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-rw-r--r--include/clang/AST/VTableBuilder.h357
-rw-r--r--lib/AST/CMakeLists.txt1
-rw-r--r--lib/AST/VTableBuilder.cpp2404
-rw-r--r--lib/CodeGen/CGVTables.cpp2380
-rw-r--r--lib/CodeGen/CGVTables.h328
5 files changed, 2763 insertions, 2707 deletions
diff --git a/include/clang/AST/VTableBuilder.h b/include/clang/AST/VTableBuilder.h
new file mode 100644
index 0000000000..59bab03826
--- /dev/null
+++ b/include/clang/AST/VTableBuilder.h
@@ -0,0 +1,357 @@
+//===--- VTableBuilder.h - C++ vtable layout builder --------------*- C++ -*-=//
+//
+// 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 generation of the layout of virtual tables.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_AST_VTABLEBUILDER_H
+#define LLVM_CLANG_AST_VTABLEBUILDER_H
+
+#include "clang/AST/BaseSubobject.h"
+#include "clang/AST/CXXInheritance.h"
+#include "clang/AST/GlobalDecl.h"
+#include "clang/AST/RecordLayout.h"
+#include "clang/Basic/ABI.h"
+#include "llvm/ADT/SetVector.h"
+#include <utility>
+
+namespace clang {
+ class CXXRecordDecl;
+
+/// VTableComponent - Represents a single component in a vtable.
+class VTableComponent {
+public:
+ enum Kind {
+ CK_VCallOffset,
+ CK_VBaseOffset,
+ CK_OffsetToTop,
+ CK_RTTI,
+ CK_FunctionPointer,
+
+ /// CK_CompleteDtorPointer - A pointer to the complete destructor.
+ CK_CompleteDtorPointer,
+
+ /// CK_DeletingDtorPointer - A pointer to the deleting destructor.
+ CK_DeletingDtorPointer,
+
+ /// CK_UnusedFunctionPointer - In some cases, a vtable function pointer
+ /// will end up never being called. Such vtable function pointers are
+ /// represented as a CK_UnusedFunctionPointer.
+ CK_UnusedFunctionPointer
+ };
+
+ VTableComponent() { }
+
+ static VTableComponent MakeVCallOffset(CharUnits Offset) {
+ return VTableComponent(CK_VCallOffset, Offset);
+ }
+
+ static VTableComponent MakeVBaseOffset(CharUnits Offset) {
+ return VTableComponent(CK_VBaseOffset, Offset);
+ }
+
+ static VTableComponent MakeOffsetToTop(CharUnits Offset) {
+ return VTableComponent(CK_OffsetToTop, Offset);
+ }
+
+ static VTableComponent MakeRTTI(const CXXRecordDecl *RD) {
+ return VTableComponent(CK_RTTI, reinterpret_cast<uintptr_t>(RD));
+ }
+
+ static VTableComponent MakeFunction(const CXXMethodDecl *MD) {
+ assert(!isa<CXXDestructorDecl>(MD) &&
+ "Don't use MakeFunction with destructors!");
+
+ return VTableComponent(CK_FunctionPointer,
+ reinterpret_cast<uintptr_t>(MD));
+ }
+
+ static VTableComponent MakeCompleteDtor(const CXXDestructorDecl *DD) {
+ return VTableComponent(CK_CompleteDtorPointer,
+ reinterpret_cast<uintptr_t>(DD));
+ }
+
+ static VTableComponent MakeDeletingDtor(const CXXDestructorDecl *DD) {
+ return VTableComponent(CK_DeletingDtorPointer,
+ reinterpret_cast<uintptr_t>(DD));
+ }
+
+ static VTableComponent MakeUnusedFunction(const CXXMethodDecl *MD) {
+ assert(!isa<CXXDestructorDecl>(MD) &&
+ "Don't use MakeUnusedFunction with destructors!");
+ return VTableComponent(CK_UnusedFunctionPointer,
+ 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);
+ }
+
+ CharUnits getVCallOffset() const {
+ assert(getKind() == CK_VCallOffset && "Invalid component kind!");
+
+ return getOffset();
+ }
+
+ CharUnits getVBaseOffset() const {
+ assert(getKind() == CK_VBaseOffset && "Invalid component kind!");
+
+ return getOffset();
+ }
+
+ CharUnits getOffsetToTop() const {
+ assert(getKind() == CK_OffsetToTop && "Invalid component kind!");
+
+ return getOffset();
+ }
+
+ const CXXRecordDecl *getRTTIDecl() const {
+ assert(getKind() == CK_RTTI && "Invalid component kind!");
+
+ return reinterpret_cast<CXXRecordDecl *>(getPointer());
+ }
+
+ const CXXMethodDecl *getFunctionDecl() const {
+ assert(getKind() == CK_FunctionPointer);
+
+ return reinterpret_cast<CXXMethodDecl *>(getPointer());
+ }
+
+ const CXXDestructorDecl *getDestructorDecl() const {
+ assert((getKind() == CK_CompleteDtorPointer ||
