// elfcpp_swap.h -- Handle swapping for elfcpp -*- C++ -*-
+// Copyright (C) 2006-2020 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.
#define ELFCPP_SWAP_H
#include <stdint.h>
-#include <endian.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
{
{
public:
// Used for template specializations.
- static const bool host_big_endian = __BYTE_ORDER == __BIG_ENDIAN;
+ 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 of the specified
-// size.
+// 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 unsigned char Valtype;
+ 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
// 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_unaligned and writeval_unaligned. The functions
-// read and write values of the appropriate size out of buffers which
-// may be misaligned.
+// 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;
typedef typename Valtype_base<8>::Valtype Valtype;
static inline Valtype
- readval_unaligned(const unsigned char* wv)
+ readval(const unsigned char* wv)
{ return *wv; }
static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
+ writeval(unsigned char* wv, Valtype v)
{ *wv = v; }
};
typedef Valtype_base<16>::Valtype Valtype;
static inline Valtype
- readval_unaligned(const unsigned char* wv)
+ readval(const unsigned char* wv)
{
return (wv[1] << 8) | wv[0];
}
static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
+ writeval(unsigned char* wv, Valtype v)
{
wv[1] = v >> 8;
wv[0] = v;
typedef Valtype_base<16>::Valtype Valtype;
static inline Valtype
- readval_unaligned(const unsigned char* wv)
+ readval(const unsigned char* wv)
{
return (wv[0] << 8) | wv[1];
}
static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
+ writeval(unsigned char* wv, Valtype v)
{
wv[0] = v >> 8;
wv[1] = v;
typedef Valtype_base<32>::Valtype Valtype;
static inline Valtype
- readval_unaligned(const unsigned char* wv)
+ readval(const unsigned char* wv)
{
return (wv[3] << 24) | (wv[2] << 16) | (wv[1] << 8) | wv[0];
}
static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
+ writeval(unsigned char* wv, Valtype v)
{
wv[3] = v >> 24;
wv[2] = v >> 16;
typedef Valtype_base<32>::Valtype Valtype;
static inline Valtype
- readval_unaligned(const unsigned char* wv)
+ readval(const unsigned char* wv)
{
return (wv[0] << 24) | (wv[1] << 16) | (wv[2] << 8) | wv[3];
}
static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
+ writeval(unsigned char* wv, Valtype v)
{
wv[0] = v >> 24;
wv[1] = v >> 16;
typedef Valtype_base<64>::Valtype Valtype;
static inline Valtype
- readval_unaligned(const unsigned char* wv)
+ readval(const unsigned char* wv)
{
return ((static_cast<Valtype>(wv[7]) << 56)
| (static_cast<Valtype>(wv[6]) << 48)
}
static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
+ writeval(unsigned char* wv, Valtype v)
{
wv[7] = v >> 56;
wv[6] = v >> 48;
typedef Valtype_base<64>::Valtype Valtype;
static inline Valtype
- readval_unaligned(const unsigned char* wv)
+ readval(const unsigned char* wv)
{
return ((static_cast<Valtype>(wv[0]) << 56)
| (static_cast<Valtype>(wv[1]) << 48)
}
static inline void
- writeval_unaligned(unsigned char* wv, Valtype v)
+ 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;
+ 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;
+ }
+};
+
+// Swap_aligned32 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 not be
+// 64-bit aligned, but are 32-bit aligned.
+
+template<int size, bool big_endian>
+struct Swap_aligned32
+{
+ typedef typename Valtype_base<size>::Valtype Valtype;
+
+ static inline Valtype
+ readval(const unsigned char* wv)
+ { return Swap<size, big_endian>::readval(
+ reinterpret_cast<const Valtype*>(wv)); }
+
+ static inline void
+ writeval(unsigned char* wv, Valtype v)
+ { Swap<size, big_endian>::writeval(reinterpret_cast<Valtype*>(wv), v); }
+};
+
+template<>
+struct Swap_aligned32<64, true>
+{
+ typedef Valtype_base<64>::Valtype Valtype;
+
+ static inline Valtype
+ readval(const unsigned char* wv)
+ {
+ return ((static_cast<Valtype>(Swap<32, true>::readval(wv)) << 32)
+ | static_cast<Valtype>(Swap<32, true>::readval(wv + 4)));
+ }
+
+ static inline void
+ writeval(unsigned char* wv, Valtype v)
+ {
+ typedef Valtype_base<32>::Valtype Valtype32;
+
+ Swap<32, true>::writeval(wv, static_cast<Valtype32>(v >> 32));
+ Swap<32, true>::writeval(wv + 4, static_cast<Valtype32>(v));
+ }
+};
+
+template<>
+struct Swap_aligned32<64, false>
+{
+ typedef Valtype_base<64>::Valtype Valtype;
+
+ static inline Valtype
+ readval(const unsigned char* wv)
+ {
+ return ((static_cast<Valtype>(Swap<32, false>::readval(wv + 4)) << 32)
+ | static_cast<Valtype>(Swap<32, false>::readval(wv)));
+ }
+
+ static inline void
+ writeval(unsigned char* wv, Valtype v)
+ {
+ typedef Valtype_base<32>::Valtype Valtype32;
+
+ Swap<32, false>::writeval(wv + 4, static_cast<Valtype32>(v >> 32));
+ Swap<32, false>::writeval(wv, static_cast<Valtype32>(v));
}
};