coreutils/m4/regex.m4
2000-07-02 15:14:04 +00:00

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2.2 KiB
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#serial 8
dnl Initially derived from code in GNU grep.
dnl Mostly written by Jim Meyering.
dnl Usage: jm_INCLUDED_REGEX([lib/regex.c])
dnl
AC_DEFUN(jm_INCLUDED_REGEX,
[
dnl Even packages that don't use regex.c can use this macro.
dnl Of course, for them it doesn't do anything.
# Assume we'll default to using the included regex.c.
ac_use_included_regex=yes
# However, if the system regex support is good enough that it passes the
# the following run test, then default to *not* using the included regex.c.
# If cross compiling, assume the test would fail and use the included
# regex.c. The first failing regular expression is from `Spencer ere
# test #75' in grep-2.3.
AC_CACHE_CHECK([for working re_compile_pattern],
jm_cv_func_working_re_compile_pattern,
AC_TRY_RUN(
[#include <stdio.h>
#include <regex.h>
int
main ()
{
static struct re_pattern_buffer regex;
const char *s;
re_set_syntax (RE_SYNTAX_POSIX_EGREP);
/* Add this third left square bracket, [, to balance the
three right ones below. Otherwise autoconf-2.14 chokes. */
s = re_compile_pattern ("a[[:]:]]b\n", 9, &regex);
/* This should fail with _Invalid character class name_ error. */
if (!s)
exit (1);
/* This should succeed, but doesn't for e.g. glibc-2.1.3. */
s = re_compile_pattern ("{1", 2, &regex);
exit (s ? 1 : 0);
}
],
jm_cv_func_working_re_compile_pattern=yes,
jm_cv_func_working_re_compile_pattern=no,
dnl When crosscompiling, assume it's broken.
jm_cv_func_working_re_compile_pattern=no))
if test $jm_cv_func_working_re_compile_pattern = yes; then
ac_use_included_regex=no
fi
test -n "$1" || AC_MSG_ERROR([missing argument])
syscmd([test -f $1])
ifelse(sysval, 0,
[
AC_ARG_WITH(included-regex,
[ --without-included-regex don't compile regex; this is the default on
systems with version 2 of the GNU C library
(use with caution on other system)],
jm_with_regex=$withval,
jm_with_regex=$ac_use_included_regex)
if test "$jm_with_regex" = yes; then
AC_LIBOBJ(regex)
fi
],
)
]
)