Use Gnulib's `regex' module.

This should help with regex portability, as reported in
<http://bugs.gnu.org/10684> for Darwin 8.11.

* m4/gnulib-cache.m4 (gl_MODULES): Add `regex'.

* configure.ac: Remove header checks for regex.h, rxposix.h, and
  rx/rxposix.h.  Remove check for the `regcomp' function.  Remove
  definition of `HAVE_REGCOMP'.  Define `ENABLE_REGEX'.

* libguile/init.c: Check for `ENABLE_REGEX' instead of `HAVE_REGCOMP'.

* libguile/regex-posix.c: Always include <regex.h>.  Remove #ifdefs for
  rxposix.h and co.

1 files changed, 39 insertions, 0 deletions

diff --git a/lib/btowc.c b/lib/btowc.c
new file mode 100644
index 000000000..485e99554
--- /dev/null
+++ b/lib/btowc.c
@@ -0,0 +1,39 @@
+/* Convert unibyte character to wide character.
+   Copyright (C) 2008, 2010-2012 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2008.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <wchar.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+wint_t
+btowc (int c)
+{
+  if (c != EOF)
+    {
+      char buf[1];
+      wchar_t wc;
+
+      buf[0] = c;
+      if (mbtowc (&wc, buf, 1) >= 0)
+        return wc;
+    }
+  return WEOF;
+}