regex.m4 revision 1.1.1.1 
1#serial 12
2
3dnl Initially derived from code in GNU grep.
4dnl Mostly written by Jim Meyering.
5
6dnl Usage: jm_INCLUDED_REGEX([lib/regex.c])
7dnl
8AC_DEFUN([jm_INCLUDED_REGEX],
9  [
10    dnl Even packages that don't use regex.c can use this macro.
11    dnl Of course, for them it doesn't do anything.
12
13    # Assume we'll default to using the included regex.c.
14    ac_use_included_regex=yes
15
16    # However, if the system regex support is good enough that it passes the
17    # the following run test, then default to *not* using the included regex.c.
18    # If cross compiling, assume the test would fail and use the included
19    # regex.c.  The first failing regular expression is from `Spencer ere
20    # test #75' in grep-2.3.
21    AC_CACHE_CHECK([for working re_compile_pattern],
22		   jm_cv_func_working_re_compile_pattern,
23      AC_TRY_RUN(
24[#include <stdio.h>
25#include <regex.h>
26	  int
27	  main ()
28	  {
29	    static struct re_pattern_buffer regex;
30	    const char *s;
31	    struct re_registers regs;
32	    re_set_syntax (RE_SYNTAX_POSIX_EGREP);
33	    [s = re_compile_pattern ("a[[:@:>@:]]b\n", 9, &regex);]
34	    /* This should fail with _Invalid character class name_ error.  */
35	    if (!s)
36	      exit (1);
37
38	    /* This should succeed, but doesn't for e.g. glibc-2.1.3.  */
39	    s = re_compile_pattern ("{1", 2, &regex);
40
41	    if (s)
42	      exit (1);
43
44	    /* The following example is derived from a problem report
45               against gawk from Jorge Stolfi <stolfi@ic.unicamp.br>.  */
46	    s = re_compile_pattern ("[[an�]]*n", 7, &regex);
47	    if (s)
48	      exit (1);
49
50	    /* This should match, but doesn't for e.g. glibc-2.2.1.  */
51	    if (re_match (&regex, "an", 2, 0, &regs) != 2)
52	      exit (1);
53
54	    exit (0);
55	  }
56	],
57	       jm_cv_func_working_re_compile_pattern=yes,
58	       jm_cv_func_working_re_compile_pattern=no,
59	       dnl When crosscompiling, assume it's broken.
60	       jm_cv_func_working_re_compile_pattern=no))
61    if test $jm_cv_func_working_re_compile_pattern = yes; then
62      ac_use_included_regex=no
63    fi
64
65    test -n "$1" || AC_MSG_ERROR([missing argument])
66    m4_syscmd([test -f $1])
67    ifelse(m4_sysval, 0,
68      [
69	AC_ARG_WITH(included-regex,
70	[  --without-included-regex don't compile regex; this is the default on
71                          systems with version 2 of the GNU C library
72                          (use with caution on other system)],
73		    jm_with_regex=$withval,
74		    jm_with_regex=$ac_use_included_regex)
75	if test "$jm_with_regex" = yes; then
76	  AC_LIBOBJ(regex)
77	fi
78      ],
79    )
80  ]
81)
82