exceptions-api.js

// Copyright 2021 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

d8.file.execute("test/mjsunit/wasm/wasm-module-builder.js");

(function TestImport() {
  print(arguments.callee.name);

  assertThrows(() => new WebAssembly.Tag(), TypeError,
      /Argument 0 must be a tag type/);
  assertThrows(() => new WebAssembly.Tag({}), TypeError,
      /Argument 0 must be a tag type with 'parameters'/);
  assertThrows(() => new WebAssembly.Tag({parameters: ['foo']}), TypeError,
      /Argument 0 parameter type at index #0 must be a value type/);
  assertThrows(() => new WebAssembly.Tag({parameters: {}}), TypeError,
      /Argument 0 contains parameters without 'length'/);

  let js_except_i32 = new WebAssembly.Tag({parameters: ['i32']});
  let js_except_v = new WebAssembly.Tag({parameters: []});
  let builder = new WasmModuleBuilder();
  builder.addImportedTag("m", "ex", kSig_v_i);

  assertDoesNotThrow(() => builder.instantiate({ m: { ex: js_except_i32 }}));
  assertThrows(
      () => builder.instantiate({ m: { ex: js_except_v }}), WebAssembly.LinkError,
      /imported tag does not match the expected type/);
  assertThrows(
      () => builder.instantiate({ m: { ex: js_except_v }}), WebAssembly.LinkError,
      /imported tag does not match the expected type/);
  assertTrue(js_except_i32.toString() == "[object WebAssembly.Tag]");
})();

(function TestExport() {
  print(arguments.callee.name);
  let builder = new WasmModuleBuilder();
  let except = builder.addTag(kSig_v_v);
  builder.addExportOfKind("ex", kExternalTag, except);
  let instance = builder.instantiate();

  assertTrue(Object.prototype.hasOwnProperty.call(instance.exports, 'ex'));
  assertEquals("object", typeof instance.exports.ex);
  assertInstanceof(instance.exports.ex, WebAssembly.Tag);
  assertSame(instance.exports.ex.constructor, WebAssembly.Tag);
})();

(function TestImportExport() {
  print(arguments.callee.name);

  let js_ex_i32 = new WebAssembly.Tag({parameters: ['i32']});
  let builder = new WasmModuleBuilder();
  let index = builder.addImportedTag("m", "ex", kSig_v_i);
  builder.addExportOfKind("ex", kExternalTag, index);

  let instance = builder.instantiate({ m: { ex: js_ex_i32 }});
  let res = instance.exports.ex;
  assertEquals(res, js_ex_i32);
})();


(function TestExceptionConstructor() {
  print(arguments.callee.name);
  // Check errors.
  let js_tag = new WebAssembly.Tag({parameters: []});
  assertThrows(() => new WebAssembly.Exception(0), TypeError,
      /Argument 0 must be a WebAssembly tag/);
  assertThrows(() => new WebAssembly.Exception({}), TypeError,
      /Argument 0 must be a WebAssembly tag/);
  assertThrows(() => WebAssembly.Exception(js_tag), TypeError,
      /WebAssembly.Exception must be invoked with 'new'/);
  let js_exception = new WebAssembly.Exception(js_tag, []);

  // Check prototype.
  assertSame(WebAssembly.Exception.prototype, js_exception.__proto__);
  assertTrue(js_exception instanceof WebAssembly.Exception);
  assertFalse(js_exception instanceof Error);

  // Check prototype of a thrown exception.
  let builder = new WasmModuleBuilder();
  let wasm_tag = builder.addTag(kSig_v_v);
  builder.addFunction("throw", kSig_v_v)
      .addBody([kExprThrow, wasm_tag]).exportFunc();
  let instance = builder.instantiate();
  try {
    instance.exports.throw();
  } catch (e) {
    assertTrue(e instanceof WebAssembly.Exception);
  }
})();

(function TestExceptionConstructorWithPayload() {
  print(arguments.callee.name);
  let tag = new WebAssembly.Tag(
      {parameters: ['i32', 'f32', 'i64', 'f64', 'externref']});
  assertThrows(() => new WebAssembly.Exception(
      tag, [1n, 2, 3n, 4, {}]), TypeError);
  assertThrows(() => new WebAssembly.Exception(
      tag, {}), TypeError, /Exception values argument has no length/);
  assertThrows(() => new WebAssembly.Exception(
      tag, []), TypeError,
      /Number of exception values does not match signature length/);
  assertDoesNotThrow(() => new WebAssembly.Exception(tag, [3, 4, 5n, 6, {}]));
})();

