#include <stdio.h>
#include <stdlib.h>
#include <wasm.h>
#include <wasi.h>
#include <wasmtime.h>
static void exit_with_error(const char *message, wasmtime_error_t *error,
wasm_trap_t *trap)
{
wasm_byte_vec_t error_message;
fprintf(stderr, "error: %s\n", message);
if (error != NULL) {
wasmtime_error_message(error, &error_message);
wasmtime_error_delete(error);
} else {
wasm_trap_message(trap, &error_message);
wasm_trap_delete(trap);
}
fprintf(stderr, "%.*s\n", (int) error_message.size, error_message.data);
wasm_byte_vec_delete(&error_message);
exit(1);
}
static wasm_trap_t *imported_func(void *env, wasmtime_caller_t *caller,
const wasmtime_val_t *args, size_t nargs,
wasmtime_val_t *results, size_t nresults)
{
(void)env;
(void)caller;
(void)args;
(void)nargs;
(void)results;
(void)nresults;
return NULL;
}
int main(void)
{
wasm_engine_t *engine;
wasmtime_store_t *store;
wasmtime_context_t *context;
wasmtime_module_t *module = NULL;
wasmtime_linker_t *linker;
wasmtime_error_t *error;
wasm_byte_vec_t wasm;
wasmtime_extern_t item;
wasm_functype_t *func_ty;
wasi_config_t *wasi_config;
FILE *file;
size_t file_size;
bool ok;
printf("Initializing...\n");
engine = wasm_engine_new();
store = wasmtime_store_new(engine, NULL, NULL);
context = wasmtime_store_context(store);
linker = wasmtime_linker_new(engine);
error = wasmtime_linker_define_wasi(linker);
if (error != NULL)
exit_with_error("failed to link wasi", error, NULL);
printf("Loading binary...\n");
file = fopen("test.wasm", "rb");
if (!file) {
printf("> Error loading file!\n");
exit(1);
}
fseek(file, 0L, SEEK_END);
file_size = ftell(file);
wasm_byte_vec_new_uninitialized(&wasm, file_size);
fseek(file, 0L, SEEK_SET);
if (fread(wasm.data, file_size, 1, file) != 1) {
printf("> Error loading module!\n");
exit(1);
}
fclose(file);
printf("Compiling module...\n");
error = wasmtime_module_new(engine, (uint8_t*)wasm.data, wasm.size,
&module);
if (!module)
exit_with_error("failed to compile module", error, NULL);
wasm_byte_vec_delete(&wasm);
printf("Setting fumction import...\n");
func_ty = wasm_functype_new_0_0();
wasmtime_linker_define_func(linker, "env", 3,
"imported_func", 13, func_ty,
imported_func, context, NULL);
wasm_functype_delete(func_ty);
printf("Initialising WASI...\n");
wasi_config = wasi_config_new();
wasi_config_inherit_env(wasi_config);
wasi_config_inherit_stdin(wasi_config);
wasi_config_inherit_stdout(wasi_config);
wasi_config_inherit_stderr(wasi_config);
error = wasmtime_context_set_wasi(context, wasi_config);
if (error)
exit_with_error("failed to initialise WASI", error, NULL);
printf("Instantiating module...\n");
error = wasmtime_linker_module(linker, context, "", 0, module);
if (error != NULL)
exit_with_error("failed to instantiate module", error, NULL);
printf("Getting function export...\n");
ok = wasmtime_linker_get(linker, context, "", 0, "exported_func", 13,
&item);
if (!ok) {
printf("> Error getting function export\n");
exit(1);
}
printf("Shutting down...\n");
wasmtime_module_delete(module);
wasmtime_store_delete(store);
wasm_engine_delete(engine);
printf("Done.\n");
return 0;
}
