Add a run-time Test for proper operation of re_compile_pattern.

diff --git a/m4/regex.m4 b/m4/regex.m4
index 2a638d6..b7a0389 100644 (file)
--- a/m4/regex.m4
+++ b/m4/regex.m4
@@ -1,6 +1,7 @@
-#serial 3
+#serial 4

 
 

-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,
   [
 
 AC_DEFUN(jm_WITH_REGEX,
   [


@@ -9,18 +10,58 @@ AC_DEFUN(jm_WITH_REGEX,
     dnl Even packages that don't use regex.c can use this macro.
     dnl Of course, for them it doesn't do anything.
 
     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])
+    # By default, don't use the included regex.c on systems with a version
+    # of glibc 2 that's new enough to pass the following run test.
+    # If cross compiling, assume the test would fail and use the included
+    # regex.c.  The failing regular expression is from `Spencer ere test
+    # #75' in grep-2.2f.
+    ac_use_included_regex=yes
+
+    if test "$ac_cv_glibc" = yes; then
+      # Without this run-test, on older glibc2 systems we'd end up
+      # using the buggy system regex.
+      AC_CACHE_CHECK([for working re_compile_pattern],
+                     jm_cv_func_working_re_compile_pattern,
+       AC_TRY_RUN(
+         changequote(<<, >>)dnl
+         <<
+#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.  */
+             exit (s ? 0 : 1);
+           }
+         >>,
+         changequote([, ])dnl
+
+                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
+    fi
+
+    test -n "$1" || AC_MSG_ERROR([missing argument])
+    syscmd([test -f $1])

     ifelse(sysval, 0,
       [
     ifelse(sysval, 0,
       [

-       # By default, don't use the included regex.c on systems with glibc 2
-       test "$ac_cv_glibc" = yes && default=no || default=yes

 
        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,
 
        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=$default)
+                   jm_with_regex=$ac_use_included_regex)

        if test "$jm_with_regex" = yes; then
          LIBOBJS="$LIBOBJS regex.o"
        fi
        if test "$jm_with_regex" = yes; then
          LIBOBJS="$LIBOBJS regex.o"
        fi