Module['compileGLSLZeroCopy'] = function(glsl, shader_stage, gen_debug, spirv_version) {
    gen_debug = !!gen_debug;

    var shader_stage_int; // EShLanguage
    switch (shader_stage) {
        case 'vertex':   shader_stage_int = 0; break;
        case 'fragment': shader_stage_int = 4; break;
        case 'compute':  shader_stage_int = 5; break;
        default:
            throw new Error("shader_stage must be 'vertex', 'fragment', or 'compute'.");
    }

    spirv_version = spirv_version || '1.0';
    var spirv_version_int; // EShTargetLanguageVersion
    switch (spirv_version) {
        case '1.0': spirv_version_int = (1 << 16) | (0 << 8); break;
        case '1.1': spirv_version_int = (1 << 16) | (1 << 8); break;
        case '1.2': spirv_version_int = (1 << 16) | (2 << 8); break;
        case '1.3': spirv_version_int = (1 << 16) | (3 << 8); break;
        case '1.4': spirv_version_int = (1 << 16) | (4 << 8); break;
        case '1.5': spirv_version_int = (1 << 16) | (5 << 8); break;
        default:
            throw new Error("spirv_version must be '1.0' ~ '1.5'.");
    }

    var p_output = Module['_malloc'](4);
    var p_output_len = Module['_malloc'](4);
    var id = ccall('convert_glsl_to_spirv',
        'number',
        ['string', 'number', 'boolean', 'number', 'number', 'number'],
        [glsl, shader_stage_int, gen_debug, spirv_version_int, p_output, p_output_len]);
    var output = getValue(p_output, 'i32');
    var output_len = getValue(p_output_len, 'i32');
    Module['_free'](p_output);
    Module['_free'](p_output_len);

    if (id === 0) {
        throw new Error('GLSL compilation failed');
    }

    var ret = {};
    var outputIndexU32 = output / 4;
    ret['data'] = Module['HEAPU32'].subarray(outputIndexU32, outputIndexU32 + output_len);
    ret['free'] = function() {
        Module['_destroy_output_buffer'](id);
    };

    return ret;
};

Module['compileGLSL'] = function(glsl, shader_stage, gen_debug, spirv_version) {
    var compiled = Module['compileGLSLZeroCopy'](glsl, shader_stage, gen_debug, spirv_version);
    var ret = compiled['data'].slice()
    compiled['free']();
    return ret;
};