/* This software is licensed by the MIT License, see LICENSE file */
/*                                Copyright © 2022 Gregory Lirent */

#include <stdlib.h>
#include "__internal/include.h"
#undef malloc

void libcdsb_stack_init(stack_t* x) {
    memset(x, 0, sizeof(*x));
}


void libcdsb_stack_push(stack_t* x, void* value) {
    stack_t* n;

    if (x->value) {
        if (!(n = malloc(sizeof(*n))))
            abort();

        n->prev  = x->prev;
        n->value = x->value;
        x->prev  = n;
    }

    x->value = value;
}

void* libcdsb_stack_pop(stack_t* x) {

    stack_t* n;
    void*    v;

    v = x->value;

    if (x->prev) {
        n = x->prev;
        x->prev = n->prev;
        x->value = n->value;
        free(n);
    } else x->value = 0;

    return v;
}


void libcdsb_stack_flush(stack_t* stack) {
    stack_t* c;

    while (stack->prev) {
        c = stack->prev;
        stack->prev = c->prev;
        free(c);
    }

    stack->value = 0;
}