diff options
Diffstat (limited to 'lib/CodeGen/CGVtable.cpp')
| -rw-r--r-- | lib/CodeGen/CGVtable.cpp | 2089 |
1 files changed, 766 insertions, 1323 deletions
diff --git a/lib/CodeGen/CGVtable.cpp b/lib/CodeGen/CGVtable.cpp index df30f47..2d1c734 100644 --- a/lib/CodeGen/CGVtable.cpp +++ b/lib/CodeGen/CGVtable.cpp @@ -138,7 +138,7 @@ private: /// AddOverriders - Add the final overriders for this base subobject to the /// map of final overriders. - void AddOverriders(BaseSubobject Base,uint64_t OffsetInLayoutClass, + void AddOverriders(BaseSubobject Base, uint64_t OffsetInLayoutClass, SubobjectOffsetsMapTy &Offsets); /// PropagateOverrider - Propagate the NewMD overrider to all the functions @@ -636,6 +636,10 @@ public: reinterpret_cast<uintptr_t>(MD)); } + static VtableComponent getFromOpaqueInteger(uint64_t I) { + return VtableComponent(I); + } + /// getKind - Get the kind of this vtable component. Kind getKind() const { return (Kind)(Value & 0x7); @@ -725,6 +729,9 @@ private: return static_cast<uintptr_t>(Value & ~7ULL); } + explicit VtableComponent(uint64_t Value) + : Value(Value) { } + /// The kind is stored in the lower 3 bits of the value. For offsets, we /// make use of the facts that classes can't be larger than 2^55 bytes, /// so we store the offset in the lower part of the 61 bytes that remain. @@ -1091,9 +1098,15 @@ public: typedef llvm::SmallSetVector<const CXXRecordDecl *, 8> PrimaryBasesSetVectorTy; + typedef llvm::DenseMap<const CXXRecordDecl *, int64_t> + VBaseOffsetOffsetsMapTy; + + typedef llvm::DenseMap<BaseSubobject, uint64_t> + AddressPointsMapTy; + private: - /// VtableInfo - Global vtable information. - CGVtableInfo &VtableInfo; + /// VTables - Global vtable information. + CodeGenVTables &VTables; /// MostDerivedClass - The most derived class for which we're building this /// vtable. @@ -1122,9 +1135,6 @@ private: /// bases in this vtable. llvm::DenseMap<const CXXRecordDecl *, VCallOffsetMap> VCallOffsetsForVBases; - typedef llvm::DenseMap<const CXXRecordDecl *, int64_t> - VBaseOffsetOffsetsMapTy; - /// VBaseOffsetOffsets - Contains the offsets of the virtual base offsets for /// the most derived class. VBaseOffsetOffsetsMapTy VBaseOffsetOffsets; @@ -1133,29 +1143,8 @@ private: llvm::SmallVector<VtableComponent, 64> Components; /// AddressPoints - Address points for the vtable being built. - CGVtableInfo::AddressPointsMapTy AddressPoints; - - /// ReturnAdjustment - A return adjustment. - struct ReturnAdjustment { - /// NonVirtual - The non-virtual adjustment from the derived object to its - /// nearest virtual base. - int64_t NonVirtual; - - /// VBaseOffsetOffset - The offset (in bytes), relative to the address point - /// of the virtual base class offset. - int64_t VBaseOffsetOffset; - - ReturnAdjustment() : NonVirtual(0), VBaseOffsetOffset(0) { } - - bool isEmpty() const { return !NonVirtual && !VBaseOffsetOffset; } + AddressPointsMapTy AddressPoints; - friend bool operator==(const ReturnAdjustment &LHS, - const ReturnAdjustment &RHS) { - return LHS.NonVirtual == RHS.NonVirtual && - LHS.VBaseOffsetOffset == RHS.VBaseOffsetOffset; - } - }; - /// MethodInfo - Contains information about a method in a vtable. /// (Used for computing 'this' pointer adjustment thunks. struct MethodInfo { @@ -1185,62 +1174,21 @@ private: /// currently building. MethodInfoMapTy MethodInfoMap; - /// ThisAdjustment - A 'this' pointer adjustment thunk. - struct ThisAdjustment { - /// NonVirtual - The non-virtual adjustment from the derived object to its - /// nearest virtual base. - int64_t NonVirtual; - - /// VCallOffsetOffset - The offset (in bytes), relative to the address point, - /// of the virtual call offset. - int64_t VCallOffsetOffset; - - ThisAdjustment() : NonVirtual(0), VCallOffsetOffset(0) { } - - bool isEmpty() const { return !NonVirtual && !VCallOffsetOffset; } - - friend bool operator==(const ThisAdjustment &LHS, - const ThisAdjustment &RHS) { - return LHS.NonVirtual == RHS.NonVirtual && - LHS.VCallOffsetOffset == RHS.VCallOffsetOffset; - } - }; - - /// ThunkInfo - The 'this' pointer adjustment as well as an optional return - /// adjustment for a thunk. - struct ThunkInfo { - /// This - The 'this' pointer adjustment. - ThisAdjustment This; - - /// Return - The return adjustment. - ReturnAdjustment Return; - - ThunkInfo() { } - - ThunkInfo(const ThisAdjustment &This, const ReturnAdjustment &Return) - : This(This), Return(Return) { } + typedef llvm::DenseMap<uint64_t, ThunkInfo> VtableThunksMapTy; - friend bool operator==(const ThunkInfo &LHS, const ThunkInfo &RHS) { - return LHS.This == RHS.This && LHS.Return == RHS.Return; - } + /// VTableThunks - The thunks by vtable index in the vtable currently being + /// built. + VtableThunksMapTy VTableThunks; - bool isEmpty() const { return This.isEmpty() && Return.isEmpty(); } - }; - - typedef llvm::DenseMap<uint64_t, ThunkInfo> ThunksInfoMapTy; + typedef llvm::SmallVector<ThunkInfo, 1> ThunkInfoVectorTy; + typedef llvm::DenseMap<const CXXMethodDecl *, ThunkInfoVectorTy> ThunksMapTy; - /// Thunks - The thunks by vtable index in the vtable currently being built. - ThunksInfoMapTy Thunks; - - typedef llvm::DenseMap<const CXXMethodDecl *, - llvm::SmallVector<ThunkInfo, 1> > MethodThunksMapTy; - - /// MethodThunks - A map that contains all the thunks needed for all methods - /// in the vtable currently being built. - MethodThunksMapTy MethodThunks; + /// Thunks - A map that contains all the thunks needed for all methods in the + /// most derived class for which the vtable is currently being built. + ThunksMapTy Thunks; /// AddThunk - Add a thunk for the given method. - void AddThunk(const CXXMethodDecl *MD, ThunkInfo &Thunk); + void AddThunk(const CXXMethodDecl *MD, const ThunkInfo &Thunk); /// ComputeThisAdjustments - Compute the 'this' pointer adjustments for the /// part of the vtable we're currently building. @@ -1341,10 +1289,10 @@ private: } public: - VtableBuilder(CGVtableInfo &VtableInfo, const CXXRecordDecl *MostDerivedClass, + VtableBuilder(CodeGenVTables &VTables, const CXXRecordDecl *MostDerivedClass, uint64_t MostDerivedClassOffset, bool MostDerivedClassIsVirtual, const CXXRecordDecl *LayoutClass) - : VtableInfo(VtableInfo), MostDerivedClass(MostDerivedClass), + : VTables(VTables), MostDerivedClass(MostDerivedClass), MostDerivedClassOffset(MostDerivedClassOffset), MostDerivedClassIsVirtual(MostDerivedClassIsVirtual), LayoutClass(LayoutClass), Context(MostDerivedClass->getASTContext()), @@ -1353,15 +1301,57 @@ public: LayoutVtable(); } + ThunksMapTy::const_iterator thunks_begin() const { + return Thunks.begin(); + } + + ThunksMapTy::const_iterator thunks_end() const { + return Thunks.end(); + } + + const VBaseOffsetOffsetsMapTy &getVBaseOffsetOffsets() const { + return VBaseOffsetOffsets; + } + + /// getNumVTableComponents - Return the number of components in the vtable + /// currently built. + uint64_t getNumVTableComponents() const { + return Components.size(); + } + + const uint64_t *vtable_components_data_begin() const { + return reinterpret_cast<const uint64_t *>(Components.begin()); + } + + const