From 6d9d80362f9932bbc87e162b8ef7df06c73e27e1 Mon Sep 17 00:00:00 2001
From: Xavier Del Campo Romero <xavi.dcr@tutanota.com>
Date: Sat, 7 Sep 2024 00:04:38 +0200
Subject: First commit

---
 src/routines/section/table.c | 117 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 src/routines/section/table.c

(limited to 'src/routines/section/table.c')

diff --git a/src/routines/section/table.c b/src/routines/section/table.c
new file mode 100644
index 0000000..56f62ae
--- /dev/null
+++ b/src/routines/section/table.c
@@ -0,0 +1,117 @@
+/*
+ * 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/log.h>
+#include <nw/routines.h>
+
+static enum nw_state get_maximum(struct nw_mod *const m)
+{
+    const struct nw_io_cfg *const cfg = &m->cfg.io;
+    struct nw_sm_tb *const tb = &m->sm.table;
+    struct nw_mod_out_mem *const ot = &m->out.table;
+    struct nw_sm_leb128 *const l = &tb->leb128;
+    const enum nw_state n = nwp_varuint32(cfg, l, &ot->max, cfg->user);
+
+    if (n)
+        return n;
+
+    m->next = nwp_section_exit;
+    return NW_AGAIN;
+}
+
+static enum nw_state get_initial(struct nw_mod *const m)
+{
+    const struct nw_io_cfg *const cfg = &m->cfg.io;
+    struct nw_sm_tb *const tb = &m->sm.table;
+    struct nw_mod_out_mem *const ot = &m->out.table;
+    struct nw_sm_leb128 *const l = &tb->leb128;
+    const enum nw_state n = nwp_varuint32(cfg, l, &ot->initial, cfg->user);
+
+    if (n)
+        return n;
+
+    m->next = tb->flags ? get_maximum : nwp_section_exit;
+    return NW_AGAIN;
+}
+
+static enum nw_state get_flags(struct nw_mod *const m)
+{
+    const struct nw_io_cfg *const cfg = &m->cfg.io;
+    struct nw_sm_tb *const tb = &m->sm.table;
+    struct nw_sm_leb128 *const l = &tb->leb128;
+    const enum nw_state n = nwp_varuint1(cfg, l, &tb->flags, cfg->user);
+
+    if (n)
+        return n;
+
+    m->next = get_initial;
+    return NW_AGAIN;
+}
+
+static enum nw_state get_element_type(struct nw_mod *const m)
+{
+    const struct nw_io_cfg *const cfg = &m->cfg.io;
+    struct nw_sm_tb *const tb = &m->sm.table;
+    struct nw_sm_leb128 *const l = &tb->leb128;
+    const enum nw_state n = nwp_varint7(cfg, l, &tb->elem_type, cfg->user);
+
+    if (n)
+        return n;
+    /* TODO: replace with enum? */
+    else if (tb->elem_type != 0x70)
+    {
+#ifdef NW_LOG
+        nwp_log("unexpected elem_type %hhx\n", (char)tb->elem_type);
+#endif
+        return NW_FATAL;
+    }
+
+    m->next = get_flags;
+    return NW_AGAIN;
+}
+
+static enum nw_state entry_loop(struct nw_mod *const m)
+{
+    const struct nw_sm_tb *const tb = &m->sm.table;
+
+    m->next = tb->entry_i < tb->count ? get_element_type : nwp_section_exit;
+    return NW_AGAIN;
+}
+
+static enum nw_state get_count(struct nw_mod *const m)
+{
+    const struct nw_io_cfg *const cfg = &m->cfg.io;
+    struct nw_sm_tb *const tb = &m->sm.table;
+    struct nw_sm_leb128 *const l = &tb->leb128;
+    const enum nw_state n = nwp_varuint32(cfg, l, &tb->count, cfg->user);
+
+    if (n)
+        return n;
+    else if (tb->count > 1u)
+    {
+#ifdef NW_LOG
+        nwp_log("got %lu tables, but only 1 supported by the MVP\n",
+            (unsigned long)tb->count);
+#endif
+        return NW_FATAL;
+    }
+
+    m->next = entry_loop;
+    return NW_AGAIN;
+}
+
+void nwp_section_table(struct nw_mod *const m)
+{
+    const struct nw_sm_tb t = {0};
+
+    m->sm.table = t;
+    m->next = get_count;
+}
-- 
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