minor optimizations
[util-vserver.git] / util-vserver / m4 / ensc_dietlibc.m4
1 dnl $Id$
2
3 dnl Copyright (C) 2002 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
4 dnl  
5 dnl This program is free software; you can redistribute it and/or modify
6 dnl it under the terms of the GNU General Public License as published by
7 dnl the Free Software Foundation; version 2 of the License.
8 dnl  
9 dnl This program is distributed in the hope that it will be useful,
10 dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
11 dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 dnl GNU General Public License for more details.
13 dnl  
14 dnl You should have received a copy of the GNU General Public License
15 dnl along with this program; if not, write to the Free Software
16 dnl Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17
18 AC_DEFUN([_ENSC_DIETLIBC_C99],
19 [
20         AH_TEMPLATE([ENSC_DIETLIBC_C99], [Define to 1 if dietlibc supports C99])
21
22         AC_CACHE_CHECK([whether dietlibc supports C99], [ensc_cv_c_dietlibc_c99],
23         [
24                 _ensc_dietlibc_c99_old_CFLAGS=$CFLAGS
25                 _ensc_dietlibc_c99_old_CC=$CC
26
27                 CFLAGS="-std=c99"
28                 CC="${DIET:-diet} $CC"
29
30                 AC_LANG_PUSH(C)
31                 AC_COMPILE_IFELSE([/* */],[
32                         AC_COMPILE_IFELSE([
33                                 #include <stdint.h>
34                                 #include <sys/cdefs.h>
35                                 #if defined(inline)
36                                 #  error 'inline' badly defined
37                                 #endif
38                                 volatile uint64_t       a;
39                         ],
40                         [ensc_cv_c_dietlibc_c99=yes],
41                         [ensc_cv_c_dietlibc_c99=no])],
42                         [ensc_cv_c_dietlibc_c99='skipped (compiler does not support C99)'])
43                 AC_LANG_POP
44
45                 CC=$_ensc_dietlibc_c99_old_CC
46                 CFLAGS=$_ensc_dietlibc_c99_old_CFLAGS
47         ])
48
49         if test x"$ensc_cv_c_dietlibc_c99" = xyes; then
50                 AC_DEFINE(ENSC_DIETLIBC_C99,1)
51         fi
52 ])
53
54 dnl Usage: ENSC_ENABLE_DIETLIBC(<conditional>[,<min-version>])
55 dnl        <conditional> ... automake-conditional which will be set when
56 dnl                          dietlibc shall be enabled
57
58 AC_DEFUN([ENSC_ENABLE_DIETLIBC],
59 [
60         AC_MSG_CHECKING([whether to enable dietlibc])
61         AC_ARG_ENABLE([dietlibc],
62                       [AC_HELP_STRING([--disable-dietlibc],
63                                       [do not use dietlibc (default: use dietlibc)])],
64                       [case "$enableval" in
65                           yes)  use_dietlibc=forced;;
66                           no)   use_dietlibc=forced_no;;
67                           *)    AC_MSG_ERROR(['$enableval' is not a valid value for --enable-dietlibc]);;
68                        esac],
69                       [: ${DIET:=diet}
70                        which "$DIET" >/dev/null 2>/dev/null && use_dietlibc=detected || use_dietlibc=detected_no])
71
72         if test "$use_dietlibc" = detected -a '$2'; then
73             _dietlibc_ver=$(${DIET:-diet} -v 2>&1 | sed '1p;d')
74             _dietlibc_ver=${_dietlibc_ver##*dietlibc-}
75             _dietlibc_ver_maj=${_dietlibc_ver%%.*}
76             _dietlibc_ver_min=${_dietlibc_ver##*.}
77             _dietlibc_cmp=$2
78             _dietlibc_cmp_maj=${_dietlibc_cmp%%.*}
79             _dietlibc_cmp_min=${_dietlibc_cmp##*.}
80
81             let _dietlibc_ver=_dietlibc_ver_maj*1000+_dietlibc_ver_min 2>/dev/null || _dietlibc_ver=0
82             let _dietlibc_cmp=_dietlibc_cmp_maj*1000+_dietlibc_cmp_min
83
84             test $_dietlibc_ver -ge $_dietlibc_cmp || use_dietlibc=detected_old
85         fi
86
87         ensc_have_dietlibc=no
88         case x"$use_dietlibc" in
89             xdetected)
90                 AM_CONDITIONAL($1, true)
91                 AC_MSG_RESULT([yes (autodetected)])
92                 ensc_have_dietlibc=yes
93                 ;;
94             xforced)
95                 AM_CONDITIONAL($1, true)
96                 AC_MSG_RESULT([yes (forced)])
97                 ensc_have_dietlibc=yes
98                 ;;
99             xdetected_no)
100                 AM_CONDITIONAL($1, false)
101                 AC_MSG_RESULT([no (detected)])
102                 ;;
103             xdetected_old)
104                 AM_CONDITIONAL($1, false)
105                 AC_MSG_RESULT([no (too old; $2+ required)])
106                 ;;
107             xforced_no)
108                 AM_CONDITIONAL($1, false)
109                 AC_MSG_RESULT([no (forced)])
110                 ;;
111             *)
112                 AC_MSG_ERROR([internal error, use_dietlibc was "$use_dietlibc"])
113                 ;;
114         esac
115
116         if test x"$ensc_have_dietlibc" != xno; then
117                 _ENSC_DIETLIBC_C99
118         fi
119 ])