waforth/experiments/waforth2c/wasm2c/wasm-rt-impl.c
2019-03-09 13:48:22 +01:00

122 lines
3.6 KiB
C

/*
* Copyright 2018 WebAssembly Community Group participants
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "wasm-rt-impl.h"
#include <assert.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#define PAGE_SIZE 65536
typedef struct FuncType {
wasm_rt_type_t* params;
wasm_rt_type_t* results;
uint32_t param_count;
uint32_t result_count;
} FuncType;
uint32_t wasm_rt_call_stack_depth;
uint32_t g_saved_call_stack_depth;
jmp_buf g_jmp_buf;
FuncType* g_func_types;
uint32_t g_func_type_count;
void wasm_rt_trap(wasm_rt_trap_t code) {
assert(code != WASM_RT_TRAP_NONE);
wasm_rt_call_stack_depth = g_saved_call_stack_depth;
longjmp(g_jmp_buf, code);
}
static bool func_types_are_equal(FuncType* a, FuncType* b) {
if (a->param_count != b->param_count || a->result_count != b->result_count)
return 0;
int i;
for (i = 0; i < a->param_count; ++i)
if (a->params[i] != b->params[i])
return 0;
for (i = 0; i < a->result_count; ++i)
if (a->results[i] != b->results[i])
return 0;
return 1;
}
uint32_t wasm_rt_register_func_type(uint32_t param_count,
uint32_t result_count,
...) {
FuncType func_type;
func_type.param_count = param_count;
func_type.params = malloc(param_count * sizeof(wasm_rt_type_t));
func_type.result_count = result_count;
func_type.results = malloc(result_count * sizeof(wasm_rt_type_t));
va_list args;
va_start(args, result_count);
uint32_t i;
for (i = 0; i < param_count; ++i)
func_type.params[i] = va_arg(args, wasm_rt_type_t);
for (i = 0; i < result_count; ++i)
func_type.results[i] = va_arg(args, wasm_rt_type_t);
va_end(args);
for (i = 0; i < g_func_type_count; ++i) {
if (func_types_are_equal(&g_func_types[i], &func_type)) {
free(func_type.params);
free(func_type.results);
return i + 1;
}
}
uint32_t idx = g_func_type_count++;
g_func_types = realloc(g_func_types, g_func_type_count * sizeof(FuncType));
g_func_types[idx] = func_type;
return idx + 1;
}
void wasm_rt_allocate_memory(wasm_rt_memory_t* memory,
uint32_t initial_pages,
uint32_t max_pages) {
memory->pages = initial_pages;
memory->max_pages = max_pages;
memory->size = initial_pages * PAGE_SIZE;
memory->data = calloc(memory->size, 1);
}
uint32_t wasm_rt_grow_memory(wasm_rt_memory_t* memory, uint32_t delta) {
uint32_t old_pages = memory->pages;
uint32_t new_pages = memory->pages + delta;
if (new_pages < old_pages || new_pages > memory->max_pages) {
return (uint32_t)-1;
}
memory->pages = new_pages;
memory->size = new_pages * PAGE_SIZE;
memory->data = realloc(memory->data, memory->size);
memset(memory->data + old_pages * PAGE_SIZE, 0, delta * PAGE_SIZE);
return old_pages;
}
void wasm_rt_allocate_table(wasm_rt_table_t* table,
uint32_t elements,
uint32_t max_elements) {
table->size = elements;
table->max_size = max_elements;
table->data = calloc(table->size, sizeof(wasm_rt_elem_t));
}