First commit

1 files changed, 104 insertions, 0 deletions

diff --git a/src/routines/find_param.c b/src/routines/find_param.c
new file mode 100644
index 0000000..eeae86d
--- /dev/null
+++ b/src/routines/find_param.c
@@ -0,0 +1,104 @@
+/*
+ * 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>
+#include <nw/types.h>
+
+static enum nw_state seek_pc(struct nw_interp *const i)
+{
+    struct nw_find_param *const fp = i->state;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const enum nw_state n = cfg->seek(fp->pc, cfg->user);
+
+    if (n)
+        return n;
+
+    fp->out.addr = i->fr.fr_start - fp->sz;
+    i->next = fp->next;
+    return NW_AGAIN;
+}
+
+static enum nw_state get_param_type(struct nw_interp *const i)
+{
+    nw_varint7 type;
+    struct nw_find_param *const fp = i->state;
+    struct nw_sm_leb128 *const l = &fp->leb128;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const enum nw_state n = nwp_varint7(cfg, l, &type, cfg->user);
+    enum nw_type param_type;
+    size_t sz;
+
+    if (n)
+        return n;
+    else if (nwp_get_type(type, &param_type)
+        || nwp_type_sz(param_type, &sz))
+    {
+        static const char *const exc = "invalid param type";
+
+        i->exception = exc;
+#ifdef NW_LOG
+        nwp_log("%s: %#x\n", exc, (unsigned)type);
+#endif
+        return NW_FATAL;
+    }
+
+    if (fp->param_i == fp->index)
+        fp->out.type = param_type;
+
+    if (fp->param_i >= fp->index)
+        fp->sz += sz;
+
+    if (++fp->param_i >= i->fr.fn.param_count)
+        i->next = seek_pc;
+
+    return NW_AGAIN;
+}
+
+static enum nw_state seek_param_types(struct nw_interp *const i)
+{
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const long offset = i->fr.fn.param_types;
+    const enum nw_state n = cfg->seek(offset, cfg->user);
+
+    if (n)
+        return n;
+
+    i->next = get_param_type;
+    return NW_AGAIN;
+}
+
+static enum nw_state tell(struct nw_interp *const i)
+{
+    struct nw_find_param *const fp = i->state;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const enum nw_state n = cfg->tell(&fp->pc, cfg->user);
+
+    if (n)
+        return n;
+
+    i->next = seek_param_types;
+    return NW_AGAIN;
+}
+
+void nwp_find_param(struct nw_interp *const i, struct nw_find_param *const f,
+    const nw_varuint32 index, enum nw_state (*const next)(struct nw_interp *),
+    void *const args)
+{
+    const struct nw_find_param fp = {0};
+
+    *f = fp;
+    f->index = index;
+    f->next = next;
+    i->state = f;
+    i->next = tell;
+    i->args = args;
+}