c99 goto past initialization

Question

While debugging a crash, I came across this issue in some code:

int func()
{
    char *p1 = malloc(...);
    if (p1 == NULL)
        goto err_exit;

    char         


        

Answer 1

As AndreyT says, jumping over the initialisation is allowed by C99. You can fix your logic by using seperate labels for the two failures:

int func()
{
    char *p1 = malloc(...);
    if (p1 == NULL)
        goto err_exit_p1;

    char *p2 = malloc(...);
    if (p2 == NULL)
        goto err_exit;

    ...

err_exit:
    free(p2);
err_exit_p1:
    free(p1);

    return -1;
}

This is a standard pattern - "early errors" cause a jump to a later part of the error exit code.