First commit1st

1 files changed, 202 insertions, 0 deletions

diff --git a/src/interp/routines/find_export.c b/src/interp/routines/find_export.c
new file mode 100644
index 0000000..f82e5f9
--- /dev/null
+++ b/src/interp/routines/find_export.c
@@ -0,0 +1,202 @@
+/*
+ * 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 <nanowasm/types.h>
+#include <nw/interp.h>
+#include <nw/io.h>
+#include <nw/log.h>
+#include <nw/routines.h>
+#include <inttypes.h>
+#include <string.h>
+
+static enum nw_state entry_loop(struct nw_interp *i);
+
+static enum nw_state get_index(struct nw_interp *const i)
+{
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    struct nw_i_sm_exp *const e = &i->sm.export;
+    struct nw_sm_leb128 *const l = &e->leb128;
+    const enum nw_state n = nwp_varuint32(cfg, l, &e->index);
+
+    if (n)
+        return n;
+
+    i->next = e->next;
+    return NW_AGAIN;
+}
+
+static enum nw_state get_kind(struct nw_interp *const i)
+{
+    uint8_t kind;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    struct nw_sm_io io = {.buf = &kind, .n = sizeof kind};
+    const enum nw_state n = nwp_io_read(cfg, &io);
+
+    if (n)
+        return n;
+    else if (kind >= NW_KINDS)
+    {
+        static const char exc[] = "invalid export kind";
+
+        i->exception = exc;
+        LOG("%s: %s: %" PRIu8 "\n", __func__, exc, kind);
+        return NW_FATAL;
+    }
+
+    struct nw_i_sm_exp *const e = &i->sm.export;
+
+    e->kind = kind;
+    i->next = get_index;
+    return NW_AGAIN;
+}
+
+static enum nw_state skip_index(struct nw_interp *const i)
+{
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    struct nw_i_sm_exp *const e = &i->sm.export;
+    struct nw_sm_leb128 *const l = &e->leb128;
+    const enum nw_state n = nwp_varuint32(cfg, l, &(nw_varuint32){0});
+
+    if (n)
+        return n;
+
+    e->entry_i++;
+    i->next = entry_loop;
+    return NW_AGAIN;
+}
+
+static enum nw_state skip_kind(struct nw_interp *const i)
+{
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    struct nw_sm_io io = {.buf = &(uint8_t){0}, .n = sizeof (uint8_t)};
+    const enum nw_state n = nwp_io_read(cfg, &io);
+
+    if (n)
+        return n;
+
+    i->next = skip_index;
+    return NW_AGAIN;
+}
+
+static enum nw_state skip_field_str(struct nw_interp *const i)
+{
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const struct nw_i_sm_exp *const e = &i->sm.export;
+    const long offset = e->len - e->len_i;
+    const enum nw_state n = cfg->seek(offset, NW_SEEK_CUR, cfg->user);
+
+    if (n)
+        return n;
+
+    i->next = skip_kind;
+    return NW_AGAIN;
+}
+
+static enum nw_state compare(struct nw_interp *const i)
+{
+    uint8_t byte;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    struct nw_i_sm_exp *const e = &i->sm.export;
+    struct nw_sm_io io = {.buf = &byte, .n = sizeof byte};
+    const enum nw_state n = nwp_io_read(cfg, &io);
+
+    if (n)
+        return n;
+    else if (byte != e->sym[e->len_i++])
+        i->next = skip_field_str;
+    else if (e->len_i >= e->len)
+        i->next = get_kind;
+
+    return NW_AGAIN;
+}
+
+static enum nw_state get_len(struct nw_interp *const i)
+{
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    struct nw_i_sm_exp *const e = &i->sm.export;
+    struct nw_sm_leb128 *const l = &e->leb128;
+    const enum nw_state n = nwp_varuint32(cfg, l, &e->len);
+
+    if (n)
+        return n;
+    else if (e->len != strlen(e->sym))
+        i->next = skip_field_str;
+    else
+        i->next = compare;
+
+    return NW_AGAIN;
+}
+
+static enum nw_state entry_loop(struct nw_interp *const i)
+{
+    struct nw_i_sm_exp *const e = &i->sm.export;
+
+    if (e->entry_i >= e->count)
+    {
+        static const char exc[] = "failed to find symbol";
+
+        i->exception = exc;
+        LOG("%s: %s: %s\n", __func__, exc, e->sym);
+        return NW_FATAL;
+    }
+
+    e->len_i = 0;
+    i->next = get_len;
+    return NW_AGAIN;
+}
+
+static enum nw_state get_count(struct nw_interp *const i)
+{
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    struct nw_i_sm_exp *const e = &i->sm.export;
+    struct nw_sm_leb128 *const l = &e->leb128;
+    const enum nw_state n = nwp_varuint32(cfg, l, &e->count);
+
+    if (n)
+        return n;
+
+    i->next = entry_loop;
+    return NW_AGAIN;
+}
+
+static enum nw_state seek(struct nw_interp *const i)
+{
+    const struct nw_mod *const m = i->cfg.m;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+
+    if (!m->sections[NW_SECTION_EXPORT])
+    {
+        static const char exc[] = "section not found";
+
+        i->exception = exc;
+        LOG("%s: %s: %s\n", __func__, exc, "export");
+        return NW_FATAL;
+    }
+
+    const enum nw_state n = cfg->seek(m->sections[NW_SECTION_EXPORT],
+        NW_SEEK_SET, cfg->user);
+
+    if (n)
+        return n;
+
+    i->next = get_count;
+    return NW_AGAIN;
+}
+
+void nwp_find_export(struct nw_interp *i, const char *sym,
+    enum nw_state (*const next)(struct nw_interp *))
+{
+    i->next = seek;
+    i->sm.export = (const struct nw_i_sm_exp)
+    {
+        .sym = sym,
+        .next = next
+    };
+}