(function TestExceptionStackTrace() {
  print(arguments.callee.name);
  let tag = new WebAssembly.Tag({parameters: []});
  let exn = new WebAssembly.Exception(tag, []);
  assertTrue('stack' in exn);
  assertEquals(undefined, exn.stack);
  exn = new WebAssembly.Exception(tag, [], {traceStack: false});
  assertTrue('stack' in exn);
  assertEquals(undefined, exn.stack);
  exn = new WebAssembly.Exception(tag, [], {traceStack: true});
  assertTrue(exn.stack.indexOf(arguments.callee.name) > 0);
  assertThrows(() => new WebAssembly.Exception(tag, [], 0), TypeError,
               /Argument 2 is not an object/);
  // The stack getter may only be used with a receiver that is a
  // WebAssembly.Exception.
  let proto = WebAssembly.Exception.prototype;
  assertThrows(() => proto.stack, TypeError);
})();

(function TestCatchJSException() {
  print(arguments.callee.name);
  let builder = new WasmModuleBuilder();
  let js_tag = new WebAssembly.Tag({parameters: []});
  let js_func_index = builder.addImport('m', 'js_func', kSig_v_v);
  let js_tag_index = builder.addImportedTag("m", "js_tag", kSig_v_v);
  let tag_index = builder.addTag(kSig_v_v);
  builder.addExportOfKind("wasm_tag", kExternalTag, tag_index);
  builder.addFunction("catch", kSig_i_v)
      .addBody([
        kExprTry, kWasmI32,
        kExprCallFunction, js_func_index,
        kExprI32Const, 0,
        kExprCatch, js_tag_index,
        kExprI32Const, 1,
        kExprCatch, tag_index,
        kExprI32Const, 2,
        kExprEnd
      ]).exportFunc();
  let tag;
  function js_func() {
    throw new WebAssembly.Exception(tag, []);
  }
  let instance = builder.instantiate({m: {js_func, js_tag}});
  tag = js_tag;
  assertEquals(1, instance.exports.catch());
  tag = instance.exports.wasm_tag;
  assertEquals(2, instance.exports.catch());
})();

function TestCatchJS(types_str, types, values) {
  // Create a JS exception, catch it in wasm and check the unpacked value(s).
  let builder = new WasmModuleBuilder();
  let js_tag = new WebAssembly.Tag({parameters: types_str});
  let js_func_index = builder.addImport('m', 'js_func', kSig_v_v);
  let sig1 = makeSig(types, []);
  let sig2 = makeSig([], types);
  let js_tag_index = builder.addImportedTag("m", "js_tag", sig1);
  let tag_index = builder.addTag(sig1);
  let return_type = builder.addType(sig2);
  builder.addExportOfKind("wasm_tag", kExternalTag, tag_index);
  builder.addFunction("catch", sig2)
      .addBody([
        kExprTry, return_type,
        kExprCallFunction, js_func_index,
        kExprUnreachable,
        kExprCatch, js_tag_index,
        kExprCatch, tag_index,
        kExprEnd
      ]).exportFunc();
  let exception;
  function js_func() {
    throw exception;
  }
  let expected = values.length == 1 ? values[0] : values;
  let instance = builder.instantiate({m: {js_func, js_tag}});
  exception = new WebAssembly.Exception(js_tag, values);
  assertEquals(expected, instance.exports.catch());
  exception = new WebAssembly.Exception(instance.exports.wasm_tag, values);
  assertEquals(expected, instance.exports.catch());
}

(function TestCatchJSExceptionWithPayload() {
  print(arguments.callee.name);
  TestCatchJS(['i32'], [kWasmI32], [1]);
  TestCatchJS(['i64'], [kWasmI64], [2n]);
  TestCatchJS(['f32'], [kWasmF32], [3]);
  TestCatchJS(['f64'], [kWasmF64], [4]);
  TestCatchJS(['externref'], [kWasmExternRef], [{value: 5}]);
  TestCatchJS(['i32', 'i64', 'f32', 'f64', 'externref'],
              [kWasmI32, kWasmI64, kWasmF32, kWasmF64, kWasmExternRef],
              [6, 7n, 8, 9, {value: 10}]);
})();

function TestGetArgHelper(types_str, types, values) {
  let tag = new WebAssembly.Tag({parameters: types_str});
  let exception = new WebAssembly.Exception(tag, values);
  for (i = 0; i < types.length; ++i) {
    assertEquals(exception.getArg(tag, i), values[i]);
  }

  let builder = new WasmModuleBuilder();
  let sig = makeSig(types, []);
  let tag_index = builder.addImportedTag("m", "t", sig);
  let body = [];
  for (i = 0; i < types.length; ++i) {
    body.push(kExprLocalGet, i);
  }
  body.push(kExprThrow, tag_index);
  builder.addFunction("throw", sig)
      .addBody(body).exportFunc();
  let instance = builder.instantiate({'m': {'t': tag}});
  try {
    instance.exports.throw(...values);
  } catch (e) {
    for (i = 0; i < types.length; ++i) {
      assertEquals(e.getArg(tag, i), values[i]);
    }
  }
}

