *Init = llvm::ConstantArray::get(Type, inits); |
| |
| llvm::GlobalVariable *VTT = |
| new llvm::GlobalVariable(CGM.getModule(), Type, /*isConstant=*/true, |
| Linkage, Init, Name); |
| CGM.setGlobalVisibility(VTT, RD); |
| |
| return VTT; |
| } |
| |
| void CGVtableInfo::GenerateClassData(llvm::GlobalVariable::LinkageTypes Linkage, |
| const CXXRecordDecl *RD) { |
| llvm::GlobalVariable *&Vtable = Vtables[RD]; |
| if (Vtable) { |
| assert(Vtable->getInitializer() && "Vtable doesn't have a definition!"); |
| return; |
| } |
| |
| Vtable = GenerateVtable(Linkage, /*GenerateDefinition=*/true, RD, RD, 0); |
| GenerateVTT(Linkage, RD); |
| } |
| |
| llvm::GlobalVariable *CGVtableInfo::getVtable(const CXXRecordDecl *RD) { |
| llvm::GlobalVariable *Vtable = Vtables.lookup(RD); |
| |
| if (!Vtable) |
| Vtable = GenerateVtable(llvm::GlobalValue::ExternalLinkage, |
| /*GenerateDefinition=*/false, RD, RD, 0); |
| |
| return Vtable; |
| } |
| |
| llvm::GlobalVariable * |
| CGVtableInfo::getCtorVtable(const CXXRecordDecl *LayoutClass, |
| const CXXRecordDecl *RD, uint64_t Offset) { |
| return GenerateVtable(llvm::GlobalValue::InternalLinkage, |
| /*GenerateDefinition=*/true, |
| LayoutClass, RD, Offset); |
| } |
| |
| void CGVtableInfo::MaybeEmitVtable(GlobalDecl GD) { |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); |
| const CXXRecordDecl *RD = MD->getParent(); |
| |
| // If the class doesn't have a vtable we don't need to emit one. |
| if (!RD->isDynamicClass()) |
| return; |
| |
| // Get the key function. |
| const CXXMethodDecl *KeyFunction = CGM.getContext().getKeyFunction(RD); |
| |
| if (KeyFunction) { |
| // We don't have the right key function. |
| if (KeyFunction->getCanonicalDecl() != MD->getCanonicalDecl()) |
| return; |
| |
| // If the key function is a destructor, we only want to emit the vtable |
| // once, so do it for the complete destructor. |
| if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() != Dtor_Complete) |
| return; |
| } else { |
| // If there is no key function, we only want to emit the vtable if we are |
| // emitting a constructor. |
| if (!isa<CXXConstructorDecl>(MD) || GD.getCtorType() != Ctor_Complete) |
| return; |
| } |
| |
| llvm::GlobalVariable::LinkageTypes Linkage; |
| if (RD->isInAnonymousNamespace() || !RD->hasLinkage()) |
| Linkage = llvm::GlobalVariable::InternalLinkage; |
| else if (KeyFunction && !MD->isInlined()) |
| Linkage = llvm::GlobalVariable::ExternalLinkage; |
| else |
| Linkage = llvm::GlobalVariable::WeakODRLinkage; |
| |
| // Emit the data. |
| GenerateClassData(Linkage, RD); |
| |
| for (CXXRecordDecl::method_iterator i = RD->method_begin(), |
| e = RD->method_end(); i != e; ++i) { |
| if ((*i)->isVirtual() && ((*i)->hasInlineBody() || (*i)->isImplicit())) { |
| if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(*i)) { |
| CGM.BuildThunksForVirtual(GlobalDecl(DD, Dtor_Complete)); |
| CGM.BuildThunksForVirtual(GlobalDecl(DD, Dtor_Deleting)); |
| } else { |
| CGM.BuildThunksForVirtual(GlobalDecl(*i)); |
| } |
| } |
| } |
| } |
| |