// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

// @dart = 2.9

// Test for hello world built using emscripten with WASI.

import "package:expect/expect.dart";
import "package:wasm/wasm.dart";
import "dart:typed_data";

void main() {
  // Hello world module generated by emscripten+WASI. Exports a function like
  // `void _start()`, and prints using `int fd_write(int, int, int, int)`.
  var data = Uint8List.fromList([
    0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00, 0x01, 0x33, 0x09, 0x60,
    0x03, 0x7f, 0x7f, 0x7f, 0x01, 0x7f, 0x60, 0x04, 0x7f, 0x7f, 0x7f, 0x7f,
    0x01, 0x7f, 0x60, 0x00, 0x00, 0x60, 0x02, 0x7f, 0x7f, 0x01, 0x7f, 0x60,
    0x01, 0x7f, 0x01, 0x7f, 0x60, 0x03, 0x7f, 0x7e, 0x7f, 0x01, 0x7e, 0x60,
    0x00, 0x01, 0x7f, 0x60, 0x01, 0x7f, 0x00, 0x60, 0x03, 0x7f, 0x7f, 0x7f,
    0x00, 0x02, 0x1a, 0x01, 0x0d, 0x77, 0x61, 0x73, 0x69, 0x5f, 0x75, 0x6e,
    0x73, 0x74, 0x61, 0x62, 0x6c, 0x65, 0x08, 0x66, 0x64, 0x5f, 0x77, 0x72,
    0x69, 0x74, 0x65, 0x00, 0x01, 0x03, 0x0f, 0x0e, 0x03, 0x04, 0x00, 0x03,
    0x02, 0x07, 0x05, 0x04, 0x03, 0x06, 0x02, 0x02, 0x08, 0x00, 0x04, 0x05,
    0x01, 0x70, 0x01, 0x04, 0x04, 0x05, 0x06, 0x01, 0x01, 0x80, 0x02, 0x80,
    0x02, 0x06, 0x09, 0x01, 0x7f, 0x01, 0x41, 0xc0, 0x95, 0xc0, 0x02, 0x0b,
    0x07, 0x2e, 0x04, 0x06, 0x6d, 0x65, 0x6d, 0x6f, 0x72, 0x79, 0x02, 0x00,
    0x11, 0x5f, 0x5f, 0x77, 0x61, 0x73, 0x6d, 0x5f, 0x63, 0x61, 0x6c, 0x6c,
    0x5f, 0x63, 0x74, 0x6f, 0x72, 0x73, 0x00, 0x05, 0x04, 0x6d, 0x61, 0x69,
    0x6e, 0x00, 0x04, 0x06, 0x5f, 0x73, 0x74, 0x61, 0x72, 0x74, 0x00, 0x0b,
    0x09, 0x09, 0x01, 0x00, 0x41, 0x01, 0x0b, 0x03, 0x08, 0x0e, 0x07, 0x0a,
    0xae, 0x0c, 0x0e, 0xbf, 0x01, 0x01, 0x05, 0x7f, 0x41, 0x80, 0x08, 0x21,
    0x04, 0x02, 0x40, 0x20, 0x01, 0x28, 0x02, 0x10, 0x22, 0x02, 0x04, 0x7f,
    0x20, 0x02, 0x05, 0x20, 0x01, 0x10, 0x02, 0x0d, 0x01, 0x20, 0x01, 0x28,
    0x02, 0x10, 0x0b, 0x20, 0x01, 0x28, 0x02, 0x14, 0x22, 0x05, 0x6b, 0x20,
    0x00, 0x49, 0x04, 0x40, 0x20, 0x01, 0x41, 0x80, 0x08, 0x20, 0x00, 0x20,
    0x01, 0x28, 0x02, 0x24, 0x11, 0x00, 0x00, 0x0f, 0x0b, 0x02, 0x40, 0x20,
    0x01, 0x2c, 0x00, 0x4b, 0x41, 0x00, 0x48, 0x0d, 0x00, 0x20, 0x00, 0x21,