+ getKind() == CK_DeletingDtorPointer) && "Invalid component kind!");
+
+ return reinterpret_cast<CXXDestructorDecl *>(getPointer());
+ }
+
+ const CXXMethodDecl *getUnusedFunctionDecl() const {
+ assert(getKind() == CK_UnusedFunctionPointer);
+
+ return reinterpret_cast<CXXMethodDecl *>(getPointer());
+ }
+
+private:
+ VTableComponent(Kind ComponentKind, CharUnits Offset) {
+ assert((ComponentKind == CK_VCallOffset ||
+ ComponentKind == CK_VBaseOffset ||
+ ComponentKind == CK_OffsetToTop) && "Invalid component kind!");
+ assert(Offset.getQuantity() <= ((1LL << 56) - 1) && "Offset is too big!");
+
+ Value = ((Offset.getQuantity() << 3) | ComponentKind);
+ }
+
+ VTableComponent(Kind ComponentKind, uintptr_t Ptr) {
+ assert((ComponentKind == CK_RTTI ||
+ ComponentKind == CK_FunctionPointer ||
+ ComponentKind == CK_CompleteDtorPointer ||
+ ComponentKind == CK_DeletingDtorPointer ||
+ ComponentKind == CK_UnusedFunctionPointer) &&
+ "Invalid component kind!");
+
+ assert((Ptr & 7) == 0 && "Pointer not sufficiently aligned!");
+
+ Value = Ptr | ComponentKind;
+ }
+
+ CharUnits getOffset() const {
+ assert((getKind() == CK_VCallOffset || getKind() == CK_VBaseOffset ||
+ getKind() == CK_OffsetToTop) && "Invalid component kind!");
+
+ return CharUnits::fromQuantity(Value >> 3);
+ }
+
+ uintptr_t getPointer() const {
+ assert((getKind() == CK_RTTI ||
+ getKind() == CK_FunctionPointer ||
+ getKind() == CK_CompleteDtorPointer ||
+ getKind() == CK_DeletingDtorPointer ||
+ getKind() == CK_UnusedFunctionPointer) &&
+ "Invalid component kind!");
+
+ 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.
+ /// (The reason that we're not simply using a PointerIntPair here is that we
+ /// need the offsets to be 64-bit, even when on a 32-bit machine).
+ int64_t Value;
+};
+
+class VTableLayout {
+public:
+ typedef std::pair<uint64_t, ThunkInfo> VTableThunkTy;
+ typedef SmallVector<ThunkInfo, 1> ThunkInfoVectorTy;
+
+ typedef const VTableComponent *vtable_component_iterator;
+ typedef const VTableThunkTy *vtable_thunk_iterator;
+
+ typedef llvm::DenseMap<BaseSubobject, uint64_t> AddressPointsMapTy;
+private:
+ uint64_t NumVTableComponents;
+ VTableComponent *VTableComponents;
+
+ /// VTableThunks - Contains thunks needed by vtables.
+ uint64_t NumVTableThunks;
+ VTableThunkTy *VTableThunks;
+
+ /// Address points - Address points for all vtables.
+ AddressPointsMapTy AddressPoints;
+
+public:
+ VTableLayout(uint64_t NumVTableComponents,
+ const VTableComponent *VTableComponents,
+ uint64_t NumVTableThunks,
+ const VTableThunkTy *VTableThunks,
+ const AddressPointsMapTy &AddressPoints);
+ ~VTableLayout();
+
+ uint64_t getNumVTableComponents() const {
+ return NumVTableComponents;
+ }
+
+ vtable_component_iterator vtable_component_begin() const {
+ return VTableComponents;
+ }
+
+ vtable_component_iterator vtable_component_end() const {
+ return VTableComponents+NumVTableComponents;
+ }
+
+ uint64_t getNumVTableThunks() const {
+ return NumVTableThunks;
+ }
+
+ vtable_thunk_iterator vtable_thunk_begin() const {
+ return VTableThunks;
+ }
+
+ vtable_thunk_iterator vtable_thunk_end() const {
+ return VTableThunks+NumVTableThunks;
+ }
+
+ uint64_t getAddressPoint(BaseSubobject Base) const {
+ assert(AddressPoints.count(Base) &&
+ "Did not find address point!");
+
+ uint64_t AddressPoint = AddressPoints.lookup(Base);
+ assert(AddressPoint && "Address point must not be zero!");
+
+ return AddressPoint;
+ }
+
+ const AddressPointsMapTy &getAddressPoints() const {
+ return AddressPoints;
+ }
+};
+
+class VTableContext {
+ ASTContext &Context;
+
+public:
+ typedef SmallVector<std::pair<uint64_t, ThunkInfo>, 1>
+ VTableThunksTy;
+ typedef SmallVector<ThunkInfo, 1> ThunkInfoVectorTy;
+
+private:
+ /// MethodVTableIndices - Contains the index (relative to the vtable address
+ /// point) where the function pointer for a virtual function is stored.
