First commit

15 files changed, 429 insertions, 0 deletions

diff --git a/src/io/CMakeLists.txt b/src/io/CMakeLists.txt
new file mode 100644
index 0000000..b7c19cb
--- /dev/null
+++ b/src/io/CMakeLists.txt
@@ -0,0 +1,23 @@
+# 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/.
+
+target_sources(${PROJECT_NAME} PRIVATE
+    leb128.c
+    leuint32.c
+    leuint64.c
+    read.c
+    toleuint32.c
+    toleuint64.c
+    varint1.c
+    varint7.c
+    varint32.c
+    varint64.c
+    varuint1.c
+    varuint7.c
+    varuint32.c
+    varuint64.c
+)
diff --git a/src/io/leb128.c b/src/io/leb128.c
new file mode 100644
index 0000000..efb599b
--- /dev/null
+++ b/src/io/leb128.c
@@ -0,0 +1,75 @@
+/*
+ * 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/.
+ */
+
+
+/* The functions below is a (somewhat heavily) modified version of that
+ * provided by the wac project: https://github.com/kanaka/wac
+ *
+ * Copyright (C) Joel Martin <github@martintribe.org>
+ * The wac project is licensed under the MPL 2.0 (Mozilla Public License
+ * 2.0). The text of the MPL 2.0 license is included below and can be
+ * found at https://www.mozilla.org/MPL/2.0/
+ */
+
+#include <nanowasm/types.h>
+#include <nw/io.h>
+#include <nw/log.h>
+
+enum nw_state nwp_leb128(const struct nw_io_cfg *const cfg,
+    struct nw_sm_leb128 *const l, const unsigned maxbits, const int sign,
+    void *const user)
+{
+    unsigned char byte;
+
+    for (;;)
+    {
+        const int n = cfg->read(&byte, sizeof byte, user);
+        unsigned long v;
+
+        if (n < 0)
+            return NW_FATAL;
+        else if (!n)
+            return NW_AGAIN;
+
+        v = (unsigned long)(byte & 0x7f) << l->shift;;
+
+        if (l->shift < 32)
+            l->result.low |= v;
+        else
+            l->result.hi |= v;
+
+        l->shift += 7;
+
+        if (!(byte & 0x80))
+            break;
+        else if (++l->bcnt > (maxbits + 7u - 1u) / 7u)
+        {
+#ifdef NW_LOG
+            long offset;
+            const enum nw_state n = cfg->tell(&offset, cfg->user);
+
+            if (n)
+                return n;
+
+            nwp_log("leb128 overflow, offset=%#lx\n", (unsigned long)offset);
+#endif
+            return NW_FATAL;
+        }
+    }
+
+    if (sign && (l->shift < maxbits) && (byte & 0x40))
+    {
+        if (l->shift < 32)
+            l->result.low |= -1l << (l->shift);
+        else
+            l->result.hi |= -1l << (l->shift);
+    }
+
+    return NW_OK;
+}
diff --git a/src/io/leuint32.c b/src/io/leuint32.c
new file mode 100644
index 0000000..41a2e3b
--- /dev/null
+++ b/src/io/leuint32.c
@@ -0,0 +1,17 @@
+/*
+ * 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>
+
+unsigned long nwp_leuint32(const struct nw_leuint32 *const v)
+{
+    return v->v[0] | (v->v[1] << 8) | ((unsigned long)v->v[2] << 16)
+        | ((unsigned long)v->v[3] << 24);
+}
diff --git a/src/io/leuint64.c b/src/io/leuint64.c
new file mode 100644
index 0000000..6d3deb0
--- /dev/null
+++ b/src/io/leuint64.c
@@ -0,0 +1,24 @@
+/*
+ * 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>
+
+void nwp_leuint64(const struct nw_leuint64 *const v,
+    struct nw_ull *const ull)
+{
+    ull->low = v->v[0]
+        | (v->v[1] << 8)
+        | ((unsigned long)v->v[2] << 16ul)
