//=== RecordLayoutBuilder.cpp - Helper class for building record layouts ---==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "clang/AST/Attr.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Expr.h"
#include "clang/AST/RecordLayout.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/Support/Format.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/Support/MathExtras.h"
#include <map>
using namespace clang;
namespace {
/// EmptySubobjectMap - Keeps track of which empty subobjects exist at different
/// offsets while laying out a C++ class.
class EmptySubobjectMap {
ASTContext &Context;
/// Class - The class whose empty entries we're keeping track of.
const CXXRecordDecl *Class;
public:
EmptySubobjectMap(ASTContext &Context, const CXXRecordDecl *Class)
: Context(Context), Class(Class) { }
};
class RecordLayoutBuilder {
// FIXME: Remove this and make the appropriate fields public.
friend class clang::ASTContext;
ASTContext &Context;
EmptySubobjectMap *EmptySubobjects;
/// Size - The current size of the record layout.
uint64_t Size;
/// Alignment - The current alignment of the record layout.
unsigned Alignment;
llvm::SmallVector<uint64_t, 16> FieldOffsets;
/// Packed - Whether the record is packed or not.
bool Packed;
/// UnfilledBitsInLastByte - If the last field laid out was a bitfield,
/// this contains the number of bits in the last byte that can be used for
/// an adjacent bitfield if necessary.
unsigned char UnfilledBitsInLastByte;
/// MaxFieldAlignment - The maximum allowed field alignment. This is set by
/// #pragma pack.
unsigned MaxFieldAlignment;
/// DataSize - The data size of the record being laid out.
uint64_t DataSize;
bool IsUnion;
uint64_t NonVirtualSize;
unsigned NonVirtualAlignment;
/// PrimaryBase - the primary base class (if one exists) of the class
/// we're laying out.
const CXXRecordDecl *PrimaryBase;
/// PrimaryBaseIsVirtual - Whether the primary base of the class we're laying
/// out is virtual.
bool PrimaryBaseIsVirtual;
typedef llvm::DenseMap<const CXXRecordDecl *, uint64_t> BaseOffsetsMapTy;
/// Bases - base classes and their offsets in the record.
BaseOffsetsMapTy Bases;
// VBases - virtual base classes and their offsets in the record.
BaseOffsetsMapTy VBases;
/// IndirectPrimaryBases - Virtual base classes, direct or indirect, that are
/// primary base classes for some other direct or indirect base class.
llvm::SmallSet<const CXXRecordDecl*, 32> IndirectPrimaryBases;
/// FirstNearlyEmptyVBase - The first nearly empty virtual base class in
/// inheritance graph order. Used for determining the primary base class.
