FreeBSD Port: valgrind-snapshot-352_3

[Charles Swiger]

On Apr 6, 2005, at 1:20 PM, Sebastien Poirier wrote:
> I would like to know if your port is aimed for Mac OS X too.
> We are looking for a memory debug tools for Mac OS X and Valgrind 
> seems to be the best for this purpose.

Hi, Sebastian--

The "leaks" command which comes with OS X is pretty darn useful:

% cat /tmp/foo.c
#include <stdlib.h>

void bad(int size)
{
     int x;
     char *leaky;

     leaky = malloc(size);
     for (x = 0; x < size; x++)
         leaky[x] = (char) x + 'a';
     leaky = NULL;
}

main()
{
     bad(10);
     bad(20);
     sleep(100);
}

% MallocStackLogging=1 /tmp/foo &
malloc[16451]: recording stacks using standard recorder

% leaks foo
Process 16451: 10 nodes malloced for 1 KB
Process 16451: 2 leaks for 48 total leaked bytes.
Leak: 0x00100150  size=32       string 'abcdefghijklmnopqrst'
         Call stack: [thread 1a27]: | 0x0 | start | _start | main | bad 
| malloc | malloc_zone_malloc
Leak: 0x00100140  size=16       string 'abcdefghij'
         Call stack: [thread 1a27]: | 0x0 | start | _start | main | bad 
| malloc | malloc_zone_malloc

Even if you don't run with that ENV variable set, simply seeing the 
size and the contents of leaked memory is often enough to help ("do you 
know how big your structures are?" :-), but having the call stack 
responsible for the allocation of the memory is a godsend.

-- 
-Chuck