(function TestGetArg() {
  print(arguments.callee.name);
  // Check errors.
  let tag = new WebAssembly.Tag({parameters: ['i32']});
  let exception = new WebAssembly.Exception(tag, [0]);
  assertThrows(() => exception.getArg(0, 0), TypeError,
      /Argument 0 must be a WebAssembly.Tag/);
  assertThrows(() => exception.getArg({}, 0), TypeError,
      /Argument 0 must be a WebAssembly.Tag/);
  assertThrows(() => exception.getArg(tag, undefined), TypeError,
      /Index must be convertible to a valid number/);
  assertThrows(() => exception.getArg(tag, 0xFFFFFFFF), RangeError,
      /Index out of range/);
  let wrong_tag = new WebAssembly.Tag({parameters: ['i32']});
  assertThrows(() => exception.getArg(wrong_tag, 0), TypeError,
      /First argument does not match the exception tag/);

  // Check decoding.
  TestGetArgHelper(['i32'], [kWasmI32], [1]);
  TestGetArgHelper(['i64'], [kWasmI64], [2n]);
  TestGetArgHelper(['f32'], [kWasmF32], [3]);
  TestGetArgHelper(['f64'], [kWasmF64], [4]);
  TestGetArgHelper(['externref'], [kWasmExternRef], [{val: 5}]);
  TestGetArgHelper(['i32', 'i64', 'f32', 'f64', 'externref'], [kWasmI32, kWasmI64, kWasmF32, kWasmF64, kWasmExternRef], [5, 6n, 7, 8, {val: 9}]);
})();

(function TestExceptionIs() {
  print(arguments.callee.name);
  let tag1 = new WebAssembly.Tag({parameters: []});
  let tag2 = new WebAssembly.Tag({parameters: []});
  assertThrows(() => new WebAssembly.Exception({}, []), TypeError,
      /Argument 0 must be a WebAssembly tag/);

  let exception = new WebAssembly.Exception(tag1, []);
  assertTrue(exception.is(tag1));
  assertFalse(exception.is(tag2));

  assertThrows(() => exception.is.apply({}, tag1), TypeError,
      /Receiver is not a WebAssembly.Exception/);
})();

(function TestJSTag() {
  print(arguments.callee.name);
  assertTrue(WebAssembly.JSTag instanceof WebAssembly.Tag);
  let desc = Object.getOwnPropertyDescriptor(WebAssembly, 'JSTag');
  assertEquals(typeof desc.value, 'object');
  assertFalse(desc.writable);
  assertFalse(desc.enumerable);
  assertTrue(desc.configurable);
})();

(function TestCatchJSTag() {
  print(arguments.callee.name);
  let builder = new WasmModuleBuilder();
  let js_tag = builder.addImportedTag("", "tag", kSig_v_r);

  // Throw a JS object and check that we can catch it and unpack it using
  // WebAssembly.JSTag.
  function throw_ref(x) {
    throw x;
  }
  let kJSThrowRef = builder.addImport("", "throw_ref", kSig_r_r);
  try_sig_index = builder.addType(kSig_r_v);
  builder.addFunction("test", kSig_r_r)
    .addBody([
      kExprTry, try_sig_index,
        kExprLocalGet, 0,
        kExprCallFunction, kJSThrowRef,
      kExprCatch, js_tag,
      kExprEnd,
    ])
    .exportFunc();

  let instance = builder.instantiate({"": {
      throw_ref: throw_ref,
      tag: WebAssembly.JSTag,
  }});

  let obj = {};
  // Creating a WA.Exception with the JSTag explicitly is not allowed.
  assertThrows(() => new WebAssembly.Exception(WebAssembly.JSTag, [obj]), TypeError);

  // Catch with implicit wrapping.
  assertSame(obj, instance.exports.test(obj));
  // Don't catch with explicit wrapping.
  let not_js_tag = new WebAssembly.Tag({parameters:['externref']});
  let exn = new WebAssembly.Exception(not_js_tag, [obj]);
  assertThrowsEquals(() => instance.exports.test(exn), exn);


  // There is a separate code path for tags with externref type, so also check
  // that everything still works when the tag is *not* the JSTag.

  instance = builder.instantiate({"": {
      throw_ref: throw_ref,
      tag: not_js_tag
  }});

  // Catch with explicit wrapping.
  assertSame(obj, instance.exports.test(new WebAssembly.Exception(not_js_tag, [obj])));
  // Don't catch with implicit wrapping.
  assertThrowsEquals(() => instance.exports.test(obj), obj);
})();

(function TestExceptionConstructorLength() {
  assertEquals(2, WebAssembly.Exception.length);
})();