WASM 工具链 ​

// 流式实例化 WASM 模块
async function loadWASMModule(url, importObject) {
    try {
        const response = await fetch(url);
        const { instance } = await WebAssembly.instantiateStreaming(
            response, 
            importObject
        );
        return instance;
    } catch (error) {
        // 回退到缓冲方式
        const response = await fetch(url);
        const bytes = await response.arrayBuffer();
        const { instance } = await WebAssembly.instantiate(bytes, importObject);
        return instance;
    }
}

// 创建内存共享环境
const memory = new WebAssembly.Memory({ 
    initial: 256, 
    maximum: 65536 
});

const importObject = {
    env: {
        memory,
        abort: (msg, file, line, column) => {
            console.error(`WASM 异常: ${msg} at ${file}:${line}:${column}`);
        }
    },
    wasi_snapshot_preview1: {
        // WASI 系统调用接口
        proc_exit: (code) => {
            console.log(`WASM 程序退出，代码: ${code}`);
        }
    }
};

// 使用示例
loadWASMModule('calculator.wasm', importObject)
    .then(instance => {
        const calculator = instance.exports;
        const result = calculator.add(5, 3);
        console.log(`计算结果: ${result}`);
    });

// 使用 WebAssembly JavaScript API 分析模块
async function analyzeModule(wasmUrl) {
    const response = await fetch(wasmUrl);
    const buffer = await response.arrayBuffer();
    const module = await WebAssembly.compile(buffer);
    
    // 获取模块自定义段信息
    const sections = WebAssembly.Module.customSections(module, "name");
    console.log("自定义段:", sections);
    
    // 分析导入/导出
    const imports = WebAssembly.Module.imports(module);
    const exports = WebAssembly.Module.exports(module);
    
    console.log("导入声明:", imports);
    console.log("导出声明:", exports);
    
    return { imports, exports, sections };
}

// 简单的 WASM 模块测试框架
class WASMTestRunner {
    constructor() {
        this.modules = new Map();
        this.testCases = [];
    }
    
    async loadTestModule(name, url) {
        const instance = await loadWASMModule(url);
        this.modules.set(name, instance);
        return instance;
    }
    
    addTestCase(moduleName, functionName, inputs, expected) {
        this.testCases.push({
            moduleName,
            functionName,
            inputs,
            expected
        });
    }
    
    runTests() {
        const results = [];
        for (const testCase of this.testCases) {
            const module = this.modules.get(testCase.moduleName);
            const func = module.exports[testCase.functionName];
            const result = func(...testCase.inputs);
            
            const passed = result === testCase.expected;
            results.push({
                testCase,
                result,
                passed
            });
            
            console.log(`测试 ${testCase.functionName}: ${passed ? '通过' : '失败'}`);
        }
        return results;
    }
}

// 使用示例
const runner = new WASMTestRunner();
await runner.loadTestModule('math', 'math_ops.wasm');
runner.addTestCase('math', 'add', [2, 3], 5);
runner.runTests();

// JavaScript 环境提供导入函数
const importObject = {
    env: {
        js_add: (a, b) => a + b,
        js_log_message: (messagePtr) => {
            const message = UTF8ToString(messagePtr);
            console.log('WASM 日志:', message);
        },
        memory: new WebAssembly.Memory({ initial: 256 })
    }
};

// WASM 性能分析工具函数
class WASMProfiler {
    constructor(instance) {
        this.instance = instance;
        this.memory = instance.exports.memory;
        this.performanceMarks = new Map();
    }
    
    startTimer(operationName) {
        this.performanceMarks.set(operationName, {
            startTime: performance.now(),
            memoryUsage: this.memory.buffer.byteLength
        });
    }
    
    endTimer(operationName) {
        const mark = this.performanceMarks.get(operationName);
        if (mark) {
            const endTime = performance.now();
            const duration = endTime - mark.startTime;
            const memoryDelta = this.memory.buffer.byteLength - mark.memoryUsage;
            
            console.log(`操作 ${operationName}: 
                耗时: ${duration.toFixed(2)}ms
                内存变化: ${memoryDelta} 字节`);
        }
    }
    
    // 分析函数调用性能
    profileFunction(funcName, ...args) {
        this.startTimer(funcName);
        const result = this.instance.exports[funcName](...args);
        this.endTimer(funcName);
        return result;
    }
}