Memory Leaks in C (MacOS)

Question

I'm a C programming student trying to find a way to detect memory leaks on MacOs Mojave.

I know about the existence of Valgrind, but it doesn't support current MacOs releases. After installing Apple Command Line Tools, I tried to run my C program with leaks tool but it doesn´t work... Running this very simple C program:

#include <stdio.h>

int main(int argc, char const *argv[]) {
  printf("Hello World\n");
  return 0;
}

Like this:

leaks ./a.out

This is the output:

leaks[875]: [fatal] unable to read input graph: The data 
 couldn’t be read because it isn’t in the correct format.

I don´t understand why this happens... How can I use the leaks tool?

Answer 1

i'm not sure is this helpful, but if the C program's status is in running, "leaks" would be available

#include <stdio.h>

int main(int argc, char const *argv[]) {
  printf("Hello World\n");
  getchar(); // just add to sleep
  return 0;
}

run above, then run belows in another terminal

leaks a.out

you can show related messages

Process:         a.out [8724]
Path:            /Users/USER/Documents/*/a.out
Load Address:    0x1078f2000
Identifier:      a.out
Version:         ???
Code Type:       X86-64
Parent Process:  bash [7876]
...

using [PID] is also available in this example

leaks 8724

---

here is a sample code that memory leak is detected,

#include <stdio.h>

void test()
{
  char* pTmp = (char*)malloc(sizeof(char)*1);
}

int main(int argc, char const *argv[]) {
  printf("Hello World\n");
  test();
  getchar();
  return 0;
}

Answer 2

Try this

#define malloc(X) my_malloc( X, __FILE__, __LINE__, __FUNCTION__)

void* my_malloc(size_t size, const char *file, int line, const char *func)
{

    void *p = malloc(size);
    printf ("Allocated = %s, %i, %s, %p[%li]\n", file, line, func, p, size);

    /*Link List functionality goes in here*/

    return p;
}

Answer 3

Unlike Valgrind, the leaks command is designed to find memory leaks in code that is already running when the "leaks" command is executed.

In order to get the functionality you are looking for you want the following command:

leaks -atExit -- ./a.out