+ typedef llvm::DenseMap<GlobalDecl, int64_t> MethodVTableIndicesTy;
+ MethodVTableIndicesTy MethodVTableIndices;
+
+ typedef llvm::DenseMap<const CXXRecordDecl *, const VTableLayout *>
+ VTableLayoutMapTy;
+ VTableLayoutMapTy VTableLayouts;
+
+ /// NumVirtualFunctionPointers - Contains the number of virtual function
+ /// pointers in the vtable for a given record decl.
+ llvm::DenseMap<const CXXRecordDecl *, uint64_t> NumVirtualFunctionPointers;
+
+ typedef std::pair<const CXXRecordDecl *,
+ const CXXRecordDecl *> ClassPairTy;
+
+ /// VirtualBaseClassOffsetOffsets - Contains the vtable offset (relative to
+ /// the address point) in chars where the offsets for virtual bases of a class
+ /// are stored.
+ typedef llvm::DenseMap<ClassPairTy, CharUnits>
+ VirtualBaseClassOffsetOffsetsMapTy;
+ VirtualBaseClassOffsetOffsetsMapTy VirtualBaseClassOffsetOffsets;
+
+ typedef llvm::DenseMap<const CXXMethodDecl *, ThunkInfoVectorTy> ThunksMapTy;
+
+ /// Thunks - Contains all thunks that a given method decl will need.
+ ThunksMapTy Thunks;
+
+ void ComputeMethodVTableIndices(const CXXRecordDecl *RD);
+
+ /// ComputeVTableRelatedInformation - Compute and store all vtable related
+ /// information (vtable layout, vbase offset offsets, thunks etc) for the
+ /// given record decl.
+ void ComputeVTableRelatedInformation(const CXXRecordDecl *RD);
+
+public:
+ VTableContext(ASTContext &Context) : Context(Context) {}
+ ~VTableContext();
+
+ const VTableLayout &getVTableLayout(const CXXRecordDecl *RD) {
+ ComputeVTableRelatedInformation(RD);
+ assert(VTableLayouts.count(RD) && "No layout for this record decl!");
+
+ return *VTableLayouts[RD];
+ }
+
+ VTableLayout *
+ createConstructionVTableLayout(const CXXRecordDecl *MostDerivedClass,
+ CharUnits MostDerivedClassOffset,
+ bool MostDerivedClassIsVirtual,
+ const CXXRecordDecl *LayoutClass);
+
+ const ThunkInfoVectorTy *getThunkInfo(const CXXMethodDecl *MD) {
+ ComputeVTableRelatedInformation(MD->getParent());
+
+ ThunksMapTy::const_iterator I = Thunks.find(MD);
+ if (I == Thunks.end()) {
+ // We did not find a thunk for this method.
+ return 0;
+ }
+
+ return &I->second;
+ }
+
+ /// getNumVirtualFunctionPointers - Return the number of virtual function
+ /// pointers in the vtable for a given record decl.
+ uint64_t getNumVirtualFunctionPointers(const CXXRecordDecl *RD);
+
+ /// getMethodVTableIndex - Return the index (relative to the vtable address
+ /// point) where the function pointer for the given virtual function is
+ /// stored.
+ uint64_t getMethodVTableIndex(GlobalDecl GD);
+
+ /// getVirtualBaseOffsetOffset - Return the offset in chars (relative to the
+ /// vtable address point) where the offset of the virtual base that contains
+ /// the given base is stored, otherwise, if no virtual base contains the given
+ /// class, return 0. Base must be a virtual base class or an unambigious
+ /// base.
+ CharUnits getVirtualBaseOffsetOffset(const CXXRecordDecl *RD,
+ const CXXRecordDecl *VBase);
+};
+
+}
+
+#endif
diff --git a/lib/AST/CMakeLists.txt b/lib/AST/CMakeLists.txt
index eefdb447d3..00fad798ef 100644
--- a/lib/AST/CMakeLists.txt
+++ b/lib/AST/CMakeLists.txt
@@ -46,6 +46,7 @@ add_clang_library(clangAST
Type.cpp
TypeLoc.cpp
TypePrinter.cpp
+ VTableBuilder.cpp
VTTBuilder.cpp
)
diff --git a/lib/AST/VTableBuilder.cpp b/lib/AST/VTableBuilder.cpp
new file mode 100644
index 0000000000..49032b49ef
--- /dev/null
+++ b/lib/AST/VTableBuilder.cpp
@@ -0,0 +1,2404 @@
+//===--- VTableBuilder.cpp - C++ vtable layout builder --------------------===//
+//
+// 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 generation of the layout of virtual tables.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/AST/VTableBuilder.h"
+#include "clang/AST/CXXInheritance.h"
+#include "clang/AST/RecordLayout.h"
+#include "clang/Basic/TargetInfo.h"
+#include "llvm/Support/Format.h"
+#include <algorithm>
+#include <cstdio>
+
+using namespace clang;
+
+#define DUMP_OVERRIDERS 0
+
+namespace {
+
+/// BaseOffset - Represents an offset from a derived class to a direct or
+/// indirect base class.
