Use AC_C_BIGENDIAN for detecting $HOST endianness

* AC_C_BIGENDIAN is fully cross-compile aware

David Seifert committed 9 years ago

Commit d2e7cb51 parent ca40d093 files · +13 −162Browse files

Unified · Split

3 files

Win32/config.h +2 −2
configure.ac +11 −5
m4/endian.m4 +0 −155

@@ -43,10 +43,10 @@ · 42 unmodified lines
43	/* Target processor clips on positive float to int conversion. */	43	/* Target processor clips on positive float to int conversion. */
44	#define CPU_CLIPS_POSITIVE 0	44	#define CPU_CLIPS_POSITIVE 0
45		45
46	/* Target processor is big endian. */	46	/* Host processor is big endian. */
47	#define CPU_IS_BIG_ENDIAN 0	47	#define CPU_IS_BIG_ENDIAN 0
48		48
49	/* Target processor is little endian. */	49	/* Host processor is little endian. */
50	#define CPU_IS_LITTLE_ENDIAN 1	50	#define CPU_IS_LITTLE_ENDIAN 1
51		51
52	/* Set to 1 to enable debugging. */	52	/* Set to 1 to enable debugging. */

configure.ac+11−5

 #====================================================================================
 # Determine endian-ness of target processor.
-AC_C_FIND_ENDIAN
+AC_C_BIGENDIAN([
+		dnl big-endian
+		ac_cv_c_big_endian=1
+		ac_cv_c_little_endian=0
+	], [
+		dnl little-endian
+		ac_cv_c_big_endian=0
+		ac_cv_c_little_endian=1
+	])
-AC_DEFINE_UNQUOTED(CPU_IS_BIG_ENDIAN, ${ac_cv_c_big_endian},
+AC_DEFINE_UNQUOTED([CPU_IS_BIG_ENDIAN], [${ac_cv_c_big_endian}], [Host processor is big endian.])
-        [Target processor is big endian.])
+AC_DEFINE_UNQUOTED([CPU_IS_LITTLE_ENDIAN], [${ac_cv_c_little_endian}], [Host processor is little endian.])
-AC_DEFINE_UNQUOTED(CPU_IS_LITTLE_ENDIAN, ${ac_cv_c_little_endian},
-        [Target processor is little endian.])
 #====================================================================================
 # Check for functions.

