First commit

1 files changed, 346 insertions, 0 deletions

diff --git a/src/section/global.c b/src/section/global.c
new file mode 100644
index 0000000..eff2e0b
--- /dev/null
+++ b/src/section/global.c
@@ -0,0 +1,346 @@
+/*
+ * 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 <nw/log.h>
+#include <nw/sections.h>
+#include <nanowasm/nw.h>
+#include <nw/interp.h>
+#include <nw/types.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+struct global_type
+{
+    bool mutable;
+    enum value_type type;
+
+    union global_value
+    {
+        int32_t i32;
+        int64_t i64;
+        float f32;
+        double f64;
+    } value;
+};
+
+static int get_i32(const struct nw_interp *const i,
+    union global_value *const value)
+{
+    if (i->stack_i != sizeof value->i32)
+    {
+        LOG("%s: expected %zu used stack bytes, got %zu\n",
+            __func__, i->stack_i, sizeof value->i32);
+        return -1;
+    }
+
+    value->i32 = *(const int32_t *)i->cfg.stack.buf;
+    return 0;
+}
+
+static int get_i64(const struct nw_interp *const i,
+    union global_value *const value)
+{
+    if (i->stack_i != sizeof value->i64)
+    {
+        LOG("%s: expected %zu used stack bytes, got %zu\n",
+            __func__, i->stack_i, sizeof value->i64);
+        return -1;
+    }
+
+    value->i64 = *(const int64_t *)i->cfg.stack.buf;
+    return 0;
+}
+
+static int get_f32(const struct nw_interp *const i,
+    union global_value *const value)
+{
+    if (i->stack_i != sizeof value->f32)
+    {
+        LOG("%s: expected %zu used stack bytes, got %zu\n",
+            __func__, i->stack_i, sizeof value->f32);
+        return -1;
+    }
+
+    value->f32 = *(const float *)i->cfg.stack.buf;
+    return 0;
+}
+
+static int get_f64(const struct nw_interp *const i,
+    union global_value *const value)
+{
+    if (i->stack_i != sizeof value->f64)
+    {
+        LOG("%s: expected %zu used stack bytes, got %zu\n",
+            __func__, i->stack_i, sizeof value->f64);
+        return -1;
+    }
+
+    value->f64 = *(const double *)i->cfg.stack.buf;
+    return 0;
+}
+
+static int get_value(const struct nw_interp *const i,
+    const enum value_type type, union global_value *const value)
+{
+    static int (*const get[])(const struct nw_interp *, union global_value *) =
+    {
+        [VALUE_TYPE_I32] = get_i32,
+        [VALUE_TYPE_I64] = get_i64,
+        [VALUE_TYPE_F32] = get_f32,
+        [VALUE_TYPE_F64] = get_f64
+    };
+
+    if (get[type](i, value))
+    {
+        LOG("%s: get failed with type %d\n", __func__, type);
+        return -1;
+    }
+
+    return 0;
+}
+
+static int check_global_type(FILE *const f, struct global_type *const g)
+{
+    const struct nw_interp_cfg cfg =
+    {
+        .stack = NW_BUF(sizeof (union global_value))
+    };
+
+    struct nw_interp i;
+    enum value_type vtype;
+    varint7 content_type;
+    varuint1 mutability;
+    union global_value value;
+
+    if (varint7_read(f, &content_type))
+    {
+        LOG("%s: varint7_read failed\n", __func__);
+        return -1;
+    }
+    else if (get_value_type(content_type, &vtype))
+    {
+        LOG("%s: get_value_type failed\n", __func__);
+        return -1;
+    }
+    else if (varuint1_read(f, &mutability))
+    {
+        LOG("%s: varuint1_read failed\n", __func__);
+        return -1;
+    }
+    else if (interp_start(&cfg, f, &i))
+    {
+        LOG("%s: interp_start failed\n", __func__);
+        return -1;
+    }
+    else if (interp_run_limited(&i, &interp_initexpr_set))
+    {
+        LOG("%s: interp_run failed\n", __func__);
+        return -1;
+    }
+    else if (get_value(&i, vtype, &value))
+    {
+        LOG("%s: get_value failed\n", __func__);
+        return -1;
+    }
+
+    *g = (const struct global_type)
+    {
+        .mutable = mutability,
+        .type = vtype,
+        .value = value
+    };
+
+    return 0;
+}
+
+static int set_i32(struct nw_interp *const i, void *const dst,
