Peter M. Groen / libmodbus

Commit 702d2603b39b0e9b2ab4b6a390b2797d7126085e

Authored by Stéphane Raimbault
1 parent 50c155a3

Portable use of bswap_32

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Showing 2 changed files with 27 additions and 1 deletions
configure.ac
  View file @702d260
... ... @@ -72,6 +72,7 @@ AM_CONDITIONAL(OS_QNX, test "$os_qnx" = "true")
72 72 LT_INIT([disable-static win32-dll pic-only])
73 73 AC_CHECK_HEADERS([ \
74 74 arpa/inet.h \
  75 + byteswap.h \
75 76 errno.h \
76 77 fcntl.h \
77 78 limits.h \
... ...
src/modbus-data.c
  View file @702d260
... ... @@ -24,10 +24,35 @@
24 24 #endif
25 25 #include <string.h>
26 26 #include <assert.h>
27   -#include <byteswap.h>
28 27  
29 28 #include "modbus.h"
30 29  
  30 +#if defined(HAVE_BYTESWAP_H)
  31 +# include <byteswap.h>
  32 +#endif
  33 +
  34 +#if defined(__GNUC__)
  35 +# define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__ * 10)
  36 +# if GCC_VERSION >= 430
  37 +// Since GCC >= 4.30, GCC provides __builtin_bswapXX() alternatives so we switch to them
  38 +# undef bswap_32
  39 +# define bswap_32 __builtin_bswap32
  40 +# endif
  41 +#endif
  42 +
  43 +#if !defined (bswap_16) || !defined (bswap_32)
  44 +# warning "Fallback on C functions for bswap_32"
  45 +static inline uint16_t bswap_16(uint16_t x)
  46 +{
  47 + return (x >> 8) | (x << 8);
  48 +}
  49 +
  50 +static inline uint32_t bswap_32(uint32_t x)
  51 +{
  52 + return (bswap_16(x & 0xffff) << 16) | (bswap_16(x >> 16));
  53 +}
  54 +#endif
  55 +
31 56 /* Sets many bits from a single byte value (all 8 bits of the byte value are
32 57 set) */
33 58 void modbus_set_bits_from_byte(uint8_t *dest, int index, const uint8_t value)
... ...