Comment by davidwf

It's a very common pattern for C memory allocation checking. A public example I know off the top of my head can be seen here: https://github.com/zedshaw/learn-c-the-hard-way-lectures/blo... (the implementation of the CHECK macro). That's in a C tutorial but I've implemented a version of that macro frequently.

Let's say you need to dynamically allocate two buffers in a function and want to make sure they are freed at the end of your call. You can use this macro like so:

  int two_bufs(int n, int m) {
    int *buf_1 = NULL;
    int *buf_2 = NULL;
    buf_1 = calloc(n, sizeof(int));
    CHECK(buf_1);
    buf_2 = calloc(m, sizeof(int));
    CHECK(buf_2);
 
    // ... lots of cool things with buf_1 and buf_2

  error:
    free(buf_1);
    free(buf_2); // Safe if null

  }