uint64_t *vtable_components_data_end() const { + return reinterpret_cast<const uint64_t *>(Components.end()); + } + + AddressPointsMapTy::const_iterator address_points_begin() const { + return AddressPoints.begin(); + } + + AddressPointsMapTy::const_iterator address_points_end() const { + return AddressPoints.end(); + } + + VtableThunksMapTy::const_iterator vtable_thunks_begin() const { + return VTableThunks.begin(); + } + + VtableThunksMapTy::const_iterator vtable_thunks_end() const { + return VTableThunks.end(); + } + /// dumpLayout - Dump the vtable layout. void dumpLayout(llvm::raw_ostream&); }; -void VtableBuilder::AddThunk(const CXXMethodDecl *MD, ThunkInfo &Thunk) { - if (isBuildingConstructorVtable()) - return; +void VtableBuilder::AddThunk(const CXXMethodDecl *MD, const ThunkInfo &Thunk) { + assert(!isBuildingConstructorVtable() && + "Can't add thunks for construction vtable"); - llvm::SmallVector<ThunkInfo, 1> &ThunksVector = MethodThunks[MD]; + llvm::SmallVector<ThunkInfo, 1> &ThunksVector = Thunks[MD]; // Check if we have this thunk already. if (std::find(ThunksVector.begin(), ThunksVector.end(), Thunk) != @@ -1410,6 +1400,17 @@ void VtableBuilder::ComputeThisAdjustments() { Overriders.getOverrider(BaseSubobject(MD->getParent(), MethodInfo.BaseOffset), MD); + // Check if we need an adjustment at all. + if (MethodInfo.BaseOffsetInLayoutClass == Overrider.Offset) { + // When a return thunk is needed by a derived class that overrides a + // virtual base, gcc uses a virtual 'this' adjustment as well. + // While the thunk itself might be needed by vtables in subclasses or + // in construction vtables, there doesn't seem to be a reason for using + // the thunk in this vtable. Still, we do so to match gcc. + if (VTableThunks.lookup(VtableIndex).Return.isEmpty()) + continue; + } + ThisAdjustment ThisAdjustment = ComputeThisAdjustment(MD, MethodInfo.BaseOffsetInLayoutClass, Overrider); @@ -1417,22 +1418,48 @@ void VtableBuilder::ComputeThisAdjustments() { continue; // Add it. - Thunks[VtableIndex].This = ThisAdjustment; + VTableThunks[VtableIndex].This = ThisAdjustment; if (isa<CXXDestructorDecl>(MD)) { // Add an adjustment for the deleting destructor as well. - Thunks[VtableIndex + 1].This = ThisAdjustment; + VTableThunks[VtableIndex + 1].This = ThisAdjustment; } - - AddThunk(Overrider.Method, Thunks[VtableIndex]); } /// Clear the method info map. MethodInfoMap.clear(); + + if (isBuildingConstructorVtable()) { + // We don't need to store thunk information for construction vtables. + return; + } + + for (VtableThunksMapTy::const_iterator I = VTableThunks.begin(), + E = VTableThunks.end(); I != E; ++I) { + const VtableComponent &Component = Components[I->first]; + const ThunkInfo &Thunk = I->second; + const CXXMethodDecl *MD; + + switch (Component.getKind()) { + default: + llvm_unreachable("Unexpected vtable component kind!"); + case VtableComponent::CK_FunctionPointer: + MD = Component.getFunctionDecl(); + break; + case VtableComponent::CK_CompleteDtorPointer: + MD = Component.getDestructorDecl(); + break; + case VtableComponent::CK_DeletingDtorPointer: + // We've already added the thunk when we saw the complete dtor pointer. + continue; + } + + if (MD->getParent() == MostDerivedClass) + AddThunk(MD, Thunk); + } } -VtableBuilder::ReturnAdjustment -VtableBuilder::ComputeReturnAdjustment(BaseOffset Offset) { +ReturnAdjustment VtableBuilder::ComputeReturnAdjustment(BaseOffset Offset) { ReturnAdjustment Adjustment; if (!Offset.isEmpty()) { @@ -1444,8 +1471,8 @@ VtableBuilder::ComputeReturnAdjustment(BaseOffset Offset) { VBaseOffsetOffsets.lookup(Offset.VirtualBase); } else { Adjustment.VBaseOffsetOffset = - VtableInfo.getVirtualBaseOffsetOffset(Offset.DerivedClass, - Offset.VirtualBase); + VTables.getVirtualBaseOffsetOffset(Offset.DerivedClass, + Offset.VirtualBase); } // FIXME: Once the assert in getVirtualBaseOffsetOffset is back again, @@ -1512,14 +1539,10 @@ VtableBuilder::ComputeThisAdjustmentBaseOffset(BaseSubobject Base, return BaseOffset(); } -VtableBuilder::ThisAdjustment +ThisAdjustment VtableBuilder::ComputeThisAdjustment(const CXXMethodDecl *MD, uint64_t BaseOffsetInLayoutClass, FinalOverriders::OverriderInfo Overrider) { - // Check if we need an adjustment at all. - if (BaseOffsetInLayoutClass == Overrider.Offset) - return ThisAdjustment(); - // Ignore adjustments for pure virtual member functions. if (Overrider.Method->isPure()) return ThisAdjustment(); @@ -1576,7 +1599,7 @@ VtableBuilder::AddMethod(const CXXMethodDecl *MD, } else { // Add the return adjustment if necessary. if (!ReturnAdjustment.isEmpty()) - Thunks[Components.size()].Return = ReturnAdjustment; + VTableThunks[Components.size()].Return = ReturnAdjustment; // Add the function. Components.push_back(VtableComponent::MakeFunction(MD)); @@ -1776,6 +1799,25 @@ VtableBuilder::AddMethods(BaseSubobject Base, uint64_t BaseOffsetInLayoutClass, MethodInfoMap.insert(std::make_pair(MD, MethodInfo)); MethodInfoMap.erase(OverriddenMD); + + // If the overridden method exists in a virtual base class or a direct + // or indirect base class of a virtual base class, we need to emit a + // thunk if we ever have a class hierarchy where the base class is not + // a primary base in the complete object. + if (!isBuildingConstructorVtable() && OverriddenMD != MD) { + // Compute the this adjustment. + ThisAdjustment ThisAdjustment = + ComputeThisAdjustment(OverriddenMD, BaseOffsetInLayoutClass, + Overrider); + + if (ThisAdjustment.VCallOffsetOffset && + Overrider.Method->getParent() == MostDerivedClass) { + // This is a virtual thunk for the most derived class, add it. + AddThunk(Overrider.Method, + ThunkInfo(ThisAdjustment, ReturnAdjustment())); + } + } + continue; } } @@ -1866,20 +1908,32 @@ VtableBuilder::LayoutPrimaryAndSecondaryVtables(BaseSubobject Base, // Compute 'this' pointer adjustments. ComputeThisAdjustments(); - // Record the address point. - AddressPoints.insert(std::make_pair(BaseSubobject(Base.getBase(), - OffsetInLayoutClass), - AddressPoint)); - - // Record the address points for all primary bases. - for (PrimaryBasesSetVectorTy::const_iterator I = PrimaryBases.begin(), - E = PrimaryBases.end(); I != E; ++I) { - const CXXRecordDecl *BaseDecl = *I; + // Add all address points. + const CXXRecordDecl *RD = Base.getBase(); + while (true) { + AddressPoints.insert(std::make_pair(BaseSubobject(RD, OffsetInLayoutClass), + AddressPoint)); + + const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); + const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); - // We know that all the primary bases have the same offset as the base - // subobject. - BaseSubobject PrimaryBase(BaseDecl, OffsetInLayoutClass); - AddressPoints.insert(std::make_pair(PrimaryBase, AddressPoint)); + if (!PrimaryBase) + break; + + if (Layout.getPrimaryBaseWasVirtual()) { + // Check if this virtual primary base is a primary base in the layout + // class. If it's not, we don't want to add it. + const ASTRecordLayout &LayoutClassLayout = + Context.getASTRecordLayout(LayoutClass); + + if (LayoutClassLayout.getVBaseClassOffset(PrimaryBase) != + OffsetInLayoutClass) { + // We