    0x03, 0x03, 0x40, 0x20, 0x03, 0x22, 0x02, 0x45, 0x0d, 0x01, 0x20, 0x02,
    0x41, 0x7f, 0x6a, 0x22, 0x03, 0x41, 0x80, 0x08, 0x6a, 0x2d, 0x00, 0x00,
    0x41, 0x0a, 0x47, 0x0d, 0x00, 0x0b, 0x20, 0x01, 0x41, 0x80, 0x08, 0x20,
    0x02, 0x20, 0x01, 0x28, 0x02, 0x24, 0x11, 0x00, 0x00, 0x22, 0x03, 0x20,
    0x02, 0x49, 0x0d, 0x01, 0x20, 0x00, 0x20, 0x02, 0x6b, 0x21, 0x00, 0x20,
    0x02, 0x41, 0x80, 0x08, 0x6a, 0x21, 0x04, 0x20, 0x01, 0x28, 0x02, 0x14,
    0x21, 0x05, 0x20, 0x02, 0x21, 0x06, 0x0b, 0x20, 0x05, 0x20, 0x04, 0x20,
    0x00, 0x10, 0x03, 0x1a, 0x20, 0x01, 0x20, 0x01, 0x28, 0x02, 0x14, 0x20,
    0x00, 0x6a, 0x36, 0x02, 0x14, 0x20, 0x00, 0x20, 0x06, 0x6a, 0x21, 0x03,
    0x0b, 0x20, 0x03, 0x0b, 0x59, 0x01, 0x01, 0x7f, 0x20, 0x00, 0x20, 0x00,
    0x2d, 0x00, 0x4a, 0x22, 0x01, 0x41, 0x7f, 0x6a, 0x20, 0x01, 0x72, 0x3a,
    0x00, 0x4a, 0x20, 0x00, 0x28, 0x02, 0x00, 0x22, 0x01, 0x41, 0x08, 0x71,
    0x04, 0x40, 0x20, 0x00, 0x20, 0x01, 0x41, 0x20, 0x72, 0x36, 0x02, 0x00,
    0x41, 0x7f, 0x0f, 0x0b, 0x20, 0x00, 0x42, 0x00, 0x37, 0x02, 0x04, 0x20,
    0x00, 0x20, 0x00, 0x28, 0x02, 0x2c, 0x22, 0x01, 0x36, 0x02, 0x1c, 0x20,
    0x00, 0x20, 0x01, 0x36, 0x02, 0x14, 0x20, 0x00, 0x20, 0x01, 0x20, 0x00,
    0x28, 0x02, 0x30, 0x6a, 0x36, 0x02, 0x10, 0x41, 0x00, 0x0b, 0x82, 0x04,
    0x01, 0x03, 0x7f, 0x20, 0x02, 0x41, 0x80, 0xc0, 0x00, 0x4f, 0x04, 0x40,
    0x20, 0x00, 0x20, 0x01, 0x20, 0x02, 0x10, 0x0d, 0x20, 0x00, 0x0f, 0x0b,
    0x20, 0x00, 0x20, 0x02, 0x6a, 0x21, 0x03, 0x02, 0x40, 0x20, 0x00, 0x20,
    0x01, 0x73, 0x41, 0x03, 0x71, 0x45, 0x04, 0x40, 0x02, 0x40, 0x20, 0x02,
    0x41, 0x01, 0x48, 0x04, 0x40, 0x20, 0x00, 0x21, 0x02, 0x0c, 0x01, 0x0b,
    0x20, 0x00, 0x41, 0x03, 0x71, 0x45, 0x04, 0x40, 0x20, 0x00, 0x21, 0x02,
    0x0c, 0x01, 0x0b, 0x20, 0x00, 0x21, 0x02, 0x03, 0x40, 0x20, 0x02, 0x20,
    0x01, 0x2d, 0x00, 0x00, 0x3a, 0x00, 0x00, 0x20, 0x01, 0x41, 0x01, 0x6a,
    0x21, 0x01, 0x20, 0x02, 0x41, 0x01, 0x6a, 0x22, 0x02, 0x20, 0x03, 0x4f,
    0x0d, 0x01, 0x20, 0x02, 0x41, 0x03, 0x71, 0x0d, 0x00, 0x0b, 0x0b, 0x02,
    0x40, 0x20, 0x03, 0x41, 0x7c, 0x71, 0x22, 0x04, 0x41, 0xc0, 0x00, 0x49,
    0x0d, 0x00, 0x20, 0x02, 0x20, 0x04, 0x41, 0x40, 0x6a, 0x22, 0x05, 0x4b,