+struct BaseOffset {
+ /// DerivedClass - The derived class.
+ const CXXRecordDecl *DerivedClass;
+
+ /// VirtualBase - If the path from the derived class to the base class
+ /// involves a virtual base class, this holds its declaration.
+ const CXXRecordDecl *VirtualBase;
+
+ /// NonVirtualOffset - The offset from the derived class to the base class.
+ /// (Or the offset from the virtual base class to the base class, if the
+ /// path from the derived class to the base class involves a virtual base
+ /// class.
+ CharUnits NonVirtualOffset;
+
+ BaseOffset() : DerivedClass(0), VirtualBase(0),
+ NonVirtualOffset(CharUnits::Zero()) { }
+ BaseOffset(const CXXRecordDecl *DerivedClass,
+ const CXXRecordDecl *VirtualBase, CharUnits NonVirtualOffset)
+ : DerivedClass(DerivedClass), VirtualBase(VirtualBase),
+ NonVirtualOffset(NonVirtualOffset) { }
+
+ bool isEmpty() const { return NonVirtualOffset.isZero() && !VirtualBase; }
+};
+
+/// FinalOverriders - Contains the final overrider member functions for all
+/// member functions in the base subobjects of a class.
+class FinalOverriders {
+public:
+ /// OverriderInfo - Information about a final overrider.
+ struct OverriderInfo {
+ /// Method - The method decl of the overrider.
+ const CXXMethodDecl *Method;
+
+ /// Offset - the base offset of the overrider in the layout class.
+ CharUnits Offset;
+
+ OverriderInfo() : Method(0), Offset(CharUnits::Zero()) { }
+ };
+
+private:
+ /// MostDerivedClass - The most derived class for which the final overriders
+ /// are stored.
+ const CXXRecordDecl *MostDerivedClass;
+
+ /// MostDerivedClassOffset - If we're building final overriders for a
+ /// construction vtable, this holds the offset from the layout class to the
+ /// most derived class.
+ const CharUnits MostDerivedClassOffset;
+
+ /// LayoutClass - The class we're using for layout information. Will be
+ /// different than the most derived class if the final overriders are for a
+ /// construction vtable.
+ const CXXRecordDecl *LayoutClass;
+
+ ASTContext &Context;
+
+ /// MostDerivedClassLayout - the AST record layout of the most derived class.
+ const ASTRecordLayout &MostDerivedClassLayout;
+
+ /// MethodBaseOffsetPairTy - Uniquely identifies a member function
+ /// in a base subobject.
+ typedef std::pair<const CXXMethodDecl *, CharUnits> MethodBaseOffsetPairTy;
+
+ typedef llvm::DenseMap<MethodBaseOffsetPairTy,
+ OverriderInfo> OverridersMapTy;
+
+ /// OverridersMap - The final overriders for all virtual member functions of
+ /// all the base subobjects of the most derived class.
+ OverridersMapTy OverridersMap;
+
+ /// SubobjectsToOffsetsMapTy - A mapping from a base subobject (represented
+ /// as a record decl and a subobject number) and its offsets in the most
+ /// derived class as well as the layout class.
+ typedef llvm::DenseMap<std::pair<const CXXRecordDecl *, unsigned>,
+ CharUnits> SubobjectOffsetMapTy;
+
+ typedef llvm::DenseMap<const CXXRecordDecl *, unsigned> SubobjectCountMapTy;
+
+ /// ComputeBaseOffsets - Compute the offsets for all base subobjects of the
+ /// given base.
+ void ComputeBaseOffsets(BaseSubobject Base, bool IsVirtual,
+ CharUnits OffsetInLayoutClass,
+ SubobjectOffsetMapTy &SubobjectOffsets,
+ SubobjectOffsetMapTy &SubobjectLayoutClassOffsets,
+ SubobjectCountMapTy &SubobjectCounts);
+
+ typedef llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBasesSetTy;
+
+ /// dump - dump the final overriders for a base subobject, and all its direct
+ /// and indirect base subobjects.
+ void dump(raw_ostream &Out, BaseSubobject Base,
+ VisitedVirtualBasesSetTy& VisitedVirtualBases);
+
+public:
+ FinalOverriders(const CXXRecordDecl *MostDerivedClass,
+ CharUnits MostDerivedClassOffset,
+ const CXXRecordDecl *LayoutClass);
+
+ /// getOverrider - Get the final overrider for the given method declaration in
+ /// the subobject with the given base offset.
+ OverriderInfo getOverrider(const CXXMethodDecl *MD,
+ CharUnits BaseOffset) const {
+ assert(OverridersMap.count(std::make_pair(MD, BaseOffset)) &&
+ "Did not find overrider!");
+
+ return OverridersMap.lookup(std::make_pair(MD, BaseOffset));
+ }
+
+ /// dump - dump the final overriders.
