First commit

1 files changed, 67 insertions, 0 deletions

diff --git a/src/op/end.c b/src/op/end.c
new file mode 100644
index 0000000..9eb575d
--- /dev/null
+++ b/src/op/end.c
@@ -0,0 +1,67 @@
+/*
+ * 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/interp.h>
+#include <nw/log.h>
+#include <nw/ops.h>
+#include <nw/routines.h>
+
+static enum nw_state run(struct nw_interp *const i)
+{
+    const struct nw_i_sm_end *const e = &i->sm.end;
+    struct nw_frame *const f = &i->fr;
+
+    if (i->set)
+        return NW_OK;
+    else if (f->block_i)
+    {
+        f->block_i--;
+        nwp_interp_resume(i);
+    }
+    else
+    {
+        const long expected = f->start + f->body_size;
+
+        if (e->offset != expected)
+        {
+            static const char *const exc = "unexpected end";
+
+#ifdef NW_LOG
+            nwp_log("%s\n", exc);
+#endif
+            i->exception = exc;
+            return NW_FATAL;
+        }
+        else if (f->child)
+            nwp_unwind(i);
+    }
+
+    return NW_AGAIN;
+}
+
+static enum nw_state get_offset(struct nw_interp *const i)
+{
+    struct nw_i_sm_end *const e = &i->sm.end;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const enum nw_state n = cfg->tell(&e->offset, cfg->user);
+
+    if (n)
+        return n;
+
+    return run(i);
+}
+
+void nwp_op_end(struct nw_interp *const i)
+{
+    static const struct nw_i_sm_end e = {0};
+
+    i->sm.end = e;
+    i->next = get_offset;
+}