Move VTable builder to AST

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140510 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGVTables.h b/lib/CodeGen/CGVTables.h
index 44b9804..828330e 100644
--- a/lib/CodeGen/CGVTables.h
+++ b/lib/CodeGen/CGVTables.h
@@ -20,6 +20,7 @@
 #include "clang/AST/BaseSubobject.h"
 #include "clang/AST/CharUnits.h"
 #include "clang/AST/GlobalDecl.h"
+#include "clang/AST/VTableBuilder.h"
 
 namespace clang {
   class CXXRecordDecl;
@@ -27,333 +28,6 @@
 namespace CodeGen {
   class CodeGenModule;
 
-/// 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 llvm::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);
-};
-
 class CodeGenVTables {
   CodeGenModule &CGM;