Re: Fix regexp compiler with translation table

[Andreas Schwab <schwab at suse dot de>]

Jakub Jelinek <jakub@redhat.com> writes:

> On Wed, May 12, 2004 at 01:50:34PM +0200, Andreas Schwab wrote:
>> build_wcs_buffer didn't set mbs when a translation table is used.  This
>> can result in all kinds of random behaviour during parsing due to use of
>> uninitialized memory.
>> 
>> 2004-05-12  Andreas Schwab  <schwab@suse.de>
>> 
>> 	* posix/regex_internal.c (build_wcs_buffer): Also set pstr->mbs
>> 	when translating.
>
> Do you have a testcase?  It would be greatly appreciated.

Since it is about uninitialized memory it is hard to test reliably.  We
noticed it because "awk -Fbcd '{ print $1 }'" was generating a spurious
error on i686.  Here is a reduced test case, although it may not be
minimal, since it took some time until I fully understood the issue.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <regex.h>
#include <locale.h>
#include <time.h>

#define PATTERN "bcd"

char casetable[256];

int
main (void)
{
  struct re_pattern_buffer *r1, *r2;
  const char *s;
  int i;

  setlocale (LC_ALL, "");
  re_set_syntax (RE_SYNTAX_GNU_AWK);
  r1 = malloc (sizeof (*r1));
  memset (r1, 0, sizeof (*r1));
  r1->fastmap = malloc (256);
  s = re_compile_pattern (PATTERN, strlen (PATTERN), r1);
  if (s)
    {
      fprintf (stderr, "%s\n", s);
      exit (1);
    }
  r2 = malloc (sizeof (*r2));
  memset (r2, 0, sizeof (*r2));
  r2->fastmap = malloc (256);
  r2->translate = casetable;
  srand (time (0));
  for (i = 0; i < 256; i++)
    r2->fastmap[i] = rand () % 256;
  s = re_compile_pattern (PATTERN, strlen (PATTERN), r2);
  if (s)
    {
      fprintf (stderr, "%s\n", s);
      exit (1);
    }
  
  exit (0);
}


Andreas.

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Andreas Schwab, SuSE Labs, schwab@suse.de
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