m4/endian.m4+0−155

@@ -1,155 +0,0 @@
1	dnl @synopsis AC_C_FIND_ENDIAN
2	dnl
3	dnl Determine endian-ness of target processor.
4	dnl @version 1.1 Mar 03 2002
5	dnl @author Erik de Castro Lopo <erikd AT mega-nerd DOT com>
6	dnl
7	dnl Majority written from scratch to replace the standard autoconf macro
8	dnl AC_C_BIGENDIAN. Only part remaining from the original it the invocation
9	dnl of the AC_TRY_RUN macro.
10	dnl
11	dnl Permission to use, copy, modify, distribute, and sell this file for any
12	dnl purpose is hereby granted without fee, provided that the above copyright
13	dnl and this permission notice appear in all copies. No representations are
14	dnl made about the suitability of this software for any purpose. It is
15	dnl provided "as is" without express or implied warranty.
16
17	dnl Find endian-ness in the following way:
18	dnl 1) Look in <endian.h>.
19	dnl 2) If 1) fails, look in <sys/types.h> and <sys/param.h>.
20	dnl 3) If 1) and 2) fails and not cross compiling run a test program.
21	dnl 4) If 1) and 2) fails and cross compiling then guess based on target.
22
23	AC_DEFUN([AC_C_FIND_ENDIAN],
24	[AC_CACHE_CHECK(processor byte ordering,
25	ac_cv_c_byte_order,
26
27	# Initialize to unknown
28	ac_cv_c_byte_order=unknown
29
30	if test x$ac_cv_header_endian_h = xyes ; then
31
32	# First try <endian.h> which should set BYTE_ORDER.
33
34	[AC_TRY_LINK([
35	#include <endian.h>
36	#if BYTE_ORDER != LITTLE_ENDIAN
37	not big endian
38	#endif
39	], return 0 ;,
40	ac_cv_c_byte_order=little
41	)]
42
43	[AC_TRY_LINK([
44	#include <endian.h>
45	#if BYTE_ORDER != BIG_ENDIAN
46	not big endian
47	#endif
48	], return 0 ;,
49	ac_cv_c_byte_order=big
50	)]
51
52	fi
53
54	if test $ac_cv_c_byte_order = unknown ; then
55
56	[AC_TRY_LINK([
57	#include <sys/types.h>
58	#include <sys/param.h>
59	#if !BYTE_ORDER \|\| !BIG_ENDIAN \|\| !LITTLE_ENDIAN
60	bogus endian macros
61	#endif
62	], return 0 ;,
63
64	[AC_TRY_LINK([
65	#include <sys/types.h>
66	#include <sys/param.h>
67	#if BYTE_ORDER != LITTLE_ENDIAN
68	not big endian
69	#endif
70	], return 0 ;,
71	ac_cv_c_byte_order=little
72	)]
73
74	[AC_TRY_LINK([
75	#include <sys/types.h>
76	#include <sys/param.h>
77	#if BYTE_ORDER != LITTLE_ENDIAN
78	not big endian
79	#endif
80	], return 0 ;,
81	ac_cv_c_byte_order=little
82	)]
83
84	)]
85
86	fi
87
88	if test $ac_cv_c_byte_order = unknown ; then
89	if test $cross_compiling = yes ; then
90	# This is the last resort. Try to guess the target processor endian-ness
91	# by looking at the target CPU type.
92	[
93	case "$target_cpu" in
94	alpha* \| i?86* \| mipsel* \| ia64*)
95	ac_cv_c_byte_order=little
96	;;
97
98	m68* \| mips* \| powerpc* \| hppa* \| sparc*)
99	ac_cv_c_byte_order=big
100	;;
101
102	esac
103	]
104	else
105	AC_TRY_RUN(
106	[[
107	int main (void)
108	{ /* Are we little or big endian? From Harbison&Steele. */
109	union
110	{ long l ;
111	char c [sizeof (long)] ;
112	} u ;
113	u.l = 1 ;
114	return (u.c [sizeof (long) - 1] == 1);
115	}
116	]], , ac_cv_c_byte_order=big,
117	)
118
119	AC_TRY_RUN(
120	[[int main (void)
121	{ /* Are we little or big endian? From Harbison&Steele. */
122	union
123	{ long l ;
124	char c [sizeof (long)] ;
125	} u ;
126	u.l = 1 ;
127	return (u.c [0] == 1);
128	}]], , ac_cv_c_byte_order=little,
129	)
130	fi
131	fi
132
133	)
134
135	if test $ac_cv_c_byte_order = big ; then
136	ac_cv_c_big_endian=1
137	ac_cv_c_little_endian=0
138	elif test $ac_cv_c_byte_order = little ; then
139	ac_cv_c_big_endian=0
140	ac_cv_c_little_endian=1
141	else
142	ac_cv_c_big_endian=0
143	ac_cv_c_little_endian=0
144
145	AC_MSG_WARN([[*****************************************************************]])
146	AC_MSG_WARN([[*** Not able to determine endian-ness of target processor. ]])
147	AC_MSG_WARN([[*** The constants CPU_IS_BIG_ENDIAN and CPU_IS_LITTLE_ENDIAN in ]])
148	AC_MSG_WARN([[*** src/config.h may need to be hand editied. ]])
149	AC_MSG_WARN([[*****************************************************************]])
150	fi
151
152	]
153	)# AC_C_FIND_ENDIAN
154
155

Use AC_C_BIGENDIAN for detecting $HOST endianness

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