436 lines
10 KiB
C++
436 lines
10 KiB
C++
// elfcpp_swap.h -- Handle swapping for elfcpp -*- C++ -*-
|
|
|
|
// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
|
|
// Written by Ian Lance Taylor <iant@google.com>.
|
|
|
|
// This file is part of elfcpp.
|
|
|
|
// This program is free software; you can redistribute it and/or
|
|
// modify it under the terms of the GNU Library General Public License
|
|
// as published by the Free Software Foundation; either version 2, or
|
|
// (at your option) any later version.
|
|
|
|
// In addition to the permissions in the GNU Library General Public
|
|
// License, the Free Software Foundation gives you unlimited
|
|
// permission to link the compiled version of this file into
|
|
// combinations with other programs, and to distribute those
|
|
// combinations without any restriction coming from the use of this
|
|
// file. (The Library Public License restrictions do apply in other
|
|
// respects; for example, they cover modification of the file, and
|
|
/// distribution when not linked into a combined executable.)
|
|
|
|
// This program is distributed in the hope that it will be useful, but
|
|
// WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
// Library General Public License for more details.
|
|
|
|
// You should have received a copy of the GNU Library General Public
|
|
// License along with this program; if not, write to the Free Software
|
|
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
|
|
// 02110-1301, USA.
|
|
|
|
// This header file defines basic template classes to efficiently swap
|
|
// numbers between host form and target form. When the host and
|
|
// target have the same endianness, these turn into no-ops.
|
|
|
|
#ifndef ELFCPP_SWAP_H
|
|
#define ELFCPP_SWAP_H
|
|
|
|
#include <stdint.h>
|
|
|
|
// We need an autoconf-generated config.h file for endianness and
|
|
// swapping. We check two macros: WORDS_BIGENDIAN and
|
|
// HAVE_BYTESWAP_H.
|
|
|
|
#include "config.h"
|
|
|
|
#ifdef HAVE_BYTESWAP_H
|
|
#include <byteswap.h>
|
|
#else
|
|
// Provide our own versions of the byteswap functions.
|
|
inline uint16_t
|
|
bswap_16(uint16_t v)
|
|
{
|
|
return ((v >> 8) & 0xff) | ((v & 0xff) << 8);
|
|
}
|
|
|
|
inline uint32_t
|
|
bswap_32(uint32_t v)
|
|
{
|
|
return ( ((v & 0xff000000) >> 24)
|
|
| ((v & 0x00ff0000) >> 8)
|
|
| ((v & 0x0000ff00) << 8)
|
|
| ((v & 0x000000ff) << 24));
|
|
}
|
|
|
|
inline uint64_t
|
|
bswap_64(uint64_t v)
|
|
{
|
|
return ( ((v & 0xff00000000000000ULL) >> 56)
|
|
| ((v & 0x00ff000000000000ULL) >> 40)
|
|
| ((v & 0x0000ff0000000000ULL) >> 24)
|
|
| ((v & 0x000000ff00000000ULL) >> 8)
|
|
| ((v & 0x00000000ff000000ULL) << 8)
|
|
| ((v & 0x0000000000ff0000ULL) << 24)
|
|
| ((v & 0x000000000000ff00ULL) << 40)
|
|
| ((v & 0x00000000000000ffULL) << 56));
|
|
}
|
|
#endif // !defined(HAVE_BYTESWAP_H)
|
|
|
|
// gcc 4.3 and later provides __builtin_bswap32 and __builtin_bswap64.
|
|
|
|
#if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
|
|
#undef bswap_32
|
|
#define bswap_32 __builtin_bswap32
|
|
#undef bswap_64
|
|
#define bswap_64 __builtin_bswap64
|
|
#endif
|
|
|
|
namespace elfcpp
|
|
{
|
|
|
|
// Endian simply indicates whether the host is big endian or not.
|
|
|
|
struct Endian
|
|
{
|
|
public:
|
|
// Used for template specializations.
|
|
static const bool host_big_endian =
|
|
#ifdef WORDS_BIGENDIAN
|
|
true
|
|
#else
|
|
false
|
|
#endif
|
|
;
|
|
};
|
|
|
|
// Valtype_base is a template based on size (8, 16, 32, 64) which
|
|
// defines the type Valtype as the unsigned integer, and
|
|
// Signed_valtype as the signed integer, of the specified size.
