shada: Use glibc functions to convert from big endian, add a fallback

This commit is contained in:
ZyX 2015-04-26 03:36:06 +03:00
parent 244dbe3a77
commit 38c688d7be

View File

@ -5,6 +5,15 @@
#include <inttypes.h>
#include <errno.h>
#include <assert.h>
#if defined (__GLIBC__)
# ifndef _BSD_SOURCE
# define _BSD_SOURCE 1
# endif
# ifndef _DEFAULT_SOURCE
# define _DEFAULT_SOURCE 1
# endif
# include <endian.h>
#endif
#include <msgpack.h>
@ -45,6 +54,43 @@
#define home_replace_save(a, b) \
((char *)home_replace_save(a, (char_u *)b))
// From http://www.boost.org/doc/libs/1_43_0/boost/detail/endian.hpp + some
// additional checks done after examining `{compiler} -dM -E - < /dev/null`
// output.
#if defined (__GLIBC__)
# if (__BYTE_ORDER == __BIG_ENDIAN)
# define SHADA_BIG_ENDIAN
# endif
#elif defined(_BIG_ENDIAN) || defined(_LITTLE_ENDIAN)
# if defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)
# define SHADA_BIG_ENDIAN
# endif
// clang-specific
#elif defined(__BIG_ENDIAN__) || defined(__LITTLE_ENDIAN__)
# if defined(_BIG_ENDIAN) && !defined(_LITTLE_ENDIAN)
# define SHADA_BIG_ENDIAN
# endif
// pcc-, gcc- and clang-specific
#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__)
# if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
# define SHADA_BIG_ENDIAN
# endif
#elif defined(__sparc) || defined(__sparc__) \
|| defined(_POWER) || defined(__powerpc__) \
|| defined(__ppc__) || defined(__hpux) || defined(__hppa) \
|| defined(_MIPSEB) || defined(_POWER) \
|| defined(__s390__)
# define SHADA_BIG_ENDIAN
#elif defined(__i386__) || defined(__alpha__) \
|| defined(__ia64) || defined(__ia64__) \
|| defined(_M_IX86) || defined(_M_IA64) \
|| defined(_M_ALPHA) || defined(__amd64) \
|| defined(__amd64__) || defined(_M_AMD64) \
|| defined(__x86_64) || defined(__x86_64__) \
|| defined(_M_X64) || defined(__bfin__)
// Define nothing
#endif
/// Possible ShaDa entry types
///
/// @warning Enum values are part of the API and must not be altered.
@ -1027,6 +1073,22 @@ static void shada_free_shada_entry(ShadaEntry *const entry)
}
}
#ifndef __GLIBC__
static inline uint64_t be64toh(uint64_t big_endian_64_bits)
{
#ifdef SHADA_BIG_ENDIAN
return big_endian_64_bits;
#else
uint8_t *buf = &big_endian_64_bits;
uint64_t ret = 0;
for (size_t i = 8; i; i--) {
ret |= ((uint64_t) buf[i - 1]) << ((8 - i) * 8);
}
return ret;
#endif
}
#endif
/// Read next unsigned integer from file
///
/// Errors out if the result is not an unsigned integer.
@ -1088,8 +1150,9 @@ static int msgpack_read_uint64(FILE *const fp, const int first_char,
return FAIL;
}
}
uint8_t buf[8];
size_t read_bytes = fread((char *) &(buf[0]), 1, length, fp);
uint8_t buf[sizeof(uint64_t)] = {0, 0, 0, 0, 0, 0, 0, 0};
size_t read_bytes = fread((char *) &(buf[sizeof(uint64_t)-length]), 1,
length, fp);
if (ferror(fp)) {
emsg2("System error while reading ShaDa file: %s",
strerror(errno));
@ -1100,11 +1163,7 @@ static int msgpack_read_uint64(FILE *const fp, const int first_char,
(int64_t) fpos);
return FAIL;
}
// TODO(ZyX-I): Just cast if current platform is big-endian.
*result = 0;
for (size_t i = length; i; i--) {
*result |= ((uint64_t) buf[i - 1]) << ((length - i) * 8);
}
*result = be64toh(*((uint64_t *) &(buf[0])));
}
return OK;
}