don't want to add this class (or any of its primary bases). + break; + } + } + + RD = PrimaryBase; } bool BaseIsMorallyVirtual = BaseIsVirtual; @@ -2062,8 +2116,8 @@ void VtableBuilder::dumpLayout(llvm::raw_ostream& Out) { // Since an address point can be shared by multiple subobjects, we use an // STL multimap. std::multimap<uint64_t, BaseSubobject> AddressPointsByIndex; - for (CGVtableInfo::AddressPointsMapTy::const_iterator I = - AddressPoints.begin(), E = AddressPoints.end(); I != E; ++I) { + for (AddressPointsMapTy::const_iterator I = AddressPoints.begin(), + E = AddressPoints.end(); I != E; ++I) { const BaseSubobject& Base = I->first; uint64_t Index = I->second; @@ -2106,7 +2160,7 @@ void VtableBuilder::dumpLayout(llvm::raw_ostream& Out) { if (MD->isPure()) Out << " [pure]"; - ThunkInfo Thunk = Thunks.lookup(I); + ThunkInfo Thunk = VTableThunks.lookup(I); if (!Thunk.isEmpty()) { // If this function pointer has a return adjustment, dump it. if (!Thunk.Return.isEmpty()) { @@ -2154,7 +2208,7 @@ void VtableBuilder::dumpLayout(llvm::raw_ostream& Out) { if (DD->isPure()) Out << " [pure]"; - ThunkInfo Thunk = Thunks.lookup(I); + ThunkInfo Thunk = VTableThunks.lookup(I); if (!Thunk.isEmpty()) { // If this destructor has a 'this' pointer adjustment, dump it. if (!Thunk.This.isEmpty()) { @@ -2253,13 +2307,12 @@ void VtableBuilder::dumpLayout(llvm::raw_ostream& Out) { Out << "\n"; } - if (!MethodThunks.empty()) { - + if (!Thunks.empty()) { // We store the method names in a map to get a stable order. std::map<std::string, const CXXMethodDecl *> MethodNamesAndDecls; - for (MethodThunksMapTy::const_iterator I = MethodThunks.begin(), - E = MethodThunks.end(); I != E; ++I) { + for (ThunksMapTy::const_iterator I = Thunks.begin(), E = Thunks.end(); + I != E; ++I) { const CXXMethodDecl *MD = I->first; std::string MethodName = PredefinedExpr::ComputeName(PredefinedExpr::PrettyFunctionNoVirtual, @@ -2273,7 +2326,9 @@ void VtableBuilder::dumpLayout(llvm::raw_ostream& Out) { I != E; ++I) { const std::string &MethodName = I->first; const CXXMethodDecl *MD = I->second; - const llvm::SmallVector<ThunkInfo, 1> &ThunksVector = MethodThunks[MD]; + + ThunkInfoVectorTy ThunksVector = Thunks[MD]; + std::sort(ThunksVector.begin(), ThunksVector.end()); Out << "Thunks for '" << MethodName << "' (" << ThunksVector.size(); Out << (ThunksVector.size() == 1 ? " entry" : " entries") << ").\n"; @@ -2283,1099 +2338,42 @@ void VtableBuilder::dumpLayout(llvm::raw_ostream& Out) { Out << llvm::format("%4d | ", I); + // If this function pointer has a return pointer adjustment, dump it. + if (!Thunk.Return.isEmpty()) { + Out << "return adjustment: " << Thunk.This.NonVirtual; + Out << " non-virtual"; + if (Thunk.Return.VBaseOffsetOffset) { + Out << ", " << Thunk.Return.VBaseOffsetOffset; + Out << " vbase offset offset"; + } + + if (!Thunk.This.isEmpty()) + Out << "\n "; + } + // If this function pointer has a 'this' pointer adjustment, dump it. if (!Thunk.This.isEmpty()) { - Out << "this: "; - Out << Thunk.This.NonVirtual << " nv"; + Out << "this adjustment: "; + Out << Thunk.This.NonVirtual << " non-virtual"; if (Thunk.This.VCallOffsetOffset) { Out << ", " << Thunk.This.VCallOffsetOffset; - Out << " v"; + Out << " vcall offset offset"; } } Out << '\n'; } - } - } -} - -} - -namespace { -class OldVtableBuilder { -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<const CXXMethodDecl *, Index_t> VCall; - llvm::DenseMap<GlobalDecl, Index_t> VCallOffset; - llvm::DenseMap<GlobalDecl, Index_t> VCallOffsetForVCall; - // This is the offset to the nearest virtual base - llvm::DenseMap<const CXXMethodDecl *, 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; - - /// AddressPoints - Address points for this vtable. - CGVtableInfo::AddressPointsMapTy& AddressPoints; - - typedef CXXRecordDecl::method_iterator method_iter; - 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) { - CGVtableInfo::AddrMap_t *&oref = cgm.getVtableInfo().AddressPoints[l]; - if (oref == 0) - oref = new CGVtableInfo::AddrMap_t; - - llvm::DenseMap<CtorVtable_t, int64_t> *&ref = (*oref)[c]; - if (ref == 0) - ref = new llvm::DenseMap<CtorVtable_t, int64_t>; - return *ref; - } - - bool DclIsSame(const FunctionDecl *New, const FunctionDecl *Old) { - FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); - FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); - - // C++ [temp.fct]p2: - // A function template can be overloaded with other function templates - // and with normal (non-template) functions. - if ((OldTemplate == 0) != (NewTemplate == 0)) - return false; - - // Is the function New an overload of the function Old? - QualType OldQType = CGM.getContext().getCanonicalType(Old->getType()); - QualType NewQType = CGM.getContext().getCanonicalType(New->getType()); - - // Compare the signatures (C++ 1.3.10) of the two functions to - // determine whether they are overloads. If we find any mismatch - // in the signature, they are overloads. - - // If either of these functions is a K&R-style function (no - // prototype), then we consider them to have matching signatures. - if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || - isa<FunctionNoProtoType>(NewQType.getTypePtr())) - return true; - - FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); - FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); - - // The signature of a function includes the types of its - // parameters (C++ 1.3.10), which includes the presence or absence - // of the ellipsis; see C++ DR 357). - if (OldQType != NewQType && - (OldType->getNumArgs() != NewType->getNumArgs() || - OldType->isVariadic() != NewType->isVariadic() || - !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), - NewType->arg_type_begin()))) - return false; - -#if 0 - // C++ [temp.over.link]p4: - // The signature of a function template consists of its function - // signature, its return type and its template parameter list. The names - // of the template parameters are significant only for establishing the - // relationship between the template parameters and the rest of the - // signature. - // - // We check the return type and template parameter lists for function - // templates first; the remaining checks follow. - if (NewTemplate && - (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), - OldTemplate->getTemplateParameters(), - TPL_TemplateMatch) || - OldType->getResultType() != NewType->getResultType())) - return false; -#endif - - // If the function is a class member, its signature includes the - // cv-qualifiers (if any) on the function itself. - // - // As part of this, also check whether one of the member functions - // is static, in which case they are not overloads (C++ - // 13.1p2). While not part of the definition of the signature, - // this check is important to determine whether these functions - // can be overloaded. - const CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); - const CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); - if (OldMethod && NewMethod && - !OldMethod->isStatic() && !NewMethod->isStatic() && - OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) - return false; - - // The signatures match; this is not an overload. - return true; - } - - typedef llvm::DenseMap<const CXXMethodDecl *, const CXXMethodDecl*> - ForwardUnique_t; - ForwardUnique_t ForwardUnique; - llvm::DenseMap<const CXXMethodDecl*, const CXXMethodDecl*> UniqueOverrider; - - void BuildUniqueOverrider(const CXXMethodDecl *U, const CXXMethodDecl *MD) { - const CXXMethodDecl *PrevU = UniqueOverrider[MD]; - assert(U && "no unique overrider"); - if (PrevU == U) - return; - if (PrevU != U && PrevU != 0) { - // If already set, note the two sets as the same - if (0) - printf("%s::%s same as %s::%s\n", - PrevU->getParent()->getNameAsString().c_str(), - PrevU->getNameAsString().c_str(), - U->getParent()->getNameAsString().c_str(), - U->getNameAsString().c_str()); - ForwardUnique[PrevU] = U; - return; - } - - // Not set, set it now - if (0) - printf("marking %s::%s %p override as %s::%s\n", - MD->getParent()->getNameAsString().c_str(), - MD->getNameAsString().c_str(), - (void*)MD, - U->getParent()->getNameAsString().c_str(), - U->getNameAsString().c_str()); - UniqueOverrider[MD] = U; - - for (CXXMethodDecl::method_iterator mi = MD->begin_overridden_methods(), - me = MD->end_overridden_methods(); mi != me; ++mi) { - BuildUniqueOverrider(U, *mi); - } - } - - void BuildUniqueOverriders(const CXXRecordDecl *RD) { - if (0) printf("walking %s\n", RD->getNameAsCString()); - for (CXXRecordDecl::method_iterator i = RD->method_begin(), - e = RD->method_end(); i != e; ++i) { - const CXXMethodDecl *MD = *i; - if (!MD->isVirtual()) - continue; - - if (UniqueOverrider[MD] == 0) { - // Only set this, if it hasn't been set yet. - BuildUniqueOverrider(MD, MD); - if (0) - printf("top set is %s::%s %p\n", - MD->getParent()->getNameAsString().c_str(), - MD->getNameAsString().c_str(), - (void*)MD); - ForwardUnique[MD] = MD; - } - } - 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()); - BuildUniqueOverriders(Base); - } - } - - static int DclCmp(const void *p1, const void *p2) { - const CXXMethodDecl *MD1 = *(const CXXMethodDecl *const *)p1; - const CXXMethodDecl *MD2 = *(const CXXMethodDecl *const *)p2; - - return (DeclarationName::compare(MD1->getDeclName(), MD2->getDeclName())); - } - - void MergeForwarding() { - typedef llvm::SmallVector<const CXXMethodDecl *, 100> A_t; - A_t A; - for (ForwardUnique_t::iterator I = ForwardUnique.begin(), - E = ForwardUnique.end(); I != E; ++I) { - if (I->first == I->second) - // Only add the roots of all trees - A.push_back(I->first); - } - llvm::array_pod_sort(A.begin(), A.end(), DclCmp); - for (A_t::iterator I = A.begin(), - E = A.end(); I != E; ++I) { - A_t::iterator J = I; - while (++J != E && DclCmp(I, J) == 0) - if (DclIsSame(*I, *J)) { - if (0) printf("connecting %s\n", (*I)->getNameAsString().c_str()); - ForwardUnique[*J] = *I; - } - } - } - - const CXXMethodDecl *getUnique(const CXXMethodDecl *MD) { - const CXXMethodDecl *U = UniqueOverrider[MD]; - assert(U && "unique overrider not found"); - while (ForwardUnique.count(U)) { - const CXXMethodDecl *NU = ForwardUnique[U]; - if (NU == U) break; - U = NU; - } - return U; - } - - GlobalDecl getUnique(GlobalDecl GD) { - const CXXMethodDecl *Unique = getUnique(cast<CXXMethodDecl>(GD.getDecl())); - - if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Unique)) - return GlobalDecl(CD, GD.getCtorType()); - - if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(Unique)) - return GlobalDecl(DD, GD.getDtorType()); - - return Unique; - } - - /// 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: - OldVtableBuilder(const CXXRecordDecl *MostDerivedClass, - const CXXRecordDecl *l, uint64_t lo, CodeGenModule &cgm, - bool build, CGVtableInfo::AddressPointsMapTy& AddressPoints) - : 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)), - AddressPoints(AddressPoints), - 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); - } - BuildUniqueOverriders(MostDerivedClass); - MergeForwarding(); - } - - // getVtableComponents - Returns a reference to the vtable components. - const VtableComponentsVectorTy &getVtableComponents() const { - return VtableComponents; - } - - llvm::DenseMap<const CXXRecordDecl *, uint64_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("CLANG_VTABLE_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, - MostDerivedClass->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().getVirtualBaseOffsetOffset(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; - - D1(printf(" vfn for %s at %d\n", - dyn_cast<CXXMethodDecl>(GD.getDecl())->getNameAsString().c_str(), - (int)Methods.size())); - - // We didn't find an entry in the vtable that we could use, add a new - // entry. - Methods.AddMethod(GD); - - VCallOffset[GD] = Offset/8 - CurrentVBaseOffset/8; - - if (MorallyVirtual) { - GlobalDecl UGD = getUnique(GD); - const CXXMethodDecl *UMD = cast<CXXMethodDecl>(UGD.getDecl()); - - assert(UMD && "final overrider not found"); - - Index_t &idx = VCall[UMD]; - // Allocate the first one, after that, we reuse the previous one. - if (idx == 0) { - VCallOffsetForVCall[UGD] = Offset/8; - NonVirtualOffset[UMD] = Offset/8 - CurrentVBaseOffset/8; - idx = VCalls.size()+1; - VCalls.push_back(Offset/8 - CurrentVBaseOffset/8); - D1(printf(" vcall for %s at %d with delta %d\n", - dyn_cast<CXXMethodDecl>(GD.getDecl())->getNameAsString().c_str(), - (int)-VCalls.size()-3, (int)VCalls[idx-1])); - } - } - } - - 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); - } - } + Out << '\n'; - 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()); - uint64_t o = Offset + Layout.getBaseClassOffset(Base); - StartNewTable(); - GenerateVtableForBase(Base, o, MorallyVirtual, false, - true, Base == PrimaryBase && !PrimaryBaseWasVirtual, - 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(); - VCallOffsetForVCall.clear(); - VCallOffset.clear(); - NonVirtualOffset.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(), MostDerivedClass->getNameAsCString(), - LayoutClass->getNameAsCString(), (int)Offset, (int)AddressPoint)); - subAddressPoints[std::make_pair(RD, Offset)] = AddressPoint; - AddressPoints[BaseSubobject(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(), MostDerivedClass->getNameAsCString(), - LayoutClass->getNameAsCString(), (int)Offset, (int)AddressPoint)); - subAddressPoints[std::make_pair(RD, Offset)] = AddressPoint; - AddressPoints[BaseSubobject(RD, Offset)] = AddressPoint; - } - } - - - void FinishGenerateVtable(const CXXRecordDecl *RD, - const ASTRecordLayout &Layout, - const CXXRecordDecl *PrimaryBase, - bool ForNPNVBases, bool WasPrimaryBase, - 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; - Index_t AddressPoint = 0; - int VCallInsertionPoint = 0; - if (!ForNPNVBases || !WasPrimaryBase) { - bool DeferVCalls = MorallyVirtual || ForVirtualBase; - 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); - - 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); - } - - if (!ForNPNVBases || !WasPrimaryBase) - AddAddressPoints(RD, Offset, AddressPoint); - - if (alloc) { - delete Path; - } - } - - 