+ void dump() {
+ VisitedVirtualBasesSetTy VisitedVirtualBases;
+ dump(llvm::errs(), BaseSubobject(MostDerivedClass, CharUnits::Zero()),
+ VisitedVirtualBases);
+ }
+
+};
+
+#define DUMP_OVERRIDERS 0
+
+FinalOverriders::FinalOverriders(const CXXRecordDecl *MostDerivedClass,
+ CharUnits MostDerivedClassOffset,
+ const CXXRecordDecl *LayoutClass)
+ : MostDerivedClass(MostDerivedClass),
+ MostDerivedClassOffset(MostDerivedClassOffset), LayoutClass(LayoutClass),
+ Context(MostDerivedClass->getASTContext()),
+ MostDerivedClassLayout(Context.getASTRecordLayout(MostDerivedClass)) {
+
+ // Compute base offsets.
+ SubobjectOffsetMapTy SubobjectOffsets;
+ SubobjectOffsetMapTy SubobjectLayoutClassOffsets;
+ SubobjectCountMapTy SubobjectCounts;
+ ComputeBaseOffsets(BaseSubobject(MostDerivedClass, CharUnits::Zero()),
+ /*IsVirtual=*/false,
+ MostDerivedClassOffset,
+ SubobjectOffsets, SubobjectLayoutClassOffsets,
+ SubobjectCounts);
+
+ // Get the the final overriders.
+ CXXFinalOverriderMap FinalOverriders;
+ MostDerivedClass->getFinalOverriders(FinalOverriders);
+
+ for (CXXFinalOverriderMap::const_iterator I = FinalOverriders.begin(),
+ E = FinalOverriders.end(); I != E; ++I) {
+ const CXXMethodDecl *MD = I->first;
+ const OverridingMethods& Methods = I->second;
+
+ for (OverridingMethods::const_iterator I = Methods.begin(),
+ E = Methods.end(); I != E; ++I) {
+ unsigned SubobjectNumber = I->first;
+ assert(SubobjectOffsets.count(std::make_pair(MD->getParent(),
+ SubobjectNumber)) &&
+ "Did not find subobject offset!");
+
+ CharUnits BaseOffset = SubobjectOffsets[std::make_pair(MD->getParent(),
+ SubobjectNumber)];
+
+ assert(I->second.size() == 1 && "Final overrider is not unique!");
+ const UniqueVirtualMethod &Method = I->second.front();
+
+ const CXXRecordDecl *OverriderRD = Method.Method->getParent();
+ assert(SubobjectLayoutClassOffsets.count(
+ std::make_pair(OverriderRD, Method.Subobject))
+ && "Did not find subobject offset!");
+ CharUnits OverriderOffset =
+ SubobjectLayoutClassOffsets[std::make_pair(OverriderRD,
+ Method.Subobject)];
+
+ OverriderInfo& Overrider = OverridersMap[std::make_pair(MD, BaseOffset)];
+ assert(!Overrider.Method && "Overrider should not exist yet!");
+
+ Overrider.Offset = OverriderOffset;
+ Overrider.Method = Method.Method;
+ }
+ }
+
+#if DUMP_OVERRIDERS
+ // And dump them (for now).
+ dump();
+#endif
+}
+
+static BaseOffset ComputeBaseOffset(ASTContext &Context,
+ const CXXRecordDecl *DerivedRD,
+ const CXXBasePath &Path) {
+ CharUnits NonVirtualOffset = CharUnits::Zero();
+
+ unsigned NonVirtualStart = 0;
+ const CXXRecordDecl *VirtualBase = 0;
+
+ // First, look for the virtual base class.
+ for (unsigned I = 0, E = Path.size(); I != E; ++I) {
+ const CXXBasePathElement &Element = Path[I];
+
+ if (Element.Base->isVirtual()) {
+ // FIXME: Can we break when we find the first virtual base?
+ // (If we can't, can't we just iterate over the path in reverse order?)
+ NonVirtualStart = I + 1;
+ QualType VBaseType = Element.Base->getType();
+ VirtualBase =
+ cast<CXXRecordDecl>(VBaseType->getAs<RecordType>()->getDecl());
+ }
+ }
+
+ // Now compute the non-virtual offset.
+ for (unsigned I = NonVirtualStart, E = Path.size(); I != E; ++I) {
+ const CXXBasePathElement &Element = Path[I];
+
+ // Check the base class offset.
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(Element.Class);
+
+ const RecordType *BaseType = Element.Base->getType()->getAs<RecordType>();
+ const CXXRecordDecl *Base = cast<CXXRecordDecl>(BaseType->getDecl());
+
+ NonVirtualOffset += Layout.getBaseClassOffset(Base);
+ }
+
+ // FIXME: This should probably use CharUnits or something. Maybe we should
+ // even change the base offsets in ASTRecordLayout to be specified in
+ // CharUnits.
