comparison src/libsamplerate-0.1.8/M4/endian.m4 @ 0:c7265573341e

Import initial set of sources

+dnl @synopsis AC_C_FIND_ENDIAN
+dnl
+dnl Determine endian-ness of target processor.
+dnl @version 1.1	Mar 03 2002
+dnl @author Erik de Castro Lopo <erikd AT mega-nerd DOT com>
+dnl
+dnl Majority written from scratch to replace the standard autoconf macro 
+dnl AC_C_BIGENDIAN. Only part remaining from the original it the invocation
+dnl of the AC_TRY_RUN macro.
+dnl
+dnl Permission to use, copy, modify, distribute, and sell this file for any 
+dnl purpose is hereby granted without fee, provided that the above copyright 
+dnl and this permission notice appear in all copies.  No representations are
+dnl made about the suitability of this software for any purpose.  It is 
+dnl provided "as is" without express or implied warranty.
+
+dnl Find endian-ness in the following way:
+dnl    1) Look in <endian.h>.
+dnl    2) If 1) fails, look in <sys/types.h> and <sys/param.h>.
+dnl    3) If 1) and 2) fails and not cross compiling run a test program.
+dnl    4) If 1) and 2) fails and cross compiling then guess based on target.
+
+AC_DEFUN([AC_C_FIND_ENDIAN],
+[AC_CACHE_CHECK(processor byte ordering, 
+	ac_cv_c_byte_order,
+
+# Initialize to unknown
+ac_cv_c_byte_order=unknown
+
+if test x$ac_cv_header_endian_h = xyes ; then
+
+	# First try <endian.h> which should set BYTE_ORDER.
+
+	[AC_TRY_LINK([
+		#include <endian.h>
+		#if BYTE_ORDER != LITTLE_ENDIAN
+			not big endian
+		#endif
+		], return 0 ;, 
+			ac_cv_c_byte_order=little
+		)]
+				
+	[AC_TRY_LINK([
+		#include <endian.h>
+		#if BYTE_ORDER != BIG_ENDIAN
+			not big endian
+		#endif
+		], return 0 ;, 
+			ac_cv_c_byte_order=big
+		)]
+
+	fi
+
+if test $ac_cv_c_byte_order = unknown ; then
+
+	[AC_TRY_LINK([
+		#include <sys/types.h>
+		#include <sys/param.h>
+		#if !BYTE_ORDER || !BIG_ENDIAN || !LITTLE_ENDIAN
+			bogus endian macros
+		#endif
+		], return 0 ;, 
+
+		[AC_TRY_LINK([
+			#include <sys/types.h>
+			#include <sys/param.h>
+			#if BYTE_ORDER != LITTLE_ENDIAN
+				not big endian
+			#endif
+			], return 0 ;, 
+				ac_cv_c_byte_order=little
+			)]
+				
+		[AC_TRY_LINK([
+			#include <sys/types.h>
+			#include <sys/param.h>
+			#if BYTE_ORDER != LITTLE_ENDIAN
+				not big endian
+			#endif
+			], return 0 ;, 
+				ac_cv_c_byte_order=little
+			)]
+
+		)]
+
+ 	fi
+
+if test $ac_cv_c_byte_order = unknown ; then
+	if test $cross_compiling = yes ; then
+		# This is the last resort. Try to guess the target processor endian-ness
+		# by looking at the target CPU type.	
+		[
+		case "$target_cpu" in
+			alpha* | i?86* | mipsel* | ia64*)
+				ac_cv_c_byte_order=little
+				;;
+			
+			m68* | mips* | powerpc* | hppa* | sparc*)
+				ac_cv_c_byte_order=big
+				;;
+	
+			esac
+		]
+	else
+		AC_TRY_RUN(
+		[[
+		int main (void) 
+		{	/* Are we little or big endian?  From Harbison&Steele.  */
+			union
+			{	long l ;
+				char c [sizeof (long)] ;
+			} u ;
+			u.l = 1 ;
+			return (u.c [sizeof (long) - 1] == 1);
+			}
+			]], , ac_cv_c_byte_order=big, 
+			)
+
+		AC_TRY_RUN(
+		[[int main (void) 
+		{	/* Are we little or big endian?  From Harbison&Steele.  */
+			union
+			{	long l ;
+				char c [sizeof (long)] ;
+			} u ;
+			u.l = 1 ;
+			return (u.c [0] == 1);
+			}]], , ac_cv_c_byte_order=little, 
+			)
+		fi	
+	fi
+
+)
+
+if test $ac_cv_c_byte_order = big ; then
+	ac_cv_c_big_endian=1
+	ac_cv_c_little_endian=0
+elif test $ac_cv_c_byte_order = little ; then
+	ac_cv_c_big_endian=0
+	ac_cv_c_little_endian=1
+else
+	ac_cv_c_big_endian=0
+	ac_cv_c_little_endian=0
+
+	AC_MSG_WARN([[*****************************************************************]])
+	AC_MSG_WARN([[*** Not able to determine endian-ness of target processor.       ]])
+	AC_MSG_WARN([[*** The constants CPU_IS_BIG_ENDIAN and CPU_IS_LITTLE_ENDIAN in  ]])
+	AC_MSG_WARN([[*** src/config.h may need to be hand editied.                    ]])
+	AC_MSG_WARN([[*****************************************************************]])
+	fi
+
+]
+)# AC_C_FIND_ENDIAN
+
+