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(), MostDerivedClass->getNameAsCString())); - Primaries(PrimaryBase, PrimaryBaseWasVirtual|MorallyVirtual, Offset, - updateVBIndex, current_vbindex, CurrentVBaseOffset); - } - - D1(printf(" doing vcall entries for %s most derived %s\n", - RD->getNameAsCString(), MostDerivedClass->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(), MostDerivedClass->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(), MostDerivedClass->getNameAsCString())); - GenerateVBaseOffsets(RD, Offset, updateVBIndex, current_vbindex); - - if (RDisVirtualBase || bottom) { - Primaries(RD, MorallyVirtual, Offset, updateVBIndex, current_vbindex, - CurrentVBaseOffset); - } - } - - void GenerateVtableForBase(const CXXRecordDecl *RD, int64_t Offset = 0, - bool MorallyVirtual = false, - bool ForVirtualBase = false, - bool ForNPNVBases = false, - bool WasPrimaryBase = true, - int CurrentVBaseOffset = 0, - Path_t *Path = 0) { - if (!RD->isDynamicClass()) - return; - - // Construction vtable don't need parts that have no virtual bases and - // aren't morally virtual. - if ((LayoutClass != MostDerivedClass) && - RD->getNumVBases() == 0 && !MorallyVirtual) - return; - - 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(), MostDerivedClass->getNameAsCString())); - - if (ForVirtualBase) - extra = VCalls.size(); - - if (!ForNPNVBases || !WasPrimaryBase) { - VBPrimaries(RD, MorallyVirtual, Offset, !ForVirtualBase, 0, - ForVirtualBase, CurrentVBaseOffset, true); - - if (Path) - OverrideMethods(Path, MorallyVirtual, Offset, CurrentVBaseOffset); - } - - FinishGenerateVtable(RD, Layout, PrimaryBase, ForNPNVBases, WasPrimaryBase, - 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", - MostDerivedClass->getNameAsCString(), Base->getNameAsCString())); - GenerateVtableForBase(Base, BaseOffset, true, true, false, - 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 - -bool OldVtableBuilder::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; - GlobalDecl OGD2; - - 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; - - OGD2 = OGD; - - // 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 (!ComputeReturnAdjustmentBaseOffset(CGM.getContext(), MD, - OMD).isEmpty()) { - CanQualType &BaseReturnType = BaseReturnTypes[Index]; - - // Insert the base return type. - if (BaseReturnType.isNull()) - BaseReturnType = - CGM.getContext().getCanonicalType(OverriddenReturnType); - } - - Methods.OverrideMethod(OGD, GD); - - GlobalDecl UGD = getUnique(GD); - const CXXMethodDecl *UMD = cast<CXXMethodDecl>(UGD.getDecl()); - assert(UGD.getDecl() && "unique overrider not found"); - assert(UGD == getUnique(OGD) && "unique overrider not unique"); - - ThisAdjustments.erase(Index); - if (MorallyVirtual || VCall.count(UMD)) { - - Index_t &idx = VCall[UMD]; - if (idx == 0) { - VCallOffset[GD] = VCallOffset[OGD]; - // NonVirtualOffset[UMD] = CurrentVBaseOffset/8 - OverrideOffset/8; - NonVirtualOffset[UMD] = VCallOffset[OGD]; - VCallOffsetForVCall[UMD] = OverrideOffset/8; - idx = VCalls.size()+1; - VCalls.push_back(OverrideOffset/8 - CurrentVBaseOffset/8); - 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], MostDerivedClass->getNameAsCString())); - } else { - VCallOffset[GD] = NonVirtualOffset[UMD]; - VCalls[idx-1] = -VCallOffsetForVCall[UGD] + 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], MostDerivedClass->getNameAsCString())); - } - int64_t NonVirtualAdjustment = -VCallOffset[OGD]; - QualType DerivedType = MD->getThisType(CGM.getContext()); - QualType BaseType = cast<const CXXMethodDecl>(OGD.getDecl())->getThisType(CGM.getContext()); - int64_t NonVirtualAdjustment2 = -(getNVOffset(BaseType, DerivedType)/8); - if (NonVirtualAdjustment2 != NonVirtualAdjustment) { - NonVirtualAdjustment = NonVirtualAdjustment2; - } - 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; - } - - VCallOffset[GD] = VCallOffset[OGD2] - OverrideOffset/8; - - int64_t NonVirtualAdjustment = -VCallOffset[GD]; - QualType DerivedType = MD->getThisType(CGM.getContext()); - QualType BaseType = cast<const CXXMethodDecl>(OGD.getDecl())->getThisType(CGM.getContext()); - int64_t NonVirtualAdjustment2 = -(getNVOffset(BaseType, DerivedType)/8); - if (NonVirtualAdjustment2 != NonVirtualAdjustment) { - NonVirtualAdjustment = NonVirtualAdjustment2; - } - - 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 OldVtableBuilder::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) { +void CodeGenVTables::ComputeMethodVtableIndices(const CXXRecordDecl *RD) { // Itanium C++ ABI 2.5.2: // The order of the virtual function pointers in a virtual table is the @@ -3481,7 +2479,7 @@ void CGVtableInfo::ComputeMethodVtableIndices(const CXXRecordDecl *RD) { NumVirtualFunctionPointers[RD] = CurrentIndex; } -uint64_t CGVtableInfo::getNumVirtualFunctionPointers(const CXXRecordDecl *RD) { +uint64_t CodeGenVTables::getNumVirtualFunctionPointers(const CXXRecordDecl *RD) { llvm::DenseMap<const CXXRecordDecl *, uint64_t>::iterator I = NumVirtualFunctionPointers.find(RD); if (I != NumVirtualFunctionPointers.end()) @@ -3494,7 +2492,7 @@ uint64_t CGVtableInfo::getNumVirtualFunctionPointers(const CXXRecordDecl *RD) { return I->second; } -uint64_t CGVtableInfo::getMethodVtableIndex(GlobalDecl GD) { +uint64_t CodeGenVTables::getMethodVtableIndex(GlobalDecl GD) { MethodVtableIndicesTy::iterator I = MethodVtableIndices.find(GD); if (I != MethodVtableIndices.end()) return I->second; @@ -3508,36 +2506,8 @@ uint64_t CGVtableInfo::getMethodVtableIndex(GlobalDecl GD) { 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; - - AddressPointsMapTy AddressPoints; - OldVtableBuilder b(RD, RD, 0, CGM, false, AddressPoints); - D1(printf("vtable %s\n", RD->getNameAsCString())); - b.GenerateVtableForBase(RD); - b.GenerateVtableForVBases(RD); - - for (OldVtableBuilder::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::getVirtualBaseOffsetOffset(const CXXRecordDecl *RD, - const CXXRecordDecl *VBase) { +int64_t CodeGenVTables::getVirtualBaseOffsetOffset(const CXXRecordDecl *RD, + const CXXRecordDecl *VBase) { ClassPairTy ClassPair(RD, VBase); VirtualBaseClassOffsetOffsetsMapTy::iterator I = @@ -3549,7 +2519,6 @@ int64_t CGVtableInfo::getVirtualBaseOffsetOffset(const CXXRecordDecl *RD, BaseSubobject(RD, 0), /*BaseIsVirtual=*/false, /*OffsetInLayoutClass=*/0); - for (VCallAndVBaseOffsetBuilder::VBaseOffsetOffsetsMapTy::const_iterator I = Builder.getVBaseOffsetOffsets().begin(), @@ -3573,128 +2542,588 @@ int64_t CGVtableInfo::getVirtualBaseOffsetOffset(const CXXRecordDecl *RD, return I->second; } -uint64_t CGVtableInfo::getVtableAddressPoint(const CXXRecordDecl *RD) { - uint64_t AddressPoint = - (*(*(CGM.getVtableInfo().AddressPoints[RD]))[RD])[std::make_pair(RD, 0)]; - +uint64_t +CodeGenVTables::getAddressPoint(BaseSubobject Base, const CXXRecordDecl *RD) { + uint64_t AddressPoint = AddressPoints.lookup(std::make_pair(RD, Base)); + assert(AddressPoint && "Address point must not be zero!"); + return AddressPoint; } -llvm::GlobalVariable * -CGVtableInfo::GenerateVtable(llvm::GlobalVariable::LinkageTypes Linkage, - bool