First commit

1 files changed, 243 insertions, 0 deletions

diff --git a/src/routines/break.c b/src/routines/break.c
new file mode 100644
index 0000000..3ee94a1
--- /dev/null
+++ b/src/routines/break.c
@@ -0,0 +1,243 @@
+/*
+ * 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/io.h>
+#include <nw/log.h>
+#include <nw/routines.h>
+
+static enum nw_state get_pc(struct nw_interp *);
+
+static enum nw_state seek_dst(struct nw_interp *const i)
+{
+    const struct nw_i_sm_break *const b = &i->sm.brk;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const unsigned long dst = nwp_leuint32(&b->dst);
+    const enum nw_state n = cfg->seek(dst, cfg->user);
+
+    if (n)
+        return n;
+
+    nwp_interp_resume(i);
+    return NW_AGAIN;
+}
+
+static enum nw_state skip(struct nw_interp *const i)
+{
+    struct nw_i_sm_break *const b = &i->sm.brk;
+    const unsigned long n_labels = nwp_leuint32(&b->n);
+
+    if (++b->label_i >= n_labels)
+    {
+        static const char *const exc = "no label found";
+
+        i->exception = exc;
+#ifdef NW_LOG
+        nwp_log("%s from offset: %ld\n", exc, b->pc);
+#endif
+        return NW_FATAL;
+    }
+    else
+    {
+        struct nw_sm_io io = {0};
+
+        io.buf = &b->lpc;
+        io.n = sizeof b->lpc;
+        b->io = io;
+        i->next = get_pc;
+    }
+
+    return NW_AGAIN;
+}
+
+static enum nw_state get_dst(struct nw_interp *const i)
+{
+    struct nw_i_sm_break *const b = &i->sm.brk;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const unsigned long pc = nwp_leuint32(&b->lpc);
+    const enum nw_state n = nwp_io_read(cfg, &b->io, cfg->user);
+
+    if (n)
+        return n;
+    else if (pc == b->pc)
+        i->next = seek_dst;
+    else
+        return skip(i);
+
+    return NW_AGAIN;
+}
+
+static enum nw_state get_pc(struct nw_interp *const i)
+{
+    struct nw_i_sm_break *const b = &i->sm.brk;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const enum nw_state n = nwp_io_read(cfg, &b->io, cfg->user);
+
+    if (n)
+        return n;
+    else
+    {
+        struct nw_sm_io io = {0};
+
+        io.buf = &b->dst;
+        io.n = sizeof b->dst;
+        b->io = io;
+        i->next = get_dst;
+    }
+
+    return NW_AGAIN;
+}
+
+static enum nw_state get_n(struct nw_interp *const i)
+{
+    struct nw_i_sm_break *const b = &i->sm.brk;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const enum nw_state n = nwp_io_read(cfg, &b->io, cfg->user);
+
+    if (n)
+        return n;
+    else if (!nwp_leuint32(&b->n))
+    {
+        static const char *const exc = "function has no labels";
+
+        i->exception = exc;
+#ifdef NW_LOG
+        nwp_log("%s\n", exc);
+#endif
+        return NW_FATAL;
+    }
+    else
+    {
+        struct nw_sm_io io = {0};
+
+        io.buf = &b->lpc;
+        io.n = sizeof b->lpc;
+        b->io = io;
+    }
+
+    i->next = get_pc;
+    return NW_AGAIN;
+}
+
+static enum nw_state seek_start(struct nw_interp *const i)
+{
+    struct nw_i_sm_break *const b = &i->sm.brk;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const unsigned long offset = nwp_leuint32(&b->offset);
+    const enum nw_state n = cfg->seek(offset, cfg->user);
+
+    if (n)
+        return n;
+    else
+    {
+        struct nw_sm_io io = {0};
+
+        io.buf = &b->n;
+        io.n = sizeof b->n;
+        b->io = io;
+        i->next = get_n;
+    }
+
+    return NW_AGAIN;
+}
+
+static enum nw_state get_start(struct nw_interp *const i)
+{
+    struct nw_i_sm_break *const b = &i->sm.brk;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const enum nw_state n = nwp_io_read(cfg, &b->io, cfg->user);
+
+    if (n)
+        return n;
+
+    i->next = seek_start;
+    return NW_AGAIN;
+}
+
+static enum nw_state seek_lo(struct nw_interp *const i)
+{
+    const struct nw_mod *const m = i->cfg.m;
+    struct nw_i_sm_break *const b = &i->sm.brk;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    long offset = m->c_sections[NW_CUSTOM_LO];
+    enum nw_state n;
+
+    if (!offset)
+    {
+        static const char *const exc = "nw_lo section not found";
+
+        i->exception = exc;
+#ifdef NW_LOG
+        nwp_log("%s\n", exc);
+#endif
+        return NW_FATAL;
+    }
+    else if (i->fr.fn.index < m->import_count)
+    {
+        static const char *const exc = "invalid function index";
+
+        i->exception = exc;
+#ifdef NW_LOG
+        nwp_log("%s: %lu\n", exc, (unsigned long)i->fr.fn.index);
+#endif
+        return NW_FATAL;
+    }
+
+    offset += sizeof b->offset * (i->fr.fn.index - m->import_count);
+
+    if ((n = cfg->seek(offset, cfg->user)))
+        return n;
+    else
+    {
+        struct nw_sm_io io = {0};
+
+        io.buf = &b->offset;
+        io.n = sizeof b->offset;
+        b->io = io;
+        i->next = get_start;
+    }
+
+    return NW_AGAIN;
+}
+
+static enum nw_state tell(struct nw_interp *const i)
+{
+    struct nw_i_sm_break *const b = &i->sm.brk;
+    const struct nw_io_cfg *const cfg = &i->cfg.io;
+    const enum nw_state n = cfg->tell(&b->pc, cfg->user);
+
+    if (n)
+        return n;
+    else if (i->fr.block_i < b->relative_depth)
+    {
+        static const char *const exc = "relative depth exceeds block level";
+
+        i->exception = exc;
+#ifdef NW_LOG
+        nwp_log("%s, rdepth: %lu, blvl: %lu\n", exc,
+            (unsigned long)i->fr.block_i, (unsigned long)b->relative_depth);
+#endif
+        return NW_FATAL;
+    }
+
+    i->fr.block_i -= b->relative_depth;
+    i->next = seek_lo;
+    return NW_AGAIN;
+}
+
+void nwp_break(struct nw_interp *const i, const nw_varuint32 relative_depth)
+{
+    const struct nw_i_sm_break b = {0};
+    struct nw_i_sm_break *const pb = &i->sm.brk;
+
+    *pb = b;
+    pb->relative_depth = relative_depth;
+    i->next = tell;
+}