First commit

1 files changed, 78 insertions, 0 deletions

diff --git a/src/op/check/br_table.c b/src/op/check/br_table.c
new file mode 100644
index 0000000..d104669
--- /dev/null
+++ b/src/op/check/br_table.c
@@ -0,0 +1,78 @@
+/*
+ * nanowasm, a tiny WebAssembly/Wasm interpreter
+ * Copyright (C) 2023-2025  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/ops.h>
+
+static enum nw_state loop(struct nw_mod *m);
+
+static enum nw_state get_default_target(struct nw_mod *const m)
+{
+    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;
+    nw_varuint32 target;
+    const enum nw_state n = nwp_varuint32(cfg, l, &target, cfg->user);
+
+    if (n)
+        return n;
+
+    m->next = c->next;
+    return NW_AGAIN;
+}
+
+static enum nw_state get_entry(struct nw_mod *const m)
+{
+    const struct nw_io_cfg *const cfg = &m->cfg.io;
+    struct nw_sm_c *const c = &m->sm.code;
+    struct nw_sm_c_t *const t = &c->u.target;
+    struct nw_sm_leb128 *const l = &c->leb128;
+    nw_varuint32 entry;
+    const enum nw_state n = nwp_varuint32(cfg, l, &entry, cfg->user);
+
+    if (n)
+        return n;
+
+    t->i++;
+    m->next = loop;
+    return NW_AGAIN;
+}
+
+static enum nw_state loop(struct nw_mod *const m)
+{
+    const struct nw_sm_c *const c = &m->sm.code;
+    const struct nw_sm_c_t *const t = &c->u.target;
+
+    m->next = t->i >= t->count ? get_default_target : get_entry;
+    return NW_AGAIN;
+}
+
+static enum nw_state get_target_count(struct nw_mod *const m)
+{
+    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;
+    struct nw_sm_c_t *const t = &c->u.target;
+    const enum nw_state n = nwp_varuint32(cfg, l, &t->count, cfg->user);
+
+    if (n)
+        return n;
+
+    m->next = loop;
+    return NW_AGAIN;
+}
+
+void nwp_op_check_br_table(struct nw_mod *const m)
+{
+    static const struct nw_sm_c_t t = {0};
+
+    m->sm.code.u.target = t;
+    m->next = get_target_count;
+}