GenerateDefinition, - const CXXRecordDecl *LayoutClass, - const CXXRecordDecl *RD, uint64_t Offset, - bool IsVirtual, - AddressPointsMapTy& AddressPoints) { - if (GenerateDefinition) { - if (LayoutClass == RD) { - assert(!IsVirtual && - "Can only have a virtual base in construction vtables!"); - assert(!Offset && - "Can only have a base offset in construction vtables!"); - } +llvm::Constant *CodeGenModule::GetAddrOfThunk(GlobalDecl GD, + const ThunkInfo &Thunk) { + const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); + + // Compute the mangled name. + llvm::SmallString<256> Name; + if (const CXXDestructorDecl* DD = dyn_cast<CXXDestructorDecl>(MD)) + getMangleContext().mangleCXXDtorThunk(DD, GD.getDtorType(), Thunk.This, + Name); + else + getMangleContext().mangleThunk(MD, Thunk, Name); + + const llvm::Type *Ty = getTypes().GetFunctionTypeForVtable(MD); + return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl()); +} + +static llvm::Value *PerformTypeAdjustment(CodeGenFunction &CGF, + llvm::Value *Ptr, + int64_t NonVirtualAdjustment, + int64_t VirtualAdjustment) { + if (!NonVirtualAdjustment && !VirtualAdjustment) + return Ptr; + + const llvm::Type *Int8PtrTy = + llvm::Type::getInt8PtrTy(CGF.getLLVMContext()); + + llvm::Value *V = CGF.Builder.CreateBitCast(Ptr, Int8PtrTy); + + if (NonVirtualAdjustment) { + // Do the non-virtual adjustment. + V = CGF.Builder.CreateConstInBoundsGEP1_64(V, NonVirtualAdjustment); + } + + if (VirtualAdjustment) { + const llvm::Type *PtrDiffTy = + CGF.ConvertType(CGF.getContext().getPointerDiffType()); + + // Do the virtual adjustment. + llvm::Value *VTablePtrPtr = + CGF.Builder.CreateBitCast(V, Int8PtrTy->getPointerTo()); + + llvm::Value *VTablePtr = CGF.Builder.CreateLoad(VTablePtrPtr); + + llvm::Value *OffsetPtr = + CGF.Builder.CreateConstInBoundsGEP1_64(VTablePtr, VirtualAdjustment); + + OffsetPtr = CGF.Builder.CreateBitCast(OffsetPtr, PtrDiffTy->getPointerTo()); + + // Load the adjustment offset from the vtable. + llvm::Value *Offset = CGF.Builder.CreateLoad(OffsetPtr); - VtableBuilder Builder(*this, RD, Offset, - /*MostDerivedClassIsVirtual=*/IsVirtual, - LayoutClass); + // Adjust our pointer. + V = CGF.Builder.CreateInBoundsGEP(V, Offset); + } + + // Cast back to the original type. + return CGF.Builder.CreateBitCast(V, Ptr->getType()); +} + +void CodeGenFunction::GenerateThunk(llvm::Function *Fn, GlobalDecl GD, + const ThunkInfo &Thunk) { + const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); + const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); + QualType ResultType = FPT->getResultType(); + QualType ThisType = MD->getThisType(getContext()); - if (CGM.getLangOptions().DumpVtableLayouts) - Builder.dumpLayout(llvm::errs()); + FunctionArgList FunctionArgs; + + // FIXME: It would be nice if more of this code could be shared with + // CodeGenFunction::GenerateCode. + + // Create the implicit 'this' parameter declaration. + CXXThisDecl = ImplicitParamDecl::Create(getContext(), 0, + MD->getLocation(), + &getContext().Idents.get("this"), + ThisType); + + // Add the 'this' parameter. + FunctionArgs.push_back(std::make_pair(CXXThisDecl, CXXThisDecl->getType())); + + // Add the rest of the parameters. + for (FunctionDecl::param_const_iterator I = MD->param_begin(), + E = MD->param_end(); I != E; ++I) { + ParmVarDecl *Param = *I; + + FunctionArgs.push_back(std::make_pair(Param, Param->getType())); } + + StartFunction(GlobalDecl(), ResultType, Fn, FunctionArgs, SourceLocation()); - 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(); + // Adjust the 'this' pointer if necessary. + llvm::Value *AdjustedThisPtr = + PerformTypeAdjustment(*this, LoadCXXThis(), + Thunk.This.NonVirtual, + Thunk.This.VCallOffsetOffset); + + CallArgList CallArgs; + + // Add our adjusted 'this' pointer. + CallArgs.push_back(std::make_pair(RValue::get(AdjustedThisPtr), ThisType)); - llvm::GlobalVariable *GV = CGM.getModule().getGlobalVariable(Name); - if (GV == 0 || CGM.getVtableInfo().AddressPoints[LayoutClass] == 0 || - GV->isDeclaration()) { - OldVtableBuilder b(RD, LayoutClass, Offset, CGM, GenerateDefinition, - AddressPoints); + // Add the rest of the parameters. + for (FunctionDecl::param_const_iterator I = MD->param_begin(), + E = MD->param_end(); I != E; ++I) { + ParmVarDecl *Param = *I; + QualType ArgType = Param->getType(); + + // FIXME: Declaring a DeclRefExpr on the stack is kinda icky. + DeclRefExpr ArgExpr(Param, ArgType.getNonReferenceType(), SourceLocation()); + CallArgs.push_back(std::make_pair(EmitCallArg(&ArgExpr, ArgType), ArgType)); + } - D1(printf("vtable %s\n", RD->getNameAsCString())); - // First comes the vtables for all the non-virtual bases... - b.GenerateVtableForBase(RD, Offset); + // Get our callee. + const llvm::Type *Ty = + CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD), + FPT->isVariadic()); + llvm::Value *Callee = CGM.GetAddrOfFunction(GD, Ty); - // then the vtables for all the virtual bases. - b.GenerateVtableForVBases(RD, Offset); + const CGFunctionInfo &FnInfo = + CGM.getTypes().getFunctionInfo(ResultType, CallArgs, + FPT->getExtInfo()); + + // Now emit our call. + RValue RV = EmitCall(FnInfo, Callee, ReturnValueSlot(), CallArgs, MD); + + if (!Thunk.Return.isEmpty()) { + // Emit the return adjustment. + bool NullCheckValue = !ResultType->isReferenceType(); + + llvm::BasicBlock *AdjustNull = 0; + llvm::BasicBlock *AdjustNotNull = 0; + llvm::BasicBlock *AdjustEnd = 0; + + llvm::Value *ReturnValue = RV.getScalarVal(); - 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(); + if (NullCheckValue) { + AdjustNull = createBasicBlock("adjust.null"); + AdjustNotNull = createBasicBlock("adjust.notnull"); + AdjustEnd = createBasicBlock("adjust.end"); + + llvm::Value *IsNull = Builder.CreateIsNull(ReturnValue); + Builder.CreateCondBr(IsNull, AdjustNull, AdjustNotNull); + EmitBlock(AdjustNotNull); + } + + ReturnValue = PerformTypeAdjustment(*this, ReturnValue, + Thunk.Return.NonVirtual, + Thunk.Return.VBaseOffsetOffset); + + if (NullCheckValue) { + Builder.CreateBr(AdjustEnd); + EmitBlock(AdjustNull); + Builder.CreateBr(AdjustEnd); + EmitBlock(AdjustEnd); + + llvm::PHINode *PHI = Builder.CreatePHI(ReturnValue->getType()); + PHI->reserveOperandSpace(2); + PHI->addIncoming(ReturnValue, AdjustNotNull); + PHI->addIncoming(llvm::Constant::getNullValue(ReturnValue->getType()), + AdjustNull); + ReturnValue = PHI; } + + RV = RValue::get(ReturnValue); } + + if (!ResultType->isVoidType()) + EmitReturnOfRValue(RV, ResultType); + + FinishFunction(); + + // Destroy the 'this' declaration. + CXXThisDecl->Destroy(getContext()); - return GV; + // Set the right linkage. + Fn->setLinkage(CGM.getFunctionLinkage(MD)); + + // Set the right visibility. + CGM.setGlobalVisibility(Fn, MD); } -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!"); +void CodeGenVTables::EmitThunk(GlobalDecl GD, const ThunkInfo &Thunk) +{ + llvm::Constant *Entry = CGM.GetAddrOfThunk(GD, Thunk); + const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); + + // Strip off a bitcast if we got one back. + if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Entry)) { + assert(CE->getOpcode() == llvm::Instruction::BitCast); + Entry = CE->getOperand(0); + } + + // There's already a declaration with the same name, check if it has the same + // type or if we need to replace it. + if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != + CGM.getTypes().GetFunctionTypeForVtable(MD)) { + llvm::GlobalValue *OldThunkFn = cast<llvm::GlobalValue>(Entry); + + // If the types mismatch then we have to rewrite the definition. + assert(OldThunkFn->isDeclaration() && + "Shouldn't replace non-declaration"); + + // Remove the name from the old thunk function and get a new thunk. + OldThunkFn->setName(llvm::StringRef()); + Entry = CGM.GetAddrOfThunk(GD, Thunk); + + // If needed, replace the old thunk with a bitcast. + if (!OldThunkFn->use_empty()) { + llvm::Constant *NewPtrForOldDecl = + llvm::ConstantExpr::getBitCast(Entry, OldThunkFn->getType()); + OldThunkFn->replaceAllUsesWith(NewPtrForOldDecl); + } + + // Remove the old thunk. + OldThunkFn->eraseFromParent(); + } + + // Actually generate the thunk body. + llvm::Function *ThunkFn = cast<llvm::Function>(Entry); + CodeGenFunction(CGM).GenerateThunk(ThunkFn, GD, Thunk); +} + +void CodeGenVTables::EmitThunks(GlobalDecl GD) +{ + const CXXMethodDecl *MD = + cast<CXXMethodDecl>(GD.getDecl())->getCanonicalDecl(); + + // We don't need to generate thunks for the base destructor. + if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base) + return; + + const CXXRecordDecl *RD = MD->getParent(); + + // Compute VTable related info for this class. + ComputeVTableRelatedInformation(RD); + + ThunksMapTy::const_iterator I = Thunks.find(MD); + if (I == Thunks.end()) { + // We did not find a thunk for this method. return; } + + const ThunkInfoVectorTy &ThunkInfoVector = I->second; + for (unsigned I = 0, E = ThunkInfoVector.size(); I != E; ++I) + EmitThunk(GD, ThunkInfoVector[I]); +} + +void CodeGenVTables::ComputeVTableRelatedInformation(const CXXRecordDecl *RD) { + uint64_t *&LayoutData = VTableLayoutMap[RD]; - AddressPointsMapTy AddressPoints; - Vtable = GenerateVtable(Linkage, /*GenerateDefinition=*/true, RD, RD, 0, - /*IsVirtual=*/false, - AddressPoints); - GenerateVTT(Linkage, /*GenerateDefinition=*/true, RD); + // Check if we've computed this information before. + if (LayoutData) + return; + + VtableBuilder Builder(*this, RD, 0, /*MostDerivedClassIsVirtual=*/0, RD); - for (CXXRecordDecl::method_iterator i = RD->method_begin(), - e = RD->method_end(); i != e; ++i) { - if (!(*i)->isVirtual()) - continue; - if(!(*i)->hasInlineBody() && !(*i)->isImplicit()) - continue; + // Add the VTable layout. + uint64_t NumVTableComponents = Builder.getNumVTableComponents(); + LayoutData = new uint64_t[NumVTableComponents + 1]; - 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)); + // Store the number of components. + LayoutData[0] = NumVTableComponents; + + // Store the components. + std::copy(Builder.vtable_components_data_begin(), + Builder.vtable_components_data_end(), + &LayoutData[1]); + + // Add the known thunks. + Thunks.insert(Builder.thunks_begin(), Builder.thunks_end()); + + // Add the thunks needed in this vtable. + assert(!VTableThunksMap.count(RD) && + "Thunks already exists for this vtable!"); + + VTableThunksTy &VTableThunks = VTableThunksMap[RD]; + VTableThunks.append(Builder.vtable_thunks_begin(), + Builder.vtable_thunks_end()); + + // Sort them. + std::sort(VTableThunks.begin(), VTableThunks.end()); + + // Add the address points. + for (VtableBuilder::AddressPointsMapTy::const_iterator I = + Builder.address_points_begin(), E = Builder.address_points_end(); + I != E; ++I) { + + uint64_t &AddressPoint = AddressPoints[std::make_pair(RD, I->first)]; + + // Check if we already have the address points for this base. + assert(!AddressPoint && "Address point already exists for this base!"); + + AddressPoint = I->second; + } + + // If we don't have the vbase information for this class, insert it. + // getVirtualBaseOffsetOffset will compute it separately without computing + // the rest of the vtable related information. + if (!RD->getNumVBases()) + return; + + const RecordType *VBaseRT = + RD->vbases_begin()->getType()->getAs<RecordType>(); + const CXXRecordDecl *VBase = cast<CXXRecordDecl>(VBaseRT->getDecl()); + + if (VirtualBaseClassOffsetOffsets.count(std::make_pair(RD, VBase))) + return; + + for (VtableBuilder::VBaseOffsetOffsetsMapTy::const_iterator I = + Builder.getVBaseOffsetOffsets().begin(), + E = Builder.getVBaseOffsetOffsets().end(); I != E; ++I) { + // Insert all types. + ClassPairTy ClassPair(RD, I->first); + + VirtualBaseClassOffsetOffsets.insert(std::make_pair(ClassPair, I->second)); + } +} + +llvm::Constant * +CodeGenVTables::CreateVTableInitializer(const CXXRecordDecl *RD, + const uint64_t *Components, + unsigned NumComponents, + const VTableThunksTy &VTableThunks) { + llvm::SmallVector<llvm::Constant *, 64> Inits; + + const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGM.getLLVMContext()); + + const llvm::Type *PtrDiffTy = + CGM.getTypes().ConvertType(CGM.getContext().getPointerDiffType()); + + QualType ClassType = CGM.getContext().getTagDeclType(RD); + llvm::Constant *RTTI = CGM.GetAddrOfRTTIDescriptor(ClassType); + + unsigned NextVTableThunkIndex = 0; + + llvm::Constant* PureVirtualFn = 0; + + for (unsigned I = 0; I != NumComponents; ++I) { + VtableComponent Component = + VtableComponent::getFromOpaqueInteger(Components[I]); + + llvm::Constant *Init = 0; + + switch (Component.getKind()) { + case VtableComponent::CK_VCallOffset: + Init = llvm::ConstantInt::get(PtrDiffTy, Component.getVCallOffset()); + Init = llvm::ConstantExpr::getIntToPtr(Init, Int8PtrTy); + break; + case VtableComponent::CK_VBaseOffset: + Init = llvm::ConstantInt::get(PtrDiffTy, Component.getVBaseOffset()); + Init = llvm::ConstantExpr::getIntToPtr(Init, Int8PtrTy); + break; + case VtableComponent::CK_OffsetToTop: + Init = llvm::ConstantInt::get(PtrDiffTy, Component.getOffsetToTop()); + Init = llvm::ConstantExpr::getIntToPtr(Init, Int8PtrTy); + break; + case VtableComponent::CK_RTTI: + Init = llvm::ConstantExpr::getBitCast(RTTI, Int8PtrTy); + break; + case VtableComponent::CK_FunctionPointer: + case VtableComponent::CK_CompleteDtorPointer: + case VtableComponent::CK_DeletingDtorPointer: { + GlobalDecl GD; + + // Get the right global decl. + switch (Component.getKind()) { + default: + llvm_unreachable("Unexpected vtable component kind"); + case VtableComponent::CK_FunctionPointer: + GD = Component.getFunctionDecl(); + break; + case VtableComponent::CK_CompleteDtorPointer: + GD = GlobalDecl(Component.getDestructorDecl(), Dtor_Complete); + break; + case VtableComponent::CK_DeletingDtorPointer: + GD = GlobalDecl(Component.getDestructorDecl(), Dtor_Deleting); + break; + } + + if (cast<CXXMethodDecl>(GD.getDecl())->isPure()) { + // We have a pure virtual member function. + if (!PureVirtualFn) { + const llvm::FunctionType *Ty = + llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()), + /*isVarArg=*/false); + PureVirtualFn = + CGM.CreateRuntimeFunction(Ty, "__cxa_pure_virtual"); + PureVirtualFn = llvm::ConstantExpr::getBitCast(PureVirtualFn, + Int8PtrTy); + } + + Init = PureVirtualFn; + } else { + // Check if we should use a thunk. + if (NextVTableThunkIndex < VTableThunks.size() && + VTableThunks[NextVTableThunkIndex].first == I) { + const ThunkInfo &Thunk = VTableThunks[NextVTableThunkIndex].second; + + Init = CGM.GetAddrOfThunk(GD, Thunk); + + NextVTableThunkIndex++; + } else { + const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); + const llvm::Type *Ty = CGM.getTypes().GetFunctionTypeForVtable(MD); + + Init = CGM.GetAddrOfFunction(GD, Ty); + } + + Init = llvm::ConstantExpr::getBitCast(Init, Int8PtrTy); + } + break; + } + + case VtableComponent::CK_UnusedFunctionPointer: + Init = llvm::ConstantExpr::getNullValue(Int8PtrTy); + break; + }; + + Inits.push_back(Init); + } + + llvm::ArrayType *ArrayType = llvm::ArrayType::get(Int8PtrTy, NumComponents); + return llvm::ConstantArray::get(ArrayType, Inits.data(), Inits.size()); +} + +/// GetGlobalVariable - Will return a global variable of the given type. +/// If a variable with a different type already exists then a new variable +/// with the right type will be created. +/// FIXME: We should move this to CodeGenModule and rename it to something +/// better and then use it in CGVTT and CGRTTI. +static llvm::GlobalVariable * +GetGlobalVariable(llvm::Module &Module, llvm::StringRef Name, + const llvm::Type *Ty, + llvm::GlobalValue::LinkageTypes Linkage) { + + llvm::GlobalVariable *GV = Module.getNamedGlobal(Name); + llvm::GlobalVariable *OldGV = 0; + + if (GV) { + // Check if the variable has the right type. + if (GV->getType()->getElementType() == Ty) + return GV; + + assert(GV->isDeclaration() && "Declaration has wrong type!"); + + OldGV = GV; + } + + // Create a new variable. + GV = new llvm::GlobalVariable(Module, Ty, /*isConstant=*/true, + Linkage, 0, Name); + + if (OldGV) { + // Replace occurrences of the old variable if needed. + GV->takeName(OldGV); + + if (!OldGV->use_empty()) { + llvm::Constant *NewPtrForOldDecl = + llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); + OldGV->replaceAllUsesWith(NewPtrForOldDecl); } + + OldGV->eraseFromParent(); } + + return GV; } -llvm::GlobalVariable *CGVtableInfo::getVtable(const CXXRecordDecl *RD) { - llvm::GlobalVariable *Vtable = Vtables.lookup(RD); +llvm::GlobalVariable *CodeGenVTables::GetAddrOfVTable(const CXXRecordDecl *RD) { + llvm::SmallString<256> OutName; + CGM.getMangleContext().mangleCXXVtable(RD, OutName); + llvm::StringRef Name = OutName.str(); + + ComputeVTableRelatedInformation(RD); - if (!Vtable) { - AddressPointsMapTy AddressPoints; - Vtable = GenerateVtable(llvm::GlobalValue::ExternalLinkage, - /*GenerateDefinition=*/false, RD, RD, 0, - /*IsVirtual=*/false, AddressPoints); + const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGM.getLLVMContext()); + llvm::ArrayType *ArrayType = + llvm::ArrayType::get(Int8PtrTy, getNumVTableComponents(RD)); + + return GetGlobalVariable(CGM.getModule(), Name, ArrayType, + llvm::GlobalValue::ExternalLinkage); +} + +void +CodeGenVTables::EmitVTableDefinition(llvm::GlobalVariable *VTable, + llvm::GlobalVariable::LinkageTypes Linkage, + const CXXRecordDecl *RD) { + // Dump the vtable layout if necessary. + if (CGM.getLangOptions().DumpVtableLayouts) { + VtableBuilder Builder(*this, RD, 0, /*MostDerivedClassIsVirtual=*/0, RD); + + Builder.dumpLayout(llvm::errs()); } - return Vtable; + assert(VTableThunksMap.count(RD) && + "No thunk status for this record decl!"); + + const VTableThunksTy& Thunks = VTableThunksMap[RD]; + + // Create and set the initializer. + llvm::Constant *Init = + CreateVTableInitializer(RD, getVTableComponentsData(RD), + getNumVTableComponents(RD), Thunks); + VTable->setInitializer(Init); + + // Set the correct linkage. + VTable->setLinkage(Linkage); } -void CGVtableInfo::MaybeEmitVtable(GlobalDecl GD) { +llvm::GlobalVariable * +CodeGenVTables::GenerateConstructionVTable(const CXXRecordDecl *RD, + const BaseSubobject &Base, + bool BaseIsVirtual, + VTableAddressPointsMapTy& AddressPoints) { + VtableBuilder Builder(*this, Base.getBase(), Base.getBaseOffset(), + /*MostDerivedClassIsVirtual=*/BaseIsVirtual, RD); + + // Dump the vtable layout if necessary. + if (CGM.getLangOptions().DumpVtableLayouts) + Builder.dumpLayout(llvm::errs()); + + // Add the address points. + AddressPoints.insert(Builder.address_points_begin(), + Builder.address_points_end()); + + // Get the mangled construction vtable name. + llvm::SmallString<256> OutName; + CGM.getMangleContext().mangleCXXCtorVtable(RD, Base.getBaseOffset() / 8, + Base.getBase(), OutName); + llvm::StringRef Name = OutName.str(); + + const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGM.getLLVMContext()); + llvm::ArrayType *ArrayType = + llvm::ArrayType::get(Int8PtrTy, Builder.getNumVTableComponents()); + + // Create the variable that will hold the construction vtable. + llvm::GlobalVariable *VTable = + GetGlobalVariable(CGM.getModule(), Name, ArrayType, + llvm::GlobalValue::InternalLinkage); + + // Add the thunks. + VTableThunksTy VTableThunks; + VTableThunks.append(Builder.vtable_thunks_begin(), + Builder.vtable_thunks_end()); + + // Sort them. + std::sort(VTableThunks.begin(), VTableThunks.end()); + + // Create and set the initializer. + llvm::Constant *Init = + CreateVTableInitializer(Base.getBase(), + Builder.vtable_components_data_begin(), + Builder.getNumVTableComponents(), VTableThunks); + VTable->setInitializer(Init); + + return VTable; +} + +void +CodeGenVTables::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 = GetAddrOfVTable(RD); + EmitVTableDefinition(VTable, Linkage, RD); + + GenerateVTT(Linkage, /*GenerateDefinition=*/true, RD); +} + +void CodeGenVTables::EmitVTableRelatedData(GlobalDecl GD) { const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); const CXXRecordDecl *RD = MD->getParent(); @@ -3702,20 +3131,34 @@ void CGVtableInfo::MaybeEmitVtable(GlobalDecl GD) { if (!RD->isDynamicClass()) return; + // Check if we need to emit thunks for this function. + if (MD->isVirtual()) + EmitThunks(GD); + // Get the key function. const CXXMethodDecl *KeyFunction = CGM.getContext().getKeyFunction(RD); + TemplateSpecializationKind RDKind = RD->getTemplateSpecializationKind(); + TemplateSpecializationKind MDKind = MD->getTemplateSpecializationKind(); + if (KeyFunction) { // We don't have the right key function. if (KeyFunction->getCanonicalDecl() != MD->getCanonicalDecl()) return; + } else { + // If this is an explicit instantiation of a method, we don't need a vtable. + // Since we have no key function, we will emit the vtable when we see + // a use, and just defining a function is not an use. + if ((RDKind == TSK_ImplicitInstantiation || + RDKind == TSK_ExplicitInstantiationDeclaration) && + MDKind == TSK_ExplicitInstantiationDefinition) + return; } if (Vtables.count(RD)) return; - TemplateSpecializationKind kind = RD->getTemplateSpecializationKind(); - if (kind == TSK_ImplicitInstantiation) + if (RDKind == TSK_ImplicitInstantiation) CGM.DeferredVtables.push_back(RD); else GenerateClassData(CGM.getVtableLinkage(RD), RD); |
