src/op/check/br_if.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

/*
 * nanowasm, a tiny WebAssembly/Wasm interpreter
 * Copyright (C) 2023-2024  Xavier Del Campo Romero
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#include <nanowasm/nw.h>
#include <nw/io.h>
#include <nw/log.h>
#include <nw/ops.h>

static enum nw_state get_relative_depth(struct nw_mod *const m)
{
    nw_varuint32 relative_depth;
    const struct nw_io_cfg *const cfg = &m->cfg.io;
    struct nw_sm_c *const c = &m->sm.code;
    struct nw_sm_leb128 *const l = &c->leb128;
    const enum nw_state n = nwp_varuint32(cfg, l, &relative_depth);

    if (n)
        return n;
    else if (relative_depth >= c->fn.blocks)
    {
        LOG("%s: invalid relative depth %lu\n", __func__,
            (unsigned long)relative_depth);
        return NW_FATAL;
    }

    m->next = c->next;
    return NW_AGAIN;
}

void nwp_op_check_br_if(struct nw_mod *const m)
{
    m->next = get_relative_depth;
}