+        | ((unsigned long)v->v[3] << 24ul);
+    ull->hi = v->v[4]
+        | (v->v[5] << 8)
+        | ((unsigned long) v->v[6] << 16ul)
+        | ((unsigned long)v->v[7] << 24ul);
+}
diff --git a/src/io/read.c b/src/io/read.c
new file mode 100644
index 0000000..d4222b5
--- /dev/null
+++ b/src/io/read.c
@@ -0,0 +1,31 @@
+/*
+ * 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 <stddef.h>
+
+enum nw_state nwp_io_read(const struct nw_io_cfg *const cfg,
+    struct nw_sm_io *const io, void *const user)
+{
+    void *const buf = (unsigned char *)io->buf + io->read;
+    const size_t rem = io->n - io->read;
+    const int n = cfg->read(buf, rem, user);
+
+    if (n < 0 || (!n && cfg->eof(user)))
+        return NW_FATAL;
+
+    if ((io->read += n) >= io->n)
+    {
+        io->read = 0;
+        return NW_OK;
+    }
+
+    return NW_AGAIN;
+}
diff --git a/src/io/toleuint32.c b/src/io/toleuint32.c
new file mode 100644
index 0000000..c1c96c7
--- /dev/null
+++ b/src/io/toleuint32.c
@@ -0,0 +1,19 @@
+/*
+ * 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>
+
+void nwp_toleuint32(const unsigned long v, struct nw_leuint32 *const r)
+{
+    r->v[0] = v;
+    r->v[1] = v >> 8;
+    r->v[2] = v >> 16;
+    r->v[3] = v >> 24;
+}
diff --git a/src/io/toleuint64.c b/src/io/toleuint64.c
new file mode 100644
index 0000000..57856c2
--- /dev/null
+++ b/src/io/toleuint64.c
@@ -0,0 +1,23 @@
+/*
+ * 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>
+
+void nwp_toleuint64(const struct nw_ull *const v, struct nw_leuint64 *const r)
+{
+    r->v[0] = v->low;
+    r->v[1] = v->low >> 8;
+    r->v[2] = v->low >> 16;
+    r->v[3] = v->low >> 24;
+    r->v[4] = v->hi;
+    r->v[5] = v->hi >> 8;
+    r->v[6] = v->hi >> 16;
+    r->v[7] = v->hi >> 24;
+}
diff --git a/src/io/varint1.c b/src/io/varint1.c
new file mode 100644
index 0000000..502765b
--- /dev/null
+++ b/src/io/varint1.c
@@ -0,0 +1,27 @@
+/*
+ * 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/types.h>
+#include <nw/io.h>
+
+enum nw_state nwp_varint1(const struct nw_io_cfg *const cfg,
+    struct nw_sm_leb128 *const l, nw_varint1 *const out, void *const user)
+{
+    const enum nw_state ret = nwp_leb128(cfg, l, 1, 1, user);
+
+    if (!ret)
+    {
+        static const struct nw_sm_leb128 ll;
+
+        *out = l->result.low;
+        *l = ll;
+    }
+
+    return ret;
+}
diff --git a/src/io/varint32.c b/src/io/varint32.c
new file mode 100644
index 0000000..f1c58cd
--- /dev/null
+++ b/src/io/varint32.c
@@ -0,0 +1,27 @@
+/*
+ * 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/types.h>
+#include <nw/io.h>
+
+enum nw_state nwp_varint32(const struct nw_io_cfg *const cfg,
+    struct nw_sm_leb128 *const l, nw_varint32 *const out, void *const user)
+{
+    const enum nw_state ret = nwp_leb128(cfg, l, 32, 1, user);
+
+    if (!ret)
+    {
+        static const struct nw_sm_leb128 ll;
+
+        *out = l->result.low;
+        *l = ll;
+    }
+
+    return ret;
+}
diff --git a/src/io/varint64.c b/src/io/varint64.c
new file mode 100644
index 0000000..5d0a3fd
--- /dev/null
+++ b/src/io/varint64.c
@@ -0,0 +1,28 @@
+/*
+ * 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/types.h>
+#include <nw/io.h>
+
+enum nw_state nwp_varint64(const struct nw_io_cfg *const cfg,
+    struct nw_sm_leb128 *const l, nw_varint64 *const out, void *const user)
