Valgrind showing memory leak for printf and unused blocks

Question

#include 
#include 
#include 

int main(int argc, char *argv[]){
  char *str = malloc(sizeof(char)*5);
  str = strcpy(         


        

Answer 1

Until the Valgrind team prioritizes OS X, you can safely assume that it will not give correct results on Apple systems running OS X versions newer than 10.7.

On my Mavericks (10.9.5) machine, I still get the following warning from Valgrind (3.9.0)

WARNING: Support on MacOS 10.8/10.9 is experimental and mostly broken.
WARNING: Expect incorrect results, assertions and crashes.
WARNING: In particular, Memcheck on 32-bit programs will fail to
WARNING: detect any errors associated with heap-allocated data.

For what it's worth, Valgrind 3.10.0 shows no leaks on my Debian Jessie installation.

Answer 2

It isn't telling you that there is a leak:

==77215== LEAK SUMMARY:
==77215==    definitely lost: 0 bytes in 0 blocks
==77215==    indirectly lost: 0 bytes in 0 blocks
==77215==      possibly lost: 0 bytes in 0 blocks
==77215==    still reachable: 4,096 bytes in 1 blocks
==77215==         suppressed: 25,115 bytes in 373 blocks

it's telling you that there is a block which is still reachable; whether or not there is a leak is dependent on your definition of 'leak'. What it does mean is that there is a pointer to the block somewhere.

Refer to Still Reachable Leak detected by Valgrind for more information.