|
|
|
|
template<int size>
|
|
struct Valtype_base;
|
|
|
|
template<>
|
|
struct Valtype_base<8>
|
|
{
|
|
typedef uint8_t Valtype;
|
|
typedef int8_t Signed_valtype;
|
|
};
|
|
|
|
template<>
|
|
struct Valtype_base<16>
|
|
{
|
|
typedef uint16_t Valtype;
|
|
typedef int16_t Signed_valtype;
|
|
};
|
|
|
|
template<>
|
|
struct Valtype_base<32>
|
|
{
|
|
typedef uint32_t Valtype;
|
|
typedef int32_t Signed_valtype;
|
|
};
|
|
|
|
template<>
|
|
struct Valtype_base<64>
|
|
{
|
|
typedef uint64_t Valtype;
|
|
typedef int64_t Signed_valtype;
|
|
};
|
|
|
|
// Convert_endian is a template based on size and on whether the host
|
|
// and target have the same endianness. It defines the type Valtype
|
|
// as Valtype_base does, and also defines a function convert_host
|
|
// which takes an argument of type Valtype and returns the same value,
|
|
// but swapped if the host and target have different endianness.
|
|
|
|
template<int size, bool same_endian>
|
|
struct Convert_endian;
|
|
|
|
template<int size>
|
|
struct Convert_endian<size, true>
|
|
{
|
|
typedef typename Valtype_base<size>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
convert_host(Valtype v)
|
|
{ return v; }
|
|
};
|
|
|
|
template<>
|
|
struct Convert_endian<8, false>
|
|
{
|
|
typedef Valtype_base<8>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
convert_host(Valtype v)
|
|
{ return v; }
|
|
};
|
|
|
|
template<>
|
|
struct Convert_endian<16, false>
|
|
{
|
|
typedef Valtype_base<16>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
convert_host(Valtype v)
|
|
{ return bswap_16(v); }
|
|
};
|
|
|
|
template<>
|
|
struct Convert_endian<32, false>
|
|
{
|
|
typedef Valtype_base<32>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
convert_host(Valtype v)
|
|
{ return bswap_32(v); }
|
|
};
|
|
|
|
template<>
|
|
struct Convert_endian<64, false>
|
|
{
|
|
typedef Valtype_base<64>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
convert_host(Valtype v)
|
|
{ return bswap_64(v); }
|
|
};
|
|
|
|
// Convert is a template based on size and on whether the target is
|
|
// big endian. It defines Valtype and convert_host like
|
|
// Convert_endian. That is, it is just like Convert_endian except in
|
|
// the meaning of the second template parameter.
|
|
|
|
template<int size, bool big_endian>
|
|
struct Convert
|
|
{
|
|
typedef typename Valtype_base<size>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
convert_host(Valtype v)
|
|
{
|
|
return Convert_endian<size, big_endian == Endian::host_big_endian>
|
|
::convert_host(v);
|
|
}
|
|
};
|
|
|
|
// Swap is a template based on size and on whether the target is big
|
|
// endian. It defines the type Valtype and the functions readval and
|
|
// writeval. The functions read and write values of the appropriate
|
|
// size out of buffers, swapping them if necessary. readval and
|
|
// writeval are overloaded to take pointers to the appropriate type or
|
|
// pointers to unsigned char.
|
|
|
|
template<int size, bool big_endian>
|
|
struct Swap
|
|
{
|
|
typedef typename Valtype_base<size>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
readval(const Valtype* wv)
|
|
{ return Convert<size, big_endian>::convert_host(*wv); }
|
|
|
|
static inline void
|
|
writeval(Valtype* wv, Valtype v)
|
|
{ *wv = Convert<size, big_endian>::convert_host(v); }
|
|
|
|
static inline Valtype
|
|
readval(const unsigned char* wv)
|
|
{ return readval(reinterpret_cast<const Valtype*>(wv)); }
|
|
|
|
static inline void
|
|
writeval(unsigned char* wv, Valtype v)
|
|
{ writeval(reinterpret_cast<Valtype*>(wv), v); }
|
|
};
|
|
|
|
// We need to specialize the 8-bit version of Swap to avoid
|
|
// conflicting overloads, since both versions of readval and writeval
|
|
// will have the same type parameters.
|
|
|
|
template<bool big_endian>
|
|
struct Swap<8, big_endian>
|
|
{
|
|
typedef typename Valtype_base<8>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
readval(const Valtype* wv)
|
|
{ return *wv; }
|
|
|
|
static inline void
|
|
writeval(Valtype* wv, Valtype v)
|
|
{ *wv = v; }
|
|
};
|
|
|
|
// Swap_unaligned is a template based on size and on whether the
|
|
// target is big endian. It defines the type Valtype and the
|
|
// functions readval and writeval. The functions read and write
|
|
// values of the appropriate size out of buffers which may be
|
|
// misaligned.
