mk/endian.mk

   1 # $NetBSD: endian.mk,v 1.5 2007/03/08 23:11:20 rillig Exp $
   2 #
   3 # Determine the endianness of the platform by checking header files.
   4 #
   5 # This file is used as follows:
   6 #
   7 # .include "../../mk/endian.mk"
   8 #
   9 # .if ${MACHINE_ENDIAN} == "big"
  10 # # ...big endian stuff...
  11 # .elif ${MACHINE_ENDIAN} == "little"
  12 # # ...little endian stuff...
  13 # .else
  14 # BROKEN=       "Unknown endianness"
  15 # .endif
  16
  17 .include "../../mk/bsd.prefs.mk"
  18
  19 .if !defined(MACHINE_ENDIAN)
  20 .  if exists(/usr/include/endian.h)
  21 _ENDIAN_H=      endian.h                        # Linux
  22 .  elif exists(/usr/include/sys/endian.h)
  23 _ENDIAN_H=      sys/endian.h                    # NetBSD>=1.5
  24 .  elif exists(/usr/include/machine/endian.h)
  25 _ENDIAN_H=      machine/endian.h                # NetBSD<1.5
  26 .  elif exists(/usr/include/sys/byteorder.h)
  27 _ENDIAN_H=      sys/byteorder.h                 # Solaris
  28 .  else
  29 _ENDIAN_H=      /dev/null
  30 .  endif
  31
  32 MACHINE_ENDIAN!=                                                        \
  33         { ${ECHO} "\#if defined(__sgi)";                                \
  34           ${ECHO} "\#  include <standards.h>";                          \
  35           ${ECHO} "\#endif";                                            \
  36           ${ECHO} "\#include <${_ENDIAN_H}>";                           \
  37           ${ECHO} "\#ifndef BYTE_ORDER";                                \
  38           ${ECHO} "\#ifdef _BIG_ENDIAN";                                \
  39           ${ECHO} "\#define BYTE_ORDER 4321";                           \
  40           ${ECHO} "\#else";                                             \
  41           ${ECHO} "\#define BYTE_ORDER 1234";                           \
  42           ${ECHO} "\#endif";                                            \
  43           ${ECHO} "\#endif";                                            \
  44           ${ECHO} "BYTE_ORDER"; } | ${CC} -E - |                        \
  45         { while read line; do                                           \
  46                 case $$line in                                          \
  47                 1234)   ${ECHO} "little"; exit 0 ;;                     \
  48                 4321)   ${ECHO} "big"; exit 0 ;;                        \
  49                 esac;                                                   \
  50           done;                                                         \
  51           ${ECHO} "unknown"; }
  52
  53 MAKEFLAGS+=     MACHINE_ENDIAN=${MACHINE_ENDIAN:Q}
  54 .endif