+    const struct global_type *const g)
+{
+    *(int32_t *)dst = g->value.i32;
+    return 0;
+}
+
+static int set_i64(struct nw_interp *const i, void *const dst,
+    const struct global_type *const g)
+{
+    *(int64_t *)dst = g->value.i64;
+    return 0;
+}
+
+static int set_f32(struct nw_interp *const i, void *const dst,
+    const struct global_type *const g)
+{
+    *(float *)dst = g->value.f32;
+    return 0;
+}
+
+static int set_f64(struct nw_interp *const i, void *const dst,
+    const struct global_type *const g)
+{
+    *(double *)dst = g->value.f64;
+    return 0;
+}
+
+static int add_global(struct nw_interp *const i,
+    const struct global_type *const g)
+{
+    const struct nw_gframe f =
+    {
+        .mutable = g->mutable,
+        .type = g->type
+    };
+
+    const size_t sz = sizeof f + get_type_size(g->type),
+        max = i->cfg.global.n;
+
+    if (max < sz || i->global_i > max - sz)
+    {
+        LOG("%s: global memory overflow\n", __func__);
+        i->exception = "global memory overflow";
+        return -1;
+    }
+
+    void *const buf = (char *)i->cfg.global.buf + i->global_i;
+    struct nw_gframe *const dst = buf;
+
+    if (i->gfp)
+        i->gfp->next = dst;
+
+    *dst = f;
+
+    static int (*const set[])(struct nw_interp *, void *,
+        const struct global_type *) =
+    {
+        [VALUE_TYPE_I32] = set_i32,
+        [VALUE_TYPE_I64] = set_i64,
+        [VALUE_TYPE_F32] = set_f32,
+        [VALUE_TYPE_F64] = set_f64
+    };
+
+    if (set[g->type](i, dst + 1, g))
+    {
+        LOG("%s: set failed with type %d\n", __func__, g->type);
+        return -1;
+    }
+
+    i->global_i += sz;
+    i->gfp = dst;
+    return 0;
+}
+
+static int check_global_types(FILE *const f,
+    struct nw_interp *const in)
+{
+    varuint32 count;
+
+    if (varuint32_read(f, &count))
+    {
+        LOG("%s: varuint32_read failed\n", __func__);
+        return -1;
+    }
+
+    for (varuint32 i = 0; i < count; i++)
+    {
+        struct global_type g;
+
+        if (check_global_type(f, &g))
+        {
+            LOG("%s: check_global_type\n", __func__);
+            return -1;
+        }
+        else if (in && add_global(in, &g))
+        {
+            LOG("%s: add_global failed\n", __func__);
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+static int check(FILE *const f, const unsigned long len)
+{
+    const long start = ftell(f);
+
+    if (start < 0)
+    {
+        LOG("%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check_global_types(f, NULL))
+    {
+        LOG("%s: check_global_types failed\n", __func__);
+        return -1;
+    }
+
+    const long end = ftell(f);
+
+    if (end < 0)
+    {
+        LOG("%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+
+    const unsigned long size = end - start;
+
+    if (size != len)
+    {
+        LOG("%s: size exceeded (%lu expected, got %lu)\n",
+            __func__, len, size);
+        return -1;
+    }
+
+    return 0;
+}
+
+int section_global_check(const struct section *const s, struct nw_mod *const m,
+    const unsigned long len)
+{
+    FILE *const f = s->f;
+
+    if (m->sections.global)
+    {
+        LOG("%s: ignoring duplicate section\n", __func__);
+        return fseek(f, len, SEEK_CUR);
+    }
+
+    const long offset = ftell(f);
+
+    if (offset < 0)
+    {
+        LOG("%s: ftell(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check(f, len))
+    {
+        LOG("%s: check failed\n", __func__);
+        return -1;
+    }
+
+    m->sections.global = offset;
+    return 0;
+}
+
+int section_global_push(FILE *const f, const struct nw_mod *const m,
+    struct nw_interp *const i)
+{
+    if (fseek(f, m->sections.global, SEEK_SET))
+    {
+        LOG("%s: fseek(3): %s\n", __func__, strerror(errno));
+        return -1;
+    }
+    else if (check_global_types(f, i))
+    {
+        LOG("%s: check_global_types failed\n", __func__);
+        return -1;
+    }
+
+    return 0;
+}