Comments on mudflap

[Eyal Lebedinsky]

Doug Graham wrote:
> Frank Eigler suggested that I send this to the list.  His comments
> follow mine.

[trimmed]

> One other minor thing.  On the Fedora Core 1 Linux system that I'm
> using for testing (with GLIBC 2.3.2), I get a mudflap violation every
> time I use one of the ctype routines (isdigit, isupper, islower, etc.)
> I assume that's because there is some array in the library that is
> accessed by the ctype macros, but which hasn't been registered with
> the mudflap runtime.  For the tests above, I've been using my own ctype
> replacement so as to avoid this problem.
> 
> Regards,
> Doug.
> 
> --------------------
> 
> From: "Frank Ch. Eigler" <fche@redhat.com>
> 
> Hi, Doug -

[trimmed]

> With respect to ctype, yes, these types of static arrays used by
> libc macros pose a problem.  One solution would require adding a few
> autoconf-sensitive lines to mf-runtime.c to register these during
> initialization much as environment variables and std* FILE objects are.
> 
> - FChE

The abovementioned patch should be simple, just add the last three
__mf_register call statements to this function in
	gcc/libmudflap/mf-runtime.c.
Do include <ctype.h> somewhere at the top.

int
__wrap_main (int argc, char* argv[])
{
   extern char **environ;
   extern int main ();
   static int been_here = 0;

   if (__mf_opts.heur_std_data && ! been_here)
     {
       unsigned i;

       been_here = 1;
       __mf_register (argv, sizeof(char *)*(argc+1), __MF_TYPE_STATIC, "argv[]");
       for (i=0; i<argc; i++)
         {
           unsigned j = strlen (argv[i]);
           __mf_register (argv[i], j+1, __MF_TYPE_STATIC, "argv element");
         }

       for (i=0; ; i++)
         {
           char *e = environ[i];
           unsigned j;
           if (e == NULL) break;
           j = strlen (environ[i]);
           __mf_register (environ[i], j+1, __MF_TYPE_STATIC, "environ element");
         }
       __mf_register (environ, sizeof(char *)*(i+1), __MF_TYPE_STATIC, "environ[]");

       __mf_register (& errno, sizeof (errno), __MF_TYPE_STATIC, "errno area");

       __mf_register (stdin,  sizeof (*stdin),  __MF_TYPE_STATIC, "stdin");
       __mf_register (stdout, sizeof (*stdout), __MF_TYPE_STATIC, "stdout");
       __mf_register (stderr, sizeof (*stderr), __MF_TYPE_STATIC, "stderr");

       /* ctype.h tables */
       __mf_register (__ctype_b, sizeof (unsigned short int)*256,
                 __MF_TYPE_STATIC, "__ctype_b");
       __mf_register (__ctype_tolower, sizeof (__int32_t)*256,
                 __MF_TYPE_STATIC, "__ctype_tolower");
       __mf_register (__ctype_toupper, sizeof (__int32_t)*256,
                 __MF_TYPE_STATIC, "__ctype_toupper");
     }

#ifdef PIC
   return main (argc, argv, environ);
#else
   return __real_main (argc, argv, environ);
#endif
}




-- 
--
Eyal Lebedinsky (eyal@eyal.emu.id.au) <http://samba.org/eyal/>