    0x0d, 0x00, 0x03, 0x40, 0x20, 0x02, 0x20, 0x01, 0x28, 0x02, 0x00, 0x36,
    0x02, 0x00, 0x20, 0x02, 0x20, 0x01, 0x28, 0x02, 0x04, 0x36, 0x02, 0x04,
    0x20, 0x02, 0x20, 0x01, 0x28, 0x02, 0x08, 0x36, 0x02, 0x08, 0x20, 0x02,
    0x20, 0x01, 0x28, 0x02, 0x0c, 0x36, 0x02, 0x0c, 0x20, 0x02, 0x20, 0x01,
    0x28, 0x02, 0x10, 0x36, 0x02, 0x10, 0x20, 0x02, 0x20, 0x01, 0x28, 0x02,
    0x14, 0x36, 0x02, 0x14, 0x20, 0x02, 0x20, 0x01, 0x28, 0x02, 0x18, 0x36,
    0x02, 0x18, 0x20, 0x02, 0x20, 0x01, 0x28, 0x02, 0x1c, 0x36, 0x02, 0x1c,
    0x20, 0x02, 0x20, 0x01, 0x28, 0x02, 0x20, 0x36, 0x02, 0x20, 0x20, 0x02,
    0x20, 0x01, 0x28, 0x02, 0x24, 0x36, 0x02, 0x24, 0x20, 0x02, 0x20, 0x01,
    0x28, 0x02, 0x28, 0x36, 0x02, 0x28, 0x20, 0x02, 0x20, 0x01, 0x28, 0x02,
    0x2c, 0x36, 0x02, 0x2c, 0x20, 0x02, 0x20, 0x01, 0x28, 0x02, 0x30, 0x36,
    0x02, 0x30, 0x20, 0x02, 0x20, 0x01, 0x28, 0x02, 0x34, 0x36, 0x02, 0x34,
    0x20, 0x02, 0x20, 0x01, 0x28, 0x02, 0x38, 0x36, 0x02, 0x38, 0x20, 0x02,
    0x20, 0x01, 0x28, 0x02, 0x3c, 0x36, 0x02, 0x3c, 0x20, 0x01, 0x41, 0x40,
    0x6b, 0x21, 0x01, 0x20, 0x02, 0x41, 0x40, 0x6b, 0x22, 0x02, 0x20, 0x05,
    0x4d, 0x0d, 0x00, 0x0b, 0x0b, 0x20, 0x02, 0x20, 0x04, 0x4f, 0x0d, 0x01,
    0x03, 0x40, 0x20, 0x02, 0x20, 0x01, 0x28, 0x02, 0x00, 0x36, 0x02, 0x00,
    0x20, 0x01, 0x41, 0x04, 0x6a, 0x21, 0x01, 0x20, 0x02, 0x41, 0x04, 0x6a,
    0x22, 0x02, 0x20, 0x04, 0x49, 0x0d, 0x00, 0x0b, 0x0c, 0x01, 0x0b, 0x20,
    0x03, 0x41, 0x04, 0x49, 0x04, 0x40, 0x20, 0x00, 0x21, 0x02, 0x0c, 0x01,
    0x0b, 0x20, 0x03, 0x41, 0x7c, 0x6a, 0x22, 0x04, 0x20, 0x00, 0x49, 0x04,
    0x40, 0x20, 0x00, 0x21, 0x02, 0x0c, 0x01, 0x0b, 0x20, 0x00, 0x21, 0x02,
    0x03, 0x40, 0x20, 0x02, 0x20, 0x01, 0x2d, 0x00, 0x00, 0x3a, 0x00, 0x00,
    0x20, 0x02, 0x20, 0x01, 0x2d, 0x00, 0x01, 0x3a, 0x00, 0x01, 0x20, 0x02,
    0x20, 0x01, 0x2d, 0x00, 0x02, 0x3a, 0x00, 0x02, 0x20, 0x02, 0x20, 0x01,
    0x2d, 0x00, 0x03, 0x3a, 0x00, 0x03, 0x20, 0x01, 0x41, 0x04, 0x6a, 0x21,
    0x01, 0x20, 0x02, 0x41, 0x04, 0x6a, 0x22, 0x02, 0x20, 0x04, 0x4d, 0x0d,
    0x00, 0x0b, 0x0b, 0x20, 0x02, 0x20, 0x03, 0x49, 0x04, 0x40, 0x03, 0x40,
