c99 goto past initialization

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You can ask gcc to warn you when you jump over a variable definition by using -Wjump-misses-init and then you can use -Werror (or, more precisely, -Werror=jump-misses-init) to force the users to deal with it. This warning is included in -Wc++-compat so the gcc developers are aware that the code behaves differently in C versus C++.

You could also change the code slightly:

int func()
{
    char *p1 = malloc(...);
    if (p1 == NULL)
        goto err_exit_1;

    char *p2 = malloc(...);
    if (p2 == NULL)
        goto err_exit_2;

    ...

err_exit_2:
    free(p2);
err_exit_1:
    free(p1);

    return -1;
}

… and just keep pairing labels with initialized variables. You’ll have the same problem with calling many other functions with unitialized variables, free just happens to be a more obvious one.

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