How to turn on JIT mode when using the C interface?

[csbinghu]

Downloaded the daslang-bundle-windows-x86_64.zip file for daslang version 0.6.3 preop. A C++ application uses daslang in an embedded way. Calling daslang's C interface can successfully run programs written in the daslang language. However, after adding the [jit] attribute to a function, calling the jit_enabled() function returns false. The specific code is as follows: [code not provided in the original text]. How can JIT be enabled?

int main() {
// 1. 初始化 Daslang 引擎
das_initialize();

// 2. 创建必要的辅助对象
das_text_writer *tout = das_text_make_printer();        // 用于输出信息
das_module_group *module_group = das_modulegroup_make(); // 模块组
das_file_access *file_access = das_fileaccess_make_default(); // 文件访问器

// 3. ★★★ 关键步骤：将字符串注册为虚拟文件 ★★★
//    参数: 文件访问器, 虚拟文件名, 源代码字符串, 0 表示借用字符串(不复制)
das_fileaccess_introduce_file(file_access, "script.das", SCRIPT_SOURCE, 0);

// 4. 编译虚拟文件
das_program *program = das_program_compile(
    (char*)"script.das",           // 虚拟文件名
    file_access,            // 文件访问器
    tout,                   // 文本输出
    module_group            // 模块组
);

// 5. 检查编译错误
if (das_program_err_count(program)) {
    printf("Compilation failed!\n");
    // 可以遍历并打印具体错误信息
    for (int i = 0; i < das_program_err_count(program); i++) {
        char buf[1024];  // 用于存放格式化后的错误信息
        das_error *err = das_program_get_error(program, i);
        das_error_report(err, buf, sizeof(buf));  // 将错误信息写入 buf
        printf("%s\n", buf);
    }
    das_program_release(program);
    das_fileaccess_release(file_access);
    das_modulegroup_release(module_group);
    das_text_release(tout);
    das_shutdown();
    return -1;
}

// 6. 创建运行时上下文并执行模拟
das_context *ctx = das_context_make(das_program_context_stack_size(program));
if (!das_program_simulate(program, ctx, tout)) {
    printf("Simulation failed!\n");
    das_context_release(ctx);
    das_program_release(program);
    das_fileaccess_release(file_access);
    das_modulegroup_release(module_group);
    das_text_release(tout);
    das_shutdown();
    return -1;
}

// 7. 查找并调用导出的函数
das_function *fn_test = das_context_find_function(ctx, "main");
if (!fn_test) {
    printf("Function 'test' not found!\n");
} else {

    // 无参数函数，第三个参数传 NULL
    auto start = high_resolution_clock::now();
    das_context_eval_with_catch(ctx, fn_test, NULL);
    auto end = high_resolution_clock::now();
    auto duration = duration_cast<microseconds>(end - start).count();
    std::cout << "耗时: " << duration << " 微秒" << std::endl;

    // 检查是否有异常抛出
    char *exception = das_context_get_exception(ctx);
    if (exception) {
        printf("Exception: %s\n", exception);
    }
}

//das_function *fn_add = das_context_find_function(ctx, "add");
//if (!fn_add) {
//    printf("Function 'add' not found!\n");
//} else {
//    vec4f args[2];
//    args[0] = das_result_int(10);   // 第一个参数
//    args[1] = das_result_int(20);   // 第二个参数
//    auto result=das_context_eval_with_catch(ctx, fn_add, args);
//    // 检查是否有异常抛出
//    char *exception = das_context_get_exception(ctx);
//    if (exception) {
//        printf("Exception: %s\n", exception);
//    }
//    int sum = das_argument_int(result);
//    printf("%d\n", sum);
//}

// 8. 释放所有资源 (顺序很重要)
das_context_release(ctx);
das_program_release(program);
das_fileaccess_release(file_access);
das_modulegroup_release(module_group);
das_text_release(tout);
das_shutdown();

return 0;

}

#daslang code:
options gen2=true
options gc=true
options jit_enabled=true

[jit]
def test(var a){
for( i in range(1,100000001)){
a=a+i
}
return a
}

[export]
def main() {
//if (jit_enabled()) {
// print("JIT is enabled!\n");
//} else {
// print("JIT is NOT enabled.\n");
//}
var a=test(1)
print("{a}\n")
}

[csbinghu]

The compilation environment is Visual Studio.

[borisbat]

Fixed on master by #3889 — the next release bundle will carry it.

JIT is a host-side policy, so options jit_enabled = true inside the script has no effect (that was the trap you hit). With the new API your setup becomes:

/* if your exe does not live in the bundle's bin/ folder, point daslang at the bundle root
   (the folder that holds daslib/, modules/ and lib/) */
das_set_root("C:/path/to/daslang-bundle");

das_file_access * file_access = das_fileaccess_make_default();
/* resolve modules/dasLLVM - the LLVM JIT backend */
das_register_dynamic_modules(file_access, "C:/path/to/daslang-bundle", NULL, 0, tout);
/* what the CLI's -jit switch injects */
das_fileaccess_add_extra_module(file_access, "just_in_time",
    "C:/path/to/daslang-bundle/daslib/just_in_time.das");

das_policies * pol = das_policies_make();
das_policies_set_bool(pol, DAS_POLICY_JIT_ENABLED, 1);

das_program * program = das_program_compile_policies(
    "script.das", file_access, tout, module_group, pol);

After das_program_simulate() your [jit] function runs natively and jit_enabled() returns true. The full recipe is in the embedding reference (doc/source/reference/embedding/c_api.rst, "Enabling JIT"). The bundle's lib/LLVM.dll must be present — it ships in the Windows bundle.

You can drop the [jit] attribute if you want everything jitted: with JIT on, all functions are jitted by default.