/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2017 Jason King
 * Copyright 2019, Joyent, Inc.
 */

#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include "demangle-sys.h"
#include "demangle_int.h"

void *
zalloc(sysdem_ops_t *ops, size_t len)
{
        void *p = ops->alloc(len);

        if (p != NULL)
                (void) memset(p, 0, len);

#ifdef DEBUG
        /*
         * In normal operation, we should never exhaust memory.  Either
         * something's wrong, or the system is so hosed that aborting
         * shouldn't hurt anything, and it gives us a more useful stack
         * trace.
         */
        if (p == NULL)
                abort();
#endif

        return (p);
}

void *
xcalloc(sysdem_ops_t *ops, size_t n, size_t elsize)
{
        uint64_t sz;

        if (mul_overflow(n, elsize, &sz)) {
                errno = ENOMEM;
                return (NULL);
        }

#ifndef _LP64
        if (sz > SIZE_MAX) {
                errno = ENOMEM;
                return (NULL);
        }
#endif

        return (zalloc(ops, sz));
}
void
xfree(sysdem_ops_t *ops, void *p, size_t len)
{
        if (p == NULL || len == 0)
                return;

        ops->free(p, len);
}

void *
xrealloc(sysdem_ops_t *ops, void *p, size_t oldsz, size_t newsz)
{
        if (newsz == oldsz)
                return (p);

        VERIFY3U(newsz, >, oldsz);

        void *temp = zalloc(ops, newsz);

        if (temp == NULL)
                return (NULL);

        if (oldsz > 0) {
                (void) memcpy(temp, p, oldsz);
                xfree(ops, p, oldsz);
        }

        return (temp);
}

char *
xstrdup(sysdem_ops_t *ops, const char *src)
{
        size_t len = strlen(src);
        char *str = zalloc(ops, len + 1);

        if (str == NULL)
                return (NULL);

        /* zalloc(len+1) guarantees this will be NUL-terminated */
        (void) memcpy(str, src, len);
        return (str);
}

/*ARGSUSED*/
static void
def_free(void *p, size_t len)
{
        free(p);
}

static sysdem_ops_t i_sysdem_ops_default = {
        .alloc = malloc,
        .free = def_free
};
sysdem_ops_t *sysdem_ops_default = &i_sysdem_ops_default;