    0x20, 0x02, 0x20, 0x01, 0x2d, 0x00, 0x00, 0x3a, 0x00, 0x00, 0x20, 0x01,
    0x41, 0x01, 0x6a, 0x21, 0x01, 0x20, 0x02, 0x41, 0x01, 0x6a, 0x22, 0x02,
    0x20, 0x03, 0x47, 0x0d, 0x00, 0x0b, 0x0b, 0x20, 0x00, 0x0b, 0x06, 0x00,
    0x10, 0x0c, 0x41, 0x00, 0x0b, 0x03, 0x00, 0x01, 0x0b, 0x7e, 0x01, 0x03,
    0x7f, 0x23, 0x00, 0x41, 0x10, 0x6b, 0x22, 0x01, 0x24, 0x00, 0x20, 0x01,
    0x41, 0x0a, 0x3a, 0x00, 0x0f, 0x02, 0x40, 0x20, 0x00, 0x28, 0x02, 0x10,
    0x22, 0x02, 0x45, 0x04, 0x40, 0x20, 0x00, 0x10, 0x02, 0x0d, 0x01, 0x20,
    0x00, 0x28, 0x02, 0x10, 0x21, 0x02, 0x0b, 0x02, 0x40, 0x20, 0x00, 0x28,
    0x02, 0x14, 0x22, 0x03, 0x20, 0x02, 0x4f, 0x0d, 0x00, 0x20, 0x00, 0x2c,
    0x00, 0x4b, 0x41, 0x0a, 0x46, 0x0d, 0x00, 0x20, 0x00, 0x20, 0x03, 0x41,
    0x01, 0x6a, 0x36, 0x02, 0x14, 0x20, 0x03, 0x41, 0x0a, 0x3a, 0x00, 0x00,
    0x0c, 0x01, 0x0b, 0x20, 0x00, 0x20, 0x01, 0x41, 0x0f, 0x6a, 0x41, 0x01,
    0x20, 0x00, 0x28, 0x02, 0x24, 0x11, 0x00, 0x00, 0x41, 0x01, 0x47, 0x0d,
    0x00, 0x20, 0x01, 0x2d, 0x00, 0x0f, 0x1a, 0x0b, 0x20, 0x01, 0x41, 0x10,
    0x6a, 0x24, 0x00, 0x0b, 0x04, 0x00, 0x42, 0x00, 0x0b, 0x04, 0x00, 0x41,
    0x00, 0x0b, 0x31, 0x01, 0x01, 0x7f, 0x20, 0x00, 0x21, 0x02, 0x20, 0x02,
    0x02, 0x7f, 0x20, 0x01, 0x28, 0x02, 0x4c, 0x41, 0x7f, 0x4c, 0x04, 0x40,
    0x20, 0x02, 0x20, 0x01, 0x10, 0x01, 0x0c, 0x01, 0x0b, 0x20, 0x02, 0x20,
    0x01, 0x10, 0x01, 0x0b, 0x22, 0x01, 0x46, 0x04, 0x40, 0x20, 0x00, 0x0f,
    0x0b, 0x20, 0x01, 0x0b, 0x62, 0x01, 0x03, 0x7f, 0x41, 0x80, 0x08, 0x21,
    0x00, 0x03, 0x40, 0x20, 0x00, 0x22, 0x01, 0x41, 0x04, 0x6a, 0x21, 0x00,
    0x20, 0x01, 0x28, 0x02, 0x00, 0x22, 0x02, 0x41, 0x7f, 0x73, 0x20, 0x02,
    0x41, 0xff, 0xfd, 0xfb, 0x77, 0x6a, 0x71, 0x41, 0x80, 0x81, 0x82, 0x84,
    0x78, 0x71, 0x45, 0x0d, 0x00, 0x0b, 0x02, 0x40, 0x20, 0x02, 0x41, 0xff,
    0x01, 0x71, 0x45, 0x04, 0x40, 0x20, 0x01, 0x21, 0x00, 0x0c, 0x01, 0x0b,
    0x03, 0x40, 0x20, 0x01, 0x2d, 0x00, 0x01, 0x21, 0x02, 0x20, 0x01, 0x41,
    0x01, 0x6a, 0x22, 0x00, 0x21, 0x01, 0x20, 0x02, 0x0d, 0x00, 0x0b, 0x0b,
    0x20, 0x00, 0x41, 0x80, 0x08, 0x6b, 0x0b, 0x0c, 0x00, 0x02, 0x7f, 0x41,
    0x00, 0x41, 0x00, 0x10, 0x04, 0x0b, 0x1a, 0x0b, 0x66, 0x01, 0x02, 0x7f,
