v8/src/d8.js
cbruni b7ff2bd5cd [proxies] Better print for proxies in d8
Function proxies would not be printed so far since they ended up in Function.prototype.toString which only works with Function as a receiver but no Proxy. Additionally added support for more gracefully dealing with recursive __proto__ structures introduced by proxies.

drive-by-fix: use IS_PROXY if possible in .js files.

BUG=v8:1543
LOG=n

Committed: https://crrev.com/8bfb7189a3472bc9d0820a1bd4534eaaf78ff847
Cr-Commit-Position: refs/heads/master@{#32985}

Review URL: https://codereview.chromium.org/1530293004

Cr-Commit-Position: refs/heads/master@{#33010}
2015-12-22 13:50:17 +00:00

92 lines
2.8 KiB
JavaScript

// Copyright 2008 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.
"use strict";
// A more universal stringify that supports more types than JSON.
// Used by the d8 shell to output results.
var stringifyDepthLimit = 4; // To avoid crashing on cyclic objects
// Hacky solution to circumvent forcing --allow-natives-syntax for d8
function isProxy(o) { return false };
function JSProxyGetTarget(proxy) { };
function JSProxyGetHandler(proxy) { };
try {
isProxy = Function(['object'], 'return %_IsJSProxy(object)');
JSProxyGetTarget = Function(['proxy'],
'return %JSProxyGetTarget(proxy)');
JSProxyGetHandler = Function(['proxy'],
'return %JSProxyGetHandler(proxy)');
} catch(e) {};
function Stringify(x, depth) {
if (depth === undefined)
depth = stringifyDepthLimit;
else if (depth === 0)
return "...";
if (isProxy(x)) {
return StringifyProxy(x, depth);
}
switch (typeof x) {
case "undefined":
return "undefined";
case "boolean":
case "number":
case "function":
return x.toString();
case "string":
return "\"" + x.toString() + "\"";
case "symbol":
return x.toString();
case "object":
if (IS_NULL(x)) return "null";
if (x.constructor && x.constructor.name === "Array") {
var elems = [];
for (var i = 0; i < x.length; ++i) {
elems.push(
{}.hasOwnProperty.call(x, i) ? Stringify(x[i], depth - 1) : "");
}
return "[" + elems.join(", ") + "]";
}
try {
var string = String(x);
if (string && string !== "[object Object]") return string;
} catch(e) {}
var props = [];
var names = Object.getOwnPropertyNames(x);
names = names.concat(Object.getOwnPropertySymbols(x));
for (var i in names) {
var name = names[i];
var desc = Object.getOwnPropertyDescriptor(x, name);
if (IS_UNDEFINED(desc)) continue;
if (IS_SYMBOL(name)) name = "[" + Stringify(name) + "]";
if ("value" in desc) {
props.push(name + ": " + Stringify(desc.value, depth - 1));
}
if (desc.get) {
var getter = Stringify(desc.get);
props.push("get " + name + getter.slice(getter.indexOf('(')));
}
if (desc.set) {
var setter = Stringify(desc.set);
props.push("set " + name + setter.slice(setter.indexOf('(')));
}
}
return "{" + props.join(", ") + "}";
default:
return "[crazy non-standard value]";
}
}
function StringifyProxy(proxy, depth) {
var proxy_type = typeof proxy;
var info_object = {
target: JSProxyGetTarget(proxy),
handler: JSProxyGetHandler(proxy)
}
return '[' + proxy_type + ' Proxy ' + Stringify(info_object, depth-1) + ']';
}