Use proper quoting so brackets appear in the test program.

[gnulib.git] / m4 / regex.m4

diff --git a/m4/regex.m4 b/m4/regex.m4
index e5468c6..66b39c3 100644 (file)
--- a/m4/regex.m4
+++ b/m4/regex.m4
@@ -1,21 +1,81 @@
-#serial 2
+#serial 10
 
-dnl Derived from code in GNU grep.
+dnl Initially derived from code in GNU grep.
+dnl Mostly written by Jim Meyering.
 
-AC_DEFUN(jm_WITH_REGEX,
+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.
 
-    syscmd([test -f lib/regex.c])
-    ifelse(sysval, 0,
+    # 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;
+           struct re_registers regs;
+           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);
+
+           if (s)
+             exit (1);
+
+           /* The following example is derived from a problem report
+               against gawk from Jorge Stolfi <stolfi@ic.unicamp.br>.  */
+           s = re_compile_pattern ("[[anù]]*n", 7, &regex);
+           if (s)
+             exit (1);
+
+           /* This should match, but doesn't for e.g. glibc-2.2.1.  */
+           if (re_match (&regex, "an", 2, 0, &regs) != 2)
+             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 $1])
+    ifelse(m4_sysval, 0,
       [
        AC_ARG_WITH(included-regex,
-           [  --without-included-regex don't compile regex (use with caution)],
+       [  --without-included-regex don't compile regex; this is the default on
+                          systems with version 2 of the GNU C library
+                          (use with caution on other system)],
                    jm_with_regex=$withval,
-                   jm_with_regex=yes)
+                   jm_with_regex=$ac_use_included_regex)
        if test "$jm_with_regex" = yes; then
-         LIBOBJS="$LIBOBJS regex.o"
+         AC_LIBOBJ(regex)
        fi
       ],
     )