wasm-micro-runtime/samples/basic/src/main.c

/*
 * Copyright (C) 2019 Intel Corporation.  All rights reserved.
 * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 */

#include "wasm_export.h"
#include "bh_read_file.h"

int intToStr(int x, char* str, int str_len, int digit);
int get_pow(int x, int y);
int32_t calculate_native(int32_t n, int32_t func1, int32_t func2);

void print_usage(void)
{
    fprintf(stdout, "Options:\r\n");
    fprintf(stdout, "  -f [path of wasm file] \n");
}


int main(int argc, char *argv_main[])
{
    static char global_heap_buf[512 * 1024];
    char *buffer, error_buf[128];
    int opt;
    char * wasm_path;

    wasm_module_t module = NULL;
    wasm_module_inst_t module_inst = NULL;
    wasm_exec_env_t exec_env = NULL;
    uint32 buf_size, stack_size = 8092, heap_size = 8092;
    wasm_function_inst_t func = NULL;
    wasm_function_inst_t func2 = NULL;
    char * native_buffer = NULL;
    uint32_t wasm_buffer = 0;

    RuntimeInitArgs init_args;
    memset(&init_args, 0, sizeof(RuntimeInitArgs));

    while ((opt = getopt(argc, argv_main, "hf:")) != -1)
    {
        switch (opt)
        {
        case 'f':
            wasm_path = optarg;
            break;
        case 'h':
            print_usage();
            return 0;
        case '?':
            print_usage();
            return 0;
        }
    }
    if (optind == 1) {
        print_usage();
        return 0;
    }

    // Define an array of NativeSymbol for the APIs to be exported.
    // Note: the array must be static defined since runtime
    //            will keep it after registration
    // For the function signature specifications, goto the link:
    // https://github.com/bytecodealliance/wasm-micro-runtime/blob/main/doc/export_native_api.md

    static NativeSymbol native_symbols[] =
    {
        {
            "intToStr", 		// the name of WASM function name
            intToStr, 			// the native function pointer
            "(i*~i)i",			// the function prototype signature, avoid to use i32
            NULL                // attachment is NULL
        },
        {
            "get_pow", 		    // the name of WASM function name
            get_pow, 			// the native function pointer
            "(ii)i",			// the function prototype signature, avoid to use i32
            NULL                // attachment is NULL
        },
        {
            "calculate_native",
            calculate_native,
            "(iii)i",
            NULL
        }
    };

    init_args.mem_alloc_type = Alloc_With_Pool;
    init_args.mem_alloc_option.pool.heap_buf = global_heap_buf;
    init_args.mem_alloc_option.pool.heap_size = sizeof(global_heap_buf);

    // Native symbols need below registration phase
    init_args.n_native_symbols = sizeof(native_symbols) / sizeof(NativeSymbol);
    init_args.native_module_name = "env";
    init_args.native_symbols = native_symbols;

    if (!wasm_runtime_full_init(&init_args)) {
        printf("Init runtime environment failed.\n");
        return -1;
    }

    buffer = bh_read_file_to_buffer(wasm_path, &buf_size);

    if(!buffer) {
        printf("Open wasm app file [%s] failed.\n", wasm_path);
        goto fail;
    }

    module = wasm_runtime_load(buffer, buf_size, error_buf, sizeof(error_buf));
    if(!module) {
        printf("Load wasm module failed. error: %s\n", error_buf);
        goto fail;
    }

    module_inst = wasm_runtime_instantiate(module,
                                         stack_size,
                                         heap_size,
                                         error_buf,
                                         sizeof(error_buf));

    if(!module_inst) {
        printf("Instantiate wasm module failed. error: %s\n", error_buf);
        goto fail;
    }

    exec_env = wasm_runtime_create_exec_env(module_inst, stack_size);
    if(!exec_env) {
        printf("Create wasm execution environment failed.\n");
        goto fail;
    }

    uint32 argv[4];
    double arg_d = 0.000101;
    argv[0] = 10;
    // the second arg will occupy two array elements
    memcpy(&argv[1], &arg_d, sizeof(arg_d));
    *(float*)(argv+3) = 300.002;

    if(!(func = wasm_runtime_lookup_function(module_inst, "generate_float", NULL))){
        printf("The generate_float wasm function is not found.\n");
        goto fail;
    }

    // pass 4 elements for function arguments
    if (!wasm_runtime_call_wasm(exec_env, func, 4, argv) ) {
        printf("call wasm function generate_float failed. %s\n", wasm_runtime_get_exception(module_inst));
        goto fail;
    }

    float ret_val = *(float*)argv;
    printf("Native finished calling wasm function generate_float(), returned a float value: %ff\n", ret_val );

    // Next we will pass a buffer to the WASM function
    uint32 argv2[4];

    // must allocate buffer from wasm instance memory space (never use pointer from host runtime)
    wasm_buffer = wasm_runtime_module_malloc(module_inst, 100, (void**)&native_buffer);

    *(float*)argv2 = ret_val;   // the first argument
    argv2[1] = wasm_buffer;     // the second argument is the wasm buffer address
    argv2[2] = 100;             //  the third argument is the wasm buffer size
    argv2[3] = 3;               //  the last argument is the digits after decimal point for converting float to string

   if(!(func2 = wasm_runtime_lookup_function(module_inst, "float_to_string", NULL))){
        printf("The wasm function float_to_string wasm function is not found.\n");
        goto fail;
    }

    if (wasm_runtime_call_wasm(exec_env, func2, 4, argv2) ) {
        printf("Native finished calling wasm function: float_to_string, returned a formatted string: %s\n", native_buffer);
    }
    else {
        printf("call wasm function float_to_string failed. error: %s\n", wasm_runtime_get_exception(module_inst));
        goto fail;
    }

    wasm_function_inst_t func3 = wasm_runtime_lookup_function(module_inst,
                                                              "calculate",
                                                              NULL);
    if (!func3) {
        printf("The wasm function calculate is not found.\n");
        goto fail;
    }

    uint32_t argv3[1] = {3};
    if (wasm_runtime_call_wasm(exec_env, func3, 1, argv3)) {
        uint32_t result = *(uint32_t*)argv3;
        printf("Native finished calling wasm function: calculate, return: %d\n", result);
    } else {
        printf("call wasm function calculate failed. error: %s\n", wasm_runtime_get_exception(module_inst));
        goto fail;
    }

fail:
    if(exec_env) wasm_runtime_destroy_exec_env(exec_env);
    if(module_inst) {
        if(wasm_buffer) wasm_runtime_module_free(module_inst, wasm_buffer);
        wasm_runtime_deinstantiate(module_inst);
    }
    if(module) wasm_runtime_unload(module);
    if(buffer) BH_FREE(buffer);
    wasm_runtime_destroy();
    return 0;
}