    0x41, 0x90, 0x08, 0x28, 0x02, 0x00, 0x22, 0x00, 0x28, 0x02, 0x4c, 0x41,
    0x00, 0x4e, 0x04, 0x7f, 0x41, 0x01, 0x05, 0x20, 0x01, 0x0b, 0x1a, 0x02,
    0x40, 0x41, 0x7f, 0x41, 0x00, 0x10, 0x0a, 0x22, 0x01, 0x20, 0x01, 0x20,
    0x00, 0x10, 0x09, 0x47, 0x1b, 0x41, 0x00, 0x48, 0x0d, 0x00, 0x02, 0x40,
    0x20, 0x00, 0x2d, 0x00, 0x4b, 0x41, 0x0a, 0x46, 0x0d, 0x00, 0x20, 0x00,
    0x28, 0x02, 0x14, 0x22, 0x01, 0x20, 0x00, 0x28, 0x02, 0x10, 0x4f, 0x0d,
    0x00, 0x20, 0x00, 0x20, 0x01, 0x41, 0x01, 0x6a, 0x36, 0x02, 0x14, 0x20,
    0x01, 0x41, 0x0a, 0x3a, 0x00, 0x00, 0x0c, 0x01, 0x0b, 0x20, 0x00, 0x10,
    0x06, 0x0b, 0x0b, 0x3d, 0x01, 0x01, 0x7f, 0x20, 0x02, 0x04, 0x40, 0x03,
    0x40, 0x20, 0x00, 0x20, 0x01, 0x20, 0x02, 0x41, 0x80, 0xc0, 0x00, 0x20,
    0x02, 0x41, 0x80, 0xc0, 0x00, 0x49, 0x1b, 0x22, 0x03, 0x10, 0x03, 0x21,
    0x00, 0x20, 0x01, 0x41, 0x80, 0x40, 0x6b, 0x21, 0x01, 0x20, 0x00, 0x41,
    0x80, 0x40, 0x6b, 0x21, 0x00, 0x20, 0x02, 0x20, 0x03, 0x6b, 0x22, 0x02,
    0x0d, 0x00, 0x0b, 0x0b, 0x0b, 0xb1, 0x02, 0x01, 0x06, 0x7f, 0x23, 0x00,
    0x41, 0x20, 0x6b, 0x22, 0x03, 0x24, 0x00, 0x20, 0x03, 0x20, 0x00, 0x28,
    0x02, 0x1c, 0x22, 0x04, 0x36, 0x02, 0x10, 0x20, 0x00, 0x28, 0x02, 0x14,
    0x21, 0x05, 0x20, 0x03, 0x20, 0x02, 0x36, 0x02, 0x1c, 0x20, 0x03, 0x20,
    0x01, 0x36, 0x02, 0x18, 0x20, 0x03, 0x20, 0x05, 0x20, 0x04, 0x6b, 0x22,
    0x01, 0x36, 0x02, 0x14, 0x20, 0x01, 0x20, 0x02, 0x6a, 0x21, 0x06, 0x41,
    0x02, 0x21, 0x05, 0x20, 0x03, 0x41, 0x10, 0x6a, 0x21, 0x01, 0x03, 0x40,
    0x02, 0x40, 0x02, 0x7f, 0x20, 0x06, 0x02, 0x7f, 0x20, 0x00, 0x28, 0x02,
    0x3c, 0x20, 0x01, 0x20, 0x05, 0x20, 0x03, 0x41, 0x0c, 0x6a, 0x10, 0x00,
    0x04, 0x40, 0x20, 0x03, 0x41, 0x7f, 0x36, 0x02, 0x0c, 0x41, 0x7f, 0x0c,
    0x01, 0x0b, 0x20, 0x03, 0x28, 0x02, 0x0c, 0x0b, 0x22, 0x04, 0x46, 0x04,
    0x40, 0x20, 0x00, 0x20, 0x00, 0x28, 0x02, 0x2c, 0x22, 0x01, 0x36, 0x02,
    0x1c, 0x20, 0x00, 0x20, 0x01, 0x36, 0x02, 0x14, 0x20, 0x00, 0x20, 0x01,
    0x20, 0x00, 0x28, 0x02, 0x30, 0x6a, 0x36, 0x02, 0x10, 0x20, 0x02, 0x0c,
    0x01, 0x0b, 0x20, 0x04, 0x41, 0x7f, 0x4a, 0x0d, 0x01, 0x20, 0x00, 0x41,
    0x00, 0x36, 0x02, 0x1c, 0x20, 0x00, 0x42, 0x00, 0x37, 0x03, 0x10, 0x20,