+ return BaseOffset(DerivedRD, VirtualBase, NonVirtualOffset);
+
+}
+
+static BaseOffset ComputeBaseOffset(ASTContext &Context,
+ const CXXRecordDecl *BaseRD,
+ const CXXRecordDecl *DerivedRD) {
+ CXXBasePaths Paths(/*FindAmbiguities=*/false,
+ /*RecordPaths=*/true, /*DetectVirtual=*/false);
+
+ if (!const_cast<CXXRecordDecl *>(DerivedRD)->
+ isDerivedFrom(const_cast<CXXRecordDecl *>(BaseRD), Paths)) {
+ llvm_unreachable("Class must be derived from the passed in base class!");
+ }
+
+ return ComputeBaseOffset(Context, DerivedRD, Paths.front());
+}
+
+static BaseOffset
+ComputeReturnAdjustmentBaseOffset(ASTContext &Context,
+ const CXXMethodDecl *DerivedMD,
+ const CXXMethodDecl *BaseMD) {
+ const FunctionType *BaseFT = BaseMD->getType()->getAs<FunctionType>();
+ const FunctionType *DerivedFT = DerivedMD->getType()->getAs<FunctionType>();
+
+ // Canonicalize the return types.
+ CanQualType CanDerivedReturnType =
+ Context.getCanonicalType(DerivedFT->getResultType());
+ CanQualType CanBaseReturnType =
+ Context.getCanonicalType(BaseFT->getResultType());
+
+ assert(CanDerivedReturnType->getTypeClass() ==
+ CanBaseReturnType->getTypeClass() &&
+ "Types must have same type class!");
+
+ if (CanDerivedReturnType == CanBaseReturnType) {
+ // No adjustment needed.
+ return BaseOffset();
+ }
+
+ if (isa<ReferenceType>(CanDerivedReturnType)) {
+ CanDerivedReturnType =
+ CanDerivedReturnType->getAs<ReferenceType>()->getPointeeType();
+ CanBaseReturnType =
+ CanBaseReturnType->getAs<ReferenceType>()->getPointeeType();
+ } else if (isa<PointerType>(CanDerivedReturnType)) {
+ CanDerivedReturnType =
+ CanDerivedReturnType->getAs<PointerType>()->getPointeeType();
+ CanBaseReturnType =
+ CanBaseReturnType->getAs<PointerType>()->getPointeeType();
+ } else {
+ llvm_unreachable("Unexpected return type!");
+ }
+
+ // We need to compare unqualified types here; consider
+ // const T *Base::foo();
+ // T *Derived::foo();
+ if (CanDerivedReturnType.getUnqualifiedType() ==
+ CanBaseReturnType.getUnqualifiedType()) {
+ // No adjustment needed.
+ return BaseOffset();
+ }
+
+ const CXXRecordDecl *DerivedRD =
+ cast<CXXRecordDecl>(cast<RecordType>(CanDerivedReturnType)->getDecl());
+
+ const CXXRecordDecl *BaseRD =
+ cast<CXXRecordDecl>(cast<RecordType>(CanBaseReturnType)->getDecl());
+
+ return ComputeBaseOffset(Context, BaseRD, DerivedRD);
+}
+
+void
+FinalOverriders::ComputeBaseOffsets(BaseSubobject Base, bool IsVirtual,
+ CharUnits OffsetInLayoutClass,
+ SubobjectOffsetMapTy &SubobjectOffsets,
+ SubobjectOffsetMapTy &SubobjectLayoutClassOffsets,
+ SubobjectCountMapTy &SubobjectCounts) {
+ const CXXRecordDecl *RD = Base.getBase();
+
+ unsigned SubobjectNumber = 0;
+ if (!IsVirtual)
+ SubobjectNumber = ++SubobjectCounts[RD];
+
+ // Set up the subobject to offset mapping.
+ assert(!SubobjectOffsets.count(std::make_pair(RD, SubobjectNumber))
+ && "Subobject offset already exists!");
+ assert(!SubobjectLayoutClassOffsets.count(std::make_pair(RD, SubobjectNumber))
+ && "Subobject offset already exists!");
+
+ SubobjectOffsets[std::make_pair(RD, SubobjectNumber)] = Base.getBaseOffset();
+ SubobjectLayoutClassOffsets[std::make_pair(RD, SubobjectNumber)] =
+ OffsetInLayoutClass;
+
+ // Traverse our bases.
+ for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
+ E = RD->bases_end(); I != E; ++I) {
+ const CXXRecordDecl *BaseDecl =
+ cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl());
+
+ CharUnits BaseOffset;
+ CharUnits BaseOffsetInLayoutClass;
+ if (I->isVirtual()) {
+ // Check if we've visited this virtual base before.
