Problem with __malloc_hooks :-(

[Andreas Jaeger <aj at suse dot de>]

The following program shows a problem I noticed with a current glibc
2.1.3 CVS versions and XEmacs [1]:

#define _GNU_SOURCE 
#include <stdlib.h>
#include <malloc.h>

int
main (int argc, char argv[])
{
  char *p;
  
  if (argc == 1)
    {
      __malloc_hook = NULL;
      __realloc_hook = NULL;
      __free_hook = NULL;
    }

  p = malloc (1000);
  printf ("%p\n", p);
  return 0;
}

Have a look at the output:

gromit:/tmp:[0]$ ./malloc 
(nil)
gromit:/tmp:[0]$ ./malloc 1
0x8049670

If __malloc_hook is NULL, malloc returns NULL.  The problem is that
malloc internally uses __malloc_hook and the current CVS version
doesn't call malloc before main any more :-(.

Wolfram, can you give me some feedback, please?

Thanks,
Andreas

Footnotes: 
[1]  XEmacs set __malloc_hook as one of its first instructions.

-- 
 Andreas Jaeger   
  SuSE Labs aj@suse.de	
   private aj@arthur.rhein-neckar.de