-## --------------------------------- ##
-## 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"
+#serial 28
+
+# Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005 Free
+# Software Foundation, Inc.
+#
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+dnl Initially derived from code in GNU grep.
+dnl Mostly written by Jim Meyering.
+
+AC_PREREQ([2.50])
+
+AC_DEFUN([gl_REGEX],
+[
+ AC_LIBSOURCES(
+ [regcomp.c, regex.c, regex.h,
+ regex_internal.c, regex_internal.h, regexec.c])
+
+ AC_ARG_WITH([included-regex],
+ [AC_HELP_STRING([--without-included-regex],
+ [don't compile regex; this is the default on
+ systems with recent-enough versions of the GNU C
+ Library (use with caution on other systems)])])
+
+ case $with_included_regex in
+ yes|no) ac_use_included_regex=$with_included_regex
+ ;;
+ '')
+ # 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],
+ [gl_cv_func_re_compile_pattern_broken],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [AC_INCLUDES_DEFAULT
+ #include <regex.h>],
+ [[static struct re_pattern_buffer regex;
+ const char *s;
+ struct re_registers regs;
+ /* Use the POSIX-compliant spelling with leading REG_,
+ rather than the traditional GNU spelling with leading RE_,
+ so that we reject older libc implementations. */
+ re_set_syntax (REG_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 does not 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 ("[an\371]*n", 7, ®ex);
+ if (s)
+ exit (1);
+
+ /* This should match, but does not 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 did not
+ work with a negative RANGE argument. */
+ if (re_search (®ex, "wxy", 3, 2, -2, ®s) != 1)
+ exit (1);
+
+ /* The version of regex.c in older versions of gnulib
+ ignored REG_IGNORE_CASE (which was then called RE_ICASE).
+ Detect that problem too. */
+ memset (®ex, 0, sizeof (regex));
+ re_set_syntax (REG_SYNTAX_EMACS | REG_IGNORE_CASE);
+ s = re_compile_pattern ("x", 1, ®ex);
+ if (s)
+ exit (1);
+
+ if (re_search (®ex, "WXY", 3, 0, 3, ®s) < 0)
+ exit (1);
+
+ /* REG_STARTEND was added to glibc on 2004-01-15.
+ Reject older versions. */
+ if (! REG_STARTEND)
+ exit (1);
+
+ exit (0);]])],
+ [gl_cv_func_re_compile_pattern_broken=no],
+ [gl_cv_func_re_compile_pattern_broken=yes],
+ dnl When crosscompiling, assume it is broken.
+ [gl_cv_func_re_compile_pattern_broken=yes])])
+ ac_use_included_regex=$gl_cv_func_re_compile_pattern_broken
+ ;;
+ *) AC_MSG_ERROR([Invalid value for --with-included-regex: $with_included_regex])
+ ;;
+ esac
+
+ if test $ac_use_included_regex = yes; then
+ AC_LIBOBJ([regex])
+ gl_PREREQ_REGEX
fi
-else
- AC_MSG_RESULT(rx)
- AC_CHECK_FUNC(re_rx_search, , [LIBOBJS="$LIBOBJS rx.o"])
-fi
-AC_SUBST(LIBOBJS)dnl
+])
+
+# Prerequisites of lib/regex.c and lib/regex_internal.c.
+AC_DEFUN([gl_PREREQ_REGEX],
+[
+ AC_REQUIRE([AC_GNU_SOURCE])
+ AC_REQUIRE([gl_C_RESTRICT])
+ AC_REQUIRE([AM_LANGINFO_CODESET])
+ AC_CHECK_HEADERS_ONCE([locale.h wchar.h wctype.h])
+ AC_CHECK_FUNCS_ONCE([isblank mbrtowc mempcpy wcrtomb wcscoll])
])