+ if (SubobjectOffsets.count(std::make_pair(BaseDecl, 0)))
+ continue;
+
+ const ASTRecordLayout &LayoutClassLayout =
+ Context.getASTRecordLayout(LayoutClass);
+
+ BaseOffset = MostDerivedClassLayout.getVBaseClassOffset(BaseDecl);
+ BaseOffsetInLayoutClass =
+ LayoutClassLayout.getVBaseClassOffset(BaseDecl);
+ } else {
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+ CharUnits Offset = Layout.getBaseClassOffset(BaseDecl);
+
+ BaseOffset = Base.getBaseOffset() + Offset;
+ BaseOffsetInLayoutClass = OffsetInLayoutClass + Offset;
+ }
+
+ ComputeBaseOffsets(BaseSubobject(BaseDecl, BaseOffset),
+ I->isVirtual(), BaseOffsetInLayoutClass,
+ SubobjectOffsets, SubobjectLayoutClassOffsets,
+ SubobjectCounts);
+ }
+}
+
+void FinalOverriders::dump(raw_ostream &Out, BaseSubobject Base,
+ VisitedVirtualBasesSetTy &VisitedVirtualBases) {
+ const CXXRecordDecl *RD = Base.getBase();
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+
+ for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
+ E = RD->bases_end(); I != E; ++I) {
+ const CXXRecordDecl *BaseDecl =
+ cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl());
+
+ // Ignore bases that don't have any virtual member functions.
+ if (!BaseDecl->isPolymorphic())
+ continue;
+
+ CharUnits BaseOffset;
+ if (I->isVirtual()) {
+ if (!VisitedVirtualBases.insert(BaseDecl)) {
+ // We've visited this base before.
+ continue;
+ }
+
+ BaseOffset = MostDerivedClassLayout.getVBaseClassOffset(BaseDecl);
+ } else {
+ BaseOffset = Layout.getBaseClassOffset(BaseDecl) + Base.getBaseOffset();
+ }
+
+ dump(Out, BaseSubobject(BaseDecl, BaseOffset), VisitedVirtualBases);
+ }
+
+ Out << "Final overriders for (" << RD->getQualifiedNameAsString() << ", ";
+ Out << Base.getBaseOffset().getQuantity() << ")\n";
+
+ // Now dump the overriders for this base subobject.
+ for (CXXRecordDecl::method_iterator I = RD->method_begin(),
+ E = RD->method_end(); I != E; ++I) {
+ const CXXMethodDecl *MD = *I;
+
+ if (!MD->isVirtual())
+ continue;
+
+ OverriderInfo Overrider = getOverrider(MD, Base.getBaseOffset());
+
+ Out << " " << MD->getQualifiedNameAsString() << " - (";
+ Out << Overrider.Method->getQualifiedNameAsString();
+ Out << ", " << ", " << Overrider.Offset.getQuantity() << ')';
+
+ BaseOffset Offset;
+ if (!Overrider.Method->isPure())
+ Offset = ComputeReturnAdjustmentBaseOffset(Context, Overrider.Method, MD);
+
+ if (!Offset.isEmpty()) {
+ Out << " [ret-adj: ";
+ if (Offset.VirtualBase)
+ Out << Offset.VirtualBase->getQualifiedNameAsString() << " vbase, ";
+
+ Out << Offset.NonVirtualOffset.getQuantity() << " nv]";
+ }
+
+ Out << "\n";
+ }
+}
+
+/// VCallOffsetMap - Keeps track of vcall offsets when building a vtable.
+struct VCallOffsetMap {
+
+ typedef std::pair<const CXXMethodDecl *, CharUnits> MethodAndOffsetPairTy;
+
+ /// Offsets - Keeps track of methods and their offsets.
+ // FIXME: This should be a real map and not a vector.
+ SmallVector<MethodAndOffsetPairTy, 16> Offsets;
+
+ /// MethodsCanShareVCallOffset - Returns whether two virtual member functions
+ /// can share the same vcall offset.
+ static bool MethodsCanShareVCallOffset(const CXXMethodDecl *LHS,
+ const CXXMethodDecl *RHS);
+
+public:
+ /// AddVCallOffset - Adds a vcall offset to the map. Returns true if the
+ /// add was successful, or false if there was already a member function with
+ /// the same signature in the map.
+ bool AddVCallOffset(const CXXMethodDecl *MD, CharUnits OffsetOffset);
+
+ /// getVCallOffsetOffset - Returns the vcall offset offset (relative to the
+ /// vtable address point) for the given virtual member function.
+ CharUnits getVCallOffsetOffset(const CXXMethodDecl *MD);
+
+ // empty - Return whether the offset map is empty or not.
+ bool empty() const { return Offsets.empty(); }
+};
+
+static bool HasSameVirtualSignature(const CXXMethodDecl *LHS,
+ const CXXMethodDecl *RHS) {
+ ASTContext &C = LHS->getASTContext(); // TODO: thread this down
+ CanQual<FunctionProtoType>
+ LT = C.getCanonicalType(LHS->getType()).getAs<FunctionProtoType>(),
+ RT = C.getCanonicalType(RHS->getType()).getAs<FunctionProtoType>();
+
+ // Fast-path matches in the canonical types.