|
|
|
|
template<int size, bool big_endian>
|
|
struct Swap_unaligned;
|
|
|
|
template<bool big_endian>
|
|
struct Swap_unaligned<8, big_endian>
|
|
{
|
|
typedef typename Valtype_base<8>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
readval(const unsigned char* wv)
|
|
{ return *wv; }
|
|
|
|
static inline void
|
|
writeval(unsigned char* wv, Valtype v)
|
|
{ *wv = v; }
|
|
};
|
|
|
|
template<>
|
|
struct Swap_unaligned<16, false>
|
|
{
|
|
typedef Valtype_base<16>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
readval(const unsigned char* wv)
|
|
{
|
|
return (wv[1] << 8) | wv[0];
|
|
}
|
|
|
|
static inline void
|
|
writeval(unsigned char* wv, Valtype v)
|
|
{
|
|
wv[1] = v >> 8;
|
|
wv[0] = v;
|
|
}
|
|
};
|
|
|
|
template<>
|
|
struct Swap_unaligned<16, true>
|
|
{
|
|
typedef Valtype_base<16>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
readval(const unsigned char* wv)
|
|
{
|
|
return (wv[0] << 8) | wv[1];
|
|
}
|
|
|
|
static inline void
|
|
writeval(unsigned char* wv, Valtype v)
|
|
{
|
|
wv[0] = v >> 8;
|
|
wv[1] = v;
|
|
}
|
|
};
|
|
|
|
template<>
|
|
struct Swap_unaligned<32, false>
|
|
{
|
|
typedef Valtype_base<32>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
readval(const unsigned char* wv)
|
|
{
|
|
return (wv[3] << 24) | (wv[2] << 16) | (wv[1] << 8) | wv[0];
|
|
}
|
|
|
|
static inline void
|
|
writeval(unsigned char* wv, Valtype v)
|
|
{
|
|
wv[3] = v >> 24;
|
|
wv[2] = v >> 16;
|
|
wv[1] = v >> 8;
|
|
wv[0] = v;
|
|
}
|
|
};
|
|
|
|
template<>
|
|
struct Swap_unaligned<32, true>
|
|
{
|
|
typedef Valtype_base<32>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
readval(const unsigned char* wv)
|
|
{
|
|
return (wv[0] << 24) | (wv[1] << 16) | (wv[2] << 8) | wv[3];
|
|
}
|
|
|
|
static inline void
|
|
writeval(unsigned char* wv, Valtype v)
|
|
{
|
|
wv[0] = v >> 24;
|
|
wv[1] = v >> 16;
|
|
wv[2] = v >> 8;
|
|
wv[3] = v;
|
|
}
|
|
};
|
|
|
|
template<>
|
|
struct Swap_unaligned<64, false>
|
|
{
|
|
typedef Valtype_base<64>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
readval(const unsigned char* wv)
|
|
{
|
|
return ((static_cast<Valtype>(wv[7]) << 56)
|
|
| (static_cast<Valtype>(wv[6]) << 48)
|
|
| (static_cast<Valtype>(wv[5]) << 40)
|
|
| (static_cast<Valtype>(wv[4]) << 32)
|
|
| (static_cast<Valtype>(wv[3]) << 24)
|
|
| (static_cast<Valtype>(wv[2]) << 16)
|
|
| (static_cast<Valtype>(wv[1]) << 8)
|
|
| static_cast<Valtype>(wv[0]));
|
|
}
|
|
|
|
static inline void
|
|
writeval(unsigned char* wv, Valtype v)
|
|
{
|
|
wv[7] = v >> 56;
|
|
wv[6] = v >> 48;
|
|
wv[5] = v >> 40;
|
|
wv[4] = v >> 32;
|
|
wv[3] = v >> 24;
|
|
wv[2] = v >> 16;
|
|
wv[1] = v >> 8;
|
|
wv[0] = v;
|
|
}
|
|
};
|
|
|
|
template<>
|
|
struct Swap_unaligned<64, true>
|
|
{
|
|
typedef Valtype_base<64>::Valtype Valtype;
|
|
|
|
static inline Valtype
|
|
readval(const unsigned char* wv)
|
|
{
|
|
return ((static_cast<Valtype>(wv[0]) << 56)
|
|
| (static_cast<Valtype>(wv[1]) << 48)
|
|
| (static_cast<Valtype>(wv[2]) << 40)
|
|
| (static_cast<Valtype>(wv[3]) << 32)
|
|
| (static_cast<Valtype>(wv[4]) << 24)
|
|
| (static_cast<Valtype>(wv[5]) << 16)
|
|
| (static_cast<Valtype>(wv[6]) << 8)
|
|
| static_cast<Valtype>(wv[7]));
|
|
}
|
|
|
|
static inline void
|
|
writeval(unsigned char* wv, Valtype v)
|
|
{
|
|
wv[0] = v >> 56;
|
|
wv[1] = v >> 48;
|
|
wv[2] = v >> 40;
|
|
wv[3] = v >> 32;
|
|
wv[4] = v >> 24;
|
|
wv[5] = v >> 16;
|
|
wv[6] = v >> 8;
|
|
wv[7] = v;
|
|
}
|
|
};
|
|
|
|
} // End namespace elfcpp.
|
|
|
|
#endif // !defined(ELFCPP_SWAP_H)
|