Memtrack

Memtrack is a utility that overloads malloc, realloc, and free functions to detect memory leaks.

It does not detect double free, it can only detect memory leaks.

Example

#include <stdio.h>
#include <memtrack.h>

int main(void) {
    void *p = malloc(10);
    p = realloc(p, 20);
    p = realloc(p, 30);

    void *q = malloc(20);
    q = realloc(q, 40);
    q = realloc(q, 60);

    memtrack_print_leaks();
    return 0;
}

Expected output:

memtrack: leak detected, allocated 10 bytes in example.c:5
    reallocated to 20 bytes in example.c:6
    reallocated to 30 bytes in example.c:7

memtrack: leak detected, allocated 20 bytes in example.c:9
    reallocated to 40 bytes in example.c:10
    reallocated to 60 bytes in example.c:11

memtrack leak summary:
    2 items leaked
    90 bytes leaked

memtrack_iter_leaks example

#include <stdio.h>

#include "memtrack.h"

int example_init_callback(void *userdata, size_t malloc_count) {
    printf("init: malloc_count = %zu\n", malloc_count);
    // 0 = success, continue iteration
    // non-zero = failure, abort iteration
    return 0;
}

int example_malloc_callback(void *userdata, size_t realloc_count, size_t size, const char *file, int line) {
    printf("malloc: realloc_count = %zu, size = %zu, %s:%i\n", realloc_count, size, file, line);
    return 0;
}

int example_realloc_callback(void *userdata, size_t new_size, const char *file, int line) {
    printf("realloc: new_size = %zu, %s:%i\n", new_size, file, line);
    return 0;
}

int main() {
    void *p = malloc(123);
    p = realloc(p, 456);

    void *q = malloc(654);
    q = realloc(q, 321);

    memtrack_iter_info info = {
        .userdata = NULL,
        .init_callback = example_init_callback,
        .malloc_callback = example_malloc_callback,
        .realloc_callback = example_realloc_callback
    };
    memtrack_iter_leaks(&info);
    return 0;
}

Expected output:

init: malloc_count = 2
malloc: realloc_count = 1, size = 123, example2.c:23
realloc: new_size = 456, example2.c:24
malloc: realloc_count = 1, size = 654, example2.c:26
realloc: new_size = 321, example2.c:27