+{
+    const enum nw_state ret = nwp_leb128(cfg, l, 64, 1, user);
+
+    if (!ret)
+    {
+        static const struct nw_sm_leb128 ll;
+
+        out->low = l->result.low;
+        out->hi = l->result.hi;
+        *l = ll;
+    }
+
+    return ret;
+}
diff --git a/src/io/varint7.c b/src/io/varint7.c
new file mode 100644
index 0000000..d22d25c
--- /dev/null
+++ b/src/io/varint7.c
@@ -0,0 +1,27 @@
+/*
+ * 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/types.h>
+#include <nw/io.h>
+
+enum nw_state nwp_varint7(const struct nw_io_cfg *const cfg,
+    struct nw_sm_leb128 *const l, nw_varint7 *const out, void *const user)
+{
+    const enum nw_state ret = nwp_leb128(cfg, l, 7, 1, user);
+
+    if (!ret)
+    {
+        static const struct nw_sm_leb128 ll;
+
+        *out = l->result.low;
+        *l = ll;
+    }
+
+    return ret;
+}
diff --git a/src/io/varuint1.c b/src/io/varuint1.c
new file mode 100644
index 0000000..2f9587c
--- /dev/null
+++ b/src/io/varuint1.c
@@ -0,0 +1,27 @@
+/*
+ * 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/types.h>
+#include <nw/io.h>
+
+enum nw_state nwp_varuint1(const struct nw_io_cfg *const cfg,
+    struct nw_sm_leb128 *const l, nw_varuint1 *const out, void *const user)
+{
+    const enum nw_state ret = nwp_leb128(cfg, l, 1, 0, user);
+
+    if (!ret)
+    {
+        static const struct nw_sm_leb128 ll;
+
+        *out = l->result.low;
+        *l = ll;
+    }
+
+    return ret;
+}
diff --git a/src/io/varuint32.c b/src/io/varuint32.c
new file mode 100644
index 0000000..1ad2c35
--- /dev/null
+++ b/src/io/varuint32.c
@@ -0,0 +1,27 @@
+/*
+ * 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/types.h>
+#include <nw/io.h>
+
+enum nw_state nwp_varuint32(const struct nw_io_cfg *const cfg,
+    struct nw_sm_leb128 *const l, nw_varuint32 *const out, void *const user)
+{
+    const enum nw_state ret = nwp_leb128(cfg, l, 32, 0, user);
+
+    if (!ret)
+    {
+        static const struct nw_sm_leb128 ll;
+
+        *out = l->result.low;
+        *l = ll;
+    }
+
+    return ret;
+}
diff --git a/src/io/varuint64.c b/src/io/varuint64.c
new file mode 100644
index 0000000..5538bb8
--- /dev/null
+++ b/src/io/varuint64.c
@@ -0,0 +1,27 @@
+/*
+ * 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/types.h>
+#include <nw/io.h>
+
+enum nw_state nwp_varuint64(const struct nw_io_cfg *const cfg,
+    struct nw_sm_leb128 *const l, nw_varuint64 *const out, void *const user)
+{
+    const enum nw_state ret = nwp_leb128(cfg, l, 64, 0, user);
+
+    if (!ret)
+    {
+        static const struct nw_sm_leb128 ll;
+
+        *out = l->result;
+        *l = ll;
+    }
+
+    return ret;
+}
diff --git a/src/io/varuint7.c b/src/io/varuint7.c
new file mode 100644
index 0000000..e3c2e91
--- /dev/null
+++ b/src/io/varuint7.c
@@ -0,0 +1,27 @@
+/*
+ * 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/types.h>
+#include <nw/io.h>
+
+enum nw_state nwp_varuint7(const struct nw_io_cfg *const cfg,
+    struct nw_sm_leb128 *const l, nw_varuint7 *const out, void *const user)
+{
+    const enum nw_state ret = nwp_leb128(cfg, l, 7, 0, user);
+
+    if (!ret)
+    {
+        static const struct nw_sm_leb128 ll;
+
+        *out = l->result.low;
+        *l = ll;
+    }
+
+    return ret;
+}