+ if (LT == RT) return true;
+
+ // Force the signatures to match. We can't rely on the overrides
+ // list here because there isn't necessarily an inheritance
+ // relationship between the two methods.
+ if (LT.getQualifiers() != RT.getQualifiers() ||
+ LT->getNumArgs() != RT->getNumArgs())
+ return false;
+ for (unsigned I = 0, E = LT->getNumArgs(); I != E; ++I)
+ if (LT->getArgType(I) != RT->getArgType(I))
+ return false;
+ return true;
+}
+
+bool VCallOffsetMap::MethodsCanShareVCallOffset(const CXXMethodDecl *LHS,
+ const CXXMethodDecl *RHS) {
+ assert(LHS->isVirtual() && "LHS must be virtual!");
+ assert(RHS->isVirtual() && "LHS must be virtual!");
+
+ // A destructor can share a vcall offset with another destructor.
+ if (isa<CXXDestructorDecl>(LHS))
+ return isa<CXXDestructorDecl>(RHS);
+
+ // FIXME: We need to check more things here.
+
+ // The methods must have the same name.
+ DeclarationName LHSName = LHS->getDeclName();
+ DeclarationName RHSName = RHS->getDeclName();
+ if (LHSName != RHSName)
+ return false;
+
+ // And the same signatures.
+ return HasSameVirtualSignature(LHS, RHS);
+}
+
+bool VCallOffsetMap::AddVCallOffset(const CXXMethodDecl *MD,
+ CharUnits OffsetOffset) {
+ // Check if we can reuse an offset.
+ for (unsigned I = 0, E = Offsets.size(); I != E; ++I) {
+ if (MethodsCanShareVCallOffset(Offsets[I].first, MD))
+ return false;
+ }
+
+ // Add the offset.
+ Offsets.push_back(MethodAndOffsetPairTy(MD, OffsetOffset));
+ return true;
+}
+
+CharUnits VCallOffsetMap::getVCallOffsetOffset(const CXXMethodDecl *MD) {
+ // Look for an offset.
+ for (unsigned I = 0, E = Offsets.size(); I != E; ++I) {
+ if (MethodsCanShareVCallOffset(Offsets[I].first, MD))
+ return Offsets[I].second;
+ }
+
+ llvm_unreachable("Should always find a vcall offset offset!");
+}
+
+/// VCallAndVBaseOffsetBuilder - Class for building vcall and vbase offsets.
+class VCallAndVBaseOffsetBuilder {
+public:
+ typedef llvm::DenseMap<const CXXRecordDecl *, CharUnits>
+ VBaseOffsetOffsetsMapTy;
+
+private:
+ /// MostDerivedClass - The most derived class for which we're building vcall
+ /// and vbase offsets.
+ const CXXRecordDecl *MostDerivedClass;
+
+ /// LayoutClass - The class we're using for layout information. Will be
+ /// different than the most derived class if we're building a construction
+ /// vtable.
+ const CXXRecordDecl *LayoutClass;
+
+ /// Context - The ASTContext which we will use for layout information.
+ ASTContext &Context;
+
+ /// Components - vcall and vbase offset components
+ typedef SmallVector<VTableComponent, 64> VTableComponentVectorTy;
+ VTableComponentVectorTy Components;
+
+ /// VisitedVirtualBases - Visited virtual bases.
+ llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBases;
+
+ /// VCallOffsets - Keeps track of vcall offsets.
+ VCallOffsetMap VCallOffsets;
+
+
+ /// VBaseOffsetOffsets - Contains the offsets of the virtual base offsets,
+ /// relative to the address point.
+ VBaseOffsetOffsetsMapTy VBaseOffsetOffsets;
+
+ /// FinalOverriders - The final overriders of the most derived class.
+ /// (Can be null when we're not building a vtable of the most derived class).
+ const FinalOverriders *Overriders;
+
+ /// AddVCallAndVBaseOffsets - Add vcall offsets and vbase offsets for the
+ /// given base subobject.
+ void AddVCallAndVBaseOffsets(BaseSubobject Base, bool BaseIsVirtual,
+ CharUnits RealBaseOffset);
+
+ /// AddVCallOffsets - Add vcall offsets for the given base subobject.
+ void AddVCallOffsets(BaseSubobject Base, CharUnits VBaseOffset);
+
+ /// AddVBaseOffsets - Add vbase offsets for the given class.
+ void AddVBaseOffsets(const CXXRecordDecl *Base,
+ CharUnits OffsetInLayoutClass);
+
+ /// getCurrentOffsetOffset - Get the current vcall or vbase offset offset in
+ /// chars, relative to the vtable address point.
+ CharUnits getCurrentOffsetOffset() const;
+
+public:
+ VCallAndVBaseOffsetBuilder(const CXXRecordDecl *MostDerivedClass,
+ const CXXRecordDecl *LayoutClass,
+