    0x00, 0x20, 0x00, 0x28, 0x02, 0x00, 0x41, 0x20, 0x72, 0x36, 0x02, 0x00,
    0x41, 0x00, 0x20, 0x05, 0x41, 0x02, 0x46, 0x0d, 0x00, 0x1a, 0x20, 0x02,
    0x20, 0x01, 0x28, 0x02, 0x04, 0x6b, 0x0b, 0x21, 0x04, 0x20, 0x03, 0x41,
    0x20, 0x6a, 0x24, 0x00, 0x20, 0x04, 0x0f, 0x0b, 0x20, 0x01, 0x41, 0x08,
    0x6a, 0x20, 0x01, 0x20, 0x04, 0x20, 0x01, 0x28, 0x02, 0x04, 0x22, 0x07,
    0x4b, 0x22, 0x08, 0x1b, 0x22, 0x01, 0x20, 0x04, 0x20, 0x07, 0x41, 0x00,
    0x20, 0x08, 0x1b, 0x6b, 0x22, 0x07, 0x20, 0x01, 0x28, 0x02, 0x00, 0x6a,
    0x36, 0x02, 0x00, 0x20, 0x01, 0x20, 0x01, 0x28, 0x02, 0x04, 0x20, 0x07,
    0x6b, 0x36, 0x02, 0x04, 0x20, 0x06, 0x20, 0x04, 0x6b, 0x21, 0x06, 0x20,
    0x05, 0x20, 0x08, 0x6b, 0x21, 0x05, 0x0c, 0x00, 0x00, 0x0b, 0x00, 0x0b,
    0x0b, 0x4d, 0x06, 0x00, 0x41, 0x80, 0x08, 0x0b, 0x12, 0x68, 0x65, 0x6c,
    0x6c, 0x6f, 0x2c, 0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64, 0x21, 0x00, 0x00,
    0x00, 0x18, 0x04, 0x00, 0x41, 0x98, 0x08, 0x0b, 0x01, 0x05, 0x00, 0x41,
    0xa4, 0x08, 0x0b, 0x01, 0x01, 0x00, 0x41, 0xbc, 0x08, 0x0b, 0x0e, 0x02,
    0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0xb8, 0x04, 0x00, 0x00, 0x00,
    0x04, 0x00, 0x41, 0xd4, 0x08, 0x0b, 0x01, 0x01, 0x00, 0x41, 0xe3, 0x08,
    0x0b, 0x05, 0x0a, 0xff, 0xff, 0xff, 0xff,
  ]);

  WasmMemory mem = null;
  String out = "";
  var getI32 = (int p) {
    // Read a little-endian I32.
    int n = 0;
    for (var i = p + 3; i >= p; --i) {
      n *= 256;
      n += mem[i];
    }
    return n;
  };
  var inst = WasmModule(data)
      .instantiate()
      .addFunction("wasi_unstable", "fd_write",
          (int fd, int iovs, int iovs_len, int unused) {
    // iovs points to an array of length iovs_len. Each element is two I32s,
    // a char* and a length.
    String o = "";
    for (var i = 0; i < iovs_len; ++i) {
      var str = getI32(iovs + 8 * i);
      var len = getI32(iovs + 4 + 8 * i);
      for (var j = 0; j < len; ++j) {
        o += String.fromCharCode(mem[str + j]);
      }
    }
    out += o;
    return o.length;
  }).build();
  mem = inst.memory;

  var fn = inst.lookupFunction("_start");
  fn();
  Expect.equals("hello, world!\n", out);
}