-## --------------------------------- ##
-## Check if --with-regex was given. ##
-## --------------------------------- ##
-
-# serial 1
-
-# The idea is to distribute rx.[hc] and regex.[hc] together, for a while.
-# The WITH_REGEX symbol (which should also be documented in acconfig.h)
-# is used to decide which of regex.h or rx.h should be included in the
-# application. If `./configure --with-regex' is given (the default), the
-# package will use gawk's regex. If `./configure --without-regex', a
-# check is made to see if rx is already installed, as with newer Linux'es.
-# If not found, the package will use the rx from the distribution.
-# If found, the package will use the system's rx which, on Linux at least,
-# will result in a smaller executable file.
-
-AC_DEFUN(AM_WITH_REGEX,
-[AC_MSG_CHECKING(which of GNU rx or gawk's regex is wanted)
-AC_ARG_WITH(regex,
-[ --without-regex use GNU rx in lieu of gawk's regex for matching],
-[test "$withval" = yes && am_with_regex=1],
-[am_with_regex=1])
-if test -n "$am_with_regex"; then
- AC_MSG_RESULT(regex)
- AC_DEFINE(WITH_REGEX)
- AC_CACHE_CHECK([for GNU regex in libc], am_cv_gnu_regex,
- AC_TRY_LINK([], [extern int re_max_failures; re_max_failures = 1],
- am_cv_gnu_regex=yes, am_cv_gnu_regex=no))
- if test $am_cv_gnu_regex = no; then
- LIBOBJS="$LIBOBJS regex.o"
- fi
-else
- AC_MSG_RESULT(rx)
- AC_CHECK_FUNC(re_rx_search, , [LIBOBJS="$LIBOBJS rx.o"])
-fi
-AC_SUBST(LIBOBJS)dnl
+#serial 15
+
+dnl Initially derived from code in GNU grep.
+dnl Mostly written by Jim Meyering.
+
+AC_DEFUN([gl_REGEX],
+[
+ jm_INCLUDED_REGEX([lib/regex.c])
+])
+
+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 <string.h>
+#include <regex.h>
+ int
+ main ()
+ {
+ static struct re_pattern_buffer regex;
+ const char *s;
+ struct re_registers regs;
+ re_set_syntax (RE_SYNTAX_POSIX_EGREP);
+ memset (®ex, 0, sizeof (regex));
+ [s = re_compile_pattern ("a[[:@:>@:]]b\n", 9, ®ex);]
+ /* 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. */
+ memset (®ex, 0, sizeof (regex));
+ s = re_compile_pattern ("{1", 2, ®ex);
+
+ if (s)
+ exit (1);
+
+ /* The following example is derived from a problem report
+ against gawk from Jorge Stolfi <stolfi@ic.unicamp.br>. */
+ memset (®ex, 0, sizeof (regex));
+ s = re_compile_pattern ("[[anĂ¹]]*n", 7, ®ex);
+ if (s)
+ exit (1);
+
+ /* This should match, but doesn't for e.g. glibc-2.2.1. */
+ if (re_match (®ex, "an", 2, 0, ®s) != 2)
+ exit (1);
+
+ memset (®ex, 0, sizeof (regex));
+ s = re_compile_pattern ("x", 1, ®ex);
+ if (s)
+ exit (1);
+
+ /* The version of regex.c in e.g. GNU libc-2.2.93 didn't
+ work with a negative RANGE argument. */
+ if (re_search (®ex, "wxy", 3, 2, -2, ®s) != 1)
+ exit (1);
+
+ exit (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])
+ m4_syscmd([test -f $1])
+ ifelse(m4_sysval, 0,
+ [
+ AC_ARG_WITH(included-regex,
+ [ --without-included-regex don't compile regex; this is the default on
+ systems with version 2 of the GNU C library
+ (use with caution on other system)],
+ jm_with_regex=$withval,
+ jm_with_regex=$ac_use_included_regex)
+ if test "$jm_with_regex" = yes; then
+ AC_LIBOBJ(regex)
+ jm_PREREQ_REGEX
+ fi
+ ],
+ )
+ ]
+)
+
+# Prerequisites of lib/regex.c.
+AC_DEFUN([jm_PREREQ_REGEX],
+[
+ dnl FIXME: Maybe provide a btowc replacement someday: solaris-2.5.1 lacks it.
+ dnl FIXME: Check for wctype and iswctype, and and add -lw if necessary
+ dnl to get them.
+
+ dnl Persuade glibc <string.h> to declare mempcpy().
+ AC_REQUIRE([AC_GNU_SOURCE])
+
+ AC_REQUIRE([AC_FUNC_ALLOCA])
+ AC_REQUIRE([AC_HEADER_STDC])
+ AC_CHECK_HEADERS_ONCE(limits.h string.h wchar.h wctype.h)
+ AC_CHECK_FUNCS_ONCE(isascii mempcpy)
+ AC_CHECK_FUNCS(btowc)